Does boiling water remove chloramine?

No. Boiling does not remove chloramine from water. This is the single most important distinction between chloramine and free chlorine. Free chlorine is volatile — it escapes during boiling and aeration. Chloramine (specifically monochloramine, the form used in municipal water treatment) is significantly more stable in water and does not evaporate or boil off. Boiling chloraminated water actually concentrates it slightly as water volume reduces. The only effective commercial methods for chloramine removal are: catalytic activated carbon filtration, high-dose UV photolysis (1,000–2,000 mJ/cm²), chemical reduction (sodium metabisulfite, ascorbic acid), and reverse osmosis.

Does carbon filter remove chloramine?

Standard granular activated carbon (GAC) removes chloramine poorly unless the empty bed contact time (EBCT) exceeds 10 minutes — a much larger carbon bed than most standard filters provide. Catalytic activated carbon (CAC), such as Calgon Centaur or equivalent, removes chloramine significantly faster through a catalytic surface reaction and can achieve adequate removal at EBCT of 2–3 minutes (high-performance catalytic carbon) to 6–8 minutes for general commercial use. The difference matters enormously: at the flow rates of most commercial applications, standard carbon beds are undersized for chloramine removal while catalytic carbon beds of the same volume perform adequately.

Does a Brita filter remove chloramine?

Brita standard pitcher filters use granular activated carbon or carbon block, which removes chlorine (free chlorine) effectively but chloramine poorly. Brita's own certification claims cover taste and odor reduction — not chloramine removal. At the flow rates and carbon contact times typical of pitcher filters, chloramine removal is minimal. Brita does offer some filters certified for chloramine reduction, but the standard pitcher filter cartridge is not among them. For any commercial application, pitcher-style filtration is inadequate for chloramine removal regardless of brand.

What is the difference between chloramine and chlorine?

Chlorine (free chlorine, HOCl) and chloramine (primarily monochloramine, NH₂Cl) are both water disinfectants, but they behave very differently in treatment. Free chlorine evaporates readily — you can remove it by boiling, aerating, or letting water stand. Chloramine is chemically stable and does not evaporate; it requires active removal (catalytic carbon, UV, or chemical reduction). Chloramine is about 200 times less reactive with organic matter, which means it produces far fewer trihalomethane (THM) disinfection byproducts — the primary reason municipalities are switching to it. For commercial operators, this stability is the core problem: treatment systems designed for chlorine are often inadequate for chloramine.

Chloramine in Water: What Removes It, What Doesn’t, and Commercial Treatment Methods (2026)

Q: Does reverse osmosis remove chloramine?

Reverse osmosis (RO) removes 85–99% of chloramine from water. However, there is a critical counterintuitive issue: chloramine at municipal concentrations (1.5–4.0 mg/L) irreversibly damages standard thin-film composite (TFC) RO membranes over time. Every commercial RO system treating chloraminated municipal water must have effective upstream chloramine removal — typically catalytic carbon or sodium metabisulfite injection — before the membrane. RO is a chloramine removal technology, but it must be protected from the chloramine it removes.

More than 1 in 5 Americans now receives drinking water disinfected with chloramines rather than free chlorine — a shift that has fundamentally changed what commercial water treatment systems need to do. Chloramine is more persistent, more stable, and far harder to remove than free chlorine. Treatment methods that worked perfectly on chlorinated water may be completely inadequate on chloraminated water. This guide covers the chemistry, the methods that actually work, and the methods that don’t.

The most important thing to know

Boiling does not remove chloramine. Free chlorine evaporates — chloramine does not. Boiling chloraminated water concentrates it. The standard dechlorination procedures that worked for free chlorine are inadequate for chloramine. If your utility has switched to chloramine and your treatment system was designed for chlorine, it needs to be upgraded.

In this guide

What chloramine is and why utilities use it
Chloramine vs. chlorine — key differences
What actually removes chloramine
What does NOT remove chloramine
Catalytic carbon — the primary commercial solution
EBCT — the critical design parameter
UV photolysis
Chemical reduction methods
Reverse osmosis and chloramine
Commercial sector recommendations
EPA limits and regulatory context

What Chloramine Is and Why Utilities Use It

Chloramine is a family of compounds formed when ammonia and chlorine react in water. The form used in municipal water treatment is monochloramine (NH₂Cl), produced by adding ammonia to chlorinated water:

  NH3  +  HOCl  →  NH2Cl  +  H2O

The reason utilities are switching: free chlorine reacts with naturally occurring organic matter in water to form trihalomethanes (THMs) — regulated disinfection byproducts linked to bladder cancer risk. Monochloramine is 200 times less reactive with organics, dramatically reducing THM formation. It is also significantly more stable in water, providing better residual disinfection protection through large distribution systems. The City of Denver has used chloramination since 1918; it is not a new technology, but its adoption has accelerated sharply as EPA tightens THM regulations.

