The purpose of the ban, which takes effect today (March 1), is to keep the long-lasting herbicide from potentially contaminating compost. The ban is initially in effect for 120 days. At the end of the four months, the department plans to make the ban permanent and will consider additional restrictions on the use of the herbicide.

"This ban is meant to keep clippings from grass that has been treated with clopyralid from being sent to municipal and commercial compost facilities," said Cliff Weed, manager of the Pesticide Compliance Program for the Department of Agriculture. "We focused on grass clippings because they are the major source of contaminated materials."

Clopyralid kills broadleaf weeds such as dandelions, clover and thistles and has been registered for use in this state since the late 1980s. Evidence has been growing that when clopyralid-tainted compost is used to enrich soils, it can harm certain flowers, such as asters and sunflowers. Damage also has been found with vegetables, such as beans, peas and tomatoes.

The new restrictions make products containing clopyralid "state restricted use" pesticides when labeled for use on lawns and turf, including golf courses. This means they can be sold only by licensed dealers and bought only by licensed pesticide applicators. Pesticide dealers and applicators licensed by the Department of Agriculture are being notified of the new restrictions.

Clopyralid products will still be able to be used on golf courses if no grass clippings, leaves or other vegetation are removed from the site and sent to composting facilities that provide product to the public.

"These restrictions are our first step in resolving compost contamination issues," Weed said. "We'll continue to work on the issue with our stakeholders and advisory committee." For the past four months, Weed has led an advisory committee involving the agricultural community, composters and government regulators.

Information on clopyralid in compost is available on the Department of Agriculture's Web site at http://www.wa.gov/agr/clopyralid.htm.

Wahington State Department of Agriculture

Wahington State Department of Agriculture

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