CNAS-EL-19：2021 Specific requirements for raw materials to be pure substances in the certification of reference material/standard sample producers (English Version)
In order to clarify the technical requirements for review when raw materials are purity substances involved in the accreditation of reference material/reference sample (RM) producers and ensure the consistency of on-site review of RMP accreditation capabilities, CNAS has specially formulated this document. This document is applicable to the assessment of all accreditation activities of the applicant/accredited RM producer in the chemical field involving the preparation of solution RM using pure substances as raw materials.