Does Reverse Osmosis Remove Chloramine from Water?

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Chloramine is a commonly used disinfectant in municipal water systems throughout the world. In fact, you may be surprised to learn that one-third of all public water systems in the United States use chloramine rather than chlorine as a disinfectant.

While highly effective at disinfection, chloramine can leave a distinct taste and odor in your tap water, and, although it’s considered safe to consume, you may prefer to remove it from your drinking water for a number of reasons.

But how do you actually do that? Does reverse osmosis remove chloramine from water for example? Let’s take a look!

Key Takeaways

  • Reverse osmosis systems are equipped with activated carbon filters that very effectively remove chloramine. The RO membrane itself does not do much to reduce chloramine concentrations in water.
  • A chloramine removal rate of 95-97% is considered good for an RO filtration system using activated carbon.
  • The optimal water pH range for chloramine removal using an RO system is 6.0-8.0.
  • Chloraminated water with a high pH (>9.0) can result in damage to the RO membrane and reduce its effectiveness.

Does Reverse Osmosis Remove Chloramine from Water?

So, does reverse osmosis remove chloramine from water? The answer is yes and no!

While the reverse osmosis membrane itself used in a reverse osmosis system does not remove chloramine effectively, pretty much all RO systems use carbon pre and post-filters that do remove chloramine.

It is these carbon filters – not the RO membrane – that do the heavy lifting. In fact, carbon filtration is one of the most effective methods of chloramine removal.

For these reasons, RO systems have become a popular strategy for getting rid of chloramine from household tap water.

Under Sink Reverse Osmosis System

How Does a Reverse Osmosis System Remove Chloramine?

How exactly does an RO system remove chloramine?

As mentioned above, the answer is adsorption by carbon filters!

Carbon filters are a common component of RO systems and are used as both pre-filters and post-filters to remove a wide range of contaminants from household water. They provide the slow contact time necessary to ensure effective chloramine removal.

When water passes through a carbon filter, many contaminants – including chloramine molecules – are attracted to, or ‘adsorbed’ onto the surface of the carbon. This process of adsorption effectively removes nearly all chloramine from the water, leaving it as clean as possible for the RO membrane.

The adsorption of chloramine onto a carbon filter is an effective method for removing it from your water because it does so without the need for chemical reactions or other complex processes.

In addition to using carbon filters, RO systems also utilize a semipermeable membrane to filter out any remaining contaminants. This membrane is made up of tiny pores that allow purified water to pass through while trapping any remaining contaminants on the other side.

The combination of carbon filtration followed by membrane filtration makes RO systems a highly effective method for removing chloramine and other contaminants. So if you want to ensure the purity of your drinking water, an RO filtration system is the way to go!

Doesn’t Chloramine Damage the RO Membrane?

It’s true that chloramine can cause damage if not properly removed before reaching the RO membrane. This is because chloramine can react with some types of membrane materials, resulting in reduced performance and efficiency, as well as a shortened lifespan. Luckily, your carbon pre and-filters will eliminate any chloramine before it reaches the Ro membrane, preventing corrosion and damage.

It’s worth noting that to prevent damage, the pH of the water should be maintained at an appropriate level. This can typically be done by adding a pH adjustment agent to the water if needed, before it is treated by the RO system.

In general, a neutral pH level between 6.0 and 8.0 is considered optimal for chloramine removal using activated carbon. At a pH below 6.0, the effectiveness of the carbon filter may be reduced, while at a pH above 9.0, the chloramine can break down, allowing ammonia ions to reach the RO membrane, causing damaging. So, try to keep your pH within a neutral range of 6.0 – 8.0 for optimal performance.

How Much Chloramine Does an RO System Remove?

One of the most important factors in the removal effectiveness of chloramine is the efficiency of the carbon filters being used. In general, RO systems that use high-quality carbon filters like granular activated carbon (GAC) can handle significantly higher chloramine concentrations. A good GAC filter will remove about 95-97 percent of chloramine from your water, rendering it virtually harmless.

