Organisation d’une comparaison inter-laboratoires dans le domaine des essais sur les antiseptiques et les désinfectants

Centre Technologique Méditerranéen de Métrologie (CT2M) Centre des Creusets 13250 SAINT-CHAMAS

bgeynet@ct2m.fr

Abstract

CT2M (Mediterranean Metrology Technology Centre) has been requested by several ISO/CEI 17025 accredited laboratories to organize an interlaboratory comparison in the field of antiseptics and disinfectants testing according to NF EN 1275 et NF EN 1276 standards. Participating in proficiency testing is a requirement for accredited laboratories but results from precedent European campaigns could not be used by participants. The objectives of this interlaboratory comparison are to assess the laboratories ability to perform these tests, to ensure the quality of results and to estimate the measurements uncertainties. The test organisms are Candida albicans and Staphylococcus aureus according to NF EN 1275 and NF EN 1276 standards respectively. Our innovative ICL protocol takes place in two steps. During the first step, the tested concentrations of disinfectant are not imposed in order to obtain a reference value of two measurands (bactericidal activity and yeasticidal activity), leaving the participating laboratories apply their own routine procedure. During the second step, the concentrations of the disinfectant are imposed in order to better compare laboratories with each other. Successive dilutions of the initial solution / disinfectant neutralized mixture provide a quantitative result for all laboratories and let a statistical exploitation of the reduction rate R according to ISO 13528. This paper will explain the protocol proposed for this interlaboratory comparison, and the statistical treatment to establish participants’ performances scores and measurement uncertainty.