Development of pesticide volatile organic compound (VOC) emission adjustment factors

AGRO 83

Terrell A. Barry, tbarry@cdpr.ca.gov and Randy Segawa, rsegawa@cdpr.ca.gov. Department of Pesticide Regulation, California Environmental Protection Agency, 1001 I Street, Sacramento, CA 95814
Each year, the Department of Pesticide Regulation (DPR) calculates a May-October pesticide VOC emission inventory for specified areas and compares emissions on a relative basis to a base year. Fumigants are among the highest VOC contributors. DPR currently assumes 100% of applied fumigants volatilize to the air. However, field monitoring shows fumigant emissions typically less than 100%, varying with application method. DPR has developed application method- and fumigant-specific emission adjustment factors, expressed as proportion of mass applied emitted to the air, for methyl bromide, metam sodium and metam potassium, 1,3-D, chloropicrin, dazomet, and sodium tetrathiocarbonate. Drip application methods for all fumigants show small adjustment factors, between 9 and 15%. The bed/tarp application method for methyl bromide shows the largest adjustment factor at 100%. Other methods with large adjustment factor values include shallow soil injection methods or no tarp methods.