Since the beginning of the pandemic, many employers in the United States, out of concern for the safety and health of their employees, have required employees to be vaccinated, wear masks, practice social distancing, and otherwise take steps to assure workers that their workplace is safe. Employers have been challenged, though, by inconsistent state laws and executive edicts contrary to these requirements, as well as by protests by significant numbers (if a minority) of employees who have objected to these mandates, whether on religious, medical, or political grounds.

The OSHA emergency temporary standard (ETS) would require all employers with 100 or more employees to develop, implement, and enforce either a mandatory vaccine policy, or a policy requiring employees to elect either to get vaccinated or to undergo regular COVID-19 testing and wear a face covering at work. OSHA took the position that the mandate is required to protect unvaccinated workers from the risk of contracting COVID-19 at work.