Dusts 1
Dusts 1 : Finely divided solid. Strictly speaking particles with a diameter less than 1 micron become `smoke', dust particles having diameters greater than 1 micron (1053 mm) and less than 76 microns (200 BS mesh sieve). Powder being particles with a maximum dimension of less than 1000 microns (16 BS mesh sieve). See also: Combustible Dusts and Explosibility Tests