283—7.27 (261,ExecOrd11,17A) Defense. After the commission issues an order granting a waiver, the order is a defense within its terms and the specific facts indicated therein for the person to whom the order pertains in any proceeding in which the rule in question is sought to be invoked. The order is not assignable, and it shall not inure to the benefit of the heirs or successors in interest of the person first obtaining the waiver.