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Why Doesn't Chlorine Kill Recreational Water Illness (RWI) Germs?

Close-up of the lane line of a pool.

Chlorine (in swimming pools and hot tubs) kills the germs that cause recreational water illnesses (RWIs), but the time it takes to kill each germ varies.

In pools and hot tubs with the correct pH and disinfectant levels, chlorine will kill most germs that cause RWIs in less than an hour. However, chlorine takes longer to kill some germs, such as Crypto (short for Cryptosporidium). Crypto can survive for days even in a properly disinfected pool. This is why it is so important for swimmers to keep germs out of the water in the first place.

To protect yourself, your family, and other swimmers from RWIs, it is essential to learn and practice healthy swimming behaviors.

For more information on recreational water illnesses, including brochures, posters, and educational materials, please see Healthy Swimming's Resources and Publications page.


 
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