Survey report: control technology for manual powder weigh-out operations at Merck and Company, Wilson, North Carolina.
Heitbrink WA; Farwick DR
Cincinnati, OH: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, ECTB 197-13a, 1994 Dec; :1-22
The use of a commercially available booth for manually weighing out powdered materials at Merck and Company, Wilson, North Carolina was evaluated. Scoops were used by workers to transfer material from drums. The supply drums ranged in height from 24 to 33 inches, while the drums receiving the material were 17 inches in height. They were all lined with plastic bags. Air was drawn through exhaust grates along the booth's back wall and then through filters by a fan. High efficiency particulate filters located in the ceiling of the booth allowed about two thirds of the air to be recycled. The ceiling of the booth acted as an air shower. Dry ice was used to visualize the flow of air. This test indicated that there were no eddies present which would force contaminated air to flow into the worker's breathing zone. Activities that caused dust exposure were identified using aerosol instrumentation. An aerosol photometer and an optical particle counter were used to determine worker dust exposure. Videotape recordings were made of the worker's activities. When the worker opened or closed the plastic liner of the drum, the exposure to dust was increased. About 80 to 90% of the total dust exposure was due to the manipulation of the plastic liner of the drum. Dust exposure also increased when the worker reached too far into the drum containing the powder.
NIOSH-Author; NIOSH-Survey; Field-Study; Region-4; Air-quality-monitoring; Ventilation-systems; Airborne-dusts; Control-technology; Pharmaceutical-industry; Dust-control; Industrial-engineering; Exhaust-ventilation
Field Studies; Control Technology
NTIS Accession No.
National Institute for Occupational Safety and Health