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Introduction

What is cellulose acetate?

Cellulose acetate is a transparent plastic material that has been widely used (and continues to be used today) as a base for photographic and motion picture film, microfilm, aerial film and transparent overlays, and for sound recordings. Originally marketed as ‘safety film’ and believed to be of archival quality, it is now known that cellulose acetate material can undergo significant deterioration within 30-40 years if stored at or near room temperature (Bigourdan & Reilly, 2000, p.14).

This deterioration, which initially involves the release of acetic acid, has been termed the ‘vinegar syndrome’. The latter stages of degradation are accompanied by shrinkage, channelling and buckling with crystals and bubbles appearing on the surface of the film, and ultimately embrittlement and loss of information. (For further details about the degradation of cellulose acetate, see the ‘Assessment Guidelines’ available at http://www.nla.gov.au/anica/AssGuidelines2.doc).

This paper aims to summarise some of the important issues emerging from the recent literature discussing preservation and storage of cellulose acetate based film. It also provides information about cool storage facilities in Australia. It is hoped that this information will assist institutions considering options for the storage of their cellulose acetate collections. For more in-depth discussion of the relevant issues the reader should consult the cited literature.

Risks to cellulose acetate collections

Apart from the vinegar syndrome, a range of other risks to cellulose acetate collections may exist. These include other forms of chemical deterioration, such as colour dye fade, physical damage, fungal growth, or loss of important information about the materials themselves arising from poor collection control. If information about what is actually present in the collection is not available, it is difficult to make educated storage decisions that support preservation of the collection.

Colour film

Colour film has its own storage requirements which reflect the instability of many of the colour dyes used in colour photographic emulsions. This document does not attempt to deal with storage of colour photographic materials, except to point out that cellulose acetate materials may be colour.

Occupational Health & Safety

Occupational health and safety guidelines should be carefully followed when working in an environment where acid vapours from deteriorated film may be present. These acetic acid vapours, if present in sufficient concentrations1, can pose a health risk.

“Exposure to acid vapours can cause eye irritation including conjunctivitis, blepharitis, and keratisis, tearing (lacrimation), irritation of the nose, throat and lungs; pharyngeal edema; skin sensitisation; hyperkeratosis (growth of hard skin layers) and dental erosion” (Nishimura, 1995, p.378)

Gloves made of natural rubber, neoprene or vinyl are recommended when handling deteriorated materials, and the wearing of contact lenses should be avoided. If substantial amounts of deteriorated material need to be handled, it is be advisable to use a fume hood, limit exposure time and/or ensure excellent ventilation (Nishimura, 1995, p.378).

It is often the case that cellulose nitrate negatives are mixed in with cellulose acetate negatives. These are of significant OH & S concern. For more information on how to identify and distinguish film base materials, see the ‘Assessment Guidelines’ available on this website.


(1) For acetic acid the Time Weighted Average Exposure (TWA) is 10 parts per million (ppm) or 25 milligrams per cubic metre of air (mg m3). TWA is defined as the time-weighted average airborne concentration of a particular substance when calculated over a normal 8-hour work day, for a five-day working week.

(source: http://www.nohsc.gov.au/ohsinformation/databases/exposurestandards/az/acetic_acid.htm)


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