Standard: 2003 NELAC
Link to relevant standard
Question via email to Carl Kircher, May 8, 2008:
Based upon a question from a customer I checked the FOT tables and NELAC Chapter 2 and I can't find a requirement for evaluation of "less than" (<) values. This was in the Criteria Document and I think was supplemented by a NELAC Board policy both or which would be invalid now. If you agree, I think the PT Board needs to implement a Policy on "less than" reporting immediately to fill the gap until the TNI Standard, which is very poor, in this area is implemented.
Response from Carl Kircher May 8, 2008:
I think this issue is more in the domain of the NELAP Board since the Accreditation Bodies make laboratory accreditation decisions based on the PT results. I do know that the NELAP Board is collecting all the former NELAC Board FAQ decisions, as well as the old NELAC AAC decisions / policies. The purpose, I think, is to use those decisions and policies within the auspices of TNI until the TNI PT Standard is accepted for use. I also think that the TNI Lab. Accreditation System Committee may put forth a recommendation on how AB's should handle PT results based on "less than" reported laboratory results (along with any recommendations on PT sample participation frequency). If you want my opinion as one Analytical Chemist, I can provide that opinion in a separate e-mail.
TNI FINAL RESPONSE:
(PT Board / NELAP Board, 10-11-09)
The TNI PT Board concurs with the need to define a policy, as a stop gap measure until such time as the TNI Standard Volume 3 is implemented, on the evaluation/scoring of PT results reported as "less than" (<) or zero values. This new policy will replace previous policy as outlined in the NELAC BOD Policy #16 (effective 12/14/2000) and the EPA National Standards for Water Proficiency Testing Studies Criteria Document (January 31, 2001). The drafting of a policy document on this topic by the PT Board is now underway. Once completed, this new policy document will be recommended to the Policy committee and TNI Board for adoption.