Why Do Microwave Ovens Rust? (Common Reasons and Ways to Prevent It)

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If you’ve ever opened up your microwave to find a thick coating of rust on the inside, you know it’s not a pretty sight. But why do microwaves rust? And what can you do to prevent it?

Read on!

Why do microwave ovens rust?

If you find rust inside your microwave, it’s likely due to spilled liquid from food that was left uncleaned. Generally, it’s not unusual that someone would clean their microwaves once a week, but with age and improper maintenance, rust can buildup. This can lead to safety and health risks.

In the following, we’ll discuss the origins such as why this happens, what health factors this can cause, and how to prevent it.

In order to understand the situation, let’s briefly go over where this rust comes from.

How does a microwave oven get rusty?

According to wonderopolis.org rust forms when metals corrode. The surface of the metal (often iron) will corrode first due to the presence of water and oxygen. And over time rust can and will entirely rust over becoming dust.

This process is very similar to a combustion reaction, like fire.

Oxygen is all around us so there’s no preventing that from getting into the microwave.

One variable that we can really control is the water part. This can actually be any liquid substance. Almost all liquid substances have a percentage of water in them.

Minor concentrations of water can also be found in solid foods as well.

If the old food or liquids are left and not cleaned, they will slowly react with the surface of the microwave and over time corrode the metal and turn it in to rust.

What causes microwave ovens to rust?

Microwave ovens are typically made of metal and plastic components, and the metal components can rust over time due to exposure to moisture.

Rusting is a chemical process that happens when iron or steel is exposed to water and oxygen. This causes iron oxide (rust) to form.

Moisture can get into a microwave oven in a number of ways, like when condensation forms while cooking or when the oven is exposed to humid air. If the metal components of the microwave are not properly coated or protected, the moisture can cause rust to form.

Additionally, if the microwave oven is not kept clean and dry, moisture can accumulate inside the microwave and contribute to rust formation. This is especially true if you don’t use the microwave very often, because it may be more likely to get wet.

What causes microwave ovens to rust?

Microwave ovens are typically made of metal and plastic components, and the metal components can rust over time due to exposure to moisture. Rusting is a chemical process that happens when iron or steel is exposed to water and oxygen. This causes iron oxide (rust) to form.

Are rusty microwave ovens dangerous to cook from?

There are many dangers to using a rusty microwave. Below are some of the most dangerous issues that can arise from a rusty microwave.

Rust in your food

Rusty microwave ovens can pose a poisoning threat to the food you cook.

Radiation is very bad for humans and living things and it certainly doesn’t help if you are heating your food along with the rust in the same closed container.

In contrary to how other websites are claiming that rust is not harmful to consume, I found this article from the U.S. Department of Agriculture. It states that

“Rust is not a food-safe material so it should not be ingested”
-USDA

Sparks and fire

As rust forms inside the surface chamber of a microwave oven, it begins to eat into the paint of the oven. This exposes the metal underneath the paint.

Microwave ovens use radiation to cook food. Radiation comes in the form of waves and these waves are left to bounce throughout the inside of the microwave oven. When these waves have a frequency that doesn’t do well when it makes contact with bare metals.

If the wave hits the rust and exposed metal, you’ll see a spark occur. These waves bounce thousands and maybe even millions of times in a short period.

If enough sparks occur, you might be in danger of your microwave exploding or starting a fire.

Radiation leak

The paint that coats the inside of the microwave chamber not only protects the waves from sparks but also covers the non-metal, glass door as well.

A microwave chamber basically works as a Faraday cage. This is the kind of container that blocks EMPs and blocks your phone from getting a signal.

There’s a permeable layer of special conductive paint that covers the entire chamber including your glass door. If rust were to eat away at that paint, radiation can likely penetrate through the window and out to the external environment.

We’ve all peaked into our microwave ovens while it’s cooking our meals just to see the progress of the food. It’s not considered dangerous because the paint that covers the door keeps the radiation waves at bay.

Unfortunately, if that covering were rusted and eaten through, there would be little protection from the radiation waves and this can certainly cause harm to people and living things over time.

The proper way to remove rust from a microwave safely

When you’ve identified that rust has plagued the inside of your microwave, it’s time to start taking measures to remove it. You might even notice a layer of paint beginning to chip and peel around the outer edges of the rust. That’s another thing you’ll have to rectify.

Take these steps to make sure you properly get rid of the rust first.

With a scraper or metal brush, gently scrape off the cracked and peeling paint.
Brush gently until you no longer see any deformed areas of paint.
Using a sander or any sanding surface, gently sand over the rusted area breaking and detaching the rust from the surface.
Continue sanding until you find a smooth metallic surface.
Repaint the surface with specialized ceramic paint.

How can you prevent your microwave from rusting?

Clean your microwave regularly

One of the most important things you can do to prevent rust from forming in your microwave is to clean it regularly. This will help remove any moisture, food, or debris buildup that could contribute to rust formation.

Check for rust and treat it if found

It’s important to regularly check your microwave for any signs of rust and treat it as soon as possible if any are found. This can prevent further damage and help extend the lifespan of your microwave.

Don’t leave wet dishes in the microwave

Leaving wet dishes in the microwave can lead to a buildup of moisture and make rust more likely to form. Make sure to remove any dishes as soon as possible after use and wipe down the interior with a dry cloth or paper towel.

Don’t put metal utensils in the microwave

Metal utensils can make sparks and damage the inside of the microwave, which can make it more likely that rust will form. Instead, use microwave-safe containers and utensils made of plastic, glass, or ceramic.

Clean off any food or debris buildup

Food or debris buildup in the microwave can also contribute to moisture buildup and rust formation. Make sure to wipe down the interior of the microwave with a damp paper towel or cloth after each use.

