This part of ISO 15181 is one of a series of standards dealing with the sampling and testing of paints, varnishes and related products. This part of ISO 15181 specifies a general method for extracting biocides from paint films of antifouling paints into a specified artificial seawater under specified conditions. It is used in conjunction with ISO 15181-2 to determine the amount of copper biocides in the extract and allow the calculation of the release rate of the biocide from the paint film.