Page
1
of
12
UNITED
STATES
ENVIRONMENTAL
PROTECTION
AGENCY
WASHINGTON,
D.
C.
20460
OFFICE
OF
PREVENTION,
PESTICIDES
AND
TOXIC
SUBSTANCES
MEMORANDUM
Date:
June
29,
2006
Subject:
Revised
Sodium
Cyanide
Reregistration
Eligibility
Decision
(
RED).
Summary
of
Analytical
Chemistry
and
Residue
Data.

DP
Number:
D330275
PC
Code:
Hydrogen
cyanide:
045801;
Sodium
cyanide:
074002
Chemical
Class:
Cyanide
40
CFR
§
180.130
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:
Rebecca
Daiss,
Risk
Assessor
Reregistration
Branch
4
Health
Effects
Division
(
7509P)

The
Residue
Chemistry
document
was
originally
prepared
under
contract
by
Versar
Inc.
(
6850
Versar
Center,
Springfield,
VA
22151).
The
document
have
been
reviewed
by
the
HED
and
revised
to
reflect
current
OPP
policies
and
to
summarize
current
submitted
data.
Recently
submitted
residue
data
(
MRID
46868001)
have
been
summarized
in
this
revision.
Hydrogen
Cyanide
Summary
of
Analytical
Chemistry
and
Residue
Data
Barcode:
D330275
Executive
Summary
Hydrogen
cyanide
(
HCN)
is
a
pesticide
used
for
quarantine
fumigation
of
surface
pests.
Currently,
there
are
no
active
registrations
for
HCN
with
food/
feed
uses;
however,
there
is
one
Special
Local
Needs
(
SLN)
food/
feed
use
registration
for
sodium
cyanide,
which
is
used
a
source
of
hydrogen
cyanide
gas.
The
SLN
end­
use
product
is
formulated
as
a
granular
containing
98%
sodium
cyanide
as
the
active
ingredient
(
ai)
and
is
applied
to
citrus
as
a
post­
harvest
fumigant
at
a
rate
of
6
oz
HCN
gas
per
1000
ft3.
Sodium
cyanide
is
also
registered
for
use
on
forest,
pastures,
and
rangelands
for
the
control
of
wild
canids
suspected
of
preying
on
livestock.
When
an
above
ground
trap
loaded
with
sodium
cyanide
capsules
is
triggered
by
wild
canids,
the
device
ejects
a
sodium
cyanide
capsule
into
the
predator's
mouth.
As
the
use
of
these
devices
are
not
allowed
where
food
crops
are
planted
and
sodium
cyanide
is
expected
to
rapidly
dissipate
as
hydrogen
gas
if
inadvertently
discharged
into
surrounding
areas,
this
use
is
not
considered
a
food/
feed
use.

The
nature
of
the
residue
in
citrus
is
adequately
understood
based
on
data
submitted
for
the
citrus
petition.
The
available
data
show
that
over
90%
of
the
HCN
can
be
accounted
for
as
such
in
the
treated
citrus
or
as
unsorbed
HCN.
A
study
subsequently
obtained
from
U.
of
California,
Riverside
indicates
that
when
citrus
is
fortified
with
HCN,
about
10%
of
the
HCN
is
unrecoverable.
The
nature
of
residues
in
animals
has
not
been
defined;
however,
small
quantities
of
HCN
residue
in
livestock
are
thought
to
be
detoxified
into
carbon
dioxide
and
thiocyanate.

The
titrimetric
method
is
the
method
of
choice
for
enforcement.
This
method,
which
involves
the
distillation
of
HCN
from
acidified
substrate
into
an
alkaline
solution
followed
by
titration
with
silver
nitrate,
has
been
included
in
the
Pesticide
Analytical
Manual
(
PAM),
Volume
II.
The
method
is
considered
to
be
adequate
to
determine
residues
of
1
ppm
or
more.
Residue
data
for
citrus
were
obtained
by
a
GLC
procedure
using
a
Coulson
electrolytic
nitrogen
detector
cell.
EPA
determined
that
the
method
is
adequate
for
data
collection
purposes.

