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Chemical Sampling Information (CSI)
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General Description

Synonyms: NDMA; DMNA; DMN; Dimethylnitrosamine; N,N-Dimethyl- nitrosamine; N-Methyl-N-nitrosomethanamine; N-Nitroso-N,N-dimethylamine

OSHA IMIS Code Number: 1942

Chemical Abstracts Service (CAS) Registry Number: 62-75-9

NIOSH Registry of Toxic Effects of Chemical Substances (RTECS) Identification Number: IQ0525000

NIOSH Pocket Guide to Chemical Hazards, N-Nitrosodimethylamine: chemical description, physical properties, potentially hazardous incompatibilities, and more

Exposure Limits

OSHA Permissible Exposure Limit (PEL):
General Industry: 29 CFR 1910.1016 requirements identical to 29 CFR 1910.1003 -- 13 Carcinogens (4-Nitrobiphenyl, etc.) -- Cancer-Suspect Agent

Construction Industry: 29 CFR 1926.1116 requirements identical to 29 CFR 1910.1003 -- 13 Carcinogens (4-Nitrobiphenyl, etc.) -- Cancer-Suspect Agent

Maritime: 29 CFR 1915.1016 requirements identical to 29 CFR 1910.1003 -- 13 Carcinogens (4-Nitrobiphenyl, etc.) -- Cancer-Suspect Agent
American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Value (TLV): Exposure by all routes should be carefully controlled to levels as low as possible; Skin; Appendix A3 - Confirmed Animal Carcinogen with Unknown Relevance to Humans

National Institute for Occupational Safety and Health (NIOSH) Recommended Exposure Limit (REL): Appendix A - NIOSH Potential Occupational Carcinogens

Health Factors

Carcinogenic Classification:
Environmental Protection Agency (EPA): Group B2, probable human carcinogen

International Agency for Research on Cancer (IARC): Group 2A, probably carcinogenic to humans

National Toxicology Program (NTP): Reasonably anticipated to be a human carcinogen [444 KB PDF, 23 pages]
Potential Symptoms: Irritation of eyes, skin, respiratory tract; nausea, vomiting, diarrhea, abdominal cramps; headache; sore throat, cough; weakness; fever; enlarged liver, jaundice; decreased liver, kidney, and pulmonary function; low platelet count; [potential occupational carcinogen]

Health Effects: Cancer (HE1); Liver cirrhosis (HE3); Suspect teratogen (HE5)

Affected Organs: Liver, kidneys, lungs

  1. N-Nitrosodimethylamine is an OSHA Regulated Carcinogen without a PEL (29 CFR 1910.1003).
  2. It undergoes activation by cytochrome P450 2E1 to reactive metabolites that result in the chemical modification of DNA and consequent apoptotic cell death.
  3. The main chemical modification of DNA involves the methylation of guanine residues to form N7-methylguanine (major adduct) and O6-methylguanine, which are thought to be involved in the mutagenicity of N-nitrosodimethylamine.
  4. In addition to worker exposure in the rubber industry and wide exposure to users of tobacco products, recent research has focused on the formation of N-nitrosodimethylamine during water disinfection using chlorination or chloramination processes.
  5. In April 1998, the California Department of Health Services established an "action level" (now termed notification level) for N-nitrosodimethylamine of 10 nanograms per liter of drinking water.
  6. Biological monitoring of worker exposure may be facilitated by the recent development of a sensitive ELISA assay for DNA adducts in peripheral blood lymphocytes.
Date Last Revised: 11/10/2005

Literature Basis:
  • NIOSH Pocket Guide to Chemical Hazards: N-Nitrosodimethylamine.
  • International Chemical Safety Cards (WHO/IPCS/ILO): N-Nitrosodimethylamine.
  • EPA Air Toxics Website: N-Nitrosodimethylamine. U.S. Environmental Protection Agency Technology Transfer Network.
  • Agency for Toxic Substances and Disease Registry (ATSDR): Toxicological Profile for N-nitrosodimethylamine. Atlanta, GA: U.S. Department of Health and Human Services, Public Health Service, 1989.
  • California Department of Health Services: NDMA and Other Nitrosamines - Drinking Water Issues.
  • Choi, J. and Valentine, R.L.: Formation of N-nitrosodimethylamine (NDMA) from reaction of monochloramine: a new disinfection by-product. Water Res. 36(4): 817,824, 2002.
  • Lin, H.L., Parsels, L.A., Maybaum, J. and Hollenberg, P.F.: N-Nitrosodimethylamine-mediated cytotoxicity in a cell line expressing P450 2E1: evidence for apoptic cell death. Toxicol. Appl. Pharmacol. 157(2): 117-124, 1999.
  • Mitch, W.A., Gerecke, A.C. and Sedlak, D.L.: A N-nitrosodimethylamine precursor analysis for chlorination of water and wastewater. Water Res. 37(15): 3733-3741, 2003.
  • Niot-Mansart, V., Muhamedi, A. and Arnould, J.P.: A competitive ELISA detecting 7-methylguanosine adduct induced by N-nitrosodimethylamine exposure. Hum. Exp. Toxicol. 24(2): 89-94, 2005.
  • No Author: Nitrosamines, 15 Listings [444 KB PDF, 23 pages]. Report on Carcinogens (latest edition); U.S. Department of Health and Human Services, Public Health Service, National Toxicology Program.
  • Oury, B., Limasset, J.C. and Protois, J.C.: Assessment of exposure to carcinogenic N-nitrosamines in the rubber industry. Int. Arch. Occup. Environ. Health 70(4): 261-271, 1997.
  • Pohanish, R.P. (editor): N-Nitrosodimethylamine. In, Sittig's Handbook of Toxic and Hazardous Chemicals and Carcinogens, Fourth Ed., Vol. 2. Norwich, NY: Noyes Publications, William Andrew Publishing, 2002, pp. 1731-1733.
  • Siddiqui, M. and Atasi, K.Z.: N-Nitrosodimethylamine: a disinfectant byproduct and its occurrence in wastewater. Water Environ. Res. 76(4): 316-326, 2004.
  • Straif, K., et al.: Exposure to high concentrations of nitrosamines and cancer mortality among a cohort of rubber workers. Occup. Environ. Med. 57(3): 180-187, 2000.

Monitoring Methods used by OSHA

Laboratory Sampling/Analytical Method:
  • sampling media: ThermoSorb/N Tube
    analytical solvent: (75:25) Dichloromethane:Methanol
    maximum volume: 75 Liters
    maximum flow rate: 1.0 L/min
    current analytical method: Gas Chromatography; GC/TEA
    method reference: OSHA Analytical Method (OSHA 27)
    method classification: Fully Validated
    note: OSHA personnel may obtain ThermoSorb/N Tube from SLTC. Store sample in freezer.
Bulk Method:
  • Limit the amount of bulk submitted to one gram or one mL.
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