Fire extinguisher inspection requirements run on a layered schedule: a visual check every month, a hands-on maintenance service every year, an internal examination every six years, and a hydrostatic pressure test every 5 or 12 years depending on the extinguisher type. OSHA sets the workplace mandate in 29 CFR 1910.157, and NFPA 10 supplies the technical detail that most local fire codes adopt. Miss a tier and you face citations up to $16,550 per violation, plus equipment that may not work when someone needs it.
Who Has to Follow These Rules
OSHA’s portable fire extinguisher standard applies to every employer that provides extinguishers for employee use. One extinguisher on the wall is enough to trigger the full standard: monthly checks, annual maintenance, hydrostatic testing, and training.
There is a single narrow exemption. An employer that has adopted a written policy of immediate and total evacuation on any fire alarm, and has removed all extinguishers from the workplace, is exempt from 29 CFR 1910.157. The policy must include an emergency action plan and a fire prevention plan meeting 29 CFR 1910.38 and 29 CFR 1910.39. Few employers qualify, because other OSHA standards for their industry often require extinguishers on site anyway.
Residential properties fall outside OSHA, but most local fire codes incorporate NFPA 10. Landlords and property managers of multi-unit buildings face effectively the same inspection schedule, enforced by the local fire marshal. Single-family homeowners have no legal inspection mandate in most jurisdictions.
Monthly Visual Inspection
Every portable extinguisher in the workplace has to be visually inspected once a month. OSHA does not spell out the checklist. NFPA 10 does, and local codes generally adopt it. The person doing the check confirms:
- The extinguisher is in its designated location, visible, and not blocked by equipment or stored items.
- The pressure gauge needle sits in the operable range.
- The tamper seal is intact and the pull pin is properly seated.
- There is no corrosion, denting, leaking agent, or clogged nozzle.
- The operating instructions are legible and face outward.
- The unit weighs what it should, verified by hefting or weighing, to catch slow leaks the gauge might miss.
Anyone on staff can do the monthly check. NFPA 10 does not require the inspector to hold a certification. If any item fails, pull the extinguisher from service and repair or replace it. Commercial kitchens, chemical storage areas, and other high-hazard spaces may need more frequent checks under the local fire code, so confirm with your fire marshal.
Annual Professional Maintenance
Once a year, a certified technician performs a hands-on maintenance service that goes well past the monthly scan. NFPA 10 requires the technician to have passed a certification test based on the standard’s content, administered by an organization the local fire authority accepts. Factory training for the specific brand often qualifies as well.
The annual service covers the discharge hose and nozzle, the weight and condition of the extinguishing agent, and all mechanical components. The technician removes the tamper seal by operating the pull pin, confirms the mechanism works freely, then installs a fresh listed tamper seal before returning the unit to service. That new seal is the physical proof the work actually happened.
Stored-pressure extinguishers are not opened during the annual check. They are evaluated externally and by weight. If anything during the annual service suggests an internal problem, the unit gets a full internal examination ahead of its normal six-year interval.
Six-Year Internal Examination
Every six years, stored-pressure extinguishers on the 12-year hydrostatic cycle must be emptied, opened, and examined inside. This catches corrosion, agent clumping, and valve deterioration that no external check will find. The technician discharges the contents, inspects the interior of the cylinder, replaces seals and valve components as needed, refills with fresh agent, and repressurizes the unit.
If the cylinder shows significant corrosion, dents, or other structural damage, it comes out of service. Replacement is usually cheaper than repair at that point, especially for units 15 to 20 years old or older where parts may no longer be manufactured.
Hydrostatic Testing
Hydrostatic testing checks whether the metal cylinder can still safely hold its pressurized contents. The unit goes into a specialized water jacket and is pressurized above its normal operating range. If it expands beyond acceptable limits or fails to hold pressure, it is condemned and destroyed.
