The Joint Research Centre (JRC) of the European Commission develops certified matrix reference materials for laboratory diagnostics, environmental and food analytics, as well as industrial quality control. We offer a wide range of materials, from markers for Alzheimer's in cerebrospinal fluid to polybrominated biphenyl ethers in fish and sediment, from pesticides in vegetables and cereals to heavy metals in environmental samples and metals/alloys. Our certificates clearly specify traceability and uncertainty of the certified values. In the certification report for each certified reference material (CRM) , the material processing, homogeneity, stability and characterisation studies are described. All CRMs are produced according to the ISO 17034 accredited quality system.