In March 2012, the Department of Pesticide Regulation (DPR) released its annual report on volatile organic compound (VOC) emissions from pesticides. This report included information on VOC emissions based on 1990-2010 pesticide use data for five ozone nonattainment areas (NAAs) in California. The pesticide VOC emissions were compared to the goals described in the ozone state implementation plan (SIP). Since the report’s release, DPR found an error that primarily affects the pesticide VOC emissions for the San Joaquin Valley NAA in 2010.

What error was found that requires a correction to the report?

With the assistance of the Department of Food and Agriculture, DPR found an error in the pesticide use report data and VOC emissions for a single product containing bifenthrin. The error was in the data for Fanfare 2EC (registration number 66222-99-AA), first registered in California in 2006. This error caused overestimates in the use and VOC emissions for Fanfare. For this product, the pesticide use reports record the amount of pesticide applied as gallons of product. There was an error was in DPR's data processing which converted the gallons applied to pounds applied based on the product density. For Fanfare, the
product density was incorrectly assigned as 67.739 pounds per gallon.

The correct product density is 8.13 pounds per gallon. The amount of product and active ingredient of Fanfare applied was 8.33x (67.739/8.13) too high.

How does this correction impact the VOC emissions estimates in the San Joaquin Valley?

For the San Joaquin Valley NAA during May-October 2010, DPR originally estimated that the VOC emissions from all bifenthrin products were 1.55 tons/day (#2 pesticide VOC contributor). DPR now estimates that the VOC emissions from bifenthrin products were 0.24 tons/day. Bifenthrin products are no longer among the top 10 pesticide VOC contributors for the San Joaquin Valley. Total pesticide VOC emissions changed from 16.8 tons/day to 15.5 tons/day. Relative to the 1990 base year, total pesticide VOC emissions for 2010 changed from an 18% reduction to a 24% reduction. The goal in the pesticide element of the SIP is at least a 12% reduction from 1990, equivalent to emissions no greater than 18.1 tons/day. There are also changes for other years and other NAAs tracked by DPR, but use of Fanfare was much lower in other years and NAAs, so the differences are minor. Similar relative changes apply to the amount of bifenthrin active ingredient reported.

What steps is DPR taking to address this error?

DPR is revising its most recent VOC emission inventory report to correct the error for all years and all NAAs. DPR will also upload the corrected pesticide use report data to its California Pesticide Information Portal website, and other databases. DPR should complete the revised report in a few weeks, and complete the data uploads in a few days. This change will cause no revisions to DPR’s proposed regulations for VOC emissions from nonfumigant pesticides.

Please contact me if you have any questions.

Randy Segawa, Environmental Program Manager, Air Program

Department of Pesticide Regulation
PO Box 4015
Sacramento, CA 95812-4015