The "soap and solvent" is sodium hydroxide (lye) and DMSO at 120 degC. Those are... fairly... well behaved chemicals, but lye is stout stuff and DMSO attacks nitrile gloves.
You could imagine a remediation process that uses this process but the combo ain't exactly Dawn dish soap. I'd almost prefer pyroprocessing over it.
About 40 years ago I boarded my horse with an old cowboy who used DMSO as a horse liniment. He had been using it for years any time one of his mounts was worked pretty hard or when someone brought a lame horse to him. He would rub the joints, calves, and thighs of the horse down good with DMSO for a few days and then they were good to go again.
He also used it on his wife. He told me that she had type I diabetes and neuropathy as a result. Her feet were always cold from poor circulation. That was true until he happened to rub her feet one day after treating a horse. Her feet warmed up in minutes and became normal pink again. After that, he used it on her feet and legs since it improved circulation.
You can say what you will about it being reactive and possibly not good for you but she was able to dance again and get back on her horse so it definitely does have some benefit. They did this for at least 30 years and both of them were past 75 years old when they passed away.
Like another poster said, it is used as a carrier for some medications since it pulls them straight into the bloodstream. I don't think it's magic but I also don't think you'll suffer much using it even with bare hands.
As far as lye is concerned, the sodium hydroxide in this paper, you can easily make that yourself with wood ash and water. It is pretty handy if you are tanning hides since the treatment of a raw hide with lye causes the hair to slip right off leaving a smooth skin ready for the next step.
Are you certain it was DMSO and not DMSO2? I ask because quite a few ointments for horses have DMSO2/MSM. I use it on horses with horse specific formulas and on myself in a cream designed for humans called Penetrex.
I can not be 100% certain this far down the road what he used on his horses or his wife but at the time, he told me that it was DMSO. I don't know where he got it but he was well-connected in the horse world.
He had a long career as a wrangler for Hollywood westerns after setting several records himself as a young cowboy in rodeo events as a bronc-buster, calf roper, header/heeler even setting one record in a rodeo at Madison Square Garden. He participated in founding the American Quarter Horse Association. He told me he had trained several actors over the years including a couple from the old TV series Rawhide who had never ridden a horse before that show. He knew Gene Autry, Tom Mix, Roy Rogers and Dale Evans, and worked with them and other western movie stars at one time or another. He knew horses, mules, saddles and tack like the back of his hand and he understood cigars, whiskey, and women intimately as any real man did back then.
My wife uses Penetrex here at home for sore muscles. She claims to get some benefit from it. I was not aware that there were two compounds, DMSO and DMSO2 but we definitely have Penetrex here at home.
It is possible that the product he used back then was DMSO2 if it was widely used in the 60's through 80's in horse liniment. I actually had to look them up to get a feel for the differences between them.
DMSO also makes your breath smell like garlic after you’ve had it on your skin. I wouldn’t want to be around a horse that’s had a healthy dose, and I certainly wouldn’t love if my wife had to use it every day.
Yeah, so I've heard. Life is full of trade-offs and if I knew that it would help my wife I'd rub that shit all over her and buy lots of Peppo-mint Life Savers so she never had to do without.
To fix such a serious issue OP is mentioning for your life companion? WTF is wrong with people? If you are married and will stay together till end, worse things will come along from both sides. Will you just ignore her then or tell her to not ruin your day with her petty issues?
Btw garlic consumption and subsequent breath is fairly common in many cultures for millennia due to its very positive health effects, just not among snobbish posh ones. There are plenty of solutions to bad odor, easiest being along the line of "if you can't beat them join them" - if you eat even just a bit of raw garlic, nobody smells bad to you anymore.
Oh come on - obviously I would deal with it if it was necessary for my wife's health/happiness. Don't jump to judgy conclusions over what was primarily a joke.
DMSO is not well-behaved. It easily penetrates human skin, and carries solutes with it. Don't touch!
"DMSO can cause contaminants, toxins, and medicines to be absorbed through the skin, which may cause unexpected effects.
"Because DMSO easily penetrates the skin, substances dissolved in DMSO may be quickly absorbed. Glove selection is important when working with DMSO. Butyl rubber, fluoroelastomer, neoprene, or thick (15 mil / 0.4 mm) latex gloves are recommended. Nitrile gloves, which are very commonly used in chemical laboratories, may protect from brief contact but have been found to degrade rapidly with exposure to DMSO."
Have heard that many times, but in grad school it was determined orthogonally to any funded/published project, with n>3 subjects of various skin phenotypes, that many super-potent small molecule compounds were not active topically in DMSO even at 100-10000x doses regardless of polarity... Read between the lines of course. Would not trust safety to that observation with any non-fun chemicals but still.
Unrelatedly, microwave assisted reactions in DMSO solvent wete found to have some totally gross failure modes that were a pain to clean up and got banned in the lab
I once had a long-running (weeks) experiment that used DMSO as a solvent. Early on it was realized that the DMSO was degrading all non-glass rubbers and plastics in the chemical "circuit", which began to sag like an old TinkerToy structure. Had to rebuild/rerun with parts that were resistant to DMSO.
From my understanding, when a solution like DMSO with PFAS enters our blood stream it gets highly dilute. Solvation binding of solvent (DMSO) and the solute (PFAS) now has to compete with binding from all sorts of other proteins, fats, carbohydrates, etc.
In this incredibly dilute state, the previous mixture of molecules now spreads out and gets taken up by different tissues. The tissues that take up the compounds depends in the molecular properties of the compound in question, so something like PFAS which are highly lipophilic (iirc) meaning fat soluble, they will be taken up by cells pretty readily as they can easily cross the lipid bilayer membrane but will be stored in adipose tissue and continue impacting those cells and possibly be slowly released over time to impact the organism systemically. This of course will depend on initial dose concentration, duration of exposure, adioposity of the organism, along with a multitude of other factors.
