* Copper's Role: The green color isn't directly from the chlorine. It's from oxidized copper. Copper can get into your hair from various sources:
* Pipes: Copper pipes are common in plumbing systems, and small amounts of copper can dissolve into the water, especially if the water is slightly acidic.
* Algaecides: Some algaecides used in pools contain copper to control algae growth.
* Hair Products: Some hair products, although less common, might contain copper or other minerals that can contribute to the problem.
* Bleach and Porosity: Bleaching hair makes it more porous and damaged. This increased porosity allows the hair to absorb more of the copper from the water. The outer layer of the hair (cuticle) is lifted by the bleaching process, making it easier for copper to penetrate.
* Chlorine's Role: Chlorine acts as an oxidizer. It essentially rusts the copper, causing it to turn green. This oxidized copper then binds to the proteins in the hair, causing the green tint.
Why Some Bleached Hair Doesn't Turn Green:
* Low Copper Levels: If the water in the pool (or your shower) has very low levels of copper, the reaction may not occur, or the green tint may be very faint.
* Protective Products: Using hair products specifically designed to protect against chlorine can help create a barrier between the hair and the water, reducing the amount of copper absorbed.
* Well-Maintained Pools: Pools that are properly maintained with balanced pH levels and appropriate algaecide use often have lower copper levels.
* Hair Type and Condition: Although all bleached hair is more porous, some hair types and conditions might absorb less water than others.
* Timing: How long and how often you are exposed to chlorinated water will also play a role.
In short, while bleached hair is more susceptible to turning green in chlorinated water, it's not a guarantee. The presence of copper, the degree of hair porosity, and protective measures all play a part.