Science

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.