is the recycling of all materials back into nature or the marketplace in a manner that protects human health and the environment.




Summary: Health concerns of chlorine exposure include, but are not limited to: possible increased risk of miscarriage, birth defects, rectal and bladder cancer, respiratory complaints, corrosion of the teeth, inflammation of the mucous membranes of the nose, and increased susceptibility to tuberculosis. There is an alarming lack of comprehensive test data.

Note: To test for chlorine, use an ordinary pool test kit.


PHILADELPHIA, Pa., Feb 1, 1999 / PRNewswire/ -- The U.S. Environmental Protection Agency (EPA) has set a maximum limit for chlorine in drinking water that is 33% higher than chlorine used in pool water. Pool chemical suppliers instruct pool owners to limit the chlorine level to between 1.0 - 3.0 milligrams per liter (mg/l). On February 16, the new maximum of 4.0 mg/l chlorine in drinking water will become effective nationwide.

The given justification for 4.0 mg/l chlorine in drinking water is that, under federal law, water companies must ensure a minimum of 0.02 mg/l to customers living at the end of, sometimes, very lengthy water mains. This means that customers living at the front end of the pipe will be drinking water with higher levels of chlorine. (Note: Water treatment facilities that use alternative disinfectant processes to chlorination may be exempt from the 0.02 mg/l chlorine minimum).

On the adverse health effects of chlorinated water, the EPA says, "…studies show an association between bladder and rectal cancer and chlorination byproducts in drinking water….Reports from the older literature stated that chronic exposure to concentrations of chlorine of around 5 ppm {ppm = mg/l}caused respiratory complaints, corrosion of the teeth, inflammation of the mucous membranes of the nose, and increased susceptibility to tuberculosis."

There is a disturbing lack of comprehensive test data on the health effects of chlorine. The EPA says that "Limited information is available on the chronic effects of chlorine in humans." And, "…no information is available on the developmental or reproductive effects of chlorine in humans or animals via inhalation exposure or on the carcinogenic effects of chlorine in humans from inhalation exposure." Chlorine is inhaled during activities such as, baths, showers, washing dishes, laundry, and watering lawns.

Peter Montegue, of the Environmental Research Foundation, reported in May 1998, that recent studies by researchers, including the California Department of Health and the U.S. Agency for Toxic Substances and Disease Registry, indicate that miscarriages and birth defects, including spina bifida, may be caused by adding chlorine to drinking water.

Many European cities and some Canadian cities have abandoned chlorination in favor of ozone technology to disinfect water. According to The American Water Works Association (AWWA), ozone is being used or considered for use at drinking water facilities because it is a powerful oxidant that disinfects without increasing the disinfection by-products that chlorine produces.


NOTE: Reports sometimes use different measurements for the same value, example: 
milligrams per liter (mg/l) = ppm (parts per million). This can be very confusing for the non-professional researcher.

  • Effective 2/16/99: Federal Register Notice of 'Maximum Residual Disinfectant Levels for Chlorine' (MRDLC)
  • EPA's webpage for Chlorine Health Effects
  • Rachel's #599 (05/21/98): Dangers of Chlorine in Water - "In the U.S., chlorine is added to public drinking water supplies as a public health measure to kill harmful bacteria in the water. The added chlorine reacts with naturally-occurring organic matter in the raw water (chiefly humic and fulvic acids), creating a host of chlorinated chemicals as by-products. Health agencies, including the federal EPA [Environmental Protection Agency] simply ignore most of these by-products and know almost nothing about them. Instead, they focus on four by-products, allowing these four to act as surrogates for all the others. The four that EPA pays attention to are chloroform, bromoform, bromodichloromethane, and chlorodibromomethane. Together, these four are called "trihalomethanes" or THMs."
  • Greenpeace: CHLORINE - This century's most notorious environmental villains all have a common origin...chlorine chemistry." Also see - 
    • "Ultraviolet light (UV), ozone treatment, and improved filtration can eliminate the use of chlorine and hazardous by-products in water treatment systems. Hundreds of municipalities around the world are already using these alternative disinfection technologies, and several large cities in Europe are relying on those methods to deliver safe, chlorine-free drinking water to their communities. These include Amsterdam in the Netherlands, Nice and Paris, in France and Berlin, Munich and Muenster in Germany. Chlorine-free alternatives that use oxygen, ozone, UV, ionic treatment and other methods are available to disinfect swimming pools, as well."

SEE: ZWA's WATER Issues,Technologies, and Remediation