Toxicity and human health assessment of an alcohol-to-jet (ATJ) synthetic kerosene developed under an international agreement with Sweden

ABSTRACT

Alcohol-to-jet (ATJ) Synthetic Kerosene with Aromatics (SKA) fuels are produced by dehydration and refining of alcohol feed stocks. ATJ SKA fuel known as SB-8 was developed by Swedish Biofuels as a cooperative agreement between Sweden and AFRL/RQTF. SB-8 including standard additives was tested in a 90-day toxicity study with male and female Fischer 344 rats exposed to 0, 200, 700, or 2000 mg/m³ fuel in an aerosol/vapor mixture for 6 hr/day, 5 days/week. Aerosols represented 0.04 and 0.84% average fuel concentration in 700 or 2000 mg/m³ exposure groups. Examination of vaginal cytology and sperm parameters found no marked changes in reproductive health. Neurobehavioral effects were increased rearing activity (motor activity) and significantly decreased grooming (functional observational battery) in 2000 mg/m³ female rats. Hematological changes were limited to elevated platelet counts in 2000 mg/m³ exposed males. Minimal focal alveolar epithelial hyperplasia with increased number of alveolar macrophages was noted in some 2000 mg/m³ males and one female rat. Additional rats tested for genotoxicity by micronucleus (MN) formation did not detect bone marrow cell toxicity or alterations in number of MN; SB-8 was not clastogenic. Inhalation results were similar to effects reported for JP-8. Both JP-8 and SB fuels were moderately irritating under occlusive wrapped conditions but slightly irritating under semi-occlusion. Exposure to SB-8, alone or as 50:50 blend with petroleum-derived JP-8, is not likely to enhance adverse human health risks in the military workplace.

KEYWORDS:

• Jet fuels
• alternative fuels
• synthetic kerosene with aromatics
• JP-8
• biobased/bio-based
• toxicity/toxicology
• alcohol-to-jet
• inhalation toxicity
• 90-day study

Acknowledgments

The views expressed in this article are those of the authors and do not necessarily reflect the official policy or position of the U.S. Air Force, the Department of the Navy, Department of Defense, nor the U.S. Government. This work was prepared as part of official duties by employees of the U.S. Government. Title 17, U.S.C. §105 provides that copyright protection under this title is not available for any work of the U.S. Government. Cleared for public release 18 Oct 2022, case number AFRL-2022-4730.

Disclosure statement

No potential conflict of interest was reported by the authors.

Data availability statement

When a citation includes an AFRL number and an ADA number, data are available in a published Air Force technical report that can be found in the Defense Technical Information Center (DTIC): https://discover.dtic.mil/.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/15287394.2023.2186295.

Additional information

Funding

These toxicity studies were funded by The Office of the Secretary of Defense (OSD), Coalition Warfare Program (CWP) as part of an international agreement with Sweden. The effort was also supported by the former Air Force Research Laboratory Aerospace Toxicology Program at WPAFB, OH.