This fire was responsible for the loss of most of the silent films produced by Fox Film Corporation before 1932. Also destroyed were Educational Pictures negatives and films of several other studios. It brought attention to the potential for decaying nitrate film to spontaneously ignite, and changed the focus of film preservation efforts to include a greater focus on fire safety.
The early motion picture industry primarily used nitrocellulose film stock, commonly called nitrate film. This film is flammable, and produces its own oxygen supply as it burns. Nitrate fires burn rapidly, and cannot typically be extinguished, capable of burning even underwater. Additionally, nitrocellulose is subject to thermal decomposition and hydrolysis, breaking down over time in the presence of high temperatures and moisture. This decaying film stock releases nitrogen oxides that themselves contribute to the decay and make the damaged film burn more easily. Under the right conditions, nitrate film can even spontaneously combust. In part because of substantial variability in the manufacturing of early film, there is considerable uncertainty about the circumstances necessary for self-ignition. Sustained temperatures of 106 °F (41 °C) or higher, large quantities of nitrate film, increased humidity, poor ventilation, and aged or decaying film have all been considered risk factors. Most such fires in film archives have taken place in heat waves during summer months, in closed facilities with limited ventilation, exacerbating several of these variables. Especially in confined areas, such fires can result in explosions.
Large and dangerous fires sometimes resulted. On 4 May 1897, one of the first major fires involving nitrate film began when a Lumière projector caught fire at the Bazar de la Charité in