November 30, 2004

Margaret Sheppard

Environmental Protection Agency

1200 Pennsylvania Ave., NW (6205J)

Washington, DC 20460

Dear Ms. Sheppard,

	My company has developed a solvent-based drilling fluid using n-propyl
bromide (US patent # 6,326,338 B1). The fluid would be used in the
aerospace industry as an aid in drilling holes during final assembly of
commercial jets where it would function as a lubricant and provide
cooling to drills. The fluid, a blend of nPB and other solvents, would
be used in areas where the clean-up of water dilutable fluids is
prohibitively expensive and too time consuming. The inclusion of nPB as
a component is vital to the function of the fluid: its high
heat-of-vaporization is necessary to cool the metal being drilled at the
point of cut. The other crucial properties of the fluid consist of its
high vapor pressure, assuring complete and rapid evaporation, and
non-flammability. 

There is concern on the part of industry however that because nPB has
not been granted final SNAP approval, any product containing nPB could
be taken off the market in the unlikely event n-PB fails to be approved.
This concern has prevented products containing nPB from being
implemented within parts of the aerospace industry, including the
customer for whom we developed our drilling fluid.

Would you please explain, from the EPA’s perspective, whether the use
described for the Garrett drilling fluid falls within the use areas
defined under SNAP for n-propyl bromide? If the fluid was put into use,
would the failure of nPB to receive SNAP approval cause the Garrett
drilling fluid to be prohibited?

Very sincerely yours,

Andy Garrett

Garrett Services, Inc.

Garrett Services, Inc.

P.O. Box 2233    Gig Harbor, WA 98335

Phone: 253-858-4090    Fax: 253-858-4070

E-Mail: agarret@centurytel.net

