AIHA submits comment on OSHA's proposed silica rule
February 4, 2014
OSHA Docket Office
Docket No. OSHA-2010-0034
U.S. Department of Labor
Room N-2625
200 Constitution Avenue, NW
Washington, DC 20210
Docket Officer:
The American Industrial Hygiene Association (AIHA) expresses its appreciation to the Occupational Safety and Health Administration (OSHA) for the opportunity to comment on the OSHA Proposed Rule on Occupational Exposure to Respirable Crystalline Silica. The Proposed Rule was published in the Federal Register on September 12, 2013, Volume 78, No. 177, beginning on Page 56274.
AIHA is the premier association serving the needs of professionals practicing industrial hygiene in industry, government, labor, academic institutions, and independent organizations. The AIHA mission is to promote healthy and safe working environments by advancing the science, principles, practice, and value of industrial hygiene. A healthy workforce is essential to the success of American industry, our economic recovery, and our future position in the global economy.
As stated by OSHA in the announcement of the proposed rule “Exposure to silica can be deadly, and limiting that exposure is essential. This proposal is expected to prevent thousands of deaths from silicosis as well as lung cancer, other respiratory diseases and kidney disease.” The agency currently enforces 40-year-old permissible exposure limits (PELs) for crystalline silica in general industry, construction and shipyards that are outdated, inconsistent between industries and do not adequately protect worker health.
OSHA develops proposed rules based on the best available published information. OSHA industrial hygienists, toxicologists, economists and epidemiologists use this information to examine risks posed by various exposure levels and identify feasible controls available through existing technology. The main issue at stake with this proposed rule appears to be the PEL.
AIHA believes the PEL needs to be based on scientific evidence and health effects as established by published National Institute for Occupational Safety and Health (NIOSH) and American Conference of Governmental Industrial Hygienists (ACGIH) documents, which conclude that the current PEL is inadequate and that change is needed.
More than any substance OSHA has regulated since asbestos and lead, silica has an extensive record of past health issues based on accumulated evidence of its hazards. Fortunately, the evidence also shows that feasible controls can be used to protect workers from silica.
As an organization, AIHA’s members and goals focus on preventing occupational illness and injury as a fundamental principle of the industrial hygiene field. AIHA also develops science-based public policy and practice through collaboration across scientific and technical communities, and works to ensure that safe and healthy environments are provided for all workers and communities. This focus needs to be maintained throughout this rulemaking process.
In the end, the question that must be answered is “will this proposal be better or worse for employee health and safety?” To this, AIHA believes the answer is a resounding “yes”, and AIHA supports OSHA efforts to move forward with the proposed rule.
AIHA comments on the proposed rule were drafted by several AIHA Volunteer Groups, including the AIHA Construction Committee, the AIHA Occupational and Environmental Medicine Committee, the AIHA Occupational and Environmental Epidemiology Committee, and the AIHA Exposure Assessment Strategies Committee.
AIHA Comments to Specific Questions Posed by OSHA
18d. Are OSHA’s estimates of exposure assessment costs reasonable?
For the compliance strategy cited, OSHA costs may be reasonable. But for a truly protective, accurately assessed exposure profile, they will be low. Explanation: The AIHA Exposure Assessment Strategies Committee (EASC) has developed a series of professional development courses over time that has drawn from the technical experts making up the EASC. An evaluation of exposure assessment strategies formulated to identify the risk of exceeding permissible exposure limits (as published by OSHA) or other occupational exposure limits (as recently pointed out by OSHA in their communication on this subject regarding the Annotated Tables) demonstrates that a compliance strategy based on the collection and analysis of a single sample is not suitable for understanding the exposure profile, as it is does not have statistical power to reliably detect exposures that would exceed the limit cited. Instead, the AIHA strategy has been shown to have superior power to detect exposures exceeding the limit, and that power comes from collection of a sufficient sample set, usually numbering from 6 to 10 samples, for demonstrating compliance to the limit. The OSHA Policy formulators are encouraged to consult the Exposure Assessment Strategies Committee information and Professional Development course content offered thru AIHA for more information.
