OSHA issued the National Emphasis Program – Respirable Crystalline Silica effective 2/4/2020. See the full directive here.

This Instruction describes policies and procedures for implementing a National Emphasis Program (NEP) to identify and reduce or eliminate worker exposures to respirable crystalline silica (RCS) in general industry, maritime, and construction industries.

This replacement NEP addresses enforcement of OSHA’s standards for RCS, promulgated in 2016. One standard covers general industry and maritime, and the other covers construction. Both standards set a permissible exposure limit (PEL) for RCS of 50 micrograms per cubic meter (μg/m3) as an 8-hour time-weighted average (TWA). The former TWA PELs for respirable quartz silica were calculated based on silica content and were approximately equivalent to 100 μg/m3 for general industry and 250 μg/m3 for construction and shipyards (81 FR at 16294, March 25, 2016).