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Standard Interpretation

Standard: 2009 TNI
Section: V1M4, Section and (b)


A laboratory in our program states that it is using "marginal exceedences" as part of its evaluation criteria for determining initial demonstrations of capability. The question is "Is the use of 'marginal exceedences' as described for evaluation of laboratory control samples also allowed for the evaluation of data associated with initial demonstrations of capability?" Thank you for your assistance.


(Quality Systems Expert Committee and NELAP AC, 2-24-14)

The 2009 TNI Standard requires that all analytes meet the corresponding acceptance criteria for precision and accuracy stated in the method (if applicable) or in laboratory-generated acceptance criteria (if there is not a reference method with established mandatory criteria) for an Initial Demonstration of Capability (IDOC) prior to the analysis of actual samples. If any one of the analytes does not meet the acceptance criteria, the performance is unacceptable for that analyte.