March 18, 2002
Volume 80, Number 11
CENEAR 80 11 p. 10
ISSN 0009-2347
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Syngenta seeks to block registration of racemic metolachlor


EPA is considering the registration of generic versions of racemic metolachlor, a popular herbicide developed by Syngenta. Its patent expired in 1993.

In 1999, Syngenta developed a new version, S-metolachlor, under EPA's Reduced Risk Pesticide Initiative and replaced the old version of the chemical. Now, several generic agrochemical companies are seeking to revive the original material.

In either form, metolachlor is a herbicide used to control yellow nutsedge and crabgrass, among other landscape weeds. It is used on golf courses, sod farms, and football and baseball fields.

Syngenta is suing to prevent EPA from allowing the registration of the original, racemic version. "The granting of this conditional registration would be a clear statement to the public and to the agrochemical industry that EPA no longer values the environmental benefits associated with reduced risk products," says Vince Alventosa, counsel for Syngenta.

Dave Deegan, spokesman for the agency, says a decision on generic registration is pending.

Herbicides may be essential to modern agriculture, but, obviously, the less required for a given result, the better. To encourage companies to produce herbicides that can be used in smaller quantities, EPA launched the reduced risk initiative in the early 1990s. In response, Syngenta developed the single-isomer version of metolachlor. This improved material is an 88% pure version of the active component of the metolachlor isomer mixture.

Indeed, S-metolachlor offers several advantages over the original isomer mixture, say Syngenta and its supporters in the regulatory and environmental communities. S-Metolachlor is equally effective at killing weeds at only 65% of the application rate for original metolachlor. Through the 2001 season, the replacement of original metolachlor with S-metolachlor reduced the material that entered the environment by about 60 million lb.

Following the launch of S-metolachlor, EPA said it would cancel the registration for the original product, but, according to Syngenta, it failed to formalize the action. Now, generic pesticide companies--particularly Cedar Chemical--are pulling out all the stops in an effort to win registrations for their versions of the original product.

Cedar and other generic companies claim that there is little or no difference in the weed-control activity of the two versions. They also claim that the per-acre cost to farmers for the new material is actually 5% higher than that of the original version.

The original compound stood the test of time, they say, through 25 years of use. Cedar calls Syngenta's development of the new version "an ingenious scheme to try to keep their lucrative monopoly for another two decades."

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