SUBJECT: PESTICIDE VOLATILE ORGANIC COMPOUND EMISSION ADJUSTMENTS FOR FIELD CONDITIONS AND ESTIMATED VOLATILE ORGANIC COMPOUND REDUCTIONS–INITIAL ESTIMATES

Abstract

The purposes of this memorandum is to develop refined emission adjustment factors to account for the effect of application method on volatile organic compound (VOC) emissions from pesticides, with particular emphasis on fumigants, and to estimate the VOC reductions associated with changes to fumigant application methods. Each year, the Department of Pesticide Regulation (DPR) updates an inventory of pesticide VOC emissions for May–October for specified areas and compares the emissions on a relative basis to 1990 or 1991 as the base year. DPR currently assumes 100 % of applied fumigants volatilize to the air. Field monitoring data shows that fumigant emissions are less than 100 % and vary with application method. There are several dozen field studies that measured fumigant emissions. Emissions vary from 9 to 100 % of the amount applied, depending on the fumigant and application method. However, data is not available for all application methods in current use or in use during the 1990/91 base year. When no data is available, emissions have been estimated with surrogate data. In addition to emission estimates associated with each application method, DPR has estimated the frequency with which the various application methods were used during 1990/91 base year, as well as currently. Registrant data and pesticide use reports (PURs) were used for these estimates