Emerging Contaminant - N-Nitroso-
dimethylamine (NDMA)
April 2008
FACT SHEET
Introduction
At a Glance
* Classified as a B2 carcinogen -
reasonably anticipated to be a
human carcinogen.
* Formerly used in the production of
rocket fuel, antioxidants, and
softeners for copolymers.
Currently used only for research
purposes.
* Unintended byproduct of
chlorination of wastewater at
wastewater treatment plants that
use chloramines for disinfection,
causing significant concern as a
drinking water contaminant.
* Highly mobile in soil, with potential
to leach into ground water.
* Oral route is the primary human
exposure pathway.
* Listed as a priority pollutant by
EPA, but no federal standards have
been established for drinking water.
* Most common treatment method is
via photolysis by ultraviolet
radiation ranging in wavelengths of
225 to 250 nanometers.
* Potential for aerobic and anaerobic
biodegradation exists.
An "emerging contaminant" is a chemical or material that is
characterized by a perceived, potential, or real threat to human health or
the environment or a lack of published health standards. A contaminant
may also be "emerging" because a new source or a new pathway to
humans has been discovered or a new detection method or treatment
technology has been developed (DoD 2006). This fact sheet, developed
by the U.S. Environmental Protection Agency (EPA) Federal Facilities
Restoration and Reuse Office (FFRRO), provides a brief summary for N-
Nitrosodimethylamine (NDMA), including physical and chemical
properties; environmental and health impacts; existing federal and state
guidelines; detection and treatment methods; and additional sources of
information.
NDMA is an emerging drinking water contaminant that is of interest to
the environmental community because of its miscibility with water, as
well as its carcinogenicity and toxicity. This fact sheet is intended for
use by site managers and other field personnel addressing NDMA
contamination at a cleanup site or in a drinking water supply.
What is NDMA?
* Synonyms include dimethylnitrosamine (DMNA),
nitrosodimethylamine, N-methyl-N-nitrosomethanamine, and N,N-
dimethylnitrosamine (EPA IRIS 2006).
* NDMA is not currently produced in pure form or commercially used,
except for research purposes. It was formerly used in production of
liquid rocket fuel, antioxidants, and softeners for copolymers
(ATSDR 1999; HSDB 2007).
* NDMA can be produced and released from industrial sources
through chemical reactions, such as those involving alkylamines with
nitrogen oxides, nitrous acid, or nitrite salts. Potential industrial
sources include byproducts from tanneries, pesticide and rocket fuel
manufacturing plants, rubber and tire manufacturers, alkylamine
manufacture and use sites, fish processing facilities, foundries, and
dye manufacturers (ATSDR 1989).
* NDMA is also an unintended byproduct of chlorination of wastewater
and drinking water at treatment plants that use chloramines for
disinfection (Mitch and others 2003; Bradley and others 2005).
* NDMA is currently on the DoD Emerging Contaminant Watch List
(Yaroschak 2006).
United States
Environmental Protection
Agency
Solid Waste and
Emergency Response
(5106P)
1
EPA 505-F-07-006
April 2008
-------
Exhibit 1: Physical and Chemical Properties of N-Nitrosodimethylamine
(CHEMFATE 2003; ATSDR 1989)
Property
CAS Number
Value/Description
62-75-9
Physical Description (physical state at room
temperature)
Yellow liquid with no distinct odor
Molecular weight (g/mol)
74.08
Water solubility (g/L at 25 C)
Miscible
Boiling point (°C)
154
Specific gravity (g/mL)
1.0059
Vapor pressure at 25 C (mm Hg)
2.7
Log organic carbon partition coefficient (log Koc)
1.079
Log octanol-water partition coefficient (log Kow)
-0.57
Henry's Law Constant (atm m /mol)
2.63x10"
Notes: g/mol - Grams per mole; g/mL - Grams per milliliter; g/L - Grams per liter; °C - Degrees Celsius; mm Hg - Millimeters of mercury.
What are the environmental impacts of NDMA?
NDMA contamination may be found in air, water,
and soil, from the various sources described
earlier (ATSDR 1989).
In water, NDMA is completely miscible and does
not sorb onto solid particles or sediment (HSDB
2007).
When released to soil, NDMA can be highly
mobile and has the potential to leach into ground
water (ATSDR 1999; HSDB 2007).
