Pesticidal plants face legal hurdle.

Pesticidal plants face legal hurdle

As scientists prepare genetically altered plants for commercial sales, federal policymakers are planning a difficult regulatory obstacle for plants genetically engineered to kill viral or insect pests. The Environmental Protection Agency has proposed considering a pesticidal product produced by a plant gene to be a chemical pesticide, subject to the exposure tolerance and registration requirements under the pesticide law, says Fred S. Betz of EPA's Office of Pesticide Programs.

Before EPA proposed the new rule, the only regulatory certainty regarding pesticide-producing transgenic plants was that the U.S. Department of Agriculture has jurisdiction over small-scale field trials, says Robert B. Nicholas, a Washington, D.C.-based attorney. No large-scale trials have yet been conducted with pesticidal plants, Betz says.

Under the new rule, genetically engineered plants would be treated differently from similar, traditionally bred plants, which do not have to go through the pesticide review process. The engineered varieties also would undergo more legal scrutiny than biological pest-control agents, whose approval process typically takes one to two years and costs less than $500,000. This contrasts with the five to 10 years and $10 million to $50 million required for approval of chemical pesticides, Nicholas says.

In its new delivery system, the Bacillus thuringiensis toxin gene -- the insect-killing molecule most frequently inserted into plants -- may have to be partially reevaluated as a chemical pesticide despite the toxin's long history of use in its natural form -- from bacteria -- as a biological pest-control agent, Nicholas told SCIENCE NEWS.

An EPA working group must now draft the specifics of the proposed regulation before it can become official policy, Betz says.