Non-Stick Cooking Surfaces

[beauregard]

I have always resisted cooking with non-stick pots & pans because I believe that the chemical constituents of the non-stick surfaces get into the food and can't possibly be harmless to the body.

But I'm guessing that eGullet members have been researching this for years, and I'd be glad to hear comments about general non-stick safety, and specifics of products that are deemed safe.

Thanks!

~ beau

Edited February 25, 2009 by beauregard (log)

[tim]

Beau,

It is obvious that seasoned cast iron and carbon steel pans, both non-stick, are completely safe, from your perspective.

I am not aware of any research that documents your belief for pans that are used as recommended by manufacturers.

Tim

[beauregard]

Tim ~

>> seasoned cast iron and carbon steel pans, both non-stick <<

It's good to be reminded of the basics. I've used carbon steel for years but never thought of it as non-stick, so after reading your post I did a search for seasoning carbon steel, and now I'll season all my carbon steel pans.

This is the method I found . . . let me know if you know of a better way.

Get pan hot, carefully brush pan with fat, keep heating pan until all fat blackens, rinse pan, dry pan, and repeat all in sequence, until a dark, enamel-like finish is achieved.

Thanks!

~ beau

[slkinsey]

I should point out that carbon steel and cast iron, regardless of how well seasoned, are not "nonstick" in the same sense as PTFE coated cookware is "nonstick." There is a vast gulf between their food-releasing properties.

[paulraphael]

The safety issues with PTFE have been wildly exagerated (and sometimes fabricated) by the online pseudoscience community.

Here's all you need to know:

1) PTFE is chemically inert as far as your body is concerned. You could eat a pound of it. And you'd poop out a pound of it. There isn't a single known solvent in your body that can absorb PTFE. This is one reason that it's routinely used in permanent implants in the body, like artificial limbs and heart valves.

2) The gaseous chemicals produced by overheating PTFE to the point of destruction are poisonous. Exactly how harmful they are is a subject of debate; they're known to be very harmful to small creatures like birds. Kind of like the canaries in coal mines that would die from methane gas before any people were effected.

However, this is just one reason not to overheat your teflon pan to the point of destruction. If you're reaonably careful, and don't preheat the pan on high heat for a long time, and don't use it for aggressive browning of foods (which these pans are lousy for anyhow), you'll be fine.

This destruction won't catch you by surprise. You'll actually see the coating smoking and deteriorating. If this happens, take it off the heat, open a window, and when the pan cools down, pitch in the recycling.

3) You probably only need one or two of these pans anyhow. If you consider them specialty items, for cooking eggs and delicate fish, then you'll never have to worry about heating them past the point of no return.

[tim]

Beau,

Sam is exactly right about the difference between PTFE (especially new) and seasoned carbon steel but understanding the pans limits may make the effort worthwhile.

Carbon steel requires the use of some fats when you use the pan. In my experience, that bridges about 85% of the "vast gulf" with PTFE pans. While, eggs do not stick to my carbon steel pan, but they may need a swipe with a soft silicone spatula to completely release with no residue remaining in the pan. That's pretty close.

You also have to be careful about cleaning the pan; there is potential to leave inappropriate flavors in the pan when cooking. You don't want your cheese omelet to have the taste of last nights sauteed trout.

I cannot say the same about my rough textured cast iron pans. They tend to stick.

When seasoning, it is helpful to turn the pan upside down in your oven with a sheet of foil to catch the drips. You want an even, shiny coat on the steel.

Tim

[Fat Guy]

I have some really well seasoned cast iron and carbon steel skillets and I have to agree with Mr. Kinsey that they're not even close to Teflon when it comes to the ability to release food. Of course, any pan with enough fat in it will become "nonstick" but the whole point of real nonstick cookware is that it has those nonstick properties without the fat. In terms of nonstick surfaces -- real ones -- from a safety standpoint they're all the same. They're all PTFE, aka Teflon, just with different fancy names meant to confuse and misdirect consumers and the media. I think they're all perfectly safe. But if one of them isn't safe, they all aren't.

