October
7,
2002
Donald
R.
Lynam
Vice
President,
Air
Conservation
Ethyl
Corporation
330
South
Fourth
Street
Richmond,
VA
23219­
4304
Dear
Dr.
Lynam,

On
July
30,
2002,
the
Ethyl
Corporation
(
Ethyl)
submitted
to
the
Environmental
Protection
Agency
(
EPA)
a
health
study
protocol
for
MMT
as
required
under
the
Alternative
Tier
2
Health
Effects
Testing
Requirements.
The
protocol
submission
deals
with
revised
protocols
associated
with
the
90­
day
primate
pharmacokinetic
(
PK)
health
study.
These
requirements
were
finalized
in
the
notification
received
by
Ethyl
on
May
25,
2000.
As
you
know,
the
notification
requires
EPA
review
and
approval
of
these
protocols.

The
revised
protocol
had
two
main
changes
involving
the
addition
of
two
animals
to
the
control
and
low­
dose
exposure
groups,
and
the
addition
of
two
animals
to
serve
as
replacements,
if
needed.
We
believe
that
both
of
these
changes
will
strengthen
the
study
design.
Also,
the
Chemical
Industry
Institute
of
Toxicology
(
CIIT)
indicates
that,
depending
on
the
laboratory
used,
clinical
chemistry
and
hematology
assessments
may
not
be
performed
under
the
U.
S.
EPA's
Good
Laboratory
Practices
regulations.
In
this
particular
case,
we
believe
this
is
acceptable
as
long
as
the
laboratories
maintain
records
clearly
indicating
how
samples
were
tracked
and
managed.
This
letter
conveys
the
Agency's
approval
of
the
July
30,
2002,
revised
protocol.

If
you
have
any
questions
concerning
our
review,
please
contact
Joe
Sopata
of
my
staff
at
(
202)
564­
9034.

Sincerely,

/
s/

Suzanne
Rudzinski
Director
Transportation
and
Regional
Programs
Division
cc:
Tim
Backstrom,
OGC
Kevin
Fast,
Hunton
&
Williams
