Flammable Liquids

Flammable Liquids is OSHA's general industry standard, 29 CFR 1910.106, covering how flammable liquids are stored, handled and used. It sets limits on container sizes and quantities, rules for storage cabinets, storage rooms and tanks, and controls on ignition sources, to prevent the fires and explosions these liquids can cause.

Gasoline, acetone, many solvents, paint thinners, alcohols and some cleaning products are flammable liquids. Any facility that keeps them, from a maintenance shop with a few safety cans to a plant with bulk tanks, has obligations under this standard.

What Is OSHA 1910.106?

29 CFR 1910.106 sits in Subpart H, Hazardous Materials. It is organized by type of operation:

• (a) Definitions. Including the flammable liquid categories.
• (b) Tank storage. Design, spacing, venting, diking and installation of aboveground and underground tanks.
• (d) Container and portable tank storage. Containers up to 60 gallons and portable tanks up to 660 gallons, including cabinets and inside storage rooms.
• (e) Industrial plants. Where flammable liquid use is incidental to the main business.
• (f) to (i). Bulk plants, service stations, processing plants and refineries, chemical plants and distilleries.

Flammable liquid categories

Since OSHA aligned the standard with the Globally Harmonized System in its 2012 Hazard Communication update, 1910.106(a)(19) defines a flammable liquid as any liquid with a flashpoint at or below 199.4°F (93°C), divided into four categories:

• Category 1: flashpoint below 73.4°F (23°C) and boiling point at or below 95°F (35°C).
• Category 2: flashpoint below 73.4°F (23°C) and boiling point above 95°F (35°C).
• Category 3: flashpoint at or above 73.4°F (23°C) and at or below 140°F (60°C).
• Category 4: flashpoint above 140°F (60°C) and at or below 199.4°F (93°C).

The older terms Class IA, IB, IC, II and IIIA no longer appear in OSHA's definitions, though fire codes still use them. Check the classification in Section 2 and the flashpoint in Section 9 of the liquid's safety data sheet. Many rules treat Category 3 liquids with a flashpoint below 100°F more strictly, so record the actual flashpoint as well as the category.

Who Must Comply?

1910.106 applies to general industry employers that store, handle or use flammable liquids. Which paragraphs apply depends on the operation. A manufacturer that uses solvents in production falls mainly under (d) and (e). A fuel distributor falls under (f), and a facility dispensing fuel into vehicles falls under (g).

The container storage rules in (d) do not apply to storage in bulk plants, service stations, refineries, chemical plants and distilleries, which have their own paragraphs, or to beverages in individual containers of 1 gallon or less. Construction sites follow a parallel standard at 29 CFR 1926.152. Local fire codes, often based on NFPA 30 or the International Fire Code, apply alongside OSHA and are frequently stricter, so check with your fire marshal. State-plan states may also have their own rules.

Key Requirements

Approved containers and size limits

Under 1910.106(d)(2), only approved containers and portable tanks may be used, and Table H-12 limits container size by category. For example:

• Category 1: glass or plastic 1 pint, metal 1 gallon, safety can 2 gallons.
• Category 2: glass or plastic 1 quart, metal 5 gallons, safety can 5 gallons.
• Categories 3 and 4: glass or plastic 1 gallon, metal 5 gallons, safety can 5 gallons.
• All categories: metal drums meeting DOT specifications up to 60 gallons, approved portable tanks up to 660 gallons.

Flammable storage cabinets

1910.106(d)(3) limits each storage cabinet to 60 gallons of Category 1, 2 or 3 liquids, or 120 gallons of Category 4 liquids. Cabinets must be designed so that the internal temperature does not exceed 325°F during a 10-minute fire test, and they must be labeled with conspicuous lettering, "Flammable - Keep Fire Away."

Inside storage rooms

Inside storage rooms under 1910.106(d)(4) must meet fire resistance, spill containment and ventilation requirements. Table H-13 limits quantities by room size and protection, for example up to 10 gallons per square foot in a room with a 2-hour rating and fire protection. Rooms need ventilation capable of at least six complete air changes per hour, at least one clear aisle 3 feet wide, and containers over 30 gallons may not be stacked.

Quantities outside cabinets and rooms

In industrial plants, 1910.106(e)(2)(ii)(b) limits how much may be kept outside an inside storage room or cabinet in any one fire area of a building: 25 gallons of Category 1 liquids in containers, 120 gallons of Category 2, 3 or 4 liquids in containers, and 660 gallons of Category 2, 3 or 4 liquids in a single portable tank. Flammable liquids may never block exits, stairways or normal egress routes.

