Date: 3/30/99

Time: 5:00

Type: Symposium

Number: 177

Science policy implications of FQPA implementation - Industry perspective

*M. Shaw, Dow AgroSciences, Indianapolis, IN 46268
Contact e-mail: mcshaw@dowagro.com

Two and a half years have passed since the passage of the FQPA, yet many critical decisions on science issue policies remain unresolved. Data are now required on pesticide toxicology and exposure which have never previously been required or utilized in tolerance evaluations. Nine key science issues have been identified which will have a tremendous impact on defining what data will be required for tolerance reassessment and determining what tolerances and use patterns a specific pesticide will retain. Conservative safety factors and default assumptions are utilized in risk assessments when data are not available, particularly exposure data. Risk assessments were conducted for the organophosphate insecticide, chlorpyrifos, using validated real world dietary and non-dietary exposure data and compared to assessments conducted using default assumptions. Use of default assumptions for dietary residues compared to market basket residue data for one commodity (apples) resulted in a 20X overestimation of dietary exposure. Conducting an acute dietary risk assessment at the 99.9th percentile resulted in estimation of exposure 8X and 4X greater than when the same assessment was conducted at the 97.5th and 99th percentiles. Interpretation in exposure assessments of "no residues detected" has significant impact on use pattern RfD consumption for commodities with high consumption in U.S. sub-populations such as children. Tolerance reassessment as defined by the FQPA cannot be implemented with best science until these nine science issue policies are addressed and data needs clearly defined.

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