The study of how compounds circulate in this way is a subfield of pharmacology known as Absorption, Distribution, Metabolism, and Excretion (ADME)
To be fair to the op - in chemistry well behaved means - it is more stable than nitroglycerin, less reactive than fluorine and less toxic than dimethylmercury.
Aka - won't kill you outright if you are just properly careful.
I think they meant well behaved in the sense that it isn't highly reactive - e.g. doesn't explode in contact with air. Not so much what it does to humans.
We're talking about fluorine chemistry here, so things get kind of extreme.
Well that's the problem, right? The more stable the substance you're trying to degrade, the more intense the conditions or chemicals you need. Teflon is inert as a rock, so if you for some reason needed to dissolve it in acid then you have to reach deep into the realm of impracticality and pull out demonic reagents like chlorine trifluoride or trihydridoboron.
DMSO is used in pain relief in other countries (eg Mexico). It's also excellent for burns as it allows the body to repair a tiny amount of nerve damage or prevents it. Hard to say. This is demonstrable by burning yourself, I guess. My family and I have used it for burns for over 20 years. Granted, we don't get burned/encounter people who have been burned at home that often. I had a close friend with a rare disease (McCune Albright's Syndrome) who used it for pain relief, after I treated a burn she received.
It has been reported that it use has repaired massive nerve damage, which is probably coincidental. It is sold in healthfood stores in the US, but you want to dilute it 1/100 parts water. While it is primarily used as an industrial lubricant, on contact, it immediately travels through the skin to the nervous system. Most people get the strange reaction of the taste of oysters, when it's absorbed. There is a small percentage of people with various allergic reactions, like with many chemicals.
I would never mix it with soap, for any reason. It's like mixing shoe polish or granola with soap, you just end up with a mess of concerns.
it was an expensive prescription med a few years back. I get dyspepsia from NSAIDs so I thought, "Could I make an ointment like that with ibuprofen?" and looked in the literature and found that ibuprofen is absorbed quickly with DMSO even more so than diclofenac. So I made a batch, but when I tried it I found I'd get dyspepsia very quickly after applying it to my skin so I guess the ibuprofen was being absorbed efficiently.
DMSO was purportedly involved in the case of the “Toxic Lady”[1], who apparently used it as a pain relief agent and ended up intoxicating the hospital workers assisting her.
> Computer calculations by colleagues at the University of California, Los Angeles, revealed DMSO knocks off the carboxylic acid group. “Once that happens it causes the entire molecule to fall apart in a cascade of reactions,” Dichtel says.
Big if true. I'm slightly skeptical that just decarboxylating PFAS causes the rest of the backbone to "fall apart" - I would expect it to form CF3[CF2]· (carbon radical) which would readily react with water to form -H or -OH, which is basically back to square one. But maybe it can eliminate HF in the presence of UV, forming CF3[CH2]CF=CFOH, which gets hydrolyzed, oxidized, then cleaved, but boy is that an unfavorable process.
(edit: skimmed the paper, I was pretty close. Forms CF3[CF2]- which goes to CF3[CH2]CF=CF2 which then gets hydrolyzed, but...DMSO/NaOH at 80-120°C ...yikes. This is the ochem equivalent of "nuke the site from orbit", very few compounds survive these conditions)
I've been out of the chemistry game for a few years now so I'm a bit rusty but gut instinct is that this is far from a slam dunk. But anything to reduce FC's is a boon to the world, so I'm hopeful this is a breakthrough.
Edit2:
> This high fluoride recovery indicates that most of the perfluoroalkyl fluorines were defluorinated and mineralized rather than being transformed to smaller-chain PFAS or being lost as volatile fluorocarbons.
So the surprising thing isn't the decarboxylation, it's that NaOH encourages the perflourylalkenes to cleave at sites away from the alpha (splitting, rather than carbon-by-carbon), which is neat. Still doesn't touch PFOS, unfortunately.
Headline is a lie: as we finally find out halfway through the article, it's not soap but lye, sodium hydroxide. The solvent is the fairly nontoxic dimethyl sulfoxide, so both of these are safe to release into the environment. In https://news.ycombinator.com/item?id=32515659 sbierwagen reports that the reaction requires 120-degree temperatures so this isn't suitable for in-situ remediation.
The reaction doesn't "require" 120C, that was simply the first experiment they described. They began by confirming that this reaction actually takes place and discovering which PFAs were neutralized by it. To that end they boiled a mixture of the stuff for 24 hours.
The reaction can occur at more moderate temperatures. There is more analysis (with experimental results) further down in the paper:
> Substantial defluorination still occurred when the isolated PFOA degradation product (perfluoro-1H-heptane 2) was subjected to degradation conditions but heated to only 40°C (table S3).
Okay, but you can't, for example, heat up large masses of contaminated dirt to 40° without killing everything in them. And you probably can't even saturate them with DMSO, both because even though it's relatively nontoxic it's not that nontoxic, and because it's expensive.
Ummm... What?
120C NaOH does *not* sound safe "to release". I've worked with similar solutions. That stuff eats through so much and it's a pretty scary solution, if at high concentration.
As with everything, It very much depends on the concentration.
NaOH is only unsafe because it's highly alkaline, but it doesn't stay highly alkaline after it encounters buffers like bicarbonate or hydrogenphosphate, which are abundant in the natural environment. After it's been neutralized in this way, it's just sodium ions, and while enough of those will indeed cause environmental damage (witness salinization-induced desertification in much of the Middle East) it takes truly massive quantities.
