Depends on what you mean microwave safe? Read the box info as it should tell you what you need to know but that IMO is only a part of the story….the story that “allows” for cheap mass packaging of cheap mass packaged food product.
Anything plastic will give off “gases” of monomers when heated…none of which IMO are good for you in any quantity. The food packaging industry for years embraced epoxy based coatings in cans and bottles and 5 years ago BPA has become the voodo child of all things evil for contact with what we consume. I make epoxy, I know chemicals, I know what they don’t want you to know. I avoid heating in anything plastic, especially foam take home cartons as you will cook off a veritable chemical soup when you do. Believe what works for you, I believe in what I know and I almost wish I didn’t know!