The Oddy Test and the Photographic Activity Test (PAT): A Direct Comparison of Accelerated Aging Test Methods for Assessing Storage, Display, and Transport Materials

Abstract

ABSTRACT Two accelerated aging tests, the Oddy test and the Photographic Activity Test (PAT), are used to predict the safety of storage, display, or transport materials used near cultural heritage objects. Despite being designed to predict possible chemical damage for metallic and photographic objects, respectively, results from both tests are often applied toward other collection types. A direct comparison between the two tests was completed by evaluating the same set of thirty-five materials. Results indicated very little correlation between the tests, both when comparing overall results as well as on the level of individual detector responses. An additional comparison with the lead acetate test (LAT), a selective test for reduced sulfur compounds, provided further evidence that while the Oddy and PAT are reliable at predicting the effect of volatile gases on metals or reactions with materials in direct contact with photographs, respectively, they are responding to reactive species differently. The Oddy test and PAT are selective and sensitive, but each to different species and concentrations of reactive chemicals. The tests are most effective when applied toward the object types each was intended to mimic, and results from the two tests should neither be equated nor applied globally toward all collection types.