In-depth survey report: control of silica exposure from hand tools in construction grinding concrete at Frank Messer and Sons Construction Company, Newport, Kentucky, report no. CT-247-15c.
NIOSH 2002 Jan; :1-8
When construction workers use hand-held grinders to smooth poured concrete surfaces after forms are stripped, they risk overexposure to respirable dust and crystalline silica. This report examines the performance of a local exhaust ventilation system for hand-held grinders. The system consisted of the grinder, which was equipped with a ventilated shroud, a length of flexible corrugated hose, and a portable electric vacuum cleaner that acted as the fan and dust collector for the ventilation system. Air samples for respirable dust and crystalline silica were collected during five days of grinding. Eight-hour TWA respirable dust results ranged 0.55mg/m3 to 1.2 mg/m3, or from 0.45 to 1.5 times the PEL. These results exceeded the OSHA PEL for respirable dust containing greater than or equal to 1 % quartz on 4 of 5 sampling days. Eight-hour time weighted average quartz exposures ranged from 0.036mg/m3 to 0.13mg/m3, or from 0.72 to 2.6 times the REL of 0.05mg/m3. These results exceeded the NIOSH REL for crystalline silica on 4 of 5 sampling days. The results of air sampling indicate that this .vacuum cleaner and shroud system control exposures within the range of protection provided by a half-mask respirator.
Region-4; Dust-control; Dust-control-equipment; Dust-exposure; Dusts; Dust-suppression; Particulates; Particulate-dust; Airborne-particles; Airborne-dusts; Quartz-dust; Silica-dusts; Construction-workers; Construction-materials; Demolition-industry; Ventilation-systems
Control Technology; Field Studies
NTIS Accession No.
National Institute for Occupational Safety and Health