Is It Safe to Use a Microwave With Rust Inside? (How To Stop Rusting)

Nearly every home has a microwave to enhance the kitchen processes. Although microwaves are highly convenient, if they aren’t cared for properly, they can become dangerous. Rust can form both inside and outside after years of usage or by leaving liquids in your microwave for a more extended period. So, is it safe to use a microwave with rust inside? And how do you stop it from rusting?

A rusty microwave interior can be a threat to your health and physical safety if the issue isn’t addressed. This is especially true of a rusty microwave door, which can leak radiation. However, rust outside your microwave isn’t dangerous unless it finds its way through the interior cavity, leading to arcing

Read on to learn more about microwave rust and the associated safety hazards.

Is it safe to use a microwave with rust inside? how to stop rusting

What causes a microwave to rust inside?

Like any other kitchen appliance, microwaves will wear out after several years of usage. Usually, the paint inside the microwave will start chipping, after which oxidation occurs, forming rust.

Once rust forms, it begins to weaken the metal and eventually breaks it down. A failure to clean the inside of the microwave oven for long periods of time will lead to an accumulation of food debris, contributing to rusting.

Is it safe to use a microwave with rust inside?

So when is a microwave unsafe to use?

Microwave radiation can emanate from a rusted microwave. While rust on the outside poses no danger to human safety, it can be a threat elsewhere. Disconnect the oven occasionally and check the inside walls and handles for any traces of rust.

Note that rust may not be visible immediately but may form beneath the surface. Wiping a cloth over the surface will expose the rusty areas. Properly cleaning your microwave after each use will go a long way to keep your microwave out of risk.  

1. Arcing and rust arcing

Arcing is the reaction that occurs in a microwave oven when there is exposed metal.

If you’ve ever asked the question, “Is exposed metal in microwave dangerous” just observe the effects of arcing in a microwave oven, and the answer becomes obvious. This occurs when microwave rays reflect against metal and cause sparks in the middle of cooking.

If this happens, check for any metal utensils in your microwave. Sparks often occur when the inner coating of the oven is eroded, causing arcing. Switch off the microwave and disconnect it from the main socket as soon as you observe microwave sparks. Because of arcing and other factors, using a microwave with rust inside is not a good idea.

is it safe to use a microwave with rust inside?

2. Microwave radiation leakage

Microwave radiation leakage is often a result of a rusty oven or the door.

According to researchers, microwave radiation can interfere with human biological processes and cause problems like sterility and leukemia. Frequent exposure to radiant microwaves can also lead to internal issues, such as erythema and necrosis. However, this is not a worry for exposure to small doses. 

A cheap way to check for microwave radiation leakage is to put a cell phone inside a microwave and close the lid. Dial the phone’s number and observe the response. If the phone rings inside a rusty microwave, the chances are that radiation will also seep out from the rusted surface.

There are a few problems with this test, however. The cell phone’s microwaves are operating at a different frequency than the microwaves oven’s waves.

This may suggest that the microwave oven door cannot block the waves at the cell phone’s frequency, but this doesn’t mean it can’t block the waves it emits itself. Also, cell phones are highly sensitive and can operate even if only a few waves can pass through. Your microwave oven may not be allowing harmful levels of microwaves to escape, but it could still allow your cell phone to ring through the door.

Alternatively, place a fluorescent bulb in front of a microwave that’s switched on. The bulb will flicker or even light up if there’s leakage radiation. Of course, you can always pick up a cheap microwave detector from your local hardware store as well.

How to clean the rust of the microwave?

If you start observing rust inside your microwave, it might be time to look for a replacement. But before then, determine the possible cause of the rust. If the rust is a consequence of an eroded metal, your microwave isn’t repairable, as it can lead to explosions. If not, you may be able to fix the problem yourself.

However, it’s often the case that rust in a microwave results from the condensed hard water in the oven. This means that rust is just a stain that can be removed.

Do this by cleaning the interior of a microwave using a damp cloth. Failure to clean the interior of a microwave will lead to grease and food debris accumulation, which hardens and forms rust. 

Meanwhile, you can tackle stubborn stains with the following method:

  • Add ½ cup of water to ½ cup of white vinegar, and bring to a boil for one minute. Place the mixture inside the microwave and let the vapor do its magic. The vapor will reduce the dirt accumulation on the sides of the microwave for more enhanced cleaning. 
  • Use salt and baking soda to rub the stain. This is a combination of soft abrasives and will form a paste when moistened with a damp sponge. They are perfect for eliminating hard water stains. If the colors do not come out after a single cleaning, leave the paste to sit for about 15 minutes and rub again. 
  • For bleach stains, bring a cleaning cloth to saturation with bleach. Bleaches can be harsh to the skin, so avoid skin contact by all means. Meanwhile, let it sit on the stain for 15 minutes, then use the baking soda and salt paste to rub the stain and bleach. 
  • Use a damp cloth to wipe the entire surface of your microwave. This will eliminate anything from stains to rust.