A
tolerance
of
50
ppm
for
citrus
has
been
established
under
40
CFR
§
180.130
for
residues
of
hydrogen
cyanide
from
postharvest
fumigation
as
a
result
of
application
of
sodium
cyanide.
Residue
studies
have
been
conducted
on
oranges
and
lemons,
applying
the
pesticide
in
the
manner
described
on
the
label
of
the
currently
registered
product.
The
results
indicate
that
there
is
little,
if
any,
significant
difference
in
residue
levels
under
the
various
test
conditions
at
a
given
concentration
of
HCN.
Residues
were
essentially
dose
responsive
and
the
percentage
of
absorbed
HCN
was
in
the
range
of
70.5
to
95%
with
most
values
reported
as
>
80%.
Under
the
conditions
of
the
studies,
the
current
doses
described
in
the
label
would
yield
maximum
theoretical
residues
of
30
ppm
on
lemons
and
27.9
ppm
on
oranges;
maximum
residues
found
were
24
ppm
for
lemons
and
22
ppm
for
oranges.
The
petition
concluded
that
maximum
residues
of
the
order
of
35
ppm
could
occur
on
the
small
types
of
citrus,
but
would
be
less
than
30
ppm
on
the
larger
and
usually
more
important
types,
i.
e.,
grapefruit,
lemons,
oranges,
tangelos
and
tangerines.
In
a
recently
submitted
study
(
MRID
46868001),
residues
of
hydrogen
cyanide
in
orange
peel
averaged
1.2
ppm
8
hours
after
fumigation
with
1
ounce
sodium
cyanide/
100
ft3,
0.9
ppm
24
hours
after
fumigation,
and
0.45
ppm
48
hours
after
fumigation.
Residues
of
hydrogen
cyanide
in
orange
pulp
averaged
0.06
ppm
8
hours
after
fumigation,
0.02
ppm
24
hours
after
fumigation,
and
<
0.01
ppm
48
hours
after
fumigation.
Residues
in
whole
oranges
were
not
determined.
Hydrogen
Cyanide
Summary
of
Analytical
Chemistry
and
Residue
Data
Barcode:
D330275
A
food/
feed
processing
study
was
not
conducted.
It
appears
that
EPA
previously
concluded
that
residues
in
edible
pulp
and
juice
would
be
considerably
less
than
20
ppm,
based
on
the
assumption
that
HCN
residues
are
largely
in
the
peel
fraction.
Additionally,
EPA
previously
concluded
that
feed
uses
of
dried
pulp
are
of
little
concern.

Regulatory
Recommendations
and
Residue
Chemistry
Deficiencies
A
tolerance
has
been
established
under
40
CFR
§
180.130
for
residues
of
hydrogen
cyanide
on
citrus
at
50
ppm.
Currently,
only
a
SLN
registration
from
1984
exists
for
this
commodity.
If
the
tolerance
will
no
longer
be
supported
by
the
registrant,
HED
recommends
that
the
tolerance
be
revoked.
If
the
tolerance
will
be
supported
by
the
registrant,
HED
supports
this
tolerance,
provided
that
the
following
deficiencies
and
data
gaps
are
resolved:

·
The
information
available
regarding
the
reassessment
of
hydrogen
cyanide
is
based
solely
on
EPA's
responses
to
petitions
submitted
by
the
registrant.
These
responses,
which
were
written
more
than
30
years
ago,
indicate
that
EPA
previously
determined
that
the
established
tolerance
for
citrus
is
adequate.
The
decisions
were
based
on
reviews
of
a
number
of
studies;
however,
the
responses
do
not
cite
the
relevant
studies
and
failed
to
provide
adequate
data
that
could
be
analyzed
for
this
current
assessment.
Therefore,
the
conclusions
of
this
document
are
based
on
the
second­
hand
approval
from
the
EPA
review
of
the
petitions.

·
The
following
deficiencies
were
found
with
regard
to
the
current
OPPTS
guidelines:

1)
Storage
stability
data
for
citrus
are
required.

2)
Additional
data
are
required
to
validate
MRID
46868001.
Residue
data
from
an
additional
two
trials
are
required
along
with
residue
data
on
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.

3)
Analytical
standards
for
sodium
and
hydrogen
cyanide
are
not
currently
available
in
the
National
Pesticide
Standards
Repository.
Analytical
Reference
standards
of
sodium
and
hydrogen
cyanide
must
be
supplied
and
supplies
replenished
as
requested
by
the
Repository.
Hydrogen
Cyanide
Summary
of
Analytical
Chemistry
and
Residue
Data
Barcode:
D330275
Background
The
PC
Code
and
nomenclature
of
hydrogen
cyanide
are
listed
below
in
Table
1
and
the
physicochemical
properties
of
hydrogen
cyanide
are
listed
in
Table
2.

