All Washingtonians will be required to wear masks or facial coverings in public starting Friday, according to a public health order from Gov. Jay Inslee and Secretary of Health John Weisman.

The mandate applies to all indoor public spaces and outdoor public spaces where social distancing is difficult, according to the announcement. 

Masks are one of the best defenses against COVID-19 until a vaccine or treatment becomes available, Inslee said in a press conference Tuesday. 

Editor’s note: This article has been updated to correctly identify the mandate as a public health order, not a law.