When released to the air, NDMA is broken down
very quickly by sunlight (ATSDR 1999).
NDMA has been found at high concentrations
(3,000 nanograms per liter [ng/L] or parts per
trillion [ppt]) in ground water near rocket engine
testing facilities and also downgradient of
drinking water wells, especially in locations
where wastewater effluent was used for aquifer
recharge (Mitch and others 2003).
What are the health effects of NDMA?
NDMA exposure may occur through ingestion of
food containing nitrosamines, such as smoked
or cured meats and fish; beer; contaminated
drinking water; and breathing or inhaling
cigarette smoke. Workplace exposure can
occur at tanneries, pesticide manufacturing
plants, and rubber and tire plants (ATSDR
1989).
The oral route is the primary human exposure
pathway for NDMA (OEHHA 2006).
Exposure to high levels of NDMA may cause
liver damage in humans. Symptoms of
overexposure include headache, fever, nausea,
jaundice, vomiting, and dizziness (ATSDR 1999;
HSDB 2007).
NDMA is classified as a B2 carcinogen -
reasonably anticipated to be a human
carcinogen (ATSDR 1999; EPA IRIS 2006;
USDHHS 2002).
Are there any existing federal and state guidelines and health standards for NDMA?
Drinking Water Standards:
• Although NDMA is listed as a priority
pollutant (CFR 2001), no federal maximum
contaminant level (MCL) has been
established for drinking water. A MCL is not
necessary for establishing cleanup levels.
At a Superfund site in California, EPA
established a cleanup level of 0.7 ng/L
NDMA in ground water, based on a 1 in 10~6
lifetime excess cancer risk in drinking water
(EPA 2001).
-------
Are there any existing federal and state guidelines and health standards for NDMA?
(continued)
• EPA Regions 3 and 6 have calculated 0.42
ng/L as the non-enforceable screening level
for NDMA in tap water, based on a 1 in 10~6
lifetime excess cancer risk (EPA 2007a and
b).
• California has established a public health
goal of 3 ng/L in drinking water, based on a
1 in 10~6 lifetime excess cancer risk (OEHHA
2006).
Workplace Exposure Limits:
• Although no permissible exposure limits
(PEL) or other occupational exposure limits
have been established by the Occupational
Safety and Health Administration (OSHA),
National Institute for Occupational Safety
and Health (NIOSH), or the American
Conference of Industrial Hygienists
(ACGIH), NDMA is regulated along with 13
other chemicals as a "potential occupational
carcinogen" (OSHA 2006).
OSHA regulations promulgated in the Code
of Federal regulations (CFR) (29 CFR
1910.1003 and 29 CFR 1910.1116) state
that exposure by all routes to NDMA should
be reduced to the lowest possible levels.
What detection and site characterization methods are available for NDMA?
The following methods can be used to analyze
for NDMA:
• For wastewater, EPA Method 607 uses
methylene chloride extraction, gas
chromatography (GC), and a nitrogen-
phosphorus detector (EPA 2002).
• For drinking water, EPA Method 521 uses
solid phase extraction (SPE) and capillary
column GC with large-volume injection and
chemical ionization tandem MS (MS/MS)
(Munch and Bassett 2004).
For wastewater, EPA Method 1625 uses
isotope dilution, GC and MS (EPA 2002).
An analytical method has also been
developed specifically for NDMA precursors
such as alkylamines in waste or wastewater
(Mitch, Gerecke, and Sedlak2003).
A recently developed method using liquid
chromatography tandem MS (LC/MS/MS)
detects both thermally stable and unstable
nitrosamines (Zhao and others 2006).
What technologies are being used to treat NDMA?
The most common method to treat NDMA in
drinking water systems is photolysis by
ultraviolet (UV) radiation in the wavelength
range of 225 to 250 nanometers (nm). This
treatment cleaves the N-N bond, yielding nitrite
and small quantities of dimethylamine (Mitch
and others 2003).
Recent studies have shown that aerobic and
anaerobic biodegradation of NDMA water may
be possible (Bradley and others 2005).
Biological treatment, microfiltration, and reverse
osmosis treatment may be used to remove
NDMA precursors from wastewater prior to
chlorination (Mitch and others 2003).
Where can I find more information about NDMA?
