This document specifies a method to quantify and identify air concentration (number of particles/cm³) of particles of either carbon black or amorphous silica, or both, by size in air samples collected in a mixed dust, industrial, manufacturing environment.

This method is applicable to air samples collected with an electrical low pressure cascade impactor (ELPCI) for sampling in manufacturing environments where there are a variety of particle types contributing to the overall atmosphere. This method is applicable only to environments with chemically and physically distinct particles contributing to aerosols or where confounders can be controlled (e.g. diesel sources).