29 CFR § 1953.3 - General policies and procedures.
(a) Effectiveness of State plan changes under State law. Federal OSHA approval of a State plan under section 18(b) of the OSH Act in effect removes the barrier of Federal preemption, and permits the State to adopt and enforce State standards and other requirements regarding occupational safety or health issues regulated by OSHA. A State with an approved plan may modify or supplement the requirements contained in its plan, and may implement such requirements under State law, without prior approval of the plan change by Federal OSHA. Changes to approved State plans are subject to subsequent OSHA review. If OSHA finds reason to reject a State plan change, and this determination is upheld after an adjudicatory proceeding, the plan change would then be excluded from the State's Federally-approved plan.
(b) Required State plan notifications and supplements. Whenever a State makes a change to its legislation, regulations, standards, or major changes to policies or procedures, which affect the operation of the State plan, the State shall provide written notification to OSHA. When the change differs from a corresponding Federal program component, the State shall submit a formal, written plan supplement. When the State adopts a provision which is identical to a corresponding Federal provision, written notification, but no formal plan supplement, is required. However, the State is expected to maintain the necessary underlying State document (e.g., legislation or standard) and to make it available for review upon request. All plan change supplements or required documentation must be submitted within 60 days of adoption of the change. Submission of all notifications and supplements may be in electronic format.
(c) Plan supplement availability. The underlying documentation for identical plan changes shall be maintained by the State. Annually, States shall submit updated copies of the principal documents comprising the plan, or appropriate page changes, to the extent that these documents have been revised. To the extent possible, plan documents will be maintained and submitted by the State in electronic format and also made available in such manner.
(d) Advisory opinions. Upon State request, OSHA may issue an advisory opinion on the approvability of a proposed change which differs from the Federal program prior to promulgation or adoption by the State and submission as a formal supplement.
(e) Alternative procedures. Upon reasonable notice to interested persons, the Assistant Secretary may prescribe additional or alternative procedures in order to expedite the review process or for any other good cause which may be consistent with the applicable laws.