The case for using borates in termite control in tropical Australia

IRG/WP 11-30573

B M Ahmed (Shiday), J R J French

A brief historical overview of boron based wood preservatives efficacy against subterranean termite management worldwide, and in Australia, is presented. The boron based compounds to be used in H2 hazard conditions, may be applied as a surface treatment by dip, flood coat or spray, and rapidly penetrates to the centre of timber substrates, whether containing sapwood or heartwood. However, section 8, clause 8.2.2 (c) of the Australian Standard AS 1604.1-2010 bans the use of boron compounds for use in termite management north of the Tropic of Capricorn. In this paper we argue the case for the adoption of boron compounds in termite management systems north of the Tropic of Capricorn, as either single or multi-component biocide systems. We have searched the numerous papers for “boron and termites” in the IRG data base since 1969 to the present, and other scientific evidence from a consistent science worldview; our own results of boron against termites in our ‘whole-of-house’ above-ground and in-ground field test using simulated houses and wood stakes respectively at Nhulunbuy, Arnhem Land, in tropical Australia. In these test sites, active populations of Coptotermes spp., Heterotermes spp., Nasutiterme spp., Schedorhinotermes spp., and Mastotermes darwiniensis, were present. After 5 years in the ‘whole-of-house’ above-ground trial and 2 years of the in-ground trial, no termite damage has occurred to boron-treated timbers. Furthermore, we refer to analytical data by two NATA certified laboratories in Brisbane of the Tru-Core® Timber Preservation Process which was applied as a spray treatment from a mobile unit. This system is a boron-based multi-component biocide system, incorporating glycol borates, deltamethrin, permethrin and the fungicide propiconazole, that surpassed all the minimum requirements of AS 1604.1-2010 for the H2 status, even penetrating the heartwood of radiata pine and oregon. While, this standard does not specify the methods of preservative treatment that may be adopted to achieve the specified penetrations and retentions. It states that the standard is only intended for application in approved industrial treatment plants. In the current climate of extreme environmental challenges out standards need to broaden the scope of protection and treatment and also consider the new generation of biocides are different than the traditional wood preservatives. Standards specify the minimum requirements of a preservative to protect timber from attack and damage from termites and the document must encourage innovative systems for access into the industry and the protection of structural timbers.

Keywords: simulated houses, field test north of Tropic of Capricorn, boron compounds, biocide, retentions, Coptotermes spp., Heterotermes spp., Nasutitermes spp., Schedorhinotermes spp., and Mastotermes darwiniensis, AS 1604.1-2010, Tru-Core®, multi-component biocide systems

Conference: 11-05-08/12 Queenstown, New Zealand

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