Coming unstuck: Is your non-stick frying pan harming your health?

Question:

Our old Teflon-coated frying pan is scratched, so I plan to buy a new one. Are Teflon-coated frying pans still considered safe?

Answer:

The key to nonstick cookware coatings such as Teflon is a smooth ingredient called polytetrafluoroethylene (PTFE). Although PTFE has generally been considered a safe and stable coating for cookware, recent studies have shown that plastic compounds migrate into food and once the Teflon is damaged, millions of microplastic particles also leach from those scratches into the environment. So, should we be concerned?

PTFE belongs to a group of chemicals known for being highly stable and resistant to degradation. It has a very high melting point (327°C) and is resistant to many chemicals, hence its use as a cookware coating. PTFE is also considered biologically inert and non-biodegradable in the human body and so is used to coat pacemakers, line the tubes used to replace arteries and in facial plastic surgery.

PTFE is also part of a group of compounds known as per- and polyfluoroalkyl substances (PFAS) that have excellent chemical and thermal stability. More than 4700 known compounds belong to this group, many of which have been used for various commercial and industrial uses over the past 60 years. For example, these chemicals are used to treat paper products and packaging to improve their moisture and oil resistance. Microwave popcorn bags, for example, are often lined with these polymers.

The primary concern with PTFEs in the early 2000s was the discovery that a chemical called perfluoro­octanoic acid (PFOA) used to manufacture these nonstick coatings was linked to cancer and birth defects. The International Agency for Research on Cancer consequently classified PFOA as “possibly carcinogenic to humans”.

Environmental agencies worldwide worked together to phase out the use of PFOA by the end of 2015. However, that is just one of more than 4700 compounds belonging to the group known as PFAS.

A 2022 review published in the journal Toxics raised concerns about the effect of this large group of compounds on both wildlife and human health because of their now widespread distribution. They persist in the environment and thus have the potential to accumulate in bodies.