Document ID: EPA-HQ-OPP-2005-0043-0080
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2006-07-26T04:00Z

UNITED
STATES
ENVIRONMENTAL
PROTECTION
AGENCY
WASHINGTON
D.
C.,
20460
OFFICE
OF
PREVENTION,
PESTICIDES
AND
TOXIC
SUBSTANCES
February
16,
2006
PC
Code
069001;
Case
No.
2580
DP
Barcode:
D324663
MEMORANDUM
SUBJECT:
Revised
Pyrethrins
RED
Chapter
After
Additional
60­
Day
Comment
Period,
Phase
5
FROM:
Miachel
Rexrode,
Ph.
D.,
Senior
Aquatic
Biologist
José
Luis
Meléndez,
Chemist
Environmental
Risk
Branch
V
Environmental
Fate
and
Effects
Division
(
7507C)

THROUGH:
Jean
Holmes,
DVM,
Acting
Chief
Environmental
Risk
Branch
V
Environmental
Fate
and
Effects
Division
(
7507C)

TO:
Cathryn
O'Connell,
Risk
Manager
Reviewer
Tom
Myers,
Review
Manager
#
52
Special
Review
and
Reregistration
Division
(
7508C)

This
memo
summarizes
the
revised
Environmental
Fate
and
Effects
Division's
(
EFED)
screening­
level
Environmental
Risk
Assessment
for
the
Reregistration
Eligibility
Decision
of
Pyrethrins.
The
Pyrethrins
are
a
broad­
spectrum
insecticide
used
in
four
major
sectors:
agricultural
settings,
commercial/
industrial/
institutional/
food
&
non­
food/
mosquito
abatement,
domestic
home
and
garden,
and
pet
care.
Pyrethrins
are
a
mixture
of
naturally
occurring
insecticides
derived
from
the
flowers
of
Chrysanthemum
cinerariaefolium
and
Chrysanthemum
cineum.
The
six
individual
pyrethrins
are
pyrethrin
1,
pyrethrin
2,
cinerin
1,
cinerin
2,
jasmolin
1,
and
jasmolin
2.
The
technical
grade
active
ingredient
(
FEK­
99)
is
commonly
referred
to
as
pyrethrum
extract,
which
is
the
sum
of
Pyrethrins
I
(
the
esters
of
chrysanthemic
acid
­
pyrethrin
1,
cinerin
2
and
jasmolin
1)
and
Pyrethrins
II
(
the
esters
of
pyrethric
acid
­
pyrethrin
2,
cinerin
2,
and
jasmolin
2),
also
called
"
the
pyrethrins",
and
this
mixture
constitutes
45
to
55%
of
pyrethrum
extract.
The
product
pyrenone
crop
spray,
a
formulation
that
contains
pyrethrins,
piperonyl
butoxide
and
inert
ingredients,
was
used
as
a
test
material
in
many
of
the
ecological
effects
laboratory
studies.
There
are
many
other
formulation
types,
such
as
aerosol,
combustible
coil,
dust,
emulsifiable
concentrate,
ready
to
use
liquid,
shampoo,
and
wettable
powder.
All
six
pyrethrins
have
the
same
backbone
molecular
structure
with
different
substituents
at
two
sites.
Since
all
the
structures
at
the
two
sites
are
similar,
they
are
expected
to
have
similar
environmental
fate
properties.
Risk
to
Aquatic
and
Terrestrial
Organisms
The
Agency
evaluated
potential
pyrethrin
exposure
to
aquatic
and
terrestrial
organisms
by
considering
maximum
and
typical
application
rates.
The
conclusions
from
this
risk
assessment
are
as
follows:

Agricultural
Uses:

Model
generated
exposure
values
suggests
that
maximum
rates
can
result
in
acute
risk
to
fish
and
aquatic
invertebrates
(
freshwater
and
estuarine/
marine)
with
triggers
that
included
restrictive
use
and
endangered
species
concern
(
although
estuarine/
marine
endangered
invertebrate
was
triggered,
EFED
realizes
that
at
this
time
there
are
no
listed
species
under
this
category).
Evaluating
chronic
risk
from
this
exposure
scenario
showed
that
LOC
triggers
were
exceeded
for
estuarine/
marine
invertebrates,
while
fish
(
freshwater
and
estuarine/
marine)
and
freshwater
invertebrates
may
not
be
at
chronic
risk
from
pyrethrin
exposure
in
the
water
column.

Typical
application
rate
appears
to
have
the
potential
to
reduce
risk
to
aquatic
systems.
Evaluation
of
four
crop
scenarios
using
the
TGAI
(
ID
potatoes,
PA
tomatoes,
CA
onions,
OR
snap
beans)
suggests
that
LOCs
for
freshwater
and
estuarine/
marine
fish
and
invertebrates
should
not
be
exceeded
if
typical
application
rate
is
used.

The
Agency
also
assessed
the
maximum
and
typical
rates
for
a
pyrethrin
formulation
with
PBO
but
only
evaluated
acute
exposure
to
aquatic
organisms.
The
calculated
EECs
show
that
acute
risk
from
the
maximum
formulation
rate
appeared
to
be
higher
than
risk
calculated
only
from
the
TGAI.
This
evaluation
showed
that
acute
risk
from
the
formulation
was
about
2­
7X
greater
for
freshwater
and
estuarine/
marine
fish
and
about
10X
greater
for
estuarine/
marine
invertebrates.
However,
the
typical
formulation
rate
appears
to
reduce
the
risk
(
freshwater
and
estuarine/
marine
fish
and
freshwater
invertebrates),
but
this
reduction
in
exposure
still
presents
the
potential
for
acute
high,
acute
restrictive,
and
chronic
risk
to
estuarine/
marine
invertebrates
species.

Mosquito
Abatement:

The
maximum
rate
showed
that
there
did
not
appear
to
be
the
potential
for
acute
risk
to
freshwater
fish
and
invertebrates
or
esrtuarine/
marine
fish
but
there
was
the
potential
for
acute
LOCs
being
exceeded
for
estuarine/
marine
invertebrates.
However,
this
risk
to
estuarine/
marine
invertebrates
appeared
to
be
eliminated
if
the
boom
height
is
set
at
150
ft
and
the
droplet
size
at
40
um.

The
Agency
also
evaluated
the
typical
rate
and
found
that
potential
acute
risk
to
estuarine/
marine
invertebrates
could
be
eliminated
with
a
boom
height
of
75ft
and
a
50
um
droplet
size.

Down­
the­
Drain
The
Agency
evaluated
the
pharmacological
uses
of
pyrethrin
in
a
Down­
the­
Drain
model
and
found
that
aquatic
LOCs
were
not
exceeded
for
freshwater
or
estuarine/
marine
organisms.

Risk
to
Terrestrial
Organisms
In
this
screening­
level
risk
assessment,
the
Agency
did
not
find
acute
and
chronic
risks
to
listed
or
non­
listed
mammalian
and
avian
species.
Although
the
Agency
does
not
conduct
a
quantitative
risk
assessment
for
beneficial
insects,
acute
toxicity
studies
with
honey
bees
show
that
pyrethrins
are
highly
toxic,
both
on
a
contact
basis,
and
an
acute
oral
basis.
This
also
suggests
that
pyrethrins
are
toxic
to
nontarget
beneficial
insects,
as
well
as
listed
insect
species.

Risks
to
Endangered
Species
The
acute
level
of
concern
(
LOC)
is
exceeded
for
endangered
and/
or
threatened
species
of
freshwater
fish
and
invertebrates
that
live
in
the
water
column
and
are
associated
with
the
agricultural
uses
of
pyrethrins.
Based
on
a
probit
slope
analysis
to
calculate
the
chance
of
an
individual
event
corresponding
to
the
freshwater
fish,
the
estimated
individual
mortality
associated
with
the
calculated
RQ
values
(
0.05
to
0.54)
range
from
1
in
3.34
x
1014
to
1
in
4.17
x
108
.
For
the
freshwater
invertebrate,
the
estimated
individual
mortality
associated
with
the
calculated
RQ
values
(
0.05
­
0.24)
range
from
1
in
1.0
x
1016
to
1
in
8.44
x
109.

The
acute
level
of
concern
(
LOC)
is
exceeded
for
endangered
and/
or
threatened
species
of
estuarine/
marine
fish
and
invertebrates
that
live
in
the
water
column
and
are
associated
with
the
agricultural
and
mosquito
abatement
uses
of
pyrethrins.
For
estuarine/
marine
fish,
the
estimated
individual
mortality
associated
with
the
calculated
RQ
values
(
0.05
to
0.17)
is
1.0
X
1016.
For
estuarine/
marine
invertebrates
for
agriculture
and
mosquito
abatement
uses,
the
probit
slope
analysis
was
completed
for
both
active
ingredient
and
formulated
product.
Based
on
the
default
slope
estimate
of
4.5,
the
corresponding
chance
of
individual
mortality
for
estuarine/
marine
invertebrates
following
exposure
to
the
formulation
is
1
in
4.17
x
108;
and
based
on
the
slope
estimate
of
4.1,
the
corresponding
chance
of
individual
mortality
for
estuarine/
marine
invertebrates
following
exposure
to
the
technical
grade
active
ingredient
is
1
in
2.08
x
107.

The
listed
species
acute
LOC
is
exceeded
for
sediment
dwelling
estuarine/
marine
invertebrates
that
live
near
the
agricultural
areas.
However,
there
are
no
listed
estuarine/
marine
invertebrates,
so
this
risk
concerns
only
applies
to
non­
listed
species.

The
Agency
is
also
concerned
for
endangered
terrestrial
invertebrates
such
as
beneficial
insects,
as
well
as
listed
species.

Outstanding
Data
Requirements
and
Data
Gaps
Environmental
Fate:
The
environmental
fate
database
for
the
pyrethrins
was
completed
with
a
representative
pyrethrin:
pyrethrin
1.
However,
the
toxicity
testing
was
done
with
the
mixture
of
compounds.
As
indicated
earlier,
pyrethrin
consists
of
a
mixture
of
six
compounds
that
are
structurally
related,
which
have
the
same
backbone
molecular
structure,
but
different
substituents
at
two
key
sites
of
the
molecule.
These
different
substituents
are
not
expected
to
substantially
change
the
fate
and
transport
properties
of
the
chemicals.
The
general
chemistry
of
the
molecule
is
dictated
by
the
ester
link
located
near
the
center
of
the
structure.
The
environmental
fate
database
is
substantially
complete,
but
it
consists
mostly
of
supplemental
studies.
At
this
time,
the
database
has
been
considered
sufficient
for
a
Tier
I
assessment;
however,
should
additional
refinements
be
needed,
additional
data
may
be
required.

Ecological
Effects:
The
ecological
effects
toxicity
database
is
complete
and
adequate
to
conduct
a
Tier
I
risk
assessment.
Most
of
the
studies
were
classified
as
Core
and
were
conducted
with
the
technical
grade
active
ingredient
(
FEK­
99)
and
a
formulated
product
(
pyrenone
crop
spray).
Further
ecological
effects
data
are
needed
on
pyrethrin
because
of
its
phytotoxic
effects
on
plants
and
potential
risk
to
benthic
organisms.

There
were
no
chronic
studies
with
the
technical
grade
active
ingredient
or
the
formulation
for
estuarine
/
marine
invertebrates
or
fish.
Pyrethrins
are
acutely
toxic
to
estuarine
/
marine
invertebrates
and
fish
at
levels
below
1ppm
(
EC
50
/
LC
50
s
are
less
than
1
ppm)
and
the
chemical
may
be
applied
directly
to
water
for
mosquito
abatement
use.
These
factors
trigger
a
data
requirement
for
submission
of
chronic
studies
with
estuarine
/
marine
fish
and
invertebrates.
However,
using
the
acute
to
chronic
ratio
estimation
method,
it
does
appear
that
chronic
risk
will
be
a
concern
to
invertebrates
in
estuarine/
marine
environments
(
water
column
and
sediment).
Under
guideline
§
72­
4
(
a)
and
(
b),
EFED
is
requesting
submission
of
a
life­
cycle
study
with
an
estuarine/
marine
invertebrate
(
e.
g.,
mysid
shrimp)
and
fish
early
life­
stage
study
with
an
estuarine/
marine
fish
(
e.
g.,
sheepshead
minnow).

No
data
were
submitted
to
evaluate
the
effects
of
pyrethrin
exposure
to
terrestrial
or
aquatic.
However
the
Agency
does
not
consider
pyrethrin
or
the
other
pyrethroids
as
being
phytotoxic
for
the
following
reasons:
1)
the
compound
is
used
as
a
spray
on
agricultural
crops
with
no
phytotoxic
effects;
2)
the
neural
toxic
mode
of
action
precludes
phtotoxic
concerns;
3)
the
Agency
is
not
aware
of
any
incidents
involving
plants
and
cypyrethrin
alone.
The
Agency
is
not
requiring
plant
toxicity
data
at
this
time.

Since
pyrethrins
can
bind
to
particulate
and
sediment
and
are
highly
toxic
to
aquatic
invertebrates,
EFED
has
a
concern
for
acute
and
chronic
risk
to
benthic
organisms.
Therefore,
EFED
is
requesting
that
a
whole
sediment
acute
test
with
the
freshwater
organism,
Chironomus
ripirians
(
Guideline
number
850.1735)
and
the
marine
water
organism,
Leptocheirus
plumulosus
(
Guideline
number
850.1740)
be
submitted
to
fully
evaluate
potential
risk
to
benthic
organisms.

Additionally,
no
chronic
avian
toxicity
data
were
submitted,
but
the
Agency
is
not
requesting
these
data
at
this
time.

Uncertainties:
There
is
uncertainty
with
respect
to
the
environmental
fate
studies
that
were
deemed
supplemental.
Some
problems
were
found
in
these
studies
and
there
is
uncertainty
associated
with
the
use
of
these
end
points.
Furthermore,
the
terrestrial
field
dissipation
study
was
waived
and
the
results
of
the
laboratory
study
could
not
be
corroborated
with
real
life
situations
in
the
field.
The
fact
that
a
single
chemical
(
pyrethrin
1)
was
chosen
as
a
surrogate
compound
or
representative
for
the
other
six
pyrethrins
may
be
a
source
of
some
uncertainty.
The
uncertainties
associated
with
pyrethrin
exposure
in
the
environment
are
mainly
focused
on
the
possible
impact
to
aquatic
ecosystems.
Since
pyrethrin
is
highly
toxic
to
fish
and
invertebrates,
there
is
a
question
of
sustaining
functional
diversity
in
a
system
that
has
been
exposed
to
toxic
drift
or
runoff.
Proponents
for
the
use
of
pyrethrin
in
agricultural
settings
argue
that
invertebrates
are
resilient
and
affected
populations
will
reintroduce
themselves
in
time.
EFED
believes
that
the
degree
of
reintroduction
of
species
that
are
keystone
to
an
ecosystem
is
uncertain,
and
the
impact
of
diminished
invertebrate
diversity
on
ecosystem
integrity
has
not
yet
been
adequately
evaluated.
In
addition
to
a
direct
impact
on
invertebrate
diversity,
EFED
is
also
concerned
with
the
indirect
effects
of
food
chain
alterations
that
could
influence
fish
populations
that
are
dependent
upon
aquatic
invertebrates
Although
pyrethrins
bind
and
accumulate
in
sediments,
EFED
did
not
have
sediment
monitoring
or
toxicity
data
to
adequately
evaluate
this
potential
risk
to
benthic
organisms.
However,
this
uncertainty
was
addressed
by
using
model
derived
exposure
values
for
sediment
and
pore
water.
The
estimated
environmental
concentrations
(
EECs)
that
were
used
to
calculate
RQ
values
were
the
pore
water
output
of
the
PRZM/
EXAMS
model,
while
the
effects
data
were
standard
worst
case
water
column
test
(
e.
g.,
EC50
daphnia).
Although
the
sediment
systems
is
assumed
to
adsorbed
a
large
portion
of
the
chemical
over
a
short
period
of
time,
EFED
chose
to
use
the
resulting
concentrations
in
pore
water
that
are
at
equilibrium
with
sediment
loads
for
the
EECs.
However,
EFED
also
realizes
that
there
is
uncertainty
regarding
the
amount
of
sorbed
pesticide
that
may
contribute
to
the
toxicity
of
organisms
that
feed
directly
on
the
sediment
itself.
Therefore,
the
assumed
risk
to
benthic
organisms
has
the
potential
to
be
greater
than
originally
surmised.

EFED
Label
Recommendations
Manufacturing
Use:
Do
not
discharge
effluent
containing
this
product
into
lakes,
streams,
ponds,
estuaries,
oceans
or
other
waters
unless
in
accordance
with
the
requirements
of
a
National
Pollutant
Discharge
Elimination
System
(
NPDES)
permit
and
the
permitting
authority
has
been
notified
in
writing
prior
to
discharge.
Do
not
discharge
effluent
containing
this
product
to
sewer
systems
without
previously
notifying
the
local
sewage
treatment
plant
authority.
For
guidance
contact
your
State
Water
Board
or
Regional
Office
of
the
EPA.
Do
not
contaminate
water
when
disposing
of
equipment
washwaters

End
Use
Products:
This
product
is
toxic
to
fish
and
aquatic
invertebrates.
This
product
may
contaminate
water
through
drift
of
spray
in
wind
or
via
runoff
events.
Use
care
when
applying
in
areas
adjacent
to
any
body
of
water.
Do
not
apply
directly
to
water,
to
areas
where
surface
water
is
present
or
to
intertidal
areas
below
the
mean
high
water
mark.
Do
not
apply
when
weather
conditions
favor
drift
from
target
area.
Do
not
contaminate
water
when
disposing
of
equipment
wash­
waters
or
rinsate.

Label
statements
for
spray
drift
management:
The
Agency
has
been
working
with
the
Spray
Drift
Task
Force,
EPA
Regional
Offices
and
State
Lead
Agencies
for
pesticide
regulation
and
other
parties
to
develop
the
best
spray
drift
management
practices.
The
Agency
is
proposing
interim
mitigation
measures
for
aerial
applications
that
should
be
placed
on
product
labels/
labeling.
The
Agency
has
completed
its
evaluation
of
the
new
data
base
submitted
by
the
Spray
Drift
Task
Force,
a
membership
of
U.
S.
pesticide
registrants,
and
is
developing
a
policy
on
how
to
appropriately
apply
the
data
and
the
AgDRIFT
computer
model
to
its
risk
assessments
for
pesticides
applied
by
air,
orchard
airblast
and
ground
hydraulic
methods.
After
the
policy
is
in
place,
the
Agency
may
impose
further
refinements
in
spray
drift
management
practices
to
reduce
off­
target
drift
and
risks
associated
with
aerial
as
well
as
other
application
types
where
appropriate.

The
results
of
this
risk
assessment
indicate
that
for
many
of
the
crop
scenarios
the
level
of
spray
drift
is
an
important
component
of
the
concentrations
observed
in
adjacent
bodies
of
water.
Since
pyrethrin
was
found
to
be
highly
toxic
to
various
aquatic
animals,
the
risk
managers
have
to
pay
special
attention
to
the
labels
statements
placed
to
the
pyrethrin
products.

For
mosquito
abatement,
application
directions
in
the
label
are
insufficient
to
accurately
estimate
aquatic
exposures
that
result
from
application
of
pyrethrin
for
controlling
mosquitoes.
Limitations
(
as
opposed
to
recommendations)
on
product
labels
for
key
parameters
such
as
droplet
size,
wind
speed,
release
height,
application
interval,
and
number
of
applications
allowed
per
year
are
not
specified.
This
exposure
assessment
represents
the
water
concentrations
expected
from
a
typical,
low­
level
aerial
application.
Concentrations
resulting
from
actual
application
of
pyrethrin
for
mosquito
control
could
be
significantly
higher
than
modeled
concentrations
if
applicators
used
different
application
parameters.
Tables
A
and
B
show
the
Ecological
Effects
and
Environmental
Fate
Data
Requirements
for
Pyrethrin
Table
A.
Ecological
Effects
Data
Requirements
for
Pyrethrin.

Guideline
number
Data
requirement
Are
further
data
needed?
Study
ID
#
Study
classificationa
71­
1
Avian
oral
LD50
No
420109­
01
Core
71­
2
Avian
dietary
LC50
No
419688­
01
419688­
02
Core
71­
4
Avian
reproduction
No
No
data
No
data
72­
1
Freshwater
fish
LC50
No
430823­
01
430823­
02
430823­
03
430823­
04
Core
Core
Core
Core
Core
Core
72­
2
Freshwater
invertebrate
acute
LC50
No
430823­
05
430823­
06
Core
Core
72­
3(
a)
Estuarine/
marine
fish
LC50
No
430823­
07
430823­
08
Core
Core
72­
3(
b)
Estuarine/
marine
mollusk
LC50
No
430823­
09
430823­
10
Core
Core
72­
3(
c)
Estuarine/
marine
shrimp
LC50
No
430823­
11
430823­
12
Core
Core
72­
4(
a)
Freshwater
fish
early
life­
stage
No
432527­
01
Core
72­
4(
a)
Estuarine/
marine
fish
early
lifestage
Yes
No
data
No
data
72­
4(
b)
Freshwater
Aquatic
invertebrate
life­
cycle
No
432527­
02
Core
72­
4(
b)
Estuarine/
marine
invertebrate
lifecycle
Yes
No
data
No
data
72­
5
Freshwater
fish
full
life­
cycle
No
No
data
No
data
122­
1(
a)
Seed
germination/
seedling
emergence
(
Tier
I)
No
No
data
No
data
122­
1(
b)
Vegetative
vigor
(
Tier
I)
No
No
data
No
data
122­
2
Aquatic
algal
growth
No
No
data
No
data
123­
2
Duckweed
(
Lemna
gibba)
No
No
data
No
data
Table
A.
Ecological
Effects
Data
Requirements
for
Pyrethrin.

Guideline
number
Data
requirement
Are
further
data
needed?
Study
ID
#
Study
classificationa
123­
1(
a)
Seed
germination/
seedling
emergence
(
Tier
II)
No
No
data
No
data
123­
1(
b)
Vegetative
vigor
(
Tier
II)
No
No
data
No
data
123­
2
Aquatic
plant
growth
No
No
data
No
data
144­
1
Honey
bee
acute
contact
LD50
No
419688­
03
Atkins
et
al.,
1967
Stevenson,
1968
Stevenson,
1978
Core
Supplemental
Supplemental
Supplemental
141­
2
Honey
bee
residue
on
foliage
No
N/
A
N/
A
850.1735
Whole
sediment
acute,
freshwater
Yes
N/
A
N/
A
850.174
Whole
sediment
acute,
marine
Yes
N/
A
N/
A
aCore:
study
satisfies
guideline;
Supplemental:
study
is
scientifically
sound,
but
does
not
satisfy
guideline
Table
B.
Environmental
Fate
Data
Requirements
for
Pyrethrin.

Guideline
#
Data
Requirement
Are
further
data
needed?
MRID
#'
s
Study
Classification
161­
1
835.2120
Hydrolysis
no
43188201,
43567502
Core
161­
2
835.2240
Photodegradation
in
Water
no
43096601,
43567601
Supplemental
161­
3
835.2410
Photodegradation
on
Soil
no
43096602
Supplemental
161­
4
835.2370
Photodegradation
in
Air
no
NA
Waived
162­
1
835.4100
Aerobic
Soil
Metabolism
no
43499803
Supplemental
162­
2
835.4200
Anaerobic
Soil
Metabolism
no
43499802
Supplemental
162­
3
835.4400
Anaerobic
Aquatic
Metabolism
no
NA
Not
Required
162­
4
835.4300
Aerobic
Aquatic
Metabolism
no
43499801
Supplemental
163­
1
835.1240
835.1230
Leaching­
Adsorption/
Des
orption
no
43096603
Core
163­
2
835.1410
Laboratory
Volatility
no
43096604
Core
163­
3
835.8100
Field
Volatility
no
NA
Waived
164­
1
835.6100
Terrestrial
Field
Dissipation
no
42745501
Waived1
164­
2
835.6200
Aquatic
Field
Dissipation
no
43818501
Waived1
164­
3
835.6300
Forestry
Dissipation
no
NA
Not
Required
165­
4
850.1730
Accumulation
in
Fish
no
43302301,
43884102
Core
Table
B.
Environmental
Fate
Data
Requirements
for
Pyrethrin.

Guideline
#
Data
Requirement
Are
further
data
needed?
MRID
#'
s
Study
Classification
165­
5
850.1950
Accumulation
 
Aquatic
Nontarget
Organisms
no
NA
Waived
166­
1
835.7100
Groundwater
 
Small
Prospective
no
NA
Waived1
201­
1
840.1100
Droplet
Size
Spectrum
no
NA
Not
Required2
202­
1
840.1200
Spray
Drift
Field
Evaluation
no
NA
Not
Required2
1.
Waived
based
on
its
low
persistence
and
mobility
and
other
environmental
fate
characteristics.
2.
The
registrant
is
a
member
of
the
Spray
Drift
Task
Force
and
the
data
requirement
is
covered
by
the
data
produced
by
this
coalition.
Preliminary
Science
Assessment
for
the
Reregistration
Eligibility
Decision
(
RED)
Document
for
Case
2580:
PYRETHRIN
Prepared
by:
Jerry
L.
Ellis,
Jr.,
Biologist
José
L.
Meléndez,
Chemist
Miachel
Rexrode,
Ph.
D.,
Fishery
Biologist
United
States
Environmental
Protection
Agency
Office
of
Pesticide
Programs
Environmental
Fate
and
Effects
Division
Environmental
Risk
Branch
V
Ariel
Rios
Building
1200
Pennsylvania
Ave.,
NW
Mail
Code
7507C
Washington,
DC
20460
Reviewed
by:
Jean
Holmes,
RAPL
Mah
T.
Shamim,
Ph.
D.,
Chief
Environmental
Risk
Branch
V
­
1­
Table
of
Contents
Table
of
Contents
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1
I.
Executive
Summary
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1
A.
Risks
to
Non­
target
Organisms
.
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2
B.
Nature
of
Chemical
Stressor
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3
C.
Conclusions
­
Exposure
Characterization
.
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3
D.
Conclusions
­
Effects
Characterization
.
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5
II.
Problem
Formulation
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.
5
A.
Stressor
Source
and
Distribution
.
.
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.
.
5
1.
Physical­
Chemical
and
Fate
and
Transport
Properties
.
.
.
.
.
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.
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.
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.
.
.
6
2.
Mode
of
Action
.
.
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.
.
7
3.
Overview
of
Pesticide
Usage
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
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.
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.
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.
.
.
.
8
B.
Receptors:
Ecological
Effects
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
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.
.
.
.
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.
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.
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.
.
.
.
.
.
.
.
8
C.
Assessment
Endpoints
.
.
.
.
.
.
.
.
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.
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.
.
9
D.
Conceptual
Model
.
.
.
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11
1.
Risk
Hypotheses
.
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.
11
2.
Diagram
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11
E.
Analysis
Plan
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15
1.
Develop
Assessment
Design
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15
2.
Identification
of
Data
Gaps
and
Methods
for
Conducting
Assessment
.
.
.
.
.
15
3.
Measures
to
Evaluate
Risk
Hypotheses
and
Conceptual
Model
.
.
.
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16
a.
Measures
of
Exposure
.
.
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16
b.
Measures
of
Effect
.
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19
III.
Analysis
.
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19
A.
Use
Characterization
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19
B.
Exposure
Characterization
.
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.
23
1.
Environmental
Fate
and
Transport
Characterization
.
.
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.
23
2.
Measures
of
Aquatic
Exposure
.
.
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.
.
33
a.
Aquatic
Exposure
Modeling
for
Agricultural
Crops
.
.
.
.
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.
.
33
b.
Aquatic
Exposure
Modeling
for
Mosquito
Abatement
.
.
.
.
.
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.
.
45
c.
Aquatic
Exposure
"
Down­
the­
Drain"
Assessment
.
.
.
.
.
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.
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.
.
.
57
d.
Aquatic
Exposure
Monitoring
(
Field
Data)
.
.
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.
.
59
3.
Measures
of
Terrestrial
Exposure
.
.
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.
59
4.
Non­
Target
Plant
Exposures
.
.
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.
60
C.
Ecological
Effects
Characterization
.
.
.
.
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.
.
60
1.
Aquatic
Effects
.
.
.
.
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.
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.
.
60
a.
Aquatic
Animals
.
.
.
.
.
.
.
.
.
.
.
.
.
.
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.
.
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.
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.
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.
.
.
60
b.
Aquatic
Plants
.
.
.
.
.
.
.
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.
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.
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.
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.
.
.
.
.
.
.
68
2.
Terrestrial
Effects
.
.
.
.
.
.
.
.
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.
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.
.
.
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.
.
.
.
.
.
68
­
2­
a.
Terrestrial
Animals
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
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.
.
.
.
.
.
.
.
.
.
.
.
68
b.
Terrestrial
Plants
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
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.
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.
.
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.
.
.
.
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.
.
.
.
.
69
IV.
Risk
Characterization
.
.
.
.
.
.
.
.
.
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.
.
60
A.
Risk
Estimation
­
Integration
of
Exposure
and
Effects
Data
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
60
1.
Non­
target
Aquatic
Animals
and
Plants
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
60
a.
Fish
and
Aquatic
Invertebrates
­
Agricultural
Uses
and
Mosquito
Abatement
Uses
and
Down
the
Drain
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
70
b.
Sediment
Organisms
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
87
2.
Non­
target
Terrestrial
Animals
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
89
a.
Mammals
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
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.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
89
b.
Birds
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
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.
.
.
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.
.
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.
.
.
.
.
.
.
.
.
.
89
c.
Insects
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
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.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
90
3.
Non­
target
Terrestrial
and
Semi­
aquatic
Plants
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
91
B.
Risk
Description
­
Interpretation
of
Effects
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
91
1.
Estimating
Risks
to
Aquatic
Systems
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
92
2.
Estimating
Risks
to
Terrestrial
Organisms
(
Mammals
and
Birds)
.
.
.
.
.
.
.
.
.
95
3.
Review
of
Incident
Data
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
96
a.
Incidents
Involving
Aquatic
Organisms
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
97
b.
Incidents
Involving
Terrestrial
Organisms
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
97
4.
Endocrine
Effects
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
99
5.
Threatened
and
Endangered
Species
Concerns
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
99
a.
Taxonomic
Groups
Potentially
at
Risk
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
100
b.
Action
Area
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
100
c.
Indirect
Effects
Analysis
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
101
d.
Critical
Habitat
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
103
C.
Description
of
Assumptions,
Uncertainties,
Strengths,
and
Limitations
.
.
.
.
.
.
.
.
.
103
1.
Assumptions
and
Limitations
Related
to
Exposure
For
All
Taxa
.
.
.
.
.
.
.
.
103
2.
Assumptions
and
Limitations
Related
to
Exposure
For
Aquatic
Species
.
.
103
3.
Assumptions
and
Limitations
Related
to
Exposure
For
Terrestrial
Species
.
103
4.
Assumptions
and
Limitations
Related
to
Effects
Assessment
.
.
.
.
.
.
.
.
.
.
.
105
5.
Assumptions
Associated
With
the
Acute
LOCs
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
106
V.
Literature
Cited
.
.
.
.
.
.
.
.
.
.
.
.
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.
.
.
107
ACKNOWLEDGMENT
.
.
.
.
.
.
.
.
.
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.
.
.
.
.
.
107
VI.
Appendices
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
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.
.
.
.
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.
.
.
.
.
.
.
.
.
.
.
.
Appendices
Page
Number
APPENDIX
A.
Environmental
Fate
Studies
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
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.
.
.
.
.
.
.
1
APPENDIX
B.
Aquatic
Exposure
Assessment
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
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.
.
.
.
.
.
.
15
APPENDIX
C.
T­
REX
Model
and
Results
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
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.
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.
.
.
.
.
.
.
.
134
APPENDIX
D.
TerrPlant
Model
and
Results
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
137
APPENDIX
E.
Ecological
Effects
Data
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
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.
.
.
.
.
.
.
.
.
138
APPENDIX
F.
Risk
Quotient
Method
and
Levels
of
Concern
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
151
­
3­
APPENDIX
G.
Literature
Cited
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
153
APPENDIX
H.
Summary
of
Endangered/
Threatened
Species
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
154
APPENDIX
J.
Data
Requirements
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
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.
.
.
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.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
175
APPENDIX
K.
Ecotoxicity
and
Environmental
Fate
Bibliography
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
182
APPENDIX
L.
Mosquito
Abatement
Modeling
Using
AGDISP
v.
8.07
.
.
.
.
.
.
.
.
.
.
189
APPENDIX
N.
T­
REX
Output
File
for
Typical
Application
Rate..........................
388
APPENDIX
O.
AgDRIFT
®
and
PRZM/
EXAMS
Input
and
Output
Files
for
Drift
and
Buffer
Zones
Analysis..
........................................................
392
APPENDIX
P.
Equilibrium
Partitioning
Model
and
Risk
Estimation
for
Benthic
Organisms...........................
........................................................
448
APPENDIX
Q.
EPIWIN
Output
Files
and
"
Down­
the­
Drain"
Output
Files.....................................
........................................................
452
­
1­
I.
Executive
Summary
A.
Risks
to
Non­
target
Organisms
The
Agency's
screening­
level
risk
assessment
for
pyrethrin,
is
focused
on
maximum
and
typical
application
rates
for
agricultural,
and
mosquito
abatement
uses.
Consideration
was
also
given
for
pharmacological
uses
in
a
"
Down­
the­
Drain"
scenario.

For
terrestrial
organisms,
the
level
of
concern
was
not
exceeded
for
acute
or
chronic
risk
to
listed
or
non­
listed
mammals
or
birds.
Although
EFED
does
not
conduct
risk
assessments
on
non­
target
terrestrial
insects,
toxicity
studies
show
that
pyrethrins
are
toxic
to
the
honey
bee
on
an
acute
contact
and
oral
basis.

Risk
to
Aquatic
Organisms
(
Maximum
and
Typical
Application
Rates)

°
Agricultural
Uses:
Maximum
application
of
pyrethrin
to
various
crops
can
result
acute
and
chronic
risks
to
aquatic
organisms:
freshwater
and
estuarine/
marine
fish
and
invertebrates
(
including
sediment­
dwelling
organisms).
This
screening­
level
assessment
shows
the
potential
for
exceeding
LOCs
for
acute
risk,
restricted
use,
and
endangered
species,
as
well
as
chronic
risk.

°
The
greatest
risk
(
i.
e.,
highest
exceedance
of
LOCs)
among
aquatic
receptors
evaluated
was
for
aquatic
invertebrates
(
both
freshwater
and
estuarine/
marine).

°
Typical
application
rates
appear
to
reduce
risk
to
aquatic
organisms.
The
LOCs
for
freshwater
and
estuarine/
marine
fish
and
invertebrates
should
not
be
exceeded
under
this
exposure
scenario.

Mosquito
abatement:
In
general
maximum
application
showed
that
the
major
acute
risk
concern
was
for
estuarine/
marine
invertebrates.
However,
the
acute
risk
to
estuarine/
marine
invertebrates
appears
to
be
eliminated
if
boom
height
is
set
at
150ft
and
the
droplet
size
set
at
40
um.
Acute
risk
to
freshwater
fish
and
invertebrates
or
estuarine/
marine
fish
does
not
appear
to
be
an
ecological
concern
from
mosquito
abatement
use
(
maximum
or
typical
application
rate).

°
The
typical
application
rate
reduced
residue
exposure
to
aquatic
areas
by
about
20
­
50%.
The
risk
to
the
most
vulnerable
aquatic
organisms
(
estuarine/
marine
invertebrates)
could
be
eliminated
if
boom
height
is
set
at
a
minimum
boom
height
of
75ft
and
a
corresponding
droplet
size
of
50
um.

°
Down­
the­
Drain:
The
Agency
evaluated
the
possible
exposure
to
aquatic
systems
from
the
pharmacological
uses
of
pyrethrin.
The
Down­
the­
Drain
assessment
(
various
processing
scenarios
of
wastewater
through
treatment
plants)
showed
that
expected
pyrethrin
residues
should
not
exceed
the
LOCs
for
freshwater
and
estuarine/
marine
fish
or
invertebrates.
­
2­
°
Pyrethrins
have
generally
effective
"
knockdown"
potential
but
their
toxicity
is
usually
enhanced
through
the
use
of
synergist
like
piperonyl
butoxide
(
PBO).
In
order
to
be
inclusive,
EFED
has
addressed
potential
aquatic
risk
from
the
PBO
formulation.
Risk
quotients
were
calculated
using
the
technical
grade
active
ingredient
for
the
agricultural
uses
and
formulated
product
(
PYRENONE
®

Crop
Spray,
EPA
Registration
No.
432­
1033
)
for
the
mosquito
abatement
uses.
However,
EFED
also
calculated
potential
risk
from
PBO
formulation
use
on
agricultural
crops,
which
showed
that
acute
risk
to
freshwater
and
estuarine/
marine
fish
and
invertebrates
could
increase
up
to
10X
for
all
crop
scenarios.
Piperonyl
butoxide,
as
a
synergist,
is
used
to
enhance
the
pesticidal
properties
of
the
active
ingredients
by
competitive
inhibition
of
detoxifying
enzymes
(
cytochrome
P450).

°
Acute
and
chronic
risk
estimates
for
birds
and
small
mammals
associated
with
the
agricultural
uses
The
acute
and
chronic
levels
of
concern
(
LOCs)
were
not
exceeded
for
listed
or
non­
listed
mammals
or
birds.

°
Toxicity
and
risk
concerns
about
degradates
of
pyrethrins
Although
toxicity
studies
on
the
degradates
were
not
provided,
an
evaluation
of
the
structures
indicate
that
they
are
the
result
of
the
rupture
of
the
ester
bridge
of
the
parent,
resulting
in
a
carboxylic
acid
(
chrysanthemic
acid),
and
an
alcohol
(
that
subsequently
can
be
degraded
to
an
acid
as
well).
The
resulting
molecules
have
lost
their
pyrethroid
toxicological
activity,
therefore,
in
this
assessment,
they
were
not
considered
of
concern.
Furthermore,
the
available
data
indicated
that
chrysanthemic
acid
was
formed
at
low
levels
except
under
hydrolytic
conditions
at
pH
9.

B.
Nature
of
Chemical
Stressor
Pyrethrin
is
a
mixture
of
naturally
occurring
insecticides
derived
from
the
flowers
of
Chrysanthemum
cinerariaefolium
and
Chrysanthemum
cineum.
The
six
individual
pyrethrins
are
pyrethrin
1,
pyrethrin
2,
cinerin
1,
cinerin
2,
jasmolin
1,
and
jasmolin
2.
These
compounds
are
esters
of
a
carboxylic
acid
and
a
cyclopentenolone
(
chrysanthemic
acid
and
pyrethric
acid)
and
three
cyclopentenolones
(
pyrethrolone,
cinerolone,
and
jasmolone).
The
technical
grade
active
ingredient
(
FEK­
99)
is
commonly
referred
to
as
pyrethrum
extract,
which
is
the
sum
of
Pyrethrins
I
(
the
esters
of
chrysanthemic
acid
­
pyrethrin
1,
cinerin
1,
and
jasmolin
1)
and
Pyrethrins
II
(
the
esters
of
pyrethric
acid
­
pyrethrin
2,
cinerin
2,
and
jasmolin
2),
also
called
"
the
pyrethrins",
and
this
mixture
constitutes
45
to
55%
of
pyrethrum
extract.
In
the
US,
the
pyrethrum
extract
is
standardized
as
45­
55%
w/
w
total
pyrethrins,
as
indicated
earlier.
The
typical
proportion
of
Pyrethrins
I
to
II
is
1:
14,
while
the
ratio
of
pyrethrin:
cynerins:
jasmolins
is
71:
21:
7
(
Tomlin
1997).

Pyrethrins
are
used
as
insecticides
in
agriculture,
pet
care,
domestic
home
and
garden,
and
commercial/
industrial/
institutional
settings,
and
for
mosquito
abatement.
The
final
formulation
and
application
method
depends
upon
the
market
sector
for
which
pyrethrins
are
being
used.
Pyrethrins
are
non­
systemic
insecticides
that
work
by
physical
contact
to
the
insect
or
by
ingestion,
and
they
have
a
slight
repellent
effect.
The
toxicity
of
pyrethrins
is
due
to
their
action
on
the
sodium
channel
­
3­
of
nerve
cells.
The
formulated
pyrethrins
pesticide
mixture
usually
contain
a
synergist,
such
as
piperonyl
butoxide,
piperonyl
sulfoxide,
or
sesamex.
These
compounds
enhance
the
insecticidal
activity
of
the
pesticide
by
preventing
some
enzymes
in
the
organism
from
breaking
down
the
pyrethrins.

According
to
the
Master
Label
there
are
19
formulation
types
and
45
application
equipment
types
for
pyrethrin
products
for
agricultural
purposes.
There
are
17
formulation
types
for
pet
care,
16
formulation
types
for
domestic/
home
and
garden,
and
20
formulation
types
for
commercial/
industrial/
institutional
settings.
Equipment
types
for
agricultural
crops
include
such
examples
as
fixed
wing
aircraft,
and
helicopter.

Since
it
is
difficult
to
evaluate
the
environmental
fate
properties
of
a
mixture,
pyrethrin
1
was
selected
as
a
surrogate
for
all
the
pyrethrins
to
generate
the
environmental
fate
data.
As
indicated
earlier,
the
six
compounds
have
similar
molecular
structure,
but
with
different
substituents
at
two
sites.
The
individual
chemical
structures
of
all
six
pyrethrins
are
shown
in
Figure
1
of
Appendix
A.
Since
the
chemicals
are
structurally
very
similar,
they
are
expected
to
have
similar
environmental
fate
properties.
However,
the
toxicity
testing
was
done
with
the
mixture
of
compounds.
FEK­
99
was
used
to
estimate
risk
to
non­
target
organisms
that
are
associated
with
the
agricultural
crop
scenarios.
Toxicity
data
on
the
formulated
product,
PYRENONE
®
Crop
Spray
(
EPA
Registration
No.
432­
1033),
were
used
to
evaluate
risk
to
non­
target
organisms
in
the
scenarios
that
involve
direct
application
to
water
(
such
as
the
mosquito
abatement
use).

C.
Conclusions
­
Exposure
Characterization
Based
on
the
data
obtained
with
pyrethrin
1,
which
was
chosen
as
a
surrogate
for
all
the
six
pyrethrins,
the
following
conclusions
were
derived
for
these
compounds:
Pyrethrins
are
considered
to
be
persistent
in
certain
environments
and
short
lived
in
other
environments.
They
are
stable
to
hydrolysis
under
neutral
and
acidic
conditions
(
pH
5
&
7)
but
quickly
photodegrade
in
shallow
clear
water.
Pyrethrins
adsorb
strongly
to
soil
surfaces
and
are
generally
considered
immobile
in
soils
(
K
oc
range
12,400
to
37840);
therefore,
the
potential
to
leach
into
groundwater
is
considered
low.
They
could
reach
surface
water
via
spray
drift
or
runoff
events
accompanied
by
erosion
where
they
quickly
adsorb
to
suspended
solids
in
the
water
column,
and
partition
into
the
sediment.
Sediments
are
likely
to
be
an
environmental
sink
for
any
non­
degraded
pyrethrins
since
they
appear
to
persist
under
anaerobic
conditions.
Biodegradation
under
aerobic
conditions
occurs
fairly
rapidly
with
half­
lives
of
a
few
days
Hydrolysis
under
alkaline
conditions
is
also
an
important
route
of
dissipation
for
pyrethrins
in
water
(
half­
life
at
pH
9
14­
17
hours);
however,
this
reaction
appears
to
be
relatively
slow
under
neutral
or
acidic
conditions.
Volatilization
is
not
expected
to
be
an
important
transport
process
since
pyrethrins
tend
to
have
relatively
low
vapor
pressure
and
Henry's
Law
constant.

An
evaluation
of
the
structures
of
the
degradation
products
of
pyrethrins,
indicate
that
they
are
the
result
of
the
rupture
of
the
ester
bridge
of
the
parent,
resulting
in
a
carboxylic
acid
(
chrysanthemic
acid),
and
an
alcohol
(
that
could
subsequently
be
degraded
to
an
acid
as
well).
The
available
data
indicated
that
chrysanthemic
acid
was
formed
in
small
amounts
except
under
hydrolytic
conditions
at
pH
9
and
the
degradation
products
were
deemed
of
low
concern.
In
the
majority
of
the
studies
­
4­
multiple
degradates
at
very
low
concentrations
were
observed,
but
not
characterized.
The
only
other
significant
isomer
observed
in
the
aqueous
photolysis
study
was
designated
(
E)­
isomer
of
pyrethrin
1.

The
bioconcentration
factor
for
14C
residues
in
edible
tissues
of
fish
was
found
to
be
127X.
The
predominant
species
present
in
the
tissues
were
parent
pyrethrin
and
chrysanthemic
acid.

