It shall be the duty of the director of labor and industries of Washington to enforce all the provisions and rules of this chapter and the director is hereby empowered upon hearing to amend, alter and change any and all rules herein contained, or any part thereof, and to supplement the same by additional rules and requirements, after first giving reasonable public notice and a reasonable opportunity to be heard to all affected thereby: PROVIDED, That no rule amending, altering or changing any rule supplementary to the rules herein contained shall provide a less measure of safety than that provided by the rule amended, altered or changed.

A violation of any rule herein contained or of any rule or requirement made by the director of labor and industries which it is hereby permitted to make shall be deemed a violation of this chapter.