On December 19, 2024, the Cal/OSHA Standards Board unanimously approved a proposal to make permanent amendments to its regulation regarding occupational exposures to respirable crystalline silica (RCS) in the general industry sector. The new requirements will become effective after approval by the Office of Administrative Law (OAL), anticipated in late January or early February 2025.

This final regulation follows a series of emergency temporary standards (ETS) that Cal/OSHA approved beginning in December 2023 to respond to an exponential rise in the number of documented cases of occupational silicosis in California, many of which involved young immigrant workers, who developed the severe illness after short exposure periods.

Which Employers Are Covered by the New Regulation?

While Cal/OSHA officials have stated that the regulation is intended to apply only to a narrow slice of operations involving the manufacturing of engineered stone, the text of the regulation does not define the scope of engineered stone manufacturing operations to be covered. Theoretically, the regulation could be applicable to employers across the general industry whose employees are exposed to RCS with the exception of three specific industries:

(1) construction work covered under Title 8 Section 1532.2;

(2) agricultural operations covered under Section 3436; and

(3) exposures that result from the processing of sorptive clays.

The regulation also states that it does not apply “where the employer has objective data demonstrating that employee exposure to respirable crystalline silica will remain below 25 micrograms per cubic meter of air (25µg/m3) as an 8-hour time weighted average (TWA) under any foreseeable conditions.” While this exception could broadly exclude many industries, it has already been subject to various criticisms. A result for California employers is uncertainty as to how broadly Cal/OSHA’s enforcement unit might seek to apply the new regulation, despite the repeated claims by Cal/OSHA during the rulemaking process that it is intended to apply to one specific industry only.

What Does the New RCS Regulation Require?

Under the regulation, covered employers in California must ensure that no employee is exposed to an airborne concentration of RCS above the permissible exposure limit.¹ The regulation further requires that such employers implement various safety measures including the following:

Exposure Assessments: Each employee who is or may reasonably be expected to be exposed to RCS must be assessed for exposure to RCS using one of two methods,² with specific requirements for high-exposure trigger tasks. Employers must repeat this monitoring at least every six months, with some testing results requiring follow-up monitoring as soon as three months after initial testing. Employers must then conduct exposure reassessments when certain changes in the work environment occur, and written notification of the assessment or reassessment results must be provided to employees, along with the corrective actions to be taken, if any.

Engineering and Work Practice Controls: Engineering and work practice controls designed to reduce exposure to RCS must be implemented, such as effective housekeeping practices. In addition, specific engineering controls and additional work practices are required for high-exposure trigger tasks.

Medical Surveillance and Medical Removal: Employers must provide initial and periodic medical examinations at no cost to employees, and at a reasonable time and place. Likewise, if an employee is removed from a job assignment per the regulation, the employer must maintain the employee’s current earnings, seniority, and other benefits for up to six months.

Written Exposure Control Plan: A written exposure control plan must be implemented that incorporates many of the elements discussed above, with additional information for areas where high-exposure tasks occur. The plan must be reviewed annually, and a copy of the plan must be readily available for examination and copying upon request from a covered employee.

Reporting of Silicosis: Employees must be encouraged to report symptoms of RCS exposure without fear of retaliation. Furthermore, employers must report, within 24 hours, any confirmed RCS exposure-related silicosis or cancer case to the California Department of Health and Cal/OSHA. Likewise, healthcare providers who have been contracted by employers to evaluate their employees must report confirmed silicosis cases to Cal/OSHA.

Recordkeeping: Employers will also be responsible for maintaining records of air monitoring data, data the employer used to comply with the regulation, and medical surveillance data.³

In addition to these measures, the regulation also requires that employers properly demarcate and limit access to regulated areas, provide respiratory protection, and provide additional training related to RCS hazards.

Regulation of Engineered Stone Remains Under Active Development

The development and adoption of the new RCS regulation illustrate features of the current administrative rulemaking process that should be of broader interest to California employers. This includes a recurring question about whether a particular kind of workplace safety issue might be achieved through more effective enforcement of existing regulations rather than by devoting limited agency resources to the development of complex and arguably burdensome regulations. The final RCS regulation was no exception, as Cal/OSHA’s Special Emphasis Program (SEP) found widespread non-compliance with the regulation that already existed, and industry representatives argued that the agency should focus their efforts on these non-compliant employers instead of the rulemaking process.

Likewise, the adoption of the final regulation provides another example of the Cal/OSHA’s Standards Board voting to approve a proposal that many (or all) Board Members criticized because of many unresolved questions or problems with the regulations at issue at a time when the Board was prevented by applicable timing constraints from further delaying a vote. Similar to other recent examples involving items such as several of the COVID emergency temporary standards, the indoor heat illness prevention regulation, and others, fast-changing circumstances and/or new data appear to have increasingly outpaced the ability of the regulatory rulemaking process to adjust.

Additionally, there is pending legislation that, if adopted, would address many of the same RCS issues covered by the final regulation. Senate Bill (SB20), supported by the engineered stone industry, was introduced in early December 2024, and would entirely prohibit “dry production” methods, create requirements for the certification of any operations engaged in engineered stone manufacture, and prohibit the use of materials not produced in certified facilities. This could lead to duplicative and potentially conflicting requirements for covered employers.

Littler will continue to monitor this highly dynamic issue. Employers should continue to review and revise their safety policies and practices proactively to promote worker safety, and should consult with counsel to ensure compliance with fast-changing regulatory requirements.