Mouse baits got Australia emergency permits

There is a mouse plague in some states. Farmers are faced with extensive mouse control programs to protect crops. There is an effective vertebrate poison product registered for mice control on the market. Farmers, however, argue that it is too expensive. Some have also expressed the view that supplies of it are limited. Accordingly, they have supported an Emergency Use Permit (EUP) application to the APVMA to allow on-farm mixing of the active constituent (zinc phosphide) with grain.

An emergency use permit provides authority to use an unregistered product or active constituent (or one registered for a different purpose) in an emergency situation.

An emergency situation is loosely defined in the APVMA legislation as one where there is a genuinely believed need for the use of the product or constituent. Because the definition is broad, the APVMA has developed broad policies to guide action. These include the principle that an EUP is time-limited to address a need, will generally not be issued when there is product registered for the proposed use with good availability, and that EUPs will generally not be issued on the basis of a cost preference.

These matters aside, in considering a permit application the APVMA must be satisfied that the use of the product concerned will be safe in terms of human health, the environment, trade and occupational health and safety (OHS). Supporting data relating to the proposed use must be supplied with the application for the APVMA to make an assessment.

The APVMA has been involved in many discussions with farmer groups, state government officials and registrants over several months on mice control issues. In these discussions a range of zinc phosphide options have been discussed including the use of unsterilized grain (to make the product cheaper), regional bait mixing stations as well as the idea of on-farm mixing.

The APVMA has consistently raised the issue that, apart from the policy issues, the major concern with any option that involved farmers mixing the product themselves is ensuring operator and bystander safety. Zinc phosphide is a Schedule 7 poison. This is the highest level of scheduling and substances with this scheduling level are labelled as ‘dangerous poisons’. There are access restrictions to Schedule 7 poisons at state level, but even then, there are very real OHS concerns.

On this basis, the APVMA advised that any permit application that involved on farm application would need extensive data from reputable studies that could demonstrate that the health risks could be effectively managed. The APVMA also advised that it would have less concerns if the states or grower groups could develop regional bait mixing stations where risks to operators and bystanders could be more effectively controlled.

An emergency use permit for on-farm mixing of zinc phosphide with grain was received and accepted on Thursday 5 May. The permit is being assessed. Discussions with stakeholders about the application and alternative options are ongoing.