Fire Glossary

Every important fire term explained.

A

ADC Methods

Various techniques used by accelerant detection canines and their handlers to effectively identify traces of accelerants. Methods include systematic search patterns and thorough training protocols to ensure accuracy.

Absolute Temperature

A scale of temperature measured relative to absolute zero, where all thermal motion of particles theoretically ceases. The Kelvin scale is commonly used for absolute temperature in scientific contexts.

Accelerant

Any substance or mixture that increases the rate of combustion when introduced to a fire. Accelerants are often used in arson incidents to spread fire quickly and enhance its intensity.

Accelerant Detection Canines (ADC)

Specially trained dogs used in fire investigations to detect trace amounts of accelerants. These canines can pinpoint specific locations where accelerants may have been used, aiding investigators in determining fire origins and causes.

Access

The means or opportunity to enter or approach a fire scene. In firefighting, maintaining clear access routes is critical for rapid response and safe operations.

Accident

An unplanned and unexpected event that results in damage, injury, or loss. In fire investigations, the term is used to describe incidents where fire ignition was unintentional and not due to malicious activity.

Acetylene

A highly flammable hydrocarbon gas commonly used as a fuel for welding and cutting. Acetylene poses a fire and explosion hazard due to its unstable nature under certain conditions.

Acrolein

A toxic, flammable compound released during the combustion of organic materials. It is known for its pungent odor and can be dangerous if inhaled, posing serious risks during firefighting operations.

Active Fire Protection System

A system designed to detect and respond to a fire by suppressing or controlling it, such as sprinklers and fire alarms. Active fire protection works in conjunction with passive systems to enhance overall building safety.

Advancing Fire

A fire that is moving forward or spreading due to wind, slope, or fuel conditions. Understanding the behavior of an advancing fire is critical for strategic firefighting efforts and containment planning.

Aerial Fuels

Vegetation that is located above the ground level, such as tree branches, leaves, and vines. These fuels can allow a fire to climb from the ground and spread into the canopy, increasing the potential for a crown fire.

Alert

A notification or signal indicating the presence of a potential or active fire threat. Alerts can range from local community warnings to official government-issued fire advisories.

Alert Point

The designated location or point at which a fire watch or warning is triggered. It serves as a threshold for taking specific precautionary measures to ensure public and firefighter safety.

Aliphatic

A type of hydrocarbon compound characterized by carbon and hydrogen atoms arranged in straight chains, branched chains, or non-aromatic rings. Aliphatic compounds, such as alkanes, alkenes, and alkynes, are known for their flammability and are commonly found in fuels and solvents used in various fire scenarios.

Alligatoring

The formation of a cracked, scale-like char pattern on the surface of burned materials. This phenomenon can help fire investigators determine the heat level and direction of fire spread.

Ambient

The surrounding environmental conditions, such as temperature, humidity, and atmospheric pressure. Ambient conditions can influence fire behavior, including ignition and rate of spread.

Ampacity

The maximum amount of electric current a conductor or device can carry before overheating. Understanding ampacity is crucial in assessing potential electrical faults and fire risks.

Amperage

The strength of an electric current measured in amperes (amps). High amperage levels can indicate potential fire hazards, especially if wiring or circuits are not properly rated.

Ampere (Amp)

The unit of electric current, defined as one coulomb per second. This measure is fundamental in evaluating electrical systems in the context of fire investigations and safety assessments.

Anneal

The process of heating and then cooling a material, typically metal, to reduce its hardness and increase its ductility. In fire investigations, annealed metals may indicate exposure to high temperatures over a sustained period.

Arc Map

A diagram or representation showing the locations and paths of electrical arcing within a structure or electrical system. Arc maps help fire investigators trace the origin of an electrical fire.

Arc Melting

The melting of materials caused by an electrical arc, which can result in molten metal droplets and potential fire hazards. Arc melting may leave distinct patterns useful in fire analysis.

Arc Site

The specific location where an electrical arc occurs. Identifying the arc site is essential for understanding the fire's origin in cases involving electrical failures.

Arc Survey

The examination and documentation of all instances of electrical arcing within a fire scene. This process helps establish whether electrical issues contributed to the fire's ignition.

Arc/Arcing

The discharge of electrical energy that jumps between two conductive surfaces, often accompanied by intense heat and light. Arcing can result in fire ignition if nearby flammable materials are present.

Arcing Through Char

The phenomenon where an electrical arc passes through a charred, non-conductive surface, reigniting it or producing further heat. This condition can be critical in fire investigations involving electrical faults.

Area of Origin

The specific location where a fire started. Determining the area of origin is a fundamental step in fire investigation and helps identify the cause of the fire.

Aromatic

A type of hydrocarbon compound characterized by its stable ring-like molecular structure. Aromatic compounds can be flammable and are relevant in understanding the properties of certain accelerants.

Arrow Pattern

A burn pattern resembling an arrow, often used by investigators to determine the direction of fire spread. Arrow patterns can provide insight into the fire's progression and point of origin.

Arson

The intentional act of setting fire to property, often with malicious intent. Arson is a criminal offense, and investigations focus on identifying evidence to determine intent and responsible parties.

Authority Having Jurisdiction (AHJ)

The designated organization, office, or individual responsible for enforcing fire safety codes and regulations. The AHJ can include fire marshals, building inspectors, or other officials.

Auto-Ignition Temperature

The lowest temperature at which a material will spontaneously ignite without an external ignition source. This temperature varies for different materials and is crucial for fire prevention and safety.

Autoignition

The spontaneous ignition of a substance without an external flame or spark due to heat buildup. This process can occur when a material reaches its autoignition temperature under specific conditions.

B

BLEVE

A type of explosion that occurs when a vessel containing a pressurized liquid is heated until the liquid reaches its boiling point, causing the vessel to rupture and release vapor explosively. BLEVEs are highly dangerous and often result in intense fireballs.

BTU

British Thermal Unit (BTU) is a common unit for measuring energy in the context of heating and fire behavior. The BTU is essential for understanding the energy output of various fuels and the potential intensity of a fire.

Backdraft

A dangerous explosion that occurs when oxygen is suddenly introduced into an enclosed space filled with combustible gases and low oxygen levels. Firefighters are trained to recognize the signs of potential backdrafts to prevent injury.

Backdraft

Backfire

A controlled fire intentionally set by firefighters to consume fuel in the path of an advancing wildfire. This technique helps slow or stop the spread of the main fire and is an essential part of wildfire management.

Backing Fire

A fire that spreads against the wind or downslope, moving slower but with high intensity at its base. This type of fire behavior is an important consideration for fire containment and firefighting strategies.

Backpack Pump

A portable firefighting tool consisting of a water tank worn on the back with a hand pump for spraying water or fire suppressant. It is used to extinguish small fires and hotspots, especially in wildland firefighting.

Bambi Bucket

A collapsible bucket attached to a helicopter for aerial firefighting, capable of carrying and dropping large amounts of water onto fires. This tool is used to target areas that are difficult to access by ground crews.

Battery Abuse Testing

A set of tests conducted to determine how a battery reacts to conditions beyond its normal operation, such as extreme temperatures, overcharging, puncturing, and impact. These tests help assess the potential for battery fires and explosions.

Battery Capacity Fail

A situation where a battery loses its ability to store and release energy effectively, which can lead to overheating, leakage, or fire hazards. Capacity failure can result from aging, poor design, or extreme operational conditions.

Battery Cell Casing

The outer shell of a battery cell that protects its internal components. If damaged or compromised, the casing can leak or overheat, potentially leading to a fire.

Battery Cell Overheating

The condition in which a battery cell's temperature rises beyond safe levels, posing a risk of thermal runaway and fire. This overheating can be caused by overcharging, high ambient temperatures, or internal failures.

Battery Chemistry

The specific combination of chemical materials used in a battery to store and release energy. Different chemistries, such as lithium-ion, nickel-cadmium, and lead-acid, have unique characteristics and safety profiles relevant to fire risk assessment.

Battery Cooling

The process or system used to regulate the temperature of battery cells and packs to prevent overheating and potential fires. Battery cooling can involve liquid or air-based systems to maintain safe operating temperatures.

Battery Degradation

The gradual reduction in a battery’s ability to hold and deliver charge over time, often due to repeated cycles of charging and discharging. Degraded batteries are more susceptible to failures that can lead to overheating or fire.

Battery Drain Protection

Safety features designed to prevent the battery from discharging beyond its safe capacity. Over-discharge can damage the cells and potentially lead to overheating or fire.

Battery Enclosure

A protective housing for battery cells or modules designed to contain any thermal, electrical, or chemical events that may occur. Properly designed enclosures are critical for fire safety and prevention.

Battery Energy Storage System (BESS)

A large-scale energy storage solution that uses batteries to store and release electrical energy. BESS installations are essential for grid management but require stringent fire safety measures due to the risk of thermal incidents.

Battery Explosion

A violent rupture or failure of a battery, often caused by overheating, overcharging, or internal damage. Battery explosions can release hazardous chemicals and pose significant fire risks.

Battery Failure

Any malfunction or breakdown of a battery that affects its performance or safety. Battery failure can manifest as overheating, reduced capacity, leakage, or thermal runaway, potentially leading to a fire.

Battery Failure Modes

The different ways in which a battery can malfunction, such as short circuits, thermal runaway, electrolyte leakage, and mechanical damage. Identifying these failure modes is crucial for mitigating fire hazards in battery applications.

Battery Fire Containment

The use of barriers, insulation, and specialized materials to prevent a fire originating from a battery from spreading. Effective containment strategies are critical for safety in electric vehicles, consumer electronics, and large-scale energy storage systems.

Battery Fire Drill

A simulated exercise to train individuals on how to respond to a battery fire incident. These drills ensure that safety personnel and users know how to act quickly and effectively to mitigate risks and damage.

Battery Fire Prevention

Measures taken to reduce the risk of battery fires, such as temperature monitoring, proper charging protocols, and the use of safety circuits. Prevention strategies are essential for both consumer and industrial battery applications.

Battery Fire Suppression Foam

A specialized foam used to extinguish battery fires by cooling and smothering the flames. This foam is designed to counter the unique properties of battery fires, which can reignite due to thermal runaway.

Battery Incident Analysis

The process of investigating battery failures to determine the cause and prevent future occurrences. Analysis may involve examining battery components, usage data, and environmental conditions.

Battery Insulation

The use of heat-resistant materials around battery cells or packs to prevent overheating and maintain safe operation. Proper insulation is crucial for preventing fire propagation within battery systems.

Battery Isolation

The practice of separating individual battery cells or modules to prevent electrical and thermal interactions. Isolation can prevent a failing cell from affecting adjacent cells, reducing the risk of fire spread.

Battery Isolation Unit

A device or mechanism designed to disconnect a faulty battery from the rest of the system to prevent further damage or fire. Isolation units are key safety features in battery management systems.

Battery Leakage

The escape of electrolyte or other internal fluids from a battery, often due to physical damage, overcharging, or manufacturing defects. Leakage can lead to short circuits and pose a fire hazard.

Battery Management System (BMS)

An electronic system that monitors and controls the charging and discharging of a battery to ensure safe and efficient operation. A BMS helps prevent conditions that can lead to battery failure and fire.

Battery Module

A grouping of battery cells connected together to form a single unit. Modules are used in larger battery packs and are designed to enhance performance and manage risks, including fire prevention.

Battery Over-discharge

The condition where a battery is discharged beyond its designed minimum voltage level, potentially causing irreversible damage and safety risks. Over-discharge can lead to cell degradation and fire hazards.

Battery Pack Design

The configuration and construction of a battery pack, including its cells, modules, and safety features. Effective design aims to optimize performance and minimize risks such as overheating and fire.

Battery Pack Housing

The protective casing that holds the components of a battery pack. The housing is designed to prevent damage from external impacts and contain any internal incidents such as thermal runaway or fires.

Battery Puncture

Physical damage to a battery cell or pack that can lead to internal short circuits and potential fire hazards. Battery punctures can result from accidents, improper handling, or manufacturing flaws.

Battery Recycling

The process of reclaiming and reusing materials from used or damaged batteries to reduce environmental impact and manage hazardous waste. Safe recycling practices help mitigate fire risks associated with battery disposal.

Battery Safety Standards

Established guidelines and regulations to ensure the safe design, use, and disposal of batteries. Compliance with these standards helps prevent failures and fire incidents in consumer and industrial applications.

Battery Separator

A thin, permeable layer inside a battery that keeps the positive and negative electrodes apart while allowing the flow of ions. If damaged or compromised, a separator failure can lead to internal short circuits and fires.

Battery Shutdown Mechanism

A safety feature designed to automatically disconnect a battery or reduce its output in the event of overheating or other dangerous conditions. This mechanism helps prevent thermal runaway and fire.

Battery Swelling

The expansion of a battery cell due to gas buildup caused by internal reactions or overcharging. Swelling can indicate a potential failure mode that may lead to leaks, overheating, or fire.

Battery Temperature Monitoring

The process of continuously measuring the temperature of a battery to ensure it stays within safe operational limits. Monitoring helps prevent overheating and fire risks.

Battery Testing Standard

Protocols and procedures established for evaluating the safety, performance, and reliability of batteries under different conditions. Standards such as those from UL or IEC are used to certify batteries for safe use.

Battery Thermal Insulation

Materials and techniques used to insulate battery cells or packs to control heat transfer. Effective thermal insulation helps prevent overheating and limits fire spread in case of a failure.

Battery Thermal Runaway

A self-sustaining, uncontrollable increase in temperature within a battery cell or pack that can lead to fire or explosion. Thermal runaway is a critical risk in battery safety, triggered by factors such as overcharging or internal damage.

Battery Ventilation

The system or process designed to dissipate heat and release gases produced during the operation or failure of a battery. Proper ventilation is essential to prevent heat buildup and potential fire hazards.

Beading

The formation of small, rounded drops of molten metal that can occur during electrical arcing. Beading patterns can help fire investigators determine the direction and nature of an electrical fault.

Behave

A term referring to the behavior or characteristics of a fire, including its spread, intensity, and reaction to fuel and environmental conditions. Understanding fire behavior is essential for effective firefighting and prevention strategies.

Bilge Fire

A fire that occurs in the bilge area of a boat or ship, where fuel, oil, and other flammable materials can accumulate. Bilge fires are particularly dangerous due to limited space and potential for rapid spread.

Bilge Pump Failure

The malfunction of a pump designed to remove water or other liquids from the bilge of a vessel. Failure of this pump can lead to water accumulation and increase the risk of fire due to submerged electrical components.

Binder

A substance used to hold or bond materials together, often found in composite or layered materials. In the context of fire, the flammability and behavior of binders can influence fire spread and intensity.

Bladder Bag

A flexible, portable container used to transport water for firefighting. Bladder bags can be used in areas where conventional water sources are not readily available.

Blast Analysis

The examination of an explosion's effects, including the pressure wave, damage patterns, and debris distribution. This analysis helps investigators determine the type and source of an explosive event.

Blast Pressure Front

The leading edge of the high-pressure wave produced by an explosion. This front can cause significant structural damage and influence the spread of fire in a blast scenario.

Blow-up

A sudden and rapid increase in fire intensity and spread, typically due to changes in weather conditions, fuel, or topography. Blow-ups are dangerous and can quickly overwhelm firefighting efforts.

Boat Wiring Inspection

The process of examining electrical wiring in boats to ensure it is in good condition and free from faults that could lead to electrical fires. Regular inspections are crucial for preventing onboard fire hazards.

Boiling Point

The temperature at which a liquid changes to vapor when heated. Knowing the boiling points of various liquids is important in fire safety and prevention, as some flammable liquids can vaporize and ignite at relatively low temperatures.

Bonding

The practice of electrically connecting two or more conductive objects to equalize their electrical potential and prevent static sparks. Proper bonding is essential in environments where flammable vapors are present.

Bracketing

A method used in fire investigations to narrow down the potential time frame of a fire’s ignition by analyzing available data and evidence. Bracketing helps investigators determine when the fire likely started.

Brisance

The shattering effect of an explosive and its ability to break surrounding materials. Brisance is a key factor in differentiating between high and low explosives in a fire or explosion investigation.

British Thermal Unit (BTU)

A unit of measurement for heat energy, defined as the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit. BTUs are used to quantify energy output and fire intensity.

Brush

Vegetation such as small trees, shrubs, and undergrowth that can serve as fuel for a fire. The density and type of brush can significantly impact fire spread and behavior.

Brush Fire

A fire that burns in low-lying vegetation such as grasses, shrubs, and small trees. Brush fires can spread rapidly, especially in dry and windy conditions, posing a risk to property and wildlife.

Bucket Drops

A firefighting method where water or fire retardants are released from a bucket suspended from a helicopter. Bucket drops are used to target and suppress specific areas of a fire, especially in hard-to-reach locations.

Buffer Zones

Areas of reduced vegetation or other fuel sources created to slow down or stop the spread of a fire. Buffer zones are commonly used in wildfire-prone areas as a preventive measure to protect communities and assets.

C

CFEI

A designation awarded to individuals who have demonstrated knowledge and competence in investigating fires and explosions. Certification helps establish credibility and expertise in legal and investigative settings.

CFEI Certification

The process by which a fire investigator becomes certified as a CFEI, typically involving training, examination, and adherence to industry standards. This certification is recognized in courts and investigations to validate expertise.

CFEI Standards

The guidelines and practices that CFEI-certified investigators follow to ensure thorough and accurate fire and explosion investigations. These standards help maintain consistency and reliability in investigative work.

CFI

A professional certification for individuals who have completed specialized training in fire investigation and have demonstrated the ability to determine the origin and cause of fires. This certification is often recognized by fire service agencies and legal systems.

CFI Certification

The process of becoming a Certified Fire Investigator, which typically involves coursework, examination, and practical experience in fire investigation techniques and standards.

Calcination

The process of heating a material to a high temperature to induce thermal decomposition. In fire investigations, calcination of building materials, such as gypsum, can indicate exposure to prolonged high heat.

Calcination of Gypsum

The process where gypsum (calcium sulfate dihydrate) loses water content when exposed to high heat, turning into anhydrous calcium sulfate. This transformation can help investigators estimate fire temperatures and intensity.

Calorie

A unit of measurement for energy, defined as the amount of energy required to raise the temperature of one gram of water by one degree Celsius. Calories are often used to quantify the energy release during combustion.

Calorie Meter

A device used to measure the heat energy released during combustion or other exothermic reactions. This tool can help in fire analysis and the assessment of material flammability.

Campfire

A small outdoor fire used for cooking, warmth, or recreation. Campfires can pose a risk of starting wildfires if not properly managed or extinguished.

Candle/Candling

The phenomenon where flames travel up the trunk of a tree or column of vegetation, resembling the flame of a candle. This effect can indicate a fire moving from ground-level fuels to aerial fuels, contributing to fire spread.

Canine-Handler Team

A trained dog and its handler that work together in fire investigations to detect the presence of accelerants or other substances that might indicate arson. Canine-handler teams are highly effective at identifying trace evidence that may not be immediately visible.

