Everything you need to know about chlorine in tap water—why it's added, the health effects, and the best ways to filter it out for better-tasting, safer drinking water.
Chlorine has been added to public water supplies in the United States for more than a century. It's one of the most effective and affordable ways to kill harmful bacteria, viruses, and parasites that would otherwise cause waterborne illnesses like cholera, typhoid, and dysentery. In fact, water chlorination is often cited as one of the most important public health achievements of the 20th century.
Municipal water treatment plants typically add chlorine in one of two forms: free chlorine (chlorine gas or sodium hypochlorite) or chloramine (chlorine combined with ammonia). Chloramine is increasingly common because it stays active longer in water distribution pipes, maintaining disinfection all the way to your tap.
At the levels found in municipal tap water, chlorine is generally considered safe for healthy adults. The EPA, CDC, and World Health Organization all affirm that the benefits of chlorinated water (preventing serious waterborne disease) far outweigh the risks at regulated levels.
However, "safe" doesn't mean "ideal." Many people choose to remove chlorine for three main reasons: taste and odor, potential long-term exposure concerns, and the formation of disinfection byproducts (DBPs) when chlorine reacts with organic matter in water.
Most people don't notice any direct health effects from drinking chlorinated water at regulated levels. Some individuals with sensitive skin may experience dryness or irritation when showering, and the chlorine smell can be off-putting. People with asthma sometimes report worsened symptoms from inhaling chlorine vapors in hot showers.
The bigger concern isn't chlorine itself—it's what happens when chlorine reacts with naturally occurring organic matter in water. This creates disinfection byproducts like trihalomethanes (THMs) and haloacetic acids (HAAs). Long-term exposure to elevated DBP levels has been linked in some studies to increased risk of certain cancers (particularly bladder cancer) and reproductive issues.
The EPA regulates total THMs at 80 parts per billion and HAAs at 60 parts per billion. Most municipal water stays well below these limits, but some systems—particularly those with older infrastructure or warm source water—come closer to the threshold.
The easiest clue is your nose. If your tap water smells like a swimming pool, you're smelling chlorine. You can also:
The good news: chlorine is one of the easiest contaminants to filter out. Here are the most effective options, ranked by convenience and cost.
| Method | Effectiveness | Cost | Best For |
|---|---|---|---|
| Activated carbon pitcher | Good (free chlorine) | $ | Renters, small households |
| Faucet-mounted filter | Good | $ | Kitchen sink only |
| Under-sink carbon filter | Excellent | $$ | Whole kitchen setup |
| Whole-house carbon system | Excellent (all fixtures) | $$$ | Homeowners, shower concerns |
| Reverse osmosis | Excellent (plus DBPs) | $$$ | Comprehensive filtration |
| Boiling (5+ min) | Fair (free chlorine only) | Free | Emergency use |
| Letting water sit | Fair (free chlorine only) | Free | Small amounts |
If your utility uses chloramine instead of free chlorine, standard carbon filters work more slowly. Look for a catalytic carbon filter or a filter specifically rated for chloramine removal. Reverse osmosis systems also handle chloramine effectively.
Our top-rated carbon filters remove chlorine, chloramine, and common DBPs—so your water tastes clean and fresh again.
See Top-Rated Filters Under-Sink OptionsA carbon pitcher or faucet-mount filter is the cheapest fix. Brands like Brita, PUR, and ZeroWater all handle chlorine well for about $20-40 upfront. Filter cartridges run $5-15 each and last 1-3 months.
Hot showers release chlorine vapors that can irritate lungs and skin. A dedicated shower filter or whole-house system solves this. Shower filters use KDF media (a copper-zinc alloy) combined with carbon to remove chlorine from hot water more effectively.
A whole-house filter treats water as it enters your home. This protects plumbing, appliances, skin, and lungs—not just drinking water. Expect to spend $500-2,000 for a quality system plus installation.
Can I just boil water to remove chlorine?
Boiling works for free chlorine—about 15-20 minutes of boiling drives off most of it. However, boiling doesn't remove chloramine effectively, and it won't touch DBPs. Boiling also concentrates other contaminants as water evaporates.
Does chlorine evaporate if I let water sit out?
Free chlorine will dissipate over 24 hours in an open container, especially in sunlight. Chloramine doesn't evaporate and requires filtration to remove.
Is chlorinated water bad for plants or aquariums?
Yes—both free chlorine and chloramine can harm fish and damage beneficial bacteria in soil and aquariums. Use a dechlorinator for fish tanks, or let water sit 24 hours for free chlorine. Chloramine requires a specific aquarium conditioner.
How do I know if my utility uses chlorine or chloramine?
Check your annual Consumer Confidence Report (CCR) or call your water utility directly. The method matters because chloramine requires specialized filtration.
Will a refrigerator filter remove chlorine?
Yes, most fridge filters contain activated carbon that removes free chlorine effectively. Check the filter's NSF certification—Standard 42 covers chlorine reduction specifically.
Chlorine in tap water is doing an important job: keeping pathogens at bay. But once water reaches your home, you don't need the chlorine anymore—and removing it improves taste, odor, and reduces exposure to disinfection byproducts. A quality carbon filter is one of the best home investments you can make for water quality, and options exist for every budget.
For related reading, see our guides on fluoride in water, lead contamination, and common tap water contaminants.