[slkinsey]

2) The gaseous chemicals produced by overheating PTFE to the point of destruction are poisonous. Exactly how harmful they are is a subject of debate; they're known to be very harmful to small creatures like birds.

There is a rather extensive thread on polytetrafluoroethylene exploring and clarifying many of these issues, which may be found here.

Just to clarify this point: PTFE doesn't produce "gaseous chemicals." (I'm not sure that a chemical can be "gaseous" to begin with, but that's neither here nor there and largely a matter of definition and usage.) When PTFE is heated to very high temperature, it can "shed ultrafine particles" into the atmosphere. In certain animals with very small and/or fragile respiratory apparatus, these ultrafine particles can clog up the works and produce symptoms up to and including death. It is not a great idea to keep your parakeet in the kitchen for a variety of reasons, and this is one more of them. My understanding is that it is the "ultrafine-ness" of the particles that makes them harmful, not necessarily the fact that these particles are composed of PTFE. Once the particles are inside your lungs, they're no better or worse than a similar coating of, say, ultrafine dust particles or wheat flour particles would be.

[paulraphael]

Just to clarify this point:  PTFE doesn't produce "gaseous chemicals."  (I'm not sure that a chemical can be "gaseous" to begin with, but that's neither here nor there and largely a matter of definition and usage.)  When PTFE is heated to very high temperature, it can "shed ultrafine particles" into the atmosphere.

I'm not sure where you're getting this. Thermal breakdown products of PTFE include toxic gasses such as perfluoroisobutene, octafluoroisobutylene, and tetrafluoroethylene.

(And I'm using the term "gaseous" because it describes the physical state of the chemical in the situation we're talking about).

Some more info can be found here and here.

But again, this isn't a panic alert, just an addtional reason beyond common sense to avoid incinerating your teflon pans. Significant pyrolysis doesnt occur until 530°F or so ... well past the point where any oil in the pan would be turning into clouds of smoke.

[Dave the Cook]

Just to clarify this point:  PTFE doesn't produce "gaseous chemicals."  (I'm not sure that a chemical can be "gaseous" to begin with, but that's neither here nor there and largely a matter of definition and usage.)  When PTFE is heated to very high temperature, it can "shed ultrafine particles" into the atmosphere.

I'm not sure where you're getting this. Thermal breakdown products of PTFE include toxic gasses such as perfluoroisobutene, octafluoroisobutylene, and tetrafluoroethylene.

(And I'm using the term "gaseous" because it describes the physical state of the chemical in the situation we're talking about).

←

To expand on this: all plastics outgas, especially in the period closely following manufacture. An example almost everyone knows: that "new car" smell.

But Sam and paulraphael are correct. Used according to manufacturer's directions, PTFE is perfectly safe for humans.

[slkinsey]

Just to clarify this point:  PTFE doesn't produce "gaseous chemicals."  (I'm not sure that a chemical can be "gaseous" to begin with, but that's neither here nor there and largely a matter of definition and usage.)  When PTFE is heated to very high temperature, it can "shed ultrafine particles" into the atmosphere.

I'm not sure where you're getting this. Thermal breakdown products of PTFE include toxic gasses such as perfluoroisobutene, octafluoroisobutylene, and tetrafluoroethylene.

These are all pyrolysis products, Let's just say that I have my doubts as to whether meaningful pyrolysis happens in real-world situations with PTFE all that often. And when it does, I'd suggest that whatever minute amounts of perfluoroisobutene, etc. that might be produced would be the least of your worries (certainly when contextualized relastive to the various outgassings that happen all around us all the time, as Dave points out). DuPont says that PTFE coatings don't start to degrade significantly until around 660F and above.

More to the point, when people overheat their PTFE-coated pans and the finches they keep in the kitchen die, this is because their lungs were clogged with the microfine particles I posted about above -- not because they succumbed to a cloud of poisonous octafluoroisobutylene gas.

Edited March 4, 2009 by slkinsey (log)

[tim]

  In certain animals with very small and/or fragile respiratory apparatus, these ultrafine particles can clog up the works and produce symptoms up to and including death.  It is not a great idea to keep your parakeet in the kitchen for a variety of reasons, and this is one more of them.  My understanding is that it is the "ultrafine-ness" of the particles that makes them harmful, not necessarily the fact that these particles are composed of PTFE.  Once the particles are inside your lungs, they're no better or worse than a similar coating of, say, ultrafine dust particles or wheat flour particles would be.

