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Chlorine Tolerance Test, Chlorine Sensitivity Test, Chlorine Tests for Drinking Water

What Is Chlorine?

Chlorine is a naturally occurring element found in gaseous form at room temperature. The highly reactive nature of chlorine means it is usually bound with other elements, such as sodium chloride (salt). A strong oxidizing agent, Chlorine deactivates microorganisms by breaking through the cell membrane.

What Is Chlorine Used For?

Chlorine was first added to drinking water systems in the 19th century to combat diseases such as cholera. Since then, chlorine has been widely adopted as a disinfectant across multiple applications, including in swimming pools and for washing food produce. As with all disinfectants, monitoring of residuals and dosing is important to ensure that levels are not too high or low.

Chlorine levels are routinely monitored to ensure that water is free of harmful bacteria. However, because it is very sensitive to pH and temperature, both those parameters must be tested and carefully controlled to achieve optimum performance.

Chlorine in Drinking Water

Most drinking water is treated with chlorine to prevent harmful bacteria from causing illness in humans and animals. Whether added as free chlorine or combined chlorine depends very much on how quickly the water is to be consumed and the potential for disinfection by-product formation.

Is Chlorine in My Drinking Water Dangerous?

At the concentrations found in drinking water, chlorine is nontoxic to humans. Many municipalities add chlorine to their water to help kill harmful organisms such as viruses and bacteria that could make us sick if we ingested them.

This disinfecting ability is also why swimming pool facilities add chlorine to their water.

People started adding chlorine to water as early as the 1800s when they realized it had disinfectant properties. During that time, when the water went untreated, it was common for people to contract waterborne diseases such as cholera, typhoid, and dysentery. The initial introduction of chlorine as a disinfectant helped to lower disease rates and keep city-dwellers safe.

What are the health concerns?

Chloride is considered to be an essential nutrient for human health and the main source of chloride is from foods, with drinking water making up only a small portion of normal dietary intake. Chloride in drinking water is not harmful, and most concerns are related to the frequent association of high chloride levels with elevated sodium levels.

Chlorine sensitivity can occur when swimming pools increase the amount of chlorine, for example, in response to health scares such as “Swine Flu” or E. coli. Finding facilities with lower chlorine concentrations may resolve your sensitivity.


Skin sensitivity to chlorine can present the following symptoms:

  • Skin redness, tenderness, inflammation, and/or itchiness at the site of contact

  • Skin lesions or rash

  • Scales or crust on the skin

Hives (urticaria) share some of these symptoms (itchiness and redness), but with raised patches or bumps with well-defined edges. Hives may appear suddenly and may grow in size.

People with asthma, EIB, and allergic rhinitis, who already have sensitive airways, might also have the following symptoms:

  • Coughing, especially at night, with exercise, or when laughing

  • Trouble breathing

  • A tight feeling in the chest

  • Wheezing a squeaky or whistling sound

  • Runny nose

  • Itching

  • Sneezing

  • Stuffy nose due to blockage or congestion


If you feel like you have a chlorine allergy or sensitivity, it’s time to see an allergist. With the help of testing they can diagnose your symptoms and help you find relief so you can continue to enjoy swimming.


Chloride in drinking water is not harmful, and most concerns are related to the frequent association of high chloride levels with elevated sodium levels.

Chlorination is the method of killing parasites, bacteria, and viruses by adding chlorine to drinking water. To achieve safe chlorine levels in drinking water, a variety of techniques can be used.



  • https://www./chlorine-in-drinking-water

  • https://allergic-conditions/chlorine-allergy

  • https://www.environment-energy-and-climate-action


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