Washington State Bans Use of Clopyralid-Containing Herbicides

Less than two years after losing chlorpyrifos, one of the industry's most popular insecticides, to environmenal regulation, Dow AgroSciences finds iteslf defending one of its leading herbicides against a similar attack.

In an effort to control the amount of clopyralid making its way to municipal and commercial compost facilities, the Department of Agriculture in Washington State on March 1 instituted a ban on the use of herbicides containing this ingredient on lawns and turf for 120 days. Golf courses are exempt from this ban.

Under the new restrictions, products containing clopyralid are now considered “state restricted use” pesticides, which means they can be sold only by licensed dealers and purchased only by licensed pesticide applicators, explained Scott Eicher, senior marketing manager and technical sales manager, Dow AgroSciences, Indianapolis, Ind. Dow’s herbicide Confront is included in the ban.

“During the 120 days, the Department of Agriculture is going to try to figure out what to do from a permanent standpoint,” Eicher explained. “The Department is evaluating requests from other users, such as the state or city park employees, who use clopyralid-containing products as part of their Integrated Pest Management program.”

The clopyralid issue arose when farmers complained that compost they purchased and applied to their fields was harming their crops becaus of clopyralid's presence. The herbicide, used mainly to kill weeds, is not deadly to humans or animals, but it can kill vegetables such as peppers, tomatoes and potatoes. Eicher related that Dow is also investigating this problem in an effort to come up with a reasonable solution to the situation.

“For a number of years these products have been used and with all the investigations, there have only been a few plant injuries,” Eicher asserted. “Although it’s important to ensure the problem doesn’t get worse, we hope a valuable product won’t be banned.”

For its part, Dow is in talks with the federal Environmental Protection Agency to change its labeling on its clopyralid-containing products to communicate more clearly to homeowners the dangers of sending clippings to be composted. “Unfortunately, working at the federal level is not a fast process,” Eicher advised. In the meantime, Dow is drafting letters that will be sent to distributors and to the landscape industry as a whole explaining the situation in Washington. “We also want to communicate to them our recommendations regarding the proper disposal of clippings and best management practices for recycling,” he remarked.

The Department of Agriculture advised that at the end of the 120-day ban, it plans to make the ban permanent and will consider other additional restrictions on the use of the herbicide.

“These restrictions are our first step in resolving compost contamination issues,” remarked Cliff Weed, manager of the Pesticide Compliance Program for the Department of Agriculture. “We’ll continue to work on the issue with our stakeholders and advisory committee.”

Information on clopyralid in compost is available on the Department of Agriculture’s Web site.