"The nonstick coating used in Teflon pans has been found to release one or more of 15 different toxic gases when heated to certain temperatures. Which chemicals are released depends on the temperature of the pan. This outgassing is fatal to pet birds and can cause "polymer fume flu," also known as "Teflon flu," in humans.
Teflon flu creates flu-like symptoms of chills, headache, fever and nausea. Usually, symptoms subside within a few days, and chances are many people who have experienced it mistook it for the flu. However, there are also more serious risks.
One of the main chemicals used in the manufacturing process of Teflon and other nonstick pans is perflurooctanoic acid (PFOA) also known as C-8. This chemical has led to cancer and birth defects in lab animals, and may have led to birth defects in DuPont plant workers. In 2005, an independent panel reporting to the Environmental Protection Agency (EPA) declared PFOA a likely human carcinogen.
Though DuPont is quick to point out the safety of Teflon and to distance it from the chemical PFOA, studies show Teflon cookware releases PFOA when heated to 680°F (360°C). This temperature can be reached within a few minutes if, for example, a forgotten pan is left empty preheating on a burner. DuPont acknowledges this, but points out that this is incorrect use of the cookware."
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