Myths about airport X-rays

Discussion in 'Film and Processing' started by aquilanebula, Jul 14, 2004.

  1. Following on from Rowland Mowray's myths and facts about film
    technology, I thought it might be useful to add a similar thread
    about airport X-ray machines. This is information has been obtained
    from research on the web, but I have also backed this up with my own
    observations from having a Geiger counter when passing through
    security checks at airports and public buildings.

    MYTH: X-ray machines for hand luggage can fog film. Films faster
    than ISO 400 require hand inspection.

    FACT: An X-ray scanner for hand luggage gives a dose of around 1 uGy
    (= 0.1 mR). This is an extremely small amount of radiation. A roll
    of film will obtain a similar dose of background radiation in Paris
    in 8 hours, in Denver in 4 hours, and in an aircraft cabin at
    cruising altitude in 20 minutes. The amount of cosmic radiation
    received on even the shortest flight outweighs the X-ray dose from an
    airport scanner.

    Technically speaking, X-rays, cosmic rays and gamma radiation each
    have a different effect on materials. Nevertheless, at such doses,
    the effect on film is negligible.

    MYTH: As a result of 9/11, X-ray machines have been introduced which
    use much higher levels of X-rays.

    FACT: Terrorism was a problem in many countries before 9/11. X-ray
    machines were already designed to look for guns, knives, explosives
    and drugs. New detector technology has allowed X-ray doses to be
    reduced over time, not increased.

    MYTH: Film left in checked luggage will definitely be ruined because
    higher X-rays doses are used for luggage going in the hold.

    FACT: True and false. Some X-ray scanners for checked luggage give
    a similar dose to those used for hand luggage. Some might use a much
    higher dose. A dose 1000 times higher than from that a hand luggage
    X-ray machine would be similar to the amount of background radiation
    a film would receive stored at home in a freezer in one year. Since
    it is not possible to keep tabs what is happening to your checked
    luggage, camera film should always be carried in hand luggage.

    MYTH: Lead pouches offer protection against X-rays

    FACT: A lead X-ray pouch might reduce the dose to your film by a few
    percent. So will most of the other items in your luggage. There is
    nothing magical about lead. All materials, even air, absorb a
    certain amount of X-rays and nuclear radiation. Lead is used for
    shielding because it is more compact for a given weight than other
    materials such as steel or concrete.

    A film pouch which puts 500 grams of lead between your film and the X-
    ray machine provides little more benefit than 500 grams of camera
    magazines or clothes.

    This leads me to another myth: a lead pouch will cause the operator
    to increase the strength of the X-ray beam in order to see through
    the lead. In fact, a scanner for hand luggage can see through 25mm
    (1 inch) of steel, and therefore doesn't have a problem with a small
    lead bag. The websites of the manufacturers listed below include
    specifications and some interesting X-ray images of cars and
    motorbikes:

    (a) http://www.dsxray.com (b)
    http://www.bombdetection.com

    The following link may also be useful as it gives information about
    the cosmic ray dose experienced on aircraft:

    http://www.acpa.ca/safety/cosrad.pdf

    Although I have brushed over the subtleties of some of the physics,
    this information is accurate to best of my knowledge. I have visited
    some 30 countries and have never had any film fogged by X-rays. I'm
    happy to be put right with any factual errors or omissions.
     
  2. My experience is entirely consistent with what you report. I haven't even been able to detect differences between Delta 3200 (exposed at and developed for EI 3200) which was hand inspected versus scanned with carry on luggage.
     
  3. david_henderson

    david_henderson www.photography001.com

    Agreed, and all good stuff, but I still think that someone will be
    on here within days asking how to ensure a hand inspection or
    whatever either because they don't bother to read what's up here
    or because they think their film is somehow more vulnerable
    than anyone else's.

    Did you consider also issues of whether the operator can
    actually turn the machine up; and the effect of cumulative
    passes?
     
  4. "MYTH: Film left in checked luggage will definitely be ruined because higher X-rays doses are used for luggage going in the hold.

    FACT: True and false. Some X-ray scanners for checked luggage give a similar dose to those used for hand luggage. Some might use a much higher dose. A dose 1000 times higher than from that a hand luggage X-ray machine would be similar to the amount of background radiation a film would receive stored at home in a freezer in one year. Since it is not possible to keep tabs what is happening to your checked luggage, camera film should always be carried in hand luggage."


    Standard baggage X-ray scanners will not fog film. Computer aided tomography (CAT) scanners made by InVision and L3 can fog film because of the directed X-ray beam. If your film is going to go through a CAT scanner - very good chance it will be fogged. Most large US airports are using CAT scanners for all baggage. Those few airports that do not have baggage CAT scanners will have them installed within the next 12-14 months.
     
