Fumed Silica Particle Deagglomeration Associated with Instrument Techniques

Fumed silica is used in insulation products because of its thixotropic properties and low thermal conductivity. Exposures to crystalline silica are of most concern, but there is evidence that exposures to nanometer sized fumed silica may also lead to adverse health outcomes. Direct reading real time instruments are used to assess concentrations of airborne particles, they often contain an aerosol pre-separator-cyclone, which may cause measurement variation by dispersing agglomerated particles. The cyclone effect was determined by evaluating three instruments measuring airborne fumed silica as a case study. This result indicated that the measured nanoparticle concentrations of fumed silica increased with cyclone use, thus correction should be made for measuring fumed silica using cyclone attached instrument.