UNITED
STATES
ENVIRONMENTAL
PROTECTION
AGENCY
WASHINGTON,
D.
C.
20460
Office
of
Prevention,
Pesticides
and
Toxic
Substances
December
20,
2005
MEMORANDUM
SUBJECT:
Inorganic
Chlorates:
Response
to
Registrant
Phase
1
Comments
on
the
HED
Chapter
of
the
Reregistration
Eligibility
Decision
(
RED)
Document.
Case#:
4049
DP
Barcode:
D324278
PC
Codes:
Sodium
chlorate:
073301
(
active)
and
873301
(
inert)
Calcium
chlorate:
073302
(
active)
and
875606
(
inert)
Potassium
chlorate:
073303
(
active)
and
900583
(
inert)
Magnesium
chlorate:
530200
(
active)

FROM:
Susan
V.
Hummel,
Branch
Senior
Scientist
Reregistration
Branch
4
Health
Effects
Division
(
7509C)

THROUGH:
Raymond
Kent,
Branch
Chief
Reregistration
Branch
4
Health
Effects
Division
(
7509C)

TO:
Felicia
Fort,
Chemical
Review
Manager
Reregistration
Branch
3
Special
Review
and
Reregistration
Division
(
7508C)

Attached
is
the
Agency's
response
to
the
Phase
1
comments
submitted
by
Lewis
&
Harrison
(
letter
dated
12/
05/
2005)
on
behalf
of
the
Sodium
Chlorate
Reregistration
Task
Force
to
the
EPA
preliminary
human
health
risk
assessment
for
inorganic
chlorates.
The
intent
of
this
document
is
to
illustrate
how
the
registrants
error
correction
comments
were
considered
in
the
revisions
to
the
risk
assessment.
The
Task
Force
comments
followed
by
the
Agency's
responses
are
present
below.
Page
2
of
4
Sodium
Chlorate
Reregistration
Task
Force
Comment
1:
In
the
"
Executive
Summary"
section
(
page
1
of
141,
2nd
paragraph),
the
document
states
"
As
an
active
ingredient,
sodium
chlorate
(
073301)
is
used
primarily
as
a
precursor
in
chlorine
dioxide
generation
through
a
closed
system
to
bleach
wood
pulp/
paper".
This
statement
implies
that
the
bleaching
of
wood
pulp/
paper
is
a
pesticidal
use.
The
bleaching
of
wood
pulp/
paper
does
not
involve
any
biocidal
or
pesticidal
claims
and,
therefore,
is
not
a
pesticidal
use.
The
Task
Force
suggests
the
following
revision:
"
The
primary
use
for
sodium
chlorate
is
as
a
precursor
for
chlorine
dioxide
generation,
through
a
closed
system,
to
bleach
wood
pulp/
paper".

Agency
Response:
In
agreement
with
Task
Force
Comment
1,
the
2nd
paragraph
of
the
Executive
Summary
(
Section
1.0)
of
the
HED
Chapter
of
the
Inorganic
Chlorates
RED
document
will
be
amended
to
the
following:

"
Chlorates
are
strong
oxidizers
used
in
the
manufacture
of
dyes,
explosives,
matches,
printing
fabric,
paper
pulp
processing,
weed
killers,
and
as
a
weak
antiseptic,
2­
3%
solutions
have
been
used
in
mouth
washes
(
OEHHA,
2002).
The
primary
use
for
sodium
chlorate
is
as
a
precursor
in
chlorine
dioxide
generation,
through
a
closed
system,
to
bleach
wood
pulp/
paper.
Only
a
small
percentage
(
less
than
2
percent)
is
used
in
water
systems
as
a
precursor
to
chlorine
dioxide
generation
or
as
a
defoliant/
desiccant
on
a
number
of
crops
to
aid
harvest.
As
inert
ingredients,
sodium
chlorate
(
873301)
and
potassium
chlorate
(
900583)
are
present
in
conventional
(
agricultural)
pesticides
used
on
food
crops
or
in
poultry
premises.
Also,
as
inert
ingredients,
sodium
chlorate
(
873301)
and
calcium
chlorate
(
875606)
are
present
in
antimicrobial
agents
used:
(
1)
as
fruit,
vegetable,
and
egg
sanitizing
washes;
(
2)
to
control
bacterial
blotch
on
mushrooms;
(
3)
as
treatment
to
seed
used
for
sprouting;
(
4)
for
conditioning
live
oysters;
(
5)
in
poultry
drinking
water;
(
6)
in
fish
filleting;
(
7)
pecan
cracking/
dyeing."

Sodium
Chlorate
Reregistration
Task
Force
Comment
2:
In
the
["
Executive
Summary"
section]
(
page
1
of
141,
2nd
paragraph),
there
are
a
number
of
uses
noted
for
sodium
chlorate
and
calcium
chlorate
when
they
are
used
as
inert
ingredients
in
antimicrobial
agents.
The
Task
Force
was
not
aware
of
most
of
these
uses.
Therefore,
a
reference
(
e.
g.
Agency
records,
public
literature,
etc.)
should
be
provided
for
these
uses.

