Airborne polyvinyl alcohol (PVA) and cellulose fibre levels in fibre-cement factories in seven European countries

Because of their relatively high diameter, polyvinyl alcohol (PVA) fibres, as used in fibre-cement, are not fibres as defined by WHO (or other) regula tions. Nevertheless, as with all particulate raw materials, it can be quest ioned if and to what extent particles with critical fibrous dimensions migh t be generated by the handling or machining of this material. In order to i nvestigate any tendency of PVA fibres to release airborne particles with cr itical fibrous dimensions (WHO fibres), static and/or personal samples were taken in eight fibre-cement factories at locations where potential exposur es to PVA fibres were expected to be the highest. The following locations w ere surveyed: the PVA fibre weighing station, where PVA bales are opened me chanically and the PVA fibres are dispersed and weighed in a dry state; the fibre-cement slate punching machine; the slate 'riven edge' cutting machin e or sheet sawing machine, whichever was present in the respective factorie s. Since cellulose fibres are an important constituent of fibre-cement, the organic fibre concentrations observed at the machining operations include cellulose. At each factory a control sample was taken in open air. Sampling , sample preparation and sample analysis by scanning electron microscopy (S EM) were performed according to standard German procedures. Only very low n umber concentrations of organic WHO fibres, ranging from below detection li mit to 0.006 f/ml, were found. These levels are lower than the typical leve ls of organic fibres commonly found in the normal personal environment (0.0 09-0.02 f/ml), stemming from the release of particles by a person's activit ies and from clothing and other textiles (bed sheets, blankets, pillow,...) . We conclude that the handling of PVA fibres as well as the machining of PVA and cellulose fibre containing cement products in the fibre-cement factori es surveyed have a low potential to release fibres with critical fibrous (W HO) dimensions. (C) 2001 British Occupational Hygiene Society. Published by Elsevier Science Ltd. All rights reserved.