How can this be a debate? This stuff has broadly poisoned the water supplies of entire regions in a way that won’t be easy to fix and they are still debating. Is that really the line?

Look at this map.

https://pubs.acs.org/doi/10.1021/acs.estlett.2c00502

Look at the known effects:

https://www.atsdr.cdc.gov/pfas/health-effects/index.html

Where they outline the nine PFAS are: - Perfluorooctanoic acid. - Perfluorooctanesulfonic acid - Perfluorobutanesulfonic acid. - Hexafluoropropylene oxide-dimer acid. - Perfluorononanoic acid. - Perfluorohexanesulfonic acid. - Perfluorodecanoic acid. - Perfluorohexanoic acid. - Perfluorobutanoic acid.

I remember dealing with these substances in tiny quantities in the lab, and they were treated as carefully as cholorosifonic super acids. A lot of care goes into their disposal or recycle. One problem is making methods that can detect waste streams at under ppt levels, which is pretty difficult, but that's the best effort for dealing with these substances at the moment.

Are you aware of the usage of PFAS in textiles, food packaging, and waterproof-treated goods? I'm a little confused what you mean by care goes into their disposal. PFAS treatments on textiles for example are disposed of by pouring down a washing machine drain into municipal sewers and from there into natural waterways.

Because of the "forever", small amounts add up, perpetually and over time could become not-small amounts.

No, because that's not true. Teflon (the substance used widely in waterproof goods and food packaging) is not the same thing as PFAS [1] (which is actually not one thing, but a whole class of things). Teflon is PTFE [2], which is different.

The terminology being casually flung around this issue is misleading. Certain PFAS types were used in the manufacture of PTFE (specifically Perfluorooctanoic acid [3]) which is the actual answer to GPs question -- this is primarily an issue of industrial concern. PFOA is far more reactive than PTFE, which is one of the most inert substances known to man. You can't just group these chemicals together in the bucket of "things that have fluoride polymers" and panic about all of them.

We regularly put teflon parts in humans, because they don't react with anything. Proving harm here is an incredibly high bar.

[1] https://en.wikipedia.org/wiki/Per-_and_polyfluoroalkyl_subst... [2] https://en.wikipedia.org/wiki/Polytetrafluoroethylene [3] https://en.wikipedia.org/wiki/Perfluorooctanoic_acid

https://www.consumerreports.org/health/food-contaminants/dan...

Also, PTFE is decidedly not among the nine proposed by the EPA to be classified as hazardous.

Even if there were lingering PFOA in Teflon, it would be quickly washed away.

Some people try to confuse the issue by grouping together anything with a poly-CF2 chain as "PFAS", but this is wrong.

There are new PFAS free DWR finishes, but don't know if Gore-Tex is using them yet.

Gore does not consider PTFE to be environmentally friendly and is working on flourocarbon free fabrics.

Source: https://www.nist.gov/news-events/news/2024/01/wear-and-tear-...

There is no “away”. “away” is our waterways and soil.

[1] https://www.epa.gov/pfas/pfas-explained#:~:text=Scientific%2....

polytetrafluoroethylene is a polyfluoroalkyl substance.

They're common only in that they both contain polyfluorinated carbon chains.

I fail to see how a polymer made entirely of fluorinated alkyl substances is not a polyfluorinated alkyl substance. I'm not really sure how one could argue they're not if we ignore politics and just look at chemical nomenclature

"PTFE, or polytetrafluoroethylene, belongs to a subgroup of PFAS called fluorinated polymers"

And eggs from chickens kept in your own yard are considered unsafe to eat, in a pretty big area. Unless you want to have them tested regularly at ~€600 each time.

Let's not get too relaxed here. There's gigantic masses of plastic all over the world that would like to say that anything mass produced and cumulative "WILL become 'not-small' amounts".

For outdoor goods like backpacks or bags that you want to stay waterproof, I personally recommend PU and TPU coated drybags. For clothing like pants or shirts, I'd recommend opting for non-water-resistant/non-waterproof versions, and just buy an umbrella or raincoat with a PU or TPU coating to shield you rather than trying to wear clothing that will have water bead. Waxed canvas clothing is another option but it can be heavy. Cool if you are into it though, Fjallraven is famous for it, as is Filson.

