Let’s cover the original misinformation first: The earliest missives warned that microwaved plastic releases cancer-causing chemicals called dioxins into food. The problem with that warning is that plastics don’t contain dioxins. They are created when garbage, plastics, metals, wood, and other materials are burned. As long as you don’t burn your food in a microwave, you aren’t exposing yourself to dioxins.
Want to know more about whether to microwave in plastic or not, please click on this link: http://www.health.harvard.edu/staying-healthy/microwaving-food-in-plastic-dangerous-or-not?