Reducing Microbial Contamination on Historical Leather Artifacts at the Auschwitz-Birkenau State Museum (A-BSM) using ethanol in the form of mist

Krzysztof Kraśnicki ¹ Natalia Pydyn ^1* Aleksandra Papis ¹ Krystyna Guzińska ² Dorota Kaźmierczak ² Urszula Maciołek ³ Anna Wawrzyk ¹

• ¹ Auschwitz-Birkenau State Museum, Oświęcim, Poland
• ² Łukasiewicz Research Network - Lodz Institute of Technology, Łódź, Poland
• ³ Maria Curie Sklodowska University, Lublin, Poland

The aim of the study was to evaluate the biocidal efficacy and determine the influence of 90% ethyl alcohol applied in the form of a mist on the surface of model and historical leather.The main object of the study were historical leather shoes from the collections of the Auschwitz-Birkenau State Museum (A-BSM) in Oświ ęcim (Poland).Microorganisms found before on historical leather objects in A-BSM were inoculated onto samples of model and historical leather. Ethanol mist was applied with an airbrush with optimized parameters for 15 s at a concentration of 90%. To increase the biocidal effectiveness, the samples were sealed in a tight package and stored for 22 hours. The effect of disinfection was assessed using culture-dependent methods. Changes on the surfaces was assessed using SEM, FTIR and XPS techniques.Results: On surfaces inoculated with microorganisms in the following quantities: 10 5 -10 8 CFU bacteria and 10 5 CFU fungi, a reduction of 99.51 to 99.99% was observed. Ethanol disinfection had no negative effect on the surface morphology and collagen structure.Conclusions: Disinfection with ethanol applied in the form of mist can be effectively used to eliminate microbiological contamination of historical objects made of leather in A-BSM.