The accuracy of chemical oceanographic measurements depends on calibration against reference materials to ensure comparability over time and among laboratories. Several key parameters lack reference materials for measurements in seawater, particles in the water column, and sediments. Without reference materials it is difficult to produce the reliable data sets or long-term baseline studies that are essential to verify global change and oceanic stability. Chemical Reference Materials : Setting the Standards for Ocean Science identifies the most urgently required chemical reference materials based on key themes for oceanographic research and provides suggestions as to how they can be developed within realistic cost constraints. Chemical analyses of seawater are uniquely difficult given the poorly known speciation and the low concentration of many of the analytes of interest. Analyses of suspended and sedimentary marine particulate materials present their own distinct challenges, primarily due to potential interference by predominant mineral phases of different types. Of all the analytical methods applied to marine waters and particles, at present only a small fraction can be systematically evaluated via comparison to reference materials that represent the appropriate natural concentrations and matrices. Specifically, the committee was charged with the following tasks: - compile from available sources a list of important oceanographic research questions that may benefit from chemical reference standards; - create a comprehensive list of reference materials currently available for oceanographic studies; - identify and prioritize the reference materials needed to study the identified research questions; - determine for each priority analyte whether reference materials and/or analytic methods should be standardized; and - identify the most appropriate approaches for the development and future production of reference materials for ocean sciences.