SCREENING MAN-MADE VITREOUS FIBRE EXPOSURES BY GRAVIMETRIC DUST MEASUREMENTS

In most studies of exposures to man-made mineral fibres both fibre number and total mass concentration have been measured, but, generally, correlations between these measures were found only for data pooled by plant or activity rather than for individual samples; also, there were differences between fibre types. Gravimetric measurements have practical advantages and suggestions have been made to approach MMMF exposure evaluation either on a dual gravimetric/fibre count basis or by use of a gravimetric screening test. This paper describes Danish experience in the derivation and performance of a gravimetric screening limit value (SLV) as against a ‘correct’ hygienic index which combines both respirable fibre and total mass concentrations. The system is considered to have many advantages, but the adopted SLV should be checked before use under new or changed conditions.