Mold In Microwave: How To Clean And Prevent Moldy Microwaves

Opening your microwave door to prepare some food and finding mold and mildew growing on the walls is a nauseating and irritating experience.

Mold can be harmful to health and is plain unsightly, so what can you do about it? In this article, we will be covering why your microwave became moldy in the first place, explaining whether the molds found growing there could be potentially dangerous, how to clean it safely, and how to prevent it from happening again, all this and a few more tips and tricks thrown in for good measure, so keep reading!

To remove mold from a microwave, make a solution of 1 part white vinegar to one part water inside a large bowl. Place the bowl in the microwave and run a cycle of ten minutes on its highest temperature setting. Whilst boiling, the vinegar vapors will kill mold and any spores it comes into contact with.

mold in microwave how to clean and prevent

Why does mold grow in microwaves?

Mold can grow in the most unlikely of places as long as the conditions are correct. It only needs a few things to thrive, which are:

  • A source of moisture
  • A source of nutrients
  • A lack of natural sunlight
  • An ambient temperature between 60-80 Fahrenheit (15-26 Celsius)

As you will see, the environment within your microwave provides nearly everything that mold needs to grow happily, and surprisingly, mold is not killed by microwave radiation, so using it will not keep your microwave free and clean of fungi.


Inside a microwave is a device called a magnetron that produces electromagnetic radiation. These “microwaves”, cause the water molecules to vibrate at an incredibly fast rate, causing the temperature to increase.

As the water molecules are vibrating, some of the liquid within the food will escape as steam. Moisture left in the machine will condensate on the outer walls and remain inside the oven, creating a humidity level greater than 55%, exactly what mold needs.


Mold can use any organic matter it finds as a source of nutrients. The mold you find around your home tends to live off of dust, which is mostly made up of dead skin cells and other organic compounds.

In the case of a microwave, the source of nutrients is, of course, food and debris collected whilst heating meals.

You may be thinking that your microwave isn’t that dirty. After all, you don’t leave chunks of last night’s pizza in there, but mold doesn’t need great quantities of food in order to thrive. Even small foodstuffs left under the central rotating disc are enough to provide all the nutrients it needs.

Natural sunlight

Mold hates natural sunlight, as its UV rays will kill it, along with its spores. This is why mold usually grows in dark places such as cupboards and basements.

As microwaves are commonly stored in the kitchen and have a protective coating on the glass, the levels of UV rays that can penetrate into the microwave’s interior are limited. This provides protection for any mold patches that have begun to grow.

Ambient temperatures

The perfect temperature for mold to grow is between 60-80 degrees Fahrenheit (15.5-26 Celsius). Most American homes have a thermostat set to between 68 degrees and 76 degrees Fahrenheit, giving mold the perfect temperatures to grow colonies.

What types of mold grow in a microwave?

The most common forms of mold found growing within a home are Aspergillus, Cladosporium, and Penicillium.

These strains come in varying color shades, from black, and whiteish-grey to greens, reds, and even shades of orange. They also have varying appearances in regard to texture, as some can appear velvety, powdery, and others slimy.

The strains that you may find growing in your attic or on the walls of your bathroom could be what you find growing within your microwave too. Although there are common molds that people are often familiar with, (such as black mold), there are actually thousands of different strains.

Is it safe to use a microwave with mold in it?

It is not safe to use a microwave if you have discovered even a small amount of mold within it. Whilst there are many types of mold that are entirely harmless to humans, several strains have the ability to produce mycotoxins, which can be hazardous to humans.

As you will not know which strain of mold you are dealing with, it is never advised to use a microwave until it has been thoroughly cleaned of mold.

Symptoms of mold exposure that could result from using an uncleaned microwave include:

  • Breathlessness
  • Nausea
  • Skin irritation

For those with immune system deficiencies, exposure to mold and its spores can result in liver damage and asthma attacks and may possibly require hospitalization in extreme cases.

How does mold survive in a microwave?

You may be under the impression that the high temperatures created within a microwave would be sufficient to kill both mold colonies and their spores, but certain strains of mold can survive extreme temperatures and will not be killed by the microwaves emitted either.

It’s true that some spores may succumb to heat generated by microwaves, but many will survive. Even dead mold can cause some of the symptoms listed above, so it is best to ensure there is no mold or residue left in a microwave before it is used.

