The problem is not PFAS. It is extreme regulatory capture that got us to the this point. Even if we ban PFAS tomorrow, there are other alternatives that will be used and another 2 decades of lies and cover ups before we find out what harm those chemicals have.
Example: look at what happened when BPAs harms became known. Manufacturers switched to using any of the other 40 chemicals in the same bisphenol family (BPS, etc) many of which had even worse safety profiles, while proudly proclaiming their products were "BPA free".
We need to flip the approval process on its head -- from "safe until proven otherwise" to "unsafe until (independently) proven safe". The tally of harm to all life caused by these chemicals is on a massive scale that any mass murderer would be proud of.
> Example: look at what happened when BPAs harms became known. Manufacturers switched to using any of the other 40 chemicals in the same bisphenol family (BPS, etc) many of which had even worse safety profiles, while proudly proclaiming their products were "BPA free".
It's worse than that. I remember when some 10 years ago Johnson&Johnson baby bottles were banned in one market, they were still available in others, and the FAQ on their website said they do this because they don't believe BPA is harmful. It is only after the total ban in 2012 that they stopped doing this.
Which isn't without issues of its own of course, for example the EU is notoriously backwards on the issue of genetically modified crops which may turn out to be a vital lifeline if climate change causes agricultural collapse. Another example I can think of off the top of my head is the atrociously bad legislation to what was then the new technology of vaping, it came in pre-Brexit just when I was considering quitting smoking (which I eventually managed and never could have done without a vape) and it was so poorly thought out I'm convinced the tobacco industry had a hand in drafting it!
The precautionary principle has its merits, but I think it's often cargo-culted and its limitations not well articulated. In cases such as GM crops where the stakes may within a human lifetime be "devestating famine" versus "less famine", or cases like vaping where although the harm is unknown it's certainly less than what it's replacing (vaping is uncontroversially less harmful than smoking) the precautionary principle actually has a harmful effect in itself.
Sure, banning GMO's outright would be a huge problem, but is it so awful that they be tested first?
I don't know if they test for this, but GMOs do run the risk of become invasive or destructive species which could potentially tilt things towards the "devastating famine" side of the equation.
I don't think the ecological concern is what most people worry about when they think GMOs, and I'm not of the mind that GMOs = Bad, but I think we owe it to ourselves to study the ecological impact of GMOs we plan to grow widely.
I think what the argument comes down to is how much risk we're willing to tolerate as a society. There's definitely a middle ground to be had between an under-cautious world where things like leaded petrol and thalidomide are on the market causing immense human suffering, and an overly cautious world where progress is suffocated by the glacially slow wheels of bureaucracy and endless spurious "safety" objections by lobbyists attempting to kill their competition in its crib.
Having said that, the EU is a bit of a unique specimen when it comes to things like this. I'm perhaps being a little unfair to the precautionary principle per se when I suppose it's more the EU's implementation of it that I'm criticising. I don't want this to come across as an anti-EU polemic either, there's obviously pros and cons here and I realise the EU is very much in a class by itself when it comes to political polities which make comparisons quite difficult. My own biases are probably at play here too, for various reasons I'd say my risk tolerance is probably higher than most.
I've enough friends who work for the Canadian government or university administration to know that there is a coveted and illusive middle ground where vital regulation doesn't grind all it touches to a hapless stand-still.
Hot take: I think the HN software dev crowd might not be the worst equipped to help towards addressing these sorts of problem. From the horror stories I hear, disciplined approaches to tooling could solve a class of problems that appear to be pervasive.
On one hand, the multiple levels of bureaucratic red tape and regulatory approval keeps a lot of technology from progressing onto the market and into people's lives at the rate it could otherwise.
On the other hand, the multiple levels of bureaucratic red tape and regulatory approval keeps a lot of technology from progressing onto the market and into people's lives at the rate it could otherwise.
> GMOs do run the risk of become invasive or destructive species
Crop plants don't run the risk to become invasive or destructive species. They are bred to be easily digestible food sources, which the exact opposite of the strategy for surviving in the wild.
That's true and a relief, but they're also bred to be resistant to certain insecticides and to be robust.
I guess my point is that we don't always get what we think we're getting when it comes to GMOs/selection: when farmers selected for Red Delicious apples that were entirely red, they also selected out the gene that made them palatable. Surely they wouldn't have done what they had if they knew we'd be left with the mealy mess Red Delicious apples are today.
We hope we'll get edible plants that also don't do well in the wild, but there's a lot of room for error and testing is warranted in my not-an-expert opinion (I've a degree in Biochemistry, not Ecology or Agriculture).
We're still decades from a potential global agricultural collapse caused by climate change, there's plenty of time to study effects of GMO crops on environment and human health.
Decades is a short time on a planetary scale, at risk of sounding alarmist I really do believe we should be hoping for the best but preparing for the worst when it comes to climate change. If there was ever a time for action it was fifty years ago, but now is better than further delay.
> the EU is notoriously backwards on the issue of genetically modified crops
The EU has more efficient agriculture by area compared to the US. Part of it by necessity of course. There are problems with pesticides that could be solved with GMO in some circumstances.
But the same principle applies: It isn't stricly necessariy to employ GMO, especially not for yield (we don't have any yield problems anyway). The problems of agriculture today are economic in nature and there still could be negative consequences if GMO strains are spread in nature.
So I don't see anything as backwards really. There just isn't a problem that requires GMO currently. I think saying GMO will be vital instrument against climate change is ridiculous to be honest. Maybe if plants could be modified to use less water?
Part of the issue with GM crops is the corporations involved, and how to operate them ethically under capitalism. The EU has a much stronger stance against capitalism run amok, than the US' does, so even if you do trust the science, the science doesn't operate in a vacuum. The EU understands this.
This is my main gripe with GMO those days. With GMO, the farmers effectively buy a one-year _license_ for a seed (SaaS-like) which can't be used in next years. Also there were stories of farmers going broke due to neighbors' GMO crops taking over their fields, and being sued for license breach.
We must find a way to bound the corporate greed with a good regulatory framework because GMO sooner or later might become inevitable.
Should the data be collected without consent by exposing the public to it for decades or provided by clinical trials funded by the company that wants to bring it to market?
You are asking for the impossible. It can be impossible to tell with things that only have no - to mild effects. Proving a negative ("this is not dangerous") is hard :)
> It can be impossible to tell with things that only have no - to mild effects.
If any effects are unmeasurable with standard clinical trial practices, then it's safe. People care about things that actually are harmful.
> Proving a negative ("this is not dangerous") is hard :)
Which is why I never asked for it. Safety standards are always phrased positively. OSHA doesn't say "workplaces must not be dangerous", they say "wear a hard hat, the employer shall do ___, employees must not be forced to do ___". It's very easy to regulate that "new compounds must be shown not to affect human hormone levels at X concentration, must be shown not to be carcinogenic in Y model of cancer" etc.
