29 CFR 1926.152(a)(2)
Flammable or combustible liquids shall not be stored in areas used for exits, stairways, or normally used for the safe passage of people.
29 CFR 1926.152(b)
"Indoor storage of flammable and combustible liquids."
29 CFR 1926.152(b)(1)
No more than 25 gallons of flammable or combustible liquids shall be stored in a room outside of an approved storage cabinet. For storage of liquefied petroleum gas, see 1926.153.
29 CFR 1926.152(b)(2)
Quantities of flammable and combustible liquid in excess of 25 gallons shall be stored in an acceptable or approved cabinet meeting the following requirements:
29 CFR 1926.152(b)(2)(i)
Acceptable wooden storage cabinets shall be constructed in the following manner, or equivalent: The bottom, sides, and top shall be constructed of an exterior grade of plywood at least 1 inch in thickness, which shall not break down or delaminate under standard fire test conditions. All joints shall be rabbeted and shall be fastened in two directions with flathead wood screws. When more than one door is used, there shall be a rabbeted overlap of not less than 1 inch. Steel hinges shall be mounted in such a manner as to not lose their holding capacity due to loosening or burning out of the screws when subjected to fire. Such cabinets shall be painted inside and out with fire retardant paint.
29 CFR 1926.152(b)(2)(ii)
Approved metal storage cabinets will be acceptable.
29 CFR 1926.152(b)(2)(iii)
Cabinets shall be labeled in conspicuous lettering, "Flammable-Keep Fire Away."
29 CFR 1926.152(b)(3)
Not more than 60 gallons of flammable or 120 gallons of combustible liquids shall be stored in any one storage cabinet. Not more than three such cabinets may be located in a single storage area. Quantities in excess of this shall be stored in an inside storage room.