EDN is a gas used to kill common pests found in wood. The active ingredient of EDN, ethanedinitrile, has not been previously assessed by the EPA.
The decision-making committee:
- approved EDN on the basis that its benefits are significant, and adverse effects are negligible with the appropriate control measures
- accepted the evidence that EDN is the most viable replacement for methyl bromide for treating timber and logs
- also acknowledged the concerns of Māori and the wider public regarding the health and environmental effects of EDN.
Controls for EDN
Controls are set to manage the risks of EDN under the HSNO Act and the Health and Safety at Work Act 2015.
There is a maximum application rate
The maximum application rate is 120 g of EDN/m³.
Use is restricted
EDN is restricted to fumigating export logs or timber under a sheet or in a shipping container. Using EDN in a ship’s hold is not allowed.
Average wind speed must be at least two metres per second (2 m/s) in the 10 minutes before ventilation takes place.
Tolerable exposure limit
The tolerable exposure limit for ethanedinitrile has been set at 0.034 ppm (as a 24-hour average).
Notification and reporting
Controls under the HSNO Act require that:
- relevant local authorities are notified of intended fumigations
- relevant local authorities are notified as soon as practicable and within 24 hours if the tolerable exposure limit is exceeded
- a copy of the annual report of fumigation activities (required by WorkSafe) is provided to the EPA.
Controls under the Health and Safety at Work Act are covered by WorkSafe Safe Work Instruments:
- Health and Safety at Work (Hazardous Substances—Requirements for Specified Fumigants) Amendment Safe Work Instrument 2022 – WorkSafe website
- Health and Safety at Work (General Risk and Workplace Management—Exposure and Health Monitoring Requirements for Ethanedinitrile) Safe Work Instrument 2022 – WorkSafe website.
New Zealand EPA, 27-07-22