Even still, PFAS started being used in the 50s. If it took us this long to figure out there is something dangerous about it, chances are a small study would not have found anything either. We’ve had lots of time and a huge N.
You collect data on a smaller scale, like clinical trials do for medications. There's a big range between "no data" and "we've enrolled eight billion humans in an uncontrolled trial".
>We need to flip the approval process on its head -- from "safe until proven otherwise" to "unsafe until (independently) proven safe". The tally of harm to all life caused by these chemicals is on a massive scale that any mass murderer would be proud of.
That isn't always practically feasible and its a really tough problem to solve. Consider all the ways a compound released into the environment can break down and how long it might take for any exposure or even low levels of exposure might take to have any adverse health affects. The type of evidence you'd need to gather to demonstrate any compound is fully safe with that bar would make it nearly impossible to declare anything safe.
Microplastics, PFAS, and other compounds with potential long-acting health impacts are very hard to predict far in advance. Strong evidence against any adverse health effects would take considerable effort to gather while in the mean time they would offer massive clear benefits and solve so many problems. Plastics have massively reduced costs in almost every industry and have become almost irreplaceable in some applications such as medical equipment (think packaging for syringes, surgical tools, or anything that requires contamination control). Yet how they break down into microplastics in the environment and then eventually bioaccumulate in our tissues through the food chain is something that would've been extremely hard to predict at the onset of their creation. Even now we don't know if they're necessarily harmful.
Associated with sure, but at what exposure levels? Can we expect all microplastics to have this affect? What if the lower fertility rates are tolerable compared to the benefits of plastic use overall?
From your first source:
>Data are still preliminary but suggest that ingested MPs bio-accumulate in mammalian tissue, including the testis, with outcomes on semen quality in rodents, as a consequence of inflammatory state and oxidative stress damage.
>The mechanisms decreasing fertility rate during the lifespan are still poorly understood.
>Taken together, although studies in mammals are still limited, preliminary observations point out a possible risk of MPs for male fertility.
The evidence is still "preliminary" and data "suggests" some outcomes but nothing is close to definitive. There are lots of confounding factors that can cause lower fertility that are explicitly noted in the that source. For example they even suggest that the microplastics themselves might not be causing harm, but rather that they act as "sponges" or vehicles for concentrating other pollutants that are actually decreasing fertility.
>>We need to flip the approval process on its head -- from "safe until proven otherwise" to "unsafe until (independently) proven safe".
Totally agree in principle.
There is one fly in the ointment - it is impossible to prove a negative, such as "X does not exist" or "there is no possible harm from this to any person ever" (water would not meet that standard).
So, this needs to be implemented in such a way as to not completely halt progress.
Should be straightforward to require testing to reasonable standards levels of biological harm to humans and ecology, persistence/degradability, etc. the levels need to be set by NEITHER the industry NOR the perfectionist eco-activists. Finding such a panel will be tricky.
I consider progress to be getting closer to technology that gets us out of the unsustainable ecological/biosystems hole which we have dug for ourselves.
We are not going to put the technological genie back in the bottle, short of eliminating 98+% of all humans and reverting back to hunter-gatherer tribes.
The only solution is to go through this dirty technology cycle and build and implement clean sustainable technologies that allow us to live with something resembling current populations without destroying the climate system, breaking the food web, or poisoning ourselves (& everything else).
So, yes, the only thing worse than halting all progress now would be to do it a decade age before solar, wind, etc. became viable, but we need a lot more progress, i.e., better performance for lower costs - both ecological & economical - for most of our technologies, and eliminating those destructive technologies. That would be progress.
It's not entirely regulatory capture. Progress in science requires the ability to understand and accept that new information can arrive that invalidates prior decisions. In the political sphere, this is known as a "flip-flop" and is sadly considered to be a poor trait by a good chunk of the public. So long as governments represent the public, and a cross section of the general public thinks that flip-flopping is a bad thing, I don't think it's possible to have decisions driven by the best available science.
Side note: even scientists get things wrong. Businesses thrive on certainty, so some level of damping of changes in regulatory direction is required. Finding the right balance is, however, not something humans have done as well as we need to just yet.
California law TB117 required fire retardant foam until 2015 so a lot of couches have PFAS. This is an example of creating a problem by trying to avoiding another. Of course, this is not to single out CA as this is a global problem.
Could be wrong but it seems like the general rule is that manufacturers are allowed to "experiment in public" when it comes to chemical science. PFAS alternatives are already in the wild and we don't know what those do either.
Here's what you can do:
1. Open windows to your house, but also your car which contains PFAS in the upholstery
2. Minimize dust w/ vacuum, HEPA filters
3. Reduce use of old couches which stirs up dust until you replace it
4. Minimize polyurethane foam products - polyster foam is better
5. Paper/biodegradable takeout containers and fast food packaging have PFAS lined so the paper doesn't absorb oil etc.
PBDEs have been shown to have hormone-disrupting effects, in particular, on estrogen and thyroid hormones.[10] A 2009 animal study conducted by the US Environmental Protection Agency (EPA) demonstrates that deiodination, active transport, sulfation, and glucuronidation may be involved in disruption of thyroid homeostasis after perinatal exposure to PBDEs during critical developmental time points in utero and shortly after birth.[11] The adverse effects on hepatic mechanism of thyroid hormone disruption during development have been shown to persist into adulthood.[citation needed] The EPA noted that PBDEs are particularly toxic to the developing brains of animals.[11] Peer-reviewed studies have shown that even a single dose administered to mice during development of the brain can cause permanent changes in behavior, including hyperactivity.[12]
Swedish scientists first reported substances related to pentaBDE were accumulating in human breast milk.[13] Studies by the Swedish Society for Nature Conservation found for the first time very high levels of more highly brominated PBDEs (BDE-209) in eggs of peregrine falcons.[14] Two forms of PBDEs, penta- and octaBDE, are no longer manufactured in the United States because of health and safety concerns. Based on a comprehensive risk assessment under the Existing Substances Regulation 793/93/EEC, the European Union has completely banned the use of penta- and octaBDE since 2004.[15] However, both chemicals are still found in furniture and foam items made before the phase-out was completed. The most common PBDEs used in electronics are decaBDE. DecaBDE is banned in Europe for this use and in some U.S. states. For PBDE, EPA has set reference dose of 7 micrograms per kilogram of body weight, which is "believed to be without appreciable effects". However, Linda Birnbaum, PhD, a senior toxicologist formerly with the EPA (now at NIEHS) notes concern: "What I see is another piece of evidence that supports the fact that levels of these chemicals in children appear to be higher than the levels in their parents; I think this study raises a red flag."[16]
Increasing levels of PBDEs in the environment may be responsible for the increasing incidence of feline hyperthyroidism.[17] A study in 2007 found PBDE levels in cats 20- to 100-fold greater than median levels in U.S. adults, although it was not adequately powered to establish an association between hyperthyroid cats and serum PBDE levels.[18] Subsequent studies have indeed found such an association.[19][20][21]
An experiment conducted at Woods Hole Oceanographic Institution in 2005 showed that the isotopic signature of methoxy-PBDEs found in whale blubber contained carbon-14, the naturally occurring radioactive isotope of carbon. Methoxy-PBDEs are produced by some marine species.[22] If the methoxy-PBDEs in the whale had come from artificial (human-made) sources, they would have contained only stable isotopes of carbon because virtually all PBDEs that are produced artificially use petroleum as the source of carbon; all carbon-14 would have long since completely decayed from that source.[23] The isotopic signatures of the PBDEs themselves were not evaluated. The carbon-14 may instead be in methoxy groups enzymatically added to man-made PBDEs.
