UNITED
STATES
ENVIRONMENTAL
PROTECTION
AGENCY
WASHINGTON,
D.
C.
20460
OFFICE
OF
PREVENTION,
PESTICIDES
AND
TOXIC
SUBSTANCES
March
31,
2005
MEMORANDUM
SUBJECT:
Review
of
Sodium
Chlorate
and
Calcium
Chlorate
Incident
Reports
DP
Barcode
D310573,
Chemical
#
073301,
073302
FROM:
Jerome
Blondell,
Ph.
D.,
Health
Statistician
Chemistry
and
Exposure
Branch
Health
Effects
Division
(
7509C)

THRU:
David
P.
Miller,
Acting
Chief
Chemistry
and
Exposure
Branch
Health
Effects
Division
(
7509C)

TO:
Bonnie
Cropp­
Kohlligian,
Environmental
Scientist
Reregistration
Branch
4
Health
Effects
Division
(
7509C)

BACKGROUND
The
following
data
bases
have
been
consulted
for
the
poisoning
incident
data
on
the
active
ingredient
Sodium
Chlorate
(
PC
Code:
073301)
and
Calcium
Chlorate
(
PC
Code:
073302):

1)
OPP
Incident
Data
System
(
IDS)
­
reports
of
incidents
from
various
sources,
including
registrants,
other
federal
and
state
health
and
environmental
agencies
and
individual
consumers,
submitted
to
OPP
since
1992.
Reports
submitted
to
the
Incident
Data
System
represent
anecdotal
reports
or
allegations
only,
unless
otherwise
stated.
Typically
no
conclusions
can
be
drawn
implicating
the
pesticide
as
a
cause
of
any
of
the
reported
health
effects.
Nevertheless,
sometimes
with
enough
cases
and/
or
enough
documentation
risk
mitigation
measures
may
be
suggested.

2)
Poison
Control
Centers
­
as
the
result
of
a
data
purchase
by
EPA,
OPP
received
Poison
Control
Center
data
covering
the
years
1993
through
1998
for
all
pesticides.
Most
of
the
national
Poison
Control
Centers
(
PCCs)
participate
in
a
national
data
collection
system,
the
Toxic
Exposure
Surveillance
System
which
obtains
data
from
about
65­
70
centers
at
hospitals
and
universities.
PCCs
provide
telephone
consultation
for
individuals
and
health
care
providers
on
suspected
poisonings,
involving
drugs,
household
products,
pesticides,
etc.
2
3)
California
Department
of
Pesticide
Regulation
­
California
has
collected
uniform
data
on
suspected
pesticide
poisonings
since
1982.
Physicians
are
required,
by
statute,
to
report
to
their
local
health
officer
all
occurrences
of
illness
suspected
of
being
related
to
exposure
to
pesticides.
The
majority
of
the
incidents
involve
workers.
Information
on
exposure
(
worker
activity),
type
of
illness
(
systemic,
eye,
skin,
eye/
skin
and
respiratory),
likelihood
of
a
causal
relationship,
and
number
of
days
off
work
and
in
the
hospital
are
provided.

4)
National
Pesticide
Telecommunications
Network
(
NPTN)
­
NPTN
is
a
toll­
free
information
service
supported
by
OPP.
A
ranking
of
the
top
200
active
ingredients
for
which
telephone
calls
were
received
during
calendar
years
1984­
1991,
inclusive
has
been
prepared.
The
total
number
of
calls
was
tabulated
for
the
categories
human
incidents,
animal
incidents,
calls
for
information,
and
others.

5)
National
Institute
of
Occupational
Safety
and
Health's
Sentinel
Event
Notification
System
for
Occupational
Risks
(
NIOSH
SENSOR)
performs
standardized
surveillance
in
seven
states
from
1998
through
2002.
States
included
in
this
reporting
system
are
Arizona,
California,
Florida,
Louisiana,
Michigan,
New
York,
Oregon,
Texas,
and
Washington.
Reporting
is
very
uneven
from
state
to
state
because
of
the
varying
cooperation
from
different
sources
of
reporting
(
e.
g.,
workers
compensation,
Poison
Control
Centers,
emergency
departments
and
hospitals,
enforcement
investigations,
private
physicians,
etc.).
Therefore,
these
reports
should
not
be
characterized
as
estimating
the
total
magnitude
of
poisoning.
The
focus
is
on
occupationallyrelated
cases
not
residential
or
other
non­
occupational
exposures.
However,
the
information
collected
on
each
case
is
standardized
and
categorized
according
the
certainty
of
the
information
collected
and
the
severity
of
the
case.