Three forms of chloramine exist:

Form	Formula	Status	Taste/odor threshold
Monochloramine	NH₂Cl	Primary form used in municipal water treatment; most stable	~0.5 mg/L
Dichloramine	NHCl₂	Undesirable byproduct; forms when Cl:N ratio is too high; “swimming pool” odor	0.80 mg/L
Nitrogen trichloride (trichloramine)	NCl₃	Most volatile and most pungent; forms at very high Cl:N ratios or low pH; primary inhalation hazard in pools and food processing facilities	0.02 mg/L

Chloramine vs. Chlorine — What Changes for Commercial Operators

Property	Free chlorine	Monochloramine	Commercial implication
Volatility	Volatile — evaporates readily	Non-volatile — does not evaporate	Boiling, aeration, and letting water stand remove chlorine but NOT chloramine
Reactivity with organics	High — rapidly forms THMs	Low — 200× less reactive	Chloramine produces fewer THM byproducts; its own byproducts (nitrosamines, iodoacetic acid) are different concerns
Distribution persistence	Degrades rapidly	Highly stable	Chloramine reaches commercial premises at higher residual concentrations than chlorine would
Removal by standard GAC carbon	Efficient at low EBCT	Poor unless EBCT >10 minutes	Existing carbon systems sized for chlorine removal may be completely inadequate for chloramine
Effect on RO membranes	Damages TFC membranes	Also damages TFC membranes	RO membrane protection is required for both; the same upstream treatment applies
Effect on dialysis patients	Hazardous	Hazardous — causes hemolytic anemia	Both require removal to <0.1 mg/L before dialysis water use; same AAMI standard applies
Removal by boiling	Yes — partially effective	No — concentrates on boiling	The most dangerous misconception in water treatment for utilities that have switched to chloramine

What Actually Removes Chloramine

Method	Removal efficiency	Best commercial application	Key requirement
Catalytic activated carbon (CAC)	95–99%+	Brewing, food/bev, whole-facility POE, general commercial	Correct EBCT (6–10 min for commercial; 10 min for dialysis)
High-dose UV (1,000–2,000 mJ/cm²)	Up to 99.5%	Pharmaceutical, beverage, dialysis, pre-RO, CIP systems	High-dose UV system — NOT standard disinfection UV (40 mJ/cm²)
UV + CAC combination	Near-complete; synergistic	Critical applications — pharma, food/bev, dialysis	UV upstream of CAC; reduces carbon load, extends service life, prevents bacterial bed colonization
Sodium metabisulfite (SMBS) injection	Complete at correct dose	Pre-RO membrane protection, large-volume process water	Continuous ORP monitoring downstream; metering pump and static mixer
Ascorbic acid / sodium ascorbate	Complete neutralization	Batch treatment only; aquaculture; short-term emergency	Degrades in 24–48 hours — cannot be used for continuous systems
Potassium metabisulfite (Campden tablets)	Complete (batch)	Homebrewing and small craft brewery batch treatment	1 tablet per 20 gallons; 20 minutes contact time; not for continuous flow
Reverse osmosis (TFC membrane)	85–99%	Pharmaceutical, dialysis, ultra-pure water — but must be protected upstream	Upstream catalytic carbon or SMBS required to protect membrane from chloramine damage

What Does NOT Remove Chloramine

Common misconceptions — these do not work

Boiling: Does not remove chloramine — concentrates it. The most dangerous misconception.

Standard granular activated carbon (GAC) at typical flow rates: Removes chloramine poorly unless EBCT exceeds 10 minutes. Most commercial carbon systems are undersized.

Letting water stand / aeration: Works for free chlorine; completely ineffective for chloramine.

Standard water softeners: Ion exchange softeners remove hardness ions; they have no effect on dissolved chloramine.

Brita and standard pitcher filters: GAC pitcher filters remove chlorine taste and odor; chloramine removal is minimal at typical filter flow rates.

