Seyfarth Synopsis: OSHA’s new Silica Rule will have a lasting effect on nearly 2.3 million workers and over 675,000 employers. The chances are high that the new Silica Rule will affect your business and may require you to implement new policies and programs to protect your employees’ safety.


The Occupational Safety and Health Administration (OSHA) released its new Respirable Crystalline Silica Rule (Silica Rule) on March 25, 2016. Crystalline silica particles are commonly dispersed in the air when workers cut, grind, crush, or drill silica-containing materials such as concrete, masonry, tile, and rock. OSHA estimates that 2.3 million American workers are exposed to respirable silica, with 1.85 million of those workers in the construction industry. Other common sources of exposure are building products manufacturing, sandblasting, and hydraulic fracturing (fracking) of oil and gas wells.

Revised Exposure Limits

OSHA’s new Silica Rule establishes permissible silica exposure limits (PEL) for all workers at 50 micrograms per cubic meter (μg/m3) of air over an 8-hour day (8-hour TWA), cutting allowable exposures in half in general industry and even more in the construction and maritime industries. OSHA found that, even with a PEL of 50 μg/m3, there is still a significant risk remaining for workers. However, OSHA determined that 50 μg/m3 is the lowest level that can be reasonable achieved through the use of engineering controls and work practices at a majority of employers. OSHA also established an “action level” of 25 μg/m3 over an 8-hour day.

Compliance Deadlines

OSHA identified a new Silica Rule as a top priority since the beginning of the Obama administration. The Agency published a Notice of Proposed Rule Making in the Federal Register on September 12, 2013 (78 Fed. Reg. 56274). The Final Rule was published in the Federal Register on March 25, 2016 (81 Fed. Reg. 16286). The Final Rule will be effective on June 23, 2016. The obligations under the Final Rule commence on June 23, 2017 for the Construction and Maritime Industries, and on June 23, 2018 for General Industry. Separate obligations for General Industry employers engaged in hydraulic fracturing in the oil and gas industry commence on June 23, 2021.

Crystalline Silicia Health Hazards

OSHA and the National Institute for Occupational Safety and Health (NIOSH) believe that crystalline silica exposure can cause lung cancer, chronic obstructive pulmonary disease (COPD), and silicosis. The National Institutes of Health’s National Toxicology Program has designated crystalline silica as a known human carcinogen. While medical science is not yet clear whether crystalline silica poses the same threat to worker safety as asbestosis and mesothelioma, OSHA, NIOSH, and other national safety agencies are taking steps to protect workers from hazards associated with respirable crystalline silica dust.

While exposure to crystalline silica dust is ubiquitous, the main industries affected include:

  • Construction
  • Glass manufacturing
  • Pottery products
  • Structural clay products
  • Concrete products
  • Foundries
  • Dental laboratories
  • Paintings and coatings
  • Jewelry production
  • Refractory products
  • Landscaping
  • Ready-mix concrete
  • Cut stone and stone products
  • Abrasive blasting in o Maritime work, Construction, General industry
  • Refractory furnace installation and repair
  • Railroads
  • Hydraulic fracturing for gas and oil
  • Asphalt products manufacturing

OSHA proposed and implemented the Silica Rule for various reasons. First, the Agency felt the previous PELs for silica were outdated and inconsistent and therefore did not adequately protect worker health. In the 45 year gap between establishing the previous PELs and the new Silica Rule, scientific evidence has shown that low-level exposure to crystalline silica can pose serious health concerns such as silicosis and lung cancer. Second, previous PELs were based on methods of measuring worker exposures that are not currently used today. Finally, the previous PELs for the construction and maritime industries were more than twice as high as the PELs for general industry.

OSHA expects the Silica Rule to protect worker health by requiring employers to use engineering controls such as ventilation and wet methods to reduce worker exposure to crystalline silica dust. OSHA predicts that the Silica Rule will prevent 600 deaths per year from silica-related diseases and to prevent more than 900 new cases of silicosis per year.

OSHA expects compliance to come at a high cost: up to $1 billion dollars per year. The Agency expects the cost of compliance to be so high because the Silica Rule is among the broadest set of standards OSHA has ever issued, covering 2.3 million workers and 676,000 employers. However, OSHA expects the costs to be spread evenly over each employer, meaning each employer should expect to spend upwards of $1,500 per year on compliance (with compliance costs being higher initially). OSHA predicts compliance costs for small businesses will be slightly less per year: around $560 per employer per year.

Exposure Monitoring

The Silica Rule requires employers in all industries to assess the exposure of each employee who is, or may reasonably be expected to be, exposed to respirable crystalline silica at or above the action level of 25 μg/m3 over an 8-hour day. The Rule provides two avenues to conduct the monitoring: (1) the “performance option” and (2) the “scheduled monitoring option.”

Performance Option

The performance option requires the employer to assess the 8-hour time-weighted average (TWA) for each employee on the basis of air monitoring data or “objective data” to accurately characterize the exposure to respirable crystalline silica.

Scheduled Monitoring Option

The scheduled monitoring option requires the employer to complete an initial 8-hour TWA for each employee on the basis of “personal breathing zone” air samples that reflect exposures for employees on (1) each shift, (2) each job classification, and (3) in each work area. When more than one employee works on a shift, in a job classification, or in a work area, the employer is required to sample a representative fraction of employees to meet the requirement. When conducting representative sampling, employers are expected to sample employee(s) who have the highest expected exposure to respirable crystalline silica. If initial monitoring shows that employee exposure is below the action level, the employer can discontinue monitoring these employees. Where monitoring indicates that exposure is at or above the action level but below the PEL, the employer is required to repeat the scheduled monitoring within six months of the most recent monitoring. Finally, where monitoring indicates that exposure is at or above the PEL, employers must repeat the monitoring within three months of the most recent monitoring.

