The National Defense Authorization Act for Fiscal Year 2020 (FY 2020 NDAA) was signed into law on December 19, 2019. Section 7361 of the FY 2020 NDAA directs the U.S. Environmental Protection Agency (EPA) to publish interim guidance on the destruction and disposal of perfluoroalkyl and polyfluoroalkyl substances (PFAS) and materials containing PFAS and to update the guidance at least every three years, as appropriate. The EPA is releasing an update to the December 20, 2020, interim guidance for public comment. The updated guidance builds on information pertaining to technologies that may be feasible and appropriate for the destruction or disposal of PFAS and PFAS-containing materials. The 2024 interim guidance also identifies key data gaps and uncertainties that must be resolved before the EPA can issue more definitive recommendations about PFAS destruction and disposal technologies.