The Minimum Clearance for Fire Extinguishers

Clearances

• All indoor, mounted fire extinguishers, regardless of their ratings, require at least 3 feet of space in front and around the unit, says the National Fire Protection Association (NFPA). Mounted fire extinguishers are units that hang approximately 4 to 5 feet above the floor in a glass case. The U.S. Occupational Safety and Health Administration (OSHA) also mandates fire extinguisher clearances. According to OSHA, a fire extinguisher with a rating no less than 10B must be within 50 feet whenever more than 5 gallons of flammable substances are present. Also, a 2A-rated fire extinguisher must be present for every 3,000 square feet of a protected building.

Organizations

• The two U.S. organizations responsible for creating fire extinguisher clearance standards are the NFPA and OSHA. The NFPA is a trade association that provides home safety standards that are adopted by local governments. OSHA is a division of the U.S. Department of Labor. The major difference between the two organizations is that NFPA standards serve only as the association's recommendations, while OSHA's standards are mandated by law.

Ratings

• A fire extinguisher's rating determines how close it should be to flammable objects. Fire extinguisher ratings are based on a scale of A through D and are labeled with colored pictograms. A-rated fire extinguishers feature green, triangle pictograms and are used for putting out flames caused by wood or paper. Gasoline- and oil-aggravated fires should be put out by B-rated extinguishers, which have red, square pictograms. C-rated extinguishers feature blue, circled pictograms and are used for electrically charged fires, while D-rated extinguishers are yellow and used for flammable metals. The official standards for fire extinguisher ratings in the United States are set by the NFPA.

Mounted Extinguishers

• The minimum clearance standard set by the NFPA is designed for mounted fire extinguishers. Mounted extinguishers are usually in rectangular cases that hang horizontally on the wall. Some mounted extinguishers are not within a case. Cases have glass doors to protect the extinguishers from dust. A major reason for the minimum clearance is to allow room for a case's door to open. The Industrial Accident Prevention Association recommends placing mounted fire extinguishers in visible areas, such as hallways and lobbies, and not in a place where it will be knocked off the wall by heavy machinery.