Chlorine bleach is considered one of the best products to remove stains. Most containers of chlorine bleach are sold in a mixture of 6 percent sodium hypochorite and 94 percent water. Sodium hypochlorite is actually salt water changed slightly by electricity. Chlorine bleach works on whites and colorfast materials to remove stains. However, the chlorine does not really remove the stain.
Natural stains are produced by food, grass and mildew, to name a few. The stains come from chemical compounds called chromophores. When the chlorine reacts with the water in the washing machine, it produces hydrochloric acid and oxygen. The oxygen reacts with the chromophores and eliminates the part of the molecular structure that caused the colored stain.
If you are not sure if the material is colorfast, do a pretest. Put a drop of chlorine bleach on the inside of the garment such as the seam or hemline. Wait a minute, rinse and blot with a towel. If the color did not change, than you can use chlorine bleach. Never apply the chlorine bleach directly on a stain. It's too strong and can actually make a hole in the material. Add the chlorine bleach to the wash water right along with the laundry detergent. Most directions call for 3/4 cup of bleach for a regular load of laundry. You can also add the bleach through a bleach dispenser, or add it 5 minutes into the wash cycle, eliminating the chance of it splashing directly on the clothes. Once the clothes have finished the final rinse cycle, check to see if the stains are still noticeable. It's better to hang the garments to dry to make sure the stains are removed. If you place them in the dryer, it will set any stains if they are still present. If any stains are still there, either wash the garments again with the chlorine bleach or consider using a pretreatment product first.