Hydrogen cyanamide has been used in Aotearoa New Zealand since 1988. It is used mainly in kiwifruit orchards to promote bud growth. It is also used in some apple, cherry, apricot, and kiwiberry crops, but to a lesser extent.

There are six hydrogen cyanamide products approved for use. They are restricted to commercial use, and can only be used by trained professionals.

Latest application update

Submissions closed on 20 December 2021. We received 199 submissions, which will be published with the application documents as they are processed.

Read the hydrogen cyanamide application documents

Why we are reassessing hydrogen cyanamide

We have assessed the risks to people and the environment, and economic benefits of hydrogen cyanamide use in New Zealand. Our assessment was based on risk analyses, economic assessments, information on alternative bud-break agents, and general comments we received from industry groups, iwi, and individuals.

Other significant information included a European Food Safety Authority review, and assessments published by regulators in the United States and Europe.

Human health risks

Hydrogen cyanamide is toxic to the reproductive system and thyroid if people are exposed to it over time. It is a suspected carcinogen, and is corrosive to skin and eyes. The risks to operators are of concern.

Environmental health risks

There are risks to the aquatic environment, non-target plants, pollinators, non-target arthropods, and birds. Risks can be mitigated by using buffer zones, restrictions on application rate and timing, and prohibiting use when bees are present.

Impact on Māori culture and social wellbeing

The continued use of hydrogen cyanamide is likely to enhance Māori economic and social development in terms of prosperity, livelihoods, and lifestyles. But it is likely to adversely affect the relationship of Māori and their culture and traditions with their environment and taonga, including culturally significant species, resources, and places, and the customary values, practices and uses associated with these taonga.

In mid-2021 we held hui in kiwifruit-growing regions to gather information for our Māori impact assessment report. In advance of the hui, we provided two documents summarising the key issues identified in our risks and benefits assessments.

Hydrogen cyanamide reassessment: preliminary information for Māori consultation (PDF, 419KB)

Summary document for Maori consultation (PDF, 461KB)

Draft proposal and recommendations

We recommend that current approvals for hydrogen cyanamide be declined, and the substance banned.

We propose it is phased out over five years, with tighter controls taking immediate effect after the final decision. A gradual phase out would allow existing stock to be used up, for growers to get familiar with alternatives, and to introduce additional alternatives to New Zealand.

We propose implementing the following controls, taking immediate effect, subject to a short transitional period to update labelling and packaging.

• Update hazard classifications to:
  • classify the soluble concentrate as skin and eye corrosive, rather than an irritant
  • include a carcinogenicity classification
  • change the specific target organ toxicity classification (from Category 1 to 2)
  • classify as hazardous to soil organisms.
• Lowest possible application rates, keeping the benefits of hydrogen cyanamide, while minimising risk.
• Buffer zones of up to 50 metres to protect bystanders, aquatic habitats and plants.
• Maximum wind speed of between 3 km/h and 20 km/h.
• Update labelling and packaging requirements.
• Users should be appropriately trained and qualified to handle hydrogen cyanamide substances and manage the environmental risks.