Protecting Firefighters from PFAS Act This bill addresses firefighter and veteran exposure to perfluoroalkyl and polyfluoroalkyl substances, commonly referred to as PFAS. These substances are man-made and may have adverse human health effects. A variety of products contain the compounds (e.g., weatherproof clothing). The bill authorizes the use of pre-disaster hazard mitigation funding for the remediation of PFAS at fire training facilities. The National Institute of Standards and Technology in the Department of Commerce must commence a study and report on the contents and composition of new and unused personal protective equipment worn by firefighters in relation to PFAS. For certain conditions associated with exposure to PFAS, the bill provides eligibility for Department of Veterans Affairs (VA) hospital care and medical services to veterans who served on active duty at military installations at which individuals were exposed to PFAS. Service by veterans as reservists or civilian firefighters shall be considered active duty service for eligibility purposes if such service occurred during a period specified by the VA on the applicable military installations. The bill also provides eligibility for VA hospital care and medical services for exposure-related conditions to the family members of such veterans and civilian firefighters. The bill establishes a presumption of service-connection for specified illnesses or diseases related to PFAS exposure that manifest in veterans (including reservists or veterans serving as civilian firefighters) who served on active duty at a military installation where they were exposed to PFAS. Under a presumption of service-connection, specific conditions diagnosed in certain veterans are presumed to have been caused by the circumstances of their military service. Health care benefits and disability compensation may then be awarded.