Air Quality in Storage Cabinets – Cause and Effect
"The Schinkel’s Legacy Project at the Kupferstichkabinett Berlin: Air Quality in Storage Cabinets – Cause and Effect" is the summary of a multi-annual investigation of Fabienne Meyer/Dagmar Hansen/Vladimir Knjasev/Gerhard Volland.
The publlication appeared in Restaurator. International Journal for the Preservation of Library and Archival Material. Band 35, Heft 2, Seiten 81–112, ISSN (Online) 1865-8431, ISSN (Print) 0034-5806, DOI: 10.1515/rest-2014-1002, June 2014. KLUG-CONSERVATION was part of the project.
In the Kupferstichkabinett (Museum of Prints and Drawings) of the Staatliche Museen zu Berlin (National Museums in Berlin), the collection of the drawings and prints of Karl Friedrich Schinkel (1781–1841) is stored in cabinets made of laminated chipboard panels. The works are enclosed in portfolios that sit inside the cabinets on shelves made of bonded beech wood. Oddy tests carried out on the various storage materials showed their high corrosive potential on lead. In particular, the two wood composite materials caused a corrosion rate that was even higher than that of 5 % acetic acid or 5 % formic acid. The analysis of the air composition inside the storage cabinets confirmed this showing a considerably high concentration of acetic acid (4.7 mg/m3 on an average) and a slightly elevated concentration of formaldehyde. Filling the cabinet and measuring its air composition in several steps allowed the determination of the main emission sources which were the shelves for acetic acid, and the cabinet walls for acetic acid as well as for formaldehyde. Further research on the organic acid content in the beech wood shelves together with a literature review led to the conclusion that formic acid is also expected to be present in elevated concentrations inside the cabinet. However, due to technical reasons it could not be detected in the air quality measurements. In a next step, the ability of various historical and modern papers with and without alkaline reserve to adsorb acetic acid and formic acid was tested. It was shown that all papers adsorbed acidic VOCs in a relatively short period of time, whereas afterwards the adsorption proceeded more slowly. It was further shown that the sorption capacity of alkaline papers on acetic acid and on formic acid was five times as high as of neutral or acidic papers. Finally, the effectiveness of various measures to reduce the emergence of volatile organic compounds in the objects’ surroundings was tested. The removal of the beech wood shelves led to a significant decrease in the acetic acid concentration, while the addition of alkaline papers did not show any positive effect at all.
