As libraries reopen, one concern is how to deal with books that have been returned by patrons. The Australian Library and Information Association is recommending the following:
“For paper-based products, leave books untouched in a dedicated quarantine area for a 24-hour period prior to handling and recirculating. Sanitising books with liquid disinfectants can damage books and is not recommended.”
For more information on the subject, you may want to look at the Reopening Archives, Libraries, and Museums Project.