a nonstick pan with minor wear and tear

XEs in the Kitchen: Nonstick Pans

Nonstick pans have quickly become common in our kitchens since PTFE was discovered on accident in 1938. Dr. Roy Plunkett accidentally invented PTFE (polytetrafluoroethylene) while experimenting with various refrigerants, and was clever enough to recognize the value of his unintended creation. It was very slippery while also managing to be extremely stable, meaning it rarely reacts with other chemicals. It was trademarked with the name Teflon by the DuPont Company and in 2006, 90% of aluminum cookware sold was coated with Teflon. That’s a pretty big number. Problem is, new research shows that PTFE coated cookware can release very dangerous chemicals and vapors when heated to high temperatures, temperatures that are not hard to reach during normal cooking practices. And when that happens a compound called PFOA can be produced, which is a xenohormone.

WHAT IS PTFE AND PFOA

The Teflon coating is actually polytetrafluoroethylene, or PTFE. PTFE is also found in other nonstick surfaces, but Teflon is by far the most common. In addition to its nonstick properties, these compounds are also used in a variety of products for their stain and water resistant properties. There is another chemical known as PFOA (perfluorooctanoic acid) that is used in the creation of PTFE, which may not be entirely safe either. DuPont and several other manufacturing companies stopped using PFOA to make PTFE in 2013, but pans manufactured before that, or pans made from companies that did not stop using PFOA will still contain it.

PFCs

PTFE and PFOA are PFCs, which stands for perfluorinated compound. There are a number of health concerns about PFCs, given their ability to accumulate in the body over time, and taking a very long time to break down or be otherwise neutralized. Since they are so stable, they can build up to dangerous levels within the environment, including in the water 1. PFCs are almost certainly quite bad for your health. In animals, they can cause tumors and neonatal death (miscarriages) and may have toxic effects on a number of the body’s systems, like the endocrine system or the immune system 2. The EPA considers them to be harmful 3 and likely carcinogenic 4.

PFA

PTFE is a PFA, which is a perfluoroalkoxy alkane. A lot of very similar acronyms here for very similar sounding compounds, it can be hard to keep track of. But what you’ve probably noticed is that they all contain “fluor” in them. That stands for fluorine, which is used in the manufacturing process for all of them. Fluorine has a number of uses and interesting properties, and fluorine compounds are used to add fluoride to drinking water.

Now while some companies have stopped using PFOA to make PTFE thanks to public concern and the EPA’s PFOA Stewardship Program 5 , they have switched it out for similar compounds which may not be much better 6.


HOW DOES IT ENTER THE BODY

Alright, so let’s take a break from all that for a minute and talk about something more straightforward. We’ll take a break from all the PFC and PFA information from now, as that’s a much broader and more complicated subject, and focus on this nonstick coating. As a recap, these coatings such as Teflon are called PTFE, and are made with PFOA and similar compounds.

INHALED FROM THE GASSES PRODUCED BY NONSTICK PANS AT HIGH TEMPERATURES

PTFE is quite safe usually. It requires high temperatures before it begins to break down and release toxic vapors. Unfortunately, reaching high temperatures is exactly what most nonstick pans are made to do. When heated to high temperatures, PTFE breaks down into 15 toxic gases and particles 7. One of which happens to be the very same PFOA mentioned previously. How hot? About half of them aren’t released until above 878°F which is not very likely in a conventional kitchen, fortunately. It may be possible to reach those temperatures if an empty pan is forgotten on a burner for too long, though. However, the other half of those toxic gases and particles are released at and below 680°F which is still pretty high, but not all that rare. You might reach that temperature cooking a thick steak, for example.

Teflon coatings can produce ultrafine particulate matter at temperatures as low as 464°F 8. These can settle deep within the respiratory tract 9 and may serve as the means for the most toxic gases to penetrate deep into the body 10.

IN FOOD COOKED IN A PAN THAT HAS BEEN OVERHEATED

When these compounds are produced by a high-temperature Teflon pan, allowed to cool, and then reheated, they were found to be extremely toxic. The resulting low weight PTFE killed 2 out of 3 rats 11. It is also possible that after being overheated, a nonstick pan’s coating will be sufficiently degraded to produce the toxic gases at lower temperatures than before.

two birds in a cage, hopefully not near any nonstick pans
Birds are extremely vulnerable to the fumes produced by overheated nonstick pans.

Birds are extremely sensitive to the gases produced by PTFE coatings, and have been killed by Teflon coatings at temperatures as low as 396°F 12. So don’t keep your pet birds in the kitchen.
PFOA can enter the body either through consumption or inhalation. It can be produced by PTFE at high temperatures. It may also contaminate food that was burned on a Teflon coated pan, and then it can be eaten and absorbed. PFOA can even be found in some foods without being cooked at all 13.

