Respirable crystalline silica (RCS) safety standards have changed for the general, maritime and construction industries in the National Emphasis Program (NEP), said officials at the Occupational Safety and Health Administration (OSHA).
The adjustments to the directive were enacted in an effort to further protect worker exposures to the naturally-occurring mineral.
Inhaling silica particles generated during cutting, sawing, grinding, drilling, and crushing materials such as stone, rock, concrete, brick, block and mortar can cause negative health consequences including silicosis, an incurable lung disease, lung cancer, and chronic obstructive pulmonary disease.
Specific industry standards related to RCS, which became effective in June 2016, are outlined in general industry and maritime (29 CFR § 1910.1053) and construction (29 CFR § 1926.1153).
Compliance dates for respirable crystalline silica were Sept. 23, 2017 for construction employers and June 23, 2018 for employers in the general and maritime industries.
However, now the agency enacted a revised application to the lower permissible exposure limit (PEL) to 50 micrograms per cubic meter (µg/m3) as an 8-hour time-weighted average in general industry, maritime, and construction.
The replacement NEP sets the 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 was equivalent to 100 μg/m3 for general industry and 250 μg/m3 for construction and shipyards.
In addition, the NEP contains an updated list of target industries, listed by North American Industry Classification System (NAICS) codes.
While OSHA’s regional and area outlets must follow the NEP, they are not required to create and implement their own regional or local emphasis programs. However, because of silica exposure is a national issue, state-run plans must participate, according to the agency.
OSHA area offices must now curate a randomized establishment list of employers in their respective jurisdictions for targeted inspections, based on updated target industries found in the appendix of the NEP.
Compliance safety and health officers will continue to reference current enforcement guidance for RCS inspection procedures, according to the agency.
Before initiating programmed inspections in accordance with the NEP, OSHA will offer 90 days of compliance assistance for stakeholders affected by the new measures.