In August 2013, OSHA announced a newly proposed rule to regulate respirable crystalline silica, a hazardous substance known to cause serious health issues like silicosis, lung cancer, and kidney disease. Following years of public hearings, testimonies, and input from stakeholders, OSHA finalized the rule in March 2016 after the Office of Management and Budget completed its review. Enforcement began in September 2017 for the construction industry and June 2018 for general industry and maritime sectors.

Now that the respirable crystalline silica rule is in effect, what does it mean for employers and team members?
Key Provisions of the Respirable Crystalline Silica Rule

Permissible Exposure Limit (PEL): 
50 µg/m³

Employers must ensure that workers’ exposures do not exceed 50 µg/m³ (micrograms per cubic meter) over an eight-hour, time-weighted average (TWA). 

Action Level: 25 µg/m³

The rule also establishes an action level of 25 µg/m³. If workplace exposure reaches or exceeds this level, employers must take these proactive measures to monitor and reduce exposure, even if the PEL has not been exceeded:

Exposure Assessment 
Written Exposure Plan 
Regulated Areas 
Housekeeping 
Medical Surveillance 
Training/Hazard communication 
Recordkeeping

One of the major requirements of the standard is to conduct exposure assessments. According to the standard, the employer shall assess the initial exposure of each employee who is or may reasonably be expected to be exposed to respirable crystalline silica at or above the action level (25 ug/m3). The team member’s exposure shall be assessed via the Scheduled Monitoring Option or the Performance Option. 

According to the Scheduled Monitoring Options as seen in Table 1, if employees’ exposures are at or above the action level but below the PEL then sampling must be conducted every six months. If the exposures are above the PEL (50 µg/m³), then sampling must be done every three months. 

Managing a Scheduled Monitoring Option can be very time consuming. It requires significant administrative effort to compile and analyze data, maintain an accurate sampling plan, and coordinate plant operations with sampling opportunities that may occur semi-annually, quarterly, or even more frequently.

For many facilities, the greatest challenge lies in managing the ongoing costs of maintaining a Scheduled Monitoring plan. By this stage, facilities have often already invested heavily in medical examinations, respiratory protection equipment, and engineering controls. In some cases, significant expenditures have been made to implement various engineering controls aimed at reducing exposure—investments that can total millions of dollars. These substantial costs are further compounded by the expenses associated with collecting personal air samples for respirable crystalline silica. Depending on the size of the facility and the scope of its Scheduled Monitoring plan, sampling costs can run into tens of thousands of dollars. 

As seen in the graphics on this page, the Scheduled Monitoring Options involves 

1) Characterizing your workplace, job, and tasks to get an idea of who, where, when and how much (2) exposure monitoring to conduct. Once the exposure baseline has been established, then (3) an exposure control plan can be developed. This will identify how the facility plans to control exposures based on the exposure monitoring results. To help document financial investments in implemented engineering controls (4) an engineering control plan can be developed. 

After implementing or updating controls, additional exposure monitoring is conducted to verify their effectiveness. This step is performed alongside the ongoing “scheduled monitoring” requirements. The process continues until two consecutive non-initial monitoring results, taken at least seven days apart but within six months of each other, are below the action level. Once this criterion is met, monitoring can be discontinued, provided there are no subsequent changes that could impact exposure levels.

The Performance Option

Given the considerations mentioned, is there another viable option? Yes: the Performance Option.

 This option allows for a more flexible and potentially less resource-intensive approach compared to the Scheduled Monitoring Option, while still ensuring effective controls and reduction of exposure levels.

The Performance Option allows an employer to assess the eight-hour TWA exposure for each employee based on a combination of air monitoring data or subjective data to accurately characterize employee exposures. This option may save time and costs, but it is not a one-and-done option.

Similar to the Scheduled Monitoring Option, the Performance Option requires facilities to characterize the exposure of each employee on every shift where crystalline silica exposure is reasonably anticipated. This characterization is verified through exposure monitoring, which forms the foundation for developing an exposure control plan.

Once the workplace has been thoroughly sampled and characterized, and if exposures meet or exceed the action level, facilities can opt for the Performance Option. However, this is contingent on meeting all other requirements of the Respirable Crystalline Silica Standard, including:

Maintaining a written exposure control plan.
Ensuring appropriate respiratory protection is in use.
Identifying and properly controlling access to regulated areas.
Implementing regular housekeeping practices.
Completing all required medical surveillance.

By adhering to these requirements, the Performance Option provides a compliant and cost-effective pathway for managing exposures. However, keep in mind that the facility must reassess their exposures whenever there is a change in process, production, engineering controls, work practices and/or raw materials that may be expected to result in a new exposure.