After a lengthy reassessment process first approved late 2020, it now proposes to ban the insecticide in New Zealand, and has called for submissions by 12 February.
Chlorpyrifos is a broad-spectrum organophosphate used in agriculture and horticulture, and for biosecurity treatment of pest species.
Fifteen products containing this active ingredient, from thirteen crop protection companies, are currently listed on the ACVM register.
They cover many crops, including avocados, kiwifruit, wine grapes, pip and stone fruit, onions, squash and potatoes.
Chlorpyrifos-based insecticides are also approved for use in cereals, lucerne, forage brassica, fodder beet, maize and pasture.
Labelled pests range from grass grub, porina, Argentine stem weevil and cutworm to aphids, white butterfly, leafroller, diamond back moth and mealy bug.
In addition to these ACVM registered products, several more are approved but no longer registered.
In October, Australian regulators removed most agricultural and urban pest control uses of chlorpyrifos for worker health and safety and environmental risks. It has been banned in Canada; is not approved in the European Union and is under review in the United States.
The EU has also proposed that chlorpyrifos be listed as a persistence organic pollutant under the Stockholm Convention. If this goes ahead, the EPA says it would prevent the manufacture, export and import, supply and use of the substance in NZ.
Further, it says in a 100-page staff assessment report, “there is evidence to indicate that the value of chlorpyrifos as a plant protection product on crops for export markets has decreased.
“Maximum Residue Levels (MRL) values and tolerances in international markets are being revoked or significantly reduced.
“This and other social and market pressures suggest that markets are likely to move away from the use of chlorpyrifos.”
As international import markets ban its use of chlorpyrifos and/or consumers move away from it, the ability to use chlorpyrifos on export crops in NZ and/or the value of crops treated with chlorpyrifos for export markets will become increasingly limited.
“Alongside any decline in acceptance, a proportion of the monetary benefits associated with the use of chlorpyrifos in turn decreases.
”The report lists alternative crop protection options for currently labelled use patterns, with diazinon one of the few active ingredients listed for army caterpillar, lucerne flea, porina, grass grub and manuka beetle in pasture. However, diazinon is itself being phased out, and must not be used after 1 July 2028.
The only other chemical family listed as an alternative for controlling grass grub in pasture – the neonicotinoids clothianidin and imidacloprid – is also being reassessed by the EPA.
Hazardous substances reassessments manager Dr Shaun Presow says the authority wants information from organisations that use chlorpyrifos to better understand benefits of using it, and any potential impacts of a ban.
“We have assessed the risks to human health and the environment, but we need to carefully consider all the evidence about how chlorpyrifos is used and its risks.
“It’s important to hear from as many people as possible before we make final decisions.”
The EPA reassessed plant protection products containing chlorpyrifos as part of a larger reassessment of organophosphate and carbamate substances in 2013.
At that time risks of its use to human health and the environment were deemed as ranging from negligible to high, but significant benefits were derived from plant protection and biosecurity uses.
With application of additional controls, it was approved for plant protection. Since then, international regulatory reviews have been undertaken, and in the case of human health, the toxicological threshold for adverse effects is now 10 times lower than the 2013 NZ assessment.
The new assessment shows most uses now have human health risks which may not be mitigated with controls, the EPA says.
“Those which can be mitigated are those with low application rates and would require significant restrictions.
“All uses are considered to present risks to the environment. Our assessments, and those of international regulators, show chlorpyrifos presents significant risks to the environment for all uses, and to human health for most uses.”