Section 10(c) of the Occupational Safety and Health Act of 1970, 29 U.S.C. § 659(c), confers on the Occupational Safety and Health Review Commission jurisdiction to hold hearings to determine the validity of citations issued by the Secretary of Labor for violations of the Act. To invoke the jurisdiction of the Commission, a cited employer must file a written notice of contest within 15 working days of receipt of any citation. 29 U.S.C. § 659(a). Failure to do so results in the citation becoming a final order of the Commission “not subject to review by any court or agency.” Id.