Illinois Statutes Chapter 740. Civil Liabilities § 174/15. Retaliation for certain disclosures prohibited

(a) An employer may not take retaliatory action against an employee who discloses or threatens to disclose to a public body conducting an investigation, or in a court, an administrative hearing, or any other proceeding initiated by a public body, information related to an activity, policy, or practice of the employer where the employee has a good faith belief that the activity, policy, or practice (i) violates a State or federal law, rule, or regulation or (ii) poses a substantial and specific danger to employees, public health, or safety.

(b) An employer may not take retaliatory action against an employee for disclosing or threatening to disclose information to a government or law enforcement agency information related to an activity, policy, or practice of the employer, where the employee has a good faith belief that the activity, policy, or practice of the employer (i) violates a State or federal law, rule, or regulation or (ii) poses a substantial and specific danger to employees, public health, or safety.

(c) An employer may not take retaliatory action against an employee for disclosing or threatening to disclose to any supervisor, principal officer, board member, or supervisor in an organization that has a contractual relationship with the employer who makes the employer aware of the disclosure, information related to an activity, policy, or practice of the employer if the employee has a good faith belief that the activity, policy, or practice (i) violates a State or federal law, rule, or regulation or (ii) poses a substantial and specific danger to employees, public health, or safety.