This part of ISO 8502 describes a method of extracting, for analysis, soluble contaminants from a surface by use of flexible cells in the form of adhesive patches which can be attached to any surface, regardless of its shape (flat or curved) and its orientation (facing in any direction, including downwards). The method described is suitable for use in the field to determine the presence of soluble contaminants before painting or a similar treatment. This part of ISO 8502 does not cover the subsequent analysis of the contaminants that have been dissolved off. Methods of analysis suitable for field use are described in other parts of ISO 8502.