Businesses face daunting operational challenges as the rapid spread of COVID-19 causes employees to call in sick and customer counts to dwindle. Managers can reduce workplace disruptions with measures such as revisiting sick-leave policies and allowing some employees to work from home. Whatever the details of an organization’s response program, though, it must begin with the maintenance of a virus-free environment.

“An employer’s general duty is to maintain the health and safety of the workplace,” says Joseph Deng, an employment law partner at Baker & McKenzie in Los Angeles. “A business must be free of hazards that are likely to ...