The new range of FAPAS Reference Materials brings an increased measurement certainty for our customers. The implementation of quality control procedures in a laboratory is always recommended, whether or not this is driven by formal accreditation to the relevant standard. The quality control monitoring should include participation in FAPAS proficiency testing programmes and/or the use of reference materials. Monitoring and reviewing the resultant data has to be a planned activity for accredited laboratories. These matrix-matched reference materials are an essential tool for quality assurance, method validation and training.