N-Nitroso-n-methylurea
Hazard Summary-Created in April 1992; Revised in January 2000
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N-Nitroso-n-methylurea has been studied in mutagenicity
and genetics studies and for use as a cancer chemotherapy agent.
No commercial use of N-nitroso-n-methylurea is known.
Acute (short-term) exposure to N-nitroso-n-methylurea in
humans causes dermatitis. No information is available on the chronic
(long-term), reproductive, developmental, or carcinogenic effects of N-nitroso-n-methylurea
in humans or animals. Tumors have been reported in the offspring
of animals treated with N-nitroso-n-methylurea during their
pregnancy. Animal studies have reported tumors of the brain, spinal
cord, nerves, stomach, pancreas, and kidneys from oral exposure to N-nitroso-n-methylurea.
EPA has classified N-nitroso-n-methylurea as a Group B2,
probable human carcinogen.
Please Note: The main sources of information for this fact sheet are the International Agency for Research on Cancer's (IARC's), Monograph on the Evaluation of the Carcinogenic Risk of N-Nitroso-n-Methylurea, the Hazardous Substances Data Bank (HSDB), a database of summaries of peer-reviewed literature, and the Registry of Toxic Effects of Chemical Substances (RTECS), a database of toxic effects that are not peer reviewed.
Uses
- N-Nitroso-n-methylurea was used in the past for the laboratory synthesis of diazomethane, but it has been largely replaced by other reagents. (1,5)
- N-Nitroso-n-methylurea has been studied in mutagenicity and genetics studies and for use as a cancer chemotherapy agent (alone or in combination with cyclophosphamide). (1,5)
Sources and Potential Exposure
- Occupational exposure to N-nitroso-n-methylurea may occur for a small number of individuals, primarily those who use the chemical in research laboratories. (1)
- No information is available on environmental exposure to N-nitroso-n-methylurea.
Assessing Personal Exposure
- No information is available on the assessment of personal exposure to N-nitroso-n-methylurea.
Health Hazard Information
Acute Effects:- N-Nitroso-n-methylurea causes dermatitis in humans. (2).
- Acute animal tests in rats have shown N-nitroso-n-methylurea to have high acute toxicity from oral exposure. (3)
- No information is available on the chronic (long-term) effects of N-nitroso-n-methylurea in humans or animals.
- EPA) has not established a Reference Concentration (RfC) or a Reference Dose (RfD) for N-nitroso-n-methylurea. (4)
- No information is available on the reproductive or developmental effects of N-nitroso-n-methylurea in humans.
- Animal studies have reported tumors of the nervous system and kidneys in the offspring of rats treated with N-nitroso-n-methylurea during their pregnancy. (1)
- No information is available on the carcinogenic effects of N-nitroso-n-methylurea in humans.
- Animal studies have reported tumors of the brain, spinal cord, nerves, stomach, pancreas, and kidneys from oral exposure to N-nitroso-n-methylurea. (1,2,5)
- Skin tumors have been reported in mice, rats, and hamsters when N-nitroso-n-methylurea was administered topically. (5)
- EPA has classified N-nitroso-n-methylurea as a Group B2, probable human carcinogen. (4)
Physical Properties
- N-Nitroso-n-methylurea exists as pale, yellow crystals. (2)
- The odor threshold for N-nitroso-n-methylurea is not available.
- The chemical formula for N-nitroso-n-methylurea is C2H5N3O2, and the molecular weight is 103.10 g/mol. (1)
- The vapor pressure and the log octanol/water partition coefficient (log Kow) are not available for N-nitroso-n-methylurea.
Note: There are very few health numbers or regulatory/advisory numbers for N-nitroso-n-methylurea; thus, a graph has not been prepared for this compound. The health information cited in this factsheet 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-nitroso-n-methylurea: 1 ppm = 4.2 mg/m3.
References
- 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.
- 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.
- U.S. Environmental Protection Agency. Health Effects Assessment Summary Tables. FY 1997 Update. Office of Research and Development, Office of Emergency and Remedial Response, Washington, DC. EPA/540/R-97-036. 1997.
- U.S. Department of Health and Human Services (DHHS). The 8th Report on Carcinogens. 1998 Summary. Public Health Service, National Toxicology Program. 1998.