An independent Office of Technology Assessment (OTA) report of the deacidification program underway at the Library of Congress, this report was undertaken at the request of the House Appropriations Committee. Because of the particular concerns of engineering and safety which have been raised regarding this program, this report focuses on its effectiveness and safety, and compares the current program to other alternatives. The Library of Congress' program, which uses DEZ (diethylzinc) as a paper deacidifier, is discussed in detail, and the safety and environmental effects of this program are considered. The OTA findings suggest that more research and planning should be undertaken before embarking on a full-scale program using the DEZ process, and it is recommended that other alternative strategies be more fully explored. The text is supplemented by photographs, tables, and figures, and bibliographic notes/references are provided. (EW)