30 CFR 56.6132 - Magazine requirements.
(a) Magazines shall be -
(1) Structurally sound;
(2) Noncombustible or the exterior covered with fire-resistant material;
(3) Bullet resistant;
(4) Made of nonsparking material on the inside;
(5) Ventilated to control dampness and excessive heating within the magazine;
(6) Posted with the appropriate United States Department of Transportation placards or other appropriate warning signs that indicate the contents and are visible from each approach, so located that a bullet passing through any of the signs will not strike the magazine;
(7) Kept clean and dry inside;
(8) Unlighted or lighted by devices that are specifically designed for use in magazines and which do not create a fire or explosion hazard;
(9) Unheated or heated only with devices that do not create a fire or explosion hazard;
(10) Locked when unattended; and
(b) Metal magazines shall be equipped with electrical bonding connections between all conductive portions so the entire structure is at the same electrical potential. Suitable electrical bonding methods include welding, riveting, or the use of securely tightened bolts where individual metal portions are joined. Conductive portions of nonmetal magazines shall be grounded.
(c) Electrical switches and outlets shall be located on the outside of the magazine.