Opinion: Historical films may be decaying much faster than we thought

Writing for The Conversation, PhD student Ida R. Ahmad (UCL Institute for Sustainable Heritage) explains that precious historical documents are under threat from 'vinegar syndrome', which causes film to decompose. A significant chunk of the world's history is facing an existential threat. US government deeds ,  recordings of Indigenous Australians  and  photographs of English seaside life spanning three decades  are just some of the historical documents recorded on acetate film that are suffering irreversible damage due to what's known as vinegar syndrome. Vinegar syndrome happens when acetate film is stored in a warm, humid room. These conditions cause the film to decompose. As the film starts to rot, it gives off acetic acid, the same ingredient in household vinegar that gives its distinctive smell and taste. The acid speeds up degradation in the affected film, and can even damage metal storage containers and other films stored nearby.