This SOP establishes the requirements for viable air sampling in sterile compounding areas—including use of volumetric impaction samplers, TSA and SDA/MEA media, defined sampling locations (PECs, buffer rooms, anterooms, passthroughs), incubation at specified temperatures, documentation of CFU results, and corrective actions for alert and action level excursions—to ensure environmental quality, contamination control, and compliance with USP <797> and <1116>.