(a) Compliance Safety and Health Officers shall be in charge of inspections and questioning of persons. A representative of the employer and a representative authorized by his employees shall be given an opportunity to accompany the Compliance Safety and Health Officer during the physical inspection of any workplace for the purpose of aiding such inspection. A Compliance Safety and Health Officer may permit additional employer representatives and additional representatives authorized by employees to accompany him where he determines that such additional representatives will further aid the inspection. A different employer and employee representative may accompany the Compliance Safety and Health Officer during each different phase of an inspection if this will not interfere with the conduct of the inspection.

(b) Compliance Safety and Health Officers shall have authority to resolve all disputes as to who is the representative authorized by the employer and employees for the purpose of this section. If there is no authorized representative of employees, or if the Compliance Safety and Health Officer is unable to determine with reasonable certainty who is such representative, he shall consult with a reasonable number of employees concerning matters of safety and health in the workplace.

(c) The representative(s) authorized by employees may be an employee of the employer or a third party. When the representative(s) authorized by employees is not an employee of the employer, they may accompany the Compliance Safety and Health Officer during the inspection if, in the judgment of the Compliance Safety and Health Officer, good cause has been shown why accompaniment by a third party is reasonably necessary to the conduct of an effective and thorough physical inspection of the workplace (including but not limited to because of their relevant knowledge, skills, or experience with hazards or conditions in the workplace or similar workplaces, or language or communication skills).

(d) Compliance Safety and Health Officers are authorized to deny the right of accompaniment under this section to any person whose conduct interferes with a fair and orderly inspection. The right of accompaniment in areas containing trade secrets shall be subject to the provisions of § 1903.9(d). With regard to information classified by an agency of the U.S. Government in the interest of national security, only persons authorized to have access to such information may accompany a Compliance Safety and Health Officer in areas containing such information.