Document ID: EPA-HQ-OPPT-2004-0122-0100
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2008-02-04T05:00Z

Additional Responses to Environmental Defense Arguments

From May 22, 2006 Letter to Ann Klee

Environmental Defense Comment:

As noted in the Conference Report accompanying TSCA's enactment:

"[T]he most desirable time to determine the health and environmental
effects of a

substance, and to take action to protect against any potential adverse
effects, occurs before commercial production begins. Not only is human
and environmental harm avoided or alleviated, but the cost of any
regulatory action in terms of loss of jobs and capital investments is
minimized. For these reasons the conferees have given the Administrator
broad authority to act during the notification period."

It is inconceivable that Congress would have intended to accompany that
broad grant of

authority with a narrow interpretation of which chemicals qualify as
"new" under TSCA.

EPA Response:

The quoted legislative history identifies the benefits of new chemical
review.  However, Congress also contemplated that EPA could take action
after manufacture.  Significant new use rules under TSCA §5(a)(2) is
just one example of such authority.  At present, EPA has not concluded
that pre-manufacture review is necessary or appropriate for all
nanomaterials.  EPA hopes to use information it obtains from the NMSP
and other activities to help inform judgments regarding appropriate
regulatory approaches for nanomaterials.  Had Congress desired that EPA
have the kind of broad authority to characterize chemical substances as
now urged by ED, Congress could have enacted TSCA without a definition
of chemical substance, or with a more expansive definition.  That
Congress put in a definition that is tied to molecular identity
indicates that Congress intended to put some limits on what may be
reviewed as a new chemical, notwithstanding the benefits of
premanufacture review.  

EPA disagrees with the suggestion that the Agency’s approach to the
definition of “chemical substance” is narrow.  EPA considers
differences at the molecular level as giving rise to different chemical
substances.  However, EPA does not believe that substances with
molecules that are identical in every respect have different molecular
identities. 

Environmental Defense Comment:

Nothing in TSCA precludes the definition of “chemical substance”
from including physical and chemical properties....[T]he definition of a
chemical substance never mentions physical or chemical properties, which
is true. The...conclusion that the definition thus somehow excludes such
properties...is wholly unsupported. 

EPA Response:

TSCA §3(2)(A) defines a chemical substance as a substance of “a
particular molecular identity.”  EPA therefore considers a substance
that is identical at the molecular level to a substance on the TSCA
Inventory to be the same chemical substance, regardless of physical or
chemical properties.

Environmental Defense Comment:  

[TSCA] Section 26(c)(2)(A)’s definition of chemical identity...does
refer to physical and chemical (as well as biological) properties. By
noting that such properties can be similar, thereby supporting the
grouping of chemical substances into a category, Congress implicitly
recognizes the converse: that physical and chemical properties can also
be used to distinguish chemical substances. 

EPA Response:

Section 26(c)(1) provides in part, “Any action authorized or required
to be taken by the Administrator under any provision of this chapter
with respect to a chemical substance or mixture may be taken by the
Administrator in accordance with that provision with respect to a
category of chemical substances or mixtures.” Section 26(c)(2)(A)
provides that a category may be created to include, among other things,
chemical substances or mixtures that are “similar in molecular
structure, in physical, chemical, or biological properties.” In
EPA’s view, this does not imply that substances with different
properties but identical molecules should be considered to have
different molecular identities.

Environmental Defense Comment:  

In describing its “Inventory Review,” an explicit step in EPA’s
PMN review procedure, EPA makes clear [in Chemistry Assistance Manual
for Premanufacture Notification Submitters, EPA 744-R-97-003, March
1997, Chapter 1, p. 15, available online at
www.epa.gov/opptintr/newchems/pubs/chem-pmn/] that it considers factors
beyond chemical structure, including process-related factors, in
establishing a chemical substance’s name for purposes of listing it on
the Inventory: 

“The Inventory review is an extremely important component of the PMN
review process, from both legal and technical standpoints. The Inventory
review, performed by chemists within ICB [the Industrial Chemicals
Branch], has two major functions. The first is to establish a complete
and accurate chemical name for the new substance. The chemist compares
the chemical structure, molecular formula, the reactants, and the
reaction scheme for consistency with the CAS name submitted in the
PMN.” (emphases added [by ED]) 

Hence, factors such as the reaction process are considered by EPA in the
fundamental practice of naming a chemical substance for TSCA purposes. 

EPA Response

Factors such as reactants and reaction scheme are used with respect to
UVCB substances, to characterize the complex combination of species that
is a UVCB substance.  These attributes serve as a practical approach to
set the boundaries of a combination that contains many different
molecules (and which is often variable).  The Inventory guidance cited
by the submitter does not serve as precedent for using such factors to
divide a single molecular identity into several different chemical
substances.