Fire prevention requirements

You must install electrical wiring and equipment for light, heat, or power in compliance with the electrical requirements in 29 CFR Part 1926 Subpart K. See 1926.151(a)(1) and the broader 1926 Subpart K requirements.

• Ensure wiring methods, grounding, overcurrent protection, and equipment installation follow the Subpart K rules.
• Use listed/approved equipment for the intended location and assignment.
• Keep temporary wiring protected from damage and located to avoid creating ignition or trip hazards.

Internal combustion engine exhausts must be located well away from combustible materials, and if exhaust piping runs to the outside, keep at least 6 inches clearance from combustible material. See 1926.151(a)(2).

• Position engines so hot exhaust and mufflers cannot ignite nearby combustibles.
• When piping exhaust outdoors, maintain the required 6-inch clearance between the exhaust pipe and combustible materials.
• Inspect piping and clearances regularly during operations to prevent heat-ignition risks.

Smoking and open flames must be prohibited at operations that constitute a fire hazard, and employers must post conspicuous "No Smoking or Open Flame" signs where the hazard exists. See 1926.151(a)(3).

• Identify work areas (welding, fuel storage, handling flammables, etc.) that create fire hazards and enforce a no-smoking/no-open-flame rule.
• Post clear signage at entrances and near the hazardous operations.
• Combine signage with worker training and active supervision to ensure compliance.

Portable battery-powered lighting used where flammable gases or liquids are stored, handled, or used must be approved for hazardous locations. See 1926.151(a)(4).

• Use lighting listed or certificated for the specific class/division or zone of the hazardous location.
• Avoid improvised lights or ordinary portable lamps in areas where vapors or mists may be present.
• Maintain and inspect approved fixtures to ensure intact housings and seals to prevent ignition sources.

The nozzle of air, inert gas, or steam lines used to clean or ventilate tanks with flammable concentrations must be bonded to the tank or vessel shell, and bonding devices must not be attached or detached while hazardous concentrations are present. See 1926.151(a)(5).

• Use a secure bonding clamp or cable that provides a low-resistance connection to equalize charges and prevent static sparks.
• Only attach or remove bonding connections after testing confirms the atmosphere is no longer at hazardous concentrations.
• Include bonding procedures and checks in your confined space or tank-cleaning permit and training.

You must not erect a temporary building where it will adversely affect any means of exit. See 1926.151(b)(1).

• Before siting a temporary structure, check that it does not block or reduce width, path, or accessibility of existing exits and egress routes.
• Keep exit signage, lighting, and travel-distance requirements intact and unobstructed.
• If changes are necessary, update evacuation routes and notify workers of any alternate exits.

Temporary buildings located inside another building must be noncombustible or, if combustible, must have at least 1 hour of fire resistance. See 1926.151(b)(2).

• Use fire-rated materials or fire-resistant assemblies to meet the one-hour rating when placing temporary enclosures inside buildings.
• Coordinate with the host building owner to confirm fire-resistance compliance.
• Keep records of material specifications and any fire-resistance tests or listings.

Outdoor temporary buildings not used for hazardous occupancies must be at least 10 feet from another building or structure, and groups of temporary buildings not exceeding 2,000 square feet are considered a single temporary building for these rules. See 1926.151(b)(3).

• Keep the 10-foot minimum distance to reduce fire spread risks between structures.
• If multiple temporary buildings total 2,000 square feet or less, treat them as one unit when applying other provisions of the part.
• Do not locate temporary buildings used for flammable/combustible liquids, gases, explosives, or similar hazards within this exemption.

Combustible materials in open yard storage must be piled with regard for stability and may not be higher than 20 feet. See 1926.151(c)(1).

• Keep piles stable and avoid creating overhanging or leaning stacks that could collapse.
• Consider material type and pile method—solid, orderly piles are preferred per 1926.151(c)(5).
• Inspect piles periodically and after weather events or equipment activity that could affect stability.

Driveways between and around combustible storage piles must be at least 15 feet wide, kept free of rubbish or equipment, and spaced so the maximum grid unit is 50 feet by 150 feet. See 1926.151(c)(2).

• Maintain clear, unobstructed 15-foot driveways for emergency access and firefighting apparatus.
• Arrange piles so no grid exceeds 50 by 150 feet, which helps limit fire spread and improves access.
• Assign periodic inspection and housekeeping responsibilities to ensure driveways remain clear.

