UNITED
STATES
ENVIRONMENTAL
PROTECTION
AGENCY
WASHINGTON,
D.
C.
20460
Office
of
Prevention,
Pesticides
and
Toxic
Substances
MEMORANDUM
May
27,
2004
TXR#:
0052572
SUBJECT:
2,4­
D
­
Phase
2
Toxicology
Chapter
Revision
TO:
Mark
Seaton
Reregistration
Branch,
SRRD
(
7508W)
and
William
Hazel
Reregistration
Branch
I,
HED
(
7509C)

FROM:
Linda
L.
Taylor,
Ph.
D.
Reregistration
Branch
I
Health
Effects
Division
(
7509C)

THRU:
Whang
Phang,
Ph.
D.
Branch
Senior
Scientist,
Reregistration
Branch
I
Health
Effects
Division
(
7509C)

Submitter:
Industry
Task
Force
II
on
2,4­
D
Research
Data
Chemical:
2,4­
Dichlorophenoxyacetic
acid
Synonym:
2,4­
D
Caswell
No.:
315
CAS
No.
94­
75­
1
PC
Code:
030001
DP
Barcode:
D302262
Registration:
RED­
0073­
19048
Action
Requested:
Revise
Toxicology
Chapter
as
needed.

INTRODUCTION:
Industry
Task
Force
II
on
2,4­
D
Research
Data
has
submitted
their
error
only
comments.
The
HED
Toxicology
Chapter
on
2,4­
D
[
TXR#:
0052068]
has
been
revised
to
incorporate
the
errors/
corrections
that
are
considered
appropriate.

It
is
to
be
noted
that
it
would
have
been
more
useful
had
the
error
correction
submission
from
the
Industry
2
Task
Force
II
on
2,4­
D
Research
Data
not
duplicate
a
whole
section
of
the
chapter
when
a
simple
statement
of
the
"
error"
would
have
sufficed.
For
example,
two
sentences
of
a
paragraph
were
highlighted
[
italicized]
to
indicate
what
the
chapter
said;
these
were
duplicated
un­
italicized
to
show
the
correction.
The
error
[
typo]
was
in
the
first
word
of
the
first
sentence
[
The
vs
there].
This
was
the
case
through
the
document;
whole
tables
being
reproduced
twice,
only
to
show
an
error
such
as
65­
8%
should
read
65.8%.
This
resulted
in
a
cumbersome
document,
which
appeared
to
contain
numerous
errors
when
in
fact
there
were
very
few.

Specific
revisions
to
the
Toxicology
Chapter
include:

(
1)
Under
HAZARD
CHARACTERIZATION,
page
4,
the
first
paragraph
has
been
revised
and
the
fourth
paragraph
on
inhalation
exposure
has
been
modified;
(
2)
Table
1
[
page
6],
a
notation
b
has
been
added
for
870.3465
stating
that
a
28­
day
inhalation
study
requirement
has
not
been
satisfied;
(
3)
Table
2a
[
page
8]
has
been
revised
to
include
corrected
MRIDs
for
DMA,
TIPA
and
EHE
,
change
in
eye
irritation
category
for
the
esters;
(
4)
beginning
on
page
11,
the
subchronic
oral
toxicity
studies
summary
table
has
been
revised
to
include
the
ai
or
ae
dose
levels
where
these
were
missing;
(
5)
page
41,
added
statement
referring
to
study,
which
is
referenced
in
Section
7.0,
which
showed
apparent
saturation
of
renal
clearance
in
the
rat
at
a
dose
level
of
50
mg/
kg/
day;
(
6)
under
Special/
Other
Studies
[
pages
42­
44],
table
revised
to
include
dose
levels
used
(
where
available);
(
7)
the
summary
paragraph
of
the
open
literature
studies
[
page
42]
was
revised
to
include
a
statement
that
the
effects
reported
in
the
open
literature
occur
at
dose
levels
above
the
threshold
of
saturation
of
renal
clearance;
(
8)
page
45,
revised
description
of
fetal
effects
[
skeletal
abnormalities]
due
to
the
fact
that
there
is
some
controversy
about
whether
the
findings
are
malformations.
However,
the
findings
are
considered
real/
adverse
and
remain
the
endpoints
used
in
the
risk
assessment;
(
9)
page
69,
9.2,
the
superscript
number
has
been
removed;
(
10)
page
69,
the
acute
RfDs
have
been
corrected
[
0.0025
should
read
0.025
and
0.0067
should
read
0.067
mg/
kg].
These
changes
were
previously
incorporated
into
the
HIARC
document
[
TXR#
0052303].

Discrepancies
in
the
Task
Force
error
report
include:

(
1)
on
page
58,
it
states
that
MRID
00101603
should
be
substituted
under
the
acute
oral
toxicity
for
DMA
in
the
table
and
test
material
is
said
to
be
a
manufacturing
use
product
(
soluble
liquid);
however,
the
reproduced
[
corrected]
table
showing
the
correction
lists
MRID
00157512
[
page
64]
and
LD50
of
949
mg/
kg.
The
LD50
in
00101603
is
listed
as
1090
mg/
kg
(
males)/
863
mg/
kg
(
females)
on
page
58.
NOTE:
In
the
Task
Force
response
to
EFFD,
it
indicates
that
the
test
material
used
in
MRID
00101603
was
a
technical
2,4­
D
DMA,
and
the
LD50
is
listed
as
863
mg
ai/
kg.
(
2)
on
page
58,
it
states
that
MRID
44725303
is
the
correct
study
for
technical
EHE
[
eye
irritation].
The
corrected
table
on
page
65
lists
MRID
41413504
for
EHE
[
see
(
3)
below].
(
3)
on
page
65,
the
corrected
table
with
primary
eye
irritation
lists
the
same
MRID
for
TIPA
salt
and
EHE
ester
[
MRID
41413504]
(
4)
on
page
79,
the
corrected
table
of
the
rabbit
developmental
studies
is
not
correct
as
to
the
species
tested
for
2,4­
D.
CD
®
Sprague­
Dawley
rats
should
have
been
changed
to
rabbits.
(
5)
on
pages
72
and
73,
the
acid
equivalent
doses
for
BEE
and
DEA
are
the
same
%
a.
e..
Is
this
accurate?
(
6)
on
page
77,
the
table
for
BEE
developmental
toxicity
study
in
rabbits
supposedly
what
was
in
HED
tox
chapter
[
italicized]
shows
the
data
for
the
rat
developmental
study.
The
Task
Force
corrected
table
on
page
3
79
shows
the
same
rat
data
with
the
acid
equivalent
%
incorrect
[
65­
8%].
I
believe
the
toxicology
chapter
correctly
listed
rabbits
and
the
rabbit
data
for
BEE.
The
error
in
the
tox
chapter
rabbit
developmental
toxicity
studies'
table
occurred
in
the
2,4­
D
box
where
rats
were
listed
as
the
test
species
[
see
(
4)
above].
