J.CAC VOLUME 45 (2020)

Disinfection of Photographic Materials with Ethanol Vapours: Preliminary Evaluation of the Effects on Chromogenic Prints

Chloé Lucas, Greg Hill, Nancy E. Binnie

The biodeterioration of photographic collections by mould is a recurring problem. In 2017, Lucas et al. demonstrated that exposing photographs to 70:30 (v/v) ethanol-water vapours for two hours kills five of the most common fungal species found in photographic collections. The goal of this project was to evaluate any side effects of this treatment on chromogenic prints. Sixty non-mouldy historic photographs, grouped by decade from the 1940s through to the 2000s, were exposed in small chambers to the ethanol-water vapour treatment. Treatment effects were evaluated by a combination of spectrophotometric measurements and visual observations of colour, surface sheen and planarity. The measurements indicated colour change on a majority of the treated samples. The magnitude of colour change varied with sample date of production. Samples from the 1980s and 2000s exhibited the highest percentage of significant alteration by treatment (89%), with significant colorimetric change and, in most cases, colour changes visible to the eye (67%). Samples from earlier decades were less affected by the treatment both in the percentage of affected samples and in the magnitude of the colour change.

Download: JCAC45 Lucas et al.