That's honestly one of the things I wish we could get a handle on.
Company gets sued for using and hiding the danger of a compound they learned fairly quickly was toxic. Goes and invents another compound and switches to it without having to prove its safety. After it becoming public that they were intentionally hiding dangers for a half century, I feel we should take away their ability to be given the benefit of the doubt.
All I think they learn from these lawsuits is that they need to get better at identifying and removing people who will call them out on their bullshit.
Edit - I know the whole thing with DuPont was using PFOAs in the manufacturing process and leaking (intentionally dumping) them into the environment, but it's not like the final product (Teflon) is safe to ingest either, which as a cooking surface, you most definitely will in some quantity.
> but it's not like the final product (Teflon) is safe to ingest either
Sure it is. I don't think a less toxic material than Teflon even exists. It's toxicity is comparable to water.
The LD50 of Teflon is > 11,280 mg/kg. Water by comparison is 90,000 mg/kg. They were not able to measure the exact toxicity because it's impossible to eat so much.
Is LD50 a meaningful measurement for biopersistent and accumulated compounds? It seems like it would be quite useless, or worse, misleading.
I recall that large blobs of mercury was used as a homemade remedy for stomach issues which turned out to not be a great idea for obvious reasons, although it's LD50 would probably have been similarly high.
LD50 only tells you acute lethal toxicity. LD50 can be astronomically high and a compound might still have long term, non-lethal toxic effects like injuring specific tissues.
No one is even suggesting lethal toxicity is the issue here, so how is it relevant?
Bullshit. There is “toxic” and there is “causes cancer, even outside California, reduces fertility, and negatively affects fetal development.” Just because something doesn’t kill you immediately does not mean it isn’t harmful.
Even inert materials can do stuff, such as prevent other reactions or act catalytically or have physical impacts (collision which defold molecules, make certain things heavier by being enclosed or enclosing ... ).
Furthermore PTFE is know to interact with Gallic Acid [1] somewhat. The body contains gallic acid
I really appreciate you making the effort to debunk the witch-burners; have you thought about doing it in a less ephemeral medium? Your comment will probably be here for a decade or more but nobody will read it after this month.
But the claim in question is one of the best-known and most thoroughly established claims in all of toxicology. Asking for scientific research supporting the biocompatibility of PTFE is akin to asking for scientific research supporting biological evolution or the claim that people have landed on the moon: it's a sure sign that the person making the demand has a pre-existing flimsy pretext for rejecting literally all the research in the relevant field, which did indeed turn out to be the case; see https://news.ycombinator.com/item?id=32517203.
If it's truly such a well established claim it should be trivial to find and link a study actually demonstrating its safety when ingesting small amounts over a large period of time. No such study was linked. Probably because longitudinal studies are extremely rare.
It's not a rejection of all research to say that some questions remain unanswered. In fact, I'd say it is the foundation of good science to understand which claims are supported by evidence, and which claims are not.
There are half a dozen studies per year, going back decades, assessing the safety of PTFE in implants. Many of them are longitudinal. Chemists routinely boil PTFE in acids such as hydrochloric and sulfuric for hours without degrading it even slightly; such degradation would contaminate their reactions.
I bet you can't find a study demonstrating natural selection in the split-leaf philodendron, either, but that isn't a good reason to go around saying "some questions remain unanswered" about whether the split-leaf philodendron is an exception to the laws of evolution.
The two comment threads are the same discussion so I'm merging my responses.
> I bet you can't find a study demonstrating natural selection in the split-leaf philodendron, either, but that isn't a good reason to go around saying "some questions remain unanswered"
It absolutely is! The criterion for whether a question has been answered is whether that question has actually been asked, studied, and answered. In cases where there is no specific evidence, you attempt to make assumptions that extend existing evidence into spaces that it does not explicitly cover. But these aren't answers; they are educated guesses. Some guesses are better than others, and really the fundemental act of science is feeling out these hypotheses and deciding which ones are sturdy and which are shaky.
So for example consider the claim 'PTFE doesn't affect human health when ingested, because there is strong evidence that is safe in implants and is chemically inert in acids.' This claim relies on two assumptions in the absence of quality direct supporting evidence: (1) Safety in one biological context directly transfers to other biological contexts and (2) Chemically inert compounds cannot affect human health. There is mounting evidence against ~both~ of these assumptions, and so claims based on them should be treated with caution, and probably as warranting further study. This is no witch-hunt, this is simply using critical thinking and available evidence to gauge the validity of assumptions, and updating the validity of claims based on changes in the validity of underlying assumptions. This process ~is~ the scientific method.
> Nanometer-sized pores matter enormously, (...) but not in ways that make other forms of amorphous silica more toxic than silica gel.
Try replacing your morning cheerios with silica gel and let me know the results. The pores in silica gel are specifically interesting because they allow silica to readily form hydrates. The human body has a lot of water in it. There are absolutely health effects that depend on the physical shape of silica in addition to its chemistry compared to say, consuming an equal mass of fully dense quartz particles.
You'd probably have to eat a lot of silica gel to really feel the effects, but there are other more accessible and serious health concerns that are driven by nanometer or smaller physical effects. The reaction between diet coke and mentos is primarily physical, driven by nanometer-scale surface roughness on the candy. Proteins sometimes fold in abnormal shapes, and in the right circumstances, the presence of a chemically identical but differently-shaped protein can induce other proteins to change shape as well, leading to prion diseases such as Mad Cow and CJD, both of which can be acquired via ingestion of the trigger protein shapes.
The claim that nanometer-sized structural changes in a compound can have no effect on human health when ingested is demonstrably false. Obviously, this calls directly into question the dependent claim that chemically inert compounds can have no possible impact on human health when ingested.
