Cellulose acetate
The safer replacement for celluloid, and still a material that warps, crazes and blooms rather than simply getting dirty.
What not to do
Water is unsafe on Cellulose acetate
Unsafe
Do not do this. The risk is established, and it is described below.
Evidence
Supported
Sources
Conserve O Gram 8/4: Care and Identification of Objects Made from Plastic
National Park Service, US Department of the Interior · Government or regulator
Relied on for: That solvents and water must not be used to clean plastic, and that if in-depth cleaning is needed a conservator should be consulted. (states this directly)
Precautions
- Ventilate the area
In detail
Cellulose acetate replaced cellulose nitrate in many applications as a less flammable semi-synthetic plastic, and it appears in spectacle frames, combs, handles, buttons and film. It is more stable than what it replaced and it is not stable. The conservation literature illustrates its failure mode directly: a distorted and discoloured acetate comb showing severe crazing and a white powdery bloom caused by migrating plasticizer. Distortion, crazing and bloom together are the signature, and an acidic odour can precede all of them. The important point is the diagnosis. Every one of those signs looks like something that ought to come off, and none of it will. The guidance is dry cleaning only — wiping, brushing or vacuuming — with solvents and water excluded, and storage that is cool, dark, dry and ventilated rather than sealed.
Why
- Cellulose acetate is explained by Damage versus soiling
Related
- Cellulose acetate is commonly affected by Sticky plastic
Sources for this page
Sources
Conserve O Gram 8/4: Care and Identification of Objects Made from Plastic
National Park Service, US Department of the Interior · Government or regulator
Relied on for: That plastics are subject to ageing and degradation, that the first visible signs are weeping, tackiness, discoloration, distortion, warping, crazing and embrittlement, that once present deterioration is rapid and irreversible, and that solvents and water must not be used to clean plastic. (states this directly)
Conserve O Gram 8/4: Care and Identification of Objects Made from Plastic
National Park Service, US Department of the Interior · Government or regulator
Relied on for: That a distorted and discoloured cellulose acetate comb showed severe crazing and a white powdery bloom caused by migrating plasticizer, and that cellulose nitrate and cellulose acetate materials should be stored or exhibited in a well ventilated environment. (states this directly)