Hydrogen cyanamide reassessment

We will be reassessing the substance hydrogen cyanamide, a spray ingredient used in New Zealand by orchardists, particularly kiwifruit and apple growers, to promote bud formation.

In preparation for consultation with Māori stakeholders, we have circulated some preliminary information on the background of the hydrogen cyanamide reassessment. 

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

Call for information

Our call for information closed on 29 May 2020. We received 12 responses.

The information we received will be used to prepare our reassessment application, informing our risk and benefits assessments, and help us make an initial proposal on how the substance should be managed in the future. 

A reassessment is a formal review of the rules controlling a substance that is already in use in New Zealand.

Once a reassessment application is lodged, you will have an opportunity to make a formal submission on the reassessment application and proposal.

Read more about the reassessment process

Information we were looking for

We sought any relevant information from industry, users, other interested parties or the public relating to the use, practices, and effects of hydrogen cyanamide-containing substances.

This included any information relating to the effects of the substances, positive or adverse, such as toxicology, ecotoxicology, economic impact, environmental fate studies, or monitoring results.

As the current risk management framework for hydrogen cyanamide-containing substances relies heavily on industry requirements, we also wanted to get a better understanding of current industry requirements throughout the life cycle of these substances, such as:

  • the identification and nature of the risks being managed
  • what measures are implemented to manage risks (including equipment and engineering measures, spray drift mitigation and exposure prevention)
  • the effectiveness of the current requirements in managing risks to human health and the environment
  • how the industry requirements align with other regulatory requirements under different pieces of legislation (for example the Hazardous Substances and New Organisms Act 1996, Health and Safety at Work Act 2015 and Resource Management Act 1991).

Current approval for hydrogen cyanamide

There is one Hazardous Substances and New Organisms (HSNO) Act approval that covers six of the hydrogen cyanamide bud-break products currently in use (soluble concentrate containing 520 to 540 g/L hydrogen cyanamide, HSC000001).

The products currently registered with NZ Food Safety at the Ministry of Primary Industries are:

  • Hi-Cane (P003566)
  • Treestart (P007333)
  • Hortcare Hi-break (P007018)
  • Synergy HC (P007840)
  • Gro-Chem HC-50 (P005858)
  • Cyan (P007190)

The numbers in brackets are the Agricultural Compounds and Veterinary Medicines registration.

Grounds for reassessment

The grounds to reassess hydrogen cyanamide products were established in September 2019. The establishment of grounds is the first step toward reassessing a substance under the HSNO Act.

Previous reassessment decision

Hydrogen cyanamide has been used in New Zealand since 1988 and was last reassessed in 2006 (HRC05001). That reassessment indicated that risk to bystanders could occur through exposure to spray drift, if the substance was not used in a manner that adheres to best practice.

It was decided that risks would be managed by an industry-led approach to ensure safe use of hydrogen cyanamide substances. The Decision-making Committee recommended that we monitor the reporting of incidents over the following five years, to assess the effectiveness of changes in technology and the impact of the regulatory controls.

Our 2012 HSNO Monitoring Report subsequently concluded that it could be assumed hydrogen cyanamide was being used more safely than before the reassessment. This was attributed to the introduction of better spraying technology (air inclusion spray nozzles), and the promotion of safe use of hydrogen cyanamide by regional councils.

The report noted that these monitoring requirements were not controls as such, and concluded that they were not as successful as the monitoring controls set for other substances.

Background documents

Below are links to application documents for the grounds to reassess hydrogen cyanamide in 2019, documents from the previous reassessment undertaken in 2006, and our 2012 HSNO Monitoring Report.

Read the grounds for reassessment documents (2019)

Read the previous reassessment documents (2006)

Read the grounds for the 2006 reassessment (2004)

Read the 2012 HSNO Monitoring Report (PDF, 611 KB)