Yes, you can dehydrate your tissues by eating dehydrated silica gel. But when hydrated it's a Generally Recognized As Safe food additive in quantities up to 3% (5% in the EU). You can probably eat a lot more than that but it will grind up your teeth. (By the same token, someone could strangle you with a PTFE cord, a fact that has no bearing on its toxicity.)
Quartz is not amorphous silica, and unlike amorphous silica, it's carcinogenic if you inhale it.
You don't get nanometer-sized structural changes in teflon by scraping it off your skillet with a spatula. You're being ridiculous.
I'm interested to hear what response you get from biologists when you propose to them that natural selection might be inoperative in the split-leaf philodendron. I imagine they'll wish they had a PTFE cord handy.
> Quartz is not amorphous silica, and unlike amorphous silica, it's carcinogenic if you inhale it.
Crystalline silica is still silica.
> You don't get nanometer-sized structural changes in teflon by scraping it off your skillet with a spatula. You're being ridiculous.
The words of someone who has not spent time analyzing electron microscopy of fracture surfaces :) It absolutely does without any possible shred of doubt. But that's not even the point; the point is that the fine physical structure of compounds can matter in biological systems. If you accept this, that it is plainly obvious that chemical inertness of a compounds is an obviously insufficent condition for safety.
> I'm interested to hear what response you get from biologists when you propose to them that natural selection might be inoperative in the split-leaf philodendron. I imagine they'll wish they had a PTFE cord handy.
If you spend a lot of time around people with science PhDs, you will quickly learn that most of us are keenly aware of how little we actually know and how much of it is guessing. Murdering people over disagreements is the domain of religions, not science. Sadly for many these two are interchangable.
And you think that ingesting PTFE is somehow worse than an actual PTFE implant? Why you insisting it must be a digestion study? Do you make such requirements for everything you interact with? Has someone done a study on using paper straws? Or plastic plates? Or metal spoons?
Do you understand that when you eat PTFE it comes out exactly the same way it went in?
Even powerful acids can't do anything to PTFE, what makes you think the body can do anything to it?
Titanium is a common biocompatible implant material, widely considered safe in this context. One of the primary benefits of titanium implants is that that they readily form a TiO2 passivation layer. TiO2 is also common in many topical lotions and sunscreen, where it is considered safe.
TiO2 also has a signficant body of evidence demonstrating that it is a carcinogen when inhaled in particulate form. Just because some compound is safe in one context does NOT mean it is safe in all contexts.
> Do you understand that when you eat PTFE it comes out exactly the same way it went in?
I bet if I asked you to eat shards of glass, they would leave your body pretty close to how they went in :) Whether your body would remain unchanged is another question. While this is an extreme example, there are more subtle ways a compound could interact with the body. For instance, glyphosate has long been considered a safe compound because it "leaves the body the way it comes in." However, recent research has revealed substantial evidence that glyphosate may adversely interact with the human microbiome, which is linked to many various health conditions. This is an active thrust of a lot of new medical research that wasn't strongly considered 20 years ago. It is simply not enough to say the compound remains unchanged, the real question is whether the body is unchanged, and the body is pretty complex and our understanding is very incomplete.
It's not clear which version of the scientific method you subscribe to from your posts, but in general proving a negative is ~really, really~ hard. This list of all possible interactions in the human body with arbitrary chemicals is quite long. The list of things that have been 'proven safe' only to be considered unsafe when studied more carefully is quite long. To suggest that our knowlegde of the safety of ~any~ compound is complete is impossible.
You're confusing TiO2 with SiO2. There is some interesting evidence suggesting that TiO2 nanoparticles may accumulate in the body, in particular in the pancreas, but there is definitely not a significant body of evidence suggesting that inhaled TiO2 is a carcinogen.
It would be pretty interesting if it turned out that TiO2 added to food as a white colorant were responsible for the obesity pandemic --- the epidemiological correlations are about right --- but so far the evidence that it has any kind of harmful effect at all is fairly weak.
Shards of glass are commonly used as a mild abrasive in toothpaste, an inert excipient in pill formulations, and a gas reducing agent in simethicone; they go by the name "amorphous silica" or "silica gel". They're also added to grains as an insecticide in the form of diatomaceous earth. It's commonly accepted by people who study this stuff that they are absolutely harmless to humans at that size.
What about larger sizes :) Physical effects can matter as much as chemical. Diatomacious earth has conflicting evidence anyway. Silica gel and glass aren't really the same thing.
I did mean TiO2. There is a reason the EU considers it a carcinogen and is banning it from several classes of products.
Silica gel is glass with nanometer-sized pores in it. Bottle glass has additional additives that lower its melting point and increase its solubility (oxides of sodium and calcium).
The EU has irrationally banned all sorts of things since the witch-burners have seized control of the government apparatus. Borate fire retardants and fertilizers is one of my favorite examples.
Nanometer-sized pores matter enormously, which is why we make silica gel in the first place, but not in ways that make other forms of amorphous silica more toxic than silica gel.
I'm not dismissing research that disagrees with me as witch-burning. I'm dismissing people who disagree with literally all the research.
> And you think that ingesting PTFE is somehow worse than an actual PTFE implant?
I think that it isn't even close to being equivalent.
> Why you insisting it must be a digestion study
You are the one who made the statement: "It's about the most inert material that you can possibly ingest." so prove it, or admit that this is your opinion and not backed by research.
I'm not even asking for research comparing the effects of the ingestion of PTFE with every other "material that you could possibly ingest", just for any data, at all, on the long term effects of ingesting PTFE.
It's my understanding that the toxicity of ingested PTFE is still an open question, that there is no consensus on the safety or dangers of Teflon in food, and no research into the effects of ingesting it over/after long periods of time (say > 20 years).
