Chlorine vs Chloramine

Water Treatment Plant

Chlorine vs Chloramine in drinking water

Regulatory bodies such as the Environmental Protection Agency (EPA) were required to set the drinking water quality standards for all public water systems in their respective countries. While the regulations vary from country to country. These regulations require that all municipal water supplies including those meant for drinking and home use be treated to restrict bacterial growth and other hazardous contaminants. It was up to the individual water treatment firms to decide on the approach they used for treating the water as long as it complied with the regulations of the country. Historically chlorine was used as the main disinfectant however now many water treatment plants have moved to using chloramine. Chloramines are a combination of ammonia with chlorine. Unlike plain chlorine, which quickly dissipates when exposed to open air, chloramines remain in the water even if you leave the water in open containers for days. Chloramine is a weaker germicide than chlorine but it is more stable, which is why city water systems are turning to using it more often these days. Hence it’s viewed as being more efficient by water treatment companies to control microbes. While complaints from Chlorine are mostly aesthetic, such as taste and smell, complaints from Chloramine include skin rashes, respiratory and digestive problems. There have been several debates and ongoing dialogues between the public and the water treatment/utility companies to switch from Chloramines to Chlorine however there is no conclusive stance on the debate. The process for removing chlorine is very different from removing Chloramine so it’s important to know what was used to disinfect the water.


  • In Europe, Chlorine was first used to disinfect drinking water in the late 1800s.
  • In the US, Chlorine was first used in 1908 in Jersey City, New Jersey

What is Chloramine?

Chloramine exists as three different forms: monochloramine (NH2Cl), dichloramine (NHCl2) and trichloramine (NCl3). They are chemically related and are easily converted into each other. Thus, they are more appropriately called chloramines. The form that ultimately results is dependent on pH, temperature, turbulence, and the chlorine to ammonia ratio.
Chloramine is a less effective disinfectant than chlorine. A study from World Health Organization (WHO, PDF 145 KB ) says that “monochloramine is about 2,000 to 100,000 times less effective than free chlorine for the inactivation of E. Coli and rotaviruses, respectively.”

Is there Chlorine or Chloramine in my drinking water?

The surest way of determining what is in your tap water is to call your utility/water company and ask them directly what they use to treat the water supply. It is required by law that they make the composition of your water available to you on request or in most cases on their website. However if requesting them directly isn’t your cup of tea, you can get testing kits to help you measure the contents of the water. While these kits are not very expensive perhaps the most inexpensive option is to test the water only for ammonia. Since chloramine is composed of Chlorine + Ammonia – a high concentration of Ammonia in the water is a sure give away that the water treatment uses Chloramine.

Dechlorinating the water

While all dechlorinator will remove chlorine not all of them will neutralize chloramine. If your source water contains chloramine, make sure you arrange for a dechlorinator that will remove chloramine from the water. Make sure you read the product description to seek evidence if the product is meant to neutralize the chlorine or if it neutralizes chloramine.


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