A versatile food wrap that will (ideally) cling to both food and food containers, forming an airtight seal, hence sometimes called clingfilm. Unfortunately, in the process it can also form an unbreakable seal with itself, which can lead to extreme frustration in the inept, among whom I am sometimes numbered. I have heard that if you keep Saran Wrap, a major culprit here, in the freezer, it won't stick to itself, but I haven't tried this trick.
So what is this stuff anyway, that has replaced waxed paper as the food covering of choice in much of the world? Well, apparently some brands are made from polyethylene, a substance which they say is not absorbed by foods at all. However, polyethylene isn't clingy enough to make an airtight seal, so the really clingy brands of plastic wrap are made from polyvinyl chloride (PVC), which requires the addition of plasticizers for added flexibility. Problem is that the plasticizers are absorbed by food they're in direct contact with, and process which is exacerbated by heating, as in a microwave. The wording I've seen on this tends to be pretty careful, of the "no current evidence shows harm caused by ingestion" type, but that kind of language raises the hair on the back of my neck.
Seems to me that the best advice here is, if you still want to use plastic wrap, use it to seal a container, but don't allow it to come in contact with food at all. Not in the fridge, not in the microwave. And as for me, I'm pulling out the waxed paper.