Abstract
The presence of respirable glass fibers in the dust from grinding, drilling and cutting of reinforced polyester plastics was investigated. The results show that 10% of the Swedish Threshold Limit Value (TLV®) for synthetic inorganic fibers (3 fibers/mL) seldom will be exceeded. On the other hand, the results indicate that the Swedish TLV for thermosetting plastic dust (3 mg/m3) will be exceeded quite often. The authors examined the possibility of longitudinal glass fiber division during the working of reinforced polyester plastic and whether respirable glass fibers were produced. The results show that such a division does not occur for glass fibers embedded in polyester plastic and that the respirable fibers are related to fiber-shaped plastic particles or organic fiber particles.