The same kind of peel off paper backing that stickers come on. Some people would call it "wax paper", although I don't think any wax is involved anymore...

So you mean those paper food boxes with a 'fat' resistant coating?

That's pretty much all takeaway food boxes, no?

Yes.

It depends on where you get it from, but in general it seems like it's the same stuff.

https://www.consumerreports.org/toxic-chemicals-substances/p...

Cups are typically coated with polyethylene to make them waterproof, but I think I read somewhere that they are then coated with PTFE to make them slide apart easier when stacked.

The level of PFAs during the pandemic must have just skyrocketed if this packaging is indeed a culprit.

Think of the formed paper bowls at Qdoba or similar fast casual. The ones that don’t seem coated yet magically don’t disintegrate when they are covered in oil.

I believe it’s specifically those, not so much things like butcher paper or soda cups.

Any kind of food wrapping paper or food box.

Are these the faux-cardboard impregnated with plastic lining take out boxes?

Probably the same as “parchment paper” you get for baking - ptfe