A 2010 study found that children with higher concentrations of PBDE congeners 47, 99 and 100 in their umbilical cord blood at birth scored lower on tests of mental and physical development between the ages of one and six. Developmental effects were particularly evident at four years of age, when verbal and full IQ scores were reduced 5.5 to 8.0 points for those with the highest prenatal exposures after correcting for sex, ethnicity, tobacco smoke exposure, and mother's IQ.[24]
I don't want flame retardants in my products. I suspect most of these requirements came from the era when a lot more people smoked. Sure, put flame retardants in oven mitts and things that will reasonably catch fire, rather than things like pillowcases.
Even still, how common were couch fires 20+ years ago when flame based (non-vaping) smoking was so much more common?
Like my sibling sort of did I want to point out that this possibly was meant to counter another trend. Unfortunately furniture nowadays burn much faster than before.
They did an experiment. Built one room with old furniture made from solid wood and other "old style materials" and set it on fire. Then they built another one with modern materials with the typical particle board furniture. Set it on fire.
Also, California's law that makes everyone label everything with "this product contains some measurable level of an identified carcinogen" means that no one pays attention to those labels when it's plastered on something like an asbestos breathing mask or lick-and-paint radon clocks, making them even worse than useless.
Or the alternative: there are a huge amount of dangerous products in the market that we all shouldn’t be using. Thank you California for bringing this to our consciousness.
Personally I’m very content with these labels and actually avoid products that contain the warning. It’s only because of prop 65 that I recently learned many seaweeds contain high levels of arsenic, lead, and other heavy metals.
Bruce Ames, biochemist and molecular biologist, inventor of the Ames Test and a prolific and accomplished scientist in the areas of cancer and aging[1], believes that prop 65 is a, "thoroughly silly law, with an enormous cost and no gain in public health"[2]. Interesting and relevant discussion in this PDF[3] about the fire retardants discussed elsewhere in this thread.
I'm having trouble figuring out what kind of filter I can use for my furnace. I've read a little bit about it and it seems that a residential furnace might not be able to handle the HEPA filter due to the higher airflow resistance. Even MERV 13 might already be too high.
The MERV or other rating of a filter is not what's important to your furnace (it's what's important to the humans) but what matters is how much airflow through the filter can be achieved by the furnace fan and how much pressure drop the filter induces.
If you get a MERV 12 filter with LOTS of filter material, it may flow more air at a lower pressure drop than a MERV 6 filter with minimal filter material. Look for more pleats in the filter or modify (or hire an HVAC contractor to modify) your furnace filter cabinet to accept a thicker filter cartridge.
For reference, in my furnace during an HVAC consultation, we saw the same 0.5 inches of water pressure drop from a cheap 3M Filtrete MERV 7 filter as with a K&N reusable MERV 12 filter. The K&N has MUCH more filter material.
You don't want to restrict the airflow to your furnace any more than is necessary. Most furnaces will have their required maximum pressure drop from the duct work and filter printed on a label inside. You can get a differential pressure meter to measure the actual pressure drops yourself, or hire an HVAC technician to do an audit of your furnace (often they'll do lots of other neat tests and give you lots of data and reports and info, too).
I recently retrofit a new HVAC system and as a result have also gone on a bit of a deep dive on indoor air quality. The big thing I learned is that most homes -- even old "leaky" builds -- have rather poor ventilation, meaning all sorts of compounds build up in the air... CO2, formaldehyde, VOCs, PFAS, etc. Air purifiers work for particulate, but don't really make a dent for chemicals. IIRC, You would need like a 50 gallon drum of activated carbon to do anything on the chemical front.
A quick solution is to crack the windows, or if you live in a non-temperate climate, install an energy recovery ventilating system.
Energy Recovery Ventilators or Heat Recovery Ventilators are absolutely essential (and, I think, part of code in many places!) in this era of tight and sometimes extraordinarily tight (e.g. Passivhaus) home building.
When we bought our home, the HRV wasn't working and once I replaced a bunch of parts in it, the difference in the quality of the air was noticeable just in the fact that it smelled fresh like the outdoors.
In your deep dive, you probably ran into the evergreen debate about running ERV/HRVs in the summer... I just gave up, turn it off when we run the A/C and open the windows occasionally... BUT I think you could probably run a humidistat/hygrostat hooked to the HRV (a common option in the new units, I believe).
I’m based in Tokyo and have spent the past few months going down the rabbit hole of indoor air quality. It started out of concern for the health of our four-year old - lots of time indoors on account of the pandemic, etc.
We have HEPA filters in every room now and portable CO2, PM2.5, VOC monitors, etc for keeping an eye on things. As others have stated, however, this does nothing to address the VOC issue and so I am very keen to take the additional step of installing an Energy Recovery Ventilator or Heat Recovery Ventilator, as you suggest.
If anyone here has Japan or Tokyo-specific information on manufacturers, suitable systems and/or contractors capable of doing the work, I for one would certainly be grateful to hear it!
I'm in SF. The tricky thing here is that outdoor humidity is often so high that a humidistat would only result in an 'always on' system. I think CO2 is an objectively better measure anyway. You can remove humidity and particulate with energy efficient machines. You can't (realistically) do that with CO2 / VOCs.
Did you find any industry ventilation standards related to all the compounds you listed? IIRC, ASHRAE 60.1 is the industry standard but years ago at least, it was based mainly on using "bio-effluence" as a proxy for air quality. I.e., reducing stink.
>install an energy recovery ventilating system.
These are a good idea, but the exact type is important or else you risk cross-contamination between the exhaust and intake. That's why many designs (e.g., heat recovery wheels) are generally banned in some applications like healthcare.
With the crowd that HN attracts, I'd be interested if anybody has implemented some sort of demand-control ventilation in their home.
