Peer Review
Report is
now
Available
Final
Development
Support
Document is
now
Available
What: Letter
peer review
of the DSD
for
1,3-Butadiene
prepared by
TCEQ. Six
to eight
experts will
review the
document and
supporting
materials
and submit
written
comments
addressing
the charge
questions.
A follow up
conference
call will be
held
approximately
2 weeks
after
written
comments
have been
received.
When:
Review
package will
be
distributed
to the
experts and
posted on
this webpage
at the end
of August
2007.
Written
comments
will be due
in
September;
the follow
up
conference
call is
tentatively
scheduled
for early
October
2007.
Where: The
public is
invited to
listen to
the follow
up
conference
call.
Please check
this site
for call-in
information
which will
be provided
once it is
available.
TERA is
supporting
the Texas
Commission
on
Environmental
Quality (TCEQ)
in
conducting
an expert
external
peer review
of Development
Support
Document for
1,3-Butadiene,
Proposed August
2007,
being
scheduled
for
August-September
2007.
This peer
review is
being
conducted as
a letter
review with
a follow up
conference
call. The
Toxicology
Section (TS)
of the Chief
Engineer’s
Office has
prepared a
Development
Support
Document
that
outlines the
hazard
assessment
and
dose-response
processes
used to
derive
Effects
Screening
Levels (ESLs),
Reference
Values (ReV),
and Unit
Risk Factors
(URFs) for
1,3-Butadiene
(Cas. No.
106-99-0).
The toxicity
values were
developed
using RG-442 Guidelines
to Develop
Effects
Screening
Levels,
Reference
Values, and
Unit Risk
Factors (TCEQ 2006).
ESLs are
chemical-specific
air
concentrations
set to
protect
human health
and welfare.
Short-term
ESLs are
based on
data
concerning
acute health
effects,
odor
potential,
and
vegetative
effects,
while
long-term
ESLs are
generally
based on
data
concerning
chronic
noncarcinogenic
and/or
carcinogenic
health
effects.
ESLs are
used in the
evaluation
of air
permit
applications
as well as
proposed
rules and
regulation
(e.g.
Permits by
Rule). ReVs
and URFs,
used as the
basis of
ESLs, are
used in the
evaluation
of air
monitoring
data and in
the
development
of
Protective
Concentration
Levels for
remediation
sites.
The TCEQ
document
relies on
the US EPA Health
Assessment
of
1,3-Butadiene (EPA/600/P-98/001F),
released in
October
2002, to
provide
detailed
information
on the
following
topics for
1,3-butadiene:
overview of
exposure,
pharmacokinetics,
mutagenicity,
reproductive
and
developmental
effects,
toxicity in
animals,
epidemiologic
studies of
carcinogenicity,
hazard
characterization,
and
pharmacokinetic
modeling.
However,
TCEQ has
incorporated
new data and
statistical
analyses not
available to
US EPA in
2002, and
therefore,
has derived
new
dose-response
assessments
for
1,3-butadiene.
The
1,3-Butadiene
DSD, panel
biographical
sketches,
and review
materials
will be
posted when
they become
available.
Prior to the
follow-up
conference
call, the
experts’
comments
will also be
posted. A
meeting
report
summarizing
discussions
and
conclusions
will be
posted on
the website
following
the
meeting.
Meeting
Documentation
For
additional
information,
contact Dr. Michael Dourson |