Daily News Archive
From July 31, 2002

Residential Use of Herbicide Clopyralid To Be Discontinued

A widely used herbicide will no longer be used on U.S. residential lawns, as a result of an action taken to address regulatory concerns by the product's primary manufacturer, Dow AgroSciences LLC, who has petitioned the U.S. Environmental Protection Agency to delete residential turf uses from the clopyralid product label. Additionally, under the amended label professional applicators will now be required to notify property managers not to compost clippings from treated grass. Clopyralid products will continue to be used on golf courses and certain other forms of nonresidential turf, including farm, ranch and forestry uses.

Clopyralid, the active ingredient in Confront, kills broadleaf weeds such as dandelions, clover and thistles. Products containing clopyralid have been in the U.S. for more than 15 years. 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.

In March, the Washington Department of Agriculture banned the use of clopyralid on lawns and turf because of concerns of the herbicide contaminating compost. The herbicide has been found in compost made from recycled grass, straw, and manure in California, Washington, Pennsylvania, and New Zealand. Clopyralid does not break down during the commercial composting process. It remains lethal up to 18 months after initial use.

"The decision to discontinue residential turf use of the herbicide was made to address regulatory concerns about the potential for damage to sensitive plants from clopyralid residues in compost," said Dow AgroSciences vice president for urban pest control products Elin Miller. "This action is based on a few isolated reports of plant damage, not on concerns about human health."

Label directions for products from Dow AgroSciences containing the active ingredient clopyralid warn against
using compost containing treated material. However, inadvertent composting of clopyralid-treated grass clippings (e.g., via curbside pickup) may be a factor in residential use. "We see amending the clopyralid product label to discontinue residential turf use as a prudent step while gathering data to better understand the many ways that the composting industry processes compost and the breakdown of our product in these materials," Miller said. "Considerable research is now underway that will help shed light on this issue."

The Washington state 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."

The herbicide is popular with many crop farmers and commercial lawn-care companies. Compost companies receive about 28 million tons of yard trimmings each year. Unless the herbicide is eliminated, compost and recycling companies told the Los Angeles Times that their businesses could go bankrupt. "You cannot have a system that mandates recycling of green waste and license a garden chemical that makes the waste unrecyclable," said Gabriella Uhlar-Heffner, solid waste manager for Seattle's public utility company.

For more information contact Beyond Pesticides.