Canopy

The upper layer of foliage formed by the crowns of trees and other tall plants. The density of a canopy can influence fire behavior, as fires reaching this level can spread rapidly through aerial fuels.

Carbon

A chemical element that is a major component of organic materials and a fundamental part of fire fuels. When combusted, carbon can produce heat, light, and various combustion byproducts, such as carbon dioxide and carbonmonoxide.

Carbon Black

A fine black powder composed of elemental carbon, often formed as a residue from incomplete combustion of hydrocarbons. It can be found in soot and smoke and may be used as evidence in fire investigations.

Carbon Dioxide

A colorless, odorless gas produced as a byproduct of combustion. It is non-flammable and often used in fire suppression systems because it displaces oxygen, thereby smothering the fire.

Carbon Monoxide

A colorless, odorless, and highly toxic gas produced during incomplete combustion of carbon-based materials. High levels of carbon monoxide are dangerous to humans and can be a key indicator of fire behavior and ventilation conditions in fire investigations.

Carbon Monoxide Buildup

The accumulation of carbon monoxide gas in an enclosed space due to inadequate ventilation or incomplete combustion. This buildup poses significant health risks and can indicate the presence and behavior of a fire.

Cargo Hold Fire

A fire that occurs in the cargo area of a ship, aircraft, or truck. Cargo hold fires can be particularly dangerous due to the presence of various types of flammable or hazardous materials.

Catalytic Converter

An emissions control device in vehicles that reduces harmful gases by catalyzing redox reactions. Catalytic converters can become extremely hot and may be a potential ignition source for fires under certain conditions.

Cathode Material

Cathode material is the substance used as the positive electrode in a battery, where it accepts electrons during discharge and facilitates the flow of current. It greatly influences the battery's energy density, performance, and overall efficiency, with common examples including lithium cobalt oxide and lithium iron phosphate.

Cause

The specific factor or action that initiates a fire. In fire investigations, determining the cause is essential for classifying the fire as accidental, incendiary, or natural.

Ceiling Jet

A layer of hot gases and smoke that spreads out horizontally beneath the ceiling during a fire. The ceiling jet can help investigators understand fire dynamics, such as heat distribution and flame spread.

Cell Balancing

A process in battery management that ensures all individual cells within a battery pack maintain the same voltage level. Proper cell balancing helps prevent overheating and reduces the risk of thermal events or fires.

Cell to Cell Propagation

The phenomenon where a failure in one battery cell leads to a chain reaction affecting adjacent cells, potentially resulting in a fire. Battery pack designs often include safety measures to prevent this type of propagation.

Celsius

A scale for measuring temperature where water freezes at 0 degrees and boils at 100 degrees under standard atmospheric pressure. Celsius is commonly used in fire investigation and analysis for temperature documentation.

Centigrade

An older term synonymous with the Celsius temperature scale. It is still occasionally used but has largely been replaced by the term "Celsius" in scientific and technical contexts.

Certification

The official recognition that an individual has met the required qualifications and training in a specific field, such as fire investigation or firefighting. Certifications often adhere to established industry standards.

Certified Fire Investigator

A professional who has completed training and passed examinations in fire investigation, ensuring expertise in determining the origin and cause of fires. Certification is often granted by recognized organizations like the International Association of Arson Investigators (IAAI).

Chain

A unit of length used in fire management and land surveying, equal to 66 feet or approximately 20.12 meters. Chains are often used to measure distances in wildfire operations and mapping fire perimeters.

Chain of Custody

The documented and unbroken transfer of evidence from the scene of a fire to its presentation in court. Maintaining a clear chain of custody ensures that the evidence has not been tampered with and remains admissible in legal proceedings.

Char

The burned residue of material that has undergone thermal decomposition but not complete combustion. Char patterns are analyzed to understand fire behavior, direction, and possible ignition sources.

Char Blisters

Raised areas on charred surfaces that indicate the presence of intense heat. These blisters can help investigators determine the temperature and conditions of the fire at specific locations.

Charcoal

The black, carbon-rich residue that remains after incomplete combustion of organic materials. Charcoal can provide information about fire intensity and progression during an investigation.

Charge Rate Limit

The maximum safe speed at which a battery can be charged without causing overheating or damage. Exceeding the charge rate limit can lead to thermal runaway and potential fires.

Charging Infrastructure

The network of equipment and facilities used for recharging electric vehicles (EVs) and other battery-operated devices. Proper design and maintenance of charging infrastructure are essential for preventing electrical fires.

Chemical Storage

The proper containment and management of chemical substances to prevent accidental release, reaction, or fire. Safe chemical storage practices include labeling, segregation, and temperature control.

Chimney Effect

The phenomenon where hot air and gases rise through a vertical space, such as a shaft or chimney, drawing in cooler air from below. This effect can accelerate fire spread within buildings.

Cinder

A partially burned piece of material that is lightweight and capable of being carried by the wind. Cinders can ignite new fires when they land on flammable surfaces, contributing to spot fires and the spread of wildfires.

Circuit Breaker

An electrical safety device designed to interrupt the flow of current in an electrical circuit when it exceeds a safe level. Circuit breakers help prevent electrical fires by cutting off power in the event of an overload or short circuit.

Circuit Protection Device

Equipment, such as fuses or circuit breakers, used to protect electrical circuits from damage due to excessive current or faults. Proper use of these devices reduces the risk of electrical fires.

Circumstantial Evidence

Indirect evidence that implies a fact but does not directly prove it. In fire investigations, circumstantial evidence may include burn patterns, the presence of accelerants, or witness testimony to suggest arson or accidental ignition.

City Gas

A type of gas, such as natural gas or propane, used for heating and energy in urban areas. City gas leaks can be highly flammable and pose significant fire and explosion risks.

Clean Burn

A fire condition where combustion is complete, resulting in minimal smoke and residue. Clean burns leave little evidence of soot or unburned fuel, making it harder to identify fire patterns and causes.

Closure

The official sealing off or restriction of an area after a fire for safety, investigation, or recovery purposes. Closure ensures that the fire scene is protected for analysis and prevents unauthorized access.

Code

A set of standards or regulations that outline requirements for fire safety, building construction, and electrical systems. Compliance with codes helps prevent fires and ensure occupant safety.

Cold Front

A meteorological phenomenon characterized by the movement of cooler air into a region, often causing sudden weather changes. Cold fronts can affect fire behavior by shifting wind direction and speed, potentially increasing fire intensity and spread.

Cold Trailing

A method used in wildfire suppression where firefighters carefully inspect and extinguish any remaining hot spots along the fire perimeter by using water, soil, or other means. This helps prevent rekindling and ensures the fire is fully controlled.

Combustible

A material or substance that is capable of catching fire and burning when exposed to heat or a flame. Combustible materials are classified based on their ignition temperature and fire behavior.

Combustible Dust

Finely divided particles of a combustible material that, when suspended in the air, can ignite and cause explosions. Dust explosions are a significant hazard in industries such as manufacturing, grain handling, and woodworking.

Combustible Gas Indicator

A device used to detect the presence and concentration of combustible gases in the air. It helps firefighters and safety personnel identify potential fire and explosion risks in confined or hazardous areas.

Combustible Liquids

Liquids that can catch fire at temperatures above their flash point but below their boiling point. Examples include diesel fuel and some lubricating oils, which require careful storage and handling to prevent fire hazards.

Combustible Materials

Any substance that can ignite and sustain combustion, such as wood, paper, or fabric. Understanding the properties of combustible materials is crucial in fire safety and prevention.

Combustible Solids

Solid materials that can catch fire when exposed to sufficient heat or flame. These include organic materials like wood and synthetic materials like certain plastics.

Combustion

A chemical reaction between a fuel and an oxidizing agent (typically oxygen) that releases heat and light. Combustion is the fundamental process behind fire and varies in intensity based on fuel type and environmental conditions.

Combustion Products

The substances produced during the combustion process, including heat, light, smoke, gases (such as carbon dioxide and carbon monoxide), and particulate matter. The analysis of combustion products can help determine the type of fire and its behavior.

Combustion Reactions

Chemical processes that occur during the burning of fuels, resulting in the release of energy. Complete combustion produces minimal pollutants, while incomplete combustion can lead to hazardous byproducts like carbon monoxide.

Command Staff

A group of senior personnel in the Incident Command System (ICS) responsible for various support roles in managing emergency incidents. Command staff typically include positions such as the Safety Officer, Liaison Officer, and Public Information Officer.

Community Wildfire Protection Plan (CWPP)

A strategic plan developed by communities in wildfire-prone areas to reduce the risk of wildfires and increase community resilience. CWPPs outline strategies for vegetation management, public education, and emergency response.

Competency of a Witness

The legal assessment of whether a witness is qualified to testify in court based on their knowledge, experience, or relation to the case. In fire investigations, witness competency may affect the credibility of testimony regarding fire causes.

Competent Ignition Source

An ignition source that has sufficient heat energy and duration to ignite a particular type of fuel under given conditions. Determining whether an ignition source is competent is crucial in assessing fire causation.

Complex

A group of multiple wildfires burning in close proximity that are managed as a single incident. Fire complexes often require coordinated efforts from multiple firefighting agencies.

Computational Fluid Dynamics Model

A simulation technique used to analyze fluid flow and heat transfer, including the movement of smoke and fire spread within a structure. This modeling helps investigators understand fire dynamics and predict fire behavior.

Condition of Vegetation

The moisture content, type, and state of vegetation in an area, which influences how a fire spreads. Dry, dead vegetation poses a higher fire risk compared to lush, green vegetation.

Conduction

The transfer of heat through a material without the movement of the material itself. Conduction plays a role in fire spread through walls, floors, and other building components.

Conflagration

An extensive and destructive fire that spreads rapidly over a large area, often causing significant damage to buildings, forests, or urban areas. Conflagrations require large-scale firefighting efforts and pose severe risks to life and property.

Consume

The process in which fire burns through available fuel until it is completely reduced to ash or residue. The amount and type of fuel consumed can indicate the fire's intensity and progression.

Contain a Fire

The act of limiting the spread of a fire to prevent it from expanding beyond designated boundaries. Fire containment involves creating fire lines, using water or retardant drops, and other firefighting strategies.

Contract

A legally binding agreement between two or more parties outlining specific terms and responsibilities. In the context of fire management, contracts may involve agreements for firefighting services, equipment rentals, or mutual aid between agencies.

Contract Mala Is Se

A contract involving illegal actions or purposes, considered inherently wrong by law. In the context of fire investigation, this could relate to agreements that violate safety codes or regulations.

Contract of Insurance

A policy or agreement between an insurer and an insured party where the insurer agrees to compensate for losses covered under the terms of the policy. Fire insurance contracts cover damages resulting from fire incidents.

Control Line

A barrier, natural or man-made, that is used to prevent a fire from spreading beyond a specific point. Control lines are constructed by removing vegetation, digging trenches, or using fire-retardant chemicals.

Control a Fire

The process of managing a fire so that it no longer poses a threat to life or property. Fire control is achieved when the fire perimeter is secured, and all significant sources of fire activity are suppressed.

Controlled Burn

A planned and carefully monitored fire set intentionally for land management, such as reducing wildfire fuel, controlling pests, or managing ecosystems. Controlled burns help prevent larger, unplanned wildfires.

Convection

The transfer of heat through the movement of gases or liquids, such as hot air rising from a fire. Convection currents can spread fire and heat to upper levels of a structure or to nearby vegetation.

Conversion of Centigrade to Fahrenheit

A mathematical formula to convert temperature measurements from Celsius to Fahrenheit: F=(C×95)+32F = (C \times \frac{9}{5}) + 32F=(C×59)+32. This conversion is important for standardized reporting in fire investigations.

Conveyor Belt Fire

A fire that occurs on or around a conveyor belt system, often due to friction, overheating, or contact with flammable materials. Conveyor belt fires can quickly spread if not detected and managed early.

Cooperating Agency

An organization or group that assists in fire management operations but does not have primary jurisdiction. Cooperating agencies may provide resources, personnel, or technical support during fire incidents.

Corpus Delicti

A legal term referring to the "body of the crime"—evidence that proves a crime has been committed. In fire investigations, establishing corpus delicti involves showing that a fire was intentionally set and that a criminal act occurred.

Coyote Tactics

A firefighting strategy where crews use fire to fight fire, working from a secure position and igniting controlled burns to reduce fuel in the path of an approaching wildfire. This method helps prevent the fire from spreading uncontrollably.

Crazing

The formation of fine, irregular cracks on the surface of glass or ceramics due to rapid heating and cooling. Crazing patterns can be analyzed to understand the heat conditions during a fire.

Creep

The slow, smoldering spread of a fire along the ground, often through dense vegetation or duff. Creeping fires can go unnoticed for longer periods but still pose significant risks.

Creeping Fire

A fire that spreads slowly across the forest floor or other low-lying vegetation. Although less intense than fast-moving fires, creeping fires can still reignite and expand if conditions change.

Crew Boss

The leader of a team of firefighters responsible for managing their activities and ensuring their safety. The crew boss coordinates efforts during fire suppression and communicates with higher-level incident command.

Crime

An act that violates the law and is punishable by the state. In fire investigation, crimes can include arson, fraud, and negligence leading to a fire.

Curtain Boards

Vertical barriers installed near the ceiling of a building to control the movement of smoke and heat during a fire. Curtain boards help channel smoke towards exhaust systems and improve fire safety in large structures.

D

Dashboard Fire

A fire that originates in the dashboard area of a vehicle, often due to electrical faults or overheating components. Dashboard fires can spread rapidly and pose risks to vehicle occupants.

Data Analysis

The systematic examination and interpretation of data to extract useful information. In fire investigations, data analysis can include studying patterns of fire behavior, response times, and fire statistics.

Daubert Challenge

A legal standard used in the U.S. to determine the admissibility of expert witness testimony based on scientific validity. In fire investigations, Daubert challenges may address the methods and reliability of fire origin and cause analysis.

Dead Fuels

Vegetation that is no longer alive and has lost its moisture content, making it highly flammable. Dead fuels contribute significantly to the intensity and spread of wildfires.

Debris

The remnants of destroyed materials left after a fire. Debris analysis can provide insights into the progression and intensity of a fire, as well as possible points of origin.

Debris Burning

The act of burning waste materials, such as leaves, branches, or household refuse, often in outdoor settings. Improperly managed debris burning is a common cause of wildfires and requires safety measures to prevent fire spread.

Debris Fire

A fire that originates in a pile of combustible debris. Debris fires can be accidental or intentional and may spread quickly if not controlled, posing a risk to surrounding structures and vegetation.

Decomposition Explosion

An explosion that results from the rapid decomposition of unstable chemical compounds, releasing large amounts of gas and energy. These explosions can occur in industrial settings or during chemical fires.

Decomposition, Heat of

The energy released or absorbed during the chemical breakdown of a compound. This process can contribute to fire intensity, especially in cases involving volatile or reactive substances.

Deductive Reasoning

The logical process of drawing specific conclusions from general information. Fire investigators use deductive reasoning to analyze evidence and determine the most likely cause of a fire.

Defensible Space

A buffer zone created around a building or structure to reduce fire risk by clearing or thinning vegetation and combustible materials. Defensible space is essential for protecting homes in wildfire-prone areas.

Deflagration

A type of combustion that propagates through a gas or along the surface of a combustible material at a speed less than the speed of sound. Deflagrations are characterized by rapid flame spread and can result in significant damage.

Delayering

The process of carefully removing layers of debris or materials during a fire investigation to reveal underlying evidence or burn patterns. Delayering helps investigators analyze the fire's origin and progression.

Density

The mass per unit volume of a substance, which affects how a material burns. Denser materials may burn more slowly, while less dense materials can ignite and spread fire more rapidly.

Deployment

The act of positioning firefighting resources and personnel to effectively respond to and manage a fire incident. Deployment strategies are based on the fire's behavior, terrain, and available resources.

Deposition

The formal process of taking sworn, out-of-court testimony from a witness as part of pre-trial discovery in legal proceedings. In fire investigations, depositions may be used to gather testimony from witnesses or experts.

Detection

The discovery and identification of fire at an early stage, which can be done using alarms, sensors, or visual observation. Early detection is crucial for effective fire suppression and minimizing damage.

Detonation

An explosion in which the combustion process propagates through a medium at a speed greater than the speed of sound, producing a shock wave. Detonations are more destructive than deflagrations and can be associated with high explosives.

Detonators

Devices used to initiate the detonation of an explosive material. They play a crucial role in controlled demolitions, mining, and certain industrial processes but can also be involved in criminal activities, including arson.

Diffuse Explosion

An explosion that occurs when a flammable gas or vapor mixes uniformly with air and ignites, resulting in a widespread and rapid combustion. Diffuse explosions are characterized by a broad area of effect and can cause significant damage.

Diffuse Fuel

Combustible material that is dispersed in the form of fine particles or vapors. Diffuse fuels, such as dust or gas, can create explosive environments when mixed with air and exposed to an ignition source.

Diffusion Flame

A type of flame where the fuel and oxidizer are separate and mix at the flame front. Diffusion flames are common in open fires and tend to produce visible smoke and soot.

Direct Attack

A firefighting strategy that involves directly applying water, foam, or other fire suppression agents to the burning edge of a fire. This method is effective for controlling small fires or portions of larger fires.

Direct Evidence

Evidence that directly proves a fact without the need for inference, such as eyewitness testimony or video footage. In fire investigations, direct evidence can help establish the cause and circumstances of a fire.

Discovery

The legal process during which parties in a case exchange information and evidence before trial. Discovery can include documents, witness lists, and expert reports related to fire investigations.

Dispatch

The process of sending firefighting resources to the scene of a fire in response to an alarm or call for assistance. Dispatch centers coordinate the response and ensure the appropriate resources are mobilized efficiently.

Dispatch Center

A facility or location that receives emergency calls and coordinates the dispatching of firefighting resources, law enforcement, and medical services. Dispatch centers play a crucial role in ensuring timely and efficient responses to fire incidents.

Dispatcher

A person responsible for managing communication between the public, emergency responders, and resources during fire or emergency incidents. Dispatchers handle the deployment of fire services and keep track of units on the scene.

Distillation

A process used to separate components in a liquid mixture based on differences in boiling points. In fire investigations, distillation analysis can be used to identify accelerants or other flammable substances found at the scene.

Division

A designated area within an incident response, often divided by geographical boundaries or responsibilities. Divisions help organize large-scale firefighting operations by assigning tasks and resources to specific sectors.

Dozer

A heavy equipment vehicle equipped with a large blade, used to create firebreaks or clear vegetation and debris during firefighting operations. Dozers help prevent fire spread and provide access for ground crews.

Dozer Line

A firebreak created by a bulldozer that clears away vegetation down to the soil, forming a barrier to slow or stop the spread of a fire. Dozer lines are an essential tool in wildfire management.

Drip Torch

A handheld tool used to ignite controlled burns by dripping a flammable liquid mixture of diesel and gasoline onto the ground. Drip torches are used in backburning and prescribed fire operations to manage vegetation and reduce fuel loads.

Drop Down

The process in which burning materials from higher levels in a structure fall to lower levels, potentially igniting new fires or spreading an existing fire. Understanding drop down can help investigators trace fire progression in multi-story structures.