Employers are required to be reassess employees whenever there is a change in production, process, control equipment, or work practices that is expected to result in new or additional exposures at or above the action level. Employers are required to notify employees of monitoring results within 15 working days (5 working days for the construction industry) of completing the exposure assessment. All initial exposure monitoring must be completed by an employer prior to the compliance dates outlined above so the employer is in compliance from day one.


Training requirements under the Silica Rule is similar to OSHA’s pre-existing Hazardous Communication Standard, 29 C.F.R. § 1910.1200. Specifically, employers are required to inform employees about:

  • the hazards associated with respirable crystalline silica;
  • specific tasks in the workplace that could result in exposure;
  • specific measures that the employer has implemented to protect employees from exposure (including engineering controls, work practices, and respiratory protection);
  • the purpose and a description of the medical surveillance program; and
  • for the construction industry only: the identity of the competent person tasked with ensuring compliance with the employer’s written exposure control plan, discussed below.

Engineering and Work Practice Controls

OSHA included preferred engineering methods for controlling exposure in the Silica Rule -- such as using water saws to reduce airborne silica dust (wet methods) or localized ventilation (such as a vacuum) to remove dust from the area. The Rule also includes preferred work practices to control worker exposure including wetting down dust before sweeping it up.

Respirators are only allowed when engineering and work practice controls are unable to maintain worker exposures at or below the PEL. This is because OSHA has found that respirators are often not as protective as engineering controls and are also less practical. For example, employers who must use respirators to control worker exposure to crystalline silica will be required to implement a comprehensive respiratory protection program meeting OSHA standards for fit testing, medical monitoring, cleaning and maintaining respiratory equipment, and changing filters. Respirators must be worn consistently and correctly by employees to be effective and can often be uncomfortable, especially in hot weather, making worker compliance an issue.

In addition, employers are required to demarcate and limit access to areas where an employee’s exposure to crystalline silica is expected to be above the PEL. Regulated areas are to be demarcated with signs stating:


Written Exposure Control Plan

All employers will be required to prepare a written exposure control plan for crystalline silica exposure. The plan is required to contain the following information and is to be updated at least annually:

  • a description of the tasks in the workplace that involve exposure to respirable crystalline silica;
  • a description of the engineering controls, work practices, and respiratory protection used to limit employee exposure to respirable crystalline silica for each task; and
  • a description of the housekeeping measures used to limit employee exposure to respirable crystalline silica.

The construction industry standards contain several additional requirements that must be included in the written exposure control plans, including:

  • that the plan must include a description of the procedures used to restrict access to work areas, when necessary, to minimize the number of employees exposed to respirable crystalline silica and their level of exposure, including exposures generated by other employers or sole proprietors; and
  • that an employer must designate a competent person to make frequent and regular inspections of the job sites, material, and equipment to ensure the written exposure control plan is properly implemented.

Medical Surveillance and Monitoring

The Silica Rule also includes updated medical surveillance requirements that were not present, or were less stringent, in the previous rule. This surveillance includes a first-time “baseline’ exam where chest X-rays, respiratory examinations, pulmonary function examinations, tuberculosis tests, and a medical and work history will be completed.

For general industry and maritime employers, when a worker is potentially exposed to crystalline silica at or above the PEL of 50 μg/m3 over an 8-hour day for 30 or more days in a single year, the employer must offer medical surveillance and monitoring to employees by June 23, 2018. The requirement to offer medical surveillance and monitoring expands to all employees exposed above the “action level” of 25 μg/m3 over an 8-hour day for 30 or more days in a single year on June 23, 2020. In other words, by June 23, 2020, all employers who potentially expose workers to crystalline silica levels above the “action level” will be required to obtain a written medical opinion from a physician or other licensed health care professional. However, these opinions will be limited in nature and will only provide employers with (1) the date of the examination; (2) a statement that the examination has met the requirements of the standard; and (3) any recommended limitations on an employee’s use of respirators. Employees will be given more detailed information that will not be passed on to the employer. Employers in the construction industry must provide the same medical surveillance and monitoring by June 23, 2017 if an employee is required to wear a respirator 30 or more days in a single year.


Employers are required to maintain records showing all exposure measurements taken to assess employee exposure to respirable crystalline silica including:

  • the date of measurement for each sample taken;
  • the task monitored;
  • sampling and analytical methods used;
  • number, duration, and results of samples taken;
  • identity of the laboratory that performed the analysis;
  • type of personal protective equipment, such as respirators, worn by the employees monitored; and
  • name, social security number, and job classification of all employees represented by the monitoring, indicating which employees were actually monitored.

Employers are also required to maintain information related to “objective data” showing the crystalline silica-containing materials at the workplace, testing data related to that material, and a nebulous requirement to keep “other data relevant to the process, task, activity, material, or exposures on which the objective data were based.” Finally, employers must maintain medical surveillance data for each employee.

Additional Construction Industry Requirements

The construction industry rules include an example “Table 1” that includes “Specified Exposure Control Methods when Working with materials Containing Crystalline Silica.” Table 1 lists 18 examples of equipment and tasks that are covered by the Silica Rule and provides preferred engineering and work practice control methods. Table 1 also lists required respiratory protection and minimum, assigned protection factors for each task covered. For tasks that require respiratory protection, as identified in Table 1, the employer is required to have a respiratory protection program sufficient to satisfy the requirements of 29 C.F.R. § 1910.134.


OSHA’s new Silica Rule contains many new requirements that must be implemented within a relatively short time frame. Employers should take steps to ensure that they are in compliance with OSHA and local laws and regulations as quickly as possible. Proactive steps in the face of this regulatory scrutiny now may allow the employer to avoid costly enforcement and litigation in the future.