37. The proposed rule defines “respirable crystalline silica”. Comments?
The OSHA proposed rule for Respirable Crystalline Silica establishes a Permissible exposure limit of 50 ug/m3. The proposed rule defines Respirable Crystalline Silica as: “airborne particles that contain quartz, cristobalite, and/or tridymite and whose measurement is determined by a sampling device to meet the characteristics for respirable-particle-size-selective samplers specified in the International Organization for Standardization (ISO)7708:1995: Air Quality-Particle Size Fraction Definitions for Health-Related Sampling.”
AIHA recommends that OSHA change the definition to read: “airborne particles of quartz, cristobalite, and/or tridymite and whose measurement is determined by a sampling device to meet the characteristics for respirable-particle-size-selective samplers specified in the International Organization for Standardization (ISO)7708:1995: Air Quality-Particle Size Fraction Definitions for Health-Related Sampling.”
The current proposed definition defines the entirety of a sample of dust containing any miniscule but detectable quantity of quartz, cristobalite or tridymite, as respirable crystalline silica. The proposed definition is more precise.
44. Is the wording of the two options for periodic exposure assessment understandable and clearly indicate what would constitute compliance? See page 548 thru 552 (d)(3)(i) and (ii)
NO. OSHA Field Operations Manual indicates that “compliance” decisions involve sampling data with incorporation of a sampling and analytical error. The standard does not address the use of SAE’s into the employer judgment. In addition, the performance option only calls for the use of data “sufficient to accurately characterize employee exposures”. Again, it should point to American Industrial Hygiene Association language on what an acceptable judgment of exposure can be based upon: number of samples for statistical validity, an acceptable tolerance for an error in that statistical judgment, and the connection of the sample set to a set of conditions occurring during the worker exposure measurement. AIHA data collection prior to training has demonstrated time and again the consistent errors made with professional judgments by industrial hygienists, without basing judgment on sampling, models, or other quantitative information. The odds that employers both with and without competent exposure assessment expertise could make these judgments accurately is very low.
54. Is exemption from exposure assessment PROCESS a good idea for those tasks found in the proposed Table 1 of the standard?
No. As previously identified, AIHA Exposure Assessment Strategies Committee experts have demonstrated that limited data sets will not sufficiently nor accurately characterize exposures over time. Hazardous materials management principles would dictate a need for continuing demonstration of the effectiveness of controls, consistent operator behaviors, and proper levels of respiratory protection. All of these are shown through the occasion of air monitoring, over time, for airborne silica.
56. Should employers working to control sets published in Table 1 of section (f) be required to comply with the PEL thru air monitoring provisions? (or paraphrased, Is the allowance for the employer to assurance exposure control without exposure monitoring a good idea or bad?
Compliance with the PEL should be required until sufficient data is assembled for the variability of workers, tasks and materials demonstrating exposure levels as acceptable (below), uncertain (indeterminate) or unacceptable (above) the Permissible Exposure Limit. A collection of sufficient data may come from an employer, an organization of similar business operations, and published as well as peer reviewed literature. Any of these could then serve as objective data sets. At such time as these objective data sets are available, then acceptable work practice and workplace controls can be assigned to tasks and activities. Once the performance of these controls are verified, then techniques such as work permits, job observations and workplace assessments can be conducted real time to see if the controls are being properly administered. Employers should be allowed to implement strategies other than monitoring, as long as they have researched the appropriateness of these strategies to control worker exposures below the permissible exposure limit, and have some mechanism(s) to assure that the strategies are working on a day-to-day basis.
54-68. Response regarding the use of Table 1 controls.