I think an ideal heat recovery system would probably sit mid-stream in a central air system with a built in CO2 trigger. Basically, the return air gets exhausted while heating the incoming/supply air when CO2 concentration > X. Obviously you run into the capex vs ongoing energy cost tradeoff in designing the system.
Strangely, I couldn't find a ventilator on market with a CO2 sensor, but there are plenty with humidity sensors. I think CO2 sensors are on the horizon though, here's a study featuring such a system: https://core.ac.uk/download/pdf/43245317.pdf
My current system is actually ductless however, so I will probably have to rely on natural diffusion... I do have an air quality monitor which indicates that diffusion is likely sufficient (for a one floor open plan condo), but you'll optimally need to sleep with the bedroom doors open.
Edit: I haven't looked too deeply at the standards. My little sensor indicates that if you keep CO2 in range, VOCs will also also be in range, which conforms with my intuition.
CO2 sensors are common in commercial HVAC systems - especially for large auditoriums or rooms where you expect high occupancy. Economizers will automatically open to increase the exchange of outside air. My church has an auditorium that can seat up to 1500 - all four AC units have CO2 detection built into them and the concentration is displayed on the controls too.
>Basically, the return air gets exhausted while heating the incoming/supply air when CO2 concentration > X.
That’s the basic idea of demand control ventilation but how are the two air streams interfacing? If our concern is air quality, how is cross contamination between the two mitigated?
I was confused at first by a lot of diagrams I found online, but the wiki is pretty good. Basically think of a two way radiator. Hot air flows through air channel blades on the way out, cold air flows around the blades on the way in, with filtering optional at this point. Some systems indicate that they literally mix the air, which is obviously not going to be optimal, the air needs to be fully separated with the energy exchanging through a metal layer.
As someone who immigrated from France to the US, it’s pretty obvious why people in the US are obese: people don’t know / don’t have the time to know how to eat properly and eat junk food, all the time, at any hour, and don’t move around. It’s pretty obvious when you realize that there is a lot less overweight people in upper middle class areas.
When did you do that? In last twenty years France has become one of the fattest countries in Europe. I was there in 2008 and 2019. Huge difference.
The upper middle class in USA is fatter than it used to be. Very few people actually lean as opposed to having much less fat. The class disparity is real but not the only explanation.
2014, I still go back annually. You have a large portion of the lower middle class that’s more overweight now but it’s not like in the US where you can be somewhere where it’s impossible to find healthy food for 100 miles, and where you can go inside a Walmart and almost everyone is overweight. There’s obviously some bias given I live in the Bay Area, I’m sure there are areas where upper middle class folks are more overweight.
even among people who say what you're saying - there's just so many things that raise insulin levels or contribute to insulin-resistance.
people assume it's sugar. and a lot of it is and it's the first thing people should cut back on.
but people are surprised zero-calorie artificial sweeteners and crystalized versions of stevia and monk fruit do.
people aren't even aware that omega6s PUFAs (which we're supposed to have a 1:1 ratio with omega3s, and are supposed to have both in fairly low levels) also impact insulin resistance
activity does, sleep does, things impact it positively like a wide range of plant foods or teas.
but more simply - without going into the whys or the science, if generally speaking people cut out A. Sugar and B. processed foods (thus removing a ton of salt and omega6s) people would be a million times better off.
It may be a contributor but there are so many "obvious" things that cause obesity in the modern world that a paper needs really strong arguments with a rigorous statistical analysis with confounding factors in order to draw conclusions.
The obvious include: high availability of energy-rich, cheap food, lower amount of physical activity, food designed to be addictive (usually with lots of sugar),...
There is also a strong correlation between obesity and low socioeconomic status, that can be also explained by "obvious" factors, like irregular meals, less physical activity, cheap, energy-rich, nutrient-poor food and poor education regarding healthy habits.
There appears to be a similar issue with other endocrine disruptor chemicals like phthalates (plastic softeners) possibly increasing the risk of obesity. But those are typically polluting food rather than air.
I can't stomach the science "journalism" here. Most of the statements about the research is that studies "found" the chemicals here or there. Ok, I can "find" various sources of cancer-related radiation in my sock drawer. Particularly annoying:
"It found particularly high levels in several kindergarten classrooms and also checked the supply room of an outdoor clothing store, offices, several university classrooms, university labs and an elevator."
Thank goodness we the public have the crucial information that the study checked these places.
"HEPA filters capture pollen, dirt, dust, moisture, bacteria (0.2-2.0 μm), virus (0.02-0.3 μm), and submicron liquid aerosol (0.02-0.5 μm).[8][9][10] Some microorganisms, for example, Aspergillus niger, Penicillium citrinum, Staphylococcus epidermidis, and Bacillus subtilis are captured by HEPA filters with photocatalytic oxidation (PCO). HEPA is also able to capture some viruses and bacteria which are ≤0.3 μm."
"Eleven particle-size-segregated samples were taken to investigate the particle-size distribution of perfluoroalkyl substances (PFASs) using two five stage impactors in parallel. ... Particle-size distribution varied between perfluorooctane sulfonate (PFOS) and other perfluoroalkyl sulfonates (PFSAs), perfluorooctane carboxylate (PFOA) and other perfluoroalkyl carboxylates (PFCAs) and n-methyl-perfluorooctanesulfonamido ethanol (MeFOSE). Whereas PFOA and MeFOSE were predominantly observed in smallest size fraction (<0.14 μm), maximum PFOS mass fractions were observed in the coarser size fractions between 1.38 and 3.81 μm."
Hold on, that is very much the opposite of my interpretation.
HEPA filters are typically designed with 0.3μm pores this is mostly a legacy of medical applications (i.e. to guarantee they catch bacteria).
Submicron performance (< 0.3μm) is kind of down to luck. You need the submicron particle to travel on a larger liquid particule for it to adhere to the filter lattice.
The PFAS is a group of substances, the article is specifically talking about 6:2 FTOH (one of many PFAS substances) that is found in carpets etc.
6:2 FTOH specifically is a sub-micron compound, from the GP article the closest particle to it is PFOA which is <0.14 μm. So unless your 6:2 FTOH compound is travelling on a moisture particle it is unlikely it would be filtered.
To answer GGP question, a high MERV rating filter will probably catch some of these compounds but not the totality. Open your windows frequently (if outside air pollution allows wherever you live) and make sure you understand what products you have in your house.
> You need the submicron particle to travel on a larger liquid particule for it to adhere to the filter lattice
That's what intuition would suggest, but intuition turns out to be wrong when dealing with filters for microscopic things. There are at least four mechanisms by which a filter can trap particles, three of which work on particles smaller than the pores [1].
