Reviewed November 7, 2026
Chlorine and Your Hair: What Pool Water Actually Does, and the Rinse That Fixes Most of It
Chlorine strips sebum and oxidizes hair proteins, leaving hair dry, rough, and prone to breakage, and it fades color. The green tint is not chlorine: it is copper from pool pipes and algaecides binding to porous hair. Wetting hair with clean water before swimming and washing immediately after prevents most of the damage.
Every regular swimmer knows the feeling: hair that comes out of the pool dry, rough, and tangled, and over a summer, lighter, weaker, and sometimes faintly green. Chlorine gets the blame for all of it, and it deserves most of it. But the green tint is not chlorine's work, and the fix is not a special shampoo. It is a rinse, before and after, and the timing matters more than the product.
Chlorine is an oxidizer. That is its job in the pool, killing bacteria, and it does the same thing to hair: it strips the natural oils, oxidizes the proteins in the fiber, and lifts the cuticle. The damage is cumulative, and it shows up first on hair that is already porous from bleach or heat.
What chlorine does to the fiber
Chlorine strips sebum, the scalp's natural oil, from the hair and scalp. Sebum is the hair's first line of defense: it keeps the cuticle smooth and the fiber flexible. Without it, the cuticle lifts, the hair feels rough, and it tangles more easily. Repeated exposure oxidizes the keratin itself, weakening the fiber and making it more likely to snap.
Color-treated hair suffers most. Chlorine fades dye by oxidizing the color molecules, and blonde hair goes brassy or green fastest, because the porous, lightened fiber absorbs everything in the water. A swimmer with fresh highlights will see the color change in a few sessions, not a few months.
The green tint is copper, not chlorine
The green tint swimmers blame on chlorine is actually copper. Copper comes from pool pipes, heaters, and copper-based algaecides, and it binds to the hair, especially porous, blonde hair. Chlorine's role is indirect: it oxidizes the hair and opens the cuticle, which lets the copper in and hold on.
That matters because the fix is different. A chlorine-removal shampoo will not remove copper. A chelating shampoo, one with EDTA on the label, binds metal ions and lifts them off the hair. If your hair is green, you need a chelator, not a clarifier. A swimmer's shampoo that lists EDTA is the right product; one that only promises chlorine removal is not.
The routine that prevents most of it
Wet your hair with clean water before you get in. Dry hair absorbs pool water like a sponge; wet hair is already saturated and absorbs far less. For extra protection, work a leave-in conditioner or a little coconut oil through the lengths before swimming: the coating gives the chlorine and copper less hair to reach.
Wear a swim cap if you swim more than twice a week. It will not keep your hair fully dry, but it cuts exposure dramatically. After swimming, rinse immediately with clean water, then wash with a gentle shampoo. Do not wait until you get home: the longer chlorinated water sits on the hair, the more damage it does. A chelating wash once a week during swim season keeps the copper from accumulating.
Related reading
Readers working through this topic often find these earlier guides useful as well: Bleach and Bond Builders: What They Protect and What They Cannot Rebuild, Hard Water and Breakage: The Chelating Wash That Stops the Snap, and Heat Protectants: What the Film Can and Cannot Do.
Frequently asked questions
Does chlorine turn blonde hair green?
Not directly. The green tint is copper from pool pipes and algaecides binding to porous hair. Chlorine opens the cuticle, which lets the copper in. A chelating shampoo with EDTA removes copper; a chlorine-removal shampoo does not.
How do I protect my hair before swimming?
Wet it with clean water first, so it absorbs less pool water, and work a leave-in conditioner through the lengths. A swim cap helps if you swim more than twice a week. Rinse with clean water immediately after getting out.
Will chlorine ruin color-treated hair?
It fades dye by oxidizing the color molecules, and blonde hair goes brassy or green fastest because the porous fiber absorbs more. Wetting hair first, capping it, and washing immediately after are the protections that matter most.
How often should swimmers use a chelating shampoo?
About once a week during swim season, to keep copper and minerals from accumulating. More often than that on bleached hair can be drying, so follow it with a deep conditioner.