Dangerous chemicals found in recycled plastics, making them unsafe for use

https://theconversation.com/dangerous-chemicals-found-in-recycled-plastics-making-them-unsafe-for-use-experts-explain-the-hazards-220498

by PaulHoule • 2 years ago

132 115 2 years ago

theconversation.com

bell-cot• 2 years ago

[sigh/]

Obviously, labeling things "Recyclable" satisfies an intense emotional need for many people. Regardless of where the stuff they dump into their "Recycling" bins actually ends up.

But at what point would it actually be better - for both the environment and human health - to invent a clean (~no toxic outputs) and efficient-ish way to burn mixed plastic waste as fuel, and to just use that?

UncleOxidant• 2 years ago

There used to be a startup near me that was turning plastic into crude oil.

Looks like they're still around: https://www.agilyx.com/

PaulHoule5• 2 years ago

Polystyrene is relatively easy to depolymerize with enzymes, catalysts and moderate amounts of heat, see

https://pubs.acs.org/doi/10.1021/acssuschemeng.1c08400

The pyrolysis route they are using can be problematic because it produces carcinogenic aromatic compounds like

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

which has a metabolite which is almost a cancer-causing drug. In principle you could pyrolyze plastics all the way down to carbon monoxide + hydrogen syngas and then build that up to molecules you want with C1 chemistry

https://en.wikipedia.org/wiki/C1_chemistry

but most of the people who are trying chemical recycling by pyrolysis are trying to cook the molecules partially so the output fuel is a witches brew rich in hazardous aromatics. There is a lot of research into cleaner processes for chemical recycling such as

https://www.nature.com/articles/s41598-021-83659-2

and that one at the top but every large scale plant I've seen is a pyrolysis plant that's had to fight with environmentalists to start operations. From the viewpoint of a chemical engineer making fuel is for the birds because gasoline costs 50 cents a pound and (almost) any other chemical costs a lot more than that.

jacobolus2• 2 years ago

It would be better to only allow a small list of approved plastics for uses like packaging with much more obvious labeling to distinguish them (e.g. require a particular color or very clear markings), more carefully regulate mixed/composite materials, charge manufacturers an extra cleanup tax for whatever materials they use, and try to carefully regulate many types of single-use plastics out of existence in favor of biodegradable or environmentally neutral alternatives (as a trivial example, there's no good excuse for candy wrappers to involve plastic), and force every municipal trash collector to also collect "compost" including food waste, soiled cardboard, and biodegradable plastics.

It should be possible for relatively incompetent consumers to tell at a glance precisely which plastic something is made of and figure out how to sort all of their recyclable plastic waste into 2 or 3 categories.

* * *

Or at a higher level, there should be some people with significant systems thinking training doing full society-wide audits of the sources and treatment of materials including plastics, and then regulators should be making targeted policy to fix harms (whether environmental, human health, economic, ...), starting with the most significant ones and working their way down from there.

maxerickson• 2 years ago

Do you honestly think that would be sufficient? I expect you'd get significant amounts of the wrong material in all the bins.

shados• 2 years ago

People can't even properly sort cardboard vs plastic...

bryanlarsen• 2 years ago

Given that your input stream of plastic waste contains a very large number of toxic inputs, burning it without releasing toxic outputs seems pretty much impossible. It seems a similar level of problem: burning it without releasing toxins and recycling it without incorporating toxins.

CoastalCoder• 2 years ago

Chemistry-ignoramous question:

Is there a burn-temperature above which everything dangerous is basically rendered inert?

I.e., you make stuff so hot that whatever survives is perma-bonded to oxygen, carbon, chlorine, fluorine, etc., and has almost zero chance of reacting with living creatures?

(Ignoring radioactive stuff, I mean.)

FooBarBizBazz2• 2 years ago

Most of it is hydrocarbons, which a sufficiently thorough decomposition process ought to be able to turn into CO2 and H2O. (And maybe HCl in the case of the chlorinated plastics? I guess that's neutralized with a base to make a salt?)

I don't know a ton about this, but it looks like plasma gasification plants achieve something like this -- producing syngas (mostly H, CO), metal nodules, and a slag material (which seems to roughly be, "igneous rocks or sand, but man made"). I'm curious about the composition of the output products. But it seems to usually be net-energy-positive. This seems like a good intro:

https://science.howstuffworks.com/environmental/energy/plasm...

