Sources: Occupational Safety and Health Administration; CP staff
As indicated in initial proposals to revise and harmonize respirable silica dust thresholds for general industry and construction worksites, OSHA maintains limits—25 and 50 micrograms per cubic meter of air, averaged over an eight-hour shift—for action levels and offering workers medical surveillance, respectively, in its final Occupational Exposure to Respirable Crystalline Silica rule.
In addition to lowering the crystalline permissible exposure limit (PEL), the agency reports, the final rule, released March 24:
- Requires employers to use water, ventilation or other engineering controls and work practices to limit worker exposure; provide respiratory protection when controls are not able to limit exposures to the PEL; limit access to high exposure areas; train workers; and provide medical exams to highly exposed workers.
- Provides greater certainty and ease of compliance to construction employers, including smaller contractors and builders, with a table of specified controls they can follow to be in compliance, without having to monitor exposures.
- Staggers compliance dates to ensure employers have sufficient time to meet the requirements, e.g., extra time for all general industry employers to offer medical surveillance to employees exposed between the PEL and 50 micrograms per cubic meter and the action level of 25 micrograms per cubic meter.
The final rule is written as separate standards. Employers covered by the construction version have until June 23, 2017 to comply with most requirements; those subject to the general industry and maritime version have another year. OSHA officials foresee the new rule curbing lung cancer, silicosis, plus chronic obstructive pulmonary and kidney disease in workers.
“More than 80 years ago, Labor Secretary Frances Perkins identified silica dust as a deadly hazard and called on employers to fully protect workers,” says Secretary of Labor Thomas Perez. “This rule will save lives. It will enable workers to earn a living without sacrificing their health. It builds upon decades of research and a lengthy stakeholder engagement process—including the consideration of thousands of public comments—to finally give workers the kind of protection they deserve and that Frances Perkins had hoped for them.”
“The previous exposure limits were outdated and did not adequately protect workers,” adds Assistant Secretary of Labor for Occupational Safety and Health Dr. David Michaels. “Limiting exposure to silica dust is essential. Every year, many exposed workers not only lose their ability to work, but also to breathe. We are taking action to bring worker protections into the 21st century in ways that are feasible and economical for employers to implement.”
About 2.3 million men and women face exposure to respirable crystalline silica in their workplaces, including two million construction workers who drill and cut silica-containing materials such as concrete and stone, and 300,000 workers in operations such as brick manufacturing, foundries and hydraulic fracturing. OSHA notes that most employers can limit harmful dust exposure by using equipment that is widely available, generally using water to keep dust from getting into the air or a ventilation system to capture dust where it is created.
The agency estimates that when fully effective, the final Occupational Exposure to Respirable Crystalline Silica rule will a) save more than 600 lives and prevent more than 900 new cases of silicosis annually; and, b) provide an estimated $7.7 billion in net benefits per year.