Discussion
The AIHA endorses the concept of Table 1 and the option it provides to construction contractors. AIHA encourages air monitoring as an important part of an overall worker exposure assessment program. However, the reality of construction sites is that things that impact the workers’ exposures such as:
• Specific work task being performed
• Duration of that task
• Materials being used
• Weather conditions
• Amount of natural ventilation
• Condition of work tools
• Surrounding activities
are constantly changing and therefore altering workers’ exposure. This can reduce the effectiveness of air monitoring in regards to determining proper worker protection procedures. In addition, air monitoring for determination of 8 hour time weighted average (TWA) results requires the samples to be sent off for laboratory analysis. Even in the best case situation, this can cause a delay of 2-3 days before results are available. Excessive exposures may have already occurred, tasks may have been completed, workers dispersed to other jobs and the usefulness of the monitoring results minimized. Use of Table 1 allows contractors to anticipate and implement protective measures from the start of the project and avoid the expense of air monitoring and its possibly minimal gain.
Table 1 also allows more ‘silica friendly’ job bid estimates. Table 1 allows contractors to anticipate what controls (and their expense and impact on production) will be required on the jobsite. This then can be factored into the job bid to produce a quote that will contain both time and money to allow management and workers to perform a silica safe job. This assists smaller contractors, who typically do not have dedicated safety professionals on staff, to avoid having to guess what may be required to properly protect their workers. While these controls and respirators may add cost to a job, it is a cost that can be accurately estimated and factored into the bid. This can also assist project owners in evaluating contractor bids to ensure there is proper forethought and moneys in the contractor bid for silica control.
Utilization of the Table 1 as a compliance option when respirators are required means the surrounding area must be considered a regulated area or under an access control plan. This combined with the engineering controls can help address the common problem of adjacent workers being inadvertently exposed to silica particulates. The need for a regulated area or control plan would now be an objective determination by the competent person. This in turn would help identify workers or areas where inadvertent exposure may occur and consequently allow procedures to be implemented to prevent this.
The AIHA also endorses the dual table format (i.e. less than 4 hours/greater than 4 hours duration). Many silica producing tasks on construction sites are of limited duration during a shift. This acknowledges that the limited duration of exposure on the jobsite provides a significant level of protection against silica (which has an 8 hour TWA PEL verses a STEL or ceiling level PEL). This in turn reduces the unnecessary use of respirators (including the expense) when the limited duration control provides an additional source of protection combined with the required engineering controls.
While AIHA endorses the use of Table 1 as a compliance option, there are several recommendations for OSHA to consider:
Recommendations
1. In the Engineering and Work Practice Control Methods column, several operations state equipment should be operated “…such that no visible dust is emitted from the process”. AIHA is concerned that this is a subjective determination and can be influenced by several factors such as lighting, wind and direction, and angle of observation. Rounded corners, rough surfaces and other surface topography may make it impossible to keep a shroud or LEV inlet flush with the surface, thereby letting intermittent dust to escape. AIHA recommends this requirement be removed. Ensuring the proper use and functioning of the equipment is one of duties of the competent person, tool operator and employer. They can evaluate the overall situation on a case by case basis and determine if excessive dust is being released and if so take all required action.
2. As noted in the discussion section, silica exposure can be influenced by numerous variables. Several of the tasks in the less than 4 hour/day column do not require any supplemental respiratory protection. AIHA is concerned that these variables (and their inevitable, numerous and unpredictable combinations) may in some cases lead to exposures that are not adequately controlled. To account for some of this uncertainty, AIHA suggests OSHA require the employer to provide a minimum 1/2 face piece respirator, upon either employee request or competent person determination of need, for any Table 1 task that does not require a respirator. A filtering facepiece respirator supplied due to an employee request would be considered voluntary use under 29CFR1910.134. Use of an elastomeric respirator or a competent person determination would require full compliance with 29CFR1910.134.
3. In conjunction with recommendation #2, because engineering controls play such a critical role in worker exposure control, AIHA recommends OSHA require the employer to have a competent person whenever Table 1 is used for compliance purposes – regardless if respirator use is required or not.
