This document specifies a method for the determination of the toxic values of a wood preservative against the Reticulitermes species of European termites 1. This method is applicable to: water-insoluble chemicals which are being studied as active insecticides; organic water-dispersible formulations as supplied or as prepared in the laboratory by dilution of concentrates; and water-soluble materials, for example salts. NOTE This method can be used in conjunction with an ageing procedure, for example EN 73 or EN 84.