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

With the advancement in technology, the usage of microwaves has increased immensely. Nearly every home has a microwave to enhance the kitchen processes. Although microwaves are highly convenient, they raise the alarm upon rusting. Rust can form both inside and outside after years of usage or by leaving liquids in your microwave for a more extended period. 

That said, a rusty microwave can be a threat to your health and physical safety if action isn’t observed. However, rust outside your microwave isn’t dangerous unless it finds its way through the interior cavity, leading to arcing

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 to form rust.

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

Dangers of Rusted Microwave

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. Proper maintenance will also go a long way to keep your microwave out of risk.  

1. Arcing and rust Arcing

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 oven and disconnect from the main socket when you first observe your microwave sparks. 

2. Microwave radiation leakage

Microwave radiation leakages are often a result of a rusty oven or the door. According to science experts, microwave radiation can interfere with human biological processes and cause problems like sterility and leukemia.  Frequent exposure to microwaves can also lead to internal issues, such as erythema and necrosis. However, there is no scientific proof that confirms this to be true. 

To check for microwave radiation leakage, 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. 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.

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. Don’t worry if you’re unable to afford one at the moment because you can always fix the problem. 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. 

However, it’s often the case that rust in a microwave result 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 as follows:

  • Into ½ cup of white vinegar, add ½ cup of water, 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 set 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 surfaces of your microwave. This will eliminate anything from stains to rust.

How to Stop Microwave Rusting?

Like you won’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 will also enhance the cleaning process. 

2. Clean the 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 a 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, please a professional to help you out. 

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.

Once finished, apply microwave-safe paint to cover the exposed areas while enhancing the interior decor. If you’re skeptical about fixing rust in a microwave, please contact a professional to handle the task for you. Experts are well-knowledgeable about such appliances.

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. And because chipping paint can be hazardous to safety, it would be best to fix the problem immediately. 


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 prevent the paint from peeling. If you notice any peelings, though, use fine-grit sandpaper to gently remove the hanging peelings of color to avoid further damage. 

Remember, the microwave is safe to use if the peeling isn’t severe. However, it would help if you still repainted the damaged areas to protect them from rust. If the peeling is severe, it would be best to replace it with a new one. Repairing a damaged appliance can be expensive compared to buying a brand new one. 


Meanwhile, it would help if you got rid of the peeling paint before you can repaint the microwave. Also, ensure that the microwave is unplugged from the power switch, so there is no electric current flowing through the appliance. Clean the interior of the microwave to eliminate the chipped paint and any traces of grease or debris. After that, wipe the entire microwave using a dry cloth or paper towel, then sand a few areas of the peelings. 

Once everything is done, you can repaint the inside of your microwave. You can find microwave-safe paint in all types of appliance stores. If you’re unable to find the right paint, please ask the store attendant for alternative options. You might be surprised to find out that spray paints are way better than the paint itself. 

Before you can start painting, test a small section of the damaged area and see how it goes. If everything goes well, repaint the whole interior and let dry. After that, run the microwave at high speed for about a minute. The painted region shouldn’t be warmer than the other parts of the microwave. Once you’re done with the painting, let the oven rest for at least 24 hours in a well-ventilated room before using. 

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, avoiding 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 like the budget you have when your microwave breaks down. For example, it would not be ideal for repairing 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 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?

Your microwave calls for an alarm 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.