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Accreditation vs. Certification

The terms "accreditation" and "certification" are sometimes used interchangeably, however, they are not synonymous. Certification is used for verifying that personnel have adequate credentials to practice certain disciplines, as well as for verifying that products meet certain requirements.

NVLAP is a system for accrediting laboratories found competent to perform specific tests or calibrations or types of tests or calibrations. NVLAP is not a certifier of test data, a certifier of products, or an operator of a certification program.

Accreditation is used to verify that laboratories have an appropriate quality management system and can properly perform certain test methods (e.g., ANSI, ASTM, and ISO test methods) and calibration parameters according to their scopes of accreditation.

NVLAP accreditation covers both the management system of a laboratory and the technical capabilities of a laboratory. The assessment of laboratories is performed to check compliance with the requirements of ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories.  NVLAP, as a member of the International Laboratory Accreditation Cooperation (ILAC) and a signatory to the ILAC Mutual Recognition Arrangement, performs the assessment and offers accreditation services in conformance with the requirements of ISO/IEC 17011, Conformity assessment - General requirements for accreditation bodies accrediting conformity assessment bodies.

Upon satisfactory assessment and successful completion of proficiency testing (where applicable), the laboratory is issued a Certificate of Accreditation along with a Scope of Accreditation listing the test methods or calibration parameters that the laboratory is accredited to perform. The NVLAP accreditation period is one year. To renew its accreditation, a laboratory must demonstrate that it continues to satisfy all NVLAP requirements for accreditation.

For more information about NVLAP accreditation, visit the NVLAP website at

Created June 11, 2010, Updated May 31, 2023