Dustiness of different high-temperature insulation wools and refractory ceramic fibres

Recent regulations are encouraging the replacement of older types of man-ma de mineral fibre by more soluble and, thus, less biopersistent compositions . In order for there to be any health benefits from this policy and to gain maximum benefit from such substitutions, the use of the new materials shou ld not increase exposure. The work reported here was undertaken to investig ate the use of new high-temperature glass insulation wools in place of refr actory ceramic fibres (RCF), Airborne fibre levels occurring during the man ufacture of both RCF and calcium magnesium silicate wools (CMS) were compar ed using measurements of genuine workplace exposure from a routine monitori ng operation on the same plant. Exposures during use were compared in one c ustomer facility where RCF and CMS blankets were used for the same task. Fu rther comparisons were made in a laboratory test of dustiness using a "shak ing box test", For some manufacturing tasks there are only a few workplace samples and there are few opportunities for genuine comparisons with both R CF and CMS in identical uses. However, both materials produced very similar exposure levels during manufacture, use and in the laboratory test. The no vel magnesium silicate fibre was significantly dustier in the laboratory te st. (C) 2001 British Occupational Hygiene Society. Published by Elsevier Sc ience Ltd. All rights reserved.