Briefly:
1. Big particles don't fit between the fibers of the filter. Think fish in a fish net. This is called sieving.
2. Particles too small for sieving but heavier than the surrounding flow don't make the turns as well as the surrounding flow when the flow goes around the fibers. The particles can get embedded in the fibers. This mechanism is called inertial impaction.
3. The smallest might be too small to actually be affected much by the flow of the surrounding fluid through the filter. The move by diffusion, and many will randomly hit the fibers and get stuck.
4. Particles too big for diffusion but too light for inertial impaction still can run into fibers and get stuck. This is called interception.
The effectiveness of sieving, inertial impaction, and interception all follow S shaped curves that start out low for small particles, then at some point start rising, and then level out. The sieving curve's rise is almost vertical. The rise for inertial impaction is steep but not nearly as steep as it is for sieving. The curve for interception's rise is much more relaxed.
The effectiveness for diffusion goes the other way. Much more effective for very small particles, then above some size drops down and is low from then on.
When you put all these together, you get a curve that is effective at the small end, and at some point as size goes up effectiveness drops, reaching a minimum, and then rises again to reach high effectiveness for particles above some certain size.
There is also a fifth mechanism in some filters where electrostatic attraction between the fibers and the particles catches some particles.
I don't claim to know one way or the other. I was basing my interpretation on GGP's quotation from Wikipedia, which seems to indicate that HEPA filters can capture down to 0.02 μm. I note now, however, that it then goes on to suggests that HEPA filters don't reliably capture some other categories of larger particles, which is consistent with your comment. Edited accordingly.
Regular HEPA filters should be able to filter these, but I'll admit I don't know what size these particles are. If they're single molecules it may be a problem.
Wicking materials don't use PFAS (although see edit below). The properties that PFAS endows a fabric are pretty much of the opposite of what you need for wicking. Wicking fabrics such as Capilene and polypropylene must be wettable in order to work. PFAS reduces the wettability of fibers. That's its whole point.
PFAS is used in nearly all current water resistant fabrics, including clothing, upholstery, and carpet. The industry calls these Durable Water Resistant (DWR) treatments.
PFAS-free treatments are only just recently hitting the market, but there are only a few so far and they're expensive. The North Face's Futurlight, Helly Hanson's Lifa are the only ones I know by name, but I've heard that Marmot and Mountain Hardware have some PFC-free garments as well.
EDIT:
I searched "PFAS wicking" and I see a some underwear makers are claiming their DWR treated products have enhanced wicking properties. This is confusing marketing. The DWR isn't actually enhacing the wicking. Rather, it's keeping the surface of the fabric that's next to the skin dry, while the untreated bulk of the fabric wicks moisture away. This is sort of like the thin perforated polyethylene membrane used in Band Aids to keep the would dry and prevent adhesion of the dressing.
Nevertheless, it appears we now have to be wary of forever chemicals in our underwear. Lame.
I’ve put off buying a sleeping bag from REI because of DWR. I like to sleep outside as much as I can, and when temps are freezing a well-insulated bag is great. I’ve switched to wool blankets for now. I’m also more and more okay with going without various comforts; the cost of having whatever I want is too high.
It is strange! It's a recent thing in the US, yes. Probably in the past 4-5 years nearly all major brands put some sort of special chemical that gives it 'moisture wicking' (usually in partnership with Dow or 3M).
I just bought some new underwear from Marks & Spencer in the UK which has their "Cool & Fresh" treatment. I haven't worn it yet but this thread is putting me off.
M&S publish a Manufacturing Restricted Substances List [1] for their suppliers, which seems to ban the use of all per- and poly-fluorinated chemicals in the manufacture of textiles for them.
Either I'm misunderstanding, or some of these underwear treatments don't involve PFAs. Who knows what they use instead?
I'm designing a wearable device, and I'm looking for resistant materials, different from metals, that are safe to use on the skin. According to Wikipedia PTFE (teflon) is not harmful. Could someone recommend materials to protect the electronics from sweat/dirt and the skin from the device silicone?
There are no mobile PFAS chemicals in nonstick cookware. Nonstick coatings are made from PTFE, which is a completely inert polymer that cannot be broken down into mobile components unless it's overheated. The fluorinated chemicals used in the manufacture of the coatings (largely surfactants) are completely removed when the coating is baked on, and they have to be or else the coating would fail.
PTFE is used in medical implants. You can eat it. In no case that I'm aware of have these things resulted in detectable fluorinated compounds in someone's blood stream.
People "overheat" their cookware all the time. Do you know anyone who measures the temp of the surface of their cookware?
Teflon and nonstick coatings kill birds (house pets) when overheated. A nonstick pan in the oven to catch the drippings from your chicken baking at 400 or 425 can kill your parrot quickly. A nonstick wok left unattended for a few minutes during a high-heat stir fry easily reaches 400, enough to kill your cockatiel.
And as another poster has noted, those coatings always start flaking off.
Why buy something that produces fumes enough to kill your house pets and also has planned obsolescence built in when you can get a cast iron pan that's indestructible and will increase your iron intake a bit? It's not hard to develop a great seasoning on it that's essentially non-stick. I use cast iron for almost everything, and enamel for a few remaining applications.
I was maybe (mis)remembering studies that showed the pans had to be heated to a high-temperature relatively fast (in the order of under a second) for the off-gassing to occur, but I couldn't find that yet. I did find some interesting information about the dangers at different temperatures [1] and common cooking temperatures[2]. Without finding that study about quickly heating being necessary, they seem to corroborate your point.
Notice that the reports in your first link of PTFE coatings breaking down at less than 260 deg C are anecdotal. The lowest temperature at which PTFE coatings have been verified to give off breakdown products is 240 deg C. Even then, the only detected product was PTFE sublimate (small particles of PTFE flying off), which can lead to what we call "fume fever" if it's inhaled in large quantities, but reports of this happening in real life are rare, even in factory workers who are exposed at higher levels.
PTFE is chemically stable well past 300 deg C (540 deg F) and many nonstick cookware lines are marketed for these temperatures. For example, I have Calphalon pans labelled for use up to 550 deg F, which are advertised for searing steak. I get them pretty hot, and they show no signs of degradation.
At around 360 deg F (650 deg F), PTFE starts to give off detectable pyrolysis products, which are theoretically able to cause health problems, but even then reports of actual harm are few and far between. This is remarkable given that billions of pieces of nonstick cookware have been in use every day around the world for the past seventy years. Between the end users and the factory workers who make stuff, and all of the accidents and episodes of overheating that occur all the time, if there were going to be significant health effects I think they'd show up by now.
The real problem is the PFAS chemicals that are sprayed on our clothes, upholstery, carpeting and other home furnishings, that the military and civilian airports have dumped in our water supplies. This is a shaping up to be a true environmental catastrophe, and the manufacturers of nonstick coatings have no doubt contributed to this pollution. But the teflon cookware itself is not the slightest threat.
