SEATTLE -

What is clopyralid and what is the concern?
Recently, compost facilities in the region have found trace amounts of a herbicide that is used mostly in commercial lawn and agricultural applications. This herbicide is used to kill broadleaf weeds and the residue from this chemical could be present on hay and straw that WPZ uses for feedstock and bedding. This chemical, called clopyralid (klo-PEER-uh-lid), is non-toxic to humans and animals. However, it is very persistent and is not neutralized after passing through the animal nor in the manure composting process. Many common broadleaf garden plants are very sensitive to this chemical and very low amounts can cause plant damage.

What is the status of our Zoo Doo and related products?
An outside lab has tested all of our compost products containing Zoo Doo. The results were negative showing no detectable trace of clopyralid down to 1 part per billion (ppb), the lowest measurable level. Bioassay tests of Zoo Doo, currently being performed by the UW botany department, have initially shown no visible damage to the test plants.

What is WPZ doing to protect Zoo Doo from clopyralid contamination?
We are currently working with our hay vendor to guarantee a continued supply of high-quality hay to the zoo that is free of this herbicide residue. We are also putting into place an ongoing testing regimen that includes offsite lab tests combined with on-site bioassay plantings to visually support the lab analysis. WPZ Zoo Doo will continue to be a premium compost and perennial choice for discriminating gardeners throughout the Northwest.

Public or media inquiries
Please refer public inquiries to Dan Shepherd (Dr. Doo) at 206.684.4828 and media inquiries to the public relations department at 206.684.4838.