Preparation and handling conditions of MMVF for in-vivo experiments

The fundamental prerequisite conditions in standardized testing of man-made vitreous fiber (MMVF) as formulated in the European Commission Directive 97/69/EC (1997) are as follows: c The distribution of diameter and length as prescribed for the test material represents the situation found at workplaces. c The amount of test material required for the several test assays as prescribed in the directive lies in the range of 100 grams to kilograms. A procedure has been developed for the production and preparation of MMVF samples that are representative of commercial insulation wool fiber types and suitable for experimental purposes. The diameter distribution is controlled by the fiberizing procedure, but the length distribution is controlled by using a dry compression procedure in one or two steps. Nonfibrous particles are partially removed by a differential sedimentation procedure using dry alcohol as a dispersion media. For inhalation and artificial applications respectively, control of the concentrations in the aerosol, control of the concentrations in dispersions, and reproducibility are described.