The U.S. Centers for Disease Control and Prevention issued a mask mandate this weekend for all public transit — planes, trains and buses. The mask mandate also includes public boats, subways, taxis, ride shares, and inside airports and other transportation venues. The mandate takes effect Monday, February 1 at 11:59 p.m. In response, the U.S. Department of Homeland Security gave enforcement authority to TSA employees “at TSA screening checkpoints and throughout the commercial and public transportation system,” read a Determination of a National Emergency signed by the department’s acting secretary, David Pekoske.

“The purpose of this Executive Order is to save lives and allow all Americans, including the millions of people employed in the transportation industry, to travel and work safely,” Pekoske’s declaration said. “I specifically direct the Transportation Security Administration to use its authority to accept the services of, provide services to, or otherwise cooperate with other federal agencies, including through the implementation of countermeasures with appropriate departments, agencies, and instrumentalities of the United States in order to address a threat to transportation, recognizing that such threat may involve passenger and employee safety.”