How to remove mold from a microwave (2 options)

Before you begin to clean your microwave of mold, you will need a few things, these include:

  • Breathing mask
  • Rubber gloves
  • Eye protection
  • A solution of 1 part white (distilled) vinegar and water
  • A clean cloth
  • Detergent and water solution

Ensure that you are wearing all protective equipment listed above before you begin to tackle a mold problem anywhere in your home for your own safety.

Option 1

Step 1.

Begin by wiping down the interior of the microwave with the detergent and water solution, ensuring that any food residue and mold patches are removed. Then wipe down the interior of the microwave with a clean cloth.

Step 2.

Dab a clean cloth or sponge into the white vinegar/water solution and wipe down the interior surface of the microwave. The vinegar is powerful enough to kill any mold spores that may have been left behind after the initial cleaning. Leave the solution to work for ten minutes.

Step 3.

Using a clean cloth, wipe down the surfaces that you cleaned with the vinegar solution. The smell of vinegar will dissipate after a few hours, and you can leave the door open to speed up this process if the smell of vinegar bothers you.

Option 2

If all the wiping and measuring above sounds like a little too much hassle, and you are looking for something that is completed in a matter of minutes, then you have the option to let the microwave do all the hard work for you.

Step 1.

Take half a cup of distilled white vinegar and mix it with an equal quantity of tap water.

Step 2.

Place the solution into a large microwavable bowl. It needs to be large enough so that the solution can boil without pouring over the sides.

Step 3.

Set the microwave to its highest temperature and let it run for ten minutes. As the water is boiling, the vinegar will penetrate every part of the microwave where mold can grow, killing it.

Step 4.

Once the cycle has ended, carefully remove the bowl (as it will be hot), and leave the microwave door open for a few minutes to allow it to cool. Once it has cooled, use a dry, clean cloth or paper towel to wipe down the interior of the microwave.

Can you use bleach to clean mold from a microwave?

Bleach should not be used to kill mold within a microwave for several reasons. Firstly, it is a powerful alkaline that can be corrosive, so, cleaning your microwave with it could easily damage the plastic components.

Secondly, it really isn’t necessary, as either vinegar (as suggested above) or baking soda will do a perfectly adequate job of removing vinegar and killing its spores. Using bleach is somewhat overkill for this task, and its scent may permeate through into food items heated within it afterward.

How to prevent mold growth in a microwave

Prevention is always the best cure, and luckily there are several simple preventative steps you can take to make sure your microwave never gets moldy again.

  1. Clean up any spills or messes made after each use. 
    The more time food remains in the microwave, the more chance mold has to begin forming.
  2. Wipe down the interior after each meal is heated. 
    Moisture will be released from the food as steam, which will then condense on the walls of the microwave. Wipe down the walls after each use to ensure the interior stays as dry as possible.
  3. Clean your microwave regularly. 
    Deep cleaning of your microwave is not necessary after each use, but once every few months should be good enough to prevent mold from being able to form. Wipe down the surfaces with either white vinegar or baking soda to make an environment where it is impossible for mold to grow as a preventative measure.

How to get the smell of mold out of a microwave

Mold has a distinct and unpleasant aroma likened to that of a basement. It is sometimes also described as “stale, musty, and earthy”. This is clearly not the type of scent you want to be experiencing each time you open the door to prepare some food.

To remove this unpleasant smell (after you have thoroughly cleaned your microwave using the above tips), follow these simple steps.

  1. In a microwaveable bowl, place half a lemon and fill around halfway up with tap water.
  2. Turn on the microwave on full power for ten minutes.
  3. Allow the lemon water to cool in the microwave.
  4. Take out the bowl (carefully if it’s still hot) and wipe down all the interior surfaces, making sure they are completely dry.

After completing these steps, your microwave will have a light lemon scent which will replace the smell of mold, and even the vinegar you used to clean it.


Having mold in your microwave can be potentially hazardous to your health as well as putting you off your food. In this article, you will learn why it’s growing in the first place, whether it’s dangerous, and how to remove and prevent it from coming back in the future.

Chris Walker

Chris Walker has struggled for several years with mold after buying his own property. After finding the solutions to several issues around his home, he decided to create this site in order to answer as many questions about mold and mildew as possible to help others dealing with the same problems.

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