Reviewing existing pesticides according to current scientific standards

A pesticide is always authorised for a limited period only, so that at the end of this period a review can take place according to current scientific standards. In The Netherlands the maximum period for authorisation used to be ten years. Authorisations were usually given for only a few years, but within the ten-year period the authorisation could be renewed rather easily. For example, the authorisation holder would not have to apply for a renewal and the review would not be as strict as for a new authorisation. As we have seen, this changed after the implementation of Directive 91/414. According to this Directive, authorisations can still be given for a fixed period of up to ten years. A renewal, however, has to be treated in the same way as a new authorisation. It has to be applied for and the competent authority has to verify that all the criteria have been met (article 4(4)). During the verification period a provisional renewal can be granted, as we saw before. The system in the Biocides Directive is more or less the same, although in the Biocides Directive the period for granting an authorisation is more in tune with the inclusion period of the active substance (article 3(6), Directive 98/8). In the US the registration period under FIFRA used to be a maximum of five years, but in 1996 this was extended to a maximum of fifteen years.

Although one would think that with this system of periodical renewals new scientific standards would more or less automatically be applied to the existing pesticides, when time for renewal has come up, in practice special review programmes appear to be necessary to apply new standards to the products that are already on the market. And in practice these review programmes are not always successful, as the following experiences show.

As described above, the EC review of 'existing substances' is a process which is progressing at a slow pace. Until now this review process has resulted in very few definitive decisions on whether or not to list substances. It is not only at the EC level that the pace of decision making on existing substances according to new scientific standards is progressing so slowly. In the US the re-registrations of older pesticides have been going on for a very long time. The first re-registration programme dates from 1972. Because this re-registration did not work in practice, a second start was attempted in 1984. In 1988 a FIFRA amendment planned the re-registration of around 600 active substances that were on the market. Once again the planning could not be put into effect. Among the reasons mentioned for these delays were lack of finances and inefficient management of information (Ferguson & Gray (1989) for the arguments given by both the EPA and the Government Accounting Office; also Miller 1997). The 1996 amendments for the new standards for residues in food have an implementation period of ten years in total.

As already described, in The Netherlands there are also delays in the application of new standards to products already on the market. This is sometimes the case because regulations containing these new standards at the same time provide for lengthy transitional measures for ongoing applications and for pesticides already on the market, which allows for the application of older, less strict standards. Therefore the new environmental standards in a 1995 decree did not apply until 2000 to significant substances that were already on the market and did not meet the new standards. Several of these transitional provisions were declared void by the courts, often as a result of legal proceedings commenced by environmental organisations. Recently the Pesticides Act was amended to keep some of these substances on the market for a further period. In addition to these delays caused by the legislation, the application of new standards is often delayed by the authorisation practice, where provisional renewals are so often granted when the authorisation period ends and evaluations have not yet been completed.

These experiences-the review of existing substances at the EC level, the re-registration in the US and the application of new standards in The Netherlands-show how problematic the review and re-authorisation or 're-registration' can be. Sometimes this seems to result from the legislation; more often, however, the delays seem to be caused by the authorisation practice. These delays in the application of current scientific standards to the products already on the market seem rather structural. Still, an experience with re-registration in Sweden shows that a re-registration project can be completed within several years.

The Swedish review included a hazard and risk analysis, a benefit analysis and a risk benefit assessment. Cut-off criteria were applied to reject or phase out certain pesticides. (These criteria identify pesticides that are clearly unacceptable from the point of view of health and the environment or both; when an inherent property of a pesticide exceeds one of these criteria, an application will usually be rejected.) The idea behind the cut-off criteria was to facilitate prompt and easy authorisation procedures and predictability in the outcome of the decision. After the 1990-1995 review period, of the 180 'old' active substances for agricultural products, only 100 remained. Some 20 substances were removed from the market for health reasons and around 20 for environmental reasons. Many of these substances were substituted by others posing less risk. Some 15 substances were severely restricted. Many renewed approvals did get different kinds of restrictions (Bergkvist et al. 1996). This Swedish review process illustrates that completing a substantial review within a restricted time is not impossible, under certain conditions.

From the foregoing examples, one may conclude that the application of current scientific standards to pesticide products which are already on the market usually only takes place after a very long time and that the delays in applying new standards on review and re-authorisation seem rather structural. The history of reviewing and re-authorising shows that reviewing to current scientific standards is not only a lengthy but also an ongoing process, because new scientific insights and standards continuously appear. For example, there are new developments in the scientific insights in the field of cumulative effects and in oestrogen or other endocrine effects that pesticide residues might have. Endocrine effects, according to the FQPA, are a factor in tolerance setting under FIFRA (Sec. 408(b)(2)(D)(viii)).

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