This one comes from a different direction than the rest of your tank calendar. Extinguishers are an OSHA obligation under 29 CFR 1910.157, with your local fire code and fire marshal layered on top, and it runs on four intervals rather than one. Monthly, annual, six years, twelve years.
Where the authority sits. Nothing here comes from 40 CFR 280. The federal baseline below is OSHA's. Your fire code and the authority having jurisdiction can require more, and at a fuel site they usually have opinions about placement and rating as well as service.
Monthly: your own people
1910.157(e)(2) requires portable extinguishers to be visually inspected monthly. Not by a contractor. By you.
This is the interval that goes missing, for the same reason the 30-day UST walkthrough does: nothing about it generates an invoice, so nothing about it generates a reminder. The service company's annual visit leaves a signed tag on the wall and a bill in the post. The eleven months in between leave nothing at all unless somebody writes them down.
What the visual is looking for is unglamorous. The unit is where it should be and not blocked. The pin and seal are intact. The gauge is in the green. The shell is undamaged and the hose is not cracked. The label is legible.
Annually: the tag
1910.157(e)(3) requires an annual maintenance check. This is the one the service company performs and signs.
The rule adds a clarification worth knowing before you are quoted for work: stored pressure extinguishers do not require an internal examination as part of the annual check. The internal work belongs to the six year service.
The record rule is unusual. Record the annual maintenance date and retain that record for one year after the last entry, or the life of the shell, whichever is less, available to OSHA on request. Measured from the last entry rather than from a calendar year, and capped by the life of the unit.
Six years: emptied and serviced
1910.157(e)(4) is the one operators are least likely to have on a calendar. Stored pressure dry chemical extinguishers that require a 12-year hydrostatic test must be emptied and subjected to applicable maintenance procedures every 6 years.
Two carve-outs. Dry chemical extinguishers with non-refillable disposable containers are exempt. And where the unit is recharged or hydrostatically tested in the meantime, the six year requirement begins again from that date, so a discharge and refill after an incident resets the clock.
Six years is long enough that it falls outside anybody's working memory and outside most staff tenures. It is the classic case for a date on a system rather than a date in a head.
Twelve years, or five: hydrostatic
The hydrostatic interval depends on what the unit is made of. Table L-1 in 1910.157(f)(2) sets it at 12 years for dry chemical stored pressure with mild steel, brazed brass or aluminium shells, for cartridge or cylinder operated dry chemical with mild steel shells, and for Halon 1211 and 1301. It sets 5 years for carbon dioxide, for dry chemical with stainless steel, and for the water, antifreeze, foam and AFFF types.
So a site with a mix of dry chemical units on the forecourt and CO2 units in the store is running two different clocks, and the CO2 one comes round more than twice as often.
Five conditions in 1910.157(f)(2) take a unit out of the interval entirely and require testing regardless: repair by soldering, welding, brazing or patching compound; damaged cylinder or shell threads; corrosion that has caused pitting, including under a removable nameplate; the extinguisher having been burned in a fire; or a calcium chloride agent used in a stainless steel shell. Corrosion under the nameplate is the one worth remembering, because it is the one you cannot see.
Records for hydrostatic testing work differently again. 1910.157(f)(16) requires a certification record with the date, the signature of the person who performed the test, and the serial number or other identifier of the extinguisher, kept until the unit is retested or taken out of service, whichever comes first.
The training nobody schedules
1910.157(g) is a separate obligation from the hardware and it is the one most often missing. Where extinguishers are provided for employee use, the employer has to run an educational programme covering the general principles of extinguisher use and the hazards of incipient stage fire fighting, on initial employment and at least annually after that.
Employees designated to use fire fighting equipment under an emergency action plan get training in that equipment, again on assignment and at least annually.
In a business with the staff turnover a forecourt has, initial employment training is a recurring event rather than a one-off, and it belongs in onboarding rather than on a compliance calendar. The annual refresher belongs on the calendar.
A gap on the wall is a gap in coverage
1910.157(e)(5) requires alternate equivalent protection while an extinguisher is removed from service for maintenance and recharging.
So the service visit is not a moment to stop thinking about it. An extinguisher that went away in a van and has not come back has left a hole, and at a fuel site that hole is next to a dispenser. Service companies generally leave loaners; it is worth confirming that they do before the van arrives rather than after.
Why it belongs on the same calendar
Extinguishers come from a different regulator on a different cycle to everything else at the site, which is exactly why they end up on a different piece of paper and then on no piece of paper.
The site does not care which agency asked. The person walking the forecourt on a Tuesday has one list, and a fire extinguisher tag that expired in March belongs on it next to the spill bucket that needs draining.
How FastDragon handles it
Fire extinguisher service sits on the compliance calendar alongside the tank work, with its authority recorded as the fire code rather than the UST rules, so nobody reading the record later assumes an environmental regulator asked for it.
The monthly visual is a checklist item on the same phone walk as the rest of the site, which is what stops it being the interval nobody remembers. The annual tag is a record with the service report attached, and the six year date is computed from the last service rather than from a year somebody wrote down.
Common questions
How often does an extinguisher have to be checked?
Two different intervals under OSHA 29 CFR 1910.157(e). A visual inspection monthly, which is your own staff. And an annual maintenance check, which is the tag a service company signs. The monthly one is the one that gets skipped, because nothing about it produces an invoice.
Who keeps the record, and for how long?
The employer records the annual maintenance date and retains the record for one year after the last entry or the life of the shell, whichever is less, under 1910.157(e)(3). The record has to be available to OSHA on request. That is a shorter retention than most of your UST records, and it is measured from the last entry rather than from the year.
What is the six-year service?
1910.157(e)(4) requires stored pressure dry chemical extinguishers that need a 12-year hydrostatic test to be emptied and put through applicable maintenance procedures every 6 years. Dry chemical extinguishers with non-refillable disposable containers are exempt. If the unit is recharged or hydrostatically tested in the meantime, the six year clock restarts from that date.
Does an annual check mean opening it up?
Not necessarily. 1910.157(e)(3) says stored pressure extinguishers do not require an internal examination as part of the annual maintenance check. The internal work is what the six year service is for.
What if an extinguisher goes away for service?
1910.157(e)(5) requires alternate equivalent protection while a portable extinguisher is removed from service for maintenance and recharging. A gap on the wall is a gap in coverage, and swapping in a loaner is the ordinary answer.