State Cancels Clopryalid Herbicide Use On Urban Lawns

In response to the problem of clopryalid residues in commercial compost, the California Department of Pesticide Regulation (DPR) began cancellation action against 15 herbicide products in late March.

The cancellations will target herbicide products containing clopryalid that are sold for use on residential lawns in California, since green waste from that source is a common ingredient in commercial compost. Composting of grass clippings from residential lawns is widely promoted in state urban areas in response to state laws mandating reductions in the amount of waste sent to landfills.

“Composting helps reduce our waste stream while helping urban gardeners and commercial agriculture,” DPR director Paul Helliker said. “In taking this action, DPR reaffirms its support for composting in California.”

The department’s action will not affect clopryalid products used on farmland, rangeland and forests.

DPR’s action prompted clopyralid herbicide manufacturers, Dow AgroSciences and Riverdale Chemical Company, to notify the U.S. Environmental Protection Agency of their intent to remove residential lawn uses from their product labels. The companies have also requested that lawn care operators, chemical dealers and distributors not sell clopryalid products for home use.