Cast iron pans are wonderful. I inherited one that was purchased originally in 1929. It's used every day or two to cook eggs for breakfast, and as I've found over the years butter is fantastic for keeping the seasoning in great shape. It's more non-stick than teflon, just a little shake is enough to send my eggs sliding to the other side of the pan. All it takes is discipline.
Best part is, this same pan will probably live well beyond 100 years. Possibly 150 or more. How many household items last that long? This is what we've lost with our culture's planned obsolescence, products that last for generations. It my have been expensive back then, but that was the last person in my family to buy this type of cookware. Safe, long lasting products isn't an innovation, it's a very welcomed regression.
I agree, I love vintage cookware. My favorite pans are a bunch of All-Clad LTD's I assembled from Ebay over the years. I use them for omelettes and french toast. Super thick aluminum clad with a stainless cooking surface, made sometime in the 1980s. They're as tough as cast iron, but they heat way more evenly, they're much lighter, and you don't have to worry about hurting the seasoning.
With cast iron, you can easily destroy the seasoning by overheating the pan, or if your mother who doesn't know how to care for cast iron puts it in the dishwasher. I put my All-Clads in the sink and scrub them with a steel tuffy. They're probably the most indestructable tools I own.
i'd have to buy a new stove if i had a cast iron pan
i have a glass top stove.
cast iron has several problems. Learning how to "season" it (which i never figured out how to do when i had a different oven), the fact it's usually expensive and there's no "one size fits all scenarios" type of pan to use and re-use, thus resulting in you have to buy several.
Then there's stainless steel pans but good luck with that - everything sticks to that.
I just want to cook some eggs without having to use some chemical solvent to actually clean the egg remnants off the pan.
I might go with “because they are lazy” for many of the shortcuts we take. We have one well-seasoned cast-iron pan and several not-so-well-seasoned which I’ve been too lazy to properly treat, so for now I spend the extra time scrubbing. I even use soap (!), though only after the dog gets the big stuff off. Teflon pans required too much care, so we never repaced them.
I agree that rice sticks easily to iron pans, so I usually cook rice in inox/stainless saucepans or in ceramic in the pressure cooker.
Eggs we cook in the seasoned iron pan.
We can change our habits so that we don’t do so much harm to life on earth.
I think that you are correct in most cases, people choose nonstick for the easy cleanup afterwards. But that's not what I'm referring to. I have not found a pan, other than PTFE coated, which can fry rice to crispy without using excessive tons of oil. All of the best crispy rice will get stuck to the pan and become inedible.
When you tried the carbon steel pan, was it properly seasoned? They stick like hell before they are well seasoned, but seasoning them gives the carbon steel its non-stick properties. Woks are the ultimate tool for this, as they are carbon steel (so non-stick when seasoned) and their shape minimizes the amount of oil necessary to fry the rice. It is ubiquitous for fried rice across almost all of Asia.
Yeah but they use a lot of oil in those woks, and they get them really hot. Any Chinese street vendor with an open fire and cheap steel wok can do shit I can't dream of doing in my fancy ass American kitchen.
J Kenji Lopez-Alt has a lot of great wok content for American kitchens. In [0], he uses a butane torch to get the smoky wok flavor (wok hei) in a standard kitchen. He also reviews outdoor wok setups for those who want something close to Chinese street vendor-type vibe.
I cook with my carbon steel somewhat often, and it seems to have built up a nice thin black layer that keeps most things from sticking. Cleaning is a breeze, some dish soap and a couple scrubs. None of the black layer comes off.
Rice does not stick at first, but as it gets hot it does, unless I put around 3x the oil I would prefer. I have a gas range with a large burner so it gets very hot.
This is my experience as well. I also use a lot of slowly sauteed garlic, like pretty much every day, and I'm completely reliant on a small nonstick pot to do it without sticking and burning.
Scrambled eggs too, especially the soft-scrambled kind ala Gordon Ramsay's famous short video. They simply wipe out of nonstick pan, and I've never seen this work with any other kind of cookware.
> Do you know anyone who measures the temp of the surface of their cookware?
Yes, I do. I have a cheap IR thermometer with my kitchen utensils, and I use it all the time. I use it every time I roast seeds and spices, because I'm picky that way. I've also used it when I've accidentally left a pan on the burner too long. I'm careful but I screw up now and then. I accidentally heated a stainless pan to nearly 500 deg F once, but 've never gotten a nonstick pan over about 400 deg F.
> Teflon and nonstick coatings kill birds (house pets) when overheated. A nonstick pan in the oven to catch the drippings from your chicken baking at 400 or 425 can kill your parrot quickly. A nonstick wok left unattended for a few minutes during a high-heat stir fry easily reaches 400, enough to kill your cockatiel.
Stories of such low temperatures killing birds are anecdotal. The lowest temperature that has lead to bird deaths in a controlled laboratory setting is 280 deg C, which is about 580 deg F. [1]
Keep in mind that birds are easily killed by common cooking smoke and fumes, as well as natural gas. The problem with these anecdotes is that it's likely there were other fumes involved, and there's no way to know what actually kills a bird oustide a controlled lab setting.
> And as another poster has noted, those coatings always start flaking off.
As I noted in another comment, it's not hard to keep a nonstick pan indefinitely. I have a lot of ten and fifteen year old nonstick pans that are as good as the day I bought them. My daily drivers are about five years old now, good as new. I'm careful not to overheat them and I never use metal utensils in them. Following those two rules, even my kids were able to use them without damaging them.
> Why buy something that produces fumes enough to kill your house pets and also has planned obsolescence built in when you can get a cast iron pan that's indestructible and will increase your iron intake a bit?
If you overheat that cast iron pan, or if you burn food in it, it will kill birds just as easily as a nonstick pan. Also note, there is vastly more evidence of harm from excess iron consumption than there is of harm from overheated PTFE coatings.
That said, I like steel and iron pans. I regularly use enameled steel pans for toasting spices, and I cook crepes and pancakes on steel pans. I don't use cast iron for much because it's heavy as shit and its heat distribution sucks.
I've actually had good luck with seasoned bare aluminum pans. This is more common in some restaurant kitchens, but not so much in home kitchens. Aluminum seasons just as well as iron, and the heat distribution is way way better. But for some reason "cast aluminum" doesn't have quite the same old-timey panache as does cast iron.
+1 for measuring temp. I recommend everyone to buy $10 IR thermometer from AliExpress, despite it's not absolutely accurate, it's very helpful to measure and see changing temperature.
There aren't any long term studies comparing people who cook with non-stick vs stainless or cast iron, so we can only guess about long term and population level effects based on limited information.
I personally would not take the risk given the benefit is just a pan that things stick to less. Medical uses are more justifiable.
