California Code of Regulations
Title 8 - Industrial Relations
Division 1 - Department of Industrial Relations
Chapter 3.2 - California Occupational Safety and Health Regulations (Cal/OSHA)
Subchapter 2 - Regulations of the Division of Occupational Safety and Health
Article 1 - Employers' Obligation to Provide Information to Employees
Section 340.1 - Rights of Employees to Observe Monitoring or Measuring

(a) Whenever an employer is required to conduct tests or to engage in monitoring or measuring, to determine employee exposure to hazards by specific standards promulgated under Labor Code Section 142.3, the employer shall notify the affected employee or employees or their representative, prior to commencement of the date, time and place of the testing, monitoring or measuring of employee exposure. The employer shall provide the affected employee or employees, or their representatives with the opportunity to observe the testing, sampling, monitoring or measuring undertaken pursuant to such standards.

(b) The affected employee, employees or their representatives shall be allowed access to the records and reports of the results of the testing monitoring or measuring when carried out under the requirements of a standard promulgated under Labor Code Section 142.3.