November
28,
1995
EPA­
SAB­
CASAC­
LTR­
96­
001
Honorable
Carol
M.
Browner
Administrator
U.
S.
Environmental
Protection
Agency
401
M
Street,
SW
Washington,
DC
20460
RE:
CASAC
Closure
on
the
Air
Quality
Criteria
for
Ozone
and
Related
Photochemical
Oxidants
Dear
Ms.
Browner:

A
Panel
of
the
Clean
Air
Scientific
Advisory
Committee
(
CASAC)
of
EPA's
Science
Advisory
Board
(
SAB)
met
on
July
20
and
21,
1994
and
March
21
and
22,
1995,
to
review
drafts
of
the
document
entitled
Air
Quality
Criteria
for
Ozone
and
Related
Photochemical
Oxidants.
At
these
meetings
and
in
subsequent
written
comments,
the
Committee
made
extensive
recommendations
for
strengthening
the
document.
In
August
1995,
revisions
to
the
Criteria
Document
were
mailed
to
the
CASAC
members
for
review.
On
September
19,
1995,
the
Panel
met
to
complete
this
review.
The
resulting
comments
by
the
Committee
members
note
with
satisfaction
the
improvements
made
in
the
scientific
quality
and
completeness
of
the
Criteria
Document.
The
changes
are
consistent
with
CASAC's
recommendations.

At
the
September
1995
meeting
the
Panel
came
to
closure
on
the
Criteria
Document.
It
was
the
consensus
of
the
Panel
members
that
the
Criteria
Document
provides
an
adequate
review
of
the
available
scientific
data
and
relevant
studies
of
ozone
and
related
photochemical
oxidants.
The
document
is
quite
comprehensive
and
will
provide
an
adequate
scientific
basis
for
regulatory
decisions
on
ozone
and
related
photochemical
oxidants
based
on
available
information.
At
the
meeting
and
subsequently
in
writing,
Panel
members
provided
the
Agency
with
additional
comments
for
consideration.
Most
of
these
comments
were
directed
at
Chapter
5,
the
ecological
effects
chapter.
Although
the
Panel
would
like
to
have
these
comments
considered
for
incorporation
in
the
Criteria
Document,
the
Panel
did
not
feel
that
it
was
necessary
to
review
another
revised
version.

On
behalf
of
the
Panel,
I
would
like
to
thank
EPA
staff
for
their
efforts
in
preparing
the
Criteria
Document
on
the
accelerated
schedule.
Our
comments
on
the
OAQPS
Staff
Paper
will
follow
shortly.

Sincerely,

Dr.
George
T.
Wolff,
Chair
Clean
Air
Scientific
Advisory
Committee
