Historical Perutz film canisters and the acetic acid syndrome

OBJECT OF THE MONTH JULY 2024

This month we are presenting three special 35mm film canisters from the Perutz company, which were found in our archive. These historic black and white films not only represent a piece of photographic history, but also illustrate the challenges of archiving and preserving old film materials.

Founded in 1896, the Perutz company was a pioneer in the production of photographic films and plates. Perutz became particularly well-known for its X-ray films and the higher-contrast, double-side-coated X-ray films developed after the First World War. From 1927, Perutz marketed specialty plates for reproduction photography and, from 1932, produced the panchromatic Rectepan film. After the Second World War, Perutz films were especially important in television, where they were used as standard film stock for news and documentary programs. In 1964, the company was acquired by Agfa, although many films continued to be sold under the Perutz name.

The green color of the film boxes was typical for Perutz and a kind of trademark. The company attributed the green color to the particularly high yellow-green sensitivity of the first panchromatic emulsions, a characteristic that was referred to as the "green seal" in advertising strategy.

Upon examining the Perutz film canisters, we immediately noticed a strong vinegar smell – a sure sign of acetic acid syndrome (also known as vinegar syndrome). This phenomenon occurs when older cellulose acetate films react with humid air. The acidic hydrolysis of the base material leads to the formation of acetic acid, which not only causes the characteristic odor but also leads to the decomposition of the film. The emulsion layer becomes brittle and can detach from the base, making digitization and preservation of the material considerably more difficult or even impossible. In our case, it is no longer possible to reconstruct which images were originally on the films.

Cellulose acetate films, also known as safety films, have been used from around 1925 to the present day and, unlike the highly flammable nitrate cellulose films, are difficult to ignite. Despite their safety, they are not protected against acetic acid syndrome, which occurs particularly when stored improperly in warm and humid environments. We can therefore assume that the film canisters were not stored in the required cool and dry conditions.

Our three Perutz film canisters are therefore more than just historical artifacts; they also bear witness to the challenges faced by archives and estate administrators in preserving film material. The smell of vinegar and the visible damage to the film serve as a reminder of the importance of proper storage and care for these valuable historical documents.

Images: © Peter Schulte, Hamburg