No person trained in a qualified program of hazardous substance emergency response certified by the State Fire Marshal pursuant to rules promulgated by authority of subsection (a), section five-a, article three, chapter twenty-nine of this code, who in good faith renders advice or assistance at the scene of an actual or threatened discharge of any hazardous substance and receives no remuneration for rendering such advice or assistance, is liable for any civil damages as the result of any act or omission in rendering such advice or assistance: Provided, That the exemption from liability for civil damages of this section shall be extended to any such person who receives reimbursement for out-of-pocket expenses incurred in rendering such advice or assistance or compensation from his or her regular employer for the time period during which he or she was actually engaged in rendering such advice or assistance but is not extended to any such person who by his or her act or omission caused or contributed to the cause of such actual or threatened discharge of any hazardous substance.

For the purposes of this section, "hazardous substance" means any "hazardous substance" as defined in chapter eighty-eight, Acts of the Legislature, regular session, one thousand nine hundred eighty-five; any "chemical substances and materials" listed in the rules promulgated by the commissioner of labor pursuant to section eighteen, article three, chapter twenty-one, of this code; and any "hazardous waste" as defined in section three, article eighteen, chapter twenty-two of this code.