Microplastics Are Everywhere. Don’t Make It Worse

Standing near your microwave almost certainly won’t give you cancer, but that doesn’t mean the popular kitchen appliance isn’t linked to health concerns. While glass, ceramic and porcelain are safe to use in a microwave, certain food storage vessels present a clear and present danger when nuked at such high temperatures.

The microwave is an undoubtedly handy tool for reheating leftovers — though better options exist — softening butter, or even quickly cooking meats with this surprisingly effective microwave grill plate, but what you put in the microwave matters to avoid the risk of ingesting microplastics. 

Study after study has shown that the resulting chemical exposure from microplastics could pose significant health risks, and they have been linked to increases in medical issues like infertility and even cancer. Cheap plastic containers can leach microplastics into food, and that risk increases when you heat them in the microwave. 

Read more: Is Your Kitchen Full of Microplastics? Swap These 7 Tools Before Your Next Meal

Here’s everything you need to know about microwaving plastic.

Most takeout containers are not microwave-safe

“If you’re using takeout containers to reheat food, they need to be labeled as heat-safe,” advises Ricardo Jarquin, executive chef of Loews Coral Gables in Miami. “Most restaurants do not use them because they’re more expensive.” 

Best Food Storage Containers for 2026

Aluminum, cardboard and paper-based containers are typically plastic-free and safe for storing and reheating food. Cheap plastic takeout containers are often unsafe and should never be used to reheat food. Styrofoam is even worse because it melts in the microwave, a clear sign it’s unsafe for reheating food.

Read more: These 7 Takeout Containers Don’t Belong in the Recycling

What to use instead of plastic  

So what’s the best way to reheat that delicious meal? We chatted with Jarquin, who has overseen culinary operations and food safety protocols for major hotel chains including Four Seasons, Hilton, and Marriott, and Hope Montgomery, owner of Brick & Mortar in St. Petersburg, Florida, to get the skinny on safely using takeout containers.  

Ideally, the restaurant is using compostable paper, aluminum or cardboard products, which can be found at Brick & Mortar and is Montgomery’s material of choice. A surefire way to ensure food is stored and reheated in a heat-safe container (whether by initial temperature or via microwave) is to use your own. 

“The safest containers are BPA-free, or even better, glass ones like Pyrex,” recommends Jarquin. “Stainless steel and aluminum are great, too, just not for the microwave.”

One of our favorite options is this colorful 10-piece set that offers the convenience of multiple sizes. This means you can choose the right shape for what you plan to reheat or take home, from an entire entree to a few bites of dessert. 

Beware of plastic containers marketed as microwave- and freezer-safe

Many plastic containers are marketed as “freezer- and microwave-safe,” but that’s mostly marketing jargon. Plastic containers should really never be frozen or microwaved. Ziploc and Rubbermaid both faced a 2025 class-action lawsuit for advertising their plastic containers as “microwave-safe” and “freezer-safe.” When heated, plastic containers can leach chemicals into food. When frozen, the plastic often breaks off, which can contaminate food.

How to reheat food safely

More important than reheating food so it tastes good is making sure it’s safe to eat. Never reheat your leftovers in a non-heat-safe vessel. That includes most cheap plastic containers restaurants use, such as plastic clamshells or black plastic containers. Deli containers like the ones you get your grocery store chicken salad in are considered “food safe” for storage, but it’s still not recommended to use them to reheat food at high temperatures.

When reheating food in the microwave, always use glass or ceramic. Keep any containers, lids or utensils that contain plastic or rubber out and use for serving only.

How to reheat food so it tastes good

Beyond the risks of plastic exposure when hot food is stored in those containers, you’ll want to ensure reheating leftovers maintains overall quality. 

“Though microwaving is quick and easy, better results can often be achieved by reheating on the stovetop,” says Montgomery. “A little extra fat like olive oil and butter, as well as seasoning, can also be helpful,” she adds, noting that this doesn’t pertain to some dishes like her restaurant’s famed beef tenderloin carpaccio, which should be consumed in its entirety on location. 

Jarquin echoes these sentiments. “You get a much better result when reheating leftovers in a frying pan or in the oven,” he stresses, adding that some dishes may even taste better the next day. “At Americana Kitchen, the rigatoni with vodka sauce keeps getting tastier the next day. Also, our pizzas and mushroom pasta definitely get better the next day. The flavors soak in even more and the texture stays great when reheated slowly,” he says. 

Jarquin also recommends enjoying at-home foods like “stews, curries, chili, and lasagna,” where flavors can keep developing overnight.

Concerns about bacterial growth 

Another risk with leftovers is the rapid growth of bacteria, which can cause brief but sometimes serious illnesses. In short, the longer food sits out, the quicker these bacteria grow. 

“The general rule is that it takes about two hours at room temperature and one hour if it’s really hot out”  (usually above 90 degrees Fahrenheit), said Jarquin. “After that, bacteria can grow quickly, and you don’t always see or smell it. That’s why it’s important to either serve food hot, chill it fast or keep it properly stored.”

Read more: I’m Not Messing Around With Leftover Rice — You Shouldn’t Either

At the end of the day, if you’re even slightly fearful of microplastics and/or foodborne illnesses, no leftover is worth the temporary satisfaction. Accept your losses and whip up your own homemade delicacy to ensure safe, plastic-free bites in the comfort of your own kitchen. 

For a comprehensive guide to food safety protocols, check out the US Centers for Disease Control’s Four Steps to Food Safety. 

Joey is a writer/editor, TV/radio personality, lifestyle expert, former entertainment publicist and author of “Basic Bitchen.” His written work has been featured in major food and travel outlets, and he is an on-air contributor for the Today Show. In his spare time, he enjoys volleyball, the beach, interior design and perfecting his stand-up comedy routine.

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