The
effect
of
spray
drift,
and
the
use
of
buffer
zones
in
reducing
exposure
to
bodies
of
water
adjacent
to
treated
areas
was
investigated.
The
first
step
was
to
determine
if
spray
drift
was
the
predominant
mode
for
transport
of
pyrethrins
to
surface
water.
Four
crop
scenarios
were
selected
for
this
evaluation
which
represented
a
wide
range
of
geographical
locations
within
the
continental
US.
PRZM/
EXAMS
model
was
run
with
the
spray
drift
set
to
0%
and
the
results
were
compared
to
the
runs
where
the
spray
drift
was
set
at
5%.
For
ID
potato
and
CA
grapes,
the
percent
of
the
peak
EEC
attributable
to
spray
drift
was
very
high
(
88.5
and
94.5%,
respectively),
for
FL
citrus
and
GA
peaches,
the
percent
of
the
peak
EEC
related
to
spray
drift
appeared
to
be
more
moderate
(
44.9
and
47.6%,
respectively).
The
next
step
was
the
buffer
zone
analysis,
where
the
choice
of
crop
scenarios
was
narrowed
down
to
GA
peaches
and
ID
potatoes.
AgDRIFT
®
model
was
used
to
run
a
"
high
end"
(
conservative)
and
a
"
low
end"
(
best
case)
drift
scenario.
Two
sets
of
spray
drift
values
were
generated:
using
a
spray
volume
of
10
gal./
A
for
orchards
and
2
gal./
A
for
other
crops,
each
with
buffer
zones
of
0,
50,
100,
150
ft.
The
resulting
spray
drift
values
were
used
as
inputs
in
PRZM/
EXAMS
for
the
two
crop
scenarios.
As
expected,
the
low
end
(
best
case)
drift
scenario
resulted
in
substantially
lower
EECs.
Using
the
endpoint
for
the
most
sensitive
species,
RQs
were
calculated
for
the
GA
peaches
which
also
represented
orchards.
The
magnitude
of
the
exceedance
for
the
high
end
drift
scenario
with
50
ft.
buffer
zone
was
about
3.6
times
higher
compared
to
the
low
end
drift
scenario
with
150
ft.
buffer
zone.
For
the
ID
potatoes
(
representative
of
other
crops),
the
magnitude
of
the
exceedance
of
the
RQs
was
about
25
times
higher
for
the
high
end
scenario
with
a
50
ft.
buffer
zone
compared
with
the
low
end
drift
scenario
with
a
150
ft.
buffer
zone.
The
results
of
the
ground
application
and
the
low
end
drift
scenario
with
a
150
ft.
buffer
zone
yielded
RQs
of
similar
order
of
magnitude.

For
the
mosquito
adulticide
use,
pyrethrins
are
applied
as
very
small
droplets
to
create
a
mist
which
remains
suspended
over
the
field
to
more
efficiently
target
the
mosquitoes.
Therefore,
they
are
susceptible
to
drift
towards
an
adjacent
body
of
water.
To
determine
the
deposition
of
the
pesticide
to
adjacent
water
bodies,
the
computer
model
AGDISP
[
AGricultural
DISPersal
(
computer)
model
(
AGDISP)]
was
used.
The
results
from
AGDISP
were
subsequently
used
as
input
parameters
in
PRZM/
EXAMS
to
model
the
degradation
and
partitioning
in
sediment
for
water
bodies
of
various
depths
(
6
in,
1
ft.,
1
m,
and
2
m)
that
may
be
exposed
to
drift
from
the
mosquito
adulticide.
It
was
found
that
the
shallow
pond
shows
the
lower
concentration,
possibly
due
to
partitioning
of
the
chemical
with
the
sediment.
Variables
that
have
a
high
impact
on
the
aquatic
EECs
are
the
boom
height
(
the
higher
the
boom
height,
the
levels
of
deposition),
the
droplet
size
(
the
smaller
droplets,
the
lower
the
levels
of
deposition),
the
wind
speed
(
too
low
wind
speeds
favor
higher
deposition),
and
obviously
the
application
rate
(
it
appears
that
for
many
of
the
products
the
maximum
application
rate
is
lower
than
the
maximum
application
rate
stated
in
the
Master
Label
[
0.0025
lb
a.
i./
A
vs
0.008
lb
a.
i./
A]).
The
interval
between
applications
and
the
number
of
applications
are
expected
to
have
­
5­
also
an
effect
on
the
EECs
(
similar
to
an
agricultural
application).

D.
Conclusions
­
Effects
Characterization
The
ecological
effects
laboratory
studies
were
conducted
with
the
technical
grade
active
ingredient
(
FEK­
99)
for
agricultural
uses
and
the
formulated
product,
PYRENONE
®
Crop
Spray
(
EPA
Registration
No.
432­
1033)
for
mosquito
abatement
uses.

For
aquatic
species,
pyrethrins
are
shown
to
be
very
highly
toxic
on
an
acute
basis
to
both
freshwater
and
estuarine/
marine
fish
and
invertebrates
(
based
on
the
TGAI
and
formulation).
Acute
studies,
conducted
with
the
formulation,
showed
slightly
more
toxic
endpoints
compared
to
studies
with
the
TGAI.
Chronic
toxicity
studies
(
using
the
TGAI)
with
freshwater
organisms
show
that
the
most
sensitive
endpoint
for
fish
is
growth
(
length
and
dry
weight)
and
reproduction
for
invertebrates.
The
chronic
NOAEC
for
freshwater
fish
and
invertebrates
was
1.9
and
0.86
:
g/
L,
respectively.
No
data
were
submitted
to
evaluate
the
chronic
risk
to
estuarine/
marine
fish
or
invertebrates.
However,
the
acute­
to­
chronic
ratio
method
was
used
to
estimate
NOAECs
for
estuarine/
marine
fish
(
NOAEC
estimate
of
5.9
ppb)
and
invertebrates
(
NOAEC
estimate
of
0.10
ppb).
Since
pyrethrins
tend
to
partition
into
the
sediment
compartment,
toxicity
data
for
the
sediment
dwelling
organisms
are
needed.

The
TGAI
was
the
test
substance
used
in
the
bird
and
laboratory
rat
toxicity
tests.
Pyrethrins
appear
to
be
practically
non­
toxic
to
avian
species
on
an
acute
oral
and
dietary
basis.
Chronic
avian
risk
was
extrapolated
by
using
surrogate
data
(
pyrethrin
Bobwhite
quail
NOAEC
=
125
mg/
kg/
diet)
and
suggest
minimal
chronic
risk
to
avian
species.
Toxicity
studies
with
rats
suggest
that
pyrethrins
can
be
categorized
as
slightly
toxic
to
small
mammals
on
an
acute
oral
basis.
Acute
toxicity
studies
with
honey
bees
show
that
pyrethrins
are
highly
toxic
on
both
a
contact
and
an
oral
basis.

Although
there
were
no
aquatic
or
terrestrial
plant
data
submitted
to
the
Agency
does
not
consider
pyrethrin
or
the
other
pyrethroids
as
being
phytotoxic
for
the
following
reasons:
1)
the
compound
is
used
as
a
spray
on
agricultural
crops
with
no
phytotoxic
effects;
2)
the
neural
toxic
mode
of
action
precludes
phtotoxic
concerns;
3)
the
Agency
is
not
aware
of
any
incidents
involving
plants
and
pyrethrin
alone
(
incidents
that
were
reported
for
terrestrial
ornamental
plants
were
inconclusive
and
suggest
that
inerts
in
the
formulation
or
other
circumstances
related
to
application
may
have
caused
the
problem.
The
Agency
is
not
aware
of
any
reported
incidents
of
pyrethrin
phytotoxicity
on
agricultural
crops).

II.
Problem
Formulation
A.
Stressor
Source
and
Distribution
Pyrethrins
are
nonvolatile
hydrocarbons
produced
by
certain
species
of
the
chrysanthemum
plant
(
genus
Chrysanthemum)
and
have
been
used
as
insecticides
since
the1800'
s.
The
plant
species
with
the
most
toxic
content
that
can
be
efficiently
used
for
industrial
purposes
are
C.
cinerariaefolium
and
C.
coccineum
which
are
grown
mainly
in
Australia
and
East
Africa.
The
active
insecticidal
­
6­
components
are
collectively
known
as
pyrethrins
and
consist
of
six
esters.
Although
the
ground
flowers
can
be
used
as
a
dust,
a
more
concentrated
and
efficacious
pyrethrin
product
is
possible
through
solvent
extraction.
Pyrethrin
containing
dusts
and
extracts
usually
have
an
active
ingredient
content
of
about
30%.
However,
after
filtration
and
reextraction
the
concentration
can
reach
90­
100%
(
Matsumura,
1985).
These
compounds
are
contact
poisons
which
can
quickly
penetrate
the
neural
system.
Although
the
pyrethrins
have
an
effective
"
knockdown"
action
(
induction
of
temporary
paralysis)
they
do
not
necessarily
have
high
killing
properties
by
themselves.
These
compounds
are
moderately
persistent
under
certain
environmental
conditions
but
are
quickly
metabolized
under
other
conditions
such
as
in
the
presence
of
sunlight
(
photolysis).
However,
in
order
to
delay
the
metabolic
action
(
inhibition
of
microsomal
enzymes)
so
that
a
lethal
dose
is
assured,
organophosphates,
carbamates,
or
synergists
(
such
as
piperonyl
butoxide)
may
be
added
to
the
pyrethrins
(
Ecobichon
and
Donald,
1991).
Pyrethrin
compounds
have
been
used
primarily
to
control
human
lice,
mosquitoes,
cockroaches,
beetles,
and
flies.
Some
pyrethrin
compounds
used
to
control
insects
in
horticultural
crops,
are
only
0.3%
to
0.5%
pyrethrins,
and
are
used
at
rates
of
up
to
50
lb/
A.
Other
pyrethrin
compounds
may
be
used
in
grain
storage
and
in
poultry
pens
and
on
dogs
and
cats
to
control
lice
and
fleas.

Natural
pyrethrins
have
their
limitations
for
use
on
a
large
scale
for
agricultural
purposes
because
of
their
cost
and
instability
in
sunlight.
Therefore,
in
recent
decades,
many
synthetic
pyrethrin­
like
compounds
were
developed
and
are
referred
to
as
synthetic
pyrethroids.
These
compounds
are
stable
in
sunlight
(
lower
reactivity
of
side­
chains)
and
are
generally
effective
against
most
agricultural
insect
pests
when
used
at
the
very
low
rates.
The
synthetic
pyrethroids
have
evolved
over
a
period
of
time
and
can
be
divided
into
four
generations.

The
formulated
products
of
pyrethrin
usually
contain
a
synergist,
such
as
pyperonyl
butoxide,
pyperonyl
sulfoxide,
or
sesamex.
These
compounds
enhance
the
insecticidal
activity
of
pyrethrin.
The
Agency
does
not
routinely
include,
in
its
screening
risk
assessments,
an
evaluation
of
more
than
one
active
ingredient.
In
the
case
of
product
formulations
of
active
ingredients,
each
active
ingredient
is
subject
to
an
individual
risk
assessment
for
regulatory
decision.
It
is
noted,
however,
that
some
formulations
of
pyrethrin
contain
up
to
60%
PBO,
with
only
about
5
to
6%
pyrethrin.
It
is
not
clear
if
pyperonyl
butoxide
would
have
an
effect
in
the
solubility
or
on
other
physicochemical
characteristics
of
pyrethrin
or
on
its
environmental
fate
characteristics.
This
remains
as
an
uncertainty.

1.
Physical­
Chemical
and
Fate
and
Transport
Properties
The
pyrethrins
are
moderately
persistent
under
certain
environmental
conditions
and
are
very
unstable
under
other
conditions.
In
soil
and
water,
pyrethrins
are
degraded
by
a
combination
of
abiotic
and
biotic
processes,
and
the
rate
of
these
reactions
influences
the
amount
of
chemical
that
is
ultimately
available
to
aquatic
and
terrestrial
organisms.
Pyrethrins
are
not
highly
volatile
and
inhalation
is
not
likely
to
be
a
major
exposure
pathway
for
mammals
and
birds.
Pyrethrins
are
considered
unstable
in
the
presence
of
sunlight
and
are
quickly
photodegraded.
If
released
to
water,
photolysis
in
shallow
sunlit
surface
waters
may
occur
rapidly,
with
a
half­
life
on
the
order
of
several
hours
to
about
a
day.
Biodegradation
under
aerobic
conditions
also
occurs
fairly
rapidly
with
half­
lives
on
the
order
of
days.
­
7­
On
the
other
hand,
pyrethrins
are
stabe
to
hydrolysis
under
acidic
and
neutral
environments
(
pH
5
&
7).
Pyrethrins
adsorb
strongly
to
soil
surfaces
and
are
generally
considered
immobile
in
soils,
showing
a
low
potential
to
leach
into
groundwater,
but
a
high
potential
to
reach
surface
water
in
runoff
events
accompanied
by
erosion.
Pyrethrins
are
expected
to
adsorb
to
suspended
solids
and
sediment
in
the
water
column,
and
sediment
is
likely
to
be
an
environmental
sink
for
any
non
degraded
pyrethrins
since
they
appear
to
persist
under
anaerobic
conditions
(
half­
life
>
80
days).

The
degradation
products
of
pyrethrin
are
the
result
of
the
rupture
of
the
ester
bridge
of
the
parent,
resulting
in
a
carboxylic
acid
and
an
alcohol.
No
data
about
possible
degradates
related
to
the
cyclopentene
ring
are
available.
The
major
degradate
observed
in
many
of
the
studies
was
chrysanthemic
acid
which
was
observed
at
a
maximum
of
4.0%
in
the
aerobic
soil
metabolism
study,
7.0%
in
the
sediment
phase
of
the
anaerobic
aquatic
metabolism
study,
8.4%
and
8.1%
in
the
aqueous
and
sediment
phases
respectively
in
the
aerobic
aquatic
metabolism
study.
The
only
exception
was
observance
of
this
degradate
at
a
maximum
of
64.5%
in
a
hydrolysis
study
at
pH
9
which
is
an
unlikely
environmental
condition.
Although,
based
on
the
octanol
water
coefficient,
pyrethrins
are
expected
to
bioaccumulate
in
the
organic
compartment,
a
fish
bioaccumulation
study
showed
low
bioaccumulation
potential
due
to
metabolism
of
the
parent
compound
to
chrysanthemic
acid.
Pyrethrin
is
stable
in
the
anaerobic
aquatic
environment,
however,
a
relatively
minor
degradate,
chrysanthemum
dicarboxylic
acid,
was
detected
at
a
maximum
of
14.2%
of
the
applied
at
364
days.
In
the
majority
of
the
studies
multiple
degradates
at
very
low
concentrations
were
observed,
but
not
characterized.
The
only
other
significant
isomer
observed
in
the
aqueous
photolysis
study
was
designated
(
E)­
isomer
of
pyrethrin
1.

2.
Mode
of
Action
The
pyrethroids
(
including
pyrethrin)
share
similar
modes
of
action,
resembling
that
of
DDT,
and
are
considered
axonic
poisons
that
affect
both
the
peripheral
and
central
nervous
system.
It
is
now
well
established
that
severe
neurological
symptoms
of
poisoning
with
pyrethroids
and
DDT
in
mammals
and
insects
are
the
result
of
modification
of
Na+
channel
activity
(
cellular
pores
through
which
sodium
ions
are
permitted
to
enter
the
axon
to
cause
excitation)
(
Matsumura,
1985).
Advanced
electrophysiological
experiments
using
voltage
clamp
and
patch
clamp,
together
with
ligand­
binding
and
ionic
flux
experiments,
have
unveiled
unique
actions
of
pyrethroids
of
keeping
the
Na+
channel
in
the
open
state
for
an
extremely
long
period,
sometimes
as
long
as
several
seconds.
This
modification
of
Na+
channel
properties
leads
to
hyperactivity
of
the
nervous
system.
Pyrethroids
have
also
been
shown
to
suppress
GABA
and
glutamate
receptor­
channel
complexes
and
voltage­
activated
Ca
2+
channels,
but
the
toxicological
significance
of
these
actions
is
uncertain.
Relative
to
physiological
responses,
researchers
have
designated
two
types
of
pyrethroids,
Type
I
(
e.
g.,
pyrethrins,
S­
bioallethrin,
resmethrin,
pyrethrin)
and
Type
II
(
e.
g.,
cypyrethrin,
deltamethrin,
fenvalerate).
Type
I
pyrethroids'
action
is
mainly
associated
with
compounds
that
cause
nerve
excitation
symptoms
typified
by
the
appearance
of
repetitive
firing
of
axons
in
the
peripheral
nervous
system
and
a
negatively
correlated
temperature
reversible
knockdown
property
(
similar
to
DDT)
(
Clark
and
Matsumura,
1987).
Pyrethrins
are
non­
systemic
insecticides
that
work
by
physical
contact
to
the
insect
or
by
ingestion,
and
they
have
a
slight
repellent
effect.
­
8­
The
paralyzing
effects
caused
by
pyrethrins
usually
cannot
occur
without
a
synergist.
For
example,
the
synergist
compound
in
PYRENONE
®
Crop
Spray
(
EPA
Reg.
No.
432­
1033)
is
piperonyl
butoxide,
and
it
blocks
the
metabolic
pathway
that
would
breakdown
pyrethrin
before
the
toxic
effect
occurs.
Products
that
contain
pyrethrins
are
primarily
used
as
a
knock­
down
agent
on
the
insects
and
the
addition
of
a
synergist
does
contribute
to
the
killing
efficiency
of
a
formulation
(
Casida
and
Quistad,
1995).

3.
Overview
of
Pesticide
Usage
Pyrethrins
(
CAS
number
8003­
34­
7)
are
a
group
of
naturally
occurring
insecticides
effective
against
a
broad
range
of
pests
used
in
four
major
sectors:
agricultural,
commercial/
industrial/
institutional/
food
&
non­
food/
mosquito
abatement,
domestic
home
and
garden,
and
pet
care.
Some
of
these
sectors
are
not
currently
assessed
by
EFED
because
they
do
not
involve
exposure
to
wildlife
or
to
drinking
waters.
There
are
six
naturally
occurring
pyrethrins
derived
from
the
flowers
of
Chrysanthemum
cinerariaefolium
and
Chrysanthemum
cineum:
pyrethrin
1,
pyrethrin
2,
cinerin
1,
cinerin
2,
jasmolin
1
and
jasmolin
2.

The
final
formulation
type
depends
upon
the
end
use,
examples
include
aerosol,
combustible
coil,
dust,
emulsifiable
concentrate,
ready
to
use
liquid,
shampoo,
and
wettable
powder.
Pyrethrins
are
often
mixed
with
other
insecticides
or
used
in
conjunction
with
synergists
such
as
piperonyl
butoxide
or
sesamex.
Recent
statistics
on
agricultural
uses
of
numerous
pesticides
across
the
United
States
during
the
1990'
s
are
recorded
in
the
National
Center
for
Food
and
Agricultural
Policy's
National
Pesticide
Use
Database
available
from
USGS
(
2004;
http://
ca.
water.
usgs.
gov/
pnsp/
use92/)
and
NFCAP
(
2002;
http://
www.
ncfap.
org/
database/
default.
htm);
however,
these
databases
do
not
include
data
or
maps
on
uses
of
pyrethrins
[
refer
to
Section
III.
A.
for
additional
information
about
Use
Characterization].
As
indicated
earlier,
natural
pyrethrins
have
their
limitations
for
use
on
a
large
scale
for
agricultural
purposes
because
of
their
cost
and
instability
in
sunlight.

B.
Receptors:
Ecological
Effects
Table
1
gives
examples
of
taxonomic
groups
and
test
species
evaluated
for
ecological
effects
in
screening
level
risk
assessments.
Within
each
of
these
very
broad
taxonomic
groups,
an
acute
and/
or
chronic
endpoint
is
selected
from
the
available
toxicity
data
(
see
Section
2(
C)).
Additional
ecological
effects
data
on
honey
bees
(
Apis
mellifera)
have
been
incorporated
into
the
risk
characterization
as
an
additional
line
of
evidence.

A
complete
discussion
of
all
toxicity
data
available
for
this
risk
assessment
and
the
resulting
measurement
endpoints
selected
for
each
taxonomic
group
are
included
in
Appendix
E.
­
9­
Table
1.
Taxonomic
groups
and
test
species
evaluated
for
ecological
effects
in
screening
level
risk
assessments.

Taxonomic
group
Example(
s)
of
representative
species
Birdsa
Mallard
duck
(
Anus
platyrhynchos)
Bobwhite
quail
(
Colinus
virginianus)

Mammals
Laboratory
rat
Freshwater
fishb
Bluegill
sunfish
(
Leopomis
macrochirus)
Rainbow
trout
(
Oncorhynchus
mykiss)

Freshwater
invertebrates
Water
flea
(
Daphnia
magna)

Estuarine/
marine
fish
Sheepshead
minnow
(
Cyprinodon
variegatus)

Estuarine/
marine
invertebrates
Eastern
Oyster
(
Crassostrea
virginica)
Mysid
Shrimp
(
Americamysis
bahia)

Terrestrial
plantsc
Monocots
 
corn
(
Zea
mays)
Dicots
 
soybean
(
Glycine
max)

Aquatic
plants
and
algae
Duckweed
(
Lemna
gibba)
Green
algae
(
Selenastrum
capricornutum)

aBirds
may
be
surrogates
for
amphibians
(
terrestrial
phase)
and
reptiles.
bFreshwater
fish
may
be
surrogates
for
amphibians
(
aquatic
phase).
cFour
species
of
two
families
of
monocots,
of
which
one
is
corn;
six
species
of
at
least
four
dicot
families,
of
which
one
is
soybeans.

C.
Assessment
Endpoints
Assessment
endpoints
are
defined
as
"
explicit
expressions
of
the
actual
environmental
value
that
is
to
be
protected."
Defining
an
assessment
endpoint
involves
two
steps:
1)
identifying
the
valued
attributes
of
the
environment
that
are
considered
to
be
at
risk;
and
2)
operationally
defining
the
assessment
endpoint
in
terms
of
an
ecological
entity
(
i.
e.,
a
community
of
fish
and
aquatic
invertebrates)
and
its
attributes
(
i.
e.,
survival
and
reproduction).
Therefore,
selection
of
the
assessment
endpoints
is
based
on
valued
entities
(
i.
e.,
ecological
receptors),
the
migration
pathways
of
pesticides,
and
the
routes
by
which
ecological
receptors
are
exposed
to
pesticide­
related
contamination.
The
selection
of
clearly
defined
assessment
endpoints
is
important
because
they
provide
direction
and
boundaries
in
the
risk
assessment
for
addressing
risk
management
issues
of
concern.

A
summary
of
the
assessment
and
measurement
endpoints
selected
to
characterize
potential
ecological
risks
associated
with
exposure
to
pyrethrins
is
provided
in
Table
2.
­
10­
This
ecological
risk
assessment
considers
maximum
application
rates
on
vulnerable
soils,
maximum
number
of
applications
(
as
well
as
single
applications),
and
minimum
intervals
between
application
for
uses
on
representative
crops
to
estimate
exposure
concentrations.
This
assessment
is
not
intended
to
represent
a
site
or
time­
specific
analysis.
Instead,
this
assessment
is
intended
to
represent
high­
end
exposures
at
a
national
level.
Likewise,
the
most
sensitive
toxicity
endpoints
are
used
from
surrogate
test
species
to
estimate
treatment­
related
direct
effects
on
acute
mortality
and
chronic
reproductive,
growth
and
survival
assessment
endpoints.
Toxicity
tests
are
intended
to
determine
effects
of
pesticide
exposure
on
birds,
mammals,
fish,
terrestrial
and
aquatic
invertebrates,
and
plants.
These
tests
include
short­
term
acute,
subacute,
and
reproduction
studies
and
are
typically
arranged
in
a
hierarchical
or
tiered
system
that
progresses
from
basic
laboratory
tests
to
applied
field
studies.
The
toxicity
studies
are
used
to
evaluate
the
potential
of
a
pesticide
to
cause
adverse
effects,
to
determine
whether
further
testing
is
required,
and
to
determine
the
need
for
precautionary
label
statements
to
minimize
the
potential
adverse
effects
to
non­
target
animals
and
plants
(
40
CFR
§
158.202,
2002).

Table
2.
Summary
of
assessment
and
measurement
endpoints.

Assessment
Endpoint
Measurement
Endpoint
1.
Abundance
(
i.
e.,
survival,
reproduction,
and
growth)
of
birds.
1a.
Bobwhite
quail
acute
oral
LD50.
1b.
Bobwhite
quail
and
mallard
duck
subacute
dietary
LD50.
1c.
Bobwhite
quail
and
mallard
duck
chronic
reproduction
NOAEC
and
LOAEC.

2.
Abundance
(
i.
e.,
survival,
reproduction,
and
growth)
of
mammals.
2a.
Laboratory
rat
acute
oral
LD50.
2b.
Laboratory
rat
developmental
and
chronic
NOAEC
and
LOAEC.

3.
Survival
and
reproduction
of
individuals
and
communities
of
freshwater
fish
and
invertebrates.
3a.
Rainbow
trout
and
bluegill
sunfish
acute
LC50.
3b.
Rainbow
trout
chronic
(
early­
life)
NOAEC
and
LOAEC.
3c.
Water
flea
(
and
other
freshwater
invertebrates)
acute
EC50.
3d.
Water
flea
chronic
(
life­
cycle)
NOAEC
and
LOAEC.

4.
Survival
and
reproduction
of
individuals
and
communities
of
estuarine/
marine
fish
and
invertebrates.
4a.
Sheepshead
minnow
acute
LC50.
4b.
Estimated
chronic
NOAEC
and
LOAEC
values
based
on
the
acute­
to­
chronic
ratio
for
freshwater
fish.
4c.
Eastern
oyster
and
mysid
shrimp
acute
LC50.
4d.
Mysid
shrimp
chronic
(
life­
cycle)
NOAEC
and
LOAEC.
4e.
Estimated
NOAEC
and
LOAEC
values
for
mollusks
based
on
the
acute­
to­
chronic
ratio
for
mysids.

5.
Perpetuation
of
individuals
and
populations
of
non­
target
terrestrial
and
semi­
aquatic
species
(
crops
and
non­
crop
plant
species).
5a.
Monocot
and
dicot
seedling
emergence
and
vegetative
vigor
EC25
values.

6.
Survival
of
beneficial
insect
populations.
6a.
Honeybee
acute
contact
LD50.

7.
Abundance
(
i.
e.,
survival,
reproduction,
and
growth)
of
earthworm
populations.
7a.
Acute
and
subchronic
earthworm
LC50
values.
Table
2.
Summary
of
assessment
and
measurement
endpoints.

Assessment
Endpoint
Measurement
Endpoint
­
11­
8.
Maintenance
and
growth
of
individuals
and
populations
of
aquatic
plants
from
standing
crop
or
biomass.
8a.
Algal
and
vascular
plant
(
i.
e.,
duckweed)
EC50
values
for
growth
rate
and
biomass
measurements.

LD
50
=
Lethal
dose
to
50%
of
the
test
population.
NOAEC
=
No­
observed­
adverse­
effect
concentration.
LOAEC
=
Lowest­
observed­
adverse­
effect
concentration.
LC
50
=
Lethal
concentration
to
50%
of
the
test
population.
EC
50
/
EC
25
=
Effect
concentration
to
50/
25%
of
the
test
population.

D.
Conceptual
Model
1.
Risk
Hypotheses
Risk
hypotheses
are
specific
assumptions
about
potential
adverse
effects
(
i.
e.,
changes
in
assessment
endpoints)
and
may
be
based
on
theory
and
logic,
empirical
data,
mathematical
models,
or
probability
models
(
EPA
1998a).
For
this
assessment,
the
risk
is
stressor­
initiated,
where
the
stressor
is
the
release
of
pyrethrin
to
the
environment.
The
following
risk
hypothesis
is
presumed
for
this
screening
level
assessment:

The
use
of
pyrethrins
for
agricultural
purpuses
and
vector
control
(
as
a
mosquito
adulticide)
involve
situations
where
terrestrial
and/
or
aquatic
animals
may
be
exposed
to
the
chemical.
Based
on
pyrethrins'
persistence,
mode
of
action,
direct
toxicity
and
potential
indirect
effects
to
trophic
food
webs,
the
Agency
assumes
that
this
compound
has
the
potential
to
cause
reduced
survival,
and
reproductive
impairment
to
both
terrestrial
and
aquatic
organisms.

Adequate
protection
is
defined
as
protection
of
growth,
reproduction,
and
survival
of
aquatic
and
terrestrial
ecological
populations,
and
individuals
of
threatened
and
endangered
species,
as
needed.

2.
Diagram
The
conceptual
model
(
shown
in
Figure
1
for
agricultural
uses
and
1b
for
mosquito
abatement
uses)
is
a
generic
graphic
depiction
of
the
risk
hypothesis.
It
includes
the
potential
pesticide
or
stressor
(
pyrethrins),
the
source
of
the
pesticide
and/
or
transport
pathways,
exposure
media,
exposure
point,
biological
receptor
types,
and
attribute
changes.

In
the
specific
case
of
pyrethrin,
the
source
and
mechanism
of
release
of
pyrethrins
may
include
ground
or
aerial
spray
applications
to
agricultural
crops,
or
ground
or
aerial
applications
of
the
chemical
as
a
mosquito
adulticide.
Note
that
in
both
cases,
the
conditions
of
applications
are
very
different.
Surface
runoff
from
the
areas
of
application
is
assumed
to
depend
on
factors
such
as
topography,
irrigation,
and
rainfall
events.
Additional
transport
mechanisms
include
spray
drift
and
wind
erosion,
which
may
potentially
transport
contaminants
to
the
surrounding
sites.
In
addition,
direct
deposition
may
result
in
contamination
of
food
items
that
may
be
consumed
by
terrestrial
organisms.
­
12­
The
major
point
of
exposure
for
aquatic
organisms,
is
direct
contact
with
contaminated
water
(
gill/
integument
uptake),
while
for
terrestrial
animals,
it
is
likely
that
they
will
eat
certain
food
items
contaminated
with
pyrethrins,
such
as
grass,
foliage,
and
small
insects.
For
plants,
it
is
direct
contact.

The
representative
aquatic
receptors
are
certain
freshwater
and
estuarine/
marine
fish,
invertebrates,
and,
in
certain
cases,
aquatic
plants.
The
representative
terrestrial
receptors
are
certain
mammals,
birds,
and,
in
certain
cases,
terrestrial
plants.
It
should
be
noted,
that
these
species
do
not
cover
all
the
possible
species
in
the
animal
and
plant
kingdoms.
For
example,
no
reptiles
are
represented
in
this
scheme.

The
attribute
changes
depend
on
the
type
of
test
(
eg.
reduced
survival,
growth,
or
reproduction,
and
for
plants,
seedling
emergence
and
vegetative
vigor).
­
13­
­
14­
­
15­
E.
Analysis
Plan
1.
Develop
Assessment
Design
For
aquatic
receptors,
the
main
pathway
of
exposure
is
through
direct
contact
with
surface
water
contaminated
with
runoff
from
agricultural
fields
and
spray
drift.
Risks
to
aquatic
species
were
based
on
estimated
environmental
concentrations
(
EECs)
using
the
Tier
2
model
PRZM/
EXAMS,
and
for
adulticide
uses,
with
the
help
of
AGDISP.
Residues
in
potential
dietary
sources
for
mammals
and
birds
(
e.
g.,
vegetation,
insects,
fruits/
pods,
and
seeds)
were
estimated
using
the
Tier
1
model
T­
REX.

2.
Identification
of
Data
Gaps
and
Methods
for
Conducting
Assessment
The
adequacy
of
the
submitted
data
was
evaluated
relative
to
Agency
guidelines.
The
following
identified
data
gaps
for
ecological
fate
and
effects
endpoints
result
in
a
degree
of
uncertainty
in
evaluating
the
ecological
risk
of
pyrethrins.

°
Chronic
data
for
estuarine
/
marine
fish
and
invertebrates
were
not
submitted
by
the
registrant
for
pyrethrins.
Therefore,
chronic
risks
could
not
be
calculated
for
these
particular
taxa;
however
based
on
an
acute
to
chronic
ratio
method
done
by
EFED,
NOAECs
were
estimated
for
these
species.
In
the
absence
of
data,
the
estimated
NOAECs
suggest
that
chronic
risk
quotients
for
estuarine/
marine
invertebrates
exceed
the
level
of
concern.
However,
pyrethrins
do
not
pose
a
risk
concern
for
estuarine/
marine
fish.
Chronic
toxicity
data
for
estuarine
/
marine
fish
and
invertebrates
(
fish
early
life
cycle
and
invertebrate
life
cycle)
are
needed
to
fully
characterize
effects
to
these
animals.

°
No
field
study
data
were
identified
to
estimate
pyrethrin
residues
on
plants
and
provide
estimates
of
foliar
dissipation
half­
lives.
Therefore,
in
the
terrestrial
exposure
assessment
a
half­
life
of
1­
14days
was
used
to
represent
dissipation
of
pyrethrins
on
plant
surfaces.

°
Risks
to
terrestrial
and
semi­
aquatic
plants
were
not
evaluated
because
toxicity
data
on
these
receptors
were
not
available.
However,
there
are
significant
incidence
data
reported
that
provides
evidence
of
possible
phytotoxicity
of
the
pyrethrin
compounds
and
formulated
products.
Toxicity
data
are
needed
for
terrestrial
and
aquatic
plants
to
fully
understand
the
extent
of
phytotoxicity
of
products
that
contain
pyrethrins.

°
Chronic
risks
to
birds
were
not
evaluated
because
toxicity
data
on
avian
species
were
not
available.

°
Inhalation
and
dermal
pathways
for
terrestrial
mammals
and
birds
were
not
evaluated
because
these
routes
of
exposure
are
considered
to
be
minimal
compared
to
the
dietary
ingestion
pathways.
Uncertainties
associated
with
exposure
pathways
for
­
16­
terrestrial
animals
are
discussed
in
Section
4(
C)(
3).

°
Risks
to
semiaquatic
wildlife
via
consumption
of
pesticide­
contaminated
fish
were
not
evaluated.
However,
given
that
bioaccumulation
of
pyrethrins
is
low,
ingestion
of
fish
by
piscivorous
wildlife
(
such
as
bears)
is
not
likely
to
be
of
concern.

C
Exposure
to
birds
and
small
mammals
(
up
to
1000
g)
via
ingestion
of
grasses,
plants,
fruits/
pods,
seeds,
and
insects
was
considered.
Risk
to
mammals
of
large
body
weights
(
such
as
wolves
or
bears)
were
not
evaluated
because
the
toxic
endpoints
from
laboratory
tests
with
the
surrogate
mammal
(
laboratory
rat)
are
based
on
small
body
weight.

°
In
the
absence
of
sediment
toxicity
and
exposure
data,
a
screening
method
developed
by
the
Office
of
Water
(
OW),
that
relies
on
equilibrium
partitioning
(
EqP)
of
the
chemicals,
was
used
to
estimate
the
risk
quotients
for
sediment
dwelling
organisms.
Pyrethrin
degrades
with
an
aerobic
soil
half­
life
of
about
10
days;
however,
it
is
relatively
persistent
under
anaerobic
conditions
in
the
aquatic
environments.
Nondegraded
pyrethrins
are
likely
to
bind
to
sediment
and
be
available
to
sediment
dwelling
organisms
for
extended
periods
of
time.
To
estimate
the
exposure
to
pyrethrins
in
sediment,
EFED
calculated
the
pore
water
concentrations
using
PRZM/
EXAMS.
Furthermore,
using
the
OW
methodology,
toxicity
data
for
the
water
column
invertebrates
were
used
to
estimate
the
toxicity
and
associated
risk
to
benthic
organisms.

°
Surrogates
were
used
to
predict
potential
risks
for
species
on
which
the
Agency
does
not
have
data
(
e.
g.,
birds
as
surrogates
for
reptiles
and
terrestrial
phase
amphibians
and
fish
as
surrogate
species
for
aquatic
phase
amphibians).
It
was
assumed
that
use
of
surrogate
effects
data
is
sufficiently
conservative
to
apply
the
broad
range
of
species
within
taxonomic
groups.
If
other
species
are
more
or
less
sensitive
to
pyrethrins,
and
its
associated
degradates,
risks
may
be
under­
or
overestimated,
respectively.

°
The
pyrethrins
label
supports
a
minimum
interval
between
applications
of
one
day,
although
a
three
day
interval
is
recommended
for
typical
uses.
Most
EECs
were
estimated
using
the
more
protective
assumption
of
a
one
day
interval
for
each
of
10
applications
(
high
pest
pressure).
There
were
a
few
selected
crops
that
were
modeled
using
the
same
number
of
applications,
but
with
the
three
day
interval
to
represent
exposure
based
on
typical
use
(
normal
pest
pressure).

3.
Measures
to
Evaluate
Risk
Hypotheses
and
Conceptual
Model
a.
Measures
of
Exposure
C
The
major
routes
of
dissipation
of
pyrethrins
in
the
environment
are
photolysis
(
both
in
water
­
17­
and
soil)
and
to
a
lesser
degree,
aerobic
soil
metabolism.
The
pyrethrins
are
relatively
stable
under
hydrolytic
conditions
at
pH
5
and
7,
and
under
anaerobic
conditions.
Pyrethrins
adsorb
strongly
to
soil
surfaces
and
are
generally
considered
immobile
in
soils.
The
degradation
products
of
pyrethrin
are
considered
of
low
concern.
Pyrethrins
are
unlikely
to
reach
ground
waters,
but
they
can
reach
surface
waters
via
spray
drift
and
rainfall
events
that
cause
runoff
accompanied
by
erosion.
Once
in
the
water,
they
are
expected
to
partition
in
the
sediment
where
they
may
persist
for
a
long
period
of
time.

C
For
agricultural
uses,
exposure
concentrations
for
aquatic
ecosystems
assessments
were
estimated
based
on
EFED's
aquatic
Tier
2
model
PRZM/
EXAMS.
A
graphical
user
interface
(
pe4v01.
pl),
developed
by
the
EPA
(
http://
www.
epa.
gov/
oppefed1/
models/
water),
was
used
to
facilitate
inputting
chemical
and
use
specific
parameters
into
the
appropriate
PRZM
input
files
(
inp)
and
EXAMS
chemical
files.
This
approach
employs
PRZM,
which
simulates
runoff
and
erosion
from
an
agricultural
field
on
a
daily
time
step.
The
runoff
and
erosion
flux
output
data
from
PRZM
are
used
as
chemical
loadings
to
EXAMS,
which
simulates
surface
water
in
order
to
predict
the
EECs.
Thirteen
PRZM
field
scenarios
were
modeled:
GA
Peaches,
FL
Citrus,
CA
Wheat,
OR
Snapbeans,
IL
corn,
ME
Potato,
MS
Cotton,
PA
Tomato,
ND
Wheat,
CA
Onion,
NC
Apple,
ID
Potato,
MN
Alfalfa,
and
CA
Grapes.
These
scenarios
were
selected
to
represent
a
variety
of
crops
and
sites
in
the
continental
US.
EECs
for
ecological
risk
assessment
were
determined
using
a
Mississippi
Pond
modeling
scenario
which
describes
a
generic
scenario
for
the
EXAMS
component
of
the
modeling
exercise.

C
For
agricultural
scenarios,
a
subset
of
the
selected
scenarios
were
analyzed
with
the
typical
application
rate
and
number
of
applications.
Priority
was
provided
to
vegetable
crops.

C
For
the
mosquito
adulticide
use,
pyrethrins
are
applied
as
very
small
droplets
to
create
a
mist
which
remains
suspended
over
the
field
to
more
efficiently
target
the
mosquitoes.
Therefore,
they
are
susceptible
to
drift
towards
an
adjacent
body
of
water.
To
determine
the
deposition
of
the
pesticide
to
adjacent
water
bodies,
the
computer
model
AGDISP
[
AGricultural
DISPersal
(
computer)
model
(
AGDISP
v.
8.08)]
was
used.
The
outputs
of
interest
from
AGDISP
are
the
application
efficiency
(
fraction
of
the
material
that
deposits
in
the
target
area
under
the
aircraft),
and
the
downwind
deposition
(
fraction
of
the
material
that
deposits
in
the
designated
area
or
the
standard
pond).
These
results
were
subsequently
used
as
input
parameters
in
PRZM/
EXAMS
to
model
the
degradation
and
partitioning
in
sediment
for
water
bodies
of
various
depths
(
6
in,
1
ft.,
1
m,
and
2
m)
that
may
be
exposed
to
drift
from
the
mosquito
adulticide.
Furthermore,
the
analysis
was
performed
using
boom
height
of
75
ft
and
150
ft
(
which
were
found
to
by
typical
for
adulticide
applications),
and
droplet
sizes
of
40
and
50
:
m,
and
the
maximum
application
rate
supported
by
the
PJV
in
the
Master
Label
(
0.008
lb
a.
i./
A),
and
a
typical
application
rate
(
of
0.0025
lb
a.
i./
A).

C
Analysis
of
the
most
conservative
scenario
(
1
day
interval
between
applications,
which
is
the
interval
for
high
pest
pressure)
was
performed
for
13
crops;
however,
three
crops
were
selected
and
run
with
a
less
conservative
scenario,
which
will
be
nominated
typical
scenario
(
3
days
interval,
designated
as
the
interval
between
applications
for
normal
pest
pressure).
­
18­
A
comparison
of
the
results
was
provided.
These
crops
represented
the
range
of
EECs
that
were
observed
among
the
13
crops
run
originally
with
1
day
interval
between
applications.

C
The
effect
of
spray
drift
and
buffer
zones
on
exposure
to
bodies
of
water
adjacent
to
treated
areas
was
investigated
using
the
AgDRIFT
®
model.
As
a
first
step,
the
evaluation
of
spray
drift
as
a
possible
predominant
route
of
exposure
for
a
number
of
crops
scenarios
was
performed
using
the
PRZM/
EXAMS
model.
Representative
crops
were
run
in
PRZM/
EXAMS
with
spray
drift
set
to
0%
(
to
detect
the
extent
of
spray
drift
for
that
crop
scenario),
and
1%
(
to
simulate
ground
application).
EFED
bracketed
the
spray
drift
options
by
running
a
"
high
end"
(
conservative)
and
a
"
low
end"
(
best
case)
drift
scenarios.
The
simulations
were
performed
using
AgDRIFT
®
with
spray
drift
levels
for
buffer
zones
of
0,
50,
100,
and
150
ft.
at
the
"
low"
end
and
"
high"
end
drift
scenarios.
The
output
values
from
AgDRIFT
®
were
used
as
input
values
in
PRZM/
EXAMS.

C
Screening
level
RQs
for
sediment
dwelling
organisms
were
estimated
with
an
extrapolation
method
recommended
by
the
Office
of
Water
(
USEPA).
This
was
based
on
the
Agency
Equilibrium
Partitioning
Sediment
Guidelines
(
ESG)
under
the
Clean
Water
Act
[
CWA
Section
304(
a)(
2)].
After
consultation
with
the
OW,
EFED
adopted
the
equilibrium
partitioning
(
EqP)
sediment
method
to
be
used
when
sediment
toxicity
and
exposure
data
are
not
available.
This
extrapolation
method
is
useful
for
estimating
potential
sediment
exposure
values,
as
well
as
sediment
toxicity
values
that
can
be
used
in
a
screening
level
risk
assessment.
The
EqP
theory
holds
that
a
nonionic
chemical
in
sediment
partitions
between
sediment
organic
carbon,
interstitial
(
pore)
water
and
benthic
organisms.
At
equilibrium,
if
the
concentration
in
any
phase
is
known,
then
the
concentration
in
the
other
phases
can
be
predicted
through
the
organic/
carbon
soil
partition
coefficient.
The
EECs
are
calculated
from
the
pore
water
concentration
(
an
output
from
PRZM/
EXAMS)
through
the
K
OC
.
In
the
absence
of
sediment
toxicity
data,
the
endpoints
are
extrapolated
from
the
water
column
invertebrate
toxicity
tests.

C
Residues
in
potential
dietary
sources
for
mammals
and
birds
(
e.
g.,
vegetation,
insects)
were
estimated
using
the
conceptual
approach
given
in
the
Tier
1
model
T­
REX
Version
1.4
(
TREX
2004).

