Degradation of pre-1950 photographs by acid hydrolysis in photographic archives

Abstract

Photographic patrimonies on plastic substrates, whether of cellulose nitrate or cellulose acetates, are exposed to degradation by an autocatalytic process of acid hydrolysis. Despite the existence of extensive literature on procedures for conservation and preservation of this material, the one which analyzes the actual present of the collections kept by documentation centers is not abundant. The aim of this paper is to present the state of conservation of this sort of materials in Catalonia, as well as the conditions of conservation. Results show that proper conservation procedures have been implemented only recently and environmental control facilities are underused. Even though about 85% of the material has not reached a state of self-induced catalysis yet, quick actions must be taken to preserve it because a third of the material studied is close to this fatal situation.