ProFume Gas Fumigant—An Overview

Christopher Voglewede
Technology Transfer Leader
Brian Schneider
Biology Research and Development
Dow AgroSciences
9330 Zionsville Road
Indianapolis, IN 46033

Dow AgroSciences has been developing ProFume* gas fumigant (99.8% sulfuryl fluoride) for over 7 years to control stored- product pests in milling, food processing, and food storage facilities. The large research and development program has been undertaken in cooperation with academic, industry, and government researchers, as well as with fumigators and millers.

Sulfuryl fluoride (SF) possesses many positive fumigant qualities, including efficacy in controlling a broad spectrum of insect pests, a low boiling point, excellent penetration qualities, low reactivity potential, limited sorption, and rapid aeration. SF is inorganic, not combustible, has no flash point, and is very stable under most fumigation environments. Over 30 wheat flour, rice mill, pet food processing, and dried fruit and tree nut chamber fumigations have been conducted with no effects on computer, electrical, or mechanical systems. Also, Vikane* gas fumigant (sulfuryl fluoride), another formulation of sulfuryl fluoride, has been successfully used for over 40 years in structures containing sensitive electronic equipment and a wide variety of materials and contents.

Research in both the laboratory and field confirms that SF is effective on all life stages of postharvest insect pests. Tested species include Indian meal moth, red and confused flour beetles, warehouse beetle, Mediterranean flour moth, sawtoothed grain beetle, codling moth, navel orangeworm, Turkish grain beetle, yellow mealworm, lesser grain borer, granary weevil, and rice weevil. Larvae, pupae, and adult insects are highly susceptible to SF while eggs are more tolerant. However, effective dosages for all life stages can be obtained by varying concentration and exposure time. Lower dosages can be used at higher temperatures because of increased insect metabolism.

Results from over 30 research fumigations in actual mills have been conducted in the United States, Germany, Italy, France, Switzerland, and the United Kingdom. These ProFume fumigations have provided insect control that is equivalent to or better than current methyl bromide programs. These trials have also indicated no damage to sensitive equipment or electronic controls and no increase in total fumigation time or mill down time when compared with present methyl bromide fumigations.

The mode of action of SF is disruption of the glycolysis and fatty acid cycles, thus preventing insects from metabolizing the stored fats they need to maintain a sufficient source of energy for survival. Modeling studies conducted on Indian meal moth and red flour beetle indicated that there is a very low probability for resistance development. Preliminary results testing SF on a strain of phosphine-resistant red flour beetle indicated no cross-resistance. ProFume can also be used as part of an active, planned management program as a rotational treatment to prevent or delay development of insecticide resistance or as a tool to control phosphine-resistant insect populations.

Food residue studies have been conducted on a variety of commodities. With some limitations, tolerances and maximum residue limits for both SF and fluoride (the two terminal food residues of interest) will be established to support the fumigation of a wide variety of grains, dried fruits, tree nuts, and processed foods. Country approval in Switzerland has already occurred for empty mills. Registrations are anticipated in the United States in 2003 and in the European Union in 2004.

Extensive taste and quality trial results indicate that dried fruit and tree nuts are not negatively affected by ProFume. Wheat kernel quality trials showed that ProFume exposure did not affect the nutritional characteristics or the rheological properties of the milled fractions of hard red winter, soft red winter, and durum wheat kernels.

Fumigation with ProFume will require the use of the Fumiguide* Program for ProFume gas fumigant (ProFume Fumiguide). The ProFume Fumiguide, a PC-based software program, will be an excellent educational and operational tool, allowing the fumigator to consider multiple fumigation scenarios prior to deciding on the optimal fumigation plan. Also, by helping the fumigator apply only the fumigant necessary to control the target pests, use of the ProFume Fumiguide will refine precision fumigation techniques, increase the use of precision fumigation practices, and help achieve a very high stewardship standard. Precision fumigation is defined as optimizing fumigant use to maximize efficiency and minimize risk.

Dow AgroSciences has a long history of responsible stewardship with gas fumigants, particularly with SF for the structural fumigation market. As with Vikane, Dow AgroSciences will deliver comprehensive ProFume training and implement a stewardship program emphasizing worker, bystander, and environmental safety. The stewardship program will consist of classroom training, an examination to demonstrate competency in key areas of label and precision fumigation practices, simulated on-the-job critical fumigation scenarios, and Dow AgroSciences—assisted fumigations. Additionally, an annual training update, label review, and quality assurance review will be conducted. Only licensed fumigators who have completed this training will be allowed to purchase and use ProFume.

*Trademark of Dow AgroSciences LLC. ProFume is not yet registered and is not for sale in the United States.

Last Updated: April 9, 2004