DPR targeted products containing the Dow AgroSciences-manufactured herbicide clopyralid that are intended for use on residential lawns in California, since green waste from those areas is a common source of compost. DPR will take no action against clopyralid products intended for other areas, including farmland, rangeland and forests.
Used to control broadleaf weeds, clopyralid is a low-toxicity chemical that poses little hazard to people, animals and most vegetation. However, research has shown that even low levels of clopyralid in compost can damage some vegetables. Some compost facilities in California recently reported detections of clopyralid. Dow AgroSciences reported in a media advisory that clopyralid breaks down readily in a natural soil environment, but not as readily in compost.
“In taking this action, DPR reaffirms its support for composting in California,” said DPR Director Paul Helliker. “Composting helps reduce our waste stream while helping urban gardeners and commercial agriculture. Taking preventive action to eliminate some clopyralid products will protect compost while preserving beneficial uses of this herbicide.”
In response to the DPR proposal, Dow AgroSciences issued the following statement: "We have just received notice of the DPR proposal and will be evauating it carefully over the next few days," the release read. "We are committed to working with both the DPR and others to protect compost adn with our customers to support their continued access to these products for many important uses."
Clopyralid is the active ingredient in Dow AgroSciences’s Confront herbicide. The company’s media advisory offers advice for proper composting techniques. “A better option: recycle clipping by leaving them on the lawn,” the release read. “Homeowners who use community or personal compost in gardens and beds should follow the recommendation of the compost industry. That is, when using compost, blend it with soil. If clopyralid is applied to a home lawn, homeowners should not mix the grass clippings into community or personal compost.”
According to the release, Dow AgroSciences plans to take the following actions to remedy the clopyralid situation:
- Send letters to important business partners reminding them to inform their customers to keep treated grass clippings on the lawn – and out of compost.
- Develop literature and other resources explaining the issue for these business groups to use.
- Work with the U.S. Environmental Protection Agency, state regulatory agencies and the U.S. Composting Council to develop a revised product use label that will impose additional notification requirements to homeowners and lawn care operators, informing them about restrictions regarding grass clippings treated with clopyralid and compost material.
- Complete field research that will help answer questions such as: “If a detectable level of clopyralid is over a certain level, what are the recommended best management practices for use of that compost?” We expect to have answers to our questions in the next several weeks and will share the answers with all interested stakeholders as the data and recommendations become available.
Washington State authorities recently banned some uses of clopyralid after it was linked to compost that damaged tomato plants. No crop damage reports have been confirmed in California. However, DPR holds authority to cancel the registration of any pesticide product when detrimental effects on the environment outweigh benefits.
Garry Hamlin, manager, public affairs resources – government and public affairs, Dow AgroSciences, Indianapolis, Ind., said the company had recently been in discussions about possible label changes, and that the issue might soon become a national consideration. "Our perspective is that this will have to be resolved on a federal basis," he said.
DPR will send cancellation notices to seven registrants who market 15 clopyralid products. While these products are non-restricted pesticides (no permit required for purchase), they are generally marketed to licensed, professional applicators for commercial use.
The registrants, with affected products in parentheses, are:
- The Andersons Lawn Fertilizer (Tee Time 18-5-9 With Millennium Ultra Herbicide, United Horticultural Supply Professional Turf Products 22-3-4 With Millennium Ultra, The Andersons Professional Turf Products 16-4-8 With Millennium Ultra Herbicide & PCSCU)
- Dow AgroSciences LLC (Lontrel Turf and Ornamental, Lawn Fertilizer Plus Confront Weed Control, Turf Fertilizer Contains Confront, Confront)
- Howard Johnson’s Enterprises Inc. (Howard Johnson’s Weed & Feed with Millennium Ultra)
- Lebanon Chemical Corporation (Lebanon Proscape Homogeneous Fertilizer With Confront Herbicide Broadleaf Weed Control)
- Lesco Inc. (Lesco Momentum Premium Weed & Feed)
- Monterey Chemical Company (Millennium Ultra Selective Herbicide)
- Riverdale Chemical Company (Riverdale Millennium Ultra Selective Herbicide, Riverdale Millennium Ultra Weed And Feed, Riverdale Trupower Selective Herbicide, Riverdale XRM-5202 TM Premium Weed And Feed).
All pesticide products used in the United States legally must be registered with the U.S. Environmental Protection Agency (EPA), which dictates product label language, including specific uses. California law requires that any pesticide product approved by U.S. EPA also must be registered by DPR before the product can be used in the state.
DPR’s cancellation notice currently affects the sale and use of clopyralid products in California only. Cancellation could take effect within 30 days, barring an appeal. In lieu of cancellation or appeal, a registrant could voluntarily seek product label changes from the U.S. EPA that would eliminate uses that concern DPR.
DPR also announced creation of a clopyralid workgroup that includes members of the compost industry, registrants, the California Integrated Waste Management Board, the California Department of Food and Agriculture and other stakeholders. The workgroup will continue gathering information on clopyralid use patterns, potential pathways of contamination, regulatory options and other issues.