UNITED
STATES
ENVIRONMENTAL
PROTECTION
AGENCY
WASHINGTON,
D.
C.

OFFICE
OF
PREVENTION,
PESTICIDES
AND
TOXIC
SUBSTANCES
June
09,
2006
DP
Barcode
D293411
PC
Code
109702
MEMORANDUM
SUBJECT:
Response
to
Comments
of
Phase
3
Period
on
the
Revised
Draft
EFED
RED
Chapter
for
Cypermethrin
FROM:
Miachel
Rexrode,
Fishery
Biologist,
Senior
Scientist
Michael
Hoffmann,
Biologist
Ronald
Parker,
Senior
Environmental
Engineer
José
Luis
Meléndez,
Chemist
Environmental
Risk
Branch
V
Environmental
Fate
and
Effects
Division
(
7507P)

THROUGH:
Karen
Whitby,
Acting
Chief
Environmental
Risk
Branch
V
Environmental
Fate
and
Effects
Division
(
7507P)

TO:
Dirk
Helder,
Chemical
Review
Manager
Veronique
C.
LaCapra,
Chemical
Review
Manager
Margaret
Rice,
Branch
Chief,
Reregistration
Branch
II
Special
Review
and
Reregistration
Division
(
7508P)

The
registrants
of
cypermethrin,
and
various
interested
parties,
provided
comments
related
to
water
quality
and
other
matters
on
the
Draft
of
the
EFED
Chapter
of
the
Reregistration
Eligibility
Document
(
RED).
The
purpose
of
this
memorandum
is
to
address
those
comments.
In
a
separate
cover,
the
EFED
RED
Chapter,
also
addressing
those
comments
will
be
issued.

EFED
used
a
format
to
address
the
comments,
with
abbreviations
to
identify
the
party
that
submitted
the
comment,
side
by
side
with
the
responses.
The
comments
were
sometimes
written
verbatim,
and
other
times
they
were
summarized,
as
needed.
The
Agency
also
numbered
each
of
the
comments
in
order
to
streamline
and
focus
Agency
responses.
2
Abbreviations:

 
SWRCB,
State
Water
Resources
Control
Board,
Division
of
Water
Quality,
California
Waterboards
 
CRWQCB,
California
Regional
Water
Quality
Control
Board,
San
Francisco
Bay
Region
 
Supporting
Documents:
CDFG,
State
of
California
Department
of
Fish
and
Game
o
TDC
Environmental,
Pesticides
in
Urban
Surface
Water
Urban
Pesticides
Use
Trends
Annual
Report
2005,
Prepared
for
the
San
Francisco
Estuary
Project
o
UP3P
K.
Moran,
UP3
Project,
Sources
of
Pyrethroids
in
Urban
Runoff
o
Oros
and
Werner,
Pyrethroids
Insecticides:
An
Analysis
of
Use
Patterns,
Distributions,
Potential
Toxicity
and
Fate
in
the
Sacramento­
San
Joaquin
Delta
and
Central
Valley
(
UP3)
o
WestonSecondUrban:
Amweg,
E.
L.,
D.
P.
Weston,
et
al.
(
2006)
"
Pyrethroid
Insecticides
and
Sediment
Toxicity
in
Urban
Creeks
from
California
and
Tennessee."
Environ.
Sci.
Technol.
In
press
(
ASAP
article),
web
release
date:
January
31,
2006.
o
Weston
ET&
C
04­
05
corrected:
Amweg,
E.
L.,
D.
P.
Weston,
et
al.
(
2005)
"
Use
and
Toxicity
of
Pyrethroid
Pesticides
in
Central
Valley,
California,
U.
S.
A."
Environ.
Toxicol.
and
Chem.
24(
15):
1300
o
WestonFirstUrban:
Weston,
D.
P.,
et
al.
(
2005)
"
Aquatic
Toxicity
Due
to
Residential
Use
of
Pyrethroid
Insecticides."
Environ.
Sci.
and
Technol.
39(
24):
9778­
9784
o
Medina,
M,
et
al.(
2002)
"
Age­
and
sex
related
variation
in
sensitivity
to
pyrethroid
cypermethrin
in
the
marine
copepod/
Acartia
tonsa
Dana."
Arch.
Environ.
Contam.
Toxicol.
42(
1):
17­
22
o
Maund,
S.
J.,
et
al.
(
2002)
"
Partitioning,
Bioavailability,
and
toxicity
of
the
pyrethroid
insecticide
cypermethrin
in
sediments."
Environ.
Toxicol.
Chem.
21(
1):
9­
15
o
EcoWise
Certified
Standards
for
IPM
Certification
in
Structural
Pest
Management
for
Structural
Pest
Control
Board
Branch
2
Licenses.
 
