A grade-seven student named Claire Nelson discovered that diethylhexyladepate (DEHA; please note this is NOT the same as DHEA), a known carcinogen, lurks in plastic wrap. Even more shocking, she found out that the FDA didn't bother to study what happens to plastic food wrap in the microwave oven. Turns out, the news is very bad: Nelson's more recent research since her seventh grade revelations found that carcinogens and xenoestrogen are migrating into foods. Unfortunately, xenoestrogens are linked to low sperm counts in men.
My company, Medical Muscle's preferred covering to avoid this is tin/aluminum foil.