No, we have lots of long term information about nonstick cookware. People forget we've been using teflon cookware since the 1950's. There have been billions of pieces of nonstick cookware in use every day around the world for decades.
The problem is that because there are so many free PFAS chemicals around us from other sources, studying the possible effects of cookware is a bit like studying whether it contains evil spirits. You won't be able to come up with a falsifiable hypothesis, because our PFC exposure via other routes is so high.
Another reason long term studies aren't viable is that there is no plausible mechanism of action of toxicity from nonstick cookware under the sort of use that it almost always gets. Unless it's badly overheated, PTFE is completely stable in inert.
Think about this logically: if you handle a water resistant jacket and then eat a sandwich, you'll ingest measureable quanities of PFAS. Every time kids or babies play on a stain-resistant carpetting and furniture, then ingest far greater quantities from their hands and toys.
In contrast, any PFAS that remains in nonstick cookware would be on the edge of detectability. PFAS surfactants are used in the manufacture of the coatings, but it boils off when the coating is baked on, and as far as I know, no detectable PFAS has ever been verified in finished cookware. Even when agressively overheated, nonstick cookware doesn't emit PFAS. It sublimates micro-size PTFA particles, which can lead to what we call "fume fever" but reports of this actually happening are rare, even in factory workers who are exposed at much higher levels than a home cook is.
So put these two things together: you are likely ingesting millions of times more PFAS from your clothes, carpets, and furniture than you ever could from nonstick cookware.
Worrying about nonstick cookware is sort of like a lifeguard who works in the sun all day, but obsessively blacks out the windows in his home because he's worried about UV radiation getting in his house. It makes no sense.
> No, we have lots of long term information about nonstick cookware. People forget we've been using nonstick cookware since the 1950's.
That’s not a study.
> You won't be able to come up with a falsifiable hypothesis, because our PFC exposure via other routes is so high.
We’re so poisoned by these chemicals it’s impossible to run a study to figure out if one possible source of them specifically is measurably poisoning us. Maybe we should consider banning them, or just avoiding them in general.
> PFAS surfactants are used in the manufacture of the coatings, but it boils off when the coating is baked
See sibling comments.
> if you handle a water resistant jacket and then eat a sandwich, you'll ingest measureable quanities of PFAS
I try to avoid synthetic fabrics when I can, so in my case it’s not like your lifeguard scenario.
I also think the government should step in to limit the use of plastics generally.
> We’re so poisoned by these chemicals it’s impossible to run a study to figure out if one possible source of them specifically is measurably poisoning us.
Sort of. My point is that teflon cookware is not a plausible source of PFAS, because there is no detectable PFAS in finished cookware. Further, because there have been billions of pieces of nonstick cookware in use around the world for decades, if there were negative health effects we would probably notice them by now. But there aren't.
Contrast this to the lead that has been widely used in glass and ceramic cookware and dishes over the same period of time. Manufacturers claimed that lead bearing glazes were perfectly safe. This is false, but we don't need any "studies" to tell us that. Rather we've plainly seen tangible health effects from the use of these items in many medical reports over the years, and we can easily test and verify the presence of lead that is leached into foods that are cooked and served in them.
This is not the case with teflon cookware. There is no detectable PFAS in nonstick cookware, nor are there verifiable reports of health effects from its use, in spite of the millions or billions of such uses happening every day over decades.
> See sibling comments.
Which ones? The ones where I addressed the poorly substantiated risks of overheating?
> I try to avoid synthetic fabrics when I can, so in my case it’s not like your lifeguard scenario.
I guarantee you're not able to avoid PFAS-treated upholstery, carpeting, and other home furnishings. And depending on where you live, chances are good that you ingest significant amounts of PFAS in your drinking water. If you've ever eaten fast food, the wrapper it came in was probably coated in PFAS. Due to these and other sources, I guarantee you have measurable levels of PFAS in your blood and tissues.
So by all means, avoid nonstick cookware if you want. It won't hurt, and it may have value just because it makes you feel better. That's legit. But in terms of actual harm reduction it is very much like the theoretical lifeguard blacking out his windows.
> Further, because there have been billions of pieces of nonstick cookware in use around the world for decades, if there were negative health effects we would probably notice them by now.
Dropping testosterone levels and sperm counts, increasing levels of obesity. I think we're seeing the health effects, although as mentioned it is hard to pick apart exactly what is having what impact. Our lives are flooded with plastic, I suppose non-stick cookware is kind of like a drop in the bucket.
> This is not the case with teflon cookware. There is no detectable PFAS in nonstick cookware, nor are there verifiable reports of health effects from its use, in spite of the millions or billions of such uses happening every day over decades.
I would need a lot of evidence to be convinced there's not a risk. I think we'll look back on plastics a similar way to how we look back on our naivety about things like cigarettes, lead, asbestos, etc.
> I guarantee you're not able to avoid PFAS-treated upholstery, carpeting, and other home furnishings. And depending on where you live, chances are good that you ingest significant amounts of PFAS in your drinking water. If you've ever eaten fast food, the wrapper it came in was probably coated in PFAS. Due to these and other sources, I guarantee you have measurable levels of PFAS in your blood and tissues.
I don't dispute this. I just try to avoid plastics when it's practical. As mentioned I would like to have regulations passed to reduce sources. I would not like to give up and say "well alright I'm being so poisoned already, might as well risk having a bit more by using non-stick pans".
I also don't want to support the manufacturing of these chemicals generally. Putting aside the end consumer, the manufacturing seems very likely to have been harmful to people, and chemicals from the manufacturing could also end up spreading in the environment.
Non-stick pans may not be the absolute worst thing to come out of the plastics industry, but getting rid of them still seems like a step in the right direction.
With every non-stick pan I've ever owned, the coating eventually starts flaking off. Usually after less than 1 year of use. I'm pretty sure I must have ingested plenty of these coatings over the years...
I have many pieces of well-used nonstick cookware well over a decade old, which are in pretty much the same condition as when I bought them. This includes cheap IKEA pans that my kids used. Some of them get used literally every day. We don't overheat them, and don't use metal utensils in them, and there's no reason they can't last forever.
Regardless, you can eat the entire coating off of your pan, and there will be no detectable fluorinated compounds in your blood. PTFE is completely inert and indigestible. It is widely used in medical implants inside people's bodies, with no detectable leaching of any chemicals.
Hmm, sounds like you've got lucky with your pans - everyone I've ever mentioned this too has had the same problem with non-stick pans! Lifetime of 6-12 months tops :/
I never did use metal utensils with them; it might be I overheated some, but certainly not all, and a pan isn't much use if you can't get it hot!
