Acetic acid is in vinegar and that accounts its smell. It is the acid in photographic stop baths used to neutralize the alkalinity of the developer carried over. Silver halide holographic materials, like photographic and lithographic films, are usually washed free of developer, as hydrogen bubble are a by product of the neutralization, and can cause unsightly pinholes.
That same smell is exuded by boxes of Ilford Holographic Film of the early 1990's, particularly the SP737T and other T-suffixed alphanumerics, the T standing for triacetate. As the unstable triacetate base decays it evolves acetic acid.
The first incarnation of Jeff Blyth's Copper Sulfate Bleach used acetic acid, but later incarnations of that formula use sodium bisulfate, or powdered sulfuric acid, as the buffer.
Here is what the Photo-Lab Index from Morgan & Morgan has to say about it: