OSHA fuel can colors are not fully governed by federal regulation. The only color OSHA actually requires is red, which 29 CFR 1910.144 assigns to containers holding gasoline and other highly flammable liquids, with yellow lettering identifying the contents. The familiar yellow-for-diesel, blue-for-kerosene, and green-for-oil conventions come from industry practice and NFPA 30, not from OSHA itself.
That distinction matters. Employers often assume the whole color scheme is federally mandated, when OSHA’s rules focus on container approval, labeling, safe storage, and training rather than assigning a color to every fuel.
The One Color OSHA Requires
Under 29 CFR 1910.144, red identifies containers of flammable liquids like gasoline, and those red containers must carry yellow lettering or stenciling naming the contents. That is the extent of OSHA’s color mandate. The flammable liquids standard (29 CFR 1910.106) and the Hazard Communication standard (29 CFR 1910.1200) do not assign colors to diesel, kerosene, or any other fuel. They require only that each container be identified clearly enough for workers to know what is inside and what hazards it presents.
OSHA gives employers flexibility on how they meet that identification requirement. Color coding, written labels, signs, or a combination can all satisfy the rule, so long as the system works and employees understand it. A workplace could use purple cans for diesel and still comply with OSHA, provided the containers are properly labeled and every employee knows what purple means. Straying from recognized conventions, though, invites the exact mistakes color coding exists to prevent.
The Industry Color Convention
The widely adopted color scheme for fuel cans runs as follows:
- Red: gasoline and other highly flammable liquids (the only color OSHA specifically requires)
- Yellow: diesel fuel
- Blue: kerosene
- Green: oils and combustible liquids
These associations are recognized in most U.S. workplaces and align with NFPA 30, the Flammable and Combustible Liquids Code, which is enforceable through state and local fire codes in more than 30 states, including California, Texas, Florida, New York, Illinois, and Ohio. So even though OSHA mandates only red for gasoline, your state fire code may independently require the full scheme. Meeting OSHA’s federal minimum while ignoring an adopted NFPA 30 code can still generate fire code violations.
Color alone is never enough. Perception varies under different lighting, and roughly one in twelve men has some form of color vision deficiency. Every container should carry a written label identifying its contents alongside any color coding.
Labeling Fuel Cans in the Workplace
Containers shipped from a manufacturer must carry full GHS-compliant labels. Workplace containers, meaning the cans you fill on-site from bulk storage, have more flexible rules. An employer can use the manufacturer’s label format or an alternative system that uses words, pictures, symbols, or a combination to convey the general hazard information.
A red safety can with “GASOLINE” stenciled on it, backed by an accessible Safety Data Sheet and documented employee training, satisfies the workplace labeling requirement. Color coding without any written identification does not.
For stationary bulk tanks, employers can substitute signs, placards, or written operating procedures for individual labels, as long as those materials identify the containers they apply to and stay accessible to workers on every shift.
What “Approved” Fuel Containers Are
OSHA’s flammable liquids standard repeatedly requires “approved” containers. Approval means the container has been tested and certified by a nationally recognized testing laboratory that OSHA recognizes. The two most common certifiers are Underwriters Laboratories (UL) and FM Global (FM Approvals). Look for their marks on any fuel container you buy for workplace use.
A generic plastic gas can from a hardware store is not the same thing as an approved safety can. OSHA defines a safety can as an approved container of no more than five gallons with a spring-closing lid and spout cover, designed to safely relieve internal pressure when exposed to fire. An OSHA interpretation letter also specifies that safety cans must include a flash-arresting screen in the spout, which prevents an external flame from igniting vapors inside the can.
How Much Fuel You Can Store
OSHA caps how much flammable liquid can sit outside an approved cabinet or storage room in any single fire area of a building. For Category 1 flammable liquids like gasoline, the limit is 25 gallons in containers. For Category 2, 3, or 4 liquids (including diesel and many solvents), the limit is 120 gallons in containers or 660 gallons in a single portable tank.
Approved storage cabinets can hold up to 60 gallons of Category 1, 2, or 3 liquids, or up to 120 gallons of Category 4 liquids. Each cabinet must display “Flammable—Keep Fire Away” in prominent lettering. The cabinets are not fireproof vaults. They are designed to slow heat transfer to the contents long enough for workers to evacuate.
Bonding and Grounding During Transfers
Static electricity is a real ignition risk when pouring flammable liquids between containers. Under the general industry standard, Category 1 or 2 flammable liquids, and Category 3 liquids with a flashpoint below 100°F, cannot be dispensed into a container unless the nozzle and container are electrically interconnected. In practice, that means using a bonding wire clipped between the source and receiving containers, or setting the container on a grounded metal plate during filling. Gasoline is the fuel this most often applies to, and the requirement catches many workplaces off guard because filling gas cans is such a routine task.
Training Employees on the Color System
A color-coded fuel can only prevents accidents if workers know what the color means. OSHA’s Hazard Communication standard requires employers to train every employee who works around hazardous chemicals, including fuels, at the time of initial assignment and whenever a new chemical hazard is introduced to the work area.
Training must cover how to detect the presence or release of hazardous chemicals, the physical and health hazards of the chemicals in the work area, protective measures and emergency procedures, and how to read container labels and use Safety Data Sheets. If you use a color-coding system for fuel cans, your training program has to explicitly explain what each color means. An undocumented convention that “everyone just knows” will not survive an OSHA inspection.
Penalties for Getting It Wrong
Violations involving flammable liquid storage are typically classified as serious, meaning the inspector determined the hazard could cause death or serious physical harm. The maximum penalty for a serious violation is $16,550. Willful or repeated violations carry a maximum of $165,514 per violation. Those amounts reflect the inflation adjustment effective January 15, 2025, and are updated annually each January.
Common citation triggers around fuel containers include using unapproved containers, storing more than the permitted quantity outside a cabinet, failing to label containers or cabinets, skipping bonding or grounding during transfers, and leaving containers open when not in use. An inspector doesn’t need an incident to write these up. A walkthrough where gasoline sits in an unmarked plastic jug is enough. The fixes are usually cheap compared to the fine: buy approved red safety cans, stencil the contents in yellow, add labels that match your training, and store quantities within the code.