UV at standard disinfection dose (40–120 mJ/cm²): Disinfection-level UV kills pathogens but does not remove chloramine — chloramine photolysis requires 1,000–2,000 mJ/cm², 25× higher. A UV system sized for disinfection is not a chloramine removal system.

Catalytic Carbon — The Primary Commercial Solution

Catalytic activated carbon (CAC) is the Water Quality Association’s recommended treatment technology for both point-of-entry and point-of-use chloramine removal. It is the method universally specified by water treatment professionals for applications from brewing to dialysis to food processing.

The difference between standard GAC and catalytic carbon is mechanistic, not just a matter of grade. Standard carbon removes chloramine primarily through adsorption — the chloramine molecule must physically attach to a surface site and be held there. This is a slow process that requires long contact time. Catalytic carbon has been surface-modified to have reactive functional groups that act as a catalyst: the chloramine contacts the surface, undergoes a chemical reduction reaction (NH₂Cl → Cl♠ + NH₃), and the surface site is immediately available for the next molecule. The reaction is substantially faster — which means a much smaller bed volume achieves the same removal.

Catalytic carbon vs. standard GAC

Factor	Standard GAC	Catalytic activated carbon (CAC)
Chlorine removal	Excellent	Excellent
Chloramine removal	Poor to moderate — requires EBCT >10 minutes	Good at EBCT 2–3 min (high-performance); excellent at 6–10 min
Required bed volume for chloramine	Very large	3–5× smaller bed achieves same removal
Carbon service life at same EBCT	40,000–60,000 gallons at 10 min EBCT (2 mg/L influent)	~88,000 gallons at 10 min EBCT (2 mg/L influent)
Unit cost	Lower	Higher — but lower total system cost due to smaller bed volume
Recommended brands	Not recommended as primary treatment for chloramine	Calgon Centaur, Haycarb WAC-1000, Jacobi CX-MCA, Cabot Filtrasorb 400
Source: WQA Chloramine Fact Sheet; Pure Water Products technical guide; Urbans Aqua activated carbon EBCT document (2023).

For commercial point-of-entry applications, backwashing catalytic carbon filters are the standard configuration. Unlike cartridge-based filters requiring periodic replacement, backwashing filters use a large vessel of loose catalytic carbon media that is periodically backwashed to remove accumulated particulates. Carbon media itself must be replaced when it exhausts — backwashing removes particulates but does not restore catalytic capacity.

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EBCT — The Critical Design Parameter

Empty Bed Contact Time (EBCT) is the single most important design parameter for any carbon-based chloramine removal system:

EBCT (minutes) = Carbon Bed Volume (gallons) ÷ Flow Rate (GPM)

EBCT	Chloramine removal (CAC)	Chloramine removal (standard GAC)	Application
<2 min	Marginal	Inadequate	Not suitable for chloramine treatment
2–3 min	Good (high-performance CAC only)	Inadequate	Minimum for high-performance CAC; lower-risk applications only
4–7 min	Very good (CAC)	Poor to moderate	General commercial: food/bev, brewing, HVAC
8–10 min	Excellent (CAC)	Adequate (GAC)	Standard commercial target; 10 min is the FDA/AAMI dialysis standard
>10 min	Complete	Good	Dialysis; pharmaceutical USP water; critical applications
Source: Pure Water Products technical guide; WQA Chloramine Fact Sheet; AAMI RD62 (dialysis). Carbon service life at 10-min EBCT with 2 mg/L influent: ~88,000 gallons (high-performance CAC); ~11,000 gallons at 2-min EBCT.

Why the 10-minute EBCT standard exists for dialysis: The 10-minute contact time for dialysis water treatment was established before catalytic carbon existed, based on standard GAC performance. FDA regulates dialysis water treatment as a medical device, and the 10-minute requirement has remained in place despite the improved performance of modern catalytic carbon. For non-dialysis commercial applications, 6–8 minutes of EBCT with high-performance catalytic carbon is a practical and cost-effective design target. (Source: Pure Water Products; Pure Water Products EBCT technical guide.)

UV Photolysis for Commercial Chloramine Removal

UV photolysis is an established commercial method for chloramine removal, widely accepted in pharmaceutical, beverage, and dialysis applications. At sufficient dose, UV cleaves the nitrogen-chlorine bond in monochloramine, achieving up to 99.5% reduction.

Critical distinction: UV systems designed for pathogen disinfection (40–120 mJ/cm²) do NOT remove chloramine. Chloramine photolysis requires 1,000–2,000 mJ/cm² — 10–25 times the dose used for biological disinfection. Specifying a disinfection-grade UV system for chloramine removal is a common and consequential error.