It can also contaminate water supplies, which was discovered studying an unfortunate community near DuPont’s Washington Works Washington, WV facility 14.


WHAT ARE THE EFFECTS OF “TEFLON” POISONING

Breathing the fumes from overheated nonstick pans at temperatures as low as 500°F, which can happen simply by forgetting to turn off a burner or just being bad at cooking, can give you the “Teflon flu”. The Teflon flu 15, formally known as Polymer fume fever, predictably causes flu-like systems. This includes chills, headaches, and fevers, and also chest tightness and coughing. Birds don’t get the Teflon flu, instead they just die. It is unknown if there are long-term effects after getting the Teflon flu. And there is woefully little research on the effect of regular low-dose exposure to the chemicals that cause this affliction. Even if you do not get severe symptoms from breathing small amounts of the gas, many parts of it (such as PFOA) are known to build up in the body and persist for very long periods of time. This may have serious health effects that are currently unknown. Gases produced by heated Teflon pans have been found to kill rats quite easily 16

While PTFE is made dangerous by all the extremely toxic gases it produces when heated to around 500°F or high, PFOA is plenty dangerous all on its own. PFOA is a known carcinogen, which means that it can cause cancer. It is highly toxic to the liver and the immune system, as well as developing bodies 17. If that wasn’t bad enough, it can cause hormone issues by altering thyroid hormones. In also seems to function as a xenoestrogen in rainbow trout 18, which may also apply to humans. It has been found to disrupt the endocrine system in animals, and cause a number of issues related to reproduction such as delayed physical development, reduced birth size 19, and neonatal death (miscarriages) 20.


HOW TO AVOID “TEFLON” POISONING FROM NONSTICK PANS

The best route to avoid any possible exposure to these chemicals is to simply not use nonstick pans. Although they are very convenient, being easy to cook with and easy to clean, it seems that their risks outweigh those benefits. Instead, consider using cast iron or stainless steel pans. These will be much safer. Cast iron in particular is much preferred by many cooking enthusiasts, and a proper “seasoned” pan is regarded by many to be “naturally non-stick.”

If you are forced to cook with nonstick pans for whatever reason, there are a few things you can do to minimize the risks. First, never preheat an empty pan. Doing so causes it to reach very high temperatures very quickly. Even putting a bit of oil in the pan will slow it down, but of course will not stop it from reaching dangerous temperatures. Secondly, do not use non-stick cookware in the oven. And third, use Teflon cookware in a well ventilated environment, preferably with an overhead exhaust fan. And don’t forget to keep your birds out of the kitchen, they don’t belong in there anyway.

 

(Header image credit to Lcarsdata at WikiMedia)

Notes:

