[Evaluation of the biological effect of polishing powders]

Polishing powders are applied as abrasives at the treatment of various metal surfaces prior to their electroplating. The polishing powder is composed of: technical paraffin, dibutyl phthalate, technical borax, ammonium sulfate, aloxite or corundum and, as a carrier, sawdust of decidous or coniferous trees. Evaluated were: exposure to the polishing powder dust of workers operating polishing machines, as well as fibrogenic properties of the powder in an experiment on animals polishing machines, and irritating and allergic effects upon human skin (determination of irritation halftime, rubbing, damping and epidermal tests). The results demonstrated that the mean geometric concentrations of the dust ranged from 3.1 to 6.4 mg/m3 of air, whereas the dust respirable fraction constituted approx. 20% of the total dust concentration. The content of free crystalline silica in the dust did not surpans 2%. In the experiment on animals the dust exhibited cytolytic effects and induced reactive lesions in form of granulomas. The content of hydroxyproline in rats' lungs when affected by the polishing powder approximated the values obtained with quartz of weak fibrogenic properties. Basing on dermatological studies, the irritating effects of the polishing powder were defined as medium, whereas the allergic effects as weak.