I don't think you'll be too sad if your disposable food packaging gets a little soggier. You'll probably be a little more sad if you get cancer :(

So over time, hopefully you own fewer and fewer goods that are destroying the planet! Happy friday.

Eg:

https://www.polartec.com/news/polartec-announces-full-use-of...

https://www.patagonia.com/our-footprint/pfas.html

https://www.theguardian.com/environment/2023/jan/06/pfas-tox...

We could pose all of your same questions about, say, asbestos.

The superficial answer:

Yes, there are indeed times when human screwups necessitate hazmat disposal trucks in residential areas.

The deeper answer:

The optimal solution to a compounding problem is not to politicize it with absurd rhetoric.

It is to stop whatever's feeding into the compounding as quickly as possible. Because that is the only reliable way to reduce the long term costs that you'll ultimately have to pay.

Indeed we could. And the answer we would find is that no, such requirements were not generally imposed on ordinary homeowners, but on manufacturers and construction firms, in the form of requirements not to use asbestos in future projects and to be forced to undertake remediation efforts when asbestos was found at an existing side that needed to be modified. And we would also find that, as a result, many of those same homeowners ended up with long term health issues from asbestos exposure because they were never informed of the risks or given any feasible way to mitigate them. Nor was any cost benefit calculation done in either case (homeowners or manufacturers/construction firms) to see whether the policy that was actually adopted could reasonably be argued to be a fair tradeoff.

Here at least we are being informed of the (claimed) risk. But there is still no cost benefit analysis being done that I can see.

Is this actual knowledge or just a prediction?

> If you're legitimately concerned

I am, but not just about the impact on me personally. I'm more generally concerned about whether the actual costs of such a regulation will be less than the actual benefits.

Seems taking your fluorescents and lead based batteries to specialized recycle is about it on the consumer side. Personally I'm happy to do that to prevent poisoning my kids and my neighbor. Also happy for industry to identify safer alternative products.

Please free yourself from the libertarian fever dream.

This PFAs decision would be a prime example of something the EPA won't be able to regulate without a new congressional bill approving it.

The EPA pretend like there's accountability

  What is the real change that is going to occur?

What a silly statement. Adding a single oxygen atom to CO makes it far less toxic. Even among the class of chemicals we call PFAS, there are profound differences measured by the difference of only a few atoms.

Once you see it, you can't unsee it. The US is incredibly corrupt.

Think of it like an engineer. We try to test products before deploying them to production (e.g. make all of humanity ingest it). If our tests are wrong some significant portion of the time, or if being wrong is much more damaging than we realized, then absolutely it's time to start the conversation of "How do we get better test coverage?"

I bet if you put some paltry amount of money, say 100B (compare this to a bailout) into devising tests around the long-term safety of various chemicals some creative solutions would come up. For example, off the top of my head, if reproductive health is a concern, perhaps do a study where some animal that reproduces frequently is exposed to it for 10+ generations. We can validate if this is a viable way of testing by taking some known endocrine-disruptors and validating this test catches them effectively.

For whatever reason, some people don't seem to see engineering chemicals that are safe for humanity to be a worthy enterprise, but I think it's as important as any tech company and we should make the financial incentives to reflect that and get the right minds on this problem.

Also, tests where minute traces of anything, like coffee, are purified to extreme amounts and injected into animals to cause cancer only add confusion, especially when California considers adding cancer warnings to coffee.

Do you actually know which tests the EPA runs and if so could you cite your source?

> no ethical tests can determine the full truth.

That's an all-or-nothing fallacy.

Also you didn't respond to the core of my remark, which is about increasing the financial incentives by an order of magnitude. Lastly I take your complaint about coffee as support my argument that the current testing mechanisms are likely too simple.

No. Ethical tests cannot determine the full truth - that is just a simple fact.

