; and (2) to provide guidance on designating perfluoroalkyl or polyfluoroalkyl substances as essential or nonessential. (b) Agreement (1) In general Not later than 60 days after the date of enactment of this Act, the Administrator (in consultation, as the Administrator determines appropriate, with the heads of other Federal departments and agencies with relevant expertise regarding the essential uses of perfluoroalkyl or polyfluoroalkyl substances) shall seek to enter into a 10-year agreement to carry out the duties described in this section. (2) Extension The Administrator and the National Academies may extend the agreement described in paragraph (1) in 5-year increments. (c) Review of scientific evidence (1) In general Under an agreement under subsection (b), the National Academies shall, in accordance with the policy described in section 103(a), review and summarize the scientific evidence, and assess the strength of that scientific evidence, with respect to— (A) uses of perfluoroalkyl or polyfluoroalkyl substances that should be designated as essential uses; and (B) the criteria for designating essential uses. (2) Inclusions In carrying out the review described in paragraph (1), the National Academies shall— (A) analyze the definition of the term essential use under section 2(3) as it relates to perfluoroalkyl or polyfluoroalkyl substances; (B) conduct an assessment of how perfluoroalkyl or polyfluoroalkyl substances are integrated into the society of the United States, in which sectors of the economy of the United States perfluoroalkyl or polyfluoroalkyl substances are used, and in which sectors those uses are essential uses; (C) describe any research gaps with respect to the uses of perfluoroalkyl or polyfluoroalkyl substances, including consideration of mitigation strategies and safer alternatives; and (D) develop recommendations with respect to— (i) the research and development activities necessary to transition the United States from the use of perfluoroalkyl or polyfluoroalkyl substances