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    SiteKiln, Your rights on site. In plain English.

    Fire Extinguishers: Class, Placement, Paperwork

    Which extinguisher fights which fire, what OSHA actually requires on a jobsite, and the records an inspector asks for.

    The classes

    A Wood, paper, cloth, most plastics
    B Flammable liquids and gases: gasoline, oil, paint, propane
    C Energized electrical equipment. The agent must be non-conductive.
    D Combustible metals: magnesium, titanium, sodium
    K Cooking oils and animal fats. Wet chemical.
    Getting it wrong Water or foam on a class B fire spreads it. On energized equipment it is an electrocution risk.

    What OSHA requires on a jobsite (29 CFR 1926.150)

    Coverage At least one extinguisher rated 2A per 3,000 sq ft of protected building area, or major fraction of it
    Travel distance No more than 100 ft from any point to the nearest extinguisher
    Multistory One per floor, and one adjacent to the stairway
    Flammables A 10B unit within 50 ft of more than 5 gallons of flammable liquid, or 5 lb of flammable gas, in use
    Prohibited Carbon tetrachloride extinguishers

    NFPA 10, which is stricter

    Class A travel distance 75 ft
    Class B travel distance 30 to 50 ft by hazard level
    Class K travel distance 30 ft
    Mounting height Top no more than 5 ft above the floor. Units OVER 40 LB mount lower, top no more than 3-1/2 ft. That threshold is WEIGHT, not accessibility.
    Floor clearance At least 4 in from the bottom to the floor

    Inspection and records

    Monthly Visual check: condition, gauge, tamper seal, still accessible and unobstructed
    Annual Maintenance by a qualified person, with the date recorded on the tag
    6 years Internal maintenance on stored-pressure units
    12 years Hydrostatic test on dry chemical units
    On a construction site 29 CFR 1926.150 is the enforceable rule and it points at NFPA 10 for maintenance procedure. The NFPA placement figures above are tighter than OSHA's and are only independently enforceable where a state plan or the local authority has adopted NFPA 10 directly. The annual-maintenance recordkeeping wording most often quoted comes from 1910.157, the general industry standard, so check which one your inspector is working from. State-plan states can be stricter than federal OSHA throughout.

    Sources: osha.gov · nfpa.org

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