Except as provided in subsection (c) of this section, and notwithstanding any other provision of this subtitle but subject to the limitations on emergency adoption in Title 10, Subtitle 1 of the State Government Article, the Commissioner may adopt immediately an emergency occupational safety and health standard that the Commissioner determines is needed to protect employees from the grave danger of: a new hazard; or exposure to an agent or circumstance determined to be toxic or physically harmful. An emergency occupational safety and health standard adopted under this section remains in effect until the earlier of: expiration of a period that the Joint Committee on Administrative, Executive, and Legislative Review sets; expiration of a period, not exceeding 6 months, that the Commissioner sets; or replacement of the emergency occupational safety and health standard by another regulation.