This article focuses on the new data protection requirements of the EU's Biocidal Products Regulation (BPR), in the context of a comparison with equivalent provisions of the U.S. Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). The basic protections made available for studies submitted to support biocidal active substances and products under the BPR appear in many respects more limited than the data protections that U.S. pesticide registrants are accustomed to under FIFRA. Moreover, the untested nature of many of these requirements may pose challenges for both EU authorities and the regulated community alike, as data compensation disputes -- including disagreements over the level of effort used to resolve such disputes -- are examined and decided in the future by any number of national courts in the EU.