By Evan Gurley
Occupational Safety Health Administration held public hearings last spring to address industry concerns about the proposed amendments to its current standards for occupational exposure to respirable crystalline silica. However, this was not the end of the briefing period. Due to industry pushback, shortly after the public hearings, William Perry, directorate of standards and guidance, notified interested parties that the docket for the OSHA Notice of Proposed Rulemaking on Occupational Exposure to Respirable Crystalline Silica remained open to allow additional time for post-hearing brief submissions. Final briefs, arguments and summations were accepted through Aug. 18.
Since OSHA’s last published announcement on June 17, notifying the public that it was extending the submittal period, there has been no further action or published updates by OSHA. It’s safe to say that OSHA is currently reviewing the extensive number of industry comments/feedback and is preparing a response along with a plan of action.
Makeup of new crystalline silica rule
OSHA is proposing a new Permissible Exposure Limit for respirable crystalline silica (quartz, cristobalite and tridymite) of 50 micrograms per cubic meter in all industry sectors covered by the rule. For the precast industry, the current rule is for 100 micrograms per cubic meter, so the proposal rule would cut the exposure level in half. OSHA is also proposing other elements of a comprehensive health standard, including requirements for exposure assessment, preferred methods for controlling exposure, respiratory protection, medical surveillance, hazard communication and recordkeeping.
Under the proposed rule, precasters would be obligated to monitor the airborne concentration of silica in the workplace, unless they can objectively demonstrate there is no silica released above the action level of 25 µg/m³.
This means employers would be required to conduct periodic exposure monitoring for employees. The rule states that precasters can choose between retesting the air on a fixed schedule or using the performance option, which calls for assessing exposure based on any combination of air monitoring data or objective data sufficient to accurately characterize employee exposures to silica. OSHA also stated employers must provide:
- Provisions for measuring how much silica workers face
- Limits on workers’ access to areas where exposures are high
- Medical exams for workers with high silica exposures
- Training for workers about silica-related hazards and how to limit exposure
The standard would make controlling silica dust the primary method for reducing employee exposure. Rules about personal protective equipment are included, but PPE would be a last resort to reduce exposure after first taking measures to control dust. Other methods used to control dust include:
- Wetting work areas to keep the dust from getting into the air
- Enclosing the work area, known as, process isolation
- Using a vacuum to collect dust at the point it is created, before workers can inhale it
Cost for precasters
OSHA has claimed that the revision will cost $637 million annually, averaging to $1,242 per workplace. OSHA also stated that companies with fewer than 20 workers will incur average costs of $550. The proposal’s estimated costs include $330 million for engineering controls, $91 million for respirators, $76 million for medical surveillance, and $73 million for exposure assessments. However, some claim adding all these ancillary provisions to the silica standard would actually cost $5.1 billion per year, eight times greater than OSHA’s estimate.1
Current practices used to address OSHA regulations
Don Graham, chairman of the NPCA Safety, Health and Environmental Committee and director of safety at Jensen Precast, recently spoke about how Jensen plants have addressed current OSHA regulations, as well as how they will have to adjust if OSHA approves proposed PEL for respirable crystalline silica.
Graham said Jensen plants perform air sampling at every facility about every three years looking for silica levels. To date, all samplings have produced results below the current OSHA PEL for respirable crystalline silica. Jensen plants use a wet method when grinding, sawing or drilling on finished concrete products, although this is hard to enforce on a day-to-day basis.
“Over the years our workman’s comp insurance companies have required us to demonstrate that there is not a silica exposure risk at our production facility,” Graham said.
Graham stated that if the PEL is lowered, OSHA will require a silica exposure program that mandates regular medical screening of exposed employees, regular air sampling to determine exposure levels, training on silica, PPE such as respirator use, as well as full body protection when exposed to silica dust. The new OSHA regulation will also require different tooling such as heap vacuum drills/grinders, or tools that provide a water wash or flow to reduce dust.
In addition, Graham said precast plant workers could receive an exposure above the proposed PEL by grinding on concrete without any other control method.
He said OSHA has fact sheets addressing the highlights of the proposed respirable crystalline silica rule, information for small businesses, training materials, publications, data and statistics, and examples of dust control methods precasters can use to help keep their plants in compliance.
NPCA urges OSHA to withdraw proposal
National Precast Concrete Association opposes the OSHA proposed rule and has submitted public comments in support of retaining the current PEL of 100 µg/m³. NPCA supports adherence to existing standards and more OSHA education about best practices for controlling exposure and encouraging respirator usage. In addition, NPCA and a coalition of concrete-related trade associations are members of the American Chemistry Council’s Crystalline Silica Panel and support ACC’s scientific argument that the current PEL is sufficient.
Whether you agree with the proposed reduction in the PEL for respirable crystalline silica or not, if OSHA decides to move forward with the approval of this more stringent regulation, precasters will need to know how to keep their plants in compliance. NPCA is continuing to closely monitor this ruling, but precasters can check the status of the proposal and review any supplementary documents and information on the OSHA website2.
Evan Gurley is a technical services engineer with NPCA.
1 American Chemistry Council, 2011
Stephen E Key says
Crushed limestone aggregate is the primary road construction material on Texas rural roads and the road crews experience constant exposure to high levels of silicate dust. A secondary issue is during dry weather conditions the road dust containing high levels of silicate particles are major source of environmental airborne pollution potentially causing a public health hazard. Is OSHA going to have rules dealing directly with road construction employees?