The cellulose was decaying and creating acetic acid (vinegar syndrome) which would in time destroy the image.
The problem became known as the "vinegar syndrome."
They provide a nondestructive method of determining the extent of vinegar syndrome in film collections.
Sealed metal containers can trap the decay products released by the film, promoting the spread of vinegar syndrome.
Magnetic sound on an acetate base is also more prone to vinegar syndrome than a film with just the image.
Cellulose acetate film, which was the initial replacement for nitrate, has been found to suffer from 'vinegar syndrome'.
However, color fading of certain color stocks and vinegar syndrome threaten the preservation of films made since about this time.
The films undergo periodic inspection to confirm that they have not been afflicted with any damaging chemical problems, such as vinegar syndrome.
This is known as vinegar syndrome.
However, the archive material is in various states of deterioration, with some film already suffering from vinegar syndrome.