(a) Compliance Safety and Health Officers of the Department of Labor are authorized to enter without delay and at reasonable times any factory, plant, establishment, construction site, or other area, workplace or environment where work is performed by an employee of an employer; to inspect and investigate during regular working hours and at other reasonable times, and within reasonable limits and in a reasonable manner, any such place of employment, and all pertinent conditions, structures, machines, apparatus, devices, equipment and materials therein; to question privately any employer, owner, operator, agent or employee; and to review records required by the Act and regulations published in this chapter, and other records which are directly related to the purpose of the inspection. Representatives of the Secretary of Health, Education, and Welfare are authorized to make inspections and to question employers and employees in order to carry out the functions of the Secretary of Health, Education, and Welfare under the Act. Inspections conducted by Department of Labor Compliance Safety and Health Officers and representatives of the Secretary of Health, Education, and Welfare under section 8 of the Act and pursuant to this part 1903 shall not affect the authority of any State to conduct inspections in accordance with agreements and plans under section 18 of the Act.

(b) Prior to inspecting areas containing information which is classified by an agency of the United States Government in the interest of national security, Compliance Safety and Health Officers shall have obtained the appropriate security clearance.