NIOSH officials say a multi-stakeholder partnership involving industry, union and government experts on respirable crystalline silica has evaluated a range of engineering controls in field studies that are effective at keeping exposures to the toxic dust during road milling below the research agency's 50-microgram recommended exposure limit (REL) for silica dust – a level mirroring the compulsory exposure cap in OSHA's planned silica rule – and suggest use of the developed controls could obviate a need for respirator use over full shifts in road milling operations.
December 28, 2025