From baking sheets to muffin pans, frying pans to woks, non-stick cookware coated with perfluorinated chemicals (PFCs) are common items found in most kitchens. They were certainly a mainstay of my kitchen for many years, until I found out that these products can release toxic fumes that can kill pet birds in a matter of minutes, even when used under normal cooking conditions. I’m from coal country, so let’s say this hypothetical canary was my wake-up call to ditch the non-stick for good.
It’s not just birds that suffer from toxic cookware, of course. Accidentally overheat a Teflon pan for a long period of time and you may end up in hospital with ‘Teflon Flu’ or ‘polymer fume fever’, a condition characterized by severe respiratory distress. Even if you take care to use these non-stick pans according to manufacturers’ instructions, they still pose an unnecessary risk to health.
Teflon and non-stick cookware
Often sold under the Teflon brand, as well as Tefal, Silverstone, Anolon, Circulon, and Calphalon, conventional non-stick cookware makes use of fluoropolymers that repel oil and water. These non-stick coatings are also used in food packaging and pop up in some unlikely places, including:
- Some types of dental floss
- Microwave popcorn bags
- Pizza boxes
- Other food containers
- Carpet treatments
- Windshield cleaning solution
- The non-stick insert in some rice cookers
As for Teflon itself, this was manufactured by DuPont Co. and is the best-known brand name of non-stick coatings made with polytetrafluoroethylene (PTFE). DuPont Co. discovered the compound in 1938 and the coating quickly became popular because, let’s face it, non-stick pans make for easier cooking and clean-up.
Top tip: Beware non-stick pans that claim to be Teflon-free. This may be true, in that the pans don’t use the brand-name Teflon, but they may still use a PTFE non-stick coating.
Fluoropolymer coatings are generally made using poly- and perfluoroalkyl substances (PFAS) and were originally applied to cookware using solvents such as perfluorooctanoic acid (PFOA). After significant research showing undesirable health effects of PFOA, and a not inconsiderable lawsuit (R), DuPont and other manufacturers phased out their use of this chemical in the production of non-stick coatings as part of the PFOA Stewardship Program.
The PFOA Stewardship Program was launched in 2006 by the U.S. Environmental Protection Agency (EPA). DuPont and seven other leading PFOA-using companies promised to eliminate PFOA use and emissions by 2015. All of the companies met this target. In fact, Teflon products have been PFOA-free since 2013 (R), but this hardly excuses the several decades in which this company and other PTFE-producing manufacturers allegedly hid evidence showing the negative health effects of the chemicals (R).
Rather worryingly, a report in The New York Times from October 2017 noted that Nancy Beck, a Trump appointee in the EPA, made changes to the rules regarding PFOA which make it harder to regulate (R). Specifically, the changes to the rules make it more difficult to track the health consequences of PFOA contamination. Beck previously worked as a lobbyist for the American Chemistry Council, whose members include those making and using PFOA, such as DuPont, as well as other chemical giants such as Dow Chemical, Monsanto, ExxonMobil Chemical, and Bayer (R).
The Problem with PFOA
Studies show that residual PFOA is not completely removed during the fabrication of non-stick coatings for cookware. This means that, when heated under normal cooking temperatures, non-stick cookware made with PFOA releases PFOA.
PTFE starts to dissociate at about 600 degrees Fahrenheit (300 degrees Celsius), whereupon toxic fumes such as PFOA begin to be released into the air. This might seem like a very high temperature, but it only takes a couple of minutes of heating an empty pan for it to reach 500 degrees F and cooking a steak can require a temperature of around 600 degrees F. As such, even seemingly normal cooking conditions can easily lead to PFOA and other toxic fumes being released into the air from PTFE coatings.
PFOA is a greenhouse gas and has adverse effects on health, including being a probable carcinogen (R). It is also a suspected hormone disrupter, with its effects made worse by the fact that it lingers in the body and in the environment. Most adults have some PFOA in their blood, and the chemical has also been found in newborns and in marine animals and polar bears (R).
So, if Teflon and other non-stick products are now made without PFOA, are these products safe and non-toxic? Not quite.
Polymer Flu Fever
PFOA was certainly a major health concern associated with these non-stick coatings, but it wasn’t the only toxic fume released from PTFE.
In fact, since PFOA has been phased out and there are still reports of bird deaths related to new non-stick cookware, this strongly suggests that the mix of toxic fumes released from a PFOA-free pan coated with PTFE remains dangerous. As such, if you have a pet bird in the home, you probably still want to avoid using Teflon or similar non-stick cookware.
For the rest of us, these polymer coatings, which can include polyethersulphone, PTFE, and bisphenol A/epichlorohydrin, also pose health risks. Indeed, there’s even a medical term for the negative effects of breathing in these toxic gases: Polymer fume fever. Or, more colloquially, Teflon flu.
Polymer flu fever is caused by inhalation of toxic fumes, typically from overheating of a polytetrafluoroethylene-coated cooking pan. Case reports detail people admitted to hospital in serious respiratory distress after being exposed to such fumes for several hours. In some cases individuals have been hospitalized after accidentally leaving a pan on a hot stove overnight, with the Teflon coating burning away (R, R).
Even if you are simply exposed to PTFE fumes during normal use of non-stick cookware, this may still pose a risk to health.
