Yellow spots on plastic are usually caused by food, sunlight, or a chemical reaction. There are several ways to get rid of these stains by soaking the plastic in bleach, rubbing alcohol, or hydrogen peroxide. If instead of soaking, you want to try scrubbing the yellow stain, use lemon juice, salt, or baking soda paste.
Steps
Method 1 of 2: Soaking the plastic

Step 1. Dissolve the stains by covering them with rubbing alcohol
If there are yellow spots inside a plastic container, pour rubbing alcohol into it and let it sit for a few minutes. If the plastic object is not intended to contain liquid, pour alcohol into another container, and place the plastic object in it.
- After pouring out the alcohol, wash the plastic with soap and water.
- If you don't have rubbing alcohol, use hand sanitizer instead.

Step 2. Remove stains by dissolving denture cleaning tablets in hot water
Buy them from a pharmacy or supermarket and dissolve two tablets in hot water. Pour this mixture over the stained plastic and wait for the stain to disappear. Wash the plastic with soap and water.
Instead of tablets for cleaning dentures, you can use "Alka-Seltzer", since it has a similar effect

Step 3. Try using a strong bleach like bleach
Mix 1 tablespoon (15 ml) bleach with 1 cup (240 ml) water. Cover the plastic with this bleaching solution and wait 1–2 hours. Wash the plastic with soap and water after pouring out the bleach.
Before completely covering the plastic with the bleach solution, test it in a small, inconspicuous area to make sure it won't harm the plastic

Step 4. Use white vinegar if you are worried that the bleach may harm the item
Like bleach, white vinegar can help remove stains from plastic with ease, but it is also less harmful. Mix white vinegar with water in a 1: 1 ratio before covering the plastic with the mixture. Wait a few hours before rinsing the plastic item with soap and water.
- If you're trying to remove stains from an object that can't hold liquid in it, pour the vinegar solution into a container and then place the plastic in it.
- The vinegar smell will disappear after you rinse and dry the plastic item.

Step 5. Correct the discoloration by coating the plastic with hydrogen peroxide
Use peroxide to clean plastic that is completely yellow, not just dirty in one place. Pour enough hydrogen peroxide into a plastic bag to completely cover the plastic item. Place the plastic in a bag of hydrogen peroxide and leave it in direct sunlight. Wait 3-4 hours before rinsing the plastic with clean water.
- You can buy hydrogen peroxide at a pharmacy or supermarket.
- If you are dealing with some kind of plastic mechanism, then before placing it in the peroxide, be sure to remove from it all parts that are not made of plastic.
- If desired, the plastic can also be brushed with an old peroxide-soaked toothbrush.

Step 6. Rinse the plastic thoroughly to remove all liquids from it
After you remove the stain with the product of your choice, rinse it off the plastic with clean running water. If desired, the plastic can be washed with soap and water.
If the stain persists, reapply and repeat the entire process, or try another method
Method 2 of 2: Cleaning the stain

Step 1. Use a damp cloth to rub salt into the stain to remove it
Dampen a rag or towel with warm water. Sprinkle a little salt on a rag, or sprinkle it directly on the plastic. Use a rag to rub salt into the stain to remove it. Continue rubbing until the stain is gone.
When done, rinse the plastic with clean water

Step 2. Make a baking soda paste to remove yellow stains
Pour some baking soda into a small glass or similar container. Add water slowly to form a paste. Apply the paste to the plastic before leaving it for a few hours. Use a sponge or paper towel to rub the paste over the stain and then rinse it off.

Step 3. Rub lemon juice into the plastic and leave the item in the sun
Take a fresh lemon, cut it in half with a knife, and start rubbing it into the plastic so that the juice completely covers all the stains. Take the plastic item outside and leave it in the sun for a few hours or all day. Sunlight will help get rid of yellow spots.
Make sure that the juice has penetrated all the grooves and crevices of a stained plastic object, such as yellow spots on a cutting board

Step 4. Check the store tool to see if it can handle the task
Some supermarket or hardware store cleaning products can help remove yellow stains. Buy a product designed to clean yellow stains off plastic to see if it can do the job. Follow the directions, often using a paper towel or rag to apply the product to the stains.
Melamine sponges (and many cleaning powders) can sometimes help remove yellow stains from plastic

Step 5. Rinse the plastic thoroughly to remove the cleaning agent
Wash the plastic with clean running water and soap (if necessary) to rinse off the cleaning solution and / or paste. If the first time you can't get rid of the stains, you can repeat the entire process and clean the plastic again.
Advice
If the first time you are unable to get rid of the stain, repeat the entire process and try again
Warnings
- You are unlikely to be able to remove stains that appear on plastic after heating food with tomatoes in the microwave.
- Do not try to remove stains with abrasive materials such as steel wool or metal kitchen scouring pads, as they will scratch the plastic.