Each employer subject to the provisions of this part, unless exempted by regulation issued by the commissioner or as hereinafter provided, shall keep at the place of employment for a period of three years a true and accurate record of the hours worked by, and the wages paid by him to, each employee, as required by the applicable regulations issued by the Labor Commissioner, and shall furnish to the commissioner or his authorized representative, upon demand, a sworn statement of the same provided if the place of employment is designed primarily as an establishment for the housing and use of coin-operated service or vending machines, such records may be kept by the employer in some location approved by the commissioner other than at the place of employment. Such records shall be open to inspection by the commissioner or his authorized representative at any reasonable time. Each employer subject to this part or to a minimum fair wage order shall keep a copy of such order and the regulations issued by the Labor Commissioner posted at the place of employment where it can be read easily by the employees. Employers shall be furnished copies of orders and regulations on request, without charge.