Supporting data for an internal EPA report and peer reviewed journal article on refinement, standardization, and performance of a four-day Daphnia magna survival and growth test method. Version 1: reviewed internally by co-authors but not peer reviewed. Includes chemical analysis data, preliminary study data, raw toxicity test data, additional endpoints, and additional statistical power tables. This dataset is associated with the following publication: Kadlec, S., J. Lazorchak, D. Mount, and S. Goodrich. DAPHNIA MAGNA 4-DAY SURVIVAL AND GROWTH TEST. U.S. Environmental Protection Agency, Washington, DC, USA.