Sorption of sulfuryl fluoride by food commodities

BACKGROUND: The use of sulfuryl fluoride, a structural fumigant for termite and woodborer control, has recently been expanded to treating stored food commodities and food facilities. There is, however, a lack of data on the sorption of sulfuryl fluoride by food commodities. Knowledge about sorption is important in the context of effective treatment and residues. RESULTS: When sulfuryl fluoride was applied at a dose of 50 g m−3 to various food commodities (total 68) with 300 g per replicate in 0.75 L gas wash bottles (fumigation chambers) at 25 ± 1 °C, in most cases (81%) the gas concentrations in the free space of the commodities exceeded 50 g m−3 (range 51–80 g m−3) at the end of 24 h exposure. In chambers without the substrate, an average concentration of 49.7 g m−3 was recorded. About 54% of the commodities showed low‐level ( ≤ 25%) sorption of sulfuryl fluoride, 34% showed medium‐level (26–50%) sorption and only 12% were highly sorptive (>50%). The latter include white oats (terminal gas concentration 17.8 g m−3), some of the decorticated split pulses (24.0–29.3 g m−3), chickpea flour (26.3 g m−3), dried ginger (29.0 g m−3), refined wheat flour (30.3 g m−3) and coriander powder (40.5 g m−3). In unfumigated control commodities, owing to interfering volatiles, Fumiscope® readings in the range 0–13 were noted. CONCLUSION: Sulfuryl fluoride has the advantage of a low or moderate level of sorption with the majority of the food commodities. Copyright © 2008 Society of Chemical Industry