How to Choose the Right Fire Extinguisher for Your Facility

Understand Fire Classes

The first step in fire extinguisher selection is identifying what could potentially catch fire in your facility. 

Class A: Ordinary Combustibles - Class A fires involve ordinary combustible materials such as wood, paper, cloth, rubber, and many plastics. They are common in offices, warehouses, schools, and other commercial spaces. Water, foam, and multipurpose dry chemical fire extinguishers may be appropriate for Class A hazards, depending on the specific application. 

Class B: Flammable Liquids - Class B fires involve gasoline, oil, paints, solvents, and other flammable liquids. Manufacturing facilities, garages, workshops, and areas where flammable liquids are stored may require Class B fire extinguisher protection. OSHA requires Class B extinguishers to be positioned so the travel distance from the hazard to an extinguisher is no more than 50 feet. 

Class C: Electrical Equipment - Class C fires involve energized electrical equipment. Offices, server rooms, manufacturing facilities, and electrical rooms may have Class C hazards. It’s important to remember that Class C is a rating applied to extinguishers that are suitable for energized electrical equipment; it isn’t a standalone extinguishing agent. 

Class D: Combustible Metals - Class D fires involve combustible metals such as magnesium and sodium. These hazards are more specialized and may be found in certain manufacturing, machining, and laboratory environments. Class D extinguishing agents are specifically designed for the metal involved and should be selected based on the particular combustible metal hazard. 

Class K: Cooking Oils and Fats-  Commercial kitchens have a unique fire hazard: hot cooking oils and fats. Class K fire extinguishers are designed specifically for these types of fires and are commonly used near commercial cooking equipment to support restaurant and facility fire safety. 

Consider the Facility's Specific Hazards 

A single facility may need several types of fire extinguishers. For example, an office might primarily need protection against Class A and Class C hazards, while a manufacturing facility could also require Class B or Class D protection. A commercial kitchen will have Class K hazards in addition to other potential fire risks. 

Walk through the facility and identify areas that may affect fire extinguisher placement, fire protection planning, and OSHA compliance, including spaces containing: 

• Flammable liquids 
• Electrical equipment 
• Combustible materials 
• Cooking equipment 
• Combustible metals 
• Machinery and heat-producing equipment 

The goal is to match the extinguisher to the hazard—not simply place identical fire extinguishers throughout the building. 

Don't Forget Extinguisher Ratings

You’ll notice numbers and letters on fire extinguisher labels, such as 2-A:10-B. These ratings indicate the types and relative sizes of fires the extinguisher has been tested to handle. The numbers are important when determining whether an extinguisher provides adequate fire protection for a particular hazard. 

Inspection and Maintenance 

Fire extinguishers aren’t a “buy it and forget it” product. OSHA requires employers to keep workplace fire extinguishers fully charged, operable, and in their designated locations. They must also receive regular fire extinguisher inspections, maintenance, and testing, including annual maintenance checks. 

Choosing the right fire extinguisher starts with understanding the fire hazards in your facility. From ordinary combustibles and electrical equipment to flammable liquids and commercial cooking oils, the right extinguisher provides an important layer of protection against developing fires and helps support a safer, more compliant workplace fire safety program.