  5. Another great thread that should be archived on a static page in the Learn section.

    Thank you for your efforts Christian.
     
  6. Pretty much reflects my experiences and view too. There are a lot of myths of this subject, good thing to post this list.
     
  7. I brought a Geiger counter on a flight and was amazed by how much radiation there was. From my crude little instrument I estimated that in flight exposure was about 200X greater than ground level (Washington D.C.) From that reading I always suspected that in flight radiation exposure is greater than anything from an X-ray machine. I was always too nervous to send my Geiger counter through an airport X-ray machine with the audio turned on, though.

    Forget about the lead bag for the film, try lead underwear for the flight :)
     
  8. Christian;

    Thanks for a good thread. Very good information.

    Fuji has added a warning to its 1600 Superia boxes to avoid X-Ray scans at airports. Interesting side note I thought you might enjoy.

    FWIW, my impression is that heat is probably worse than radiation in damaging any film. I'm not sure, but the tests that I ran on 400 speed film suggested that this was the case.

    In addition, I have flown film at higher altitudes than most of you normally fly at, with nothing over me but a canopy, and the films survived at least 8 hours in the air with no significant fog.

    I have had film exposed to high intensity radar with no effects, but all of the flashbulbs being carried with us went off at one time. Nearly set one of the men on fire. He had several dozen in his pockets.

    I would be interested in knowing whether repeated exposures to low levels of radiation by going through several airports would cause a problem. This might accentuate the appearance of fog somewhat. I have seen that before. Flashing film to a level of light that causes no effect may only be considered mild latensification, but doing the same flash several times over a period of several weeks may begin to show up as a problem.

    Just some thoughts and observations.

    Ron Mowrey
     
  9. I posted this on a different thread, but I think this is a good place to repost it. Kodak has done studies of the effects of X-raying, and the effect on film in checked baggage is frightening. It will ruin your film in one pass. The page about it, which has pictures and examples, is here. They have a less informative page without pictures here. Some interesting bits include that underexposed film is more vulnerable to X-rays, and pushing film exaggerates its effects. Since the fogging is usually in a pattern, it can't be compensated for while printing.
     
  10. Thanks much, Christian! Question on "film will [get a 1 uGy] dose of
    background radiation in an aircraft cabin at cruising altitude in 20 minutes." How can film best be protected while flying?
     
  11. Well, that Kodak data suggests that the checked baggage scan and CAT scans are worse, and repeated scans progressivly damage film badly.

    Christian, we are trying to collect these myths into one collection. Would you be willing to place your addition there?

    Ron Mowrey
     
  12. It also depends on what country you are in. I had two rolls of C41 100 EI film damaged by a SINGLE pass in a carry on screening machine. It was in Rome on 9/20/2001 with very tight security. The 400 ISO B&W film was not damaged.

    Kodak says up to 4 passes are safe in the current TSA screening machines for carry on (Assuming that they are in spec); after that ANY film is subject to damage.

    The TSA warns people NOT to put film in checked bags; they use much stronger xray machines.

    I sent the TSA an email asking for their official position on the use of lead bags for film; that was a month ago and I'm still waiting for an answer.

    To say that ALL x-ray scanners are safe for film is not true; machines go out of calibration; operators can reverse the belt and give your items another dose of xrays ect. That is a myth itself.

    The only true safe way to avoid xray damage is to get a hand inspection and not have your film xrayed at all. Period.
     
  13. A few comments - I have had 400 speed, both traditional B&W and C-41 color, fogged by an x-ray inspection machine in Tel Aviv despite assurances of the personell about the machine being safe for all film up to 1600 speed. The 1600 speed film I had with me got hand inspected and was not fogged. The second comment concerns the effectivness of the lead protective opouches - I once tried to use one, and apparently it did obscure the content of it, because the the inspector had me take it out and let them see the film inside. Of course, if they make you take the film out of it and let it pass through the machine, the pouch will not be effective at all.
     
  14. david_henderson

    david_henderson www.photography001.com

    Ron.

    "we are trying to collect these myths into one collection."

    Who is "we" please?


    Antony

    I was also in Rome on 20/9/01 and had no problems at all with a
    mix of colour transparency films 50/100/400 and 400 b&w. I did
    not ask for or get a hand inspection.

    Christian

    If you haven't looked at the Kodak web-site then you might want
    to do so. Seems to me from past reading that it contains a load
    of backside-covering , scaremongering junk, but it is (or was) at
    least partly in conflict with what you're saying. It's the existence of
    misinformation like that (the objective of which, IMO , is to provide
    a vehicle to dismiss or dispute complaints,) that makes it very
    hard to persuade people -like Antony for example- that it really
    isn't necessary to worry about your film or create irritation and
    delays at airports by getting hand inspections.
     
