Green hair is pretty common at the New York City St. Patrick's Day parade, and some people even dye their hair green all year long as a fashion statement. But others develop green hair accidentally WITHOUT hair dye. Today, I'll tell you the cause and how to treat it.
The culprit is exposure of hair to high levels of copper. Yes, what causes hair to look green is literally copper coating hair shafts. And this is much more common in people with blond, chemically lightened, grey or white hair.
The two most common situations in which this occurs are usage of regular tap water in the shower or bath, and also from swimming pools. Additionally, copper coatings on the surface of the hair shafts which cause the green coloration... These coatings are much more apt to occur if the cuticle of the hair has been damaged... whether by frequent hot air drying, sun exposure, chlorine exposure, peroxide bleaching, or chemical straightening.
High copper levels in tap water are usually caused by copper leaching out from old copper pipes in the house despite the copper levels in the water being normal before the water enters the home plumbing system. And high copper levels can also occur naturally in hard well water.
Green hair from swimming pools is not caused directly by the chlorine. Instead, while chlorine damages the cuticle making it more susceptible to copper coating, the chlorine itself doesn't turn the hair green. Again it's excess copper coating on the hair, either from high levels in the water put into the pool, or from old copper pipes going to the pool... or most commonly from copper algaecides used to kill algae in swimming pools.
If your hair does turn green, you can remove the discoloration easily by using a shampoo that chelates the metal, which is just a chemists way of saying removing it. Ask your dermatologist or hair dresser for recommendations.
SO green hair is most apt to occur when damaged, light colored hair is exposed to elevated copper levels in water. But interestingly, if you consistently drink water with too much copper causing elevated copper levels inside your body and inside the hair shaft, the hair doesn't turn green.
If you want to know why, ask Kermit.