VINEGAR SYNDROME

Vinegar syndrome is a term used to describe the chemical reaction that goes on during the deterioration of cellulose triacetate film support.When cellulose triacetate begins to decompose, ‘deacetylation’ occurs and the acetate ion reacts with moisture to form acetic acid, producing a vinegar odour when the can is opened.The presence of the odour does not mean the film has degraded, but rather that the reaction is taking place. However, the reaction is continuous, and once started, it cannot be stopped or reversed. In fact, the reaction is autocatalytic, which means it feeds on itself and speeds up over time. The acid produced can also react with the dyes in colour films, causing dye fading and damage to both the image as well as the base. (NATIONAL FILM AND SOUND ARCHIVE OF AUSTRALIA)