Understanding different types of fire extinguishers is essential for protecting people and property in any environment. Fire extinguishers are not one-size-fits-all. Each type is designed to handle specific classes of fire, and using the wrong extinguisher can make a situation worse.
At Pye-Barker Fire & Safety, we help businesses, facility managers, and safety officers select the right extinguishers for their unique needs. Below is a guide to the five primary types of fire extinguishers recognized by the National Fire Protection Association, along with their ideal use cases and maintenance requirements.
WATER (CLASS A) FIRE EXTINGUISHERS
Water extinguishers are designed for use on ordinary combustibles such as wood, paper, cloth, and some plastics. These extinguishers work by cooling the burning material and are typically used in office buildings, schools, and residential settings.
According to NFPA 10, water extinguishers are only appropriate for Class A fires. They must never be used on flammable liquids or electrical fires, as they can spread the fire or pose a shock hazard.
CARBON DIOXIDE (CO2) FIRE EXTINGUISHERS
CO₂ extinguishers are most effective against Class B and Class C fires, which involve flammable liquids and energized electrical equipment. These extinguishers displace oxygen and suppress the fire without leaving residue, making them ideal for use in data centers, labs, and electrical rooms.
However, CO₂ is not effective on Class A materials and is not recommended for use in confined spaces due to asphyxiation risk. Regular inspection and weighing of the cylinder are required to confirm adequate pressure and agent level.
DRY CHEMICAL (ABC OR BC) FIRE EXTINGUISHERS
Dry chemical extinguishers are the most widely used and versatile. ABC extinguishers contain monoammonium phosphate, which works on Class A, B, and C fires by interrupting the chemical reaction and smothering the fire. BC models contain sodium bicarbonate or potassium bicarbonate and are designed for flammable liquids and electrical fires but not ordinary combustibles.
These extinguishers are found in warehouses, vehicles, restaurants, and most commercial facilities. Regular annual maintenance and monthly visual inspections are required to ensure pressure levels and nozzle accessibility.
WET CHEMICAL (CLASS K) FIRE EXTINGUISHERS
Class K extinguishers are specifically designed for commercial kitchens. They are used to extinguish fires involving cooking oils and fats in appliances such as deep fryers and grills. Wet chemical extinguishers discharge a potassium-based solution that cools the fire and creates a soapy layer over the burning oil, preventing re-ignition.
Class K systems are required in restaurants, cafeterias, and any commercial facility with deep fat cooking operations. These extinguishers must be UL 300-compliant and should be inspected every six months along with the kitchen hood suppression system.
FOAM (CLEAN AGENT) FIRE EXTINGUISHERS
Clean agent extinguishers use halocarbon-based gases such as FM-200 or Novec 1230. These agents interrupt the combustion process without leaving any residue, making them ideal for areas with sensitive electronics like server rooms, telecom centers, and control rooms.
Clean agent extinguishers are effective on Class B and C fires and are safe for use in occupied spaces when properly designed. Systems using clean agents must comply with NFPA 2001 and be inspected at least annually to confirm pressure, nozzle condition, and functional readiness.
SELECTING THE RIGHT FIRE EXTINGUISHER
Fire extinguishers should be selected based on the types of hazards present in your facility. NFPA 10 provides the standard for selection, installation, and maintenance. The size, placement, and accessibility of extinguishers are all regulated to ensure rapid response and effective use in the event of a fire.
Facilities with mixed hazards may need multiple types of extinguishers to ensure complete coverage.
MAINTAINING CODE COMPLIANCE
All portable extinguishers must be visually inspected monthly and professionally serviced annually. Additional requirements apply for recharge, hydrostatic testing, and tamper seal replacement. Failing to maintain extinguishers can result in fines, liability exposure, or failure during a real emergency.
COMPLETE FIRE EXTINGUISHER SERVICES
Pye-Barker Fire & Safety provides comprehensive fire extinguisher services including equipment sales, installation, inspections, maintenance, and training. Our technicians are certified to service all major extinguisher brands and help clients remain compliant with NFPA 10, OSHA, and local fire codes.
Contact your local Pye-Barker team to schedule a fire extinguisher evaluation or visit our online Fire Extinguisher Buying Guide to learn more about our services.