Chlorine Vs. Chloramine For Water Disinfection

Chlorine and chloramine are both disinfectants commonly used in public water supplies to kill bacteria, viruses, and other microorganisms that can cause illnesses. While the two compounds have similar disinfection properties, there are significant differences when choosing which is best for your system.

Why Disinfect Drinking Water?

Disinfecting drinking water is essential in ensuring access to safe, clean water for public consumption. Water that has not been adequately treated can contain dangerous pathogens, such as bacteria and viruses, which can cause severe illnesses if consumed. To combat this potential risk, water treatment plants typically use chlorine or chloramine effective disinfectants to kill any remaining pathogens in the water before it is distributed to the public.

Why Disinfect Drinking Water?
Disinfect Drinking Water

What Is Chlorine?

Chlorine is a chemical element that is used for the disinfection of water. It’s naturally present in seawater and can also be obtained from salt, often extracted by electrolysis. Chlorine is widely used to kill bacteria and other harmful organisms in drinking water and wastewater treatment plants. The chlorine molecules act as oxidants, meaning they react with organic and inorganic molecules in water to destroy them.

Chlorine is often used as a primary disinfectant, meaning it’s added directly to the water supply before being distributed. It is effective at killing most bacteria, viruses, and other microorganisms that can be found in water supplies. Additionally, it is relatively inexpensive and easy to use.┬áIt has been used for over a century and is still one of the most commonly-used water treatment methods.

What is Chlorine

What Is Chloramine?

Chloramine is a combination of chlorine and ammonia primarily used as a disinfectant in municipal water systems. The EPA has approved it as an acceptable alternative to chlorine for disinfection because it is more stable in water and can provide longer-term protection against microbial contamination.

What Is Chloramine?

Chlorine vs. Chloramine for Water Disinfection

Chlorine and chloramine are two disinfecting agents commonly used to treat public water supplies. Both substances have their distinct advantages for killing bacteria and other microorganisms. Still, it is essential to understand their differences before deciding which one is right for your needs.

  • Formation: Chloramine is a combination of chlorine and ammonia. It works as a longer-lasting disinfectant than chlorine because it does not break down as quickly. This means that chloramine can remain in the water supply for extended periods, providing continuous protection against bacteria and other microorganisms.
  • Safety: When it comes to safety, chlorine, and chloramine have advantages. Chlorine is considered to be toxic if ingested in large quantities, while chloramine has been proven to be generally safe for human consumption. However, it can irritate some people’s eyes, nose, and throat.
  • Taste and odor: Chlorine reacts with organic matter to form compounds that cause taste and odor issues in drinking water. Chloramine is less likely to react with organic matter, resulting in fewer taste and odor complaints. However, chloramine can produce undesirable byproducts when exposed to sunlight or through reactions with other chemical treatments.
  • Cost: Chlorine is the preferred disinfectant because it is inexpensive. It can be added at levels much lower than needed to achieve adequate disinfection with chloramine, making chlorine more cost-effective for most communities.
  • Health effects: When it comes to health effects, there is a difference between chlorine and chloramine. Chlorine is associated with a higher risk of certain diseases, such as cancer and respiratory problems, due to its byproducts. On the other hand, chloramine has much lower levels of toxins in its byproducts and therefore is less likely to cause adverse health effects.


  • History: Chlorine has been a water disinfectant since the early 1900s. It kills bacteria and other microorganisms on contact, making it an effective way to purify water quickly. Chlorine also has a short half-life, which will break down over time. This means that chlorine needs to be added regularly to maintain its effectiveness as a disinfectant.

Chloramine is a combination of chlorine and ammonia, and it has been used as an alternative to chlorine for water disinfection since the 1920s. Chloramine works in a few ways, such as removing bacteria, viruses, and other microorganisms. It’s also more stable than chlorine in water systems that contain organic matter or other substances that tend to break down chlorine.

What Makes Chloramine Different from Chlorine?

Chloramine is less volatile: Chloramine, unlike chlorine, will stay in the water longer and is more difficult to remove. This means that it can be used to keep the water disinfected over long periods without needing to be replenished regularly.

Chloramine has a less distinct taste and odor: Chloramine doesn’t have the same distinct smell and taste as chlorine, making it a more palatable option for those who don’t want their water to be heavily chlorinated.

