U.S. Geological Survey Manual
55.203 (d) Type 4 magazines. Magazines for the storage of low explosives, subject
to the limitations prescribed by Secs. 55.206(b), 55.210(b), and 55.213. Blasting
agents may be stored in type 4 magazines, subject to the limitations prescribed
by Secs. 55.206(c), 55.211(b), and 55.213. Detonators that will not mass detonate
may also be stored in type 4 magazines, subject to the limitations prescribed
by Secs. 55.206(a),
55.210(b), and 55.213.
Sec. 55.206 Location of magazines
Sec. 55.206(a) Outdoor magazines in which high explosives are stored must be located no closer to inhabited buildings, passenger railways, public highways, or other magazines in which high explosives are stored, than the minimum distances specified in the table of distances for storage of explosive materials in Sec. 55.218
Sec. 55.206(b) Outdoor magazines in which low explosives are stored must be located no closer to inhibited buildings, passenger railways, public highways, or other magazines in which explosive materials are stored, than the minimum distances specified in the table of distances for storage of low explosives in Sec. 55.219, except that the table of distances in Sec. 55.224 shall apply to the storage of display fireworks. The distances shown in Sec. 55.219 may not be reduced by the presence of barricades.
Sec. 55.206(c) Outdoor magazines in which blasting agents
in quantities of more than 50 pounds are stored must be located no closer to
inhabited buildings, passenger railways, or public highways than the minimum
distances specified in the table of distances for storage of explosive materials
in Sec. 55.218
Sec 55.210: Construction of Type 4 Magazines
Sec. 55.210(b) (b) Indoor magazine—
(1) General. Indoor magazines are to be fire-resistant and theft-resistant. They need not be weather-resistant if the buildings in which they are stored provide protection from the weather. No indoor magazine is to be located in a residence or dwelling. The indoor storage of low explosives must not exceed a quantity of 50 pounds. More than one indoor magazine may be located in the same building if the total quantity of explosive materials stored does not exceed 50 pounds. Detonators that will not mass detonate must be stored in a separate magazine and the total number of electric detonators must not exceed 5,000.
(2) Construction. Indoor magazines are to be constructed of masonry, metal-covered wood, fabricated metal, or a combination of these materials. The walls and floors are to be constructed of, or covered with, a non-sparking material. The doors must be metal or solid wood covered with metal.
(3) Hinges and hasps. Hinges and hasps are to be attached to doors
by welding, riveting, or bolting (nuts on inside of door). Hinges and
hasps must be installed so that they cannot be removed when the doors
are closed and locked.
(4) Locks. Each door is to be equipped with (i) two mortise locks; (ii) two padlocks fastened in separate hasps and staples; (iii) a combination of a mortise lock and padlock; (iv) a mortise lock that requires two keys to open; or (v) a three-point lock. Padlocks must have at least five tumblers and a case-hardened shackle of at least \3/8\ inch diameter. Padlocks must be protected with not less than \1/4\ inch steel hoods constructed so as to prevent sawing or lever action on the locks, hasps, and staples. Indoor magazines located in secure rooms that are locked as provided in this subparagraph may have each door locked with one steel padlock (which need not be protected by a steel hood) having at least five tumblers and a case-hardened shackle of at least \3/8\ inch diameter, if the door hinges and lock hasp are securely fastened to the magazine. These requirements do not apply to magazine doors that are adequately secured on the inside by means of a bolt, lock, or bar that cannot be actuated from the outside.
Sec. 55.213 Quantity and storage restrictions.
(b) Detonators are not to be stored in the same magazine with other explosive
materials, except under the following circumstances:
(1) In a type 4 magazine, detonators that will not mass detonate may
be stored with electric squibs, safety fuse, igniters, and igniter cord.
(2) In a type 1 or type 2 magazine, detonators may be stored with
delay devices and any of the items listed in paragraph (b)(1) of this