14.1 Fire Protection and Prevention (29 CFR 1926 Subpart F)
Key Takeaways
- 29 CFR 1926.150(c)(1)(i) requires a fire extinguisher rated not less than 2A for each 3,000 square feet of protected building area, with travel distance from any point to the nearest extinguisher not exceeding 100 feet.
- A fire extinguisher rated not less than 10B must be provided within 50 feet of any location where more than 5 gallons of flammable or combustible liquid or 5 pounds of flammable gas are in use.
- No more than 25 gallons of flammable liquids may be stored in a room outside of an approved storage cabinet (29 CFR 1926.152(b)(3)).
- Under 29 CFR 1926.24, the employer is responsible for developing and maintaining an effective fire protection and prevention program throughout all phases of construction, repair, alteration, or demolition.
- Extinguisher classes map to fuel type: A for ordinary combustibles, B for flammable liquids and gases, C for energized electrical equipment, and D for combustible metals.
14.1 Fire Protection and Prevention (29 CFR 1926 Subpart F)
Fire Protection and Prevention is one of the fifteen Elective topics in the OSHA 30-Hour Construction Outreach curriculum, governed by 29 CFR 1926 Subpart F (1926.150 – 1926.155) plus the general duty at 1926.24.
A construction fire is a different problem from a building fire. The structure has no compartmentation yet, no sprinklers, no functioning alarm, no fire-rated assemblies, and it is full of temporary combustibles: form lumber, foam insulation, tarps, packaging, solvents, propane, and gasoline. The egress paths are unfinished stairs. Firefighters arriving at a mid-rise under construction face a fuel-loaded structure with unknown stability.
1. The Program Duty — 29 CFR 1926.24
"The employer shall be responsible for the development and maintenance of an effective fire protection and prevention program at the job site throughout all phases of the construction, repair, alteration, or demolition work."
"Throughout all phases" is the operative language. Fire risk is not constant: it peaks during framing and rough-in when combustible loading is highest and detection is lowest, then again during finishes when solvents and adhesives arrive.
1926.150(a) adds the operating requirements: firefighting equipment must be provided, must be conspicuously located, must be periodically inspected and maintained in operating condition, and access to all available firefighting equipment shall be maintained at all times. Equipment that is defective or has been used must be immediately replaced or restored to operable condition.
2. Portable Fire Extinguishers — The Testable Math
29 CFR 1926.150(c)(1) contains four numbers that appear on almost every OSHA 30 final exam.
| Requirement | Value | Citation |
|---|---|---|
| Extinguisher rating and coverage | One 2A-rated extinguisher per 3,000 sq ft of protected building area, or major fraction thereof | 1926.150(c)(1)(i) |
| Maximum travel distance | 100 feet from any point in the protected area to the nearest extinguisher | 1926.150(c)(1)(i) |
| Each floor | One or more 2A extinguishers on each floor; in multistory buildings, at least one adjacent to the stairway | 1926.150(c)(1)(iv) |
| Flammable liquid / gas operations | One 10B-rated extinguisher within 50 feet wherever more than 5 gallons of flammable or combustible liquid or 5 pounds of flammable gas are being used. Does not apply to integral fuel tanks of motor vehicles | 1926.150(c)(1)(vi) |
Permitted substitutions for a 2A extinguisher:
- One 55-gallon open drum of water with two fire pails (1926.150(c)(1)(ii))
- A ½-inch garden-type hose line, not over 100 feet long, with a nozzle, capable of discharging at least 5 gallons per minute with a minimum horizontal stream range of 30 feet (1926.150(c)(1)(iii))
Working the coverage problem
A 12,000 sq ft floor plate requires $12{,}000 \div 3{,}000 = \mathbf{4}$ extinguishers rated at least 2A on that floor — and they must be placed so no point on the floor is more than 100 feet of travel from one. Four extinguishers clustered at the stair core satisfy the count and fail the travel distance. Both conditions must be met.
[!CAUTION] Exam Trap: "major fraction thereof" means you round up. A 7,000 sq ft area needs 3 extinguishers ($7{,}000 \div 3{,}000 = 2.33$), not 2.
3. Extinguisher Classes and Use
| Class | Fuel | Typical Construction Source |
|---|---|---|
| A | Ordinary combustibles — wood, paper, cloth, most plastics | Form lumber, packaging, insulation, tarps |
| B | Flammable liquids and gases | Gasoline, diesel, solvents, adhesives, propane |
| C | Energized electrical equipment | Temporary power, generators, panels |
| D | Combustible metals — magnesium, titanium, sodium, lithium | Metal fabrication; requires a special dry-powder agent, never water |
| K | Cooking oils and fats | Site kitchens and canteens; rare on construction proper |
A multipurpose ABC dry chemical extinguisher is the construction default. Note that the C rating means the agent is non-conductive, not that the extinguisher deals with electricity specially — the first action on an electrical fire is still de-energize (Chapter 3).
Operating a portable extinguisher — PASS:
P ─ PULL the pin (breaking the tamper seal)
A ─ AIM low, at the BASE of the fire, not the flames
S ─ SQUEEZE the handle to discharge
S ─ SWEEP side to side across the base of the fire
Stand 8 to 10 feet back, keep an unobstructed exit at your back, and never fight a fire that is larger than you are, that is spreading, or that has cut off your egress. A typical 10-pound ABC unit discharges in roughly 10 to 25 seconds.
Inspection: portable extinguishers must be inspected periodically and maintained in accordance with the incorporated NFPA maintenance standard (1926.150(c)(1)(viii)); or, alternatively under (c)(1)(ix), they may be inspected monthly.
