Does PVC give off toxic fumes at 600 degrees F?

• A. False
• B. It varies with ventilation
• C. Only under combustion
• D. True

Answer: (D)

When PVC is heated to high temperatures, it doesn’t just soften—it decomposes. The chlorine in PVC is released as hydrogen chloride gas, which is toxic and corrosive to the lungs and eyes. At around 600°F, the heat is enough to drive this breakdown, so toxic fumes are produced. The danger increases if there’s flame or incomplete combustion, which can add more hazardous gases. In practice, this means heating PVC requires good ventilation and proper protection, because the fumes from heating PVC at that temperature are indeed hazardous.