Cellulose Nitrate Film Base. Synonyms: Nitrate, Celluloid
Cellulose Nitrate was used for most film formats from the start of the cinema except for some 28mm, 9.5mm, Standard 8mm and Super 8mm. 16mm is almost always safety; 16mm nitrate is very rare - Russia sometimes slit 35mm nitrate into 16mm.
Cellulose Nitrate is HIGHLY INFLAMMABLE (see pictures below of a nitrate fire), can spontaneously combust, self ignite and decomposes.
A piece of film about 1/8" inch wide is put in a bulldog clip with a similar piece of known acetate film. A lighted match is applied to the safety film; it will not burn upwards. The flame is applied to the nitrate and it will rapidly burn upwards
The first safety film base was Cellulose Diacetate introduced for 28mm amateur format in 1911. Cellulose TriAcetate introduced around 1940.
