On June 20, 2022, the California Department of Public Health (CDPH) issued COVID-19 guidance, titled “Isolation and Quarantine Q&A,” that offers insight into the recent change to the definition of “close contact.” On June 8, 2022, the CDPH issued a revised order with new definitions of “close contact” and “infectious period.” Because the June 8 order was an “order of the CDPH,” these revised definitions were immediately incorporated into the California Division of Occupational Safety and Health’s (Cal/OSHA) COVID-19 Emergency Temporary Standards (ETS) requirements for exclusion of close contacts, which in turn impacted employers’ obligations under the ETS. The revised definitions expanded the scope of “close contact,” potentially impacting the number of employees who may be required to isolate or quarantine after exposure to a COVID-19 case.

Under the June 8 CDPH order, the revised definition of “close contact” is now as follows:

Close Contact is defined as someone sharing the same indoor airspace (e.g., home, clinic waiting room, airplane[,] etc.) for a cumulative total of 15 minutes or more over a 24-hour period (for example, three individual 5-minute exposures for a total of 15 minutes) during an infected person’s … infectious period.

The terminology “same indoor airspace” is a deviation from prior definitions and terminology used since the beginning of the COVID-19 pandemic in 2020. Previously, “close contacts” meant “being within six feet of a COVID-19 case for a cumulative total of 15 minutes or greater in any 24-hour period within or overlapping with the infectious period.” The updated CDPH guidance expands the definition of “close contact” beyond the meaning used during the last two years.

While the revised “close contact” definition offered some examples of “same indoor space” (e.g., home, clinic waiting room, airplane, etc.), there appears to be some ambiguity in the definition of “same indoor space,” especially when dealing with larger indoor workspaces, such as warehouses and manufacturing plants. The June 20 CDPH Isolation and Quarantine Q&A offers further guidance to the recently revised “close contact” definition.

The June 20 Q&A guidance explains that the recent definition that expands the meaning of “close contacts” is due to CDPH’s position that “COVID-19 is an airborne disease (similar to measles and varicella), rather than one spread by respiratory droplets” and that the CDPH “has moved away from risk mitigation strategies that include physical distancing and physical barriers, and instead has adopted approaches that mitigate the risk of inhalation of infectious aerosols, including ventilation, air filtration, use of masks whenever indoors, and attention to mask fit and filtration.” In other words, the CDPH indicates it is implementing strategies to address airborne transmission of COVID-19.

The CDPH also offered the guidance for “prioritizing” an employers’ response to “close contacts” under the revised definition. The CDPH advised that “entities” may “prioritize” the response to “close contacts” by:

• “Identifying close contacts who may be considered ‘high-risk contacts’ based on their proximity to the case in the setting, the duration or intensity of their exposure, and/or their greater risk of severe illness or death from an exposure. Although SARS-CoV-2 is airborne, those closest to the infected person will be at greatest risk of exposure.

• Determining any smaller spaces within the larger indoor setting for the purposes of assessing potential exposure. For example, individual rooms, waiting areas, bathrooms, or break or eating areas within larger areas could be identified as the shared airspace area. When a larger indoor space cannot be easily divided into smaller discrete spaces, then close contacts may be determined based on proximity to the positive case, particularly in high-risk settings where close contacts might be considered for quarantine, cohorting, or work exclusion. Viral particles are less likely to concentrate in larger indoor spaces (e.g., department store or indoor shopping mall, or warehouse, gymnasium) so only those closer to the infectious person or in a more enclosed shared airspace would be considered at great enough risk of becoming infected to be called a close contact.

• Determining any transient exposures totaling

While the June 20 CDPH Isolation and Quarantine Q&A is not incorporated into the Cal/OSHA ETS because it is not a “regulation or order of the CDPH,” it may offer some insight into an employer’s obligations for “close contacts” under the ETS, especially in larger indoor settings. Employers may want to update their policies and procedures for excluding close contacts pursuant to the CDPH guideline tables in light of the updated CDPH definition of “close contact” and related guidance.