Q: At work, we're supposed to use plastic covers to keep the microwave clean. Are they safe?
A: Microwave covers are inexpensive, and they're dishwasher-safe and reusable, which makes them even cheaper (and green). Some are just a flat sheet of plastic, while others are dome-shaped. Most brands come in several sizes to fit different plates and dishes. Many are made of plastic that the FDA has approved for microwave use.
Plastic microwave covers are meant to replace the plastic wrap that many people cover their food with in the microwave to keep it from splattering. The FDA says plastic wrap labeled "microwave safe" is indeed safe. But if plastic wrap -- even microwave-safe plastic wrap -- touches food, especially food with high fat content, it can melt, as well as cause steam burns when unwrapped.
Chemicals can also leach into the food if plastic wrap or plastic covers make contact with the food being heated. The FDA says those chemicals aren't dangerous. But your safest bet is to check labels carefully and use only the plastic wrap and covers that are specifically approved for microwaves.
Want an easier solution? Cover your food with a ceramic plate or with a piece of biodegradable wax paper or paper towel.
-- Kathleen Zelman, MPH, RD, LD