The ABC’s of Fire Extinguishers
Just as there is a right tool for every job, there is a right extinguisher for every fire. The class of an extinguisher, identified on its nameplate, corresponds to the class or classes of fire the extinguisher controls. On most construction jobs, we are concerned with Class A, B and C fires. Consequently, the best extinguisher to have on a job is a multi-purpose Class ABC extinguisher, which contains a dry, powdered chemical under pressure. The following describes the classes of fire and the kind of extinguisher that can be used on each.
CLASS A FIRES
Wood, paper, trash, and other materials that have glowing embers when they burn. Extinguisher to Use: For Class A fires use a Class A or Class ABC extinguisher. Always remember that a Class A extinguisher contains water and should be used only on a Class A fire. Used on gasoline, it can spread the fire; used on electrical fires, it can cause you to be electrocuted.
CLASS B FIRES
These are fires involving flammable liquids and gases, such things as gasoline, solvents, paint thinners, grease, LPG, and acetylene.
Extinguisher to Use: Use Class B or Class ABC extinguishers.
CLASS C FIRES
These are fires in energized electrical equipment.
Extinguisher to Use: Use a Class BC or Class ABC extinguisher.
SOME IMPORTANT POINTS TO REMEMBER
1. Use the fire extinguisher whose class corresponds to the class of the fire.
2. Never use a Class A extinguisher, which contains water or foam, on a liquid or electrical fire.
3. Know where extinguishers are located and how to use them. Follow the directions printed on the label.
4. Keep the area around the fire extinguisher clear for easy access.
5. Don’t hide the extinguisher by hanging coats, rope, or other materials on it.
6. Take care of the extinguishers just as you do your tools.
7. Never remove tags from extinguishers. They indicate the last time the extinguisher was serviced and inspected.
8. Report defective or suspect extinguishers to your Supervisor, so that they can be replaced or repaired.
9. When inspecting extinguishers, look for cracked hoses, plugged nozzles, and corrosion. Also, look for damage that may have been done by equipment running into the extinguishers.
10. Don’t use extinguishers for purposes other than fighting fires.
Nobody wants a fire.
But if one starts, know what extinguishers to use and how to use them.
Have you inspected your fire extinguishers lately? Are they fully charged, strategically located, accessible and ready for use? Or, are they laden with dust, obscurely hidden in some corner, affording a false sense of security?
So often, fire extinguishers are purchased with enthusiasm, a vital need; and then, suddenly, because they are not regularly used, they are relegated to a secondary position in our operation.
The fact that fire extinguishers are our first line of defense in the event of fire should warrant a periodic and thorough inspection of them. Fire extinguishers must be kept clean to attract attention, they must be kept accessible to eliminate lost time when needed, and the rubber hose, horn or other dispensing component must be checked to guard against blockage.
The following is a brief resume of the classification of fires, and the recommended extinguisher to be used on each:
CLASS "A" FIRES: Ordinary combustible such as rubbish, paper, rags, scrap lumber, etc. These are fires that require a cooling agent for extinguishment. Recommended extinguishers are—water through use of hose, pump type water cans, pressurized extinguishers.
CLASS "B" FIRES: Flammable liquids, oils and grease. Fires that require a smothering effect for extinguishment. Recommended extinguishers–Carbon Dioxide, Dry Chemical and Foam.
CLASS "C" FIRES: Electrical equipment. Fires that require a non-conducting, extinguishing, agent. Recommended extinguishers—Carbon Dioxide and Dry Chemical.
Emergency Planning for Construction Sites
As creatures of habit, people sometimes do things "routinely" without thinking about them. Remember your routine this morning? Did you go through the motions without much thought? At work, do you take the same path "automatically?" This is not necessarily wrong, because your routines often save time and energy. But when it comes to emergency situations involving escape and evacuation, people tend to use the most familiar route too. Sometimes that route may not be the best way to escape.
To ensure your safety and well being, it is important to prepare carefully for emergencies. In the ever changing construction environment, this is particularly important. Construction sites are continuously faced with changes in the physical layout, changes in emergency devices available and in harmful exposures. Careful pre-planning of emergency procedures, prior to the start of a project and during changes in different construction phases, must be done and all crew members must be aware of these procedures.
The following steps are important components of an emergency action plan:
1. Get to know your entire layout–site, building or structure as best you can. Review a floor plan that identifies emergency exits, emergency equipment (i.e., fire extinguishers, hoses, standpipes, pull stations, etc.). This plan should be posted in conspicuous areas and show evacuation routes as well as meeting points.
2. Analyze potential emergency situations at your work site. Will the hazards change regularly, gradually or stay the same over a period of time?
3. Know where emergency phone numbers are posted at your work location. These include medical emergency personnel, police, fire, EPA, Coast Guard, health department, OSHA, utilities, insurance carriers, etc. Numbers should be conspicuously posted near telephones.
4. Know who has responsibility during emergencies. Who is assigned to contact emergency personnel, first aid responders, fire brigades and a cleanup team? Who is assigned to talk to the media if they show up? Responses will be more efficient if everyone knows whose job it is to serve as incident commander, or to take specific steps.
5. When emergency devices such as personnel protective equipment, fire extinguishers, etc. must be used, do all co-workers know how to use this equipment correctly?
6. Practice the emergency procedures to ensure their effectiveness.
7. Remember that emergency procedures must be updated whenever there is a change in the operation, hazardous exposures, physical layout or if new employees are working in the location. Weekly safety meetings are a good time for review.
The last thing you want to think about during an emergency is how to evacuate or escape–especially if your most familiar route is not accessible. Knowing the emergency plan and being aware of surrounding conditions can mean the difference between quick action and the wrong action. Your safety and the survival of all crew members depends on taking the right action!