How can anything be tested on on enough humans ethically? We can use animal models to detect some negatives. But if animal tests show a substance is "safe", doubt would still remain until tested on humans. It is normal that humanity creates new technology without knowing the future impact. Some people think that we shouldn't introduce new technology since we can't afford the risks. But technology has ethically positive outcomes - not only negative risk. Doing nothing has risks too.

There is neither lack of effort nor lack of incentive for human-analog testing ( which would lead to curing cancer, weightloss, hairloss, vaccines, etc. etc. etc.). You can't just write unit tests for the real world. Please do some reading before you try and hand-wave away a whole field as trivial.

One could even go a step further and mandate outcomes instead of means, that substances must be proven to either have a low environmental half-life or to not bio-accumulate.

[0] https://www.gesetze-im-internet.de/npsg/anlage.html

You can still progress technologically without being reckless.

Which countries do it that way?

> Europe has chosen a precautionary approach in regulating, while the U.S. governing bodies tend to be more reactive. In other words, in the United States, food additives are innocent until proven guilty, while in Europe, only those additives proven not to be harmful are approved for use.

http://www.germinalorganic.com/2018/02/eu-versus-us-a-closer...

Until you get into pharmaceuticals, then the world standard is a step beyond "prove it's harmful" to "no evidence of harm is proof that it is safe".

Everything is chemicals. You just described 2/3 of all industrial activity and proposed we should stop them. Are you willing to take the consequences which follow from that proposal? (And somehow forgot the 1/3 “dump chemicals in air”)

In this case it's about PFAS, a subgroup of organofluorine compounds. There's only 5 known organofluorine compounds produced by organisms.

There are plenty of counter examples to this (and also pretty unclear what is meant by "natural")

Lead is natural. Mercury is natural.

See how that works?

Real productive mode of conversation, huh.

https://www.latimes.com/environment/story/2022-05-18/heres-w...

Okay, no more fertilizer on the crops then. Enjoy the famine.

Words have different meanings in different contexts. Pretending that "chemicals" can only ever be used to refer to all material substances equally is just intentionally trying to sabotage productive discussion.

Well define it then.

Nobody is complaing that there might be an alternative definition of chemical.

The complaint is that you're not using any widely known definition of "chemical" and not providing your own definition.

You can shut everyone up by just defining how you are using the word. I doubt you will since i think you are lying about there existing some other definition that makes sense in the context you are arguing, and you lack the knowledge/ability to make up your own definition that would fit your argument.

> "It’s pretty simple, don’t dump chemicals in water or on land period."

Then i still maintain anyone using that definition of chemical in the context of that statement is an utter idiot.

> Now would you like to discuss which "substances produced by chemical processes" are likely to be the most impactful upon the environment

Why? There is already a government department tasked with that, that can probably do a better job then you or i could.

If you're trying to argue that the status quo is fine and we shouldn't change anything, then you have a weird way of doing so.

This is a thought terminating cliche and pedantically destroys the conversation.

It is not. Quite contrary. The thought it provokes is "what chemicals do you want to ban?" Do you want to ban water? Should we throw anyone in a prison who transports it? It is a chemical after all. One which is quite dangerous in many circumstances.

But surely that is not what edgyquant meant. Should we prohibit people selling soap? It is a chemical! But that is silly. We would probably lose more by banning that than by not banning it.

Should we ban plastics? Maybe? Which types? All types? All uses?

Should we sell hydrazine in grocery stores? Oh, we better not. Can we use hydrazine in special applications like fuelling satellites? If so what do we require from people who handle/store/dispose of it?

So many thoughts provoked by that simple observation.

I mean, there's a good example there with phosphate compounds in detergents.

All of these have hazards in specific circumstances, and huge benefits in others. All are chemicals.

All are well known and characterized. Many other compounds are too new for that level of knowledge and characterization. They are chemicals too.

If we allow someone to make new chemicals (it’s hard to stop, frankly!), either we say ‘no, not until they are fully understood and characterized’, or ‘yes, unless we learn it’s too hazardous’.

Saying no first is a bit of a catch-22 since how are you going learn anything and characterize the dangers if you don’t make and use it a bunch?

