Flammable Liquids Storage and Handling

Flashpoint and the four categories

Flashpoint

The flashpoint is the lowest temperature at which a liquid gives off enough vapor to form an ignitable mixture with the air near its surface.

Flammable liquid

Any liquid with a flashpoint at or below 199.4 °F (93 °C) is a flammable liquid. They are divided into four categories:

Construction uses the same four categories: 1926.152 applies to flammable liquids with a flashpoint at or below 199.4 °F (93 °C), and 1926.155(h) defines Categories 1 to 4 the same way.

Many rules in this course apply to Categories 1, 2 and 3. Check the label or Safety Data Sheet for the flashpoint and category.

Reference: 29 CFR 1910.106(a)(14) · 29 CFR 1910.106(a)(19) · 29 CFR 1910.106(a)(19)(i) · 29 CFR 1910.106(a)(19)(ii) · 29 CFR 1910.106(a)(19)(iii) · 29 CFR 1910.106(a)(19)(iv) · 29 CFR 1926.152(h) · 29 CFR 1926.155(h)

Approved containers, kept closed

On a construction site

• Only approved containers and portable tanks may be used to store and handle flammable liquids.
• For 5 gallons or less, use an approved safety can or a DOT approved container.
• Exceptions: highly viscid liquids (extremely hard to pour) may be used and handled in their original shipping containers, and for one gallon or less the original container may be used.

What a safety can is

General industry (1910.106(a)(29)): an approved container of not more than 5 gallons, with a spring-closing lid and spout cover, designed to safely relieve internal pressure when exposed to fire.

Construction (1926.155(l)): an approved closed container of not more than 5 gallons with a flash-arresting screen, spring-closing lid and spout cover, designed to safely relieve internal pressure when exposed to fire.

Keep it closed

On a construction site, keep Category 1, 2 and 3 flammable liquids in closed containers when not actually in use. In general industry, the same applies to Category 1 and 2 liquids and Category 3 liquids with a flashpoint below 100 °F: covered containers when not in use.

Not in the way out

Never store flammable liquids in exits, stairways or areas normally used for the safe passage of people (construction, 1926.152(a)(2)). General industry has the same rule: flammable liquids shall not be stored so as to limit use of exits, stairways, or areas normally used for the safe egress of people (1910.106(d)(5)(i)).

Reference: 29 CFR 1926.152(a)(1) · 29 CFR 1910.106(a)(29) · 29 CFR 1926.152(f)(1) · 29 CFR 1910.106(e)(2)(iv)(a) · 29 CFR 1926.152(a)(2) · 29 CFR 1926.155(l) · 29 CFR 1910.106(d)(5)(i)

How much, and where

Construction sites (1926.152)

• No more than 25 gallons may be stored in a room outside an approved storage cabinet. More than 25 gallons goes in an acceptable or approved cabinet.
• One cabinet holds not more than 60 gallons of Category 1, 2 and/or 3 liquids, or 120 gallons of Category 4.
• Not more than three cabinets in a single storage area. More than that goes in an inside storage room.
• Cabinets are labeled "Flammable-Keep Away from Open Flames."

Plants where flammable liquids are incidental to the business (1910.106)

Outside a storage room or cabinet, in a building or any one fire area, the limit is:

• 25 gallons of Category 1 liquids in containers
• 120 gallons of Category 2, 3 or 4 liquids in containers
• 660 gallons of Category 2, 3 or 4 liquids in a single portable tank

A storage cabinet holds not more than 60 gallons of Category 1, 2 or 3, or 120 gallons of Category 4, and is labeled "Flammable-Keep Fire Away."

Reference: 29 CFR 1926.152(b)(1) · 29 CFR 1926.152(b)(2) · 29 CFR 1926.152(b)(2)(iii) · 29 CFR 1926.152(b)(3) · 29 CFR 1910.106(d)(3)(i) · 29 CFR 1910.106(d)(3)(ii) · 29 CFR 1910.106(e)(2)(ii)(b) · 29 CFR 1910.106(d)(7)(iii)

Bond, transfer the right way, keep ignition away

Bond before you pour

On a construction site (1926.152(e)(2)), transfer Category 1, 2 or 3 liquids from one container to another only when the containers are electrically interconnected (bonded).

In general industry (1910.106(e)(6)(ii)), Category 1 or 2 liquids, or Category 3 liquids with a flashpoint below 100 °F (37.8 °C), shall not be dispensed into containers unless the nozzle and container are electrically interconnected.

Allowed ways to transfer on a construction site (1926.152(e)(3))

• Through a closed piping system
• From safety cans
• With a device drawing through the top
• From a container or portable tank, by gravity or pump, through an approved self-closing valve

Air pressure on the container or portable tank is prohibited as a way to transfer.

In general industry (1910.106(e)(2)(iv)(d)), transfers within a building follow the same list, except that the last item reads "from a container or portable tanks by gravity through an approved self-closing valve." Transferring by air pressure on the container or portable tanks is prohibited there too.

Keep ignition sources away

• On a construction site, use Category 1, 2 or 3 liquids only where there are no open flames or other ignition sources within 50 feet of the operation, or more if conditions warrant.
• In general industry, Category 1 or 2 liquids, or Category 3 liquids with a flashpoint below 100 °F (37.8 °C), may be used only where there are no open flames or other sources of ignition within the possible path of vapor travel.
• In general industry, adequate precautions must be taken to prevent the ignition of flammable vapors. Ignition sources include open flames, lightning, smoking, cutting and welding, hot surfaces, frictional heat, static, electrical and mechanical sparks, spontaneous ignition and radiant heat.

Spills

On a construction site, leakage or spillage must be disposed of promptly and safely (1926.152(f)(2)). In general industry, where flammable liquids are used or handled, except in closed containers, means must be provided to dispose promptly and safely of leakage or spills (1910.106(e)(2)(iv)(b)).

Reference: 29 CFR 1926.152(e)(2) · 29 CFR 1926.152(e)(3) · 29 CFR 1926.152(f)(2) · 29 CFR 1926.152(f)(3) · 29 CFR 1910.106(e)(2)(iv)(c) · 29 CFR 1910.106(e)(6)(i) · 29 CFR 1910.106(e)(6)(ii) · 29 CFR 1910.106(e)(2)(iv)(d) · 29 CFR 1910.106(e)(2)(iv)(b)

Engines off, no smoking, extinguisher close

When you fuel equipment on a construction site (1926.152(g))

• Shut off the motor of the equipment being fueled during fueling.
• No smoking or open flames where fueling or dispensing happens. No-smoking signs must be posted.
• The dispensing nozzle must be an approved automatic-closing type without a latch-open device. Good practice: do not wedge it open either.

Where the extinguishers go on a construction site (1926.152(d) and (g)(11))

Reference: 29 CFR 1926.152(g)(4) · 29 CFR 1926.152(g)(8) · 29 CFR 1926.152(g)(9) · 29 CFR 1926.152(g)(10) · 29 CFR 1926.152(g)(11) · 29 CFR 1926.152(d)(1) · 29 CFR 1926.152(d)(2) · 29 CFR 1910.106(d)(7)(i)(a) · 29 CFR 1910.106(d)(7)(i)(b)