This Technical Report provides information on the effect of water-soluble chloride and sulfate contamination levels on steel surfaces, before the application of paint or related products to surfaces prepared in accordance with standard mechanical or blast-cleaning surface preparation methods. NOTE The tolerance for water-soluble salt contamination may be different for different paint types. This information may be used when evaluating the adequacy of surface preparation prior to painting. This document is concerned only with measured levels of salt contamination based upon either laboratory or field testing. The levels of soluble chloride and sulfate discussed in this document are to be compared using soluble surface densities of the species as determined after extraction in accordance with ISO 8502-6 (the Bresle method), or other methods giving equivalent results. Total soluble-salt contamination may be determined by conductometric testing, but such testing will not determine the nature and concentration of the specific salts present, e.g. whether chloride or sulfate is present, or its concentration. This document does not define specific levels of cleanliness or methods of salt removal.