NVLAP Lab Bulletin LB-161-2025

Department of Commerce
National Institute of Standards and Technology
National Voluntary Laboratory Accreditation Program

Issue date:     August 4, 2025
Number:         LB-161-2025
LAP:                   Asbestos Fiber Analysis
Subject:          Release of NIST Handbook 150-3, 2025 Edition

NIST Handbook 150-3, which represents the technical requirements for the accreditation of Polarized Light Microscopy (PLM) testing laboratories under the NVLAP Asbestos Fiber Analysis Laboratory Accreditation Program, has been revised. The new edition was revised with the participation of NIST technical experts for the represented PLM testing parameters.

The following main changes have been made to this handbook with respect to the previous edition:

• The numbering has been updated to reflect that used by ISO/IEC 17025:2017, General requirements for the competence of testing and calibration laboratories; (hereafter referred to as ISO/IEC 17025);
• all references to applicable international guides and standards have been updated;
• Laboratory Bulletins previously issued for clarification, have been incorporated into this edition of the handbook; and
• On-site assessment checklists and the test method selection list are no longer included as they are provided as separate documents.

The 2025 edition of NIST Handbook 150-3 supersedes and replaces the 2006 edition. It is available on the NVLAP website. As these revisions are updates, this edition is effective immediately for all PLM testing asbestos laboratories.

The NIST Handbook 150-3 Checklist has also been updated and is available in the NVLAP Interactive Web System (NIWS) Portal.

Please contact your program manager, Derek Ho (derek.ho [at] nist.gov (derek[dot]ho[at]nist[dot]gov)) or Shelby Williamson (Shelby.conyers [at] nist.gov (Shelby[dot]conyers[at]nist[dot]gov)) for questions concerning the revised handbook or requirements for accreditation.