Should You Microwave Plastic?

We've been zapping leftovers this way for decades, but arguments about the potential health dangers have heated up. Here's what we know.

- KORIN MILLER

While research is ongoing, the toxicologists we spoke to say there's enough evidence to suggest that you should avoid nuking food in plastic containers. No one knows the health effects of occasionally reheating food in plastic, but transferring it to a glass or ceramic container whenever possible is worth the extra effort.

There are a few big reasons for concern: One has to do with two common chemical additives in plastics, bisphenol A (BPA) and phthalates, says Jamie Alan, Ph.D., an associate professor of pharmacology and toxicology at Michigan State University. BPA is used to make hard, clear plastics, and phthalates are added to make plastics soft. These chemicals are considered endocrine disruptors, meaning they can interfere with the actions of hormones like estrogen and testosterone in the body, Alan explains, with chronic exposure potentially having an impact on fertility, childhood development, and other endocrine system functions.

While BPA has been phased out by many companies, it's FDA-approved for use in food packaging—and it can leach into food, especially when heated. Phthalates are common in containers, and small amounts are released when the containers are heated, says Alan.