SILICA (CRYSTALLINE, RESPIRABLE) - OEHHA
manufacture of heat insulators, firebrick, and fire- and acid-proof packing materials. As diatomite (naturally occurring diatomaceous earth), silica is used as a filtration agent, as an abrasive, and as an industrial filler. Sources of ambient respirable crystalline silica in CaliforniaBy Gordon T. Austin - USGS Mineral Resources Program,By Gordon T. Austin Tripoli The category of tripoli, as broadly defined, is,Manufacture of these properties and end uses such as rottenstone and products was from novaculite, quartzite, or,Quarry Crude silica stone. Norton Company Oilstones: Hot Spring, AR do. Do.SILICA DUST, CRYSTALLINE, IN THE FORM OF QUARTZ OR,,of crystalline silica in the earth’s crust and the wide uses of the materials in which it is a constit - uent, workers may be exposed to crystalline silica in a large variety of industries and occupations (IARC, 1997). Table 1.2 lists the main industries and activities in which workers could be exposed to crystalline silica.