If you have actual knowledge of advancements in the science I'd like to see what was found, but otherwise let's just acknowledge that there is still far too much work to be done before we can make meaningful claims about the safety of ingesting PTFE. At best, what we can say right now is that it won't instantly kill you, but the long term effects of ingesting PTFE on the body are unknown.
You can't have a long term study given that PTFE doesn't stay in the system, so there's nothing to study.
Are you planning on feeding people PTFE every couple hours?
> the long term effects of ingesting PTFE on the body are unknown.
They are known. They are non-existent.
You are arguing from bad faith and profound lack of knowledge of chemistry. To even hypothesize that PTFE can do anything, anything at all, to the body would require some new magical chemistry that doesn't exist.
There is nothing in the body, nothing, that can affect the stability of the chemical bonds that make up PTFE - if you had even a tiny bit of scientific understanding you know that, and not embarrass yourself with these demands for studies.
Teflon in isolation may be fine, but your average cookware still contains enough PFOA left over from the synthesis process to cause harm. The replacement to PFOA (GenX?) has also been found in modern Teflon cookware as well.
Also, Teflon out-gasses at temperatures well below your average stovetop flame. Toxic enough that you can't use Teflon cookware if you own birds. It'll kill them.
Not necessarily; if it were oil they would notice the smoke, while the fumes generated by teflon are quite subtle until a much higher temperature. So there have been many cases where people killed their birds before noticing that anything was wrong.
While I'm totally comfortable with eating teflon, I'm absentminded enough that I've overheated cookware many times, so I wouldn't use it if I had birds.
It does not build up in your body, it builds up in the environment. The amount in your body is basically exactly the same as whatever environment you are in.
On top of that, how much PFOA would you imagine is even in a frying pan? It's already so little it's considered negligible, so unless you are buying new ones every day, even the negligible amount is not "building up".
> Yet that negligible amount is enough to kill birds.
No it's not. You misunderstood what you read.
To kill birds you have to burn the Teflon, and the Teflon smoke kills them. And you have the get the pan HOT - way hotter than anyone cooks. Teflon is not easy to burn, you can put a blowtorch on it for a short time and not affect it.
The new chemical is https://en.wikipedia.org/wiki/GenX and while I'm not a chemist as best I can tell, it also contains a carboxylic acid group, so this method would work on it.
KOH is not soap, it is used in the production of soap and KOH will make your skin to soap. Destroying anything organic by cooking it in strong lye at 120 °C with quite polar solvent is not something unexpected. It might be optimised with crown ethers or other phase-transfer catalysts, but I cannot see how this is a milder treatment than simple heating it until decomposition. To make this reaction affordable one has to extract/purify these forever-chemicals first. Otherwise, mostly other stuff will be destroyed. Lime (Ca(OH)₂) is somewhat cheaper in this quantities, maybe this reaction can be done with it. This will also bind any fluoride ions, which would make this way less toxic.
I was excited for a moment but PFOS (Perfluorooctanesulfonic acid, a PFAS) doesn't have a carboxyl group so I guess Minnesota's (US state) 3M polluted waters won't get any respite.
Same 3M contamination of groundwater happened in Belgium (Zwijndrecht plant) and the Netherlands (Dordrecht plant), with very little international coverage.
The fact that they refuse to get certified / conduct any independent rigorous testing (like in NSF/ANSI certification) should have clued you in.
"We also cut open a pair of Black Berkey filters to see how they are constructed and to look for evidence that, as Berkey marketing claims, they contain “at least” six different filtering elements. We found that though the Berkey filters are larger and denser than filters from Brita and 3M Filtrete, they appear to share their filtration mechanisms: activated charcoal impregnated with an ion-exchange resin.
"
I wouldn't count on any of this to filter chemicals, much less PFAS.
Slightly off topic, I’m keen to dispose of our Teflon frying pan. Does anyone have a good recommendation for an alternative, ideally one that doesn’t take too much “maintenance”?
We also have a Teflon milk pan but that is never used at a high tempriture so I’m less concerned about that.
Nothing beats cast iron. They aren't hard to take care of.(In spite of the rhetoric.) Actually easier, once you get a good surface on them. Pots, frying pans, woks, etc. They work very well. The most important thing is to give them time to heat up. Once they are, they hold the heat very well, so can cook at any temperature.
its just because they don't bother polishing them or turning them on a lathe. iron it pretty soft, you can sand down the rough ones without much trouble (or just buy an old Griswold!)
Do you have recommendations for seasoning them without a thermostat or a suitable thermometer? I successfully burned my new cast-iron skillet clean, but even after four thin coats of poppyseed and flaxseed oil, each heated up for an hour or so to a temperature that chars garlic skin after a few minutes, eggs still stick if I try to cook them on it without oil.
(I'm a fan of teflon but I like cast iron even more.)
I’m not sure you’ll ever get to cooking with no oil on cast iron. I have very well seasoned pans and I cook with oil, even then eggs will stick a little occasionally. My advice is to cook regularly and whenever you see the surface dry out a bit, apply oil (I find almost any oil or grease works) with some paper towel. I never clean it with soap, there is no need. When more involved cleaning is necessary, I’ll put water in it and let sit, and then wipe clean. If there’s lots of crap stuck to it, sometimes I’ll heat the water to a simmer, although this tends to ruin the seasoning somewhat.
Think of it kind of like a barbecue surface (more accurately like a griddle), which people generally don’t soak in soapy water. I never do the “oil and then bake it” stuff, I don’t think it’s necessary.
