There is a considerable amount of general information already known about mass deacidification that can be helpful in understanding how to proceed with evaluating and eventually using these processes. The technical basis for the paper stabilization as accomplished by deacidification is well understood, and this effect has been observed many times. Laboratory experiments predict a three- to five-fold increase in the useful lifetime of properly deacidified paper having a one to two percent alkaline reserve. Translating this prediction into years of estimated life can be complicated, since papers of different quality will have very different life expectancies to begin with. At two extremes, for example, are a cheap groundwood pulp acidic paper with only a lO-year original lifetime, and a high-quality chemical-pulp acidic paper with 100 years of original lifetime. In these hypothetical cases, the life of the paper with an original 1O-year lifetime could be extended to perhaps 30 or 50 years with deacidification. Likewise, the paper with an original 100 years of life might survive for 300 to 500 years with treatment. As has been discovered, actual library and archival collections contain a very broad range of paper strengths and rates of deterioration that in turn yield an equally broad range of stabilized papers after deacidification.

There are both liquid and gaseous approaches for the delivery of a deacidification chemical, and under each of these general classes there are several different process variations. Although this rapidly changing field of possibilities may appear to complicate the issue at first, this is a positive situation for the library and archives field, because each institution will have the opportunity to evaluate and select an approach that best suits the needs of its particular collections and budget.

There are at least five different mass deacidification technologies on the market in different stages of development, and two of them have come on the scene only in the last two years. If this pattern continues, there will most likely be several new processes available for consideration in the next ten years to compete with the processes that are adopted first. The need for a long-range procurement strategy to provide for timely reevaluation is apparent.

It has been possible to engineer several technologies successfully from the laboratory bench scale to a pilot plant demonstration level. This is very important, because the fact that a chemical process works in the laboratory does not mean that it will work the same way at the pilot or production levels. Evaluation of the engineering of a process at the pilot plant level is necessary for most industrial processes as they move to production level design. It is even more critical to the careful evaluation procedure of mass deacidification processes because there must be reassurance that they will work at the production level. Also, as much as possible must be known about processes–including their engineering–before committing collections for treatment.

Several technologies with pilot plant facilities have done production runs; in particular, the facility at the National Archives in Canada has extensive operational experience. The experience and data of such facilities can be very valuable in evaluating the day-to-day operations of processes in order to ascertain how they will really work in a production mode.