I'll bite, your friend may be a professional scientist, but their response was simply "absolutely not". I had a biologist friend who had the same attitude towar

I'll bite, your friend may be a professional scientist, but their response was simply "absolutely not". I had a biologist friend who had the same attitude toward eating raw eggs. The fact is the science has not looked at risks of sous vide plastics. There's maybe no money for such research, unless like in this article the professor became a father and had to microwave food for his newborn baby. In their research, they showed that those particular nanoplastics cause kidney damage, but only in vitro (EDIT: Ah yes, a quick Google shows a horrifying 2023 study that says nanoplastics do get absorbed into the bloodstream...). That's like a doubly indirect argument for concerns about sous vide. I think a more nuanced answer is that we just don't know, and so it is reasonable to invoke the precautionary principle. Other people, when made aware of the risks, might go ahead but that's their informed choice to do so. So unless there's a series of studies that shows, "Sous vide produces X amount of polyethylene nanoplastics, and adult/child/rat consumption shows measurable harm", the best we have is precautionary principle and informed risk. It would be nice to have something definitive like "Cigarette smoking causes lung cancer", or more recently from WHO "Drinking alcohol causes breast and gastro/rectal cancer", but we don't have that scientific closure to an open question for sous vide yet.