How Often Does OSHA Require a Fire Alarm Test?

The horn in the fabrication shop was last tested in June. It's now October, and the shop superintendent isn't sure whether that's a problem or a paperwork detail. Under OSHA's general industry rule it's a problem: a non-supervised employee alarm is tested every two months. And the question that follows, "does that rule apply to our jobsites too?", has a less obvious answer.

OSHA requires a non-supervised employee alarm system to be tested every two months and a supervised system at least once a year, under 29 CFR 1910.165(d)(2) and (d)(4). Each test of a multi-device system uses a different actuation device. In construction, 1926.35(c) requires an alarm with distinctive signals but Part 1926 sets no test interval.

At a glance: Non-supervised: test every 2 months, rotating the actuation device (1910.165(d)(2)). Supervised: test at least annually (1910.165(d)(4)). Restore to normal after each test, keep spares (1910.165(c)(2)). Back-up means while out of service (d)(3). Testing by trained persons (d)(5). Construction: alarm with a distinctive signal for each purpose (1926.35(c)), alarm code and reporting instructions posted (1926.150(e)), no federal test interval.

What 1910.165 says about testing

The testing rules sit in 29 CFR 1910.165(d), "Maintenance and testing":

Two neighboring paragraphs matter on test day. Under 1910.165(c)(2), the system is restored to normal operating condition as promptly as possible after each test or alarm, and spare devices and components subject to wear are kept on hand. Under 1910.165(e), manual actuation devices, the pull stations and buttons, are unobstructed, conspicuous and readily accessible.

Which test interval applies to your alarm?

A supervised system watches itself. 1910.165(d)(4) describes it as circuitry that provides positive notification to assigned personnel whenever a deficiency exists in the system: a cut wire, a dead battery, a failed horn. Because it reports its own faults, it gets the annual test.

A non-supervised system can fail silently. An air horn on a post, a bell on a manual switch, a strobe on a battery: none of them tells anyone when it stops working. That's why they get tested every two months, and why the rule asks you to rotate the actuation device. A building with six pull stations that always tests the one by the office has proved one pull station works.

If you're not sure which you have, ask whoever installed or services the system. Under 1910.165(d)(4), circuitry installed after January 1, 1981 that can be supervised has to be.

Which alarms the rule covers

29 CFR 1910.165(a)(1) applies to emergency employee alarms installed to meet a particular OSHA standard, such as the alarm an emergency action plan requires under 1910.38(d). Paragraph (a)(2) widens the testing part: the maintenance, testing and inspection requirements apply to all local fire alarm signaling systems used for alerting employees, whatever else the system does.

The alarm also has to work as an alarm. Under 1910.165(b)(2) it's perceived above ambient noise or light levels by all employees in the affected area, with tactile devices for employees who can't recognize the audible or visual signal. Under (b)(3) it's distinctive and recognizable as a signal to evacuate or to take the actions the plan assigns. And under (b)(5), a workplace with 10 or fewer employees may sound the alarm by direct voice, as long as everyone can hear it.

Your local fire code sets its own testing schedule for building fire alarm systems, often based on NFPA 72. That's a separate requirement from OSHA's, enforced by the fire marshal. Meeting one doesn't excuse the other.

Construction: an alarm, but no federal interval

Construction has two alarm rules. 29 CFR 1926.35(c)(1) requires an employee alarm system when an emergency action plan is required, and 1926.35(c)(2) requires a distinctive signal for each purpose when the system does more than one thing. Separately, on every jobsite, 29 CFR 1926.150(e)(1) requires an alarm system, such as a telephone system or a siren, that alerts employees on the site and the local fire department, and (e)(2) requires the alarm code and reporting instructions to be posted at phones and employee entrances.

Neither sets a test interval. 1926.35(c)(1) points to a § 1926.159 for the alarm system's requirements, but Subpart F as published on the eCFR runs from 1926.150 to 1926.155 and contains no § 1926.159 (checked on October 13, 2026). So Part 1926 gives no federal testing frequency for a jobsite alarm.

What contractors do in practice is borrow the general industry schedule: test the air horn or the site siren every two months, from the farthest corner of the site, and write it down. It costs five minutes, and it's the easiest way to find out that the horn can't be heard over the concrete saw on level 3.

What a test record should hold

OSHA doesn't prescribe a form. A record that answers the questions an inspector or an insurer will ask holds:

• The system and the area it covers. "Air horn, fabrication shop", "Siren, north yard".
• The date, and the date the next test is due.
• The actuation device used, so the rotation required by 1910.165(d)(2) shows on paper.
• The result. Heard everywhere it should be, or not, and where it wasn't.
• Who tested it, trained in the system under 1910.165(d)(5).
• Restored, with the time, under 1910.165(c)(2).
• Any outage, with the back-up means used under 1910.165(d)(3) and the date it came back.

A failed test isn't a test passed late. The system stays due until it passes.

How HazComFast keeps the alarm tests

In HazComFast, alarm systems are declared in the emergency action plan: the type, the area covered, whether the system is supervised, and its signals, one per purpose. The same signal can't be entered for two purposes, which is the rule of 1910.38(d) and 1926.35(c)(2).

Recording a test takes a date, a result and a note. The next test is scheduled for you: two months after the last passed test, or twelve months for a supervised system, citing 29 CFR 1910.165(d). A failed test leaves the system due. On a construction plan the screen uses the same intervals and says plainly that they're HazComFast's, not a federal requirement in construction. An outage is recorded with its compensating measures and closed when the system is returned to service.

The plan's PDF prints each declared alarm system with its signals and the date of its last test, so the document the crews read and the register match.

Related: OSHA fire safety requirements · Which OSHA standards require an emergency action plan? · How many fire extinguishers does a jobsite need? · Emergency action plans for construction

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Sources & verification (read on the eCFR, edition of 2026-10-01): 29 CFR 1910.165(a) to (e); 1910.38(d); 1926.35(c); 1926.150(e). Structure of Part 1926 Subpart F (1926.150 to 1926.155) checked on the eCFR on 2026-10-13. General guidance, not legal advice.*