Mass deacidification is a process where an alkaline buffer is added to acidic paper via a non-water-based solution. The alkaline element neutralizes the acids, and extends the life of the paper. With the implementation of the Permanent Paper Law in the United States in 1990, mass deacidification is applied to older books and papers that are intact and not yet brittle. It is often performed on collections manufactured in developing nations due to the inherent poor quality of the paper.
The process is outsourced to a vendor near Pittsburgh, Preservation Technologies. PTLP's web site has a wealth of information about the Bookkeeper process.
If you are interested in having collections deacidified, see the guidelines to see if your collection is a good fit for the criteria.
Books during the mass deacidification process