Methyl bromide Chemical Review

In September 2005, the APVMA began a review of methyl bromide because of environmental concerns. The review focused on the appropriateness of the warnings and instructions on product labels, particularly in the light of known environmental concerns about methyl bromide and Australia’s obligations under the Montreal Protocol on Substances that Deplete the Ozone Layer.

Methyl bromide is the most potent ozone-depleting substance still in use today. In 1991, it was identified as such by the Montreal Protocol. In accordance with the protocol, the Australian manufacture and importation of methyl bromide was to have been phased out completely by 1 January 2005. However, uses of methyl bromide in quarantine pre-shipment (QPS) and as a chemical feedstock are currently exempt from the phase-out under the protocol.

The APVMA had not conducted any previous regulatory action concerning methyl bromide, as the chemical’s use in Australia had been regulated by the Department of the Environment and its predecessors since 1996.

In April 2006, the APVMA released the Methyl bromide preliminary review findings report, in which it proposed:

• varying product labels with general fumigation uses to delete all uses with the exception of QPS uses and including a recommendation that recapture technology be used where appropriate
• varying product labels that have both soil fumigation and general fumigation uses to delete soil fumigation uses
• cancelling the registration and approvals for methyl bromide products that only have soil fumigation uses and cannot be varied.

In June 2007, the APVMA released the Methyl bromide final review report and regulatory decision. The APVMA found that the use of methyl bromide products in accordance with current label instructions may have an unintended effect that is harmful to the environment.

However, the APVMA was satisfied that the labels of all methyl bromide products could be varied in such a way that the continued use of methyl bromide products would not be likely to have an unintended effect that is harmful to the environment.

In June 2007, the APVMA board decided to:

• vary product labels with general fumigation uses to allow such fumigation for QPS and approved critical use exemption (CUE) situations only
• vary product labels with in-field plant-bed/turf soil fumigation and stored soil/compost/hay fumigation uses to allow such use for QPS and approved CUE situations only
• vary product labels with only in-field horticultural-crop soil fumigation uses to allow such use for QPS and approved CUE situations only
• vary all labels to include the direction that recapture is recommended, where feasible
• allow a 24-month phase-out period, consistent with the Montreal Protocol, for stock bearing old labels.

The APVMA will continue a project to see whether low-dose variable concentration and time options (flexible CT) are feasible and acceptable to the Australian quarantine authorities. It will liaise with any registrant willing to submit an application for flexible CT products to be assessed for approval onto their methyl bromide product label.

The APVMA will also keep a watching brief on developments in recapture technology and liaise with the peak fumigators group on developments in the economics and logistics of its possible implementation as a registration requirement. The APVMA proposes to monitor any changes in the Australian threshold limit value for methyl bromide and any implications they may have for mandatory degassing and/or recapture immediately after fumigation.