Ask an Expert

What are the four classes of fire extinguishers?

Fire extinguishers are labeled using symbols indicating the classes of fires on which they are effective. A red line through any of the symbols tells you the extinguisher won’t work on that class of fire. If a symbol is missing this tells you that the extinguisher has not been tested for that class of fire, but may be used if an extinguisher labeled for that class of fire is not available.

How often should you have your fire extinguishers inspected?


What are the types of fires?

CLASS A: Combustibles: wood, cloth, and paper.

CLASS B: Flammable Liquids: gasoline, oil and oil-based paint.

CLASS C: Energized Electrical Equipment: wiring, fuse boxes, circuit breakers, machinery and appliances.

CLASS D: Combustible Metals: magnesium or sodium.

What happens if I drop a fire extinguisher?

An ABC rated dry chemical fire extinguisher is pressurized to about 190 PSI. A CO2 extinguisher is pressurized to 2000 PSI. Dropping it will likely damage the integrity of the extinguisher. If it is dropped, keep it in a safe and isolated area until Tyler Fire picks it up or you can drop it off at our office to be tested and/or replaced. Many possible issues from knocking the extinguisher off its hook can go unnoticed.

Why is the fire extinguisher pin sealed?

The seal is proof that the fire extinguisher has not been tampered with or used since the last inspection or service and it keeps the safety pin from accidentally falling out. The seal provides the last date of inspection. If you are missing a seal on an extinguisher, contact Tyler Fire immediately.

How do you know if a fire extinguisher is unsafe?

To the average person, this isn’t easy to spot. However, everyone can check the pressure gauge. There is a green zone between the two red ones. If the indicator is in either of those red zones, your fire extinguisher needs service. You can also check for a safety pin. If the pin is removed or lost, the unit has to be serviced. If there are dents or engravings on the cylinder, it’s possible that the extinguisher is in need of service or replacement.

How do I know if I have enough fire extinguishers in my building?

While the specifics vary from building to building, in general, you want to have enough fire extinguishers so that you don’t have to travel more than 50–75 ft to reach one. This will minimize the necessary response time.

Do I need to train my employees on how to use fire extinguishers?

Yes. According to the Code of Federal Regulations (CFR) Title 29, part 1910 (OSHA) section 157 paragraph g.1 & 2 states… “Where the employer has provided Portable Fire Extinguishers for employee use in the workplace, the employer shall also provide an educational program to familiarize employees with the general principles of fire extinguisher use and the hazards involved with incipient stage fire fighting. The employer shall provide the education required in paragraph (g)(1) of this section upon initial employment and at least annually thereafter.”

What type of fire extinguisher do I need in a commercial kitchen?

K-Class combustible cooking media fires typically involve kitchen appliances containing quantities of cooking greases or oils that present special hazard extinguishing and re-flash concerns. Only extinguishing agents with the ability to saponify and create a thick, heavy, long-lasting type of foam blanket upon the hot cooking media surface seal out the oxygen, cool the cooking media and prevent reflash. The K-Class listed fire extinguishers have effectively demonstrated the ability to address these commercial kitchen types of fire hazard situations.

What are the different types of chemicals used in fire extinguishers?

Water extinguishers use water to cool the burning material. This can be pump type water, air pressurized water and water mist.

Dry chemical extinguishers use a powder-based agent which prevents chemical reactions involving heat, oxygen and fuel, this extinguishes the fire. The substances used for this are Monoammonium phosphate, sodium bicarbonate, potassium bicarbonate, potassium chloride and sodium bicarbonate based dry chemical (Foam compatible).

Foam extinguishers use an aqueous film-forming foam, alcohol-resistant foams, film-forming fluoro protein and a compressed air foam system. These smother the fires and prevent oxygen from fueling it.

Carbon Dioxide extinguishers put out fires by displacing oxygen and removing heat from the combustion zone.

Water Mist extinguishers have no chemicals, but they do contain water. What makes water mist different or standard water extinguishers is the nozzle on the extinguisher disperses ‘dry’ water mist particles at a microscopic scale.

Wet chemical and water additives extinguish a fire by forming a soapy foam blanket over burning oil and cooling the oil down below its ignition temperature. They use wetting agents, antifreeze and loaded stream (an alkali metal salt solution which when added to water lowers its freezing point).

Serving East Texas Since 1949