Just like it sounds, vinegar syndrome is a malady that affects your microfilm records and makes them smell like … vinegar! The acetate chemicals in the film break down and turn into acetic acid, which is also present in vinegar and gives it its distinct aroma.
If you have acetate-based microfilm, your records are susceptible to deterioration if not kept in proper storage conditions. You may notice a slightly sour smell which indicates the process of deterioration has begun, and is a precursor to the full-blown aroma of vinegar. If you think that your microfilm has a sour scent to it, a simple test is to take a reel out of its container and smell near the center of the roll. In most instances the smell will be more pronounced within the center of the roll, so if you think you caught a whiff of something, this may help you find out quickly without having to do any formal testing.
Not sure if you have cellulose acetate-based film? Take a look at the Northeast Document Conservation Center’s overview of film bases to check. Here are some ways to check if you have acetate-based film:
- The word “Safety” is printed on the border of the film strips. Acetate-based film was dubbed “Safety Film.”
- Your film has a sour or vinegar smell (finding out this way isn’t fun!).
- Testing using acid-detection strips (A-D strips).
- Your microfilm was created prior to the mid-1980s (not necessarily an identifier, but puts your film in the range that could be acetate-based).
Once the process of deterioration begins, it cannot be stopped; even more exciting, once the deterioration has begun, the products created from the degradation actually induce further deterioration! That’s a mouthful, but basically what it’s saying is that it’s a cycle of destruction. And microfilm that’s affected by vinegar syndrome can infect your other film records, so quarantine them as soon as you notice the issue to prevent a mass outbreak of this disease.
Vinegar syndrome affects cellulose acetate-based film, which was prevalent mostly before the mid-1980s. Most microfilm processed after the mid-1980s uses a polyester-based film not subject to vinegar syndrome.
If afflicted with vinegar syndrome, your microfilm and microfiche with follow certain phases of deterioration as the issue becomes more severe. Below is an excerpt from the Wikipedia article on Cellulose Acetate Film that describes this process:
Progression of Degradation
- Acetate base deteriorates, and when it diffuses to the surface you get the characteristic vinegar smell.
- The plastic that forms the base of the film becomes brittle.
- The film begins to shrink.
- The emulsion and the film base separate, causing “buckling” or “channeling,” the latter term used by archivists.
- Bubbles appear on the emulsion, caused by additives no longer being compatible with the plastic base and oozing to the surface. This is a sign of advanced degradation.
- Pink or blue colors may appear in some film, due to anti-halation dyes.