Lighting shall be by electricity employing incandescent lights. All wiring shall be in rigid conduit installed in accordance with the provisions of Chapter 39 (relating to safety standards-general). Lighting fixtures, switches, communication and signalling equipment, other fixed portable devices, and all motors approved for such installations shall be of the explosion-proof type for Class II installations. Requirements for Class III drycleaning machinery are similar to those of Class II with the exception that explosion-proof motors and light fictures are not required for the Class III drycleaning machinery.
34 Pa. Code § 23.123