Above-ground storage tank – Storage tank that is not buried. Compare Underground storage tank. Unburied tanks are more prone to physical damage, and leaks are released to the air or ground, rather than the soil surrounding a buried tank.
Accelerant – Flammable fuel (often liquid) used by some arsonists to increase size or intensity of fire. May also be accidentally introduced when HAZMAT becomes involved in fire.
Accelerator (also exhauster) – Portion of dry-pipe system that bleeds air or shunts air pressure below the clapper valve when sprinkler pipe pressure drop is sensed, thus speeding operation of the valve to fill the system with water.
Accountability – The process of emergency responders (fire, police, SAR, emergency medical, etc…) checking into and making themselves announced as being on-scene during an incident to an incident commander or acountability officer. Through the accountability system, each person is tracked throughout the incident until released from the scene by the incident commander or accountability officer. This is becoming a standard in the emergency services arena primarily for the safety of emergency personnel. This system may implement a name tag system or personal locator device(tracking device used by each individual that is linked to a computer).Willoughbyccfd5 23:52, 3 December 2006 (UTC).
Adapter – Plumbing accessories for connecting hoses and pipes of incompatible diameter, thread, or gender. See also reducer, increaser, double male, double female, water thief. May contain combinations, such as a double-female reducer. Adapters between multiple hoses are called wye, Siamese, or distributor, which see below.
Aerial apparatus – Fire truck having an attached extension ladder, nozzle, man-lift-bucket, or similar device raised using power from the truck. May also carry other portable ladders and tools.
Aerial canopy – Fuel type comprised of trees having few low branches, making it less susceptible to ignition by low-intensity fires.
Aerial firefighting (or air attack) – Use of aircraft in support of ground resources to combat wildfires, often most effective in initial attack in light fuels.
Air drop – Delivery of supplies or retardant from the air. Supplies can be dropped by parachute. Retardant is dropped in a single salvo, or one or more “trails”, the size of which is determined by the wind and the volume speed and altitude of the airtanker (usually no less than 200 feet above the drop zone).
Air monitoring meter – Electronic device for measuring the presence of one or more chemicals in air, such as oxygen, carbon monoxide, hydrogen sulfide or volatile organic compounds; may have preset danger threshold alarms.
Air operations – Group tasked with coordinating aerial-based observation, supply, rescue and suppression at a wildfire.
Air Tactical Group Supervisor or Air Attack – Coordinates air resources for attack of a fire.
Airbags – (1) inflatable device used for lifting or spreading; (2) vehicle safety device with potential explosion hazard during vehicle extrication if not already blown.
Airpack – Jargon for self-contained breathing apparatus (SCBA).
Airtanker – Fixed-wing aircraft certified by FAA as being capable of transport and delivery of 600 to 3,0000 gallons of water or other liquid or powder fire retardants. Formerly referred to as borate bombers” before borate-based retardants became less desirable. Often accompanied by a spotter plane.
Alarm – (1) system for detecting and reporting unusual conditions, such as smoke, fire, flood, loss of air, HAZMAT release, etc; (2) a specific assignment of multiple fire companies and/or units to a particular incident, usually of fire in nature; (3) centralized dispatch center for interpreting alarms and dispatching resources. See fire alarm control panel.
All companies working – Status report at fire scene indicating that available manpower is busy, and more resources may become necessary if incident is not controlled soon.
Ammonium nitrate – Component of ANFO; contents of two ships that exploded in Texas City Disaster, killing over 500 people, including all 28 volunteer firefighters at the scene.
Anchor point – An advantageous location, usually a barrier to fire spread, from which to start constructing a fireline. The anchor point is used to minimize the chance of being flanked (or outflanked) by the fire while the line is being constructed.
ANFO – Ammonium Nitrate Fuel Oil combination making a high explosive.
Apparatus – A term usually used by firefighters describing a piece of equipment, usually a company vehicle.
Apparatus – Fire engines, trucks, tankers, and combinations; can also refer to other equipment such as the SCBA.
APW – Air-pressurized water fire extinguisher, partially filled with water and then pressurized with an air pump; popular in the US in the 2 1/2-gallon size, rated 2A.
Aqueous Film-Forming Foam (AFFF) – (pronounced “A-Triple-F”, also called “Class A”) bubbles that act as surfactant to coat and penetrate ordinary fuels (e.g., wood, paper) to prevent them from burning at normal temperatures; also used on Class B” (oil/gasoline) fires to spread a non-volatile film over the surface of the fuel. Applied using eductor or Compressed air foam system (CAFS) and pumped through firehose to a foam nozzle (or sometimes a less-effective fog nozzle).
Arson – The crime of maliciously (or perhaps recklessly) setting fire to property, especially a dwelling. Punishable in various degrees, depending upon the circumstances. Occasionally occurs as a psychotic act of a mentally ill firefighter.
Attack hose – (Attack Line) A use classification of a fire fighting hose connected to output of a pump or other pressure source (e.g., gravity). Firehose used to apply water or other fire fighting agent directly to a fire or burning substance. Typically of 2 1/2 inches (65 mm) diameter or less.
Attic ladder – Narrow, collapsible ladder used to access an attic space via a scuttle hole, which are often found in closets and other narrow passages. Also known as a closet ladder.
Authority Having Jurisdiction (or AHJ) – Organization or agency with legal authority over a given type of incident (e.g, fire, EMS, SAR, arson, HAZMAT); may change or overlap as incident changes, as where fire becomes arson investigation once danger is over, or Motor Vehicle Accident becomes police business after vehicle extrication, fire, and HAZMAT issues are complete.
Autoextended fire – Structure fire that has gone out a window or other opening on one floor and ignited materials above, on another floor or other space (attic, cockloft).
Automatic sprinkler – System of valves and pipes for automatically directing water to a fire when it is detected. May be normally pressurized with water (wet”) or with air (“dry”) depending upon the application. When a sprinkler-head (or sensor) detects fire/heat the valve opens releasing the water (hopefully onto the fire).
Available flow – Total amount of water that can be put on a fire, depending upon water supply, pump size, hoses, and distance to the fire. IC must assess available flow to determine whether additional apparatus or streams are required. See Fire flow requirement.