Two of these steps were implemented by the administration on Thursday — two vaccine rules that cover more than 100,000,000 workers.

These are the details:

Deadline Jan. 4. The Occupational Safety and Health Administration issued the first rule that applies to companies with more than 100 employees. It is applicable to approximately 84 million workers. The company must make sure that all employees are fully vaccinated against COVID-19 before January 4th or that they have a COVID-19 test negative at least once per week. This rule will be effective as soon as it is published in the Federal Register.

Workers have to be paid for time taken to get vaccinated. OSHA rules require employers to pay workers for the time they take to get vaccinated. They also must provide sick leave to workers in order to treat any side effects.

Employers do not need to pay testing fees: The rule isn’t intended to force workers to opt for vaccinations over testing. However, it does not require employers that they pay for or provide testing for workers who refuse the vaccine. But, it is possible that collective bargaining agreements and other circumstances will dictate otherwise.

People who are not vaccinated must use masks. Unvaccinated workers should also use face covers while working.

Under a separate rule, health care workers are not allowed to test. A second rule by the Centers for Medicare & Medicaid Services mandates that 17 million workers be vaccinated by Jan. 4. There is no option for weekly testing. This rule applies to all employees, clinical and not-clinical, at approximately 76,000 facilities that receive federal funds from Medicare or Medicaid.

Biden had previously ordered that federal workers and contractors be vaccinated. There was no option for testing. Federal workers can get shots up to Nov. 22, while federal contractors can wait until Jan. 4.

Although vaccine requirements have been successful, there is a potential backlash.

Officials from the Biden administration stated that vaccine requirements are good economic news and that only a fraction of workers will opt to quit their job in order to comply with the mandates. From Tyson Foods to Houston Methodist hospitals, employers have reported rates of 96% or more.

However, the Republican-led states reacted quickly to the announcement of the rules, with over a dozen state attorneys general threatening legal action against the Biden administration.

They wrote to Biden Sept. 16 warning that a vaccine requirement could increase skepticism about the COVID-19 vaccines, and force some workers to quit their jobs. This would further stress an already tight labor market. They claimed that an OSHA rule was illegal and denied that COVID-19 is considered a work-related danger that falls within the agency’s purview.

Companies that are covered by OSHA rules can challenge them in court. More challenges are anticipated in the coming days.

The Biden administration quickly outlined its legal authority by issuing the rule this week. It cited OSHA’s responsibility to ensure workers have safe and healthy work conditions, and to respond promptly to workers in grave danger.

A senior administration official stated that a virus that has claimed the lives of more than 750,000 Americans and is causing more than 70,000 cases each day is clearly a danger to workers.

In the first year of the pandemic, workplace outbreaks were numerous and varied. A congressional committee found that 59,000 workers in meatpacking were infected by COVID-19, and that at most 269 of them had died.

The federal government largely relies on the companies to enforce the rule.

Enforcement of OSHA rules will be largely left to the companies. There are only a few thousand OSHA inspectors in each state and federal, so there is no way to check on millions of workplaces and see if they have kept records for testing and vaccinations.

OSHA inspectors will instead respond to employee complaints, and add COVID inspections to their to do lists when they’re already present on-site. Employers who break the rules can be fined up to $13,653 for serious violations, and up to 10 times for repeated or willful violations.

Before the vaccine-or test rule goes into effect, there is one more step that states must take. OSHA approved state plans for workplace safety in 21 states and Puerto Rico. These states are required to adopt rules that are at least equal in effectiveness to the federal one within 30 days.

The Labor Department threatened to cancel the state plans of three states, Arizona, South Carolina, and Utah, last month. They had not yet adopted OSHA’s June emergency rule that was intended to protect health care workers.

These states and others could also delay the implementation the federal vaccine-or test rule. However, employers in these states may decide to go ahead on their own.