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I assume that small birds are also at danger when exposed to flour particles in a bakery. Is this correct?

[slkinsey]

I wouldn't think it was a great place to keep a parakeet, but I doubt that the particles of flour that might be in the air at a bakery are sufficently fine or present in sufficient concentration to be a major danger. That's just a guess, of course. The one place you definitely wouldn't want to keep your parakeet is in a flour mill, where flour dust is sufficiently fine and present that there can be a serious risk of explosion if it gets into the air.

[MaxH]

This topic belongs in an FAQ file somewhere -- I've seen it reappear in public Internet food discussions since, literally, the middle 1980s. paulraphael's comments (especially the opening pph!) were excellent. More:

a) The reason teflon-type plastics are "non-stick" is their extreme inertness, which is also why the plastics don't interact at all with food or the human body. (I've held bottles of hydrofluoric acid in PTFE -- it will dissolve glass and most minerals -- that's inertness.) That also is why I've never noticed off flavors in acidic delicate cooking (like lemon or wine sauces) in PTFE, where I have seen it from cast-iron or bare-aluminum pans, both inherently vulnerable to this whatever the dogma of their faithful. Some anodized metal pans (effectively ceramic-coated) are also inert, but much more expensive.

b) Vast misinformation circulates about nebulous vapors said to emanate (like some H. P. Lovecraft story). Here's what happens. If left unattended while cooking, at several hundred degrees F the PTFE decomposes releasing toxic gasses. (That actually is harnessed in an exotic efficient rocket engine used only in outer space called an ion drive.) As paulraphael said, you shouldn't use these pans if you are apt to leave them on heat unattended. Here's the rest of the terrible truth: you shouldn't use any pans if you are apt to leave them on heat unattended. Any surface with food, food residue, or seasoning oils releases highly toxic gasses at similar temperatures.

c) The "bird" misinformation point. (From a bird owner.) I've seen people anxious about PTFE pans because they keep birds. Wrong. They should be anxious, if at all, for all creatures including themselves. Decomposition gasses toxic to birds are toxic to humans. Birds have a faster respiration, therefore show effects at smaller gas concentrations (which is why they were early low-tech gas detectors in mining).

d) Every mainstream US commercial kitchen and restaurant-supply house I've seen for decades was full of nonstick-coated pans, they're the industry norm. With millions of them used in commercial kitchens, can you imagine the lawsuits if health problems had developed?

e) These are not new issues, they were all public by the 1960s, for anyone who cared to notice.

[gfron1]

All of the science aside, I sell a variety of lines of cookware including Cuisinart. Late last year they promised us a completely teflon/PFOA/etc free product. I haven't seen it yet, but I haven't opened my new catalog that came a couple of weeks ago. If true, that would be the safest non-stick. However, if true, I assume there would be a media blitz regarding the product.

[slkinsey]

The FDA says:

When heated for long periods at high temperatures, the resin decomposes. However, a 1959 study, conducted before FDA approved the material for use in food processing equipment, showed that the toxicity of fumes given off by the coated pan on dry heating was less than that of fumes given off by ordinary cooking oils. The study, conducted by the Haskell Laboratory for  Toxicology and Industrial Medicine, compared effects of inhaling of fumes from resin-coated pans that were overheated for four hours at 250 degrees Celsius (482 degrees Farenheit) with corn oil, peanut oil, and butter.

The investigators, J. Wesley Clayton, Ph.D., and Gayle E. Raynesford, also explored the possibility that long-term use of the coated pan also increases the chance of food contamination with the resin. Newly coated  resin pans, an aged pan (a pan that had been heated at 250 degrees Celsius (482 degrees Farenheit) for 159 hours), and a pan that had received two-and-one-half years of domestic use were used to fry hamburger meat.