If you say ‘yes, unless we learn it’s too dangerous’ then we learn a huge amount quite quickly - but inevitably have something too dangerous causing problems.

It’s a fundamentally conservative vs liberal development strategy debate.

The MSDSes will elaborate on this and you probably know that.

This thread chain has gotten impressively disingenuous very fast. We aren't arguing the colloquial definition of chemicals which if we're not being pedantic, we know brings up ideas of substances damaging to other substances or life itself.

Which is fairly obviously the line that you're giving a good traditional "but where would we POSSIBLY STOP?!" gambit that comes out of paid lobbyist's mouths more often than hello or goodbye.

The line to be crossed is obviously at least a few blocks up the way from "what is the difference between water and hydrazine though".

And also, anything cumulative becomes "too hazardous" within years. But by then profits are made, and war chests are filled to keep the spice flowing.

The world got by for thousands of years sustainably without a lot of these "huge benefits" and I'm willing to take a hit or two within my lifetime to ensure there's still lifetimes at all down the road.

Do you actually have a line? We can't make a law out of people saying "you know what i mean".

From the comment you're responding to. Damage is quantifiable, if it wasn't, the OP (EPA proposing hazardous substance classification) wouldn't even exist.

If the point is just to ban things when the risks outweigh the benefits, that is simply the status quo.

The first real problematic PFAS compounds were in fire fighting foam used to put out aircraft fires for example, and took decades for their problems to show up.

Which requires either extremely exhaustive (or essentially impossible economically) testing, or yolo’ng it. Or only using already known compounds.

How do you create a MSDS for a chemical that hasn’t been made yet?

How do you decide it’s safe to create a large enough quantity of a chemical to figure out what even should be in that MSDS?

How can you know if something is mutagenic without exposing it to DNA? Or cancer causing without exposing it to a living organism? Or causes reproductive harm without exposing it to organisms and seeing how it impacts reproduction?

Those all are potential harms.

Traditionally, some enterprising alchemist/chemist would just try it - and if they lived, would write a paper on it. Further research and experience would then inform if a better alternative should be used.

The Haber-Bosch process that allowed the creation of artificial fertilizers has allowed for the massive expansion of the human race. Roughly 3/4 of the humans on this planet right now would starve to death without it. Assuming they didn’t get nuked first. That was in 1909.

It also allowed for the creation of modern high explosives (and propellants) at scale, and the horrors of WW1 and WW2. And the mining revolution, which has provided the raw materials necessary to build our modern economies at vastly cheaper prices than were ever possible before for humanity.

Chemistry is a fundamental building block of modern society, and removing it would literally cause its sudden and violent collapse.

Deciding if ‘freezing’ it in place, or letting it continue to develop new and interesting applications is the discussion - because no, we weren’t sustainable before (unless you count constant and ongoing genocides as ‘sustainable’), and we’ve long passed the point where trying to return to that would be anything but apocalyptic.

Literally.

And keeping in mind that just because we agree to stop research in one area doesn’t mean anyone else (competitors) will do so. Regardless of if that is in the realm of drugs, or weapons, or soaps, or foods, or whatever.

The concern about the chemicals we’re talking about is that they are in the water you are using to water your lawn, anmong other things, and have been getting made at scale for over 50 years. And is a family of 6 million something chemicals, some of which we suspect now may be dangerous - including causing cancer - and some we have no idea.

We can only test for things we suspect are an actual issue and have a test for. And for which we actually test.

Which we don’t really have reasonable tests for ‘doesn’t bio degrade over decades+ and bio accumulates to potentially dangerous levels’ yet. Except watching nature, anyway, which is how we discovered this problem. There are millions more chemicals that this hasn’t happened either.

So what do you propose doing here besides freezing it until such tests can be put in place and developed?

We do need to be a bit more specific than that, or we're not gonna get anywhere.

Also, once we've specified which chemicals shouldn't be dumped, I'd like to include the atmosphere in the list of places where one shouldn't dump them. Seems to be a very popular place to dump really harmful stuff, we should stop that.

This intentional nitpicking of the colloquial usage of the word chemicals is a favorite of both, disingenuous conversationalists who like to take a chance to feel correct rather than participate earnestly, and lobbyists.

