Abrasive blasting operations in San Diego commonly use silica sand, steel grit, garnet, steel shot, shot peen, slags, walnut shell, glass bead, and aluminum oxide as blast materials. A variety of blast materials may be used on a wide range of coated and uncoated parts at one or more locations within a facility. These operations produce particulate matter emissions composed of the blast material, trace contaminants in the blast material, paint pigments, scale, and/or rust. The particulate emissions may contain varying concentrations of crystalline silica, aluminum, arsenic, cadmium, copper, chromium, iron, lead, manganese, nickel, zinc, and inert substances. Process parameters that affect emission rates include type of blast material, blast equipment, velocity, blast angle, distance to part, part dimensions, and dust controls. Accurate emission estimates require an evaluation of the blast area, procedures, and control equipment to determine particulate generation, collection, and removal efficiencies.