Teachers’ unions in all three districts, which together enroll nearly 300,000 students, are deploring the return plans as unclear, ill-conceived and insufficient to keep teachers safe during the pandemic. Educators are asking for more comprehensive cleaning, coronavirus reporting and contact tracing protocols. And they are arguing that school officials should slow down the return-to-school timeline.

“What would happen if a student or employee develops covid? We’re not sure,” said Sandy Sullivan, president of the 3,800-strong Loudoun Education Association. “It just seems there are a lot of balls up in the air with no clear answers.”

In response, school administrators are insisting teachers must return to the classroom if they cannot prove that medical necessity — such as a prexisting condition — requires they remain home. Their other options are unpaid leave or the loss of their jobs.

Arlington Public Schools recently sent an email to employees asking them to indicate