Does Microwave Safe Mean Dishwasher Safe Too?

As an Amazon Associate, I may earn from qualifying purchases if you click on Amazon from my site and choose to make a purchase.

Today, microwaves are an indispensable part of every kitchen, so integrated into our lives that almost all of us know what dishes are safe to use. However, with dishwashers also finding their place in our kitchens, you may ask, does microwave-safe mean dishwasher-safe, too?

Microwave safe usually means dishwasher-safe, too, although there’s no exact correlation between the two features. For example, most likely, microwave-safe plastic containers are also dishwasher safe. However, it’s not always the case and it’s better to check each item’s labels and packaging.

Go on and read the remainder of this article to learn more about microwave/dishwasher-safe dishes and their differences. We’ll also provide a list of compatible items with each one and tell you how to recognize them. 

Microwave vs. Dishwasher Mechanisms

Many people think that a microwave-safe label always means dishwasher-safe, too. But that’s not the case. While microwaves and dishwashers both heat the dishes, their mechanisms are different. 

Microwave ovens work by injecting food and beverages with electromagnetic waves called “microwave,” which is a form of energy. They’re invisible to the eye but fall somewhere between the radio waves and the infrared waves. 

A device called “magnetron” inside the microwave oven directs the electrical energy from an outlet to the heated filament. This process leads to a flow of electrons that transmits the microwaves into the cooking chamber via an antenna.

These microwaves bounce around and lodge in the water, sugar, and fat molecules inside the food. In fact, the food is cooked through a process called “radiation heating,” which means molecules inside an object get excited and consequently emit energy or heat from themselves.

On the other hand, dishwashers heat water up to 130-140°F (54-60°C), with the help of heating elements. To put it more precisely, the small basin at the bottom of the dishwasher fills up with water, and then heating elements start to heat it up.

After that, hot water is pumped to the spray arms that flush it out on the dirty dishes. 

This cycle of heating up water and spraying it onto the dishes repeats several times until all dishes are clean. Finally, the machine drains out the water, and if you set the dry cycle, the heating elements heat up the air inside the dishwasher to dry the dishes. 

As you see, it’s not as complicated as the microwave heating mechanism, and the way it converts and transmits electrical energy is different. However, both devices heat up the dishes, and that’s where one may feel confused. 

Why a Microwave Oven and Dishwasher Can Be Dangerous

Some types of plastic can absorb microwaves just as foods do, so they may melt down and dissolve in the microwave and contaminate your food. Metal dishes or utensils reflect microwaves and can interfere with the waves’ movement inside the cooking chamber.

On the other hand, you can’t wash dishes and utensils made of certain materials in a dishwasher. For example, hot water or strong detergents can damage wooden items or crystals and fine china. 

So, you can’t be 100% sure that what’s microwave safe is necessarily dishwasher safe, too. 

You should read the labels on your dishes and check out the instructions of your microwave or dishwasher to ensure the dish’s safety. 

However, plastics are among the most concerning types of dishes to be used in a microwave or placed inside a dishwasher. Regarding plastics, you can say that whatever doesn’t melt by the heat is most likely safe for both.

For example, reusable bags like Eco-friendly Silicone Bags from Amazon.com are usable in a microwave and a dishwasher. You can use them instead of dishes when you’re not sure a particular container is microwave- or dishwasher-safe. 

Microwave-Safe Dishes

Dishes that are microwave-safe don’t heat up when placed inside one, whether they contain food or not, because such dishes don’t absorb microwaves, while the food does.

Ceramic or glass dishware is fine, except for crystal or handmade pottery. However, not all plastics are microwavable. Thin plastics like disposable dishes and sandwich bags aren’t safe either. 

Though, if a plastic bowl has a microwave-safe label, you can be sure it won’t melt exposed to the intense heat of the oven.  

All metals, including stainless steel, brass, aluminum foil, and copper, are a no-no for microwaving. Polystyrene (styrofoam) also melts down, and paper cups or plates aren’t among microwave-safe items, either. 

Using the wrong type of dishes can seriously warp or ruin them and even damage the microwave itself. So be precautious with what you use for cooking or warming food inside a microwave oven.

Dishwasher-Safe Containers

Similarly, dishwasher safe also means that a dish can tolerate high temperatures of water. Additionally, it implies that such a dish is resistant to strong dishwashing liquids or powders, and detergents can’t damage it. 

Everyday china and ceramics, silicone and metal utensils, stainless steel, glass baking dishes, and hard plastic are usually dishwasher safe. 

But cast-iron, thin plastics, non-stick and copper pans and pots, wood, knives, silver, insulated mugs, antique, hand-printed, or metal-rimmed china aren’t dishwasher safe and may get damaged. 

How To Recognize Microwave-Safe Dishes

The first and the most reliable way is to check the back or bottom of your dishes and look for indications of being microwave-safe or its symbol. You’ll find it in the form of some wavy lines over a dish or in a microwave. 

However, sometimes your dishes are old, their labels or markings are faded, or they just have no such indication of being microwave-safe. What should you do? 

In such cases, your only solution is to test the dish. Pour a cup of water into the dish or whatever container that you want to test and put it inside the microwave. Set it on the highest power setting, and then microwave the dish for one minute. 

If your dish or container warms up or gets hot, it’s not a microwave-safe dish, which means that it has absorbed the waves. But if it’s cool and the water is hot, you can be sure that it’s microwave safe.

Note: Remember that although microwave-safe dishes don’t absorb microwave energy, they may get hot due to the transmission of the food’s heat.

How To Recognize Dishwasher-Safe Dishes

Like microwave-safe dishes, the most reliable way to say if a dish is dishwasher-safe is to check its labels and markings. Turn your dish upside down and look for a dishwasher safe symbol at its bottom. 

It’s in the shape of a glass or a plate with water drops or some straight lines. 

If you couldn’t find any such label or marking on your dish and there was no indication of it being dishwasher safe, it’s better to steer clear of it. 

I’m sure you can wash a few dishes by hand, right?

However, if you insist on finding out the answer, you can check out the original packaging or look it up on the manufacturer’s website.