This document specifies a method for the leaching of test specimens of wood which are used in the testing of the biological efficacy of wood preservatives. This standard is applicable to: a) the pre-conditioning of test specimens prior to their being subjected to a biological test ; or b) assessment of loss of effectiveness by comparing the performance in a biological test of treated test specimens subjected to this procedure with others that have not undergone any leaching procedure. NOTE The method may also be used for pre-conditioning of wood-based panel products which may or may not have received preservative treatment.