This Act applies to every public employer in this State and its employees. Nothing in this Act, however, applies to working conditions of employees with respect to which federal agencies, and State agencies acting under Section 274 of the Atomic Energy Act of 1954 (42 U.S.C. § 2021), exercise statutory authority to prescribe or enforce standards or regulations affecting occupational safety and health. Any State regulations more strict than applicable federal standards shall, before being promulgated, be the subject of hearings as required by this Act.