Development of harmonised tests to be used in the European approval scheme concerning construction products in contact with drinking water - CPDW

Scientific objectives and approach: The work is divided into four workpackages (WP). The WP on microbial growth will harmonise the ATP test that is used to measure biomass formation. It will study the growth potential in different types of test waters that will be used for leaching CPDW. The effect of different types of inoculation, the effect op product cleaning by chlorination and the effect of static versus dynamic test conditions on the biomass production will be studied. Finally, real leachates of a number of CPDW will be assessed. WP2 will review the assessments of cyto- and genotoxicity to select the variables, which may improve the existing French cytotoxicity test, and to propose a proper genotoxicity test. Next the French cytotoxicity test will be armonised and real leachates of a number of CPDW will be assessed. The WP on the assessment of non-target compounds will merge the existing French and UK GC-MS procedure. Therefore, the operation conditions and QA/QC procedures will be harmonised first. Secondly, the solvent extraction procedures will be studied followed by a study on the usefulness of solid phase extraction. The selected overall GC-MS procedure will be applied on real leachates. The WP on disinfectant by-products will review the application practices of high levels of disinfectants during repair or contamination of the water distribution system in Europe. This study will lead to the selection of the level of disinfectant and contact time to be used in the experimental part. The odour and flavour, total organic carbon, absorbable organohalogens and trihalomethane formation will be studied in leachates of a number of CPDW. If necessary, GC-MS assessment for other compounds will be applied.