Why your hair becomes green after swimming

I notice that my daughter's hair turns green during the summer months when she goes to the public pool. Is it caused by chlorine in the public pools?

This isn't an uncommon phenomenon for those with blonde or very light brown hair. Fortunately, besides possibly being a cosmetic problem, it is not a dangerous problem. Copper, not chlorine, is the culprit responsible for turning hair green. The phenomenon is similar to buildings that have turned green/turquoise as a result of oxidized copper.

Why is it that only some people's hair turns green?

Although copper will stick to any hair, the green color is not noticeable on dark brown or black hair. People with blonde hair are most susceptible to this effect, as they have little color in their hair to mask the green color. Bleached blond hair absorbs copper easier (due to damage), amplifying this effect further. Showering and rinsing your hair thoroughly with plain water after swimming can help limit the amount of copper that is stuck to the hair.

Is it dangerous?

No. We do recommend, however, that you rinse your hair (and body) thoroughly after a dip in the pool. It will help reduce the "green effect" and rinse the chlorine and other chemicals from your body.

How do you prevent hair from turning green?

If you are swimming at a public pool, not all the variables can be controlled. These can reduce your chances of getting green hair, however:

  • Choose a different pool to swim in. The presence of copper means that the water is unbalanced. While minerals like copper are not dangerous, many pools that have a good pH balance will not have any minerals that cause green hair.
  • Thoroughly shower before and after entering the pool with regular water. Wetting the hair before swimming allows your hair to absorb the regular water. This means that it is absorbing less copper-filled pool water as the hair is already saturated. Washing after swimming helps remove excess water from the hair, which can later cause discoloration. It also removes chlorine and other chemicals from the body.
  • Wearing tight swim-caps, while not the most attractive option, can limit the amount of pool water that the hair is exposed to.

How do you treat green hair?

  • Vinegar, tomato juice, and lemon juice solutions are all effective, if a little silly and messy, natural answers to treating green hair. These are all acidic, removing the copper oxides from the hair.
  • Visit a professional hair stylist, who can help reduce the green color, or change its color entirely. Keep in mind that your hair will likely turn green again if you visit the same pool again.

Will my hair color switch back without treatment?

The green color is temporary, and will fade naturally over time. If kids are hitting the pools on a daily basis, however, the color will likely persist until they stop going for a week or two. Home treatments can reverse the greening effect faster as well as visiting a professional hair stylist.