The International Laboratory Accreditation Convention (Ilac) says only suppliers complying with both ISO 17025 and ISO Guide 34 are recognised as accredited suppliers of Certified Reference Materials
Ukas, the UK accreditation body, currently lists only five such approved manufacturers in the UK.
Optiglass , manufacturer of Starna CRMs, is the only listed supplier of UV and visible spectrophotometry references, and produces a comprehensive range of Nist traceable references for wavelength, photometric accuracy, resolution and stray light.
A wide selection of heat-sealed liquid references covers the ultra-violet and visible spectrum, and includes new specially developed reference materials for the important far-UV region.
Traditional didymium, holmium oxide and neutral density glass filters are also supplied.
These products also carry a lifetime guarantee.
John Hammond, technical manager for analytical products at Optiglass, explained: "The Guide 34 accreditation involved a detailed statistical analysis of the extensive stability and homogeneity data we had already accumulated on CRM's as part of our existing ISO 17025 procedures, and a formal review of all associated customer feedback activities.
"As a result of this exercise we can now offer the end-user a lifetime guarantee on Starna CRMs, providing they have been used and stored correctly, and have been re-certified every two years."