  15. David;

    The EK site shows examples due to MRI scanning damage.

    I think that is indicative of something going on that cannot be dismissed in spite of other evidence to the contrary. EK has run some tests and it is in their interests to let the public know what they know.

    Variations around the world with the equipment can lead to varying conclusions I'm sure, but we probably have to go with the worst case scenario based on the strongest x-ray devices / tests in use.

    The other myths that I have written are being collected. We are in touch with the forum moderators as to how to proceed in placing them in some permanent area of the site. It will follow all site guidelines. See the comments by James Dainis in another thread.

    Ron Mowrey
     
  16. MRI scanning damage - is this a typo? MRI is based on radiofrequency pulses in a high magnetic field.
     
  17. Mike;

    Thanks, yes, a senior moment. I meant CAT scanning.

    Sorry.

    Ron Mowrey
     
  18. I fully agree with David Henderson in that it really isn't necessary to worry about your film.
    I am a frequent traveller, usually within Europe and never ever had any fogging problems in my films which are in the hand-luggage and are scanned with no ill effect. None of them passed more than 4-6 times through the scanning machines. German, French, Dutch, British, Greek and Italian airports have film-safe scanners. Only once I needed hand inspection for ISO 3200 TMZ, and it was granted without problems and delays.
    Other than that, I had my film scanned in Moscow Sheremetyevo-2, Budapest Ferihegy and Tokyo Narita. No problems.
    Regarding the Kodak website, they are either over cautious in view of the recent mass hysteria or they address only the problems in the domestic market. Who knows? I haven't been to the States since the Clinton era...
     
  19. I encourage you to go to the website and check out the pictures of the ruined images. Its pretty scary and I never want it to happen to me. However, those images, and most of what they say on the page, are about the luggage scanners. About carry-on baggage, which you get to see roll through the scanner, they say it can survive multiple passes - up to five - just fine. I bet X-rays have a cumulative effect on undeveloped film, and after the fifth passage through the scanner, it only then begins to possibly be visible. And I bet there are a lot of variables, like power-levels, and so on. So, I don't think its a myth to say that if you're travelling a lot -as in, at least five different airports- then its best to get your film hand-inspected.
     
  20. MYTH: X-ray machines for hand luggage can fog film. Films faster than ISO 400 require hand inspection.
    FACT: An X-ray scanner for hand luggage gives a dose of around 1 uGy (= 0.1 mR). This is an extremely small amount of radiation. A roll of film will obtain a similar dose of background radiation in Paris in 8 hours, in Denver in 4 hours, and in an aircraft cabin at cruising altitude in 20 minutes. The amount of cosmic radiation received on even the shortest flight outweighs the X-ray dose from an airport scanner.

    "TSA on "Transporting Film and Photographic Equipment""
    The equipment used to screen checked baggage will damage undeveloped film. Pack your undeveloped film in your carry-on bag. High speed and specialty film should be hand inspected at the security checkpoint. To facilitate hand-inspection, remove your undeveloped film from the canister and pack in a clear plastic bag.
    TSA on "Traveling with Film"
    WARNING: Equipment used for screening checked baggage will damage your undeveloped film.
    Never place undeveloped film in your checked baggage.
    Place film in your carry-on baggage* or request a hand inspection.
    * Carry-on screening equipment might also damage certain film if the film passes through more than 5 times. . . .
    You should remove all film from your checked baggage and place it in your carry-on baggage. The X-ray machine that screens your carry-on baggage at the passenger security checkpoint will not affect undeveloped film under ASA/ISO 800.
    If the same roll of film is exposed to X-ray inspections more than 5 times before it is developed, however, damage may occur. Protect your film by requesting a hand-inspection for your film if it has already passed through the carry-on baggage screening equipment (X-ray) more than 5 times.
    Specialty film **
    Specialty film is defined as film with an ASA/ISO 800 or higher and typically used by professionals.
    At the passenger security checkpoint, you should remove the following types of film from your carry-on baggage and ask for a hand inspection:
    Film with an ASA/ISO 800 or higher . . .
    Highly sensitive X-ray or scientific films
    Film of any speed which is subjected to X-ray surveillance more than 5 times (the effect of X-ray screening is cumulative)
    Film that is or will be underexposed
    Film that you intend to 'push process'
    Sheet film
    Large format film
    Medical film
    Scientific film
    Motion picture film
    Professional grade film . . .
     
  21. I'm grateful for the additional information that has been added to my original posting. Ron, your anecdotes are particularly valuable. Yes, I would be happy for this thread to be placed wherever it is of most benefit.

    With reference to the Kodak and TSA websites, I'm not surprised that these organizations are taking a cautious approach. They presumably want to discourage lawsuits from people who may have had their film damaged in some way.

