1.1 This guide covers the analysis and interpretation of proficiency test (PT) program results. For participants in interlaboratory proficiency test (or crosscheck, check scheme, etc.) programs, this guide describes procedures for assessing participants' results relative to the PT program results and potentially improving the laboratory's testing performance based on the assessment findings and insights (see ). For the committees responsible for the test methods included in interlaboratory proficiency testing programs, this guide describes procedures for assessing the industry's ability to perform test methods, and for potentially identifying needs for test method improvement (see 6.2).

This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.