It is our understanding based on Note 1 of Table 1, if a respirator is not required, the employer does not have to assume an overexposure to the PEL. That would mean a competent person is not required. The variability and potential magnitude of exposure during many of these tasks and the dependence solely on engineering controls indicates that a competent person should be available to ensure they are adequate for the specific situation. The use of Table 1 relieves the employer of having to do both initial and periodic air monitoring. Eliminating periodic air monitoring in turn removes one of the controls methods (as noted by OSHA in the discussion section of the NPRM) to ensure the engineering controls are functioning properly.
The AIHA White Paper Recommended Skills and Capabilities for Silica Competent Persons can be referenced as a non-regulatory guidance document on what a silica competent person should be able to do and when a qualified person needs to be called in for further situation evaluation.
4. AIHA recommends that for commercially available engineering controls (e.g. water spray, LEV) OSHA require that employers follow the manufactures’ user instructions for installation, use and maintenance of the equipment - unless there is written variance from the manufacturer.
5. AIHA recommends OSHA make the respirator requirements of Table 1 more performance oriented. Instead of specifying a particular respirator type - such as a half facepiece respirator - AIHA recommends specifying only that the respirator used meets or exceeds a specific APF as documented in 29CFR1910.134. AIHA is concerned that as Table 1 reads now, some employers may believe that the specified respirator is the type that must be used. Citing only a minimum APF makes it clear that any NIOSH approved respirator meeting or exceeding that APF may be used. This may in turn motivate employers to consider other respirator systems with higher APFs than the respirator type currently specified.
AIHA recommends OSHA clarify what time is included when determining less than or greater than 4 hours. Does time only include when dust is being actively generated (i.e. a saw is making a cut or a grinder is actually working on material)? AIHA recommends that time include overall run time of the tool i.e. actual dust generation time, positioning materials, measuring stock material in preparation for work, adjustment of tools.
69. Medical Surveillance.
Workers exposed to silica deserve medical surveillance to identify early signs of disease. Those who are exposed to higher levels (e.g. those doing silica generating tasks or working in regulated areas) are at greater risk and should be a high priority for medical surveillance, as well as those who have to wear respirators. Medical exams are not as necessary or useful for workers who have had less than 10-15 years of exposures, since the chances of finding any disease is minimal. OSHA may want to consider reducing the frequency for younger workers or reducing the frequency of tests like X-rays, as is done in the Asbestos standard.
The 30 day trigger for medical exams in the proposed rule is problematic for construction, where most workers are changing jobs and often changing employers every few weeks. Who will keep track of the number of days of exposure? How would it be verified? How would a compliance officer check? Would it lead to blacklisting workers who have had 29 days of exposure?
AIHA recommends that OSHA reconsider how medical exams are triggered in the standard to come up with a more useful trigger for a transient construction workforce.
78. Use of physicians and other licensed health care providers.
The industrial hygiene assessments and exposure monitoring are recognized to be "fairly challenging".
"Certification" is required for "B-readers (NIOSH-certified); American Board Certified Specialists (American Board of Medical Specialties (ABMS)) in Pulmonary Disease (“pulmonary specialists”); and physicians and other licensed health care providers (PLHCPs) performing medical examinations and procedures under the Standard (licensed, registered, or certified by state law).
Although the standard requires employers to conduct exposure monitoring to ensure dust controls are working properly, the standard is mute with respect to the qualification of those performing professional industrial hygiene tasks. Although the requirement for "industrial hygiene” and the use of "industrial hygienists" are written into the proposed Standard, the "certification" of the industrial hygienist is lacking. We strongly recommend that, as a minimum, the professional and technical oversight of the industrial hygiene aspects listed under the Standard be performed under the cognizance of a "Certified Industrial Hygienist (CIH)".
The inclusion of this nominal requirement ensures that the proper knowledge, skills, and abilities are held by the professionals performing this MOST IMPORTANT aspect of the proposed Standard.
Conclusion
AIHA appreciates the opportunity to work with OSHA to help achieve the mutual goal of protecting American workers from exposure to crystalline silica. As the agency moves forward, the AIHA offers its breadth of experience as a resource and we look forward to further opportunities to work with the agency on this and similar issues and regulatory priorities.
If AIHA can be of any further assistance, please contact me. Thank you.