U.S. Code / Title 15 — Commerce and Trade / Chapter 115—Perfluoroalkyl and Polyfluoroalkyl Substances and…Title 15SubchapterSubchapter Iii—Usgs Performance StandardContents§ 8931. Definitions§ 8932. Performance standard for the detection of highly fluorinated compounds§ 8933. Nationwide sampling§ 8934. Data usage§ 8935. Collaboration