Re: [ARSCLIST] [AMIA-L] Storage of Acetate Magnetic Media

[Mwcpc6@xxxxxxx]

In a message dated 1/14/2006 12:36:53 PM Eastern Standard Time, 
ArcLists@xxxxxxxxxxxxxxx writes:

(1) Some reels of tape were shipped in plastic bags, some users 
re-used the plastic bags inside the boxes. I recently found one of 
four reels of Kodak tapes recording oral history interviews with old 
Shakers (a now non-existent religious sect) had enough acetic acid 
inside the plastic bag to cause my eyes to water and almost had me 
leaving my studio. It played fine, but clearly some breakdown 
products were accumulating in the semi-sealed plastic bag without any 
opportunity to be buffered (see below). We had an extensive 
discussion of this on the ARSC list and it seems that many people are 
wary of Kodak tape.
****************

I've had an identical recent experience with a "virgin" reel of Kodak tape, 
however it was perfectly usable and much less stiff than a reel of similar 
vintage exposed to open air. I also know from personal experience that Kodak tape 
smelled strongly of acetic acid right out of the factory. I don't think 
conclusions about normal tape can be drawn from Kodak's bizarre product.

There does seem to be evidence that acetic acid in the presence of iron 
oxides catalyzes breakdown of cellulose acetate. Therefore it is not wise to 
prevent the dissipation of the acid by sealing acetate base material in bags or 
steel cans. 

It also would be a good idea to isolate Kodak tape, and any other tape 
showing signs of breakdown, from other tapes.

Mike Csontos