A chemical or mixture that may present an unreasonable risk of injury to health or the environment.

A tank, usually collapsible, used as a reservoir in the relay of water from one fire pump to another.

Technique of landing specifically trained and certified firefighters from hovering helicopters; involves sliding down ropes with the aid of friction-producing devices.

The study of the effects of fire on living organisms and their environment.

A turret-type nozzle usually mounted on an engine.

A person hired and compensated under the Pay Plan for Emergency Workers.

A person employed as an emergency worker on a forest or wildland fire which threatens damage to property under public management. Emergency firefighters are hired for the duration of the emergency only.

A person hired and compensated under the Pay Plan for Emergency Workers.

Rate of decrease of temperature with increasing height of an air parcel lifted at saturation via adiabatic process through an atmosphere in hydrostatic equilibrium. Rate varies according to the amount of water vapor in the parcel and is usually between 2.0 and 5.0 degrees F per 1000 feet (3.6 and 9.2 degrees C per 1000 meters). 

Broadest classification of landownership.