What Chemicals in a Swimming Pool Turns Bathing Suits Yellow

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If you've spent any extended time in a pool lately, you may have noticed that your once bright white and crisp bathing suit has faded to a dull yellow. This is because pools use chemicals designed for preventing bacteria but not so much for keeping swimsuits colorful. Chlorine is the most common culprit.

About Chlorine

Chlorine is an element discovered in 1774. It can be found on the periodic table with the atomic number 17 and symbol Cl. It is in the halogen group, which is a series of nonmetal elements. On its own, it forms a greenish-yellow gas. But, this gas can be dissolved into water and is often used to keep water clean.

Chlorine Uses

Chlorine is used to sanitize drinking water all over the world. It is also used to make paper products, textiles, medicines, food, solvents, paints and plastics.

Chlorine is particularly useful for keeping swimming pools clean. Because bacteria thrives in water, pools need chemicals in order to prevent them from becoming breeding grounds for diseases. When put in a swimming pool, chlorine breaks into two parts called hypochlorite ion and hypochlorous acid. The parts then kill the harmful microorganisms in the water.


You can prevent yellowing in your suit by making sure your pool has the proper chemical balance. Allow enough chlorine to kill bacteria, but not enough that it will irritate your skin or harm fabric material. You can also prevent yellowing by being sure to not leave your suit in the sun and rinsing it out as soon as you are finished wearing it. Some suits are made of material claimed to be chlorine resistant. This may help prolong the life of your suit.


If it is too late and your suit is already yellowed, you can try to repair it. First soak the suit in water combined with 2 tbsp. white distilled vinegar for 30 minutes. Then wash with just water and let it air dry. Finally, wash it again with detergent on a normal wash cycle. Make sure to never put your suit in the drier.