The specific capabilities of an RO system in terms of chloramine removal, however, will depend on the system itself and the contaminants present in the water. You may need to conduct a test or contact your treatment office to find out exactly what’s in your water before deciding on a filter model.

And, if you’re ever confused about an RO system’s ability to treat your home water, contacting the manufacturer is always an option – they’re usually happy to help!

Other Ways to Remove Chloramines from Water

Besides reverse osmosis systems, there are a few other options for removing chloramine from water. These include chemical neutralization, UV light, and just activated or catalytic carbon filtration.

Activated Carbon

Activated carbon, also sometimes known as activated charcoal, is a highly porous material that is effective at removing a range of contaminants from water through adsorption. Activated carbon is available in various forms, such as granulated activated carbon (GAC) and block carbon, and can be used alone or as part of a larger treatment system – like RO!

GAC is generally the most effective type of activated carbon for chloramine removal. It’s made up of small, porous granules that provide a large surface area for contaminants to stick to. This makes it particularly effective at removing chlorine and chloramines from water.

Granular Activated Carbon

That being said, the effectiveness of GAC at removing chloramines can vary depending on the specific brand and quality of carbon being used. As such, it’s important to choose high-quality GAC that is specifically designed for chloramine removal to ensure the best results.

Catalytic Carbon

Catalytic carbon is a type of activated carbon that has been treated with a catalyst, such as manganese dioxide, to enhance its ability at removing certain contaminants from water through chemical reactions. One of the contaminants that catalytic carbon is particularly effective at eliminating is chloramine.

When water passes through catalytic carbon filter media, the chloramine molecules react with the catalytic material, breaking the molecular bond between the chlorine and ammonia. Both are separately removed by the carbon afterwards.


Can boiling water remove chloramine from your water? Unfortunately, the answer is no. While boiling water can be an effective method for removing some contaminants, such as bacteria and viruses, it is not effective at removing chloramine.

That’s because chloramine does not evaporate or boil off easily when the water is heated.

Chemical Neutralization

One common method of chemical neutralization is to add a reducing agent such as sodium sulfite or ascorbic acid to the water. Like catalytic carbon, these chemicals react with chloramines, breaking them up into their individual components: chlorine and ammonia.

It’s worth noting that while neutralization is effective at destroying chloramine and chlorine, it still leaves behind the problem of ammonia. If you opt for neutralization, you may need further treatment to remove this pesky chemical.

What Are Chloramines and Why Are They Used in Water Treatment?

Chloramines are a chemical compound that are used to disinfect water from bacteria, viruses, and other microorganisms. They are formed by combining chlorine with ammonia and are commonly used in water treatment as an alternative to free chlorine.

Chloramines are more effective and more stable in water than chlorine, which means that they stay in the system longer without breaking up. This makes chloramine very useful for maintaining the quality of treated water as it travels throughout long distribution systems.

In addition to their effective disinfection, chloramines are also less reactive than chlorine and produce fewer disinfection byproducts (DPBs). This makes them a safer and more environmentally friendly option for disinfection.

Overall, chloramines are a widely used option in water treatment systems around the world to ensure that water is safe and free of harmful microorganisms.

From Chlorine to Chloramine

Let’s take a closer look at what makes chloramine so different from chlorine!

Chloramines are formed by combining chlorine with ammonia. There are three main types of chloramines that are used in water treatment: monochloramine, dichloramine, and trichloramine, reflecting the number of chlorine atoms present in the molecule.

To produce chloramines, chlorine and ammonia are mixed together in the desired ratio. The pH of the water is then adjusted to the appropriate level. The mixture reacts, resulting in the formation of chloramine.

So, the specific type of chloramine that is produced depends on the ratio of chlorine to ammonia, and the pH of the water:

  • Monochloramine is produced at a pH of 6.5 to 9.0
  • Dichloramine is produced at a pH of 4.0 to 6.0
  • Trichloramine is produced at a pH of <4.4

The most common form of chloramine in home water systems is monochloramine (NH2Cl), due to its superior stability.

Why Should You Eliminate Chloramine from Your Home Water?

There are several reasons why you may want to consider eliminating chloramine from your home water.

