This document specifies a laboratory method to determine the leaching behaviour of substances from coatings into water over defined time intervals. The release of substances from coatings under natural conditions cannot be determined with this method. This methods can be applied to renders, when condition (4) of the scope of CEN/TS 16637-1 is fulfilled. (4) It is assumed that the temporary contact with water (e.g. exposure to rainwater) is examined as a permanent contact by agreement. For some coatings (e.g. some plasters with organic binders according to EN 15824) that come into temporary contact with water, physical and chemical properties may change with prolonged contact with water. These products are not covered in this Technical Specification because the test method in CEN/TS 16637-2 is not suitable for testing these construction products.