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Laboratory Analysis for NDMA and Other Nitrosamines

Last Update:  May 1, 2007

Laboratories wishing to test for nitrosamines in drinking water in California (e.g., for investigations related to notification levels) should be approved by US EPA. US EPA-approved laboratories will need to be used for the federal UCMR 2. Sampling and analysis for UCMR 2 is to occur between January 2008 and December 2010.


In the late 1990s with findings of N-nitrosodimethylamine (NDMA), as mentioned elsewhere, and the establishment of a notification level for NDMA, CDHS (the California Department of Health Services, now CDPH) provided guidelines for NDMA analysis at concentrations in the low parts per trillion.  There was no formal approval process for laboratories, and CDHS provided a list of laboratories that were capable of low-level NDMA analysis.  At that time our objective was to eventually have certification for NDMA occur through certification by the Environmental Laboratory Accreditation Program (ELAP).  However, given US EPA's laboratory approval process for UCMR 2,  ELAP will not be certifying laboratories for NDMA and other nitrosamines at this time.

UCMR 2 and US EPA Laboratory Approval for Nitrosamines

NDMA and other nitrosamines are included in Screen Survey List 2 of the US EPA's the list of unregulated contaminants for which monitoring is required (UCMR 2) (see UCMR Update). These nitrosamines are:

  • N-nitrosodiethylamine (NDEA)

  • N-nitrosodimethylamine (NDMA)

  • N-nitrosodi-n-butylamine (NDBA)

  • N-nitrosodi-n-propylamine (NDPA)

  • N-nitrosomethylethylamine (NMEA)

  • N-nitrosopiperidine (NPIP) 

  • N-nitrosopyrrolidine (NPYR) 

As part of UCMR 2, US EPA has identified EPA Method 521 as the method to be used for the UCMR 2 nitrosamines, and has established a laboratory approval process.

According to US EPA's fact sheet on UCMR 2:  

Laboratories interested in analyzing samples for public water systems that are subject to the UCMR 2 monitoring requirments need to register for the EPA Laboratory Approval Program.  Laboratories will then need to complete and submit method-specific application packages.  Upon review, qualified labs wil then be eligible to participate in a Proficiency Testing (PT) proram.  Laboratories that successfully complete the PT Program will be greanted method-specific approval to analyze samples once the final UCMR 2 is promulgated.  Laboratories interesting in registering for the Laboratory Approval Program shoudl send their request to:

UCMR 2 Laboratory Approval Coordinator
USEPA, Technical Support Center
26 West Martin Luther King Drive (MS 140)
Cincinnati, OH 45268

Details are available from the US EPA's website on UCMR 2 laboratories.

Last modified on: 1/23/2008 8:49 PM