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State of California—Health and Human Services Agency
California Department of Public Health

July 12, 2023

Local Health Departments

Responding to COVID-19 Cases and Outbreaks in the Workplace


A Resource Guide for Local Health Departments


During the COVID-19 pandemic, workplaces across California have experienced COVID-19 cases and outbreaks among workers. Local health departments play an important role in working with employers to address COVID-19 in the workplace. This resource document was created to provide local health departments (LHDs) with best practices and tools for assisting employers in their jurisdictions who have identified cases of COVID-19 at the workplace.

Legal and Regulatory Requirements

A previous statewide requirement for employers to notify LHDs of COVID-19 workplace outbreaks is no longer in effect. LHDs may, however, continue to require outbreak reporting through a local order, if desired, and are encouraged to communicate required or recommended reporting thresholds to employers in their communities. LHDs can refer to the California Department of Public Health (CDPH) COVID-19 Outbreak Definitions and Reporting Guidance for additional recommendations regarding outbreak reporting.​​

Employers must provide any information requested by an LHD regarding COVID-19 cases or outbreaks in the workplace, as described in the CDPH AB 685 Outbreak Reporting Requirements.

In non-healthcare workplaces, employers are responsible for ensuring that their actions to protect workers comply with the Cal/OSHA COVID-19 Prevention Non-Emergency Regulations (COVID-19 Prevention Regulations). Employers should be advised to consult the regulatory language, Frequently Asked Questions, and other materials on the COVID-19 Prevention Regulations webpage. This resource guide is not intended to restate the comprehensive requirements of the Cal/OSHA COVID-19 Prevention Regulations.

This resource guide is also not intended for use in managing or preventing outbreaks in healthcare, correctional, shelter, or other workplace settings where Cal/OSHA's Aerosol Transmissible Diseases (ATD) standard (Title 8, Section 5199) applies.

LHDs may also wish to consult CDPH's companion Responding to COVID-19 in the Workplace for Employers resource, which includes additional details, and share this resource with employers in their communities.

Links to additional resources are provided at the end of this document. For further assistance with COVID-19 outbreaks in workplaces, LHDs may seek consultation from CDPH by emailing

1. LHDs should be prepared for identification of COVID-19 cases at workplaces in their jurisdiction. 

  • Identify a point-of-contact in your health department to receive communications from employers about COVID-19 cases among workers.
  • LHDs may set their own recommended or reporting thresholds for COVID-19 cases and should ensure employers are aware of any additional recommended or required actions.  
  • Share information with CDPH about COVID-19 workplace outbreaks.
    • If an LHD determines that t​he cases constitute an outbreak, as defined by CDPH Outbreak Definitions and Reporting Guidance, the outbreak should be reported to CDPH via the CalREDIE outbreak module, the CalCONNECT exposure event form, or the LHD's usual reporting mechanism.

2. Determine how information will be shared with partners.

  • For workplace outbreaks involving workers from multiple jurisdictions, LHDs should work together to develop an outbreak response and information sharing plan.
    • Typically, the LHD in the jurisdiction where the workplace is located manages the outbreak investigation and is responsible for sharing outbreak information with CDPH and other relevant LHDs.
    • Form an agreement among jurisdictions about how information on cases will be shared for the investigation.
  • Confirm the presence of contract or temporary workers in the facility and how information and instructions will be communicated to these individuals and their employers.
  • LHDs should consult Cal/OSHA guidance on Recording and Reporting Requirements for COVID-19 Cases and ensure employers are aware of the resources and requirements.
  • Each workplace is unique and operates under a variety of laws and regulations. LHDs should coordinate with personnel departments, legal departments, and labor unions (if applicable) to appropriately adjust this general advice to a particular industry.

3. LHDs should become familiar with requirements for workplace testing, worker notification, and work with employers in your jurisdiction to ensure they are complying with these requirements.

  • Consult the Cal/OSHA COVID-19 Prevention Regulations for more information on offering testing, acceptable test types, testing locations, and worker obligations to participate in testing.
  • LHDs should ensure that employers are aware of requirements to notify employees when cases of COVID-19 are identified in the workplace; see Labor Code 6409.6 and the Cal/OSHA COVID-19 Prevention Regulations for additional details.
  • Under certain rare circumstances, LHDs and/or employers may elect to suspend business operations when a COVID-19 outbreak has occurred in the workplace and there are concerns for ongoing transmission. ​

4. Determine when it is appropriate for cases to return to work. Communicate these requirements to employers in your jurisdiction.

  • LHDs should ensure that employers review the most recent CDPH COVID-19 Isolation Guidance​​​ to determine when workers who test positive for COVID-19 may return to work. The Cal/OSHA COVID-19 Prevention Regulations require that the CDPH guidance be followed for determining the exclusion period of workers with COVID-19. 
  • LHDs may also choose to impose stricter return-to-work requirements than those required by Cal/OSHA.

5. Ensure that employers are taking appropriate steps to reduce ongoing transmission in the workplace, in accordance with CDPH guidance and Cal/OSHA COVID-19 Prevention Regulations​.

  • LHDs should communicate with employers experiencing outbreaks regarding appropriate COVID-19 mitigation measures, including those required by the Cal/OSHA COVID-19 Prevention Regulations.
  • LHDs should ensure that employers are aware of the CDPH When and Why to Wear a Mask​​ guidance to understand how to assess the quality of a mask and the differences between masks and respirators.
    • Employers should provide masks with good fit and filtration, as described in the CDPH When and Why to Wear a Mask guidance.
    • ​In higher-risk situations, such as high-density workplaces or during workplace outbreaks, or when COVID-19 or other respiratory infection case rates are high in the community and many may be infectious to others, employers should strongly consider providing NIOSH-approved N95 respirators to employees.
  • Consult the Cal/OSHA COVID-19 Prevention Regulations to understand when masks or respirators are required for workers and what additional protective measures must be taken.
  • Review and implement ventilation measures in accordance with the COVID-19 Prevention Regulations and the CDPH Interim Guidance for Ventilation, Filtration, and Air Quality in Indoor Environments.
  • Where appropriate, LHDs may wish to conduct site visits to employers to gain additional insight into workplace-specific risk factors and appropriate mitigation measures.​

Additional Cal/OSHA Resources

Additional CDPH R​​esources

Originally Published on June 16, 2020