The Commissioner shall require licensed pesticide contractors and licensed certified commercial applicators who are not employed by or otherwise acting for a licensed pesticide contractor to maintain records with respect to applications of pesticides. Such relevant information as the Commissioner may deem necessary to be recorded and maintained may be specified by regulation. Such records shall be kept for a period of time specified by the Commissioner by regulation. The Commissioner or his authorized designee shall be permitted to inspect such records during normal business hours at the place where they are maintained. Upon request in writing, the Commissioner or his authorized designee shall be furnished with a copy of such records forthwith by the licensee.