In reply to Alexander J Collins:
Interesting stuff, thanks. I had not seen that one before. Note that I have throughout the thread been talking only about scanners for hand baggage, which Kodak seems to generally agree with:
"X-ray equipment used to inspect carry-on baggage uses a very low level of x-radiation that will not cause noticeable damage to most films."
"Travelers probably shouldn't worry about possible X-ray damage when hand-carrying their film onto the airplane unless they are carrying:
Highly sensitive X-ray or scientific films.
Film with an ISO speed or Exposure Index (EI) of 400 or higher.
Any motion picture films.
Film of any speed that is exposed to X-ray surveillance more than 5 times (the effect of X-ray screening is cumulative).
Film that is or will be underexposed. (See Note 1 below.)
Film that you intend to "push process." (See Note 2 below.)"
"Never ship unprocessed film as checked luggage with commercial airlines. Keep all unprocessed film as carry-on baggage."
(although my tests on ASA1600 including underexposed film and 10 scans showed no difference from the control image)