The classification system of ISO 9223 standard and the dose-response functions assessing the corrosivity of outdoor atmospheres

The ISO 9223 Standard Corrosion of Metals and Alloys-Corrosivity of Atmosphere-Classification which is now in force was based on the data obtained mainly in the temperate climate of Europe and North America. At present, it is being revised by using data from new programs of atmospheric tests carried out in cold, temperate, subtropical, and tropical climates. The paper tackles problems of assessing the atmospheric corrosivity from the environmental parameters. A model and dose-response functions characterising the corrosivity of the outdoor atmospheres are described. Suggestible ways of possibly improving the standard with the use of the functions derived are considered.