The Organic Materials Sector Group recently undertook to review the New Zealand situation for clopyralid and its level of contamination of green waste and subsequent compost products. Clopyralid is a herbicide used to control broadleaf weeds, particularly thistles and clovers. It can survive the composting process and actually increase in concentration as the green waste breaks down.
Full results of the survey can be viewed here Clopyralid Survey Report October 2014.
As a result of this survey the Organics Material Sector Group strongly encourages all facilities that accept grass clippings to test for clopyralid. Advice and guidance on how to test for clopyralid can be viewed here.
Also, the Organic Materials Steering Committee has recommended applying to the Environmental Protection Authority for grounds for the reassessment of clopyralid.
When reassessments are requested, it’s commonly because there is new information indicating that the risks to human health and/or the environment may not be appropriately managed by the existing controls. The application will outline the reasons the Organic Materials Steering Committee think the reassessment is needed based on the results of the survey.
For more information about this project, please contact Sarah Pritchett, Sector Group Manager for the Organic Materials Steering Committee sarahp@wasteminz.org.nz