A study conducted by researchers at the Department of Health at the University of Massachusetts-Lowell has concluded that dangerous levels of respirable silica are difficult to control during chipping and crushing activities even when dust control measures are in place. The study cites risk for both workers and bystanders.
The study analyzed more than 80 combined worker and bystander breathing zone air samples at multiple construction sites across the state of Massachusetts during chipping and crushing operations. Chipping workers and crushing machine operators were shown to have the highest exposure to respirable silica, with levels above the Occupational Safety and Health Administration’s (OSHA) permissible exposure limit (PEL) within 15 minutes to two hours for chippers — even with cartridge respirators — and crushers, respectively.
At present, OSHA has sought public input for a potential revision of its Table 1 recommendations, but it remains unclear how swiftly change might occur, if at all.