by Emily Buckley
With less than two years before the completed phaseout of methyl bromide, the milling industry is beginning actively to search for alternatives to its long-used and favored fumigant. More than a decade ago, methyl bromide was identified as an ozone depleting substance. Most millers found themselves in a state of disbelief or denial when their favorite fumigant was scheduled to be phased out from production by 2005 under the Montreal Protocol’s Copenhagen Agreement of 1991, a treaty signed by 183 countries and designed to protect the ozone layer by phasing out several ozone-depleting substances. The Protocol called to cap production levels in 1991 and further reduce them by 25% by January 1999, 50% in 2001, 70% in 2003 and 100% in 2005. Developing countries have until 2015 to complete the phaseout, although some have accelerated that schedule.
The phaseout of methyl bromide has met a large degree of resistance, especially in the global milling industry, where many are still holding on to hopes that methyl bromide isn’t going to go away quite yet.
The North American Millers Association has lobbied over the past several years against the methyl bromide ban, arguing that because developing countries have until 2015 before the complete phaseout, it gives agricultural competitors in those countries an unfair advantage. NAMA has claimed that more than U.S.$60 million in incremental costs to the flour milling industry will result from the methyl bromide ban.
In February, the U.S. government sent a request to the United Nations Ozone Secretariat for a two-year, critical use exemption to begin in 2005 for 54 U.S. companies and trade groups that want to continue using methyl bromide, including the milling industry.
Several other countries, including Australia and Canada, as well as the European Union, have also applied for critical use exemptions.
Robert Taylor, an associate to the U.K.-based Natural Resources Institute and a member of the Methyl Bromide Technical Options Committee (MBTOC), noted that the milling industry worldwide is concerned about lack of options approved for use in their home countries before the end of 2004.
"It is very much a wait and see situation here in the U.K. and elsewhere, especially for the older mills that continue to rely very much on methyl bromide for the disinfestation process," Taylor explained.
"Modern mills may be able to cope without methyl bromide, and in consequence it is not necessarily the whole of the flour milling industry that will look to critical use exemption to continue their operations," he said. "I think that because of the importance of the flour milling and other food processing industries — in the U.K. and elsewhere — millers and food processors are very hopeful that they will get critical use exemption in order to keep their industries operational and free of insects. The public would not be prepared to accept bread, flour or other confectionery products containing insect fragments, and the millers are only too aware of this and of the consequences if it were to happen."
If the critical use exemptions are passed, they will not take effect until 2005 and they would likely be time-limited. Decisions on these exemption applications are not expected until November or December this year, when Protocol members meet to vote. Applicants must prove that no comparable alternative exists and show that research is under way to develop alternatives. Most are now being reviewed by the international Methyl Bromide Technical Options Committee, and will also move on to other technical advisory committees.
The reality is that cost, or eventual lack of availability, will force companies to look at alternative fumigation options. Legitimately, there was really no option available to replace the inexpensive, fast-working and efficient methyl bromide when the phaseout agreement was signed in 1991. There are some effective options now, but the main constraint is that they are not all registered globally, particularly due to the long government registration protocols in each country.
In the milling industry where profit margins are slim, the low cost of methyl bromide was its key appeal, followed closely by the fact that it was a fast fumigation requiring the least amount of downtime. While there aren’t many options out there quite as cheap as methyl bromide, some solid alternatives are emerging for millers. And if you haven’t started looking yet, don’t wait till the next fumigation to start.
David Mueller of Insects Limited, Inc. is still doing methyl bromide fumigations for customers, but after each one he performs, he meets with the facility manager to try to explain alternatives for future fumigations — including costs, commitments and time involved.
If a facility is just beginning to plan for this, he suggests several things. First, if you are currently doing two methyl bromide fumigations per year, start with doing just one. If you are doing one per year, try not to schedule one, he encourages. Prime strategies for reducing fumigation needs are better sanitation and cleaning. Mueller emphasized better fumigation or pest control in raw ingredients, so that fewer insects are introduced into a clean plant.
Phosphine is still a very popular fumigant both for milling facilities and stored commodities. The corrosive effects of phosphine and the phenomenon of insects building resistance are the main concerns around this fumigant. Applied in its pure form, phosphine does not leave harmful residues in the environment.
Phosphine pellets used to be the most popular form of the fumigant, but that has changed since several countries have granted full food registration for cylinderized phosphine.
In the patented Eco2Fume process offered by Insects Limited, 2% phosphine is combined with 98% carbon dioxide in a cylinder. The reduced levels of phosphine increase safety and reduce corrosion risk. Often this method is combined with elevated temperatures (above 90 degrees) in a facility to increase efficacy.
Ready to use cylinders directly dispense the phosphine gas and carbon dioxide mixture into structures from the outside, preventing any worker contact with the gas. Operators can control concentration levels. This can be used in both facility structures and grain stores, usually in about 24 to 36 hours. About 70 fumigations have been completed to date. Eco2Fume is approved for use in France, the U.S., Australia, New Zealand, South Africa, Cyprus, Egypt, and is pending registration in other countries.
Fosfoquim, a Chile-based company, has created two new systems for phosphine structural or bin fumigations. Its Horn Diluphos System controls the dilution of phosphine into a sealed environment, so that phosphine stays below 1.8% of the air mixture, beyond which the mixture becomes self-inflammable.
