Fire Extinguisher Ratings

	Class A Extinguishers will put out fires in ordinary combustibles, such as wood and paper. The numerical rating for this class of fire extinguisher refers to the amount of water the fire extinguisher holds and the amount of fire it will extinguish.
	Class B Extinguishers should be used on fires involving flammable liquids, such as grease, gasoline, oil, etc. The numerical rating for this class of fire extinguisher states the approximate number of square feet of a flammable liquid fire that a non-expert person can expect to extinguish.
	Class C Extinguishers are suitable for use on electrically energized fires. This class of fire extinguishers does not have a numerical rating. The presence of the letter “C” indicates that the extinguishing agent is non-conductive.
	Class D Extinguishers are designed for use on flammable metals and are often specific for the type of metal in question. There is no picture designator for Class D extinguishers. These extinguishers generally have no rating nor are they given a multi-purpose rating for use on other types of fires.

Never use water on electrical or flamable liquid fires.

Types of Fire Extinguishers

	Dry Chemical extinguishers are usually rated for multiple purpose use. They contain an extinguishing agent and use a compressed, non-flammable gas as a propellant.
	Halon extinguishers contain a gas that interrupts the chemical reaction that takes place when fuels burn. These types of extinguishers are often used to protect valuable electrical equipment since them leave no residue to clean up. Halon extinguishers have a limited range, usually 4 to 6 feet. The initial application of Halon should be made at the base of the fire, even after the flames have been extinguished.
	Carbon Dioxide (CO2) extinguishers are most effective on Class B and C (liquids and electrical) fires. Since the gas disperses quickly, these extinguishers are only effective from 3 to 8 feet. The carbon dioxide is stored as a compressed liquid in the extinguisher; as it expands, it cools the surrounding air. The cooling will often cause ice to form around the “horn” where the gas is expelled from the extinguisher. Since the fire could re-ignite, continue to apply the agent even after the fire appears to be out.
	Water  These extinguishers contain water and compressed air and should only be used on Class A (ordinary combustibles) fires.

How To Use a Fire Extinguisher

Even though extinguishers come in a number of shapes and sizes, they all operate in a similar manner.  
If you can remember this easy acronym then you can use a fire extinguisher:

P  A  S   S  --  Pull, Aim, Squeeze, and Sweep

Should You Try to Fight the Fire?

Before you begin to fight a fire:

• Make sure everyone has left or is leaving the building

• Make sure the RUPD (x6000) has been called

• Make sure the fire is confined to a small area and is not spreading

• Make sure you have an unobstructed escape route to which the fire will not spread

• Make sure you have read the instructions and know how to use the extinguisher

It is reckless to fight a fire in any other circumstances. Instead, leave immediately and close off the area.