C
To
estimate
exposure
related
to
releases
of
pyrethrins
to
domestic
wastewater
treatment,
the
Agency
relied
on
the
Office
of
Pollution
Prevention
and
Toxics
(
OPPT)
model,
Exposure
and
Fate
Assessment
Screening
Tool
(
E­
FAST)
(
USEPA,
1999).
From
this
model,
the
Agency
used
the
"
Down­
the­
Drain"
module,
which
is
designed
for
releases
to
domestic
wastewater
treatment.
It
is
suitable
for
all
sources
of
pyrethrins
that
could
potentially
be
exposed
through
a
"
down­
the­
drain"
scenario.
The
model
provides
screening
level
estimate
concentrations
of
chemicals
in
surface
waters
that
may
result
from
household
uses
and
disposal
of
consumer
products
into
wastewater
using
a
few
simple
input
parameters
(
production
volume
and
fraction
of
the
chemical
removed
during
wastewater
treatment).

b.
Measures
of
Effect
­
19­
Measures
of
effect
are
generally
based
on
the
results
of
a
toxicity
study,
although
monitoring
data
may
also
be
used
to
provide
supporting
lines
of
evidence
for
the
risk
characterization.
A
complete
summary
of
the
measures
of
effect
based
on
toxicity
studies
for
different
ecological
receptors
and
effect
endpoints
(
acute/
chronic)
is
given
in
Table
2.
In
the
absence
of
chronic
data
for
estuarine/
marine
fish
and
invertebrates,
the
acute­
to­
chronic
ratio
method
can
be
used
to
estimate
NOAECs
for
these
animals.
Examples
of
measures
of
acute
effects
(
e.
g.,
lethality)
include
an
oral
LD
50
for
mammals
and
LC
50
for
fish
and
invertebrates.
Examples
of
measures
of
chronic
effects
include
a
NOAEL
for
birds
or
mammals
based
on
reproduction
or
developmental
endpoints,
and
an
EC
50
for
plants
based
on
growth
rate
or
biomass
measurements.

III.
Analysis
A.
Use
Characterization
Pyrethrins
(
CAS
number
8003­
34­
7)
are
a
group
of
naturally
occurring
insecticides
effective
against
a
broad
range
of
pests.
There
are
no
statistics
regarding
the
use
of
pyrethrins
in
the
National
Center
for
Food
and
Agricultural
Policy
pesticide
database
(
NCFAP)
(
NCFAP,
2003).
According
to
the
manufacturer
label,
there
are
four
main
sectors
of
use
for
pyrethrins:
1)
agriculture
2)
pet
care
3)
domestic
home
and
garden;
and
4)
commercial,
industrial,
institutional,
food
&
non
food,
mosquito
abatement.

The
major
focus
of
this
environmental
assessment
is
on
agricultural
uses
and
mosquito
abatement.
It
is
acknowledged
that,
as
indicated
earlier,
natural
pyrethrins
have
their
limitations
for
use
on
a
large
scale
for
agricultural
purposes
because
of
their
cost
and
instability
in
sunlight.
The
agricultural
preharvest
applications
to
field
crops
are
divided
into
several
cropping
groups
which
are
summarized
in
Table
3.
It
is
noted
that
this
does
not
include
the
greenhouse,
domestic,
or
commercial
uses.
According
to
the
Master
Label,
the
same
use
rate
applies
to
all
the
crops.
In
2000,
more
than
200,000
lb
of
pyrethrin
were
sold,
of
which
around
6%
was
used
for
terrestrial
non­
food
uses,
and
around
1%
was
used
for
outdoor
recreation
(
including
mosquito
abatement).

For
uses
on
crops,
the
following
assumptions
were
made:
application
rate
of
0.05
lbs
a.
i.
A,
10
applications,
and
a
1­
day
interval
or
3­
day
interval.
For
mosquito
abatement
uses,
the
following
assumptions
were
made:
application
rate
of
0.008
lbs
a.
i./
A
(
from
the
label),
26
applications,
and
a
4­
day
interval.
The
mosquito
abatement
use
covers
a
longer
time
period
in
order
to
approximate
a
period
when
mosquito
abatement
would
be
warranted.
­
20­
Table
3.
The
following
crops
appear
in
the
master
label
for
pyrethrin.
a
The
maximum
application
rate
appears
in
the
first
row.

Maximum
application
rate:
0.050
lb
a.
i./
A
Maximum
seasonal
application
rate
0.500
lb
a.
i./
A/
season
Maximum
number
of
applications:
10
Minimum
application
intervals:
1
day
(
under
extreme
pressure),
3
days
(
under
normal
pressure)

Crop
Group
1:
Root
and
Tuber
Vegetables
(
root
crop
vegetables):
arracacha,
arrowroot,
Chinese
artichoke,
Jerusalem
artichoke,
fodder
beet,
garden
beet,
sugar
beet,
edible
burdock,
edible
canna,
carrot,
cassava,
celeriac,
chayote,
turnip
rooted
chervil,
chicory,
chufa,
dasheen,
ginger,
ginseng,
horseradish,
leren,
turnip
rooted
parsley,
parsnip,
potato,
radish,
oriental
radish,
rutabaga,
salsify,
black
salsify,
Spanish
salsify,
skirret,
sweet
potato,
tanier,
taro,
turmeric,
turnip,
yam
bean,
and
true
yam.

Crop
Group
2:
Leaves
of
Root
and
Tuber
Vegetables:
fodder
beet,
garden
beet,
sugar
beet,
edible
burdock,
carrot,
cassava,
turnip
rooted
chervil,
chicory,
dasheen,
parsnip,
radish,
oriental
radish,
rutabaga,
salsify,
black
salsify,
Spanish
salsify,
tanier,
taro,
turnip,
and
true
yam.

Crop
Group
3:
Onion
(
root
crop
vegetables):
green
onions,
scallion
onions,
spring
onions,
shallot,
garlic,
leek,
great
headed
garlic,
dry
bulb
onion,
potato
onion,
tree
onion,
and
welsh
onion.

Crop
Group
4:
Leafy
Vegetables
(
leafy
and
stem
vegetables,
except
brassica
vegetables):
leafy
amaranth,
arugula,
cardoon,
celery,
Chinese
celery,
celtuce,
chervil,
edible­
leaved
Chrysanthemum,
garland
Chrysanthemum,
salad
corn,
garden
cress,
upland
cress,
dandelion,
dock,
endive,
Florence
fennel,
sea
kale,
head
lettuce,
leaf
lettuce,
orach,
parsley,
garden
purslane,
winter
purslane,
radicchio,
rhubarb,
spinach,
Chinese
spinach,
New
Zealand
spinach,
vine
spinach,
Swiss
chard,
and
Tampala.

Crop
Group
5:
Cole
Crops
(
leafy
and
stem
vegetables,
brassica
leafy
group):
broccoli,
Chinese,
broccoli,
raab
broccoli,
cabbage,
Chinese
cabbage,
bok
choy,
Chinese
mustard
cabbage,
Chinese
napa
cabbage,
cauliflower,
,
collards,
kale,
kohlrabi,
mustard
greens,
mustard
spinach,
and
rape
greens.

Crop
Group
6:
Legume
Vegetables
(
succulent
or
dried
seed
and
pod
vegetables):
bean,
adzuki
bean,
broad
bean,
dry
bean,
kidney
bean,
lablab
bean,
lima
bean,
moth
bean,
mung
bean,
navy
bean,
pink
bean,
pinto
bean,
rice
bean,
runner
bean,
snap
bean,
tepary
bean,
urd
bean,
wax
bean,
yardlong
bean,
catjang,
chickpea,
cowpea,
edible
gum,
jackbean,
lentil,
grain
lupin,
pea,
blackeyed
pea,
crowder
pea,
dry
pea,
dwarf
pea,
edible­
pod
pea,
English
pea,
field
pea,
garden
pea,
green
pea,
pigeon
pea,
snow
pea,
Southern
pea,
succulent
pea,
sugar
snap
pea,
soybean,
swordbean.

Crop
Group
7:
Foliage
of
Legume
Vegetables
(
seed
and
pod
vegetables):
dry
bean,
lima
bean,
snap
bean,
cowpea,
grain
lupin,
field
pea,
pigeon
pea,
soybean.
Table
3.
The
following
crops
appear
in
the
master
label
for
pyrethrin.
a
The
maximum
application
rate
appears
in
the
first
row.

Maximum
application
rate:
0.050
lb
a.
i./
A
Maximum
seasonal
application
rate
0.500
lb
a.
i./
A/
season
Maximum
number
of
applications:
10
Minimum
application
intervals:
1
day
(
under
extreme
pressure),
3
days
(
under
normal
pressure)

­
21­
Crop
Group
8:
Fruiting
Vegetables
(
except
cucurbits):
chili,
eggplant,
groundcherry,
pepino,
pepper,
bell
pepper,
nonbell
pepper,
nonbell
sweet
pepper,
tomatillo,
tomato.

Crop
Group
9:
Cucurbit
Vegetables:
balsam
apple,
balsam
pear,
cantaloupe,
chayote,
cucumber,
Chinese
cucumber,
West
Indian
gherkin,
edible
gourd,
melon,
citron
melon,
muskmelon,
pumpkin,
squash,
Summer
squash,
Winter
squash,
watermelon,
Chinese
waxgourd.

Crop
Group
10:
Citrus
Fruits:
calamondin,
citrus
citron,
citrus,
citrus
hybrids,
grapefruit,
kumquat,
lemon,
lime,
satsuma
mandarin,
sour
orange,
sweet
orange,
pummelo,
tangelo,
tangerine.

Crop
Group
11:
Pome
Fruits:
apple,
crabapple,
loquat,
mayhaw,
pear,
Oriental
pear,
quince.

Crop
Group
12:
Stone
Fruits:
apricot,
sweet
cherry,
tart
cherry,
nectarine,
peach,
plum,
chickasaw
plum,
damson
plum,
Japanese
plum,
prune
plum.

Crop
Group
13:
Berries:
blackberry,
blueberry,
currant,
elderberry,
gooseberry,
huckleberry,
loganberry,
black
and
red
raspberry,
canaberry.

Crop
Group
14:
Tree
Nuts:
almond,
beech
nut,
Brazil
nut,
butternut,
cashew,
chestnut,
chinquapin,
filbert,
hickory
nut,
macadamia
nut,
pecan,
pistachio,
walnut
black,
English
walnut.

Crop
Group
15:
Cereal
Grains:
barley,
buckwheat,
corn,
field
corn,
pod
corn,
pop
corn,
sweet
corn,
millet,
pearl
millet,
proso
millet,
oat,
rice,
wild
rice,
rye,
grain
sorghum,
teosinte,
tricale,
wheat,
vavilovi
wheat,
wild
einkorn
wheat,
wild
emmer
wheat.

Crop
Group
16:
Forage,
Fodder
and
Straw
of
Cereal
Grains:
barley,
field
corn,
pod
corn,
pop
corn,
sweet
corn,
millet,
pearl
millet,
proso
millet,
oat,
rice,
wild
rice,
rye,
forage
sorghum,
grain
sorghum,
teosinte,
tricale,
wheat,
vavilovi
wheat,
wild
einkorn
wheat,
wild
emmer
wheat.
Table
3.
The
following
crops
appear
in
the
master
label
for
pyrethrin.
a
The
maximum
application
rate
appears
in
the
first
row.

Maximum
application
rate:
0.050
lb
a.
i./
A
Maximum
seasonal
application
rate
0.500
lb
a.
i./
A/
season
Maximum
number
of
applications:
10
Minimum
application
intervals:
1
day
(
under
extreme
pressure),
3
days
(
under
normal
pressure)

­
22­
Crop
Group
17:
Grass
Forage,
Fodder,
and
Hay:
alkali
sacaton,
alkakigrass,
Arizona
cottontop,
bahiagrass,
beachgrass,
spike
bentgrass,
Bermudagrass,
blowoutgrass,
gluegrass,
silky
bluegrass,
Australian
bluestern,
big
bluestern,
caucasian
bluestern,
Díaz
bluestern,
little
bluestern,
sand
bluestern,
silver
bluestern,
South
African
bluestern,
yellow
bluestern,
plains
bristlegrass,
bromegrass,
broomsedge,
Buffalograss,
buffelgrass,
annual
Canarygrass,
reed
Canarygrass,
caribgrass,
carpetgrass,
broadleaf
carpetgrass,
centipedegrass,
marshhay
cordgrass,
crabgrass,
curly
mesquite,
dallisgrass,
pine
dropseed,
sand
dropseed,
tall
dropseed,
fescue,
feather
fingergrass,
creeping
foxtail,
meadow,
Eastern
gamagrass,
grass,
galleta
grass,
grama
grass,
muhly
grass,
pasture
grass,
St.
Augustine
grass,
wildrye
grass,
zoysia
grass,
tufted
hairgrass,
hardinggrass,
Indiangrass,
junegrass,
limpograss,
lovegrass,
maidencane,
mannagrass,
foxtail
millet,
Japanese
millet,
molassesgrass,
napiergrass,
needlegrass,
sand
oat,
slender
oat,
wild
oat,
tall
oat,
oniongrass,
pangolagrass,
panicgrass,
paspalum,
polargrass,
quackgrass,
redtop,
reedgrass,
rhodesgrass,
multiflower
false
rhodesgrass,
Indian
ryegrass,
Italian
ryegrass,
perennial
ryegrass,
prairie
sandreed,
sixweeks
threeawn,
sloughgrass,
smilograph,
forage
sorghum,
green
sprangletop,
Sudangrass,
sunolgrass,
tanglehead,
Timothy,
alpine
Timothy,
spike
trisetum,
vaseygrass,
perennial
veldtgrass,
velvetgrass,
wheatgrass,
bluebunch
wheatgrass,
crested
wheatgrass,
fairway
wheatgrass,
intermediate
wheatgrass,
pubescent
wheatgrass,
Siberian
wheatgrass,
slender
wheatgrass,
streambank
wheatgrass,
tall
wheatgrass,
thickspice
wheatgrass,
Western
wheatgrass,
hooded
windmillgrass.

Crop
Group
18:
Nongrass
Animal
Feeds:
alfalfa,
arrowleaf
balsamroot,
clover,
alsike
clover,
alyce
clover,
arrowleaf
clover,
ball
clover,
berseem
clover,
bigflower
clover,
crimson
clover,
hop
clover,
lappa
clover,
Persian
clover,
red
clover,
rose
clover,
seaside
clover,
strawberry
clover,
striate
clover,
sub
clover,
sweet
clover,
true
clover,
white
clover,
whitetip
clover,
crownvetch,
kudzu,
lespedeza,
lupine,
forage
lupine,
sweet
lupine,
mustard,
sainfoin,
trefoil,
velvetbean,
vetch,
milk
vetch.

Crop
Group
19:
Herbs
and
Spices:
allspice,
anise,
anise
hyssop
(
mint),
star
anise,
annatto,
balm,
basil,
borage,
burnet,
camomile,
caper,
caraway,
black
caraway,
cardamom,
cardamom
amomum,
cassia,
catnip,
celery
seed,
chervil,
chive,
Chinese
chive,
cinnamon,
clary,
clove,
coriander,
costmary,
culantro,
cumin,
curry,
dill,
dillweed,
fennel,
Florence
fennel,
fenugreek,
grains
of
paradise,
horehound,
hyssop,
juniper
berry,
lavender,
lemongrass,
lovage,
mace,
pot
marigold,
marjoram
(
oregano),
mustard,
nasturtium,
nutmeg,
parsley,
pennyroyal,
black
pepper,
white
pepper,
poppy,
rosemary,
rue,
saffron,
sage,
Summer
savory,
Winter
savory,
sweet
bay,
tansy,
tarragon,
thyme,
vanilla,
wintergreen,
woodruff,
wormwood.
Table
3.
The
following
crops
appear
in
the
master
label
for
pyrethrin.
a
The
maximum
application
rate
appears
in
the
first
row.

Maximum
application
rate:
0.050
lb
a.
i./
A
Maximum
seasonal
application
rate
0.500
lb
a.
i./
A/
season
Maximum
number
of
applications:
10
Minimum
application
intervals:
1
day
(
under
extreme
pressure),
3
days
(
under
normal
pressure)

­
23­
Subtropical
Fruits:
acerola,
avocado,
banana,
carob
bean,
cherimoya,
date,
durian,
feijoa,
fig,
guava,
kiwifruit,
lychee,
mango,
papaya,
passionfruit,
pineapple,
pomegranate.

Oriental
Vegetable:
acerola,
Chinese
artichoke,
atemoya,
balsam
pear,
mung
bean,
yardlong
bean,
Chinese
broccoli,
Chinese
cabbage,
bok
choy,
napa,
coriander
(
cilantro),
dasheen,
ginger,
ginseng,
melon,
citron,
Oriental
radish,
rambutan,
Chinese
spinach,
starfruit
(
carambola),
Chinese
waxgourd.

Miscellaneous
Crops:
asparagus,
coffee,
tea,
grapes,
strawberry,
cranberry,
hops,
sesame,
jojoba,
safflower,
sunflower,
okra,
sugarcane,
cotton.

aPHI
=
0
days
("
wait
until
the
material
applied
is
dry");
for
cotton
PHI
is
14
days
(
of
seed
harvest);
do
not
wet
plants
to
point
of
runoff
or
drip.

B.
Exposure
Characterization
1.
Environmental
Fate
and
Transport
Characterization
The
physical
and
chemical
properties
and
some
environmental
fate
properties
of
the
pyrethrins
are
summarized
in
Table
4
(
certain
references
were
obtained
from
the
TOXNET
database).

Table
4.
Summary
of
environmental
chemistry
and
fate
properties
of
pyrethrins.

Parameter
Value
Reference/
Commentsa
Selected
Physical/
Chemical
Parameters
PC
code
069001
CAS
No.
8003­
34­
7
Pyrethrum,
121­
21­
1
pyrethrin
1,
121­
29­
9
pyrethrin
2,
25402­
06­
6
cinerin
1,
121­
20­
0
cinerin
2,
4466­
14­
2
jasmolin
1,
1172­
63­
0
jasmolin
2
Table
4.
Summary
of
environmental
chemistry
and
fate
properties
of
pyrethrins.

Parameter
Value
Reference/
Commentsa
­
24­
Physical
state
Clear
pale
viscous
liquid
Budavari,
S.
(
ed.).
The
Merck
Index
 
An
Encyclopedia
of
Chemicals,
Drugs,
and
Biologicals.
Whitehouse
Station,
NJ:
Merck
and
Co.,
Inc.,
1996,
1369.
Lewis,
R.
J.,
Sr.
(
Ed.).
Hawley's
Condensed
Chemical
Dictionary.
13th
Ed.
New
York,
NY:
John
Wiley
&
Sons,
Inc.
1997.
273,
942
Odor
Faint:
Dried
flowers
Reported
by
the
registrant
Stability
Stable
at
room
temperatures
for
over
three
years
when
stored
in
the
absence
of
light
in
steel
drums
Reported
by
the
registrant.
Table
4.
Summary
of
environmental
chemistry
and
fate
properties
of
pyrethrins.

Parameter
Value
Reference/
Commentsa
­
25­
Chemical
name
pyrethrin
1:
(
Z)­(
S)­
2­
methyl­
4­
oxo­
3­(
penta­
2,4­
dienyl)
cyclo
pent­
2­
enyl
(
1R)­
trans­
2,2­
dimethyl­
3­(
2­
methylprop­
1­
enyl)
cyclopropanecarboxylate
pyrethrin
2:
(
Z)­(
S)­
2­
methyl­
4­
oxo­
3­(
penta­
2,4­
dienyl)
cyclo
pent­
2­
enyl
(
E)­(
1R)­
trans­
3­(
methoxy
carbonylprp­
enyl)­
2,2­
dimethylcyclopropanecarboxylate
cinerin
1:
(
Z)­(
S)­
3­(
but­
2­
enyl)
2­
methyl­
4­
oxocyclopent­
2­
enyl
(
1R)­
trans­
2,2­
di
methyl­
3­(
2­
methyl
prop­
1­
enyl)­
cyclopropanecarboxylate
cinerin
2:
(
Z)­(
S)­
3­(
but­
2­
enyl)­
2­
methyl­
4oxocyclopent­
2­
enyl
(
E)­(
1R)­
trans­
3­(
2­
methoxycarbonylprop
1­
enyl)­
2,2­
dimethyl
cyclopropanecarboxylate
jasmolin
1:
(
Z)­(
S)­
2­
methyl­
4­
oxo­
3­(
pent­
2­
enyl)­
cyclopent­
2­
enyl
(
1R)­
trans­
2,2­
dimethyl­
3(
2­
methylprop­
1enyl)­
cyclopropanecarboxylate
jasmolin
2:
(
Z)­(
S)­
2­
methyl­
4­
oxo­
3­(
pent­
2­
enyl)­
cyclopent­
2­
enyl
(
1R)­
trans­
3­(
2­
methoxycarbonylprop­
1­
enyl)­
2,2­
dimethylcyclopropanecarboxylate
Table
4.
Summary
of
environmental
chemistry
and
fate
properties
of
pyrethrins.

Parameter
Value
Reference/
Commentsa
­
26­
Chemical
formula
C
21
H
25
O
3,
C
21
H
25
O
5,

C
20
H
25
O
3,
C
22
H
30
O
5,
C
21
H
28
O
3
,
C
22
H
28
O
5
Molecular
weight
328.4
g/
mol
pyrethrin
1
372.4
g/
mol
pyrethrin
2
316.4
g/
mol
cinerin
1
360.4
g/
mol
cinerin
2
330.5
g/
mol
jasmolin
1
357.7
g/
mol
jasmolin
2
Water
solubility
pyrethrin
1:
0.2
ppm
pyrethrin
2:
9.0
ppm
cinerin
1:
Insoluble
cinerin
2:
Insoluble
jasmolin
1:
0.03
ppm
jasmolin
2:
0.09
ppma
Estimated
values
from
EPISUITE.
a
Other
values
from
HSDB
2001
(
Hazardous
Substances
Data
Bank,
as
cited
in
Pyrethrins
and
Pyrethroids,
Chapter
4.
Chemical
and
Physical
Information)

Solubilities
Soluble
in
alcohol,
ether,
diethyl
ether,
kerosene,
carbon
tetrachloride,
nitromethane,
and
ethylene
dichloride
Budavari,
S.
(
ed.).
The
Merck
Index
 
An
Encyclopedia
of
Chemicals,
Drugs,
and
Biologicals.
Whitehouse
Station,
NJ:
Merck
and
Co.,
Inc.,
1996,
1369
Density
pyrethrin
1:
1.5192
g/
cm3
@
18
°
C
Pyrethrum:
0.84 
0.86
g/
cm3
(
25%
pale
extract)
0.975
g/
cm3,
range
0.97 
0.98
g/
cm3
Lide,
DR
(
ed.).
CRC
Handbook
of
Chemistry
and
Physics.
81st
Edition.
CRC
Press
LLC,
Boca
Raton:
FL
2000,
p.
3 
137.
Tomlin,
C.
D.
S.
(
Ed.).
The
Pesticide
Manual
 
World
Compendium,
11th
Ed.,
British
Crop
Protection
Council,
Surrey,
England
1997
1057.
Reported
by
the
registrant.
Table
4.
Summary
of
environmental
chemistry
and
fate
properties
of
pyrethrins.

Parameter
Value
Reference/
Commentsa
­
27­
Boiling
point
146 
148
°
C
at
2x10­
3
mm
Hg,
146 
150
°
C
at
5x10­
4
mm
Hg,
and
170
°
C
at
0.1
mm
Hg
for
pyrethrin
1
196 
198
°
C
at
7x10­
3
mm
Hg,
192 
193
°
C
at
7x10­
3
mm
Hg,
200
°
C
at
0.1
mm
Hg
for
pyrethrin
2
136 
138
°
C
at
8x10­
3
mm
Hg
for
cinerin
1
182 
184
°
C
at
0.001
mm
Hg
for
cinerin
2
Partially
from:
Budavari,
S.
(
ed.).
The
Merck
Index
 
An
Encyclopedia
of
Chemicals,
Drugs,
and
Biologicals.
Whitehouse
Station,
NJ:
Merck
and
Co.,
Inc.,
1996,
1369.
Reported
by
the
registrant.

Vapor
pressure
(
25
°
C)
pyrethrin
1:
2.03x10­
5
mm
Hg
pyrethrin
2:
3.98x10­
7
mm
Hg
cinerin
1:
1.1x10­
6
mm
Hga
cinerin
2:
4.6x10­
7
mm
Hga
jasmolin
1:
4.8x10­
7
mm
Hga
jasmolin
2:
1.9x10­
7
mm
Hga.
Tomlin,
C.
D.
S.
(
Ed.).
The
Pesticide
Manual
 
World
Compendium,
11th
Ed.,
British
Crop
Protection
Council,
Surrey,
England
1997
1057,
1058
Estimated
value
from
EPISUITEa
Henry's
Law
constant
pyrethrin
1:
7.7x10­
7
Atm­
m3/
mola
pyrethrin
2:
7.4x10 
10
Atm­
m3/
mola
cinerin
1:
9.6x10­
7
Atm­
m3/
mola
cinerin
2:
9.2x10­
10
Atm­
m3/
mola
jasmolin
1:
1.3x10­
6
Atm­
m3/
mola
jasmolin
2:
1.2x10 
9
Atm­
m3/
mola
Estimated
value
from
EPISUITEa
Table
4.
Summary
of
environmental
chemistry
and
fate
properties
of
pyrethrins.

Parameter
Value
Reference/
Commentsa
­
28­
log
K
OW
pyrethrin
1:
5.9
pyrethrin
2:
4.3
Tomlin,
C.
D.
S.
(
Ed.).
The
Pesticide
Manual
 
World
Compendium,
11th
Ed.,
British
Crop
Protection
Council,
Surrey,
England
1997
1057,
1058
Persistence
Hydrolysis
t
1/
2
pH
5
pH
7
pH
9
Stable
Stable
14
days
MRID
43188201
pH
5
pH
7
pH
9
Stable
Stable
17
days
Major
degradate
chrysanthemic
acid
(
54 
64%)
at
21
days
MRID
43567502
Photolysis
t
1/
2
in
water
11.8
hours,
for
the
combination
of
pyrethrin
and
the
(
E)­
Isomer
of
pyrethrin
1
(@
55.7%
at
2
hours)
MRID
43567601
Photolysis
t
1/
2
on
soil
<
24
hours,
numerous
minor
degradation
products
MRID
43096602
Soil
metabolism
aerobic
t
1/
2
24 
25
°
C
9.5
days
(
total)
3.2
days
(
bi­
phasic
initial
halflife
MRID
43499803
Soil
metabolism
anaerobic
t
1/
2
NA
N/
A
Aquatic
metabolism
aerobic
t
1/
2
10.5
days
MRID
43499802
Aquatic
metabolism
anaerobic
t
1/
2
86
days
MRID
43499801
Mobility/
Adsorption­
Desorption
Table
4.
Summary
of
environmental
chemistry
and
fate
properties
of
pyrethrins.

Parameter
Value
Reference/
Commentsa
­
29­
Batch
equilibrium
 
unaged
soil
type
classification
K
ads
K
oc
MRID
43096603
S
Immob
198
3784
7
SL
Immob
268
1247
2
Average
K
OC
=
35,170
SiL
Immob
430
7417
5
SiClL
Immob
310
1619
0
Laboratory
volatility
Limited
volatility,
#
0.002
:
g/
cm2°
hour;
after
30
days,
volatilized
residues
totaled
a
maximum
of
~
16%
of
which
~
9%
was
CO
2
,
~
0.3%
was
pyrethrin,
~
10%
chrysanthemic
acid,
and
~#
2.4
of
two
other
degradates.
MRID
43096604
Field
Dissipation
Terrestrial
field
dissipation
1 
2
days
MRID
42745501
Aquatic
field
dissipation
Study
is
not
valid
MRID
43818501
Bioaccumulation
Accumulation
in
fish,
maximum
BCF
873X
viscera
127X
edible
tissues
predominant
species
were
parent
and
chrysanthemic
acid
MRID
43302301,
43884102
Pyrethrin
is
a
naturally
occurring
substance
that
contains
six
esters
that
are
biologically
active.
Pyrethrin
1
was
chosen
as
a
surrogate
chemical
to
represent
all
six
pyrethrin.
All
of
the
environmental
fate
studies
were
performed
with
pyrethrin
1.
­
30­
General
Stereochemistry
of
the
Pyrethrins
R
=
­
CH3
(
for
cinerin),
­
CH2CH3
(
for
jasmolin)
or
­
CH=
CH2
(
for
pyrethrin)

R'=
­
CH3
(
for
pyrethrins
I),
­
CO2CH3
(
for
the
pyrethins
II)

As
noted,
all
the
pyrethrins
have
the
same
backbone
structure,
with
the
exception
of
variations
in
the
substitutions
in
the
external
or
outermost
groups.
Due
to
the
fact
that
all
the
pyrethrins
have
very
similar
structures,
the
environmental
fate
studies
were
conducted
and
well
characterized
with
only
one
of
the
pyrethrins:
pyrethrin
1.

Except
for
the
interaction
with
polarized
light,
enantiomers
have
identical
physico/
chemical
properties.
However,
diastereoisomers
could
have
somewhat
different
basic
properties.
In
this
case
the
differences
are
in
the
substituents
at
two
sites.
The
substituents
at
­
R
are
expected
to
have
low
reactivity,
with
the
ethene
being
slightly
more
reactive.
In
any
case,
the
driving
fate
reaction
is
the
breaking
of
the
ester
bond
which
is
away
from
­
R.
On
the
other
hand,
in
the
case
of
­
R',
we
have
two
different
moieties.
The
methyl
moiety
will
be
relatively
unreactive,
while
the
acetyl
group
(
ester
bond)
will
be
susceptible
to
hydrolysis,
resulting
in
an
acid
and
an
alcohol.
It
is
noted
from
the
Table
4
that
the
water
solubility
of
the
various
pyrethrins
varies
due
to
some
structure
variations
among
them,
however,
since
the
environmental
fate
of
only
pyrethrin
1
was
characterized,
its
solubility
was
used
in
the
models.
This
may
add
some
uncertainty
to
the
assessment.
Nevertheless,
we
do
not
expect
major
differences
in
the
overall
biotic
and
abiotic
degradation
of
the
pyrethrins.

In
general,
the
environmental
fate
and
transport
data
base
of
pyrethrin
1
is
adequate
to
characterize
the
environmental
fate,
drinking
water,
and
ecological
exposure
of
the
pyrethrins.
It
is
unlikely
that
the
submission
of
additional
data
would
change
the
environmental
fate
assessment
substantially.
There
are
no
mobility
and
little
persistence
data
for
the
degradates
of
pyrethrin
1.
In
addition,
studies
using
radiolabeling
on
the
cyclopentene
side
of
the
ester
linkage
were
not
conducted
and
cold
analysis
was
not
performed
in
the
cyclopropyl
labeled
studies.
Consequently,
there
was
no
analysis
of
potential
degradates
containing
the
cyclopentene
ring
originating
from
the
cleavage
of
the
carboxylate
ester
linkage.

Degradation
and
Metabolism
Cyclopropane
ring­
labeled
[
1­
14C]
pyrethrin
[
pyrethrin
1],
at
a
nominal
concentration
of
0.4
ppm,
was
relatively
stable
in
sterile
aqueous
pH
5
and
pH
7
buffer
solutions
that
were
incubated
in
the
dark
at
25
±
1
/

C
for
30
days.
In
pH
9
solutions,
pyrethrin
1
hydrolyzed
with
a
calculated
half­
life
of
14
days
and
17
days.
The
major
degradation
product
identified
was
chrysanthemic
acid
at
up
to
64%
of
the
applied
at
21
days.

In
an
aqueous
photolysis
experiment,
pyrethrin
1
isomerized
to
the
(
E)­
isomer
of
pyrethrin
1
(
which
reached
a
maximum
50.7 
55.7%
of
the
applied
amount
at
2
hours
post­
treatment
)
with
an
observed
half­
life
of
­
31­
approximately
1
hour
in
sterile
aqueous
0.01
M
buffer
solutions
(
pH
7)
that
were
irradiated
with
sunlight
in
Irvine,
California
(
33
°
41'
N,
117
°
15'
W)
at
25
°
C
for
71
hours,
between
11
AM
on
October
7
and
10
AM
on
October
10,
1993.
The
overall
calculated
half­
life
of
dissipation
of
pyrethrin
1
and
its
(
E)­
isomer
was
11.8
hours.
In
a
soil
photolysis
study,
[
14C]
Pyrethrin
[
pyrethrin
1]
photodegraded
with
an
observed
half­
life
of
<
24
hours
(
registrant
reported
12.9
hours)
in
sandy
loam
soil
that
was
treated
at
9.0 
9.6
ppm
and
irradiated
with
natural
sunlight
in
California
at
24+
2
°
C
for
24
hours
in
mid­
November.
In
contrast,
the
dark
control
samples
degraded
with
a
reported
half­
life
of
82.9
hours.

The
reported
half­
life
of
14C­
pyrethrin
1
applied
at
a
nominal
application
rate
of
1
ppm,
in
an
aerobic
sandy
loam
soil
adjusted
to
75%
of
field
capacity
and
incubated
in
the
dark
at
25
±
1
°
C
for
up
to
181
days
was
9.5
days.
The
degradation
was
reported
as
biphasic
[
half­
lives
were
3.2
days
(
0 
14
day
data)
and
23.5
days
(
14 
59
day
data)].
Chrysanthemic
acid
was
a
minor
identified
metabolite.
Another
band
(
which
appears
to
consist
of
multiple
peaks)
could
not
be
identified.

[
14C]
pyrethrin
1
degraded
with
a
half­
life
of
10.5
days
(
r2
=
0.96)
in
flooded
sandy
loam
soil
incubated
at
25
±
1
°
C
for
up
to
30
days
in
an
aerobic
aquatic
dissipation
study.
In
an
anaerobic
aquatic
dissipation
study
the
half­
life
of
pyrethrin
1
was
86
days.

It
is
noted
that
in
all
the
studies,
the
material
was
radiolabeled
in
the
cyclopropane
ring.
As
a
result,
mostly
the
degradate
that
would
be
observed
is
chrysanthemic
acid.
Material
radiolabeled
in
the
cyclopentenolone
ring
would
result
in
different
degradation
products;
however,
the
first
step
in
the
degradation
of
pyrethrin
1
is
the
rupture
of
the
ester
bridge,
resulting
in
a
carboxylic
acid,
and
an
alcohol.
The
resulting
molecules
have
lost
their
pyrethroid
toxicological
activity;
therefore,
in
this
assessment,
they
were
not
considered
of
concern.
Furthermore,
the
available
data
show
that
chrysanthemic
acid
does
not
reach
high
levels
except
upon
hydrolysis
at
pH
9.
In
the
majority
of
the
studies
multiple
degradates
at
very
low
concentrations
were
observed,
but
not
characterized.
The
only
significant
isomer
observed
in
the
aqueous
photolysis
study
was
the
(
E)­
isomer
of
pyrethrin
1;
however,
the
half­
life
of
pyrethrin
1
was
reported
for
the
photolysis
of
pyrethrin
1
plus
the
isomer
(
as
if
it
was
parent)
in
the
calculation
(
the
resulting
half­
life
was
less
than
one
day).

The
figure
that
follows
shows
the
structures
of
the
expected
degradation
products
of
the
various
pyrethrins.
All
six
of
them
are
expected
to
be
more
soluble
and
mobile
than
their
respective
parent
compounds,
specially
the
acids.
Based
on
the
information
from
pyrethrin
1,
chrysanthemic
acid
appeared
to
be
short
lived
and
pyrethric
acid
and
chrysanthemum
dicarboxylic
acid
would
be
expected
to
behave
similarly.
The
E­
isomer
of
pyrethrin
1
was
shown
in
the
photolysis
on
soil
study
to
be
short
lived
as
well,
therefore,
it
is
of
low
concern.
­
32­
Fig.
2.
Structures
of
Degradation
Products
of
the
Pyrethrins
Soil
Sorption
and
Mobility
Based
on
batch
equilibrium
experiments,
[
14C]
pyrethrin
1
was
determined
to
be
immobile
in
sand,
sandy
loam,
silt
loam,
and
silty
clay
loam
soil:
calcium
chloride
solution
slurries
(
1:
100,
w:
v).
The
respective
Koc
values
in
were
37,847,
12,472,
74,175,
and
16,190.

Field
Dissipation
EFED
has
waived
the
Terrestrial
Field
Dissipation
Study
(
§
164­
1)
data
requirement.
EFED
believes
that
a
new
study
will
not
substantially
change
the
environmental
fate
assessment.
The
parent
degrades
rapidly
and
the
ultimate
degradate
is
CO2,
and
bound
residues
in
soil.
It
appears
that
formed
metabolites
are
of
no
significant
environmental
concern,
as
indicated
earlier.
The
proposed
use
rate
is
low
(
single
application
rate
of
0.050
lb
a.
i./
acre,
seasonal
application
rate
of
0.50
lbs
a.
i./
acre).
The
degradates
such
as
chrysanthemic
acid
may
not
reach
sufficiently
high
levels
to
pose
a
toxicological
concern.
Based
on
data
from
the
laboratory
studies,
at
the
current
application
rate,
in
field
use
conditions
the
peak
degradates'
concentrations
are
likely
to
be
below
0.01
ppm.

A
study,
providing
marginally
supplemental
data
(
bare
ground
soils
in
CA,
GA,
and
MI)
appears
to
indicate
that
dissipation
in
the
field
is
very
rapid
(~
1­
2
days).
The
test
substance
was
pyrethrum
extract
(
mixture
of
pyrethrins
I
and
pyrethrins
II).
The
results
appear
to
confirm
what
would
be
expected
from
the
laboratory
studies.
­
33­
2.
Measures
of
Aquatic
Exposure
Pyrethrins
applied
aerially
could
contaminate
shallow
surface
water
through
spray
drift,
or
runoff
and
erosion
events
which
might
occur
shortly
after
application.
In
shallow,
sunlit,
surface
water
bodies,
the
primary
route
of
dissipation
could
be
aqueous
photolysis
(
t
½
=
11.8
hours);
however,
pyrethrins
are
also
expected
to
rapidly
adsorb
to
suspended
solids
and
accumulate
into
the
sediments.
In
aquatic
environments,
pyrethrins
are
moderately
persistent
under
aerobic
metabolism
(
t
½
=
10.5
days),
but
more
persistent
under
anaerobic
conditions
(
t
½
=
86.1
days);
pyrethrins
are
hydrolytically
stable
at
pH
5
and
7,
but
have
a
hydrolysis
half­
life
of
about
14
days
at
pH
9.
Given
the
fate
of
this
chemical,
and
assuming
the
sediments
are
relatively
anoxic,
there
is
potential
for
pyrethrin
to
persist
in
the
sediments
where
it
might
pose
a
risk
to
sediment­
dwelling
organisms.
Based
on
its
octanol/
water
partition
coefficient
(
KOW
=
794,000),
pyrethrin
would
be
expected
to
bioaccumulate
substantially.
However,
pyrethrin
1
accumulated
only
moderately
in
fish
(
127x
for
the
edible
tissues,
873x
for
the
nonedible
tissues,
and
471x
for
whole
fish).
It
appears
that
fish
have
the
ability
to
metabolize
low
concentrations
of
pyrethrin
to
water
soluble
degradates
which
are
then
excreted.
Depuration
was
rapid;
by
day
1,
77%
of
the
accumulated
[
14C]
residues
were
eliminated
from
the
edible
tissues,
66%
from
the
nonedible
tissues,
and
68%
from
the
whole
fish.

Acute
studies
on
aquatic
organisms
show
that
pyrethrins
are
very
highly
toxic
to
freshwater
fish
(
96­
hour
LC50=
3.2
:
g/
L)
and
aquatic
invertebrates
(
daphnid
48­
hour
EC50
=
6.7
:
g/
L)
at
levels
well
below
the
water
solubility
of
this
chemical.

a.
Aquatic
Exposure
Modeling
for
Agricultural
Crops
Modeling
of
Agricultural
Crops:
To
determine
aquatic
ecological
risks
associated
with
agricultural
uses
of
pyrethrins,
estimated
environmental
concentrations
(
EECs)
in
surface
water
were
modeled
using
the
Tier
II
model
PRZM
(
Pesticide
Root
Zone
Model,
version
3.12
compiled
May
24,
2001),
and
EXAMS
(
Exposure
Analysis
Modeling
System,
version
2.98.04
compiled
November
12,
2002).
PRZM
simulates
runoff
and
erosion
from
an
agricultural
field
on
a
daily
time
step.
The
runoff
and
erosion
flux
output
data
from
PRZM
are
used
as
chemical
loadings
to
the
EXAMS
surface
water
program
in
order
to
predict
the
EECs.
A
graphical
user
interface
(
pe4v01.
pl),
developed
by
the
EPA
(
http://
www.
epa.
gov/
oppefed1/
models/
water),
was
used
to
facilitate
inputting
chemical
and
use
specific
parameters
into
the
appropriate
PRZM
input
files
(
inp)
and
EXAMS
chemical
files.
With
this
aquatic
model,
it
is
assumed
that
the
receiving
body
of
water,
the
EXAMS
standard
pond,
is
adjacent
to
the
treated
field,
the
direction
of
the
spray
drift
is
towards
the
pond
and
both
the
runoff
and
the
spray
drift
mix
quickly
in
the
pond,
also,
there
is
no
flow
in
the
pond.
These
assumptions
of
PRZM/
EXAMS
apply
in
all
cases
in
this
report.

The
following
13
PRZM
field
scenarios
were
modeled:
ID
potato,
ME
potato,
CA
onion,
OR
snapbeans,
PA
tomato,
FL
citrus,
NC
apple,
GA
peaches,
ND
wheat,
IL
corn,
MN
alfalfa,
CA
grapes,
MS
cotton.
The
Master
Label
provides
all
the
crops
on
which
pyrethrin
can
be
applied.
They
are
divided
into
crop
groups
which
agree
with
EPA's
classification
procedures.
There
are
19
crop
groups
plus
three
additional
special
crop
groups
(
Suptropical
Fruits,
Oriental
Vegetables,
and
Miscellaneous
Crops),
with
crops
that
could
not
be
categorized
along
with
the
others.
Probably
hundreds
of
crops
are
listed
in
the
Master
Label
(
refer
to
Table
3
for
a
sinopsis
of
the
agricultural
crops
listing).
The
13
crop
or
field
scenarios
were
selected
with
PRZM/
EXAMS
to
represent,
not
only
this
wide
variety
of
crops,
but
the
ample
geographical
regions
of
the
continental
US.
The
13
crop
scenarios
represent
the
Crop
Groups
1,
3,
7,
8,
10,
11,
12,
15,
16,
18,
and
Miscellaneous
­
34­
Crops
(
cotton).

EECs
for
ecological
risk
assessment
were
determined
using
a
Mississippi
Pond
modeling
scenario
which
describes
a
generic
scenario
for
the
EXAMS
component
of
the
modeling
exercise.
Table
5
summarizes
the
input
parameter
values
used
to
run
PRZM/
EXAMS.
The
three
critical
application
variables
required
for
this
assessment
are
the
(
1)
maximum
application
rate;
(
2)
number
of
applications
per
year,
and
(
3)
interval
between
applications.
The
maximum
application
rate
of
0.05
lbs
a.
i./
A,
maximum
number
of
applications
(
10),
and
minimum
interval
between
applications
(
1
day,
which
applies
when
there
is
extreme
pest
pressure)
was
used
for
modeling
all
crop
uses,
based
on
the
product
label
(
Table
3).
In
addition,
for
selected
crops,
runs
were
made
with
the
interval
between
applications
of
3
days
(
normal
pest
pressure).
The
variability
in
the
EECs
for
the
different
standard
scenarios
reflect
effects
of
the
environmental
setting
of
the
scenario
including
soil
properties
and
weather,
rather
than
the
agricultural
characteristics
and
chemical
properties
which
are
consistent
across
scenarios.
For
certain
crop
scenarios,
additional
special
runs
were
performed
in
which
the
value
of
spray
drift
was
set
at
0%
to
determine
if
spray
drift
is
an
important
component
of
the
EECs
for
those
crops
(
by
comparison
with
the
standard
run).

Table
5.
Input
variables
and
parameter
values
for
PRZM/
EXAMS.

Input
Variable
Parameter
Value
Source
Molecular
weight
Pyrethrin
1:
328.4
g/
mol
Water
solubility
(
20
°
C)
2.0
ppm
Maximum
solubility,
Tomlin,
C.
D.
S.,
Pesticide
manual
(
TOXNET)

10x
available
value
as
per
EFED
Model
Input
Guidance,
Version
II
(
2002)

Vapor
pressure
Pyrethrin
1:
2.03
x
10­
5
mm
Hg
Tomlin,
C.
D.
S.,
Pesticide
manual
(
TOXNET)

Henry's
Law
constant
Pyrethrin
1:
7.7
x
10­
7
atm­
m3/
mol
Estimated
value
from
EPISUITE
Hydrolysis
t
½
,
pH
7
(
25
°
C)
pH
5:
stable
pH
7:
stable
pH
9:
17
days
MRID
43567502
Spray
drift
fraction
0.05
EFED
Model
Input
Guidance,
Version
II
(
2002)

Application
efficiency
0.95
EFED
Model
Input
Guidance,
Version
II
(
2002)

Aerobic
soil
metabolism
t
½
(
3­
times
available
value)
28.5
days
MRID
43499803
Aerobic
aquatic
metabolism
t
½
(
3­
times
available
value)
31.5
days
MRID
43499802
Anaerobic
aquatic
metabolism
t
½
86
days
MRID
43499801
Table
5.
Input
variables
and
parameter
values
for
PRZM/
EXAMS.

