This guidance provides recommendations for biological product, drug, and device firms on FDA’s current thinking concerning the testing recommendations and acceptance criteria in the United States Pharmacopeia (USP) Chapter <85> Bacterial Endotoxins Test, USP Chapter <161> Transfusion and Infusion Assemblies and Similar Medical Devices,and the Association for the Advancement of Medical Instrumentation (AAMI) ST72:2002/R2010, Bacterial Endotoxins—Test Methodologies, Routine Monitoring, and Alternatives to Batch Testing (AAMI ST72).