Is chlorine in tap water safe to drink?

Yes. Chlorine in tap water at regulated levels (up to 4 mg/L) is safe to drink for healthy adults. The EPA has used chlorine as a drinking water disinfectant since the early 1900s, and it is responsible for eliminating waterborne diseases like cholera and typhoid in the U.S. The taste and odor are unpleasant to many people, but they are not health risks.

How do I remove chlorine taste and smell from tap water?

An activated carbon filter — including pitcher filters like Brita and PUR, faucet filters, and under-sink carbon block filters — is highly effective at removing chlorine taste and odor. Chlorine also dissipates naturally: leaving tap water in an open pitcher in the refrigerator for a few hours removes most chlorine through off-gassing. Chloramine (used by some utilities instead of chlorine) does not off-gas and requires an activated carbon filter with longer contact time or a reverse osmosis system.

What is the difference between chlorine and chloramine in water?

Chlorine is the traditional disinfectant — highly effective, produces a characteristic smell, and dissipates quickly. Chloramine (chlorine + ammonia) is increasingly used because it produces lower levels of regulated trihalomethane DBPs, persists longer in the distribution system, and is less detectable by smell. However, chloramine forms different DBPs (haloacetic acids), corrodes lead from plumbing more aggressively than chlorine, is harder to remove at home, and cannot be removed by simple off-gassing. Check your utility's CCR or call them to confirm which disinfectant they use.

Does chlorine cause cancer?

Chlorine itself at regulated drinking water levels is not classified as a carcinogen. However, the disinfection byproducts (DBPs) that form when chlorine reacts with organic matter — particularly trihalomethanes (TTHMs) — are associated with increased bladder cancer risk with long-term high-level exposure. This is a different question from the chlorine residual itself. An activated carbon filter significantly reduces both chlorine and DBPs.

Can I give chlorinated tap water to my fish or pets?

Pets (cats, dogs) can safely drink chlorinated tap water at regulated levels — the same water you drink. Fish are a different story: chlorine and chloramine are toxic to fish and must be removed before adding tap water to an aquarium. Chlorine can be removed by letting water sit for 24 hours or by using a dechlorinating product. Chloramine requires a specific dechlorinating product that neutralizes chloramine — it will not off-gas on its own.

Does my well water contain chlorine?

Untreated private wells do not contain chlorine — chlorine is added by municipal water utilities, not found naturally in groundwater. However, well owners sometimes add chlorine themselves to treat bacterial contamination (shock chlorination). If your well has been recently shock-chlorinated, wait for the chlorine to dissipate before using the water — typically 12–24 hours of flushing.

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Chlorine & Chloramine in Drinking Water

Chlorine and chloramine are intentionally added to public water supplies to kill bacteria, viruses, and other pathogens. At regulated levels they are safe to drink, but they cause the characteristic taste and odor that many people associate with tap water. The more important concern is disinfection byproducts (DBPs) — compounds formed when chlorine reacts with natural organic matter — which are regulated separately and linked to long-term cancer risk.

Quick Answer

Chlorine (Cl₂) has been used to disinfect U.S. drinking water since the early 1900s, and is responsible for the near-elimination of waterborne diseases like cholera and typhoid. Chloramine (a combination of chlorine and ammonia) is increasingly used as a secondary or alternative disinfectant because it produces fewer regulated disinfection byproducts, though it forms different ones (haloacetic acids) and is harder to remove at home. Both are measured as 'residual disinfectant' — the amount remaining in the distribution system to prevent bacterial regrowth.

Why Is Chlorine in Drinking Water a Concern?

The chlorine or chloramine itself is not the primary health concern at regulated levels — the concern is what it creates. When chlorine reacts with naturally occurring organic matter in source water, it forms disinfection byproducts including trihalomethanes (TTHMs) and haloacetic acids (HAA5), which are associated with increased bladder cancer risk with long-term high-level exposure. Additionally, chloramine corrodes lead from service lines and plumbing at a higher rate than chlorine, meaning utilities that switch to chloramine can see increased lead leaching — exactly what happened in Washington D.C. in 2000–2004 and contributed to the Flint crisis.

