California has become the fourth and largest state to adopt emergency workplace protections for COVID-19. Nearly 20 million workers in California will be protected by the new mandate, which includes requirements for face masks, physical distancing and reporting of outbreaks in the workplace.

Virginia, Michigan and Oregon have moved forward with similar plans, though such measures haven’t been legally required at the federal level. However, the Biden administration could change that.

The federal Occupational Safety and Health Administration, or OSHA, usually sets specific, enforceable rules for dealing with workplace dangers like hazardous chemicals and blood-borne diseases. But during the pandemic, the agency has declined to create a binding set of safety rules specific to COVID-19.

“There was no guidance anywhere, really,” said Maggie Robbins, a workplace safety advocate with the nonprofit Worksafe, which collaborated with California regulators on their new emergency rules.

“There’s no way we can control the broader circulation of COVID if we keep having outbreaks at workplaces,” she said.

Under the new emergency standard, California regulators will have new tools to enforce mask wearing and physical distancing, and employers will be required to investigate, report and test for potential outbreaks.

Robert Moutrie, of the California Chamber of Commerce, said that could unfairly burden employers as community spread surges.

“You may have no role in those cases appearing in your workplace, but you will be put under outbreak protocols,” he said.

Large clusters have been documented at meatpacking plants, garment factories and among farmworkers across the country, and the risk of workplace spread has increased as coronavirus cases mount.

Rebecca Reindel, director of occupational safety and health at the AFL-CIO, said the federal government should follow the lead of states like California.

“The virus doesn’t know boundaries,” she said. “You need national leadership to set those plans.”

The labor organization will be making recommendations to the Biden transition team for who should lead OSHA. President-elect Joe Biden has said he would move to create national workplace safety rules for COVID-19.