Why You Should NEVER Put Plastic In The Microwave (linked to Brain Damage, Sperm Damage And Cancer)

I don’t recommend storing your food in plastic or cooking it in a microwave, but if you’re going to use either, at least don’t use them together. Microwaving food in a plastic container virtually guarantees that your food will be contaminated with plastics chemicals that have leached into your food during the heating process.

There’s no arguing that plastic is convenient, inexpensive, and virtually unbreakable, making it tempting to use for food storage, especially while you’re out and about. However, though it seems perfectly safe, plastic is made with a veritable stew of chemicals.

What’s Lurking in Your Plastic Containers?

Depending on what product you’re using, your plastic might contain phthalates, for starters. Phthalates are a group of “gender-bending” chemicals causing males of many species to become more female.

These chemicals have disrupted the endocrine systems of wildlife, causing testicular cancer, genital deformations, low sperm counts, and infertility in a number of species, including polar bears, deer, whales, and otters, just to name a few.

In humans, phthalates have been linked to preterm birth and neurobehavioral problems in infants after in-utero exposure. They’ve also been found to increase blood pressure levels, and high urinary levels are associated with insulin resistance, which can lead to diabetes.

Plastic containers may also contain bisphenol-A (BPA) or any one of its similar “replacement” chemicals, including BPS (there’s also Bisphenol B, C, E, F, G, M. P, PH, TMC, and Z).

While the replacement chemicals haven’t been widely studied, BPA is a known endocrine disruptor that’s been linked to a number of health concerns, particularly in pregnant women, fetuses, and young children, but also in adults, including:

Styrofoam food trays, egg cartons, carryout containers, and opaque plastic cutlery may contain yet another chemical known as styrene, which has been classified as a possible human carcinogen by the International Agency for Research on Cancer (IARC).What else might be lurking in your plastic? Commercial-grade cling wrap (which may be used to wrap cheese or other deli items) may be made from polyvinyl chloride (PVC), which is known to cause cancer. The manufacture of PVC also leads to the formation of dioxin, another carcinogen.

Heating Accelerates the Transfer of Chemicals to Your Food

In a study of common plastic products, 70 percent tested positive for estrogenic activity, which means they’re capable of disrupting your hormone levels. However, that was before researchers subjected them to conditions in which they’re actually used.

Under real-world conditions like running the plastics through a dishwasher or heating them in a microwave, 95 percent tested positive for estrogenic, hormone-disrupting activity.

While regular use, such as washing in a dishwasher and scratches, has been found to increase the rate of chemical leaching, heat appears to be the worst offender of all, increasing the rate of chemical transfer by up to 55-fold. As written in the journal Toxicology Letters: 

“Using a sensitive and quantitative competitive enzyme-linked immunosorbent assay, BPA was found to migrate from polycarbonate water bottles at rates ranging from 0.20 ng/h to 0.79 ng/h.

At room temperature the migration of BPA was independent of whether or not the bottle had been previously used. Exposure to boiling water (100 degrees C) increased the rate of BPA migration by up to 55-fold.”

In the US, the National Institute of Environmental Health Science recommends consumers avoid microwaving food in plastic containers because heat increases the likelihood of chemical leaching.

Plastic ‘Microwaveable’ Containers Increase Your Risk of High Blood Pressure

The US Food and Drug Administration (FDA) recommends any plastic containers you use in the microwave should be labeled for microwave oven use. But such containers may not be much safer than standard plastics.

“Microwaveable” containers may be formulated with supposedly “safer” chemicals. Diisononyl phthalate (DINP) and diisodecyl phthalate (DIDP), for instance, have been used to replace di-2-ethylhexylphthalate (DEHP), an endocrine-disrupting phthalate known to cause reproductive toxicity.

DEHP is highly lipophilic (fat soluble), and when used in PVC plastic is only loosely chemically bonded to the plastic. It readily leaches into blood (when used in IV tubing, for example) or other lipid-containing solutions in contact with the plastic.

DINP and DIDP have been touted as safer alternatives, but they, too, have been linked to health concerns, including high blood pressure. Microwaving food in #7 polycarbonate plastic, in particular, should be avoided, even if it is labeled microwave-safe.

According to the National Resources Defense Council (NRDC):

“What the term ‘microwave-safe’ basically means is that any chemicals leaching from the container into food do so at levels far below those shown to have any health effects.

There is cause to be wary of this claim, however. In particular, #7 polycarbonate plastic should not be used in a microwave, even if it is labeled ‘microwave-safe,’ because it leaches hormone-disrupting bisphenol A (BPA), especially when heated.”

I would expand this to say that there is really no such thing as “microwave-safe” plastic. There are many chemicals that could potentially leach into your food, and it’s unclear which are tested for and what levels are deemed “safe” for consumption.

For instance, the Nutrition Action Newsletter reported the leakage of numerous toxic chemicals from the packaging of common microwavable foods, including pizzas and popcorn. Chemicals included polyethylene terephthalate (PET), benzene, toluene, and xylene.

Microwaving fatty foods in plastic containers also leads to the release of dioxins and other toxins into your food. You’re far better off heating your food in glass or ceramic containers – and not in a microwave at all.