Drop Zone

The designated area where aircraft release water or fire retardant during aerial firefighting operations. Drop zones are chosen strategically to maximize the effectiveness of the suppression effort.

Drought

A prolonged period of insufficient rainfall leading to dry conditions that increase fire risk. Droughts can result in dry vegetation that acts as fuel for wildfires and can create challenging firefighting conditions.

Drought Index

A measure used to assess the dryness of vegetation and soil, helping predict the likelihood of fire ignition and spread. Common indices include the Keetch-Byram Drought Index (KBDI), which helps guide firefighting strategies.

Dry Hydrant

A non-pressurized pipe system installed near a water source, such as a pond or lake, to allow quick access to water for firefighting. Dry hydrants are used in rural or remote areas where traditional hydrant systems are unavailable.

Dry Lightning Storm

A thunderstorm that produces lightning but little or no rainfall, increasing the risk of wildfire ignition. Dry lightning storms are common in arid regions and are a significant cause of wildfires.

Duff

A layer of decomposed organic material found on the forest floor that can ignite and smolder during a wildfire. Duff burns more slowly than other fuels but can retain heat and reignite fires after the main blaze has passed.

Dust Explosion

A rapid combustion event that occurs when a high concentration of combustible dust particles is suspended in the air and ignited. Dust explosions can happen in industrial settings, such as grain silos or factories.

Dynamite

A high-explosive material made from nitroglycerin and an absorbent substance, used in construction, demolition, and mining. Dynamite can be a potential hazard in fires if stored improperly or exposed to heat.

Burning Ban

A temporary restriction imposed by authorities to prevent open burning activities, usually due to high fire risk conditions such as drought or high winds. Burning bans are put in place to reduce the likelihood of uncontrolled fires.

E

EV Charging Station Safety

Protocols and safety measures used to prevent and manage fire risks associated with electric vehicle (EV) charging stations. These measures include proper installation, monitoring, and the use of fire suppression systems.

EV Fire Investigation

The specialized analysis of fire incidents involving electric vehicles. This type of investigation considers factors such as battery chemistry, charging systems, and electrical components to determine the cause and prevent future occurrences.

EV Safety Features

Built-in technologies and design elements in electric vehicles aimed at preventing fires and enhancing safety, such as thermal management systems, battery isolation units, and automatic shutoffs.

Ecology

The study of interactions between living organisms and their environment. In fire science, ecology examines how fire affects ecosystems, including plant regeneration, animal habitats, and nutrient cycling.

Ecosystem

A community of living organisms interacting with each other and their physical environment. Fire plays a natural role in many ecosystems, helping to clear dead material, promote new growth, and maintain biodiversity.

Effective Fire Temperatures

The range of temperatures at which a fire can ignite and sustain combustion. Understanding effective fire temperatures helps assess fire behavior and the potential for ignition under varying conditions.

Electric Spark

A small, intense burst of electric current that can generate enough heat to ignite flammable materials. Sparks are common ignition sources in electrical fires.

Electrical Arcing

A discharge of electric current that jumps across a gap between conductors, creating intense heat and light. Electrical arcing is a common ignition source for fires, especially in electrical equipment or wiring faults.

Electrical Discharge

The release of electric energy as a spark or arc between two conductors. This discharge can generate significant heat and potentially ignite nearby combustible materials, contributing to electrical fires.

Electrical Fire

A fire that is started by electrical equipment or wiring. Electrical fires can result from short circuits, overloading, damaged insulation, or faulty appliances and pose unique risks due to live current.

Electrical Fires

Fires that involve electrical wiring, equipment, or devices. These types of fires often require specialized suppression techniques due to the risk of electrical shock and the nature of burning materials.

Electrical Insulation

Non-conductive material used to prevent electric current from flowing where it is not intended, reducing the risk of shock or fire. Damaged or compromised insulation can lead to electrical arcing and fires.

Electrical Malfunction

A failure or irregular operation in an electrical system that can result in overheating, arcing, or short circuits. Electrical malfunctions are a common cause of fires in residential and commercial buildings.

Electrical Overload

A condition where electrical current exceeds the safe capacity of a circuit, causing overheating and potential fire hazards. Overloaded circuits can occur when too many devices are connected or when there is faulty wiring.

Electrical Panel Fire

A fire that originates in an electrical panel due to wiring faults, overload, or equipment failure. Such fires can spread quickly and pose risks to entire electrical systems.

Electrical Panel Inspection

The examination of electrical panels for signs of wear, damage, or code violations to ensure safety and prevent fire risks. Regular inspections can detect potential problems before they lead to a fire.

Electrical Safety

The practice of maintaining and using electrical systems in a way that prevents hazards, including fires. Electrical safety involves proper installation, regular maintenance, and adherence to safety codes and standards.

Electrical Short Circuits

A failure in an electrical circuit where current flows along an unintended path, often resulting in overheating or sparks. Short circuits can quickly ignite nearby flammable materials and lead to fire incidents.

Electricity

The flow of electric charge, used as a power source for lighting, heating, and operating various devices. Improper handling or faults in electrical systems can lead to fire risks.

Electrochemical Reactions

Chemical reactions that involve the transfer of electrons, often found in batteries and fuel cells. If these reactions are uncontrolled, they can generate excessive heat and potentially lead to a fire.

Electrode Degradation

The deterioration of an electrode's material over time, affecting the performance of batteries and other electrical devices. Degraded electrodes can increase the risk of overheating and fire in battery-operated systems.

Electrolyte Additives

Chemicals added to the electrolyte in a battery to improve its performance and safety. While some additives can help prevent overheating, they must be carefully managed to avoid contributing to fire risks.

Electrolyte Leakage

The escape of electrolyte fluid from a battery due to damage or faulty seals. Leakage can cause short circuits, corrosion, and increased risk of fire.

Electronically Stored Information (ESI)

Digital data stored on electronic devices, such as computers and smartphones. In fire investigations, ESI can provide evidence regarding potential causes, timelines, and related communications.

Ember

A small, glowing piece of burning material that remains after a fire. Embers can travel long distances and ignite spot fires when they land on combustible surfaces.

Emergency Evacuation

The process of removing people from a dangerous area to a safer location during a fire or other emergency. Effective evacuation plans are essential for protecting lives in fire-prone environments.

Emergency Planning

The process of preparing for potential emergency situations, such as fires, by creating plans for response, evacuation, and communication. Proper emergency planning can reduce damage and save lives during fire incidents.

Emergency Response

The actions taken by emergency personnel, such as firefighters and first responders, to address and manage fire incidents or other emergencies. This includes deploying resources, providing medical aid, and containing the fire.

Emergency Shutoff

A mechanism or switch used to quickly cut off power, fuel, or other systems in an emergency to prevent further damage or reduce fire risk. Emergency shutoffs are critical safety features in buildings and industrial sites.

Emergency Sprinklers

An automated fire suppression system designed to activate when heat or smoke is detected, releasing water or other fire-suppressant materials. Emergency sprinklers are essential for controlling fires before they spread.

Empirical Data

Information collected through observation or experimentation, rather than theory. In fire investigations, empirical data can include burn patterns, witness statements, and measured temperatures to support findings.

Endothermic Reaction

A chemical reaction that absorbs heat from its surroundings, which can lower the temperature and reduce the risk of fire. Endothermic materials may be used in fire suppression products to absorb heat.

Energy

The capacity to do work or produce heat. In the context of fire, energy is released through combustion, contributing to the spread and intensity of the fire.

Energy Density

The amount of energy stored in a given system or substance per unit volume or mass. In fire science, understanding energy density helps assess the potential for fuel sources to contribute to fire intensity.

Energy Release Component (ERC)

An index used in wildfire behavior models that quantifies the potential energy available for release during combustion. Higher ERC values indicate greater fire potential and risk.

Engine

A fire apparatus or vehicle equipped to pump water and carry firefighting equipment. Engines are used for direct fire suppression, water supply, and supporting firefighting operations.

Engine Backfire

A brief, unintended explosion in an engine's exhaust or intake system. In fire investigations, an engine backfire may be considered as a potential ignition source.

Engine Compartment Fire

A fire that starts in the engine bay of a vehicle due to fuel leaks, electrical malfunctions, or overheating. Engine compartment fires can spread quickly and require prompt attention.

Engine Crew

A team of firefighters assigned to an engine who are responsible for operating the vehicle, pumping water, and conducting firefighting and suppression activities.

Engine Overheating

A condition where an engine exceeds its normal operating temperature, potentially leading to fire. Overheating can result from cooling system failures, fluid leaks, or excessive use under harsh conditions.

Engine Room Fire

A fire occurring in the engine room of a vessel or industrial site, often involving fuel, oil, or electrical systems. Such fires require specialized firefighting techniques due to the confined space and potential for rapid heat buildup.

Engine Wiring

Electrical cables and circuits that power an engine’s components. Faulty or damaged engine wiring can be an ignition source for fires, particularly in vehicles and machinery.

Entrainment

The process by which air or gases are drawn into a flame or plume of hot gases. Entrainment affects fire behavior by supplying oxygen and influencing flame spread.

Entrapment

A situation in which firefighters or individuals are caught or surrounded by fire, making escape difficult or impossible. Entrapments can be life-threatening and require immediate rescue operations.

Environmental Assessment (EA)

A process used to evaluate the potential environmental impacts of a proposed project or activity, such as prescribed burns or land development. EAs help ensure that fire management practices do not adversely affect ecosystems.

Equilibrium Moisture Content

The moisture level at which a material is in balance with the surrounding air, neither absorbing nor losing moisture. Understanding this content is crucial in fire behavior analysis, as drier fuels ignite more easily.

Escape Route

A pre-planned path that individuals can use to evacuate safely from a dangerous area during a fire. Identifying and maintaining clear escape routes are critical for fire safety and survival during emergencies.

Escaped Fire

A fire that breaks containment lines or spreads beyond the intended boundaries of a controlled burn, becoming uncontrolled. Escaped fires require immediate action to prevent further spread and potential damage.

Evacuation

The process of moving people away from a potentially hazardous area to a safer location due to an impending or active fire. Proper evacuation plans and procedures help minimize injury and loss of life.

Evidence

Any material, documentation, or information used to support conclusions in a fire investigation. Evidence can include physical items, photographs, witness statements, and expert testimony.

Evidence Collection

The process of gathering, preserving, and documenting physical and digital evidence at the scene of a fire. Proper evidence collection is crucial for determining the cause and supporting potential legal proceedings.

Examination Under Oath

A formal, recorded interview conducted as part of an insurance investigation, where an insured person answers questions related to a claim, including those about a fire incident. EUOs help insurers assess the validity of claims.

Examination Under Oath (EUO)

Exigent Circumstance

An emergency situation that justifies immediate action, such as entry into a property, without the need for a search warrant. This concept is relevant in fire investigations where immediate access is necessary to prevent further damage or risk.

Exothermic Reaction

A chemical reaction that releases heat as it occurs. Combustion is an example of an exothermic reaction, which is central to understanding fire behavior and heat generation.

Experimental Evidence

Data or findings obtained through controlled experiments or simulations to test hypotheses or theories related to fire behavior. Experimental evidence helps validate models and inform fire investigation conclusions.

Expert Opinion Evidence

Testimony provided by individuals with specialized knowledge or expertise relevant to a case, such as fire investigators or forensicexperts. Expert opinions help courts understand complex technical aspects of a fire.

Expert Witness

A person qualified through education, training, or experience to provide expert opinions in legal cases. Fire investigators often serve as expert witnesses to explain fire origins and causes during trials.

Explosible

A characteristic of a material or substance that indicates its potential to explode when certain conditions are met. Understanding what makes a substance explosible is crucial for preventing accidental explosions and managing fire risks.

Explosion

A sudden and violent release of energy, often involving the rapid expansion of gases that generate a shock wave. Explosions can be chemical, physical, or nuclear in nature and are significant hazards in fire incidents.

Explosion Dynamics

The study of the behavior and effects of explosions, including shock waves, pressure, and the distribution of debris. This analysis helps investigators understand the cause and impact of explosions in fire-related incidents.

Explosion Risk

The potential for an explosion to occur under certain conditions, such as the presence of flammable gases, dust, or improper handling of explosive materials. Managing explosion risk is critical for safety in industrial and residential settings.

Explosion Risks

The potential for explosions to occur under certain conditions, such as the presence of flammable gases, dust, or improper handling of explosive materials. Managing explosion risks is critical for safety in industrial and residential settings.

Explosion-Proof Equipment

Devices and equipment designed to operate safely in potentially explosive environments without igniting surrounding gases or dust. Explosion-proof equipment is essential in industries dealing with flammable substances.

Explosive Limits

The concentration range of a flammable gas or vapor in the air within which it can ignite or explode. Below the lower explosive limit (LEL), the mixture is too lean, and above the upper explosive limit (UEL), it is too rich to ignite.

Explosive Material

Substances capable of undergoing a rapid chemical reaction that releases energy and gas, causing an explosion. Common examples include dynamite, gunpowder, and certain chemical compounds used in industry.

Explosives

Chemical or mechanical compounds that produce sudden, violent expansions of gases when detonated or ignited. Explosives are used in construction, demolition, and mining, but can also pose significant fire and safety hazards.

Exposed Surface

The part of a material or structure that is directly exposed to fire or heat. The characteristics of an exposed surface, such as texture and composition, affect how it reacts to and transmits heat.

Exposure

The condition of being subject to or affected by fire, heat, or smoke. In fire terms, exposure often refers to nearby buildings or structures at risk from an adjacent fire.

Extended Attack Incident

A fire incident that cannot be contained with initial resources within the first operational period, requiring additional support and strategic planning. These incidents often involve larger teams and extended resources.

Extinguish

To put out or stop a fire. Extinguishing a fire can be accomplished through various means, including the application of water, foam, or chemical agents to remove heat or interrupt the chemical reaction.

Extreme Fire

A fire exhibiting rapid growth and intense energy release, often influenced by strong winds, low humidity, and abundant fuel. Extreme fire behavior is dangerous and difficult to control, posing significant risks to firefighters and communities.

Extreme Fire Behavior

Unpredictable and fast-moving fire actions that can include crowning, spotting, and fire whirls. Understanding extreme fire behavior is crucial for safety and effective firefighting tactics.

F

Factory Insurance Claims

Insurance claims filed to cover damages and losses sustained by factory owners due to fire or other insured risks. Investigating these claims often involves determining fire origin and causation.

Fahrenheit

A temperature scale used primarily in the United States, where the freezing point of water is 32°F, and the boiling point is 212°F under standard conditions. Fahrenheit measurements are used in fire reports and investigations in regions that use this system.

Fahrenheit Temperature

The measurement of temperature expressed in degrees Fahrenheit. This scale is often used for reporting weather conditions, building temperatures, and fire behavior in relevant regions.

Failure

The breakdown or malfunction of a component or system that can lead to a fire or worsen a fire incident. Failures can be mechanical, electrical, or structural in nature.

Failure Analysis

The systematic examination of failed components or systems to determine the root cause of their failure. In fire investigations, failure analysis is critical to identifying ignition sources and preventing future incidents.

Fall Down

The process of burnt or damaged materials falling from higher structures to lower levels during or after a fire. Fall down can create additional hazards and influence fire spread.

Faller

A firefighter or crew member who specializes in felling trees, especially during wildfire management, to create fire breaks and control fire spread. Fallers play a vital role in wildfire suppression and containment strategies.

Fault Current

An abnormal current flow caused by a fault, such as a short circuit or ground fault, in an electrical system. Fault currents can generate excessive heat and lead to electrical fires.

Faulty Wiring

Electrical wiring that is damaged, improperly installed, or worn, increasing the risk of electrical faults and fires. Faulty wiring is a common cause of residential and commercial building fires.

Felony

A serious criminal offense that is more severe than a misdemeanor and is punishable by imprisonment or severe penalties. Arson is an example of a felony involving fire.

Field Observer

A person tasked with collecting on-site data regarding fire behavior, weather conditions, and fuel characteristics during an incident. Field observers play an essential role in informing fire management strategies.

Fine Fuels

Small, dry materials such as grasses, twigs, and leaves that ignite quickly and can spread fire rapidly. Fine fuels contribute to fast-moving surface fires and are an important consideration in wildfire behavior analysis.

Fingers of a Fire

Narrow extensions of a fire that project out from the main body. Fingers can create additional challenges for containment, as they spread fire further into unburned areas.

Finish Rating

The measure of how long it takes for a fire to break through a material or surface. Finish ratings help assess the fire resistance of materials used in construction and interior finishes.

Fire

A rapid chemical reaction that produces heat, light, and various combustion products. Fire results from the interaction of heat, fuel, and oxygen, forming the "fire triangle."

Fire Accelerants

Substances that are used to initiate or speed up the spread of fire. Accelerants such as gasoline, kerosene, and alcohol are often analyzed in fire investigations to determine if arson was involved.

Fire Alarm

A device that detects smoke, heat, or flames and alerts occupants to the presence of a fire. Fire alarms are essential safety features in residential, commercial, and industrial buildings to facilitate timely evacuation.

Fire Alarms

A system of interconnected devices that detect smoke, heat, or flames and trigger a warning sound or alert. Fire alarms play a key role in preventing fire-related injuries and fatalities by providing early warning.

Fire Analysis

The study of how a fire started, spread, and behaved. Fire analysis includes examining burn patterns, heat sources, and fuel loads to determine the cause and progression of a fire.

Fire Area

The total space or surface area affected by a fire, used to assess the size and impact of the incident. Fire areas help responders plan containment and suppression strategies.

Fire Behavior

The manner in which a fire reacts to various conditions, such as fuel type, weather, and topography. Understanding fire behavior is critical for effective firefighting and fire management.

Fire Behavior Analysis

The examination of the factors that influence how a fire spreads and develops, including wind, fuel moisture, and terrain. Fire behavior analysis helps guide firefighting strategies and resource allocation.

Fire Behavior Forecast

A prediction of how a fire is likely to spread and react under specific conditions. Forecasts take into account weather data, fuel characteristics, and current fire activity to aid in planning and decision-making.

Fire Behavior Specialist

A professional with expertise in analyzing and predicting fire behavior based on environmental and fuel factors. These specialists are essential in large-scale fire management efforts for providing forecasts and strategic insights.

Fire Break

A gap in vegetation or other combustible material that acts as a barrier to slow or stop the spread of a fire. Fire breaks can be natural, like rivers or rocky terrain, or man-made, like cleared strips of land.

Fire Cache

A storage facility or location that holds firefighting tools, equipment, and supplies for use during fire incidents. Fire caches are strategically placed to ensure quick access for firefighting teams.

Fire Causation

The process of determining the initial source or reason for a fire's ignition. Fire causation investigations identify if the fire was accidental, natural, or intentional.

Fire Cause

The specific action, event, or condition that leads to the ignition of a fire. Determining the fire cause is essential for investigations, safety recommendations, and legal accountability.

Fire Code

Regulations and standards designed to prevent fire hazards and ensure safety in buildings and facilities. Fire codes cover aspects such as building materials, fire alarms, sprinkler systems, and emergency exits.

