Plastic is a common American household item, found in everything from TV dinner trays and takeout containers, to cooking and eating utensils. In November 2020, new research showed that black plastic should be eliminated from the kitchen, thanks to the material containing toxic chemicals. Microplastics are another major kitchen concern, with plastic cutting boards shown to be a source of these minuscule toxins at home. 

But are other types of plastic safe to hang on to? Especially when they’re exposed to heat, and can potentially leach chemicals into the food we consume? We asked a nutritionist about heating food in plastic, particularly in the microwave, and some safe alternatives should you decide to recycle your plastic containers. 

Can You Microwave Plastic Containers?

“Many plastic containers shouldn’t be used in the microwave, because the plastic may contain chemicals like bisphenol A (BPA) that can leach into food as it’s heated,” says  Elizabeth Harris, RDN, owner of Elizabeth Harris Nutrition and Wellness in Annapolis, MD. “BPA can accumulate in human tissue, and has been linked with hormonal and metabolic disruptions and other potential health risks.”

Research in the medical journal Endocrinology published in September 2020, supports Harris’ point. According to said research, “low doses of BPA alter hormone-sensitive organs, and are related to a wide range of human noncommunicable diseases based on evidence from human studies.” That is, even trace amounts of BPA can be concerning when it comes to overall human health.  

In short, this means you should refrain from microwaving food in most plastic containers whenever possible.

What If They’re “Microwave-Safe”?

According to the USDA, many plastic containers are not meant for the microwave. For example, cold storage containers such as margarine tubs and cottage cheese and yogurt cartons are “not approved for cooking, and chemicals can migrate into food.”

On the other hand, plastic containers that are labeled “microwave safe” are generally considered fine to use in the microwave. However, this label means that the product is determined safe in that it won’t melt or warp, and shouldn’t release toxins into food, but so-called safety measures vary by region. 

The FDA states that “BPA is safe at the current levels occurring in foods” and it is not banned in the United States. Still, it’s important to note that BPA restrictions vary by region. BPA is banned across the European Union in any materials that come into contact with food, and it is also banned in Canada for health and environmental reasons. In the United States, BPA is allowed on a state-by-state basis, with various restrictions in certain states. 

What Containers Are Microwave-Safe? 

“USDA guidelines state that heat-proof glass, glass-ceramic, such as CorningWare, wax and parchment paper, most paper plates and napkins—especially plain white ones, and utensils labeled microwave-safe—are safe to use in the microwave,” says Harris. 

While common plastic household items, like deli containers, are considered microwave-safe, there is some skepticism in regards to release of toxins and microplastics. If you’re concerned, skip any type of plastic in the microwave and use the aforementioned heatproof glass or glass-ceramic vessels instead.

Additionally, brands like Anyday Microwave Cookware specifically design glass containers with microwave-safe stainless steel, ideal for food storage, reheating, and even cooking. Plastic may be convenient, but with research ongoing, you don’t need to rely on a potentially hazardous material.