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

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.

RÉSUMÉ

Deux essais de vieillissement accéléré, l'essai Oddy et l'essai d'activité photographique (PAT, Photographic Activity Test), sont employés afin de prédire l'innocuité des matériaux de stockage, d'exposition et de transport utilisés à proximité des objets du patrimoine culturel. Bien qu'ils aient été conçus pour prédire les possibles dommages chimiques pour les objets métalliques et photographiques, respectivement, les résultats des deux essais sont souvent appliqués à d'autres types de collections. Une comparaison directe entre les deux essais a été réalisée en évaluant le même ensemble de trente-cinq matériaux. Les résultats ont indiqué une très faible corrélation entre les tests, tant en ce qui concerne les résultats globaux qu'au niveau des réponses individuelles des détecteurs. Une comparaison supplémentaire avec l'essai à l'acétate de plomb (LAT, Lead Acetate Test), un essai sélectif pour les composés sulfurés réduits, a fourni des preuves supplémentaires que, bien que l'essai Oddy et le PAT soient fiables pour prédire l'effet des gaz volatils sur les métaux ou les réactions avec les matériaux en contact direct avec les photographies, ils réagissent différemment aux espèces chimiques réactives. L'essai Oddy et le PAT sont sélectifs et sensibles, mais chacun à différentes espèces et concentrations de composés chimiques réactifs. Les essais sont les plus efficaces lorsqu'ils sont appliqués aux types d'objets qu'ils étaient destinés à imiter, et les résultats des deux essais ne doivent être ni considérés comme équivalents ni appliqués de manière universelle à tous les types de collections. Traduit par Anne–Stéphanie Étienne.

RESUMO

Dois testes de envelhecimento acelerado, o teste Oddy e o Teste de Atividade Fotográfica (PAT), são usados ⁣⁣para prever a segurança de armazenamento, exibição ou transporte de materiais usados ⁣⁣perto de objetos do patrimônio cultural. Apesar de terem sido projetados para prever possíveis danos químicos em objetos metálicos e fotográficos, respectivamente, os resultados de ambos os testes são frequentemente aplicados a outros tipos de coleções. Uma comparação direta entre os dois testes foi concluída avaliando o mesmo conjunto de trinta e cinco materiais. Os resultados indicaram muito pouca correlação entre os testes, tanto na comparação dos resultados globais como no nível das respostas individuais dos detectores. Uma comparação adicional com o teste de acetato de chumbo (LAT), um teste seletivo para compostos de enxofre reduzidos, forneceu mais evidências de que, embora o Oddy e o PAT sejam confiáveis ⁣⁣na previsão do efeito de gases voláteis em metais ou reações com materiais em contato direto com fotografias, respectivamente, eles estão respondendo às espécies reativas de maneira diferente. O teste Oddy e o PAT são seletivos e sensíveis, mas cada um a diferentes espécies e concentrações de produtos químicos reativos. Os testes são mais eficazes quando aplicados aos tipos de objetos que cada um pretendia imitar, e os resultados dos dois testes não devem ser igualados nem aplicados globalmente a todos os tipos de coleção. Traduzido por Beatriz Haspo.

RESUMEN

Dos pruebas de envejecimiento acelerado, la prueba Oddy y la prueba de actividad fotográfica (PAT), se utilizaron para predecir cuán seguros son los materiales de almacenamiento, exposición o transporte utilizados en proximidad a objetos del patrimonio cultural. A pesar de haber sido diseñadas para predecir posibles daños químicos en objetos metálicos y fotográficos, respectivamente, los resultados de ambas pruebas suelen aplicarse a otros tipos de colecciones. Se realizó una comparación directa entre las dos pruebas evaluando el mismo conjunto de treinta y cinco materiales. Los resultados indicaron muy poca correlación entre las pruebas, tanto al comparar los resultados globales como a nivel de las respuestas individuales de los detectores. Una comparación adicional con la prueba de acetato de plomo (LAT), una prueba selectiva para compuestos reducidos de azufre proporcionó más pruebas de que, aunque la Oddy y la PAT son fiables para predecir el efecto de los gases volátiles sobre los metales o las reacciones con materiales en contacto directo con fotografías, respectivamente, responden a las especies reactivas de forma diferente. La prueba Oddy y la PAT son selectivas y sensibles, pero cada una a especies y concentraciones diferentes de sustancias químicas reactivas. Las pruebas son más eficaces cuando se aplican a los tipos de objetos que cada una de ellas pretende imitar y los resultados de las dos pruebas no deben equipararse ni aplicarse globalmente a todos los tipos de colecciones. Traducción Ramón Sánchez y Vera de la Cruz; revisión Amparo Rueda e Irene Delaveris.

