Fire is a chemical reaction that involves 3 elements:
- Fuel. Any combustible solid, liquid, or gas
- Oxygen. An atmosphere with at least 16% oxygen is needed for ignition (breathable air is 21%)
- Source of Ignition. A flame or spark that cause the mixture to ignite
Fires are classified by the fuel they burn.
Class A – Common combustibles such as wood, paper, cloth, rubber, and certain types of plastic.
Simple routine housekeeping can prevent Class A fires.
- Make sure storage and work areas are free of trash and clutter.
- Oily rags and debris should be placed in covered containers away from any spark-producing source.
- If your building permits smoking, smoke only in designated areas.
Class B – Flammable or combustible gases and liquids, such as gasoline, kerosene, paint, paint thinners, and propane
Taking special precautions when working around flammable liquids/gases can prevent Class B fires.
- Work only in well-ventilated areas.
- Clean up all spills of flammable liquid immediately.
- Never smoke around flammable materials.
- Make sure you are well away from any spark-producing source.
- Store flammable chemicals and liquids in tightly sealed, self-closing spill-proof containers.
- Limit portable storage containers to a maximum of five gallons each. Store anything larger in a separate building or in an approved storage container.
Class C – Energized electrical equipment such as appliances, switches, and power tools
Checking for old or worn wiring or broken, damaged electrical fittings can prevent Class C fires.
- Report any electrical hazards to the supervisor immediately.
- Extension cords should be no longer than 6’ and should never run under carpets or rugs.
- Do not overload wall sockets. No more than two plugs should be used per outlet.
- Make sure utility lights have wire guards over the bulb to shield the bulb from combustible objects.
- Never install a higher-rated fuse than is specified.
- Be aware of unusual odors from electrical equipment which could be the first sign of fire.
Class D – Certain combustible metals such as magnesium, titanium, potassium, or sodium
Following material handling guidelines can prevent Class D fires.
- Always follow proper procedures and use appropriate personal protective equipment when dealing with combustible metals.
- Keep combustible metals away from other chemicals, and store in the proper container.
WHEN TO USE FIRE EXTINGUISHERS
If taking the time to use a fire extinguisher could put a life in danger . . . DON’T.
Never fight a fire when:
- The fire is spreading beyond the spot where it started.
- You can’t fight the fire with an escape route behind you.
- The fire can block your only escape route.
- You don’t have adequate firefighting equipment.
In any event, be prepared. Get familiar with the type and location of the fire extinguishers in your area. Using a fire extinguisher means knowing the PASS methods:
- Pull the pin (or rupture the cartridge).
- Aim the nozzle at the base of the flames.
- Squeeze the trigger (or handle) while holding the extinguisher upright.
- Sweep the extinguisher from side to side, covering the fire with the extinguishing agent.
EVACUATING A BURNING BUILDING
If you have to evacuate a burning building, you should:
- Never open a closed door without feeling it first. Using the back of your hand will protect your palm. If the door is hot, use another exit. If none exists, seal the cracks around the door and vents with anything available.
- Make sure the last person out of a room closes the door, but does not lock it. Locking the door can slow search and rescue efforts.
- Proceed to the nearest safe exit.
- Do not use elevators.
- Stay low to avoid inhaling smoke and toxic gases. If you have to, crawl to stay close to the floor and the best air.
- When possible, cover your mouth and nose with a damp cloth to help you breathe.
- If the building has multiple floors, use the stairway to proceed to the ground floor. Never go up.
- Once outside of the building, report to supervisors so a head count can be taken.