11th International Working Conference on Stored Product Protection Ethyl formate fumigation an overview update Ryan, R.F*#1, De Lima, C.P.F.2 1VAPORFAZE, PO Box 4, Sans Souci NSW 2219, Australia 2Consultant Research Entomologist, Perth WA, Australia *Corresponding author, Email:
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[email protected] DOI: 10.14455/DOA.res.2014.161 Abstract The historical fumigant ethyl formate [EF] is proving to be a methyl bromide alternative. EF effectiveness against dried fruit insects was published in 1925. Non-flammable mixture of EF (14.4 vol% EF) with carbon dioxide [CO2] was reported by Jones (1933). On-site mixing of EF liquid into a stream of CO2 in export grain structures was trialed by Allen and Desmarchelier (2000). In addition to eliminating the flammability hazard, CO2 has a synergistic effect with an optimal range of 5-20%. Ryan and Bishop (2002) developed a commercial mixture of EF dissolved in liquid CO2which was compressed to 40 bar pressure in an industrial gas cylinder. EF is a highly flammable volatile liquid (b.pt.=54°C) which requires vaporization to minimize adsorption and achieve uniform distribution throughout the fumigation space. Pre- or post (on- site) EF/CO2 mixture is converted to a gaseous mixture using a proprietary high pressure vaporiser. The EF/CO2 gaseous mixture is accurately dispensed into the fumigation chambers by weighing. However, because the application rate of the EF/CO2 mixture is between 75 and 420 g/m3 fumigations need to be done in adequately tested gas-tight structures (De Lima et al., 1994) while vacuum chambers are generally satisfactory.