Life Expectancy (LE) is a term that describes the stability of imaging materials. The standard has always been "archival." But when computer folks say archival, they are talking about something that is usable in 2 months. When librarians say archival, the

Life Expectancy (LE) is a term that describes the stability of imaging materials. The standard has always been "archival." But when computer folks say archival, they are talking about something that is usable in 2 months. When librarians say archival, they mean forever. Life expectancy is a new term that accommodates both ends of this continuum. The definition of Life Expectancy is the length of time that information is predicted to be acceptable in a system of 21 degrees Celsius, and 50% relative humidity, standard office environment.