ORS 480.210: Certificate, license or permit required; display upon demand; defenses.

(1) A person may not possess an explosive unless:

      (a) The person has in immediate possession at all times during the possession of the explosive a valid certificate of possession issued to the person under ORS 480.235;

      (b) The person possesses a license or permit issued by the Bureau of Alcohol, Tobacco, Firearms and Explosives of a type that authorizes the possession; or

      (c) The person is listed as a responsible person or employee possessor under a license or permit described in paragraph (b) of this subsection.

      (2) A person in possession of an explosive shall display a certificate of possession or federal license or permit upon the demand of the State Fire Marshal, an assistant to the State Fire Marshal, a magistrate or a law enforcement agency, public fire department or fire protection agency of this state.

      (3) It is a defense to a charge under subsection (1) of this section that the person so charged produce in court:

      (a) A certificate described in subsection (1)(a) of this section that was valid at the time of the arrest of the person;

      (b) Proof that the person has a license or permit issued by the Bureau of Alcohol, Tobacco, Firearms and Explosives of a type authorizing the person to possess the explosives; or

      (c) Proof that the person is listed as a responsible person or employee possessor under a license or permit described in paragraph (b) of this subsection.