Relating to occupational diseases for purposes of workers' compensation for certain workers; and prescribing an effective date.

Specifies certain presumptions as to cause of ] compensability of covered employee's claim of benefits under workers' compensation law for death, disability or impairment of health of fire service professional, public safety personnel or employee of public or private safety agency with duties related to firefighting, police, ambulance or emergency medical services in claim for benefits related to occupational disease under workers' compensation law ]. Specifies standard of evidence necessary for rebuttal of presumption. Provides that insurer or self-insured employer may later deny compensability of claim if exposure to trauma ceases being of real importance or great consequence in causing disability, impairment of health or need for treatment. Defines "covered employee." Takes effect on 91st day following adjournment sine die.