Will X-ray damage photographic paper?

pentaxuser said:

So it sounds as if Ilford was right about its safety through carry-on luggage? If so, greatI have no idea about how its inspected for ship travel in large quantities, save to say it's obviously 100% safe

pentaxuser

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i'm not sure, the airport i depart use old x-rays and they have low intense x-rays

CrazyCockatoo said:

i'm not sure, the airport i depart use old x-rays and they have low intense x-rays

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Sorry I may have misunderstood what you meant when you said you had got the paper back safely I assumed that "safely" meant undamaged by the rays used in the carry-on scanners. So are you still unsure about whether old and new CT scanners are safe for paper despite what I had thought your word "safely" meant and Ilford's reply which I stated

If you were looking for some sort of cast iron guarantee from Ilford in writing then I fear you may have to remain unsure. I suppose you could ask it for a guarantee that both the old Xray scanners and the new CT scanners are completely safe and maybe make it easier for Ilford to give a guarantee if you were to state the number of times that a box of unexposed paper can be taken through (a) an old type scanner and (b) a new type C.T. scanner

Just a thought


Thanks

pentaxuser

Historically, the emphasis has been on damage to “higher speed” film with nary a mention of paper. Can’t find any concerns with photographic paper in and of the legacy x-ray damage research, government/industry guidance, x-ray device manufacturers data, or in the general academic/engineering/photography literature. Could it be that the potential for damage is so low for paper that is really only a theoretical concern? Or have I missed some authoritative information/data? Or has the new CT technology created a new and valid risk that heretofore didnt exist?

BrianShaw said:

Historically, the emphasis has been on damage to “higher speed” film with nary a mention of paper. Can’t find any concerns with photographic paper in and of the legacy x-ray damage research, government/industry guidance, x-ray device manufacturers data, or in the general academic/engineering/photography literature. Could it be that the potential for damage is so low for paper that is really only a theoretical concern? Or have I missed some authoritative information/data? Or has the new CT technology created a new and valid risk that heretofore didnt exist?

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No,Brian, that sums up what Ilford had to say in its reply to me It had tried paper through the new CT scanners and it said that paper seems OK, citing the very reasons you gave as to why this might be

pentaxuser

CrazyCockatoo said:

I also wonders how ilford and kodak managed to ship their film globally without getting them damaged by xrays

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Roughly the same way that items requiring refrigeration get shipped internationally - specialized (i.e. extra cost) procedures involving customs brokers, separate lines of inspection, particular carriers, etc.
Eastman Kodak had to revamp and re-vitalize (motion picture film shipping) procedures extensively after all the disruption surrounding the bankruptcy, when they had essentially all the film shipped out to a major motion picture's shooting location damaged by x-ray, resulting in a need for substantial amounts of re-shooting the film.

Many countries have “trusted shipper” conventions/programs. It would not surprise me that the major photography manufacturers and distributors would use such status.

Good to know that Harman/Ilford are still working with the DfT.

When I raised this with the DfT about three years ago they send me an electronic letter stating that all UK civil airports had been instructed to hand inspect photo film (I didn't think to ask about paper). It also mentioned that this was following notification from both Ilford and Kodak about potential harm to photographic materials from the new CT scanners at airport security checks.

It's worth remembering that X-ray damage is cumulative and the doses received by putting your film/paper through one of the older X-ray scanners used in carry-on security checks caused so little damage that it was undetectable even by lab tests in most cases - you had to do something like run delta 3200 or TMZ through the scanner a dozen times to do much damage. But the CT scanners are more damaging so more care needs to be taken. That said, the speed (ISO, if you like) of paper compared to film is very low so risks are smaller.

On the topic of equivalent sensitivity of enlaring paper, Google AI says: "However, if you're using enlarging paper as a "paper negative" in a camera, you'll need to think in terms of a film ISO equivalent. Photography Stack Exchange notes that a good starting point for modern enlarging papers used in this way is around ISO 6. Other sources suggest a range of 2-10, or even 3-6 for multigrade RC papers. "

ISO 5-10 would be about -8 to -9 EV compared to ISO1600,, or about 1/128 as sensitive as ISO 1600, and (assuing one diagnostic CT exposure is 100x the exposure of one diagnostic x-ray), one might 'ballpark' that enlarging paper undergoing CT is at-risk to same level of damage as ISO 1600 film thru security x-ray, if my logic has not failed me.
What we have no assessment about is the degree of damage from Secusity CT being same or less than the degree of damage from Cargo CT, which we know from past testing by Kodak and Ilford is very likely to damage even ordinary ISO photographic film.