Assessing Environmental Risk

Condensation on Film CansSteady temperature and humidity levels in collections were traditionally considered ideal, but in reality variations in environmental conditions are inevitable. In 1998, IPI investigated the impact of cycling conditions on library materials to determine if fluctuations are inherently damaging to collection materials. Our research showed that dynamic modeling of chemical decay rates made possible the reliable prediction of a changing environment's effect on the rate of natural aging. A second goal was to determine how quickly and to what extent materials, both with and without enclosures, feel changes in temperature and humidity (equilibration).  The study confirmed that thermal equilibration is fast (taking only hours) and moisture equilibration is slow (may take days, weeks, or months).

Knowing that the useful life of chemically unstable materials could be extended by low-temperature storage, IPI recognized the need for clear guidelines for the practical application of such a strategy. IPI's research on thermal equilibration was the basis for the design of safe access polities. This global approach to the collection environment was a natural outgrowth of IPI's earlier work and another step toward the development of safe and efficient collection management technologies.

While film, photographs, magnetic tapes, CDs, and DVDs are all vulnerable to decay under adverse storage conditions, their environmental needs vary. Designing an environment for mixed media collections was a challenge to librarians and collection managers with limited space and resources. In response, IPI created the IPI Media Storage Quick Reference (MSQR). Guidelines are based on the knowledge that the most important factor in collection preservation is the storage environment. ISO Standard 18934 is based on this approach.