The potential pathogenicity of a specific fibre type mainly depends upon the extent to which the fibres can be inhaled and can persist in the lung. The pathogenicity of a fibre is determined by animal studies. However, the comments to the Commission Directive 97/69/EC 1997 (Classification of Man-made vitreous Fibres with Respect to Carcinogenicity) express the firm EU intention, that, to the greatest possible extent, in-vitro methods should replace in-vivo studies. The last few years have seen the development of fibre types with increased bio-solubility, that still assure the relevant product qualities for the various application areas. For this work, two pH environments, pH 7.4 and pH 4.5, found in the lung environment were simulated in in-vitro dissolution measurements. The present test guideline was worked out by two working groups established by EURIMA.
