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Comment by ars | Hacker News Reader

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.

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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.

https://www.teflon.com/en/consumers/teflon-coatings-cookware...

My family learned this after replacing a stove with one that had a non-stick interior a couple decades ago. That was a pretty major bummer.

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.

Interesting. IIRC the only thing that changed before and after was the oven was replaced. Ah well.

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.

I believe that the chemical primarily responsible for bird toxicity from PTFE pyrolysis is perfluoroisobutene:

https://en.wikipedia.org/wiki/Polymer_fume_fever

https://en.wikipedia.org/wiki/Perfluoroisobutene

Although acutely toxic, this substance is not a persistent "forever chemical" because there are multiple mechanisms that rapidly degrade it in the environment:

https://pubchem.ncbi.nlm.nih.gov/compound/Perfluoroisobutyle...

While that's fair your link suggests it's found its way into schedule 2 of the chemical weapons convention.

> Perfluoroisobutene is quite toxic with an LCt = 880 mg⋅min⋅m−3 (mice).[1] It is a Schedule 2 substance of the Chemical Weapons Convention.

I don't know about you but I try and keep my ricin away from my breakfast foods. It is however reassuring that it'll be degraded in the environment.

> I don't know about you but I try and keep my ricin away from my breakfast foods.

To cause Teflon to degrade you have to heat the pan to over 500F / 260C.

No one cooks at those temperatures, even ovens don't go so high. You basically have to forget the pan on a high flame for a long time.

And the toxic chemicals you get from overheating oil are far worse, somehow everyone forgets about those.

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.

> Every oven I’ve ever had goes to 500 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.

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.

Still, I like cooking on teflon.

My gas hob burns at >450C and we’ve had several instances of a forgotten teflon pan that made a terrible smell.

I’d say it’s pretty easy to get teflon to degrade at home.

Hot oil also kills birds, and at a lower temperature than Teflon.

So if you had been using oil with your pan the birds would have still died, and earlier than they did with the Teflon.

Do you have a reference for this?

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.

Just a cursory google for Teflon killing birds yields numerous results including this one … from teflon.com - https://www.teflon.com/en/consumers/teflon-coatings-cookware...

When the product itself is actually publicly fessing up to being acutely toxic in some way, it’s a pretty safe bet it is.

There’s no reason to doubt the account here of the birds dying and this being the likely cause.

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.

Condolences. Had you had them long?

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.

I'm so sorry. I'm a fan of teflon but I'm spacey enough that I wouldn't cook on it if I had birds.

How long ago was this? I'm guessing that the relevant knowledge maybe still isn't widespread.

Probably 10-15 years ago at this point, but I still feel shitty about it.

> High temperatures do not bother Teflon,

https://en.wikipedia.org/wiki/Polymer_fume_fever

Seems totally healthy to me!

Leaching isn't the worry with non-stick coatings, flaking is. Everyone's seen pans flake off teflon into food.

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.

On the other hand, visible flakes of plastic in my food are kind of a bummer.

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