Handling and dispensing

At the point of use, Category 1 and 2 liquids, and Category 3 liquids with a flashpoint below 100°F, must be kept in covered containers when not in use. Inside a building, transfers must be made through a closed piping system, from safety cans, with a device that draws through the top of the container or by gravity through an approved self-closing valve. Transferring by applying air pressure to the container is prohibited.

Bonding, grounding and ignition sources

Static electricity can ignite vapors during transfer. Under 1910.106(e)(6)(ii), Category 1 and 2 liquids, and Category 3 liquids below 100°F, may not be dispensed into containers unless the nozzle and container are electrically interconnected. The standard also requires precautions against open flames, smoking, cutting and welding, hot surfaces, friction and static or electrical sparks. Electrical equipment in areas where flammable vapors may be present must meet the hazardous location requirements of Subpart S; see Electrical Safety in General Industry. Welding near flammable liquids also falls under the hot work rules.

Fire Protection and Housekeeping

• Extinguishers at storage rooms. At least one portable fire extinguisher rated at least 12-B must be located outside of, and not more than 10 feet from, the door of an inside storage room.
• Extinguishers at other storage areas. Where Category 1, 2 or 3 liquids are stored inside a building but outside a storage room, a 12-B extinguisher must be located at least 10 feet, but not more than 25 feet, from the storage area.
• No smoking or open flames in flammable liquid storage areas.
• Housekeeping. Clean up leaks and spills promptly, keep aisles clear for fire equipment, store combustible waste in covered metal containers and dispose of it daily.
• Maintenance. Fire protection equipment must be maintained, inspected and tested.

Common Violations and Penalties

• Too much product on the floor. Drums and cans stored outside cabinets beyond the fire area limits.
• Overfilled or crowded cabinets. More than 60 gallons of Category 1 to 3 liquids in one cabinet.
• Unapproved containers. Gasoline or solvent in open buckets, food containers or unlabeled bottles.
• No bonding or grounding. Dispensing solvent from a drum into a metal can without a bond wire.
• Ignition sources nearby. Grinding, welding or ordinary electrical equipment near open containers or dispensing areas.
• Missing or misplaced extinguishers. No 12-B unit at the required distance from the storage area.

OSHA's maximum civil penalties for penalties assessed after January 15, 2026 are $16,550 per serious violation and $165,514 per willful or repeated violation. Check OSHA's penalties page for current figures.

How to Comply: Step by Step

1. Inventory flammable liquids. List each product, its category and flashpoint from the safety data sheet, quantities and storage locations.
2. Map fire areas. Total the quantity outside cabinets and storage rooms in each fire area and compare it with the limits.
3. Use approved containers. Replace oversized or unapproved containers with safety cans, approved drums or listed containers.
4. Right-size storage. Add cabinets or an inside storage room where quantities exceed the limits, and keep each cabinet within its capacity.
5. Control transfers. Use approved pumps or self-closing faucets, and bond and ground containers during dispensing.
6. Control ignition sources. Post no-smoking signs, check that electrical equipment is rated for the location and issue hot work permits.
7. Place extinguishers. Install 12-B rated extinguishers at the required distances and include them in routine inspections.
8. Inspect regularly. Walk storage and use areas on a schedule and track findings to closure.

How SMS360 Helps

SMS360's Compliance Management module helps teams turn flammable liquid requirements into scheduled inspections and tracked tasks. Safety managers can set recurring checks for cabinets, storage rooms, dispensing stations and extinguishers, assign them by site, capture results on digital checklists and follow up on findings with corrective actions. Dashboards show overdue items across locations.

Frequently Asked Questions

How many gallons can be stored in a flammable cabinet?

Under 1910.106(d)(3), a single storage cabinet may hold no more than 60 gallons of Category 1, 2 or 3 flammable liquids, or 120 gallons of Category 4 liquids. Local fire codes may add limits on the number of cabinets in a fire area, so check those as well.

How much flammable liquid can be stored outside a cabinet?

In industrial plants, OSHA allows up to 25 gallons of Category 1 liquids in containers, and up to 120 gallons of Category 2, 3 or 4 liquids in containers, per fire area outside a cabinet or storage room. A single portable tank of up to 660 gallons of Category 2, 3 or 4 liquids is also allowed.

What is the difference between a flammable and a combustible liquid?

OSHA no longer uses the term combustible liquid in 1910.106. Since 2012, any liquid with a flashpoint at or below 199.4°F is a flammable liquid in Category 1 to 4. Fire codes such as NFPA 30 still use the older flammable and combustible classes, so you may see both systems.

When is bonding and grounding required?

OSHA requires the nozzle and receiving container to be electrically interconnected when dispensing Category 1 or 2 liquids, or Category 3 liquids with a flashpoint below 100°F. Bonding and grounding prevent static sparks from igniting vapors during transfer.