Missouri Revised Statutes Title XXII. Occupations and Professions § 324.915. Work exempt from statutory requirements, when

(1) Any employee of an electric utility, a gas corporation as defined in section 386.020, a water corporation as defined in section 386.020, a provider of cable television service, as defined in section 386.020, or a telecommunications company as defined in section 386.020;

(2) A railroad corporation;

(3) A contractor who services the construction and maintenance of power lines or substations of an electric utility corporation, a municipal utility, a rural electric cooperative, a telecommunications company as defined in section 386.020, or a provider of cable television service as defined in section 386.020, when engaged in work of the utility, the cable television service provider, or telecommunications company;

(4) A federally licensed radio or television broadcast station or a commercial mobile radio service provider licensed by the Federal Communications Commission under the commercial mobile radio services rules and regulations;

(5) A private broadcast engineering contractor possessing a valid Society of Broadcast Engineers certification; or

(6) A contractor who is engaged in the design, installation, erection, repair, maintenance, or alteration of class two or class three remote control, signaling, or power-limited circuits, optical fiber cables or other cabling, or communications circuits, including raceways, as defined in the National Electrical Code for voice, video, audio, and data signals in residential or commercial premises.