CASQA,
California
Stormwater
Quality
Association
 
CSWRCB,
California
State
Water
Resources
Control
Board,
Division
of
Water
Quality
 
CSJESD,
City
of
San
José
Environmental
Services
Department
 
SFE,
San
Francisco
Department
of
the
Environment
 
FMC,
FMC
Corporation
 
OPP
USEPA
Office
of
Pesticide
Programs
 
EFED
OPP
Environmental
Fate
and
Effects
Division
 
HED
OPP
Health
Effects
Division
 
BEAN
OPP
Biological
and
Economical
Analysis
Division
 
SRRD
Special
Review
and
Reregistration
Division
 
PWG,
Pyrethroids
Working
Group
3
SWRCB,
State
Water
Resources
Control
Board,
Division
of
Water
Quality,
Waterboards
of
California
Comment
1:
The
SWRCB,
along
with
nine
Regional
Quality
Control
Boards,
is
the
principal
state
agency
with
regulatory
responsibility
for
coordination
and
control
of
water
quality.
Recent
studies
have
raised
concerns
that
water
quality
impairments
due
to
pyrethroids
are
on
the
rise.
The
current
draft
2002
California
section
§
303(
d)
list
contains
three
recommended
listings
for
pyrethroids.

Response
to
SWRCB
comment
1:
Please
refer
to
the
Reregistration
Eligibility
Decision
for
Cypermethrin.

SWRCB
Comment
2:
The
Board
is
particularly
concerned
that
environmental
risk
related
to
aquatic
ecology
are
not
adequately
considered
in
the
registration/
reregistration
process.
They
require
of
the
OPP
complete
an
assessment
of
impacts
to
water
quality.

Response
to
SWRCB
comment
2:
The
Agency
has
been
conducting
national­
level,
aquatic
exposure/
risk
assessments
for
the
pyrethroid
insecticides
since
the
early
1990'
s
and
is
continuously
working
to
refine
its
risk
assessment
methods
and
chemical
environmental
fate
and
toxicity
databases.
Please
refer
to
the
Agency's
response
to
CRWQCB
comment
21.

SWRCB
Comment
3:
SWRCB
are
concerned
that
data
gaps
in
the
risk
assessment
preclude
a
full
evaluation
of
risks
that
may
have
implications
on
the
CWA.

Response
to
SWRCB
comment
3:
Please
refer
to
the
Agency's
response
to
SWRCB
comment
2.

SWRCB
Comment
4:
SWRCB
recommend
to
forbid
use
of
the
chemical
above
ground
outdoors
in
urban
areas
and
require
controls
to
prevent
cypermethrin
runoff
from
preconstruction
termiticide
applications.
This
to
prevent
toxicity
to
sediment
dwelling
organisms
in
urban
creeks
(
more
on
this
follows).

Response
to
SWRCB
comment
4:
The
SWRCB
comment
assumes
that
it
is
the
aboveground
outdoors
uses
which
cause
runoff
from
pre­
construction
termiticide
applications
and
are
the
direct
cause
of
the
toxicity
to
sediment­
dwelling
organisms
in
urban
creeks.
The
Agency,
however,
is
required
to
take
a
more
comprehensive
national
view
of
the
uses
of
cypermethrin.
Other
uses
or
mis­
uses
may
be
the
cause
of
exposure
and
toxicity
to
sediment­
dwelling
organisms
in
California
and/
or
other
parts
of
the
nation.

SWRCB
Comment
5:
Furthermore,
since
the
agricultural
use
of
cypermethrin
has
increased,
SWRCB
recommend
that
sufficient
analysis
evaluate
the
potential
for
impacts
due
to
off­
site
losses
from
agricultural
source
areas,
where
pyrethroids
are
applied.

Response
to
SWRCB
comment
5:
Please
refer
to
the
Agency's
response
to
SWRCB
comment
2.
4
SWRCB
Comment
6:
SWRBC
requests
that
the
EPA
complete
a
cumulative
environmental
risk
assessment
for
pyrethroids.
The
Board
does
not
believe
that
the
Agency
will
be
able
to
manage
the
pyrethroids
risk
adequately
without
a
cumulative
approach
to
environmental
risk
mitigation.