Sci-fi:

I wonder if there are methods from physics that could be used (even if not now cost effectively) to more thoroughly isolate the various elements rather than having the (it seems not totally understood?) chemical reaction of the various components of the plasma as it cools? Like a big industrial scale mass spectrometer? Like the cyclotron scheme to separate isotopes of uranium in the Manhattan Project? Then you could know, "all the lead is in this beam over here" and "all the mercury is in this beam over here", and so on... That'd be neat. Have some plasma physicists working on recycling instead of on fusion...

(At this point I Google more...)

Interesting, so here they separate copper from zinc using a plasma centrifuge:

https://www.sciencedirect.com/science/article/abs/pii/016858...

And here they're looking (hypothetically) at using plasma separation to isolate the component elements in old NdFeB magnets, to recycle them:

https://www.sciencedirect.com/science/article/abs/pii/S09596...

Hmm...

nox101• 2 years ago

Let's call it "recycling theater" like we do for security. Maybe there were good intentions at one point but so much of it seems like marketing now.

Most cities only have a few collection spots. It would make way more sense to try to separate the trash at the trash location than asking millions of individual people to try to do it correctly, 30% of which can't do it correctly, 30% of which don't care. I'm not sure I've ever seen a single trash can that has 100% of the correct trash in it, even at a FAANMG company that claims to hire the best and brightest.

Then you get ambiguous things like plastic coated paper, marked with a recycle symbol. Or cardboard milk cartons with a plastic cap and plastic infused cardboard (or is it wax?)

Sure, maybe you're supposed to cut the cap part out but lots of people don't know, can't be bothered, won't do it.

If you want this to actually be effective you really need to do it in as few places as possible, the trash collection companies, where a few inspectors can make sure it's being done correctly and a few reporters can check

throwway1203852• 2 years ago

Maybe we could try reducing or reusing in addition to recycling?

__MatrixMan__• 2 years ago

Recycling is much more meaningful if it's done by the designers of the recycled thing and not by some third party.

I'd like to see a world where if you're not sure, it should go in a pile that gets shipped back to the manufacturer... On their dime if labeling standards weren't met, on your dime if they were.

This would give manufacturers a reason to build things in a way where they want the discarded thing back (like how they do with toner cartridges).

dylan604• 2 years ago

My recent favorite is Amazon's "recyclable" packaging, but only if you bring it to one of their locations. I've seen other examples of the same thing, but this was the most recent. When you try to claim your packaging is recyclable but make the person jump through those kinds of hoops is not very conducive to having things recycled. It's one of the most obvious BS PR maneuvers

bluerooibos• 2 years ago

We found 191 pesticides, 107 pharmaceuticals and 81 industrial compounds among many others in the recycled plastic pellets.

Oh, fantasic!

kurthr2• 2 years ago

You'll easily find radioactive Potassium (K40) in bananas and potatoes. A good Geiger counter can easily pick them up. They're just bananas and potatoes.

Concentration matters and chemical detection methods are so sensitive (ppb) that without reporting how much was found in the plastic, this information is almost useless. That they didn't report concentrations is problematic.

The base study/publication is here, but I didn't see much concentration information there either.

https://www.sciencedirect.com/science/article/pii/S235234092...

refurb5• 2 years ago

The dose makes the poison.

There are naturally occurring carcinogens in things like coffee.

But we don’t worry because the amount is so low.

Clamchop• 2 years ago

The person eating the banana is more radioactive than the banana being eaten.

Not sure why bananas became the benchmark! Banana for scale?

fransje265• 2 years ago

I would be more worried of the pesticides they spray(ed) on bananas though..

https://www.bbc.com/news/world-europe-50144261

paulmd• 2 years ago

love this genre of post on HN, the “smartest boy” post

I mean sure the article is citing peer-reviewed research but on the other hand and all, but HN thinks nobody has ever heard “the dose makes the poison” before, so maybe pollution is actually fine???

hold up, science, here comes americas smartest boy!

