Accredited laboratory

An accredited laboratory is one that an independent accrediting body has assessed against a published standard and found competent to perform specific tests.

The usual standard for testing laboratories is ISO/IEC 17025, and the assessment covers methods, equipment, calibration, staff training, record keeping and participation in proficiency testing. Accreditation is granted for a defined scope of tests and is reassessed on a schedule. A laboratory that is merely licensed or registered with a state, or that describes itself as certified, is not necessarily accredited.

Not every laboratory producing certificates of analysis for hemp products is accredited, and a certificate does not always say. The accrediting body's logo or certificate number, if present, is the clue, and scopes can be looked up on the body's website. An accredited laboratory's results carry more weight because its methods have been examined by outsiders, though accreditation does not by itself make any individual result correct. Asking a company which laboratory it uses is a reasonable question.