The intention of that paper is to initiate a discussion on the basis of a French method in combination with a German approach regarding the need of a method for the determination of a fixation time and especially to obtain input as well as ideas concerning a possible test design. Since no harmonised European approach exists up to now concerning the determination of a fixation time, CEN TC 38 (2009) launched a questionnaire to identify current national requirements. If the lack of answers did not allow a global view of all the member states, it highlights that national regulations are different as expected. Fixation time is already a data necessary for national regulations in France and in Germany. Europe is globally concerned by the Biocidal Product Directive which requires recommended methods and precautions to reduce dangers from handling, storage, and transport. Various studies carried out in France or in Germany show that laboratory protocols are available to determine a fixation time for different types of wood preservatives. The French method is a laboratory protocol in order to obtain water samples coming from treated wood which has been in continuous contact with water, at increasing time intervals. This treated wood is removed from summer and winter drying conditions after a defined time (for example, 4h, 19h, 24h, 48h and 96h), and then immerged in water. Kinetic curves allow then to estimate a fixation time. The German method is nearly identical with the French method from the practical point of view. The main difference consists of the assessment of the fixation time: instead of a kinetic curve a so-called fixation index (FI) is calculated. One of these procedures could be a useful tool for wood preservative manufacturers in order to determine these data by themselves or by a third party established by the manufacturer. Beside this such a proceeding could avoid any confusion with “conventional leaching tests” which are required for the environmental assessment according to the 98/8/EC directive.

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