Glossary

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

The science and practice of measuring temperature. In fire investigations, thermometry tools help assess fire spread and the temperatures at which materials were exposed.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.