See also, “aha but what about [confounding factor that is super obvious and the paper already discusses controlling for]!”. Like at some point it’s just dismissive to the point of insulting to imply that nobody else has bothered to put minimal thought into something that probably represents person-years of work with the involvement of multiple subject-matter experts and peers.

the covid threads here etc were absolutely insufferable with this, and generally any pollution thread you will get some dork who’s obnoxious enough to pull “the dose makes the poison” on 2,4,7,8-TCDD or whatever - yes, it happened last week!

Look out EPA, here comes Americas smartest boy! /young sheldon adjusts bowtie

in particular with pollution and other things though it’s just gross because it’s so obviously an industry-centric spin that is designed to imply that pollution is generally ok and that there’s no real need for polluters to ever control pollution of any kind because hey, big ocean out there etc. The implication is, again, that nobody else could ever have thought of a lower limit before, and it really plays into the urge a lot of people have to be Americas Smartest Boy in discussions, even when it’s wildly inappropriate in general (like the 2,4,7,8-TCDD example). You can be the smart guy making the clever point in the debate if you just follow this simple talking point, brought to you by SmogCo!

Climate change threads are always lousy with it too. Aha but what about heat island, sun cycles, whatever. Yeah the climate scientists know already, Mr Boy. If you thought of it in five minutes then definitely one of the professionals studying in the field has raised the issue sometime over the last 100 years. And of course the obvious answer you’re proposing is… keep “studying” for decades to solve some minor quibble, and naturally to allow smogco to continue polluting in the meantime?

modeless2• 2 years ago

We have separate trash, recycling, and compost bins. Our city hands out free compost from the facility that handles the compost bins. I would never spread that compost on my property or eat anything grown from it. I mean, have you seen how terrible people are at sorting trash? Who knows what atrocities have happened in that composting facility!

My own wife dumps non-compostable stuff in the compost all the time, is annoyed at me when I point it out, and then somehow doesn't think twice about taking the free compost for gardening.

DANmode2• 2 years ago

The "compost takes care of it" crowd is mind-boggling to me.

Interested in health to avoid an entire societal ecosystem, but not enough to test their own soil, even once.

Tempest1981• 2 years ago

"compost takes care of it" crowd

Can you explain more? I'm not familiar with this crowd. Takes care of what?

nerdponx• 2 years ago

Same as the "commingled recycling takes care of it" crowd.

ajsnigrutin• 2 years ago

Don't worry, industrial farms buy that compost for cheap, and you then buy their food in stores.

loopdoend• 2 years ago

Wait until you hear about the nanoplastics found in rainwater

carterschonwald• 2 years ago

My understanding is that commercial composting process is much more aggressive than what’s done for home composing

modeless2• 2 years ago

Does it eliminate heavy metals? PFAS? Every type of plastic? Literally every other type of contaminant that I haven't thought of? Is every batch of the end product tested thoroughly? Even if contamination is rare, is it as rare as other sources of garden soil? Why would I chance it when I know the source is dirty?

simonsarris• 2 years ago

As much as ~88% of tested kale contained PFAS, and it's because of commercial compost. Organic kale has more PFAS than non-organic because it uses more compost rather than more synthetic fertilizer.

https://anh-usa.org/wp-content/uploads/2023/06/230621-ANH-US...

swells34• 2 years ago

Like, aggressive to the point of being nuclear? Because if not, I'm not sure how you expect it to remove a lot of the chemicals mentioned...

geysersam• 2 years ago

I was under the impression that "compost" was used for biogas and not as fertilizer? Is that not the case?

Using it for food sounds like a bad idea.

FooBarBizBazz2• 2 years ago

They've been applying sewage sludge to fields for years with the EPA's blessing:

https://www.epa.gov/sites/default/files/2019-12/documents/ep...

All kinds of shit goes into the storm water drains, including a bunch of Teflon's relatives.

On the rare occasions that they test a field for PFAS, it often comes up positive. I think it's just "don't ask, don't tell" at this point.