TABLE
1.
Test
Compound
Nomenclature
Compound
Chemical
Structure:
HC 
N
Chemical
Structure:
NaC 
N
Common
Name/
IUPAC/
CAS
Name
hydrogen
cyanide
sodium
cyanide
Synonyms
Hydrocyanic
acid,
prussic
acid,
formonitrile,
formic
anammonide,
carbon
hydride
nitride,
cyclon
cyanobrik,
cyanogran,
sodium
cyanide,
hydrocyanic
acid
sodium
salt,
cymag
CAS
#
74­
90­
8
143­
33­
9
PC
Code
045801
074002
Current
Food/
Feed
Site
Registration
Citrus
Citrus
Source:
OSHA,
2004
TABLE
2.
Physicochemical
Properties
of
the
Technical
Grade
Test
Compound
Parameter
Value:
Hydrogen
Cyanide
Value:
Sodium
Cyanide
Molecular
Weight
27.03
49.01
Boiling
Point
26
°
C
at
760
mm
Hg
1496
°
C
at
760
mm
Hg
Melting
Point
­
13.4
°
C
564
°
C
Specific
Gravity
0.7
at
20
°
C
1.7
Vapor
Density
0.94
Vapor
Pressure
620
mm
Hg
at
20
°
C
Negligible
Solubility
Miscible
with
water
and
alcohol,
slightly
soluble
in
ether.
Soluble
in
water
(
37
g/
100mL)

Source:
OSHA,
2004
860.1200
Directions
for
Use
A
product
registration
query
of
the
Agency's
OPPIN
database
identified
only
one
sodium
cyanide
end­
use
product
(
EP)
registered
for
use
on
food/
feed
sites
(
see
Table
3).
This
product,
which
is
registered
to
Washburn
and
Sons,
is
a
SLN
registration
(
CA840006)
with
sodium
cyanide
as
the
active
ingredient.
Sodium
cyanide
is
used
as
a
source
of
hydrogen
cyanide
gas
for
post­
harvest
fumigation
of
citrus.
A
summary
of
this
use
pattern
is
shown
in
Table
4.

Sodium
cyanide
is
also
currently
registered
for
use
on
forest,
pastures,
and
rangelands
for
the
control
of
wild
canids
suspected
of
preying
on
livestock.
The
sodium
cyanide
capsule
is
placed
above
ground
in
an
M­
44
device,
which
is
a
spring
loaded
trap
scented
with
carrion
to
attract
the
targeted
canids.
When
triggered,
the
device
ejects
the
sodium
cyanide
capsule
into
the
victim's
mouth.
As
the
use
of
these
devices
are
not
allowed
where
food
crops
are
planted
and
sodium
cyanide
is
expected
to
rapidly
dissipate
as
hydrogen
gas
if
inadvertently
discharged
into
surrounding
areas,
this
use
is
not
considered
a
food/
feed
use.
Hydrogen
Cyanide
Summary
of
Analytical
Chemistry
and
Residue
Data
Barcode:
D330275
A
tabular
summary
of
the
chemistry
science
assessments
is
presented
in
Table
5.
The
conclusions
listed
in
Table
5
regarding
the
reregistration
eligibility
of
hydrogen
cyanide
food/
feed
uses
are
based
on
the
use
pattern
of
the
SLN
registration.

TABLE
3.
Sodium
cyanide
End­
Use
Products
(
EPs)
with
Food/
Feed
Uses.

EPA
Reg.
No.
Formulation
Label
Acceptance
Date
Registrant
Product
Name
Commodity
SLN
CA8400005
98%
NaCN
(
Powder)
8/
12/
94
Washburn
and
Sons
Sodium
Cyanide
Citrus
TABLE
4.
Summary
of
Directions
for
Use
of
Sodium
Cyanide
on
Citrus.

