Seven surprising facts and myths about microwave ovens | Yahoo! Green
Heating plastics in a microwave can be dangerous
Status: Fact
The safest course of action is to avoid putting any plastics in the microwave.
When the Milwaukee Journal Sentinel tested plastics labeled microwave-safe and advertised for infants, even those were found to release “toxic doses” of Bisphenol A when heated in a microwave. “The amounts detected were at levels that scientists have found cause neurological and developmental damage in laboratory animals,” the paper reports.
In fact, the term “microwave safe” is not regulated by the government, so it has no verifiable meaning. According to the Journal Sentinel’s testing, BPA “is present in frozen food trays, microwaveable soup containers, and plastic baby food packaging.”
It is often found in plastics marked No. 7, but may also be present in some plastics labeled with Nos. 1, 2, and 5 as well, according to the report. Better to stick to glass or ceramics.