A long-awaited final rule to improve protections for workers exposed to respirable crystalline silica dust was released today by the Occupational Safety and Health Administration (OSHA). The final rule is written as two standards: one for construction, the other for general industry and maritime.
Regulators, occupational health experts, and industry and labor groups agree that a comprehensive standard for crystalline silica is needed to provide for exposure monitoring, medical surveillance and worker training. In the U.S., about 2.3 million workers in construction and operations such as brick manufacturing, foundries and hydraulic fracturing face silica dust exposure hazards.
The final rule establishes a permissible exposure limit (PEL) of 50 micrograms per cubic meter of air, averaged over an eight-hour shift. The current OSHA PEL for general industry is based on a formula recommended by the American Conference of Governmental Industrial Hygienists (ACGIH) in 1971: PEL=10mg/cubic meter/(% silica + 2), as respirable dust. The current PEL for construction and maritime, derived from ACGIH’s 1962 Threshold Limit Value, is based on particle counting technology, which is considered obsolete. The National Institute for Occupational Safety and Health and ACGIH recommended a 50µg/m3 exposure limit.
Under the new rule, employers will be required to:
• use engineering controls (such as water or ventilation) and other work practices to limit worker exposure
• provide respirators when engineering controls do not provide adequate protection
• limit worker access to high-exposure areas
• train workers on exposure risks and protection
• provide medical exams to monitor the health of highly exposed workers and provide information about lung health
The rule includes a table of specified controls certain employers can follow to be in compliance without having to monitor exposures.
The rule takes effect June 23, 2016. Staggered enforcement dates will be used to ensure employers have sufficient time to meet the requirements. Enforcement will go into effect June 2013, 2017, for the construction industry, June 23, 2018 for general industry and maritime, and June 23, 2018 for companies engaged in hydraulic fracturing. Enforcement of engineering controls for hydraulic fracturing will not go into effect until June 23, 2021. States with their own health and safety enforcement agencies have six months to adopt standards that are at least as stringent as the new federal rule.
OSHA estimates the revised standard will annually save more than 600 lives and prevent more than 900 new cases of silicosis, an incurable, progressive disease. The agency also estimates the final rule will provide net benefits of about $7.7 billion per year. To learn more, visit OSHA’s silica website.