Resources – Fire Extinguisher Maintenance

Residential Fire Extinguisher Inspection & Maintenance

Replace or service an extinguisher
right away if it’s been used (to any degree) or if
you notice any of the following: 
 The hose or nozzle is cracked, ripped, or blocked with debris. 
 The metal locking pin on the handle is missing or if the safety seal is missing/not intact.
 The handle is wobbly or broken. 

I. Monthly Inspection for ALL fire extinguishers:
These inspections can be done by the owner. Do the following:
 Confirm the extinguisher is visible, unobstructed, and in its designated location.
 Verify the locking pin is intact and the tamper seal is unbroken. Examine the extinguisher
for obvious physical damage, corrosion, leakage, or a clogged nozzle.
 Check for a full charge. If the pressure gauge reads within the “green” zone, or the pin
indicator pops back up when pushed, the extinguisher is properly pressurized.
 Lift the extinguisher to ensure it is still full.
 Assure the operating instructions on the nameplate are legible and facing outward.
 Check the last professional service date on the tag.
 Keep a record of inspection dates.

II. Fire extinguisher maintenance:
Always follow manufacturer maintenance guidelines.

A. For non-rechargeable (aka “disposable”) fire extinguishers:
These have a plastic valve, and the pressure gauge reads from “Full” to “Empty.”
 Invert the extinguisher several times once/month to avoid having the
extinguishing agent “cake” at the bottom of the canister.
 Replace 10 years after the original fill date, or, unavailable, the manufacture date
(located on the UL nameplate/label on the extinguisher canister or on the canister
bottom). Some manufacturers state 12 years until replacement.

B. For rechargeable extinguishers:
These have a metal valve, and the pressure gauge reads from “Undercharged” to “Overcharged.”
The life of the extinguisher and maintenance intervals are based on the original fill date, not
the date of manufacture. If the original fill date is unknown, go by the manufacture date.

  1. Dry chemical rechargeable extinguishers:
    These are primarily Class ABC (usually mono- or di-ammonium phosphate) and dry
    Class BC (usually sodium bicarbonate) extinguishers.
     Invert the extinguisher several times once/month to avoid having the
    extinguishing agent “cake” at the bottom of the canister.
     The extinguisher must be professionally inspected (includes an internal
    inspection) and recharged once every 6 years—even if unused.
     Hydrostatically test professionally (to verify strength against rupture) once every 12 years.
     Maintenance needs to be performed by a certified person.


 Each fire extinguisher should have a tag or label securely attached that indicates
that maintenance was performed.
 Extinguishers also need a verification-of-service collar located around the neck of
the canister if an internal examination was done.

  1. Water (Class A) and water mist (Class BC) extinguishers:
    For both water and water mist extinguishers:
     These extinguishers can be refilled by the owner. Fill the canister to the
    manufacturer’s specified volume.
     Discharge, disassemble, and inspect annually (NFPA 10, 4-4.1. 1). Can be done by owner.
     Hydrostatically test professionally once every 5 years
    Additional specifics:
    a.) For water extinguishers:
     Refill using regular water.
     Pressurize with air, but nitrogen is ideal. For air, one can do this using a small
    compressor or a high pressure bicycle pump.
    b.) For water mist extinguishers:
     Refill using either deionized or distilled water.
    (Regular water cannot be used for extinguishing Class C fires.)
     Ideally pressurize with nitrogen rather than air. Pressurizing usually requires a special
    adapter fitting (including all Amerex models). There are fire supply companies in Sonoma
    County that will pressurize these extinguishers with nitrogen for free.
    There is no mandatory “expiration date” for rechargeable fire extinguishers in the United
    States. The lifespan depends on a number of factors. Per Kaufman Co., “If you keep up
    with maintenance and hydrostatic testing requirements, you can expect your
    extinguishers to last for many decades.” 
    The above only pertains to the most popular and/or practical fire extinguisher types
    used by homeowners. Other types, like C0 2 extinguishers, potassium bicarbonate
    (aka “Purple K”) extinguishers, chemical foam, and Class D extinguishers, may
    require different maintenance and/or schedules.
    Information sources:
     NFPA Today: “Guide to Fire Extinguisher Inspection, Testing, and Maintenance,”
    10/30/2020, by Brian O’ Connor, Technical Services Engineer.
     California Fire Protection and Backflow: California Code of Regulations on Fire Extinguishers
     Koorsen Fire and Security website
     NFPA 10 Standard for Portable Fire Extinguishers
     Guardian Fire Protection website
     First Alert website
     State Compensation Insurance Fund: Safe at work California. Fire Extinguishers 2/12/2021
     UC San Diego Blink website
     Kauffman Company, Houston TX
    Compiled by Carl J. Wahl, Jr.