Mass Deacidification

• Diethyl zinc (DEZ) deacidification is being used by Harvard University on a modest scale. The guidelines they use for physical selection of materials have a list of materials not to send (very fragile books, bindings with artifactual value, books printed mostly on coated paper, photographs, oversize books mixed in with smaller books, and so on). The reasons for precautions are given. The guidelines are condensed from a section of a 17-page report on the 1991/92 Pilot Operational Program, available from the Preservation Office, Harvard University Library, 25 Mt. Auburn St., Cambridge, MA 02138 (617/495-8596).
• The Association of Research Libraries (ARL) is working with its member libraries to create a critical mass of libraries moving to large-scale deacidification. Twenty-five had agreed to participate at the time this was announced at ALA Midwinter.
• The Harry Ransom Humanities Research Center at the University of Texas has also been using DEZ, not for books but for archival materials, on an NEH grant project. Like Harvard, they have to select the materials: plastics react strangely, and some materials do not let the gas through. The process is evolving, and they say the results are gratifying. The material is shipped to Akzo's plant in Deer Park, Texas.
• Both Canada and France, which have been using nonaqueous MMC-based deacidification in their own plants for years, are working to improve the process. It was reported about two years ago that the Bibliothèque Nationale had contracted with a French and a German company to shorten the treatment, close up the process, and maybe strengthen the paper at the same time.

  In Canada, where they have been operating a nonaqueous MMC process for ten years, the National Archives and National Research Council will carry out a joint research project to develop a new chemical formula that will result in an effective, nontoxic and environmentally safe solution for deacidification. The lab work will be done by the Canadian Conservation Institute and the National Archives. (Under terms of the Montreal Protocol, the use of CFCs will be banned in December 1995.)

• The German Library has been working with Battelle Institute in Frankfurt am Main to improve a nonaqueous MMC process in a mixture of alcohol and CFCs. The goal was to develop a short-cycle process that could be operated onsite by librarians, without releasing environmentally harmful CFCs. [It is possible that a new method has been substituted for the MMC process, because the press release reprinted in Restauro did not refer to the method at all. An official announcement is expected after the ICOM meeting in August.]

  The pilot plant in Frankfurt was completed late in 1990, and now plans are being made for construction of a large plant with a capacity of about 400,000 volumes per year at the German Library in Leipzig. There will be two connected treatment chambers. Treatment takes place in three stages: drying, chemical neutralization and post-treatment drying (removal of solvent used in treatment). The first stage has been shortened considerably by drying under a vacuum with simultaneous warming by microwaves. The temperature of the books is kept below 122°F by an automatic mechanism. The entire process takes less than two hours. [Note: The press release does not make it clear whether only the first stage, or all three, can be completed in two hours.]