Everyone on a chlorinated public water system is exposed — that is approximately 80% of Americans. People with chemical sensitivities may notice taste and odor effects at lower concentrations. People on home dialysis machines must use specially treated water, as chloramine is toxic to dialysis patients and must be removed before treatment. Fish tank owners must dechlorinate tap water before adding it to aquariums, as chloramine is toxic to fish.

Health Effects of Chlorine in Drinking Water

At EPA-regulated levels (4 mg/L), chlorine is considered safe for healthy adults — acute toxicity is not a concern from drinking water

Chloramine at regulated levels is also considered safe for drinking; it is toxic via dialysis and to fish but not via ingestion at regulated concentrations

Disinfection byproducts (DBPs) formed by chlorine reactions are the primary long-term health concern — see the separate [disinfection byproducts guide](/contaminants/disinfection-byproducts)

Long-term high DBP exposure is associated with increased bladder cancer risk

Chloramine accelerates lead leaching from older plumbing — a secondary concern in homes with lead service lines or pre-1986 plumbing

Taste and odor effects are the most common complaint — chlorine smell is an aesthetic issue, not a health risk

How Does Chlorine Get Into Drinking Water?

Intentionally added by water utilities as a primary disinfectant — required by EPA to prevent microbial contamination

Chloramine increasingly used as an alternative disinfectant to reduce regulated DBP formation

Residual chlorine maintained throughout the distribution system to prevent bacterial regrowth

Regulatory Limit

EPA Maximum Contaminant Level (MCL)

4 mg/L (MRDL)

The EPA sets a Maximum Residual Disinfectant Level (MRDL) of 4.0 mg/L for both chlorine and chloramine. The MRDLG (goal) is also 4 mg/L — unlike many contaminants, the EPA does not consider any lower level necessary for health protection. Utilities are also required to maintain a detectable chlorine residual throughout the distribution system. Most tap water contains 0.2–2 mg/L of free chlorine — well below the limit.

How to Test for Chlorine in Your Water

Chlorine and chloramine levels are reported in your utility's annual Consumer Confidence Report (CCR). You can also test residual chlorine at home using inexpensive pool test strips, though these are for informational purposes rather than health-based decisions. If your water has a strong chlorine smell, it is almost always within legal limits — the smell is more noticeable when levels are at the higher end of the normal range or when chlorine reacts with organic matter in the pipe.

How to Remove Chlorine from Drinking Water

Best filter for Chlorine: Reverse Osmosis Filtration — also effective: Activated Carbon

These treatment methods have demonstrated effectiveness for Chlorine removal.

Reverse Osmosis

Reverse osmosis (RO) is the most comprehensive point-of-use water treatment technology available for residential use. It removes 90–99% of dissolved contaminants including PFAS, lead, arsenic, nitrates, and disinfection byproducts by forcing water through a semi-permeable membrane with pores of approximately 0.0001 microns.

PFAS / PFOA / PFOS — 90–99% removalLead — 95–99% removal

Activated Carbon

Activated carbon is the most widely used residential water treatment technology. It removes chlorine, taste and odor compounds, disinfection byproducts, many volatile organic compounds (VOCs), and — with NSF/ANSI 53 certification — lead and some PFAS. It is available as pitcher filters, under-sink units, and whole-house systems.

Chlorine and chloramine — virtually complete removalTaste and odor compounds — highly effective

Frequently Asked Questions

Reverse Osmosis Filtration

Removes: Chlorine

Activated Carbon Filtration

Removes: Chlorine

Data Sources & Provenance

All data on this page is sourced from official U.S. government or public datasets.

EPA Drinking Water Contaminant InformationView source

ATSDR ToxFAQs / Toxicological ProfilesView source

EPA SDWIS — violation and detection dataView source

Last updated: 2026-04-30

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