Stage 8 — Safety Screening
Stack limits and ambient guidelines are different things. A stack limit caps what leaves the chimney (mg/Nm³). An ambient guideline caps what people breathe after dispersion, across every source in the airshed (µg/m³). A design can meet every stack limit and still sit in an airshed that breaches the ambient guidelines — which is when an authority imposes something stricter than the table.
Combustible dust screening runs off the Stage 1 dust properties — nothing to enter here. Set flammable and, where you have a laboratory result, Kst on Stage 1.