The question about whether X-ray machines damage film is as old as Bruce Forsyth.
There are quite big devides and wars have been started over it.
*no wars have been started over it.
Well lets ask the professionals. Gatwick Airport kindly had the following to say.
Don’t worry – our x-ray machines won’t harm your film or equipment. The British Photographers’ Liaison Committee (BPLC), have given the all-clear to our hand-luggage x-ray inspection systems saying that it is safe for all normal film types (up to and including ISO 400) as well as for digital storage media.
Specialist film (ISO 800 and above) can sometimes be affected – but the effects are barely noticeable to the naked eye and do no become clearly visible until film is exposed around 32 times. But we can make special arrangements for photographers carrying professional film (ISO 800 and above) – just contact us our your airline before travel.
Professional photographers requiring more detailed information can contact the BPLC on +44 (0)20 7739 6669.
So there you go, take it in hand luggage and take 400iso and under and you will be fine.