This Standard specifies requirements for preservative-treated sawn and round timber for protection against decay, insect or marine borer attack. It incorporates borate treatment for hazard class 2, TBTN/permethrin treatment for hazard class 3, and ammoniacal copper quaternary (ACQ) for hazard classes 1 and 3 for hardwood and hazard classes 2 to 5 for softwood. This revision omits the equivalent retention levels of individual pieces expressed on a mass/volume basis. The description of the newly included preservatives is added into relevant clauses and Appendix B. Appendix C provides information on the allocation and registration of treatment plant numbers and preservative code numbers.