Seyfarth Synopsis: Ongoing wildfires in Southern California trigger Cal/OSHA regulations that require employers to train and protect employees from wildfire smoke. The regulation applies to most outdoor workplaces, requiring employers to provide N95 respirators at certain AQI trigger levels, effective communication, and training on wildfire smoke hazards.

Devastating and fast-moving wildfires have destroyed thousands of homes and businesses in several parts of Southern California, resulting in tragic deaths, upended lives, and disrupted workplaces.  As firefighters continue to battle the fires and bring them under control, the region has been blanketed by wildfire smoke, a recognized occupational hazard. Though smoke is often apparent via sight and smell, air quality can be impacted far beyond the range of the fires.

Cal/OSHA enforces a permanent regulation relating to Protection from Wildfire Smoke that applies to workplaces where the current Air Quality Index (AQI) for airborne particulate matter (PM 2.5) is 151 or greater, and where employers should reasonably anticipate that employees could be exposed to wildfire smoke. Employers must track wildfire smoke in areas where employee exposure is anticipated, using one of several options provided authorized by Cal/OSHA, including the airnow.gov website maintained by U.S. EPA. As of January 9, 2025, AirNow approximates AQI Category of 150 or more (for all particulate matter, not just PM 2.5) in the red, purple, and maroon areas below:

 Courtesy of AirNow.gov as of 9:20am January 9, 2025.

Employers can anticipate that most of the workforce of Los Angeles County and surrounding areas could be occupationally exposed to wildfire smoke in the coming days above the AQI threshold. For instance, construction sites, warehouses with open bay doors, retail workers who go outdoors, and even indoor workplaces without mechanical ventilation that rely upon open windows will all be impacted by wildfire smoke.  Indoor workplaces and enclosed vehicles with mechanical ventilation and closed windows are exempt from the standard, as are employees who are only exposed to an AQI for PM 2.5 of 151 or above for less than one hour per shift. Firefighters engaged in wildland firefighting are not covered by the standard. 

Employers with covered employees must take the following steps to protect workers who may be exposed to wildfire smoke:

  • Monitor air quality using one of the methods set out in the rule, including AirNow.gov.
  • Identify harmful exposure to airborne particulate matter from wildfire smoke at the start of each shift and periodically thereafter by checking the AQI for PM 2.5 in regions where workers are located.
  • Reduce harmful exposure to wildfire smoke if feasible, for example, by relocating work to an enclosed building with filtered air, or to an outdoor location where the AQI for PM 2.5 is 150 or lower.
  • If employers cannot reduce workers’ harmful exposure to wildfire smoke so that the AQI for PM 2.5 is 150 or lower, they must provide:
  • Filtering facepiece respirators such as N95 masks to all employees for voluntary use, and
  • Training on the hazard as required by the Injury and Illness Prevention Plan.

If employees must be exposed to an AQI for PM 2.5 of 500 or above, appropriate respiratory protection is mandatory and must be provided under a compliant respiratory protection program. Employers also need to establish and implement a system for communicating wildfire smoke hazards with employees and ensure that employees may report such hazards without fear of reprisal.

For more information on this or any related topic please contact the authors, your Seyfarth attorney, or any member of the Seyfarth Workplace Safety and Health (OSHA/MSHA) Team.