Temperature dependent emission of formic and acetic acid from paper, and its consequences for the air quality in archives

Paper records affect the indoor environment in archives, because the paper may give off acid compounds to the air. These emission products origins from the decay of cellulose and lignin in the paper. As the off-gassing origins from chemical processes within the material (e.g., acid hydrolysis) the reaction rate is therefore, among other things, depending on temperature. Some of the emission products from paper, e.g., acetic and formic acid, are problematic from a conservation point of view, because they will re-react with the paper and other archival materials and cause further deterioration. The problem is amplified by an often very large loading (mass of material vs. volume) of paper in archival rooms. Furthermore, many archives have only little ventilation, so the exchange of polluted air with ambient air is low. The general trend; higher temperature accelerates material’s emission, and a high loading increases the level of internally generated pollutants in a confined room, is well recognized. However, the decisive factors are only sparingly quantified, and in the poster we will place these in a conservation context.