UNITED
STATES
ENVIRONMENTAL
PROTECTION
AGENCY
WASHINGTON,
D.
C.
20460
OFFICE
OF
PREVENTION,
PESTICIDES
AND
TOXIC
SUBSTANCES
June
29,
2006
MEMORANDUM
SUBJECT:
Sodium
Cyanide
(
Chemical
No.
074002).
Magnitude
of
the
Residue
in
Fumigated
Citrus
Peel
and
Edible
Pulp
(
GLN
860.1500).
DP
Barcode
D330409.
Reregistration
Case
No.
3086.
MRID
No.
46868001.

FROM:
Thurston
G.
Morton,
Chemist
Reregistration
Branch
4
Health
Effects
Division
(
7509P)

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

TO:
Wilhelmena
Livingston
Special
Review
Branch
Special
Review
&
Reregistration
Division
(
7508P)

EXECUTIVE
SUMMARY:

After
fumigation
with
sodium
cyanide
at
a
rate
of
1
oz
NaCN/
100
ft3,
hydrogen
cyanide
residues
in/
on
orange
peel
averaged
1.2
ppm,
0.93
ppm,
and
0.45
ppm
at
8
hours,
24
hours,
and
48
hours
post
fumigation
respectively.
Hydrogen
cyanide
residues
in
orange
edible
pulp
averaged
0.027
ppm,
0.020
ppm,
and
0.007
ppm
at
8
hours,
24
hours,
and
48
hours
post
fumigation,
respectively.
However,
additional
data
are
required.
Residue
data
from
an
additional
two
trials
are
required
along
with
residue
data
for
whole
oranges.
A
detailed
explanation
of
the
modifications
to
EPA
335.2
along
with
validation
of
this
method
at
the
reported
LOD
of
0.01
ppm
is
required.
2
INTRODUCTION/
BACKGROUND:

Washburn
&
Sons,
Inc.
has
submitted
data
for
hydrogen
cyanide
(
HCN)
residue
in/
on
citrus
peel
and
edible
pulp
after
fumigation
with
sodium
cyanide
(
NaCN).

DISCUSSION:

Washburn
&
Sons,
Inc.
has
submitted
data
hydrogen
cyanide
residue
in/
on
citrus
peel
and
edible
pulp
after
fumigation
with
sodium
cyanide.
(
2006;
MRID
46868001)
titled:

Hydrogen
Cyanide
Residues
in
Citrus
Peel
and
Edible
Pulp
Resulting
from
Post­
Harvest
Fumigation
of
Citrus
Author:
Robert
Krieger,
Ph.
D.
Performing
Laboratory:
Personal
Chemical
Exposure
Program,
University
of
California,
Riverside,
CA
Project
ID:
UCR
Study
Number:
HCN/
5­
06
Final
Report
Date:
May
29,
2006.

Citrus
transport
trailers
were
fumigated
at
a
rate
of
1
oz
NaCN
per
100
ft3
of
trailer
volume.
Valencia
oranges
were
fumigated
at
Washburn
&
Sons,
Inc.
in
Highgrove,
CA
which
is
the
only
operator
of
a
trailer/
truck
citrus
hydrogen
cyanide
fumigation
facility
for
the
protection
of
citrus
against
surface
insects
in
California.
The
trailers
were
fumigated
in
a
closed
system
containing
NaCN
by
addition
of
sulfuric
acid
to
water
at
a
rate
of
1
oz
NaCN/
100
ft3.
After
one
hour
of
fumigation
the
trailer
was
exhausted
for
approximately
30
minutes.

