EPA exempts from FFDCA and FIFRA pesticidal substances in transgenic pest-protected plants that are derived from transgenes from sexually compatible species. The committee's questions are not in accordance with that categorical exemption. Given that transfer and manipulation of genes between sexually compatible plants could potentially result in adverse effects (for example, modulation of a pathway increases the concentration of a toxicant), the categorical exemption of pest protectants solely on the basis of derivation from sexually compatible plants could be scientifically unsound in some cases.

FDA's policy for foods derived from new plant varieties is designed to address questions 1 through 5 with respect to dietary exposure to substances that are not regulated by EPA as pesticides. For pesticidal substances, EPA may consult with FDA on allergenicity issues (see chapter 4).

3.3.2 Ecological Concerns: Guiding Principles

Nontarget effects and hybridization with weedy relatives are subjects of concern for transgenic pest-protected plants. The committee suggests that a particular pest-protected plant needs to be exempt from both of these ecological concerns in order to avoid safety assessments.

Nontarget Effects: Guiding Principle

Nontarget effects are often unknown or difficult to predict. Along with standard screens for toxicity to nontarget species, comparison with agricultural practices that would occur if the transgenic pest-protected plant were not used could be made. For example, nontarget effects of transgenic Bt cotton could be compared with nontarget effects from nontransgenic cotton and the accompanying pesticide use needed to compensate for the lack of the transgenic trait. Broader environmental consequences such as changes in soil quality, wildlife habitat, or the use of fertilizers or water could be used to determine the contribution of the new variety to the sustainability of the agricultural system in which it is grown (Cook 1999). Such general environmental considerations could have effects on nontarget organisms.

However, it is important to point out that there is disagreement among scientists, including within the committee, as to whether comparison to currently used pest control practices should be the determining factor for allowing commercialization of a transgenic pest-protected plant. Most agree that it is one of many important factors. Therefore, both toxicity testing and field tests comparing agricultural methods are suggested. The committee recognizes that the question below leaves much room for agency judgment.



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