How to Clean LEGOs

A guide to cleaning and disinfecting LEGO bricks without ruining their color

Co-authored by Kadi Dulude

Last Updated: January 9, 2023 Approved

After years of play or a "great deal" at a yard sale, you may become the proud owner of grubby clumps of dirt that could once be considered LEGO. These are not too difficult to clean, but it can be time-consuming for a large collection. While you're at it, learn how to reverse discoloration due to sun damage.

Method 1

Method 1 of 3:

Washing LEGO by Hand

1
Use this method to minimize damage. This method is more time-consuming than others, unless the LEGO only has minor dust and dirt. Use this for your favorite or most collectible LEGO, to keep them safe from accidental damage.
2
Scrub water-sensitive parts with a dry towel or toothbrush. Set aside any pieces with stickers or printed patterns, as well as any multi-part units that are not meant to be separated, such as turntables. Scrub these with a dry towel, or remove serious grime using a new toothbrush.
- Delicate electrical parts can be cleaned using alcohol wipes instead.
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3
Separate all remaining pieces. Detach all non-water-sensitive parts from each other, unless they are stuck. Make sure to pull apart multi-piece units such as tires.^{[1]
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- If you have a large collection, divide them into containers of about 200 or 300 each.
4
Agitate in soapy water. Place the separated LEGO bricks in a container. Add lukewarm water and a little dish soap or other mild detergent. Agitate the bricks gently, stirring them around with your hand.
- Never use a cleaning product that contains bleach.
- Never use water above 104ºF (40ºC).
5
Add vinegar (optional). If the bricks smell bad or if you would like to sanitize them, add white vinegar to the water. Use approximately ¼ to ½ as much vinegar as you did water.
6
Let the pieces soak. Leave them to soak for at least ten minutes, then check up on them. If the water is extremely murky, replace it with fresh soapy water and leave to soak for a full hour, or overnight if convenient.
7
Scrub the pieces if necessary. If there is still stuck-on grime, you may need to scrub it off using a new toothbrush, or a toothpick to reach crevices.^{[2]
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- Clear plastic pieces such as windshields are easily scratched. Rub them with your finger instead.
8
Rinse the pieces. Transfer the LEGO bricks to a strainer or colander and rinse them in cold water to remove the soap and loosened grime.
9
Dry the bricks. Optionally, spin the bricks in a salad spinner to remove some of the water. Next, place the wet bricks in a single layer on a towel, right-side up so water drains from the underside. To speed up the drying process, leave a fan on blowing over the bricks.
- Do not use a hair dryer, which can damage the bricks.

Method 2

Method 2 of 3:

Using a Washing Machine

1
Follow these instructions at your own risk. LEGO customer service warns against using washing machines due to the risk of damage from heat or tumbling.> Many LEGO bricks have emerged from the machine unharmed, but that is not necessarily true for your bricks and your washing machine.^{[3]
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2
Separate the pieces. Detach all pieces from each other unless they are stuck by grime. Set aside all pieces with stickers, printed ink, moving parts, electrical parts, or clear plastic. These must be scrubbed with a dry towel or alcohol wipes to avoid damage from the tumbling.
3
Put the pieces in a laundry bag or pillowcase. A fine mesh clothes bag will prevent the bricks from jamming the machine, and minimize damage to the bricks from tumbling, although scratching is still possible. You may use a pillowcase if you do not have a laundry bag, but make sure to close it tightly with a zipper or a rubber band.^{[4]
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4
Set the machine to gentle, cold wash. Use the gentlest setting on your washing machine, and cold water only. Any temperature above 104ºF (40ºC) has the potential to melt LEGO bricks.
5
Add mild detergent. Mild laundry detergent is recommended to avoid scratching. Read the labels on eco-friendly detergent if you're having trouble finding one marked mild.
6
Let the pieces air dry. Lay the pieces out on a towel on their sides or base so water can drain. Keep in a ventilated room to speed up the drying, but keep them away from heat. They may take one or two days to fully dry, depending on humidity.

Method 3

Method 3 of 3:

Restoring Discolored Lego Bricks

1
Wash the bricks first. This method will reverse the discoloration that occurs due to sun exposure, but it does not remove grime. Follow one of the methods above first to get your bricks clean before you attempt this.
- You do not need to dry your bricks before following these instructions.
2
Put the bricks in a transparent container. Sun exposure is an important part of this method, so use a glass or plastic container. Place it in an area with plenty of sun, but keep it away from children and pets, as non-edible materials will be used.
- Because the hydrogen peroxide reacts with ultraviolet light, only sunlight or a UV lamp will work.
- Do not use this method for parts with stickers and electrical parts.
3
Cover the bricks with hydrogen peroxide. Use the standard 3% hydrogen peroxide solution, available in drug stores. You'll need enough to cover your discolored bricks.^{[5]
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Kadi Dulude. Cleaning Expert.}
- Although 3% hydrogen peroxide is safe for skin contact, wear gloves and safety goggles to minimize exposure, and keep away from mouths and hair. Children should have an adult handle this for them.
4
Weigh down large, floating pieces. Some of your LEGO pieces may float in the hydrogen peroxide. Use any heavy object to weigh down the largest pieces.^{[6]
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5
Stir the pieces around once an hour. Stirring the small pieces around with a stick or gloved hand will dislodge the bubbles causing them to float. Try this every hour or so for best results. If you leave pieces floating too long, they can develop a cloudy white marking along the water line.^{[7]
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- If no bubbles form on the pieces after an hour, the hydrogen peroxide has broken down into mostly water. Dispose of the liquid down the drain and try again with a new bottle.
6
Rinse and dry bricks once color is restored. This typically takes about four to six hours. This time varies depending on the strength of the sunlight and the age of the hydrogen peroxide. Once done, transfer the bricks to a colander, rinse them, and air dry.