At least one of them gets paid for it though.

Why not just use more specific language? If indeed everyone is acting in bad faith, using clear language would shut them up. If instead they are being ernest and cannot understand you because of the "colloquial" language, then being rigorous would further your stated goal of ernest participation. Either way seems like a win-win for you.

Which, since HN is a place for technically minded people, has resulted in people arguing that chemical contamination of PFAS is categorically the same as watering my lawn.

You are technically correct, but this is called a "gotcha": it's not about continuing the conversation in earnest, if anything, it shuts down conversation about the important details by, in the writing of mike judge, "playing lawyerball" instead.

In reality we all know that none of us are writing the technical legislation, so any of us becoming enamored with defending for profit entities against hazardous chemical classification through technical usage of language is...basically the core spirit of corporate lobbyism.

I don't recognise anyone here arguing this. Let me recap the conversation: tankaiji said it is good to ban these, but expressed concern that companies will find other dangerous chemicals to replace them with. mensetmanusman responded something along the lines of this being an inevitable consequence of human technology. edgyquant responded that the problem is overly complex regulation and seemingly proposed a simpler solution.

People rightfully pointed out that his simpler solution can't distinguish between the chemical contamination of PFAS and watering ones lawn. Which is ridiculous. So clearly the problem is not that simple. In fact the problem is complex and therefore the regulations around it are complex too.

You do not appear to have done that. That's why you are arguing with the colloquial usage of the word. Because you can't offer a useful and precise definition.

(Also, look at how old my account is and consider whether or not I care about your downvote. Reply with something that directly refutes the point I'm making so we can have the vibrant discussion this website used to be known for. Downvotes are simply pathetic attempts to silence correct views. Intellectuals have discussions, not censor their opponents. Only the most indefensible and mediocre positions depend on censorship. It also explains why the most unimpressive people depend on it.)

Two problems:

1) defining the class sufficiently broadly to encompass the entire set so mfgrs can't just dodge the regulations by rearranging the molecule a bit and making the regulators play whack-a-mole, and possibly making things worse

2) not making the regulations too onerous, such as a sudden total ban. Yes, a lot of disposable uses should be discouraged or contained, and it may be reasonable to phase out all use to develop better alternatives.

My thinking is, that in the past we've been able to detect industrial pollutants that are harmful to human health because they had clear detrimental effects, like asbestos which clearly causes cancer.

Newer pollutants would probably be more subtle, because we can select out those which clearly cause harm. Agents that affect the endocrine system might currently slip under the radar, as we do not fully understand how different agents interact with it, and what the long-term repercussions are.

Surely there are different aspects of our bodies that could be negatively affected by industrial pollutants, but I just have a personal hunch that the endocrine system might be one that is subtle enough that it could evade our investigations long enough that could cause accumulative harm before we really notice it. Hope that makes some sense.

By the time it gets that low, I agree, they're done. We're a very long way from that. 85% of cars being sold globally are still ICE, and the population of vehicles on the road lags sales figures by a couple of decades. And even with the increase in EV sales figures, oil demand is not dropping, because the total demand for cars is increasing.

But if demand for oil starts to drop due to EV adoption, OPEC is for sure going to make sure it's cheap as hell to operate an oil burning car, and people in the majority of the world where it's still legal will have a huge incentive to keep buying them.

Which is to say oil wells don't shutdown when the profit goes negative because that never happens. Oil wells do shutdown (or more likely produce less because the pump is slowed) if the owner decides they want to control supply to bring the price up - but you have to have a lot of wells to even think about that. During the pandemic oil wells shutdown, but that was because there was no place to put store the oil - if you could store it there was plenty of value in pumping it (though it was an investment).

Refineries don't shutdown when the profit goes negative. Again, because the sunk cost in machinery is a large part of the cost. If the profit goes down they will often not remodel and eventually shutdown because the equipment it wore out. Many have shutdown because the right crude wasn't available (and they didn't want to invest in machinery to handle crude they can get) - and then reopened a decade later when someone started pumping the right crude again.

