Particulate matter of mass median aerodynamic diameter (MMAD) less than or equal to 2.5 micrometers.

Foam with an expansion between 1:1 and 20:1.

Water soluble substance that reduces frictional drag of solutions and dampens turbulent flow while being pumped through pipe or hose.

Thunderstorm in which negligible precipitation reaches the ground.

A burning compound or metal used to produce intense heat or flame, like a bomb.

A colorless, odorless, poisonous gas produced by incomplete fuel combustion.

Precipitation composed exclusively of water drops smaller than 0.02 inches (0.5 mm) in diameter.

Any substance except plain water that by chemical or physical action reduces flammability of fuels or slows their rate of combustion.

Any treatment applied directly to burning fuel such as wetting, smothering, or chemically quenching the fire or by physically separating the burning from unburned fuel.

Any treatment applied directly to burning fuel such as wetting, smothering, or chemically quenching the fire or by physically separating the burning from unburned fuel.