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Toolbox talk · 10 min · Fire & Hot Work

Flammable Liquids Storage

Hazards: Flash fire and burns from vapor reaching an ignition source · Fuel spilled onto a hot engine, muffler or manifold · Static discharge while transferring liquid between containers · Fire blocking an exit because product was stored in a stairway or passageway

Why it matters

Liquid does not burn — vapor does, and vapor travels. The U.S. Fire Administration put the 2023 loss from unintentional, careless nonresidential building fires at $881.2 million, up 51% over ten years. On January 2, 2019, a carpenter on a three-story residential job was refueling a gasoline air compressor when fuel touched the hot muffler. It lit. He was hospitalized with burns to his hands, face and chest (OSHA Summary Nr 112275.015). The compressor had been running all morning.

Key points

  • Approved cans only. Five gallons or less goes in an approved safety can or a DOT-approved container. One gallon or less may stay in its original container. Nothing else counts.
  • Let it cool before you pour. A hot muffler, manifold or exhaust lights fuel without a spark. Shut it down, wait, and fuel it outside and away from what else is running.
  • 25 gallons is the line indoors. More than that goes in an approved cabinet: 60 gallons of Category 1-3 or 120 gallons of Category 4 per cabinet, three cabinets maximum in one storage area.
  • Never in the way out. No flammable liquid in an exit, a stairway or a walkway. If the fire starts in the fuel, that route is gone.
  • Bond before you transfer. Pouring Category 1, 2 or 3 liquid between containers is done with them electrically connected. Static from the stream is enough on a dry day.
  • Lids on, spills up, 50 feet clear. Containers stay closed when not in use, leaks get cleaned up promptly, and there is no open flame or ignition source within 50 feet of the work.
  • A 20-B unit belongs with the fuel. Within 10 feet of a storage room door holding over 60 gallons; 25 to 75 feet from an outdoor storage area.

Do / Don't

Do

  • Keep only what the shift needs on the floor; the rest stays in the cabinet.
  • Post “No Smoking or Open Flame” where fuel is handled.
  • Label the cabinet: Flammable — Keep Away from Open Flames.
  • Point engine exhausts away from anything that can burn.

Don't

  • Decant fuel into a water bottle, a bucket or an unmarked jug.
  • Use air pressure to push product out of a container.
  • Stage cans next to the hot work, the generator or the temporary heater.
  • Leave oily rags loose — they go in a covered container.

Quick site check

  • Count the gallons on this floor right now. Are we over 25 outside a cabinet?
  • Is every container an approved can, closed, and labeled?
  • What is within 50 feet of the fuel that could light it — heater, grinder, torch, generator?
  • Where is the 20-B, and is anything parked in front of it?
Discussion — ask the crew
  1. Walk me to every container of gas, diesel or solvent on this job. How many gallons is that, and where is it at lunchtime?
  2. Which of those containers is an approved safety can, and which is a jug somebody brought from home?
  3. How long does the compressor sit before we top it up, and who decides it is cool enough?
  4. Where is the nearest 20-B extinguisher to the fuel, and how many steps is that?
  5. What is stored under the stairs right now, and would we still get out past it?
Refs: 29 CFR 1926.152 — Flammable liquids (construction): approved containers (a), indoor storage and cabinet limits (b), outside storage (c), fire control (d), dispensing and bonding (e), handling at point of use (f) · 29 CFR 1926.151 — Fire prevention: ignition hazards, engine exhausts away from combustibles, No Smoking or Open Flame posting, open yard storage · 29 CFR 1926.150 — Fire protection: the 10B extinguisher within 50 ft of more than 5 gal of flammable or combustible liquid at (c)(1)(vi) · U.S. Fire Administration — Nonresidential building fire dollar loss, 2023 national estimates ($881.2 million from other unintentional, careless fires) · OSHA Accident Search, Summary Nr 112275.015 (January 2, 2019) - a carpenter refueling a gasoline air compressor is burned on the hands, face and chest when fuel contacts the hot mufflerSign-in sheet included in the printed version

Frequently asked questions

No more than 25 gallons outside an approved storage cabinet - 29 CFR 1926.152(b)(1). Above that it goes in an acceptable or approved cabinet, and quantities beyond what the cabinets hold go to an inside storage room built to 1926.152(b)(4) or outside under (c).

Not more than 60 gallons of Category 1, 2 or 3 flammable liquids, or 120 gallons of Category 4 - 1926.152(b)(3). Not more than three such cabinets may be located in a single storage area, and every cabinet is labeled in conspicuous lettering: Flammable - Keep Away from Open Flames.

For 5 gallons or less, an approved safety can or a Department of Transportation approved container - 1926.152(a)(1). For one gallon or less the original container may be used. Highly viscid materials that are extremely hard to pour may stay in their original shipping containers. A water jug or a milk carton is none of those things.

Transfer of Category 1, 2 or 3 flammable liquids from one container to another is done only when the containers are electrically interconnected - bonded - under 1926.152(e)(2). Transferring more than 5 gallons at a time also has to be separated from other operations by 25 feet or by one-hour fire-resistant construction, with ventilation holding vapor at or below 10 percent of the lower flammable limit.

At least one 20-B unit outside the door of, and no more than 10 feet from, any room storing more than 60 gallons - 1926.152(d)(1). For an outside storage area, a 20-B unit no less than 25 and no more than 75 feet away - (d)(2). And a unit rated at least 10B within 50 feet of anywhere more than 5 gallons of flammable or combustible liquid, or 5 pounds of flammable gas, is in use - 1926.150(c)(1)(vi).

No. 1926.152(a)(2) says flammable liquids shall not be stored in areas used for exits, stairways, or normally used for the safe passage of people. Indoor storage must not obstruct or adversely affect a means of exit either - 1926.151(d)(1).

Sources & references

Content checked against these sources — last reviewed August 28, 2026.

Results are estimates for planning purposes and do not replace a competent person's evaluation or an engineer's design. Follow the OSHA standards that apply to your work and your employer's written program.

By — Editorial team of SteelToeTools.com (published by LSEA SAS) Updated