I’m torn right now because I also just replaced my nonstick pants with a high quality $70 new nonstick pan, and then came across all these articles about PFAS. I usually only use nonstick for eggs and other delicate items but I’m paranoid now. I’m curious if anyone knows what percentage of exposure is via cookware compared to other environmental sources?
How do you get it to be just above the smoke point of the oil without a thermostat or a suitable thermometer? The knob on my oven just varies the amount of gas going to the burner.
Oven thermometers are cheap, but barring that, use inexpensive canola or vegetable oil sparingly; just enough to make it shiny, and turn the knob to 350F (or whatever setting you use by default when baking or cooking).
If the coating turns white, recoat with oil and try a lower temperature or less time. Cast iron is an extremely old technology, and was common back in the days of wood stoves. It doesn’t require precision instruments to maintain it.
If you somehow ruin the seasoning, you can always scrape it with steel wool and try again. I once forgot a mini skillet in a frequentLy used propane grill for ~ 3 years, then left it outdoors with a burnt off coating for winter or two. I spent 5 minutes scrubbing rust off it in the sink, then oiled and seasoned it. We use it for sunny side up eggs these days.
You can definitely fry eggs on teflon without butter or oil or anything. I have this vague memory that I used to be able to do this on cast iron when I lived in the US, with maybe the occasional bit sticking.
Well, if one really wants to taste the subtle tastes of an egg, cooking sans oil does that.
By subtle, I mean similar to the difference between veggie oil and olive or canola oil. These all have a distinct taste to me, and I dislike canola enough to notice when it's been used.
The egg by itself has flavors that get dominated by the oil flavors.
It depends on what you're worried about and what you want out of a pan. If you use wooden cooking utensils (spatula, chopsticks etc.), then just keep using the Teflon pan. It's fine as is and you won't scratch the coating.
If you want to use metal cookware, go for cast iron (heavy) or carbon steel (light). There's a lot online about how to season or maintain them -- you can safely ignore all of this advice. These are pans you can abuse. They're not as nonstick as Teflon so you still want to use some cooking oil, but that's about it. Both kinds may rust if there's humidity, but that's fine -- just wash before (instead of after) cooking and a bit of leftover rust is just a tad extra iron in your diet ;)
I bought a couple of SolidTeknics[1] wrought iron pans, and I love them.
You have to season them first, which essentially involves blackening them by burning good cooking oils onto them. I used rice bran oil for that. It's a bit of a mission, but you only do it once.
They are great because you can get them really hot and they have excellent heat inertia. You can put them in the oven if needed. And cleanup is simple: just hot water & a brush. No chemicals. I've often got the pan clean and back in the cupboard while my protein is resting.
But if it's not protein that your cooking on your pan, but instead perhaps its an acidic sauce, then I would recommend a stainless steel pan for that.
For pots I would go with stainless also. Or copper if you can afford it.
Cast iron really doesn't require much maintenance. You can season it and never wash it and be delicate with it like a fancy chef, or you can abuse the hell out of it and it doesn't matter because it's basically indestructible. The only thing you can't do is let it sit in water or run it through the dishwasher. I mean, you can, but it rusts… which also isn't that difficult to clean if it happens.
Cast iron and a green scotchbrite pad or a stainless steel scouring pad and you are good. You can use hot water and soap to clean it. It will deteriorate any "seasoning" but so what. Clean after use, dry and store away. Takes maybe two minutes. If you want to get it seasoned so it has some non-stick to it you can, but you don't have to.
If you simmer a half inch of water in a cast iron or enameled cast iron pan, you can scrape almost anything away with a soft spatula. Like new in no time. No soap needed.
Much faster than scrubbing.
There are a few thing that are still a pain though, like eggs and fish.
Demeyere brand skillets are fantastic. They're fairly nonstick - I can scramble eggs with only a little sticking, hamburgers or sausages will leave residue, but it's easily cleanable. They aren't super cheap, but they won't break the bank and they're a lot of value for the money.
An aluminum skillet from a restaurant supply store is cheap and low-maintenance. I use this one [0] for omelets and scrambled eggs, and it's probably my favorite pan. The thickness means that the heat is incredibly even, and there's enough mass that it won't cool down much when adding food to a preheated pan.
Depends on what worries you. Stainless steel is the least reactive, but higher maintenance. Cast iron, carbon steel and aluminum are all reactive with acidic foods and will leech metals -- plus the acidic food will strip all the seasoning off. I cook with lots of tomatoes, so that rules out all of these for me. Cast iron and carbon steel (to a lesser extent) need to be seasoned to not stick like crazy and to not rust, which involves polymerizing cooking oil onto the surface. The health effects of this polymerized oil is unknown and the oil smoke is not great for indoor air quality. Digesting regular amounts of rust is also another unknown health effect, though iron can accumulate in people with certain genetic disorders.
I think the safest option is stainless steel, and funny enough, Teflon. They are both inert and Teflon is only toxic if you cook on high heat. I keep a Teflon around solely for scrambled eggs and fish on low heat, but they are very doable in a well oiled stainless fry pan as well.
I switched to stainless steel, it is more to maintain, but it's not horrible. I also use a ceramic pan on very low temperatures to cook really stick stuff like scrambled eggs.
I bought a cast iron thinking it would be a pain. its really not. they have came a long way. you can treat it like any other pan (besides being heavy) - you can use soap to clean it. - Dont get me wrong. treating it correctly will make it last a life time. i just store mine in the oven when ive finished washing it.
Crystallized citric acid is cheap. Couple of tablespoons in a suitable container and give the offending piece a bath. Wash away the rust. Bake in the oven with one layer of oil to season.
Having rust is fine though, it's just oxidized iron. Sure it won't look pretty but it's largely harmless in food.