Agency
Response:
No
changes
to
the
HED
Chapter
of
the
Inorganic
Chlorates
RED
document
will
be
made
in
response
to
Task
Force
Comment
2.
Additional
information
concerning
sodium
chlorate
and
calcium
chlorate
as
inert
ingredients
in
antimicrobial
agents
in
this
public
document
may
infringe
on
the
Confidential
Business
Information
protection
of
the
active
ingredient(
s)
registration(
s).
Page
3
of
4
Sodium
Chlorate
Reregistration
Task
Force
Comment
3:
On
page
8
of
141,
under
the
heading
"
Dietary­
Drinking
Water
Only",
2nd
paragraph,
the
document
states,
"
No
data
are
available
concerning
the
levels
of
chlorate
ion
(
ClO
3
b
)
in
finished
drinking
water
collected
from
water
treatment
facilities
which
use
sodium
chlorate
to
treat
drinking
water".
This
statement
implies
that
sodium
chlorate
is
used
to
directly
treat
drinking
water,
which
is
incorrect.
We
assume
that
the
intent
of
the
statement
was
to
indicate
that
data
is
only
available
from
facilities
that
use
sodium
chlorite
to
generate
chlorine
dioxide
for
the
treatment
of
drinking
water.

Agency
Response:
In
agreement
with
Task
Force
Comment
3,
the
2nd
paragraph
of
the
Dietary
­
Drinking
Water
Only
subsection
of
the
Executive
Summary
(
Section
1.0)
of
the
HED
Chapter
of
the
Inorganic
Chlorates
RED
document
will
be
amended
to
the
following:

"
Data
are
available
concerning
the
levels
of
chlorate
ion
(
ClO
3
b
)
found
in
finished
drinking
water
collected
from
water
treatment
facilities
which
use
chlorine
dioxide
or
hypochlorite
to
treat
drinking
water.
No
data
are
available
concerning
the
levels
of
chlorate
ion
(
ClO
3
b
)
in
finished
drinking
water
collected
from
water
treatment
facilities
which
use
sodium
chlorate
as
a
precursor
for
chlorine
dioxide
generation,
through
a
closed
system,
to
treat
drinking
water."

Sodium
Chlorate
Reregistration
Task
Force
Comment
4:
In
the
"
Ingredient
Profile"
section
on
page
14
of
141,
Table
2.1.3,
the
"
application
rates"
should
be
modified
since
sodium
chlorate
product
labels
have
been
revised
to
restrict
the
amount
of
non­
crop
area
that
can
be
treated.
In
addition,
the
occupational
handler
risks
that
are
discussed
on
the
bottom
of
page
66
of
141
are
based
on
application
rates
of
1032
and
532
lbs
ai/
A,
which
are
no
longer
valid.

Agency
Response:
No
changes
to
the
HED
Chapter
of
the
Inorganic
Chlorates
RED
document
are
warranted
at
this
time
in
response
to
Task
Force
Comment
4.
Amendments
to
product
labels
and
use
rates
are
considered
substantive
and
will
require
verification
before
there
can
be
any
revisions,
if
necessary,
to
the
ORE
assessment.

Sodium
Chlorate
Reregistration
Task
Force
Comment
5:
On
page
15
of
41,
Section
2.3,
what
is
the
source
for
the
500
ppm
maximum
use
rate
for
total
available
chlorine
in
sanitizing
wash
water.
The
regulations
under
40
CFR
§
180.940
restrict
total
available
halogen
to
200
ppm.

Agency
Response:
No
changes
to
the
HED
Chapter
of
the
Inorganic
Chlorates
RED
document
will
be
made
in
response
to
Task
Force
Comment
5.
Additional
information
concerning
sodium
chlorate
and
calcium
chlorate
as
inert
ingredients
in
antimicrobial
agents
in
this
public
document
may
infringe
on
the
Confidential
Business
Information
protection
of
the
active
ingredient(
s)
registration(
s).
As
suggested
in
Section
2.3,
the
500
ppm
maximum
use
rate
is
based
on
the
active
ingredient(
s)
product
label(
s).
Page
4
of
4
Sodium
Chlorate
Reregistration
Task
Force
Comment
6:
On
page
23
of
141,
the
date
for
the
"
90­
day
oral
toxicity
study
in
rats"
should
be
"
1987",
not
"
1997".

Agency
Response:
In
agreement
with
Task
Force
Comment
6,
all
references
to
the
90­
day
oral
toxicity
study
in
rats
(
MRID
40444801)
in
the
HED
Chapter
of
the
Inorganic
Chlorates
RED
document
will
be
amended,
as
necessary,
to
specify
the
correct
study
date
(
i.
e.,
1987).

Sodium
Chlorate
Reregistration
Task
Force
Comment
7:
On
page
138
of
141,
"
cover"
should
be
changed
to
"
covered"
in
the
sentence
"
These
dietary
exposure
concerns
are...".
In
addition,
why
is
the
reference
to
chlorine
gas
("
Under
40
CFR
180.1095,
chlorine
gas
is
exempted
from
the
requirement
of
a
tolerance
when
used
preharvest
or
postharvest
in
solution
on
all
raw
agricultural
commodities")
included
in
this
part.

Agency
Response:
In
agreement
with
Task
Force
Comment
7,
all
instances
in
Appendix
E
of
the
HED
Chapter
of
the
Inorganic
Chlorates
RED
document
which
should
state
"
covered",
and
not
"
cover",
will
be
corrected.
Also
the
reference
to
40
CFR
§
180.1095
under
the
section
of
Appendix
E
entitled,
"
Dietary
Exposure
Route
5.
Chlorate
(
ClO
3
b
)
dietary
exposure
estimates
from
potential
redox
of
chlorine
dioxide
as
the
antimicrobial
agent
in
fruit
and
vegetable
washes
and
water
used
in
poultry
processing"
will
be
deleted.