Input
Variable
Parameter
Value
Source
­
35­
Direct
aqueous
photolysis
t
½
0.5
day
MRID
43567601
Koc
35,170
Average
Value.
MRID
43096603,
EFED
Model
Input
Guidance,
Version
II
(
2002)

PLDKRT
(
foliage
pesticide
half­
life)
0
days
EFED
Model
Input
Guidance,
Version
II
(
2002)

FEXTRC
(
foliar
extraction)
0.5
EFED
Model
Input
Guidance,
Version
II
(
2002)

FILTRA
(
filtration
parameter;
required
if
CAM
set
to
3)
NA
 

PLVKRT
(
pesticide
decay
rate
on
plant
foliage)
0/
day
EFED
Model
Input
Guidance,
Version
II
(
2002)

IPSCND
(
condition
for
disposition
of
foliar
pesticide
after
harvest)
3
PRZM
Version
3.0
User's
Manual
(
Carsel
1998)

CAM
(
chemical
application
method)
2
PRZM
Version
3.0
User's
Manual
(
Carsel
1998)

UPTKF
(
plant
uptake
factor)
0
EFED
Model
Input
Guidance,
Version
II
(
2002)

DAIR
(
diffusion
coefficient
for
pesticide
in
the
air)
0
PRZM
Version
3.0
User's
Manual
(
Carsel
1998)

ENPY
(
enthalpy
of
vaporization
of
pesticide)
Not
reported
 

Benthic
layer
5
cm
EXAMS
Default
CROP
MANAGEMENT
Standard
scenarios
ID
potato,
ME
potato,
CA
onion,
OR
snapbeans,
PA
tomato,
FL
citrus,
NC
apple,
GA
peaches,
ND
wheat,
IL
corn,
MN
alfalfa,
CA
grapes,
MS
cotton
Application
rate
(
kg
a.
i./
ha/
application)
All
scenarios:
0.056
For
TYPICAL
APPLICATION
RATE:
ID
potato
0.0224
PA
tomato
0.0067
CA
onion
0.0146
OR
snap
beans
0.0235
Product
label
­­­­­­­
Typical
data
obtained
from
various
sources
and
provided
to
EFED
by
BEAD,
Table
5.
Input
variables
and
parameter
values
for
PRZM/
EXAMS.

Input
Variable
Parameter
Value
Source
­
36­
Number
of
applications
All
scenarios:
10
For
TYPICAL
APPLICATION
RATE:
ID
potato
1
PA
tomato
2
CA
onion
2
OR
snap
beans
5
Product
label
­­­­­­
No
data
were
available
on
number
of
applications
for
beans;
therefore,
the
EFED
used
a
conservative
value
of
5.

Interval
between
applications
(
days)
a
All
scenarios:
1
For
TYPICAL
APPLICATION
RATE,
and
selected
crops,
3
Product
label
Date
of
first
application
All
scenarios:
1­
June
Pyrethrin
can
be
applied
at
any
time
of
the
year,
when
there
is
pest
pressure.

Application
type
and
depth
of
incorporationa
(
cm)
Aerial/
0.0/
1
day
Interval
between
applications
(
days)
a
The
Agency
has
modeled
the
maximum
and
typical
application
rates
for
pyrethrin
(
Table
6).
The
range
of
peak
daily
EECs
(
maximum
rate)
for
all
13
scenarios
is
0.35­
2.77
:
g/
L,
while
for
typical
application
rate
can
result
in
peak
daily
EEC's
of
0.0017
­
0.056
ug/
L.
Special
runs
with
3­
day
intervals
between
applications
were
also
considered
by
the
Agency
and
show
that
the
standard
scenario
with
the
highest
EECs
is
Illinois
Corn.
The
modeled
values
for
maximum
application
rate
show
that
the
scenarios
with
the
highest
EEC's
were
Maine
Potatoes,
Pennsylvania
Tomatoes,
and
the
Mississippi
Cotton.

Table
6.
Surface
water
EECs
from
PRZM/
EXAMS
(
ppb)
for
ecological
risk
assessment
based
on
pyrethrins
use
on
several
crops.

Crop
App.
rate
(
kg/
ha)
No.
of
app./
int
between
applicat.
(
days)
Peak
96
Hour
21
Day
60
Day
90
Day
Annual
IL
corn
0.056
10/
1
2.766
1.410
0.598
0.374
0.314
0.158
ME
potato
0.056
10/
1
1.353
0.817
0.387
0.284
0.250
0.146
MS
cotton
0.056
10/
1
1.906
0.982
0.411
0.279
0.232
0.087
PA
tomato
0.056
10/
1
1.514
0.742
0.336
0.204
0.181
0.089
Table
6.
Surface
water
EECs
from
PRZM/
EXAMS
(
ppb)
for
ecological
risk
assessment
based
on
pyrethrins
use
on
several
crops.

Crop
App.
rate
(
kg/
ha)
No.
of
app./
int
between
applicat.
(
days)
Peak
96
Hour
21
Day
60
Day
90
Day
Annual
­
37­
ND
wheat
0.056
10/
1
0.683
0.366
0.228
0.134
0.112
0.058
CA
onion
0.056
10/
1
0.777
0.462
0.248
0.125
0.097
0.038
NC
apple
0.056
10/
1
0.607
0.371
0.233
0.131
0.114
0.056
OR
snapbeans
0.056
10/
1
0.452
0.340
0.186
0.102
0.083
0.042
ID
potato
0.056
10/
1
0.366
0.293
0.165
0.085
0.067
0.033
MN
alfalfa
0.056
10/
1
0.362
0.292
0.163
0.083
0.066
0.032
FL
citrus
0.056
10/
1
0.401
0.296
0.175
0.092
0.073
0.028
GA
peaches
0.056
10/
1
0.656
0.424
0.189
0.096
0.073
0.031
CA
grapes
0.056
10/
1
0.348
0.279
0.149
0.071
0.055
0.021
SPECIAL
RUNS
WITH
3­
DAY
INTERVAL
BETWEEN
APPLICATIONS
(
3
days,
normal
pest
pressure)

IL
corn
0.056
10/
3
2.402
1.168
0.501
0.334
0.285
0.151
ID
potato
0.056
10/
3
0.208
0.140
0.122
0.080
0.065
0.033
CA
onion
0.056
10/
3
0.392
0.229
0.156
0.092
0.071
0.028
TYPICAL
APPLICATION
RATE,
NUMBER
OF
APPLICATIONS,
AND
INTERVAL
BETWEEN
APPLICATIONS
Crop
App.
Rate
(
Kg
a.
i./
ha)
No
of
app./
interval
between
app.
Peak
96
Hour
21
Day
60
Day
90
Day
Annual
ID
potato
0.0224
1/(
N/
A)
0.052
0.024
0.007
0.003
0.003
0.001
Table
6.
Surface
water
EECs
from
PRZM/
EXAMS
(
ppb)
for
ecological
risk
assessment
based
on
pyrethrins
use
on
several
crops.

Crop
App.
rate
(
kg/
ha)
No.
of
app./
int
between
applicat.
(
days)
Peak
96
Hour
21
Day
60
Day
90
Day
Annual
1
Curry,
K.
K,
and
Brookman,
D.
J.
"
Pyrethrins
Master
Label"
An
unpublished
document
sponsored
by
the
Pyrethrin
Joint
Venture
c/
o
Consumer
Specialty
Products
Association,
Inc.,
Report
No.
PJV­
03­
01,
84
p.,
no
MRID.

2
AgDRIFT
®
is
a
computer
program
provided
by
the
Agency's
OPP,
as
a
product
of
the
Cooperative
Research
and
Development
Agreement
(
CRADA),
between
the
EPA's
Office
of
Research
and
Development,
and
the
Spray
Drift
Task
Force
(
SDTF,
a
coalition
of
pesticide
registrants
formed
to
develop
a
comprehensive
database
of
off­
target
drift
information
in
support
of
pesticide
registration
requirements).

­
38­
PA
tomato
0.0067
2/
3
0.033
0.017
0.008
0.005
0.004
0.002
CA
onion
0.0146
2/
3
0.042
0.022
0.008
0.004
0.003
0.001
OR
snap
beans
0.0235
5/
3
0.094
0.056
0.038
0.021
0.017
0.009
Effect
of
Spray
Drift
and
Buffer
Zones:
The
extent
to
which
spray
drift
may
be
an
important
component
of
the
concentration
of
pyrethrin
reaching
bodies
of
water
adjacent
to
treated
areas
after
their
application,
was
investigated.
There
are
numerous
pyrethrin
labels.
The
Pyrethrin
Joint
Venture,
however,
provided
a
document
entitled
"
Pyrethrins
Master
Label,"
1
which
summarizes
all
the
uses
of
pyrethrin,
application
types
and
equipment,
specific
restrictions,
etc.
Pyrethrin
can
be
used
on
hundreds
of
crops
as
shown
in
Table
3.
According
to
the
Master
Label
there
are
19
formulation
types,
and
45
application
equipment
types
for
pyrethrin
products
used
for
agricultural
purposes.
Equipment
types
include
examples
such
as
fixed
wing
aircraft,
and
helicopter.

The
Master
Label
gives
no
indication
that
there
are
buffer
zones
established
between
the
treated
areas
and
adjacent
bodies
of
water
to
minimize
the
level
of
spray
drift.
The
following
restrictions
are
found:

C
"
Aerial
applications:
do
not
apply
less
than
two
gallons
of
diluted
solution
per
acre
to
field
crops
or
less
than
10
gallons
of
diluted
solution
per
acre
to
orchard
crops."

C
"
Do
not
wet
plants
to
point
of
runoff
or
drip."

C
"
Do
not
apply
directly
to
water,
or
to
areas
where
surface
water
is
present,
or
to
intertidal
areas
below
the
mean
high
water
mark."
The
label
does
not
establish
a
range
of
droplet
sizes,
boom
height,
or
wind
speed.

Traditionally,
the
EFED
has
used
a
default
level
of
spray
drift
for
aerial
applications
of
5%.
It
would
be
useful
to
compare
this
value
to
the
data
from
AgDRIFT
®
2.
A
cursory
review
of
the
AgDRIFT
®
data
indicates
that
the
"
standard"
level
of
5%
spray
drift
is
adequate
for
ASAE
Coarse
to
Very
Coarse
and
ASAE
Medium
to
­
39­
Coarse
sprays,
but
the
level
may
be
an
underestimation
for
ASAE
Fine
to
Medium
and
ASAE
Very
Fine
to
Fine
sprays.

EFED
selected
two
scenarios,
GA
peaches
and
ID
potatoes.
Both
crops
yielded
relatively
low
EECs.
Furthermore,
one
crop
scenario
(
GA
peaches)
is
representative
of
orchards,
and
the
other
(
ID
potatoes)
is
representative
of
other
agricultural
crops
and
these
scenarios
are
located
in
opposite
sides
of
the
nation.
First,
EFED
ran
PRZM/
EXAMS
for
these
crops
(
plus
two
other
selected
crops)
with
the
same
standard
input
parameters
as
the
original
runs,
except
that
the
spray
drift
level
was
set
to
0%
instead
of
5%.
It
is
noted
that
of
the
13
scenarios
ran
by
EFED,
some
will
be
driven
by
runoff,
while
others
will
be
driven
by
spray
drift,
depending
on
weather
conditions,
soil
type
and
porosity,
site
slope,
interception,
and
other
factors.

Table
7
provides
the
peak
EECs
for
theoretical
applications
where
spray
drift
is
0%.
It
is
noted
that
for
FL
citrus
and
GA
peaches,
the
peak
EECs
decreased
by
almost
a
half,
while
for
ID
potato,
and
CA
grapes,
the
peak
EECs
decreased
substantially
more.
For
all
these
crop
scenarios,
spray
drift
is
an
important
component
of
the
peak
EEC.
By
comparison
of
the
EECs
generated
with
the
standard
run
(
5%
drift)
and
the
special
run
(
0%)
drift,
the
percentage
of
the
peak
EEC
attributable
to
spray
drift
can
be
calculated
(
see
Table
6b).
This
percentage
is
around
45%
for
FL
citrus
and
GA
peaches,
and
>
88%
for
ID
potato
and
CA
grapes.
Therefore,
drift
is
an
important
component
of
the
peak
EECs
for
the
four
selected
crops.

Table
7.
Surface
water
EECs
from
PRZM/
EXAMS
(
ppb)
for
ecological
risk
assessment
based
on
pyrethrins
use
on
selected
crops,
compared
to
same
crops
with
Spray
Drift
set
to
0%.
The
regular
runs
are
presented
for
comparison
purposes
only.

Crop
Peak
EEC
STANDARD
RUNS,
WITH
SPRAY
DRIFT
SET
TO
5%

ID
potato
0.366
FL
citrus
0.401
GA
peaches
0.656
CA
grapes
0.348
SPECIAL
RUNS
WITH
SPRAY
DRIFT
SET
TO
0%,
Concentration
/
%
attributable
to
spray
drift
ID
potato
0.042
/
88.5
FL
citrus
0.221
/
44.9
GA
peaches
0.344
/
47.6
CA
grapes
0.021
/
94.0
Second,
for
the
two
selected
scenarios,
standard
PRZM/
EXAMS
runs
were
performed
simulating
ground
applications,
for
comparative
purposes.
Then,
since
pyrethrin
yielded
RQs
that
exceeded
the
levels
of
concern
for
certain
aquatic
organisms,
a
number
of
PRZM/
EXAMS
models
were
run,
to
anticipate
the
possible
effect
of
buffer
zones
of
up
to
150
ft.
The
level
of
spray
drift
was
determined
with
the
help
of
AgDRIFT
®
.
Since
the
Master
Label
for
pyrethrin
does
not
indicate
most
of
the
conditions
for
the
aerial
applications
(
except
for
­
40­
spray
volume),
EFED
bracketed
the
options
by
running
a
"
high
end"
(
worst
case)
and
a
"
low
end"
(
best
case)
scenarios.
Essentially,
they
are
described
as
follows:

Table
8.
Drift
Scenarios
High
End
Drift
Scenario
Low
End
Drift
Scenario
high
release
height,
15
ft
low
release
height,
8
ft
high
wind
speed,
15
mph
low
wind
speed,
3
mph
small
droplets,
ASAE
Very
Fine
droplets
(
DV0.5
=
81.52
:
m)
large
droplets,
ASAE
Medium
to
Coarse
droplets
(
DV0.5
=
340.86
:
m)

The
estimation
of
the
level
of
spray
drift
is
considered
a
Tier
II
Aerial
calculation
in
AgDRIFT
®
;
however,
all
possible
AgDRIFT
®
parameters
were
kept
at
their
default
levels
for
simplicity.
Two
sets
of
values
were
generated
using
a
spray
volume
of
10
gal.
(
spray
volume
for
orchards),
and
2
gal.
(
spray
volume
for
other
crops),
with
buffer
zones
of
0,
50,
100,
150
ft.
The
output
value
of
concern
is
the
spray
drift
fraction.
These
results
are
summarized
in
Table
6c,
and
the
inputs/
outputs
of
AgDRIFT
®
and
PRZM/
EXAMS
appear
in
Appendix
O.

Table
9
presents
the
EECs
for
two
selected
crops
with
modeled
standard
ground
and
aerial
applications,
theoretical
aerial
application
with
no
spray
drift
(
partial
results
also
presented
in
Table
7),
and
modeled
aerial
runs
with
buffer
zones
and
high
end
(
worst
case)
drift
scenario
and
low
end
(
best
case)
drift
scenario.
As
expected,
the
low
end
scenario
resulted
in
substantially
lower
EECs.
It
was
noted
also
that
for
both
crops,
the
levels
of
spray
drift
also
decreased,
in
some
cases
substantially
with
the
low
end
drift
scenario.
The
results
of
the
ground
application
and
the
low
end
drift
scenario
with
a
large
buffer
zone
yielded
EECs
of
the
same
order
of
magnitude.
For
example,
the
peak
EEC
of
the
low
end
(
best
case)
drift
scenario
of
the
ID
potato
(
0.087
ppb,
buffer
zone
100
ft)
was
similar
to
the
peak
EEC
of
the
same
crop
applied
by
ground
methods
(
0.082
ppb).

Table
9.
Surface
water
EECs
(
ppb)
for
ecological
risk
assessment
based
on
pyrethrin
use
on
GA
peaches
and
ID
potatoes,
and
buffer
zones
of
50,
100,
and
150
ft.
Results
using
average
KOC
=
35,170
Crop
Peak
EEC
(
ppb)
21
day
EEC
(
ppb)
60
day
EEC
(
ppb)

Standard
Aerial
Run,
With
Spray
Drift
Set
To
5%

Georgia
Peaches
0.656
0.189
0.096
Idaho
Potatoes
0.366
0.165
0.085
Special
Run,
With
Spray
Drift
Set
To
1%,
Ground
Application
Georgia
Peaches
0.421
0.078
0.042
Idaho
Potatoes
0.082
0.038
0.020
Table
9.
Surface
water
EECs
(
ppb)
for
ecological
risk
assessment
based
on
pyrethrin
use
on
GA
peaches
and
ID
potatoes,
and
buffer
zones
of
50,
100,
and
150
ft.
Results
using
average
KOC
=
35,170
Crop
Peak
EEC
(
ppb)
21
day
EEC
(
ppb)
60
day
EEC
(
ppb)

­
41­
Special
Run,
With
Spray
Drift
Set
To
0%

Georgia
Peaches
0.344
0.054
0.028
Idaho
Potatoes
0.042
0.006
0.004
High
end,
release
height
15
ft,
wind
speed
15
mph,
very
fine
droplets
Buffer
Zone
0
ft,
24.0%
spray
drift
for
GA
peaches/
31.2%
spray
drift
for
ID
potatoes
Georgia
peaches
1.681
0.747
0.359
Idaho
Potatoes
2.259
1.002
0.514
Buffer
Zone
50
ft,
16.8%
spray
drift
for
GA
peaches/
23.1%
spray
drift
for
ID
potatoes
Georgia
peaches
1.436
0.535
0.259
Idaho
Potatoes
1.673
0.743
0.381
Buffer
Zone
100
ft,
12.7%
spray
drift
for
GA
peaches/
18.4%
spray
drift
for
ID
potatoes
Georgia
Peaches
1.164
0.415
0.202
Idaho
Potatoes
1.333
0.596
0.304
Buffer
Zone
150
ft,
10.2%
spray
drift
for
GA
peaches/
15.4%
spray
drift
for
ID
potatoes
Georgia
Peaches
0.998
0.341
0.168
Idaho
Potatoes
1.116
0.497
0.255
Low
end,
release
heigh
8
ft,
wind
speed
3
mph,
medium
to
coarse
droplets
Buffer
Zone
0
ft,
2.8%
spray
drift
for
GA
peaches/
3.0%
spray
drift
for
ID
potatoes
Georgia
peaches
0.519
0.126
0.065
Idaho
Potatoes
0.223
0.101
0.052
Buffer
Zone
50
ft,
1.4%
spray
drift
for
GA
peaches/
1.5%
spray
drift
for
ID
potatoes
Georgia
Peaches
0.431
0.087
0.046
Idaho
Potatoes
0.115
0.053
0.028
Buffer
Zone
100
ft,
1.1%
spray
drift
for
GA
peaches/
1.1%
spray
drift
for
ID
potatoes
Table
9.
Surface
water
EECs
(
ppb)
for
ecological
risk
assessment
based
on
pyrethrin
use
on
GA
peaches
and
ID
potatoes,
and
buffer
zones
of
50,
100,
and
150
ft.
Results
using
average
KOC
=
35,170
Crop
Peak
EEC
(
ppb)
21
day
EEC
(
ppb)
60
day
EEC
(
ppb)

­
42­
Georgia
Peaches
0.413
0.079
0.042
Idaho
Potatoes
0.087
0.041
0.021
Buffer
Zone
150
ft,
0.9%
spray
drift
for
GA
peaches/
0.8%
spray
drift
for
ID
potatoes
Georgia
Peaches
0.400
0.073
0.039
Idaho
Potatoes
0.067
0.031
0.016
Based
on
1­
in­
10
year
exceedance
probability
(
0.10).
Peak
EEC's
provided
with
three
decimal
points
for
information
only.

Equilibrium
Partitioning
and
Concentration
in
the
Sediment:
The
pyrethrins
are
lipophilic
compounds
that
can
adsorb
readily
to
particulate
and
sediment,
thus
possibly
limiting
its
exposure
to
aquatic
life
in
the
water
column
but
increasing
toxic
exposure
in
the
benthos.
Sediment
can
act
as
a
reservoir
for
lipophilic
persistent
compounds.
The
sediment
and
particulate
likely
adsorb
a
high
percentage
of
pyrethrin,
as
indicated
by
its
high
KOC.
Therefore,
coupled
with
pyrethrin's
persistence
in
anaerobic
environments,
sediment
bound
pyrethrin
could
present
a
toxicity
risk
for
benthic
aquatic
life
and
aquatic
ecosystems
in
general.
Exposure
to
this
sediment
can
result
in
a
direct
impact
to
aquatic
life
through
respiration,
ingestion,
dermal
contact,
as
well
as
indirect
impact
through
alterations
of
the
food
chain.

Under
the
Clean
Water
Act
(
CWA
Section
304(
a)(
2)
the
Environmental
Protection
Agency
(
EPA)
and
the
States
are
expected
to
develop
programs
for
protecting
the
chemical,
physical,
and
biological
integrity
of
the
nation's
waters.
In
order
to
meet
the
objectives
of
the
CWA,
EPA
has
periodically
issued
ambient
water
quality
criteria
(
WQC).
However,
toxic
contaminants
in
bottom
sediments
of
lakes,
rivers,
wetlands,
and
coastal
waters
create
potential
for
environmental
degradation
even
if
water
column
contamination
values
are
low
and
comply
with
EPA's
water
quality
criteria.
In
order
to
evaluate
this
possible
concern
the
USEPA's
Office
of
Water
(
OW)
also
calculates
Equilibrium
Partitioning
Sediment
Guidelines
(
ESG).

Pesticide
compounds
that
bind
readily
to
particulate
and
organic
carbon
in
the
water
column
can
eventually
settle
onto
the
benthos.
This
increase
in
particulate­
bound
pesticides
can
result
in
an
accumulation
of
compounds
in
or
on
the
sediment
that
may
have
the
potential
for
toxic
impact
to
benthic
and
epibenthic
aquatic
organisms
(
e.
g.,
early
life
stage
of
many
invertebrates
and
fish,
as
well
as
crabs
and
shrimp).
However,
evaluating
the
risk
to
aquatic
life
from
this
exposure
becomes
problematic
especially
if
there
is
a
lack
of
adequate
sediment
toxicity
and
exposure
data.
Therefore,
in
order
to
assess
this
potential
for
pesticide
risk
to
aquatic
benthic
systems,
the
Environmental
Fate
and
Effects
Division
(
EFED)
of
the
Office
of
Pesticides
Program
(
OPP)
has
adopted
the
method
used
by
the
Office
of
Water
that
relies
on
equilibrium
partitioning
(
EqP)
of
chemicals.
Th
EqP
theory
is
based
on
the
hydrophobicity
and
concentrations
of
the
chemical
normalized
to
organic
carbon
(
OC)
in
sediment
(
De
Toro
et
al.
1991)
and
holds
that
a
nonionic
chemical
in
sediment
partitions
between
sediment
organic
carbon,
interstitial
(
pore)
water
and
benthic
organisms.
At
­
43­
equilibrium,
if
the
concentration
in
any
phase
is
known,
then
the
concentration
in
the
other
phases
can
be
predicted.
A
key
component
to
this
theory
is
the
chemicals
organic
carbon
coefficient
(
Koc),
which
is
constant
for
every
chemical
and
represents
the
ratio
of
the
chemical
concentration
in
water
to
the
concentration
in
organic
carbon.
The
document,
"
Technical
Basis
for
the
Derivation
of
Equilibrium
Partitioning
Sediment
Guidelines
(
ESGs)
for
the
Protection
of
Benthic
Organisms:
Nonionic
Organics"
(
USEPA,
2000a),
demonstrates
that
biological
responses
of
benthic
organisms
to
nonionic
organic
chemicals
in
sediments
are
different
when
the
sediment
concentrations
are
expressed
on
a
dry
weight
basis,
but
similar
when
expressed
on
a
ug
chemical/
g
organic
carbon
basis
(
ug/
goc).
Similar
responses
were
also
observed
across
sediments
when
interstitial
water
concentrations
were
used
to
normalize
biological
availability.
The
Technical
Basis
Document
further
demonstrates
that
if
the
toxic
effect
concentration
in
water
is
known
(
e.
g.,
LC50),
the
effect
concentration
in
sediment
on
a
ug/
goc
basis
can
be
predicted
by
multiplying
the
effect
concentration
in
water
by
the
chemical
Koc..

(
LC50
ug/
L
x
Koc
L/
kgoc
x
1
kgoc/
1000goc
=
LC50
ug/
goc)

Since,
EFED
uses
a
deterministic
method
for
its
screening
level
risk
assessment,
the
calculation
of
risk
quotient
values
(
RQ)
is
important
for
assessing
possible
risk.
The
RQ
values
are
calculated
by
taking
the
ratio
of
the
estimated
exposure
concentrations
(
EEC)
to
the
toxicity
effect
value
(
e.
g.,
LC50,
NOAEC).
The
EEC
values
are
model
generated
(
e.
g.,
PRZM/
EXAMS)
and
reflect
peer
evaluated
and
approved
scenarios
for
assessing
pesticide
exposure
to
an
aquatic
environment.
However,
the
PRZM/
EXAMS
output
produces
water
column
EEC
values,
as
well
as
sediment
and
pore
water
EEC
values.
Therefore,
in
order
to
assess
possible
toxic
pesticide
exposure
to
aquatic
organisms
from
sediments,
EFED
is
using
the
PRZM/
EXAMS
model
which
incorporates
the
principles
of
the
equilibrium
partitioning
theory,
in
order
to
generate
EECs
from
sediment
and
pore
water.
By
relying
on
sediment
and/
or
pore
water
output
values,
EFED
has
two
ways
for
calculating
RQ
values
for
sediments
by
using
pore
water
exposure
values
and
bulk
sediment
values.

The
calculations
that
rely
on
pore
water
can
be
calculated
by
dividing
the
PRZM/
EXAMS
output
value
for
pore
water
concentrations
by
the
dissolved
concentrations
in
the
water
column
that
caused
toxicity
in
bioassays
(
e.
g.,
LC50).

EEC
pore
water
ug/
L
/
LC50
ugL
If
sediment
effects
data
are
available
(
LC50
ug/
kgoc),
RQ
can
be
produced
by
using
the
PRZM/
EXAMS
sediment
output
value
for
sediment.

EEC
sediment
ug/
ugoc
/
LC50
ug/
kgoc
Assumptions
of
the
equilibrium
partitioning
model:
Three
principle
observations
that
underlie
the
equilibrium
partitioning
(
EqP)
approach:

C
The
concentrations
of
nonionic
organic
chemicals
in
sediments
(
expressed
on
an
organic
carbon
basis)
and
in
interstitial
waters
correlate
with
observed
biological
effects
on
sediment­
dwelling
organisms
across
a
range
of
sediments.

C
Partitioning
models
can
relate
sediment
concentrations
for
nonionic
organic
chemicals
on
an
organic
carbon
basis
to
freely­
dissolved
concentrations
in
interstitial
water.

C
The
distribution
of
sensitivities
of
benthic
organisms
is
similar
to
that
of
water
column
species.

The
EqP
approach
assumes
that
the
partitioning
of
a
chemical
between
sediment
organic
carbon
and
interstitial
­
44­
water
is
at
or
near
equilibrium.
Another
assumption
is
that
the
concentration
in
either
phase
can
be
predictive
using
appropriate
partition
coefficient
and
the
measured
concentration
in
the
other
phase.
Furthermore,
it
is
assumed
that
organisms
receive
equivalent
exposure
from
water­
only
exposures
or
from
any
equilibrated
phase
(
interstitial
water
via
respiration;
from
sediment
via
ingestion
or
other
sediment
integument
exchange).
The
final
assumption
is
that
for
nonionic
compounds,
effect
concentrations
in
sediments
on
an
organic
carbon
basis
can
be
predicted
using
the
organic
carbon
partition
coefficient
(
KOC)
and
effects
concentrations
in
the
water.

The
Agency
evaluated
maximum
and
typical
application
of
pyrethin
relative
to
expected
sediment
residues
(
Table
10).
Maximum
application
rate
produced
EEC
estimates
for
benthic
pore
water
(
PRZM/
EXAMS)
that
range
from
0.029 
0.209
:
g/
L,
while
the
typical
application
rate
resulted
in
lower
EEC
values
of
0.002
­
0.010
ug/
L
(
peak
daily
concentrations).
The
range
of
EECs
follows
the
pattern
exhibited
by
the
surface
water
EECs
with
the
highest
EECs
estimated
for
the
IL
Corn
standard
scenario
and
the
lowest
EECs
for
the
CA
Grape
standard
scenario.
One
of
the
key
parameters
in
the
PRZM/
EXAMS
model
is
weather,
especially
the
rainfall
pattern.
The
amount
and
frequency
of
rain
for
scenarios
representing
MN
potato,
IL
corn,
and
PN
tomato
uses
created
conditions
for
greater
runoff
of
pyrethrins
from
the
field
and
into
the
adjacent
pond
compared
to
the
warmer,
drier
climates
of
the
CA
grape,
FL
citrus,
and
GA
peaches
standard
scenarios.

Table
10.
PRZM/
EXAMS
output
for
benthic
pore
water
EECs
(
ug/
L)
based
on
pyrethrins
use
on
several
crops.

Crop
App.
rate
(
kg/
ha)
No.
of
app./
interval
(
days)
Peak
96
Hour
21
Day
60
Day
90
Day
Annual
IL
corn
0.056
10/
1
0.209
0.208
0.204
0.182
0.169
0.103
ME
potato
0.056
10/
1
0.159
0.158
0.154
0.145
0.138
0.098
MS
cotton
0.056
10/
1
0.137
0.137
0.132
0.125
0.115
0.051
PA
tomato
0.056
10/
1
0.117
0.116
0.111
0.098
0.092
0.055
ND
wheat
0.056
10/
1
0.068
0.068
0.065
0.058
0.054
0.037
CA
onion
0.056
10/
1
0.060
0.059
0.065
0.047
0.042
0.021
NC
apple
0.056
10/
1
0.060
0.060
0.058
0.054
0.052
0.035
OR
snapbeans
0.056
10/
1
0.047
0.047
0.046
0.042
0.040
0.026
ID
potato
0.056
10/
1
0.038
0.038
0.037
0.033
0.030
0.020
Table
10.
PRZM/
EXAMS
output
for
benthic
pore
water
EECs
(
ug/
L)
based
on
pyrethrins
use
on
several
crops.

Crop
App.
rate
(
kg/
ha)
No.
of
app./
interval
(
days)
Peak
96
Hour
21
Day
60
Day
90
Day
Annual
­
45­
MN
alfalfa
0.056
10/
1
0.036
0.036
0.035
0.032
0.030
0.019
FL
citrus
0.056
10/
1
0.036
0.036
0.035
0.032
0.029
0.015
GA
peaches
0.056
10v
0.039
0.039
0.038
0.033
0.030
0.019
CA
grapes
0.056
10/
1
0.029
0.029
0.028
0.024
0.021
0.011
SPECIAL
RUNS
WITH
TYPICAL
INTERVAL
BETWEEN
APPLICATIONS
(
3
days,
normal
pest
pressure)

IL
corn
0.056
10/
3
0.193
0.192
0.187
0.167
0.155
0.100
ID
potato
0.056
10/
3
0.036
0.036
0.034
0.031
0.029
0.020
CA
grapes
0.056
10/
3
0.040
0.039
0.037
0.032
0.029
0.015
TYPICAL
APPLICATION
RATE,
NUMBER
OF
APPLICATIONS,
AND
INTERVAL
BETWEEN
APPLICATIONS
Crop
App.
Rate
(
Kg
a.
i./
ha)
No
of
app./
interval
between
app.
Peak
96
Hour
21
Day
60
Day
90
Day
Annual
ID
potato
0.0224
1/(
N/
A)
0.002
0.002
0.001
0.001
0.001
0.001
PA
tomato
0.0067
2/
3
0.003
0.003
0.002
0.002
0.002
0.001
CA
onion
0.0146
2/
3
0.002
0.002
0.001
0.001
0.001
0.001
OR
snap
beans
0.0235
5/
3
0.010
0.010
0.009
0.009
0.008
0.006
b.
Aquatic
Exposure
Modeling
for
Mosquito
Abatement
In
2000,
more
than
200,000
lb
of
pyrethrin
were
sold,
of
which
around
6%
were
used
for
terrestrial
non­
food
uses,
and
around
1%
was
used
for
outdoor
recreation
(
including
mosquito
abatement).
Pyrethrin
can
be
used
in
such
places
like
residential,
industrial,
recreational,
and
agricultural
areas
as
well
as
swamps,
marshes,
­
46­
overgrown
waste
areas,
roadsides
and
pastures
where
adult
mosquitoes
occur.
Some
of
these
places
could
involve
direct
or
indirect
exposure
to
aquatic
environments.

Mosquito
adulticides
are
more
efficacious
if
they
come
into
contact
with
insects
in
flight.
For
that
reason,
mosquito
abatement
using
pyrethrin
(
as
well
as
other
mosquito
adulticides)
is
typically
applied
via
aerial
spray
methods
with
very
fine
droplets
or
mists,
to
prevent
immediate
deposition
of
the
pesticide.

The
modeling
approach
for
this
type
of
use
included
calculations
of
spray
drift
using
the
AGricultural
DISPersal
model
(
AGDISP
v.
8.08).
This
model/
computer
program
estimates
the
deposition
of
the
pesticide
to
the
treated
area,
and,
by
means
of
its
toolbox
"
deposition
assessment,"
to
the
adjacent
bodies
of
water
(
i.
e.
the
standard
pond).
In
other
words,
AGDISP
estimates
the
application
efficiency
and
downwind
deposition
or
spray
block
deposition
(
to
the
water
body,
equivalent
to
the
level
of
spray
drift).
AGDISP
provides
a
better
prediction
of
spray
drift
under
the
circumstances
where
a
mosquito
adulticide
is
used.

The
ten
labels
for
pyrethrins
have
few
specifications
about
application
methods.
For
example,
the
intervals
between
applications
are
not
specified,
the
maximum
number
of
applications
allowed
per
time
period
are
not
specified,
and
the
boom
(
or
application
release)
height
is
not
specified
(
except
for
one
label).
Labeling
statements
dealing
with
the
spray
droplet
size
range,
wind
speed,
and
time
of
day
to
apply
pyrethrin
are
provided
as
recommendations
but
are
not
provided
as
requirements.

The
output
data
from
AGDISP
files
and
PRZM/
EXAMS
are
provided
in
Appendix
L.
Various
of
the
labels
for
pyrethrin
recommended
an
optimum
droplet
size
of
Dv0.5=
30
:
m
(
half
of
the
volume
is
contained
in
droplets
less
than
30
:
m
and
half
of
the
volume
is
contained
in
droplets
more
than
30
:
m;
however,
the
product
used
as
an
example
to
model
pyrethrins
in
AGDISP,
Pyrenone
®
25­
5
Public
Health
Insecticide,
did
not
have
specifications
for
aerial
applications.
Therefore,
the
user
defined
droplet
was
Dv0.5~
50
:
m.
The
wind
speed
in
some
of
the
labels
was
recommended
as
<
5
mph
in
some
labels
and
<
10
mph
in
others;
the
one
used
in
modeling
was
the
one
in
the
label
for
Pyrenone
®
25­
5
Public
Health
Insecticide,
that
is,
10
mph.
The
master
label
indicated
that
the
wind
speed
would
be
<
10
mph.
The
spray
volume
selected
was
0.1
gal/
A
for
the
maximum
application
rate.
It
was
assumed
that
the
product
was
diluted
in
an
oil
with
specific
gravity
of
0.8.
The
boom
height
was
varied
according
to
the
table
below,
since
the
labels
have
no
specifications.
The
maximum
application
rate
indicated
in
the
Master
Label
is
lower
than
that
for
agricultural
settings:
0.008
lb
a.
i./
A
It
appears
that
a
typical
application
rate
is
0.0025
lb
a.
i./
A.
EFED
selected
a
temperature
and
relative
humidity
of
85
°
F
and
90%,
respectively,
to
simulate
conditions
where
mosquitoes
grow.
For
the
most
part,
the
conditions
selected
were
the
default
values
in
AGDISP.

Since
the
original
pyrethrins
assessment
was
issued,
more
refinements
have
been
achieved
in
the
way
the
EFED
conducts
its
adulticide
assessment.
In
order
to
obtain
the
level
of
drift
the
EFED
uses
the
toolbox
"
Deposition
Assessment."
This
toolbox
of
the
AGDISP
model,
can
be
utilized
to
obtain
the
levels
of
spray
drift
with
buffer
zones
(
even
though
it
does
not
apply
to
this
chemical).
The
dimensions
of
the
standard
pond
are
entered
in
the
toolbox,
and
the
return
is
the
"
effective"
application
rate
on
the
standard
pond.
By
dividing
the
output
of
the
toolbox
by
the
application
rate,
the
fraction
of
drift
is
obtained.
This
is
the
input
value
that
should
be
used
in
PRZM/
EXAMS.
The
results
obtained
are
summarized
in
the
following
table
(
compare
to
the
default
values
of
95%
application
efficiency
and
5%
spray
drift,
for
agricultural
applications).
Note
that
variables
such
as
the
boom
height
and
the
application
rate
will
have
an
effect
on
the
results
obtained.
The
higher
the
boom
height,
the
lower
the
level
of
deposition
and
the
application
efficiency.
A
low
application
rate
is
expected
to
result
in
lower
EECs,
despite
the
fact
that
the
levels
of
deposition
are
similar.
In
addition,
the
droplet
size
is
an
important
factor
that
determines
the
level
of
deposition.
Large
droplets
cause
more
deposition;
they
cannot
­
47­
stay
in
the
air
as
long
as
small
droplets.
It
was
observed
that
a
buffer
zone
did
not
have
a
major
effect
on
the
level
of
deposition,
when
the
boom
height
is
75
ft.
With
a
buffer
zone
of
0,
100
and
200
ft,
the
level
of
deposition
is
around
21
±
1%.
Therefore,
only
the
75
ft
boom
height
with
different
buffer
zones
were
modeled
for
illustration;
however,
only
the
no
buffer
zone
was
calculated
or
modeled
in
PRZM/
EXAMS.
­
48­

Table
11.
Results
from
AGDISP
for
Pyrethrins
Parameter
Value
Droplet
Size
(:
m)
50
50
50
50
40
40
50
50
50
50
Boom
height
(
ft)
25
75
75
75
75
150
100
150
75
150
Application
Rate
(
lb
a.
i./
A)
0.0081
0.008
0.008
0.008
0.008
0.008
0.008
0.008
0.00252
0.0025
Application
Rate
(
Kg
a.
i./
ha)
0.009
0.009
0.009
0.009
0.009
0.009
0.009
0.009
0.0028
0.0028
Buffer
zone
(
ft)
0
0
100
200
0
0
0
0
0
0
Application
efficiency
(
fraction)
0.393
0.015
0.015
0.015
0
0
0
0
0.015
0
Downwind
deposition
or
Spray
Drift
(
fraction)
0.563
0.200
0.213
0.225
0.125
0.005
0.088
0.013
0.200
0.016
10.008
lb
a.
i./
A
is
the
maximum
application
rate
supported
by
the
registrant,
according
to
the
Master
Label.
20.0025
lb
a.
i./
A
appears
to
be
the
typical
maximum
application
rate
in
most
labels
of
the
pyrethrins.
Furthermore,
comments
from
the
Districts
and
other
interested
parties
indicated
that
they
use
the
product
at
an
application
rate
of
0.0020
to
0.0025
lb
a.
i./
A.

The
highlighted
columns
were
modeled
in
PRZM/
EXAMS.
­
49­
Using
the
results
from
AGDISP,
the
tier
2
aquatic
model
PRZM/
EXAMS
(
using
the
graphical
user
interface
pe4v01.
pl)
was
used
to
model
surface
water
EECs
using
the
FL
turf
site
scenario.
This
scenario
appears
to
be
suitable
to
represent
sites
such
as
parks,
golf
courses,
etc.
Ponds
of
various
depths
(
EXAMS
standard
ecological
Mississippi
pond)
were
simulated.
PRZM/
EXAMS
runoff
component
was
modified
according
to
the
results
of
AGDISP
(
with
an
application
efficiency
according
to
the
table
above).
Furthermore,
selected
input
parameters
were
modified
to
capture
the
depth
of
the
pond
(
e.
g.
CHARL
=
characteristic
length
=
this
is
a
measure
of
the
depth
of
the
pond).
Pond
depths
were
varied
to
examine
the
concentration
of
pyrethrin
in
shallow
(
i.
e.,
marshes)
to
deep
water
bodies
(
i.
e.,
pond).
PRZM/
EXAMS
was
implemented
individually
for
pond
depths
of
6
inches,
1
foot,
1
meter
(
3.3
feet),
and
2
meters
(
6.6
feet).
It
should
also
be
clarified
that
EXAMS
uniformly
distributes
pyrethrins
in
the
water
while
in
real
life
situations,
pyrethrins
could
be
present
in
higher
concentrations
in
the
proximity
of
the
treated
site.
This
makes
this
analysis
less
conservative
because
aquatic
animals
in
the
proximity
to
the
field
are
at
greatest
risk
than
farther
away.

AGDISP
input
parameters
were
those
typical
for
a
mosquito
adulticide
and
that
were
in
agreement
with
the
product
labels.
They
are
listed
in
the
Table
12.
Input
parameters
for
the
PRZM/
EXAMS­
pe4
modeling
are
listed
in
Table
13.
AGDISP
model
file
is
provided
in
Appendix
L.
Detailed
PRZM/
EXAMS
output
file,
for
each
pond
depth,
is
also
provided
in
Appendix
L.
The
summary
of
the
PRZM/
EXAMS
results
appear
in
Tables
14
to
19.
The
pore
water
concentrations
were
provided
in
Tables
20
to
25.

Various
trends
were
noted.
Modeled
EECs
increased
with
increasing
pond
depth.
The
trend
of
increasing
EECs
with
increasing
pond
depth
is
noticeable
because
the
EEC's
follow
the
opposite
pattern
expected
by
dilution
only.
The
results
of
these
runs
indicated
that
dilution
effects
are
not
as
influential
as
other
factors
when
modeling
pyrethrins.
Other
factors,
such
as
sediment
adsorption
of
the
chemical
appear
to
be
also
important
with
a
chemical
like
this,
with
a
very
high
KOC.

The
lower
concentrations
in
shallow
water
bodies
compared
to
deep
water
bodies
in
this
simulation,
may
be
partially
explained
by
three
depth­
dependent
variables
in
the
EXAMS
model:
Henry's
Law
constant,
KOC,
and
aqueous
photolysis
half­
life.
The
Henry's
Law
constant
suggests
a
potential
for
loss
of
pesticide
from
the
pond
via
volatilization.
Second,
with
a
very
high
KOC,
the
pyrethrin
tends
to
partition
towards
the
sediment.
This
equilibrium
will
occur
more
rapidly
in
shallow
waters
than
in
deeper
bodies
of
water.
Finally,
a
third
possible
explanation
is
the
short
aqueous
photolysis
half­
life
(
0.5
days)
for
pyrethrin.
According
to
the
Beer­
Lambert
law,
light
intensity
decreases
exponentially
with
increasing
water
depth
(
light
is
not
expected
to
penetrate
into
depths
longer
than
about
1
ft.).
When
a
chemical
has
a
short
half­
life
(
as
in
this
scenario)
and
it
is
concentrated
in
shallow
waters
(
i.
e.,
six
inches),
it
can
be
expected
to
photodegrade
more
readily
than
when
it
is
spread
throughout
a
deeper
water
column.

Given
other
same
conditions,
a
larger
droplet
size
caused
an
increase
in
the
exposure.
The
peak
EECs
observed
for
the
runs
performed
with
the
maximum
application
rate
(
0.008
lb
a.
i./
A),
a
boom
height
of
75
ft,
and
a
droplet
size
of
Dv0.5
~
40
:
m
were
0.51­
0.59
ppb;
with
a
droplet
size
of
around
50
:
m,
the
peak
EECs
were
0.81­
0.95
ppb.

The
boom
height
has
an
extraordinary
effect
on
the
level
of
exposure
observed
in
the
pond.
With
the
same
application
rate
of
0.008
lb
a.
i./
A,
and
droplet
size
of
50
:
m,
two
boom
height
were
explored:
75
and
150
ft.
The
respective
peak
EECs
were
0.81­
0.95
ppb
and
0.05­
0.06
ppb.
A
higher
boom
height
causes
more
dispersion
of
the
ULV
aerosol,
and
a
smaller
amount
of
it
reaches
the
soil
and
the
water.
­
50­
The
last
variable
that
was
changed
and
studied
was
the
application
rate.
In
this
case,
the
boom
height
was
75
ft,
the
droplet
size
was
50
:
m
and
the
application
rates
were
the
maximum:
0.008
lb
a.
i./
A,
and
what
appears
to
be
a
typical
application
rate
from
comments
obtained
in
the
Phase
5
Comment
Period.:
0.0025
lb
a.
i./
A.
The
peak
EECs'
were
respectively
0.114­
0.133
ppb
and
0.036­
0.041
ppb.