Application
Timing,
Type,
and
Equip.
Applic.
Rate
(
lb
ai/
A)
Max.
No.
Applic.
per
Season
Max.
Seasonal
Applic.
Rate
(
lb
ai/
A)
PHI
(
days)
Use
Directions
and
Limitations
For
use
in
fumigation
at
atmospheric
pressure
in
gastight
chamber.
One
hour
fumigation.
1
ounce
(
weight)
NaCN,
1.5
fl.
oz
sulfuric
acid,
and
3
fl.
oz
water
per
100
ft3
of
fumigated
volume.
This
corresponds
to
6
oz
HCN
gas
per
1000
ft3
(
or
6
mg/
L).
Not
specified
Not
specified
NA
For
use
only
by
personnel
trained
in
hazards,
administration
of
first
aid,
proper
use
techniques,
and
protective
equipment
required
for
sodium
cyanide.

Fumigate
only
if
pulp
temperature
is
above
60
°
F
and
less
than
80
°
F
Hydrogen
Cyanide
Summary
of
Analytical
Chemistry
and
Residue
Data
Barcode:
D330275
TABLE
5.
Residue
Chemistry
Science
Assessment
for
Reregistration
of
Hydrogen
Cyanide
GLN
Data
Requirements
Current
Tolerances
(
ppm)
[
§
180.130]
Additional
Data
Needed?
Reference
860.1200:
Directions
for
Use
N/
A
=
Not
Applicable
No
See
Table
4
860.1300:
Nature
of
the
Residue
­
Plants
­
Citrus
N/
A
No
PP#
1E1124
860.1300:
Nature
of
the
Residue
­
Animals
N/
A
No1
PP#
1E1124
860.1340:
Residue
Analytical
Method
­
Plant
Commodities
N/
A
No
PP#
1E1124
­
Animal
Commodities
N/
A
No2
PP#
1E1124
860.1360:
Multiresidue
Method
N/
A
No3
None
860.1380:
Storage
Stability
Data
­
Plant
Commodities
N/
A
Yes4
None
­
Animal
Commodities
N/
A
No5
None
860.1400:
Magnitude
of
the
Residue
­
Water,
Fish,
and
Irrigated
Crops
N/
A
No
None
860.1460:
Magnitude
of
the
Residue
­
Food
Handling
N/
A
No
None
860.1480:
Magnitude
of
the
Residue
­
Meat,
Milk,
Poultry,
Eggs
N/
A
No6
None
860.1500:
Crop
Field
Trials
­
Citrus
50
Yes7
PP#
1E1124,
MRID
46868001
860.1520:
Processed
Food/
Feed
N/
A
No8
None
860.1650:
Submittal
of
Analytical
Reference
Standards
NA
Yes9
None
860.1850:
Confined
Accumulation
in
Rotational
Crops
N/
A
No
None
860.1900:
Field
Accumulation
in
Rotational
Crops
N/
A
No
None
1.
A
nature
of
residue
study
for
livestock
has
not
been
submitted.
A
nature
of
the
residue
study
for
livestock
is
not
required
at
this
time.
2.
A
residue
analytical
method
for
livestock
has
not
been
submitted.
A
method
is
not
required
at
this
time.
3.
No
multiresidue
method
data
has
been
submitted.
Hydrogen
cyanide
is
not
expected
to
be
recovered.
4.
Storage
stability
data
for
citrus
are
required.
5.
If
livestock
feeding
studies
are
required
in
the
future,
then
storage
stability
studies
with
livestock
commodities
will
also
be
required.
6.
EPA
previously
determined
that
feed
uses
of
treated
citrus
are
of
little
concern;
however,
no
processing
studies
or
livestock
feeding
studies
were
conducted
to
come
to
this
conclusion.
7.
The
Agency
previously
determined
that
the
established
tolerance
was
adequate
based
on
the
submitted
fumigation
data.
However,
additional
data
are
required
to
confirm
the
result
of
the
recently
submitted
data
(
D330409,
T.
Morton,
6/
29/
06).
8.
The
Agency
previously
determined
that
HCN
residues
would
be
considerably
below
20
ppm
in
edible
pulp
and
juice.
However,
no
processing
studies
were
conducted
to
confirm
this
conclusion.
9.
Analytical
standards
for
sodium
and
hydrogen
cyanide
are
not
currently
available
in
the
National
Pesticide
Standards
Repository.
Analytical
Reference
standards
of
sodium
and
hydrogen
cyanide
must
be
supplied
and
supplies
replenished
as
requested
by
the
Repository.
Hydrogen
Cyanide
Summary
of
Analytical
Chemistry
and
Residue
Data
Barcode:
D318019
860.1300
Nature
of
the
Residue
­
Plants
The
Agency
previously
concluded
in
the
response
to
petition
PP#
1E1124
that
the
nature
of
the
residue
in
citrus
is
adequately
defined.
The
residue
of
concern
is
hydrogen
cyanide
per
se.
According
to
the
EPA
memo,
data
in
the
petition
suggest
that
HCN
is
rapidly
absorbed
by
fresh
citrus,
and
depending
upon
conditions,
between
70
to
95%
of
available
HCN
is
absorbed
within
one
hour.
Upon
aeration,
less
than
5
percent
of
the
sorbed
HCN
is
desorbed;
after
48
hours,
most
of
the
sorbed
HCN
is
"
irreversibly
bound."
There
is
no
evidence
that
any
of
the
sorbed
HCN
is
degraded
(
HCN
is
stable
under
acidic
conditions).
The
available
data
show
that
over
90%
of
the
HCN
can
be
accounted
for
as
such
in
the
treated
citrus
or
as
unsorbed
HCN.
A
study
subsequently
obtained
from
U.
of
California,
Riverside
indicates
that
when
citrus
is
fortified
with
HCN
about
10%
of
the
HCN
is
unrecoverable.
The
studies
and
data
which
the
petition
response
cites
were
not
available,
however,
to
verify
these
claims
(
PP#
1E1124;
2/
17/
71;
W.
Cox).