UV dose	Target	Application
40–120 mJ/cm²	Pathogen disinfection only	Standard building UV — does NOT remove chloramine
500–1,000 mJ/cm²	Partial chloramine reduction	Pre-treatment; first-pass before CAC in combination systems
1,000–2,000 mJ/cm²	Up to 99.5% chloramine reduction	Pharmaceutical; beverage; dialysis; pre-RO; CIP systems; stand-alone treatment

UV + catalytic carbon combination

The preferred design for critical commercial applications combines high-dose UV upstream of catalytic carbon. UV reduces the chloramine load entering the carbon bed by 90%+, dramatically extending carbon service life. UV also eliminates the bacterial contamination risk in carbon beds — carbon beds are warm, moist, organically rich environments ideal for biofilm growth, including opportunistic pathogens. In food and pharmaceutical GMP environments, adding upstream UV eliminates the need for frequent carbon bed sanitization.

Combination design: UV (1,000–2,000 mJ/cm²) → Catalytic carbon (EBCT 6–10 min) → Point of use.

Benefits: near-complete chloramine removal; THM reduction in feed water; bacterial contamination of carbon bed prevented; smaller carbon bed volume needed; longer carbon service life; reduced sanitization frequency. This is the benchmark recommendation for pharmaceutical, food and beverage, and dialysis applications.

Chemical Reduction Methods

Sodium metabisulfite (SMBS) — industrial standard

Sodium metabisulfite (Na₂S₂O₅) is the most widely used industrial chemical for chloramine removal in large commercial and industrial applications. When dissolved in water, it generates sulfurous acid which reduces monochloramine. Dosed at approximately 1.46 mg SMBS per 1 mg chloramine, it provides near-instantaneous complete neutralization.

Primary commercial use: pre-RO membrane protection. SMBS injection is standard protection for any large-scale RO system treating chloraminated municipal water. Continuous ORP monitoring downstream of the injection point is strongly recommended to verify complete neutralization. SMBS adds sulfate to treated water — monitor cumulative sulfate levels for applications with sulfate-sensitive downstream processes.

Ascorbic acid and Campden tablets

Ascorbic acid and potassium/sodium metabisulfite (sold as Campden tablets in brewing applications) completely neutralize both chlorine and chloramine with no harmful byproducts. They are food-safe and non-toxic. Critical limitation: both degrade within 24–48 hours in treated water, making them suitable only for batch or single-use applications, not continuous flow treatment. One Campden tablet per 20 gallons neutralizes chloramine completely in approximately 20 minutes.

Reverse Osmosis and Chloramine

RO removes 85–99% of chloramine from water — but with a critical caveat. Standard thin-film composite (TFC) RO membranes are irreversibly degraded by both free chlorine and chloramine. Chloramine oxidizes the polyamide polymer chain of the membrane active layer, causing loss of salt rejection and structural failure. Membrane manufacturers’ warranties are typically void if chloramine damage is identified as the cause of failure.

Every commercial RO system treating chloraminated municipal water must have effective upstream chloramine removal — catalytic carbon or SMBS injection — before the membrane. RO both removes chloramine and is damaged by it; upstream protection is not optional.

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Commercial Sector Recommendations

Highest priority

Hemodialysis / Dialysis Centers

Chloramine passes directly through dialysis membranes into the bloodstream, bypassing normal digestive neutralization. It oxidizes hemoglobin, causing hemolytic anemia that can be fatal. AAMI standard ANSI/AAMI RD62 mandates <0.1 mg/L chloramine in dialysis water. Clinical data confirm that 0.25–0.3 mg/L chloramine causes measurable hemoglobin degradation in dialysis patients, fully reversed when activated carbon columns reduce levels to <0.1 mg/L.

Required system: Dual catalytic carbon vessels in lead-lag configuration, each sized for minimum 10-minute EBCT at peak flow → 5 µm absolute pre-filter → RO (double-pass) → DI → UV → distribution. Continuous monitoring at each carbon vessel outlet at every patient shift. No compromises on this application.

Brewing & craft beer

Brewery / Craft Beer Production

Unlike chlorine, chloramine survives the boil and reacts with phenolic compounds in malt and hops to form chlorophenols — compounds with a permanent “Band-Aid” or medicinal flavor detectable at concentrations in the parts-per-billion range. There is no way to remove this flavor post-production; the affected batch is lost.