How to stop microwave rusting or remove rust

Just as you wouldn’t consume food prepared in a rusty pan, the same should apply to a rusty microwave.

The steps below will help you get rid of rust inside your microwave: 

1. Unplug the microwave

Refrain from cleaning the microwave while connected to the main socket, even if it’s switched off. Unplug the microwave and turn it upside down to access the rusted surface.

This way, you’ll be sure to get every nook and cranny!

2. Clean the cooking area

Use a damp cloth to wipe the affected areas while removing the debris. You can either use a wet cloth or a scouring pad (depending on what you have) to clean the rusted area. Meanwhile, the material should be non-abrasive to avoid scratching the surface while eliminating the rust inside a microwave.

3. Rust-removing agent

Fortunately, rust-removing agents are available in almost every store. When buying cleaning agents, look for one that can handle any kitchen appliance. Many times, multipurpose agents are more effective than agents intended for specific use. These agents will often eliminate rust, leaving behind a sheen surface. 

If the rust happens to be stubborn, let the solution sit for a few minutes for adequate penetration, then scrub it away. There are no restrictions to this process, so you can repeat it a couple of times to get rid of all the rust. If the penetration is too deep, you may need to replace your microwave oven. 

4. Clean the entire interior

Once you’ve eliminated all the rust, use a damp cloth to clean the entire interior of your microwave. Again, a combination of baking soda and dishwashing liquid will help with this process. After cleaning, leave the door open to allow the cooking area to air out.

Can I repaint the inside of my microwave?

After many years of usage, a microwave may start showing signs of wearing out. The interior paint may start chipping over time. If the interior of your microwave starts chipping paint, it’s probably time to invest in a new microwave.

Repainting the inside of your microwave is typically not a good idea. The type of radiation that the inside of a microwave receives isn’t safe for most paints you can buy at a hardware store. This is not an appliance you can pinch pennies on. If the inside of your microwave is peeling, you’re putting your health at risk by continuing to use it. You need to purchase a replacement at this point.

If you’re a stubborn DIY craftsman and still insist on repainting the inside of your microwave, it can be done. Make sure you watch the video below for the step-by-step process.

Causes of interior microwave rust

When food spills onto the surface of a microwave, and you fail to clean it immediately, it will harden, forming a “hot spot.”

As the microwave cooks, these hot spots get warmer than the entire interior and eventually damage the microwave’s paint. You should also avoid placing sharp utensils into the microwave as they can scratch the paint on the walls. 

Possible dangers

In addition to damaging the interior paint of the microwave, these hot spots can develop other problems. For example, the damaged area may produce sparks when the microwave is switched on. Even worse, this may cause fires or explosions if the problem isn’t fixed. Before you can turn on a microwave, make sure that there are no hanging peelings of paint for safety reasons. 


While prevention is the best solution, make it a habit to clean your microwave whenever spills occur to prevent the paint from peeling. If you notice any peelings, though, use fine-grit sandpaper to gently remove any peelings to avoid further damage. 

Remember, the microwave is safe to use if the peeling isn’t severe. However, it’s a good idea to start looking for a replacement. If the peeling is severe, it would be best to replace it with a new one immediately. Repairing a damaged microwave isn’t cost-effective when you compare it to the price of simply buying a new one. 

Frequently Asked Questions

1. When should a microwave be replaced?

According to different manufacturers, microwaves should last for up to 10 years, but you can increase this lifespan to even more years if you take good care of it.

You can take good care of your microwave by keeping its inside clean throughout. Avoid putting metals in your microwave, among other safety measures.

2. Is it worth getting a microwave repaired?

This is your choice and depends on several factors, such as the budget you have when your microwave breaks down.

For example, it would not be ideal to repair a microwave if you have the money at hand to get a new one. This is because the cost of repairing it will range from $70 to $100, which is half the price you’d buy it. 

3. What is the average life expectancy of a microwave?

The average lifespan of a microwave oven ranges between 7-10 years, and this will depend on how much care you give to it during its function in days.

Additionally, how regularly you use your microwave will affect how long it will serve you. For example, you may find yourself replacing a microwave after 4 to 5 years because you become over-reliant on it. 

4. Does running a microwave empty damage it?

Yes, running a microwave empty could damage the unit. Running the microwave means that energy will run around, forming large standing waves, damaging it. 

5. What are the signs that a microwave is going bad?

You can tell your microwave is going bad when you experience the following:

1. Production of smoke, sparks, and burnt smells
2. Partly cooked food 
3. Irritating sounds 
4. The door is failing
5. The keypad is no longer functional
6. It’s over 10 years old. 

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