Fire Containment

The act of stopping the forward progress of a fire by creating control lines or using suppression methods. Containment measures prevent the fire from spreading and allow for safer firefighting efforts.

Fire Crew

A group of trained firefighters assigned to work together in fire suppression and management operations. Fire crews can include ground teams, engine operators, and specialized wildfire response units.

Fire Danger Index

A numerical scale that indicates the potential risk of fire based on factors such as temperature, humidity, wind speed, and fuel moisture. The index helps fire management teams assess and prepare for fire hazards.

Fire Debris

The remnants of burned materials left after a fire, such as ash, charred wood, and melted metal. Analyzing fire debris can provide important clues about the fire's cause, intensity, and spread.

Fire Debris Analysis

The examination of burned materials and residues to identify accelerants, ignition sources, and other evidence in fire investigations. This analysis can help determine whether a fire was accidental or intentional.

Fire Department

A public or private organization responsible for providing fire prevention, suppression, and emergency response services to a community or area. Fire departments are equipped with trained personnel and firefighting apparatus.

Fire Doors

Specialized doors designed to withstand fire for a certain period, helping to contain the spread of flames and smoke. Fire doors are essential for maintaining safe egress routes and protecting building occupants.

Fire Dynamics

The study of how fires develop, spread, and interact with their environment. Fire dynamics examines factors such as heat transfer, fuel properties, and ventilation to understand fire behavior.

Fire Effects

The impact of fire on the environment, structures, and living organisms. Fire effects can range from beneficial ecological changes to destructive damage to property and ecosystems.

Fire Extinguisher

A portable device containing fire suppression agents, such as water, foam, or dry chemicals, used to put out small fires. Fire extinguishers are categorized based on the types of fires they are designed to combat.

Fire Extinguishers

Various types of portable devices used to extinguish small fires, classified by their suppression agent and the classes of fires they can handle (e.g., Class A for ordinary combustibles, Class B for flammable liquids).

Fire Extinguishing Agent

A substance used to suppress or put out a fire, such as water, carbon dioxide, dry chemical powder, or foam. The choice of agent depends on the type of fire and the materials involved.

Fire Front

The leading edge of a moving fire where combustion is most intense. Understanding the fire front's behavior is crucial for strategic firefighting and containment efforts.

Fire Gases

Gaseous byproducts produced during combustion, such as carbon monoxide, carbon dioxide, and hydrogen cyanide. Fire gases can be toxic and contribute to the spread of smoke and heat.

Fire Hazard

Any condition or material that increases the likelihood of a fire starting or spreading. Fire hazards can include flammable materials, faulty electrical wiring, or poor ventilation.

Fire Hazards

Various factors that contribute to the risk of fire ignition and spread, such as the presence of combustible materials, improper storage of chemicals, or electrical malfunctions. Identifying fire hazards is key for prevention.

Fire Hazards in HVAC

The potential fire risks associated with heating, ventilation, and air conditioning (HVAC) systems. These risks can include electrical faults, dust buildup, or malfunctioning components that may ignite fires.

Fire Head

The part of a wildfire that moves fastest and burns most intensely, driven by wind or slope. The fire head is the main focus for containment efforts as it poses the greatest threat to spread.

Fire History

The record of past fire occurrences in a specific area, including details of frequency, causes, and impacts. Fire history helps guide fire management and prevention strategies.

Fire Hydrant

A connection point to a water supply system that firefighters use to access water for fire suppression. Fire hydrants are strategically placed in urban and rural areas to aid in firefighting efforts.

Fire Incident Analysis

The detailed examination of a fire event to assess its origin, cause, spread, and impact. Incident analysis helps improve fire response tactics and informs future prevention strategies.

Fire Insurance

A type of property insurance that covers damage and losses caused by fire. Fire insurance policies may include coverage for the structure, personal property, and additional living expenses if the property is uninhabitable after a fire.

Fire Intensity

The amount of heat energy released during a fire, usually measured in terms of heat per unit length of fire front (kW/m). Fire intensity is a key factor in understanding fire behavior and planning firefighting tactics.

Fire Investigation

The process of examining a fire scene and collecting evidence to determine the cause and origin of the fire. Fire investigators use various methods, including burn pattern analysis, witness interviews, and chemical testing, to reach conclusions.

Fire Investigation Software

Specialized programs used by fire investigators to document evidence, create scene diagrams, and analyze fire dynamics. These tools aid in creating comprehensive reports and case files.

Fire Investigator

A professional trained to analyze fire scenes, collect evidence, and determine the cause and origin of a fire. Fire investigators may work for fire departments, insurance companies, or government agencies.

Fire Investigator Tools

Equipment used by fire investigators to collect and analyze evidence, such as thermal imaging cameras, moisture meters, gas detectors, and sample containers. These tools help determine fire origin and cause.

Fire Line

A cleared strip of land or a barrier created to stop or control the spread of a wildfire. Fire lines can be dug manually, created by bulldozers, or established using controlled burns.

Fire Load

The total quantity of combustible materials present in a building or space that can fuel a fire. The fire load helps assess potential fire severity and informs fire safety planning.

Fire Management

The practices and strategies used to control, suppress, and prevent fires, including both wildfire and structural fire scenarios. Fire management encompasses planning, training, and resource allocation.

Fire Management Plan (FMP)

A comprehensive document outlining strategies and procedures for preventing and responding to fires in a specific area. An FMP considers resources, risk assessment, and environmental factors.

Fire Marshal

A public official responsible for enforcing fire codes, investigating fire causes, and conducting fire safety inspections. Fire marshals often play a role in public education and fire prevention programs.

Fire Origin

The specific location or area where a fire begins. Determining the fire origin is critical for understanding the cause and for conducting thorough fire investigations.

Fire Partition

A non-combustible barrier or wall designed to prevent the spread of fire and smoke between sections of a building. Fire partitions are an important component of building fire safety systems.

Fire Pattern Analysis

The study of burn patterns to draw conclusions about a fire’s origin, spread, and cause. This analysis involves examining char depth, smoke staining, and other fire effects on materials.

Fire Patterns

The distinctive burn marks and damage left by a fire that help investigators understand its behavior and progression. Patterns such as V-shapes, hourglasses, and charring are analyzed to determine fire direction and intensity.

Fire Perimeter

The boundary line around the area affected by a fire. The fire perimeter is used to measure the extent of the fire and helps guide containment and suppression efforts.

Fire Point

The temperature at which a liquid produces enough vapor to sustain continuous combustion after ignition. The fire point is higher than the flash point and is critical for understanding fire risks of flammable liquids.

Fire Prevention

Measures taken to reduce the risk of fire starting or spreading, such as implementing fire codes, conducting inspections, and educating the public. Fire prevention is essential for protecting lives and property.

Fire Proofing

The application of fire-resistant materials to structural components to increase their resistance to fire and heat. Fireproofing helps delay the spread of fire and provides additional time for evacuation and firefighting efforts.

Fire Propagation

The process by which a fire spreads from its point of origin to surrounding areas. Factors affecting fire propagation include fuel type, wind, humidity, and topography.

Fire Protection

Systems, practices, and materials designed to prevent, detect, and suppress fires to protect people and property. Fire protection includes both active systems, like sprinklers, and passive systems, like fire-resistant building materials.

Fire Protection System

An integrated system of equipment and processes, such as fire alarms, sprinklers, and smoke detectors, aimed at detecting and controlling or extinguishing fires. These systems help ensure the safety of occupants and minimize property damage.

Fire Regime

The pattern, frequency, and intensity of wildfires in a particular ecosystem over time. Fire regimes help ecologists and fire managers understand the natural role of fire in maintaining healthy ecosystems.

Fire Residue Analysis

The examination of ash, soot, and other remnants left after a fire to determine the presence of accelerants or other chemical indicators. This analysis aids in identifying whether a fire was accidental or intentional.

Fire Resistance

The ability of a material or structure to withstand fire and maintain its integrity for a specified period. Fire resistance is tested and rated to meet safety standards for building construction.

Fire Resistance Rating

The duration for which a building component, such as a wall or door, can withstand fire exposure while maintaining its structural integrity. Ratings are typically expressed in hours and are essential for building code compliance.

Fire Resistant Roofing

Roofing materials that have been treated or manufactured to resist catching fire. Fire-resistant roofs help protect homes from wildfires and embers that can ignite roofs made of more flammable materials.

Fire Resistant Tree

A type of tree or plant that has properties that make it less likely to ignite or spread fire. Fire-resistant trees are often included in landscape designs to create defensible space around properties.

Fire Retardant Packaging

Packaging materials that have been treated or manufactured to resist catching fire or to slow the spread of flames. This is commonly used for shipping hazardous materials or in industries requiring high fire safety standards.

Fire Retardants

Chemicals or substances applied to materials or vegetation to slow down or stop the spread of fire. Fire retardants are used in aerial drops during wildfires and in building materials for added fire protection.

Fire Risk Assessment

The process of evaluating the potential fire hazards and risks in a building or area to implement appropriate safety measures. This assessment helps prioritize fire prevention efforts and ensure compliance with fire safety regulations.

Fire Safety

A set of practices and precautions aimed at preventing fire outbreaks and ensuring the safety of people and property. Fire safety includes fire prevention measures, safety protocols, and the use of fire protection systems.

Fire Safety Equipment

Devices and tools used to detect, suppress, or fight fires, such as fire extinguishers, smoke detectors, sprinkler systems, and fire blankets. Having appropriate fire safety equipment is essential for emergency preparedness.

Fire Scene Photography

The practice of documenting a fire scene through photographs to capture evidence, damage, and burn patterns. Fire scene photography is critical for investigations, insurance claims, and legal proceedings.

Fire Science

The study of the behavior, effects, and control of fire. Fire science encompasses fire dynamics, combustion processes, fire prevention, and firefighting techniques.

Fire Season

The period during which wildfires are most likely to occur, typically characterized by dry weather, high temperatures, and low humidity. Fire season varies by region and is influenced by climate and vegetation conditions.

Fire Shelter

A portable, heat-reflective tent carried by wildland firefighters for emergency protection in case they become trapped by fire. Fire shelters provide temporary refuge and help shield against radiant heat and flames.

Fire Shelter Deployment

The act of setting up and using a fire shelter during an emergency to protect oneself from intense heat and flames. Firefighters are trained to deploy shelters quickly to maximize survival chances in entrapment situations.

Fire Smart

The practice of creating and maintaining fire-resilient properties and landscapes through strategies such as vegetation management, fire-resistant building materials, and community planning. Fire smart practices help reduce the risk of fire damage.

Fire Spread

The movement of fire across an area or through a structure. Fire spread can be influenced by factors such as fuel type, wind, topography, and ventilation.

Fire Spread Analysis

The process of examining how and why a fire spread in a particular way, including analyzing burn patterns, fuel loads, and environmental conditions. Fire spread analysis helps improve fire management and prevention strategies.

Fire Spread Patterns

The visual traces and damage paths left behind that show the direction and manner in which a fire has moved. Analyzing these patterns helps investigators determine the origin and progression of the fire.

Fire Storm

An intense and often uncontrollable fire that generates powerful updrafts and can create its own wind system. Fire storms can spread rapidly and cause severe damage over a large area.

Fire Suppressant

A substance used to extinguish or control a fire by interrupting the chemical reaction of combustion. Common fire suppressants include water, foam, and chemical agents.

Fire Suppression

The act of controlling and extinguishing a fire to prevent its spread and minimize damage. Fire suppression involves various tactics, including direct and indirect attack, the use of fire retardants, and creating firebreaks.

Fire Suppression System

An automated system designed to detect and suppress fires in buildings or vehicles. Examples include sprinkler systems, foam systems, and gas suppression systems.

Fire Tetrahedron

An expanded version of the fire triangle that includes four elements necessary for combustion: heat, fuel, oxygen, and a chemical chain reaction. The fire tetrahedron helps explain how fires sustain themselves and how to extinguish them.

Fire Triangle

A model that illustrates the three essential elements required for combustion: heat, fuel, and oxygen. Removing any one of these elements can extinguish a fire.

Fire Use Module

A team of specialized personnel who manage and conduct prescribed burns and other planned fire operations to achieve land management goals. Fire use modules help reduce hazardous fuel loads and maintain ecological balance.

G

Gallery Fire

A fire that occurs within a gallery or tunnel-like space, often characterized by limited ventilation and high heat buildup. Gallery fires can be particularly challenging to control due to confined spaces.

Galvanism

The production of an electric current resulting from a chemical reaction between different metals or electrolytes. In fire investigations, galvanism can be relevant when analyzing electrical faults and corrosion.

Gas

A state of matter that is highly compressible and expands to fill any space it occupies. In fire contexts, certain gases, such as natural gas or propane, are significant fire hazards due to their flammability.

Gas Chromatography

A laboratory technique used to separate and analyze compounds in a mixture, often applied in fire investigations to detect accelerants or other chemicals present at a fire scene.

Gasoline Fire

A fire that results from the ignition of gasoline vapors, which are highly flammable and capable of rapid combustion. Gasoline fires are often associated with vehicle or fuel storage incidents.

Gasoline Vapor Ignition

The ignition of flammable vapors released by gasoline, which can ignite at relatively low temperatures when mixed with air and exposed to a spark or flame.

Gasometer

A device used to measure the volume or concentration of gases, which can be used in fire investigations to monitor combustible gas levels in enclosed spaces.

General Origin Area

The broad zone where a fire is believed to have started, identified before narrowing down to a specific point of origin. Investigators use this area to begin more detailed analyses.

General Staff

Key personnel in the Incident Command System (ICS) responsible for coordinating major sections of an emergency response, including operations, planning, logistics, and finance/administration.

Geographic Area

A defined region used in fire management for planning, resource allocation, and coordination of firefighting efforts. Understanding the geographic area helps with strategic deployment and management of fire resources.

Geometry of Fuel

The shape, arrangement, and distribution of combustible materials in an area, which influence how a fire spreads. Irregular fuel geometry can create complex fire behavior patterns.

Glowing Combustion

A stage of fire where burning occurs without flame, producing heat and light. Glowing combustion typically happens after active flaming has subsided and can reignite if conditions change.

Gram

A unit of mass in the metric system used to measure small quantities of substances, including potential accelerants or residues found in fire investigations.

Gravity

The force that pulls objects toward the center of the Earth. In fire behavior, gravity influences how burning materials fall and where embers or sparks land, potentially igniting new fires.

Green Belt

An area of vegetation, such as grass or trees, surrounding an urban region that can act as a fuel source for fires. Properly managed green belts can help prevent or slow fire spread.

Ground

The electrical connection between a circuit or device and the earth, which helps prevent electrical shocks and fires. Faulty grounding can lead to dangerous arcing and fire risks.

Ground Fault

An unintentional electrical path between a power source and a grounded surface, often causing current to flow outside its intended circuit. Ground faults can generate heat and ignite fires if not properly protected by circuit breakers or GFCIs (Ground Fault Circuit Interrupters).

Ground Fuels

Combustible materials that lie on or beneath the surface of the ground, such as roots, decomposed leaves, and duff. Ground fuels can contribute to smoldering fires that may persist for long periods and reignite under favorable conditions.

H

HVAC Fire Spread

The movement of fire and smoke through a building's heating, ventilation, and air conditioning (HVAC) system. Proper design and maintenance of HVAC systems can help prevent fire spread and improve building safety.

Haines Index

A fire weather index used to assess the potential for wildfire growth based on atmospheric stability and dryness. A higher Haines Index indicates greater potential for large and intense fires.

Halogens

A group of elements, including chlorine, fluorine, bromine, and iodine, that are often used in fire suppression systems due to their ability to inhibit combustion. Halogen-based fire extinguishers are effective for certain types of fires but may be phased out due to environmental concerns.

Hand Line

A fire control line constructed by hand using tools such as shovels, axes, and rakes. Hand lines are used to create breaks in vegetation to help prevent the spread of fire.

Handler

A person trained to work with specialized detection canines, such as those used in accelerant detection during fire investigations. Handlers guide and manage dogs to identify fire-related evidence.

Hardscape

Non-flammable features in landscaping, such as stone, concrete, and gravel. Hardscaping is used to create defensible space around structures and reduce fire risk.

Hardwood

The wood from broad-leaved trees, such as oak and maple. Hardwoods generally burn more slowly and produce less intense flames compared to softwoods, making them less likely to contribute to rapid fire spread.

Hazard

Any condition or situation that poses a risk of fire ignition, spread, or danger to life and property. Hazards can be natural (e.g., dry vegetation) or man-made (e.g., faulty wiring).

Hazard Assessment

The process of evaluating potential fire risks in a given area or structure and determining the necessary precautions and mitigation measures. This assessment helps prioritize fire prevention efforts.

Hazard Reduction

The strategies and practices used to reduce or eliminate potential fire risks, such as removing flammable vegetation, installing fire-resistant materials, and maintaining electrical systems.

Hazardous Area

A location identified as having significant fire or explosion risks due to the presence of flammable or combustible materials, gases, or dust. Proper safety protocols and equipment are required in hazardous areas to prevent incidents.

Hazardous Chemicals

Substances that pose a fire, explosion, or health risk when mishandled or improperly stored. Proper storage and handling of hazardous chemicals are crucial for fire prevention and safety.

Hazardous Fuel Reduction

The practice of removing or modifying flammable vegetation to lower the potential for wildfires. This includes activities such as controlled burns, pruning, and clearing underbrush.

Hazardous Fumes

Toxic or harmful gases released during combustion or chemical reactions that can pose a health risk. Firefighting and investigation efforts must take into account the presence of hazardous fumes to ensure safety.

Hazardous Gases

Gases that are flammable, toxic, or explosive and can pose a significant fire risk if released into the environment. Monitoring and controlling the presence of hazardous gases is essential for fire prevention.

Hazardous Material

A substance or material that poses potential fire, explosion, chemical, or health hazards. Common hazardous materials include fuels, solvents, and chemicals used in industrial processes.

Hazardous Materials

Various substances that pose fire, explosion, or chemical risks if not handled properly. Fire departments and hazmat teams are trained to respond to incidents involving hazardous materials to prevent or mitigate fire and environmental damage.

Head of a Fire

The leading and fastest-moving part of a wildfire or fire front, driven by wind and topography. The head of the fire is often the most intense and poses the greatest risk to firefighting efforts and nearby structures.

Heat

A form of energy that raises the temperature of materials and can lead to combustion when combined with fuel and oxygen. Heat transfer methods include conduction, convection, and radiation.

Heat Damage

The physical and chemical changes that occur in materials exposed to high temperatures. Heat damage can include warping, discoloration, melting, and structural weakening, and is analyzed during fire investigations to understand fire behavior.

Heat Dissipation

The process by which heat is spread or released from a material or system to the surrounding environment. Effective heat dissipation is crucial in preventing overheating that could lead to fires.

Heat Explosion

An event where a sudden release of stored thermal energy results in rapid expansion and damage. Heat explosions can occur when enclosed materials or gases are subjected to extreme heat and pressure.

