Business owners with 100 or more people on the payroll — collectively employing an estimated 80 million U.S. workers — will have to ensure a vaccinated workforce or face fines up to $14,000 per failure, as part of an upcoming OSHA regulation outlined by President Biden on Thursday.

The plan does allow for an unvaccinated worker in the private sector to undergo weekly COVID testing as an alternative. The requirement is also expected to include accommodations for religious exemptions.

Employers affected by the mandate would also have to provide paid time off for workers to get vaccinated.

The upcoming requirement sits at the core of the administration’s latest round of measures to combat COVID. The Delta variant’s increased transmissibility and a hardened but sizable anti-vaccination minority in the U.S. population have driven a spike in cases that rivals pre-vaccine numbers in some areas.

The administration’s plan extends the vaccine requirement to federal workers, but those workers would not have the option to remain unvaccinated and take weekly tests. More importantly for the HVAC industry, initial descriptions suggest that contractors who do business with the federal government would also fall under this stricter requirement.

Preliminary reactions varied. As an OSHA regulation, the administration’s initiative is not subject to Congressional approval. However, some conservative officials questioned the legality of the measures immediately, and that opposition may take the shape of litigation in the near future.

Initial union concern focused on preserving the procedure for negotiating workplace policies with collective bargaining partners.

The American Medical Association stated that with “our health system and physicians stretched thin, the AMA is pleased by the Administration’s significant efforts to help get this pandemic under control. Aggressive measures will be needed to prevent further widespread transmission of COVID-19.”

Once finalized, additional details regarding deadlines, procedures, and enforcement are likely to come via a more formal announcement from the Department of Labor.