System options by scale: Large craft (10+ BBL): Backwashing catalytic carbon filter at EBCT 6–8 minutes → RO (optional, for full mineral control) → mineral addition. Small craft / homebrew: 4.5″×20″ catalytic carbon cartridge at maximum 1.5 GPM, replaced every 6 months; or 1 Campden tablet per 20 gallons of batch water, 20-minute contact time. The UV sterilizer placed after carbon treatment provides additional biological protection.

Food & beverage processing

Food & Beverage Manufacturing

Chloramine reacts with organic precursors in food ingredients to form chlorophenols affecting taste, aroma, and shelf life. A documented commercial case: a hydrogen peroxide manufacturer (600 GPD process water) experienced product stability failures traced directly to their utility’s switch from chlorine to chloramine. Their existing carbon system was inadequate for chloramine at operating flow rates. Resolution: backwashing catalytic carbon filter sized for correct EBCT.

Recommended system: UV (500–1,000 mJ/cm²) upstream of backwashing catalytic carbon (6–8 min EBCT) → process point of use. UV upstream extends carbon life, prevents bacterial colonization, and reduces THMs in ingredient water simultaneously. For food processors using chlorine wash water on produce: assess trichloramine (NCl₃) air concentrations in worker breathing zones — IARC data document ambient air chloramine concentrations of 0.4–16 mg/m² in salad processing facilities.

Pharmaceutical manufacturing

Pharmaceutical / USP Purified Water

USP Purified Water requires conductivity ≤1.3 µS/cm and TOC ≤500 ppb — requiring virtually complete removal of all dissolved species including chloramine. Steam or hot-water sanitizable carbon vessels are required for GMP compliance.

Required system: Multimedia filter → softener → 5 µm cartridge → dual catalytic carbon (8–10 min EBCT, steam-sanitizable vessels) + SMBS injection with ORP monitoring → high-pressure RO (double-pass) → EDI → UV (254 nm for bio-kill) → 0.2 µm final filter → monitored storage loop. All monitoring continuously logged for 21 CFR Part 11 FDA audit compliance.

Commercial aquaculture

Aquaculture & Commercial Aquariums

Fish cannot metabolize chloramine through digestion as humans can. Chloramine enters the bloodstream through gill tissue, causing the same hemolytic anemia documented in dialysis patients. Even trace levels that are harmless to humans are lethal to fish at chronic exposure. Complete removal (<0.02 mg/L) is required, not just taste/odor improvement.

Required system: Catalytic carbon at EBCT ≥6 minutes → continuous chloramine monitoring on supply line. Sodium thiosulfate or ascorbic acid as emergency batch backup if carbon system fails.

EPA Limits and Regulatory Context

Jurisdiction	Chloramine limit	Notes
United States (EPA)	4.0 mg/L MRDL (as Cl₂)	Maximum Residual Disinfectant Level under Safe Drinking Water Act; typical operating range 1.5–2.5 mg/L
WHO	3.0 mg/L	Drinking-water guideline for monochloramine
Canada	3.0 mg/L maximum	Health Canada
Australia / New Zealand	3.0 mg/L	NHMRC guideline
Dialysis (AAMI/FDA)	<0.1 mg/L in dialysis water	ANSI/AAMI RD62; FDA-regulated as medical device; not a drinking water standard

The IARC (International Agency for Research on Cancer) assessed monochloramine in Volume 84 of its Monographs (2004) and assigned it Group 3: Not classifiable as to its carcinogenicity to humans. This reflects insufficient evidence to make a classification either way — not a finding of safety. The primary commercial concerns remain process interference, dialysis patient safety, aquatic toxicity, and the byproducts formed when chloramine reacts with organic matter in specific process streams.

Related reviews and guides

Matrixx DROP Bodyguard Plus Backwashing Carbon Filter review — dual GAC + catalytic carbon commercial filter for chloramine removal
Brewery water treatment guide — complete chloramine treatment sequence for craft breweries
RO water for brewing — why chloramine-free water is the foundation of consistent brewing chemistry
Crystal Quest UV sterilizer review — 6–84 GPM UV systems for post-carbon biological protection
US Water Systems Defender HD Commercial RO review — requires upstream catalytic carbon on chloraminated water
NSF water filter certifications guide — NSF 42 covers chlorine taste/odor; not all NSF 42 filters remove chloramine
Crystal Quest Thunder RO review — built-in carbon pre-filtration for chloramine removal before the RO membrane