Agency for Toxic Substances and Disease
Registry (ATSDR). 1989. Toxicological Profile
for N-Nitrosodimethylamine. Atlanta, Georgia:
U.S. Department of Health and Human Services,
Public Health Service.
ATSDR. 1999. ToxFAQs - N-
Nitrosodimethylamine.
Bradley, P.M., S.A. Carr, R.B.Baird, and F.H.
Chappelle. 2005. "Biodegradation of N-
nitrosodimethylamine in soil from a water
reclamation facility." Bioremediation Journal.
Vol.9. Pages 115-120.
-------
Where can I find more information about NDMA? (continued)
CHEMFATE. 2003. Database Listing for N-
Nitrosodimethylamine.
www.syrres.com/esc/chemfate.htm.
Code of Federal Regulations (CFR). 2001. Title
40, Chapter 1, Part 136.36. July 1 edition.
Hazardous Substance Data Bank (HSDB).
2007. Information generated for N-
Nitrosodimethylamine on January 23.
http://toxnet.nlm.nih.gov.
Mitch, W.A., A.C. Gerecke, and D.L. Sedlak.
2003. "A N-Nitrosodimethylamine (NDMA)
precursor analysis for chlorination of water and
wastewater." Water Research. Vol.37. Pages
3733-3741.
Mitch, W.A., J.O. Sharp, R.R. Trussell, R.L.
Valentine, L. Alvarez-Cohen, and D.L. Sedlack.
2003. "N-Nitrosodimethylamine (NDMA) as a
Drinking Water Contaminant: A Review."
Environmental Engineering Science. Vol. 20 (5).
Pages 389-404.
Munch, J.W. and M.V. Bassett. September
2004. "U.S. EPA Method 521: Determination of
Nitrosoamines in Drinking Water by Solid Phase
Extraction (SPE) and Capillary Column Gas
Chromatography with Large Volume Injection
and Chemical lonization Tandem Mass
Spectrometry (MS/MS)." Version 1.0. National
Exposure Research Laboratory, Cincinnati,
Ohio. EPA 600-R-05-054.
Occupational Safety and Health Administration
(OSHA). 2006. Chemical Sampling Information
- N-Nitrosodimethylamine.
www.osha.gov/dts/chemicalsampling/data/CH 2
58000.html.
Office of Environmental Health Hazard
Assessment (OEHHA). 2006. Public Health
Goals for Chemicals in Drinking Water- N-
Nitrosodimethylamine.
U.S. Department of Health and Human Services
(USDHHS). 2002. Report on Carcinogens.
Public Health Service, National Toxicology
Program. 10th edition.
U.S. Department of Defense. 2006. Emerging
Contaminants.
www.denix.osd.mil/denix/Public/Library/MERIT/
merit.html.
U.S. Environmental Protection Agency (EPA).
2001. "Record of Decision for the Western
Ground Water Operable Unit OU-3, Aerojet
Sacramento Site."
EPA. 2002. Methods for Organic Chemicals
Analysis. In: Guidelines Establishing Test
Procedures for the Analysis of Pollutants Under
the Clean Water Act; National Primary Drinking
Water Regulations; and National Secondary
Drinking Water Regulations; Methods Update;
Final Rule.
EPA. 2007a. Region 6. Human Health
Medium-Specific Screening Level.
www.epa.gov/region6.
EPA. 2007b. Region 3. Human Health Risk
Assessment - Risk-Based Concentrations
Table, www.epa.gov/region3.
EPA Integrated Risk Information System (IRIS).
2006. N-Nitrosodimethylamine.
www.epa.gov/iris/subst/0045.htm.
Yaroschak, P. 2006. "Emerging Contaminants
- The New Frontier". Presentation at the
December 2006 Federal Remediation
Technologies Roundtable (FRTR) Meeting.
www.frtr.gov/pdf/meetings/dec06/yaroschak120
606.pdf
Zhao, Y-Y., J. Boyd, S.E. Hrudey, and X-F. Li.
2006. "Characterization of New Nitrosoamines
in Drinking Water Using Liquid Chromatography
Tandem Mass Spectrometry." Environmental
Science and Technology. Vol. 40. Pages 7636-
7641.
Contact Information
If you have any questions or comments on this fact sheet, please contact: Mary Cooke, FFRRO, by phone at
(703) 603-8712 or by e-mail at cooke.maryt@epa.gov.
------- |