It is a toxic chemical compound related to affected medications.
N- nitrosodimetilamine is a member of a chemical class, the N-nitrosoamines, which are suppected carcinogens. It is toxic to the liver and other organs, and is a human carcinogen.

 
NDMA was first detected in groundwaters of Northern California in 1998. Is a semi-volatile organic chemical and has the molecular formula O=N-N (CH3)2. Yellow in color, and it has little or no taste and odor. Is soluble in water (3.978 mg/L) and is not likely to bioaccumulate, biodegradable, absorb to particulate water or volatilize. Is a semi-volatile organic chemical produced as by-product of several industrial processes and present at very low levels.

 
NDMA is formed involuntarily during several manufacturing processes, in many industrial areas and in the air, water and soil, as a consequence of reactions with other chemical substances called «alkylamines». Alkylamines are compounds that occur naturally or can be manufactured.

 
NDMA is found in the diet:
• Meat and cured meat products
• Fish and fish products
• Beer
• Milk
• Cheese
• Soybean oil
• Canned fruit
• Apple Brandy
• Tobacco smoke
It is however unlikely to bioaccumulate, in the body NDMA is formed when acidic conditions in the stomach catalyze the reaction between nitrite and dimethylamine (DMA).
NDMA occurrence in drinking water may result from industrial groundwater contamination (rocket fuel), from the chlorination/chloramination of cationic polymers, from the use of ion exchange resines, and as a chlorination/ chloramination by product.

 
In industrial processes:
• manufacture of rubber tires
• leather tanning
• production of pesticides
• fish processing

 

The EPA IRIS classification of NDMA is B2, meaning that it can be reasonably anticipated to be a human carcinogen based on animal studies, however inadequate human data exist.
The unit risk factor: the maximum admissible concentration of NDMA:
• in drinking water in lakes and streams of water is 7ng L-1, 5-50 ppm., 0.00069 ppb.

• in air 16 parts per million (ppm)

• in foods 5-100 (ppm)

 

Bibliography:

 

• ATSDR: Agency for Toxic Substances & Disease Registry
https://www.atsdr.cdc.gov/toxprofiles/tp.asp?id=884&tid=173

 

• SFWATER.ORG: Water Quality
https://web.archive.org/web/20040803064201/http://sfwater.org:80/detail.cfm/MC_ID/10/MSC_ID/51/MTO_ID/NULL/C_ID/1865

 

• NIOSH: The National Institute for Occupational Safety and Health
https://www.cdc.gov/niosh/npg/npgd0461.html

 

• AEMPS: Agencia Española de Medicamentos y Productos Sanitarios
https://www.aemps.gob.es/informa/notasInformativas/medicamentosUsoHumano/calidad/2018/NI_ICM-CONT_08-2018-retirada-valsartan.htm

 

• Wikipedia: N-nitrosodimetilamine
https://en.m.wikipedia.org/wiki/N-Nitrosodimethylamine

 

• International Agency for Research on Cancer
https://www.iarc.fr/

 

• U.S. Environmental Protection Agency
https://www.epa.gov/

 

• Colin Baird
“Quimica Ambiental” Ed. Reverte, University of Western Ontario, 2ª ed. 2001