Why is my hair green after swimming?

Dear Jenni,

Contrary to popular belief, the greening of hair from wading in swimming pools is not caused by the chlorine in pool water or by hair dye. Your hair turns green from the presence of hard metals (copper, iron, and manganese, in particular) in the pool water. Huh? Think old pennies and the Statue of Liberty. The metals are oxidized by the chlorine and then bond to your hair, causing the greenish hue.

What can be done to prevent this from happening? You can wet your 'do or run some conditioner through it, and then put on a tightly fitting swimming cap so that there's less of a chance for pool water to contact or be absorbed by your hair. People who maintain pools also need to monitor the level of hard metals in the water so that they can add chemicals that'll neutralize or remove the metals before they oxidize.

What if you already have seaweed tinted locks? You don't have to wait in vain until the tinge grows out. Buy shampoo that's specially formulated for swimmers and contains either chelating (metal removing) agents, such as ethylenediamene tetracetic acid (that's EDTA for those of you not fluent in chemistry), erythorbic acid, and possibly acetylsalicylic acid (also known as aspirin), or antioxidants, such as vitamins A and B. Too much swimmer's shampoo, however, is not recommended, so it's a good idea to quit when you get your original color back, or as close to it as possible. For more info on healthy hair for pool paddlers, check out the related questions.