Respirable Crystalline Silica Regulations – Cal/OSHA Adopts Emergency Temporary Standard for General Industry


On December 14, 2023, the Occupational Safety and Health Standards Board (OSHSB) approved Cal/OSHA language for the Emergency Temporary Standard (ETS) on respirable crystalline silica for General Industry (under California Code of Regulation, Title 8, section 5204). The ETS went into affect on December 29, 2023, which includes and emphasizes revisions to protect workers engaged in “high-exposure trigger tasks” involving work with artificial and natural stone.

Prior to its expiration date (one year), the Standards Board will vote on whether the ETS will be permanent or if they will make updates to the ETS as it currently stands. One should expect it to become permanent at the end of 2024 with some potential changes to the current language.

Most Notable Updates from the Emergency Temporary Standard (ETS) for General Industry

High Exposure Trigger Tasks

The Definition of “high-exposure trigger tasks” is defined as any dust-generating work with artificial stone that contains more than 0.1% crystalline silica by weight or with natural stone that contains more than 10% crystalline silica by weight. When conducting these tasks, exposure monitoring, regulated areas, respirator usage, hazard control plans, and stringent housekeeping are required.

  • These requirements cannot be alleviated by objective task-based exposure data from personnel monitoring. In the standard’s original language, the section did not apply to employers that had objective data demonstrating employee exposure to respirable crystalline silica would remain below 25 micrograms per cubic meter of air (25 μg/m3) as an 8-hour time-weighted average (TWA) under any foreseeable conditions. Language in the ETS states that this statement no longer applies to those who perform “high-exposure trigger tasks.”
  • Employees performing “high-exposure trigger tasks” must wear a full-face, tight-fitting powered-air purifying respirator (PAPR). There is some nuance here, but what’s clear is that a half-face negative pressure respirator won’t cut it and you may have to implement supplied air in the event of a silicosis diagnosis or at the recommendation of a physician.
  • The high exposure trigger is based on the content of silica, and the anticipated handling and manufacturing of artificial or natural stone products.
  • Those performing “high-exposure trigger tasks” must be monitored at least every 12 months or more frequently as defined in the scheduled monitoring option of the standard (e.g., every 3 months if results are above the PEL).

Additional Updates in the ETS

Additional aspects of the ETS, in general (not driven by high-exposure trigger tasks), include:

  • Respirator Protection guidelines for housekeeping activities, and donning and doffing equipment
  • Recordkeeping and airborne monitoring data retention
  • Proper reporting of Carcinogen Use (Section 5203)
  • Reporting of silicosis or cancer case to Cal/OSHA required within 24 hours of confirmation.

The ETS also allows Cal/OSHA to quickly shut down an operation if work violates the ETS and endangers employee health.

While the ETS affects Cal/OSHA’s general industry regulation only (i.e., there were no changes made to the construction industry regulation, 8 CCR 1532.3), it is an aggressive approach to limiting activities that give rise to silicosis- an occupational disease that has been recognized by industrial hygienists and the medical community for nearly a century.

Additional information on the ETS can be found at the links below:

If you’re unsure how the ETS affects your business or need assistance complying with the standard, contact FACS to speak with an expert today.