860.1300
Nature
of
the
Residue
­
Livestock
The
nature
of
the
residue
in
livestock
has
not
been
defined;
however,
it
was
previously
determined
by
the
Agency
that
feed
use
of
citrus
is
of
little
concern
because
citrus
treated
with
hydrogen
cyanide
is
mostly
destined
for
fresh
market
only.
Additionally,
the
Agency
response
to
PP#
1E1124
indicates
that
HCN,
when
ingested
by
animals
at
subtoxic
levels,
is
rapidly
detoxified
into
carbon
dioxide
and
thiocyanate,
which
is
largely
excreted
by
the
kidneys
(
PP#
1E1124;
2/
17/
71;
W.
Cox).

860.1340
Residue
Analytical
Methods
The
residue
data
for
citrus
were
obtained
by
a
GLC
procedure
using
a
Coulson
electrolytic
nitrogen
detector
cell.
No
recovery
data
as
such
were
reported,
but
the
report
notes
that
virtually
all
the
HCN
gas
was
accounted
for
either
as
unabsorbed
gas
or
as
residues
in
the
treated
citrus.
In
effect,
recoveries
were
well
in
excess
of
95%.
Background
values
were
also
not
reported
as
such,
but
data
in
the
studies
indicated
blanks
(
residue
values
at
0
­
10
minutes)
to
be
of
the
order
of
1
ppm
or
less.
EPA's
response
to
the
citrus
petition
notes
that
the
method
is
adequate
for
obtaining
residue
data
or
as
an
alternate
enforcement
method
(
PP#
1E1124;
2/
17/
71;
W.
Cox).

The
enforcement
in
PAM,
Vol
II
is
a
titrimetric
method.
This
method
involves
the
distillation
of
HCN
from
acidified
substrate
into
an
alkaline
solution
followed
by
titration
with
silver
nitrate.
This
method
is
considered
adequate
to
determine
residues
of
1
ppm
or
more
(
PP#
1E1124;
2/
17/
71;
W.
Cox).

860.1360
Multiresidue
Methods
No
multiresidue
method
studies
were
submitted
by
the
registrant.
Hydrogen
cyanide
is
not
expected
to
be
recovered
by
the
multiresidue
methods.
860.1380
Storage
Stability
No
data
regarding
storage
stability
tests
could
be
found.
Data
are
required.
Hydrogen
Cyanide
Summary
of
Analytical
Chemistry
and
Residue
Data
Barcode:
D318019
860.1400
Water,
Fish,
and
Irrigated
Crops
Hydrogen
cyanide
is
not
presently
registered
for
direct
use
on
water
and
aquatic
food
and
feed
crops;
therefore,
no
residue
chemistry
data
are
required
under
these
guideline
topics.