KEYWORDS:

• Oddy test
• photographic activity test
• lead acetate test
• accelerated aging
• corrosion
• photograph degradation
• metals
• materials testing

Acknowledgments

The authors would like to thank various staff at the Image Permanence Institute that contributed to the project through group discussions and laboratory efforts including Andrea Venosa (in memoriam), Jennifer Burger, Kelly Krish, and Jennifer Jae Gutierrez. We would also like to acknowledge specific author contributions: Conceptualization, E.B. and D.B.; methodology, E.B., D.B., C.S.; experimentation, A.B., I.B., M.N., J.T.; formal analysis, A.B., E.B., M.N., C.S.; writing—original draft preparation, M.N.; writing—review and editing, A.B., E.B., M.N., E.R. C.S., J.T. All authors have read and agreed to the published version of the manuscript. The Metropolitan Museum of Art does not endorse, approve or recommend any product. Readers are solely responsible for determining appropriate products and treatment for their individual circumstances.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Notes on contributors

E. M. Breitung

Dr. Eric M. Breitung leads the Preventive Conservation Science Laboratory at The Met. Prior to that, he was a conservation scientist at the Preservation Research and Testing laboratory at the Library of Congress, the science department of the Smithsonian’s Freer and Sackler Galleries, and the Polymer Materials Laboratory at General Electric’s Research and Development facility. Eric holds a PhD in physical organic chemistry from the University of Wisconsin, Madison and a B.S. in chemistry from Illinois State University. His current position is focused on improving the field’s understanding, reliability, and ease of materials testing and establishing best practices for improving the museum’s indoor air quality to extend the useful life of art. Prior work includes the development of analysis tools for “sticky shed syndrome” on audio tapes, ion chromatography as an assessment tool for the “paper test,” and the analysis of dyes from Central Asian ikat textiles. E-mail: [email protected]

M. S. Noyes

Meredith Sharps Noyes is a research scientist at the Image Permanence Institute (IPI) at Rochester Institute of Technology, where she performs research related to materials used for storage, display, and transport of cultural heritage collections and manages the operation of IPI’s ISO testing services. Prior to IPI, she held a postdoctoral fellowship at the Smithsonian Institution’s Museum Conservation Institute, conducting collections-based research in the microanalysis laboratory. She holds a PhD and MS in chemistry from the University of Oregon, where she gained experience in a variety of material characterization methods while studying nanomaterials for use in lithography applications. She received a BS from Emory University, where she double majored in chemistry and music. E-mail: [email protected]

D. M. Burge

Daniel M. Burge, a retired senior research scientist, was a full-time member of the Image Permanence Institute (IPI) staff for over 30 years. He received his BS degree in Imaging and Photographic Technology from the Rochester Institute of Technology in 1991. He managed IPI’s enclosure testing services from 1991 to 2006. From 2007 to 2022, he led IPI’s investigations into digital print stability including developing recommendations for the use, storage and display of these materials in cultural heritage institutions. E-mail: [email protected]

C. H. Stephens

Catherine H. Stephens is the Michael and Sally Gordon Conservation Scientist at the Museum of Modern Art in New York City. Catherine holds a PhD in macromolecular science and engineering from Case Western Reserve University and two B.A. degrees from SUNY Geneseo, one in chemistry and one in art history. Her specialties include polymer structure–property relationships, material degradation studies, and preventive conservation research focused on materials for use while displaying or handling art. She also collaborates with conservators to study and preserve the Museum's collection. E-mail: [email protected]

A. Bone

Alayna Bone was a research assistant at The Metropolitan Museum of Art (The Met) from 2019 to 2023. Prior to that, she completed internships in the Met’s Scientific Research Department, where she investigated gasket materials for use with collections and the Paper Conservation Department, where she implemented traditional paper conservation techniques. She has also worked as an assistant for a private practice paper conservator. Alayna received her B.A. from Sarah Lawrence College. Her work in Scientific Research at the Met focused on preventive conservation including materials testing and environmental monitoring. E-mail: [email protected]

J. Tétreault

Jean Tétreault studied at the University of Montréal, where he received a Master’s degree in Analytical Chemistry in 1989. That same year he joined the Canadian Conservation Institute (CCI), where he currently works as a senior conservation scientist in the Preventive Conservation Division. His main research interests focus on pollutants, products used for display and storage, paper degradation and passive environmental controls in collections. Results of his research have been published in various peer-reviewed journals. He has given more than 110 seminars in Canada and Western Europe on preventive conservation issues such as lighting, environmental guidelines, and exhibit and storage materials. He has published technical documents on coatings, products used in conservation, silica gel and on pollutants. Since 1998, he has been a board member of the Indoor Air Pollution Working Group, which holds conferences every two years. E-mail: [email protected]

E. J. Richardson

Emma Richardson is the director of research at the Image Permanence Institute (IPI) and is responsible for guiding IPI’s research agenda. Emma has extensive research and leadership experience in the applied sciences, and an impressive professional record in higher education with a focus on cultural heritage. Prior to her appointment at IPI, she held the position of group lead for analytics and modeling within the Department of Data Science, National Physical Laboratory (NPL), the UK National Measurement Institute. Before joining NPL, she was associate professor of materials and head of the material studies laboratory in the Department of History of Art, University College London. She has also held posts as research fellow at the Getty Conservation Institute and conservation research scientist at The National Archives UK, working with diverse museum and archive collections. E-mail: [email protected]

I. C. Buscarino

Isabella C. Buscarino was a research assistant at The Met from 2017 to 2019. She received her BA in chemistry from Barnard College. While at Columbia University, she worked at the Ancient Ink Laboratory – a subset of the Columbia Nano Initiative – where she reconstructed and characterized Frankfort black ink using Raman spectroscopy. She also worked as a conservator's assistant at the Columbia University Libraries Conservation Program and was a teaching assistant with the Making and Knowing Project. At The Met, Isabella conducted materials testing, environmental monitoring, and insect identification. E-mail: [email protected]