Chlorine is generally not bad for you, but frequent swimmers may find that chlorinated water still causes unwanted side effects. Chlorine can also cause allergy-like symptoms if the concentration is too high.You may develop symptoms like a skin rash, dry skin, or eye irritation.
Chlorine is a chemical disinfectant added to swimming pools to kill germs. It's a highly irritating and damaging chemical in its original gas form. Chlorine technically turns into the chemicals hypochlorous acid and hypochlorite anion when it's added to pool water.
These chemicals disinfect water and are considered safe in the right concentration, but some people may be more sensitive to them than others.Read on to learn if chlorine is bad for you and what it might do to the body.
How Much Chlorine Is Safe?
Adding a chlorine concentration of at least 1 part per million (ppm) to pool water—and 3 ppm in hot tubs—is considered safe by the Centers for Disease Control and Prevention (CDC).
Most local health departments require pools to have a combined chlorine level of 0.4 ppm or less in the U.S. Combined chlorine is chlorine that has already bound itself with germs and waste to disinfect the pool.
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Chlorine and other chemicals in pool water can irritate and dry out the skin. People can't be allergic to chlorine, but you can be sensitive to the chemical and have skin reactions. These reactions are actually irritant dermatitis caused by hypersensitivity to chlorine.
Chlorinated water can cause irritating skin symptoms like:
- Dry skin that triggers acne
- Dry, itchy skin
- Eczema or psoriasis flare-ups
- Hives or rash
- Red skin
Research has shown frequent swimmers are more prone to allergic contact dermatitis or "pool water dermatitis." This itchy rash is caused by pool chemicals like chlorine. Some people may get rashes from swim gear, such as swim caps and goggles rubbing on the skin.
Dipping in the pool can further aggravate plaque psoriasis. This autoimmune skin disorder causes thick patches of discolored skin and silver scales. Chlorine can also worsen symptoms of eczema, or a skin disorder that causes dry and itchy patches.
How To Treat It
If your skin is sensitive to chlorine, the American Academy of Dermatology Association (ADD):
- Applying moisturizer to damp skin
- Gently patting with a towel to dry off
- Moisturizing your skin before jumping in the pool
- Rinsing off with warm water after you finish swimming
2. Eye Irritation
Chlorine and other pool chemicals can wash away the thin layer of tears that coat your eyes. These chemicals can cause eye side effects like:
- Blurry vision
- Burning
- Dry eyes
- Gritty feeling
- Itching
- Redness
- Watery feeling
Chloramines, which are released when chlorine combines with human waste, also irritate the eyes. Swimmers in a pool with built-up chloramines may experience eye irritation like red, itchy eyes.
How To Treat It
The American Academy of Ophthalmology (AAO) suggests rinsing your eyes with fresh water after swimming to help remove chlorinated water from your eyes. Eye drops may also help rebalance any tears, and wearing goggles keeps chlorinated water out of your eyes.
Chlorinated water dissolves oils that coat and protect your hair, which may make it more prone to damage and dryness. Chlorine also breaks down proteins in your hair, increasing your risk of hair breakage.
People with white or blonde hair are more at risk since their hair has less melanin to protect it. Melanin is a pigment that gives skin and hair color.
Chlorine can also lighten your hair, especially if the pool water you swim in has a high concentration of chlorine. Bleach, known to lighten hair and laundry stains, is made with chlorine. Lightening hair requires high chlorine concentrations, so it takes time and lots of swimming to see the effects. Ultraviolet (UV) light from the sun can also lighten hair and increase the impact of chlorine on hair.
How To Treat It
The AAD suggests the following to keep your hair healthy while you swim:
- Apply oil or leave-in conditioner to your hair before you swim
- Rinse and wash your hair after swimming with a shampoo designed to remove chlorine and follow up with a deep conditioner
- Rinse your hair before swimming to help avoid chlorine absorption
- Wear a swim cap to keep hair away from chlorine
Chlorine Doesn't Turn Your Hair Green
Oxidized copper is what turns blonde or white hair green after a swim. Copper sulfate is sometimes added to pools to control algae growth. Copper can also leak into the pool from plumbing or copper ionizer equipment. Chlorine corrodes copper that sticks to the hair, resulting in a similar green-blue color of copper patina.
4. Respiratory Issues
High levels of combined chlorine release chloramines into the water and air, which can be highly irritating. Combined chlorine is chlorine that is bound to germs and waste to disinfect the pool.
Chlorinated pools don't usually cause respiratory problems. You can still experience respiratory issues if a pool has built up high levels of chloramines, such as:
- Asthma attack
- Coughing
- Itchy, runny, or stuffy nose
- Wheezing
Chloramines also turn into gas around the pool area. A pool that has built up too many chloramines has a strong chemical smell, which people mistakenly call a "chlorine smell." The chloramines in the air are usually responsible for respiratory issues during or after swimming. This is more common in indoor pools because they are not as well-ventilated to allow chloramine to leave the area.
How To Treat It
Pools build up chloramines when chlorine mixes with sweat, dirt, poop, pee, and dead skin cells. Even jumping in the pool with deodorant or makeup can create chloramines. You can avoid chloramines by checking chlorine levels regularly, increasing ventilation in indoor areas, and showering before getting in a pool.
See a healthcare provider right away if you have respiratory symptoms caused by chlorine. They can help diagnose and treat breathing problems.
Chlorine and other pool chemicals can cause people's teeth to form yellow and brown stains, known as swimmer's calculus. This staining happens because the pH of chlorinated pools is higher than your saliva. The proteins that protect your teeth from staining and tartar build-up break down. Chlorinated pools can also erode enamel, which makes you more likely to deal with staining.
It's unlikely your teeth will turn yellow after visiting your local pool a few times a week. Research has shown that competitive swimmers and divers—especially those who spend more than six hours a week in the pool—are more likely to develop yellow teeth.
How To Treat It
U.S. Masters Swimming advises brushing your teeth before swimming to help prevent pool chemicals from building up on plaque. Rinse your mouth with fresh water or fluoride mouthwash after a swim to help restore your mouth's pH levels. Brushing may be too harsh on your enamel after a swim.
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A Quick Review
Some people are more sensitive to chlorine than others. Chlorine can irritate the eyes, skin, hair, and teeth. Swimming occasionally doesn't cause significant side effects. People who swim frequently are more likely to experience chlorine side effects.
Chlorinated water is considered safe when pools have the correct concentration of chlorine. Pools with too high chlorine levels and built-up chloramines can irritate the respiratory system. Ask the pool manager to check the chlorine levels if you have issues breathing or have intense allergy-like symptoms.