Chloramine is more corrosive: Chloramine is more corrosive than chlorine and can damage certain metals such as copper, brass, and stainless steel. Water systems using chloramine must take extra precautions to protect plumbing components from corrosion.

chloramine is more corrosive
Chloramine is more corrosive

How Does Chlorine Inactivate Microorganisms?

Chlorine is an effective agent for water disinfection because it reacts with microorganisms such as bacteria, viruses, and parasites; the chlorine-microorganism reaction results in various compounds, such as chloramines, which are toxic to many organisms. Chlorine kills pathogens by damaging their outer cell membrane or disrupting their internal metabolism.

How Does Chlorine Inactivate Microorganisms?
Chlorine Inactivate Microorganisms

Its reactivity is due to its oxidizing properties, which essentially strip electrons away from cells. The chlorine-microorganism reaction also results in the formation of trihalomethanes (THMs), a group of chemical compounds that may be carcinogenic if ingested at high levels.

What Can I Do to Remove Chlorine & Chloramine From My Tap Water?

The removal of chlorine and chloramine from tap water is a process that requires special treatment techniques. The techniques used to remove these contaminants vary depending on the concentration level and type of contamination present in the water.

  • Carbon filters: One standard method for removing chlorine is to use carbon filters. Carbon filters are commonly found in home water filtration systems and effectively remove chlorine. Carbon filters should be replaced periodically to ensure the highest level of removal.
Carbon filter
Carbon filters
  • Reverse osmosis: Chloramine can be removed using reverse osmosis, distillation, and activated alumina filtration systems. Reverse osmosis is a popular option for removing chloramines because it removes up to 99% of contaminants. Distillation involves boiling and collecting the vapor produced, condensing it into pure water. Activated alumina filtration systems also remove chloramines by adsorbing them to their surface.


If chloramines are harmful to kidney dialysis patients and fish?

If chloramines are harmful to kidney dialysis patients and fish
chloramines are harmful to kidney

Yes, chloramines can be harmful to kidney dialysis patients and fish. Chlorinated water can irritate, and particulate matter from the treatment process may form a biofilm in dialysis machines, leading to increased levels of bacteria buildup. Additionally, because chloramines are more stable than chlorine, they remain active longer and build up in the water, making the water toxic to fish and other aquatic life.

How long has U.S. drinking water been chlorinated?

The chlorination of drinking water in the United States has a long history, going as far back as 1908. Although chlorine-based disinfectants had been used since the late 19th century to disinfect wastewater, it wasn’t until the early 20th century that chlorination became increasingly common for treating drinking water supplies.

How common is chlorine disinfection of drinking water?

Chlorine is the most widely used chemical for disinfecting drinking water. It has been used for over 100 years and is currently used to treat nearly all public water supplies in the United States.

Why does my water taste different?

The difference in taste or smell of your water may be due to the type of disinfectant used by your local water treatment facility. Chlorine and chloramine are common compounds used for disinfection, but they behave differently when added to water.

How is chlorine added to drinking water?

Chlorine is added to drinking water as a disinfectant in two common forms: free chlorine and combined chlorine (also known as chloramine). Free chlorine is created when elemental chlorine gas dissolves in water, while combined chlorine is produced by chemically bonding the element with ammonia.

Will chlorine affect my pets?

Chlorine used for water disinfection is not harmful to pets, as the concentrations are typically too low to be of any concern. However, chloramines may significantly affect pets, depending on how much they drink and their overall health.

Will chlorine increase the amount of lead or copper in my drinking water?

No, chlorine and chloramine are both disinfectants used for many years to keep drinking water safe by killing off disease-causing microorganisms. However, neither chlorine nor chloramine increases the amount of lead or copper in your drinking water.

Is chlorine responsible for the bleach taste in drinking water?

No, chlorine is not responsible for the taste of bleach in drinking water.


Both chlorine and chloramine have been proven to be effective for water disinfection. However, each use depends on local regulations, cost-effectiveness, and safety considerations. Chlorine is typically a more affordable option due to its shorter contact time and easy removal process, but it can also rapidly dissipate in water, making it less reliable. On the other hand, chloramine is more stable in water but requires a longer contact time and can be difficult to remove from the water after use. Ultimately, deciding which disinfectant to choose should be based on an assessment of local laws and regulations and cost and safety considerations.

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