The interval depends on the extinguisher type:
- Every 5 years for water-based units (stored-pressure water, water mist, loaded stream, antifreeze) and carbon dioxide extinguishers.
- Every 12 years for dry chemical extinguishers, whether stored-pressure or cartridge-operated, with mild steel, brazed brass, or aluminum shells.
After a passing test, low-pressure cylinders get a label showing the tester’s name, the date, and the test pressure. High-pressure cylinders like CO2 units get the tester’s identification number and date stamped directly into the metal at the shoulder, top, or neck. Those stamps are permanent and travel with the unit for the rest of its service life.
Recharge After Any Use
Any rechargeable extinguisher must be recharged after every use, even a partial discharge. This one gets missed constantly. Someone knocks down a small grease flare, hangs the unit back on the bracket, and assumes it is fine because it still feels heavy. It is not fine. A partially discharged extinguisher may not have the pressure or the agent to handle the next fire. NFPA 10 requires recharging any time use or an inspection shows the need.
Extinguishers That Cannot Be Kept in Service
Some extinguisher types are permanently banned under NFPA 10 regardless of condition, and they belong off the wall today, not at the next inspection. These include any inverting-type extinguisher (one that must be turned upside down to operate), soda acid and chemical foam units, carbon tetrachloride (vaporizing liquid) extinguishers, copper or brass shell units joined by soft solder or rivets (pump tanks excepted), carbon dioxide extinguishers with metal horns, stored-pressure water extinguishers made before 1971, and stored-pressure extinguishers of any type made before 1955. Dry chemical stored-pressure units made before October 1984 must be pulled at the next six-year or hydrostatic interval, whichever comes first. Any extinguisher that can no longer be serviced per the manufacturer’s maintenance manual is also considered obsolete.
Tags, Logs, and Records
Every maintenance event has to leave a paper trail on the extinguisher itself. For annual maintenance, NFPA 10 requires a tag showing at minimum the month and year of the work, the name of the person who performed it, and the name of the servicing agency. Monthly visual inspections are typically recorded on the back of the maintenance tag or in a separate log, paper or digital.
Hydrostatic tests and six-year internal examinations each generate their own permanent labels or stamped markings on the cylinder. Those are the first things a fire marshal looks at during a walkthrough.
OSHA requires the employer to record the date of each annual maintenance and keep that record for one year after the last entry or the life of the shell, whichever is less. It must be available for inspection on request. During a fire marshal visit or an OSHA audit, the burden of proof sits with the property owner. If you cannot produce the documentation, the work might as well not have happened.
Employee Training
Providing extinguishers is not the end of the obligation. OSHA requires employers to give every employee general fire extinguisher education at hiring and at least once a year after that, covering how extinguishers work and the dangers of fighting a fire that has moved past the early, incipient stage.
Employees designated to actually operate extinguishers under the emergency action plan need hands-on training with the equipment they are expected to use, again at initial assignment and annually. Neither 29 CFR 1910.157 nor 29 CFR 1910.39 explicitly requires written documentation of completed training, but sign-in sheets or training logs are the only practical way to prove compliance. An OSHA inspector asking for training records will not accept “we definitely did it” as an answer.
What Falling Behind Costs
OSHA adjusts its maximum penalty amounts each year for inflation. Effective January 15, 2025, the ceilings are:
- Up to $16,550 per violation for serious and other-than-serious violations.
- Up to $16,550 per day beyond the abatement deadline for failure to abate.
- Up to $165,514 per violation for willful or repeated violations.
Each extinguisher that is overdue for maintenance, missing its tag, or improperly mounted can be cited separately. A facility with 20 neglected units is exposed to 20 citations, not one. First-time serious penalties usually land well under the maximum, but even a fraction of $16,550 across a handful of units becomes real money quickly. Insurance carriers also routinely deny fire-related claims when inspection records are missing or maintenance has lapsed, so the financial exposure runs well past the OSHA fine itself.