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The regulation of inhibitors used in agriculture

UPDATE – August 2022

Policy proposals approved to regulate inhibitors under the ACVM Act 1997

In March 2021, Cabinet:

  • agreed to strengthen the regulation of inhibitors used in agriculture by defining inhibitors as agricultural compounds, causing them to be regulated under the ACVM Act
  • noted that agrichemical companies need time to register inhibitors under the ACVM Act, which led to a 2-year transitional period.

Cabinet paper: Proposals to strengthen regulatory oversight of inhibitors used in agriculture [PDF, 4 MB]

Bringing Inhibitors under the ACVM Act

To bring inhibitors under the ACVM Act requires an interim measure and a permanent solution.

The interim measure:

  • declares listed inhibitors as agricultural compounds by an Order in Council
  • creates a 2-year transitional period to register inhibitors listed on the Order in Council
  • commenced on 18 July 2022.

Agricultural Compounds and Veterinary Medicines (Inhibitor Substances) Order 2022

Cabinet paper for the Order in Council and Amendment Regulations [PDF, 1.4 MB]

Listed inhibitors have been eligible for registration under the ACVM Act since 18 July 2022. If products were for sale in New Zealand on 18 July, they can continue to be sold during the transitional period while product registration is sought.

The permanent solution is to amend the definition of agricultural compound in the ACVM Act to include inhibitors. This will ensure that all inhibitors will be regulated under the ACVM Act and be eligible for registration. 

Cabinet recently agreed to minor amendments across MPI legislation including amending the ACVM Act to include inhibitors. 

Primary Industries Regulatory Systems Amendment Bill – Cabinet paper [PDF, 2.5 MB]

Regulation of inhibitors under the ACVM Act – FAQ [PDF, 172 KB]

Find out more about the registation process for inhibitors


For enquiries about this work, email

For enquiries about the registration process, email the ACVM Team at

What are inhibitors?

Inhibitors are potentially important tools for primary producers to improve environmental sustainability. While there is no legislated definition of inhibitor in New Zealand, they are commonly considered to be compounds that can be applied directly or indirectly to animals or a place to inhibit the production of greenhouse gases or to reduce nutrient leaching in some way. Inhibitors vary widely in how and what they inhibit. Common types of application include as feed additives, coatings on fertilisers, or vaccines.

There is growing interest by farmers and growers in the use of these tools to reduce nitrate leaching and the effects of climate change. While this technology has some exciting potential, we need to make sure that any use of inhibitors is managed well so that any potential risks to food safety, plant and animal health and trade are minimised. As well as making sure there are no negative impacts from using inhibitors, the primary sector wants assurance that products on the market that claim to be inhibitors are effective.

Consultation closed in April 2020

The Ministry for Primary Industries (MPI) sought feedback on options to change the way inhibitors used in agriculture are managed. The discussion paper identified 3 options for managing the regulatory oversight of inhibitors to make sure the primary sector could safely and effectively use inhibitors to mitigate environmental, sustainability, and climate change issues. 

Discussion paper

The regulation of inhibitors used in agriculture [PDF, 1021 KB]

Related information

One page summary of the discussion paper [PDF, 129 KB] 

Media release about this consultation

Questions and answers about this consultation [PDF, 71 KB]