Floor, walls, and ceiling shall have a fire-resistance rating of at least 2 hours. Walls or partitions shall be continuous from floor to ceiling and shall be securely anchored. At least one wall shall be an exterior wall. Openings to other parts of the building shall not be permitted. Windows and doors shall be in exterior walls and shall be located so as to be readily accessible in case of emergency. Windows shall be of glass or plastic in metal frames.
Ventilation shall be as provided in paragraph (b)(3)(ii)(b) of this section.
Explosion venting shall be as provided in paragraph (b)(3)(ii)(c) of this section.
There shall be no sources of ignition from open flames, electrical equipment, or heating equipment.
Electrical equipment shall be in accordance with the requirements of subpart S of this part for Class I, Division 2 locations.
Heating, if provided, shall be by steam, hot water, or indirect means.