No person, on behalf of himself or of a mechanical firm, shall engage or offer to engage in, by advertisement or otherwise, any mechanical work as a journeyman or contractor who does not possess a valid and appropriate license from the Oklahoma state department of health and the city. No business entity shall act as a mechanical firm unless a contractor is associated with and responsible for complying with the provisions of this chapter and all mechanical work of such entity. (Ord. 1184, 9-8-2015)