Table
12.
Input
parameters
for
AGDISP
for
Pyrethrin.

Parameter
Value
Aircraft
type
Air
Tractor
AT­
401;
fixed
wing
Swath
Width
60
ft
Wing
semispan
24.5
ft.

Swath
Displacement
0
ft.

propeller
rpm
2000;
propeller
rad.
4.5
ft.;
1
engine
Fixed
wing
1
engine
Flight
lines
20
Flight
speed
120
mph
Boom
height
Refer
to
Supplementary
Table(
1)

Number
of
nozzles
42
Vortex
decay
rate
1.25
mph
Aircraft
drag
coefficient
0.1
Propeller
efficiency
0.8
Ambient
pressure
29.91
in
Hg
Planform
area
294
ft2
Semispan
24.5
ft.

Nozzle
spacing
(
even)
0.78
ft
=
9.36
in.

Wind
speed
10
mph
Wind
direction
­
90
°
,
Perpendicular
to
flight
path
Surface
roughness
0.0075
Stability
Daylight
(
solar
insolation)
Overcast
Relative
humidity
90%
Table
12.
Input
parameters
for
AGDISP
for
Pyrethrin.

Parameter
Value
­
51­
Temperature
85
°
F
Droplet
type
User
defined
Dv0.1
13.7
:
m
11.26
:
m
Dv0.5
51.03
:
m
41.17
:
m
Dv0.9
117.41
:
m
94.88
:
m
Relative
span
2.03
:
m
2.03
<
141
:
94.9%
97.22%

Spray
material
Oil
Specific
gravity,
carrier
0.8(
2)

Specific
gravity,
nonvolatile
0.8
Active
rate
0.008
lb
a.
i./
A
=
0.009
Kg
a.
i./
ha
Fraction
=
0.012
0.0025
lb
a.
i./
A
=
0.0028
Kg
a.
i./
ha
Fraction
=
0.012
Nonvolatile
rate
Fraction
=
1
Spray
volume
rate
0.1
gal/
A
0.0312
gal/
A
Evaporation
rate
0
:
m2/
°
C/
sec
Downwind
water
body
width
208.7
ft
Ave.
depth
0.5
ft
=
6
in;
1
ft.;
3.3
ft
~
1
m;
6.6
ft.
~
2
m(
3)

(
1).
Release
height
is
not
specified
on
product
labels.
(
2).
Value
selected
from
recommendations
in
the
label.
(
3).
2
m
or
standard
pond
scenario
(
208.7
ft.
wide,
6.6
ft.
deep,
static
water
body
receiving
runoff
from
10
hectares).

Table
13.
Input
parameters
for
PRZM/
EXAMS.

Parameter
Value
&
Units
Source
Molecular
Weight
Pyrethrin
1:
328.4
g/
mol
Table
13.
Input
parameters
for
PRZM/
EXAMS.

Parameter
Value
&
Units
Source
­
52­
Water
Solubility
(
20oC)
2.0
ppm
Max.
Solubility,
Tomlin,
C.
D.
S.,
Pesticide
manual
(
TOXNET)
10x
available
value
(
0.2
ppm)
as
per
EFED
Model
Input
Guidance
(
2002)

Vapor
pressure
Pyrethrin
1:
2.03
x
10­
5
mm
Hg
Tomlin,
C.
D.
S.,
Pesticide
manual
(
TOXNET)

Henry's
Law
Constant
Pyrethrin
1:
7.7
x
10­
7
atm­
m3/
mol
Estimated
value
from
EPISUITE
Hydrolysis
t
½
,
pH
7
(
25oC)
pH
5:
stable
pH
7:
stable
pH
9:
17
days
MRID
43567502
Spray
Drift
Fraction
0.076
Modeled
with
AGDISP
v8.07
Application
Efficiency
0.300
Modeled
with
AGDISP
v8.07
Aerobic
Soil
Metabolism
t
½
(
3X
available
value
of
9.5)
28.5
days
MRID
43499803
Aerobic
Aquatic
Metabolism
t
½
(
3X
available
value
of
10.5)
31.5
days
MRID
43499802
Anaerobic
Aquatic
Metabolism
t
½
86
days
MRID
43499801
Direct
Aqueous
Photolysis
t
½
0.5
day
MRID
43567601
Soil
Water
Partition
Coefficient
(
Kd)
N/
A
 
 
 
 

KOC
35,170
MRID
43096603;
Average
value,
EFED
Model
Input
Guidance,
Version
II
(
2002)

PLDKRT
(
foliage
pesticide
halflife
0
days
EFED
Model
Input
Guidance,
Version
II
(
2002)

FEXTRC
(
foliar
extraction)
0.5
EFED
Model
Input
Guidance,
Version
II
(
2002)

FILTRA
(
filtration
parameter;
required
if
CAM
set
to
3)
NA
­
Table
13.
Input
parameters
for
PRZM/
EXAMS.

Parameter
Value
&
Units
Source
­
53­
PLVKRT
(
pesticide
decay
rate
on
plant
foliage)
0/
day
EFED
Model
Input
Guidance,
Version
II
(
2002)

IPSCND(
condition
for
disposition
of
foliar
pesticide
after
harvest)
3
PRZM
Version
3.0
User's
Manual
(
Carsel
1998)

CAM
(
chemical
application
method)
2
PRZM
Version
3.0
User's
Manual
(
Carsel
1998)

UPTKF
(
plant
uptake
factor)
0
EFED
Model
Input
Guidance,
Version
II
(
2002)

DAIR
(
diffusion
coefficient
for
pesticide
in
the
air)
0.0
PRZM
Version
3.0
User's
Manual
(
Carsel
1998)

ENPY(
enthalpy
of
vaporization
of
pesticide)
­(
Not
reported)
­

Benthic
Layer
5
cm
EXAMS
Default
CROP
MANAGEMENT
Application
Rate
Florida
Turf:
0.008
lb
a.
i./
A/
application
=
0.009
kg
a.
i./
ha/
application
or
0.0025
lb
a.
i./
A
=
0.0028
Kg
a.
i./
ha
for
Typical
Application
Rate
Master
Label
and
Product
Label
for
Pyronyl
Mosquito
Use
Number
of
Applications
Florida
Turf:
26
Product
Label
Interval
Between
Applications
(
days)
Florida
Turf:
4
Product
Label
Date
of
First
Application
Florida
Turf:
1­
Jun
Product
Label
and
EFED
PRZM
Crop
Scenarios
(
US
EPA)

Application
Type
and
Depth
of
Incorporation
(
cm)
Aerial
Product
Label
POND
DEPTH
SCENARIOSa
Scenario
Pond
Depth
(
m)
CHARLb
(
m)

A
0.1524
(
6")
0.101
B
0.3048
(
12")
0.177
­
54­
C
1
0.525
D
2
1.025
a
Edit
Exams
Commands:
set
charl(
1)
to
"
x";
set
dep(
1)
to
"
x";
rec
env
4,
where
x
is
the
corresponding
value
listed
in
the
pond
depth
scenarios
table.
b
Characteristic
Length
=
0.5
(
Pond
Layer)
+
0.5
(
Benthic
Layer)
=
A
measure
of
pond
depth.

Table
14.
Surface
water
EECs
(
ppb
or
:
g/
L)
for
ecological
risk
assessment
based
on
pyrethrins
mosquito
abatement
applications
calculated
using
PRZM/
EXAMS
for
various
pond
depths.
a
Conditions
as
follows:
Droplet
size
50
:
m;
Boom
height
75
ft;
Application
rate
0.008
lb
a.
i./
A
FL
Turf
Scenario
Instantaneous
Peak
(
0
day)
21
day
60
day
90
day
2
m
0.133
0.078
0.074
0.069
1
m
0.122
0.059
0.054
0.050
1
ft
0.117
0.046
0.041
0.038
6
in
0.114
0.042
0.038
0.035
a
Surface
water
EECs
are
referred
to
as
water
segment
concentrations
in
the
PRZM/
EXAMS
output.
b
Three
decimal
places
are
provided
to
compare
ranges
in
PRZM/
EXAMS
output.

Table
15.
Surface
water
EECs
(
ppb
or
:
g/
L)
for
ecological
risk
assessment
based
on
pyrethrins
mosquito
abatement
applications
calculated
using
PRZM/
EXAMS
for
various
pond
depths.
a
Conditions
as
follows:
Droplet
size
40
:
m;
Boom
height
75
ft;
Application
rate
0.008
lb
a.
i./
A
FL
Turf
Scenario
Instantaneous
Peak
(
0
day)
21
day
60
day
90
day
2
m
0.083
0.049
0.046
0.043
1
m
0.076
0.037
0.034
0.031
1
ft
0.073
0.029
0.026
0.024
6
in
0.071
0.027
0.024
0.022
a
Surface
water
EECs
are
referred
to
as
water
segment
concentrations
in
the
PRZM/
EXAMS
output.
b
Three
decimal
places
are
provided
to
compare
ranges
in
PRZM/
EXAMS
output.
­
55­
Table
16.
Surface
water
EECs
(
ppb
or
:
g/
L)
for
ecological
risk
assessment
based
on
pyrethrins
mosquito
abatement
applications
calculated
using
PRZM/
EXAMS
for
various
pond
depths.
a
Conditions
as
follows:
Droplet
size
50
:
m;
Boom
height
150
ft;
Application
rate
0.008
lb
a.
i./
A
FL
Turf
Scenario
Instantaneous
Peak
(
0
day)
21
day
60
day
90
day
2
m
0.009
0.005
0.005
0.005
1
m
0.008
0.004
0.004
0.003
1
ft
0.008
0.003
0.003
0.002
6
in
0.007
0.003
0.002
0.002
a
Surface
water
EECs
are
referred
to
as
water
segment
concentrations
in
the
PRZM/
EXAMS
output.
b
Three
decimal
places
are
provided
to
compare
ranges
in
PRZM/
EXAMS
output.

Table
17.
Surface
water
EECs
(
ppb
or
:
g/
L)
for
ecological
risk
assessment
based
on
pyrethrins
mosquito
abatement
applications
calculated
using
PRZM/
EXAMS
for
various
pond
depths.
a
Conditions
as
follows:
Droplet
size
50
:
m;
Boom
height
75
ft;
Application
rate
0.0025
lb
a.
i./
A
FL
Turf
Scenario
Instantaneous
Peak
(
0
day)
21
day
60
day
90
day
2
m
0.041
0.025
0.023
0.022
1
m
0.038
0.018
0.017
0.016
1
ft
0.036
0.014
0.013
0.012
6
in
0.036
0.013
0.012
0.011
a
Surface
water
EECs
are
referred
to
as
water
segment
concentrations
in
the
PRZM/
EXAMS
output.
b
Three
decimal
places
are
provided
to
compare
ranges
in
PRZM/
EXAMS
output.

Table
18.
Surface
water
EECs
(
ppb
or
:
g/
L)
for
ecological
risk
assessment
based
on
pyrethrins
mosquito
abatement
applications
calculated
using
PRZM/
EXAMS
for
various
pond
depths.
a
Conditions
as
follows:
Droplet
size
40
:
m;
Boom
height
150
ft;
Application
rate
0.008
lb
a.
i./
A
FL
Turf
Scenario
Instantaneous
Peak
(
0
day)
21
day
60
day
90
day
2
m
0.003
0.002
0.002
0.002
1
m
0.003
0.001
0.001
0.001
1
ft
0.003
0.001
0.001
0.001
6
in
0.003
0.001
0.001
0.001
Table
18.
Surface
water
EECs
(
ppb
or
:
g/
L)
for
ecological
risk
assessment
based
on
pyrethrins
mosquito
abatement
applications
calculated
using
PRZM/
EXAMS
for
various
pond
depths.
a
Conditions
as
follows:
Droplet
size
40
:
m;
Boom
height
150
ft;
Application
rate
0.008
lb
a.
i./
A
FL
Turf
Scenario
Instantaneous
Peak
(
0
day)
21
day
60
day
90
day
­
56­
a
Surface
water
EECs
are
referred
to
as
water
segment
concentrations
in
the
PRZM/
EXAMS
output.
b
Three
decimal
places
are
provided
to
compare
ranges
in
PRZM/
EXAMS
output.

Table
19.
Surface
water
EECs
(
ppb
or
:
g/
L)
for
ecological
risk
assessment
based
on
pyrethrins
mosquito
abatement
applications
calculated
using
PRZM/
EXAMS
for
various
pond
depths.
a
Conditions
as
follows:
Droplet
size
50
:
m;
Boom
height
150
ft;
Application
rate
0.0025
lb
a.
i./
A
FL
Turf
Scenario
Instantaneous
Peak
(
0
day)
21
day
60
day
90
day
2
m
0.003
0.002
0.002
0.002
1
m
0.003
0.001
0.001
0.001
1
ft
0.003
0.001
0.001
0.001
6
in
0.003
0.001
0.001
0.001
a
Surface
water
EECs
are
referred
to
as
water
segment
concentrations
in
the
PRZM/
EXAMS
output.
b
Three
decimal
places
are
provided
to
compare
ranges
in
PRZM/
EXAMS
output.

Table
20.
Pore
water
EECs
(
ppb
or
:
g/
L)
for
ecological
risk
assessment
based
on
pyrethrins
mosquito
abatement
applications
calculated
using
PRZM/
EXAMS
for
various
pond
depths.
a
Conditions
as
follows:
Droplet
size
50
:
m;
Boom
height
75
ft;
Application
rate
0.008
lb
a.
i./
A
FL
Turf
Scenario
Instantaneous
Peak
(
0
day)
21
day
60
day
90
day
2
m
0.031
0.030
0.028
0.027
1
m
0.030
0.029
0.027
0.026
1
ft
0.028
0.027
0.025
0.024
6
in
0.026
0.025
0.023
0.021
a
Surface
water
EECs
are
referred
to
as
water
segment
concentrations
in
the
PRZM/
EXAMS
output.
b
Three
decimal
places
are
provided
to
compare
ranges
in
PRZM/
EXAMS
output.
­
57­
Table
21.
Pore
water
EECs
(
ppb
or
:
g/
L)
for
ecological
risk
assessment
based
on
pyrethrins
mosquito
abatement
applications
calculated
using
PRZM/
EXAMS
for
various
pond
depths.
a
Conditions
as
follows:
Droplet
size
40
:
m;
Boom
height
75
ft;
Application
rate
0.008
lb
a.
i./
A
FL
Turf
Scenario
Instantaneous
Peak
(
0
day)
21
day
60
day
90
day
2
m
0.020
0.019
0.018
0.017
1
m
0.019
0.018
0.017
0.016
1
ft
0.018
0.017
0.016
0.015
6
in
0.016
0.015
0.014
0.013
a
Surface
water
EECs
are
referred
to
as
water
segment
concentrations
in
the
PRZM/
EXAMS
output.
b
Three
decimal
places
are
provided
to
compare
ranges
in
PRZM/
EXAMS
output.

Table
22.
Pore
water
EECs
(
ppb
or
:
g/
L)
for
ecological
risk
assessment
based
on
pyrethrins
mosquito
abatement
applications
calculated
using
PRZM/
EXAMS
for
various
pond
depths.
a
Conditions
as
follows:
Droplet
size
50
:
m;
Boom
height
150
ft;
Application
rate
0.008
lb
a.
i./
A
FL
Turf
Scenario
Instantaneous
Peak
(
0
day)
21
day
60
day
90
day
2
m
0.002
0.002
0.002
0.002
1
m
0.002
0.002
0.002
0.002
1
ft
0.002
0.002
0.002
0.002
6
in
0.002
0.002
0.001
0.001
a
Surface
water
EECs
are
referred
to
as
water
segment
concentrations
in
the
PRZM/
EXAMS
output.
b
Three
decimal
places
are
provided
to
compare
ranges
in
PRZM/
EXAMS
output.

Table
23.
Pore
water
EECs
(
ppb
or
:
g/
L)
for
ecological
risk
assessment
based
on
pyrethrins
mosquito
abatement
applications
calculated
using
PRZM/
EXAMS
for
various
pond
depths.
a
Conditions
as
follows:
Droplet
size
50
:
m;
Boom
height
75
ft;
Application
rate
0.0025
lb
a.
i./
A
FL
Turf
Scenario
Instantaneous
Peak
(
0
day)
21
day
60
day
90
day
2
m
0.010
0.010
0.009
0.009
1
m
0.009
0.009
0.008
0.008
1
ft
0.009
0.008
0.008
0.007
6
in
0.008
0.008
0.007
0.007
Table
23.
Pore
water
EECs
(
ppb
or
:
g/
L)
for
ecological
risk
assessment
based
on
pyrethrins
mosquito
abatement
applications
calculated
using
PRZM/
EXAMS
for
various
pond
depths.
a
Conditions
as
follows:
Droplet
size
50
:
m;
Boom
height
75
ft;
Application
rate
0.0025
lb
a.
i./
A
FL
Turf
Scenario
Instantaneous
Peak
(
0
day)
21
day
60
day
90
day
­
58­
a
Surface
water
EECs
are
referred
to
as
water
segment
concentrations
in
the
PRZM/
EXAMS
output.
b
Three
decimal
places
are
provided
to
compare
ranges
in
PRZM/
EXAMS
output.

Table
24.
Pore
water
EECs
(
ppb
or
:
g/
L)
for
ecological
risk
assessment
based
on
pyrethrins
mosquito
abatement
applications
calculated
using
PRZM/
EXAMS
for
various
pond
depths.
a
Conditions
as
follows:
Droplet
size
40
:
m;
Boom
height
150
ft;
Application
rate
0.008
lb
a.
i./
A
FL
Turf
Scenario
Instantaneous
Peak
(
0
day)
21
day
60
day
90
day
2
m
0.001
0.001
0.001
0.001
1
m
0.001
0.001
0.001
0.001
1
ft
0.001
0.001
0.001
0.001
6
in
0.001
0.001
0.001
0.001
a
Surface
water
EECs
are
referred
to
as
water
segment
concentrations
in
the
PRZM/
EXAMS
output.
b
Three
decimal
places
are
provided
to
compare
ranges
in
PRZM/
EXAMS
output.

Table
25.
Pore
water
EECs
(
ppb
or
:
g/
L)
for
ecological
risk
assessment
based
on
pyrethrins
mosquito
abatement
applications
calculated
using
PRZM/
EXAMS
for
various
pond
depths.
a
Conditions
as
follows:
Droplet
size
50
:
m;
Boom
height
150
ft;
Application
rate
0.0025
lb
a.
i./
A
FL
Turf
Scenario
Instantaneous
Peak
(
0
day)
21
day
60
day
90
day
2
m
0.001
0.001
0.001
0.001
1
m
0.001
0.001
0.001
0.001
1
ft
0.001
0.001
0.001
0.001
6
in
0.001
0.001
0.001
0.001
a
Surface
water
EECs
are
referred
to
as
water
segment
concentrations
in
the
PRZM/
EXAMS
output.
b
Three
decimal
places
are
provided
to
compare
ranges
in
PRZM/
EXAMS
output.

c.
Aquatic
Exposure,
"
Down­
the­
Drain"
Assessment
The
USEPA
has
received
various
comments
from
interested
parties
during
the
60
day
comment
period,
requesting
tto
address
the
fact
that
the
pyrethrins
are
likely
to
drain
and
reach
water
treatment
plants.
They
specifically
had
­
59­
mentioned
the
approach
utilized
by
the
Agency
for
pyrethrin
with
E­
FAST
(
see
below).
The
USEPA
intends
hereby
to
address
the
issue.

In
order
to
address
this
issue
of
pyrethrin
release
to
domestic
wastewater
treatment,
the
Agency
relied
on
the
Office
of
Pollution
Prevention
and
Toxics
(
OPPT)
consumer
exposure
model,
Exposure
and
Fate
Assessment
Screening
Tool
(
E­
FAST)
(
USEPA,
1999).
This
Down­
the­
Drain
module
of
E­
FAST
is
specifically
designed
to
address
all
sources
of
pyrethrins
that
could
potentially
be
disposed
to
domestic
wastewater
from
a
"
down­
the­
drain"
application.
This
model
provides
screening
level
estimate
of
chemical
residues
in
surface
water
that
may
result
from
household
uses
and
the
disposal
of
these
consumer
products
into
wastewater.
The
model
uses
input
parameters
that
include
annual
production
volume
of
the
pesticide
and
takes
into
account
the
fraction
of
the
chemical
removed
during
wastewater
treatment.
The
assumptions
of
the
model
state
that
in
a
given
year,
the
entire
production
volume
of
the
chemical
in
question
is
parceled
out
on
a
daily
per
capita
basis
to
the
U.
S.
population
and
converted
to
a
mass
release
per
capita
(
e.
g.,
gm/
person/
day).
This
mass
is
diluted
into
the
average
daily
volume
of
wastewater
released
per
person
per
day
to
arrive
at
an
estimated
concentration
of
target
chemical
in
wastewater
prior
to
entering
a
treatment
facility.
The
target
chemical
(
pyrethrins)
concentration
in
untreated
wastewater
is
then
reduced
by
the
fraction
removed
during
wastewater
treatment
process
before
release
into
a
river
or
stream.
The
remaining
chemical
is
discharged
into
surface
water,
where
it
is
assumed
that
it
is
instantaneously
diluted,
with
no
further
removal.
A
Stream
Dilution
Factor
is
the
volume
of
the
receiving
stream
flow
divided
by
the
volume
of
the
wastewater
released
from
the
Publicly
Owned
Treatment
Works
(
POTW).
The
resulting
values
are
used
for
ecological
effects:
estimated
environmental
concentrations
(
EECs)

The
equations
used
are
as
follows:

Daily
per
capita
release
of
a
chemical
in
household
wastewater
HR
=
ProdVol
x
1000g/
Kg
x
1
year/
365
days
Pop
HR
Daily
per
capita
release
of
the
chemical
to
a
wastewater
treatment
facility
(
grams/
person/
day)
ProdVol
Production
volume
(
Kg/
year)
[
use
information
will
be
provided
by
SRRD]
Pop
US
population
(
persons)
=
2.727x108
persons
(
US
Bureau
of
the
Census,
1999)

Surface
Water
Concentrations
HR
x
1
x
(
1
­
WWT)
x
CF1
CSM
=
_______
QH___________________
SDFM
HR
x
1
x
(
1
­
WWT)
x
CF1
CSH
=
_______
QH___________________
SDFL
CSM
Median
time­
averaged
surface
water
concentration
(:
g/
L)
CSH
High
end
time
averaged
surface
water
concentration
(:
g/
L)
HR
Daily
per
capita
release
of
chemical
(
i.
e.
pre­
treatment
release,
g/
person/
day)
QH
Daily
per
capita
wastewater
volume
released
(
364
L/
person/
day,
USEPA,
1990;
Versar,
1992)
WWT
Fraction
of
chemical
removed
during
wastewater
treatment
[
see
alternative
values
below]
SDFM
50th
percentile
stream
dilution
factor
for
stream
to
which
wastewater
treatment
facilities
discharge
(
980.69,
Versar,
1992)
­
60­
SDFL
10th
percentile
stream
dilution
factor
for
stream
to
which
wastewater
treatment
facilities
discharge
(
75.44,
Versar,
1992)
CF1
Conversion
factor
(
1x106
:
g/
g)

Removal
of
Pyrethrins
(
WWT)
Information
on
the
degree
of
removal
of
pyrethrins
from
wastewater
at
POTWs
is
unavailable.
Therefore,
the
EPA
relied
in
modeling
to
obtain
this
value.
The
EPIWIN
program
was
utilized.
Two
levels
of
removal
are
obtained
from
EPIWIN,
the
most
conservative
(
the
lowest)
was
utilized
in
E­
FAST
modeling.
WWT
value
=
92.7%

Production
Volume
The
production
volume
of
pyrethrins
was
chosen
to
be
very
conservative.
The
total
volume
of
pyrethrins
produced
for
all
uses
in
the
United
States
was
reported
by
BEAD
to
be
approximately
200,000
lb
a.
i./
A
(
Biological
and
Economic
Analysis
Division,
BEAD).

Substituting
the
previous
values,
the
following
is
obtained:
HR
=
0.000911
g/
person/
day
Surface
Water
Concentrations
Surface
water
concentrations
were
modeled
using
computer
program
E­
FAST,
and
the
results
were
as
indicated
in
the
following
Table
(
please,
refer
to
Appendix
Q
for
output
files
from
EPIWIN
and
E­
FAST).

Surface
Water
Concentrations
Modeled
By
E­
FAST
WWT\
Concentration
Acute/
ppb
Chronic/
ppb
92.7%
0.00242
0.000186
d.
Aquatic
Exposure
Monitoring
(
Field
Data)

No
data
were
identified
to
provide
information
on
aquatic
exposure
monitoring.
In
addition,
at
this
time,
there
are
limited
surface
water
or
groundwater
monitoring
data
available
for
pyrethrins.
The
U.
S.
Geological
Survey's
National
Water
Quality
Assessment
program
(
NAWQA)
did
not
have
any
data
regarding
the
detection
of
pyrethrins
in
streams
or
groundwater.

3.
Measures
of
Terrestrial
Exposure
A
primary
concern
with
pyrethrins
is
that
birds
and
mammals
may
be
exposed
shortly
after
application
through
oral
or
dietary
exposure
to
vegetative
plant
material
or
insects
when
foraging
in
the
treated
fields
for
nesting
material
or
food.
The
EFED
terrestrial
exposure
model,
T­
REX
(
T­
REX,
Version
1.2.3,
dated
August
8,
2005),
is
used
to
estimate
exposures
and
risks
to
avian
and
mammalian
species.
Input
values
on
avian
and
mammalian
toxicity
as
well
as
chemical
application
and
foliar
halflife
data
are
required
to
run
the
model.
The
model
provides
estimates
of
both
exposure
concentrations
and
risk
quotients
(
RQs).
Specifically,
the
model
provides
estimates
of
concentrations
(
maximum
and
average)
of
chemical
residues
in
different
types
of
foliage
that
may
be
sources
of
dietary
exposure
to
avian,
mammalian,
reptilian,
or
terrestrial­
phase
amphibian
receptors.
The
exposure
concentration
(
ppm)
is
estimated
by
multiplying
the
application
rate
(
pounds
active
­
61­
ingredient
per
acre)
by
a
value
specific
to
each
food
item.
These
values
(
termed
the
Hoerger­
Kenaga
estimates)
along
with
a
more
detailed
discussion
of
the
methodology
implemented
by
T­
REX,
are
presented
in
Appendix
C
(
T­
REX
Model
and
Results).
By
comparing
these
estimated
concentrations
to
acute
and
chronic
toxicity
reference
values,
acute
and
chronic
RQs
are
calculated.

For
this
assessment,
T­
REX
was
run
for
a
single
crop
use
scenario
that
is
considered
generally
representative
of
the
maximum
uses
of
pyrethrins
(
see
Table
26).
The
foliar
half­
life
of
1­
14
days
found
for
phenothrin
and
pyrethrin
were
used
in
the
absence
of
foliar
dissipation
studies
on
pyrethrins.
To
explore
the
importance
of
the
foliar
half­
life
assumption,
multiple
calculations
were
performed
and
a
plot
is
provided
illustrating
the
relationship
between
foliar
half­
life
and
the
most
sensitive
scenario
­
acute
RQs
for
the
small
mammal
foraging
on
short
grass.
The
EEC
is
determined
for
multiple
application
scenarios
(
10
applications
for
pyrethrins)
by
adding
the
mass
on
the
surface
immediately
following
the
application
to
the
mass
of
the
chemical
still
present
on
the
surfaces
on
the
day
of
application
(
determined
based
on
first
order
kinetics
using
the
foliar
half­
life
as
the
rate
constant).

Table
26.
Input
parameters
for
T­
REX.

Parameter
Value
Comment
Application
rate
(
lbs
a.
i./
A)
0.05
product
label
Foliar
half­
life
(
days)
1
­
14
Total
and
dislodgeable
residues
for
phenothrin
and
pyrethrin,
respectively.
Willis,
G
and
L.
McDowell.
1987.
Pesticide
Persistance
and
Foliage.
Review
of
Environmental
Contamination
and
Toxicology.
Vol.
100.
Springer­
Verlag,
new
York,
pp
24­
73.

Frequency
of
application
(
days)
1
interpreted
as
the
minimum
interval
between
applications;
product
label
(
high
pest
pressure)

Frequency
of
applications
(
days)
3
Typical
application
interval
(
low
pest
pressure)

Maximum
applications
per
year
10
product
label
4.
Non­
Target
Plant
Exposure
No
data
were
submitted
to
evaluate
the
effects
of
pyrethrin
exposure
to
plants.
However
the
Agency
does
not
consider
pyrethrin
or
the
other
pyrethroids
as
being
phytotoxic
for
the
following
reasons:
1)
the
compound
is
used
as
a
spray
on
agricultural
crops
with
no
direct
phytotoxic
effects;
2)
the
neural
toxic
mode
of
action
precludes
phtotoxic
concerns;
3)
the
Agency
is
not
aware
of
any
incidents
involving
aquatic
or
terrestrial
plants
and
pyrethrin
alone.
Therefore,
EECs
were
not
determined.

C.
Ecological
Effects
Characterization
1.
Aquatic
Effects
a.
Aquatic
Animals
­
62­
The
complete
range
of
toxicity
reference
values
available
for
aquatic
organisms
exposed
to
pyrethrins
is
given
in
Appendix
E.
The
most
toxic
of
these
reference
values
are
summarized
in
Table
27a.
Toxicity
testing
was
conducted
with
both
pyrethrin
extracts
or
technical
grade
active
ingredient
(
TGAI),
FEK­
99
(
57.5%
a.
i.),
as
well
as
with
a
formulated
end­
use
product,
typically
a
Pyreonone
crop
spray
(
6.02%
a.
i.).
The
results
of
the
toxicity
testing
suggests
that
pyrethrins
are
very
highly
toxic
to
freshwater
fish
(
LC
50
=
3.2 
10
:
g/
L)
and
to
invertebrates
(
EC
50
=
6.7 
11.6
:
g/
L),
as
well
as
to
estuarine/
marine
fish
(
LC
50
=
3.8 
16.0
:
g/
L)
and
to
invertebrates
(
LC
50
/
EC
50
=
0.14 
1.4
:
g/
L)
on
an
acute
basis.
Toxicity
tests
on
the
formulated
product
(
60.25%
piperonyl
butoxide
PBO,
and
6.02%
pyrethrin)
show
a
relative
increase
in
toxicity
when
compared
to
tests
on
pyrethrin
alone.
Table
27b
gives
some
indication
as
to
the
synergistic
effects
of
PBO
that
help
to
increase
the
effectiveness
of
the
active
ingredient.
The
synergist
activity
can
be
seen
when
data
on
the
formulation
is
compared
to
data
on
the
TGAI.
As
shown
in
Table
27b,
when
animals
are
exposed
to
the
formulation,
there
is
a
major
difference
in
acute
toxicity
that
occurs.
Across
all
aquatic
species
tested,
the
formulation
is
more
toxic
to
fish
and
invertebrates
on
an
acute
basis
than
the
TGAI.
The
greatest
difference
in
toxicity
is
seen
with
the
estuarine/
marine
invertebrates
(
e.
g.,
shrimp).
There
is
a
90%
difference
between
LC
50s
,
when
comparing
the
TGAI
to
the
formulation.

Chronic
toxicity
studies
were
conducted
with
the
TGAI
only.
Studies
show
that
pyrethrins
impair
growth
(
length
and
weight)
of
freshwater
fish
(
LOAEC
of
3.0
:
g/
L
and
reproduction
of
freshwater
invertebrates
(
LOAEC
of
2.0
:
g/
L.
The
chronic
NOAECs
for
freshwater
fish
and
invertebrates
were
reported
as
1.9
and
0.86
:
g/
L,
respectively.
No
data
were
submitted
to
evaluate
the
chronic
risk
to
estuarine/
marine
fish
or
invertebrates.
However,
as
shown
in
Table
27c,
based
on
the
acute
to
chronic
ratio
method,
NOAECs
were
estimated
for
the
sheepshead
minnow
and
mysid
shrimp.
The
Agency
calculated
RQ
values
for
agricultural
uses
by
looking
at
maximum
and
typical
application
rates
(
TGAI
and
formulation).
For
maximum
application
there
are
differences
in
risk
quotients
calculated
for
fish
and
invertebrates
when
exposure
to
the
active
ingredient
alone
is
considered
versus
the
formulation.
Shown
in
Tables
27d
through
27g,
exposure
to
the
formulated
product
increases
the
risk
quotients,
primarily
because
of
the
higher
toxicity
to
fish
and
invertebrates.
In
this
assessment,
the
estuarine/
marine
invertebrates
are
most
sensitive
and
have
the
highest
risk
estimates.
In
general,
the
model
shows
that
maximum
application
rate
can
result
in
acute
risk
to
freshwater
invertebrates
from
exposure
to
the
formulation
was
equal
to
or
2X
greater
than
comparable
acute
risk
for
freshwater
fish.
Typical
application
rate
appeared
to
reduce
residue
exposure
to
an
aquatic
area
by
about
40%
resulting
in
no
acute
risk
to
fish
and
freshwater
invertebrates.
However,
this
same
scenario
shows
that
typical
use
(
formulation)
still
has
the
potential
for
acute
risk
to
estuarine/
marine
invertebrates.
Four
crop
scenarios
were
also
chosen
to
show
the
influence
of
drift
to
possible
risk
to
aquatic
areas.
The
Agency
modeled
these
scenarios
by
setting
the
drift
component
to
zero
from
the
normal
5%
drift
default
value.
As
shown
in
table
27h,
when
drift
is
set
to
zero,
there
is
a
reduction
in
EECs
from
45
­
89%
depending
upon
the
crop
scenatio,
suggesting
that
drift
is
a
major
contributor
to
water
concentrations
for
the
GA
peaches,
ID
potato,
FL
citrus,
and
CA
grape
crop
scenarios.

Since
pyrethrins
tend
to
partition
to
the
sediment
compartment,
data
regarding
the
toxicity
of
pyrethrins
to
sediment
dwelling
organisms
are
needed.
For
this
risk
assessment,
the
sediment
toxicity
­
63­
was
estimated
based
on
the
aquatic
toxicity
to
aquatic
invertebrates
multiplied
by
the
Koc
value
for
pyrethrins.

Table
27a.
Toxicity
reference
values
for
aquatic
organisms
exposed
to
the
pyrethrin
formulation
and
to
the
pyrethrin
technical
grade
active
ingredient
(
TGAI).

Exposure
scenario
Species
Exposure
duration
Toxicity
reference
value
Referencea
Freshwater
Fish
Acute
Rainbow
trout
(
Oncorhynchus
mykiss)
96
hours
LC50
=
3.2
:
g/
L
MRID
43082304
Core,
6.02%
a.
i.

Acute
Rainbow
trout
(
Oncorhynchus
mykiss)
96
hours
LC50
=
5.1
:
g/
L
MRID
43082303
Core,
57.5%
a.
i.

Chronic
Fathead
minnow
(
Pimephales
promelas)
early
life
stage
NOAEC
=
1.9
:
g/
L
MRID
43252701,
Core,
57.5%
a.
i.

Freshwater
Invertebrates
Acute
Waterflea
(
Daphnia
magna)
48
hours
EC50
=
6.7
:
g/
L
MRID
43082306,
Core,
6.02%
a.
i.

Acute
Waterflea
(
Daphnia
magna)
48
hours
EC50
=
11.6
:
g/
L
MRID
43082305,
Core,
57.5%
a.
i.

Chronic
Waterflea
(
Daphnia
magna)
reproduction
NOAEC
=
0.86
:
g/
L
MRID
43252702,
Core,
57.5%
a.
i.

Esutarine/
Marine
Fish
Acute
Sheepshead
minnow
(
Cyprinodon
variegatus)
96
hours
LC50
=
3.8
:
g/
L
MRID
43082308,
Core,
6.02%
a.
i.

Acute
Sheepshead
minnow
(
Cyprinodon
variegatus)
96
hours
LC50
=
16.0
:
g/
L
MRID
43082307,
Core,
57.5%
a.
i.

Chronic:
No
data
submitted;
the
acute­
to­
chronic
ration
method
was
used
to
estimate
a
NOAEC
of
5.9
:
g/
L
for
Sheepshead
minnow
Estuarine/
Marine
Invertebrates
Acute
Mysid
shrimp
(
Mysidopsis
bahia)
96
hours
LC50
=
0.14
:
g/
L
MRID
43082312,
Core,
6.02%
a.
i.

Acute
Mysid
shrimp
(
Mysidopsis
bahia)
96
hours
LC50
=
1.4
:
g/
L
MRID
43082311,
Core,
57.5%
a.
i.

Chronic:
No
data
was
submitted,
however
the
acute­
to­
chronic
ratio
method
was
used
to
estimate
a
NOAEC
of
0.10
:
g/
L
for
Mysid
shrimp
Aquatic
Plants
Table
27a.
Toxicity
reference
values
for
aquatic
organisms
exposed
to
the
pyrethrin
formulation
and
to
the
pyrethrin
technical
grade
active
ingredient
(
TGAI).

Exposure
scenario
Species
Exposure
duration
Toxicity
reference
value
Referencea
­
64­
Acute:
No
data
aThe
technical
grade
active
ingredient
(
TGAI)
is
57.5%
a.
i,
using
a
test
substance
called
FEK­
99.
The
formulation
is
6.02%
a.
i.,
using
a
product
called
PYRENONE
®
Crop
Spray
(
EPA
Reg.
No.
432­
1033)
.

Table
27b.
Comparison
of
acute
toxicity
of
pyrethrin
extract/
technical
grade
active
ingredient
(
FEK­
99)
to
the
formulated
product
(
Pyrenone
crop
spray).

Test
Species
Exposure
duration
LC50
(:
g/
L)

Percent
Difference
in
Toxicity
TGAI
Formulation
Freshwater
Fish
Acute
Rainbow
trout
(
Oncorhynch
us
mykiss)
96
hours
5.1
3.2
37%

Freshwater
Invertebrates
Acute
Waterflea
(
Daphnia
magna)
48
hours
11.6
6.7
42%

Esutarine/
Marine
Fish
Acute
Sheepshead
minnow
(
Cyprinodon
variegatus)
96
hours
16.0
3.8
76%

Estuarine/
Marine
Invertebrates
Acute
Mysid
shrimp
(
Mysidopsis
bahia)
96
hours
1.4
0.14
90%
­
65­
Table
27c
Acute
to
chronic
ratio
method
calculations
Species
Acute
LC50
(:
g/
L)
Chronic
NOAEC
(:
g/
L)

Rainbow
Trout
5.1
No
data
Fathead
minnow
No
data
1.9
Sheepshead
minnow
16.0
5.9
(
estimated)
a
Daphnia
magna
11.6
0.86
Mysid
shrimp
1.4
0.10
(
estimated)
b
aThe
NOAEC
estimated
for
the
sheepshead
minnow
is
based
on
the
acute­
to­
chronic
ratio
method,
determined
by
the
following
mathematical
relationship:
Freshwater
LC50
(
5.1)
/
Freshwater
NOAEC
(
1.9)
=
Estuarine/
marine
LC50
(
16.0
ppb)/
X
(
estimated
value
for
estuarine/
marine
NOAEC).
bThe
NOAEC
estimated
for
the
Mysid
shrimp
is
based
on
the
acute­
to­
chronic
ratio
method,
determined
by
the
following
mathematical
relationship:
Freshwater
LC50
(
11.6
ppb)/
Freshwater
NOAEC
(
0.86
ppb)
=
Estuarine/
marine
LC50
(
1.4
ppb)/
X
(
estimated
value
for
estuarine/
marine
NOAEC).
­
66­
Table
27d.
Comparison
of
the
Acute
RQs
calculated
for
the
TGAI
and
PBO
Formulation
for
freshwater
and
estuarine/
marine
fish
associated
with
agricultural
uses
of
pyrethrins.
Toxicity
values
are
based
on
studies
with
rainbow
trout
(
Oncorhynchus
mykiss)
(
LC50
=
3.2
:
g/
L
for
PBO
formulated
product;
5.1
:
g/
L
for
TGAI),
and
sheepshead
minnow
(
Cyprinodon
variegatus)
(
LC50
=
3.8
:
g/
L
for
formulated
product;
16
:
g/
L
for
TGAI).
EEC
values
are
generated
from
PRZM/
EXAMS
using
maximum
and
typical
rates.

EECs
(:
g/
L
)
Freshwater
fish
Estuarine/
marine
fish
Scenario
(
state/
crop)
peak
Acute
RQ
Formulation
Acute
RQ
TGAI
Acute
RQ
Formulation
Acute
RQ
TGAI
IL
corn
2.77
0.87a,
b,
c
0.54a,
b,
c
0.73a,
b,
c
0.17a,
b
MS
cotton
1.91
0.60a,
b,
c
0.37a,
b
0.50a,
b,
c
0.12a,
b
PA
tomato
1.51
0.47a,
b
0.29a,
b
0.40abc
0.10a,
b
ME
potato
1.35
0.42a,
b
0.26a,
b
0.36a,
b
0.08a
CA
onion
0.78
0.24a,
b
0.15a,
b
0.21a,
b
0.05a
ND
wheat
0.68
0.21a,
b
0.13a,
b
0.18a,
b
0.04
NC
apple
0.61
0.19a,
b
0.12a,
b
0.16a,
b
0.04
FL
citrus
0.40
0.13a,
b
0.08
0.11a,
b
0.03
OR
snapbeans
0.45
0.14a,
b
0.09
0.12a,
b
0.03
GA
peaches
0.66
0.21a,
b
0.13a,
b
0.17a,
b
0.04
ID
potato
0.37
0.12a,
b
0.07
0.10a,
b
0.02
MN
alfalfa
0.36
0.11a,
b
0.07
0.10a,
b
0.02
CA
grapes
0.35
0.11a,
b
0.07
0.10a,
b
0.02
SPECIAL
RUNS
USING
3­
DAY
INTERVAL
BETWEEN
APPLICATIONS,
NORMAL
PEST
PRESSURE
IL
corn
2.40
0.75a,
b,
c
0.47a,
b
0.63a,
b,
c
0.15a,
b
ID
potato
0.21
0.07a
0.04
0.06a
0.01
CA
onion
0.39
0.12a,
b
0.08a
0.10a,
b
0.02
TYPICAL
APPLICATION
RATE
AND
NUMBER
OF
APPLICATIONS
ID
potato
0.05
0.02
0.01
<
0.00
0.01
PA
tomato
0.03
0.01
0.01
<
0.00
0.01
CA
onion
0.04
0.01
0.01
<
0.00
0.01
OR
snap
beans
0.09
0.03
0.02
0.01
0.02
Table
27d.
Comparison
of
the
Acute
RQs
calculated
for
the
TGAI
and
PBO
Formulation
for
freshwater
and
estuarine/
marine
fish
associated
with
agricultural
uses
of
pyrethrins.
Toxicity
values
are
based
on
studies
with
rainbow
trout
(
Oncorhynchus
mykiss)
(
LC50
=
3.2
:
g/
L
for
PBO
formulated
product;
5.1
:
g/
L
for
TGAI),
and
sheepshead
minnow
(
Cyprinodon
variegatus)
(
LC50
=
3.8
:
g/
L
for
formulated
product;
16
:
g/
L
for
TGAI).
EEC
values
are
generated
from
PRZM/
EXAMS
using
maximum
and
typical
rates.

EECs
(:
g/
L
)
Freshwater
fish
Estuarine/
marine
fish
Scenario
(
state/
crop)
peak
Acute
RQ
Formulation
Acute
RQ
TGAI
Acute
RQ
Formulation
Acute
RQ
TGAI
­
67­
aRQ
exceeds
LOC
for
acute
endangered
species
($
0.05).
bRQ
exceeds
LOC
for
acute
restricted
use
($
0.1).
cRQ
exceeds
LOC
for
acute
high
risk
($
0.5).

Table
27e.
Comparison
of
the
Acute
RQs
calculated
for
the
TGAI
and
PBO
Formulation
for
freshwater
and
estuarine/
marine
invertebrates
associated
with
agricultural
uses
of
pyrethrins.
Toxicity
values
are
based
on
studies
with
waterflea
(
Daphnia
magna)
(
EC50
=
6.7
:
g/
L
for
PBO
formulated
product;
EC50
=
11.6
:
g/
L
for
TGAI)
and
mysid
shrimp
(
Mysidopsis
bahia)
(
LC50
=
0.14
:
g/
L
for
formulated
product;
LC50
=
1.4
:
g/
L
for
TGAI).
EEC
values
are
generated
from
PRZM/
EXAMS
using
maximum
and
typical
rates.