PFASs and Pregnancy
Non-stick coatings appear to be particularly troublesome for female reproductive health, although this imbalance may simply be due to a lack of research investigating male reproductive health effects. Regardless, PFOA and PFOS exposure has been linked to a nearly two-fold increase in the risk of preterm birth (R). Risk of preterm birth was also increased with higher exposure to perfluorononanoic acid (PFNA), perfluoroheptane sulfonate (PFHpS) and perfluorodecanoic acid (PFDA), and there appears to be an increased risk of low birth weight with exposure to PFASs. In fact, PFASs are so unsafe that the Biden administration plans to ban them.
Research also suggests that PFASs have a negative effect on blood glucose regulation in pregnancy, increasing the risk of gestational diabetes (R). In one case-control study, women exposed to PFASs in the late 1990s had a higher risk of type 2 diabetes in the following years. Higher exposure to perfluorooctanesulfonic acid (PFOS) was associated with a 62 percent increase in the risk of type 2 diabetes, and higher exposure to perfluorooctanoic acid (PFOA) was associated with a 54 percent increased risk (R).
People who use oral contraceptives also appear to have higher levels of PFASs, possibly because menstrual blood provides a way for the body to eliminate these chemicals and there is often less blood loss with the use of oral contraceptives (R).
Just how bad are PTFE non-stick pans?
Manufacturers of non-stick cookware may well point to studies that find little or no toxicity risk from their products (R), However, it’s important to note that these studies use new cookware or more favorable statistical analysis to create a healthier impression of products than might otherwise be presented. It’s also possible that current guidelines vastly underestimate the negative impact of these chemicals on our health, given the paucity of research.
Often, the results of studies looking at PFOA emissions don’t accurately reflect how the age of a pan affects the release of toxic gases or chemicals into air and food. Indeed, one study looked at levels of chemicals from cookware in the breastmilk of volunteers in Jordan and found that women who used older non-stick cookware at home had higher levels of PFOS and PFOA, as did older women (R).
Unfortunately, avoiding PFOAs and other toxic fumes isn’t as simple as just throwing out non-stick pans after a few years of use. In fact, some newer pans might actually release greater amounts of PFOA, with residual traces of PFOA decreasing as the pan is used over time and possibly increasing again as the pan degrades (R). Although this almost suggests that there is a sweet spot for all pans in terms of their emissions of toxic fumes, any sweet spot that might exist is likely short-lived and hard to predict for any single item of non-stick cookware.
In one study, researchers measured perfluoroalkyl carboxylates (PFCAs), particularly PFOA, and fluorotelomer alcohols, released from nonstick cookware under normal cooking temperatures (179 to 233 degrees Celsius) (R):
- PFOA was released at 7-337 nanograms (11-503 pg/cm2) per pan from four brands of nonstick frying pans.
- 6:2 FTOH and 8:2 FTOH were released from four brands of frying pans.
This same study also found that 5-34 ng of PFOA was released from a prepacked microwave popcorn bag, but not from plain white corn kernels popped in a polypropylene container. Two out of four brands of prepacked microwave popcorn also released 6:2 FTOH and 8:2 FTOH.
Interestingly, for one pan in this study, PFOA emissions decreased significantly with repeated use, while all the other pans showed no such decrease. In fact, more than 5 ng of PFOA was released during the fourth use of both brands of pans.
Temperature is a clear factor influencing just how much of these toxic fumes is released, with higher temperatures greatly increasing emissions (R).
What happens if you eat Teflon?
Surprisingly, there doesn’t seem to be much, if any, negative impact on health if you accidentally ingest intact particles of non-stick coatings that flake off scratched cookware. That’s because solid PTFE flakes are inert. In fact, some researchers are investigating the use of PTFE for weight management and PTFE has long been used for other health applications.
PTFE is widely considered to be the most inert material known and could be used to add bulk to food, thereby increasing satiety and reducing calorie intake (R). What’s more, some researchers are investigating the use of high-density PTFE in rebuilding cartilage and soft tissue (R), and the material is often used for surgical applications, including in cosmetic surgery.
The environmental impact of PFOA and PTFE
Due to concerns over its toxicity, PFOA has largely been replaced in the production of PTFE non-stick coatings. Unfortunately, while long-chain PFASs like PFOA have mostly been phased out due to concerns about bioaccumulation and impact on reproductive health, they continue to linger in the environment. What’s more, short-chain PFASs have also been seen to be highly mobile in soil and water and to be extremely persistent in the environment (R). This leads to rapid contamination of drinking water, with largely unknown effects on human health and the health of other animals and the wider environment.
And, again, it’s worth noting that PFOAs are just one type of toxic fume associated with non-stick coatings. According to the Madrid Statement on Poly- and Perfluoroalkyl Substances (PFASs), published by hundreds of concerned scientists from across the world:
PFASs are man-made and found everywhere [and] are highly persistent, as they contain perfluorinated chains that only degrade very slowly, if at all, under environmental conditions. It is documented that some polyfluorinated chemicals break down to form perfluorinated ones” (R). In addition to urging governments to better regulate PFSAs and scientists to investigate these chemicals further, the signatories to this statement also suggest that the individual consumer, “Whenever possible, avoid products containing, or manufactured using, PFASs. These include many products that are stain-resistant, waterproof, or nonstick. [In addition] Question the use of such fluorinated “performance” chemicals added to consumer products.Madrid Statement on Poly- and Perfluoroalkyl Substances (PFASs)
In recent years, numerous companies have developed non-stick coatings that are free from PFOA, PTFE, and other toxic substances. Some of these seem like an excellent alternative to Teflon and other conventional non-stick coatings, but some remain problematic. There is often very little, if any, data available on these new alternatives, and some are suspected to have similar toxicity (R).
I take a closer look at these ‘green’ non-stick coatings here, including a spray-on silicon dioxide coating called Thermolon.