(Edit: Ok, maybe it's "only" 5% of farmland: https://www.ewg.org/news-insights/news/2022/04/ewg-forever-c... )

I mean, maybe I shouldn't be that hard on them -- you do need to reuse human and animal waste if you want to be sustainable, and this is a plausible way to do that, and they weren't thinking about PFAS at the time (only PCBs are mentioned in that document) -- but it should be obvious now that the current sewage system is not compatible with this use case. Too many nasty things can get into it. Which does create a problem -- if you don't apply the sludge, then what do you do with it? It's like we need a whole separate system for only organic waste. Or we have to stop selling to the public -- or to industry -- any compound we're not willing to eat.

addicted• 2 years ago

Wait till you find out that plastic is an approved material to feed the animals that are slaughtered for you to eat.

bruce343434• 2 years ago

In the United states

refurb5• 2 years ago

It legal to have a certain limit of plastic in it.

But does it matter? Food touches plastic throughout the preparation phase. Most factories have plentiful plastic components. Workers have plastic gloves. Then the final product is wrapped in plastic.

Removing it from feed wouldn’t do much in terms of exposure.

nomilk2• 2 years ago

This may seem ignorant or cynical, but my baseline assumption is the contents of all bins end up in the same landfill. I'm pleasantly surprised to learn that your garden/organics/green bin actually goes somewhere other than straight to landfill. Although it's entirely possible that the capital and labour required to make it into compost and give it away for free cost more than handing out vouchers to citizens to buy compost on the free market. An analogous false economy happened in my city with a 24-hour/day train trial; when they did the math it turned out it would have been cheaper to give every single passenger an uber to their destination.

smogcutter• 2 years ago

In my city (a suburb of LA), the trash contractor says they don’t have separate bins because they “separate recycling at the facility”. What a joke! As if they’ve got someone going through your trash like a raccoon, picking out the bottles.

I get that the plastics industry has an interest in making recycling appear seamless and efficient, but what a crock.

No1• 2 years ago

The PFAS content from “compostable” food containers alone makes me cringe at the notion of city compost being used as fertilizer for crops.

herbst3• 2 years ago

I can buy a 'quality' 25l bag of earth for $14 (Switzerland) and still be sure to find visible plastic parts in it. The earth the farmers buy here locally is rainbow colored if you look closely enough.

I introduced the majority of plastic in my garden trough expensive earth & compost.

I only use Coco at this point (what is crazy considering there are no coconuts where I live)

hammyhavoc2• 2 years ago

Shit, is that really what the coloured bits are? There was me thinking it was some kind of fancy beneficial additive.

ryandamm• 2 years ago

I read the article and didn’t see any mention of concentrations. I suspect (though IANAChemist) that finding trace amounts of many hazardous chemicals might be de minimus. Which at the very least renders this article incomplete.

(That is not to say the article is wrong, or that recycling is perfect, just that certain facts in isolation don’t really allow you to draw any conclusions.)

PaulHoule5• 2 years ago

"Virgin" plastic is full of all kinds of additives which can be harmful. For instance

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

which was developed as an estrogen active drug until they found this stuff

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

which worked "better"

Plastic for use in food packaging ought to be regulated as to what you put in it, which ought to be easy for virgin plastic (though seemingly it isn't) but would be much harder if you were recycling plastic meant for different uses.

(Of course there is a lot of controversy about the mobility of plastic components. We know the carcinogenic styrene monomer exists in significant amounts in polystyrene, what's not so clear is how much of it migrates out)

vel0city• 2 years ago

Your source disagrees with you about BPA.

BPA was never used as a drug.

BPA wasn't developed as a drug, it was developed for it's resin properties.

ManBeardPc• 2 years ago

It is really difficult to recycle plastic, because there are just so much different materials that we call plastic. Some can be reshaped with heat and others need chemicals. Packaging often contains multiple different plastics and it is REALLY hard to separate them. Also the molecules break down over time/use, degrading the quality of the material.

Another nasty property is that some chemicals used to make plastic soft or change other properties (additives) often don't chemically bind with it and they leak out over time.

"Recycled" could probably be removed from the title. Plastic and its additives are very likely bad for you period. "A path towards safer reuse of plastics" is missing a more useful point: reduce single use plastic and replace if other materials make more sense for the use-case. Sure, there a many points we could improved regarding to the usage cycle but some problems are just inherent to the current set of plastics.

I try to avoid plastic as much as possible, especially for food or beverages (even more important if hot).