EECs
(:
g/
L
)
Freshwater
invertebrates
Estuarine/
marine
invertebrates
Scenario
(
state/
crop)
peak
Acute
RQ
Formulation
Acute
RQ
TGAI
Acute
RQ
Formulation
Acute
RQ
TGAI
IL
corn
2.77
0.41a,
b
0.23a,
b
19.79a,
b,
c
1.98a,
b,
c
MS
cotton
1.91
0.29a,
b
0.16a,
b
13.6a,
b,
c
1.36a,
b,
c
PA
tomato
1.51
0.23v
0.13a,
b
10.79a,
b,
c
1.08a,
b,
c
ME
potato
1.35
0.20a,
b
0.12a,
b
9.64a,
b,
c
0.96a,
b,
c
CA
onion
0.78
0.12a,
b
0.07a
5.67a,
b,
c
0.56a,
b,
c
ND
wheat
0.68
0.10a,
b
0.06a
4.86a,
b,
c
0.49a,
b
NC
apple
0.61
0.10a,
b
0.05a
4.36a,
b,
c
0.44a,
b
FL
citrus
0.40
0.10a,
b
0.03
2.86a,
b,
c
0.29a,
b
OR
snapbeans
0.45
0.10a,
b
0.04
3.21a,
b,
c
0.32a,
b
GA
peaches
0.66
0.10a,
b
0.06a
4.71a,
b,
c
0.47a,
b
ID
potato
0.37
0.10a,
b
0.03
2.64a,
b,
c
0.26a,
b
Table
27e.
Comparison
of
the
Acute
RQs
calculated
for
the
TGAI
and
PBO
Formulation
for
freshwater
and
estuarine/
marine
invertebrates
associated
with
agricultural
uses
of
pyrethrins.
Toxicity
values
are
based
on
studies
with
waterflea
(
Daphnia
magna)
(
EC50
=
6.7
:
g/
L
for
PBO
formulated
product;
EC50
=
11.6
:
g/
L
for
TGAI)
and
mysid
shrimp
(
Mysidopsis
bahia)
(
LC50
=
0.14
:
g/
L
for
formulated
product;
LC50
=
1.4
:
g/
L
for
TGAI).
EEC
values
are
generated
from
PRZM/
EXAMS
using
maximum
and
typical
rates.

EECs
(:
g/
L
)
Freshwater
invertebrates
Estuarine/
marine
invertebrates
Scenario
(
state/
crop)
peak
Acute
RQ
Formulation
Acute
RQ
TGAI
Acute
RQ
Formulation
Acute
RQ
TGAI
­
68­
MN
alfalfa
0.36
0.10a,
b
0.03
2.57a,
b,
c
0.26a,
b
CA
grapes
0.35
0.10a,
b
0.03
2.50a,
b,
c
0.25a,
b
SPECIAL
RUNS
USING
3­
DAY
INTERVAL
BETWEEN
APPLICATIONS,
NORMAL
PEST
PRESSURE
IL
corn
2.40
0.36a,
b
0.20a,
b
17.14a,
b,
c
1.71a,
b,
c
ID
potato
0.21
0.03
0.02
1.50a,
b,
c
0.15a,
b
CA
onion
0.39
0.10a,
b
0.03
2.79a,
b,
c
0.28a,
b
TYPICAL
APPLICATION
RATE
AND
NUMBER
OF
APPLICATIONS
ID
potato
0.05
0.01
<
0.00
0.36a,
b
0.04
PA
tomato
0.03
<
0.00
<
0.00
0.21a,
b
0.02
CA
onion
0.04
0.01
<
0.00
0.29a,
b
0.03
OR
snap
beans
0.09
0.01
0.01
0.64a,
b,
c
0.06a
aRQ
exceeds
LOC
for
acute
endangered
species
($
0.05).
bRQ
exceeds
LOC
for
acute
restricted
use
($
0.1).
cRQ
exceeds
LOC
for
acute
high
risk
($
0.5).
­
69­
Table
27f.
Comparison
of
the
Acute
RQs
calculated
for
the
TGAI
and
PBO
Formulation
for
freshwater
and
estuarine/
marine
fish
associated
with
mosquito
abatement
uses
of
pyrethrins.
Toxicity
values
are
based
on
studies
with
rainbow
trout
(
Oncorhynchus
mykiss)
(
LC50
=
3.2
:
g/
L
for
formulated
product;
5.1
:
g/
L
for
TGAI),
and
sheepshead
minnow
(
Cyprinodon
variegatus)
(
LC50
=
3.8
:
g/
L
for
PBO
formulated
product;
16
:
g/
L
for
TGAI).
EEC
values
are
generated
from
AGDISP
and
PRZM/
EXAMS
for
pyrethrins
applied
in
a
Florida
Turf
scenario.

EECs
(:
g/
L)
Freshwater
fish
Estuarine/
marine
fish
Depth
of
water
body
peak
Acute
RQ
Formulation
Acute
RQ
TGAI
Acute
RQ
Formulation
Acute
RQ
TGAI
6.0
inches
0.047
0.01
0.01
0.01
<
0.01
12.0
inches
0.049
0.02
0.01
0.01
<
0.01
3.3
feet
(
1
meter)
0.056
0.02
0.02
0.01
<
0.01
6.6
feet
(
2
meters)
0.066
0.02
0.02
0.02
<
0.01
Table
27g.
Comparison
of
the
Acute
RQs
calculated
for
the
TGAI
and
PBO
Formulation
for
freshwater
and
estuarine/
marine
invertebrates
associated
with
mosquito
abatement
uses
of
pyrethrins.
Toxicity
values
are
based
on
studies
with
waterflea
(
Daphnia
magna)
(
EC50
=
6.7
:
g/
L
for
formulated
product;
EC50
=
11.6
:
g/
L
for
TGAI)
and
mysid
shrimp
(
Mysidopsis
bahia)
(
LC50
=
0.14
:
g/
L
for
PBO
formulated
product;
LC50
=
1.4
:
g/
L
for
TGAI).
EEC
values
are
generated
from
AGDISP
and
PRZM/
EXAMS
for
pyrethrins
applied
in
a
Florida
Turf
scenario.

EECs
(:
g/
L
)
Freshwater
invertebrates
Estuarine/
marine
invertebrates
Depth
of
water
body
Peak
Acute
RQ
Formulation
Acute
RQ
TGAI
Acute
RQ
Formulation
Acute
RQ
TGAI
Surface
Water
6
inches
0.047
<
0.01
<
0.01
0.33a
0.03
12
inches
0.048
0.01
<
0.01
0.34a
0.03
3.3
feet
(
1
meter)
0.050
0.01
<
0.01
0.36a
0.04
6.6
feet
(
2
meters)
0.055
0.01
<
0.01
0.39a
0.04
aRQ
exceeds
LOC
for
acute
restricted
($
0.1)
and
acute
endangered
species
($
0.05).
­
70­
Table
27h.
Evaluation
of
acute
exposure
(
peak
EECs)
to
fish
and
invertebrates
for
4
selected
crop
scenarios
(
GA
peaches,
ID
potatoes,
FL
citrus,
and
CA
grapes),
when
spray
drift
is
set
to
5%
versus
when
spray
drift
is
set
to
zero.

EECs
(:
g/
L
)

Crop
Scenario
Peak
EEC
Drift
set
to
5%
Peak
EEC
Drift
set
to
zero
Percent
reduction
in
exposure
to
fish
and
invertebrates
when
spray
drift
component
is
eliminated
GA
peaches
0.66
0.344
48%

ID
potato
0.37
0.042
89%

FL
citrus
0.401
0.221
45%

CA
grapes
0.348
0.021
94%

b.
Aquatic
Plants
No
data
were
submitted
to
evaluate
the
effects
of
pyrethrin
exposure
to
non­
target
plants.

2.
Terrestrial
Effects
a.
Terrestrial
Animals
Toxicity
reference
values
for
terrestrial
organisms
exposed
to
pyrethrins
are
summarized
in
Table
28.
Pyrethrins
appear
to
be
practically
non­
toxic
to
avian
species
on
a
acute
oral
and
dietary
basis
(
oral
LD50
>
2,000
mg/
kg
bw;
dietary
LC50
>
5,620
mg/
kg
diet).
Reproductive
toxicity
data
were
not
submitted,
so
chronic
avian
risk
could
not
be
evaluated.
The
available
toxicity
data
are
listed
in
Appendix
E.

The
technical
grade
active
ingredient
was
used
as
the
test
substance
in
the
acute
and
reproductive
mammalian
toxicity
data.
Synergists,
such
as
piperonyl
butoxide,
work
as
competitive
alternative
substrate
that
bind
cytochrome
P­
450
mixed
function
oxidase
system
(
MFO)
enzymes,
thus
delaying
the
breakdown
of
toxins
like
the
pyrethrins
in
both
insects
and
mammals.
Since
the
mammalian
MFO
system
is
more
active
than
that
of
insects,
pyrethrins
are
metabolized
more
efficiently
in
these
organisms.
Studies
have
suggested
that
piperonyl
butoxide
may
enhance
the
production
of
MFO
enzymes
in
mammals.

Mammalian
toxicity
data
suggest
that
pyrethrins
are
slightly
toxic
to
small
mammals
on
an
acute
oral
basis
(
LD50
=
700
mg/
kg
body
weight).
In
the
2nd
generation
rat
reproduction
study,
parental
male
systemic
and
reproductive
toxicity
were
detected
at
1000
ppm
(
65
mg/
kg
body
weight
per
day)
and
parental
female
systemic
toxicity
was
detected
at
3000
ppm
(
196
mg/
kg
body
weight
per
day).
The
NOAEL
for
parental
systemic
(
male)
and
reproductive
toxicity
was
100
ppm
(
6.4
mg/
kg
body
weight­
day).

Acute
toxicity
studies
with
honey
bees
show
that
pyrethrins
are
highly
toxic
on
both
a
contact
and
an
oral
basis
(
contact
LC50
=
0.022
:
g
a.
i./
bee
and
oral
LD50
=
0.15
:
g
a.
i./
bee).
­
71­
Table
28.
Toxicity
reference
values
for
mammals
and
birds
exposed
to
pyrethrins.

Exposure
Scenario
Species
Exposure
Duration
Toxicity
Reference
Value
Referencea
Mammals
Acute
Rat
(
Rattus
norvegicus)
Single
dose
LD50
=
700
mg/
kg
bwb
MRID
42008101,
57.467
%
a.
i.

Chronic
Rat
(
Rattus
norvegicus)
2­
generation
reproduction
NOAEL
=
6.4
mg/
kgday
MRID
41327501,
57.6%
a.
i.

Birds
Acute
Bobwhite
quail
(
Colinus
virginianus)
5
daysc
LC50
>
5,620
mg/
kg
diet
MRID
41968801,
Core,
57.6%
a.
i.

Acute
Mallard
duck
(
Anas
platyrhynchos)
5
daysc
LC50
>
5,620
mg/
kg
diet
MRID
41968802,
Core,
57.6%
a.
i.

Chronic:
No
data
However,
chronic
data
from
permethrin
are
used
as
surrogate
information
because
of
similar
mode
of
action
NOAEC
=
500
ppm.

aTest
material
reported
as
FEK­
99,
57.467%
to
57.6%
a.
i.
pyrethrins,
is
considered
to
be
representative
of
technical
grade
active
ingredient
(
TGAI).
bFemale
rats
only;
LD50
for
males
in
the
same
study
was
2,140
mg/
kg
bw.
cReferred
to
as
a
"
subacute
study";
5­
day
dietary
exposure
followed
by
additional
3­
day
observation
period.

b.
Terrestrial
Plants
No
data
were
submitted
to
evaluate
the
effects
of
cypyrethrin
exposure
to
terrestrial
plants.
However
the
Agency
does
not
consider
pyrethrin
or
the
other
pyrethroids
as
being
phytotoxic
for
the
following
reasons:
1)
the
compound
is
used
as
a
spray
on
agricultural
crops
with
no
phytotoxic
effects;
2)
the
neural
toxic
mode
of
action
precludes
phtotoxic
concerns;
3)
the
Agency
is
not
aware
of
any
incidents
involving
plants
and
pyrethrin
alone
(
e.
g.,
incident
reports
regarding
terrestrial
plant
impact
are
inconclusive
with
regard
to
direct
effect
from
pyrethrin).

IV.
Risk
Characterization
A.
Risk
Estimation
­
Integration
of
Exposure
and
Effects
Data
1.
Non­
target
Aquatic
Animals
and
Plants
Details
regarding
RQs
and
exceedances
of
levels
of
concern
(
LOCs)
for
each
scenario
are
provided
below.
­
72­
a.
Fish
and
Aquatic
Invertebrates:
Agricultural
Uses
Table
29
shows
that
acute
LOCs
are
exceeded
for
fish
(
endangered
species,
restricted
uses,
and
acute
high
risk)
that
may
be
exposed
to
pyrethrin
residues
that
are
associated
with
agricultural
uses
and
maximum
application
rate.
The
risk
categories
and
RQ
ranges
associated
with
the
agricultural
crop
scenarios
for
freshwater
fish
are:
Acute
high
risk
(
RQ
=
0.54
for
IL
corn);
acute
restricted
use
(
RQ
range
=
0.13
to
0.54
for
GA
peaches,
OR
snapbeans,
FL
citrus,
NC
apple,
ND
wheat,
CA
onions,
ME
potato,
PA
tomato,
MS
cotton,
and
IL
corn);
and
endangered
species
risk
(
RQ
range
=
0.07
to
0.54
for
all
crop
scenarios­
CA
grapes,
MN
alfalfa,
ID
potato,
GA
peaches,
OR
snapbeans,
FL
citrus,
NC
apple,
ND
wheat,
CA
onions,
ME
potato,
PA
tomato,
MS
cotton,
and
IL
corn).
The
risk
categories
and
RQ
ranges
associated
with
the
agricultural
crop
scenarios
for
estuarine/
marine
fish
are:
Acute
restricted
use
(
RQ
range
=
0.12
to
0.17
for
MS
cotton
and
IL
corn);
and
endangered
species
risk
(
RQ
range
=
0.05
to
0.17
for
CA
onions,
ME
potato,
PA
tomato,
MS
cotton,
and
IL
corn).
Typical
application
rates
showed
no
acute
or
chronic
risk
(
RQ
<
0.0)
to
fish
(
estuarine/
marine
or
freshwater).

Table
30
shows
that
acute
LOCs
for
aquatic
invertebrates
(
endangered
species,
restricted
uses,
and
acute
high
risk)
were
exceeded
when
the
potential
for
acute
exposure
was
calculated
relative
to
several
agricultural
uses
of
pyrethrins
and
maximum
application
use.
The
risk
categories
and
RQ
ranges
associated
with
the
agricultural
crop
scenarios
for
freshwater
invertebrates
are:
Acute
restricted
use
risk
(
RQ
range
=
0.12
to
0.24;
crops
IL
corn,
MS
cotton,
PA
tomato,
and
ME
potato);
and
acute
endangered
species
risk
(
RQ
range
=
0.05
to
0.07
for
NC
apple,
ND
wheat,
GA
peaches
and
CA
onion).
The
risk
categories
and
RQ
ranges
associated
with
the
agricultural
crop
scenarios
for
estuarine/
marine
invertebrates
are:
Acute
high
risk
(
RQ
range
=
0.56
to
1.98
for
CA
onion,
ME
potato,
PA
tomato,
MS
cotton,
and
IL
corn);
acute
restricted
use
(
RQ
range
0.25
to
1.98
for
all
crop
scenarios­
CA
grapes,
MN
alfalfa,
ID
potato,
GA
peaches,
OR
snapbeans,
FL
citrus,
NC
apple,
ND
wheat,
CA
onion,
MD
potato,
PA
tomato,
MS
cotton,
and
IL
corn);
and
acute
endangered
species
risk
(
RQ
range
=
0.25
to
1.98
for
all
crop
scenarios­
CA
grapes,
MN
alfalfa,
ID
potato,
GA
peaches,
OR
snapbeans,
FL
citrus,
NC
apple,
ND
wheat,
CA
onion,
MD
potato,
PA
tomato,
MS
cotton,
and
IL
corn).
Typical
application
rates
in
general
showed
no
acute
or
chronic
risk
(
RQ
<
0.0)
to
aquatic
invertebrates
(
estuarine/
marine
or
freshwater),(
the
OR
snap
beans
scenario
produced
an
endangered
species
RQ
exceedance
for
estuarine/
marine
invertebrates.
However,
at
this
time
there
are
no
endangered
estuarine/
marine
invertebrates).

As
shown
in
Tables
29
and
30
there
were
no
chronic
risks
found
for
freshwater
fish
or
invertebrates
associated
with
the
agricultural
uses
relative
to
maximum
and
typical
application
rates..
However,
there
are
risk
concerns
for
estuarine/
marine
invertebrates
that
are
associated
with
the
agricultural
uses.
In
the
absence
of
chronic
data
for
Mysid
shrimp,
the
NOAEC
of
0.10
ppb
was
estimated
and
used
in
the
risk
assessment.
When
the
21­
day
EECs
were
compared
to
this
estimated
NOAEC,
chronic
LOCs
were
exceeded
for
all
crops
(
CA
onion,
ID
potato,
IL
corn,
CA
grapes,
MN
alfalfa,
GA
peaches,
OR
snapbeans,
FL
citrus,
NC
apple,
ND
wheat,
MS
cotton,
and
PA
tomato;
RQ
range
=
1.5
to
6).
A
acute­
to­
chronic
ratio
NOAEC
estimate
of
5.9
ppb
was
also
calculated
for
the
estuarine/
marine
fish
(
sheepshead
minnow).
All
RQs
for
chronic
risk
of
pyrethrins
to
estuarine/
marine
fish
are
below
the
LOC..
­
73­
Table
43
shows
the
peak
EECs
and
the
RQs
for
two
selected
crop
scenarios
that
were
run
for
aerial
and
ground
applications.
The
scenarios
also
included
three
buffer
zones
and
two
levels
of
spray
drift
(
high
end
and
low
end
drift
scenarios).
Even
though
all
the
RQs
are
above
the
LOC,
it
is
noted
that
the
ground
application
and
the
low
end
drift
scenario,
with
the
large
buffer
zone
yield
the
lower
EECs
and
the
lower
RQs.
The
GA
peach
crop
scenario
had
higher
RQs,
compared
to
the
ID
potato
crop
scenario.
When
the
run
with
the
drift
set
to
0%
was
compared
to
the
standard
run
with
drift
set
to
5%,
it
was
found
that
drift
was
an
important
component
of
the
peak
EECs
for
both
scenarios.
It
is
also
noted
that
even
a
small
buffer
zone
of
50
ft
reduces
the
RQs
by
more
than
20%,
compared
to
the
same
conditions
with
no
buffer
zone
(
for
both
the
high
end
and
low
end
drift
scenarios).

°
The
acute
endangered
species
LOC
and
chronic
LOC
were
slightly
exceeded
for
small
mammals
(
RQ
=
0.15
for
endangered
species
and
RQ
=
1.10
for
chronic).
Chronic
risk
to
birds
could
not
be
evaluated
because
no
bird
reproduction
data
were
submitted.

°
Although
toxicity
studies
on
the
degradates
were
not
provided,
an
evaluation
of
the
structures
indicate
that
they
are
the
result
of
the
rupture
of
the
ester
bridge
of
the
parent,
resulting
in
a
carboxylic
acid
(
chrysanthemic
acid),
and
an
alcohol
(
that
subsequently
be
degraded
to
an
acid
as
well).
The
resulting
molecules
have
lost
their
pyrethroid
toxicological
activity,
therefore,
in
this
assessment,
they
were
not
considered
of
concern.
Furthermore,
the
available
data
indicated
that
chrysanthemic
acid
was
formed
in
small
amounts
except
under
hydrolytic
conditions
at
pH
9.

The
Master
Label
provided
by
the
registrant,
indicates
that
1
day
is
used
when
pest
pressure
is
high,
but
the
normal
interval
between
applications
is
3
days.
Three
crop
scenarios
were
selected
and
run
with
PRZM/
EXAMS
with
the
same
original
input
parameters,
except
that
the
interval
between
applications
was
set
at
3
days
instead
of
1
day.
The
EEC's
obtained
are
summarized
in
Table
7,
and
the
RQs
appear
in
Tables
12
and
13.
It
was
noted
a
reduction
in
the
RQs
approximately
proportional
to
the
EECs,
which
ranged
from
around
12­
15%
for
IL
corn,
to
about
45%
for
ID
potato,
to
about
a
half
for
CA
onion.
The
RQs
for
some
of
the
crop
scenarios
(
i.
e.
alfalfa)
may
not
be
necessarily
the
most
conservative
because
certain
crops
are
grown
more
often
than
once
per
year.
This
assessment
assumed
a
single
season
per
year.
­
74­
Table
29.
Acute
and
chronic
RQs
for
freshwater
and
estuarine/
marine
fish
associated
with
agricultural
uses
of
pyrethrins
based
on
rainbow
trout
LC50
=
5.1
ug/
L,
fathead
minnow
NOAEC
=
1.9
ug/
L,
sheepshead
minnow
LC50
=
16.0
ug/
L,
and
extraoplated
NOAEC
sheepshead
minnow
5.9
ug/
L.
EEC
values
are
generated
from
PRZM/
EXAMS.

EECs
(:
g/
L
)

Scenario
(
state/
crop)
Peak
60­
day
average
Freshwater
Fish
(
Rainbow
Trout)
Acute
RQ
TGAI
Freshwater
Fish
(
Fathead
Minnow)
Chronic
RQ
TGAI
Estuarine/
marine
Fish
(
Sheepshea
d
Minnow)
Acute
RQ
TGAI
Estuarine/
marine
Fish
(
Sheepshead
Minnow)
Chronic
RQ
TGAI
RUNS
PERFORMED
WITH
MINIMUM
INTERVAL
BETWEEN
APPLICATIONS,
1
DAY,
HIGH
PEST
PRESSURE
IL
corna
2.77
0.37
0.54ab
0.19
0.17ab
0.06
MS
cottona
1.91
0.28
0.37ab
0.15
0.12ab
0.05
PA
tomatoa
1.51
0.20
0.30ab
0.11
0.09a
0.03
ME
potatoa
1.35
0.28
0.26ab
0.15
0.08a
0.05
CA
oniona
0.78
0.13
0.15ab
0.07
0.05a
0.02
ND
wheata
0.68
0.13
0.13ab
0.07
0.04
0.02
NC
applea
0.61
0.13
0.12ab
0.07
0.04
0.02
FL
citrus
0.40
0.09
0.08ab
0.05
0.03
0.02
OR
snapbeans
a
0.45
0.10
0.09ab
0.05
0.03
0.02
GA
peaches
0.66
0.10
0.13ab
0.05
0.04
0.02
ID
potatoa
0.37
0.09
0.07a
0.05
0.02
0.02
MN
alfalfaa
0.36
0.08
0.07a
0.04
0.02
0.01
CA
grapes
0.35
0.07
0.07a
0.04
0.02
0.01
SPECIAL
RUNS
USING
A
3­
DAY
INTERVAL
BETWEEN
APPLICATIONS,
NORMAL
PEST
PRESSURE
IL
corn
2.40
0.33
0.47ab
0.17
0.15ab
0.06
Table
29.
Acute
and
chronic
RQs
for
freshwater
and
estuarine/
marine
fish
associated
with
agricultural
uses
of
pyrethrins
based
on
rainbow
trout
LC50
=
5.1
ug/
L,
fathead
minnow
NOAEC
=
1.9
ug/
L,
sheepshead
minnow
LC50
=
16.0
ug/
L,
and
extraoplated
NOAEC
sheepshead
minnow
5.9
ug/
L.
EEC
values
are
generated
from
PRZM/
EXAMS.

EECs
(:
g/
L
)

Scenario
(
state/
crop)
Peak
60­
day
average
Freshwater
Fish
(
Rainbow
Trout)
Acute
RQ
TGAI
Freshwater
Fish
(
Fathead
Minnow)
Chronic
RQ
TGAI
Estuarine/
marine
Fish
(
Sheepshea
d
Minnow)
Acute
RQ
TGAI
Estuarine/
marine
Fish
(
Sheepshead
Minnow)
Chronic
RQ
TGAI
­
75­
ID
potato
0.21
0.08
0.04
0.04
0.01
0.01
CA
onion
0.39
0.09
0.08a
0.05
0.02
0.02
TYPICAL
APPLICATION
RATE
AND
NUMBER
OF
APPLICATIONSd
ID
potatoes
0.05
0.003
0.01
<
0.00
<
0.00
<
0.00
PA
tomatoes
0.03
0.005
0.01
<
0.00
<
0.00
<
0.00
CA
onions
0.04
0.004
0.01
<
0.00
<
0.00
<
0.00
OR
snap
beans
0.09
0.021
0.02
0.01
0.01
<
0.00
aRQ
exceeds
LOC
for
acute
endangered
species
($
0.05).
bRQ
exceeds
LOC
for
acute
restricted
use
($
0.1).
C
The
NOAEC
estimated
for
the
sheepshead
minnow
is
based
on
the
acute­
to­
chronic
ratio
method,
determined
by
the
following
mathematical
relationship:
Freshwater
LC50
(
5.1)
/
Freshwater
NOAEC
(
1.9)
=
Estuarine/
marine
LC50
(
16.0
ppb)/
X
(
estimated
value
for
estuarine/
marine
NOAEC).
d
For
the
60­
day
values,
three
significant
figures
were
shown.
­
76­
Table
30.
Acute
and
chronic
RQs
for
freshwater
and
estuarine/
marine
invertebrates
associated
with
agricultural
uses
of
pyrethrins
based
on
Daphnia
magna
EC50
=
11.6
ug/
L,
Daphnia
magna
NOAEC
=
0.86
ug/
L,
mysid
shrimp
EC50
=
1.4
ug/
L,
and
extraoplated
NOAEC
mysid
shrimp
0.10
ug/
L.
EEC
values
are
generated
from
PRZM/
EXAMS.

EECs
(:
g/
L
)

Scenario
(
state/
crop)
peak
21­
day
average
Freshwater
Invertebrate
(
Daphnia
magna)
Acute
RQ
TGAI
Freshwater
Invertebrate
(
Daphnia
magna)
Chronic
RQ
TGAI
Estuarine/
marine
Invertebrate
(
Mysid
Shrimp)
Acute
RQ
TGAI
Estuarine/
marine
Invertebrate
(
Mysid
Shrimp)
Chronic
RQ
TGAI
RUNS
PERFORMED
WITH
MINIMUM
INTERVAL
BETWEEN
APPLICATIONS,
1
DAY,
HIGH
PEST
PRESSURE
IL
corna
2.77
0.60
0.24ab
0.70
1.98abc
6.0
MS
cottona
1.91
0.41
0.16ab
0.48
1.36abc
4.1
PA
tomatoa
1.51
0.34
0.13ab
0.40
1.08abc
3.4
ME
potatoa
1.35
0.39
0.12ab
0.45
0.96abc
3.9
CA
oniona
0.78
0.25
0.07a
0.29
0.56abc
2.5
ND
wheata
0.68
0.23
0.06a
0.27
0.49ab
2.3
NC
applea
0.61
0.23
0.05a
0.27
0.44ab
2.3
FL
citrus
0.40
0.18
0.03
0.21
0.29ab
1.8
OR
snapbeansa
0.45
0.19
0.04
0.22
0.32ab
1.9
GA
peaches
0.66
0.19
0.06a
0.22
0.47ab
1.9
ID
potatoa
0.37
0.17
0.03
0.20
0.26ab
1.7
Table
30.
Acute
and
chronic
RQs
for
freshwater
and
estuarine/
marine
invertebrates
associated
with
agricultural
uses
of
pyrethrins
based
on
Daphnia
magna
EC50
=
11.6
ug/
L,
Daphnia
magna
NOAEC
=
0.86
ug/
L,
mysid
shrimp
EC50
=
1.4
ug/
L,
and
extraoplated
NOAEC
mysid
shrimp
0.10
ug/
L.
EEC
values
are
generated
from
PRZM/
EXAMS.

EECs
(:
g/
L
)

Scenario
(
state/
crop)
peak
21­
day
average
Freshwater
Invertebrate
(
Daphnia
magna)
Acute
RQ
TGAI
Freshwater
Invertebrate
(
Daphnia
magna)
Chronic
RQ
TGAI
Estuarine/
marine
Invertebrate
(
Mysid
Shrimp)
Acute
RQ
TGAI
Estuarine/
marine
Invertebrate
(
Mysid
Shrimp)
Chronic
RQ
TGAI
­
77­
MN
alfalfaa
0.36
0.16
0.03
0.19
0.26ab
1.6
CA
grapes
0.35
0.15
0.03
0.17
0.25ab
1.5
SPECIAL
RUNS
USING
A
3­
DAY
INTERVAL
BETWEEN
APPLICATIONS,
NORMAL
PEST
PRESSURE
IL
corn
2.40
0.50
0.21ab
0.58
1.71abc
5
ID
potato
0.21
0.12
0.02
0.14
0.15ab
1.2
CA
onion
0.39
0.16
0.03
0.19
0.28ab
1.6
TYPICAL
APPLICATION
RATE
AND
NUMBER
OF
APPLICATIONSe
ID
potatoes
0.05
0.007
<
0.00
0.01
0.04
0.07
PA
tomatoes
0.03
0.008
<
0.00
0.01
0.02
0.08
CA
onion
0.04
0.008
<
0.00
0.01
0.03
0.08
OR
snap
beans
0.09
0.038
0.01
0.04
0.06a
0.38
aRQ
exceeds
LOC
for
acute
endangered
species
($
0.05).
bRQ
exceeds
LOC
for
acute
restricted
use
($
0.1).
cRQ
exceeds
LOC
for
acute
high
risk
($
0.5).
d
The
NOAEC
estimated
for
the
Mysid
shrimp
is
based
on
the
acute­
to­
chronic
ratio
method,
determined
by
the
following
mathematical
relationship:
Freshwater
LC50
(
11.6
ppb)/
Freshwater
NOAEC
(
0.86
ppb)
=
Estuarine/
marine
LC50
(
1.4
ppb)/
X
(
estimated
value
for
estuarine/
marine
NOAEC).
e
For
the
21­
day
values,
three
significant
figures
were
shown,
because
the
values
were
small
in
magnitude.
­
78­
Mosquito
Abatement
For
mosquito
control,
application
directions
in
the
label
are
insufficient
to
accurately
estimate
aquatic
exposures
that
result
from
application
of
pyrethrin
for
controlling
mosquitoes.
Limitations
(
as
opposed
to
recommendations)
on
product
labels
for
key
parameters
such
as
droplet
size,
wind
speed,
release
height,
application
interval,
and
number
of
applications
allowed
per
year
are
not
specified.
The
exposure
assessment
conducted
here
represents
the
water
concentrations
expected
from
a
typical,
low­
level
aerial
application.
Concentrations
resulting
from
actual
application
of
pyrethrin
for
mosquito
control
could
be
significantly
higher
than
modeled
concentrations
if
applicators
used
different
application
parameters.

In
order
to
evaluate
mosquito
abatement
with
various
parameters
(
droplet
size,
boom
height,
maximum,
and
typical
rates),
a
different
modeling
approach
was
used
as
compared
to
agricultural
uses.
The
mosquito
adulticides
are
applied
as
mists
(
very
small
droplet
sizes)
that
do
not
deposit
rapidly
but
are
expected
to
drift.
Acute
risk
(
RQs),
relative
to
the
level
of
this
drift,
were
calculated
for
various
water
depths.
Typically,
the
FL
turf
scenario
is
used
in
PRZM/
EXAMS
(
or
decoupled
EXAMS)
to
calculate
the
EEC's.
The
toxicity
data
endpoints
used
for
the
mosquito
abatement
assessment
were
based
on
the
formulated
product
(
pyrenone
crop
spray)
and
maximum
and
typical
rates.
Tables
31
and
32
show
that
the
maximum
mosquito
rate
can
result
in
residues
that
exceed
the
acute
restricted
use
and
endangered
species
triggers
for
estuarine/
marine
invertebrates
(
RQ
range
=
0.81
to
0.95)
while
the
acute
risk
concerns
for
freshwater
invertebrates
or
fish
appears
to
be
low.
Using
the
maximum
rate
and
decreasing
the
droplet
size
from
50
um
to
40
um
resulted
in
about
a
37%
reduction
in
residues
but
acute
risk
still
exceeded
the
LOCs
for
these
esturine/
marine
organisms
(
Tables
32
and
34).
Raising
the
boom
height
to
150
ft.
also
reduced
the
potential
acute
risk
to
estuarine/
marine
invertebrates
by
about
90%
(
although
the
endangered
species
trigger
was
exceeded
this
scenario
appears
to
present
the
lowest
risk
since
there
are
no
endangered
estuarine/
marine
invertebrates
listed
at
this
time).
Table
40
shows
that
maintaining
droplet
size
at
40
um,
boom
height
150
ft,
maximum
application
rate
appears
to
eliminate
the
potential
for
acute
risk
to
estuarine/
marine
invertebrates.
Table
38
shows
that
by
using
the
typical
application
rate
(
0.0025lbs
ai/
A)
and
keeping
boom
height
at
75
ft
and
droplet
size
at
50
um,
acute
risk
to
estuarine/
marine
invertebrates
can
also
be
decreased
significantly.
Since
there
was
no
chronic
data
on
the
formulated
product,
chronic
risk
could
not
be
estimated
for
the
mosquito
abatement
uses.
Although
residues
may
increase
with
depth,
presumably
because
photodegradation
is
impeded
in
deeper
water
bodies,
and
the
level
of
adsorption
of
the
chemical
by
the
sediments
is
decreased
as
the
depth
of
the
water
bodies
increase,
the
expected
residue
levels
appear
to
be
below
the
LOCs
for
freshwater
organisms
and
estuarine/
marine
fish.
­
79­
Table
31.
Acute
RQs
for
freshwater
and
estuarine/
marine
fish
associated
with
mosquito
abatement
uses
of
pyrethrins.
EEC
values
are
generated
from
AGDISP
and
PRZM/
EXAMS
for
pyrethrins
applied
in
a
Florida
Turf
scenario.
Effects
values
on
the
PBO
formulation
were
rainbow
trout
LC50
=
3.2
ug/
L
and
sheepshead
minnow
LC50
=
3.8
ug/
L.
Droplet
size
50
:
m,
Boom
height
75
ft,
Application
Rate
0.008
lb
a.
i./
A
EECs
(:
g/
L)
Freshwater
fish
Estuarine/
marine
fish
Depth
of
water
body
peak
Rainbow
Trout
Acute
RQ
Formulation
Sheepshead
Minnow
Acute
RQ
Formulation
Surface
Water
6.0
inches
0.114
0.03
0.03
12.0
inches
0.117
0.04
0.03
3.3
feet
(
1
meter)
0.122
0.04
0.03
6.6
feet
(
2
meters)
0.133
0.04
0.04
Table
32.
Acute
RQs
for
freshwater
and
estuarine/
marine
invertebrates
associated
with
mosquito
abatement
uses
of
pyrethrins.
EEC
values
are
generated
from
AGDISP
and
PRZM/
EXAMS
for
pyrethrins
applied
in
a
Florida
Turf
scenario.
Effects
values
on
the
PBO
formulation
were
Daphnia
magnia
EC50
=
6.7
ug/
L
and
mysid
shrimp
LC50
=
0.14
ug/
L.
Droplet
size
50
:
m,
Boom
height
75
ft,
Application
Rate
0.008
lb
a.
i./
A
EECs
(:
g/
L
)
Freshwater
invertebrates
Estuarine/
marine
invertebrates
Depth
of
water
body
peak
Daphnia
magna
Acute
RQ
Formulation
Mysid
Shrimp
Acute
RQ
Formulation
Surface
Water
6
inches
0.114
0.02
0.81a
12
inches
0.117
0.02
0.84a
3.3
feet
(
1
meter)
0.122
0.02
0.87a
6.6
feet
(
2
meters)
0.133
0.02
0.95a
aRQ
exceeds
LOC
for
acute
($
0.5),
acute
restricted
($
0.1)
and
acute
endangered
species
($
0.05).
­
80­
Table
33.
Acute
RQs
for
freshwater
and
estuarine/
marine
fish
associated
with
mosquito
abatement
uses
of
pyrethrins.
EEC
values
are
generated
from
AGDISP
and
PRZM/
EXAMS
for
pyrethrins
applied
in
a
Florida
Turf
scenario.
Effects
values
on
the
PBO
formulation
were
rainbow
trout
LC50
=
3.2
ug/
L
and
sheepshead
minnow
LC50
=
3.8
ug/
L.
Droplet
size
40
:
m,
Boom
height
75
ft,
Application
Rate
0.008
lb
a.
i./
A
EECs
(:
g/
L)
Freshwater
fish
Estuarine/
marine
fish
Depth
of
water
body
peak
Rainbow
Trout
Acute
RQ
Formulation
Sheepshead
Minnow
Acute
RQ
Formulation
Surface
Water
6.0
inches
0.071
0.02
0.02
12.0
inches
0.073
0.02
0.02
3.3
feet
(
1
meter)
0.076
0.02
0.02
6.6
feet
(
2
meters)
0.083
0.03
0.02
Table
34.
Acute
RQs
for
freshwater
and
estuarine/
marine
invertebrates
associated
with
mosquito
abatement
uses
of
pyrethrins.
EEC
values
are
generated
from
AGDISP
and
PRZM/
EXAMS
for
pyrethrins
applied
in
a
Florida
Turf
scenario.
Effects
values
on
the
PBO
formulation
were
Daphnia
magnia
EC50
=
6.7
ug/
L
and
mysid
shrimp
LC50
=
0.14
ug/
L.
Droplet
size
40
:
m,
Boom
height
75
ft,
Application
Rate
0.008
lb
a.
i./
A
EECs
(:
g/
L
)
Freshwater
invertebrates
Estuarine/
marine
invertebrates
Depth
of
water
body
peak
Daphnia
magna
Acute
RQ
Formulation
Mysid
Shrimp
Acute
RQ
Formulation
Surface
Water
6
inches
0.071
0.01
0.51a
12
inches
0.073
0.01
0.52a
3.3
feet
(
1
meter)
0.076
0.01
0.54a
6.6
feet
(
2
meters)
0.083
0.01
0.59a
aRQ
exceeds
LOC
for
acute
($
0.5),
acute
restricted
($
0.1)
and
acute
endangered
species
($
0.05).
­
81­
Table
35.
Acute
RQs
for
freshwater
and
estuarine/
marine
fish
associated
with
mosquito
abatement
uses
of
pyrethrins.
EEC
values
are
generated
from
AGDISP
and
PRZM/
EXAMS
for
pyrethrins
applied
in
a
Florida
Turf
scenario.
Effects
values
on
the
PBO
formulation
were
rainbow
trout
LC50
=
3.2
ug/
L
and
sheepshead
minnow
LC50
=
3.8
ug/
L.
Droplet
size
50
:
m,
Boom
height
150
ft,
Application
Rate
0.008
lb
a.
i./
A
EECs
(:
g/
L)
Freshwater
fish
Estuarine/
marine
fish
Depth
of
water
body
peak
Rainbow
Trout
Acute
RQ
Formulation
Sheepshead
Minnow
Acute
RQ
Formulation
Surface
Water
6.0
inches
0.007
<
0.00
<
0.00
12.0
inches
0.008
<
0.00
<
0.00
3.3
feet
(
1
meter)
0.008
<
0.00
<
0.00
6.6
feet
(
2
meters)
0.009
<
0.00
<
0.00
Table
36.
Acute
RQs
for
freshwater
and
estuarine/
marine
invertebrates
associated
with
mosquito
abatement
uses
of
pyrethrins.
EEC
values
are
generated
from
AGDISP
and
PRZM/
EXAMS
for
pyrethrins
applied
in
a
Florida
Turf
scenario.
Effects
values
on
the
PBO
formulation
were
Daphnia
magnia
EC50
=
6.7
ug/
L
and
mysid
shrimp
LC50
=
0.14
ug/
L.
Droplet
size
50
:
m,
Boom
height
150
ft,
Application
Rate
0.008
lb
a.
i./
A
EECs
(:
g/
L
)
Freshwater
invertebrates
Estuarine/
marine
invertebrates
Depth
of
water
body
peak
Daphnia
magna
Acute
RQ
Formulation
Mysid
Shrimp
Acute
RQ
Formulation
Surface
Water
6
inches
0.007
<
0.00
0.05a
12
inches
0.008
<
0.00
0.06a
3.3
feet
(
1
meter)
0.008
<
0.00
0.06a
6.6
feet
(
2
meters)
0.009
<
0.00
0.06a
aRQ
exceeds
LOC
for
acute
endangered
species
($
0.05).
­
82­
Table
37.
Acute
RQs
for
freshwater
and
estuarine/
marine
fish
associated
with
mosquito
abatement
uses
of
pyrethrins.
EEC
values
are
generated
from
AGDISP
and
PRZM/
EXAMS
for
pyrethrins
applied
in
a
Florida
Turf
scenario.
Effects
values
on
the
PBO
formulation
were
rainbow
trout
LC50
=
3.2
ug/
L
and
sheepshead
minnow
LC50
=
3.8
ug/
L.
Droplet
size
50
:
m,
Boom
height
75
ft,
Application
Rate
0.0025
lb
a.
i./
A
EECs
(:
g/
L)
Freshwater
fish
Estuarine/
marine
fish
Depth
of
water
body
peak
Rainbow
Trout
Acute
RQ
Formulation
Sheepshead
Minnow
Acute
RQ
Formulation
Surface
Water
6.0
inches
0.036
0.01
0.01
12.0
inches
0.036
0.01
0.01
3.3
feet
(
1
meter)
0.038
0.01
0.01
6.6
feet
(
2
meters)
0.041
0.01
0.01
Table
38.
Acute
RQs
for
freshwater
and
estuarine/
marine
invertebrates
associated
with
mosquito
abatement
uses
of
pyrethrins.
EEC
values
are
generated
from
AGDISP
and
PRZM/
EXAMS
for
pyrethrins
applied
in
a
Florida
Turf
scenario.
Effects
values
on
the
PBO
formulation
were
Daphnia
magnia
EC50
=
6.7
ug/
L
and
mysid
shrimp
LC50
=
0.14
ug/
L.
Droplet
size
50
:
m,
Boom
height
75
ft,
Application
Rate
0.0025
lb
a.
i./
A
EECs
(:
g/
L
)
Freshwater
invertebrates
Estuarine/
marine
invertebrates
Depth
of
water
body
peak
Daphnia
magna
Acute
RQ
Formulation
Mysid
Shrimp
Acute
RQ
Formulation
Surface
Water
6
inches
0.036
0.01
0.25a
12
inches
0.036
0.01
0.25a
3.3
feet
(
1
meter)
0.038
0.01
0.27a
6.6
feet
(
2
meters)
0.041
0.01
0.29a
aRQ
exceeds
LOC
for
acute
restricted
($
0.1)
and
acute
endangered
species
($
0.05).
­
83­
Table
39.
Acute
RQs
for
freshwater
and
estuarine/
marine
fish
associated
with
mosquito
abatement
uses
of
pyrethrins.
EEC
values
are
generated
from
AGDISP
and
PRZM/
EXAMS
for
pyrethrins
applied
in
a
Florida
Turf
scenario.
Effects
values
on
the
PBO
formulation
were
rainbow
trout
LC50
=
3.2
ug/
L
and
sheepshead
minnow
LC50
=
3.8
ug/
L.
Droplet
size
40
:
m,
Boom
height
150
ft,
Application
Rate
0.008
lb
a.
i./
A
EECs
(:
g/
L)
Freshwater
fish
Estuarine/
marine
fish
Depth
of
water
body
peak
Rainbow
Trout
Acute
RQ
Formulation
Sheepshead
Minnow
Acute
RQ
Formulation
Surface
Water
6.0
inches
0.003
<
0.00
<
0.00
12.0
inches
0.003
<
0.00
<
0.00
3.3
feet
(
1
meter)
0.003
<
0.00
<
0.00
6.6
feet
(
2
meters)
0.003
<
0.00
<
0.00
Table
40.
Acute
RQs
for
freshwater
and
estuarine/
marine
invertebrates
associated
with
mosquito
abatement
uses
of
pyrethrins.
EEC
values
are
generated
from
AGDISP
and
PRZM/
EXAMS
for
pyrethrins
applied
in
a
Florida
Turf
scenario.
Effects
values
on
the
PBO
formulation
were
Daphnia
magnia
EC50
=
6.7
ug/
L
and
mysid
shrimp
LC50
=
0.14
ug/
L.
Droplet
size
40
:
m,
Boom
height
150
ft,
Application
Rate
0.008
lb
a.
i./
A
EECs
(:
g/
L
)
Freshwater
invertebrates
Estuarine/
marine
invertebrates
Depth
of
water
body
peak
Daphnia
magna
Acute
RQ
Formulation
Mysid
Shrimp
Acute
RQ
Formulation
Surface
Water
6
inches
0.003
<
0.00
0.02
12
inches
0.003
<
0.00
0.02
3.3
feet
(
1
meter)
0.003
<
0.00
0.02
6.6
feet
(
2
meters)
0.003
<
0.00
0.02
­
84­
Table
41.
Acute
RQs
for
freshwater
and
estuarine/
marine
fish
associated
with
mosquito
abatement
uses
of
pyrethrins.
EEC
values
are
generated
from
AGDISP
and
PRZM/
EXAMS
for
pyrethrins
applied
in
a
Florida
Turf
scenario.
Effects
values
on
the
PBO
formulation
were
rainbow
trout
LC50
=
3.2
ug/
L
and
sheepshead
minnow
LC50
=
3.8
ug/
L.
Droplet
size
50
:
m,
Boom
height
150
ft,
Application
Rate
0.0025
lb
a.
i./
A
EECs
(:
g/
L)
Freshwater
fish
Estuarine/
marine
fish
Depth
of
water
body
peak
Rainbow
Trout
Acute
RQ
Formulation
Sheepshead
Minnow
Acute
RQ
Formulation
Surface
Water
6.0
inches
0.003
<
0.00
0.02
12.0
inches
0.003
<
0.00
0.02
3.3
feet
(
1
meter)
0.003
<
0.00
0.02
6.6
feet
(
2
meters)
0.003
<
0.00
0.02
Table
42.
Acute
RQs
for
freshwater
and
estuarine/
marine
invertebrates
associated
with
mosquito
abatement
uses
of
pyrethrins.
EEC
values
are
generated
from
AGDISP
and
PRZM/
EXAMS
for
pyrethrins
applied
in
a
Florida
Turf
scenario.
Effects
values
on
the
PBO
formulation
were
Daphnia
magnia
EC50
=
6.7
ug/
L
and
mysid
shrimp
LC50
=
0.14
ug/
L.
Droplet
size
50
:
m,
Boom
height
150
ft,
Application
Rate
0.0025
lb
a.
i./
A
EECs
(:
g/
L
)
Freshwater
invertebrates
Estuarine/
marine
invertebrates
Depth
of
water
body
peak
Daphnia
magna
Acute
RQ
Formulation
Mysid
Shrimp
Acute
RQ
Formulation
Surface
Water
6
inches
0.003
<
0.00
0.02
12
inches
0.003
<
0.00
0.02
3.3
feet
(
1
meter)
0.003
<
0.00
0.02
Table
42.
Acute
RQs
for
freshwater
and
estuarine/
marine
invertebrates
associated
with
mosquito
abatement
uses
of
pyrethrins.
EEC
values
are
generated
from
AGDISP
and
PRZM/
EXAMS
for
pyrethrins
applied
in
a
Florida
Turf
scenario.
Effects
values
on
the
PBO
formulation
were
Daphnia
magnia
EC50
=
6.7
ug/
L
and
mysid
shrimp
LC50
=
0.14
ug/
L.
Droplet
size
50
:
m,
Boom
height
150
ft,
Application
Rate
0.0025
lb
a.
i./
A
EECs
(:
g/
L
)
Freshwater
invertebrates
Estuarine/
marine
invertebrates
Depth
of
water
body
peak
Daphnia
magna
Acute
RQ
Formulation
Mysid
Shrimp
Acute
RQ
Formulation
Surface
Water
­
85­
6.6
feet
(
2
meters)
0.003
<
0.00
0.02
Table
43.
Surface
water
EECs
(
ppb)
and
RQs
for
ecological
risk
assessment
based
on
pyrethrin
use
on
Georgia
peaches
and
California
grapes,
and
buffer
zones
of
50,
100,
and
150
ft.
Results
using
average
KOC
=
35,170
Crop
Peak
EEC
(
ug/
L)
Acute
RQ
for
estuarine/
marine
invertebrates
exposed
to
pyrethrin,
based
on
an
LC50
of
0.14
:
g/
L
for
mysid
shrimp*

