Workstation Design Improvements for the Reduction of Dust Exposures During Weighing of Chemical Powders

Abstract Ventilated booth workstations often do not provide complete dust control during the manual transfer and weigh out of chemical powders. In a typical process, a worker removes powder from the bulk material drum with a scoop, weighs the powder into a paper bag, and then places the full bag into a second drum. A previous study identified points of exposure in a ventilated weigh-out operation at a plastics manufacturing plant. Eddies in front of the worker and inside the weigh-out drum hindered dust control. The depth of the powder in the weigh-out drum also contributed to increased exposures. This follow-up study sought to apply and evaluate three different control modifications of the weigh-out station. The first control was the modification of the worktable to streamline the process. The second control was a local exhaust hood placed at the lip of the bulk material drum. This hood controlled the eddy in the bulk material drum. The last control was an air shower, i.e., a low-velocity, fresh air supp...