We recently added the following to the Aircraft Rescue and Fire Fighting page on the FAA website.

Part 139 CertAlert 23-01: New Military Specification for Performance-Based Standards for Fluorine-Free Aircraft Fire Fighting Foam
On January 12, 2023, the Naval Sea Systems Command (NAVSEA) released Military Specification MIL-PRF-32725, Fire Extinguishing Agent, Fluorine-Free Foam. This CertAlert provides guidance to airport operators about the use of Fluorine-Free Foam (F3).

Notice:
Be sure to check out Report DOT/FAA/TC-22/29: UASs for Live Monitoring to Enhance Situational Awareness During an Aircraft Rescue and Firefighting Response, released in July 2022. The FAA will be discussing this report at the 2023 ARFF Training Alliance ARFF Leadership Symposium (February 26-March 1).