860.1460
Food
Handling
Hydrogen
cyanide
is
not
presently
registered
for
use
in
food­
handling
establishments;
therefore,
no
residue
chemistry
data
are
required
under
this
guideline
topic.

860.1480
Meat,
Milk,
Poultry,
and
Eggs
Hydrogen
cyanide
is
not
presently
registered
for
use
as
a
direct
treatment
to
livestock;
however,
dried
pulp
from
citrus
treated
with
hydrogen
cyanide
can
be
used
as
a
feedstuff
for
beef
and
dairy
cattle.
It
does
not
appear
that
processed
food/
feed
or
livestock
feeding
studies
were
conducted
to
show
the
level
of
residues
that
will
result
in
dried
pulp,
meat,
meat
byproducts,
or
milk.
However,
the
Agency
concluded
in
the
response
to
petition
PP
#
1E1124
that
feed
uses
of
treated
citrus
is
of
little
concern
because
the
proposed
use
is,
"
in
most
cases",
for
fruit
destined
for
the
fresh
market
only.
Additionally,
the
agency
previously
concluded
(
PP#
0E0915,
W.
J.
Boodee,
1/
19/
70)
that
HCN,
when
ingested
by
animals
at
subtoxic
levels,
is
rapidly
detoxified
into
carbon
dioxide
and
thiocyanate,
which
is
largely
excreted
by
the
kidneys.
It
was
also
noted
that
the
liming
process
for
citrus
pulp
would
most
likely
reduce
residues
in
treated
citrus
(
PP#
1E1124;
2/
17/
71;
W.
Cox).
Therefore,
no
livestock
feeding
study
will
be
required
at
this
time.
If
in
the
future
other
raw
agricultural
commodities
are
added
which
are
feed
stuffs,
this
requirement
will
be
reevaluated.

860.1500
Crop
Field
Trials
The
results
of
field
trials
are
described
in
EPA's
response
to
PP#
1E1124
(
PP#
1E1124;
2/
17/
71;
W.
Cox).
The
residue
data
consist
of
studies
on
lemons
and
oranges
exposed
under
laboratory
and
simulated
commercial
conditions
to
HCN
gas
at
rates
ranging
from
6
mg/
L
(
the
same
concentration
as
the
registered
product)
to
128
mg/
L
(
21
times
greater
that
the
concentration
of
the
registered
product).
The
fruits
were
exposed
for
one
hour
periods
at
3
°
C
and
43
°
C,
in
light
and
in
the
dark,
using
both
waxed
and
unwaxed
fruit.
Tests
were
also
made
to
determine
the
amount
of
desorption
occurring
after
aeration
for
periods
of
0
to
85
minutes
after
removal
of
excess
HCN.

The
results
indicate
that
there
is
little,
if
any,
significant
difference
in
residue
levels
under
the
various
test
conditions
at
a
given
concentration
of
HCN.
Residues
were
essentially
dose
responsive
and
the
percentage
of
absorbed
HCN
was
in
the
range
of
70.5
to
95%
with
most
values
reported
as
>
80%.

Under
the
conditions
of
the
studies,
the
current
doses
described
in
the
label
would
yield
maximum
theoretical
residues
on
lemons
of
30
ppm
and
on
oranges
of
27.9
ppm;
maximum
residues
found
were
24
ppm
for
lemons
and
22
ppm
for
oranges.
The
limited
data
indicate
that
there
is
an
inverse
ratio
between
the
size
of
the
fruit
and
the
amount
residues
resulting
from
treatment
­­
this
can
he
Hydrogen
Cyanide
Summary
of
Analytical
Chemistry
and
Residue
Data
Barcode:
D318019
attributed
to
the
higher
surface/
volume
ratio
of
boxed
lemons
versus
boxed
oranges.
Thus,
for
even
smaller
citrus
fruit,
such
as
limes
and
kumquats,
the
residues
might
exceed
30
ppm,
assuming
there
would
be
similar
rates
of
absorption
for
those
fruits.
Contrariwise,
grapefruits
and
tangelos
(
which
are,
on
the
average,
larger
than
oranges)
would
probably
have
somewhat
lower
residues,
using
the
same
assumption.

