In-depth study report: control technology for crystalline silica exposures in construction: field evaluations of control measures for tuck-pointing, at the Farell Building, Huntington, West Virginia, report no. EPHB-247-20.
Heitbrink-WA; Rogers-A; Watkins-DS; Echt-A
NIOSH 2001 Aug; :1-43
During masonry restoration of a building, 4 inch diameter grinders were used to remove mortar to a depth of 0.5 to 0.75 inches. This task was performed by two workers who stood on a swing stage. The workers used exhaust shrouds which were connected to vacuum cleaners to capture the dust. One of the grinders was partially enclosed by a dust control shroud. The exhaust volume for this shroud was 111 cubic feet per minute. The other grinder was partially enclosed by a Joc Duc shroud. The exhaust volume for this shroud was 76 cfm. The workers' respirable dust and respirable crystalline silica exposures were monitored during the mortar removal activities. The respirable dust and respirable crystalline silica exposures were, respectively, less than 0.17 and 0.03 mg/m3. This indicates that the workers' dust exposures were adequately controlled at this site. Because environmental and site-related conditions vary greatly in the construction industry, additional sampling should be done to confirm that an exhaust volume of 100 cfm adequately controls the respirable dust and crystalline silica exposures during the mortar removal tasks associated with tuck pointing.
Region-1; Silica-dusts; Construction; Grinding-equipment; Masons; Engineering-controls; Control-technology; Dust-control; Dust-control-equipment; Dust-exposure; Dusts; Silica-dusts; Quartz-dust; Respirable-dust
Field Studies; Control Technology
NTIS Accession No.
National Institute for Occupational Safety and Health