The Commissioner or authorized representative of the Commissioner may enter a place of employment where work is performed, without delay at any reasonable time, to: inspect the place of employment; investigate all pertinent apparatus, conditions, devices, equipment, materials, and structures at the place of employment; and question privately an agent, employee, or employer. Subject to any regulation that the Commissioner adopts to carry out this title, a representative chosen by employees and a representative of the employer shall be given an opportunity to accompany the Commissioner or an authorized representative of the Commissioner during an inspection under this subtitle. If there is no authorized employee representative, the Commissioner shall consult with a reasonable number of employees about safety and health in the place of employment. Before or during an inspection, an employee or authorized representative of employees in a place of employment or authorized representative of the Commissioner may give the Commissioner written notice of any violation of this title that the employee or representative has reason to believe exists at the place of employment of the employee. The Commissioner shall set, by regulation, procedures for informal review of any refusal to issue a citation on the basis of notice under this subsection. If an employee or authorized representative of employees asks for informal review under this subsection, the Commissioner shall give the employee or representative a written statement of the reasons for the final disposition.