What is a USP Certified Reference Material (CRM)?
A USP Certified Reference Material (CRM) is a USP Reference Standard (RS) with a “pedigree”. It should be used as a USP RS. A CRM is a special class and the next generation of a USP Reference Standard (RS) that has undergone additional metrologically-based testing and statistical analysis. The USP CRM is issued with a Certificate of Analysis (CoA), listing a certified property value with its associated uncertainty, expiration date, and other information, according to ISO Guide 31[1]. The one or more property values are certified by a procedure which establishes its traceability to an accurate realization of the unit in which the property values are expressed [2].
