My White Microwave Has Turned Yellow! What’s Happening?

White appliances have a tendency to yellow over time, which can be a source of frustration for those who like to enjoy a crisp, pristine kitchen aesthetic.

The main reason for this yellowing is a chemical reaction that takes place between the plastic surface of your microwave, and UV from the sun.

If you’ve got a particularly sunny kitchen, you’ll run into this problem more quickly than the rest of us!

In this article I’m going to explain what’s happening in a little more detail, so you can properly understand the problem.

After that I’ll explain what you can do to make your yellow appliances white again, and minimize the risk of it happening again in the future.

A picture of a very bright sun above some trees, set against a blue sky.

Why do white appliances turn yellow?

There’s a process behind the yellowing of your white microwave, and it’s a chemical reaction known as photodegradation.

This occurs when the white plastic surfacing of your microwave is exposed to UV radiation. This is most commonly delivered by the big ball of fire in the sky (aka the sun), although artificial lighting can cause it to happen as well.

What’s actually going on here though?Well, the plastic that’s used for the majority of microwaves is a polymer known as – wait for it – acrylonitrile butadiene styrene. To make life simple, let’s just call it ABS from here on out.

ABS also contains extra compounds that are designed to make the material flame retardant and stable. Those are very useful features to have in any appliance that’s designed to get very, very hot.

When exposed to UV light though, these compounds can break down and become yellow. You’ll then notice this change of appearance on the surface of the appliance.

How do I make my yellow appliances white again?

Now we know what’s happening, what can we do to fix the problem and make your yellow microwave a pristine white once more!

You just need to follow a few simple steps to get your microwave back to sparkling form.

  • First, unplug the microwave and remove any detachable parts.
  • Next, sprinkle baking soda on a damp cloth and gently wipe away at the yellowing areas. Don’t apply too much pressure, or you’ll risk damaging the surface of your microwave even more.
  • This may take some time, but eventually the yellowing should start to fade away.
  • When it does, grab a clean damp cloth and wipe the baking soda off the surface.
  • Dry the microwave thoroughly with a soft towel.
  • Put any detachable parts back into the microwave, and reconnect it back to the power supply.

It’s pretty simple!

You might have to repeat the process a few times to get every last hint of yellow out of the surface. Even so, you should notice a definite improvement just from the first application.

How to prevent your white microwave from yellowing

This clean-up job isn’t something you’ll want to do very often, so how can you prevent the problem happening in the future?

Limit its exposure to sunlight

If it’s at all possible, position your microwave away from direct sunlight. This is the main source of UV light in your kitchen. 

Alternatively, you could consider adding some UV-blocking window film to try and limit the amount of UV light making it into your kitchen.

Reduce artificial UV light

If you have fluorescent lights in your kitchen, these can also contribute to the problem of a yellowing microwave (or any other white appliance).

To reduce the impact of your kitchen lights, consider switching over to LED lights. These still emit some UV radiation, but they put out considerably less than fluorescent bulbs.

Clean your microwave regularly

Dirt and grease on the exterior of your microwave can amplify the yellowing effect of UV light.

If you take a bit of time each week to wipe down the exterior, you’ll prevent any of that gunk from accumulating on the surface. 

Wrapping Up

After reading this guide you should now have a much better understanding of why your white microwave has turned yellow!

The good news is that you can restore your microwave back to its former glory pretty easily, and there are some preventative steps you can take as well.