Plastic seems to be the material that nobody wants to talk about. Sure, there's all the hubbub about BPA, but there are still traces of it in the "no BPA" labeled products. And then there are folks I know that just reheat in anything, the soup containers from the takeout place, the styrofoam coffee cups, anything that won't get hot! You gotta know that there's carcinogenic stuff leaching into the food that way!
I've personally stopped any reheating in all containers except glass and ceramic. Better late than never, I say. Should get more publicity and attention. And restaurants that reheat with microwaves? What containers are they using?