How to Test Fabric for Colorfastness to Bleach

When you want to wash colored clothing with bleach, but aren’t sure if it’s safe, test first. Our quick and easy colorfastness test shows you what to expect so you know when it’s safe to use bleach.

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By Mary Gagliardi

Some items with color actually can be safely bleached, but you can’t usually tell just by looking, especially if they are incorrectly labeled “do not bleach”. It doesn’t depend on the color; it depends on what type of dye was used to color the fabric, and how it was applied. When you want to bleach colored clothes, don’t just throw them in the laundry with some bleach. Testing first takes the guesswork out of knowing when you can use bleach.

Testing clothing first by applying a drop of a bleach and water solution to a hidden area will help you know when it’s safe to use bleach. When you don’t see any color change where you applied the test drop, you can wash the item with bleach. When the item doesn’t pass, the test area will change color. Since you only apply test drops to hidden areas, clothing that doesn’t pass the test won’t be ruined since the test area won’t show.

The bleachability test is also very helpful when picking clothing or fabric to treat with bleach to intentionally change the color. By testing first, you’ll know if a project (like using bleach to create tie dye effects) will actually work on the item you want to treat.

What you need

Steps for testing colorfastness to bleach

  1. Measure the water

    Add ¼ cup water to the measuring cup.

  2. Measure the bleach

    Add 2 teaspoons of Clorox® Disinfecting Bleach to the water in the measuring cup. Use the measuring spoon to stir the bleach into the water, then rinse the spoon with clean water.

  3. Find a hidden area

    Turn the item inside out so you can easily access the inside of the hem, pocket lining, or an inside seam. Testing a hidden area means a negative test result won’t be visible.

  4. Apply a test drop

    Use the smallest measuring spoon (⅛ or ¼ teaspoon) to apply only a very small drop of the test solution to the fabric. Apply the smallest possible drop so it doesn’t soak through to the outside. Wait 1 minute, then rinse and blot dry.


    If your item has multiple colors, be sure to test each color, one at a time.

  5. Look for a color change

    If there is no change to the color(s), then the clothing can be safely washed with Clorox® Disinfecting Bleach. Any change in color means the clothing is not safe for bleach. Wash these items with Clorox 2® for Colors.


    If you are testing an item to use for a DIY bleach project like tie dye, any color change shows you how well the item will respond to bleach. If the shirt you wanted to treat doesn’t change color, you’ll need to pick another one.