Wooden wash-trays, sinks or bath-tubs are prohibited (except sinks in commercial or manufacturing establishments handling acids or other liquids that are subject to attack or destroy fixtures, as hereinbefore specified) inside of buildings. Such fixtures must be constructed of non-absorbent material. Cement or artificial stone tubs will be permitted, when approved by the board or bureau of health.
No fixture having a water connection, either to or from any direct or indirect line of sewer or waste or vent-pipe, the construction of which will in any way create a potential cross connection between the fresh water for drinking or domestic purposes and the sewer, will be permitted.
53 P.S. § 4656