On March 25, 2016, the Department of Labor's Occupational Safety and Health Administration (OSHA) published the final rule for Occupational Exposure to Respirable Silica (29 CFR 1910, 1915, and 1926). This major occupational regulatory development had a drawn-out process, originating in 1971 when the previous permissible exposure limits (PELs) for respirable crystalline silica (RCS) were established. The agency estimates that approximately 2.3 million workers are exposed to RCS in construction, mining, brick manufacturing, foundries, and oil/gas drilling (hydraulic fracturing).
After 45 years of mounting evidence related to the occupational exposure, epidemiology, and toxicology of RCS, OSHA determined that the former PELs of 100 micrograms per cubic meter of air (µg/m3) for general industry and 250 µg/m3 for construction/shipyards were inadequate to protect workers. Namely, OSHA concluded that workers exposed to RCS at the preceding PELs were at an increased risk of lung cancer and premature mortality. Occupational exposures to RCS may also result in increased risk of chronic obstructive pulmonary and kidney diseases. This conclusion was based on an extensive effort encompassing literature reviews, quantitative risk assessments, consideration of industry consensus standards, and extensive stakeholder input. The findings are summarized in a 605-page Federal Register notice (Vol. 81; No. 58; 16285-168901).
To ensure the protection of workers' health going forward, OSHA has not only promulgated a significantly lower limit, but also expanded provisions for controlling exposures.
Key Provisions
- The new PEL is 50 (µg/m3; 8-hr time-weighted average).
- Employers are required to use engineering controls to limit worker exposure.
- Respirators must be provided if engineering controls are ineffective.
- Employers must reduce worker access to high exposure areas.
- Written exposure control plans must be developed.
- Worker training on silica risks and exposure controls must be provided.
- Medical exams are to be offered to exposed workers as well as lung health information.
- There are enhanced requirements for recordkeeping.
- There is one standard for the construction industry and one for general industry/maritime.
- The rule has flexibility in terms of employer compliance with exposure controls.
Risk Reduction
OSHA acknowledges that while the level of risk associated with the new PEL is still significant, the implementation of the new rule will prevent 642 premature deaths and more than 918 new cases of silicosis each year. This is in addition to the current decline in silica deaths from 4,263 in 1970 to approximately 600 currently. As with most known human carcinogens there is no known safe limit for RCS. Thus, the new 50 µg/m3 limit will help to reduce, but not eliminate, risks to workers. Maximization of exposure controls will be the key to realizing the desired benefits.
Costs and Feasibility
Although the estimated annual cost of the rule is $1 billion, the net benefit of $7.7 billion per annum far outweighs it. In its economic impact assessment, OSHA also took into consideration the technical feasibility of compliance. The value of 50 µg/m3 was deemed appropriate because it is the lowest level feasible for all affected industries.
Compliance Schedule
The final rule is effective on June 23, 2016, after which industries must comply with the following overall schedule:
- Construction industry: 1 year after effective date (June 23, 2017)
- General/maritime industries: 2 years after effective date (June 23, 2018)
Construction will have up to 2 years to comply with laboratory testing, and hydraulic fracturing will have 5 years to implement exposure controls.
Exemptions
- Agricultural operations (covered separately under 29 CFR 1928)
- Facilities demonstrating RCS exposures below 25 µg/m3 under any conditions
- Operations using sorptive clays
- Facilities that implement default exposure controls
How can GHD help?
GHD provides a wide range of technical services focused on regulatory compliance, health and safety, occupational exposure monitoring, and toxicology. For additional information on the RCS rule, please contact the following:
- Andrew Pawlisz | E: andrew.pawlisz@ghd.com | T: +1 972 679 7872
- Dyron Hamlin | E: dyron.hamlin@ghd.com | T: +1 501 766 1625
- Ben Chandler | E: benjamin.chandler@ghd.com | T: +1 501 366 3999
1 https://www.gpo.gov/fdsys/pkg/FR-2016-03-25/pdf/2016-04800.pdf