Comment submitted by H. Quemada

I thank EPA for the opportunity to comment on the proposed rule EPA-HQ-OPP- 2006-0643. Request for comment #1: EPA requested comments on options for exempting "virtually unmodified" PVCPs. The underlying assumption appears to be that since, by EPA's own analysis presented in this proposed rule, the evidence for the lack of toxicity or allergenicity of naturally occurring viral coat proteins is very compelling, those are the only proteins are of sufficiently low risk to warrant exemption from FFDCA. The concern is that novel viral proteins produced by in vitro manipulations might express new toxicological or allergenic properties. In cases where these novel viral proteins are produced by intentionally recombining known viral sequences, the likelihood of creating novel toxic or allergenic sequences by recombining manifestly safe sequences is extremely low. The likelihood of such an event would be on the order of the probablility that a random string of amino acids of typical viral coat protein length could produce toxic or allergenic proteins, and can be estimated by considering the number of known toxic or allergenic proteins isolated from viral sources, relative to the total number of protein sequences known. Therefore, I disagree with EPA's assessment that only "virtually unmodified" PVCPs are low risk and that exemptions from the requirements of FFDCA should be limited to only those proteins. Even highly modified PVCPs would present a risk profile that is sufficiently low for exemption. My argument can be applied to other viral proteins as well. Limiting exemptions to only PVCPs would continue to capture other proteins that are low risk and would be unlikely to have adverse effects in the absence of EPA oversight. Request for comment #3: EPA requested comments on whether any safety issues would be created by co- expression of coat proteins in a plant from viruses that had not normally co- infected that plant before. If viral proteins were produced in plants that had been previously used as food, whether or not those viruses were in the same plant, the combination of coat proteins that are safe individually should not produce new concerns when expressed together. Therefore, there should be no need to limit exemption under FFDCA to PVCPs from naturally co-infecting viruses, but rather, the exemption could be broader to include PVCP's, plant viral proteins, and chimeric combinations of those proteins that have been expressed in any food plants. Request for comment #5: EPA requested comments on how to view a PVC-protein that is not "virtually unmodified" and is not detected during development of a crop, but is subsequently produced (I assume now at a detectable level) at a later time. This case would only apply if the virus resistance trait is conferred by something other than the a PVC-protein. The PVC-protein would therefore not be the PIP. If that PVC-protein were to be expressed at a later time, would still not be the PIP, since it is not the substance that is intended to prevent or mitigate viral disease. Therefore, this hypothetically expressed PVC-protein would still not be subject to regulation under FFDCA. Similarly, this reasoning would apply to any other plant viral protein that might be hypothetically expressed. It is my hope that EPA is not considering regulating hypothetically produced proteins. Thank you for the opportunity to comment. Hector Quemada Adjunct Professor, Department of Biological Sciences, Western Michigan University hector.quemada@wmich.edu