The
data
from
the
residue
studies
reflect
only
total
residues
on
treated
citrus
and
do
not
indicate
how
these
residues
are
partitioned
between
the
peal
and
the
edible
pulp.
However,
the
studies
do
cite
limited
earlier
studies
which
indicate
that
the
residues
are
largely
in
the
peel
fraction.
[
This
Statement
was
confirmed
by
telecon
between
Dr.
William
E.
Westlake,
Department
of
Entomology,
University
of
California
and
J.
Wolff,
2/
8/
71.
Dr.
Westlake
stated
that
their
data
indicated
that
90%
of
the
HCN
residues
occur
in
the
peel.]

The
petition
response
concludes
that
maximum
residues
of
the
order
of
35
ppm
could
occur
on
the
small
types
of
citrus,
but
would
be
less
than
30
ppm
on
the
larger
and
usually
more
important
types,
i.
e.,
grapefruit,
lemons,
oranges,
tangelos
and
tangerines.
Although
there
is
a
lack
of
data
for
the
smaller
fruits,
the
proposed
tolerance
of
50
ppm
is
believed
to
be
adequate
for
all
citrus.

As
very
little
data
were
submitted
to
petition
PP#
1E1124,
it
is
difficult
to
determine
the
adequacy
of
the
studies
with
respect
to
the
current
OPPTS
Guideline.
For
example,
the
number
of
trials
conducted,
the
developmental
stage
of
the
fruit,
size
and
type
of
container
holding
the
commodity,
description
and
location
of
fumigation
chambers,
aeration
details,
and
sampling
procedures
were
not
provided.
According
to
the
OPPTS
Guideline
860.1500,
trials
for
the
citrus
group
should
be
conducted
on
oranges,
lemons,
and
grapefruit.
In
this
study,
only
oranges
and
lemons
were
sampled.
However,
no
data
on
grapefruit
will
be
required.

In
a
recently
submitted
study
(
MRID
46868001),
residues
of
hydrogen
cyanide
in
orange
peel
averaged
1.2
ppm
8
hours
after
fumigation
with
1
ounce
sodium
cyanide/
100
ft3,
0.9
ppm
24
hours
after
fumigation,
and
0.45
ppm
48
hours
after
fumigation.
Residues
of
hydrogen
cyanide
in
orange
pulp
averaged
0.06
ppm
8
hours
after
fumigation,
0.02
ppm
24
hours
after
fumigation,
and
<
0.01
ppm
48
hours
after
fumigation.
Residues
in
whole
oranges
were
not
determined.
Additional
data
are
required
for
this
study.
Residue
data
from
an
additional
two
trials
are
required
along
with
residue
data
on
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.

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.
Hydrogen
Cyanide
Summary
of
Analytical
Chemistry
and
Residue
Data
Barcode:
D318019
860.1520
Processed
Food
and
Feed
Significant
processed
food
and
feed
commodities
of
citrus
include
dried
pulp,
oil,
and
juice.
It
does
not
appear
that
processed
food/
feed
studies
were
submitted.
The
Agency
previously
concluded
in
response
to
petition
PP#
1E1124
that
residues
of
hydrogen
cyanide
in
edible
pulp
and
juice
will
be
considerably
below
20
ppm
(
PP#
1E1124;
2/
17/
71;
W.
Cox).
This
conclusion
appears
to
be
based
on
the
assumption
that
hydrogen
cyanide
residues
are
largely
in
the
peel
fraction.
Additionally,
it
was
also
noted
that
the
liming
process
for
citrus
pulp
and
the
evaporation
process
for
citrus
molasses
would
most
likely
reduce
residues
in
treated
citrus
(
PP#
1E1124;
2/
17/
71;
W.
Cox).
Therefore,
no
processing
study
for
hydrogen
cyanide
will
be
required.

860.1650
Submittal
of
Analytical
Reference
Standards
Analytical
standards
for
sodium
and
hydrogen
cyanide
are
not
currently
available
in
the
National
Pesticide
Standards
Repository.
Analytical
Reference
standards
of
sodium
and
hydrogen
cyanide
must
be
supplied
and
supplies
replenished
as
requested
by
the
Repository.

