As the California wildfires continue to impact communities in southern California, employers in and around the fire zones are wondering how to prioritize the health, safety, and wellbeing of their employees, while also continuing to operate. The summary below outlines considerations for making those decisions.  

General Safety Requirements for All Employees near Fire Zones

If a workplace is located within an evacuation zone, employers cannot require employees to work in those zones unless, of course, they are part of the emergency response. Employers will need to consider allowing employees to temporarily work remotely until it is safe to return the workplace, or simply place employees on a temporary layoff.

Outside the evacuation zones, employers must evaluate potential hazards and determine if it is feasible and safe for employees to return to work. 

Cal/OSHA Has a Wildfire Smoke Standard (Where there is fire, there is smoke)

Cal/OSHA has adopted a wildfire safety standard. Wildfire smoke can present hazards that affect employees, both while fires are actively burning, and after fires are extinguished. 8 CCR § 5141.1 The standard outlines requirements to protect employees exposed to wildfire smoke. The regulation applies in situations when the employer should reasonably anticipate that employees may be exposed to wildfire smoke if the current local Air Quality Index (AQI) for PM2.5 is 151 or greater.

What is the PM2.5 AQI?

The PM2.5 Air Quality Index (AQI) is a tool used to assess outdoor air quality. Monitors periodically measure the level of fine particulate matter smaller than 2.5 microns (PM2.5) in ambient air. PM2.5 is a potentially harmful component of wildfire smoke. The government measures PM2.5 throughout the day and reports the result on the web. https://www.airnow.gov/state/?name=california. These PM2.5 measurements are compared to Air Quality Indexes that range from Good (less than 50) to Hazardous (greater than 300). https://www.aqi.in/us/dashboard/united-states/california  Cal/OSHA uses a midrange level of 151 and above as the trigger for its Cal/OSHA standard.

Who is Covered by the Cal/OSHA Standard?

The standard applies to workplaces where: (A) the AQI is over 151; and (B) the employer should reasonably anticipate that employees may be exposed to wildfire smoke. The following Exemptions apply:

1. Enclosed buildings or structures in which the air is filtered by a mechanical ventilation system and the employer ensures that windows, doors, bays, and other openings are kept closed, except when it is necessary to open doors to enter or exit.
2. Enclosed vehicles in which the air is filtered by a cabin air filter and the employer ensures that windows, doors, and other openings are kept closed, except when it is necessary to open doors to enter or exit the vehicle.
3. The employer demonstrates that the concentration of PM2.5 in the air does not exceed a concentration that corresponds to a current AQI of 151 or greater by measuring PM2.5 levels at the worksite in accordance with Appendix A (found here).
4. Employees exposed to a current AQI for PM2.5 of 151 or greater for a total of one hour or less during a shift.
5. Firefighters engaged in wildland firefighting.

What Does The Cal/OSHA Standard Require?

Under the regulation, the employer must:

• Determine the employee exposure to PM2.5 for covered worksites at the start of each shift and periodically during the shift as there are changes.
• Check current and forecasted PM2.5 levels and determine the AQI levels that employees may be exposed to.
• Implement a system of communicating wildfire smoke hazards in a manner understandable to employees (translate, pictures, etc.). The communication should alert employees of the current AQI and protective measures available to employees to reduce exposures (stay inside, wear respirator masks, move to a zone where AQI is lower, limit time outside of filtered ventilation).
• Encourage employees to inform the employer if air quality worsens or adverse symptoms are experienced (asthma attacks, difficulty breathing, and chest pain).
• Provide effective training.

How Should I Apply the AQI Now and in the Future?

As noted above, the Cal/OSHA regulation does not apply to certain workplaces and operations, such as enclosed buildings in which the air is filtered by a mechanical ventilation system, or enclosed vehicles in which air is filtered by a cabin air filter, if the employer ensures that windows, doors, and other openings to buildings and vehicles are kept closed, except when entering or exiting. Employers with indoor workplaces should take appropriate steps to reduce exposure to wildfire smoke by ensuring ventilation systems are properly maintained and functioning, and masks are available if smoke levels are above the AQI of 100.