Yes of course if profit goes negative they will both shutdown. However long before profits go negative they will be managing things and so in practice they are shutdown for other reasons first.

Car industry obviously helped to build the infrastructure but I think now that it’s there, fair chance there’s going to be a lot of oil supply looking for a use. Infrastructure won’t disappear overnight.

If they’re going to turn ALL the oil into plastics, at the very least they have to have more processing steps. It’s not hard but it will require bigger refineries, in other words, more expensive plastics.

Also, they will be competing with bio-plastics and other alternatives, that will probably get more favourable regulations in many countries.

Plastics won’t go away. Even if we don’t pump for oil it’s not very hard to make the same plastics from biological hydrocarbons.

1) Halve demand

2) Price plummets

3) Sources shut off

4) Prices climb again, _but at lower volume_

Plastification requires $x/barrel oil _at insane volume_ to work.

But also, plastics can pay much more for oil and gas than fuel can. It's currently not scarce at all, and the economic restrictions are all around using the plastic in some way. So don't expect the plastic industry to suffer like your last paragraph implies.

We can make any oil from the basic atoms (mostly carbon, oxygen, and hydrogen - but some molecules may want something else). However this process costs a lot more energy (read $) vs pumping oil from the ground and so it is rarely done. This is how synthetic oils are made so if you know the cost of car oil you can get a good picture of the difference in costs.

A single stainless steel one has to be better, unless I'm just off on the math.

We make so many things that, even if they're not disposable they are "disposable" when they do not have to be.

Finding a good without plastic in it is actually one of my criteria for kitchenware. Glass, metal, wood... nothing else should touch food if I can help it (some exceptions when truly warranted, silicone can be useful).

https://www.nature.com/articles/d41586-023-03589-z

And that's part of the problem with PFAS, because you can release them in tiny fractions (not toxic at this scale) but they end up concentrating in the food chain and people are still being harmed in the end.

We know PFAS levels in the environment can only increase in practice due to their very low degradation rate (hence their “forever chemicals” nickname). So even if these harmful levels aren't being reached now, they will definitely be at some point of we keep pouring them out there. And by that time it would be too late.

You don't wait for someone to be harm before intervening when the harm is likely.

The government: There's almost no teflon in the ground, so that's good.

The market: Hold my beer.

Some of the feedstock chemicals used to produce PTFE are likely toxic. The most concerning of these is perfluorooctanoic acid (PFOA); this is one of the chemicals that the EPA proposal applies to. Most manufacturers of PTFE have already voluntarily phased out the use of PFOA. There is some debate about whether the replacement feedstock chemicals are meaningfully less toxic. These feedstock chemicals can - and should - be prevented from ever entering the environment, which would largely nullify concerns about their toxicity.

The quality of the pan also makes a difference; cheap ones often use very thin metal that doesn't spread the heat well, resulting in hot spots.

I recommend using an IR thermometer to learn how your personal cooking setup behaves.

Unfortunately, most stoves do no adequately control temperature, and it’s easy to reach that temperature by accident.

You'd think we'd finally have gotten far enough in education to not be so easily carrot and sticked. But damn. People coming out of the woodwork in this thread to defend literal world contamination.

Note that this has not historically been the case, see for example all those superfund sites in SV.

> For what it's worth, depending on the harms, a sudden total ban is not out of the question as being beneficial to humanity as a whole. It would just be disruptive to enterprise, boo hoo. We don't need to always treat bad actors with kid gloves.

Hardly the extremism you're implying.

They are arguing that even total bans should not be dismissed by default, and that there can exist situations “depending on the harms” that justifies a total ban.

And they did not say that in a vacuum, but as an answer to another comment that straight out dismissed total ban as an option.

This comment is in no way advocating for a total ban of PFAS in particular.

And they aren't even talking specifically about PFAS in this comment in the first place! They're answering, in the abstract, to a commenter that argues against total bans as a matter of principle. All they're saying is “I disagree that we should always dismiss the option of a total ban, there are situations where it is justified”. This isn't a proposal for a total ban of PFAS in any way.

