Preventive conservation actions such as maintenance of a good environment, promoting proper care, handling through staff and user education, and the use of good quality storage housings, will have a lasting, positive impact on the preservation of a collection. It is crucial to understand that only cold storage can provide long-term access to these materials. Without cold storage, temperature-sensitive materials will deteriorate in a matter of a few decades; with cold storage they can remain unchanged for many centuries. It is essential to know the type of items that are intended to be stored, because the climatic conditions required depend on the type of material, as described in the tables below.
In a summarized mode we include the necessary conditions indicated for the storage of different kinds of material:
Collectively, the ISO standards for individual media contain seven different temperature recommendations. To simplify the evaluation and planning of storage conditions for mixed media collections, the MSQR divides the range of possible temperatures into four categories: ROOM, COOL, COLD, and FROZEN. The Four Temperature Categories Even though each of the four categories represents a range of temperatures, it is useful here to define ROOM, COOL, COLD, and FROZEN by single “anchor-point” values, as shown in the table above. (It should be remembered that, in reality, the effect of temperature on decay rate is a continuum. The higher the temperature, the faster the decay, and vice versa.) Using the table above and data gathered through an environmental assessment, we should be able to place the storage environment in one of these four categories. It’s very likely that the storage temperature is not precisely one of the four shown in the table. In this case, the following rules of thumb should help to decide where the environment fits: Any environment with an average temperature at or below 0°C can be considered FROZEN. If the real-life average temperature is closer to one anchor-point temperature than another, simply apply the closer category. For example, if the storage temperature is 10°C, the environment would be considered COOL. If the average temperature is about equidistant from the temperatures on either side, consider both the cooler scenario and the warmer scenario when referring to table.