New partnership aims to reduce emissions of methyl bromide for quarantine use

By CnAgri Print

The FAO-based International Plant Protection Convention (IPPC) and the UN Environmental Program (UNEP) agreed to join forces to help countries better manage their handling of the ozone-damaging gas methyl bromide, used to treat plant products and thereby prevent the accidental spread of pests and diseases.

In a new Memorandum of Understanding signed recently, the IPPC and UNEP's Ozone Secretariat commit to working closely together to promote wider implementation of existing recommendations regarding methyl bromide (MeBr) as well as to support efforts to develop alternative phytosanitary treatments to replace it, where possible.

For decades MeBr offered a potent tool in combating the transboundary spread of plant pests and diseases, which can take a significant toll on food security, the livelihoods of farmers, and trade.

But methyl bromide is extremely damaging to the Earth's protective ozone layer, and in 1991 was added to the list of substances controlled under the Montreal Protocol, an international agreement set up to phase out the use of ozone-depleting technologies.

The Protocol discourages the use of MeBr to combat pests and disease for non-quarantine purposes during production, but does make an exception for its utilization as a phytosanitary quarantine treatment, given its effectiveness in stopping pests and diseases.

Where alternatives to methyl bromide use during quarantine do not exist or are not feasible, a recommendation by the IPPC's Commission on Phytosanitary Measures (CPM) encourages best fumigation practices that can limit unwanted emissions of the gas and calls for a shift away from MeBr as much as possible through the development of new alternative treatments.

For that to happen, plant protection authorities need information on and access to alternative treatments that are affordable, effective, and appropriate to their specific needs.

Today's MOU is intended to support these goals by:

• Strengthening information-gathering on how methyl bromide is currently being used for quarantine purposes in order to identify opportunities for shifting to alternative measures
• Improving regional and international coordination regarding MeBr management
• Fostering information exchanges and cooperative research aimed at reducing emissions of the gas and developing alternative phytosanitary treatments
• Promoting best fumigation practices in order to minimize MeBr emissions and encourage wider use of methyl bromide recovery and recycling technologies.

Fast facts: Methyl Bromide

A colorless gas at room temperature, methyl bromide both occurs naturally and is manufactured. Marine organisms are estimated to produce 1-2 billion kilograms of it each year; MeBr is also released in small quantities by some terrestrial plants.

For agricultural and industrial use, the gas is manufactured by reacting methanol with hydrogen bromide.

MeBr has potent insecticidal, fungicidal and herbicidal properties, and since the 1950s has been widely used around the globe on farm, during crop production, to control a number of pests in a broad range of crops and wood products and is particularly important for phytosanitary purposes as a quarantine treatment.

When used as fumigant, methyl bromide is applied in concentrations that are acutely toxic to these pests - as well as to people.

Handled properly, human health risks can be managed. It is the gas's role in depleting the ozone layer that has attracted the most concern.

In 1991 methyl bromide was identified by the Montreal Protocol as contributing to the depletion of the ozone layer.

However, the Protocol does allow for MeBr's use as a quarantine treatment.

The exemption requires that treatment be either performed or authorized by a national plant, animal, or environmental protection or health authority and target officially recognized quarantine pests which represent a significant potential threat to the export destination.

These quarantine fumigations can occur on farms, or central processing facilities, in lumber mills, silos or warehouses for products such as farm or construction equipment and machinery, lumber, fresh flowers and bulb, grains and cereals, hay, straw and cotton, perishable fruits, and wood products.

Fumigations performed during production, for non quarantine pests, are not exempted from phase-out under the Montreal Protocol, and as a result the past decade has seen a steady decline in the use of MeBr.