  1. http://phys.org/news/2016-08-unsafe-toxic-chemicals-million-americans.html
  2. Steenland, Kyle; Fletcher, Tony; Savitz, David A. (2010). “Epidemiologic Evidence on the Health Effects of Perfluorooctanoic Acid (PFOA)”. Environmental Health Perspectives. 118 (8): 1100–8. doi:10.1289/ehp.0901827
  3. US Environmental Protection Agency. “FAQ”. Perfluorooctanoic Acid (PFOA) and Fluorinated Telomers
  4. http://www.atsdr.cdc.gov/PHS/PHS.asp?id=1115&tid=237
  5. https://www.epa.gov/assessing-and-managing-chemicals-under-tsca/and-polyfluoroalkyl-substances-pfass-under-tsca#tab-3
  6. http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0123496
  7. http://www.ewg.org/research/canaries-kitchen/dupont-has-known-50-years
  8. Seidel, WC., Scherer, KV, Jr.., Cline, D, Jr.., Olson, AH., Bonesteel, JK., Church, DF., Nuggehalli, S and Pryor, WA. 1991. Chemical, physical, and toxicological characterization of fumes produced by heating tetrafluoroethene homopolymer and its copolymers with hexafluoropropene and perfluoro(propyl vinyl ether). Chem Res Toxicol 4(2): 229-36.
  9. Johnston CJ, Finkelstein JN, Mercer P, Corson N, Gelein R, Oberdorster G. 2000. Pulmonary effects induced by ultrafine PTFE particles. Toxicol Appl Pharmacol 168:208-15.
  10. Coleman, WE., Scheel, LD and Gorski, CH. 1968. The particles resulting from polytetrafluoroethylene (PTFE) pyrolysis in air. Am Ind Hyg Assoc J 29(1): 54-60.
  11. Seidel, WC., Scherer, KV, Jr.., Cline, D, Jr.., Olson, AH., Bonesteel, JK., Church, DF., Nuggehalli, S and Pryor, WA. 1991. Chemical, physical, and toxicological characterization of fumes produced by heating tetrafluoroethene homopolymer and its copolymers with hexafluoropropene and perfluoro(propyl vinyl ether). Chem Res Toxicol 4(2): 229-36.
  12. Boucher, M., Ehmler, TJ and Bermudez, AJ. 2000. Polytetrafluoroethylene gas intoxication in broiler chickens. Avian Dis 44(2): 449-53.
  13. Schecter A, Colacino J, Haffner D, Patel K, Opel M, Päpke O, Birnbaum L (2010). “Perfluorinated Compounds, Polychlorinated Biphenyl, and Organochlorine Pesticide Contamination in Composite Food Samples from Dallas, Texas”. Environ. Health Perspect. 118 (6): 796–802. doi:10.1289/ehp.0901347.
  14. DuPont’s Washington Works Washington, WV facility
  15. Shusterman DJ “Polymer fume fever and other fluorocarbon pyrolysis-related syndromes.” Occupational Medicine 1993 Jul-Sep;8(3):519-31.
  16. Zook BC, Malek DE, Kenney RA “Pathologic findings in rats following inhalation of combustion products of polytetrafluoroethylene (PTFE).” Toxicology 1983 Jan;26(1):25-36.
  17. Lau C, Anitole K, Hodes C, Lai D, Pfahles-Hutchens A, Seed J (October 2007). “Perfluoroalkyl acids: a review of monitoring and toxicological findings” (PDF). Toxicol. Sci. 99 (2): 366–94. doi:10.1093/toxsci/kfm128.
  18. Hood E (August 2008). “Alternative Mechanism for PFOA?: Trout Studies Shed Light on Liver Effects”. Environ. Health Perspect. 116 (8): A351. doi:10.1289/ehp.116-a351b.
  19. Betts K (November 2007). “PFOS and PFOA in humans: new study links prenatal exposure to lower birth weight”. Environ. Health Perspect. 115 (11): A550. doi:10.1289/ehp.115-a550a.
  20. Betts KS (May 2007). “Perfluoroalkyl acids: what is the evidence telling us?”. Environ. Health Perspect. 115 (5): A250–6. doi:10.1289/ehp.115-a250.

4 thoughts to “XEs in the Kitchen: Nonstick Pans”

  1. 連球毛の心配事を治す手立ては、シャンプーなどなど挙げられます。

    おまけに、ちぢれ毛には、保湿成分であるグリチルリチン酸ジカリウムや海泥タナクラクレイ他多数配合された薬用ヘアソープが一番お奨めです。

  2. こんにちは。
    通りがかりの者で急のコメントでおじゃまします。
    じぶんの露出部分のこんがり日焼けってしんどいですよね、かなり。
    敏感肌でおこまりでいる方は基本的に紫外線が怖いのでお肌がくすみ、ソバカスとかシミができて肌年齢と見た目年齢が同年齢よりも年老いて疑われるのが問題。優しいスキンケア商品で紫外線を受けたお肌のスキンケア対策をすることが肝要です。
    肌トラブルのひとは平素のスキンよりも守るシステムが弱まっていますので紫外線のダメージを受けやすい肌と言えます。
    紫外線というものは、こまめな対策を行わないでいると弱い肌は特に影響を受けやすいので肌に蓄積されるので見た目年齢が老けて見え、しみ・そばかすの原因を作ってしまうのです。
    弱い肌専用のスキンケアアイテムを用いたりして有害光線を受けた肌のスキンケアをしてあげることが肝要です。普通に言うと、太陽の光というのは太陽が消えている時でも被害を受けています。太陽の光自体は熱いものではありませんので晴れている時以外は意識する事はあまり無いかもしれません。しかし、普段の生活において、太陽の光自体は肌に影響があることを考慮しておきましょう。

  3. 万能の食べ物と言われる納豆ですが、高血圧に対しては都市伝説レベルの噂があります。体に有能なのか、効果的でないのかといったことです。

    何よりもまず、よろしいと噂されている訳ですが、ナットウキナーゼの存在が大事でしょう。この酵素が血液の流れをよくしてくれるのです。
    また、レシチンという成分は悪玉コレステロールを減らしてくれる期待させます。

    次に、悪いと噂されている根拠ですが、タレや醤油に含まれる食塩が証拠です。付属のタレだけで1日分の塩分量が含まれるためです。

    それから、ナットウキナーゼはワーファリンという薬の動きを妨げてしまいます。

    ですので、納豆は高血圧の予防に醤油やタレをかけずに食べると良いでしょう。

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