It's sad that such a useful and versatile group of material also has so many downsides.

nostrebored3• 2 years ago

Even not hot — the recent spectroscopy studies on plastic particles in bottled water should be enough to convince people to avoid them if possible

blindriver• 2 years ago

We need to have regulations and laws that only allow a handful of types of plastics to be manufacturered, and all of them must be recyclable. The fact that we have tens of thousands of different types of plastics, all so that companies can profit from that, is why we are poisoning ourselves.

I don't care how expensive some types of plastics are: we should only allow companies to produce safe, recyclable plastics and not let them poison the earth just so that they can make a few basis points of more profit.

jh00ker• 2 years ago

The US barely even recycles any plastic to begin with!

https://www.cbsnews.com/news/plastic-recycling-failed-concep...

tomxor2• 2 years ago

It's worse than that... Even for ideal, highly recyclable materials like aluminium and glass, the majority is thrown away globally.

Aluminium and glass are more economical to recycle than sourcing virgin materials! comparably simple and infinitely recyclable - and yet we still can't get that right - Plastic is expensive and complex to recycle, the idea that recycling it was ever a solution to plastic pollution is complete BS, there will always be a significant quantity that ends up in the ground and in the sea.

versteegen2• 2 years ago

Aluminium certainly, but glass is not clear cut. A quick web search leaves me thinking it depends, not just on whether you measure energy, greenhouse gases, or cost (versus cost of disposal if not recycled), but also all of those vary between countries.

Yes, economics of recycling plastic are very bad, I wonder how high the cost of landfill would need to increase to make it more expensive than recycling.

roldie• 2 years ago

I have been making an effort to only buy athletic wear with 100% recycled polyester. I guess now I throw them all out and only buy wasteful virgin polyester athletic wear?

feedsmgmt• 2 years ago

Maybe don't wear any kind of plastic? Every time you wash a synthetic garment plastic particles are going into the water system.

nostrebored3• 2 years ago

And aerosolized during the drying process… and shed during wear… I’ve eliminated polyester from my wardrobe.

buildbot• 2 years ago

This 100% - plastic clothing is sadly just a bad idea. Also, smells gross very quickly. Wool, silk, cotton and other natural fibers are great and not hideously more expensive in most cases.

throwway1203852• 2 years ago

Or you could check out alpaca or merino wool. It's better at trapping heat when it gets wet and if you let it hang dry it doesn't smell bad like plastics do so you can wear it more than once.

thsksbd4• 2 years ago

There's a very safe way to recycle plastic. It's also the only way to effectively and universally recycle plastic.

Burn it for energy in place of another fossil fuel.

lazide3• 2 years ago

Or just bury it in a landfill.

pengaru2• 2 years ago

Burning seems silly when you could sequester the carbon by just sticking it in a landfill...

thsksbd4• 2 years ago

Thats worse. Lets say you have a tonne of plastic.

Option 1, burn it:

Plastic burned release energy roughly equivalent to fossil fuels. Therefore, burning it displaces an equal amount of fossil fuels.

Option 2: landfill it

You still fossil energy so you produce it, but producing it is very energy intensive.

Also you now have a landfill filled with a molecular sponge absorbing toxins, breaking up into microscopic pieces and releasing the toxins elsewhere.

SebFender• 2 years ago

I give up - let's just trash the whole thing.

privacyisntdead• 2 years ago

Glad to see this is being brought up.

It’s obnoxious how many companies are throwing recycled plastics into consumer goods (watch bands, hats, phone cases, some clothes even) with no regard to health consequences.

I’m all about being better for the environment but I also don't want to be wearing plastic.

Ekaros2• 2 years ago

So much of this looks like green washing to me. Reminds me of those reusable coffee cups from bamboo or whatever. That ended up containing all the same chemicals...

sam345• 2 years ago

I'm so confused these days. We can't use compost. We can't use wood because that's bad. We can't use plastic or metal. We shouldn't eat meat or processed food (and definition of process takes care of most things outside of the produce aisle). A lot of plant foods apparently are poisoned with contaminants or are full of carbs, etc. If someone finds a way to live in this modern age and survive please let me know.

netsharc• 2 years ago

Fish are full of mercury, there's even plastic in fruit[1]... we've poisoned our environment so much that nothing is "clean" any more.

I suppose your comment is more of a moan against what you perceive to be "the elite"'s (the rich, the media, the Davos class, etc) fearmongering, but hey, we're not designed to survive infinitely anyway...