The entire storage site must be kept free of unnecessary combustible materials, weeds, and grass, and a regular cleanup procedure must be in place. See 1926.151(c)(3).

• Implement routine removal of rubbish, loose wood, and other flammable debris.
• Keep vegetation controlled to reduce ignition sources and fire spread.
• Document and schedule periodic cleanup activities to maintain compliance.

No; land where there is danger of an underground fire must not be used for combustible or flammable storage. See 1926.151(c)(4).

• Before placing storage, evaluate the ground for previous mining, subsidence, hot spots, or smoldering conditions.
• If underground fire risk exists, choose an alternative site and document the hazard evaluation.
• Consult local fire authorities or geotechnical experts when in doubt.

Combustible materials must be piled solidly and orderly where possible and not stored outdoors within 10 feet of a building or structure. See 1926.151(c)(5).

• Keep piles arranged to minimize internal fire spread and facilitate firefighting access.
• Maintain the 10-foot clearance from buildings to reduce exposure of structures to outdoor fires.
• Use access lanes and spacing that allow personnel and equipment to fight fires effectively.

You must provide portable fire extinguishing equipment suitable for the hazard at convenient, conspicuously accessible locations; extinguishers must be at least 2A-rated and placed so no one travels more than 100 feet to reach one. See 1926.151(c)(6).

• Select extinguisher types appropriate to stored materials (Class A for ordinary combustibles, Class B for flammable liquids, etc.).
• Mount and label extinguishers where they are visible and reachable.
• Inspect and maintain extinguishers per manufacturer guidance and OSHA/ NFPA inspection intervals.

Indoor storage must not obstruct or adversely affect means of exit, and all materials must be stored, handled, and piled with regard to their fire characteristics. See 1926.151(d)(1) and 1926.151(d)(2).

• Keep aisles, exits, and egress lighting unobstructed and clearly marked.
• Separate materials based on combustibility, flammability, and ignition risk.
• Use suitable shelving and piling methods to prevent collapse and limit fire development.

Noncompatible materials that may create a fire hazard must be segregated by a barrier with at least 1 hour of fire resistance. See 1926.151(d)(3).

• Identify chemical incompatibilities (oxidizers vs. combustibles, acids vs. bases, etc.) and store them separately behind rated barriers.
• Use fire-resistant walls, partitions, or rated storage cabinets to achieve the one-hour separation when required.
• Keep documentation of segregation plans and train employees on handling incompatible materials.

Materials must be piled to minimize internal fire spread and permit convenient firefighting access, piles must be stable, and aisle space must accommodate the widest vehicle used for firefighting. See 1926.151(d)(4).

• Arrange piles so fire cannot easily travel internally and so firefighters can approach all sides.
• Verify aisles are wide enough for sprinkler maintenance and the largest firefighting vehicle expected in the facility.
• Keep piles stable through proper stacking practices and regular inspections.

You must maintain at least 36 inches of clearance between the top level of stored material and the sprinkler deflectors. See 1926.151(d)(5).

• Measure from the top of the stored material to the bottom of the sprinkler deflector to verify the 36-inch clearance.
• Reconfigure storage, lower pile heights, or adjust sprinkler system design if necessary to maintain clearance.
• Coordinate with your fire protection engineer when storage configurations change to ensure sprinkler effectiveness.

A clearance must be maintained around lights and heating units to prevent ignition of combustible materials. See 1926.151(d)(6).

• Keep combustible storage and materials away from light fixtures and heaters per manufacturer and local code clearances.
• Regularly inspect fixtures and heaters for heat buildup, exposed wiring, or dust accumulation that could increase ignition risk.
• Use guards, shields, or relocation of storage to maintain required clearances.

You must maintain a clearance of 24 inches around the path of travel of fire doors unless a barricade is provided; material must not be stored within 36 inches of a fire door opening. See 1926.151(d)(7).

• Keep the 24-inch path of travel clear for fire doors to operate unobstructed unless a barricade is installed and maintained.
• Do not store materials within 36 inches of the fire door opening to ensure egress and fire door performance.
• If a barricade is used, ensure it is compliant and does not impede the fire protection function.