The answer is Section 11 (C) of the OSH Act. This act is supposed to protect workers who ask questions or complain about safety or take action to protect themselves from dangerous conditions.
Depending upon the circumstances of the case, "discrimination" can comprise: firing or laying off; demoting; denying overtime or promotion; disciplining; reducing pay or hours, and other actions.
These rights consist of filing an OSHA complaint, partaking in an inspection or speaking to an inspector, looking for access to employer exposure and injury records, reporting an injury, and raising a safety or health complaint with the employer.
If an employee believes that his/her employer has discriminated against you because you exercised your safety and health rights, contact your local OSHA Office right away. The OSH Act provides you only 30 days to report discrimination.