I don't think I'm lucky, but there is definitely a cost. The cost is that I'm a fucking asshole about my nonstick pots and pans. I keep my stash separate from the rest of the family, I get grumpy if I catch anyone using it, and god forbid anyone scratches my shit.
I buy separate stuff for my kids, and my wife has her own favorite pan.
Of course there's no need to be an asshole like me. But I think it's eminently doable for everyone. I do believe keeping the temperature down is key to longevity, especially for cheaper cookware with simpler two-layer nonstick coating systems. I have a lot of these too, and I just avoid going over 300 deg F or so. No problems so far.
PTFE burns at high but commonly achieved cooking temperatures, the result is a fine particulate in the air. You have to be careful (and many aren’t) to only use nonstick for low to medium temperature cooking.
The idea that PTFE doesn't break down except at very high temperatures is not true.
Breakdown begins to occur at either 200 or 260 degrees Celsius (depending on what data you're looking at). These temperatures are well within the realm of temperatures that even a home chef might encounter.
> Breakdown begins to occur at either 200 or 260 degrees Celsius (depending on what data you're looking at).
This isn't good data. The stories of PTFE coatings breaking down at less than 260 deg C are anecdotal. The most well known one comes from someone who swears their chickens were killed by coated light bulbs in a coop.
The lowest temperature that has lead to bird deaths in a controlled laboratory setting is 280 deg C, which is about 580 deg F. [1] This is way freaking hot, and likely only to be reached by accident.
Even in the case of accidental overheating of non-stick cookware, there have been only a few verifiable cases of injury, and certainly no fatalities. Most cases of polymer fume fever have been gleened from among workers in factories, which is remarkable considering that billions of pieces of nonstick cookware have been in use every day around the world for the past seventy years.
Also note that cooking fumes from food are themselves toxic, and kill birds and lead to long term respiratory issues in humans much more easily than PTFE coatings.
> The lowest temperature that has lead to bird deaths in a controlled laboratory setting is 280 deg C
"Did any birds die?" is an approach to this problem that I would expect from an undeveloped nation a hundred years ago. It is both excruciatingly short-term in focus and so imprecise that the results are useless for anyone who is not himself a rat or a canary.
Your data answers the question, "To what temperature must we heat PTFE in order to kill small animals?"
It does not answer the question, "What are the long-term effects on humans of short excursions outside of normal cooking temperatures?"
> "Did any birds die?" is an approach to this problem that I would expect from an undeveloped nation a hundred years ago. It is both excruciatingly short-term in focus and so imprecise that the results are useless for anyone who is not himself a rat or a canary.
I sort of agree, but birds do make a convenient study subject because they are exquisitely sensitive, much more so than humans.
The lowest temperature at which PTFE coatings have been seen to evolve breakdown products (that I know of) is 240 deg C. Even then, the only detected product was micro-size PTFE sublimate, which can lead to what we call "fume fever", but reports of this actually happening are rare, even in factory workers who are exposed at much higher levels.
The temperatures at which PTFE pyrolysis really starts to give off nasty shit are way higher [1], but even then, evidence of physiological harm is sketchy. Anecdotally, I know a few people, including my father, who have left a nonstick pan on the stove, got distracted, and burned the coating right the fuck off. Aside from the smell, no ill effects were observed. This isn't scientific at all, but if burning PTFE is that toxic, one might have expected some effects.
> It does not answer the question, "What are the long-term effects on humans of short excursions outside of normal cooking temperatures?"
This is true, but undertaking such a study would be both impossible and pointless, because we are exposed to millions or billions of times more fluorinated compounds from clothing, furniture, and carepeting, than we could evey hope to get from nonstick cookware, even if you overheat it regularly.
Keep in mind that billions of pieces of nonstick cookware have been in use every day around the world for the past seventy years. And all time, factory workers have been exposed to the manufacturing process. That's plenty of time for problems to have been observed on some level, but they just haven't. The problems we're seeing come from the billion-fold higher levels of PFC we get from other sources.
To repeat an analogy from an earlier comment, worrying about nonstick cookware is sort of like a lifeguard who works in the sun all day, but obsessively blacks out the windows in his home because he's worried about UV radiation getting in his house. It makes no sense.
1 - https://sci-hub.st/10.1289/ehp.7511197 - Waritz, R. S. (1975). An industrial approach to evaluation of pyrolysis and combustion hazards. Environmental Health Perspectives
The last time I needed an x-ray for a broken bone, I asked the x-ray tech for a lead vest to protect my torso and groin area.
He told me that it was pointless because I would be exposed to more background radiation throughout the course of my normal life. He did not understand that ionizing radiation damage is cumulative and that there is no safe limit for exposure. Annoyed with my request, he gave me the vest anyway.
Is there a safe limit for exposure to PFAs? I would readily concede that the risk to an individual is probably negligible, but like in the case of x-rays, population-level risks probably do exist for even the smallest exposure.
That said, I would also support eliminating all sources of PFAs, just like we tried to do with CFCs and asbestos.
You were right to ask for a shield. I would do the same thing, and I'd be a little pissed that I had to ask.
However there's a big difference, in that the x-ray you got actually delivers a substantial amount of ionizing radiation-- up to one full percent of the average annual background dose. There is no evidence that even a lot of normal x-ray scans have any effect on health, but at least it's a physical possibility.
In contrast, the level of chemical hazard from nonstick cookware is a billionth or trillionth (or even smaller) than what's in the carpets we all grew up playing on, or the clothes we wear and furniture we sit on every day.
To use another analogy, worrying about nonstick cookware is like worrying about the ionizing radiation coming from a banana that's sitting uneaten across the room from you.
I agree about absestos, and I fee the same about lead as well. Those are nasty poisons that, contrary to popular lore, cannot be used and applied safely such that they won't eventually get loose and become a health hazard. I've been thinking about asbestos this week because I've been replacing ceiling light fixtures in my house, and it's impossible to do without causing the asbstos-filled popcorn texture to rain down like snow. It's fucking unbelievable what previous generations afflicted us with.
EDIT:
I feel compelled to repeat that common cooking fumes and smoke are known toxins and carcinogens. It makes no sense to be more concerned about tiny amounts of aerosolized PTFE than the far greater amounts of cooking smoke and fumes that will inevitably be emitted by your food at the same temperatures.
Contrary responses aside, these three actions seem healthy. I’ll add that I’d like to see regulation towards cleaner air, water, and land, so that avoidance/mitigation is less necessary.
Example: look at what happened when BPAs harms became known. Manufacturers switched to using any of the other 40 chemicals in the same bisphenol family (BPS, etc) many of which had even worse safety profiles, while proudly proclaiming their products were "BPA free".
We need to flip the approval process on its head -- from "safe until proven otherwise" to "unsafe until (independently) proven safe". The tally of harm to all life caused by these chemicals is on a massive scale that any mass murderer would be proud of.