Fire Extinguishers

According to rules established by the National Fire Protection Agency, all recreational vehicles are required to have a at least a 5 lb BC fire extinguisher on board.  Unfortunately, this requirement is often satisfied by a little unit that is totally inadequate for all but the smallest fires. You will often see one about the size of a can of spray paint hanging on a wall in a motorhome or travel trailer.  I don't even like these for cooking fires since the velocity of the spray can splash and spread burning grease and they aren't big enough to really do much.   Much better to cover the burning pan with a lid or wet towel or smother the flames with baking soda.  I upgraded my motorhome with an additional fire extinguisher, a much larger, 20 lb, residential/commercial style ABC model.   See more about these funky alphabet ratings below.  The only real problem with such an upgrade is finding a place to put it.  The larger size and weight may make that difficult.  It needs to be secure and yet easily accessible.  Perhaps  having a small fire extinguisher in its original position inside the RV and a larger one in a convenient outside compartment (where it could also be accessed for engine fires) would be a good solution.

Fire extinguishers are not required by law for tent camping but it is still a good idea to have one handy.  You may need one if your tent or vehicle catches fire.   Most cooking fires can be controlled by covering the pot with a lid or wet towel or smothering the fire with baking soda or salt.   If you don't have a fire extinguisher, do carry an extra box or two of baking soda and keep it handy whenever you're cooking.  NEVER use flour to try to put out a fire.  Flour dust is highly explosive. I've heard that about a cup of flour can deliver about the same kick as a stick of dynamite!   Sugar is also highly flammable.   After all, sugar is the fuel our bodies burn!  It is basically carbon and hydrogen, same fundamental elements as gasoline!

Campfires are usually too large for a fire extinguisher, especially if the reason you're putting them out is they're out of control.  Keep a bucket of water or sand or dirt and a shovel handy to put out campfires. Y ou probably won't want to waste fresh water to put out a routine campfire at the end of the night so drain a little out of your gray water tank and use that.   Take care NOT to release anything from the black water tank!   I guaranty you won't like the results.  The smell of burning sewage will not contribute anything good to your outing or your reputation around camp and your partner may make you sleep outside after you've been exposed to the smoke.

Proper use of an appropriate fire extinguisher can prevent a small fire in your RV, tent, or tow vehicle from getting out of control and avoid more serious and expensive consequences.  Think a fire extinguisher is too expensive?  Consider how expensive it will be not to have one when you need it! Speaking of expense, don't waste your money on cheap fire extinguishers.  Many are made with plastic instead of metal parts inside that are easily broken and probably won't stand up to the rigors of RV travel and would thus be useless when you need them!

Fire extinguishers are rated according to the types of fires they are designed to put out.   The rating is important because an improper extinguisher will not be effective on fires it isn't rated for and, in some cases, can actually make things worse and create a greater hazard.  For example, using water on an electrical fire will damage the electrical equipment and could get you electrocuted!   Using water on flammable liquids may just spread the flames.

Fire and fire extinguishers are rated according to the types of materials involved.  Make sure you know how to recognize the type of fire and use only the right extinguisher for the fire.  Using the wrong one is, at best ineffective, and at worse, can be dangerous!

    Class A: ordinary combustible materials (paper, wood and most plastics)
    Class B: flammable or combustible liquids, such as gasoline, fuel oil, kerosene, diesel, grease,                    oil, and other solvents like paint thinners
    Class C: electrical fires, involving appliances, breaker boxes, wiring
    Class D: combustible metals like magnesium, titanium, and sodium
    Class K: cooking oils (deep fat fryers), mostly found in restaurant kitchens

A typical residential or commercial fire extinguisher will have an A-B-C rating, meaning it is good for Class A, B, and C fires.  This should be adequate for most RV applications.  D rated extinguishers are usually only found in chemical labs or places they routinely use exotic metals.   A "K" rated extinguisher might be useful if you have a cooking fire, but it is probably overkill.  "K" extinguishers are usually only found in commercial kitchens where they have deep fryer equipment and are usually part of an automatic fire suppression system.  You can usually snuff cooking fires by covering the pan with a lid or a wet towel or smothering them with baking soda.  By the way, soda is the main component of many "dry chemical" fire extinguishers so it is not a second rate substitute but rather a legitimate, effective, readily available, and inexpensive alternative.   The main advantage to a dry chemical fire extinguisher is that it is more effective and safer to use than trying to sprinkle soda onto a fire from a box.