    The effect of X-rays on film is indeed cumulative. Given the very low levels of X-rays from hand luggage scanners, you would need perhaps thousands of passes to have an effect. Here the warning on the Kodak website seems over cautious.

    For David and Peter, I suspect that your film was damaged by something other than X rays (especially in Rome where the ISO 400 film was unaffected). It is possible that your film was exposed to heat or chemical vapours somewhere, or perhaps compromised before you even purchased it.

    Is there anyone who's left film in their checked luggage?

    Bill, I'm not sure that there is any way you can protect your film from cosmic radiation while flying - at least not any way that would allow the plane to leave the ground! But I don't think it's something to worry about. Assuming the radiation level is 30 times greater at cruising altitude than on the surface, an 8 hour flight will give you the same dose as 240 hours on the ground. It takes a lot longer than 10 days for background radiation to fog film.

    The message here really is not to worry about your film when travelling. The security staff in many countries will not allow hand inspections and it's best just to accept this and get through the checks as simply as possible.
     
  22. [protecting film while flying] But I don't think it's something to worry about.
    Some film I recently ordered from B&H can be safely assumed to have traveled thousands of miles (far over 10000 km) before it got here and that which I have shot has been without any problems (well I haven't tried all types of film I ordered yet...) In addition, I've had film flown here from the far east (again, 10000+ km total flights), scanned as hand baggage with no ill effects. These weren't high speed films, however, but I'd be mroe careful with them due to heat. Frankly, my impression is that radiation is overrated; heat and poor storage is probably a much more common reason for film failure.
     
  23. MYTH: Film left in checked luggage will definitely be ruined because higher X-rays doses are used for luggage going in the hold.

    Well, after I got a whole box of 15 Ilford HP5+ films (ISO400) fogged by a checked luggage scanner, this is no longer a myth to me...
     
  24. I flew out of Rome on 9/20/01 on Delta. The C41 film was purchased fresh in the USA. We had 4 or 5 rolls from the same batch processed in Sicily with no problems. The last two rolls were taken in Rome but I didn't have time to get them developed before we left. The film had never been x-rayed. The only time it was x-rayed was in Rome. 2 or 3 frames were damaged by the xrays. The rest of the roll was ok.

    This is the only damage I have ever had personally. But I always get a hand inspection in the USA.
     
  25. Anthony, X-ray damage would affect the whole film rather than just 2 or 3 frames. This confirms my suspicion that the damage to your film was caused elsewhere.
     
  26. david_henderson

    david_henderson www.photography001.com

    You know, travelling a lot, as I do, I've made a point of following
    pretty much all of these threads on Photo net over more than six
    years. In that time I can't personally recall *any* example of X
    ray damage from normal hand baggage machines that has
    survived a couple of sensible questions such as we have above.

    In fact I wish that there had been some examples so it would
    then be possible to draw up some limits and say "don't do more
    than Y" with authority.

    There have been a lot of people on here saying that they have
    made many. many passes , including in relatively
    unsophisticated environments , without having a problem. Given
    the weight and uniformity of this evidence the conclusion I draw
    is that the information issued by Kodak and TSA is pretty much
    uninformed and deliberately conservative. I'm not going to worry
    about it; and I'm not going to clog up the works at airports by
    debating or asserting my "rights" unless I'm carrying 3200,
    which is unlikely.
     
  27. Is there anyone who's left film in their checked luggage?
    By mistake, I once left an exposed roll of 100-speed slide film, an unexposed roll of 100-speed b&w film, and two unexposed 120 rolls of Delta 3200 in my checked bags flying from Los Angeles to Nashville. Did a clip test on the 100-speed b&w in a tank with a roll that hadn't gone in the checked bag--absolutely no discernible difference in the base fog. Had the color film processed--no problems, either. Used the Delta 3200 at 1600--a little more base fog than really fresh film, but quite usable.
    I assume I got lucky, and they didn't see anything in the bag that had them crank up the X-rays.
     
  28. "The only true safe way to avoid xray damage is to get a hand
    inspection..........Period."

    That's fine if you never intend to leave the USA, but there are
    many airports in other parts of the world where you simply aren't
    going to get on the plane without submitting to an xray. I'm one of
    the people who've never experienced fogging, even when film
    has had around 10 passes through xray machines - on some
    journeys it's unavoidable.
     
  29. Christian,

    My damage is consistant with damage that has been documented in the past by Modern Photograhy & Popular Photography. Their test have shown that damage can and often does effect only a few frames while the latter frames are fine. I'll dig out the negative and scan them to show you what I mean.
     
  30. Don't forget that in addition to X-ray scanning at airports, most major museums, government buildings, some train stations, and most cruise ships also require a pass through the X-ray machine.
    <p>
    The airport is the least of your worries when traveling.
     

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