Hawaii Department of Health updated its interim Environmental Action Levels (EALs) for PFAS, adding HFPO-DA (GenX) to the 'Primary Terminal PFASs' category due to its recalcitrance to breakdown in the environment and TOPs processing. The guidance establishes action levels for over 24 PFAS compounds including PFOA (4 ppt), PFOS (4 ppt), PFHxS (10 ppt), PFNA (10 ppt), HFPO-DA (10 ppt), and others with levels up to 18,000 ppt. Hawaii's EAL guidance is considered one of the most comprehensive PFAS screening frameworks in the United States, incorporating Total Oxidizable Precursors (TOPs) testing, Total Organic Fluorine (TOF) methods, and a Hawaii-specific calculator for cumulative risk assessment from complex PFAS mixtures.