Sodium
Chlorate
and
Calcium
Chlorate
REVIEW
No
data
were
found
in
any
of
the
available
data
bases
on
calcium
chlorate,
so
this
review
exclusively
addresses
sodium
chlorate.

I.
Incident
Data
System
No
reports
for
sodium
chlorate
were
found
in
the
Incident
Data
System
II.
Poison
Control
Center
Data
­
1993
through
2001
A
total
of
21
cases
were
located
in
Poison
Control
Center
records
from
1993
through
2001.
Seven
reported
minor
symptoms
and
two
reported
moderate
medical
outcome,
primarily
due
to
dermal
effects
such
as
swelling
and
rash.
It
is
difficult
to
draw
any
conclusions
on
such
a
small
number
of
cases.
III.
California
Data
­
1982
through
2002
3
Detailed
descriptions
of
36
cases
submitted
to
the
California
Pesticide
Illness
Surveillance
Program
(
1982­
2002)
were
reviewed.
However,
in
just
four
of
these
cases
was
sodium
chlorate
determined
to
be
the
primary
cause
of
illness
and
all
four
occurred
in
an
agricultural
setting
(
three
in
cotton
fields,
one
unknown).
Two
of
these
cases
were
classified
as
systemic
and
one
each
involved
skin
or
eye
effects.
The
two
systemic
cases
involved
applicators;
one
with
nausea
and
the
other
with
nausea,
headache,
and
itching
skin
after
spraying
for
one
week.
Both
of
cases
were
classified
as
possibly
due
to
sodium
chlorate.
The
skin
case
involved
a
worker
exposed
to
drift
from
an
adjacent
field
and
the
eye
case
occurred
when
a
worker
bumped
into
a
spray
nozzle
while
getting
off
the
tractor
and
was
splashed
in
the
face.
The
skin
case
was
classified
as
probably,
and
the
eye
case
as
definitely
due
to
sodium
chlorate.

IV.
National
Pesticide
Information
Center
On
the
list
of
the
top
200
chemicals
for
which
NPIC
received
calls
from
1984­
1991
inclusively,
sodium
chlorate
was
not
reported
to
be
involved
in
human
incidents.

V.
NIOSH
SENSOR
Out
of
4,221
reported
cases
from
1998­
2002,
none
involved
sodium
chlorate
other
than
the
case
already
reported
under
California
data.

VI.
Scientific
Literature
A
number
of
suicidal
ingestions
of
sodium
chlorate
have
been
reported
in
the
literature.
Many
of
these
have
led
to
death
and
were
summarized
by
Clarkson
(
2001).
The
following
is
taken
from
Clarkson's
review:

Accidental
and
Intentional
Poisoning
The
majority
of
deaths
caused
by
sodium
chlorate
have
been
the
result
of
suicide
(
Mengele
et
al.,
1969;
Motin
et
al.,
1970;
Oliver
et
al.,
1972;
Timperman
and
Maes,
1966).
The
chance
of
ingesting
a
fatal
dose
accidentally
is
small
unless
the
compound
is
mistaken
for
a
drug
and
taken
purposely,
as
occurred
when
the
potassium
salt
mistakenly
was
substituted
for
potassium
chloride
(
Cochrane
and
Smith,
1940).
However,
completely
typical,
near­
fatal
poisoning
occurred
when
a
13­
year­
old
boy
"
tasted"
crystals
of
this
weed
killer
which
he
found
in
his
father's
shed.
In
spite
of
intensive
treatment,
recovery
did
not
begin
until
about
the
15th
day
and
required
a
little
over
40
days
(
Starvou
et
al.,
1978).

Poisoning
is
characterized
by
gastritis
(
nausea,
vomiting,
and
pain),
anoxia
(
cyanosis,
collapse,
and
terminal
convulsions)
secondary
to
methemoglobinemia,
possible
liver
injury,
and
nephritis
(
lumbar
pain
and
oliguria).
Nephritis
presumably
is
the
direct
result
of
chlorate
ion
as
well
as
secondary
to
the
destruction
of
corpuscles.
The
blood
pressure
4
tends
to
fall
and
the
heartbeat
becomes
irregular.
The
liver
and
spleen
may
be
enlarged
and
tender.
The
urine,
if
any,
is
brown
or
black
in
color
and
contains
casts,
red
cells,
free
hemoglobin,
and
methemoglobin.
The
blood
is
brownish
in
color,
and
the
plasm
contains
free
hemoglobin
and
free
methomoglobin.
The
red
cell
count
is
very
low
and
the
white
cell
count
is
high
(
Knight
et
al.,
1967;
Sollmann,
1957).
.
.
.
Death
from
sodium
chlorate
poisoning
has
occurred
from
4
hr
to
34
days
after
ingestion
with
an
average
of
just
over
4
days
(
Knight
et
al.,
1967;
Mengele
et
al.,
1969;
Motin
et
al.,
1970).

