In July, New Zealand’s Environmental Protection Authority (EPA) announced a ban on chlorpyrifos—a broad spectrum organophosphate insecticide primarily used to control grass grub and other insects like aphids—and introduced an 18-month phase out period. The agrichemical, first approved for use in 2004, lost its approval in the 2025 reassessment because evidence shows the risks to people and the environment outweigh the benefits.
Heading this process for the EPA is Dr Shaun Presow, Manager of Hazardous Substances Reassessments. In a recent conversation with PGG Wrightson’s podcast, Blue Shed Diary, Shaun lays out the process behind the decision.
“We received new information around the harms it was causing or could cause to people using it, particularly developmental harms to children. It is a neurotoxic agent which can lead to neurological damage through exposure,” says Shaun.
Dr Shaun Presow, Manager of Hazardous Substances Reassessments
Through their reassessment process, the EPA collects information from a variety of sources, including international regulatory bodies, to generate a science memo laying out the EPA’s position on the substance and the harm it can cause.
“In the case of chlorpyrifos, we determined that even with all the safety measures we
could put in place and personal protective equipment—masks, gloves, overalls—there
was still a potential for harm to the people using the chemical. Because we cannot
mitigate the harms, we need to remove it from the market,” Shaun explains.
New Zealand is not alone in banning chlorpyrifos. It cannot be used in Canada and European Union; and is in the process of being phased out internationally through the Stockholm Convention, of which we are a signatory.
“The Stockholm Convention was set up to deal specifically with what we call persistent organic pollutants, the chemicals that last a very long time in the environment. New Zealand, coincidentally, is working on a similar timetable,” says Shaun.
Chlorpyrifos ban timeline
- 8 July 2025 - Banned from use in all publicly available areas such as parks and
sports fields. - 19 December 2025 - PGG Wrightson stops selling all chlorpyrifos products. All prior sales are made on a non-returnable basis.
- 8 January 2026 - Approvals for liquid chlorpyrifos products end. Manufacturing and
imports will cease. - 8 July 2026 - All liquid chlorpyrifos products disposed of in line with EPA controls.
- 8 January 2027 - Approval for granular chlorpyrifos products ends. Manufacturing
and imports will cease. - 8 July 2027 - All granular chlorpyrifos products to be disposed of in line with EPA controls.