Heat Flux

The rate at which heat energy is transferred to or from a surface, typically measured in watts per square meter (W/m²). High heat flux can indicate the potential for ignition and fire spread in nearby materials.

Heat Release

The total amount of energy produced by a fire, measured over a given period. Heat release is an important metric for understanding fire intensity and its potential impact on structures and people.

Heat Release Rate (HRR)

The rate at which heat energy is generated by a fire, measured in kilowatts (kW) or megawatts (MW). HRR is used to evaluate fire growth and the effectiveness of fire suppression methods.

Heat Sensors

Devices that detect changes in temperature and alert occupants or trigger fire suppression systems. Heat sensors are used in various fire safety systems to provide early warning of fire conditions.

Heat Shadowing

A phenomenon where an object blocks heat from reaching a surface, creating a pattern or area of less heat damage. Heat shadowing can help investigators determine the source and direction of a fire.

Heat Shields

Protective barriers designed to reflect or absorb heat, protecting structures or equipment from high temperatures. Heat shields are used in various fire prevention systems and in firefighting gear.

Heat Signatures

Distinct thermal patterns produced by fire or heat-emitting objects, detectable by thermal imaging equipment. Heat signatures can be used to locate hotspots and track fire progression during firefighting efforts.

Heat Sources

Objects or processes that generate heat, such as electrical appliances, machinery, or open flames. Identifying heat sources is essential in fire investigations to determine potential ignition points.

Heat Transfer

The movement of heat energy from one place or material to another through conduction, convection, or radiation. Heat transfer plays a key role in fire spread and behavior.

Heat and Flame Vector

The directional flow of heat and flames, used to analyze how a fire spreads and what factors contribute to its movement. Understanding heat and flame vectors helps investigators determine the origin and behavior of a fire.

Heat of Combustion

The total energy released as heat when a substance undergoes complete combustion. This value helps assess the intensity and potential energy output of a fire involving different fuels.

Heat of Ignition

The minimum amount of heat energy required to initiate combustion in a specific material. Understanding the heat of ignition is crucial for assessing fire risks and prevention strategies.

Heavy Fuels

Dense, larger-sized combustible materials such as logs, tree stumps, and large branches that burn more slowly but with greater intensity. Heavy fuels contribute to longer-lasting fires.

Heavy Petroleum Distillate

A fraction of petroleum that is denser and has a higher boiling point, used in products like diesel fuel and lubricants. Heavy petroleum distillates can pose fire risks due to their flammability.

Heavy Petroleum Distillate (HPD) (C9 - C23)

A specific range of hydrocarbons found in heavier petroleum products. HPDs can be present as accelerants or fuel sources in fire investigations and require specialized analysis for detection.

Heel

The part of a fire perimeter opposite the head, typically burning more slowly. The heel is often considered a safer area for firefighters to work from when suppressing a fire.

Helibase

A designated location used for managing and operating helicopters during firefighting operations. Helibases provide support for refueling, loading firefighting equipment, and coordinating aerial efforts.

Helispot

A temporary or designated location where a helicopter can land, take off, and perform operations such as dropping water or fire retardant. Helispots are used for quick access in wildfire areas.

Helitack

The use of helicopters to support firefighting operations, including water drops, transporting personnel, and delivering equipment. Helitack crews are specially trained to manage aerial firefighting activities.

Helitack Crew

A group of firefighters trained to conduct firefighting operations using helicopters. Helitack crews are responsible for initial attack efforts and rapid response in remote or hard-to-reach areas.

High Explosive

A type of explosive that detonates and produces a shock wave at supersonic speeds. High explosives are used in demolition and military applications and can pose significant risks if improperly handled or involved in a fire.

High Explosive vs High Order Explosion

A comparison between high explosives, which produce a rapid detonation and shock wave, and a high order explosion, which refers to the complete and efficient detonation of an explosive material.

High-Order Damage

Severe destruction caused by an explosion that fully utilizes the energy of the explosive material. High-order damage is characterized by shattering and extensive structural impact.

High-Voltage Cabling

Electrical cables designed to carry high-voltage electricity. Damaged or improperly installed high-voltage cabling can pose significant fire risks due to the potential for arcing and overheating.

Holding Actions

Strategies used to maintain control of a fire's perimeter and prevent it from spreading while additional resources or tactics are deployed. Holding actions may include building fire lines and applying water or retardants.

Holding Resources

Equipment and personnel used to sustain the containment of a fire once control lines are established. These resources ensure that fire does not breach containment and spread further.

Hose Lay

The arrangement and deployment of fire hoses during firefighting operations to deliver water from a water source to the fire. Hose lays are essential for maintaining an effective water supply during suppression efforts.

Hotshot Crew

An elite team of firefighters specifically trained for rapid and aggressive wildfire suppression. Hotshot crews are highly skilled in creating fire lines, conducting backburns, and working in difficult terrain.

Hotspot

An area within or near a fire perimeter where smoldering or active flames continue to burn. Hotspots must be monitored and extinguished to prevent the fire from reigniting or spreading.

Hotspotting

The process of identifying and extinguishing hotspots to ensure that a fire does not reignite or spread beyond containment lines. This is a critical part of mopping up after a fire.

Hull Damage

Damage to the hull of a vessel, which can occur as a result of a fire on board. Hull damage assessment is important for maritime fire investigations to determine the cause and impact of the fire.

Hull Integrity

The structural soundness of a vessel’s hull, which can be compromised during a fire due to heat and flame exposure. Maintaining hull integrity is crucial for the safety and buoyancy of the vessel.

Humidity

The amount of water vapor in the air, which affects fire behavior. Low humidity levels can lead to dry conditions that increase the likelihood of fire ignition and rapid spread.

Hybrid Mixture

A combination of different materials or fuel types that can affect fire behavior. Hybrid mixtures may involve combinations of gases, solids, or liquids that influence ignition and combustion characteristics.

Hydrant

A water source connection point used by firefighters to access water for fire suppression. Hydrants are commonly located along streets and in residential areas to provide a reliable supply of water for firefighting.

Hydraulic Fluid Ignition

The ignition of hydraulic fluid when exposed to a heat source or open flame. Hydraulic fluid can be flammable, and leaks or ruptures in hydraulic systems pose fire hazards, especially in industrial and mechanical settings.

Hydrocarbon

An organic compound made up of hydrogen and carbon atoms, often found in fuels such as gasoline, propane, and natural gas. Hydrocarbons are highly flammable and are key components in fire behavior and risk analysis.

Hydrogen

A highly flammable gas that can be a byproduct of chemical reactions or used as a fuel. Hydrogen fires burn with an almost invisible flame and require specific detection and suppression methods.

Hydrogen Fluoride Release

The release of hydrogen fluoride gas, which can be toxic and pose serious health risks. Hydrogen fluoride can be released during certain chemical fires and requires specialized response measures.

Hypergolic Material

A type of material or fuel that ignites spontaneously when it comes into contact with an oxidizer. Hypergolic materials are commonly used in rocket propulsion but pose significant fire risks due to their reactive nature.

Hyperthermia

An abnormally high body temperature that can result from exposure to excessive heat, such as during a fire. Hyperthermia is a medical emergency that can lead to heat exhaustion, heat stroke, and severe health complications.

Hypoxia

A condition in which the body or a region of the body is deprived of adequate oxygen supply. Hypoxia can occur during a fire due to high levels of smoke or reduced oxygen in the environment and poses significant risks to both occupants and responders.

I

I-Zone

A term used to describe the interface zone where urban development meets wildland areas, creating a higher risk for wildfires that can impact homes and infrastructure.

IAAI

The International Association of Arson Investigators, an organization that provides training, certification, and resources for professionals involved in fire investigation. The IAAI sets standards for conducting thorough and accurate fire investigations.

Ignitible Liquid Detection Canines

Specially trained dogs used to detect the presence of ignitable liquids at fire scenes. These canines assist investigators in locating potential accelerants that may indicate arson.

Ignition

The process of starting a fire by applying sufficient heat to a fuel source. Ignition can be natural, accidental, or intentional and is a critical focus in fire investigations.

Ignition Area

The specific location where a fire first started. Determining the ignition area is essential for understanding the fire's cause and origin.

Ignition Energy

The minimum amount of energy required to initiate combustion in a particular material. Ignition energy varies by material and environmental conditions, and understanding it helps assess fire risk.

Ignition Method

The specific way in which a fire is started, such as using an open flame, electrical spark, or chemical reaction. Identifying the ignition method helps fire investigators determine whether a fire was accidental or intentional.

Ignition Probability

The likelihood that a fire will start based on the conditions of fuel, heat, and oxygen availability. Ignition probability is used in fire risk assessments to predict potential fire outbreaks.

Ignition Sources

Objects or actions that can provide the heat necessary for ignition, such as matches, lighters, electrical faults, or friction. Identifying ignition sources is crucial in fire investigations to determine fire causes.

Ignition Switch

A component in vehicles and machinery that starts the engine or system. Faulty ignition switches can be a source of electrical fires, especially if they create a spark or short circuit.

Ignition Temperature

The minimum temperature at which a material can spontaneously ignite without an external flame. Ignition temperatures are key to understanding the fire risks of different materials.

Ignition Time

The amount of time required for a material to ignite when exposed to heat. This time can vary based on the material type, heat source, and environmental conditions.

Ignition, Spontaneous

The process by which a material catches fire without an external flame or spark, often due to a chemical reaction, heat buildup, or decomposition. Spontaneous ignition poses risks in storage of materials like oily rags and certain chemicals.

Immiscible

The property of two substances that do not mix or blend uniformly, such as oil and water. Understanding immiscibility is important when considering fire suppression tactics involving liquids.

Impact Resistance

The ability of a material to withstand mechanical force without cracking or breaking. Materials with high impact resistance are often used in fire-resistant building construction to maintain structural integrity during a fire.

Impedance

The resistance of an electrical circuit to the flow of alternating current (AC), which can affect heat generation in electrical systems. High impedance can lead to overheating and potential fire hazards.

Incendiary

A type of fire that is intentionally set with the intent to cause damage or harm. Incendiary fires are often associated with arson and require investigation to identify the cause and perpetrator.

Incendiary Fire

A fire that has been deliberately ignited to cause destruction or damage. Such fires are typically illegal and are investigated as acts of arson.

Incident

An event or occurrence that requires emergency response, such as a fire, explosion, or accident. Incidents can range in severity from minor to catastrophic and may involve multiple agencies for resolution.

Incident Action Plan (IAP)

A formal document outlining the strategy, tactics, and resources needed to manage and resolve an incident. The IAP is used in firefighting and emergency management to coordinate response efforts effectively.

Incident Command Post (ICP)

The on-site location where the incident commander and key staff coordinate and manage emergency response efforts. The ICP is the central point for communication and decision-making during an incident.

Incident Command System (ICS)

A standardized framework used to manage emergency response operations, ensuring clear communication and organization. ICS allows multiple agencies to work together efficiently during complex incidents like large-scale fires.

Incident Commander

The individual responsible for overseeing all operations at the scene of an emergency. The incident commander leads the strategic and tactical response and ensures the safety of personnel and the public.

Incident Management Team

A group of trained personnel that oversees the coordination and management of large or complex incidents, such as wildfires or natural disasters. Teams can be local, regional, or national in scope.

Incident Objectives

The specific goals set for managing an incident, such as containment, suppression, and protecting life and property. Incident objectives guide the actions of response teams and ensure a unified approach.

Incident Reporting

The process of documenting the details and response to an emergency incident. Incident reports provide a record for analysis, lessons learned, and potential legal or insurance purposes.

Incipient Phase

The initial stage of a fire, characterized by low heat and limited flame spread. Early detection and response during the incipient phase can prevent a fire from growing out of control.

Inductive Reasoning

A logical approach used to develop general conclusions based on specific observations and evidence. In fire investigations, inductive reasoning helps form hypotheses about the cause of a fire based on the available data.

Inert

A substance that does not react chemically under normal conditions. Inert gases, like nitrogen, are often used in fire suppression systems to displace oxygen and smother a fire.

Infrared Detection

The use of infrared technology to detect heat sources and hot spots that are not visible to the naked eye. Infrared cameras and sensors are used in firefighting and fire investigations to monitor fire activity and locate hidden flames.

Initial Attack

The first efforts made by firefighters and response teams to control and suppress a fire when it is still small and manageable. Effective initial attacks can prevent fires from escalating into larger incidents.

Insurance

A financial product that provides compensation for losses or damage caused by covered events, such as fire. Property and fire insurance help policyholders recover after incidents and mitigate financial risks.

Insurance Adjuster

A professional responsible for assessing and evaluating insurance claims, including those related to fire damage. Adjusters determine the extent of the damage and the compensation amount for the insured party.

Insurance Agent

A representative who sells insurance policies to customers and helps them understand coverage options. Agents may assist clients in choosing policies that protect against fire and other risks.

Insurance Broker

An intermediary who represents clients to help them find the best insurance policies for their needs, including coverage for fire protection. Brokers work independently from insurance companies to find suitable policies.

Insurance Carrier

The company or organization that provides insurance coverage and pays out claims. Insurance carriers underwrite policies and assess risks, including those related to fire damage.

Insurance Claims

Requests made by policyholders to their insurance company for compensation or coverage following a loss or damage, such as from a fire. Claims must be supported with documentation and evidence of the incident.

Insurance Contract

A legal agreement between an insurer and an insured party outlining the terms, coverage, and conditions of the insurance policy. This contract specifies what is covered, such as fire damage, and the obligations of both parties.

Insurance Fraud

The act of intentionally deceiving an insurance company to receive compensation or benefits unlawfully. Insurance fraud can involve staged fires or false claims of fire damage.

Insurance Money

The funds provided by an insurance company to a policyholder as compensation for a covered loss or damage, such as fire-related destruction of property.

Insurance Policy

A document detailing the terms, conditions, and coverage of an insurance agreement. Fire insurance policies outline what fire-related damages are covered and under what circumstances.

Insure

To provide financial protection against potential losses or damages by purchasing an insurance policy. Many individuals and businesses insure properties to safeguard against fire damage.

Insured

The person or entity that holds an insurance policy and is protected under the terms of that policy. The insured party is eligible for compensation in the event of fire damage if it falls within the policy's coverage.

Insurer

The company or organization that provides insurance coverage and pays out claims when a covered event, such as a fire, occurs. Insurers assess risk and set premiums for policies.

Intent

The purpose or mindset behind an action, particularly when determining whether a fire was set intentionally or by accident. In arson cases, proving intent is key to legal proceedings.

Interested Party

Any individual or organization with a vested interest in the outcome of a fire investigation or insurance claim. This can include property owners, insurers, and other stakeholders.

Internal Resistance

The opposition to the flow of electric current within a battery or electrical system, which generates heat. High internal resistance can lead to overheating and potential fire risks.

Investigative Lead

A piece of information or evidence that guides a fire investigator towards a potential cause or suspect. Leads can come from witnesses, physical evidence, or data analysis.

Investigative Team

A group of professionals who collaborate on a fire investigation to determine the cause, origin, and contributing factors. The team may include fire investigators, forensic experts, and law enforcement officers.

Isochar

A line or marking that indicates areas of equal burn intensity on a fire-damaged surface. Isochar mapping helps investigators understand the progression and severity of a fire.

J

Job Hazard Analysis

A process of identifying potential hazards associated with specific jobs or tasks, including fire risks. This analysis helps in creating safer work practices and emergency response plans.

Joule

A unit of energy in the International System of Units (SI). In fire investigations, joules may be used to measure the energy released during combustion or electrical discharge.

Jump Spot

A designated location where smokejumpers (firefighters trained to parachute into remote areas) can safely land to begin firefighting operations.

Jump Suit

A specialized suit worn by smokejumpers that provides protection against flames, abrasion, and impact during their descent and initial firefighting efforts.

K

Keech Byram Drought Index (KBDI)

An index used to measure the dryness of soil and vegetation, indicating the potential for fire ignition and spread. Higher KBDI values suggest greater fire risk due to dry conditions.

Kilowatt

A unit of power equal to 1,000 watts, commonly used to measure the output of electrical devices and energy release during fires. Kilowatt ratings help assess the energy demands and potential heat generation in electrical systems.

Kindling

Small, dry twigs or pieces of wood that ignite easily and are used to start a fire. Kindling plays an essential role in the initial phase of fire ignition.

Kindling Temperature

The minimum temperature required for a material to ignite and sustain combustion without an external flame. Knowing the kindling temperature of materials helps assess fire risk and prevention strategies.

Kinetic

Related to motion or movement. In fire dynamics, kinetic energy contributes to the movement of gases, flames, and embers, affecting fire spread and behavior.

Kinetic Theory

A theory that explains the behavior of particles in matter, especially gases, and their response to heat. In fire science, kinetic theory helps describe how heat energy causes molecules to move and ignite.

Kinetics

The study of the rate at which chemical reactions occur, including combustion reactions in fires. Kinetics helps understand the speed of ignition and the progression of a fire.

Knock Down

The initial phase of fire suppression when water or fire retardants are applied to reduce flames and control the fire’s intensity. "Knock down" helps prevent further spread and allows firefighters to move into the overhaul phase.

L

Ladder Fuels

Vegetation or materials that allow a fire to climb from the forest floor up to the canopy. Ladder fuels contribute to the vertical spread of a fire, making it more difficult to control.

Laminar Flow

A smooth, uninterrupted flow of air or fluid, where particles move in parallel layers with minimal mixing. In fire science, understanding laminar flow helps predict smoke movement and fire spread in controlled environments.

Large Fire

A fire that exceeds the capabilities of initial attack resources and requires significant additional firefighting efforts and coordination. Large fires can spread rapidly and pose significant risks to life and property.

Latent Heat

The amount of heat energy absorbed or released during a phase change of a substance, such as water turning into steam, without changing temperature. In fire behavior, latent heat impacts the ignition and spread of flames.

Latent Heat of Vaporization

The amount of energy required for a liquid to convert into a vapor without a temperature increase. This property is important for understanding the heat transfer in fires involving water-based suppression.

Lateral Fire

The horizontal spread of fire along the ground or across a landscape. Lateral fire spread is influenced by wind, fuel type, and topography and is a key factor in fire containment strategies.

Layering

The accumulation of different types of fuels in distinct layers, such as grasses, brush, and tree limbs. Layering affects fire intensity, spread, and the difficulty of suppression.

Lead Plane

An aircraft that flies ahead of air tankers during aerial firefighting operations to mark the target area for water or retardant drops. The lead plane ensures accuracy and safety in aerial drops.

Lifesaving Appliances

Equipment designed to protect and save lives during fire emergencies, such as fire extinguishers, fire blankets, and personal protective equipment (PPE). Lifesaving appliances are essential for occupant and firefighter safety.

Light Fuels

Fine, dry materials such as grass, leaves, and needles that ignite quickly and burn with high intensity. Light fuels contribute to the rapid spread of surface fires.

Light Petroleum Distillate

A category of petroleum products that are less dense and have lower boiling points, such as gasoline and kerosene. These distillates are highly flammable and are analyzed in fire investigations as potential accelerants.

