Last month, California's Department of Public Health updated its masking guidance in response to an uptick in state COVID-19 cases and hospitalizations.
The guidance says that all people should wear face masks in public indoor places regardless of vaccination status.
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Cal/OSHA is now aligning with that guidance as more COVID-19 infections are being reported in workplaces across California.
It is not an official mask mandate. Cal/OSHA officials said employers need to provide face masks to workers who request one.
As part of California's reopening of the economy in June, the state lifted its mask mandate issued the previous summer for vaccinated people.
State health officials say masks are still required for all Californians, vaccinated or not, in some public settings such as hospitals, public transportation, schools and shelters.