Long-term effect of disinfection on collodion light-sensitive layer

Cellulose nitrate in the form of collodion has been used as a light-sensitive layer since 1851. As such, collodion photographs are often found in cultural institutions. Because of its organic structure, it is susceptible to microbiological contamination and, therefore, a need for disinfection may occur. In such cases, the disinfection method must be effective and non-destructive towards the material and restorer. Since all tried disinfection methods were proven effective by cooperating microbiologists, the non-destructivity against material became the primary concern. Model samples were prepared, disinfected, and artificially aged; to observe any possible change in properties on a long-term scale. The properties measured were: change in colour, change in the content of nitrogen and change in the degree of polymerisation obtained by viscometric measurements. From the results, we could select a disinfection method that did not pose any measurable threat towards the collodion light-sensitive layer and, therefore, can be used in practice by restorers.