Standard
Aerial
Run,
With
Spray
Drift
Set
To
5%

Georgia
Peaches
0.656
4.69a,
b,
c
Idaho
Potatoes
0.366
2.61a,
b,
c
Special
Run,
With
Spray
Drift
Set
To
1%,
Ground
Application
Georgia
Peaches
0.421
3.01a,
b,
c
Idaho
Potatoes
0.082
0.58a,
b,
c
Special
Run,
With
Spray
Drift
Set
To
0%

Georgia
Peaches
0.344
N/
A
Idaho
Potatoes
0.042
N/
A
High
end,
release
height
15
ft,
wind
speed
15
mph,
very
fine
droplets
Buffer
Zone
0
ft,
24.0%
spray
drift
for
GA
peaches/
31.2%
spray
drift
for
ID
potatoes
Georgia
peaches
1.681
12.01a,
b,
c
Table
43.
Surface
water
EECs
(
ppb)
and
RQs
for
ecological
risk
assessment
based
on
pyrethrin
use
on
Georgia
peaches
and
California
grapes,
and
buffer
zones
of
50,
100,
and
150
ft.
Results
using
average
KOC
=
35,170
Crop
Peak
EEC
(
ug/
L)
Acute
RQ
for
estuarine/
marine
invertebrates
exposed
to
pyrethrin,
based
on
an
LC50
of
0.14
:
g/
L
for
mysid
shrimp*

­
86­
Idaho
Potatoes
2.259
16.14a,
b,
c
Buffer
Zone
50
ft/
16.8%
spray
drift
for
GA
peaches/
23.1%
spray
drift
for
ID
potatoes
Georgia
peaches
1.436
10.26a,
b,
c
Idaho
Potatoes
1.673
11.95a,
b,
c
Buffer
Zone
100
ft,
12.7%
spray
drift
for
GA
peaches/
18.4%
spray
drift
for
ID
potatoes
Georgia
Peaches
1.164
8.31a,
b,
c
Idaho
Potatoes
1.333
9.52a,
b,
c
Buffer
Zone
150
ft,
10.2%
spray
drift
for
GA
peaches/
15.4%
spray
drift
for
ID
potatoes
Georgia
Peaches
0.998
7.13a,
b,
c
Idaho
Potatoes
1.116
7.97a,
b,
c
Low
end,
release
heigh
8
ft,
wind
speed
3
mph,
medium
to
coarse
droplets
Buffer
Zone
0
ft,
2.8%
spray
drift
for
GA
peaches/
3.0%
spray
drift
for
ID
potatoes
Georgia
Peaches
0.519
3.71a,
b,
c
Idaho
Potatoes
0.223
1.59a,
b,
c
Buffer
Zone
50
ft,
1.4%
spray
drift
for
GA
peaches/
1.5%
spray
drift
for
ID
potatoes
Georgia
Peaches
0.431
3.08a,
b,
c
Idaho
Potatoes
0.115
0.82a,
b,
c
Buffer
Zone
100
ft,
1.1%
spray
drift
for
GA
peaches/
1.1%
spray
drift
for
ID
potatoes
Georgia
Peaches
0.413
2.95a,
b,
c
Idaho
Potatoes
0.087
0.62a,
b,
c
Buffer
Zone
150
ft,
0.9%
spray
drift
for
GA
peaches/
0.8%
spray
drift
for
ID
potatoes
Georgia
Peaches
0.400
2.86a,
b,
c
Idaho
Potatoes
0.067
0.48
b,
c
Table
43.
Surface
water
EECs
(
ppb)
and
RQs
for
ecological
risk
assessment
based
on
pyrethrin
use
on
Georgia
peaches
and
California
grapes,
and
buffer
zones
of
50,
100,
and
150
ft.
Results
using
average
KOC
=
35,170
Crop
Peak
EEC
(
ug/
L)
Acute
RQ
for
estuarine/
marine
invertebrates
exposed
to
pyrethrin,
based
on
an
LC50
of
0.14
:
g/
L
for
mysid
shrimp*

­
87­
Based
on
1­
in­
10
year
exceedance
probability
(
0.10).
Peak
EEC's
provided
with
three
decimal
points
for
information
only.
*
Mysid
shrimp
was
the
most
sensitive
aquatic
species.
aRQ
meets
or
exceeds
LOC
for
acute
high
risk
(
LOC
=
0.5)
bRQ
meets
or
exceeds
LOC
for
acute
restricted
risk
(
LOC
=
0.1)
cRQ
meets
or
exceeds
LOC
for
acute
endangered
species
risk
(
LOC
=
0.05).

"
Down­
the­
Drain"
Exposure:
Acute
and
Chronic
Risk
The
Agency
has
assumed
that
many
of
the
indoor
uses
of
pyrethrin
should
not
impact
ecological
systems
because
of
their
reduction
in
exposure
potential.
Pyrethrin
is
used
in
various
household
products,
such
as
pyrethrin­
containing
prescription
drugs,
over
the
counter
drugs,
and
pet
products
(
like
shampoo),
available
to
the
US
consumers.
Potential
release
of
pyrethrin
in
the
domestic
wastewater
(
referred
to
as
"
down­
the­
drain"
release)
may
occur
from
using
these
household
products.
The
information
on
the
amount
of
pyrethrin
utilized
on
each
of
these
uses
is
considered
Confidential
Business
Information
and
cannot
be
provided
in
this
report,
but
it
is
stressed
that
these
uses
are
of
concern
and
included
in
The
Agency's
assessment.
The
risk
to
aquatic
systems
from
products
that
pass
through
wastewater
treatment
plants
and
the
eventual
potential
exposure
to
aquatic
organisms
was
assessed.
This
assessment
suggests
that
pyrethrin
residues
released
to
aquatic
areas
from
this
process
should
not
cause
acute
or
chronic
risk
to
freshwater
or
estuarine/
marine
fish
and
invertebrates
(
Tables
44
and
45).
­
88­
Table
44.
Acute
and
chronic
RQs
for
freshwater
and
estuarine/
marine
fish
associated
with
"
downthe
drain"
uses
of
pyrethrins
based
on
rainbow
trout
LC50
=
5.1
ug/
L,
fathead
minnow
NOAEC
=
1.9
ug/
L,
sheepshead
minnow
LC50
=
16.0
ug/
L,
and
extraoplated
NOAEC
sheepshead
minnow
5.9
ug/
L.
EEC
values
are
generated
from
PRZM/
EXAMS.

EECs
(:
g/
L
)

Scenario
(
state/
crop)
Peak
Chronic
Freshwater
Fish
(
Rainbow
Trout)
Acute
RQ
TGAI
Freshwater
Fish
(
Fathead
Minnow)
Chronic
RQ
TGAI
Estuarine/
marine
Fish
(
Sheepshea
d
Minnow)
Acute
RQ
TGAI
Estuarine/
marine
Fish
(
Sheepshead
Minnow)
Chronic
RQ
TGAI
"

downthe
drain"
0.00242
0.000186
<
0.00
<
0.00
<
0.00
<
0.00
aRQ
exceeds
LOC
for
acute
endangered
species
($
0.05).
bRQ
exceeds
LOC
for
acute
restricted
use
($
0.1).
C
The
NOAEC
estimated
for
the
sheepshead
minnow
is
based
on
the
acute­
to­
chronic
ratio
method,
determined
by
the
following
mathematical
relationship:
Freshwater
LC50
(
5.1)
/
Freshwater
NOAEC
(
1.9)
=
Estuarine/
marine
LC50
(
16.0
ppb)/
X
(
estimated
value
for
estuarine/
marine
NOAEC).

Table
45.
Acute
and
chronic
RQs
for
freshwater
and
estuarine/
marine
invertebrates
associated
with
`
down­
the­
drain"
uses
of
pyrethrins
based
on
Daphnia
magna
EC50
=
11.6
ug/
L,
Daphnia
magna
NOAEC
=
0.86
ug/
L,
mysid
shrimp
EC50
=
1.4
ug/
L,
and
extraoplated
NOAEC
mysid
shrimp
0.10
ug/
L.
EEC
values
are
generated
from
PRZM/
EXAMS.

EECs
(:
g/
L
)

Scenario
(
state/
crop)
peak
chronic
Freshwater
Invertebrate
(
Daphnia
magna)
Acute
RQ
TGAI
Freshwater
Invertebrate
(
Daphnia
magna)
Chronic
RQ
TGAI
Estuarine/
marine
Invertebrate
(
Mysid
Shrimp)
Acute
RQ
TGAI
Estuarine/
marine
Invertebrate
(
Mysid
Shrimp)
Chronic
RQ
TGAI
"
down­
thedrain
0.00242
0.000186
<
0.00
<
0.00
<
0.00
<
0.00
aRQ
exceeds
LOC
for
acute
endangered
species
($
0.05).
bRQ
exceeds
LOC
for
acute
restricted
use
($
0.1).
cRQ
exceeds
LOC
for
acute
high
risk
($
0.5).
d
The
NOAEC
estimated
for
the
Mysid
shrimp
is
based
on
the
acute­
to­
chronic
ratio
method,
determined
by
the
following
mathematical
relationship:
Freshwater
LC50
(
11.6
ppb)/
Freshwater
NOAEC
(
0.86
ppb)
=
Estuarine/
marine
LC50
(
1.4
ppb)/
X
(
estimated
value
for
estuarine/
marine
NOAEC).
­
89­
b.
Sediment
Organisms
The
pyrethrins
are
lipophilic
compounds
that
can
adsorb
readily
to
particulate
and
sediment,
thus
possibly
limiting
its
exposure
to
aquatic
life
in
the
water
column
but
increasing
toxic
exposure
in
the
benthos.
Sediment
can
act
as
a
reservoir
for
lipophilic
persistent
compounds.
Exposure
to
this
sediment
can
result
in
a
direct
impact
to
aquatic
life
through
respiration,
ingestion,
dermal
contact,
as
well
as
indirect
impact
through
alterations
of
the
food
chain.
In
order
to
evaluate
this
possible
concern
the
USEPA
Office
of
Water
(
OW)
has
developed
the
Equilibrium
Partitioning
Sediment
Guidelines
(
ESG).
The
EFED
used
the
Equilibrium
Partitioning
Guidelines,
which
are
based
on
the
hydrophobicity
and
concentrations
of
the
chemical
normalized
to
organic
carbon
(
OC)
in
sediment
(
De
Toro
et
al.
1991),
to
estimate
sediment
concentrations
and
sediment
dwellers
toxicity.

Since,
EFED
uses
a
deterministic
method
for
its
screening
level
risk
assessment,
the
calculation
of
risk
quotient
values
(
RQ)
is
important
for
assessing
possible
risk.
The
RQ
values
are
calculated
by
taking
the
ratio
of
the
estimated
exposure
concentrations
(
EEC)
to
the
toxicity
effect
value
(
e.
g.,
LC50,
NOAEC).
The
EEC
values
are
model
generated
(
e.
g.
by
PRZM/
EXAMS).
However,
the
PRZM/
EXAMS
output
produces
water
column
EEC
values,
as
well
as
sediment
and
pore
water
EEC
values.
Therefore,
in
order
to
assess
possible
toxic
pesticide
exposure
to
aquatic
organisms
from
sediments,
EFED
used
the
PRZM/
EXAMS
model
which
incorporates
the
principles
of
the
equilibrium
partitioning
theory,
in
order
to
generate
EECs
from
sediment
and
pore
water.
By
relying
on
sediment
and/
or
pore
water
output
values.

The
calculations
that
rely
on
pore
water
were
calculated
by
dividing
the
PRZM/
EXAMS
output
value
for
pore
water
concentrations
by
the
dissolved
concentrations
in
the
water
column
that
caused
toxicity
in
bioassays
(
e.
g.,
LC50).

EEC
pore
water
ug/
L
/
LC50
ugL
For
the
scenarios
modeled
in
this
assessment
on
pyrethrins,
the
benthic
pore
water
concentrations
(
EECpore)
are,
on
average,
estimated
to
be
approximately
60%
lower
than
the
surface
water
concentrations
using
PRZM/
EXAMS.
Therefore,
the
RQsed
value
is
generally
60%
lower
than
the
RQaq
value
for
the
same
scenario
and
effects
endpoint.

The
Agency
evaluated
the
potential
for
acute
and
chronic
risk
from
sediments
that
could
act
as
a
repository
for
pyrethrin
residues.
Table
46
shows
that
there
are
estimated
acute
risk
concerns
to
estuarine/
marine
invertebrates
(
restricted
use,
RQ
range
0.10
to
0.15)
as
noted
in
the
scenarios
that
represent
MS
cotton,
ME
potato,
and
IL
corn
(
endangered
species
risk
concerns
(
RQ
range
0.05
to
0.15
for
ND
wheat,
PA
tomato,
MS
cotton,
ME
potato,
and
IL
corn
were
calculated
but
the
Agency
acknowledges
that
currently
there
are
no
endangered
estuarine/
marine
invertebrates
listed).
Table
47
shows
the
potential
for
chronic
risks
to
estuarine/
marine
sediment
dwelling
invertebrates.
In
the
absence
of
chronic
data
for
estuarine/
marine
invertebrates,
the
NOAEC
estimated
for
estuarine/
marine
invertebrates
that
was
used
to
estimate
risk
to
invertebrates
in
the
water
column
was
also
used
for
sediment.
The
chronic
LOCs
were
exceeded
for
estuarine/
marine
organisms
associated
with
the
agricultural
uses
(
RQ
range
=
1.1
to
2,
Crops:
PA
tomato,
MS
cotton,
ME
potato,
and
IL
corn).
There
are
no
chronic
risks
to
freshwater
sediment­
dwelling
invertebrates
associated
with
the
agricultural
uses.
­
90­
Table
46.
Acute
Risk
Estimation
to
freshwater
and
estuarine/
marine
sediment­
dwelling
organisms
based
on
data
from
the
surrogate
species,
Daphnia
magna
(
EC50
=
11.6
:
g/
L
)
and
Mysid
Shrimp
(
LC50
=
1.4
:
g/
L).
EEC
values
reflect
pore
water
estimates
that
are
in
equilibrium
with
sediment
concentrations
(
KOC
of
35,170
L/
kg)
as
generated
from
PRZM/
EXAMS
for
the
agricultural
crop
uses.

Scenario
EEC
Acute
RQ
Pore
water
peak
(:
g/
L)
Sediment
(:
g/
kgoc)
Freshwater
TGAI
Estuarine/
marine
TGAI
IL
corn
0.21
7350
0.02
0.15ab
ME
potato
0.16
5590
0.01
0.11ab
MS
cotton
0.14
4820
0.01
0.10ab
PA
tomato
0.12
4110
0.01
0.09a
ND
wheat
0.07
2390
0.01
0.05a
CA
onion
0.06
2110
0.01
0.04
NC
apple
0.06
2110
0.01
0.04
OR
snapbeans
0.05
1650
<
0.01
0.04
ID
potato
0.04
1350
<
0.01
0.03
MN
alfalfa
0.04
1270
<
0.01
0.03
FL
citrus
0.04
1270
<
0.01
0.03
GA
peaches
0.04
1370
<
0.01
0.03
CA
grapes
0.03
1020
<
0.01
0.02
aRQ
exceeds
LOC
for
acute
endangered
species
($
0.05).
bRQ
exceeds
LOC
for
acute
restricted
($
0.1)
­
91­
Table
47.
Chronic
Risk
Estimation
to
freshwater
and
estuarine/
marine
sediment­
dwelling
organisms
based
on
data
from
the
surrogate
species,
Daphnia
magna
(
NOAEC
=
0.86
:
g/
L
)
and
Mysid
Shrimp
(
NOAEC
=
0.10
:
g/
L
).
EEC
values
reflect
pore
water
estimates
that
are
in
equilibrium
with
sediment
concentrations
(
KOC
of
35,170
L/
kg)
as
generated
from
PRZM/
EXAMS
for
the
agricultural
crop
uses.

Scenarios
EECs
Chronic
RQ
Pore
water
21­
day
(:
g/
L)
Sediment
(:
g/
kg)
Freshwater
Estuarine/
marine
IL
corn
0.20
7170
0.23
2
ME
potato
0.15
5420
0.17
1.5
MS
cotton
0.13
4640
0.15
1.3
PA
tomato
0.11
3900
0.13
1.1
ND
wheat
0.07
2290
0.08
0.7
CA
onion
0.07
2290
0.08
0.7
NC
apple
0.06
2040
0.07
0.6
OR
snapbeans
0.05
1620
0.06
0.5
ID
potato
0.04
1300
0.05
0.4
MN
alfalfa
0.04
1230
0.05
0.4
FL
citrus
0.04
1230
0.05
0.4
GA
peaches
0.04
1340
0.05
0.4
CA
grapes
0.03
985
0.03
0.3
2.
Non­
target
Terrestrial
Animals
a.
Mammals
Table
19
provides
acute
and
chronic
risk
quotient
(
RQ)
values
for
mammals
of
different
body
weight
size
classes
exposed
to
different
forage
items.
Using
the
foliar
half­
life
of
1
and
14
days,
the
acute
RQs
are
all
mammals
(
listed
and
non­
listed)
are
less
than
the
LOC
of
0.1.
All
chronic
RQs
for
listed
and
nonlisted
mammals
exposed
to
pyrethrins
in
all
dietary
scenarios
are
below
the
LOCs.
Both
scenarios
(
1
­
3
day
interval)
using
the
typical
application
rate
are
depicted
in
Table
19.
­
92­
Table
48.
Acute
and
chronic
RQ
calculations
for
mammalian
consumption
of
plant
and
insect
forage
material.
The
RQs
are
based
on
acute
LD50
of
700
mg/
kg
body
weighta
and
an
NOAEC
of
100
ppm
diet
in
rats
(
Rattus
norvegicus).
RQ
values
were
calculated
for
two
foliar
dissipation
residue
half­
lives
as
found
in
Willis
and
McDowell,
(
1987)
for
surrogate
pyrethroids,
phenothrin
and
pyrethrin.

Crop
application
rate
(
lbs
ai/
A;
no.
app.)
Forage
item
Maximum
EEC
(
ppm)
Acute
RQsb
Chronic
RQsb
15
g
35
g
1000
g
Various
crops
0.050
(
10),
interval
between
applications
1
day
Short
grass
23.98
­
97.01
0.06
0.05
0.03
0.97
Tall
grass
10.99
­
44.46
0.03
0.02
0.01
0.44
Broadleaf/
forage
plants
and
small
insects
13.49
­
55.57
0.03
0.03
0.02
0.55
Fruits/
pods/
seeds/
large
insects
1.50
­
6.06
0.0
0.0
0.0
0.06
Various
crops
0.050
(
10),
typical
interval
between
applications
3
day
Short
grass
13.71
­
67.25
0.01
­
0.04
0.1
­
0.04
0.0
­
0.02
0.67
Tall
grass
6.29
­
30.82
0.0
­
0.02
0.0
­
0.02
0.0
­
0.01
0.31
Broadleaf/
forage
plants
and
small
insects
7.71
­
37.83
0.0
­
0.02
0.0
­
0.02
0.0
­
0.01
0.38
Fruits/
pods/
seeds/
large
insects
0.86
­
4.20
0.0
0.0
0.0
0.04
aThe
acute
mammalian
LD50
is
based
on
female
mortality
of
rats
exposed
to
FEK­
999;
the
LD50
for
male
rats
in
the
same
study
was
reported
as
2,140
mg/
kg
body
weight,
suggesting
a
gender­
specific
difference
for
acute
effects
(
mortality)
of
a
factor
of
3.
b
RQ
calculated
for
foliar
dissipation
residue
half­
lives
of
1
and
14
days.
respectively
b.
Birds
Table
20
provides
acute
and
chronic
risk
quotient
(
RQ)
values
for
avian
food
items
following
application
of
pyrethrins
under
a
maximum
use
pattern
for
various
crop
species.
An
analysis
of
the
results
indicates
that
avian
acute,
restricted
use,
chronic
and
endangered
species
LOCs
are
not
exceeded
at
registered
maximum
application
rates
for
pyrethrins.
Chronic
risk
to
avian
species
was
estimated
by
using
pyrethrin
avian
NOAEC
for
Bobwhite
quail.(
NOAEC
=
125
mg/
kg/
diet)..
­
93­
Table
49.
Acute
RQ
calculations
for
bird
consumption
of
plant
and
insect
forage
material.
The
RQs
are
based
on
a
dietary
LC50
of
5,620
mg/
kg
diet
with
the
bobwhite
quail
(
Colinus
virginianus)
and
mallard
duck
(
Anas
platyrhynchos)
a.
RQ
values
were
calculated
for
two
foliar
dissipation
residue
half­
lives
as
found
in
Willis
and
McDowell,
(
1987)
for
surrogate
pyrethroids,
phenothrin
and
pyrethrin.

Crop
application
rate
(
lbs
ai/
A;
no.
appl.)
Forage
item
Maximum
EEC
(
ppm)
Acute
RQb
Chronic
RQbc
Various
crops
0.050
(
10),
interval
between
applications
1
day
Short
grass
23.98
­
97.01
0.0­
0.02
0.02
­
0.78
Tall
grass
10.99
­
44.46
0.0
­
0.01
0.09
­
0.36
Broadleaf/
forage
plants
and
small
insects
13.49
­
55.57
0.0
­
0.01
0.11­
0.44
Fruits/
pods/
seeds/
large
insects
1.50
­
6.06
0.0
0.01­
0.05
Various
crops
0.050
(
10),
typical
interval
between
applications
3
days
Short
grass
13.71
­
67.25
0.0
­
0.01
0.11
­
0.54
Tall
grass
6.29
­
30.82
0.0
­
0.01
0.05
­
0.25
Broadleaf/
forage
plants
and
small
insects
7.71
­
37.83
0.0
­
0.01
0.06
­
0.30
Fruits/
pods/
seeds/
large
insects
0.86
­
4.20
0.0
0.01
­
0.03
aThe
acute
toxicity
is
reported
as
LC50
>
5,620
mg/
kg
diet,
suggesting
that
the
actual
LC50
was
not
determined
by
the
dosing
regimen.
Use
of
this
toxicity
value
will
likely
overestimate
acute
risks.
b
RQ
calculated
for
foliar
dissipation
residue
half­
lives
of
1
and
14
days.
respectively
c
Avian
chronic
toxicity
was
substituted
with
a
NOAEC
from
pyrethrin
c.
Insects
Currently,
EFED
does
not
assess
risk
to
non­
target
insects.
Results
of
acceptable
studies
are
used
for
recommending
appropriate
label
precautions.
Pyrethrins
are
very
toxic
to
honeybees.
Therefore,
honeybees
and
other
beneficial
insects
are
expected
to
be
at
risk
based
on
aerial
applications
that
may
cause
wind
dispersal
of
pyrethrins
to
areas
where
these
insects
may
pollinate
and/
or
feed.

3.
Non­
target
Terrestrial
and
Semi­
aquatic
Plants
Since
toxicity
data
were
unavailable
for
non­
target
plants,
risks
were
not
calculated.

B.
Risk
Description
­
Interpretation
of
Effects
Pyrethrins
are
the
active
insecticidal
components
of
certain
species
of
chrysanthemum
plants
that
have
been
used
as
insecticides
for
at
least
two
centuries.
These
compound
are
moderately
persistent,
bind
to
soils
(
Koc
=
35,170)
in
the
environment
but
are
unstable
to
sunlight.
The
degradation
products
of
­
94­
pyrethrin
occur
as
a
result
of
ester
bond
breakage
resulting
in
carboxylic
acid
and
an
alcohol.
Data
on
the
toxicity
of
the
degradates
were
not
available
for
this
review,
but
because
of
the
disruption
of
the
parent
backbone
structure
during
break­
down,
EFED
assumes
a
decrease
in
effective
toxicity.
One
of
the
major
insecticidal
advantages
of
pyrethrin
is
their
"
knockdown"
action
that
induces
paralysis
in
target
organisms
which
is
in
contrast
to
their
relatively
lower
killing
potential
(
parent
can
be
metabolized).
However,
in
order
to
delay
this
metabolic
action
(
help
inhibit
microsomal
enzyme
breakdown)
and
enhance
lethality,
pyrethrins
are
often
used
in
combination
with
other
pesticides
and
synergists
(
such
as
piperonyl
butoxide).
However,
for
the
purposes
of
this
review
only
risk
to
the
parent
compound
will
be
assessed
(
exception
is
the
evaluation
for
mosquito
abatement
where
a
formulation
is
used).

1.
Estimating
Risk
to
Aquatic
Systems
EFED
risk
assessment
of
pyrethrin
shows
that
a
major
risk
of
the
chemical
exposure
in
the
environment
can
be
focused
on
aquatic
systems.
The
evaluation
of
this
risk
to
aquatic
organisms
was
approached
by
dividing
aquatic
systems
into
two
very
general
parts
or
media;
water
column
and
the
benthos.
The
first
portion
is
the
water
column,
which
is
defined
as
the
aquatic
area
between
surface
and
benthos
(
6"
above
the
bottom).
Organisms
living
in
this
area
are
free
swimming
and
can
feed
and
breed
at
the
surface,
mid
water
and/
or
on
the
benthos.
Direct
pesticidal
contact
(
e.
g.,
gill
lamella,
ingestion,
and
integument)
to
these
organisms
is
assumed
to
be
from
the
water
column
and
toxicity
assessment
points
are
the
acute
LC50
and
chronic
NOAEC
that
are
generated
through
standard
water
column
toxicity
tests.
The
second
aquatic
compartment
is
the
benthos
which
is
composed
of
sediments
and
the
area
six
inches
above
the
sediment
(
epibenthos).
The
benthos
is
composed
of
a
diversity
of
aquatic
invertebrates
(
e,
g,,
insect
larvae,
crustaceans,
mollusks),
species
of
fish
(
e.
g.,
catfish,
loach),
as
well
as
certain
critical
life
stages
of
organisms
that
reside
in
the
water
column;
the
benthos
is
also
the
initial
nursery
area
for
several
species
of
fish
especially
commercial
species
such
as
salmonids.
The
benthos
can
also
be
a
source
of
food
items
for
several
species
of
fish
(
i.
e.,
water
column)
actively
feeding
on
the
organisms
in
the
sediment
and/
or
capturing
organisms
that
are
emerging
from
this
area.

In
order
to
evaluate
the
potential
for
toxic
risk
from
pyrethrin
exposure
in
the
water
column,
EFED
used
the
standard
model
generated
EEC
ratio
to
a
most
sensitive
endpoint
as
defined
from
LC50,
EC50,
or
NOAEC.
The
evaluation
of
toxic
risk
to
the
benthos
compartment
was
approached
by
assuming
equilibrium
partitioning
of
high
Koc
compounds
between
the
sediment
and
the
interstitial
water
(
i.
e.,
this
is
the
pore
water,
the
water
found
between
particulate
in
the
sediment).
The
EEC
for
pore
water
were
model
generated
(
PRZM/
EXAMS)
and
used
to
calculate
RQ
values.
Since,
sediment
toxicity
data
was
not
available
for
this
report,
EFED
relied
on
the
most
sensitive
water
column
values.
The
RQ
for
assessing
potential
risk
to
sediment
reflects
pore
water
EEC
values/
most
sensitive
water
column
toxicity
value.
EFED
assumes
that
there
is
no
difference
in
sensitivity
between
water
column
organisms
and
comparable
benthic
organisms
regarding
toxicity
to
pyrethrin.
These
assumptions
are
supported
by
the
EPA
Office
of
Water
which
uses
a
similar
approach
and
assumption
in
developing
sediment
guidelines
(
ESG)
for
the
protection
of
benthic
organisms
(
The
ESG
Technical
Document,
USEPA,
2000a).

a.
Estimating
Risk
to
Aquatic
Systems
(
Water
Column
Exposure)

In
evaluating
possible
pyrethrin
risk
to
aquatic
systems
from
use
on
agricultural
crops,
the
Agency
chose
to
evaluate
maximum
and
typical
application
rates.
Model
generated
exposure
values
suggests
that
maximum
rates
can
result
in
acute
risk
to
fish
and
aquatic
invertebrates
(
freshwater
and
estuarine/
marine)
with
triggers
that
included
restrictive
use
and
endangered
species
concern
(
although
­
95­
estuarine/
marine
endangered
invertebrate
was
triggered,
EFED
realizes
that
at
this
time
there
are
no
listed
species
under
this
category).
Evaluating
chronic
risk
from
this
exposure
scenario
showed
that
LOC
triggers
were
exceeded
for
estuarine/
marine
invertebrates,
while
fish
(
freshwater
and
estuarine/
marine)
and
freshwater
invertebrates
may
not
be
at
chronic
risk
from
pyrethrin
exposure
in
the
water
column.
This
potential
for
acute
and
chronic
risk
reflects
exposure
from
large
acreage
crops
such
as
corn,
cotton,
wheat
and
orchards
(
e.
g.,
pome
fruit
and
stone
fruits).
Concern
from
citrus
use
appears
to
be
reflected
in
possible
acute
risk
to
estuarine/
marine
fish
and
invertebrates,
as
well
as
chronic
risk
to
estuarine/
marine
invertebrates.
The
risk
quotients
for
some
of
the
crop
scenarios
may
not
necessarily
be
the
most
conservative
because
certain
crop
scenarios
(
i.
e.
alfalfa)
are
grown
more
than
once
per
year.
This
assessment
assumed
a
single
season
per
year.

The
second
scenario
that
depicts
typical
application
rate
appears
to
have
the
potential
to
reduce
risk
to
aquatic
systems.
Evaluation
of
four
crop
scenarios
using
the
TGAI
(
ID
potatoes,
PA
tomatoes,
CA
onions,
OR
snap
beans)
suggests
that
LOCs
for
freshwater
and
estuarine/
marine
fish
and
invertebrates
should
not
be
exceeded
if
typical
application
rate
is
used.
The
Agency
also
assessed
the
maximum
and
typical
rates
for
a
pyrethrin
formulation
with
PBO
but
only
evaluated
acute
exposure
to
aquatic
organisms.
The
calculated
EECs
show
that
acute
risk
from
the
maximum
formulation
rate
appeared
to
be
higher
than
risk
calculated
only
from
the
TGAI.
This
evaluation
showed
that
acute
risk
from
the
formulation
was
about
2­
7X
greater
for
freshwater
and
estuarine/
marine
fish
and
about
10X
greater
for
estuarine/
marine
invertebrates.
However,
the
typical
formulation
rate
appears
to
reduce
the
risk
(
freshwater
and
estuarine/
marine
fish
and
freshwater
invertebrates),
but
this
reduction
in
exposure
still
presents
the
potential
for
acute
high,
acute
restrictive,
and
chronic
risk
to
estuarine/
marine
invertebrates
species.

b.
Estimating
Risk
to
Aquatic
Systems
(
Sediment
Exposure)

The
sediment
scenario
(
high
pest
pressure
application
intervals,
1
day)
modeled
in
this
assessment
showed
that
the
benthic
pore
water
concentrations
(
EECpore)
are
about
60%
lower
than
the
water
column
levels
using
the
PRZM/
EXAMS
model.
This
decrease
in
concentration
levels
suggests
lower
risk
potential.
Acute
risk
to
freshwater
sediment
dwelling
invertebrates
appears
to
be
below
our
LOC
for
all
crop
scenarios,
while
RQ
values
calculated
for
some
crops
(
e.
g.,
corn,
potatoes,
cotton,
tomatoes,
and
wheat)
suggest
acute
risk
to
estuarine/
marine
benthic
invertebrates.
However,
realistically
the
extent
of
this
acute
risk
depends
on
the
proximity
of
these
crops
to
estuatrine/
marine
environments;
wheat
acreage
is
not
usually
found
in
coastal
areas,
while
tomatoes,
cotton,
potatoes
and
corn
acreage
may
overlap
this
area
of
concern
in
costal
states.
Although
acute
risk
may
appear
to
be
low
for
freshwater
and
estuarine/
marine
invertebrates,
calculated
chronic
RQs
for
estuarine/
marine
sediments
show
LOC
exceedances
for
these
crops
(
corn,
potatoes,
cotton,
tomatoes)
and
suggest
that
there
could
be
the
potential
for
chronic
risk
to
estuarine/
marine
invertebrates
that
may
be
directly
associated
with
these
sediments.

c.
Estimating
Risk
to
Aquatic
Systems
Through
Mosquito
Abatement
EFED
used
a
different
modeling
approach
to
evaluate
mosquito
abatement
(
description
of
modeling
scenario
in
Section
III.
B.
1.
b).
Mosquito
adulticides
are
applied
as
mists
(
very
small
droplet
sizes)
with
the
intent
that
the
pesticide
will
linger
in
the
air
as
a
fog
and
that
the
eventual
deposition
onto
the
surface
will
be
relatively
slow.
Therefore,
the
level
of
drift
can
be
substantial
and
has
the
potential
for
eventual
contact
with
adjacent
bodies
of
water.
Therefore,
in
order
to
estimate
risk
to
aquatic
systems,
EFED
­
96­
calculated
the
level
of
drift
for
such
special
circumstances
(
AGDISP),
and
the
EEC
values
for
bodies
of
water
of
various
depths
using
the
FL
turf
scenario
(
PRZM/
EXAMS).
The
toxicity
data
end
points
used
for
this
scenario
were
based
on
the
formulated
product
(
Pyrenone
Crop
spray).
Calculated
RQ
values
for
surface
water
EECs
ranged
in
depth
from
½
to
6.6
feet
and
suggest
that
this
use
pattern
should
not
cause
acute
risk
to
fish
(
freshwater
and
estuarine/
marine)
or
invertebrates
(
freshwater).
However,
there
is
the
potential
for
acute
risk
to
estuarine/
marine
invertebrates
like
shrimp
(
restrictive
use
category).

The
results
of
this
assessment
found
lower
concentrations
in
shallow
water
bodies
compared
to
deep
water
bodies.
This
may
be
partially
explained
by
three
reasons:
The
Henry's
Law
constant
suggests
a
potential
for
loss
of
pesticide
from
the
pond
via
volatilization.
Second,
with
a
very
high
KOC,
the
pyrethrin
tends
to
partition
towards
the
sediment.
This
equilibrium
will
occur
more
rapidly
in
shallow
waters
than
in
deeper
bodies
of
water.
Finally,
a
third
possible
explanation
is
the
short
aqueous
photolysis
half­
life
(
0.5
days)
for
pyrethrin.
When
a
chemical
has
a
short
half­
life
(
as
in
this
scenario)
and
it
is
concentrated
in
shallow
waters
(
i.
e.,
six
inches),
it
can
be
expected
to
photodegrade
more
readily
than
when
it
is
spread
throughout
a
deeper
water
column.
Light
is
not
expected
to
penetrate
into
depths
deeper
than
about
1
ft.

It
was
found
that
for
mosquito
control,
application
directions
in
the
label
are
insufficient
to
accurately
estimate
aquatic
exposures
that
result
from
application
of
pyrethrin
for
controlling
mosquitoes.
Limitations
(
as
opposed
to
recommendations)
on
product
labels
for
key
parameters
such
as
droplet
size,
wind
speed,
release
height,
application
interval,
and
number
of
applications
allowed
per
year
are
not
specified.
The
exposure
assessment
conducted
here
represents
the
water
concentrations
expected
from
a
typical,
low­
level
aerial
application.
Concentrations
resulting
from
actual
application
of
pyrethrin
for
mosquito
control
could
be
significantly
higher
than
modeled
concentrations
if
applicators
used
different
application
parameters.

It
was
also
found
that
the
shallow
pond
shows
the
lower
concentration,
possibly
due
to
partitioning
of
the
chemical
with
particulate
and
the
sediment.
Variables
that
have
a
high
impact
on
the
aquatic
EECs
are
the
boom
height
(
higher
boom
height,
the
lower
the
level
of
deposition),
the
droplet
size
(
the
smaller
droplets,
the
lower
the
levels
of
deposition),
the
wind
speed
(
too
low
wind
speeds
favor
higher
deposition),
and
obviously
the
application
rate
(
it
appears
that
for
many
of
the
products
the
maximum
application
rate
is
lower
than
the
maximum
application
rate
stated
in
the
Master
Label
[
0.0025
lb
a.
i./
A
vs
0.008
lb
a.
i./
A]).
The
interval
between
applications
and
the
number
of
applications
are
expected
to
also
have
an
effect
on
the
EECs
(
similar
to
an
agricultural
application).
In
general
the
Agency
evaluation
of
the
adulticide
scenario
using
maximum
and
typical
application
rates.
The
maximum
rate
showed
that
there
did
not
appear
to
be
the
potential
for
acute
risk
to
freshwater
fish
and
invertebrates
or
esrtuarine/
marine
fish.
However,
the
LOCs
for
estuarine/
marine
invertebrates
were
exceeded.
This
risk
to
estuarine/
marine
invertebrates
appeared
to
be
eliminated
if
the
boom
height
was
set
at
150
ft
and
the
droplet
size
was
at
40
um.
The
Agency
also
evaluated
the
typical
rate
and
found
that
potential
acute
risk
to
estuarine/
marine
invertebrates
could
be
eliminated
with
a
boom
height
of
75ft
and
a
50
um
droplet
size.

d.
Estimating
Risk
to
Aquatic
Systems
Through
"
Down­
the­
Drain"
Consideration
of
Exposure
from
Pyrethrin
Pharmacolsoticals.
­
97­
Pyrethrin
is
used
in
various
household
products,
such
as
pyrethrin­
containing
prescription
drugs,
over
the
counter
drugs,
and
pet
products
(
like
shampoo),
available
to
the
US
consumers.
Potential
release
of
pyrethrin
in
the
domestic
wastewater
system
(
referred
to
as
"
down­
the­
drain"
release)
may
occur
from
using
these
household
products.
The
information
on
the
amount
of
pyrethrin
utilized
on
each
of
these
uses
is
considered
Confidential
Business
Information
and
cannot
be
provided
in
this
report,
but
it
is
stressed
that
these
uses
are
of
concern
and
included
in
The
Agency's
assessment.
The
risk
to
aquatic
systems
from
products
that
pass
through
wastewater
treatment
plants
and
the
eventual
potential
exposure
to
aquatic
organisms
was
assessed.
This
assessment
suggests
that
pyrethrin
residues
released
to
aquatic
areas
from
this
process
should
not
cause
acute
or
chronic
risk
to
freshwater
or
estuarine/
marine
fish
and
invertebrates.

e.
Other
Special
Considerations
for
Evaluating
Aquatic
Risk
(
Buffer
Zones)

The
extent
to
which
spray
drift
may
be
an
important
component
of
the
concentrations
of
pyrethrins
reaching
bodies
of
water
adjacent
to
treated
areas
after
their
application,
was
investigated.
EFED
ran
four
crop
scenarios
with
spray
drift
set
to
0%
and
compared
the
results
to
the
corresponding
runs
with
spray
drift
set
to
5%.
The
runs
with
drift
set
to
0%
resulted
in
EECs
lower
than
the
standard
runs.
When
the
results
of
the
standard
run
(
5%
drift)
with
the
special
run
(
0%
drift),
it
was
found
that
the
level
of
the
peak
EEC
attributable
to
spray
drift
for
GA
peach
and
for
FL
citrus
was
near
46%,
while
for
ID
potato
and
CA
grapes
it
was
>
88%.
The
selection
of
crop
scenarios
was
then
narrowed
down
to
two.
These
scenarios
were
run
with
standard
input
for
ground
applications
and
with
various
buffer
zones.
This
was
done
to
see
the
possible
affects
of
buffer
zones
in
reducing
risk
from
pyrethrin
exposure
to
aquatic
systems.
The
level
of
spray
drift
simulated
both
a
high
end
drift
scenario
(
high
boom,
high
wind
speed,
small
droplet
size),
and
a
low
end
drift
scenario
(
low
boom
height,
low
wind
speed,
large
droplet
size),
to
bracket
the
spectrum
of
possibilities.
Calculated
RQ
values
for
buffer
zones
set
at
0,
50,
100,
and
150
feet
and
spray
drift
set
at
0,1
and
5%
showed
acute
risk
to
estuarine/
marine
invertebrates.
However,
as
expected,
the
low
end
drift
scenario
yielded
lower
levels
of
drift
and
consequently
lower
EECs
and
RQs.
Combined
with
large
buffer
zones
(
150
ft),
the
RQs
were
of
similar
order
of
magnitude
than
those
yielded
by
ground
applications.
It
is
also
noted
that
even
a
small
buffer
zone
of
50
ft
reduces
the
RQs
by
more
than
20%,
compared
to
the
same
conditions
with
no
buffer
zone
(
for
both
the
high
end
and
low
end
drift
scenarios).

2.
Estimating
Risk
to
Terrestrial
Organisms
(
Mammals
and
Birds)

An
evaluation
of
possible
risk
to
terrestrial
organisms
was
conducted
using
the
T­
REX
model
that
provides
estimates
of
concentrations
of
chemical
residues
on
different
types
of
food
items
that
may
be
sources
of
dietary
exposure
to
avian,
mammalian,
reptilian,
or
terrestrial­
phase
amphibian
receptors.
Acute
and
chronic
RQ
values
for
pyrethrin
exposure
from
various
food
items
to
mammals
of
different
weight
classes
were
calculated
using
foliar
dissipation
values
(
1
­
14
days)
found
in
Willis
and
McDowell,
(
1987)
for
pyrethroids
that
have
similar
chemistry
and
mode
of
action
as
pyrethrin
(
pyrethrin
and
phenothrin).
The
use
of
maximum
and
typical
application
rate
produced
acute
and
chronic
RQ
values
that
were
less
than
the
Agency's
LOC
for
risks
to
non­
listed
and
listed
species
mammalian
species
for
all
scenarios.

