Text For Citation: 01 Item/Group: 002B Hazard:

29 CFR 1926.1153(d)(1): The employer did not ensure that employees were not exposed to an airborne concentration of respirable crystalline silica in excess of 50 g/m3, calculated as an 8-hour TWA: During demolition operations of crystalline silica containing building materials, employees were exposed to an airborne concentration of respirable crystalline silica which exceeded 50 micrograms per cubic meter of air, as an 8-hour time-weighted average as follows: a) On June 25, 2024, on the fourth floor of the courthouse, an employee's personal 8-hour time-weighted average (TWA) exposure to airborne concentrations of respirable crystalline silica was 150.0 micrograms per cubic meter of air during demolition of walls consisting of concrete-type plaster as well as other building materials. This exposure exceeded the OSHA respirable crystalline silica PEL of 50 micrograms per cubic meter of air by three times. The monitoring consisted of one sample collected during a 111-minute sampling period and one sample collected during a 260 -minute sampling period. The remaining time of 109 minutes was included in the 8-hour TWA as a zero respirable crystalline silica exposure period. b) On June 25, 2024, on the fourth floor of the courthouse, an employee's personal 8-hour time-weighted average (TWA) exposure to airborne concentrations of respirable crystalline silica was 130.0 micrograms per cubic meter of air during demolition of walls consisting of concrete-type plaster as well as other building materials. This exposure exceeded the OSHA respirable crystalline silica PEL of 50 micrograms per cubic meter of air by 2.6 times. The monitoring consisted of one sample collected during a 260 -minute sampling period and one sample collected during a 111 -minute sampling period. The remaining time of 109 minutes was included in the 8-hour TWA as a zero respirable crystalline silica exposure period.