In 1994 the National Association of Photographic Manufacturers in the USA (NAPM) conducted an extensive study - in conjunction with the country's civil aviation body, the FAA (Federal Aviation Agency) - on the effects of X-ray scanning on photographic Film. Testing was conducted at the FAA's Technical Center in Atlantic City (New Jersey) using machines identical to those in all FAA-controlled airports in the USA and representative of models installed in all the world's major international airports.
The NAPM tests were conducted in co-operation with Kodak, Fuji, Agfa, Konica, Ilford and 3M who each supplied 500 rolls of 35mm film -- color negative, color reversal and B&W - ranging in speed from ISO 50 to 1600. These were then grouped in batches that received one, four, 16 or 100 X-ray inspections at the FAA prescribed dosage of no more than one milliroentgen. In the USA this is the maximum dose permitted and FAA regulations demand that passengers be warned if a scanning machine emits more radiation during a single pass.
In addition to testing for the cumulative effects of multiple X-ray scans, and the increased susceptibility to damage of faster films, the NAPM study was also designed to show whether the arrangement and orientation of 35mm cassettes could affect the way the film was irradiated. For example, in some tests the cassettes were arranged so the light traps were faced toward the X-ray source while in others the cassettes were stacked on top of each other so they would create 'shadows’ on those below. Films were also pushed and pulled up to two stops in an effort to replicate what NAPM termed a worst case scenario; namely a professional photographer traveling through a number of airports carrying films of widely different speed ratings with all the cassettes closely packed in a container or bag. The test results indicated that, in the case of color transparency films rated between ISO 50 and 1600, up to 16 passes through the scanner didn't do any damage at all. After 100 scans only the highest speed emulsions exhibited some slight effects, and then only detectable in the D-Max areas. B&W films were similarly unaffected up to i6 scans even when pushed to ISO 3200.
The findings on color negative emulsions showed that 16 X-ray inspections produced no discernible damage and, after 100 passes, it was still difficult to detect any damage, but that "discriminatingviewers" might be able to notice some slight effects in "demanding scenes".
According to the Fuji representative who took part in the study, it was virtually impossible to see any evidence of X-ray damage even when a high speed film was subjected to the worst case scenario in terms of exposure and the way the cassettes were stacked and scanned.
In the UK, a similar study by the British Photographer's Liaison Committee (a group of various industry and professional organizations) reported similar findings to NAPM. The UK tests involved 300 rolls of films from each of the major manufacturers,spanning speeds from ISO 50 to 3200. These were subjected to a maximum of 32 X-ray inspections in a scanner of the type used by the British Airports Authority (BAA) which operates the majority of the UK's major airports. The UK report concluded that no visible damage resulted from "routine hand baggage examination under normal traveling conditions.
There are many myths surrounding airport X-ray inspection equipment and it's easy for ignorance to lead to paranoia among photographers who regularly travel by commercial airliner.
For example, while it is indeed possible to vary the dosage emitted by these machines, in the USA and a number of other countries, it is illegal to do so. Furthermore, it is not possible for the machine's operator to alter the dosage during an inspection pass because these settings are concealed inside the unit and cannot be accessed during normal operation.
It also needs to be understood that these modern machines are X-ray scanners and so the object is inspected line-by-line by a small and precisely controlled fan like emission of radiation. Only this line - which represents a very small area, even of an object as small as a 35mm cassette - receives a dose of X-rays at any one time.
Another misconception is that an object is scanned continuously so, when the conveyor belt is stopped so the display can be examined by the machine's operator, it will receive multiple dosages of radiation. In fact the X-ray signal is now amplified to create the display and the object does not receive multiple scans in order to maintain the picture. Once is sufficient. One of the problems with older equipment was that poor amplification of the X-ray signal meant it was necessary to use a much higher dosage in order to obtain a good image.
The preceding discussion applies to film examined through normal security area x-ray machines used to scan hand carried baggage. Film checked through as checked baggage is a different matter altogether. Many airports now require baggage that contains cameras to go through a special scanning device and this will definitely fog your film. The dosage is sufficient to fog all film not just faster speed film. If you fail to tell the check in operator that the checked baggage contains camera equipment, it will be scanned and if devices similar to cameras are identified, the baggage will be pulled (and you potentially along with it) for additional inspection.
1. Carry your film in carryon luggage
2. I personally put it in lead bags
3. If necessary ask for hand inspection
4. Do NOT check film through
5. Declare all luggage containing camera equipment as such
6. Be polite and helpful; being aggressive may mean you get detained and potentially bumped from the flight
7.In these times of heightened security be aware that the security people are trying to save lives.