This paper describes the projected net economic impact of a collaborative research project on the replacements for methyl bromide in timber for quarantine purposes (ACIAR PN 9406) proposed by CSIRO and FRIM1 for funding by ACIAR. The objective of the project is two-fold: first, to examine the effectiveness of various fumigants that are candidates for possible replacement of methyl bromide in quarantine fumigation of processed timber products from hardwoods including the following: phosphine; sulphuryl fluoride; carbon bisulphide; carbonyl sulphide; methyl isothiocyanate; and hydrogen cyanide. And second, to show that kilning of processed timber products from hardwoods, when done according to appropriate regimes, kills all insects in those products. The project may demonstrate that thermal disinfestation of wood is an alternative quarantine treatment for processed timber products from hardwoods. The project will recommend heat treatments appropriate for different sizes of processed timber products from hardwoods and for different insects which are of quarantine risk to Australia. While some of the research will involve the verification of models of heat transfer in hardwoods, the project intends to use existing knowledge of insect biology and heat-transfer processes. The focus of the paper is not to justify or demonstrate the merit of the science in the proposed project. ACIAR has other processes for that. This paper estimates the potential benefits from the project and compares them to the potential costs of the project over a 30-year planning horizon. The evaluation framework includes the following impacts: the human health effects of methyl bromide; impacts of research in Malaysia, Papua New Guinea and Australia that are the countries where the proposed ACIAR research project intends to focus its research effort; and price spillovers that arise when research in a significant producing country or region so shifts world supply as to change world prices.