During the pandemic there was a great deal of focus on air filtration, with “MERV 13” filtration considered the gold standard. N95 masks were also the norm. How do these compare to wildfire smoke?

COVID 19 virus particles are in the range of 0.5 microns, while PM2.5 reflects particle size of 2.5 microns (5X larger). So N95 and KN 95 masks, which filter 95% of particles 0.3 microns and larger, are effective in wildfire smoke situations. MERV 13 air system filters will remove 90% of particles 0.3 microns or larger.

Not every building installed MERV 13 filters. The EPA lists the effectiveness of filters on the MERV scale here.

At AQI levels between 150 and 500, employers must provide at no cost to employees, respirators for “voluntary use.” Above an AQI of 500, employers must require respirator use. For voluntary respirator use, an employer need only provide employees Appendix D to the respiratory protection standard. Where use is mandated by the employer (below AQI of 500) or the AQI is above 500, the employer must comply with the full OSHA respiratory protection standard, which includes fit testing, medical evaluations, and adoption of a respirator program.  https://www.dir.ca.gov/Title8/5144.html

Healthy employees can drive to work and work in buildings that have filtration. As the smoke levels exceed an AQI of 100, employers should plan to limit work outside of ventilation, because the AQI can quickly change. Adopting a specific AQI that will trigger a work from home policy should consider the precedent that will set. 

Los Angeles air quality is notoriously bad. In 2024 there were 107 days with the AQI over 100. See, Air Quality Days by Year for Los Angeles County, California. Since elevated AQIs in LA are normal, employers who create fire response policies tied to wildfire AQIs, could set precedent for the future where fires are not present.  

Other Things to Consider

• Issue a Wage Theft Prevention Act Notice to all newly hired non-exempt employees who will be working in a county where an emergency or disaster declaration has been issued in the language usually used to communicate employment-related information. Cal. Lab. Code. § 2810.5. The Labor Commissioner has provided translated versions of the forms into the most commonly used languages.
• While the OSHA standard applies to outdoor smoke, employers may consider using a monitor for indoor levels. Berkley Labs has studied 4 different low-cost indoor monitors.  Berkley Labs Report
• Employees who have respiratory health conditions may need an accommodation under state and federal law, such as the ADA. Consult an employment attorney if an employee raises a health condition as a reason for not coming to work or if you are aware of an employee health condition that may be affected.  
• Employees may be able to use accrued sick leave for absences related to wildfires.
• Employees who develop a serious health condition due to wildfires (or who have a family member who is sick) may be entitled to family and/or medical leave under the federal Family and Medical Leave Act or the California Family Rights Act.
• Employees involved in the fire response may be protected under USERRA (military leave law) if they fall under the National Disaster Medical System (NDMS)
• You may be able to help employees with a benefit plan hardship distribution, set up a charitable foundation to assist employees who lost their home, or set up a leave sharing program to allow employees to share accrued leave with those most impacted by the fires.
• Salaried exempt employees are entitled to a full week of pay, if they work any time during that week, and then are unable to work due to “inability” to work caused by fires. The inability to work v. personal reasons, is often a source of dispute in weather or other emergencies.

Conclusions

Employee communication is important. By demonstrating that you are following legal requirements and managing risk, employees may be more comfortable coming to work. Verifying your indoor filtration is sufficient and working, providing masks to employees, and communicating that you are monitoring changes in air quality, will go a long way to making employees comfortable that it is safe to come to work. Do not set a stringent work from home standard that you may have to live with after the smoke has settled. If AQI exceeds 500, and you need to mandate masks because employees will be outdoors, or you cannot manage indoor air quality due to unfiltered outside air, you may need to require masks, which requires a respiratory program. That may be the point where temporary closure is in order, rather than mask mandates.