The automated system takes cylinders of 100% phosphine and mixes it with air before dispersing it into a structure. The system requires an electrical supply, then an LCD display guides users through operation instructions. Gas concentration can be continually adjusted during the fumigation so that only the exact amount of gas needed is applied. Using 100% cylinderized phosphine is approved for use in Australia and Chile, and pending registrations in the U.S. and Europe.
Fosfoquim also offers a supplemental phosphine monitor that measures phosphine concentrations with infrared technology at one-minute intervals. Results are displayed real-time and data can also be downloaded into a computer.
ON THE HORIZON
Probably the most promising methyl bromide alternative applicable for a wide range of uses is Dow AgroSciences’ product, ProFume gas fumigant, which is currently close to receiving U.S. EPA approval. The active ingredient is sulfuryl fluoride, which has been used for more than 40 years in Dow’s registered fumigant for termites and wood-boring beetles, Vikane.
Jeffrey Welker, Dow’s global business leader, urban pest management, explained that the food industry prompted Dow to look into expanding the uses for sulfuryl fluoride. "The Dried Fruit Association of California came to us and said, ‘we’re losing methyl bromide, have you considered testing sulfuryl fluoride for the food commodity area?’"
Dow has since been working for eight years to gather appropriate research to expand the label for use on cereal grains, in storage or milling, as well as dried fruits and tree nuts.
To date, Dow has completed more than 30 trial fumigations in the U.S., Germany, Italy and the U.K. in empty food processing facilities. And according to Damon Shodrock, customer technologist for ProFume, the results have been extremely successful.
"People have said we’re getting equal or better control than methyl bromide, and to their surprise, it’s even killing rodents," Shodrock said. Many facility managers that have tried this product are anxiously awaiting registration. Approval is expected in the second quarter this year.
Currently, a registration has been submitted in Europe, with approval in U.K., Italy, France and Germany expected in 2004. Dow also plans to begin the registration process in Canada and Australia in 2003. With the many documents already assembled for the U.S., registration is expected to move more quickly in those countries.
According to MBTOC-member Robert Taylor, "In all countries, including the U.K., hope is very much placed by millers on sulfuryl fluoride as a replacement for use in those flour mills where other methods, such as integrated pest management, are not successfully applied."
Even with the critical use exemption filed, Taylor said reliance continues to be placed on the potential for using sulfuryl fluoride and many hope that it will be registered either before or soon after the phaseout date for methyl bromide.
Dow has been surprised by the amount of demand for ProFume. "Even the mill’s customers — bakeries and food processors — have contacted us about this product," said Jane MacMillan, marketing specialist for ProFume. "They want to support the methyl bromide phaseout by buying flour from mills that are using fumigation alternatives."
Long term, Welker said, Dow foresees a ProFume market in Asian countries for rice fumigation and also developing countries, as several are actively pursuing United Nations money set aside to help them investigate methyl bromide alternatives.
The company is also working to expand ProFume’s label to include food processing facilities. Approval is expected about a year after the okay for cereal grain usage, due to the quantity of residue tests required for the wide range of food processing commodities — from sugars and spices to pet food ingredients.
ProFume may also be an alternative for pre-shipment fumigations, and export food tolerances are under development. "Many countries honor U.S. tolerances, so as soon as we get U.S. federal tolerances, there are many countries that will accept those on exported commodities," Welker said. "We are also working with specific countries that will not accept U.S. levels to satisfy their regulatory requirements."
Like methyl bromide, ProFume can be used for short or long duration fumigations to meet specific time constraints. It penetrates porous materials, targets all insect life stages and rapidly aerates.
The fumigant will be made available only to licensed fumigators, said MacMillan. "Licensed fumigators agree to responsible care initiatives, training and to allow inspections to confirm a high level of stewardship."
There are several key advantages to ProFume as a methyl bromide alternative. First, it is non-corrosive, non-flammable and odorless. Also key, the cost and time involved is expected to be comparable to methyl bromide. But ProFume’s real edge lies in its precision fumigation capabilities. Dow developed a novel computer program specific to ProFume fumigations, aiming to "optimize fumigant use to maximize efficiency and minimize risk."
"We can prove that you have the concentrations in the mill for the time that’s needed to achieve control, using Dow’s Fumiguide calculator," Shodrock said. "It takes the guesswork out of fumigation, giving the fumigator a tool for precision fumigations."
The program requires a variety of input data, such as temperature, estimated half-loss time for the mill, size of structure, target pests, etc., and it specifies how much gas to use. It calculates actual half-life time by area, based on monitoring data input into the program. It gives customers clear-cut flexibility to decide the downtime of their facility for fumigation.
"The Fumiguide also provides fumigation reports for customer relations and your records, which benefits a facility’s fumigation management plan," said MacMillan.
Dow has worked since the mid-1990’s with researchers, food commodity groups, industry consultants and fumigators in Australia, Japan, the U.S. and Europe to build the technical foundation of target dosages and application recommendations.
There also are several natural options to control pests, including controlled atmospheres, intense pest management, insect growth regulators and cold.
Heat has been a valid alternative in some cases. Australia’s Stored Grain Research Laboratory is conducting further research into this approach, as "the use of chemicals to disinfest bulk food commodities, machinery and storage areas is becoming increasingly unacceptable to the Australian grain industry." SGRL said.
Kansas State University, Manhattan, Kanasas, U.S. has also been very active in trials for heat treatments of mills.