Measuring the radioactivity of organically bound tritium in environmental samples is difficult. For the past twenty years, many laboratories have been working on the development of reliable tritium measurement methods. In this context, several interlaboratory comparisons have been organised to develop these methods and enable laboratories to compare themselves. However, the trueness of the measurement methods has never been estimated due to the lack of certified reference materials available for use during the analyses. This document presents the production of the first certified reference material for the measurement of organically bound tritium radioactivity in environmental samples.