WeWork, the shared-office company already coping with a failed public offering and a corporate shake-up, disclosed a new problem on Monday: possible formaldehyde contamination of hundreds of phone booths at some of the buildings it leases.

In a note to tenants at an unspecified number of its sites in the United States and Canada, the company said it was removing the booths because of “potentially elevated levels of formaldehyde caused by the manufacturer.”

“We have identified approximately 1,600 phone booths in some of our U.S. and Canada locations that may be impacted,” said the note, a copy of which was obtained by The New York Times. “These phone booths are being taken out of service immediately, and will be removed from your location as soon as possible.”

The company said it would remove another 700 booths for testing “out of an abundance of caution.”

Several tenants who received the note posted copies on Twitter, with commentary attached.