***HALOGENATED SOLVENTS INDUSTRY ALLIANCE, INC.***

***1300 Wilson Boulevard, Arlington, VA 22209***

***Phone: 703-741-5781, Fax: 703-741-6077***

***e-mail: pdugard@hsia.org***

March 5, 2004

Attention: EPA Docket ID No. ORD-2003-0014

Via [*ORDocket@epa.gov*](mailto:ORDdocket@epa.gov)

[Neurotoxicity of Tetrachloroethylene (Perchloroethylene) - Discussion
Paper]{.underline}

[(Dated October 2003 and Designated EPA/600/P-03/005A)]{.underline}

[Comments on Behalf of the Halogenated Solvents Industry Alliance,
Inc.]{.underline}

To Whom It May Concern:

The Halogenated Solvents Industry Alliance, Inc. (HSIA) represents the
interests of the producers and users of certain halogenated solvents
including tetrachloroethylene (PERC). We greatly appreciate the
opportunity to comment on the Discussion Paper and applaud EPA for
seeking input from experts in the highly specialized fields represented
in the studies covered by this document.

HSIA sought, and has found in the Intertox group, expertise in the
fields of neuropsychology, neurophysiology, and relevant statistics; we
urge EPA to take these well-found comments into account. Many of the
points made by Intertox relating to fundamentals of study design and
interpretations (adequate number of experimental subjects, control of
bias and confounders, appropriate statistical techniques and cautious
interpretation) match those made by the PERC neurotoxicity peer
consultation panel assembled by Versar on EPA\'s behalf.

HSIA has certain concerns regarding the peer consultation. We understand
the difficulty of identifying relevant experts in the highly specialized
disciplines addressed by the panel. Nevertheless, we do not consider
that an objective and dispassionate analysis could be relied upon with a
small panel that included authors of papers under review. Drs Gobba and
Echeverria have published papers specifically on PERC, and Dr Anger has
published a paper on trichloroethylene, a chemical structurally related
to PERC. Not only is it unlikely that authors will make comments
critical of their own studies, but other panel members are likely to be
inhibited when sitting beside the author of the study under review. HSIA
considers that this problem could have been avoided had the panel
selection been an open process, either by employing a public nomination
process or, at least, allowing public comment on the panel composition.
We recognize the difficulties of identifying experts in the appropriate
disciplines. However, in our own search, we were able to identify
experts who had not worked on PERC or closely related chemicals.

Our second area of concern arises out of proposals made during the peer
consultation regarding submission of unpublished material to EPA. Dr
Echeverria may have material of publishable quality, but, because of the
complex nature and care with which findings have to be analyzed, full
peer review is a necessity. Even more troubling is the offer from Dr
Schreiber to supply information, some of which she stated had not been
considered suitable for publication. Given the nature of concerns
regarding Dr Schreiber\'s existing publications, we urge EPA not to
place weight on unpublished material from this source.

In conclusion, please add this letter, and the accompanying analysis
prepared for HSIA by Intertox, to the docket identified above.

Yours sincerely,

*Paul H. Dugard*

Paul H. Dugard, PhD

Director of Scientific Studies