Evaluation of Conservation Conditions of Nara National Archives Documents

Abstract

ABSTRACT Many government agencies have used domestic deacidification equipments to stabilize archives; how-ever, no agency has verified archives' current preservative status. We studied the Nara National Archives' documents that had treated by mass deacidification process from 2001 to 2012, in order to examine the documents' preservative status and how efficient the mass deacidification has been. Approximately 1% of total 112,970 Nara National Archives' documents treated by mass deacidification were randomly se-lected and evaluated on their current measure of acidity and color change. Regardless of the kinds of document material, a wide range of pH level was found. Especially those documents that were treated by mass deacidification equipment after 2006 showed acidic conditions that were less than pH 6.8 level. Those documents were probably not treated properly by deacidifying chemical because of tightly pack-ing style. The current measures of acidity and color records will be useful as a reference for future evalua-tions of further decay of the documents. It was the first study to evaluate acidity and color conditions of Nara National Archives' documents treated by mass deacidification equipment. We concluded that when using mass deacidification equipment, archives should not be loaded tightly in order for them to be fully in contact with deacidifying chemical.