Fire extinguisher sizes.   Fire extinguishers are usually "sized" by weight, indicating the weight of the extinguishing agent.  The larger or heavier the rating, the longer the extinguisher will be able to deliver fire suppressant onto a fire.  A 10 lb extinguisher will be fully discharged in 17-20 seconds. A 5 lb model will be used up in 8-10 seconds.  You can see the tiny little units that probably came with your RV won't last very long -- only a few seconds.   Don't give a fire time to get out of control. Tackle it as soon as possible.  Your fire extinguisher should be adequate to put out a smoldering cigarette on your sofa, but if the whole sofa is engaged, just get you and your family the heck out while you can.  Even a 10lb extinguisher isn't enough to handle that job.  You might be able to save the rest of your RV if you can come back with a water hose or a large ABC extinguisher.  A useful guideline for whether to fight a fire or escape is to compare it to a fire in a typical waste basket.   Up to that size, a hand-held fire extinguisher may be effective.  Any thing larger requires real fire fighting equipment and you'd better get you and your loved ones to safety instead of trying (most likely in vain) to put the fire out.

Using a fire extinguisher.  Always aim the fire extinguisher at the base of the fire.  The acronym, PASS describes the proper procedures for using a fire extinguisher:

    P: Pull -- pull the locking pin from the handle
    A: Aim -- aim the nozzle at the base of the fire
    S: Squeeze -- squeeze the handle to begin discharge
    S: Sweep -- sweep the spray from side to side

Once you have started to use an ABC fire extinguisher, you might as well empty it.  Particles left in the valve will keep it from closing completely when you release the handle and the pressure will leak away, making it useless.  After ANY discharge, the unit must be replaced or rebuilt to remain useful.  The only style I know that can be stopped and started is an old fashioned water extinguisher.

Fire extinguisher maintenance.  There is little user maintenance required for most fire extinguishers.  Mostly you need to monitor the inspection date and check the gauge(if it has one).  Dry chemical extinguishers should be shaken once a month to avoid the chemical "caking up" inside.  Fire extinguishers have a limited useful lifetime and need to be replaced or rebuilt (by specially trained and licensed technicians).  About the only type you can maintain yourself is water filled Class A extinguisher.  These units can be refilled with water and re-pressurized by the user using compressed air.   I keep one in my motorcycle trailer as a portable bike pressure washer, but it could also be used on any Class A fire as well.  Water extinguishers are definitely NOT recommended nor approved for Class B or Class C fires.

Fire requires three components, known as the fire triangle:  fuel, heat, and oxygen.   Take away any one of the three and the fire goes out.  Covering a burning pan removes oxygen.  Spraying a fire in ordinary combustibles (wood, paper, plastic) removes heat and, as the water soaks the potential fuel, reduces availability of fuel.  Dry chemical fire extinguishers mostly prevent the fire from getting oxygen.  Water is the most common substance used to put out fires, even by fire departments.  But NEVER use water on a fire involving live electrical devices.  Once the electricity has been turned off the fire switches from a Class C fire to what is usually an ordinary Class A fire.  A fire in a plugged in electrical appliance is a Class C fire; unplug the appliance and it usually becomes a Class A fire. Using water on a Class B fire is not recommended.   The spray often splashes and spreads the burning fuel, doing more harm than good.  I have seen professional firefighters and even trained C.E.R.T. folks put out a Class B fire using water, but it requires special techniques.  I have tried it myself and it isn't easy.   If you have no other choice but water for a flammable liquids fire, do not use a strong stream.  Use a broad spray.  Aim it at the base of the flames and use it kind of like a broom to sweep the flames off the fuel.  It may be very difficult if the fire is wide or if there is any wind.  The fire can easily ignite fumes rising or blown from the previously extinguished areas and jump back again.

Of course, fire prevention is always better than  fire suppression.  You'll always be better off avoiding a fire than fighting one so take proper precautions with your camp and cooking fires.  Watch out for potentially dangerous situations involving combustible materials. 

See also Fire Extinguisher Education for RVers for additional information.

Put it out!