Arsenic Pigments in Libraries – Testing Methods, Contaminated Spaces, and Occupational Safety Measures

Abstract Arsenic-containing pigments in library materials are a source of danger for institutional staff, conservators, scientists, and users. In a research project, the Bonn University and State Library and the Cologne University of Applied Sciences analysed the handling of arsenic in library materials. Over 300 volumes with suspicious green book components were analysed using both XRF and Raman spectroscopy, with arsenic compounds being detected in around half of them. A rapid test based on bromide test strips and the MQuant ® test were then evaluated. The MQuant ® test proved to be more useful. Dust tests at various locations in the library stacks detected arsenic concentrations that were above the permissible guideline values. In addition to arsenic, other heavy metals like lead and mercury were also detected. The secondary contamination of books standing next to arsenic-containing bindings was investigated further, showing positive results for arsenic on most of the books tested. The cause of this secondary contamination could not be discerned. The results of this study show that a precise occupational safety-based risk assessment in accordance with the (S)TOP principle, the drafting of work instructions and, above all, thorough hygiene measures are necessary. The cleaning of library rooms and hygiene standards should be pursued consistently and should be taken as seriously as the detection of arsenic compounds.