Acute
risk
quotient
(
RQ)
values
for
avian
food
items
following
application
of
pyrethrins
under
a
maximum
use
pattern
for
various
crop
species
and
foliar
dissipation
half­
life
of
1
­
14
days
were
also
­
98­
calculated.
An
analysis
of
these
results
show
that
avian
acute,
restricted
use
and
listed
species
LOCs
are
not
exceeded
at
registered
maximum
application
rates
for
pyrethrins.
Chronic
risk
to
avian
species
was
estimated
by
using
pyrethrin
NOAEC
=
500
mg/
kg/
diet
for
Bobwhite
quail.
Calculated
RQ
values
suggest
no
chronic
risk
to
listed
or
non­
listed
birds
or
mammals.

3.
Review
of
Incident
Data
Incident
reports
submitted
to
EPA
since
approximately
1994
have
been
tracked
by
assignment
of
incident
numbers
in
an
Incident
Data
System
(
IDS),
microfiched,
and
then
entered
to
a
second
database,
the
Ecological
Incident
Information
System
(
EIIS).
This
second
database
has
some
85
fields
for
potential
data
entry.
An
effort
has
also
been
made
to
enter
information
to
EIIS
on
incident
reports
received
prior
to
establishment
of
current
databases.
Incident
reports
are
not
received
in
a
consistent
format
(
e.
g.,
states
and
various
labs
usually
have
their
own
formats),
may
involve
multiple
incidents
involving
multiple
chemicals
in
one
report,
and
may
report
on
only
part
of
a
given
incident
investigation
(
e.
g.,
residues).
While
some
progress
has
been
made
in
recent
years,
both
in
getting
incident
reports
submitted
and
entered,
there
has
never
been
the
level
of
resources
assigned
to
incidents
that
there
has
been
to
the
tracking
and
review
of
laboratory
toxicity
studies,
for
example.

Incidents
entered
into
EIIS
are
categorized
into
one
of
several
certainty
levels:
highly
probable,
probable,
possible,
unlikely,
or
unrelated.
In
brief,
"
highly
probable"
incidents
usually
require
carcass
residues,
substantial
ChE
inhibition
in
avian
and/
or
mammalian
species,
and/
or
clear
circumstances
regarding
the
exposure.
"
Probable"
incidents
include
those
where
residues
were
not
available
and/
or
circumstances
were
less
clear
than
for
"
highly
probable."
"
Possible"
incidents
include
those
where
multiple
chemicals
may
have
been
involved
and
it
is
not
clear
what
the
contribution
was
of
a
given
chemical.
The
"
unlikely"
category
is
used,
for
example,
where
a
given
chemical
is
practically
nontoxic
to
the
category
of
organism
killed
and/
or
the
chemical
was
tested
for
but
not
detected
in
samples.
"
Unrelated"
incidents
are
those
that
have
been
confirmed
to
be
not
pesticide­
related.

Incidents
entered
into
the
EIIS
are
also
categorized
as
to
use/
misuse.
Unless
specifically
confirmed
by
a
state
or
federal
agency
to
be
misuse,
or
there
was
very
clear
misuse
such
as
intentional
baiting
to
kill
wildlife,
incidents
would
not
typically
be
considered
misuse.
Data
entry
personnel
often
do
not
have
a
copy
of
the
specific
label
used
in
a
given
application,
and
would
not
usually
be
able
to
detect
a
variety
of
label­
specific
violations,
for
example.

Of
the
11
reports
in
the
database,
all
but
one
incident
alleges
that
pyrethrins
caused
damage
to
non­
target
terrestrial
plants;
one
study
(
described
below)
associates
pyrethrin
use
with
effects
in
fish.
No
incidents
were
assigned
a
certainty
index
of
4
(
highly
probable).
In
addition,
most
of
these
incidents
involved
formulated
products
containing
a
very
low
concentration
of
pyrethrins
and
a
high
percentage
of
"
inert"
ingredients.
The
Agency
does
not
consider
pyrethrin
(
or
the
synergist
PBO)
to
have
phytotoxic
properties
and
assumes
that
the
reported
toxicity
to
terrestrial
plants
after
application
of
a
formulation
may
be
the
result
of
inerts
or
other
circumstances
associated
with
the
application.

Although
incidents
associated
with
pyrethroid
exposure
to
aquatic
systems
has
resulted
in
kills
to
aquatic
organisms
(
e.
g.,
pyrethrin,
cypyrethrin)
only
one
possible
incident
is
recorded
with
the
Agency
for
pyrethrin
(
noted
below).

However,
the
number
of
documented
kills
in
EIIS
are
believed
to
be
a
very
small
fraction
of
total
­
99­
mortality
caused
by
all
pesticides.
Mortality
incidents
must
be
seen,
reported,
investigated,
and
have
investigation
reports
submitted
to
EPA
to
have
the
potential
for
entry
into
the
database.
Incidents
often
are
not
seen,
due
to
scavenger
removal
of
carcasses,
decay
in
the
field,
or
simply
because
carcasses
may
be
hard
to
see
on
many
sites
and/
or
few
people
are
systematically
looking.
Poisoned
birds
may
also
move
off­
site
to
less
conspicuous
areas
before
dying.
Incidents
seen
may
not
get
reported
to
appropriate
authorities
capable
of
investigating
the
incident
because
the
finder
may
not
know
of
the
importance
of
reporting
incidents,
may
not
know
who
to
call,
may
not
feel
they
have
the
time
or
desire
to
call,
may
hesitate
to
call
because
of
their
own
involvement
in
the
kill,
or
the
call
may
be
long­
distance
and
discourage
callers,
for
example.
Incidents
reported
may
not
get
investigated
if
resources
are
limited
or
may
not
get
investigated
thoroughly,
with
residue
analyses,
for
example.
Also,
if
kills
are
not
reported
and
investigated
promptly,
there
will
be
little
chance
of
documenting
the
cause,
since
tissues
and
residues
may
deteriorate
quickly.
Reports
of
investigated
incidents
often
do
not
get
submitted
to
EPA,
since
reporting
by
states
is
voluntary
and
some
investigators
may
believe
that
they
don't
have
the
resources
to
submit
incident
reports
to
EPA.
An
effort
has
also
been
made
to
enter
information
to
EIIS
on
incident
reports
received
prior
to
establishment
of
current
databases.
Although
many
of
these
have
been
added,
the
system
is
not
yet
a
complete
listing
of
all
incident
reports
received
by
EPA.

In
addition,
there
are
a
number
of
uncertainties
associated
with
the
data
that
are
reported.
Incident
reports
are
not
received
in
a
consistent
format
(
e.
g.,
states
and
various
labs
usually
have
their
own
formats),
may
involve
multiple
incidents
involving
multiple
chemicals
in
one
report,
and
may
report
on
only
part
of
a
given
incident
investigation
(
e.
g.,
residues).
While
some
progress
has
been
made
in
recent
years,
both
in
getting
incident
reports
submitted
and
entered,
there
has
never
been
the
level
of
resources
assigned
to
incidents
that
there
has
been
to
the
tracking
and
review
of
laboratory
toxicity
studies,
for
example.
This
adds
to
the
reasons
cited
above
for
why
EPA
believes
the
documented
kills
are
but
a
fraction
of
total
mortality
caused
by
pyrethrins.

a.
Incidents
Involving
Aquatic
Organisms
One
incident
involving
several
fish
killed
in
a
small
pond
was
investigated
in
Stanly
County,
NC
on
May
5,
1994.
A
homeowner
noticed
that
several
fish
in
the
pond
were
dead
and
asked
the
NC
Department
of
Agriculture
to
investigate.
It
was
determined
that
there
were
several
possible
causes
of
the
fish
kill.
On
April
30,
1994,
the
complainant's
dog,
which
had
recently
been
treated
with
flea
powder
containing
pyrethrins,
jumped
into
the
pond,
possibly
releasing
pyrethrins
to
the
water
and
resulting
in
the
fish
kill.
While
a
mixture
of
herbicides
(
2,4­
D,
Weedone
638,
and
glyphosate)
was
applied
to
land
adjacent
to
the
pond,
the
application
date
was
reported
as
May
10,
five
days
after
the
dead
fish
began
to
appear
in
the
pond.
No
information
is
available
regarding
applications
prior
to
the
incident
and
it
is
unlikely
that
the
herbicides
were
responsible
for
the
fish
kill.
Three
weeks
after
the
herbicides
were
applied,
analysis
of
the
pond
water
and
surrounding
vegetation
gave
negative
results
(
presumably
for
the
sprayed
herbicides
and
pyrethrins).

b.
Incidents
Involving
Terrestrial
Organisms
Although
the
Agency
believes
that
the
pyrethroid
in
general
are
non­
phytotoxic,
the
incident
(
certainty
index
score
=
3)
noted
for
pyrethrin
occurred
in
Kootenai
County,
ID
on
August
25,
1999,
and
involved
damage
to
12
of
14
rose
bushes,
sunflowers,
and
several
other
plants
that
were
treated
with
an
insecticide
containing
pyrethrins
and
piperonyl
butoxide.
All
other
incidents
of
plant
or
crop
damage
associated
with
pyrethrin
uses
were
listed
as
possible
(
certainty
index
score
=
2).
The
Agency
assumes
that
toxicity
­
100­
may
have
been
related
to
inerts
in
the
formulation
or
other
circumstances
related
to
application.

Table
38.
Incident
reports
involving
pyrethrins
in
chronological
order.

Location
and
incident
#
Date
Organisms
involved
Certainty
indexa
Descriptionb
NC
I003826­
024
5/
4/
1994
Aquatic
organisms
2
Fish
from
a
pond
died
after
possible
contamination
with
pyrethrins
WI
I007155­
181
5/
9/
1994
Terrestrial
plants
2
A
complaint
alleged
the
loss
of
10,000
peppers
as
a
result
of
spraying
with
Pyrenone
Crop
Spray
TN
I007340­
671
5/
13/
1998
Terrestrial
plants
2
Damage
to
an
edible
crop
may
have
occurred
following
application
of
Ortho
Tomato
and
Vegetable
Insect
Killer
TX
I007340­
672
5/
14/
1998
Terrestrial
plants
2
Damage
to
ornamentals
may
have
occurred
following
application
of
Ortho
Tomato
and
Vegetable
Insect
Killer
GA
I007340­
700
5/
26/
1998
Terrestrial
plants
2
Damage
to
edible
crops
may
have
occurred
following
application
of
Ortho
Tomato
and
Vegetable
Insect
Killer
WI
I008693­
046
4/
29/
1999
Terrestrial
plants
2
Damage
to
plants
may
have
occurred
following
application
of
Ortho
RosePride
Rose
and
Flower
Insect
Killer
CA
I008693­
047
4/
21/
1999
Terrestrial
plants
2
Damage
to
about
12
bushes
may
have
occurred
following
2
applications
of
Ortho
RosePride
Rose
and
Flower
Insect
Killer
ID
I009262­
095
8/
24/
1999
Terrestrial
plants
3
Damage
to
roses,
snapdragons,
sunflowers,
occurred
following
the
application
of
insecticide
containing
pyrethrins.

No
location
I009825­
002
8/
31/
1999
Terrestrial
plants
2
Damage
to
unspecified
plants,
occurred
following
the
application
of
insecticide
containing
pyrethrins.
Table
38.
Incident
reports
involving
pyrethrins
in
chronological
order.

Location
and
incident
#
Date
Organisms
involved
Certainty
indexa
Descriptionb
­
101­
FL
I009916­
023
2/
1/
2000
Terrestrial
plants
2
Damage
to
about
6
or
7
roses
may
have
occurred
following
applications
of
Ortho
RosePride
Rose
and
Flower
Insect
Killer
WI
I010017­
017
3/
7/
2000
Terrestrial
plants
2
Damage
to
ornamentals
occurred
2
weeks
following
the
application
of
Ortho
RosePride
Rose
and
Flower
Insect
Killer
aCertainty
index
scoring
reflects
the
likelihood
that
the
pesticide
was
responsible
for
the
alleged
damage.
Highly
probable
(
4);
Probable
(
3);
Possible
(
2);
Unlikely
(
1);
Unrelated
(
0).
b
All
events
are
related
to
exposure
from
formulated
products
that
contain
pyrethrins
+
piperonyl
butoxide.

4.
Endocrine
Effects
There
is
no
evidence
to
indicate
that
pyrethrin
exposure
results
in
endocrine
toxicity
in
mammalian
species.
Studies
on
the
effects
of
pyrethrins
on
avian
reproduction
were
not
submitted
to
the
Agency;
thus,
no
conclusion
can
be
made
regarding
the
potential
for
pyrethrins
to
cause
endocrine
disruption
in
avian
species.
Regarding
the
potential
for
pyrethrins
to
produce
endocrine
toxicity
in
aquatic
species,
reproductive
effects
were
observed
in
full
life­
cycle
studies
in
daphnids.
Exposure
to
2.0
ppb
resulted
in
reproductive
effects,
including
the
reduced
number
of
offspring
produced
per
adult.
A
chronic
early
life
stage
study
conducted
using
the
fathead
minnow
showed
that
exposure
to
3.0
ppb
significantly
reduced
hatching
success,
length
and
wet
weight
of
freshwater
fish.
Although
limited
information
is
available,
based
on
the
reproductive
effects
observed
in
freshwater
fish
and
daphnia,
pyrethrins
exhibited
effects
that
may
be
indicative
of
endocrine
disrupting
activity.

Under
the
Federal
Food,
Drug
and
Cosmetic
Act
(
FFDCA),
as
amended
by
the
Food
Quality
Protection
Act
(
FQPA),
EPA
is
required
to
develop
a
screening
program
to
determine
whether
certain
substances
(
including
all
pesticide
active
and
other
ingredients)
"
may
have
an
effect
in
humans
that
is
similar
to
an
effect
produced
by
a
naturally­
occurring
estrogen,
or
other
such
endocrine
effects
as
the
Administrator
may
designate."
Following
the
recommendations
of
its
Endocrine
Disruptor
Screening
and
Testing
Advisory
Committee
(
EDSTAC),
EPA
determined
that
there
was
scientific
basis
for
including,
as
part
of
the
program,
the
androgen­
and
thyroid
hormone
systems,
in
addition
to
the
estrogen
hormone
system.
EPA
also
adopted
EDSTAC's
recommendation
that
the
Program
include
evaluations
of
potential
effects
in
wildlife.
For
pesticide
chemicals,
EPA
will
use
FIFRA
and,
to
the
extent
that
effects
in
wildlife
may
help
determine
whether
a
substance
may
have
an
effect
in
humans,
FFDCA
authority
to
require
the
wildlife
evaluations.
As
the
science
develops
and
resources
allow,
screening
of
additional
hormone
systems
may
be
added
to
the
Endocrine
Disruptor
Screening
Program
(
EDSP).
When
the
appropriate
screening
and
or
testing
protocols
being
considered
under
the
Agency's
Endocrine
Disruptor
Screening
Program
have
been
developed,
pyrethrin
may
be
subjected
to
additional
screening
and
or
testing
to
better
characterize
effects
related
to
endocrine
disruption.
­
102­
5.
Threatened
and
Endangered
Species
Concerns
The
acute
level
of
concern
(
LOCs)
is
exceeded
for
endangered
and/
or
threatened
species
of
freshwater
fish
and
invertebrates
and
are
associated
with
the
agricultural
uses
of
pyrethrins.
Based
on
a
probit
slope
analysis
to
calculate
the
chance
of
an
individual
event
corresponding
to
the
freshwater
fish,
the
estimated
individual
mortality
associated
with
the
calculated
RQ
values
(
0.24
to
1.10)
range
from
1
in
3.34
x
1014
to
1
in
4.17
x
108
.
For
the
freshwater
invertebrate,
the
estimated
individual
mortality
associated
with
the
calculated
RQ
values
(
0.03
­
0.41)
range
from
1
in
1.0
x
1016
to
1
in
8.44
x
109.

The
acute
level
of
concern
(
LOCs)
is
exceeded
for
endangered
and/
or
threatened
(
listed)
species
of
estuarine/
marine
fish
and
invertebrates
that
live
in
the
water
column
and
are
associated
with
the
agricultural
and
mosquito
abatement
uses
of
pyrethrins.
For
estuarine/
marine
fish,
the
estimated
individual
mortality
associated
with
the
calculated
RQ
values
(
0.24
to
1.10
)
is
1.0
X
1016.
For
estuarine/
marine
invertebrates
for
agriculture
and
mosquito
abatement
uses,
the
probit
slope
analysis
was
completed
for
both
active
ingredient
and
formulated
product.
Based
on
the
default
slope
estimate
of
4.5,
the
corresponding
chance
of
individual
mortality
for
estuarine/
marine
invertebrates
following
exposure
from
the
formulation
is
1
in
4.17
x
108;
and
based
on
the
slope
estimate
of
4.1,
the
corresponding
chance
of
individual
mortality
for
estuarine/
marine
invertebrates
following
exposure
to
the
technical
grade
active
ingredient
is
1
in
2.08
x
107.

In
terrestrial
environments,
the
Agency
does
not
expect
acute
risk
concerns
for
endangered
mammals
or
avian
species.

Listed
Species
a.
Taxonomic
Groups
Potentially
at
Risk
For
the
aquatic
species
(
fish
and
invertebrates)
evaluated
in
this
risk
assessment,
the
acute
RQs
exceeded
the
LOC
for
listed
species
for
many
of
the
crop
uses
and
exposure
scenarios
considered.
The
registrant
must
provide
information
on
the
proximity
of
Federally
listed
endangered
species
to
the
pyrethrins
use
sites.
This
requirement
may
be
satisfied
in
one
of
three
ways:
1)
having
membership
in
the
FIFRA
Endangered
Species
Task
Force
(
Pesticide
Registration
Notice
2000­
2);
2)
citing
FIFRA
Endangered
Species
Task
Force
data;
or
3)
independently
producing
these
data,
provided
the
information
is
of
sufficient
quality
to
meet
FIFRA
requirements.
The
information
will
be
used
by
the
OPP
Endangered
Species
Protection
Program
to
develop
recommendations
to
avoid
adverse
effects
to
listed
species.

b.
Action
Area
For
listed
species
assessment
purposes,
the
action
area
is
considered
to
be
the
area
affected
directly
or
indirectly
by
the
Federal
action
and
not
merely
the
immediate
area
involved
in
the
action.
At
the
initial
screening­
level,
the
risk
assessment
considers
broadly
described
taxonomic
groups
and
so
conservatively
assumes
that
listed
species
within
those
broad
groups
are
collocated
with
the
pesticide
treatment
area.
This
means
that
terrestrial
plants
and
wildlife
are
assumed
to
be
located
on
or
adjacent
to
the
treated
site
and
aquatic
organisms
are
assumed
to
be
located
in
a
surface
water
body
adjacent
to
the
treated
site.
The
assessment
also
assumes
that
the
listed
species
are
located
within
an
assumed
area
which
has
the
relatively
highest
potential
exposure
to
the
pesticide,
and
that
exposures
are
likely
to
decrease
with
­
103­
distance
from
the
treatment
area.
Section
III
Analysis
(
A.
Use
Characterization)
of
this
risk
assessment
presents
the
pesticide
use
sites
that
are
used
to
establish
initial
collocation
of
species
with
treatment
areas.

If
the
assumptions
associated
with
the
screening­
level
action
area
result
in
RQs
that
are
below
the
listed
species
LOCs,
a
"
no
effect"
determination
conclusion
is
made
with
respect
to
listed
species
in
that
taxa,
and
no
further
refinement
of
the
action
area
is
necessary.
Furthermore,
RQs
below
the
listed
species
LOCs
for
a
given
taxonomic
group
indicate
no
concern
for
indirect
effects
upon
listed
species
that
depend
upon
the
taxonomic
group
covered
by
the
RQ
as
a
resource.
However,
in
situations
where
the
screening
assumptions
lead
to
RQs
in
excess
of
the
listed
species
LOCs
for
a
given
taxonomic
group,
a
potential
for
a
"
may
affect"
conclusion
exists
and
may
be
associated
with
direct
effects
on
listed
species
belonging
to
that
taxonomic
group
or
may
extend
to
indirect
effects
upon
listed
species
that
depend
upon
that
taxonomic
group
as
a
resource.
In
such
cases,
additional
information
on
the
biology
of
listed
species,
the
locations
of
these
species,
and
the
locations
of
use
sites
could
be
considered
to
determine
the
extent
to
which
screening
assumptions
regarding
an
action
area
apply
to
a
particular
listed
organism.
These
subsequent
refinement
steps
could
consider
how
this
information
would
impact
the
action
area
for
a
particular
listed
organism
and
may
potentially
include
areas
of
exposure
that
are
downwind
and
downstream
of
the
pesticide
use
site.

c.
Indirect
Effects
Analysis
The
Agency
acknowledges
that
pesticides
have
the
potential
to
exert
indirect
effects
upon
the
listed
organisms
by,
for
example,
perturbing
forage
or
prey
availability,
altering
the
extent
of
nesting
habitat,
and
creating
gaps
in
the
food
chain.
In
conducting
a
screen
for
indirect
effects,
direct
effect
LOCs
for
each
taxonomic
group
are
used
to
make
inferences
concerning
the
potential
for
indirect
effects
upon
listed
species
that
rely
upon
non­
endangered
organisms
in
these
taxonomic
groups
as
resources
critical
to
their
life
cycle.

Because
screening­
level
acute
RQs
for
mammals
exceed
the
listed
species
acute
LOCs,
the
Agency
uses
the
dose
response
relationship
from
the
toxicity
study
used
for
calculating
the
RQ
to
estimate
the
probability
of
acute
effects
associated
with
an
exposure
equivalent
to
the
EEC
(
see
Probit
Analysis
below).
This
information
serves
as
a
guide
to
establish
the
need
for
and
extent
of
additional
analysis
that
may
be
performed
using
Services­
provided
"
species
profiles"
as
well
as
evaluations
of
the
geographical
and
temporal
nature
of
the
exposure
to
ascertain
if
a
"
not
likely
to
adversely
affect"
determination
can
be
made.
The
degree
to
which
additional
analyses
are
performed
is
commensurate
with
the
predicted
probability
of
adverse
effects
from
the
comparison
of
the
dose
response
information
with
the
EECs.
The
greater
the
probability
that
exposures
will
produce
effects
on
a
taxa,
the
greater
the
concern
for
potential
indirect
effects
for
listed
species
dependent
upon
that
taxa,
and
therefore,
the
more
intensive
the
analysis
on
the
potential
listed
species
of
concern,
their
locations
relative
to
the
use
site,
and
information
regarding
the
use
scenario
(
e.
g.,
timing,
frequency,
and
geographical
extent
of
pesticide
application).

Probit
Slope
Analysis
The
probit
slope
response
relationship
is
evaluated
to
calculate
the
chance
of
an
individual
event
corresponding
to
the
listed
species
acute
LOCs.
If
information
is
unavailable
to
estimate
a
slope
for
a
particular
study,
a
default
slope
assumption
of
4.5
is
used
as
per
original
Agency
assumptions
of
typical
slope
cited
in
Urban
and
Cook
(
1986).
­
104­
Freshwater
fish
After
an
analysis
of
raw
data
from
the
acute
toxicity
studies
(
MRID
430823­
03
and
430823­
04)
with
Rainbow
Trout,
one
slope
estimate
was
determined.
A
default
slope
of
4.5
was
used
for
data
from
MRID
430823­
03
(
FEK­
99
as
active
ingredient)
and
a
slope
of
6
was
used
for
data
from
MRID
430823­
04
(
formulated
product,
pyrenone
crop
spray).
Based
on
the
default
slope
estimate
of
4.5,
the
corresponding
estimate
chance
of
individual
mortality
for
freshwater
fish
following
pyrethrins
exposure
is
1
in
4.17
x
108.
The
slope
from
the
other
study
(
MRID
430823­
04)
is
6
and
the
estimate
of
chance
of
individual
mortality
following
pyrethrins
exposure
is
1
in
3.34
X
1014.
The
lower
and
upper
bound
estimate
of
the
slope
from
MRID
430823­
04
are
­
0.57
and
12.59,
which
provided
an
individual
chance
mortality
range
of
1
in
13
and
1
in
1.0
X
1016,
respectively.
RQ
exceedances
that
occurred
for
freshwater
fish,
ranged
from
0.07
to
0.5
compared
to
the
LOC
(
0.05).
The
estimated
individual
mortality
associated
with
the
calculated
RQ
values
(
0.07
to
0.5
)
range
from
1
in
3.34
X
1014
to
1
in
4.17
x
108.

Estuarine/
marine
fish
After
an
analysis
of
raw
data
from
the
acute
toxicity
studies
with
Sheepshead
Minnow
(
MRID
430823­
07
and
430823­
08)
two
slope
estimates
were
determined.
The
slope
from
the
study
done
with
the
technical
grade
active
ingredient
(
MRID
430823­
04)
is
13.7
and
the
estimate
of
chance
of
individual
mortality
following
pyrethrins
exposure
is
1.0
X
1016.
The
lower
and
upper
bound
estimate
of
that
slope
are
6.95
and
19.41,
which
provided
an
individual
chance
mortality
range
of
1
in
1.0
X
1016
for
both
bounds.
The
slope
from
the
study
done
with
the
formulated
product
(
MRID
430823­
08)
is
8.35
and
the
estimate
of
chance
of
individual
mortality
following
pyrethrins
exposure
is
1.0
X
1016.
The
lower
and
upper
bound
estimate
of
that
slope
are
5.08
and
11.63,
which
provided
an
individual
chance
mortality
range
of
1
in
2.56
X
1010
to
1
in
1.0
X
1016.
RQ
exceedances
that
occurred
for
estuarine/
marine
fish,
ranged
from
0.05
to
0.17
compared
to
the
LOC
(
0.05).
The
estimated
individual
mortality
associated
with
the
calculated
RQ
values
(
0.05
to
0.17
)
is
1.0
X
1016.

Freshwater
invertebrates
After
an
analysis
of
raw
data
from
the
acute
toxicity
studies
with
daphnids
(
MRID
430823­
05
and
430823­
06)
slope
estimate
were
identified.
A
default
slope
of
10.3
was
used
from
associated
with
the
technical
grade
active
ingredient
(
MRID
430823­
05)
and
a
slope
of
6.7
was
taken
from
data
with
the
formulated
product
(
MRID
430823­
06).
Based
on
the
slope
estimate
of
10.3,
the
corresponding
estimate
chance
of
individual
mortality
for
freshwater
invertebrates
following
pyrethrins
exposure
is
1
in
1.0
x
1016;
and
based
on
the
slope
estimate
of
6.7,
the
corresponding
chance
of
individual
mortality
for
freshwater
invertebrates
following
exposure
to
the
formulated
product
is
1
in
8.44
x
109.
The
lower
and
upper
bound
estimate
of
the
slopes
from
MRID
430823­
05
and
MRID
430823­
06
range
from
14.2
to
9.8
and
from
6.43
to
3.3
respectively.
These
slopes
provided
an
individual
chance
mortality
range
of
1
in
1.0
x
1016
(
technical
grade
active
ingredient)
to
1
in
1.0
X
1016
to
1
in
1.07
x
105
(
formulation).
RQ
exceedances
that
occurred
for
freshwater
invertebrates,
ranged
from
0.05­
0.24
(
formulation)
to
0.03­
0.24
(
TGAI)
compared
to
the
LOC
(
0.05).
The
estimated
individual
mortality
associated
with
the
calculated
RQ
values
(
0.03
­
0.41)
range
from
1
in
1.0
X
1016
to
1
in
8.44
x
109.

Estuarine/
marine
invertebrates
After
an
analysis
of
raw
data
from
the
acute
toxicity
studies
with
Mysid
shrimp
(
MRID
430823­
11
and
430823­
12)
slope
estimates
were
identified.
A
default
slope
of
4.5
was
used
for
data
associated
with
the
formulated
product
(
MRID
430823­
12)
because
there
was
no
slope
estimate
from
the
study.
A
slope
of
4.1was
taken
from
data
with
the
technical
grade
active
ingredient
(
MRID
430823­
11).
Based
on
the
­
105­
default
slope
estimate
of
4.5,
the
corresponding
chance
of
individual
mortality
for
estuarine/
marine
invertebrates
following
exposure
from
the
formulation
is
1
in
4.17
x
108;
and
based
on
the
slope
estimate
of
4.1,
the
corresponding
chance
of
individual
mortality
for
estuarine/
marine
invertebrates
following
exposure
to
the
technical
grade
active
ingredient
is
1
in
2.08
x
107.
The
lower
and
upper
bound
estimate
of
the
slopes
from
MRID
430823­
11
range
from
0.27
to
7.93.
These
slopes
provided
an
individual
chance
mortality
range
of
1
in
2.8
to
1
in
1.0
X
1016.
RQ
exceedances
that
occurred
for
estuarine/
marine
invertebrates,
ranged
from
19.79­
2.50
(
formulation)
to
1.98­
0.25
(
TGAI)
compared
to
the
LOC
(
0.05).
The
estimated
individual
mortality
associated
with
the
calculated
RQ
values
(
0.25
to
19.79)
range
from
1
in
4.17
x
108
to
1
in
1
in
2.08
x
107.

d.
Critical
Habitat
In
the
evaluation
of
pesticide
effects
on
designated
critical
habitat,
consideration
is
given
to
the
physical
and
biological
features
(
constituent
elements)
of
a
critical
habitat
identified
by
the
U.
S
Fish
and
Wildlife
and
National
Marine
Fisheries
Services
as
essential
to
the
conservation
of
a
listed
species
and
which
may
require
special
management
considerations
or
protection.
The
evaluation
of
impacts
for
a
screening
level
pesticide
risk
assessment
focuses
on
the
biological
features
that
are
constituent
elements
and
is
accomplished
using
the
screening­
level
taxonomic
analysis
(
risk
quotients,
RQs)
and
listed
species
levels
of
concern
(
LOCs)
that
are
used
to
evaluate
direct
and
indirect
effects
to
listed
organisms.
This
screening­
level
risk
assessment
for
critical
habitat
provides
a
listing
of
potential
biological
features
that,
if
they
are
constituent
elements
of
one
or
more
critical
habitats,
would
be
of
potential
concern.

C.
Description
of
Assumptions,
Uncertainties,
Strengths,
and
Limitations
1.
Assumptions
and
Limitations
Related
to
Exposure
For
All
Taxa
There
are
a
number
of
areas
of
uncertainty
in
the
aquatic
and
terrestrial
risk
assessments.
The
toxicity
assessment
for
terrestrial
and
aquatic
animals
is
limited
by
the
number
of
species
tested
in
the
available
toxicity
studies.
Use
of
toxicity
data
on
representative
species
does
not
provide
information
on
the
potential
variability
in
susceptibility
to
acute
and
chronic
exposures.

This
screening­
level
risk
assessment
relies
on
labeled
statements
of
the
maximum
rate
of
pyrethrins
application,
the
maximum
number
of
applications,
and
the
shortest
interval
between
applications.
Together,
these
assumptions
constitute
a
maximum
use
scenario.
The
frequency
at
which
actual
uses
approach
these
maximums
is
dependant
on
resistance
to
the
insecticide,
timing
of
applications,
and
market
forces.

2.
Assumptions
and
Limitations
Related
to
Exposure
For
Aquatic
Species
For
an
acute
risk
assessment,
there
is
no
averaging
time
for
exposure.
An
instantaneous
peak
concentration,
with
a
1
in
10
year
return
frequency,
is
assumed.
The
use
of
the
instantaneous
peak
assumes
that
instantaneous
exposure
is
of
sufficient
duration
to
elicit
acute
effects
comparable
to
those
observed
over
more
protracted
exposure
periods
tested
in
the
laboratory,
typically
48
to
96
hours.
In
the
absence
of
data
regarding
time­
to­
toxic
event
analyses
and
latent
responses
to
instantaneous
exposure,
the
degree
to
which
risk
is
overestimated
cannot
be
quantified.
However,
this
constitutes
a
conservative
approach
in
the
analysis
of
a
relatively
labile
chemical
that
is
used
in
multiple
scenarios.
For
PRZM/
EXAMS,
thirteen
scenarios
were
selected
to
represent
a
variety
of
uses,
and
use
sites
within
the
Continental
US.
Furthermore,
additional
special
runs
were
performed
to
represent
typical
application
interval,
and
to
distinguish
spray
drift
from
runoff.
­
106­
3.
Assumptions
and
Limitations
Related
to
Exposure
For
Terrestrial
Species
The
data
available
to
support
the
exposure
assessment
for
pyrethrins
is
substantially
complete,
with
the
exception
of
a
foliar
dissipation
study,
which
is
an
input
variable
for
Tier
1
modeling
of
risks
to
birds
and
mammals
(
i.
e.,
T­
REX).
The
terrestrial
modeling
was
conducted
with
a
foliar
half­
life
of
1
­
14
days,
which
represent
values
calculated
for
phenothrin
and
pyrethrin,
respectively,
and
may
not
be
a
realistic
foliar
half­
life
for
this
compound.
Photolysis
data
(
both
aqueous
and
soil)
suggest
that
pyrethrins
undergo
photolysis
in
the
environment
rapidly
with
half­
lives
of
several
hours
to
about
a
day.
Aerboic
biodegradation
also
occurs
rapidly
with
half­
lives
o
the
order
of
several
days.
Therefore,
the
35
day
half­
life
may
be
too
high.

For
screening
terrestrial
risk
assessments,
a
generic
bird
or
mammal
is
assumed
to
occupy
either
the
treated
field
or
adjacent
areas
receiving
pesticide
at
a
rate
commensurate
with
the
treatment
rate
on
the
field.
The
actual
habitat
requirements
of
any
particular
terrestrial
species
are
not
considered,
and
it
is
assumed
that
species
occupy,
exclusively
and
permanently,
the
treated
area
being
modeled.
This
assumption
leads
to
a
maximum
level
of
exposure
in
the
risk
assessment.

Screening­
level
risk
assessments
for
spray
applications
of
pesticides
consider
dietary
exposure
alone.
Other
routes
of
exposure,
not
considered
in
this
assessment,
are
discussed
below:

Incidental
soil
ingestion
exposure
This
risk
assessment
does
not
consider
incidental
soil
ingestion.
Available
data
suggests
that
up
to
15%
of
the
diet
can
consist
of
incidentally
ingested
soil
depending
on
the
species
and
feeding
strategy.
Since
pyrethrins
may
adsorb
to
soils,
this
may
be
an
important
exposure
pathway.

Inhalation
exposure
The
screening
risk
assessment
does
not
consider
inhalation
exposure.
Such
exposure
may
occur
through
three
potential
sources:
(
1)
spray
material
in
droplet
form
at
the
time
of
application
(
2)
vapor
phase
pesticide
volatilizing
from
treated
surfaces,
and
(
3)
airborne
particulate
(
soil,
vegetative
material,
and
pesticide
dusts).

Available
data
suggest
that
inhalation
exposure
at
the
time
of
application
is
not
an
appreciable
route
of
exposure
for
birds.
According
to
research
on
mallards
and
bobwhite
quail,
respirable
particle
size
in
birds
(
particles
reaching
the
lung)
is
limited
to
a
maximum
diameter
of
2
to
5
microns.
The
spray
droplet
spectra
covering
the
majority
of
pesticide
application
situations
(
AgDrift
model
scenarios
for
very­
fine
to
coarse
droplet
applications)
suggests
that
less
than
1%
of
the
applied
material
is
within
the
respirable
particle
size.

Theoretically,
inhalation
of
pesticide
active
ingredient
in
the
vapor
phase
may
be
another
source
of
exposure
for
some
pesticides
under
some
exposure
situations.
However,
considering
the
low
vapor
pressure
value,
it
is
very
unlikely
that
pyrethrins
will
exist
in
the
gaseous
phase
at
levels
high
enough
to
cause
any
adverse
effects
via
inhalation.

The
impact
from
exposure
to
dusts
contaminated
with
the
pesticide
cannot
be
assessed
generically
as
partitioning
issues
related
to
application
site
soils
and
chemical
properties
render
the
exposure
potential
from
this
route
highly
situation­
specific.
­
107­
Dermal
Exposure
The
screening
assessment
does
not
consider
dermal
exposure,
except
as
it
is
indirectly
included
in
calculations
of
RQs
based
on
lethal
doses
per
unit
of
pesticide
treated
area.
Dermal
exposure
may
occur
through
three
potential
sources:
(
1)
direct
application
of
spray
to
terrestrial
wildlife
in
the
treated
area
or
within
the
drift
footprint,
(
2)
incidental
contact
with
contaminated
vegetation,
or
(
3)
contact
with
contaminated
water
or
soil.

The
available
measured
data
related
to
wildlife
dermal
contact
with
pesticides
are
extremely
limited.
The
Agency
is
actively
pursuing
modeling
techniques
to
account
for
dermal
exposure
via
direct
application
of
spray
and
by
incidental
contact
with
vegetation.

Drinking
Water
Exposure
Drinking
water
exposure
to
a
pesticide
active
ingredient
may
be
the
result
of
consumption
of
surface
water
or
consumption
of
the
pesticide
in
dew
or
other
water
on
the
surfaces
of
treated
vegetation.
For
pesticide
active
ingredients
with
a
potential
to
dissolve
in
runoff,
puddles
on
the
treated
field
may
contain
the
chemical.
Given
that
pyrethrins
are
not
soluble
in
water
and
do
adsorb
appreciably
to
suspended
solids
and
sediment
in
the
water
column,
there
exists
the
potential
for
exposure
to
pyrethrins
from
drinking
water.

Dietary
Intake
­
The
Differences
Between
Laboratory
and
Field
Conditions
The
acute
and
chronic
characterization
of
risk
rely
on
comparisons
of
wildlife
dietary
residues
with
LC50
or
NOAEC
values
expressed
in
concentrations
of
pesticides
in
laboratory
feed.
These
comparisons
assume
that
ingestion
of
food
items
in
the
field
occurs
at
rates
commensurate
with
those
in
the
laboratory.
Although
the
screening
assessment
process
adjusts
dry­
weight
estimates
of
food
intake
to
reflect
the
increased
mass
in
fresh­
weight
wildlife
food
intake
estimates,
it
does
not
allow
for
gross
energy
and
assimilative
efficiency
differences
between
wildlife
food
items
and
laboratory
feed.

On
gross
energy
content
alone,
direct
comparison
of
a
laboratory
dietary
concentration­
based
effects
threshold
to
a
fresh­
weight
pesticide
residue
estimate
would
result
in
an
underestimation
of
field
exposure
by
food
consumption
by
a
factor
of
1.25
­
2.5
for
most
food
items.
Only
for
seeds
would
the
direct
comparison
of
dietary
threshold
to
residue
estimate
lead
to
an
overestimate
of
exposure.

Differences
in
assimilative
efficiency
between
laboratory
and
wild
diets
suggest
that
current
screening
assessment
methods
do
not
account
for
a
potentially
important
aspect
of
food
requirements.
Depending
upon
species
and
dietary
matrix,
bird
assimilation
of
wild
diet
energy
ranges
from
23
­
80%,
and
mammal's
assimilation
ranges
from
41
­
85%
(
U.
S.
Environmental
Protection
Agency,
1993).
If
it
is
assumed
that
laboratory
chow
is
formulated
to
maximize
assimilative
efficiency
(
e.
g.,
a
value
of
85%),
a
potential
for
underestimation
of
exposure
may
exist
by
assuming
that
consumption
of
food
in
the
wild
is
comparable
with
consumption
during
laboratory
testing.
In
the
screening
process,
exposure
may
be
underestimated
because
metabolic
rates
are
not
related
to
food
consumption.

Finally,
the
screening
procedure
does
not
account
for
situations
where
the
feeding
rate
may
be
above
or
below
requirements
to
meet
free
living
metabolic
requirements.
Gorging
behavior
is
a
possibility
under
some
specific
wildlife
scenarios
(
e.
g.,
bird
migration)
where
the
food
intake
rate
may
be
greatly
increased.
Kirkwood
(
1983)
has
suggested
that
an
upper­
bound
limit
to
this
behavior
might
be
the
typical
intake
rate
multiplied
by
a
factor
of
5.
­
108­
In
contrast
is
the
potential
for
avoidance,
operationally
defined
as
animals
responding
to
the
presence
of
noxious
chemicals
in
their
food
by
reducing
consumption
of
treated
dietary
elements.
This
response
is
seen
in
nature
where
herbivores
avoid
plant
secondary
compounds.

4.
Assumptions
and
Limitations
Related
to
Effects
Assessment
The
data
available
to
support
the
aquatic
and
terrestrial
effects
assessment
is
incomplete.
Chronic
toxicity
studies
with
freshwater
organisms
show
that
the
most
sensitive
endpoint
is
growth
(
length
and
dry
weight)
for
fish
and
reproduction
for
invertebrates.
No
data
were
submitted
to
evaluate
the
chronic
risk
to
estuarine/
marine
fish
or
invertebrates.
Since
pyrethrins
tend
to
partition
to
the
sediment
compartment
data
regarding
the
toxicity
of
pyrethrins
to
sediment
dwelling
organisms
is
important.

Pyrethrins
appear
to
be
practically
non­
toxic
to
avian
species
on
a
subacute
oral
and
dietary
basis.
Chronic
avian
risk
could
not
be
evaluated
because
no
reproductive
toxicity
data
were
submitted.
Toxicity
studies
with
rats
suggest
that
pyrethrins
can
be
categorized
as
slightly
toxic
to
small
mammals
on
an
acute
oral
basis.
Acute
toxicity
studies
with
honey
bees
show
that
pyrethrins
are
highly
toxic
on
both
a
contact
and
an
oral
basis.

Age
class
and
sensitivity
of
effects
thresholds
It
is
generally
recognized
that
test
organism
age
may
have
a
significant
impact
on
the
observed
sensitivity
to
a
toxicant.
The
screening
risk
assessment
acute
toxicity
data
for
fish
are
collected
on
juvenile
fish
between
0.1
and
5
grams.
Aquatic
invertebrate
acute
testing
is
performed
on
recommended
immature
age
classes
(
e.
g.,
first
instar
for
daphnids,
second
instar
for
amphipods,
stoneflies
and
mayflies,
and
third
instar
for
midges).
Similarly,
acute
dietary
testing
with
birds
is
also
performed
on
juveniles,
with
mallard
being
5­
10
days
old
and
quail
10­
14
days
old.

Testing
of
juveniles
may
overestimate
toxicity
at
older
age
classes
for
pesticidal
active
ingredients,
that
act
directly
(
without
metabolic
transformation)
because
younger
age
classes
may
not
have
the
enzymatic
systems
associated
with
detoxifying
xenobiotics.
The
screening
risk
assessment
has
no
current
provisions
for
a
generally
applied
method
that
accounts
for
this
uncertainty.
In
so
far
as
the
available
toxicity
data
may
provide
ranges
of
sensitivity
information
with
respect
to
age
class,
the
risk
assessment
uses
the
most
sensitive
life­
stage
information
as
the
conservative
screening
endpoint.

Use
of
the
Most
Sensitive
Species
Tested
Although
the
screening
risk
assessment
relies
on
a
selected
toxicity
endpoint
from
the
most
sensitive
species
tested,
it
does
not
necessarily
mean
that
the
selected
toxicity
endpoints
reflect
sensitivity
of
the
most
sensitive
species
existing
in
a
given
environment.
The
relative
position
of
the
most
sensitive
species
tested
in
the
distribution
of
all
possible
species
is
a
function
of
the
overall
variability
among
species
to
a
particular
chemical.
In
the
case
of
listed
species,
there
is
uncertainty
regarding
the
relationship
of
the
listed
species'
sensitivity
and
the
most
sensitive
species
tested.

The
Agency
is
not
limited
to
a
base
set
of
surrogate
toxicity
information
in
establishing
risk
assessment
conclusions.
The
Agency
also
considers
toxicity
data
on
non­
standard
test
species
when
available.

5.
Assumptions
Associated
With
the
Acute
LOCs
The
risk
characterization
section
of
the
assessment
document
includes
an
evaluation
of
the
potential
for
­
109­
individual
effects
at
an
exposure
level
equivalent
to
the
LOC.
This
evaluation
is
based
on
the
median
lethal
dose
estimate
and
dose/
response
relationship
established
for
the
effects
study
corresponding
to
each
taxonomic
group
for
which
the
LOCs
are
exceeded.

V.
Literature
Cited
For
list
of
literature
cited,
refer
to
Appendix
K.

ACKNOWLEDGMENT
The
Environmental
Fate
and
Effects
Division
would
like
to
thank
Syracuse
Environmental
Research
Associates,
Inc.
(
SERA),
and
Syracuse
Research
Corporation
for
their
assistance
in
developing
this
pyrethrins
risk
assessment.
Thanks
to
the
following
persons
for
their
collaboration
in
making
this
product:
Antonio
Quiñones­
Rivera,
Mario
Citra,
Molly
Ramsey,
Tim
Negley,
and
Phil
Goodrum.