Elaine asked: How do I clean yellowed plastic to make it white again?
Table of Contents:
White plastic turns yellow over time due to a chemical reaction that occurs when it is exposed to light, oils, etc. There are a couple of different ways to get rid of this discoloration, ranging from easy to more difficult. Look through the methods to find one that works best on your particular project. Some are more practical for larger projects, while others are ideal for smaller pieces.
Bleach Method
You Will Need:
- Bleach
- Water
- Bucket or large bowl
Steps to Whiten the Plastic:
- Fill a bucket or large bowl with one part bleach and one part water. Fill it enough so that it will cover the yellowed pieces when they are submerged.
- Allow the items to soak until they return to the original white color.
- When they have reached the desired level of white, remove from the solution and rinse with clean water.
- Wash with a mild detergent and allow the pieces to air dry completely.
Sanding Method
You Will Need:
- Superfine sandpaper
- Water
- Soft cloth
Steps to Whiten the Plastic:
- For this method, the goal is to lightly sand off the top layer of the plastic that is discolored to reveal a new, white layer.
- Begin by wiping down the plastic piece completely.
- Rub the superfine sandpaper over the surface to remove the yellowed portions.
- When finished, wipe with a moist cloth to remove any dust.
Comet Method
You Will Need:
- Comet
- Water
- Bucket or large bowl
- Dish detergent
- Scrubbing sponge
Steps to Whiten the Plastic:
- Start by moistening the plastic pieces.
- Place some comet on the scrubbing sponge and start scrubbing.
- This requires plenty of elbow grease and time, but will take the yellow out with some scrubbing.
- When the yellow is removed, wash the piece in water and dish detergent.
- Rinse completely with clean water and allow it to dry.
Peroxide Method (for ABS plastic)
You Will Need:
- Hydrogen peroxide
- Oxy laundry booster
- Sunshine or UV light
- Water
- Bucket or large bowl
- Rubber gloves
- Goggles
Steps to Whiten the Plastic:
- Begin by protecting yourself with rubber gloves and goggles.
- Fill the bucket with hydrogen peroxide.
- Add ΒΌ teaspoon of Oxy laundry booster for each gallon of peroxide.
- Place the yellowed plastic pieces into the solution and allow them to soak.
- The soaking time will vary with most pieces whitening in 2-6 hours. The mixture will last for up to four days before it needs to be replaced. Retr0Bright has also developed a way to make this into a gel that can be spread onto the plastic. This is especially helpful for larger items.
- Set the items under a UV light or out in the sunshine.
- When the item has reached the desired whiteness, remove and rinse thoroughly to remove any remaining cleaning products.
- If necessary, wash with dish detergent and water.
Additional Tips and Ideas
- While bleach can be an effective color remover, it may weaken the plastic over time.
- Painting the plastic pieces (if they’re not food storage containers) with a clear acrylic varnish will help prevent them from turning yellow again.
- For plastic pieces that are discolored from food dyes, see our article about How to Clean Food Dyes from Plastics.
- For additional information about removing stains from plastic food containers, see our article about How to Clean Plastic Food Containers.
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I would comment that your directions for whitening ABS plastic is incomplete, and the directions may not be understood in the way you’ve presented them.
The peroxide needs to be between 10-15%, which isn’t something you can buy at your local drug store (at least not in my state), and the items to be de-yellowed should be under the UV light _while_ in the bath of peroxide or constantly being painted with the Retr0bright gel.
My suggestion would be to just link Retr0bright and not try to transcribe their instructions, considering the process is ongoing.
I have a very expensive white electric stove. I burned something recently, and the smoke came up through the back vent and discolored the white hard vinyl/rubber parts where the knobs are. It also discolored the edging on the top of the oven door. I’ve tried using the product I use to clean the glass stove top, but with no success. Any suggestions? The stove is otherwise completely pristine, but the yellow discolored parts makes it look old dirty.
The plastic ducts on my air conditioner have yellowed in color from their previous white. They are plastic. Any suggestions as to make them white again?
I was trying to find out how to clean the white plastic trim found on the edges of refrigerators, stoves, etc. My appliances are nice and white except for that trim and it makes it look ugly. Any Help?
The hard plastic trim on my refrigerator has yellowed on an originally white refrigerator. I want to get the trim white again. I hope you have a remedy.
I’m trying to figure out how to whiten ’80s GI Joe’s, in particular Storm Shadow.
Any suggestions that will work and not damage the vintage toys?
I wouldn’t try anything with Storm Shadow because once he’s yellow, there is no coming back. Just let nature take it course and enjoy him once he’s completely yellow. He’s already brittle from the discoloration of age, light, carbon, smoke and mostly heat over the years and bleaching him will only make him more brittle. I tried putting him on a G.I. Joe stand and the foot just broke off like nothing. They’ll all turn yellow eventually so his value can’t drop that much over time. Keep your white plastic G.I. Joe’s in an air tight and dark cool place so that they’ll stay white even longer.
The white part on my bass (guitar) has turned yellow. Will the bleach method work?
The plastic around the fridge door dispenser has yellowed. I tried bleach, Comet, etc., but with no success. How do I restore the white color?
I have a Sindy house from the seventies; it has been in the loft for about 30 years in parts and it is very yellow. I have soaked it in the bath with bleach, but it has made no difference. Any help?
I decided to try and whiten the front panel of my egg yolk (pre-white) bass guitar.
Safe too say, don’t use kitchen bleach; my bass is now one of a kind since my front has been shrunken. 
Should I put bleach on the white plastic parts of my bass guitar to restore it to the original white color?