Public Service Announcement for the analog photography community: new X-ray scanners in airports will permanently ruin your films. Period. Old rules such as "It's ok under XXX ASA" are obsolete: I had a 400 film completely ruined and a few 160 badly damaged, after just two scans.
The technical name of these new scanners is "CT-scanner" and are often designated by security agents as "3D scanner" or simply "Modern scanner".