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N-Nitrosodimethylamine (NDMA), also known as dimethylnitrosamine (DMN), is a semi-volatile organic chemical, produced as by-product of several industrial processes and present at very low levels in certain foodstuffs, especially those cooked, smoked, or cured. NDMA is water-soluble, yellow in color, and it has little or no taste and odor. It is toxic to the liver and other organs, and is a probable human carcinogen. It is also used to create cancer in rats for cancer research.

Skeletal formula of N-nitrosodimethylamine
N-Nitrosodimethylamine Ball and Stick.png
N-Nitrosodimethylamine Space Fill.png
Preferred IUPAC name
N,N-Dimethylnitrous amide
3D model (JSmol)
ECHA InfoCard 100.000.500
EC Number 200-549-8
MeSH Dimethylnitrosamine
RTECS number IQ0525000
UN number 3382
Molar mass 74.08 g·mol−1
Appearance Yellow, oily liquid[1]
Odor faint, characteristic[1]
Density 1.005 g ml−1
Boiling point 153.1 °C; 307.5 °F; 426.2 K
290 mg ml−1 (at 20 °C)
log P −0.496
Vapor pressure 700 Pa (at 20 °C)
1.65 MJ mol−1
Main hazards Known carcinogen[1], extremely toxic
GHS pictograms The skull-and-crossbones pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) The health hazard pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) The environment pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)
GHS signal word DANGER
H301, H330, H350, H372, H411
P260, P273, P284, P301+310, P310
NFPA 704
Flammability code 2: Must be moderately heated or exposed to relatively high ambient temperature before ignition can occur. Flash point between 38 and 93 °C (100 and 200 °F). E.g., diesel fuelHealth code 4: Very short exposure could cause death or major residual injury. E.g., VX gasReactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g., liquid nitrogenSpecial hazards (white): no codeNFPA 704 four-colored diamond
Flash point 61.0 °C (141.8 °F; 334.1 K)
Lethal dose or concentration (LD, LC):
37.0 mg kg−1 (oral, rat)
US health exposure limits (NIOSH):
PEL (Permissible)
OSHA-Regulated Carcinogen[1]
REL (Recommended)
IDLH (Immediate danger)
Ca [N.D.][1]
Related compounds
Related compounds
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references



NDMA is a yellow, oily liquid with a faint, characteristic odor and a sweet taste. It is an industrial by-product or waste product of several industrial processes, such as manufacturing of unsymmetrical dimethylhydrazine (UDMH), which is a component of rocket fuel that requires NDMA for its synthesis. Of more general concern, water treatment via chlorination or chloramination of organic nitrogen-containing wastewater can lead to the production of NDMA at potentially harmful levels.[2] Further, NDMA can form or be leached during treatment of water by anion exchange resins.[3] Finally, NDMA is found at low levels in numerous items of human consumption including cured meat, fish, beer, tobacco smoke[3] and as an impurity in pharmaceuticals.[4] It is, however, unlikely to bioaccumulate.[citation needed]


N-Nitrosodimethylamine is highly toxic, especially to the liver, and is a known carcinogen in lab animals. The EPA classifies NDMA as a probable human carcinogen. The US Environmental Protection Agency has determined that the maximum admissible concentration of NDMA in drinking water is 7 ng l−1.[5] The EPA has not yet set a regulatory maximum contaminant level (MCL) for drinking water. At high doses, it is a "potent hepatotoxin that can cause fibrosis of the liver" in rats.[6] The induction of liver tumors in rats after chronic exposure to low doses is well documented.[7] Its toxic effects on humans are inferred from animal experiments but not well-established experimentally.

NDMA's contamination of drinking water is of particular concern due to the minute concentrations at which it is harmful, the difficulty in detecting it at these concentrations, and to the difficulty in removing it from drinking water. It does not readily biodegrade, adsorb, or volatilize. As such, it cannot be removed by activated carbon and travels easily through soils. Relatively high levels of UV radiation in the 200 to 260 nm range breaks the N-N bond and can thus be used to degrade NDMA. Additionally, reverse osmosis is able to remove approximately 50% of NDMA.[8]

It is classified as an extremely hazardous substance in the United States as defined in Section 302 of the U.S. Emergency Planning and Community Right-to-Know Act (42 U.S.C. 11002), and is subject to strict reporting requirements by facilities which produce, store, or use it in significant quantities.[9]