Lightning Activity Level (LAL)

A scale used to measure lightning activity, which indicates the potential for fire ignition from lightning strikes. Higher LAL values correlate with increased fire risk.

Line Scout

A firefighter or team member responsible for locating and marking potential fire lines in wildfire management. Line scouts identify areas where control lines can be established to contain the fire.

Line of Demarcation

A clear boundary indicating the division between burned and unburned areas at a fire scene. This line helps investigators determine the fire's progress and potential origin.

Lines of Demarcation

Multiple boundaries used to identify different stages of fire spread or areas affected by varying levels of fire intensity. These lines aid in mapping fire behavior and planning suppression tactics.

Lithium Plating

The deposition of lithium metal on a battery’s anode, which can occur during rapid charging or low-temperature charging. Lithium plating increases the risk of internal short circuits and fires.

Lithium-ion Battery

A type of rechargeable battery commonly used in electronic devices and electric vehicles. Lithium-ion batteries can pose fire risks if damaged or overheated due to thermal runaway and potential ignition.

Litter

Loose, dead plant material such as leaves, twigs, and bark on the forest floor. Litter acts as a surface fuel, contributing to the ignition and spread of wildfires.

Live Fuels

Vegetation that still has moisture content and is capable of burning, though less easily than dead fuels. Live fuels can still contribute to fire spread under dry or extreme conditions.

Lividity

The post-mortem settling of blood in the body that results in a purplish discoloration of the skin. In fire investigations involving fatalities, lividity can help determine the time and position of death.

Low Explosive

A type of explosive that deflagrates (burns rapidly) rather than detonates. Low explosives are typically used in propellants and fireworks and can pose fire risks under certain conditions.

Low Explosive vs Low Order Explosion

A comparison between the deflagration of low explosives and a low order explosion, which is characterized by incomplete combustion and minimal damage compared to a high order explosion.

Low-Ignition Construction

Building design and materials that are resistant to ignition and reduce the spread of fire. This type of construction is used in fire-prone areas to enhance safety and resilience.

Low-Ignition Landscaping

Landscaping practices that use fire-resistant plants and non-combustible materials to create defensible space around structures. This strategy helps prevent the spread of wildfire to buildings.

Low-Order Damage

Damage resulting from an explosion that is less severe, characterized by slower combustion and minimal shock wave impact. This type of damage may indicate a low explosive or incomplete detonation.

Lower Flammable Limit

The lowest concentration of a flammable vapor or gas in the air that can ignite. Concentrations below this limit are too "lean" to sustain combustion.

M

MOU

An agreement between organizations or agencies outlining cooperative actions and responsibilities, such as sharing resources or coordinating responses during fire incidents.

MOU (Memorandum of Understanding)

An agreement between organizations or agencies outlining cooperative actions and responsibilities, such as sharing resources or coordinating responses during fire incidents.

Malice

The intention to commit a harmful or unlawful act. In the context of fire investigations, proving malice is crucial in cases of arson where intent must be established for prosecution.

Manufacturing Facility

A site where goods are produced and may involve the use of flammable or hazardous materials. Fires at manufacturing facilities can be particularly dangerous due to the presence of volatile substances.

Marine Engine Fire

A fire that originates in the engine compartment of a boat or ship, often due to fuel leaks, electrical malfunctions, or overheating. Marine engine fires require specialized firefighting techniques due to confined spaces and potential fuel hazards.

Marine Fire Suppression

Techniques and systems used to control and extinguish fires on boats, ships, and other marine vessels. Marine fire suppression may involve water, foam, or specialized extinguishing agents.

Marine Firefighting

The specialized practice of combating fires on vessels, ports, and waterfronts. This type of firefighting requires knowledge of ship structure, onboard fire hazards, and the use of marine-specific equipment.

Marine Insurance Claims

Insurance claims related to damages or losses from fires that occur on ships or at sea. These claims often involve complex assessments due to the unique challenges of marine fires.

Marine Safety Protocols

Procedures and guidelines designed to prevent and manage fires and other emergencies on marine vessels. These protocols include regular inspections, fire drills, and the maintenance of fire suppression systems.

Material First Ignited

The initial material that catches fire and sustains combustion at the start of a fire incident. Identifying this material helps investigators pinpoint the fire's origin and potential ignition sources.

Mechanical Failure

The malfunction or breakdown of machinery or equipment that can lead to overheating, sparking, or other conditions conducive to fire. Mechanical failure is a common cause of industrial and vehicle fires.

Medium Petroleum Distillate

A type of petroleum product that falls between light and heavy distillates, including substances such as kerosene and diesel fuel. Medium distillates can be flammable and are significant in fire investigations involving accelerants.

Melting Point

The temperature at which a solid becomes a liquid. In fire investigations, understanding the melting point of materials helps determine the temperature and heat exposure at the scene.

Micro-Remote Environmental Monitoring System (Mirco-REMS)

A system that uses remote sensors to monitor environmental conditions, such as temperature, humidity, and wind, which can impact fire behavior. Micro-REMS data helps fire managers make informed decisions during wildfire incidents.

Mineral Soil

Soil composed mostly of inorganic materials, which is less combustible than organic soil layers like duff. Mineral soil can act as a natural firebreak in wildland fire management.

Minimum Explosible Concentration (MEC)

The lowest concentration of combustible dust or gas in the air that can ignite and cause an explosion. MEC is an important parameter for assessing fire risks in industrial settings.

Minimum Ignition Energy (MIE)

The least amount of energy needed to ignite a specific fuel-air mixture. Understanding MIE helps in assessing the likelihood of ignition under various conditions.

Miscibility

The ability of two substances to mix together in any proportion without separating. Miscibility is significant in fire scenarios involving liquid fuels and suppressants.

Misdemeanor

A criminal offense that is less severe than a felony but still punishable by fines, community service, or imprisonment. In fire cases, misdemeanors can include violations of fire safety codes or negligent acts leading to fire incidents.

Mitigation

Actions taken to reduce the severity or likelihood of a fire, such as clearing vegetation, installing firebreaks, or using fire-resistant building materials. Mitigation is essential in fire prevention and risk management.

Mobilization

The process of deploying firefighting resources and personnel to respond to a fire incident. Mobilization ensures that the appropriate equipment and responders are on-site promptly to combat a fire.

Modular Airborne Firefighting System (MAFFS)

A portable system installed in military aircraft for aerial firefighting. MAFFS units allow planes to drop water or fire retardant over wildfires to assist ground crews.

Modus Operandi

A term referring to the typical method or pattern of behavior associated with an individual or event. In fire investigations, understanding an arsonist’s modus operandi can help identify repeat offenders and predict future incidents.

Mop-up

The process of extinguishing any remaining flames, embers, or hotspots after the main fire has been suppressed. Mop-up prevents rekindling and ensures the fire is fully contained.

Motive

The reason behind an action, especially in cases of intentional fire-setting or arson. Establishing motive is essential in legal proceedings to prove intent and link suspects to the crime.

Multi-Agency Coordination (MAC)

A system that facilitates collaboration between different agencies responding to a fire or emergency. MAC ensures efficient communication, resource sharing, and strategic alignment in complex incidents.

Mutual Aid Agreement

An arrangement between emergency response agencies to provide assistance and resources during incidents that exceed the capacity of a single organization. These agreements are crucial for large-scale firefighting efforts.

N

NAFI

The National Association of Fire Investigators, a professional organization dedicated to promoting fire investigation and prevention through education, certification, and research.

NAFI Resources

Educational materials, certification programs, and training offered by the National Association of Fire Investigators (NAFI) to support fire investigators in enhancing their skills and knowledge.

NFPA

The National Fire Protection Association, an international organization that develops and publishes fire safety codes and standards. NFPA guidelines are widely used to enhance fire prevention and safety practices.

NFPA 1033

The standard outlining the professional qualifications for fire investigators. NFPA 1033 specifies the knowledge and skills required to conduct thorough and effective fire investigations.

NFPA 1321

A standard that addresses the management and operation of fire protection services, including fire department administration, training, and safety protocols.

NFPA 302 Standards

Specific NFPA standards related to fire safety practices for boats and marine vessels. These standards outline best practices for preventing and responding to fires on watercraft.

NFPA 921

A comprehensive guide for fire and explosion investigations published by the National Fire Protection Association. NFPA 921 is used by fire investigators to standardize investigative techniques and methodologies.

NFPA 921 Standards

The established criteria outlined in NFPA 921 that guide fire investigators in examining and determining the cause of fires and explosions.

NFPA Codes

A set of safety standards and regulations developed by the National Fire Protection Association to guide fire safety practices. These codes cover areas such as building design, fire prevention, and firefighting procedures.

NFPA Standards

The established safety and fire prevention protocols published by the National Fire Protection Association. NFPA standards are used globally to ensure fire safety in various industries and settings.

National Environmental Policy Act (NEPA)

A U.S. law requiring federal agencies to assess the environmental effects of their proposed actions, including those related to fire management and prevention. NEPA ensures that fire mitigation strategies do not adversely impact the environment.

National Fire Academy

An institution that provides training and education for fire and emergency services personnel. The National Fire Academy offers courses on fire prevention, investigation, and management.

National Fire Danger Rating System

A system used to evaluate and communicate the risk of wildfires in a specific area. The system considers factors such as fuel moisture, temperature, wind speed, and humidity to assess fire potential.

National Institute of Standards and Technology (NIST)

A U.S. federal agency that conducts research and sets standards in various fields, including fire safety. NIST contributes to the development of fire investigation techniques and fire protection standards.

National Wildfire Coordinating Group

An interagency group that coordinates national wildfire response and sets standards for training and procedures in wildfire management. It ensures that different firefighting agencies work cohesively.

Natural Barrier

A landscape feature, such as a river, rocky area, or road, that helps prevent or slow the spread of a fire. Natural barriers are often used in fire management plans to create containment lines.

Negligence

The failure to take reasonable precautions to prevent fire hazards, which can result in unintended fires. Legal cases involving fire may cite negligence if proper safety measures were not followed.

Nomex

A flame-resistant material used in protective clothing for firefighters and other emergency personnel. Nomex is known for its durability and ability to withstand high temperatures, providing critical protection in fire situations.

Non-Scene Data

Information and evidence collected that is not directly from the fire scene but supports the investigation, such as surveillance footage, witness statements, and historical weather data. Non-scene data helps provide context for understanding the fire.

Non-Waiver Agreement

A legal document in which an insurance company and the insured party agree that any actions taken during an investigation do not waive rights or obligations under the insurance policy. This is important in fire investigations to ensure all parties retain their legal positions.

Noncombustible

A term used to describe materials that do not ignite or burn easily. Noncombustible materials are essential in fire-resistant construction and safety designs.

Noncombustible Material

A type of material that does not burn or contribute to fire spread. Examples include certain metals, bricks, and treated materials used in building construction for added safety.

Nonflammable

Substances or materials that do not catch fire easily under normal conditions. Nonflammable materials are important for minimizing fire risk in construction and manufacturing.

Normal Fire Season

The period of the year when wildfires are most likely to occur based on historical weather patterns, vegetation conditions, and fire activity. Understanding the normal fire season helps with preparedness and resource allocation.

O

Odometer

An instrument used to measure the distance traveled by a vehicle. In fire investigations involving vehicles, the odometer reading can provide clues about usage prior to a fire event.

Ohm, Ohm’s Law

A fundamental principle in electrical engineering that states the relationship between voltage, current, and resistance in an electrical circuit: V=I×RV = I \times RV=I×R (voltage equals current times resistance). Understanding Ohm’s Law is important in determining electrical causes of fires.

Open Burning

The act of burning materials, such as yard waste or refuse, in an open space without a contained structure or fire safety measures. Open burning can lead to unintentional fires if not controlled properly.

Open Flame

A visible flame from a source such as a candle, match, or torch. Open flames can easily ignite combustible materials and are a common ignition source in fire incidents.

Operational Period

The specific time frame during which firefighting activities or emergency operations are planned and executed. Operational periods are typically 12 to 24 hours and include objectives and resource assignments.

Operations Branch Director

A leader within the Incident Command System responsible for overseeing and managing all tactical operations at a fire or emergency scene. The Operations Branch Director ensures that firefighting and suppression efforts align with incident objectives.

Origin

The specific location where a fire began. Determining the origin is a critical step in fire investigations to identify potential ignition sources and causes.

Origin & Cause

The process of determining where and how a fire started. This is a foundational aspect of fire investigation that involves analyzing evidence, fire patterns, and potential ignition sources.

Overcharging

The process of charging a battery beyond its capacity, which can cause overheating, degradation, and potential ignition. Overcharging is a significant risk in lithium-ion batteries and other rechargeable energy sources.

Overcurrent

An electrical condition where current exceeds the designed limit of a circuit, leading to overheating and potential fire risks. Overcurrent protection devices, such as circuit breakers, are used to prevent this condition.

Overcurrent and Overload

Terms describing conditions where an electrical system experiences more current than it can safely handle. This can lead to overheating, damaged wiring, and increased fire risk.

Overhaul

The process of searching for and extinguishing any remaining hot spots or smoldering materials after the main fire has been suppressed. Overhaul prevents rekindling and ensures the fire is fully extinguished.

Overhead

Personnel who provide support and leadership in a fire incident, including supervisors, coordinators, and command staff. Overhead staff play a crucial role in organizing and managing firefighting operations.

Overheating Equipment

Machinery or appliances that generate excessive heat due to malfunction, wear, or improper use. Overheated equipment is a common ignition source for fires.

Overheating Protection

Safety features and devices that prevent equipment from reaching temperatures that could cause a fire. These include thermostats, circuit breakers, and thermal cutoffs.

Overload

A condition where electrical demand exceeds the system's capacity, causing overheating and potential fire hazards. Overloaded circuits can be prevented by using properly rated electrical equipment and distribution.

Overloaded Circuits

Electrical circuits that carry more current than they are designed to handle, leading to overheating and potential ignition of surrounding materials. This is a common cause of electrical fires in homes and businesses.

Overstory

The upper layer of vegetation in a forest, consisting of the tallest trees. The overstory can influence fire behavior by providing ladder fuels that allow a fire to climb from the ground to the canopy.

Oxidation

A chemical reaction in which a substance combines with oxygen, often releasing energy in the form of heat and light. Oxidation is a fundamental process in combustion and fire behavior.

Oxide

A compound formed when an element combines with oxygen. Metal oxides, such as iron oxide (rust), can be analyzed in fire investigations to determine exposure to heat and the progression of a fire.

Oxides

Various compounds made by the reaction of oxygen with other elements. In fire science, oxides can provide clues about combustion processes and the materials involved in a fire.

Oxygen

A gas that supports combustion and is a crucial component of the fire triangle (heat, fuel, and oxygen). The presence of sufficient oxygen is necessary for a fire to ignite and continue burning.

Oxygen Deficiency

A condition where the concentration of oxygen in the air is too low to sustain life. In fire scenarios, oxygen deficiency can result from rapid combustion and can be hazardous to individuals in the affected area.

Oxygen Sensors

Devices used to measure the concentration of oxygen in an environment. In firefighting and fire investigations, oxygen sensors help assess whether a space is safe for entry and whether fire conditions may change.

Ozone

A form of oxygen (O3) that can form during electrical arcing or lightning strikes. Ozone has a distinct smell and may be present in fire scenes where electrical activity played a role.

Ozonic

Pertaining to or having the properties of ozone. The term can be used in the context of fire scenes involving electrical arcing or reactions that produce ozone as a byproduct.

P

Pack Test

A physical fitness test used to evaluate the capability of wildland firefighters. The test simulates the physical demands of firefighting to ensure that personnel are prepared for the strenuous tasks required in wildfire response.

Paracargo

Supplies or equipment delivered by parachute, typically during wildfire operations to provide resources to firefighters working in remote areas. Paracargo drops can include food, water, tools, and other essentials.

Passive Fire Protection System

Fire safety features that do not require activation and work to prevent the spread of fire and smoke, such as fire-resistant walls, doors, and firestops. These systems help maintain structural integrity and allow safe evacuation.

Patterns of Spread

The observable paths and characteristics of how a fire has moved through an area. These patterns help fire investigators determine the origin and behavior of the fire.

Peak Fire Season

The time of year when fire activity is at its highest due to conditions like dry weather, high temperatures, and wind. Knowing the peak fire season is essential for preparedness and resource planning.

Personnel Protective Equipment (PPE)

Gear worn by firefighters and emergency responders to protect them from heat, flames, smoke, and other hazards. PPE includes helmets, gloves, fire-resistant clothing, and breathing apparatus.

Pilot Light

A small, continuous flame used to ignite gas in appliances such as stoves and water heaters. Malfunctioning pilot lights can lead to unintentional gas leaks and fire hazards.

Piloted Ignition Temperature

The minimum temperature at which a material will ignite when an external ignition source, such as a spark or flame, is present. This temperature is lower than the auto-ignition temperature.

Pipe Heat Sheild

A protective barrier designed to prevent heat transfer from a hot pipe to surrounding materials, reducing the risk of fire. Pipe heat shields are commonly used in industrial and residential settings.

Plastic

A synthetic or semi-synthetic material made from polymers that can ignite and burn at varying temperatures. Plastics can produce toxic fumes and contribute to the spread of fire.

Plug Fuses

Electrical safety devices that protect circuits by breaking the connection when current exceeds safe levels. Faulty or incorrect use of plug fuses can result in electrical fires.

Plume

The column of smoke, gas, and particles rising from a fire or explosion. The behavior of a plume, including its height and spread, can provide insights into the intensity and direction of a fire.

Point of Origin

The specific location where a fire started. Identifying the point of origin is crucial for fire investigations as it helps determine the ignition source and cause of the fire.

Post-Crash Fire

A fire that occurs after a vehicle collision or crash, often due to fuel leakage, damaged electrical systems, or other factors. Post-crash fires can be especially dangerous for occupants and first responders.

Post-Fire Analysis

The detailed examination of a fire scene after the fire has been extinguished. This analysis includes collecting evidence, documenting damage, and assessing burn patterns to determine the fire’s origin and cause.

Post-Fire Inspection

A formal review of a building or area following a fire to assess damage, ensure safety, and evaluate structural integrity. Inspections are necessary to determine the next steps for repair, restoration, or demolition.

Post-Fire Reconstruction

The process of rebuilding or repairing structures that have been damaged or destroyed by fire. This may involve replacing fire-damaged materials with fire-resistant alternatives and updating fire safety systems.

Power

The rate at which energy is transferred or used, commonly measured in watts or kilowatts. In fire investigations, power analysis can help determine whether electrical faults contributed to ignition.

Premixed Flame

A flame that occurs when fuel and oxidizer are mixed before ignition, producing a more controlled and even burn. Premixed flames are common in gas appliances and laboratory burners.

Preparedness

The state of being ready to respond effectively to a fire or emergency. Preparedness includes having fire safety plans, training personnel, and maintaining equipment to handle fire incidents promptly.

Prescribed Burning/Fire

A planned fire intentionally ignited under controlled conditions to reduce fuel load, manage ecosystems, and decrease the risk of larger, uncontrolled wildfires.

