As a chemist, but without organics specialization (my specialty is rocks), I think that what we're seeing here is a collection of three main things, aside from polyethylene:

decomposition byproducts: plastics break down under heat, stress and in light. It's not surprising that some of their breakdown byproducts might be found in plastic that has been melted into a new shape.
dyes: plastic is dyed with different additives, and there are a LOT of different colors of plastic being recycled. They usually try to keep the colors generally consistent among batches for recycling, but the dyes that make a sprite bottle green are different from the ones that make a dasani bottle teal.
Plasticizers and other additives: the things the corporations add to their plastics just to eke out that 1 cent of savings from thinner, more durable plastic, or to get the texture just right, are insane. These are things like BPA. There are loads of them, and every plastic has different types. Some of them also have different heat tolerances, but it's not like the recyclers are keeping track.

So, yeah, be afraid. There's a metric fuckton of shit in there, and literally no one knows what it all is, let alone how much of it made it through the manufacturing, use, recycling and manufacturing process without becoming prone to leaching. Virtually all plastic recycling is a scam perpetrated by the corporations to get us to blithely ignore how they are destroying the planet to save money, all while convincing us to blame ourselves.

[–] nickwitha_k@lemmy.sdf.org 3 points 17 hours ago* (last edited 9 hours ago) (2 children)

Been a while since I was in a lab (I was mainly concerned with squishy, squidgy things like microbes, so not quite OChem either) but, this looks accurate to me with a minor bit of pedantry that I had to validate before mentioning. BPA is not actually a plasticizer but a monomer/co-monomer (it does frequently get incorrectly labeled as a plasticizer in retail products). Notably in polycarbonate, which is something like 90% BPA by mass.

A big issue with is the incomplete reaction of monomers, leading to things like room-temp leeching of unreacted BPA in polycarbonate (so glad that I took a Nalgene with me everywhere for years when I was younger /s).

[–] wolframhydroxide@sh.itjust.works 2 points 11 hours ago

Thanks! Edited to account for "and other additives"

[–] logi@lemmy.world 3 points 16 hours ago (1 children)

You misspelled "a minor bit of pedantry". Sorry. It had to be done.

[–] nickwitha_k@lemmy.sdf.org 1 points 9 hours ago

Thanks for that. No apology necessary - that was rather hilarious.

[–] Rivalarrival@lemmy.today 6 points 1 day ago (1 children)

All those chemicals are slightly different length hydrocarbon chains. Functionally, they are nearly identical.

[–] wolframhydroxide@sh.itjust.works 1 points 21 hours ago* (last edited 21 hours ago) (1 children)

Sucrose and cellulose are different-length chains of sugars, but that doesn't mean they're the same. Also, all of the additives in the many different types of melted-together plastic would beg to differ with your assessment.

[–] Rivalarrival@lemmy.today 0 points 6 hours ago (1 children)

There isn't a biologically significant difference between clothing made from various grades of nylon, polyester, polypropylene, spandex, Lycra, acrylonitrile, etc. You probably wear clothing made from each of these families or similar, related materials, each comprised of dozens of "chemicals".

But you'll turn up your nose at the thought of several of these materials combined into a single pellet?

[–] wolframhydroxide@sh.itjust.works 0 points 5 hours ago* (last edited 5 hours ago)

After it's been exposed to use and light for who knows how long, and after being melted together at high temperatures, inevitably higher than the decomposition temperatures of at least a few of the dyes and additives in there, because precisely zero effort has been put in to purify it before being slagged? Yes I will turn my nose up, and you should too. No self-respecting chemist sniffs chemical cocktails of unknown provenance.

ETA: Also, your clothing note is a completely false equivalence, because the chemical at issue here is polyethylene, which has a far greater range and prevalence of additives than those polymers you named for use in clothing.