As a poisonEdit

Several incidents in which NDMA was used to intentionally poison another person have garnered media attention. In 1978, a teacher in Ulm, Germany was sentenced to life in prison for trying to murder his wife by poisoning jam with NDMA and feeding it to her.[10][11] In 1978, Steven Roy Harper spiked lemonade with NDMA at the Johnson family home in Omaha, Nebraska. The incident resulted in deaths of 30-year-old Duane Johnson and 11-month-old Chad Sheldon. For his crime, Harper was sentenced to death but committed suicide in prison before his execution could be carried out.[12] In the 2013 Fudan poisoning case, Huang Yang, a postgraduate medical student at Fudan University, was the victim of a poisoning in Shanghai, China. Huang was poisoned by his roommate Lin Senhao who had placed NDMA into the water cooler in their dormitory. Lin claimed he only did this as an April Fool's joke. He received a death sentence and was executed in 2015.[13] Additionally in 2018, NDMA was used in an attempted poisoning at Queen's University.[14]


  1. ^ a b c d e f "NIOSH Pocket Guide to Chemical Hazards #0461". National Institute for Occupational Safety and Health (NIOSH).
  2. ^ ""Sources and Fate of Nitrosodimethylamine and Its Precursors in Municipal Wastewater Treatment Plants". David L. Sedlak, Rula A. Deeb, Elisabeth L. Hawley, William A. Mitch, Timothy D. Durbin, Sam Mowbray and Steve Carr. Water Environment Research Vol. 77, No. 1, Emerging Micropollutants in Treatment Systems (Jan. - Feb., 2005), pp. 32-39. Published by: Water Environment Federation". JSTOR 25045835. Missing or empty |url= (help)
  3. ^ a b Najm, I.; Trussell, R. R. (2001). "NDMA Formation in Water and Wastewater". Journal American Water Works Association. 93 (2): 92–99. ISSN 0003-150X.[permanent dead link]
  4. ^ "Europe recalls generic heart drug made in China on cancer fears". Reuters Health News. Retrieved 13 July 2018.
  5. ^ Andrzejewski, P.; Kasprzyk-Hordern, B.; Nawrocki, J. (2005). "The hazard of N-nitrosodimethylamine (NDMA) formation during water disinfection with strong oxidants". Desalination. 176 (1–3): 37–45. doi:10.1016/j.desal.2004.11.009.
  6. ^ George, J.; Rao, K. R.; Stern, R.; Chandrakasan, G. (2001). "Dimethylnitrosamine-induced liver injury in rats: the early deposition of collagen". Toxicology. 156 (2–3): 129–138. doi:10.1016/S0300-483X(00)00352-8. PMID 11164615.
  7. ^ Peto, R.; Gray, R.; Brantom, P.; Grasso, P. (1991). "Dose and Time Relationships for Tumor Induction in the Liver and Esophagus of 4080 Inbred Rats by Chronic Ingestion of N-Nitrosodiethylamine or N-Nitrosodimethylamine" (pdf). Cancer Research. 51 (23 Part 2): 6452–6469. PMID 1933907.
  8. ^ Mitch, W. A.; Sharp, J. O.; Trussell, R. R.; Valentine, R. L.; Alvarez-Cohen, L.; Sedlak, D. L. (2003). "N-Nitrosodimethylamine (NDMA) as a Drinking Water Contaminant: A Review". Environmental Engineering Science. 20 (5): 389–404. doi:10.1089/109287503768335896.
  9. ^ "40 C.F.R.: Appendix A to Part 355—The List of Extremely Hazardous Substances and Their Threshold Planning Quantities" (PDF) (July 1, 2008 ed.). Government Printing Office. Retrieved October 29, 2011.
  10. ^ Ein teuflischer Plan: Tod aus dem Marmeladeglas (in German)
  11. ^ Karsten Strey: "Die Welt der Gifte", Lehmanns, 2. Edition p. 193 (in German)"
  12. ^ Roueche, Betron (January 25, 1982). "Annals of Medicine - The Prognosis for this Patient is Horrible". The New Yorker: 57–71.
  13. ^ "15 days log in hospital". Archived from the original on 2014-01-09. Retrieved 2013-04-30.
  14. ^ Man admits to poisoning fellow researcher in Kingston

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