This International Standard specifies methods for measuring the parameters needed for corrosivity estimation used for classification of the corrosivity of atmospheres in ISO 9223. This International Standard specifies methods for the measurement of environmental parameters for — normative corrosivity estimation based on calculated first-year corrosion rates of standard metals, and — informative corrosivity estimation based on characterization of the exposure environment. This International Standard does not describe the usual analytical techniques for the measured parameters since this depends on the available analytical techniques used in laboratories. Specific methods for deposition measurement of SO2 and Cl− deposition rates and conversional factors for comparison of different measuring methods are presented in Annexes A, B, C, D, E and F. For methods pertaining to the characterization of the atmospheric exposure site in general, see ISO 8565.