The AQD derived health-based screening levels for PFOA, PFOS and 6:2 fluorotelomer sulfonic acid (6:2 FTS). For PFOA and PFOS, the screening levels are 0.07 micrograms per cubic meter (µg/m³) with a 24-hour averaging time. If both PFOA and PFOS are present in the air emissions, the combined concentration of these substances must be below 0.07 µg/m³ with a 24-hour averaging time. The screening level for 6:2 FTS is 1 microgram per cubic meter (µg/m³) with an annual averaging time. Screening levels are health protective values, such that if air concentrations do not exceed these levels, adverse health effects are not expected. Screening levels are designed to be protective for sensitive individuals, including children and the elderly. Additional screening levels could be developed as other PFAS are identified in future permit applications.
PFOS
PFOA
6:2 FTS