How about 10-15 passes through carry-on bags through multiple airports in multiple countries in multiple years without an issue? Too many horror stories and not enough damn evidence out there.
My films have passed through at least that many times in the past with no ill effect, particularly when we flew to Chile & Peru which was more than 10 flights & some airports scan twice at departure and Peru on landing as well.
In the UK there's a committee that oversees Film scanning issues and the safety/non fogging of films. This has representatives from Ilford, Kodak & Fuji as well as Professional & Amateur Photographic organizations. Thew airports no longer issue guidelines for passengers as modern carry on scanners are safe for a very high number of multiple passes before there's a detectable increase in base fog or any other issues.
ian
