Here’s a short, easy guide to plastics you shouldn’t use. As a corollary, if it’s not on this list, you can feel good about using it.
* If a plastic item has a “7” recycle symbol on it, it might be bad, most notably polycarbonate. Stay away.
* If it’s “saran wrap” style plastic wrap, ask what it’s made of. PVC plastic wrap is bad, not because of the PVC but the chemicals they add to make the PVC soft. That’s unfortunate because PVC makes plastic wrap that works the best (it’s sticky and is a great barrier). There are many plastic wraps made of other materials that aren’t toxic.
* polystyrene AKA styrofoam: bad.
I could rant at you for 20 minutes about the dangers of these plastics and how unconscionable it is that these materials are still in common usage.
The other commonly used plastics are generally safe to use! That includes polyethylene (PET, PETE, HDPE, LDPE), and polypropylene.
I gathered the most current info from this page (which is a reaffirmation of things I’ve already known)
Which Plastics Are Safe? a Care2 favorite by Annie B. Bond