Out of frying pan and into the fire: 101 on fire extinguishers.
With temperatures breaching the low 90s, it’s safe to say that summer is just around the corner. Yet with a relatively warm winter and remembrance of the fires that devastated the communities just north of Colorado Springs, Colo., last year, it’s important for Coloradoans to be prepared for another long, hot and fire plagued summer.
One of the most accessible ways to help prepare yourself in case you become involved in a fire-related emergency situation is by becoming families with one of the simplest effect fire prevention tool around: the fire extinguisher.
Fire extinguishers are an invaluable piece of fire protection when it comes to small house or confined spaced fires. They are quicker and easier to deploy than a water hose and are generally readily available for use in most public offices.
Surprisingly, not all fire extinguishers are meant to put out the same types of fire and using the wrong one could potentially make the situation worse. In order to prevent this from causing civilian harm, fire extinguishers have been separated for specific use to combat the five different fire class types. These fires class types are class A, B, C, D and K.
Class A fires involve any type of ordinary combustible materials such as wood, plastic, rubber or textiles. The materials involved in a Class A fire spread quickly through radiant heat and can consume a typical household bedroom in under a minute.
Class A fire extinguishers are designed to reduce the temperature of the ignited fuel source so that it cools down below its ignition point. Water pump extinguishers (extinguishers that use only water) and aqueous film forming extinguishers (water and chemical mix that create a film over the burnable material) are most commonly used to put out these types of fires.
Class B fires involve combustible liquids and gases such as diesel, oil, gasoline and paint products. Fires often burn at a hotter temperature due to the materials having a higher flammable range (the range between the lowest and highest heat temperatures required to
ignite a substance) and can require hazmat suits in order to shut off the gas supply.
Carbon monoxide based fire extinguishers are best used to put out Class B fires. The carbon monoxide smothers the fire, which cuts off the oxygen required for it to continue to burn. However, pressurized carbon monoxide have a limited range and can be disrupted by wind, requiring the user to get close to the fire in order for the extinguisher to be effective.
Class C fires are created by electrical energy and involve computer, appliance or other electrical equipment fires. Unlike the other fire classes, Class C fires are not caused by a fuel-based ignition. Rather, they are caused by malfunctions in a product’s wiring or the overheating of lubricants.
Along with carbon monoxide fire extinguishers, dry chemical extinguishers can be used to put out electrical-related fires. These extinguishers are commonly filled with potassium chloride and potassium bicarbonate, and are used to coat and break the chain reaction caused by the electrical malfunction that started the fire.
Class D fires are fires involving combustible metal materials. These fires are usually found in industrial areas and are extremely hazardous. The dust created from the burning of the metal materials can result in powerful explosions given enough temperature and fuel source. They can also produce extremely toxic smoke and vapors.
Not to be confused with dry chemical, Class D fires can only be put out with dry powder fire extinguishers in combination with either another chemical based on the burning metal type or by shoveling gravel onto the metal itself.
Class K fires are essentially kitchen-related fires involving oils and grease. They require extinguishing agents that are specially designed to snuff (suffocate) the ingredients involved.
Class K fire extinguishers use a process called saponification to put out their fires. Saponification uses a wet chemical that turns into an oxygen excluding foam when used.
Knowing which type of fire extinguishers that are at your disposal and what type of fires you can put out with them is critical. Using a Class A fire extinguisher while trying to put out a fire that started from an overheated computer could potentially electrocute the user not to mention make the computer unsalvageable.
Each fire extinguisher should be marked with a sticker (if not several) indicating what type of fire they can successfully be used for by indicating the fire class (A-D, K) and through an illustrated pictograph of the combustible materials.
Another thing about fire extinguishers that users should be aware of is that they only have about a minutes worth of use before they run empty. That means the user should know how to operate them efficiently to put out a fire before it has a chance to run out of hand.
A simple way to remember how to operate an extinguisher is by using the P.A.S.S. method (pull, aim, squeeze, sweep).
First, the operator needs to pull the pin that prevents the lever on the top of the extinguisher from becoming live. Once the pin is pulled, aim the nozzle of the hose at the fuel source of the fire, not the flame.
Once you squeeze down on the lever make sure you sweep the hose back and forth across the entire fuel source. If you don’t sweep the burning material and just attack it one area at a time you risk the extinguishing agent running out before the fire can be controlled.
Knowing your enemy is half the battle and uncontrolled fires are generally unforgiving to those who are not properly prepared to protect their property or themselves.