Fighting Small Fires on the Job

   Federal regulations require that employers who provide portable fire extinguishers in the workplace also provide training in their use. Used properly, portable fire extinguishers can save lives and property by putting out small fires in the work place or containing the fire until the fire department arrives.

   It is essential that all employees be familiar with the proper use of portable fire extinguishers and know when and when not to use them. In the event of a fire, employees should respond in accordance with their company's fire-emergency plan. Most employees will evacuate. Certain trained and designated employees will evaluate the fire scene and, if the fire is small and conditions are reasonably safe, use a fire extinguisher to fight the fire. If the fire is large or conditions are unsafe, all employees will evacuate.

Before Fighting a Fire

• Be sure you know how to operate your fire extinguisher and know the proper techniques for fighting fires.
• Be sure you have an unobstructed escape route should you fail to extinguish the fire.
• Know what materials are burning, and be sure the extinguisher you are using is capable of fighting the fire. Consider the possible danger posed by hazardous or highly flammable materials near the fire area.

   It is reckless to fight a fire under any other circumstances. Instead, leave immediatly, closing all doors leading to the fire area as you exit. This is so that the fire will not spread faster or farther from the area it is in at the present time.

Extinguisher Location

   Fire extinguishers in the workplace should be placed conspicuously and within easy reach so they can be accessed quickly while a fire is still small.

The Proper Extinguisher

   Fire extinguishers are tested by independent testing laboratories and are labeled for the type of fire they are intended to extinguish.

   Classes of fires: There are four classes of fire. All fire extinguishers are labeled, using standard symbols, for the classes of fires on which they can be used. A red slash through any of the symbols tells you the extinguisher cannot be used on that class of fire. A missing symbol tells you only that the extinguisher has not been tested for a given class of fire, but may be used if an extinguisher labeled for that class of fire is not available.

WARNING: It is very dangerous to use water or an extinguisher labeled only for Class A fires on a cooking-grease or electrical fire.

Extinguisher sizes: Portable extinguishers are also rated for the size of the fire they can handle. This rating is expressed as a number from 1 to 40 for Class A fires and from 1 to 640 for Class B firs. This rating will appear on the label --- 2A:10B:C for example. The larger the numbers, the larger the fire of a specific class on which the extinguisher can be used. No number accompanies an extinguisher's Class C rating. The C on the label indicates only that the extinguisher is safe to use on electrical fires.

Extinguishers for Class D fires must match the type of metal that is burning. These extinguishers do not use numerical ratings. Extinguishers for Class D fires are labeled with a list detailing the metals that match the unit's extinguishing agent.

Types of Extinguishers

   Depending on their intended use, portable fire extinguishers store specific "extinguishing agents," which are expelled onto the fire.

Pressurized water models are appropriate for use on Class A fires only. These must never be used on electrical or flammable -liquid fires.

Carbon dioxide: extinguishers contain pressurized liquid carbon dioxide, which turns to a gas when expelled. These models are rated for use on Class B and Class C fires, but can be used on Class A fire. Carbon dioxide does not leave a residue.

Dry-chemical extinguishers are either stored-pressure models or cartridge-operated models. The stored-pressure models have a lever above the handle for operation. The cartridge-operated models require two steps: Depress the cartridge lever, and then squeeze the nozzle at the end to the hose. The dry chemicals leave a residue that must be cleaned up after use.

• Ammonium phosphate dry chemical can be used on Class A,B, and C fires, but should never be used on a fire in a commercial grease fryer because of the possibility of reflash and because it will render the fryer's automatic fire-protection system less effective.
• Sodium bicarbonate dry chemical, suitable for fighting Class B and Class C fires, is preferred over other dry-chemical extinguishers for fighting grease fires. Where provided, always use the extinguishing system first. This also shuts off the heat to the appliance.
• Potassium bicarbonate, urea-based potassium bicarbonate, and potassium chloride dry chemical are more effective and use less agent than sodium bicarbonate on the same fire.

Foam (or AFFF and FFFP) extinguishers coat the surface of a burning flammable liquid with a chemical foam. When using a foam extinguisher, blanket the entire surface of the liquid to exclude the air.

Remember the PASS - word
Keep your back to an exit and, depending on the size of your extinguisher, stand 10 to 20 feet away from the fire. Follow the four-step PASS procedure. If the fire does not begin to go out immediately, leave the area at once.
PULL the pin: This unlocks the operating lever and allows you to discharge the extinguisher.
AIM low: Point the extinguisher hose (or nozzle) at the BASE of the fire.
SQUEEZE the lever above the handle: This discharges the extinguishing agent. Releasing the lever will stop the discharge. (See special instructions for cartridge operating dry-chemical extinguishers.)
SWEEP from side to side: Moving carefully toward the fire, keep the extinguisher aimed at the BASE of the fire and sweep back and forth until the flames appear to be out. Watch the fire area. If the fire reignites, repeat the process.
Always be sure the fire department inspects the fire site, even if you think you've extinguished the fire. WARNING: Portable fire extinguishers discharge faster then most people think --- many within 15 to 30 seconds.

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National Fire Protection Association

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