Prescribed Fire Plan (Burn Plan)

A detailed document outlining the objectives, conditions, and safety measures for conducting a prescribed burn. Burn plans ensure that prescribed fires are carried out safely and effectively.

Preservation

The act of protecting and maintaining evidence or a scene from tampering or degradation. Preservation is crucial in fire investigations to ensure accurate analysis and documentation.

Pressure, Explosives

The force exerted by expanding gases produced during an explosion. Understanding explosive pressure helps assess the impact and damage caused by explosive-related fire incidents.

Prevention

Actions taken to avoid fire ignition and reduce the risk of fire incidents. Prevention includes fire safety education, regular maintenance, and adherence to fire codes and regulations.

Print Data

Information or records captured in printed format, such as floor plans, maintenance logs, and emergency response documents. Print data can be valuable for fire investigations and planning.

Production Equipment Maintenance

The routine servicing and inspection of equipment used in industrial production to ensure safety and proper function. Poor maintenance can lead to mechanical failures that may cause fires.

Production Line Fire

A fire that occurs in the assembly line or manufacturing area of a facility. These fires may be fueled by machinery, flammable materials, or industrial chemicals.

Products of Combustion

Substances produced when a material burns, including gases, heat, light, smoke, and particulate matter. Understanding combustion products is important for assessing fire hazards and toxic exposure risks.

Project Fire

A large, complex fire that requires extensive coordination, multiple resources, and long-term management efforts. Project fires often span large geographic areas and pose significant challenges to firefighting operations.

Proof of Loss

A formal document submitted to an insurance company that details the loss or damage claimed by the policyholder, such as after a fire incident. This document is required for the claims process and must include supporting evidence.

Property Insurance Loss Register (PILR)

A centralized database used by insurance companies to track claims made by policyholders. The PILR helps insurers assess risk and detect potential fraud, including claims related to fire damage.

Propulsion System Fire

A fire that occurs in the propulsion system of a vehicle, such as an engine or motor. These fires can result from fuel leaks, electrical malfunctions, or overheating and pose significant risks to passengers and responders.

Protection Area

A designated region where specific fire management and protective measures are implemented to prevent and control fires. Protection areas are often established to safeguard natural resources, structures, and communities.

Protocol

A set of procedures or guidelines followed during fire response, investigation, or management. Protocols ensure that all actions are conducted systematically and in accordance with best practices for safety and effectiveness.

Proximate Cause

The primary or immediate reason for the ignition of a fire, which directly leads to its occurrence. Identifying the proximate cause is crucial in fire investigations to determine accountability and liability.

Pugilisitc Attitude (posture)

The position that a body can take during exposure to intense heat, characterized by flexed limbs due to muscle contractions. This posture can provide clues about the circumstances and intensity of a fire in investigations involving fatalities.

Pulaski

A hand tool with a combination axe and adze head, used by wildland firefighters for digging fire lines and clearing vegetation. The Pulaski is essential for creating barriers to control and contain wildfires.

Pulled Bulb

A lightbulb that has been deformed or stretched due to exposure to high heat. The appearance of a pulled bulb can help fire investigators determine the heat direction and intensity at a fire scene.

Pyrolysate

A byproduct produced during the thermal decomposition of materials in the absence of oxygen. Pyrolysates can contribute to flammable gas mixtures that lead to fire spread or explosions.

Pyrolysis

The chemical decomposition of materials due to heat in the absence of oxygen, which produces gases that can ignite and sustain a fire. Pyrolysis is a key process in understanding how fires start and develop.

Pyromania

A psychological condition characterized by an uncontrollable urge to set fires for pleasure or relief from tension. Pyromania is a recognized mental disorder and is often considered in cases of arson.

Pyrophoric Material

A substance that can spontaneously ignite when exposed to air due to its highly reactive nature. Examples include certain metals and chemical compounds used in industry.

R

Radiant Burn

A burn injury caused by exposure to intense radiant heat from a fire or hot object without direct contact. Radiant burns can occur at significant distances from the heat source.

Radiant Heat

Heat energy that is transferred through electromagnetic waves from a hot surface or flame to surrounding objects. Radiant heat can ignite nearby flammable materials and cause severe damage.

Radiant Heat Flux

The rate of heat energy emitted per unit area from a radiating source. High radiant heat flux can lead to ignition of flammable materials and contribute to fire spread.

Radiation

The transfer of heat energy through electromagnetic waves without the need for direct contact. Radiation is one of the primary ways fires spread heat to surrounding objects and materials.

Rapid Charging

The process of quickly recharging batteries at a high current, which can lead to overheating if not properly managed. Rapid charging poses a fire risk, especially with lithium-ion batteries.

Rappeling

A technique used by firefighters to descend steep or vertical surfaces with the aid of ropes and harnesses. Rappelling is often employed in rugged terrain to access areas affected by wildfires.

Rate of Spread

The speed at which a fire moves across a surface or through vegetation, typically measured in chains or meters per hour. The rate of spread helps fire managers assess fire behavior and develop suppression tactics.

Reburn

The process where a previously burned area reignites and burns again, often due to remaining fuel that was not consumed during the initial fire. Reburns can occur when conditions become favorable for ignition.

Red Card

A certification card issued to wildland firefighters indicating that they have met the training and physical fitness requirements to engage in firefighting activities. The Red Card ensures that personnel are qualified for wildfire assignments.

Red Flag Warning

A weather alert issued by meteorological agencies when conditions such as high winds, low humidity, and dry fuels create a high potential for rapid fire spread. Red flag warnings help fire managers and the public prepare for increased fire risk.

Red Zone

Areas identified as high risk for wildfire due to factors like dense vegetation, dry conditions, and proximity to populated areas. These zones require heightened fire prevention and response efforts.

Rehabilitation

The process of restoring land and infrastructure after a fire has been contained. Rehabilitation efforts include stabilizing soil, replanting vegetation, and repairing damage to minimize environmental and structural impacts.

Rekindle

The re-ignition of a fire that was previously extinguished, often due to smoldering embers or hotspots that were not completely suppressed. Preventing rekindles is a key focus during the overhaul phase of firefighting.

Relative Humidity

The amount of moisture in the air relative to the maximum amount of moisture the air can hold at a given temperature. Low relative humidity can increase fire risk by drying out fuels and making them more flammable.

Remote Automatic Weather Station (RAWS)

A weather monitoring station that provides real-time data on temperature, humidity, wind speed, and other factors that influence fire behavior. RAWS units are critical for fire prediction and management.

Rescue and Firefighting Craft

Specialized boats and vessels equipped for fire suppression and rescue operations on water. These craft are used to combat fires on ships, docks, and waterfront properties.

Resource Management Plan (RMP)

A strategic document that outlines the use and conservation of natural resources, including fire management practices. RMPs help land managers balance environmental health with fire risk reduction.

Resource Order

A formal request for specific resources, such as equipment, personnel, or aircraft, during a fire response. Resource orders ensure that firefighting efforts are well-supported and coordinated.

Resources

The personnel, equipment, and tools used in firefighting operations. Effective use of resources is essential for successful fire suppression and control.

Responsibility

The obligation to take preventive measures and respond to fire incidents in accordance with established guidelines. Responsibility can apply to individuals, organizations, or governing bodies in fire management.

Retardant

A chemical substance applied to vegetation or structures to slow the spread of fire. Fire retardants are used in aerial firefighting operations and ground-based fire prevention strategies.

Right of Entry

The legal authorization for fire investigators, firefighters, or emergency personnel to enter a property to suppress a fire, conduct an investigation, or ensure safety compliance.

Risk

The likelihood of a fire occurring and the potential consequences associated with it. Risk assessment helps fire management teams develop strategies to reduce and manage fire hazards.

Risk Management

The process of identifying, assessing, and mitigating risks associated with fire incidents. Risk management strategies aim to minimize damage and enhance safety in communities and work environments.

Rollover

The condition where hot gases and flames spread across a ceiling and roll out from the top of a compartment. Rollover is a precursor to flashover and indicates rapidly worsening fire conditions.

Run (of a fire)

A period when a fire spreads rapidly over a significant distance due to favorable conditions such as wind and fuel availability. Runs can lead to sudden increases in fire size and intensity.

Running

The movement of a fire in a continuous, fast-paced manner over a landscape. Running fires are difficult to control and can cover large areas quickly, posing significant threats to property and safety.

Rural Fire District

A designated area managed by a local fire department responsible for providing fire protection services to rural communities. These districts often rely on volunteer firefighters and may face unique challenges due to limited resources.

Rural Fire Protection

Fire prevention and suppression services provided to rural areas, often managed by volunteer fire departments or local fire districts. These services include wildfire response, structural fire protection, and public education.

S

SIU

Special Investigations Unit, a department within an insurance company or law enforcement agency that investigates suspicious claims or potential fraud. SIUs often collaborate with fire investigators in cases of suspected arson.

Sabotage

The deliberate act of damaging or interfering with equipment or processes to cause harm or disrupt operations. In fire investigations, sabotage may be considered if there is evidence of intentional tampering that led to a fire.

Saddle Burn

A burn pattern that forms on a ridge or saddle-shaped terrain, indicating how a fire moved over the topography. Saddle burns help investigators understand fire behavior in hilly or mountainous regions.

Safety Cutoff Switch

A switch designed to shut off power or fuel supply in an emergency to prevent overheating and reduce fire risk. Safety cutoff switches are commonly found in electrical and gas-powered equipment.

Safety Inspection

A thorough examination of buildings, equipment, or systems to identify potential fire hazards and ensure compliance with fire codes and safety standards. Safety inspections help prevent fires and improve overall safety.

Safety Inspections

Regular or periodic assessments conducted to identify and mitigate fire risks in facilities or properties. These inspections ensure that fire prevention measures and safety protocols are in place and functioning properly.

Safety Protocol

A set of procedures and practices established to protect individuals and property from fire hazards. Safety protocols are implemented in workplaces, residential areas, and during fire response operations to reduce risk and enhance safety.

Safety Protocols

Comprehensive guidelines followed by individuals or organizations to prevent fire incidents and ensure the safety of personnel. Safety protocols include evacuation plans, fire drills, and proper handling of flammable materials.

Safety Training

Instruction and practice provided to individuals to help them understand fire safety principles, use firefighting equipment, and respond effectively in emergencies. Safety training is essential for both firefighters and the general public.

Safety Zone

A designated area where firefighters and personnel can seek refuge from a fire without the risk of injury or death. Safety zones are critical for ensuring the well-being of firefighting teams during wildfire operations.

Salvor

A person or company involved in the recovery and preservation of property following a fire or disaster. Salvors may work with insurance companies to assess damage and determine the salvageable value of assets.

Scene

The location where a fire incident has occurred, which becomes the focus of investigation and response efforts. The scene is documented and analyzed to gather evidence, determine the cause, and assess damage.

Scene Documentation

The process of recording details and observations at a fire scene through photographs, sketches, and written reports. Documentation is essential for investigations, insurance claims, and legal proceedings.

Scene Preservation

The practice of protecting a fire scene from contamination, tampering, or destruction to ensure the integrity of evidence for investigation purposes. Proper scene preservation is vital for accurate fire analysis.

Scent Discrimination

The ability of trained canines to differentiate between various scents at a fire scene, particularly to detect accelerants or specific chemicals. This skill is valuable in arson investigations.

Scientific Method

A systematic approach used in fire investigations to collect data, form hypotheses, conduct experiments, and draw conclusions. The scientific method ensures that findings are objective and evidence-based.

Scratch Line

A shallow, quickly constructed firebreak made by removing vegetation and debris to slow the advance of a fire. Scratch lines are often created by hand crews as an initial effort to control fire spread.

Search Pattern

A systematic approach used by investigators to thoroughly examine a fire scene for evidence. Common search patterns include grid, spiral, and strip methods to ensure no area is overlooked.

Seat Upholstery Burn

The damage to the upholstery of seats caused by fire or heat exposure. The pattern and extent of these burns can help fire investigators understand fire behavior, intensity, and the direction of flames in vehicle or structural fires.

Seat of Explosion

The exact location where an explosion originates, determined by analyzing blast damage, debris patterns, and other evidence. Identifying the seat of an explosion is crucial for understanding the cause and potential accelerants involved.

Seated Explosion

An explosion that has a defined point of origin and leaves evidence of a blast seat. This type of explosion is often contrasted with diffuse explosions, which do not have a clearly defined source.

Secondary Explosion

An additional explosion that occurs after an initial explosion, often due to the ignition of unburned fuel or gases released in the first event. Secondary explosions can cause significant additional damage and pose dangers to responders.

Self-Extinguishing Materials

Materials that are capable of stopping combustion on their own once the heat source is removed. These materials help prevent the spread of fire and are used in fire-resistant construction and products.

Self-Heating

The process by which certain materials generate heat internally due to chemical reactions, oxidation, or biological activity. If not properly managed, self-heating can lead to spontaneous ignition.

Self-Ignition

The spontaneous ignition of a material without an external flame or spark, usually due to heat buildup from internal chemical reactions or friction. Self-ignition poses risks in environments with oily rags, compost, or certain chemicals.

Self-Ignition Temperature

The lowest temperature at which a material will ignite spontaneously without an external ignition source. Understanding this temperature is key for fire prevention and handling flammable materials.

Self-Incrimination

The act of implicating oneself in a crime or admitting to actions that may result in legal consequences. In fire investigations, individuals may avoid self-incrimination by exercising their legal rights during questioning.

Separator Failure

The malfunction of a battery or chemical separator that prevents contact between components such as electrodes. Separator failures can lead to short circuits and potential fires or explosions in battery systems.

Server Arc

An electrical discharge that occurs when a high-voltage connection is interrupted, creating a spark or arc. Server arcs can cause heat buildup and pose fire hazards in electrical systems.

Severity Funding

Financial resources allocated to address extreme fire conditions, often used for additional personnel, equipment, or emergency response activities. Severity funding supports proactive measures during peak fire seasons.

Short Circuit

An unintended path of electrical current that bypasses the normal circuit, causing a surge in current flow. Short circuits can generate heat, leading to electrical fires and damage to connected devices.

Single Resource

An individual piece of equipment or person assigned to a firefighting task, such as an engine or a firefighter. Single resources are deployed to specific tasks or areas as part of larger fire response operations.

Site

The location where a fire incident has occurred or is being investigated. The site may be a structure, vehicle, or open area and is crucial for evidence collection and analysis.

Size-up

The initial assessment conducted by first responders or fire commanders to evaluate the situation, identify potential hazards, and plan an effective response. Size-up is essential for determining strategies and allocating resources during a fire incident.

Slash

Debris from forestry operations, including branches, twigs, and cut vegetation, which can contribute to fire risk if not properly managed. Slash is often reduced or removed to prevent wildfires.

Sleeving

The protective covering applied to electrical wires and cables to insulate them and prevent heat transfer. Damaged or inadequate sleeving can increase the risk of electrical fires.

Sling Load

Cargo carried beneath a helicopter for delivery to remote or hard-to-reach fire locations. Sling loads may include firefighting supplies, water, or equipment and play a vital role in wildfire response.

Slop-over

The situation when a fire crosses a control line or firebreak, often due to wind, ember spotting, or changes in fire behavior. Slop-overs require immediate attention to prevent further spread.

Slope

The angle or gradient of the land, which affects fire behavior and spread. Fires tend to move more rapidly uphill due to the preheating of vegetation above the fire.

Smoke

A mixture of gases, vapor, and particulate matter produced by the combustion of materials. Smoke can contain toxic compounds and reduce visibility, posing health risks and challenges for firefighting efforts.

Smoke Condensate

The liquid or solid residue that forms when smoke cools and settles on surfaces. Analyzing smoke condensate can help fire investigators determine fire origin and the types of materials burned.

Smoke Damage

The physical harm caused to structures, furniture, or belongings by smoke from a fire. This damage can include discoloration, odor, and corrosive effects on surfaces and electronics.

Smoke Explosion

Also known as a backdraft, this occurs when a fire smolders in an enclosed space, depleting oxygen and accumulating flammable gases. When oxygen is introduced, these gases ignite explosively.

Smoke Inhalation

The intake of smoke and combustion byproducts into the respiratory system, which can lead to serious health issues or death. Smoke inhalation is a common cause of fire-related fatalities.

Smoke Jumper

A specially trained firefighter who parachutes into remote areas to combat wildfires. Smoke jumpers are deployed for rapid response to fires in locations inaccessible by traditional ground vehicles.

Smoke Management

The practice of controlling and dispersing smoke from fires to minimize its impact on air quality and visibility. Techniques include controlled burns, timing operations, and using natural wind patterns to direct smoke away from populated areas.

Smoke Patterns

The shapes and trails left by smoke deposits on surfaces, which can help fire investigators understand fire movement and ventilation conditions within a structure.

Smoke Production

The process by which smoke is generated during combustion. Smoke production varies based on fuel type, temperature, and fire conditions.

Smoke Staining

The discoloration of surfaces caused by smoke deposits. Smoke staining can be used to identify fire paths and areas of higher heat exposure during an investigation.

Smoke Ventilation

The controlled removal of smoke from a building or structure to improve visibility and reduce heat buildup during a fire. Smoke ventilation can be natural, mechanical, or performed by firefighters using equipment like fans and exhaust vents.

Smoldering

A type of combustion that occurs at a low temperature and without visible flames, producing smoke and heat. Smoldering fires can persist for long periods and reignite if exposed to oxygen or a heat source.

Smoldering Fire

A fire that burns slowly with little flame and produces large amounts of smoke. Smoldering fires are common in dense fuels like peat or insulation and can be difficult to fully extinguish.

Snag

A dead or dying tree that is still standing, which can become a fire hazard due to its dry and combustible nature. Snags can fall during a fire, posing risks to firefighters and property.

Solid-State Batteries

A type of battery that uses solid electrolytes instead of liquid or gel-based ones. While solid-state batteries are generally safer and less prone to fire, improper handling or damage can still result in combustion.

Soluble

The property of a substance that allows it to dissolve in a solvent, such as water or alcohol. Understanding solubility is important for selecting fire suppression agents and analyzing fire debris.

Soot

Black, carbon-based particulate matter produced during incomplete combustion. Soot can settle on surfaces, contributing to smoke damage and posing health risks if inhaled.

Spalling

The flaking or breaking away of a material's surface due to intense heat exposure. Spalling is commonly observed in concrete or masonry during fires and can provide clues about the heat intensity and duration at a fire scene.

Spark

A small particle of burning material or an electrical discharge that can ignite flammable substances. Sparks are a common source of fire ignition in welding, grinding, and electrical work.

Specific Gravity

The ratio of the density of a substance to the density of water. Specific gravity can be used to understand the behavior of liquid fuels and their interaction with water during fire suppression.

Specific Heat

The amount of heat energy required to raise the temperature of a unit mass of a substance by one degree Celsius. In fire science, understanding specific heat helps assess how materials absorb and transfer heat during a fire.

Specific Origin Area

The focused location within the general origin area where the fire first ignited. Identifying the specific origin area is crucial for pinpointing ignition sources and determining the cause of a fire.

Spoliation

The alteration or destruction of evidence that can compromise an investigation. In fire investigations, preserving evidence is critical to avoid spoliation and ensure accurate analysis and legal proceedings.

