Chloramine vs Chlorine in Water: How to Remove Each

Chloramine and chlorine are both disinfectants added to municipal tap water — but they’re not the same compound, and they don’t behave the same way in your plumbing or your body. The key difference: standard activated carbon filters remove chlorine effectively but do not reliably remove chloramine. If your utility uses chloramine (roughly 30% of US water systems do), a basic pitcher filter or fridge filter may be leaving a disinfectant in your water you think is being removed.

Chlorine is a stronger, faster disinfectant that dissipates quickly. Chloramine is weaker but more persistent, which is why utilities that serve large distribution systems switched to it — it maintains residual disinfection all the way to your tap. Both are considered safe at regulated levels (up to 4 mg/L), but chloramine requires a different filtration approach to remove.

The Direct Answer: Which Is in Your Water?

Call your water utility or check their annual Consumer Confidence Report (CCR), which they’re required to publish by law. Utilities must disclose the disinfectant they use. You can also find it at the EPA’s ECHO database or by searching “[your city] water quality report 2026.”

Chlorine-treated systems: Most smaller utilities and those with shorter distribution systems. Easy to detect by smell — chlorine has a distinct pool-water odor that dissipates when water sits in an open container.

Chloramine-treated systems: Common in larger metro areas — Houston, Phoenix, Philadelphia, Denver, San Diego, and others. Chloramine has a subtler odor, sometimes described as slightly medicinal or plastic-like. It does not dissipate by sitting water out, which is the tell-tale test.

Why Utilities Switched to Chloramine

The EPA regulates disinfection byproducts (DBPs) — compounds formed when disinfectants react with natural organic matter in water. Chlorine produces trihalomethanes (THMs) and haloacetic acids (HAAs) at levels that can be difficult to keep within regulatory limits in large systems.

Chlorine forms significantly higher concentrations of THMs and HAAs than chloramine. A study published in Environmental Science and Technology found chloraminated systems produce roughly 50-70% less THMs and HAAs than chlorinated systems under the same source water conditions.

The trade-off: chloramine forms its own byproducts, including N-nitrosodimethylamine (NDMA), a probable human carcinogen, and various iodo-trihalomethanes. At regulated levels in finished water, the EPA considers both disinfectants safe for drinking — but the research on long-term chloramine exposure and DBP formation is ongoing.

What Does Chloramine Do in Your Plumbing?

Chloramine is chemically more corrosive than chlorine to certain materials. The EPA flagged this connection after the Washington DC lead crisis in 2001-2004, where switching to chloramine was associated with increased lead leaching from older pipes and solder joints.

In systems with lead service lines or pre-1986 copper plumbing soldered with lead-based solder, chloramine can accelerate lead leaching into tap water. This is not universal — the interaction depends on water chemistry, pH, and pipe age — but it’s a documented risk that led the EPA to update its Lead and Copper Rule. If your home has older plumbing and your utility uses chloramine, testing your water for lead is worth doing before assuming filtration is only about taste.

Chloramine also degrades some rubber compounds over time, including certain flexible hoses and O-rings used in household plumbing fittings. In older homes, this can contribute to pinhole leaks and fitting failure over years of exposure.

Why Standard Carbon Filters Don’t Remove Chloramine

This is the most practically important difference for homeowners. Activated carbon works by adsorption — contaminant molecules bond to the carbon surface as water passes through. Chlorine bonds readily to activated carbon and is efficiently removed.

Chloramine molecules are larger and don’t bond as effectively to standard granular activated carbon (GAC). The result is poor chloramine removal — a Brita pitcher or basic refrigerator filter certified only to NSF/ANSI 42 for chlorine may remove 10-30% of chloramine rather than the 90%+ you’d expect for chlorine.

Catalytic carbon is specifically engineered to remove chloramine. Unlike standard activated carbon, catalytic carbon has a modified surface structure that catalyzes the breakdown of the chloramine molecule before adsorption. Removal rates of 95%+ are achievable with properly sized catalytic carbon contact time.

Filter certifications tell you what a system actually removes. Look for:
– NSF/ANSI 42: Chlorine reduction (taste and odor)
– NSF/ANSI 42 with specific chloramine claim: Required to confirm chloramine removal — not all NSF 42 certified filters include it
– NSF/ANSI 58 (RO): RO membranes effectively remove chloramine by a combination of membrane exclusion and carbon pre-filtration

How to Remove Chloramine from Tap Water

Whole House Catalytic Carbon Filters

The most effective solution for whole-home chloramine removal is a catalytic activated carbon filter installed at the main line. Systems using catalytic carbon media — such as the SpringWell CF1 whole house filter — are specifically rated for chloramine removal. The CF1 removes 99.6% of chloramine and is designed for this use case.

A catalytic carbon whole house filter removes chloramine from all water in the home — drinking water, shower water, and cooking water — in a single point-of-entry system.

Shower exposure to chloramine is a legitimate concern beyond drinking. The skin absorbs chloramine, and hot shower steam creates inhalation exposure. A whole house system addresses all three exposure pathways simultaneously. For shower-specific filtration, see our best shower filter for chlorine removal — though note that most shower filters are optimised for chlorine and fewer reliably address chloramine.