The main caveat I've seen is when making acidic foods with iron cookware (cast iron or carbon steel) it may affect the taste ever so slightly as some of the acid is reacted and takes off the top layer so you end up with a "stain" that looks like the food. Still just cosmetic only though.
High temperatures do not bother Teflon, there's no reason to dispose of it because of that.
According to the EPA Teflon frying pans do not leech any PFOA into food, that's not where people are exposed.
I've noticed that for some reason a ton of people think they get exposure to PFOA from cookware, and that's simply not true. PFOA exposure mainly comes from waterproofing coatings, slippery coatings (like the bottom of skis), and firefighting foam.
Paper dishes (plates, straws, etc) are a big source of exposure because they need to make them waterproof. Make sure to ask for plastic.
I don't know what's released from Teflon pans at high heat, but Teflon kills birds. I know this because I killed two birds by forgetting about a pan I was warming up. Wasn't enough to make the pan look any different; was enough to instantly kill the birds.
Although acutely toxic, this substance is not a persistent "forever chemical" because there are multiple mechanisms that rapidly degrade it in the environment:
It's true that those temperatures are too hot to cook at, but overheated oil at 260 or 270 degrees is a great deal more conspicuous than teflon pyrolysis at those temperatures. This makes the overheated oil safer, in the same way that silane is safer than hydrogen sulfide even though its lethal dose is lower.
Every oven I’ve ever had goes to 500 degrees. I have no idea why you are making this claim. Anecdotally I know I can get pans hotter than this on my gas stovetop, just judging on searing and smoke production, and a quick google for how hot pans can get on a stovetop gives results > 600 degrees.
And plenty of recipes are cooked at 450 degrees. I don't even believe there's a full-sized (i.e. not a toaster) oven that doesn't go to 500 degrees, but I'm willing to be corrected.
That's because birds are extremely sensitive to the air; it's how the phrase "canary in the coalmine", or just "canary", originated. The dosage required to kill a bird is a tiny fraction of that needed to cause a human to perceive anything.
That said, pyrolysis of fluorinated compounds does release very toxic substances, HF among one of them. On the other hand, the tradeoff is that below those temperatures at which they start degrading, they are extremely inert.
I googled, and I could not find any ovens with Teflon in them.
On top of that you have to heat the Teflon over 500F / 260C, and ovens temperatures don't go so high (except in self cleaning but a non-stick oven would not have self cleaning).
I suspect something else happened to your birds - probably simple smoke from food residue, which kills birds much easier than overheated Teflon does.
This person has been saying all over the thread that "ovens don't go to 500F" and here finally add the actual caveat "except self cleaning". At least half the ovens listed in Lowes's online inventory list self cleaning as a feature, and it's even a feature in my bargain basement level apartment oven, which happily goes up to 550F, which is great for cooking pizza.
I don't know whether they're being intellectually dishonest, or genuinely don't realize they're spreading useless info.
They're claim that nobody gets a pan hot enough to degrade teflon while cooking is slightly more reasonable, except plenty of recipes start with "heat an empty, dry pan until it is searing hot" and that leaves a lot of room to screw up your pan.
edit: I know for a fact that these birds smelled a lot of food cooking and lived. Teflon killed them in the next room.
edit2: I should really bow out of this discussion. The fact that Teflon.com thinks that Teflon is a special worry if you have birds is enough for me. Judging by the content of their page on the subject, I'm going to assume that they decided that comparisons to burning mystery oils were spurious.
No, it's even more awful. I was visiting my mother and little sister (tween at the time) on vacation from work (we lived in different states), and I was going to make them breakfast. Spaced out on the pan while trying to sort out the ingredients. Everybody tried to make me feel better (because no one else had ever heard that Teflon kills birds either), but little sister was distraught.
Teflon is very non-reactive and any small pieces you ingest should pass through unchanged pretty quickly. You likely ingest a lot more plastic from other sources.
Cast iron is low maintenance, just don't over think the seasoning thing and don't cook overly acidic things. Cook with oil, clean with soap and hot water (use a plastic scraper if you need to...), dry on the stove and once dry wipe with a paper towel you put a little drop of oil on. Wait until the oil just smokes and turn it off. Done. Takes 1min tops. You can use steel utensils, just don't go scratching at it when cleaning with a wire brush.
Just get used to the imperfect surface, its not going to be perfect, it may get to be smooth and black one day, but even my nearly hundred year old skillet I've gotten through my family sometimes gets a scratch or a flake off. Its self correcting the more you use it.
If that's still too much "maintenance" try a nice enameled cast iron skillet or pot from le creuset. Don't cheap out. These are fantastic, aren't bothered by acidic foods, and still have the same nice heat holding properties of seasoned iron. Really love these. Don't use steel utensils or bang them around the edges with sticks and they last forever, or at least long enough you feel the cost was well worth it. My mother in law had hers, used, for nearly 25 years before the enamel flaked, and she didn't bother treating it nice (scrubbed, used metal utensils, etc).
I scrape the heck out of my cast iron pan using a bit of chain mail I keep by the sink in order to clean it. I do reapply oil and heat as you suggest. Do you reckon I'm missing out on some benefits of cast iron because I scrape it so relentlessly?
You’re probably stopping the seasoning from building up, and making it more sticky. Hot water and a soft nylon brush should be enough for 90% of your cooking, the occasional sticky burger just needs a 5m hot water bath to let go.
Yum, everyone needs to consume more nylon. I use a small cheese knife that looks like a mini meat cleaver as a scraper. The pans have enough seasoning that they're similar to Teflon as far as stickiness goes.
I finally made the switch to triple clad stainless and i couldn't be happier. Kinda like a cast iron but a little less heavy for the larger pans (still much heavier than a cheapo set of steel pots), fast to heat up too and cooks really evenly with the thickened walls. They only get things stuck to them if you screw up your technique. Just a sponge and dish soap is all it needs most of the time.
