RUBBING TEST RESPONSES OF THE SKIN TO MAN-MADE MINERAL FIBERS OF DIFFERENT DIAMETERS

The irritant potency of 5 types of insulation wools (2 types of rockwo ol and 3 types of glasswool) were studied on the basis of their differ ences in diameter by a standardized rubbing test. Assessment was done by laser Doppler flowmetry (LDF) and erythema scores. Insulation wools show a wide distribution of the diameter around the mean. Of the rock wool material, 30% consisted of small grains, called ''shot''. The con trol test site did not change over time; thus, the rubbing procedure i tself does not seem to contribute to the skin reactions. All fibre typ es proved to be irritant to the skin. The irritant reactions did not c orrespond with the mean diameter, although the fibre type with the sma llest diameter was the least irritant and the fibre type with the larg est diameter the strongest. The presence of ''shot'' had a significant effect on the LDF responses. ''Shot'' and the distribution around the mean diameter may play a role in eliciting the skin irritation by ins ulation wools.