Reference data sets of species sensitivities to compare the results of fitting species sensitivity distributions using software such as ssdtools and Burrlioz'. It consists of curated data sets for individual chemicals from Australian, New Zealand and Canadian organizations, several data sets from anonymous sources, and larger uncurated compilations drawn from the ANZTOX, WQBench and EnviroTox databases. It also includes a data set of the results of fitting various distributions using different software.