Use a damp paper towel to clean your microwave

When cleaning your microwave, use a damp paper towel or cloth instead of harsh cleaning products. This will help prevent damage to the interior and reduce the risk of rust formation.

Clean your microwave’s interior with products designed for this purpose

If you do need to use a cleaning product to clean the interior of your microwave, make sure it’s specifically designed for this purpose. Harsh chemicals can damage the interior and increase the risk of rust formation.

Check your microwave’s door and make sure it’s secure

A loose or damaged microwave door can allow moisture to enter the interior and increase the risk of rust formation. Make sure to regularly check your microwave’s door and ensure it’s properly secured.

Keep up with regular microwave maintenance services

Regular maintenance services, such as cleaning and inspection, can help identify and prevent issues that could contribute to rust formation in your microwave.

Make sure to keep up with these services to help extend the lifespan of your microwave.

Tips to prevent and properly maintain a microwave from getting rusty

Like all electronic devices and things in the house, if you don’t properly maintain and clean them, you’ll likely not be able to use them for long.

You have to properly maintain your microwave oven.

To keep it in good working condition, make sure to regularly scrub or wipe down the chamber with a dry cloth at least once a week.

Make sure the inner chamber is as dry as you can make it. Make sure there are no bits of food or liquid lingering in the microwave because as you now know, it will be the catalyst for rust to form.

There are actually a few neat tricks on how to prevent rust in a microwave. The following is a list.

Place a container with lemon slices inside the microwave oven.
Turn on the microwave and let it heat up the lemon water.
Dry the entire microwave chamber with a soft, dry, non-abrasive cloth.

This acts as a cleaning agent that mystifies and spreads throughout the entire microwave. Be sure to gently wipe it all dry when done. Take care not to scratch any paint from the inside.

How do I know if my microwave is rusting?

If you suspect that your microwave is rusting, there are several signs you can look for to confirm your suspicions. Here are a few things to check:

Discoloration or stains: Rust can appear as brownish or reddish discoloration on the surface of metal components in your microwave. Check the interior of your microwave for any stains or discoloration that may indicate rust.
Rough or pitted surfaces: Rust can cause the surface of metal components in your microwave to become rough or pitted. Check for any rough or uneven spots on the interior of your microwave that may indicate rust formation.
Peeling or flaking paint: If the paint on the interior of your microwave is peeling or flaking off, this may be a sign of rust formation underneath. Check for any areas where the paint is coming off to see if there is rust underneath.
Unusual odors: Rust can create an unpleasant odor, so if you notice any unusual smells when you use your microwave, this may be a sign of rust formation.

Is it safe to use a rusty microwave oven?

It is generally not safe to use a rusty microwave oven, as the rust can create a number of health and safety hazards. Here are a few reasons why:

Rust can create sparks: Rusty metal components in a microwave can create sparks, which can damage the interior of the microwave and potentially start a fire.
Rust can contaminate food: Rust can contain harmful bacteria and other contaminants, which can be transferred to food that is cooked in a rusty microwave. This can pose a risk to your health and well-being.
Rust can cause leaks: If rust has formed on the interior of your microwave, it may have created small holes or leaks that can allow microwaves to escape. This can cause damage to nearby electronic devices, as well as pose a risk to your health and safety.

How often should I clean my microwave oven to prevent rusting?

It’s recommended to clean your microwave oven regularly to prevent rusting. How often you should clean it will depend on how frequently you use it and how messy your cooking tends to be.

As a general guideline, you should aim to wipe down the interior of your microwave with a damp cloth or paper towel after each use.

You may also want to do a more thorough cleaning once a week or as needed to remove any food or debris buildup.

What is the best way to remove rust from a microwave oven?

If you discover rust in your microwave, it’s important to address it as soon as possible to prevent further damage. Here are a few steps you can take to remove rust from a microwave oven:

Mix a small amount of baking soda with water to create a paste.
Apply the paste to the rust spots and let it sit for a few hours.
Use a scrub brush or scouring pad to gently scrub away the rust.
Wipe down the interior of the microwave with a damp cloth or paper towel to remove any residue.

It’s important to avoid using abrasive cleaners or steel wool, as these can scratch the interior of the microwave and cause further damage.

At what point must someone replace a microwave oven?

So it might be time to buy a new microwave. But what are the signs?

Watch out for these issues:

The buttons to operate the microwave no longer works.
The microwave door is broken and won’t shut.
Food is no longer cooking.
You smell something metal burning every time you use it.
It’s been more than 10 years plus any of the issues above.

Relate Topics

Does age affect the chances of a microwave oven rusting?

Yes, age can be a factor in the likelihood of a microwave oven rusting. As a microwave gets older, the parts inside it may wear out or get broken, which can make it more likely to rust. Also, some older microwaves may have been made with materials or coatings that rust more easily.

But it’s important to remember that proper care and maintenance can help your microwave last longer and reduce the chance that rust will form.

Regular cleaning, checking for rust and treating it promptly, and avoiding leaving wet dishes in the microwave or using metal utensils can all help keep your microwave in good working order, regardless of its age.

If you’re concerned about rust formation in an older microwave, it may be a good idea to have it inspected by a professional to assess its condition and recommend any necessary repairs or maintenance.

Are there any health risks associated with a rusty microwave oven?

Some common symptoms of lead poisoning include:

Abdominal pain or cramping
Headaches
Fatigue or weakness
Irritability or mood changes
Loss of appetite or weight loss
Constipation
Joint pain or stiffness
Memory loss or difficulty concentrating
Developmental delays or learning difficulties in children
High blood pressure

Final thoughts

Once in a while, make sure there’s no rust in your microwave.

Proper cleaning and maintenance will make your microwave lasting long and provide you with as many meals.

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