30 C.F.R. § 56.6901 – Black powder.

(a) Black powder shall be used for blasting only when a desired result cannot be obtained with another type of explosive, such as in quarrying certain types of dimension stone.
(b) Containers of black powder shall be—
1. (1) Nonsparking;
2. (2) Kept in a totally enclosed cargo space while being transported by a vehicle;
3. (3) Securely closed at all times when—
  1. (i) Within 50 feet of any magazine or open flame;
  2. (ii) Within any building in which a fuel-fired or exposed-element electric heater is operating; or
  3. (iii) In an area where electrical or incandescent-particle sparks could result in powder ignition; and
4. (4) Opened only when the powder is being transferred to a blasthole or another container and only in locations not listed in paragraph (b)(3) of this section.
(c) Black powder shall be transferred from containers only by pouring.
(d) Spills shall be cleaned up promptly with nonsparking equipment. Contaminated powder shall be put into a container of water and shall be disposed of promptly after the granules have disintegrated, or the spill area shall be flushed promptly with water until the granules have disintegrated completely.
(e) Misfires shall be disposed of by washing the stemming and powder charge from the blasthole, and removing and disposing of the initiator in accordance with the requirement for damaged explosives.
(f) Holes shall not be reloaded for at least 12 hours when the blastholes have failed to break as planned.