It should be obvious to anyone at this point that anything that promises to be a "healthy" alternative to teflon and is not stainless steel / cast-iron / carbon steel is most probably a scam.
Cast iron is fine once you get the hang of it, but I find myself just using my stainless steel pans exclusively. I also wonder how healthy the polymerized surface really is (would love to hear from anyone who knows).
You can effectively make stainless steel non-stick with correct use of a neutral oil and either cooking at a slightly lower heat and/or keeping the contents moving. Have to be ok with some oil though, for most foods it shouldn't be a problem.
It's not teflon, but I haven't come across anything that sticks to the pan in a consequential manner. Scrub with stainless steel scrubber to clean, done.
A lot of cookware sold online (especially places like amazon) are outright lying about what they are made with. "PFAS free" is more or less a meaningless marketing term at this point. The FDA is doing nothing to stop people from making false claims about these types of products.
In materials science "ceramic" means basically any inorganic, nonmetallic solid: https://en.wikipedia.org/wiki/Template:Fundamental_aspects_o.... This includes perfectly safe materials like alumina, mullite, and silicon nitride, as well as things you definitely do not want in your food like lead oxide, lead zirconate titanate, barium titanate, uranium oxide, and beryllia.
So it is not accurate to say, "Ceramic itself is safe".
(I have no idea what is used in the surfaces of "ceramic" pans but it is unlikely to be any of the substances I listed above; they all have high surface energy.)
What bad ways? Teflon is not harmful. Teflon is not the same as PFAS, and Teflon cookware does not leech any PFAS into food. See my other reply: https://news.ycombinator.com/item?id=32515717
And to answer your question, ceramics sometimes have heavy metals to get bright colors (cadmium mostly). Make sure to buy from a reputable manufacturer.
You probably know what you are talking about but the lack of research doesn't fill me with confidence [1]:
> However, at temperatures above 500°F (260°C), Teflon coatings on nonstick cookware start to break down, releasing toxic chemicals into the air. [...] Polymer fume fever consists of temporary, flu-like symptoms such as chills, fever, headache, and body aches. The onset occurs after 4–10 hours of exposure, and the condition usually resolves within 12–48 hours.
You keep repeating this "ovens don't go to 500F" claim all over the thread and it is just wrong. Looking at lowes.com, around half their oven inventory has a self cleaning option, requiring the oven to be able to get to that high temperature. Even a cheap electric oven will often have a self cleaning feature and a max temp above 500F.
Turning my burner up to max my carbon steel wok has gotten up to 700. Before I knew better, I had an old non-stick wok and on the first use the coating came off at high temperatures. Never actually cooked in it, threw it out and went for the carbon steel instead.
Many ovens have their top temp at 550F. And when the broiler is on, it can go well above that (although in a smaller more focused area).
Thanks, I guess my point is more like: how do we know this new "ceramic" coating (if it is some metamaterial) is better than Teflon for the environment from the cradle to the grave? Are there worse risks we don't know about?
I would prefer to study and perfect our manufacturing and use of Teflon if there is no alternative to it that is much safer.
Teflon is certainly a perfluoroalkyl substance but it is perfectly safe as long as you aren't thermally decomposing it at temperatures that are too hot to cook at.
They're "forever" because they persist in the environment. You're not likely to find this specific combination of temperature and solvents in the wild. It's something you might be able to use in water treatment plants in areas where the supply has been contaminated.
As the article notes, we already had ways of breaking them down, just with difficultly: "current PFAS-destruction techniques, such as incineration, can require vast amounts of energy, superhigh temperatures, and millions of dollars".
Yes, extracting contaminated materials from an environment and decontaminating them would removing life because it's destructive. That's what cleaning this stuff up involves.
I'm all for "environmentally damaging" or someother name but "forever chemicals" is just a bad name for this that is going to get picked up on by people.
I'm not suggesting burn so much co2 that the planet gets to 120C, although it'd have less human problems at that point.
Pumping high-strength lye heated to 40-120C into the environment (soil and water supply) in large enough quantities to neutralize PFOA over large areas is right up there with alt.pave.the.earth in terms of practicality and environmentalism.
some serious HackerNews brain right there, just needs an app and I can get my bingo.
There aren't many chemicals that won't be destroyed in those conditions, the lye will just rip hydrogen off most molecules, but, it'll also do it to, you know, pretty much everything else too. You ever see a chemical burn before? Literally this, but imagine a solution of the lye that's hot to make it even more reactive...
> What’s left behind, Trang says, is mostly easily captured fluorine ions, and a mixture of harmless, naturally occurring carbon and oxygen containing byproducts, her team reports today in Science.
> Roughly 40% of PFAS compounds contain carboxylic acid groups, and thus could potentially be degraded by the new approach, Trang says. Though it has yet to be tested in the field, she adds that the most likely strategy would be to use conventional means to filter PFAS chemicals from, say drinking water, and then treat them off-site.
> The method doesn’t work on all types of PFAS, however. Compounds used in flame retardants and batteries, for example, contain a sulfonate group instead of a carboxylic acid group and won’t break down with this approach.
PFAS seems to be used in keeping water out, so that makes sense. I suppose we might be able to find PFAS anywhere products are exposed to water with negative consequences.
The "soap and solvent" is sodium hydroxide (lye) and DMSO at 120 degC. Those are... fairly... well behaved chemicals, but lye is stout stuff and DMSO attacks nitrile gloves.
You could imagine a remediation process that uses this process but the combo ain't exactly Dawn dish soap. I'd almost prefer pyroprocessing over it.