Telephone call with Dr. Shiela Harper, ATK

From:  Margaret Sheppard, EPA/SNAP program

To:  Dr. Shiela Harper, ATK

Date:  October 11, 2005

Tel. 435-863-2846

Re: Availability of other methyl chloroform substitutes for the Lake
City Army Ammunition Plant

	I called Dr. Harper to verify some information about the process used
to select nPB as a substitute for methyl chloroform in ammunition
coatings at the Lake City Army Ammunition Plant.  Dr. Harper worked on a
team for ATK Thiokol that did the basic research and development for the
Army in selecting an alternative to methyl chloroform for ammunition
coatings.  She gave a presentation at the annual solvent substitution
conference in Arizona in 2003.

	I asked if it was necessary that the alternative be non-flammable.  Dr.
Harper said that this was a useful feature, but not absolutely
necessary.  nPB and the methyl chloroform it replaces are in a mixture
with ethyl acetate, which is flammable.

	I recalled from Dr. Harper’s presentation that ATK had evaluated a
number of alternatives for methyl chloroform.  She confirmed this, and
said that they tested 29 different solvents in up to eight categories. 
Of the different alternative solvents, only nPB met the Army’s
performance criteria that allowed them to continue to use the same
process.  This was because of the unique combination of nPB’s solvency
and its high evaporation rate.

	Dr. Harper also mentioned some of the health and industrial hygiene
concerns that she and her team had concerning the use of nPB.  She
indicated that ATK does not use nPB for cleaning because of health
concerns.  She said she only felt comfortable with nPB in the ammunition
application at Lake City Army Ammunition Plant because of some
particular features of the process:

A small area [Note:  I wasn’t clear if it was a small area within the
plant, or the small surface area where the nPB was applied that she
referred to.]

The process is largely controlled remotely, with minimal staff exposure
to nPB.  Exposure only occurs when refilling the pot.

Proper ventilation installed at Lake City plant.

Dr. Harper said that the Army might investigate a complete revision to
the process for sealing ammunition that would eliminate the use of
solvent.  However, it was not yet clear that this would happen.

	I 

