N-Nitrosomorpholine
Hazard Summary-Created in April 1992; Revised in January 2000
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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.
Uses
- N-Nitrosomorpholine is not used commercially in the United States. (3)
Sources and Potential Exposure
- N-Nitrosomorpholine was detected as an airborne contaminant inside some cars; levels ranging from trace to 2.5 grams per cubic meter (g/m3) were detected. (1)
- 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:- No information is available on the acute effects of N-nitrosomorpholine in humans.
- Tests involving acute exposure of rats have shown N-nitrosomorpholine to have moderate to high acute toxicity from oral exposure. (2)
- 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.
- No information is available on the reproductive or developmental effects of N-nitrosomorpholine in humans or animals.
- No information is available on the carcinogenic effects of N-nitrosomorpholine in humans.
- Animal studies have reported tumors of the liver, lung, nasal cavity, and kidneys from oral exposure to N-nitrosomorpholine. (1,3-5)
- EPA has not classified N-nitrosomorpholine for carcinogenicity.
- The IARC has classified N-nitrosomorpholine as a Group 2B, possible human carcinogen. (3)
- The California Environmental Protection Agency (CalEPA) has calculated an inhalation unit risk factor of 0.0019 (µg/m3)-1 and an oral cancer slope factor of 6.7 (mg/kg/d)-1. (4)
Physical Properties
- N-Nitrosomorpholine exists as yellow crystals. (1,3)
- The chemical formula for N-nitrosomorpholine is C4H8N2O2, and the molecular weight is 116.1 g/mol. (3)
Note: There are very few health numbers or regulatory/advisory numbers for N-nitrosomorpholine; thus, a graph has not been prepared for this compound. The health information cited in this fact sheet was obtained in December 1999.
Conversion Factors:
To convert concentrations in air (at 25°C) from ppm to mg/m3: mg/m3 = (ppm) × (molecular weight of the compound)/(24.45). For N-nitrosomorpholine: 1 ppm = 4.7 mg/m3. To convert concentrations in air from µg/m3 to mg/m3: mg/m3 = (µg/m3) × (1 mg/1,000 µg).
References
- 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. 1993.
- 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.
- International Agency for Research on Cancer (IARC). IARC Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Humans. Volume 17. World Health Organization, Lyon. 1978.
- 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.
- U.S. Department of Health and Human Services (DHHS). The 8th Report on Carcinogens. 1998 Summary. Public Health Service, National Toxicology Program. 1998.