Glass fiber exposure assessment during ceiling installation by European Standard EN 689: study of airborne fiber distribution

Synthetic vitreous fibers belong to a class of inorganic fibers that include glass wool, rock and slag wool, and refractory ceramic fibers. They are used as thermal and acoustical insulation. The aim of this work is to evaluate the exposure of installers of ceiling panels to glass fibers and to study the size distribution of airborne fibers during working day. Thirty two personal samplings were carried out during the installation of pressed mineral wool panels employed as false ceilings. The fibers collected on the filter were analyzed and measured by scanning electron microscope equipped with energy-dispersive X-ray analysis. Four workers were investigated for eight working days. The mean exposure value was around 0.006 fiber/cm3 with a maximum value of 0.036 fiber/cm3. The worker exposure evaluated by EN 689 was always below the threshold limit value set by American Conference of Governmental Industrial Hygienists (1 fiber/cm3). The experimental data were analyzed to calculate some statistical parameters and to verify the normality plots of fiber-length and fiber-diameter measurements using Kolmogorov-Smirnov test. The geometric mean diameter and length of airborne fibers were 1.2 μm and 22.8 μm, respectively. The airborne fiber distributions were log-normal and when the fibers are dispersed into air during handling or cutting only thin fibers remains airborne.