Flammable & Combustible Liquids
Recently, to dramatize the danger of hauling gasoline in the trunk of a car, a test was conducted igniting ONE gallon of gasoline inside a car trunk — the resulting explosion blasted the trunk lid along with a huge fireball, some 80 feet into the air, with a force that would have killed anyone in that car.
Since you can’t move fast enough to get away from an explosion, you had better do what’s necessary to avoid one.
Handling flammable and combustible liquids is a common occurrence on construction projects. When you’re the one that’s handling them, do you follow proper guidelines, or do you tend to ignore and underestimate the dangers? To fully understand the real dangers of these liquids, you must know the difference between them.
A FLAMMABLE LIQUID like gasoline, lacquer thinner, alcohol, some paint thinners, etc. are much more volatile — their vapors can ignite below 100° F, even down to freezing and below.
A COMBUSTIBLE LIQUID such as fuel oil, kerosene, linseed oil, etc, must exceed 100° F in order to release enough vapors to ignite.
Whenever handling liquids in containers marked flammable or combustible, READ THE WARNING
LABEL and remember, in addition to the danger of fire and explosion, there may be other serious health threats from these liquids–inhaling vapors, contact with skin, eyes, etc.
Listed safety containers are required for storing, handling and transporting of flammable or combustible liquids of any quantity.
I once heard of a workman who used a flammable solvent for cleaning and spilled some of it on his clothing. After he finished the job, he paused to smoke. The instant he struck the match to light his cigarette, he became a human torch. I’ve heard of other cases where flammable liquids have caused serious fires, which resulted in a great loss of life and tremendous property damage. We use many kinds of flammable liquids every day on this job: gasoline, cleaning fluids, paints, and thinners, to name just a few. The danger of these materials can be controlled.
SOME FACTS YOU MAY NOT KNOW
Flammable liquids themselves will not burn, as many people think. But as the liquid evaporates it gives off vapors that mix with the air to form dangerous gases that can be set off by the smallest spark. Take gasoline, for example. Gasoline evaporates at temperatures as low as 45OF below zero. As the temperature rises, the rate of evaporation increases and more and more vapors are given off. This also is true for other flammable liquids, except that the temperature at which they give off vapors varies with the kind of liquid.
FOLLOW THESE COMMON SENSE RULES
If we remember a few simple common sense rules when storing, handling, and using flammable liquids, we can help prevent this job, or any of us, from going up in flames.
Keep flammable liquids away from open flame and sparks. This means that you should never smoke around them.
Always use approved metal safety cans or the original manufacturer’s container to store flammable liquids. Keep these containers closed when not in use, and never store them near exits or passageways. Practice good housekeeping in flammable liquid storage areas.
Clean up spills immediately and then place the rags you used to do the job in a tightly closed metal container.
Be careful not to get a flammable liquid on you. It not only could burn you if it catches fire, but it could cause painful skin irritation that could easily become infected. If you get it on you, wash it off as soon as you can.
Never try to boost a fire with a flammable liquid. You are in for trouble if the fire flares up.
DON’T TRUST YOUR NOSE – VENTILATE
Don’t trust your nose to tell you whether an area or container is vapor free. Not all dangerous liquids give off vapors that you can smell. Some vapors are poisonous as well as flammable. Use flammable liquids only where there is plenty of ventilation.
Vapors given off by flammable liquids are usually heavier than air and collect in the lowest area they can reach. Without good ventilation to dissipate them, you have a potential disaster awaiting that one small spark to set it off.
READ THE LABEL
Carefully read the manufacturer’s label on the container of any flammable liquid before using it.
FRIEND OR FOE – IT’S UP TO YOU!
Like many other substances, flammable liquids can make a good friend or a bad enemy, depending on how you use them. Whether at home or on the job, treat flammable liquids with respect and use them for the purposes for which they were made.
The Fire Triangle
Let’s talk about what makes a fire and what we can do to prevent one. Fire can be compared to a triangle. Three sides are necessary to make a triangle and three ingredients are necessary to cause a fire. These are heat, air, and fuel. If any one of these three sides is missing, there can be no fire.
Heat, the first side of the fire triangle, can come from many sources. It can be generated by sparks from welding operations, discarded cigarette butts, electrical shorts, frayed wiring, friction from power tools, and hot exhaust pipes.
Fuel, the second side of the fire triangle, may be liquid, such as gasoline or solvents; a solid, such as paper or wood scraps; or a gas, such as propane.
Air, the third side of the fire triangle, contains oxygen which is necessary to sustain a fire. This is one side of the triangle we can’t do much about. Air is usually present. Heat, fuel, and air must be in the proper proportion for fire to occur. It is possible to have these three ingredients without causing a fire. For example, there may not be enough heat or air to ignite the fuel and cause it to burn.
ELIMINATING THE TRIANGLE
Let’s talk about what we can do to prevent the fire triangle from forming. Remember that if you remove any one of the three ingredients, you will prevent or extinguish
the fire. We can help prevent fires by doing the following:
1. Maintaining a Neat and clean work area, thus preventing an accumulation of rubbish.
2. Putting oily or paint-soaked rags in covered metal containers.
3. Observing all "No Smoking" signs
4. Keeping all combustible materials away from furnaces or other sources of ignition.
5. Reporting any fire hazards we, personally, cannot eliminate. This includes electrical hazards, which are the source of many fires.
6. Arranging cold weather heating devices so that tarps won’t blow into them.
WHEN YOU KNOW THE ANGLES
When you know the angles, it’s easier to prevent and control fires. Remember the fire triangle: heat, air, and fuel. When you find these three ingredients present, take heed. A fire could be in the making.