[1] https://www.bbc.com/future/article/20230103-how-plastic-is-g...

lazide3• 2 years ago

I take it more as frustration.

All available information sources are full of bullshit and conflicting information too, so good luck quantifying any of the available information on hazards.

Frankly, ignoring it all and just living a reasonable life with reasonably low processed foods seems about right though.

belorn• 2 years ago

There are ways to live that can tick all the boxes except for one: It does not scale.

If we accept non-scaleable methods then household chickens are great. They keep pets away from gardens, it reduce the need to cut grass, and they are much better than composts. Naturally this method is limited to people who own a house and have garden/outdoor area that is suitable, and where local government allows it.

An other great but non-scalable method is to eat anything that is invasive or which population is a major threat to bio diversity, assuming one do not cultivate or raise it. There are some obvious risk of perverse incentives, but it can be utilized to benefit the environment when done right.

Ferret7446• 2 years ago

Not possible, studies have shown that living is harmful to your health. Life has a 100% death rate.

Our ability to identify things that might shorten our lifespan has far outpaced our ability to apply that knowledge usefully. For most of human history you ate what you could and hoped it didn't kill you in a few weeks. It was only relatively recently we even had the capability of discussing things like long term cancer risk or what not.

mercer• 2 years ago

well and also relatively recently that we've had the capability of fucking things up on global eco-system scales.

delfinom• 2 years ago

To be fair, for most of history, food didn't have cancer risks attached.

tmikaeld• 2 years ago

“Living has a 100% death rate”

There’s a tshirt idea

theNJR2• 2 years ago

Our food system is pretty well poisoned. You have to be incredibly intentional, and even then it’s hard to escape all of the negative effects.

refurb5• 2 years ago

What are the negative effects?

dkasper• 2 years ago

I think you can use compost, you should just test it if you don’t know what was put into it.

standardUser• 2 years ago

We have to stop trying to make plastic recycling work, at least until it can actually work, because it seriously hurts the reputation of recycling other materials, most of which work great. It also complicates the entire process, depending on your jurisdiction, which also acts to deter recycling other materials.

fransje265• 2 years ago

Well, the "recyclable" plastics was a great lie pushed by the oil industry to counter regulations that would restrict their usage. That's fairly well documented by now.

Maybe it's time to restrict/forbid their usage, like has been done for other products and chemicals that have turned out unhealthy and/or dangerous although highly profitable. (Asbestos, CFCs, leaded gas, tobacco, [...])

nostrebored3• 2 years ago

One thing to note here is the intersection with emerging technology. A huge amount of work is going into modified plastics which self biodegrade.

But what does this degradation do when these dangerous adulterants are trapped inside of plastics?

glial• 2 years ago

Does anyone know whether this applies to clothing that uses recycled plastic? I know Patagonia uses lots of recycled polyester: https://www.patagonia.com/shop/collections/recycled-polyeste...

judge2020• 2 years ago

The study doesn't go into how these plastics are harmful to your health. I doubt something like plastic in your clothing would harmful since it's not necessarily being absorbed through your skin. The most harm is likely in plastic containers that hold liquids or food which tend to be the primary source of microplastic ingestion. The article also mentions that this isn't exclusive to recycled plastic, since making virgin plastic requires tons of chemicals itself.

CrHn3• 2 years ago

BPA has been shown to be absorbed transdermally [1]. Patagonia was recently found to have high levels of BPA, along with other brands [2].

Bluesign and Oeko-tex certifications test for BPA. You can find recycled polyester without this (if you have kids, Hanna Andersson's polyester lines claim to be BPA and PFAS free, most Cat and Jack clothing is Oeko-tex certified and Mamavation puts out good information on PFAS in things like children's clothing, backpacks, lunch kits [3]).

1. https://pubmed.ncbi.nlm.nih.gov/33313651/

2. https://www.forbes.com/sites/ariannajohnson/2023/05/18/worri...

3. https://www.mamavation.com/product-investigations

andrewstuart• 2 years ago

I throw all my plastic in the waste bin because I don’t believe in recycling plastics and don’t want to contribute to the plastics recycling system.

Dangerous chemicals found in recycled plastics, making them unsafe for use

Related Stories