U.S. Sen. Michael Bennet joined 20 other members of the Democratic caucus on Thursday in asking the Federal Transit Administration to explicitly recommend how transit agencies should address the use of personal protective equipment and assist organizations in acquiring it for their workers.

“The Guidance FTA issued last Thursday, noted that FTA did not recommend the use of PPE at that time. Since then, the Centers for Disease Control and Prevention issued guidance recommending members of the public cover their face with cloth when in public,” the senators wrote. “We believe FTA should explicitly update its guidance and proactively provide support to help transit agencies acquire PPE and provide it to their workers.”

The FTA referred transit operators to the CDC’s frequently asked questions webpage when determining whether to wear equipment like gloves or masks. However, the page was last updated on March 14 and mainly addresses the concerns of healthcare providers.

The letter referenced the deaths of transit workers from COVID-19, including Jason Hargrove, a Detroit bus driver who posted a video online complaining about a passenger who did not cover her mouth when coughing. Senators asked the FTA to ensure that transit systems switch to rear-door boarding and avoid having operators touch screens or keyboards that could lead to infection.

Last week, the Regional Transportation District announced that it would suspend fare collection and implement rear-door boarding. The agency also has hand sanitizer on order and a supply of gloves. Respirators, however, are difficult to procure due to the need to equip medical personnel.