Experimental and parametric study on the uptake factor of tungsten oxide particles resulting from a dropped storage container

A test procedure was developed and verified to measure the airborne concentrations of particles of different sizes (0.5-20μm) within the vicinity of a dropped container, when a significant portion of the contained tungsten oxide powder is ejected. The tests were carried out in a full-scale stainless steel environmental chamber with an interior volume of 24.1 m³. A total of thirty two drop tests were performed, covering variations in dropping height, room air movement, landing scenario, and lid condition. Assuming a breathing rate of 1.2 m³/h, the uptake factor during the first 10 minutes was calculated to be between 1.13×10^-9 and 1.03×10^-7 in reference to the amount loaded; or between 6.44×10-8 and 3.55×10-4 in reference to the amount spilled. The experimental results of this study provide previously unavailable data for estimating the exposure and associated risk to building occupants in the case of an accidental dropping of heavy powder containers.