Understanding portable fire extinguishers

September 01, 2020 | SECURA Insurance

Fire extinguishers can be an important tool in preventing a small fire from growing larger. In the event of a fire, the correct use of a portable fire extinguisher could mean the difference between suffering a minor loss or a major one. There are several things to consider in using fire extinguishers correctly: 

Common classes of fires and fire extinguishers
  1. Class A: Involves ordinary combustibles such as paper, wood, cloth, rubber, or plastics. The common extinguishing medium for these types of fires is water or dry chemicals. Class ABC fire extinguishers would suffice in these circumstances. 
  2. Class B: This category includes flammable liquids, grease, or gases. Common extinguishing mediums in these types of fires include foam, carbon dioxide, or dry chemicals. Class ABC fire extinguishers would suffice in these circumstances. 
  3. Class C: Live electrical fires are Class C fires. CO2  or dry chemical extinguishers should be used on these types of fires. However, the actual burning product may be class A items. In this case, Class ABC fire extinguishers would suffice. 
  4. Class D: Burning materials include combustible metals such as magnesium and sodium. Special extinguishing agents, approved by recognized testing laboratories are needed when working with these metals. 
  5. Class K: These fires involve cooking oils and greases such as animal and vegetable fats. A special Class K extinguisher is needed to put out these fires. 
Fire extinguisher limitations: 
  • A dry chemical fire extinguisher such as the common red "ABC" extinguishers will reach a distance between five and 20 feet. It's important to be familiar with the models used in your work areas and the effective distance they can be used for. 
  • Not all extinguishers will be able to put out certain classes of fires. For instance, the common red "ABC" extinguisher would not be able to put out a Class K grease fire. 
  • A 10-pound to 20-pound dry chemical fire extinguisher will last anywhere from 10 to 25 seconds. Again, this depends on the model and the weight you are using. 
  • Fire extinguishers are only designed to fight small fires. A rule of thumb that a lot of professionals use is the size of the fire should not be any larger than the size of a small trash can. 
Remember to P-A-S-S when using an extinguisher: 
  • P - Pull. Pull the locking pin before using the fire extinguisher. 
  • A - Aim. Aim the fire extinguisher at the base of the fire. Not at the flames or smoke. 
  • S - Squeeze. Squeeze the lever of the fire extinguisher to operate and discharge. 
  • S - Sweep. Sweep the fire extinguisher from side to side at the base of the fire to extinguish. 

The most important thing to do during a fire is to get yourself to safety, then call the appropriate authorities to combat the fire. A building and the property inside is not worth putting yourself or anyone at risk trying to put it out with a fire extinguisher. It's important to understand how to use a fire extinguisher and the limitations they have. Good housekeeping, proper storage procedures, and safe work practices will go a long way toward reducing the likelihood that a fire will destroy valuable property or injure either you or a fellow employee.