The Labor Department released a workplace safety standard for risks posed by the coronavirus on Thursday after more than a year of debate, ending months of speculation about the administration’s plans after it missed a self-imposed March deadline.

The emergency temporary standard (ETS), as it is called, will apply only to health-care facilities — a much narrower purview than many advocates, labor unions and Democrats who work on labor policy had pushed for dating to the Trump administration.

The standard requires health-care facilities where coronavirus patients are treated to implement precautions such as mandatory mask-wearing, social distancing, and cleaning and disinfecting procedures, and notify workers when they are exposed to infections among co-workers, under the threat of penalty. It will also require employers to provide paid time off for workers to get vaccinated or rest while dealing with side effects.

It will become effective when it is published in the Federal Register, which officials said would happen soon; employers will have two weeks to comply with most of the provisions.

The Labor Department will also issue updated guidance for facilities that have an elevated risk of transmission, such as meatpacking plants, grocery stores and high-volume retail locations.

The move ties the knot on one of the Biden administration’s biggest questions about labor policy.

Labor advocates and former federal officials including David Michaels, the head of the Occupational Safety and Health Administration during the Obama administration, had hoped that President Biden would move swiftly after his inauguration to implement an ETS, as the pandemic continued to surge nationwide.

Workplace transmission has not been studied in depth in the United States amid a larger lack of robust contact tracing, but it is believed to have been a significant driver of infections, as hundreds of thousands of workers have become sick. The state of Oregon, which tracked workplace infections of five or more cases, at workplaces larger than 30 employers, found that workplace outbreaks made for at least 11 percent of the states’ 204,000 cases, according to the most recent data.

The Trump administration had declined a safety standard early on in the pandemic when outbreaks were speeding through workplaces, opting instead for guidance or recommendations that did not come with the threat of enforcement.

Biden issued an executive order on his second day in office that directed the Labor Department to issue an ETS by March 15, if necessary. The Senate confirmed a labor secretary, former Boston mayor Marty Walsh, in March, and the department missed the deadline.

The issue languished even after Walsh’s confirmation — former Hill and Labor Department officials said they were concerned in April that it could be done away with entirely. But, with vaccination rates nationwide appearing to have significantly reduced — but not eliminated — the threat of the virus, the standard released Thursday represents a half measure.

Administration officials said that the standard presented a challenge, as understanding about the virus has continued to shift.

“It’s been very tricky with guidance and the virus changing over the last couple of months,” Walsh said Thursday on a call with reporters. “The science tells us workers, particularly those who come into regular contact with the virus, are most at risk at this stage of the pandemic.”

Rep. Virginia Foxx (N.C.), the ranking Republican on the House Education and Labor Committee, slammed the regulation in a statement.

“Placing new and burdensome regulations on this heroic industry at this stage of the pandemic is completely unnecessary,” she said. “Further, we cannot endorse an inflexible, restrictive regulation that is unable to keep up with the ever-evolving science regarding covid-19.”

Democratic leaders on the committee, which has been pushing for the standard for more than a year, said they were disappointed the rule didn’t go further.

“I am disappointed by both the timing and the scope of this workplace safety standard,” said the committee’s chairman, Rep. Robert C. “Bobby” Scott (Va.). “This ETS is long past due, and it provides no meaningful protection to many workers who remain at high risk of serious illness from COVID-19. Workers in meat processing plants, prisons, homeless shelters, grocery stores, and many other workplaces will be forced to continue relying on voluntary safety guidance, which has failed to protect hundreds of thousands of workers and families from preventable infections throughout the pandemic.”

Labor advocates said they were disappointed by the move, pointing out that only about half of the working-age population is vaccinated.

“Unvaccinated workers remain at risk and must be protected,” said Debbie Berkowitz, a former OSHA official who has been one of the most prominent proponents of a wider standard. “We know that workers in many industries outside of health care faced elevated risks of covid, especially in low-wage industries like meat processing, that are disproportionately Black and Brown workers, and we need to make sure these workers are still protected with mitigation measures such as ventilation and filtration to control airborne exposures, and masks and social distancing.”