The NARA Advisory Committee on Preservation met on September 14, 1993, to discuss a number of issues relating to the storage of acetate film materials. Committee members included Norbert S. Bear, New York University, who served as chairman; David Francis, Library of Congress; Mark McCormick-Goodhart, Smithsonian Institution; Klaus Hendriks, National Archives of Canada; Jan-Christopher Horak, George Eastman House; Philip Murphy, Paramount Pictures; A. Tulsi Ram and Ron E. Uhlig, Eastman Kodak; James Reilly, Image Permanence Institute; Edward Richmond, UCLA Film and Television Archive; Leslie E.Smith, National Institute of Standards and Technology; and Peter Williamson, Museum of Modern Art. Numerous people from NARA units also attended.

Members discussed their experiences with acetate deterioration. NARA described problems affecting the 1950 census microfilm which has undergone severe curling. Richmond indicated that the majority of acetate deterioration at UCLA appeared among release prints, including Dye Transfer Technicolor prints and 16 mm RKO prints processed in Mexico. Williamson said that MOMA staff began noticing acetate deterioration as early as 1958. Subsequently, in a survey of films produced between 1935 and 1950, about 700 reels of decomposing acetate were found, primarily projection prints from the 1930s and 1940s. Francis reported that vinegar odour was not very noticeable at the Library of Congress, but that their plans for inspection are in abeyance due to an internal health advisory that requires special ventilation equipment. Based on his experience at the National Film Archive, however, he reported a 1% incidence of vinegar syndrome of films produced between 1948 and 1965; the worst ones were magnetic stripe films and poorly processed television prints.

A discussion followed about the merits of retaining film originals after copying, a policy practised by all archives. However, NARA's past decision to destroy its nitrate after copying was criticised.

Ram minimised the role of plasticizers and solvents as catalysts in the degradation of acetate film, indicating that powdery exudation and dimensional change can occur with or without acetate deterioration.

Reilly said that once degradation starts, the amount of free acid determines the rate of change. Reilly recommended cooler temperatures for storage to slow down the development of free acid and thus considerably lengthen the time to solve preservation and verification issues.

Ram reported on the application of "molecular sieves" as acid scavengers in archival storage. Tests conducted by Kodak demonstrated that the sieves, composed of zeolite materials in polyethylene packets, effectively absorbed acidic gases and moisture, thereby slowing down the process of deacetylation and preventing the premature fading of colour dyes.

There followed some criticism of the sieve proposal. Reilly cautioned that the sieves were no substitute for cool and dry storage conditions. Others were concerned with the possibility of over desiccation, though Kodak's tests only showed moisture reduction to recommended levels. Still others questioned the feasibility of inserting and replacing the sieves in large collections. Several archives, nonetheless, plan to implement pilot programs for testing the sieves under practical vault conditions.

The last part of the conference focused on several specific questions which the committee generally answered as follows:
1. There were no real benefits to be gained by segregating various acetates.
2. Outside of a chemical laboratory there were no practical or non-destructive tests for tracking deterioration, except for nose sniffing. Activated carbon tests, however, are effective for analysing air in the vaults.
3. Film deterioration does vary by format (e.g., roll film, cut film, x-rays, etc.); loose film may deteriorate more quickly.
4. More study is needed on the application of molecular sieves; at the outset the process seems expensive and labour intensive.
5. Cool and dryer storage conditions, particularly below 55 degrees F, together with monitoring, will benefit all films.
6. Duplication of all acetate holdings does not seem warranted as long as there are procedures for identifying what is likely to be destroyed from usage or deterioration. Generally everyone agreed that some combination of cooler storage and systematic copying would be the most viable strategy. No consensus could be reached on the merit of using polyester film because, as some argued, they suspected long-term adhesion problems, although the National Academy of Sciences has endorsed its use for microfilm.
7. The use of HDTV and other high resolution image media does not currently offer practical alternatives except perhaps for reference use. Nonetheless, the technology should be closely watched for future applications. The other questions concerned storage recommendations for NARA microfilm of the 1950 census and the need for further research on film containers.

The minutes of the day-long conference, together with post-meeting notes and appendices, are available from Alan Calmes, Preservation Officer, Preservation Policy and Services Division, National Archives and Records Administration, Washington, D.C. 20408.

Calmes served as Executive Secretary for the conference. In addition, the minutes are available on an Internet FTP directory at CU.NIH.GOV (128.231.64.7). Log on as an anonymous user; type "guest" at the password prompt. The directory in which this information is stored is NARA_AUDIOVISUAL. The document is ACETATE.TXT. Use the FTP GET command to retrieve a copy of the file.

