(a) The board shall be entitled to inspect the plant, workroom, shop, farm, mine, quarry, operation and all other property or premises of any subscriber and shall be entitled to examine from time to time the books, records and payrolls of any subscriber or intending subscriber for the purpose of determining the amount of the premium payable to such subscriber or intending subscriber. The board shall have the power to appoint those inspectors and auditors as may be necessary to carry out the powers given in this section. The board may, with the consent of the department and commissioner, cause this inspection and examination to be made by the inspectors of the department and the auditors of the Insurance Department. These inspectors and auditors shall have free access to all such premises, books, records and payrolls during the regular working and office hours.

(b) The board shall make reasonable rules and regulations for the prevention of injuries upon the premises of the subscribers, and they may refuse to insure or may terminate the insurance of any subscriber who refuses to permit such examinations or disregards such rules or regulations and may forfeit one-half of the unearned premiums previously paid by him.