Spontaneous Combustion (Spontaneous Ignition)

The self-ignition of materials due to chemical reactions or heat buildup without an external flame or spark. This can occur with materials like oily rags, compost piles, or certain chemicals under the right conditions.

Spontaneous Heating

The process by which a material generates heat internally, often due to oxidation or microbial activity. If spontaneous heating reaches the material’s ignition point, it can lead to spontaneous combustion.

Spontaneous Ignition

The process by which a material ignites on its own without an external ignition source due to internal heat generation. This phenomenon is common in certain organic materials or improperly stored chemicals.

Spot Weather Forecast

A weather prediction specific to a small area or incident, often used for managing wildfires or planned burns. Spot weather forecasts help fire managers anticipate changes in wind, temperature, and humidity that could affect fire behavior.

Spotter

A person responsible for observing and providing guidance during aerial firefighting operations. Spotters ensure that drops are accurate and safe for firefighting crews on the ground.

Spotting

The process where burning embers or brands are carried by wind or convection and start new fires away from the main fire. Spotting can significantly increase the spread of wildfires.

Staging Area

A location where firefighting resources, such as equipment and personnel, are assembled and prepared for deployment. Staging areas are strategically chosen to facilitate efficient response and coordination.

State of Charge (SOC)

The current level of electrical charge in a battery, expressed as a percentage of its total capacity. Monitoring SOC is essential for battery safety to prevent overcharging and potential fires.

Static Electricity

An electrical charge that builds up on the surface of an object and can discharge suddenly. Static electricity can be an ignition source for fires, especially in environments with flammable gases or liquids.

Stoichiometric Mixture

The ideal air-to-fuel ratio for complete combustion without excess fuel or oxygen. In fire science, understanding stoichiometric mixtures helps assess the conditions that lead to efficient or incomplete burning.

Strategy

The overarching plan developed to manage and contain a fire incident. Strategies outline objectives, resource deployment, and tactics to achieve fire suppression or prevention goals.

Strike Team

A group of similar resources, such as fire engines or hand crews, assigned to work together for a specific task. Strike teams operate under a leader and are used in both wildland and structural fire operations.

Strike Team Leader

The individual responsible for coordinating and supervising a strike team during fire response. The leader ensures that the team's actions align with the incident objectives and safety protocols.

Structural Damage

The physical harm or weakening of a building's structural components due to fire, heat, or smoke. Structural damage assessments are crucial for determining building safety after a fire.

Structural Fire Safety

Measures and protocols implemented to protect buildings and their occupants from fire. This includes fire-resistant materials, sprinkler systems, fire doors, and adherence to fire codes.

Structural Integrity

The strength and stability of a building's structure, which can be compromised during a fire. Assessing structural integrity helps determine whether a building is safe for occupancy or requires repairs.

Structural Protection

Efforts made to shield buildings from fire, including creating defensible space, applying fire-retardant materials, and using protective barriers. Structural protection is important in areas prone to wildfires.

Structure Fire

A fire involving a building or other constructed facility. Structure fires can pose significant risks to occupants, firefighters, and the surrounding environment due to enclosed spaces and potential for rapid fire spread.

Structure Triage

The process of assessing buildings at risk during a wildfire or fire incident to determine which ones can be protected, which are defensible, and which are too dangerous to defend. This assessment helps prioritize resources and safety.

Subrogation

The legal process by which an insurance company, after paying out a claim, seeks to recover the amount from a third party responsible for the loss. Subrogation can be relevant in fire cases involving negligence or product defects.

Suppression

The act of controlling and extinguishing a fire to prevent further spread and damage. Suppression activities include direct attack with water or foam, building fire lines, and using fire retardants.

Suppression Systems

Fire protection systems designed to detect and extinguish fires automatically or manually. These include sprinkler systems, gas suppression systems, and foam-based systems in buildings and vehicles.

Surface Fire

A fire that burns along the forest floor or ground surface, consuming low-lying vegetation, leaves, and debris. Surface fires are typically easier to control than crown fires but can still spread quickly under certain conditions.

Surface Fuels

Combustible materials found on the ground, such as leaves, grass, and twigs. Surface fuels play a key role in fire ignition and spread, especially in wildland fire scenarios.

Swamper

A member of a firefighting crew responsible for assisting with tasks such as clearing brush, cutting fire lines, and maintaining equipment. Swampers provide essential support in fire suppression efforts.

T

Tactics

The specific methods and actions taken to achieve fire suppression or control, such as using water drops, building containment lines, or performing backburns. Tactics are part of the larger fire management strategy.

Target Fuel

The primary type of combustible material that is anticipated to ignite and burn in a fire scenario. Identifying target fuels helps in planning fire prevention and suppression strategies.

Telephone Toll Analysis

The review of phone call records to track communication activity, which can be used in fire investigations to establish timelines or identify potential suspects in cases of arson.

Temperature

The measure of heat in a given environment or substance. Temperature plays a critical role in fire behavior, influencing ignition, combustion, and heat transfer processes.

Temperature Sensor

A device that detects and measures temperature changes, used in fire detection systems to alert occupants or trigger fire suppression mechanisms when a certain threshold is reached.

Temporary Fire Restrictions

Measures implemented during high-risk periods to limit activities that could start fires, such as campfires, open burning, or using certain equipment. Temporary fire restrictions help reduce the likelihood of wildfires.

Terra Torch

A device used for igniting prescribed burns or backfires, which disperses a flammable mixture to create controlled flames. Terra torches help manage fuel loads and prevent larger wildfires.

Test Fire

A small, controlled fire set to observe and analyze fire behavior under specific conditions. Test fires are used in training and research to develop fire management strategies and firefighting techniques.

Thermal Analysis

The examination of heat distribution and transfer within a material or system during a fire. Thermal analysis helps understand how fire affects different substances and structures.

Thermal Column

A vertical flow of hot gases, smoke, and particulates rising from a fire. Thermal columns influence fire spread by carrying embers and heat upward, which can lead to spotting.

Thermal Damage

The deterioration or alteration of materials caused by exposure to high temperatures. Analyzing thermal damage helps investigators determine the heat intensity and duration of a fire.

Thermal Expansion

The increase in volume of a material as it is heated. In fire scenarios, thermal expansion can cause structural components to warp or crack, influencing fire behavior and building stability.

Thermal Imaging

The use of infrared technology to detect heat patterns and temperature variations, often used by firefighters to locate hidden flames, hotspots, or people trapped in smoke-filled environments. Thermal imaging cameras provide critical information during fire response and investigations.

Thermal Imaging Use

The practical application of thermal imaging technology in firefighting and fire investigation. It includes identifying heat sources, assessing fire spread, and finding victims in low-visibility conditions.

Thermal Inertia

The ability of a material to resist changes in temperature. Materials with high thermal inertia absorb and store heat, affecting how quickly they ignite or transfer heat during a fire.

Thermal Insulation

Materials used to slow down heat transfer, protecting structures and occupants from extreme temperatures. Effective thermal insulation can prevent the spread of fire and reduce energy consumption.

Thermal Management

Techniques and systems used to regulate temperature and prevent overheating in buildings, vehicles, or devices. Proper thermal management can prevent fires caused by equipment failure or excessive heat buildup.

Thermal Patterns

The distribution of heat marks and damage at a fire scene, which can help fire investigators determine the fire’s origin, spread, and intensity. Thermal patterns include charring, blistering, and heat shadows.

Thermal Runaway Protection

Safety mechanisms designed to prevent thermal runaway in batteries, a condition where heat generated by chemical reactions causes a chain reaction leading to combustion. Protection systems include thermal cutoffs and battery management systems.

Thermocouple

A temperature-measuring device consisting of two different conductors that produce a voltage when exposed to heat. Thermocouples are used to monitor temperatures in fire detection systems and experiments.

Thermodynamics

The branch of physics that deals with the relationships between heat, energy, and work. Understanding thermodynamics is crucial for analyzing fire behavior, heat transfer, and combustion processes.

Thermometry

The science and practice of measuring temperature. In fire investigations, thermometry tools help assess fire spread and the temperatures at which materials were exposed.

Thermoplastic

A type of plastic that softens or melts when heated and hardens when cooled. Thermoplastics can contribute to fire spread due to their flammability and potential to produce toxic fumes when burning.

Thermoset Plastics

Plastics that harden permanently after being molded, and do not soften upon reheating. Although more heat-resistant than thermoplastics, thermoset plastics can still combust at high enough temperatures.

Thermostat

A device that controls temperature by turning heating or cooling systems on or off. Faulty thermostats can lead to overheating and potential fire hazards in homes or industrial settings.

Time Line

A chronological sequence of events or activities, often used in fire investigations to piece together what occurred before, during, and after a fire. A time line helps identify the sequence of ignition, fire spread, and suppression efforts.

Timelag

The amount of time it takes for fuel to reach moisture equilibrium with its environment. Timelag categories are used in fire science to estimate how quickly fuels can ignite under changing conditions.

Tire Protection

Fire protection measures for tires, particularly in heavy vehicles or aircraft. These measures may include specialized tire covers or sprays to prevent ignition during high-heat conditions.

Topography

The physical features of a landscape, such as hills, valleys, and slopes. Topography significantly influences fire behavior, as fires typically spread faster uphill and can be affected by natural barriers.

Torching

The burning of individual trees or small clusters of trees from the ground up to the canopy. Torching is a sign of active fire behavior and can lead to crown fires if conditions are right.

Tort

A legal term for a civil wrong or act that results in injury or damage, which can be the basis for a lawsuit. In fire cases, torts may involve negligence or liability for fire-related damages.

Total Burn

The complete consumption of fuel in a fire. A total burn indicates high fire intensity and may leave minimal residue, complicating investigations to determine the fire’s cause.

Toxic Fumes

Harmful gases released during the combustion of certain materials, such as plastics or synthetic fabrics. Toxic fumes pose serious health risks and can be a leading cause of fire-related injuries and fatalities.

Toxicity

The degree to which a substance can cause harm to humans or animals. In fire contexts, toxicity is relevant when assessing smoke, fumes, or residues produced during combustion, as certain materials release hazardous chemicals when burned.

Trailer

A device or combustible path used intentionally to spread fire from one point to another, often found in cases of arson. Trailers can include paper, flammable liquids, or other materials arranged to facilitate fire spread.

Transformer

An electrical device used to transfer electrical energy between circuits through electromagnetic induction. Transformers can overheat, malfunction, or experience electrical faults, leading to potential fire hazards.

Transition Zone

The area between different types of fuels or between ground-level fuels and crown fuels. Transition zones can influence fire behavior, such as when a surface fire transitions into a crown fire.

Tree Crown

The upper part of a tree, including its branches and leaves. The crown can play a significant role in fire behavior, as crown fires spread rapidly through the tops of trees, increasing the overall intensity and reach of a wildfire.

Two-Way Radio

Communication devices used by firefighters and emergency response teams to maintain contact and coordinate activities during fire incidents. Reliable communication is essential for safety and effective fire management.

Type

A classification used in fire management to categorize resources such as engines, crews, or helicopters based on their capabilities. Type classifications help allocate appropriate resources for specific fire scenarios.

U

Uncontrolled Fire

A fire that is spreading without being contained or managed, posing significant risks to life, property, and the environment. Uncontrolled fires require immediate response efforts to prevent escalation.

Underburn

A fire that spreads under the forest canopy, consuming surface fuels without igniting the upper layers or tree crowns. Underburns can be part of controlled burns or natural fire processes that help manage forest health.

Understanding or Agreement

A mutual consensus between parties, often relating to fire response protocols, resource sharing, or cooperative efforts in fire management. Agreements between agencies help streamline operations and improve outcomes.

Understory

The layer of vegetation beneath the main canopy of a forest, including shrubs and smaller plants. The understory can act as ladder fuel, allowing fires to climb from the ground into the crowns of trees.

Upper Layer

The section of heated air, smoke, and gases that accumulates near the ceiling of an enclosed space during a fire. The upper layer is critical to understanding fire behavior and potential flashover conditions.

Urban Interface

The area where urban development meets wildland areas, creating a higher risk for wildfires to impact homes and infrastructure. The urban interface is a key focus for fire prevention and safety planning.

V

Vapor

A gaseous form of a substance that is usually liquid or solid at room temperature. Vapors from flammable liquids can ignite when mixed with air and exposed to an ignition source, posing fire risks.

Vapor Density

The relative weight of a vapor compared to air. Vapors with a density greater than one are heavier than air and tend to settle in low areas, increasing the potential for ignition in confined spaces.

Vapor Pressure

The pressure exerted by a vapor in equilibrium with its liquid or solid form at a given temperature. High vapor pressure indicates a substance that can easily release flammable vapors, contributing to fire risk.

Vectors

The directional flow or movement of heat, flames, or smoke during a fire. Understanding vectors helps fire investigators and responders determine how a fire spread and where it might move next.

Vehicle Fire Containment

Measures taken to prevent or control fires in vehicles, such as fire-resistant materials, automatic extinguishing systems, and proper maintenance. Vehicle fire containment reduces the risk of damage and injury.

Vehicle Fire Prevention

Strategies and practices to minimize the risk of fires in vehicles, including regular inspections, proper storage of flammable materials, and maintenance of electrical and fuel systems.

Vehicle Recall

An action taken by a manufacturer to address safety defects in vehicles, such as issues with fuel systems or electrical components that could lead to fires. Vehicle recalls help prevent potential fire incidents by repairing or replacing faulty parts.

Vent

An opening designed to allow air, gas, or smoke to escape from an enclosed space. Proper venting can help control the buildup of heat and pressure during a fire and improve the safety of a structure.

Ventilation

The intentional process of directing the flow of air to control smoke, heat, and gases during a fire. Ventilation techniques are critical for improving visibility, reducing temperature, and aiding in fire suppression efforts.

Ventilation Impact

The effect that ventilation has on a fire’s behavior, including changes in flame spread, smoke movement, and heat release. Ventilation impacts are considered when planning firefighting strategies and tactics.

Ventilation-Controlled Fire

A fire where the rate of burning is limited by the amount of oxygen available. Ventilation-controlled conditions can lead to dangerous situations, such as backdrafts, if oxygen is suddenly reintroduced.

Venting

The act of allowing heat, smoke, and gases to escape from a building or structure during a fire. Venting can be achieved through natural openings, mechanical systems, or by cutting holes in roofs or walls.

Venting Mechanism

The method or system by which air, smoke, and gases are expelled from a structure during a fire. Common venting mechanisms include roof vents, windows, and mechanical exhaust systems.

Viscosity

A measure of a fluid's resistance to flow. The viscosity of flammable liquids can influence how they spread and ignite during a fire, with lower viscosity fluids tending to flow more readily and pose greater fire risks.

Voir Dire

A legal process used to select impartial jurors for a trial. In fire-related cases, voir dire may include questions to identify potential biases or conflicts of interest related to the case.

Volatile

A term describing a substance that evaporates easily at normal temperatures and can form flammable or explosive mixtures with air. Volatile substances, such as gasoline or alcohol, are significant fire hazards.

Volatility

The tendency of a substance to vaporize and release flammable vapors. High volatility indicates a greater potential for ignition and fire risk, especially in the presence of an ignition source.

Volt (V)

The unit of measurement for electrical potential or electromotive force. High voltage can contribute to electrical fires if wiring or equipment is improperly handled or malfunctions.

Volunteer Fire Department

A fire department staffed primarily by volunteer firefighters who provide fire protection and emergency response services to their communities. Volunteer departments are often essential in rural and underserved areas.

Volunteer Firefighter

An individual who serves in a fire department on a volunteer basis, often balancing firefighting duties with other employment. Volunteer firefighters play a vital role in community safety and fire response.

W

Water Supply

The availability and access to water sources for firefighting operations, such as hydrants, tanks, and natural bodies of water. Adequate water supply is critical for effective fire suppression.

Water Tender

A firefighting vehicle equipped to transport and supply water to areas where water sources are limited. Water tenders are especially useful in rural or remote locations.

Watercraft Electrical Hazards

Fire risks associated with the electrical systems on boats and ships, including issues such as faulty wiring or overloaded circuits. Proper maintenance and inspection help prevent electrical fires on watercraft.

Watt (W)

The unit of power that measures the rate of energy transfer or consumption. Understanding wattage helps assess electrical loads and prevent overheating or overloading circuits that could lead to fires.

Weather Information and Management System (WIMS)

A tool used by fire management agencies to collect and analyze weather data for predicting fire behavior. WIMS provides real-time weather information crucial for strategic planning during wildfires.

Welding Sparks

Sparks produced during welding that can ignite nearby combustible materials. Proper safety measures, such as using fire blankets and maintaining a clean work area, are essential to prevent fires caused by welding.

Wetline

A line of water or fire retardant applied on the ground to create a temporary barrier to slow or stop the spread of fire. Wetlines are often used as an initial control measure while building more permanent firebreaks.

Wildfire

An uncontrolled fire that spreads rapidly through vegetation and forested areas. Wildfires pose significant risks to life, property, and natural ecosystems and often require coordinated suppression efforts.

Wildfire Causes

The various factors that lead to the ignition of wildfires, such as lightning strikes, human activities (e.g., unattended campfires, arson), and spontaneous combustion. Understanding the causes is crucial for prevention and mitigation strategies.

Wildland

Land areas covered in vegetation, such as forests, grasslands, and shrublands, that are susceptible to wildfires. Wildlands often require specialized firefighting techniques due to the unique challenges they present.

Wildland Fire

A fire that occurs in natural areas, burning vegetation such as trees, grass, and brush. Wildland fires can vary in size and intensity, ranging from small, controlled burns to large, destructive wildfires.

Wildland Fire Implementation Plan (WFIP)

A detailed plan developed by fire management agencies outlining the strategies, objectives, and resources needed for managing a wildland fire. The WFIP ensures that responses are efficient and align with safety and environmental guidelines.

Wildland Fire Protection

Measures taken to prevent, control, and suppress wildland fires, including the creation of firebreaks, controlled burns, and public education. Wildland fire protection is essential for safeguarding communities and natural resources.

Wildland Fire Situation Analysis (WFSA)

A comprehensive assessment of a wildland fire, evaluating factors such as fire behavior, weather conditions, and available resources. The WFSA helps incident commanders make informed decisions on fire response and management strategies.

Wildland Fire Use

The practice of allowing a naturally ignited fire to burn under controlled conditions for ecological or resource management purposes. This approach can help reduce fuel loads and promote healthy ecosystems.

Wildland Urban Interface (WUI)

Areas where human developments meet or intermingle with wildland vegetation, posing an increased risk of wildfire impacting homes and infrastructure. The WUI is a focal point for fire prevention and mitigation strategies.

Wildland–Urban Interface (WUI)

Wind Vectors

The direction and speed of the wind, represented as arrows in fire modeling and weather forecasting. Wind vectors are critical for predicting fire spread and developing firefighting strategies.

Work Plans

Detailed schedules and strategies outlining the tasks and resources needed for fire response or prevention projects. Work plans help ensure that operations are organized and effective in achieving objectives.