Chlorine keeps pool water safe by killing germs that cause diarrhea, ear and skin infections. In a well-maintained pool, the benefits far outweigh the risks. Surprisingly, the red eyes and strong “chlorine” smell many people blame on chlorine are mostly caused by something else: chloramines, formed when chlorine mixes with sweat, urine and dirt from swimmers.
Quick answer
- Properly chlorinated pools are safe and protect you from germs.
- Red, stinging eyes and a strong smell usually mean chloramines, a sign of a poorly maintained or overused pool.
- Shower before swimming, never pee in the pool, and rinse off afterwards.
Why pools use chlorine
Pools can spread germs that cause stomach illness, ear infections (swimmer’s ear) and skin rashes. Chlorine and similar disinfectants kill most of these germs within minutes, which is why public pools must keep levels within safe limits.
What really causes red eyes and the “chlorine smell”
When chlorine reacts with sweat, urine, body oils, lotions and dirt, it forms chloramines. These irritate the eyes, skin and airways and cause the sharp smell people associate with pools. A clean, well-run pool should have little smell. A strong smell means the pool needs better cleaning or ventilation, not that there is too much chlorine.
Possible health effects
- Eye irritation: redness, stinging and watery eyes.
- Dry, itchy skin and, in some people, an irritant rash. True chlorine allergy is rare.
- Dry, brittle hair, and a green tint in light-colored hair (from copper in the water, not chlorine).
- Breathing irritation: chloramines in poorly ventilated indoor pools can cause coughing and may trigger asthma symptoms in some swimmers and pool workers.
- Dental enamel erosion in frequent swimmers if pool pH is poorly controlled.
Pool chemical accidents, such as mixing chemicals or handling them without protection, cause thousands of emergency visits each year. Always follow the label and store pool chemicals safely away from children.
How to swim safely and comfortably
- Shower before you swim. Even one minute removes most of the sweat and dirt that form chloramines.
- Never pee in the pool, and take children for regular toilet breaks.
- Wear goggles to protect your eyes.
- Rinse off and moisturize after swimming.
- Wet your hair before swimming or wear a cap to reduce damage.
- Choose well-ventilated pools if you have asthma.
- Do not swim if you have diarrhea, and wait 2 weeks after diarrhea from Cryptosporidium.
Home pools: keep levels right
Test the water regularly. Generally, free chlorine should be kept around 1 to 3 parts per million (ppm) and pH around 7.2 to 7.8. Follow the guidance for your pool and local regulations.
When to see a doctor
- eye pain, blurred vision or redness that does not settle within a day
- a rash that blisters, spreads or does not improve
- wheezing, chest tightness or breathing problems after swimming
- ear pain or discharge after swimming
If someone inhales or swallows pool chemicals, or gets them in the eyes, call emergency services or a poison control center right away.
Frequently asked questions
Is it safe to swim every day?
Yes, for most people. Rinse off and moisturize afterwards to protect your skin and hair.
Is chlorine safe for babies?
Swimming in a well-maintained pool is generally fine for babies. Keep sessions short, warm and supervised.
Are saltwater pools chlorine-free?
No. Saltwater pools produce chlorine from salt; they usually just feel gentler.
This article is for general information and does not replace advice from your doctor. Last reviewed: November 2026.
Sources
- CDC: Preventing eye irritation from pool chemicals
- CDC: Chloramines and pool operation
- Cleveland Clinic: How to keep chlorine out of your eyes
- Cleveland Clinic: Chlorine rash
- CDC: Pool chemical injuries
