Chlorine in tap water

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States Affected
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People Affected
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Toxicity Rating
Health Effects

Cancer, liver and kidney problems, caused by chlorine disinfection byproducts

The legal limit is
Health Guideline
4 ppm
what is considered unhealthy
Legal Limit
4 ppm
What is chlorine?
Chlorine is a chemical disinfectant that kills bacteria and viruses that live in water. As a result, disinfection with chlorine prevents several infectious waterborne diseases such as typhoid fever, hepatitis, and cholera.
Is chlorine in my tap water?
Since 1908, chlorine has been added to municipal water supplies to kill harmful disease-causing bacteria and viruses. Today, under the Safe Water Drinking Act, disinfection is required by the United States Environmental Protection Agency (EPA). Chlorine is the most common chemical used for this purpose, so it is most likely that your tap water contains chlorine.
Is chlorine in my tap water harmful?
Yes. While chlorine is effective at reducing the spread of infectious waterborne diseases, it reacts with naturally-occurring materials in water to form dangerous chemical byproducts that threaten your health: Trihalomethanes (THM)
Two of these THM compounds, bromodichloromethane and chloroform, are classified by the World Health Organization as possible human carcinogens. THM can also cause liver, kidney, and nervous system problems. Haloacetic acids (HAA)
HAA are classified by the EPA as possible human carcinogens and can have reproductive and developmental effects, as well as cause damage to the brain and nervous system at high levels.
How much chlorine is safe?
The EPA sets a safe limit of 40 parts per million (ppm) for chlorine. However, chlorine creates harmful disinfection byproducts, even at safe levels. These disinfection byproducts are so toxic that their EPA safe limits are as low as 0. So even though the benefits of chlorine are indisputable in terms of disease prevention, chlorine at any level poses a serious risk because of the health-threatening byproducts it creates.
How do I remove chlorine from my tap water?
Clearly Filtered® with Affinity® Filtration Technology gives you the power to remove up to 99.5% of chlorine from your tap water, giving you peace of mind that comes from knowing your drinking water is finally clean and safe. Basic water filters that rely on simple carbon or charcoal can also remove chlorine, but not the more harmful disinfection byproducts TTHM and HAA. Instead, they allow these harmful chemicals to pass right through the filter into the water you're drinking. More sophisticated technology like Clearly Filtered is required to provide this type of contaminant removal. What’s more, Clearly Filtered also removes up to 99.9% of Cryptosporidium, a disease-causing microorganism that chlorine cannot eliminate.
How does Clearly Filtered do at Removing Chlorine in tap water?
Clearly Filtered with
Affinity Filtration Technology Product
Water Pitcher Filter
Under-the-Sink FIlter
Water Bottle Filter
Refrigerator Filter
Chlorine in tap water Removal

1. US EPA. National primary Drinking Water Regulations. Accessed September 2, 2019.