Researchers compared the results with those from frying hamburger in an uncoated aluminum pan, measuring levels of fluoride, which serve as an index to Teflon residue. (Aluminum contains traces of fluoride as impurities.) An analysis showed basically the same amount of fluoride in the hamburger cooked in the new resin-coated pan as in the one cooked in the plain aluminum pan. Slightly more fluoride but well within safe limits showed up in the hamburgers fried in the heat-aged pan and the old pan.

[slkinsey]

All of the science aside, I sell a variety of lines of cookware including Cuisinart.  Late last year they promised us a completely teflon/PFOA/etc free product.  I haven't seen it yet, but I haven't opened my new catalog that came a couple of weeks ago.  If true, that would be the safest non-stick.  However, if true, I assume there would be a media blitz regarding the product.

A few things here:

1. To the best of my knowledge, there is no "nonstick" without PTFE. Some manufacturers have offered non-PTFE products that they claimed were nonstick, but which in fact offered nowhere near the food releasing properties of a PTFE coating.

2. Supposing that a company invents a nonstick coating that offers the same food releasing properties as PTFE. Who is to say that this coating will be any "safer" than PTFE? It seems rather likely that most anything that offers the same benefits as PTFE is also going to release some small amount of funky stuff when heated up to 600 degrees. It seems doubtful to me that no one has ever discovered a coating that is just as "nonstick' as PTFE. Rather, it's likely that any such discovered non-PTFE coating has turned out to degrade into more/worse stuff when heated, is less durable, etc.

[MaxH]

All of the science aside, I sell a variety of lines of cookware including Cuisinart.  Late last year they promised us a completely teflon/PFOA/etc free product.  ... If true, that would be the safest non-stick. 

←

It sounds to me like superstition-based marketing, if they stress "teflon/PFOA/etc free," and here's why. There have long been inert non-PTFE coatings anyway as I mentioned, the anodized or similar products, which tend to be high-end but built to last. Stainless also is extremely inert -- I didn't mention it before because this is a thread about "non-stick."

I don't know Cuisinart's products but if their coating is inorganic mineral then it's in the anodized class I mentioned, and if it's a plastic it will decompose like teflon at high temperatures, and marketing such a product on the basis of "teflon-free" would be highly cynical (even if welcomed by some really, realy clueless consumers as such things sometimes are.)

[cbread]

I can't imagine cooking without Teflon. It is incredibly inert, so I don't see how it's a danger.

[paulraphael]

My take on this is similar to Slkinesy's, with a few shades of difference.

I think there's reason to be more cautious with PTFE pans on high heat than with other pans. I routinely preheat my stainless lined cookware to temperatures that would incinerate food if the food itself didn't act as a heat sink, lowering the temperature of the pan on contact. With seasoned iron or steel cookware, I don't go quite as far, but almost. The biggest risk there is damage to the seasoning, which is renewable.

But I never heat PTFE like this. Not just because foods suited to nonstick pans rarely require it, but because it will damage the pan. At best it will shorten the already short useful life of the coating. At worst it will kill it in one session.

And the breakdown products of radically overheated PTFE ARE more toxic than the breakdown products of cooking oil. Take a look at the sources I linked above.

The 1950s FDA study that was mentioned specifically sites temperatures of 482 degrees F. This is considerably lower than the temperatures a pan might reach when preheating for an aggressive sear. Even DuPont's current FAQ is based on the assumption that 500°F is a higher temperature than a pan will encounter outside the broiler. Not in my house! Above 530°F, significant quantities of organic gasses, of the types you probably don't want to be huffing, start liberating into the kitchen.

So my habits with PTFE pans are significantly different from my habits with anything else. If I owned pans lined with tin, which melts a bit below 500°, I'd treat them similarly.

As far as the comment on birds being more sensitive to airborn toxins, yes, that's true. But toxicity is ALWAYS a factor of dose. The world is full of chemicals that are harmless or even beneficial at one dose, and deadly at another. In fact most earthly substances could be described this way. Birds, not just because of size but because of their exceptionally efficient respiratory systems, suffer from many airborn toxins and irritants at radically lower concentrations than we do.

The sensible conclusion isn't "don't expose the bird to anything you wouldn't expose yourself to." Rather, it's "keep the f'ing bird far away from the kitchen no matter what kind of pan you use." Because there all kinds of airborn vapors and particulates in the kitchen--ones we can breathe deeply if not happily for a lifetime--that can knock birds off their perches in short order.

