LCS Laboratory offers air sampling equipment, laboratory testing, and comprehensive laboratory reporting for the assessment of air quality and potential exposure to crystalline silica.
Silica or Silicon Dioxide, is a white polymorphous material. Silica is very common and it’s concentration in soil and construction materials varies from a few percent (soil, clay, limestone) to 30-100% in gravel and sand. Silica can be found in amorphous or crystalline forms. The amorphous form of silica is natural mineral Opal or man made Silica Gel. The most common form of crystalline Silica is alpha-Quartz, which represents more than 99% of geological deposits of silica. A typical example of pure quartz is sand. The second most common natural form is Cristobalite, which is a high temperature modification of quartz recrystallized in volcanic lava. For example, Cristobalite can be found as inclusion in volcanic obsidian.
Workers can be exposed to crystalline silica during any production activity where sand or natural rocks are used: demolition, cement production, mining, metal forging, metal casting, tool making, and so on. Only a very fine fraction of crystalline silica (with a particle size smaller than 10 microns) is dangerous. This fraction of dust is called “respirable” because it can penetrate deep into lungs. There are several standard methods for the measurement of crystalline silica. The most common is a method where a personal sample of respirable dust is collected with a sampling cyclone on a 37 mm cassette and a PVC filter in accordance with the NIOSH 7602 method. The cyclone removes large quartz particles from the air stream and allows us to collect the respirable fraction only on the filter. The sampling procedure is relatively simple and can be seen here.
To order the supplies for silica sampling, or to discuss your project, please email LCS Laboratory Inc.
