SEEKING SOLUTIONS, PROPOSING PRECAUTIONS
INDUSTRIES RESPOND TO THE CLOPYRALID CONTROVERSY
The U.S. Composting Council and the Grass Roots Recycling Network call for restrictions on clopyralid use while Dow AgroSciences says it’s all about the label.
Robert Rynk

CONTAMINATION of compost with the herbicide clopyralid (pronounced clo-peer a-lid) first surfaced in 2000 in Eastern Washington (see “Dealing with Herbicide Residues in Compost,” September 2000). Since then, clopyralid has grown from a curiosity to a controversy.

Problems from the original incidents remain unresolved and new incidents have been reported in locations as widespread as Pennsylvania and New Zealand. The list of feedstocks associated with clopyralid also has grown. In addition to grass clippings, feedstocks that can carry clopyralid to composting facilities include straw, cattle manure, horse manure, spent mushroom media, mint slugs and grain. While the situation falls far short of a crisis, the apparent increase in potential contamination has raised the concern of the composting, recycling and agricultural chemical industries. The concern has led to official responses from a number of groups, including Dow AgroSciences, the U.S. Composting Council (USCC) and the Grass Roots Recycling Network (GRRN).

DOW AGROSCIENCES’ RESPONSE

Dow AgroSciences, the manufacturer of clopyralid, issued a position statement called “Clopyralid and Compost” that reviews the incidents in which clopyralid was detected in compost “at a level sufficient to cause damage to sensitive plants.” The position paper suggests that these incidents involved “unique or unusual circumstances” or resulted from off-label uses. According to the position paper, labels of products using clopyralid state that the vegetation should not be used for composting (see USCC response below). The position paper implies that the problem with clopyralid is largely confined to grass clippings and that it (clopyralid) serves important functions for managing hard to control weeds, especially for minor crops.

Dow AgroSciences states that it is committed to finding solutions and is taking the following steps to do so: 1) Conducting or funding studies to determine the breakdown of clopyralid during composting and methods to speed its degradation when it is detected at phytotoxic levels; 2) Studying the decrease in clopyralid residues on treated grass after subsequent mowings; 3) Strengthening the label language about the handling of treated vegetation; and 4) Developing education programs among users, property owners and applicators about the proper handling of treated vegetation. To minimize clopyralid contamination of compost, the position paper places heavy emphasis on the role of the herbicide product label and users’ understanding of it. The Dow AgroSciences position paper is available as a PDF file on the Grass Roots Recycling Network web site: www.grrn.org/dow/DOW_Clopyralid_Compost_10-5-01.pdf

THE USCC AND RECYCLING VIEW

As one might expect, the position of the composting industry differs considerably from Dow AgroSciences’. At the end of October, the U.S. Composting Council (USCC) issued a position paper that refutes many of Dow’s assertions. First, the USCC claims that the herbicide labels are ambiguous and likely inaccurate in their instructions about handling treated vegetation. The position paper cites the label from the herbicide ConfrontTM as an example: “Do not use compost containing grass clippings from turf treated with Confront in the growing season of application.” The USCC observes that this statement hardly prohibits the composting of treated grass clippings. Furthermore, the USCC states that the labels imply clopyralid residues can be sufficiently degraded in a year. However, both research and experience demonstrate that even a year is not long enough.

Secondly, the USCC position paper states that an accurate label is not enough to solve the problem: “Even if clopyralid applicators are provided with an unambiguous, accurate label, there would still be a long chain of communication that must be maintained among applicators, land owners, harvesters of the plant residuals, haulers and the compost facility operators…. As a practical matter, it would be impossible to ensure this essential chain of communication, rendering any improvements to the label ineffectual. A solution to the clopyralid-compost issues must provide for effective and continuous communications among all of the parties involved. If such communication cannot be ensured, the USCC strongly questions the appropriateness of continued uncontrolled use of clopyralid.” (Note the USCC’s statements relate to clopyralid and a similar herbicide compound, picloram.)

In the position paper, the USCC urges the pesticide industry to take the following corrective measures: 1) Correct the flaws with the herbicide product labels. “At a minimum, the label should have a clear and concise statement that treated plant residuals cannot be placed into a compost system;” 2) Determine the extent of the clopyralid contamination of compost via an independent investigation through a “geographically diverse procedure of sampling, bioassays and analytical chemical tests;” 3) Assess the potential for clopyralid to enter composting facilities via residues for all approved applications of clopyralid in addition to grass. The position paper states that contamination from agricultural residues is not only possible, it has already occurred. (Dow does not dispute this but claims the possibilities are slim); 4) Suspend efforts to develop new products or register new applications that include clopyralid until the extent of the problem is determined. The statement adds: “The USCC will be asking the U.S. Environmental Protection Agency [EPA] and appropriate state agencies to consider the use and safety of products made from treated residues as a criteria when reviewing new and existing pesticide products”; 5) Where clopyralid has been found to affect compost quality, discontinue the “critical applications of clopyralid.”

The USCC position paper also states that the herbicide industry must share the financial responsibility when clopyralid contamination does cause harm. This responsibility includes compensating compost producers and users for lost sales, damage to crops, loss of organic certification, the cost of recertification, and the cost of treating contaminated soil. The USCC position paper can be accessed at the USCC web site: www.compostingcouncil.org (click the “Issues” button in the index).

At least one recycling organization, the Grass Roots Recycling Network (GRRN), has thrown its support toward removing clopyralid from the market. GRRN, which promotes the principle of zero waste, is running an e-letter campaign aimed at Michael Parker, the CEO of Dow Chemical (parent company to Dow AgroSciences). The campaign is intended to convince Dow to take clopyralid products off the market until “Dow can demonstrate their safety to both backyard and centralized composting processes.” In a press release about the topic, Anne Morse, president of GRRN, states: “Confront [the most widely used clopyralid product] is totally contradictory to all our goals for recycling, resource conservation and sustainability.” The e-letter campaign can be accessed through the GRRN web site: www.grrn.org/dow/index.html.

CHANGES AFOOT?

The clopyralid controversy, and the reaction of the affected industries, appears to be leading to changes. For example, the Washington State Department of Agriculture (WSDA) has initiated a procedure to reevaluate the registration and use of clopyralid in that state. In September and October, the WSDA gathered evidence about clopyralid use and contamination plus took comments from the public. The agency will develop a draft policy based on the comments and evidence received (expected early in 2002). WSDA will solicit public comments on the draft policy. (BioCycle will cover the findings of the WSDA evaluation after the draft is released.) At the national level, the U.S. EPA also appears to be interested in the clopyralid issue and is seeking data on clopyralid levels in compost, composting feedstocks and critical concentrations of clopyralid that result in crop damage. If you have relevant data (not anecdotal evidence), contact the Public Information and Records Integrity Branch (PIRIB), Information Resources and Services Division (75052C), Office of Pesticide Programs (OPP), Environmental Protection Agency, 1200 Pennsylvania Ave., N.W., Washington, D.C., 20460. In your comments, refer to the title of this article.

The key argument of the composting and recycling industries is that organic residues such as grass clippings, straw and manure, are no longer just discarded waste products. They are no longer handled in the least-cost manner. They are now feedstocks, raw materials in a manufacturing process that yields a marketable commodity — compost. Product quality is crucial to the composting and recycling industries. Herbicide residues could have a devastating effect. Therefore, the impact of pesticide residues on the quality and uses of treated residuals must become an important criterion when pesticides are considered for registration by the governing authorities.