"(4) To ascertain and fix such reasonable standards and to prescribe, modify and enforce such reasonable orders for the adoption of safety devices, safeguards and other means or methods of protection to be as nearly uniform as possible, as may be necessary to carry out all laws and lawful orders relative to the protection of the life, health, safety and welfare of employees in employments and places of employment or frequenters of places of employment.

"(5) To ascertain, fix and order such reasonable standards for the construction, repair and maintenance of places of employment as shall render them safe.

"(6) To investigate, ascertain and determine such reasonable classifications of persons, employments and places of employment as shall be necessary to carry out the purposes of sections 2394-41 to 2394-71, inclusive…

"Section 2394-59. 2. Every order of the commission shall, in every prosecution for violation thereof, be conclusively presumed to be just, reasonable and lawful, unless prior to the institution of prosecution for such violation an action shall have been brought to vacate and set aside such order, as provided in section 2394-68 of the statutes."