Any person subject to any order issued under this subchapter may file with the Secretary a petition stating that any such order or any provision of such order or any obligation imposed in connection therewith is not in accordance with law and requesting a modification thereof or an exemption therefrom. The petitioner shall thereupon be given an opportunity for a hearing on the petition, in accordance with regulations issued by the Secretary. After such hearing, the Secretary shall make a ruling on the petition, which shall be final if in accordance with law.