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Center for Plant Health Science and Technology
Treatment Quality Assurance Unit |
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Pressure Testing and Methyl Bromide Degradation In Containers
The use of fumigation as a phytosanitary treatment depends on the ability to deliver consistent concentrations during specified time periods to the targeted commodity. The use of methyl bromide fumigation as a phytosanitary treatment for containerized cargo depends on the ability to seal the container or to provide a sealed environment by using enclosures such as tarpaulins specifically designed to provide a sealed environment.
During FY 2007, CPHST scientists conducted laboratory and field testing of containers using a pressure monitoring device (developed by an Australian team associated with a semi-governmental group: Australian Quarantine and Inspection Service, AQIS) to confirm treatment delivery. Recently, CPHST personnel have begun field validations using the finger manifold technology, an alternative delivery and pressure monitoring mechanism. This new equipment and method of testing has the potential to develop into a new procedure for pressure testing containers to determine if they hold air pressure as required (in terms of delivered concentration and duration) for the methyl bromide treament.
The methyl bromide degradation component of this study is designed to determine whether a correlation exists between methyl bromide loss during various exposures and dosages relative to "pressure-halving" time. This degradation study is critical to determine if containers can be used for fumigation without a tarpaulin. The finger manifold, and pressure-halving time process was developed by and is currently being used by the Australian Quarantine and Inspection Service and is explained in the Treatments and Fumigants AQIS Methyl Bromide Fumigation Standard, 1.3 on pages 48-51. See the following link:
This finger manifold is designed to deliver compressed air between the container doors within a container and then measure the internal pressure of the container. Click on following images to enlarge.
A finger manifold can be attached to a container like shown below with pressurized cylinders.
The information on the finger device and this testing process will be updated as new findings are recorded by our research teams.