How Many Extinguishers are Required?


There are four topics to review when installing portable fire extinguishers. You must first identify the hazards that are present, and recognize even trace amounts of each fire classification to determine the proper number of extinguishers required. Next, you must determine the size of the fire extinguisher, and establish the quantity of extinguishers needed by the coverage allowed per Local and National fire codes. Last, you must distribute the portable fire extinguishers per the allowable travel distance to each fire extinguisher.


Class A Locations



Light (Low) Hazard Occupancy

Ordinary (Moderate) Hazard Occupancy 

Extra (High) Hazard Occupancy

Minimum Rated single extinguisher  2-A 2-A 4-A
Maximum floor area per unit of A  3,000 ft2 1,500 ft2 1,000 ft2
Maximum floor area for extinguisher  11,250 ft2 11,250 ft2 11,250 ft2
Maximum travel distance to extinguisher 75 ft 75 ft 75 ft


 Source: NFPA 10, 2007 edition Table Fire Extinguisher Size and Placement for Class A Hazards

Class B Locations


Type of Hazard 

Basic Minimum Extinguisher Rating 

Maximum Travel Distance to Extinguisher 

  5-B 30 ft
Light (Low)  10-B 50 ft
  10-B 30 ft
Ordinary (Moderate)  20-B 50 ft
  40-B 30 ft
Extra (High)  80-B 50 ft



Source: NFPA 10, 2007 edition Table Fire Extinguisher Size and Placement for Class B Hazards

Class C Locations

Class C extinguishers are required where energized electrical equipment is directly involved in or surrounding electrical equipment.


Class D Locations

Class D extinguisher locations shall not be located more than 75 ft. from the hazard. Size determination for Class D locations is based on the specific combustible metal, particle size, area to be covered, and manufacturer recommendations.


Class K Locations

Class K hazards shall have a fire extinguisher located where there is a potential for a fire involving combustible cooking media (vegetable or animal oils and fats). The extinguisher shall be located no more than 30 ft. from the hazard.

NFPA 10 requires you to maintain your fire protection equipment in good working order and maintain inspection,
testing and maintenance records. Inspections will be performed on an Annual basis.