What is the Difference Between Chlorine and Chloramine

Chlorine and chloramine are essential compounds widely used in water treatment for disinfection purposes. Despite their effectiveness in disinfection, there is a difference between chlorine and chloramine in terms of stability, odor, taste, and the formation of disinfection byproducts, which influence their selection for water treatment processes.

What is the difference between chlorine and chloramine? Chlorine, made of two chlorine atoms (Cl2), is fast-acting and widely used for primary disinfection. Chloramine, formed by mixing chlorine with ammonia, offers longer-lasting disinfection.

Key Areas Covered

1. What is Chlorine 
      – Definition, Features 
2. What is Chloramine
      – Definition, Features 
3. Similarities Between Chlorine and Chloramine
      – Outline of Common Features
4. Difference Between Chlorine and Chloramine
      – Comparison of Key Differences
5. FAQ: Chlorine and Chloramine
      – Answers to Frequently Asked Questions

Key Terms

Chlorine, Chloramine

Difference Between Chlorine and Chloramine - Comparison Summary

What is Chlorine

Chlorine is a highly reactive chemical element with the symbol Cl and atomic number 17. It belongs to the halogen group, found in Group 17 of the periodic table. As a diatomic molecule (Cl₂), chlorine exhibits a distinctive, pale green color and a strong, pungent odor.

One of chlorine’s major applications is as a disinfectant in water treatment. Its powerful oxidizing properties make it effective in eliminating bacteria, viruses, and other contaminants from drinking water and swimming pools. Despite its essential role in maintaining water hygiene, the use of chlorine has raised environmental concerns due to the formation of disinfection by-products, which can have adverse health effects.


Chlorine is also a key component in the production of various chemicals, including PVC (polyvinyl chloride), which is widely used in construction materials, pipes, and other plastic products. Additionally, chlorine compounds play a crucial role in pharmaceuticals, agriculture, and the manufacturing of solvents.

While chlorine is integral to various industries, mishandling or exposure to high concentrations can pose health risks. Inhalation of chlorine gas can irritate the respiratory system, leading to coughing and difficulty breathing.

What is Chloramine

Chloramine is a compound formed by the combination of chlorine and ammonia, commonly used as a disinfectant in water treatment. Unlike free chlorine, chloramine has greater stability and a longer-lasting disinfectant effect in water distribution systems. This makes it a preferred choice for municipalities striving to maintain water quality throughout the entire distribution network.

One key advantage of chloramine is its reduced formation of disinfection by-products (DBPs) compared to chlorine. DBPs, such as trihalomethanes, result from the reaction of chlorine with organic matter in water and are potential health concerns. By using chloramine, water treatment facilities can mitigate these risks and adhere to regulatory standards.


However, chloramine has its challenges. Some people may be more sensitive to its residual presence in water, experiencing skin irritation or allergic reactions. Moreover, chloramine-treated water can corrode certain plumbing materials, potentially leading to the release of heavy metals into the water supply.

In addition to its application in drinking water treatment, chloramine is used in aquaculture to control pathogens, demonstrating its versatility in various water treatment contexts.

Similarities Between Chlorine and Chloramine

  1. Chlorine and chloramine are chemical compounds used for water disinfection.
  2. Both contain chlorine atoms.
  3. The effectiveness of both chlorine and chloramine as disinfectants can be influenced by the pH of the water.

Difference Between Chlorine and Chloramine


  • Chlorine is a chemical element represented by Cl and exists as a diatomic molecule (Cl2) in its gaseous form. Chloramine, on the other hand, is a compound created by the combination of chlorine and ammonia, typically existing as monochloramine (NH2Cl) or dichloramine (NHCl2).


  • Chlorine often has a noticeable taste and odor to water, which some people find unpleasant. Chloramine tends to have a less noticeable taste and odor compared to chlorine, making water treated with chloramine potentially more palatable.

Reaction Rate

  • Moreover, chlorine can provide rapid disinfection but may also produce higher levels of disinfection byproducts (DBPs) due to its strong oxidative properties. Chloramine reacts more slowly and forms fewer DBPs, making it a preferred disinfectant in systems where DBP control is a concern.


  • Chlorine is more volatile and tends to dissipate more quickly from water compared to chloramine, which provides a longer-lasting residual disinfectant.


In conclusion, the difference between chlorine and chloramine lies in their form and function. Chlorine, a reactive gas, plays a pivotal role in water disinfection but raises environmental and health concerns. On the other hand, chloramine, a stable compound of chlorine and ammonia, offers a longer-lasting disinfectant effect with reduced by-products, yet poses challenges such as taste and plumbing issues. Both serve as water disinfectants, but their application requires careful consideration. Despite their effectiveness, chloramines can be harmful to respiratory health, emphasizing the importance of proper water treatment methods.

FAQ: Chlorine and Chloramine

1. Are chloramines harmful to humans?

Chloramine can cause and aggravate respiratory problems. Chloramine fumes can cause an individual to become congested and cause sneezing, sinus congestion, coughing, choking, wheezing, shortness of breath and asthma.

2. What kills chloramines?

Using a granular activated carbon (GAC) filtration system is the most effective way to remove chloramines from water. GAC effectively adsorbs chloramines, breaking them down into harmless components, and thus ensuring the elimination of chloramines from the water supply.

3. What is chloramine used for?

Chloramines are disinfectants used to treat drinking water. They are most commonly formed by adding ammonia to chlorine during the water treatment process, resulting in a compound that effectively controls microbial growth while ensuring safe and potable drinking water for consumers.

4. What is an example of a chloramine?

Some examples of chloramine include N-chloromorpholine (ClN(CH2CH2)2O), N-chloropiperidine, and N-chloroquinuclidinium chloride.

5. Does UV destroy chloramines?

UV radiation has been successfully used in the pharmaceutical and food industries to destroy free chlorine and/or chloramines present in water.


1. “Chlorine.” Encyclopedia Britannica. 
2. “Monochloramine.” Wikipedia. Wikipedia Foundation.

Image Courtesy:

1. “Chlorine in bottle” By W. Oelen(CC BY-SA 3.0) via Commons Wikimedia
2. “Chloramine-2D” By Benjah-bmm27 – Own work (Public Domain) via Commons Wikimedia

About the Author: Hasini A

Hasini is a graduate of Applied Science with a strong background in forestry, environmental science, chemistry, and management science. She is an amateur photographer with a keen interest in exploring the wonders of nature and science.

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