2/24/2009 US EPA
CHLORAMINES-RELATED RESEARCH
14) How did EPA evaluate the safety of monochloramine for use as a
drinking water disinfectant?
EPA evaluated monochloramine primarily through an analysis of
human health and animal data.
•	Research reviewed in EPA's safety analysis is contained in EPA's
Drinking Water Criteria Document for Chloramines.1
•	The criteria document for monochloramine provides a complete summary
of health and other data considered in establishing a monochloramine
standard.
•	EPA periodically updates the monochloramine "criteria document."
EPA's monochloramine standard2 is set at a level where no human health
effects are expected to occur.
•	Data from animal and human studies provide information on the health
effects of monochloramine.
•	EPA reviews and considers new research results as they become
available.3
•	EPA's standard for monochloramine takes data gaps and uncertainty into
account by building safety factors4 into the regulatory standard.
EPA reviewed historical data in its evaluation of monochloramine.
•	Monochloramine has been in use as a drinking water disinfectant since
the 1930's.5
•	Decades of use in the US, Canada, and Great Britain shows that
monochloramine is an effective secondary drinking water disinfectant.
•	Denver, Philadelphia, and other large cities have used monochloramine as
part of their water treatment process for years.
Additional Supporting Information:
1.	The Drinking Water Criteria Document for Chloramines can be found at
http://www.epa.gov/ncea/pdfs/water/chloramine/dwchloramine.pdf. Publication No.:
ECAO-CIN-D002, March, 1994.
2.	The Maximum Residual Disinfectant Level (MRDL) for chloramines is 4 parts per
million (ppm).
3.	See the Contaminant Candidate List online at
http://www.epa.gov/OGWDW/ccl/ccl3.html for contaminants that EPA proposes to
review. EPA scientists review regulations of disinfectants and disinfection byproducts
every six years. For information on EPA's six-year review visit:
http://epa.gov/safewater/review.html
4.	For additional information regarding how uncertainty factors (also known as safety
factors) are applied to risk assessments to provide a wide margin of safety see:
http://epa.gov/risk/dose-response.htm.
5.	Cleveland, OH, Springfield, IL, and Lansing, Ml were among the first cities to use
monochloramine in 1929 (see Chapter 1 of The Quest for Pure Water Vol II, AWWA,
1981).

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