>For what it's worth, depending on the harms, a sudden total ban is not out of the question as being beneficial to humanity as a whole.

Total ban should be considered against harms.

>It would just be disruptive to enterprise, boo hoo.

Harms are trivial because they are to enterprise.

>We don't need to always treat bad actors with kid gloves.

Implying that enterprises are bad actors, and deserve more harms.

But they said nothing about PFAS, and made no proposal to ban them.

Again, this is an abstract statement that says “stop shying away from punishing those bastards when they kill people”, not a proposal to ban PFAS in particular in this situation.

There's no comment from a user called “tehjoker” nor any comments talking about total bans, in this thread.

Also, in another, different, threat, “tehjoker” is also not proposing a total ban, you're reading his comment wrong.

[1]: https://news.ycombinator.com/item?id=39231091

They have a lot of properties that can be useful in materials - hydrophobicity, lipophobicity, chemical resistance, low friction, etc.

They are certainly used in some niches (like medical devices, protective clothing, advanced manufacturing) that people would agree are Important, but a significant percentage of production goes into, and a significant amount of contamination comes out of, stuff like stain-proofing couches and making food packaging grease resistant. I’m under the impression that a lot of environmental contamination likely also comes from their use in firefighting foams - a useful application to be sure, but there are some things it’s not a great idea to spray straight into the environment.

> Are they chemically bonded to something that reduces bio-interactivity?

A huge part of the story of PFAS is that they are quite resistant to (permanent) chemical bonding, which has often lead to them being thought of as “inert” in a sense that is conflated with safety. But this sense of inertness is a bit of a red herring when it comes to biology (plenty of things interact with receptors without covalently bonding) and meanwhile makes them highly persistent both within organisms and in the environment.

“PFAS” as a literal chemical category feels pretty broad. The ones best established to be harmful are fluorosurfactants like the whole list explicitly targeted here. But broadness is also kind of the point because there are tons of chemicals in use that are likely to have similar accumulative properties that have never really been studied for health effects, and which can’t really be assumed to be harmless if the others aren’t.

Try breathing in a bag.

Air is 21% oxygen. On average, a resting adult breathes in about 250ml of oxygen per minute.

Air is about about 0.04%. The average adult expels approximately 200ml to 250ml of carbon dioxide per minute. Roughly the same as the o then they intake.

So the relative percentage of C02 increases extremely rapidly in any small volume of air, compared to relative reduction in oxygen.

Up to 0.5% (5,000 parts per million): Considered safe for prolonged exposure, this level is typically used as an occupational exposure limit.

1% to 2%: Can cause drowsiness and poor air quality perception.

3%: May lead to impaired hearing, headache, and increased blood pressure and pulse rate.

5% and above: Can lead to shortness of breath, dizziness, confusion, and even loss of consciousness. Exposure at this concentration for several hours can be dangerous to human health.

Above 8%: Can be fatal.

More? Once someone expires, the percentages reach an unwanted steady state!

Even in a tightly closed building, CO2 buildup can impact cognition.

And build up in the atmosphere impacts the heat balance of the planet.

Your exhalations are only pollution when they destabilize healthy levels. So that’s a bit of a straw man concern.

Breathing (outside of plastic bags, and unventilated buildings): fits within normal planetary balance of C02. Not a concern as a pollutant.

Continuously burning billions of tons C02 generating chemicals for decades, another matter.

Dumb argument. Is water a pollutant because of the drowning risk?

> Your exhalations are only pollution when they destabilize healthy levels. So that’s a bit of a straw man concern.

So CO2 is not a pollutant because it is a product of breathing.

Regarding,

> Dumb argument. Is water a pollutant because of the drowning risk?

It might be counter intuitive - because water is not a risk in most contexts. But on another planet where water is an unusual corrosive, then of course it could be a pollutant.

And even on Earth, if some production system kept pumping our environment full of water as a side effect of some process, to the point of endangering or killing ecosystems, in that context it would be a pollutant.

A pollutant is when the accumulation of some left over of a process significantly alters and harms its environment.

Pollutant is a statement about some material’s impact in its context. It isn’t something inate, without context.