1926.151: Fire Prevention on Construction Sites
Employers must control ignition hazards: install wiring per subpart K, keep engine exhausts away from combustibles (at least 6 inches when piped outside), prohibit and post no smoking near fire hazards, and use approved lighting and bonded nozzles around flammables. Temporary buildings must not block exits, must be noncombustible or 1-hour fire resistant inside other buildings, and must meet spacing rules outside.
Key takeaways
- 1926.151 is part of OSHA's construction standards (29 CFR Part 1926, Subpart F).
- OSHA cited it 5 times in the last 3 years, in 5 inspections, with $20,758 in current penalties.
- Most-cited part: 1926.151(a) Ignition hazards (4 citations).
- Free 5-minute toolbox talk for your crew below.
In this article
What this rule covers
29 CFR 1926.151, "Fire prevention", is an OSHA construction standard (Part 1926, Subpart F). It has 25 numbered 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
Show the full text of 1926.151 (25 paragraphs)
(a) Ignition hazards. Open (a) 4 citations
(1) Electrical wiring and equipment for light, heat, or power purposes shall be installed in compliance with the requirements of subpart K of this part.
(2) Internal combustion engine powered equipment shall be so located that the exhausts are well away from combustible materials. When the exhausts are piped to outside the building under construction, a clearance of at least 6 inches shall be maintained between such piping and combustible material.
(3) Smoking shall be prohibited at or in the vicinity of operations which constitute a fire hazard, and shall be conspicuously posted: “No Smoking or Open Flame.” 4 citations
(4) Portable battery powered lighting equipment, used in connection with the storage, handling, or use of flammable gases or liquids, shall be of the type approved for the hazardous locations.
(5) The nozzle of air, inert gas, and steam lines or hoses, when used in the cleaning or ventilation of tanks and vessels that contain hazardous concentrations of flammable gases or vapors, shall be bonded to the tank or vessel shell. Bonding devices shall not be attached or detached in hazardous concentrations of flammable gases or vapors. Open (a)(5)
(b) Temporary buildings.
(1) No temporary building shall be erected where it will adversely affect any means of exit.
(2) Temporary buildings, when located within another building or structure, shall be of either noncombustible construction or of combustible construction having a fire resistance of not less than 1 hour.
(3) Temporary buildings, located other than inside another building and not used for the storage, handling, or use of flammable or combustible liquids, flammable gases, explosives, or blasting agents, or similar hazardous occupancies, shall be located at a distance of not less than 10 feet from another building or structure. Groups of temporary buildings, not exceeding 2,000 square feet in aggregate, shall, for the purposes of this part, be considered a single temporary building.
(c) Open yard storage. 1 citations
(1) Combustible materials shall be piled with due regard to the stability of piles and in no case higher than 20 feet.
(2) Driveways between and around combustible storage piles shall be at least 15 feet wide and maintained free from accumulation of rubbish, equipment, or other articles or materials. Driveways shall be so spaced that a maximum grid system unit of 50 feet by 150 feet is produced.
(3) The entire storage site shall be kept free from accumulation of unnecessary combustible materials. Weeds and grass shall be kept down and a regular procedure provided for the periodic cleanup of the entire area.
(4) When there is a danger of an underground fire, that land shall not be used for combustible or flammable storage.
(5) Method of piling shall be solid wherever possible and in orderly and regular piles. No combustible material shall be stored outdoors within 10 feet of a building or structure.
(6) Portable fire extinguishing equipment, suitable for the fire hazard involved, shall be provided at convenient, conspicuously accessible locations in the yard area. Portable fire extinguishers, rated not less than 2A, shall be placed so that maximum travel distance to the nearest unit shall not exceed 100 feet. 1 citations
(d) Indoor storage.
(1) Storage shall not obstruct, or adversely affect, means of exit.
(2) All materials shall be stored, handled, and piled with due regard to their fire characteristics.
(3) Noncompatible materials, which may create a fire hazard, shall be segregated by a barrier having a fire resistance of at least 1 hour.
(4) Material shall be piled to minimize the spread of fire internally and to permit convenient access for firefighting. Stable piling shall be maintained at all times. Aisle space shall be maintained to safely accommodate the widest vehicle that may be used within the building for firefighting purposes.
(5) Clearance of at least 36 inches shall be maintained between the top level of the stored material and the sprinkler deflectors.
(6) Clearance shall be maintained around lights and heating units to prevent ignition of combustible materials.
(7) A clearance of 24 inches shall be maintained around the path of travel of fire doors unless a barricade is provided, in which case no clearance is needed. Material shall not be stored within 36 inches of a fire door opening.
[44 FR 8577, Feb. 9, 1979; 44 FR 20940, Apr. 6, 1979, as amended at 51 FR 25318, July 11, 1986]
Source: eCFR, text current as of 2026-10-15.
Where and how often it was cited
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Most-cited parts of this rule
- 1926.151(a) Ignition hazards 4 citations
- 1926.151(a)(5)
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Frequently asked questions
How far must engine exhaust piping be from combustibles?
When piped outside the building, a clearance of at least 6 inches must be kept between the piping and combustible material.
What sign is required where smoking is prohibited?
"No Smoking or Open Flame," posted conspicuously.
Can a temporary building block an exit?
No. A temporary building shall not be erected where it will adversely affect any means of exit.
About this page
Sources
- 29 CFR 1926.151 (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.