DMN Q&A: Who can use the sprout suppressant under the new EAMU?

Wednesday, 16 December 2020

An emergency authorisation (EA) for the use of the as yet unapproved sprout suppressant 1,4-dimethylnaphthalene (DMN) was secured last week - following an application from AHDB, supported by the Potato Processors Association (PPA) and approval holders DormFresh.

The successful AHDB application, covering 192,000 tonnes across seven key crisping and French Fry varieties, was made after an initial application for all market sectors was rejected by the Chemical Regulations Division (CRD) of HSE.

We consulted with the PPA, NFU, the Fresh Potato Suppliers Association (FPSA) and the British Potato Trade Association (BPTA) before making both applications.

Here, we have prepared a 'frequently asked questions' document for store managers who wish to know more.

How will the industry be able to use DMN this season?

DMN, marketed by DormFresh Ltd as 1,4-Sight®, is only available under a UK controlled emergency authorisation for use on specific pre-nominated varieties which are contracted for delivery from April 2021 onwards from long-term storage.

Use will be confined to crop within supply chains where disposal of waste can be closely regulated as Chemical Regulation Division (CRD) have currently made it a condition of authorisation to prevent DMN‑treated crop entering the livestock feed chain.

Crops, to be eligible for treatment, will also have to demonstrate that they have a Maleic Hydrazide (MH) residue below 12 mg/kg.

Crop eligibility in summary

  • Pre-nominated varieties for crisp and French Fry processing
  • Ability to demonstrate MH residue levels < 12 mg/kg
  • Access to controlled waste supply chain demonstrating segregation from livestock feed chain in line with stewardship requirements

How will I know if I can use DMN?

Talk to your market to establish whether you have an eligible variety, access to a controlled waste supply chain and, if these criteria are met, get the crop tested to see if it will meet the MH threshold.

How can I test for MH residue?

Residue tests for agrochemicals are generally available to the industry as a service provided by commercial testing laboratories. Ask your market to recommend a lab or search ‘Pesticide Residue Testing’ to find one close to you.

Tests must be carried out on samples taken in accordance with a specific MRL sampling protocol available below. 

Download: Guidelines for potato sampling

Why hasn’t my sector been included?

With the emergency approval restricted to less than 6% of the nationally stored crop, it has been impossible to secure DMN for all of the potato industry. Some sectors, such as fresh chipping, cannot unfortunately meet the necessary criteria for control of waste potatoes. And, even for some sectors that can, such as fresh pre-packing, it has been acknowledged that the need for DMN is greater in the long-term processing sector.

We consulted with trade associations PPA, NFU, FPSA and BPTA at each step, so they could advise us, on behalf of levy payers, on what steps would be best for the industry as a whole.

Will DMN be available to all of the industry next year?

The current emergency approval is for this 2020-21 storage season only. 

DormFresh Ltd made an application for full approval of 1,4-Sight® in September and this is currently under consideration by CRD. Availability for the 2021/22 season is dependent on that approval being granted. 

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