11 Things You Should Never Put in the Microwave

Here’s how to avoid putting your appliance and yourself in danger.

October 21, 2021


Photo by: GK Hart/Vicky Hart/Getty

GK Hart/Vicky Hart/Getty

Microwaves can be a magical kitchen gadget. From baking brownies to making potato chips, this appliance can practically do anything. Most importantly, it’s an essential time-saving device in any kitchen. As convenient as microwaves may be, however, there are some kitchen tasks they're simply not up for, so it’s imperative to understand their limitations. Using the wrong material or heating up the wrong food in the microwave can be dangerous or ruin the appliance altogether. So, here we breakdown all the things that you should never put in a microwave.



Photo by: MirageC/Getty


Aluminum Foil

The most commonly-used household item you should never put in the microwave is aluminum foil. It’s essentially very thin metal which, when exposed to microwave radiation, will reflect the energy instead of absorbing it. This, in turn, can create sparks that could ruin the appliance, or worse, start a fire.

Anything with Metal or Stainless Steel

Plates with shiny metal rims and stainless-steel travel mugs can also cause a fire if put inside a microwave. Moreover, these vessels will prevent your food and beverage from warming up because, as with aluminum foil, the metal will bounce the heat from the microwave instead of allowing your grub to absorb it.

Single-Use Plastic

Plastic bags and containers like yogurt tubs should never be microwaved because they may contain bisphenol A, more commonly known as BPA. These materials can easily melt inside the appliance releasing BPA into your food which research has linked to a variety of health issues.

Takeout Containers

Chinese restaurant takeout containers tend to have a metal rim and are sometimes lined with plastic materials. However, the containers that most restaurants use are usually microwave-friendly. To be sure, always check for the microwave safe sign which usually looks like a box with squiggly lines in the middle. Containers labeled #5, which are made using polypropylene (or PP), are also generally considered microwave-safe.


Styrofoam (a.k.a. polystyrene foam) isn’t just bad for the environment, it also melts quickly if exposed to radiation. Much like plastic, this can release dangerous chemicals into your food and potentially cause long term illnesses.



Photo by: Yulia Reznikov/Getty

Yulia Reznikov/Getty

The no-no list for microwaves also includes a number of foods. From explosions to burns to ruined dinners, there are so many reasons why the following foods should never be exposed to microwave radiation.


Popping a mug of water in the microwave for some tea seems like a harmless and practical thing to do, but it can actually be quite dangerous. Microwaving water can superheat it without boiling, which if splattered can cause severe burns.

Raw Spicy Peppers

Raw peppers won’t explode in the microwave. However, they do contain a compound known as capsaicin which vaporizes at high temperatures. The fumes can be highly dangerous if exposed to your eyes or breathed in.


Microwaving an entire egg in its shell can be both dangerous and messy. The rapid heating process can create a lot of steam inside the egg, which can cause it to explode into an eggy mess. So please, despite what the internet says, don’t try to make hard boiled eggs in a microwave.

Frozen Protein

We’ve all inevitably forgotten to take the meat out of the freezer, but cooking it in the microwave is not the solution! Microwaving frozen proteins can cause them to cook unevenly and even grow and spread dangerous bacteria. If you must, thaw your protein the microwave and then cook it completely in an oven, stovetop or grill before consuming.


This may come as a surprise but according to the Journal of the Science of Food and Agriculture, microwaving broccoli can destroy its nutrients. Try gently steaming or blanching them to maintain both their nutritional integrity and color!

Uncovered Pasta Sauces

The most notorious culprit responsible for a messy microwave are tomato-based pasta sauces. If warmed uncovered, they can spit and splatter all over the appliance. This is because the thick consistency of the sauce can trap the steam until it explodes. Instead, reheat your pasta or pasta sauce in a pot or saucepan on the stove.

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