Which additional hazards are commonly present in smoke from burning plastics, besides CO and HCN?

• A. Irritants and particulates.
• B. Oxygen
• C. Pure nitrogen
• D. Water vapor only

Answer: (A)

When plastics burn, the smoke carries more than just CO and HCN. The combustion of plastics releases a range of irritant gases and a large amount of fine particles. These irritants—such as aldehydes and other toxic or reactive gases—can irritate the eyes, throat, and airways, while the particulates (soot and other aerosols) can deposit in the lungs and reduce visibility. The specific mix depends on the polymer and the fire conditions, but irritants and particulates are a common additional hazard in plastic smoke.

Oxygen isn’t an added hazard in smoke—it's typically depleted in a fire. Pure nitrogen, while present as a diluent, isn’t itself a hazard in this context. Water vapor is a normal combustion byproduct and not a hazardous feature of the smoke.