Investigation on the biodurability of chemically different stone wool fibres

The biodurability is one of the essential factors for a carcinogenic potential of mineral fibres. The in vivo solubility of commercial fibre products can be influenced by systematic modification of the chemical composition. Two types of experimental stone wool samples with increased magnesium and decreased aluminia content were compared to a commercial stone wool sample. Sized fractions of these samples were intratracheally instilled in female Wistar rats. Five animals per group were sacrificed after 2 days, 1, 3, 6, and 12 months. After low-temperature ashing of the lungs about 200 fibres were analysed in SEM for length and diameter per animal. Number of fibres in the total lung was calculated.