The U.S. Occupational Safety and Health Administration on Thursday released its long-awaited emergency temporary standard mandating that employers with 100 or more workers enforce COVID-19 vaccine or testing requirements on their workforces.

The mandate, which does not require employers to pay for vaccines or face masks, will go into full effect on Jan. 4, 2022.

According to the standard, employees will have to submit proof that they have been vaccinated or comply with weekly COVID-19 testing.

The standard requires employers to provide paid time off to workers to get vaccinated and recover from side effects of the vaccine.

Other requirements for employers in the nearly 500-page document include:

• Determine and maintain records of the vaccination status of the vaccination of each employee.
• Require employees to provide prompt notice when they test positive or are diagnosed with COVID-19. Employers must then remove the employee from the workplace.
• Ensure that unvaccinated workers wear a face mask when indoors or in a vehicle with others.

OSHA estimates that the mandate will cover two-thirds of the U.S. private workforce.

The mandate will be published in the federal register on Friday, and employers must comply with most requirements within 30 days and with the testing requirements within 60 days or face possible fines. Employers and others have 30 days to comment on the standard.

OSHA said it anticipates the standard will be in effect for six months. It said it will continue to monitor the effect of COVID-19 and update the standard when it finds a “grave danger” from the virus no longer exists.

The publication ends months of speculation as to what OSHA would require of employers regarding vaccines.

The standard is clearly intended to encourage mandatory vaccinations, said David Michaels, professor of environmental and occupational health at the Milken Institute School of Public Health at George Washington University, and a former assistant secretary of labor for OSHA.

He was speaking during a webinar Thursday sponsored by Axiom Medical Consulting LLC.

“Testing can be expensive, it can be time-consuming, so this will encourage people to get vaccinated,” he said.

Employers likely won’t see large numbers of employees refusing the requirements and quitting, Mr. Michaels said. Large employers that previously imposed their own vaccination and testing mandates on employees did not see widespread resignations, he said.