ProFumeŽ gas fumigant (sulfuryl fluoride) has recently been registered for stored bulk grains. Recent lab and field studies on introduction methods, recirculation, and sorption are summarized. Due to low sorption rates in cereal grains compared to other fumigants the displacement of the commodity must be factored in to accurately calculate targeted concentrations. Adjustment for displacement has the effect of reducing the amounts of fumigant required to achieve a desired CT product. Desorption is very rapid allowing relatively quick aeration periods after fumigation. While ProFume gas fumigant penetrates substrates very rapidly, passive distribution inside a storage structure is generally too slow for practical application, as is generally the case with fumigant gases. A closed recirculation system during fumigant introduction is required for even distribution of the fumigant within the grain mass.