William T. Murphy

Le Comité consultatif de préservation de la National Archives and Records Administration (NARA) s'est réunie en septembre 1993 dans le but de faire le point de la situation sur le débat au sujet de la conservation de la pellicule en acétate.

Sous la présidence de Norbert S. Baer de la New York University et avec la participation des représentants des Institution invitées (Library of Congress, Smithsonian Institution, National Archives of Canada, George Eastman House, Paramount Pictures, Eastman Kodak, Image Permanence Institute, UCLA Film and Television Archive, National Institute of Standards and Technology, MoMA et NARA), le Comité s'est fixé pour but d'échanger les conclusions concernant le problème de la dégradation des supports en acétate.

Les réponses aux sept catégories de questions posées lors de la réunion sont, sommairement, les suivantes:

1. Il n'y n'y a pas d'intérêt particulier à considérer séparément les divers types d'acétate.
2. Il n'y a pas d'autres méthodes d'analyse de la détérioration de l'acétate que celle du laboratoire (coûteuse et entraînant la destruction du matériel analysé) et l'odorat (bon marché et épargnant le matériel analysé car il suffit d'avoir du nez). Cette dernière s'avère encore et toujours comme la plus pratique...
3. La détérioration du support en acétate varie selon les formats et la fragmentation des films considérés (bobine, extrait de bobine, film pour radiographie, microfilm, microfiche, etc.). Les petits bouts de film se détériorent plus rapidement que les bobines entières.
4. Il serait utile d'approfondir l'étude de l'application dite du "tamis moléculaire". Mais c'est cher à installer et requiert beaucoup de main d'oeuvre.
5. L'entreposage à basse température et à HR moindre bénéficie tous les films.
6. La duplication généralisée des films acétate ne suffit pas à garantir leur survie. La meilleure stratégie possible devrait combiner l'entreposage à basse température avec la duplication systématique. La pellicule en polyester ne fait pas l'unanimité (surtout à cause de problèmes d'adhésion).
7. La HDTV et d'autres images à haute définition n'offrent pas d'alternatives pratiques réelles, excepté pour la consultation. Cette technologie doit cependant être suivie de près dans ses développements futurs.
Les actes de la réunion peuvent être consultées suivant les instructions figurant dans l'article.

Conservación de pel'culas de acetato: situación del debate en el seno de la NARA

El Comité consultativo de preservación de la National Archives and Records Administration (NARA) se reunió en septiembre de 1993 para actualizar el debate sobre la conservación de pel'culas de acetato.

Bajo la presidencia de Norbert S. Baer de la New York University y con la participación de los representantes de las Instituciones invitadas (Library of Congress, Smithsonian Institution, National Archives of Canada,George Eastman House, Paramount Pictures, Eastman Kodak, Image Permanence Institute, UCLA Film and Television Arcive, National Institute of Standards and Technology, MoMA y NARA), el Comité se fijó como objetivo el intercambio de las conclusiones referentes al problema de la degradación de la pel'cula de acetato.

Las respuestas a siete categor'as de preguntas formuladas en la reunión son, en resœmen, las siguientes:

1. La separación entre distintos tipos de acetato no ofrece ningœn interés particular
2. No existen otros métodos de análisis del deterioro del acetato que el del laboratorio (costoso y destructor del material analizado) y el organoléptico (barato y respetuoso del material analizado ya que es suficiente con tener un buen olfato...). La nariz sigue siendo el método más práctico para el análisis de deterioro del acetato.
3. El deterioro del acetato var'a con los formatos y el grado de fragmentación de la pel'cula (rollo, fragmento, lámina para rayos X, microfichas, etc.). Los fragmentos de pel'cula se deterioran más rápido que los rollos completos.
4. Ser'a œtil de profundizar el estudio de la aplicación del "tamiz molecular", aunque sea costosa tanto en su instalación como en su funcionamiento.
5. El almacenaje a bajas temperatura y humedad relativa favorece a todas las pel'culas.
6. El duplicado generalizado de las pel'culas de acetato no alcanza para garantizar su supervivencia. La mejor estrategia posible deber'a combinar el almacenaje a baja temperatura con la duplicación sistemática.
7. La HDTV y otras imágenes de alta definición no ofrecen alternativas concretas excepto para fines de consulta. Sin embargo se debe seguir de cerca el desarrollo futuro de esta tecnolog'a.
Las minutas de la reunión pueden ser consultadas siguiendo las instrucciones que figuran en el art'culo.