Specifies requirements for preservative treatment of sawn and round timber for protection against decay, insect or marine borer attack for allexposure conditions throughout Australia.Updates the retention levels for ammoniacal copper quaternary (ACQ)in hazard classes H3 and H4,includes copper azole treatment for hazard classes H3 and H4,and preservative specification for high temperature creosote originally given in AS 1143-1973. The description of the newly included preservatives is added into Appendix B. Appendix C provides information on the allocation and registration of treatment plant numbers and preservative code numbers, and includes a new flow chart showing the procedures for preservative registration in National Registration Authority. The updated matural durability rating of timber species is given in Appendix F.