Film-Tech Forum ARCHIVE: Storing vinegar syndrome film: Hazards?

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Posted by Patrick J. McCart (Member # 1043) on 02-02-2004, 06:54 PM:

I obtained a collection of safety film intros on 35mm (circa 1955-1965), but they seem to have some bad vinegar syndrome. Visually, the worst damage is color fading on the Eastman clips, but nothing else.

Any suggestions on how these should be stored? Can the decomposing film cause any kind of hazards?

Posted by John Pytlak (Member # 331) on 02-02-2004, 07:01 PM:

They should be stored cool and dry --- reduced temperature and low humidity greatly slow vinegar syndrome, which is a chemical reaction that is dependent on moisture. You should also "exercise" (carefully rewind or project) the rolls to allow any trapped acid vapors to vent. Storage should be in well vented containers, in a storage area away from unaffected films that is well vented itself. Or you can use Molecular Sieves in a sealed container:

http://www.kodak.com/country/US/en/motion/support/technical/molecular.shtml

http://www.kodak.com/country/US/en/motion/support/technical/vinegar.shtml

http://www.kodak.com/US/en/motion/support/technical/storage1.shtml

The acetic acid vapors released by advanced "vinegar syndrome" will accelerate dye fading, and the acid vapors can "infect" other films, so anything you do to vent or adsorb the acid vapors will help. Cool and dry storage also slows dye fading.

Posted by Jason Black (Member # 684) on 02-02-2004, 07:04 PM:

If I recall what I've read in the past, a little Film-Gaurd will help control the development of VS as well as cleaning up those prints!

Posted by Leo Enticknap (Member # 534) on 02-03-2004, 01:23 AM:

quote:
The acetic acid vapors released by advanced "vinegar syndrome" will accelerate dye fading, and the acid vapors can "infect" other films...

...which affects the decision as to whether to use vented cans, molecular seives or a combination thereof. An 'ideal' film archive would have a special isolation vault specifically for acetate elements which an acidity detector (a/d) strip indicates have reached the autocatalytic point (pH 4). This would have air filtration which removes acetic vapour and the elements would be stored in vented cans. However, a lot of even relatively well-funded archives can't go that far, and have to store stable and autocatalytic elements in the same vault. In these circumstances you would normally store the stable elements in sealed cans with sieves and the seriously smelly ones in vented cans. That way, the offgases produced by the worst elements won't infect those in better shape.

Queries from private film collectors about preservation issues seem to come up quite frequently on Film-Tech now: might it be worth knocking up a FAQ page and sticking it in the manuals section? I'm sure most of it could be done quite quickly by copying and pasting bits of previous threads followed by some minor editing, and would be willing to spend an hour or two over the weekend on it if people think it might be useful...

Posted by Jeff Taylor (Member # 443) on 02-03-2004, 02:57 PM:

All of the above information is correct, but above all VENTILATE effectively and continuously, exercise as noted above, and do not store near uncontaminated film. FWIW, in my own experience with VS I haven't noticed a major problem with color fading (perhaps you're noticing that color fading and VS coincidentally occur in older acetate film). Most of the effect of VS will be in the form of cupping, ribboning, and shrinkage which will ultimately render it unusable, or at the least will drive you crazy with focus problems. Film-Guard may help in cleaning off the acidic product and certainly hides the smell, but if it has reached the autocatalytic stage nothing will really stop it despite rampant claims from the new producer of VitaFilm to the contrary.

Posted by Leo Enticknap (Member # 534) on 02-03-2004, 04:43 PM:

To be honest I think that colour fading is more specific to the emulsion type than storage conditions, especially if you're faced with an element which has been stored goodness knows where and for decades before it came into your possession. Everyone knows that '60s and '70s combined coupler stocks go pink as buggery; earlier combined coupler stocks fade to various different shades over a variable timescale; and Kodachrome is bulletproof (apart from 1935-38 Kodachrome, which also goes pink). I couldn't explain the chemistry behind these observations for the life of me, but from opening hundreds of rusty old cans and examining the contents I'd argue that this is a pretty good rule of thumb. But whatever sort of element you're dealing with now, the same conditions will always inhibit further fading and/or decomposition: the cooler and drier, the better.

Posted by John Pytlak (Member # 331) on 02-10-2004, 07:49 PM:

In doing accelerated testing using Arrhenius predictions to evaluate the effectiveness of Molecular Sieves, we found that the lower pH caused by the acid by-products of "vinegar syndrome" definitely had an adverse effect on dye stability, mostly of the yellow and cyan dye classes. In the paper I gave at the SMPTE conference, we noted the significant improvement in dye stability when using Molecular Sieves.