Regulating the installation and repair of piping containing hazardous substances; including systems of piping hazardous substance in the definition of high pressure piping and defining hazardous substance; prohibiting interference with or refusal of entry to inspectors lawfully engaged in the duties of inspecting hazardous substance piping; requiring issuance of an individual contracting pipefitter license by the department of labor and industry for the installation, repair or alteration of piping, appurtenances and equipment for the purpose of containing hazardous substances used to produce a product or issuance of a license for plumbing work by the department of health, exception; imposing a penalty for false statements in pipefitter license applications, inspection requests, certificates or other forms or statements provided to inspectors (ra)