This International Standard provides suggested guidelines for four temperature and humidity macro-environments for archives that contain a variety of recording media, based on the corresponding ISO storage standards for those media. Whenever possible, this International Standard recommends that users follow the storage environments in the ISO storage standards. This International Standard does not replace those ISO storage standards. In addition to environment recommendations, those standards also include other vital information pertinent to the long-term keeping of recording materials, such as inspection, housing, and handling guidelines. Although microenvironments within a storage enclosure can be dependent upon the macro-environment, they are not the focus of this International Standard. The storage of traditional paper collections is not within the scope of this International Standard. However, many archives containing mixed recording media also include such collections. Archivists are encouraged to review the appropriate standards (see References [1] and [2]) for those materials. Nitrate-base photographic films are also included in this International Standard, since they are often stored together with other materials. NOTE Nitrate-base films represent a fire hazard and need to be stored in accordance with the National Fire Protection Association standard[3] in the United States, or other applicable national standards. Moreover, fumes from decomposing nitrate film and acetate-base film can have detrimental effects on other materials stored in the same area[11]. A solution to this problem is to isolate such films in a separate storage area. This International Standard does not address the various strategies to upgrade substandard environments that deviate from those recommended by ISO standards.