NIOSH suggests reducing the exposure limit, provide respirators where needed, find a substitute if possible and conduct more research.
NIOSH reviews crystalline silica hazards
June 21, 2002
NIOSH's study notes that there is a substantial risk of a worker contracting silicosis if exposed to crystalline silica over a lifetime at the current OSHA permissible exposure limit. This substance is also believed to cause lung cancer, emphysema, bronchitis, upper respiratory ailments and autoimmune disease.