Proposed Development
Support Documents (DSDs) Now Available!!
What is a Development Support Document?
A Development Support Document (DSD) summarizes how
chemical-specific toxicity values were derived based on
RG-442,
Guidelines to Develop Effects Screening Levels, Reference
Values, and Unit Risk Factors.
When are Proposed and Final DSDs Published?
A proposed DSD is published at the TCEQ web site for a 60-day
public review and comment period. After public comments are
received, the TS will address and resolve all relevant issues and
make scientifically defensible changes to the DSD and toxicity
values, if needed.
The final DSDs with a Response to Comments, if applicable, are
then published on the TCEQ website. Registrants on the Toxicology
Announcement List will be notified by e-mail when proposed or final
DSDs are posted.
The TS is accepting comments
on proposed DSDs for the following chemicals through January 5,
2009:
1,4-dichlorobenzene
silica all forms**
vinyl chloride
xylenes all isomers
**
Special consideration regarding silica:
Toxicology Excellence for Risk Assessment (TERA)
supported the Texas Commission on Environmental Quality (TCEQ) by
arranging a scientific technical evaluation of the April 2008
Proposed Silica Development Support Document (DSD) (TCEQ contract
582-7-80167-03). The objectives of a technical evaluation were to
provide the TCEQ with scientific comments on the document that
would be similar to an in-house, senior-level, quality assurance
review of the document. The April 2008 Proposed Silica DSD was not
posted for public comment on the TCEQ website but instead was
reviewed by Dr. Andy Maier of TERA and Dr. David F. Goldsmith of
The George Washington University.
The April 2008 Proposed Silica DSD was revised based on the
evaluators' comments and is now being posted for public comment as
the September 2008 Proposed Silica DSD. See the
Silica Response to Comments for more detailed information.
Public comments should address only the September 2008 Proposed
Silica DSD, not the evaluators' comments or the April 2008 Proposed
Silica DSD (Appendix B of the Silica Response to
Comments).
Procedure to Submit Comments
Submit comments by
e-mail to
tox@tceq.state.tx.us or by
mail (must be received at the TCEQ
no later than January 5,
2009) to:
Regular mail:
Toxicology Section, MC 168
Texas Commission on Environmental Quality
P.O. Box 13087
Austin, TX 78711-3087
Mail delivery services:
Toxicology Section, MC 168
Texas Commission on Environmental Quality
12100 Park 35 Circle, Bldg. F
Austin, TX 78753
Please register to join the
Toxicology Announcement
List, or stay tuned for more information.
Contact the TCEQ About DSDs and Fact Sheets
Call: 877-992-8370
(toll free) or 512-239-1795
E-mail: tox@tceq.state.tx.us
Write: Texas Commission on
Environmental Quality
Toxicology
Section, MC 168
P.O.
Box 13087
Austin,
TX 78711-3087
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