What are duties of a firefighter that relate to chemicals in the workplace?

To exercise due diligence, an employer must implement a plan to identify possible workplace hazards and carry out the appropriate corrective action to prevent accidents or injuries arising from these hazards. The results indicate that firefighters are frequently exposed to significant concentrations of hazardous materials including carbon monoxide, benzene, sulphur dioxide, hydrogen cyanide, aldehydes, hydrogen chloride, dichlorofluoromethane, and particulates.

hope this helps :')

some sources quote the lethal dose, for an average 170lbs opiate-naive individual is between 75 and 375 mg