PFAS are used in many different products. They make rain jackets water-proof, keep soggy fast food from leaking through the wrapping and are an important component of the foam found in fire extinguishers [2]. They are often used to make surfaces water repellant and to reduce friction. PFAS is an umbrella term for thousands of chemicals including Teflon, which is used in some non-stick cookware [3]. One concerning trait of PFAS is that once they are discarded they degrade over very long time scales; they are also called ‘forever chemicals’. Moreover, they bioaccumulate, meaning that they build up in organisms that are exposed to them over time [1]. In fact, traces of PFAS can be found in the blood of 98% of US citizens [4] and in water samples from across the globe [5, 6]. Some PFAS have been indicated in diverse health issues ranging from thyroid, liver or kidney disease to cancer [7, 8].

One particular PFAS that was specifically found to cause adverse health effects is PFOA (perfluorooctanoic acid), a substance that was used in the manufacturing process of Teflon cookware until 2013. In addition to the aforementioned health conditions, it has been linked to infertility and low birth weight [9, 10]. Since 2013 PFOA has no longer been used in the production of non-stick cookware, yet it is still used in other applications such as in sealants, floor wax or textiles. Hence, unsurprisingly, studies have shown that banning cookware containing PFOA did not significantly decrease overall PFOA exposure [11].

However, many modern non-stick cookware items still contain other PFAS whose potential health effects, especially long term, are often unclear [12]. Generally, new types of PFAS are often used without toxicological studies, which has led to an ambiguous picture of PFAS biosafety [12]. Therefore, some governments are passing precautions legislation – the European Union has started to ban certain PFAS [13] and the US state Maine has even passed a law that will prohibit the sale of products containing PFAS from 2030 on [14].

Apart from PFAS, non-stick cookware can cause adverse health effects if used incorrectly. Usually, the non-stick coating will start to deteriorate when heated above 260°C (500°F) [15] – conventional electric stoves reach up to 600°C (1100°F). Such high heat causes the pan to release toxic fumes that, upon inhalation, can cause polymer fume fever [16] – temporary flu-like symptoms that last up to 48h – or, in severe cases, lung damage [17]. Therefore, it is crucial to use non-stick cookware only within the temperature range recommended by the manufacturer.

Moreover, non-stick coating can become damaged by long-term use, sharp objects or dishwashers, causing it to flake off. When such cookware is continued to be used, some of the plastic coating ends up in the food and will be ingested. While Teflon itself has been classified as safe in that regard [18], it still accumulates in internal organs such as the stomach lining or the kidneys [19] and it is unclear what the long term effects of this will be. Consequently, damaged non-stick cookware should be replaced.