An
entirely
different
kind
of
danger
also
arises
from
the
strong
oxidizing
action
of
sodium
chlorate.
Its
storage
constitutes
a
special
fire
hazard.

Sodium
chlorate
can
explode
if
subjected
to
intense
heat
with
or
without
sudden
pressure.
.
.
.

Use
Experience
When
used
as
a
pesticide,
sodium
chlorate
may
cause
irritation
of
the
skin,
eyes,
or
upper
respiratory
tract.

Dosage
Response
Dermal
absorption
associated
with
agricultural
use
of
sodium
chlorate
is
not
sufficient
to
cause
systemic
poisoning.
Even
by
mouth,
a
large
dose
is
required
to
produce
illness.
A
6.35%
solution
of
potassium
chlorate
was
long
used
as
a
gargle,
or
a
300­
mg
tablet
was
allowed
to
dissolve
slowly
in
the
mouth
to
treat
pharyngitis
before
modern
antibiotics
became
available.
The
toxicities
of
the
sodium
and
potassium
salts
are
similar.
It
was
considered
that
a
dose
of
10,000
mg
was
fatal
(
Cochrane
and
Smith,
1940);
Sollmann,
1957).
The
smallest
recorded
fatal
dose
was
7500
mg
(
Bernstein,
1930).
However,
vigorous
treatment
saved
one
person
who
had
ingested
about
40,000
mg
(
Knight
et
al.,
1967).

Reigart
and
Roberts
(
1999)
also
reviewed
the
poisoning
data
concerning
sodium
chlorate
and
came
to
similar
conclusions
as
Clarkson
(
2001).
"
Sodium
chlorate
is
irritating
to
skin,
eyes,
and
mucous
membranes
of
the
upper
respiratory
tract.
Dermal
absorption
is
slight.
Even
though
gastrointestinal
absorption
is
also
inefficient,
severe
(
sometimes
fatal)
poisoning
follows
ingestion
of
a
toxic
dose,
estimated
at
about
20
grams
in
the
adult
human.
.
.
.
The
principal
mechanism
of
toxicity
are
hemolysis,
methemoglobin
formation,
cardiac
arrhythmia
(
partly
secondary
to
hyperkalemia),
and
renal
tubular
injury."

De
Roos
et
al.
(
2003)
found
a
significant
association
between
sodium
chlorate
ever
used
and
non­
Hodgkin's
lymphoma
(
NHL).
However,
this
finding
was
still
elevated
and
nonsignificant
when
hierarchical
techniques
were
used
to
adjust
for
the
influence
of
multiple
exposures.
The
authors
acknowledge
that
such
a
finding
could
be
due
to
chance
and
that
further
study
will
be
needed
to
determine
whether
sodium
chlorate
has
any
influence
on
NHL
incidence.

VII.
Conclusion
5
Sodium
chlorate
has
been
documented
to
cause
irritation
to
skin,
eyes,
and
mucous
membranes
of
the
upper
respiratory
tract.
Death
can
occur
from
ingestion
of
substantial
quantities,
almost
always
due
to
suicide.
About
20
grams
is
the
estimated
fatal
oral
dose
in
humans.

VIII.
Recommendations
Usual
protection
for
skin
and
eyes
is
recommended
to
prevent
the
irritation
effects
that
can
occur
from
exposure
to
sodium
chlorate.
No
other
recommendations
are
made
based
on
the
very
limited
incident
data
available
for
this
pesticide.

References
Clarkson
TW.
2001.
Chapter
61:
Inorganic
and
organometallic
Pesticides.
In
Handbook
of
Pesticide
Toxicology
Second
Edition.
Edited
by
RI
Krieger.
Volume
2,
Agents
pages
1411­
1413.
Academic
Press,
San
Diego.

De
Roos
AJ,
Zahm
SH,
Cantor
KP,
Weisenburger
DD,
Holmes
FF,
Burmeister
LF,
Blair
A.
2003.
Integrative
assessment
of
multiple
pesticides
as
risk
factors
for
non­
Hodgkin's
lymphoma
among
men.
Occup
Environ
Med.
60(
9):
E11.

Reigart
JR
and
Roberts
JR.
1999.
Recognition
and
Management
of
Pesticide
Poisonings,
Fifth
Edition.
U.
S.
Environmental
Protection
Agency,
Washington,
DC
(
EPA
735­
R­
98­
003).

cc:
Sodium
Chlorate
file
(
073301)
Calcium
Chlorate
file
(
073302)
Matthew
Crowley
(
7509C)
Jacqueline
Guerry
(
7508C)
