Cellulose nitrate
One of the first man-made plastics and one of the least stable. An acidic smell is the warning that arrives before anything looks wrong.
What not to do
Water is unsafe on Cellulose nitrate
Unsafe
Do not do this. The risk is established, and it is described below.
Why we say this
Supported
Stated as a flat prohibition in the leaflet's do-not column, for plastics generally.
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)
Verification: a person has read the passage relied on.
Read on — The sections headed Plastics Identification, Causes of Deterioration and Signs of Deterioration, plus the ventilation guidance. Supports the claim as stated. Gives the household-plastics record a deterioration mechanism and explains the sticky-remote-control problem, which the catalogue previously had no account of at all. Also establishes that improper cleaning is itself a named cause.
Last reviewed by a person on .
Precautions
- Ventilate the area
- Consider professional help
In detail
Cellulose nitrate is a semi-synthetic plastic made from modified natural material, developed in the late nineteenth century and used through the early twentieth for combs, handles, buttons, spectacle frames and countless small domestic objects. It is among the most unstable materials a household is likely to own. Conservation guidance is explicit that the earliest plastics are often the most vulnerable, because many of the chemical additives used in the late 19th and early 20th centuries are unstable. Before any visual clue appears, a degrading object may emit an ODOUR — an acidic smell, like vinegar — and once crazing, cracking, discoloration or brittleness is visible, deterioration is occurring at a rapid rate and is irreversible. Cleaning it is almost entirely a refusal. Dry wiping, brushing or vacuuming only; solvents and water are not to be used. It should be ventilated rather than sealed, kept cool and dark, and stored away from metals and other organics, because the gases it releases are corrosive to its neighbours.
Why
- Cellulose nitrate is explained by Damage versus soiling
- Cellulose nitrate is explained by Plasticizer migration
Related
- Cellulose nitrate is commonly affected by Skin oil
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)
Verification: a person has read the passage relied on.
Read on — The sections headed Plastics Identification, Causes of Deterioration and Signs of Deterioration, plus the ventilation guidance. Supports the claim as stated. Gives the household-plastics record a deterioration mechanism and explains the sticky-remote-control problem, which the catalogue previously had no account of at all. Also establishes that improper cleaning is itself a named cause.
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 the first man-made plastics were produced from modified natural materials in the late 19th century, that the earliest plastics are often the most vulnerable because early chemical additives are unstable, and that an acidic odour such as vinegar may indicate early degradation. (states this directly)
Verification: a person has read the passage relied on.
Read on — The sections headed Plastics Identification, Causes of Deterioration and Signs of Deterioration, plus the ventilation guidance. Supports the claim as stated. Gives the household-plastics record a deterioration mechanism and explains the sticky-remote-control problem, which the catalogue previously had no account of at all. Also establishes that improper cleaning is itself a named cause.
Last reviewed by a person on .