Chloramine can cause unpleasant taste and odor, corrosion of certain plumbing materials, and health issues for some people. Plants and fish can also experience a potentially negative reaction to chloramine.

Overall, whether or not you should eliminate chloramine from your home water will depend on your specific needs and preferences. If you are concerned about the taste, smell, or potential health effects of chloramine, or if you are interested in purifying your home water for aquatic use, you may want to consider eliminating chloramine with an RO filter.

Bad Water Taste + Odor

Some people are sensitive to the taste and smell of chloramine and find that it gives their water a strong, unpleasant flavor.

young woman drinking water

The specific taste and odor of chloramines can vary depending on the type and concentration of chloramine present in the water. Monochloramine, dichloramine, and trichloramine each can give water a different taste and odor.

Likewise, the pH of your water can impact the taste and odor of chloramines, with higher pH levels resulting in a stronger taste and odor.

Skin and Eye Irritation

Some people may experience skin and eye irritation when exposed to chloraminated water.

The specific symptoms can vary depending on the individual and the concentration of chloramine, but common issues may include redness, itching, dryness, and swelling of the skin or eyes.

Usually, irritation from chloramine is higher in individuals with sensitive skin or eyes, or who have compromised immune systems. If you or someone in your household is concerned about the potential for skin and eye irritation from chloramine, an RO purifier is a great solution.

Respiratory Issues

While chloramine is widely considered a very safe water disinfectant, some individuals may experience respiratory issues when exposed to chloramine. The range of symptoms include coughing, wheezing, shortness of breath, and chest tightness. People with compromised respiratory systems or pre-existing conditions, like asthma, may be at a higher risk for these side effects.

If you or a household member has a compromised respiratory system or a pre-existing condition, you may consider using a water treatment system like reverse osmosis specifically designed to remove chloramine.

And remember, if you think you’re experiencing respiratory effects from chloramine but are unsure, make sure you contact a healthcare professional for advice!


Chloramine can be toxic to plants, causing a variety of symptoms. These can include yellowed leaves, wilting, and even death. The specific symptoms will depend on the type of plant and the concentration of chloramine in your water.

Generally, plants with sensitive or delicate leaves such as ferns, orchids, and bromeliads, are more likely to be affected by chloramine than plants with thicker, wax-coated leaves.

It’s a good idea to monitor your plants for symptoms of chloramine toxicity and take steps to address any concerns.


Chloramines can be a serious threat to the health of aquatic animals, and it is important to be aware of the specific sensitivities of your pets. As you already know, monitoring your aquatic animals and providing them with clean, safe water is crucial to their well-being.

Small fish and invertebrates are some of the species most affected by chloramine. Symptoms of chloramine toxicity in aquatic animals include difficulty breathing and skin irritation. Chloramine can even affect the gills of fish, leading to a lack of oxygen and eventually death.

If you notice that your aquatic animals may be experiencing symptoms of chloramine toxicity, it is essential that you take action quickly to protect their health!

Plumbing and Appliances

Chloramine can be corrosive to certain plumbing materials, causing a variety of issues. These include the deterioration of rubber seals and gaskets, and the corrosion of metal pipes and fixtures.

The specific effect of chloramine on your plumbing and appliances will vary; some materials like PVC, CPVC and stainless steel are more resistant to the corrosive effects of chloramine, whereas materials like copper piping or brass fittings are easily corroded and damaged over time by chloraminated water.

Rubber gaskets are heavily affected by chloramine, too. This is because they are made of organic material that can be broken down by the chloramine molecule. The molecule reacts with rubber, causing it to degrade and become brittle. This can eventually lead to cracks, leaks, and ultimately failure of the seal.

If you have any thoughts about the question, does RO remove chloramine, please don’t hesitate to leave a comment below!

About the Author Gene Fitzgerald

Gene Fitzgerald is one of the founders of BOS and currently head of content creation. She has 8+ years of experience as a water treatment specialist under her belt making her our senior scientist. Outside of BOS, Gene loves reading books on philosophy & social issues, making music, and hiking.
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