A summary report on environmental conditions at 13 European man made mineral fibre plants

A full description of a series of environmental surveys was carried out at 13 European Man Made Mineral Fibre Production Plants on behalf of the Joint European Medical Research Board. The principle aim of these surveys was to determine the airborne fibre concentrations and fibre size distributions. This report summarises the fibre number and mass “”concentration”” data, along with brief description of the fibre size data from the rockwool and glasswool plants, the size data will be published elsewhere.At each plant a series of occupational groups was identified. Representatives from each occupation were selected on a stratified random sampling basis and their personal exposure monitored using the membrane filter technique. The methods used throughout these surveys were uniform and consistent with those used in similar studies carried out in the USA by the Thermal Insulation Manufacturers Association (TIMA).For the six plants producing rockwool the average respirable fibre concentrations for the main occupational groups was approximately 0.04 fibres/ml while the corresponding concentration for the four glasswool plants was 0.02 fibres/ml. The average respirable fibre concentration for the same occupations at the three continuous fibre plants was 0.004 fibres/ml. The highest fibre concentrations were observed in specialised secondary process groups, particularly where fine fibres were being produced. For these specialised secondary processes the group average fibre concentrations ranged from 0.03 fibres/ral to 0.45 fibres/ml. The average mass concentrations for the various occupations within all 13 plants ranged from 0.3 mg/m3 to 7.87 mg/m3 . The highest respirable fibre concentration recorded in all 13 surveys was 1.89 fibres/ml. These measured mass and fibre concentrations were in good general agreement with the results from the TIMA. studies at mineral wool plants in the USA. For the rockwool and glasswool factories the plant median fibre lengths were within the range 8μm to 20μm while the median diameters were within the range 0.7μm to 2μm. “”