The
reference
standards
should
be
sent
to
the
Analytical
Chemistry
Lab,
which
is
located
at
Fort
Meade.
You
should
send
them
to
the
attention
of
either
Theresa
Cole
or
Frederic
Siegelman
at
the
following
address:

USEPA
National
Pesticide
Standards
Repository/
Analytical
Chemistry
Branch/
OPP
701
Mapes
Road
Fort
George
G.
Meade,
MD
20755­
5350
860.1850
Confined
Accumulation
in
Rotational
Crops
As
the
pesticide
is
applied
after
harvesting,
no
studies
are
required
for
confined
accumulation
in
rotational
crops.

860.1900
Field
Accumulation
in
Rotational
Crops
As
the
pesticide
is
applied
after
harvesting,
no
studies
are
required
for
field
accumulation
in
rotational
crops.

TOLERANCE
REASSESSMENT
SUMMARY
Tolerance
Reassessments
for
Hydrogen
cyanide
Tolerances
for
residues
of
hydrogen
cyanide
in/
on
plant
commodities
are
expressed
in
terms
of
hydrogen
cyanide
per
se.
Hydrogen
Cyanide
Summary
of
Analytical
Chemistry
and
Residue
Data
Barcode:
D318019
Tolerances
Listed
Under
40
CFR
§
180.130:

According
to
the
Agency's
previous
conclusions,
adequate
residue
data
have
been
submitted
to
establish
tolerances
for
citrus.
However,
based
on
current
guideline
requirements,
additional
data
may
be
required.
Based
on
available
data,
the
established
tolerance
for
this
commodity
is
adequate.

TABLE
6.
Tolerance
Summary
for
Hydrogen
cyanide
Commodity
Established
Tolerance
(
ppm)
Recommended
Tolerance
(
ppm)
Comments
(
correct
commodity
definition)

Fruit,
citrus
50
50
Fruit,
citrus,
group
10
Tolerances
Which
May
Be
Need
Under
40
CFR
§
180.130:

The
Agency
previously
concluded
that
hydrogen
cyanide
residues
in
the
edible
pulp
and
juice
will
be
considerably
below
20
ppm;
however,
it
does
not
appear
that
processing
studies
were
conducted
to
come
to
this
conclusion.
Processing
studies
may
need
to
be
conducted
and
a
tolerance
for
processed
commodities
of
citrus
(
dried
pulp,
oil,
and
juice)
may
need
to
be
established.
Additionally,
the
Agency
previously
concluded
that
feed
uses
of
treated
citrus
pulp
are
of
little
concern;
however,
no
feeding
studies
were
conducted.
If
HCN
residues
are
above
the
LOQ
in
dried
pulp,
feeding
studies
may
need
to
be
conducted
and
tolerances
established
for
milk
and
meat.

Codex/
International
Harmonization
Codex
maximum
residue
limits
(
MRLs)
do
not
currently
exist
for
hydrogen
cyanide;
therefore,
no
questions
of
compatibility
with
U.
S.
tolerances
exist.

References
Occupational
Safety
and
Health
Administration,
2004.
Health
Guidelines:
Hydrogen
Cyanide.
http://
www.
osha­
slc.
gov/
SLTC/
healthguidelines/
hydrogencyanide/
recognition.
html
Last
Accessed
August
2,
2004.
Hydrogen
Cyanide
Summary
of
Analytical
Chemistry
and
Residue
Data
Barcode:
D318019
Agency
Memoranda
Citations
Agency
Memoranda
Citations.

Date
DP
Barcode
CB
No.
ID
Number
From
To
MRID
Nos.
Subject
8/
23/
71
 
 
PP#
1E1124
D.
Baker
F.
J.
McFarland
Deputy
Assistant
Administrator
for
Pesticides
Programs
 
PP#
1E1124 
Proposal 
Hydrogen
Cyanide
(
Citrus).

1/
19/
70
 
 
PP#
0E0915
W.
J.
Boodee
 
 
PP#
0E0915 
Calcium
Cyanide
on
Greenhouse
Vegetables
3/
19/
93
D187797
1134
­­
B.
Cropp­

Kohlligan
K.
Depukat/
K.

Davis
41285607
Sodium
Cyanide.
Product
Chemistry
and
Directions
for
Use
Submissions.

6/
29/
06
D330409
_
_
T.
Morton
W.
Livingston
46868001
Sodium
Cyanide
(
Chemical
No.

074002).
Magnitude
of
the
Residue
in
Fumigated
Citrus
Peel
and
Edible
Pulp
(
GLN
860.1500).
