Sulfuryl Fluoride (Vikane®) Risk Characterization Document Volume II Exposure Assessment
Abstract
Sulfuryl fluoride has been used as a structural fumigant to control wood-destroying pests since 1957. In 2002, reported use of sulfuryl fluoride in California was 3,045,084 pounds. With the phase-out of methyl bromide use, sulfuryl fluoride is actively being developed as an alternative, which will likely increase its use in the future. This exposure assessment was prepared as part of the Department of Pesticide Regulation’s risk assessment process mandated by California law. Due to its high vapor pressure, the expected primary route of sulfuryl fluoride exposure is through inhalation. Worker and non-worker short-term, intermediate and long-term sulfuryl fluoride exposures were estimated using sulfuryl fluoride air concentrations detected in chemical-specific studies performed at submaximal applications rates (11-16 oz/1,000 ft3 or 11-16 g/m3). Worker and bystander exposures resulting from applications performed at the maximal application rate may be 10-15 times greater than that listed below.
Short-term exposure from tasks performed by fumigation workers, expressed as absorbed daily dosage (mg/kg/day; 18% inhalation absorption), were estimated as follows:
• fumigant introduction, 0.029
• initial ventilation (fan placement, structure opening), 0.0001
• structure closing following first hour of aeration, 0.000006
• clearance certification, 0.009
• ground snake removal, 0.04
• ground seam opening, 0.30
• roof seam opening, 0.31
• tarpaulin folding, 0.06
• all fumigator only tasks, 0.04
• all tent crew only tasks (general detarping), 1.13
• commodity handler, 0.43
Short-term exposure of male or female residents or other individuals during the first day of reentry into cleared structures, expressed as absorbed daily dosage (mg/kg/day; 18% inhalation absorption), were estimated as follows:
• <1 year, 0.57
• 6-8 years, 0.32
• 12-14 years, 0.23
• adults, 0.24
Short-term exposure of male or female bystanders to structural (s) or nonfood commodity (c) fumigation sites, expressed as absorbed daily dosage (mg/kg/day; 18% inhalation absorption), were estimated as follows:
• <1 year, 0.90 (s); 2.3 (c)
• 6-8 years, 0.58 (s); 1.5 (c)
• 12-14 years, 0.41 (s); 1.0 (c)
• adults, 0.43 (s); 1.1 (c)