1926.602(a)(9): Horns and Backup Alarms on Earthmoving Equipment
Bidirectional machines such as rollers, compactors, front-end loaders and bulldozers must have a working horn that can be heard over surrounding noise, used as needed when moving in either direction. Earthmoving or compacting equipment with an obstructed rear view may not be used in reverse unless it has a working reverse signal alarm that can be heard over the noise or an employee signals that it is safe.
Key takeaways
- 1926.602(a)(9) is part of OSHA's construction standards (29 CFR Part 1926, Subpart O).
- OSHA cited it 56 times in the last 3 years, in 55 inspections, with $78,739 in current penalties.
- Most citations: SC (18), MI (12), NY (5).
- Related part: 1926.602(a) Earthmoving equipment; General (75 citations).
- Free 5-minute toolbox talk for your crew below.
In this article
What this rule covers
29 CFR 1926.602(a)(9) ("Audible alarms") is one requirement inside 1926.602 Material handling equipment, an OSHA construction standard (Part 1926, Subpart O). It includes 2 sub-paragraphs. The official text below is copied word for word from the Electronic Code of Federal Regulations (eCFR). The numbers, injury cases and training on this page show how OSHA enforces it on real job sites.
Official text
(9) Audible alarms. 56 citations
(i) All bidirectional machines, such as rollers, compacters, front-end loaders, bulldozers, and similar equipment, shall be equipped with a horn, distinguishable from the surrounding noise level, which shall be operated as needed when the machine is moving in either direction. The horn shall be maintained in an operative condition. Open (a)(9)(i) 25 citations
(ii) No employer shall permit earthmoving or compacting equipment which has an obstructed view to the rear to be used in reverse gear unless the equipment has in operation a reverse signal alarm distinguishable from the surrounding noise level or an employee signals that it is safe to do so. Open (a)(9)(ii) 31 citations
Source: eCFR, text current as of 2026-10-15. Read all of 1926.602.
Where and how often it was cited
| Year | Citations |
|---|---|
| 2023 | 6 |
| 2024 | 16 |
| 2025 | 20 |
| 2026 | 14 |
Top states: SC (18), MI (12), NY (5), TX (5), IN (5)
Largest penalties
| Employer | Location | Penalty for this rule |
|---|---|---|
| MGC CONTRACTORS INC. | SCOTTSDALE, AZ | $11,823 |
| KMI INC | JERSEY CITY, NJ | $8,276 |
| 77244 - COOGLER CONSTRUCTION CO INC | ORANGEBURG, SC | $7,000 |
| JERRY'S INC. | MILLSBORO, DE | $6,621 |
| MASTER PAVERZ INC. | HOMESTEAD, FL | $4,965 |
Free toolbox talk
A 5-minute crew talk on 1926.602(a)(9), plus alerts when this rule changes. Free.
OSHA interpretation letters
- Permissible methods of operating trucks in reverse on construction sites. (2010-03-02)
- Whether "discriminating [back-up] alarms" may be used to meet the requirements of 29 CFR 1926.602(a)(9)(ii). (2007-09-20)
- Alternatives to common back-up alarms on construction motor vehicles; use of other effective technology or observers/signal persons. (2004-09-27)
- Equipment reverse signal alarms must be audible above surrounding noise level. (2004-05-27)
- Requirements for back-up alarms on construction vehicles. (1998-11-03)
- Noise and potential hazard of backup alarms on equipment at construction sites. (1991-10-29)
- Horns and audible alarms. (1987-08-20)
- "Obstructed view to the rear" relative to use of back-up alarms. (1987-01-21)
- Use of an electronic back-up mirror used with a with a reverse audible alarm. (1984-12-18)
- Requirements for back up alarms. (1982-06-25)
Related parts of this rule
- 1926.602(a) Earthmoving equipment; General 75 citations
- 1926.602(a)(9)(ii) 31 citations
- 1926.602(a)(9)(i) 25 citations
- 1926.602(a)(3)(i) 10 citations
- 1926.602(a)(3) Access roadways and grades 10 citations
- 1926.602(a)(2)(i) 5 citations
- 1926.602(a)(2) Seat belts 5 citations
- 1926.602(a)(4) Brakes 3 citations
- 1926.602(a)(1) 1 citations
- 1926.602(a)(6) Rollover protective structures (ROPS)
- 1926.602(a)(2)(ii)
Get your crew competent
Trainers on Black Belt Safety: Marc Harvey, Dana Reyes
Trainers and suppliers: feature your business on this rule for $25/month.
Frequently asked questions
Do bulldozers and loaders need a horn?
Yes. Bidirectional machines must have a horn distinguishable from the surrounding noise, kept operative.
When is a backup alarm required?
When earthmoving or compacting equipment with an obstructed rear view is used in reverse, unless an employee signals that it is safe.
Can a spotter replace a backup alarm?
Yes, the rule allows an employee to signal that it is safe to back up.
About this page
Sources
- 29 CFR 1926.602 (eCFR), text current as of 2026-10-15
- U.S. Department of Labor enforcement data: OSHA inspections, citations and accident records, copied nightly; data as of 2026-10-19
3-year window. Federal OSHA only; state-plan rules are not counted. Plain-language text is a summary, not legal advice; the official text controls. Black Belt Safety is not part of OSHA or the Department of Labor.