Mo. Rev. Stat. § 293.170: Fire safety requirements.

1. Each mine shall be provided with suitable firefighting equipment, adequate for the size of the mine and the type of operations conducted.

2. Underground storage places for highly combustible material, lubricating oil and grease shall be of fireproof construction. Lubricating oil and grease kept in face regions or other working places shall be in portable, closed, metal containers.

3. Underground structures, transformer stations, battery-charging stations, substations, and permanent pumprooms shall be of fireproof construction.