Carriers engaged in commerce, and persons receiving hazardous substances in commerce or holding such substances so received, shall upon the request of an officer or employee duly designated by the Director permit such officer or employee, at reasonable times, to have access to and to copy all records showing movement in commerce of any hazardous substance, or the holding thereof during or after such movement, and the quantity, shipper, and consignee thereof, and it is unlawful for any such carrier or person to fail to permit access to and copying of any such records so requested when such request is accompanied by a statement in writing specifying the nature or kind of hazardous substance to which the request relates; provided, that evidence obtained under this section shall not be used in a criminal prosecution of the person from whom obtained and carriers shall not be subject to the other provisions of this Act by reason of their receipt, carriage, holding or delivery of hazardous substances in the usual course of business as carriers.