Point-of-Use Catalytic Carbon Filters

For under-sink drinking water only, several certified systems handle chloramine:

Aquasana AQ-5300: NSF-certified for chloramine reduction, uses a catalytic carbon block
Clearly Filtered 3-Stage: Certified for chloramine removal under NSF/ANSI 42 with the chloramine-specific claim
Berkey (Black filters): Addresses chloramine, though Berkey’s certification position has been inconsistent — verify current NSF status before purchasing

Reverse Osmosis Systems

RO membranes combined with carbon pre-filtration effectively remove chloramine. The carbon pre-filter in an RO system must be catalytic or must provide sufficient contact time for standard carbon. Most quality RO systems (including those in our best reverse osmosis system roundup) are rated for chloramine removal because they include carbon pre-filtration upstream of the membrane.

What Doesn’t Work

Boiling water: Does not remove chloramine. Boiling removes chlorine (which is volatile) but chloramine is more thermally stable.
Letting water sit out: Chlorine dissipates over hours with aeration. Chloramine does not.
Standard pitcher filters (Brita, PUR basic models): Certified for chlorine only — verify the specific claim before assuming chloramine is removed.
Vitamin C neutralization: Ascorbic acid (vitamin C) does neutralise both chlorine and chloramine — used in aquarium applications and by some home brewers. Not practical for drinking water at scale, but effective for single-use applications like filling a bathtub for sensitive skin or a garden pond.

Health Considerations at Regulated Levels

At the EPA’s maximum residual disinfectant level of 4 mg/L (4 ppm), both chlorine and chloramine are considered safe by the CDC and EPA for the general population. The regulated levels leave a substantial safety margin from known adverse health thresholds.

Special populations with different requirements:

Dialysis patients: Both chlorine and chloramine must be removed from water used in dialysis machines. Chloramine can enter the bloodstream during dialysis and damage red blood cells. Standard dialysis centers handle this with point-of-use carbon filtration at the machine — but home dialysis patients should confirm their system is rated for chloramine, not just chlorine.
Fish tanks: Chloramine is toxic to fish and aquatic invertebrates even at tap water levels. Standard dechlorinators (sodium thiosulfate) neutralise chlorine but not chloramine. Use a dechlorinator specifically rated for chloramine (sodium thiosulfate plus a chelating agent, or a product containing potassium metabisulfite).
Homebrewing: Both chlorine and chloramine affect beer flavor. Chlorine is easily removed by filtering or campden tablets (potassium metabisulfite). Chloramine requires campden tablets specifically — a half tablet per 10 gallons eliminates both at typical municipal concentrations.

How to Test Whether Your Water Contains Chlorine or Chloramine

The sit test: Fill a glass of tap water and leave it uncovered for 30 minutes. Sniff before and after. If the chlorine smell mostly disappears, your water likely uses chlorine. If the smell persists or barely changes, chloramine is probable.

Test strips: Chloramine-specific test strips are available from pool supply stores and online (LaMotte, Hach brands). These give a quantitative reading — useful for confirming the type and verifying filter performance before and after.

Contact your utility: The most reliable method. Your utility’s CCR is required to state the primary disinfectant used and the measured residual in finished water.

Frequently Asked Questions

Is chloramine more dangerous than chlorine?

At regulated levels, neither is considered acutely dangerous for the general population. Chloramine’s byproducts (NDMA) are of concern at higher concentrations, but finished water levels are regulated well below harm thresholds. The practical concern for most households is effective removal — chloramine is harder to filter out, so confirming your filter is rated for it matters more than relative toxicity.

Why does my water smell like chlorine if the city uses chloramine?

The two smells are similar and often confused. Chloramine has a subtler, sometimes described as “medicinal” or “plasticky” odor rather than the sharp pool smell of chlorine. If you’re unsure, the sit test (above) distinguishes them reliably.

Can chloramine damage my pipes?

In homes with lead service lines or older lead solder, yes — chloramine has been associated with increased lead leaching. In modern plumbing (post-1986 copper with lead-free solder, PVC, PEX), this is not a documented concern. If you have older plumbing, test your water for lead directly using a certified home test kit or a lab like National Testing Laboratories.

Do I need a whole house filter if I only care about drinking water?

Not necessarily. A point-of-use under-sink filter with a catalytic carbon block addresses drinking and cooking water. The argument for a whole house system is shower and bath exposure — chloramine is absorbed through skin during bathing and inhaled as steam. Whether that exposure is a meaningful health concern at regulated levels is debated; the established need is at the drinking water tap. For background on tap water safety broadly, that article covers the full contaminant landscape.

Will a Brita filter remove chloramine?

The standard Brita pitcher filter (Brita Standard filter) is NSF 42 certified for chlorine taste and odor reduction only — it does not reliably remove chloramine. The Brita Longlast+ filter does include a chloramine claim, but at 50% reduction — lower than dedicated catalytic carbon systems. If your utility uses chloramine and you’re using a pitcher filter, verify the specific filter’s chloramine certification rather than assuming NSF 42 covers it.

Practical Takeaway

If you’re on a chloramine system and using a carbon filter that was chosen for chlorine removal, check the certification. Standard activated carbon and most basic pitcher filters won’t get the job done. Catalytic carbon — in a whole house filter, an under-sink system, or an RO pre-filter — is what you need.

To identify what your utility actually puts in your water, check the annual Consumer Confidence Report. To understand the full picture of what might be in your tap water beyond disinfectants, our guide on is tap water safe to drink covers the regulatory landscape and most common contaminants in detail.