Free rapid COVID-19 test kits sit in a box as they await to be handed out to residents at Contra Costa County Supervisor John Gioia's office in El Cerrito, Calif., Tuesday, Dec. 21, 2021. Credit: Jessica Christian / San Francisco Chronicle via AP

BOSTON — Massachusetts has purchased 200,000 at-home testing kits that will be distributed to school districts throughout the state so teachers and staff can test for COVID-19 before they return to work after the holiday break, school officials said Wednesday.

Every district will receive enough tests to ensure that two can be distributed to each staff member, one of which should be taken no more than 24 hours before they return to work, with the second kept to be used at the staffer’s discretion, the state Department of Elementary and Secondary Education said in a statement.

Tests are not required to return to school.

There were about 8,500 student cases and 1,500 employee cases confirmed in the state’s public schools for the week that ended Dec. 23, the latest data available. The state’s public schools have about 920,000 students and 140,000 employees.

“Doing everything we can to keep students learning in classrooms is critical. Providing these tests to teachers and staff is one more thing we can do to ensure that is possible,” Education Commissioner Jeffrey Riley said in a statement.

Last week, the state distributed more than six million KN95 masks to schools for employees.