The non-stick properties of Teflon cookware are achieved with a coating of PTFE (polytetrafluoroethylene), which is a plastic polymer that starts to leach toxins when heated above 572°F. These toxic fumes lead to flu-like symptoms called polymer fume fever, informally known as Teflon flu. They’re not only dangerous to people, but they’re also fatal to pet birds, like parrots.
Aluminum is a neurotoxic metal. Elevated aluminum levels have been linked to several central nervous system diseases, including Alzheimer’s and ALS. Though aluminum cookware is usually coated, the coating is prone to chipping, releasing the toxic metal into your food.
Like some other heavy metals, copper is very important for human health in small quantities. But an excess amount of it in the body can lead to heavy metal poisoning. When copper cookware isn’t coated, it can release copper when cooking acidic foods. And when it’s coated, the coating often contains nickel, which is another toxic element.
The soft ceramic coating isn’t the most durable and starts chipping after several months of everyday use. When that happens, lead and cadmium that is sometimes found in the coating will end up in your food and later in your body. Lead poisoning is one of the most dangerous types of metal poisoning and can result in abdominal pain, headaches, infertility, and other health complications (and in severe cases, coma and death). Even when the coating is lead-free, chipped cookware can still present dangers — it’s usually neurotoxic aluminum that’s under the ceramic coating.