90-Day Inhalation Toxicity Study of Swedish Biofuel Alcohol-to-Jet (ATJ) Synthetic Kerosene with Aromatics (SPA) in Rats with Neurotoxicity Testing and Genotoxicity Assay

Abstract : Alcohol-to-Jet (ATJ) Synthetic Kerosene with Aromatics (SKA) fuels are produced by dehydrating and refining of alcohol feed stocks. An ATJ SKA fuel was developed by Swedish Biofuels AB. Through a cooperative agreement between Sweden and AFRL/RQTF, this ATJ SKA including standard Department of Defense jet fuel additives, in combination known as SB-8, was tested in a 90-day toxicity study with male and female Fischer 344 rats. Rats were exposed to 0, 200, 700, or 2000 mg/m3 fuel in an aerosol/vapor mixture for six hours per day, five days per week. Aerosols represented 0.04 and 0.84 percent of the total average jet fuel concentration in the 700 or 2000 mg/m3 exposure groups. No indications of changes in reproductive health were found when vaginal cytology and sperm parameters were examined. Neurobehavioral effects were limited to increased rearing activity in the 2000 mg/m3 females (motor activity assay) and significantly decreased grooming among rats of the same group (functional observational battery). Hematological changes (including clotting and clinical chemistry) were limited to increased platelet counts in the 2000 mg/m3 exposure group males. Minimal focal alveolar epithelial hyperplasia with increased alveolar macrophages was noted in some 2000 mg/m3 male rats and one 2000 mg/m3 female rat. Additional rats were included to test for genotoxicity by micronucleus formation. Neither bone marrow cell toxicity nor an increase in micronuclei was observed; SB-8 is not clastogenic. Inhalation of SB-8, alone or in a 50:50 blend with petroleum-derived JP-8, is unlikely to increase human health risks in the military workplace.