Response
to
SWRCB
comment
6:
The
EFED
does
not
conduct
cumulative
environmental
risk
assessments
with
regard
to
individual
REDs;
however,
at
this
time,
the
Division
is
conducting
a
comparative
assessment
of
selected
synthetic
pyrethroids.
Please
refer
to
the
Reregistration
Eligibility
Decision
for
Cypermethrin.

SWRCB
Comment
7:
SWRBC
requests
that
the
Agency
provide
another
opportunity
for
public
participation
in
the
cypermethrin
reregistration
process
prior
to
the
reregistration
elegibility
decision.
Given
the
substantial
water
quality
risks,
the
additional
information
that
the
Agency
has
requested
and
is
receiving,
the
additional
analysis
that
the
Agency
will
undertake
and
the
additional
costs
associated
with
the
risk
management
decision,
a
full
public
participation
process
is
warranted.

Response
to
SWRCB
Comment
7:
Please
refer
to
the
Reregistration
Eligibility
Decision
for
Cypermethrin.

SWRCB
Comment
8:
Pyrethroids
are
widespread,
found
in
surface
water,
ground
water,
surface
water
sediment,
air,
rain,
and
sewage
sludge.
Some
pyrethroids
are
used
primarily
in
urban
areas.
As
Oros
and
Werner
report
indicates,
agricultural
use
of
pyrethroids
has
increased
steadily
since
1991.
Recent
studies
found
pyrethroids
in
75%
of
sediment
samples
taken
in
the
Central
Valley.
Recent
investigations
of
sediments
in
more
than
15
Northern
California
urban
creeks
found
pyrethroids
in
almost
every
sample.

Response
to
SWRCB
Comment
8:
Please
refer
to
the
Reregistration
Eligibility
Decision
for
Cypermethrin.

SWRCB
Comment
9:
The
pyrethroids
replaced
organophosphorous
pesticides
as
the
most
commonly
used
pesticide
in
California
urban
areas
(
after
phase
out
of
diazinon
and
chlorpyrifos).
The
shift
in
pesticide
use
appears
to
be
causing
widespread
toxicity
to
sediment­
dwelling
organisms
that
reside
in
California
urban
surface
water
sediments.
Cypermethrin
is
a
significant
contributor
to
the
identified
toxicity.

Response
to
SWRCB
Comment
9:
Please
refer
to
the
Reregistration
Eligibility
Decision
for
Cypermethrin.

SWRCB
Comment
10:
These
findings
are
activating
EPA's
requirements
to
designate
many
California
waters
as
impaired
in
accordance
with
CWA
§
303(
d),
We
anticipate
that
recently
published
data
will
be
considered
in
the
next
round
of
listings
in
2006.

Response
to
SWRCB
Comment
10:
Please
refer
to
the
Reregistration
Eligibility
Decision
for
Cypermethrin.
5
SWRCB
Comment
11:
There
are
three
possible
outcomes
from
reregistration
decisions:
 
Few
or
no
changes
 
Allowable
uses
of
pyrethroids
are
changed,
shifting
the
market
to
different
pyrethroids,
or
 
Problematic
uses
of
pyrethroids
are
phased
out
Response
to
SWRCB
Comment
11:
Please
refer
to
the
Reregistration
Eligibility
Decision
for
Cypermethrin.

SWRCB
Comments
12:
The
Agency
needs
to
act
in
a
comprehensive
manner:

A.
Complete
a
cumulative
environmental
risk
assessment
of
pyrethroids.

Response
to
SWRCB
Comment
12A:
Please
refer
to
the
Reregistration
Eligibility
Decision
for
Cypermethrin.

B.
Complete
an
"
alternatives
assessment"
that
considers
alternative
types
of
pesticides.

Response
to
SWRCB
Comment
12B:
Please
refer
to
the
Reregistration
Eligibility
Decision
for
Cypermethrin.

C.
Complete
a
"
cluster
assessment"
for
problematic
outdoor
urban
insecticide
applications
(
e.
g.
ant
control
around
buildings,
which
has
been
identified
as
a
source
of
urban
runoff).

Response
to
SWRCB
Comment
12C:
Please
refer
to
the
Reregistration
Eligibility
Decision
for
Cypermethrin.

D.
Complete
laboratory
and
field
studies
to
fill
data
gaps
that
coordinate
pyrethroids
use
patterns
(
agricultural
and
urban)
with
field
chemical
measurements
at
important
fish
spawning
and
rearing
areas.

