This study was commissioned to produce a protocol or guidance manual for waste management and -regulation organisations carrying out the determination of red list substances in leachate. This was to comprise draft analytical methods based on current best practice for each substance, together with method performance data derived from round robin testing. Recommendations for the statistical interpretation of data were also required, including information on estimating the significance of measurements made at levels close to statutory limits. A range of quasi-reference materials with known analyte levels was needed for the study in order to carry out the round robin tests and for subsequent use by analysts determining red list analytes in leachates. Analytes which were shown in the round robin tests to be impossible to measure at the required concentrations were to be identified so that future method development could be targeted on these analytes.