Zefon’s EoS (End of Shift) silica cassette was designed to work with the new NIOSH silica monitoring approach. This cassette is designed to work with a portable FTIR (Fourier Transform Infrared) for field-based monitoring of respirable crystalline silica. Air samples are taken using a traditional cyclone and the EoS cassette. After sampling, the inlet and outlet of the cassette are removed. The middle section is then placed into a portable FTIR for a direct-on-filter analysis. The results are interpreted through a software program developed by NIOSH called FAST (Field Analysis of Silica Tool). A pre-weighed version of the cassette can be reassembled and sent to a laboratory for respirable dust analysis.