N-Nitrosomorpholine
59-89-2
Hazard Summary
N-Nitrosomorpholine is not used commercially in the United States. Limited information is available on the
health effects of N-nitrosomorpholine. No information is available on the acute (short-term), chronic
(long-term), reproductive, developmental, or carcinogenic effects of N-nitrosomorpholine in humans.
Animal studies have reported effects on the liver from chronic exposure as well as tumors of the liver, nasal
cavity, lung, and kidneys from oral exposure to N-nitrosomorpholine. EPA has not classified N-
nitrosomorpholine for carcinogenicity. The International Agency for Research on Cancer (IARC) has
classified N-nitrosomorpholine as a Group 2B, possible human carcinogen.
Please Note: The main sources of information for this fact sheet are the Hazardous Substances Data Bank (HSDB)
(1), a database of summaries of peer-reviewed literature, and the IARC monographs on chemicals carcinogenic to
humans. (3)
Uses
	N-Nitrosomorpholine is not used commercially in the United States. (3)
Sources and Potential Exposure
s N-Nitrosomorpholine was detected^as an airborne contaminant inside some cars; levels ranging from trace
to 2.5 grams per cubic meter (g/m ) were detected. (1)
s N-Nitrosomorpholine has been found in rubber-stoppered blood collection tubes. (1)
Assessing Personal Exposure
 No information is available on the assessment of personal exposure to N-nitrosomorpholine.
Health Hazard Information
Acute Effects:
a No information is available on the acute effects of N-nitrosomorpholine in humans.
a Tests involving acute exposure of rats have shown N-nitrosomorpholine to have moderate to high acute
toxicity from oral exposure. (2)
Chronic Effects (Noncancer):
	No information is available on the chronic effects of N-nitrosomorpholine in humans.
	Animal studies have reported effects on the liver from chronic exposure to N-nitrosomorpholine. (1,3)
	EPA has not established a Reference Concentration (RfC) or a Reference Dose (RfD) for N-
nitrosomorpholine.
Reproductive/Developmental Effects:
 No information is available on the reproductive or developmental effects of N-nitrosomorpholine in
humans or animals.

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Cancer Risk:
s No information is available on the carcinogenic effects of N-nitrosomorpholine in humans.
s Animal studies have reported tumors of the liver, lung, nasal cavity, and kidneys from oral exposure
to N-nitrosomorpholine. (1,3-5)
a EPA has not classified N-nitrosomorpholine for carcinogenicity.
a The IARC has classified N-nitrosomorpholine as a Group 2B, possible human carcinogen. (3)
a The California^ n^ vironmental Protection Agency (CalEPA) has calcula t^ed an inhalation unit risk factor
of 0.001 9 (|jg/m ) and an oral cancer slope factor of 6.7 (mg/kg/d) .(4)
Physical Properties
a N-Nitrosomorpholine exists as yellow crystals. (1,3)
a The chemical formula for N-nitrosomorpholine is C^H^N^O^, and the molecular weight is 1 1 6.1 g/mol. (3)
Note: There are very few health numbers or regulatory/advisory numbers for N-nitrosomorpholine; thus, a grapl
has not been prepared for this compound. The health information cited in this fact sheet was obtained in Decern
1999.
Conversion Factors:
3	3
To convert concentrations in air (at 2 5C) from ppm to mg/m : mg^m = (ppm) x (molecular weight of the
compound)/(24.45). For N-nitrosomorpholine: 1 ppm = 4.7 mg/m . To convert concentrations in air from
|jg/m to mg/m : mg/m = (jjg/m ) x (1 mg/1,000 |jg).
References	Summary created in April 1992, updated in January 2000
1.	U.S. Department of Health and Human Services. Hazardous Substances Data Bank (HSDB, online database).
National Toxicology Information Program, National Library of Medicine, Bethesda, MD. 1 993.
2.	U.S. Department of Health and Human Services. Registry of Toxic Effects of Chemical Substances (RTECS,
online database). National Toxicology Information Program, National Library of Medicine, Bethesda, MD.
1993.
3.	International Agency for Research on Cancer (IARC). IARC Monographs on the Evaluation of the
Carcinogenic Risk of Chemicals to Humans. Volume 1 7. World Health Organization, Lyon. 1 978.
4.	California Environmental Protection Agency. Air Toxics Hot Spots Program Risk Assessment Guidelines:
Part II. Technical Support Document for Describing Available Cancer Potency Factors. Office of
Environmental Health Hazard Assessment, Berkeley, CA. 1999.
5.	U.S. Department of Health and Human Services (DHHS). The 8th Report on Carcinogens. 1 998 Summary.
Public Health Service, National Toxicology Program. 1 998.

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