4. Flammable and Combustible Liquids — 29 CFR 1926.152
OSHA aligned this section with the GHS hazard categories in the 2012 HazCom update. Category 1, 2, and 3 flammable liquids correspond to what the older standards called Class I and II; Category 4 corresponds to Class III.
| Rule | Quantity | Citation |
|---|---|---|
| Only approved containers and portable tanks may be used for storage and handling | — | 1926.152(a)(1) |
| Flammable liquids must be kept in closed containers when not actually in use | — | 1926.152(a)(2) |
| Quantity kept in the vicinity of the work operation limited to that required to do the job | — | 1926.152(b)(2) |
| Maximum stored in a room outside of an approved storage cabinet | 25 gallons | 1926.152(b)(3) |
| Maximum Category 1, 2, or 3 liquids in any one storage cabinet | 60 gallons | 1926.152(b)(4)(i) |
| Maximum Category 4 liquids in any one storage cabinet | 120 gallons | 1926.152(b)(4)(i) |
| Maximum cabinets in a single storage area | 3 | 1926.152(b)(4)(i) |
Safety cans and dispensing
An approved safety can has a spring-closing lid, a spout cover, and a flame arrester screen, and is designed to relieve internal pressure when exposed to fire. Ordinary buckets, milk jugs, and unlabeled containers are violations on sight.
Bonding and grounding is required when transferring flammable liquids between metal containers. The transfer of liquid generates a static charge; bonding equalizes potential between the two containers and grounding drains charge to earth. A static spark at the fill point is a classic ignition source. 1926.152(g)(11) also requires that engines be shut off during refueling, except for diesel-powered equipment where the manufacturer permits otherwise.
5. Ignition Sources — 29 CFR 1926.151
| Provision | Requirement |
|---|---|
| 1926.151(a)(1) | Electrical wiring and equipment for light, heat, or power must be installed in compliance with Subpart K |
| 1926.151(a)(2) | Internal combustion engine powered equipment must be located so exhausts are well away from combustible materials; where exhausts are piped outside the building, a clearance of at least 6 inches must be maintained between piping and combustible material |
| 1926.151(a)(3) | Smoking must be prohibited at or in the vicinity of operations that constitute a fire hazard, and conspicuously posted: "No Smoking or Open Flame" |
| 1926.151(a)(4) | Portable battery-powered lighting used with flammable gases or liquids must be approved for the hazardous location |
| 1926.151(a)(5) | Nozzles of air, inert gas, and steam lines used to clean or ventilate tanks containing hazardous concentrations of flammable gases or vapors must be bonded to the tank or vessel shell |
| 1926.151(b) | Combustible materials must be piled with due regard to stability and orderly storage; driveways between and around combustible storage piles must be at least 15 feet wide and maintained free of accumulated material |
| 1926.151(c) | Portable fire extinguishing equipment suitable for the fire hazard must be provided at convenient, conspicuously accessible locations in the yard area |
Temporary heating devices — 1926.154
Temporary heaters are a leading cause of construction fires and of carbon monoxide poisoning during winter work.
- Ventilation (1926.154(a)): fresh air must be supplied in sufficient quantities to maintain the health and safety of workers. Where natural means of fresh air supply are inadequate, mechanical ventilation is required.
- Clearance (1926.154(b)): heaters must be installed with the clearances to combustible material required by the standard's table, and must be set horizontal and level unless designed otherwise.
- Stability (1926.154(c)): heaters used near tarpaulins, canvas, or similar coverings must be located at least 10 feet from the covering, and the covering must be securely fastened to prevent it from igniting or upsetting the heater.
- Solid fuel salamanders are prohibited in buildings and on scaffolds (1926.154(d)).
- Liquefied petroleum gas heaters: governed by 1926.153, including container placement, valve protection, and quantity limits.
[!CAUTION] The carbon monoxide trap. An unvented propane or kerosene heater in a partially enclosed structure produces CO continuously. The OSHA construction PEL is 50 ppm as an 8-hour TWA (Section 5.5), and a salamander in a poly-wrapped floor can pass that within an hour. Ventilation and CO monitoring are not optional cold-weather extras.
6. Fixed Systems and Water Supply
Water supply (1926.150(b)): a temporary or permanent water supply of sufficient volume, duration, and pressure to operate the firefighting equipment must be made available as soon as combustible materials accumulate. Where underground water mains are to be provided, they must be installed, completed, and made available as soon as practicable.
Standpipes (1926.150(d)): in all structures where standpipes are required — or where they exist in structures being altered — they must be brought up as soon as applicable laws permit and maintained as construction progresses so that they are always ready for fire protection use. Standpipes must be provided with Siamese fire department connections on the outside of the structure at street level, conspicuously marked, with valve caps in place.
Fire cutoffs (1926.151(d)): fire walls and exit stairways required for the completed building must be given construction priority, and fire doors with automatic closing devices must be hung on openings as soon as practicable.
Alarms (1926.159): where an employee alarm system is required, it must provide warning for necessary emergency action and must be capable of being perceived above ambient noise or light levels by all employees in the affected portions of the workplace.
A 15,000-square-foot floor plate in a mid-rise under construction is being protected with portable fire extinguishers. How many 2A-rated extinguishers does 29 CFR 1926.150(c)(1)(i) require on that floor, and what additional condition governs their placement?
A painting subcontractor sets up a finishing room in a shell building and wants to keep solvent-based coatings on hand. Under 29 CFR 1926.152, what quantity limits apply?
A crew is using an unvented propane salamander to keep a poly-enclosed floor above freezing for a concrete pour. Which combination of Subpart F requirements applies?