[CPEO-MEF] JP-8 Assessment

[dickboyd@aol.com]

In a message dated 1/25/2003 3:52:23 AM Pacific Standard Time, 
cpeo-military@igc.topica.com writes:


> A prepublication version of the "Toxicologic Assessment of
> Jet-Propulsion Fuel 8," presented by the Subcommittee on Jet-Propulsion
> Fuel 8 of the Committee on Toxicology of the National Research Council,
> is now available for online viewing.
> 
> Below is an excerpt from the Summary section of the assessment.  The
> full text can be viewed at http://www.nap.edu/catalog/10578.html (take
> the link on the left side of the screen that says "Read it Online").

Thanks for the link. 

Some comments.

As pointed out in the report, fuels are a mixture. Aromatic (e.g., benzene 
ring molecules), aliphatic (fat or oil), alienee, olefin, alkyd are some of 
the descriptions of the individual molecules. Other than the vapor pressure 
requirement, there does not seem to be a requirement to exclude molecules 
that are carcinogen or are precursor carcinogens. Perhaps someone more 
familiar with fuels can enlighten us.

Perhaps the follow on report will examine individual molecules that are 
allowed (or prohibited) in aviation fuels. The follow on report might 
highlight things that are done to remove or reduce unwanted molecules.

JP-8 is blended to have a high flash point. This minimizes accidental fires. 
Commercial jet fuel, as pointed out, may be cut (diluted) with gasoline. The 
higher vapor pressure of commercial fuel leads to explosive mixtures in fuel 
tanks. There have been several 747 fuel tank fires and explosions. Possibly 
commercial aviation should review fuel specifications.

Use of JP-8 leads to more difficult starting. Possibly more raw fuel in 
aerosol form expelled by the engine during start. One implication is that 
runway design and downwind land use should be controlled in light of 
transient contaminants. The aerosol cloud of unburned fuel should disperse 
before reaching places where there are people. There would be no enclosed 
structures to concentrate the aerosols. Certain maintenance activities would 
be curtailed when the wind blows across inhabited areas. 

A threshold concentration of 350 mg per cubic meter may be misleading. There 
may be certain fractions that are the villains and the exposure should 
address each molecule, rather than some undefined mixture. Terrain and 
weather should be checked for inversions.

Since tetraethyl lead is still used for reciprocating aircraft engines, 
downwind land use is of importance in general aviation as well.

I believe most fuel storage areas have some type of ground water monitoring 
requirement. The fuel tank leaks in Fairfax County, Virginia may have set in 
motion some type of monitoring activity around fuel handling and storage 
areas. A few years ago, the federal gasoline tax had dedicated money to 
replace old style gasoline storage tanks to reduce fuel leaks. Does anyone 
know the status of the tank replacement program?

Additives to fuel prevent the growth of microorganisms. Not much was 
mentioned about the material used to inhibit organic growth in fuel. Is there 
a quality control screen to ensure dilution? Or to prevent concentration of 
the additives?

One remediation for spilled fuel is to introduce bacteria to digest it. Are 
the additives strong enough to preclude digestion of spilled fuel?

This might be somewhat off topic for base closure or Restoration Advisory 
Boards. Can anyone suggest a site where a discussion of fuel controls would b
e appropriate?

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