In-depth survey report: control of silica exposure in construction scabbling concrete at Frank Messer and Sons Construction Company, Hebron, Kentucky, report no. CT-247-15d.
Echt-A; Sieber-WK; Jones-A; Jones-E
NIOSH 2002 Apr; :1-10
Scabbling concrete involves dressing the surface of the concrete to remove surface imperfections or surface coatings. Analysis of a novel control designed and constructed by the site superintendent for use with a small, gasoline-powered, walk-behind scabbIer showed that it was effective at reducing employee exposure to respirable dust and, should also be effective in reducing exposure to crystalline silica. The control consisted of a 15-inch spray bar made from 3/4-inch schedule 40 polyvinyl chloride pipe with 15 slots cut in it spaced 3/4 to I-inch apart. The spray bar was attached to a lifting handle on the front of the scabbIer with hose clamps, and oriented with the slots facing downward, toward the work surface. An elbow connected the spray bar to a length of flexible hose mounted on the upright of the handle of the scabbIer, with a valve mounted about midway down the handle. The hose mounted on the scabbIer was fitted with a standard garden hose fitting to allow it to be connected to a water supply hose. An 80% reduction in mean exposure levels of respirable dust was found with the use of the water control, from 3.88 mg/m3 to 0.64 mg/m3. This difference was statistically significant at the p=0.05 level. The difference was detected with 50% power in the 10 pairs of samples using a standard two-group t-test for equality of means.
Silica-dusts; Respirable-dust; Concretes; Construction; Construction-equipment; Construction-industry; Construction-materials; Construction-workers; Control-technology; Grinding-equipment; Engineering-controls; Silicosis; Environmental-control-equipment; Exposure-limits; Region-4
Control Technology; Field Studies
NTIS Accession No.
National Institute for Occupational Safety and Health