This European Standard specifies the reference methods for determining the penetration and retention of creosote in timber freshly treated with creosote, principally in order to ascertain whether the treated timber conforms to specifications written in terms of EN 351-1. It also provides guidance on the acquisition of test samples and their handling between sampling and analysis. NOTE In the day-to-day practice at the plant, other methods (e.g. weighing the charge before and after treatment) can be used for determining the retention, provided that a significant relationship can be established with this method.