Note: We’re talking about the classes of fire extinguishers here, as in fire extinguisher classification, not fire extinguisher training. For training, contact your local fire department.

The use of a fire extinguisher by a trained person can be a life and property saving tool. However, many people do not know much about various fire extinguishers, or how to use them properly. The use of a fire extinguisher requires sound training and prompt decision making capabilities. Aside from this, it is also important to maintain them properly so that are ready for use as when you need them.

You will have to use different types of fire extinguishers for different types of fire, for instance, an electrical fire and a grease fire may require different extinguishing agents to be fully effective and to safely put the fire out. Basically, there are 5 different types of extinguishing agents. Most of the fire extinguishers display proper symbols to show the kind of fires for which they can be used.

Let’s have a close look at different fire extinguisher classes that are found in the U.S.A. and the kind of fires they can be used for.

  • Fire Extinguisher Classes by Symbol and PictogramClass A - They can put out fires that comprise of combustible material such as wood, cloth, paper, rubber, and many types of plastics. The attached numerical rating indicates the capacity of water in US gallons, which goes from 1-40.
  • Class B – They can be used on all fires involving various inflammable liquids, such as gasoline, grease, oil and various oil based paints. Their numerical rating indicates the square feet of fire they can extinguish, and goes from 1-640.
  • Class C – These fire extinguishers are used on fires involving tools, appliances, and equipment that are still plugged in or are electrically energized. This extinguishing agent is fully non-conductive, and doesn’t have any numerical rating.
  • Class D - These fire extinguishers are designed for use on various flammable metals and are mostly specific to the type of metal in question. They are used only in factories that use these metals. They are type-1 (sodium chloride), and type-2 (copper powder). There is no numerical rating for this class.
  • Class K – These fire extinguishers are used on fires involving animal oils, vegetable oils, or fats used in cooking appliances. These fire extinguishers are used in commercial kitchens such as cafeterias, restaurants, and by caterers. One of the most widely used fire extinguisher classes, these are the type of fire extinguishers found in many kitchens, hence the name. They do not have any numerical rating.

Muli-purpose fire extinguishers

These fire extinguishers are often labeled as B-C, A-K and A-B-C fire extinguishers. They can be used for two or more of the above types of fires.

The labeling of different types of fire extinguishes (depending upon their classification) is now done using a pictogram, and/or geometric symbol and/or their associated letter(s). Multi-purpose fire extinguishers have more than one picture for indicating its abilities. However, there is no symbol for class D.

The OSHA (The Occupational Safety and Health Administration), ANSI (American National Standards Institute), and NFPA (the National Fire Protection Association) have their own specific guidelines for fire protection and prevention.

Aside from various fire extinguisher classes, the capacity of a specific fire extinguisher depends on the size of the fire extinguisher. So a bigger fire extinguisher will have a much hire fire dousing capacity, but will also be heavy.

A fire extinguisher should be used only if:

  • You have alerted others and somebody has called the fire dept
  • The fire is not big, and is limited to just one single object
  • You are away from toxic smoke due to fire
  • You can easily escape from the fire scene and there is no fire between you and the escape route

In fact, your instincts will tell you if it is really safe to use a fire extinguisher. If all these conditions are not there, then you should never try to use a fire extinguisher. Instead, you should immediately alert the occupants, and leave the area and building immediately. Immediately sound the fire department using a cell phone, or request your neighbor to do so.

Fire Extinguisher Care and Maintenance

You should regularly check your fire extinguisher and ensure that:

  • It is not blocked by doorways, furniture, or anything that might make it difficult for you to access it.
  • Its pressure is at recommended level. In fact, many fire extinguishers come with gauges that indicate its pressure
  • All operable parts are functioning properly and are not restructured or damaged. Also check and ensure that its nozzles are free from debris or rust.

Hopefully now you feel a bit more educated on fire extinguisher classes and their general use, safety and maintenance tips.