Click.

Edited March 6, 2009 by paulraphael (log)

[tim]

Akzo-Nobel hase developed a polymer-based silicone-hybrid non-stick cookware coating. Cookware featuring this coating is now available.

Tim

[slkinsey]

Tim, any more information on that. It's interesting in light of the fact that Akzo-Nobel recently agreed to "divest its non-stick coatings business to privately-owned, US-based company Whitford Worldwide. I'm guessing you're speaking of their Eterna product? I haven't seen anything saying that it's not fundamentally a formulation of PTFE -- but maybe I'm looking in the wrong places?

[MaxH]

Not to say teflon-type coatings are for everything. The coatings (inert plastics) are relatively soft and don't tolerate much contact with metal utensils. As already mentioned, they aren't suited to the highest direct-flame dry cooking; I use them for things like toasting sesame seeds and Sichuan "peppercorns," but with moderate heat and with constant stir-fry. For that matter, bonded cookware, like Farberware and others with bottoms of different metal than the cookware surface, aren't suited to full direct flame either, for a different reason: It stresses the bond and could potentially cause de-lamination. (Farber warns of that.)

By about 450 F, most hydrocarbons (including foods!) decompose to smoke and toxic (and combustible) gases; as you may know, this (not the heat) is what typically kills people in fires.

My point on birds isn't, either, that if it's OK for you, it's OK for birds. I'm careful with birds, there's no reason to expose them to cooking anyway, where other gases issue in low concentrations routinely, incl. minor food smokes and gas-flame combustion byproducts. My point is, rather, that if it's not good for birds, it also is not good for you, and should be treated so. That's explicitly true of examples in paulraphael's link (carbon monoxide, ammonia, etc.) The common myth I hear is that somehow only birds are sensitive to toxic gases, implying that if you didn't have birds, you could safely leave your teflon cookware on heat, empty and unattended.

toxicity is ALWAYS a factor of dose.

←

A profound point. Water is toxic at extreme dose, botulinum toxin is medicine at very low dose. This needs emphasis to writers (like some latter-day absinthe experts) who blithely label things "toxic" or not according to their notions, as if it were a yes-or-no property.

[...tm...]

I'm a dirty hippy, but not one that is worried, ipso facto, about "man-made" chemicals getting into my body (as I'm also a scientist), but one who abhors waste and buying things for temporary use, especially if they are extremely difficult to reuse/repurpose. The thing I dislike most about PTFE-coated pans is that the coating generally starts flaking off after a year of use or so. Even if this is because the pan was used against manufacturer's instructions, I do not keep my pans under lock and key, nor am I usually extrememely careful when cooking, and this type of thing is bound to happen.

I'm wondering if anyone has tried the "Green Pan" that keeps tempting me at Target. It claims "Thermolon is high heat resistant - up to 850 F". What is Thermolon? I don't really have any idea after looking at their website http://www.green-pan.com/ and some minimal google attempts. "Thermolon is a non-stick mineral coating base on Sol-Gel technology with superior release properties but contains absolutely zero PTFE (and zero PFOA) and no silicone oil."

So I guess I would like to know if the Green Pan is non-stick enough that it easily releases eggs without much oil and if there are any problems with the coating flaking off the underlying material (although it may be too early to tell, as I've only seen the pans the last several months).

[tim]

I'm wondering if anyone has tried the "Green Pan" that keeps tempting me at Target.  It claims "Thermolon is high heat resistant - up to 850 F".  What is Thermolon?  I don't really have any idea after looking at their website http://www.green-pan.com/ and some minimal google attempts.  "Thermolon is a non-stick mineral coating base on Sol-Gel technology with superior release properties but contains absolutely zero PTFE (and zero PFOA) and no silicone oil."

So I guess I would like to know if the Green Pan is non-stick enough that it easily releases eggs without much oil and if there are any problems with the coating flaking off the underlying material (although it may be too early to tell, as I've only seen the pans the last several months).

←

I think this is the pan that uses the Akzo-Noble coating.

Tim