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An evaluation of a local exhaust ventilation control system for a foundry casting-cleaning operation.
Am Ind Hyg Assoc J 1997 May; 58(5):354-358
The ability of a local exhaust ventilation system to control silica (14808607) dust exposures during foundry casting and cleaning operations was evaluated. The original system consisted of a down draft booth containing a turntable mounted on a table approximately 5 feet (ft) long and 2.5ft deep. The exhaust system consisted of a 12 inch diameter duct that led to a cutoff saw located elsewhere. The damper on this branch was opened when the saw was being used. The average airflow during the duct was 5,400 cubic feet per minute (ft3/min) when the damper was closed and 2,900ft3/min when it was closed. The new system was installed and connected to the facility's existing ventilation system through the original ductwork. A direct reading light scattering based aerosol monitoring meter was used to measure exposure to respirable dust, as a surrogate for silica dust, while cleaning casts over an entire work shift. The work activities of the operator were videotaped. A similar experiment was performed using the facility's original ventilation system for comparison purposes. The recorded activities of the operator included using a cup grinder, a cone grinder, the cutoff wheel, and a pneumatic chisel. The new ventilation system achieved an overall reduction of the operator's respirable dust exposure of 72% compared to the original ventilation system. When the various tools were used, the decrease in exposure was 46% when the pneumatic chisel was used, 77% when the cup grinder was used, 59% when the cone grinder was used, and 75% when the cutoff wheel was used. The author concludes that this ventilated workstation which relies on local exhaust ventilation can effectively reduce airborne dust exposures.
NIOSH-Author; Foundries; Exhaust-ventilation; Control-technology; Equipment-design; Occupational-exposure; Dust-control-equipment; Respirable-dust; Ventilation-systems; Author Keywords: foundry operations; silica; ventilation
Issue of Publication
American Industrial Hygiene Association Journal
Page last reviewed: March 11, 2019
Content source: National Institute for Occupational Safety and Health Education and Information Division