A number of research studies on jet-fuel toxicology in the last two decades have produced valuable information for scientists and fuel developers alike. But that information is only as useful as it is accessible.
With a mission to share the wealth of existing information – and comprehensively pursue additional research – nearly 50 scientists, developers, consultants and others with vital interests in jet fuel gathered in Dayton, Ohio, Nov. 16 and 17, 2004 to address issues of fuel toxicity – and how to resolve them. The Jet Fuel Toxicology Workshop was sponsored by the von Ohain Fuels and Combustion Center at the University of Dayton and the Air Force Research Laboratory at Wright-Patterson Air Force Base. Participants represented government, industry and academia.
The workshop – a first of its kind, according to organizers – was keyed to a central theme: How toxic is jet fuel?
“Fuel technology is very pervasive, affecting a wide variety of jobs and people – from fuel developers to fuel handlers to people on the flight lines. There are a lot of people exposed to jet fuel out there,” said Bill Harrison, Senior Advisor, Clean Fuel Initiative of the Deputy Under Secretary of Defense for Advanced Systems and Concepts and former Chief of the Fuel Branch at WPAFB. “As a fuel developer, you have to ask ‘where do we bring in toxicology?’ And how do you compare new fuel technologies against baselines – what’s already been done?”
Harrison said a number of studies have been done in the last 20 years on effects of inhalation and dermal contact, toxicity levels and more. But there is as yet no method established to uniformly and regularly disseminate the information gleaned from those studies to all the people who could benefit from it. “Through this workshop, we’re bringing together people from academia, government and industry to share with one another not only what we already know, but also to capture and document where there are gaps in research and use them as a springboard to obtain funding for additional study.”
David Mattie, Senior Research Toxicologist at AFRL’s Human Effectiveness Directorate, said the toxicology workshop provided the first opportunity for such a diverse group of experts to come together to explore the issues of jet fuel toxicity. “We wanted to bring together people in the health fields, fuel development, chemistry, industry and logistics, and identify where to go from here. This is the first time we brought this group of people together, and the first time we really sat down to talk about what is the way to move forward – how we find funding, how we can expand the excellent collaborations we already have in place, and how we can bring together all the different components of information and use them to our advantage.”
“We’re also trying to formalize a process to conduct health-effects studies in conjunction with fuel development,” Mattie added.
Melanie Thom, President of Baere Aerospace Consulting in West Lafayette, Ind., was one of several consultants to attend the workshop. As a chemist with limited background in toxicology, Thom said the information presented at the workshop would help her better serve her clients – as well as herself. “My role is as a gateway between the science community and end users (component manufacturers, crew chiefs, pilots, fixed-base operators and others),” she said. “And because my end users are not chemists, they depend on me to educate and protect them.”
“As a chemist, I’ve always felt I’ve taken on a certain level of exposure risk,” Thom added. “This workshop is a forum useful to me because, as an educated chemist – but not in toxicology – the information I take away from here will allow me to take better-educated risks on the job.”
Dilip Ballal, Director of the von Ohain Fuels and Combustion Center, said one of the main goals of the workshop was to come up with recommendations for future study areas and for ways to store and share research.
“We were able to pinpoint several areas where more research is required,” Ballal said. “One of those areas is to relate animal toxicology studies to human studies. We need to carefully look at examples from other chemical industries, and study the existing databases of information. For instance, perhaps there is a database already housed at the Environmental Protection Agency.”
Another recommendation was to build a database at AFRL, Ballal added.
As for the overarching question, how toxic is jet fuel? “The workshop participants felt that if at all there is a hazard posed by jet fuel, its effects are more likely short-term than long-term,” Ballal said. “And only when there is severe exposure – if someone is completely doused or immersed in fuel – is there a concern for toxic effects. Even then, there is no demonstrated evidence that such exposure will have long-term effects.”
Ballal said commercial and military aircraft fueling practices was also discussed at the workshop, adding that, on a related note, the von Ohain Fuels and Combustion Center has announced it will hire a senior level microbiologist to investigate the toxicity of biologically contaminated fuel.
“When a commercial aircraft flies in from overseas, any remaining fuel in its tanks is disposed of before maintenance is done on the plane,” Ballal said. “But when a military plane flies in from abroad, the fuel is drained and stored in a tank before maintenance. That fuel is often mixed with virgin fuel, so whatever may have contaminated the fuel in the plane will contaminate the virgin fuel also. Even small amounts of water in fuel provides a great environment for the growth of certain bacteria and fungi. Left unchecked, this can cause problems in a fuel system and possibly lead to jet engine failure.”
The study will be part of a five-year Air Force contract awarded to the von Ohain Fuels and Combustion Center in 2003 for research and development of versatile affordable advanced fuels and combustion technologies.
February 21, 2005