Non-stick cookware is often coated with polytetrafluoroethylene (PTFE), which when heated excessively, releases toxic fumes containing perfluorooctanoic acid (PFOA). This chemical has been linked to various health issues, including thyroid problems, infertility, and even cancer. While some modern non-stick cookware brands claim to be PFOA-free, the long-term safety of their alternatives remains uncertain.