The working range is 0.5 to 10 mg/m³ for a 200-L air sample. The method measures the mass concentration
of any non-volatile respirable dust. In addition to inert dusts [4], the method has been recommended for respirable coal
dust. The method is biased in light of the recently adopted international definition of respirable dust, e.g., ≈ +7% bias for
non-diesel, coal mine dust [5].