TNI Stationary Source Audit Sample Program Survey

Date Posted: 6-5-2019

TNI Stationary Source Audit Sample Program Survey

The NELAC Institute’s (TNI) Stationary Source Audit Sample (SSAS) program is seeking your input.

As you may be aware, SigmaAldrich has stopped manufacturing Stationary Source Audit Samples.  This has caused the EPA to suspend the requirement for Audit Samples to be performed with regulatory compliance testing.  ERA has indicated that they will continue to provide Stationary Source Audit Samples as long as there is sufficient demand.

From EPA’s website:

“The EPA restructured program requires that two accredited providers be available, and available audit samples must be listed on the EMC website 60 days before audits are required.”

From the Air Emission Measurement Center’s website (EMC):

“Since there are no longer two providers, the requirement to obtain these audit samples is no longer in effect until such time as another independent AASP has audit samples available for purchase.”
The SSAS Committee has gotten feedback from a handful of regulators and testers.

Some regulators have indicated that, while they cannot require an audit sample be run with a given testing plan, they intend to strongly encourage the continued use of audit samples.
Some testing firms have indicated that they intend to continue to purchase and run audit samples as a means of generating more defensible data.

The TNI SSAS Committee is a voluntary group which created a Standard for Audit Providers, Provider Accreditors, and Testers and Laboratories, to ensure that the Audit Program was being followed in a manner consistent with generating well documented data of high integrity.  The SSAS Committee has no authority over the requirement for audit samples to be run with regulatory compliance testing.

The TNI SSAS Committee is responsible for the following:

  1. Managing the Standard which applies to the production of SSAS Audit Samples (Module 1);
  2. Managing the Standard which applies to the accreditation of Audit Providers (Module 2); and,
  3. Managing the Standard which applies to the use of the Audit Samples by Facilities, Testers, and Laboratories.

TNI supports this program by maintaining the SSAS Database and by providing staff support to the committee. The TNI SSAS Committee is actively working to revise the consensus standards that control this program, to update acceptance limits, and to address technical issues such as the poor performance for EPA Method 8.  In addition, the TNI SSAS Committee has recently been working on creating Standard Operating Procedures to provide a means of expanding the concentration ranges of Audit Samples, particularly at the low end of the concentration range, as well as creating a consensus set of statistical analyses to demonstrate that audit concentration ranges are applicable to the methods.

Since this program started in 2013, 21,730 Audit Sample results have been returned by 114 laboratories, with an average pass rate of 97.6%.  Roughly 75% of the Audit Samples were analyzed by ten laboratories, consequently, those ten laboratories may be skewing the pass/fail rate of all Audit Sample results reported.

Until recently, 215 regulators in 47 states, including all EPA regions, participated in the program.  At this time, the EPA lacks the resources to manage this program in a manner similar to how TNI is managing the program.  It is likely that without the TNI SSAS program, there will be no oversight of the program.

We would like your feedback regarding the TNI SSAS program and whether you feel this program is still a necessary component of what is now a voluntary Source Sampling Audit program.  In particular, we would like to know if:

  1. You feel that the TNI SSAS Committee has been a viable mechanism for supporting the EPA regulations regarding Audit Samples;
  2. You feel that the EPA’s audit program adds value to source testing in general;
  3. You feel that the cost of the program to the facilities reflects the benefits of the program;
  4. You plan on continuing to promote the use of audit samples for regulatory compliance testing projects or testing events; and,
  5. You have suggestions for how to improve the TNI SSAS Program.

Please go to the TNI website, under “News”, and click on the SSAS Program Survey ( to submit your comments, feedback, answers and concerns.  As we are seeking the most feedback we can obtain in this matter, please feel free to forward this message to whomever you feel has an interest in the outcome. Please respond no later than July 15, 2019. The feedback will be compiled and discussed during future TNI SSAS Committee meetings.

The TNI SSAS Committee’s meetings are open to the public and we value your input.  We usually meet by conference call at 2pm Eastern on the third Monday of each month.  There will be a public meeting held on Tuesday, August 6, 2019, at the TNI Summer Conference in Jacksonville, Florida.  If you would like to participate in the meetings or join the Committee, please contact any member of the Committee ( ) and we will make sure you get invitations to join the meetings.


Sheri Heldstab
Vice Chair, TNI SSAS Committee