Field studies in pesticide registration: Questioning the answers

Abstract

The principal conclusion of a workshop in October 2005 at RIVM (Bilthoven, The Netherlands) on the assessment of field studies with pesticides for authorization is that the lack of a definition of acceptability of effects is recognized as a problem by all stakeholders: Industry, risk assessors, and regulators. Because of this lack of definition in the legislation, it is unclear what critical effect values should be assessed in field studies. Despite the extensive documentation on field study performance, the decision making is not based on justifiable scientific opinions or publicly shared values but on technical limitations of the test design instead. In the workshop, research was identified that should result in a scientific basis for value judgments applied in decision making.

Opinion of the Scientific Panel on Plant protection products and their residues (PPR) related to the revision of Annexes II and III to Council Directive 91/414/EEC concerning the placing of plant protection products on the market - Ecotoxicological studie

“…Different strategies, like the extrapolation of dose-response-relationships, in combination with the appropriate use of uncertainty factors, should be examined. The PPR Panel has commented on these issues in several recent opinions, and also refers to useful comments made in other recent publications (EFSA, 2005a;De Jong et al, 2005;EFSA, 2005b;Van den Brink, 2006;EFSA, 2006d;EFSA, 2006e;Montforts & De Jong, 2007). However, the PPR Panel is aware that further research is needed to clarify the extent of uncertainty.…”

“…In any case, it should be clear that the higher tier study is related to the concern that rose in the first tier, and is performed in order to demonstrate absence of unacceptable adverse effects. The current guidelines on field testing, are unsatisfactory, since many existing field tests are designed in a way that less than 50% effect will not be detected (Montforts & De Jong, 2007). Overruling the first tier assessment with uncertain field experiments is not justified.…”