Valencia
oranges
were
sampled
before
fumigation
to
be
used
as
control
samples.
Additional
oranges
were
sampled
at
8
hours
post
fumigation,
24
hours
post
fumigation,
and
48
hours
post
fumigation.
Samples
were
shipped
to
the
laboratory
where
samples
of
peel
and
edible
pulp
were
prepared
by
hand.
Orange
peel
represented
approximately
29
%
of
the
total
fresh
weight
of
medium
oranges.
Peel
and
pulp
samples
were
placed
in
frozen
storage
and
transported
to
Microbac
Laboratories,
Inc.
in
Corona,
CA.
Samples
were
analyzed
for
hydrogen
cyanide
residues
following
Microbac
Laboratories
Standard
Operating
Procedure
for
EPA
Method
335.2
modified
for
analysis
of
citrus.
EPA
Method
335.2
is
applicable
to
drinking
water
and
waste
water.
No
detailed
explanation
of
the
modifications
to
this
method
was
given.
This
information
is
required.
Procedures
for
the
analysis
of
water
and
waste
water
samples
were
submitted
with
the
data
package.
One
sample
was
spiked
with
a
level
of
0.10
ppm
HCN.
This
spike
gave
a
recovery
of
74%.
Another
sample
was
fortified
at
0.40
ppm
and
gave
a
96
%
recovery.
The
registrant
stated
the
method
detection
limit
was
0.05
ppm
but
lower
levels
were
reported
based
on
using
larger
sample
sizes.
Validation
of
this
lower
level
was
not
submitted.
No
storage
stability
data
were
submitted
with
the
data
package.
Samples
were
stored
less
than
30
days
from
sampling
to
analysis,
therefore,
no
storage
stability
data
are
required.
A
summary
of
HCN
residues
in/
on
orange
peel
and
edible
pulp
are
listed
in
Table
1.
No
residue
data
were
submitted
for
whole
oranges.
Residue
data
from
an
additional
two
trials
are
required.
In
addition,
residue
data
on
3
whole
oranges
are
required.

Since
the
use
on
citrus
is
for
citrus
destined
for
the
fresh
market
in
Arizona
only,
the
8
hour
samples
will
not
be
used
in
the
dietary
exposure
analysis.
The
residue
data
for
the
24
and
48
hour
samples
will
be
used
to
refine
the
dietary
exposure
analysis.
The
residue
input
for
citrus
peel
in
DEEM
FCID
 
model
will
be
0.69
ppm
and
the
residue
input
for
citrus
pulp
will
be
0.013
ppm.
This
recently
submitted
residue
data
for
citrus
peel
and
citrus
edible
pulp
should
be
used
for
the
dietary
exposure
analysis
instead
of
the
previously
submitted
data
which
did
not
reflect
residues
which
would
be
incurred
in/
on
pulp
and
peel.

Table
1.
Summary
of
Hydrogen
Cyanide
Residues
in
Orange
Peel
and
Edible
Pulp
after
Fumigation
with
Sodium
Cyanide
at
1
oz/
100
ft3.
Sample
Matrix
Hours
After
Fumigation
Total
HCN
Residues
(
ppm)
Control
<
0.005*,
<
0.005,
<
0.005
8
1.0,
1.3,
1.4
24
1.3,
0.70,
0.80
Orange
Peel
48
0.65,
0.40,
0.30
Control
<
0.005,
<
0.005,
<
0.005
8
0.04,
0.01,
0.03
24
0.02,
0.02,
0.02
Orange
Edible
Pulp
48
0.01,
<
0.005,
<
0.005
*
½
of
the
stated
LOD.
No
validation
of
this
LOD
was
submitted.

CONCLUSION:

After
fumigation
with
sodium
cyanide
at
a
rate
of
1
oz
NaCN/
100
ft3,
hydrogen
cyanide
residues
in/
on
orange
peel
averaged
1.2
ppm,
0.93
ppm,
and
0.45
ppm
at
8
hours,
24
hours,
and
48
hours
post
fumigation
respectively.
Hydrogen
cyanide
residues
in
orange
edible
pulp
averaged
0.027
ppm,
0.020
ppm,
and
0.007
ppm
at
8
hours,
24
hours,
and
48
hours
post
fumigation,
respectively.
However,
additional
data
are
required.
Residue
data
from
an
additional
two
trials
are
required
along
with
residue
data
for
whole
oranges.
A
detailed
explanation
of
the
modifications
to
EPA
335.2
along
with
validation
of
this
method
at
the
reported
LOD
of
0.01
ppm
is
required.

cc:
Chem
F,
Chron
F.
Morton
RDI:
Team:
6/
28/
06;
SVH:
6/
29/
06
TM,
Thurston
Morton,
Cubicle
s­
10922,
305­
6691,
mail
code
7509P
