#$%^&*AU2016100445A420160526.pdf#####H: szp\Interwoven\NRPortbl\DCC\SZP\10029232_1.doc-22/04/2016 Abstract The present invention relates to a method of treating timber and wood products to protect against damage by insects such as termites or other biological organisms such as bacteria and fungi. The method comprises treating timber or wood products with a composition 5 comprising bifenthrin, such that bifenthrin is applied to the wood in an amount of less than 4 g/m3 . Compositions for use in the method are also described.