Response
to
SWRCB
Comment
12D:
Please
refer
to
the
Agency's
response
to
SWRCB
comment
2.
The
Agency
is
continuously
working
to
refine
its
pyrethroid
chemical
environmental
fate
and
toxicity
databases.

E.
Develop
best
management
practices
for
agricultural
and
urban
uses
to
prevent
pyrethroids
from
entering
the
aquatic
environments.

Response
to
SWRCB
Comment
12E:
Please
refer
to
the
Reregistration
Eligibility
Decision
for
Cypermethrin.

SWRCB
Comment
13:
The
preliminary
risk
assessment
indicates
that
urban
uses
of
pyrethroids
have
the
potential
to
impact
aquatic
systems.
­
The
SWRCB
believes
that
there
is
more
than
a
potential
risk.
The
toxicity
to
sediment­
dwelling
organisms
in
urban
6
creeks
is
documented
and
widespread,
and
cypermethrin
contributes
significantly
to
this
adverse
impact.

Response
to
SWRCB
Comment
13:
Please
refer
to
the
Reregistration
Eligibility
Decision
for
Cypermethrin.

SWRCB
Comment
14:
The
Board
is
also
concerned
that
the
risk
of
pyrethroid
runoff
from
agricultural
areas
has
been
underestimated.

Response
to
SWRCB
Comment
14:
The
Agency
finds
this
comment
difficult
to
address
without
having
more
information.
We
are
unaware
that
our
modeling
produces
concentration
values
that
underestimate
exposure.
If
the
SWRCB
has
data
that
would
indicate
underestimation,
we
would
appreciate
that
data
being
presented
to
us.

SWRCB
Comment
15:
Simple
fate
and
transport
models
should
be
developed
to
demonstrate
the
water
quality
impact
of
pyrethroid
runoff
from
both
agricultural
and
urban
areas.

Response
to
SWRCB
Comment
15:
Please
refer
to
the
Reregistration
Eligibility
Decision
for
Cypermethrin
and
the
Agency's
response
to
CRWQCB
comment
21.

SWRCB
Comment
16:
The
Agency
should
consider,
develop,
and
implement
pest
control
alternatives,
other
risk
mitigation
options,
best
management
practices
and
sustainable
farming
practices.
It
should
also
consider
cost­
benefit
analysis
for
risk
management,
with
the
need
to
address
urban
as
well
as
agricultural
uses
and
the
cost
of
non­
compliance
with
the
CWA
requirements.

Response
to
SWRCB
Comment
16:
Please
refer
to
the
Reregistration
Eligibility
Decision
for
Cypermethrin.

CRWQCB
Comment
1:
Numerous
scientific
studies
have
demonstrated
that
the
use
of
pesticides
in
accordance
to
FIFRA
can
result
in
violations
of
water
quality
standards.
As
a
result,
many
waters
have
been
designated
as
"
impaired"
in
accordance
to
the
Federal
Clean
Water
Act.
The
CRWQCB
has
recognized
the
need
for
the
USEPA
to
minimize
the
potential
for
registered
pesticides
to
impair
surface
water
quality.

Response
to
CRWQCB
Comment
1:
Please
refer
to
the
Reregistration
Eligibility
Decision
for
Cypermethrin.

CRWQCB
Comment
2:
The
pyrethroids
replaced
organophosphorous
pesticides.
The
pyrethroid
insecticides
are
widespread.
They
have
been
detected
in
surface
water,
ground
water,
surface
water
sediments,
air,
rain,
and
sewage
sludge.

Response
to
CRWQCB
Comment
2:
The
EFED
recognizes
the
issues
brought
up
by
the
CRWQCB.
The
pyrethroids
are
relatively
persistent,
and
some
are
highly
persistent.
For
that
reason,
they
may
be
observed
in
a
variety
of
locations.
The
Agency
would
be
7
happy
to
have
access
to
any
monitored
data
for
use
in
its
risk
assessments.
Please
refer
to
the
Reregistration
Eligibility
Decision
for
Cypermethrin
for
additional
information.

CRWQCB
Comment
3:
Some
pyrethroids,
including
cypermethrin,
are
used
primarily
in
urban
areas.
Recent
investigations
of
sediments
in
more
than
15
Northern
California
urban
creeks
found
pyrethroids
in
almost
every
sample.

Response
to
CRWQCB
Comment
3:
Please
refer
to
the
Reregistration
Eligibility
Decision
for
Cypermethrin.

CRWQCB
Comment
4:
The
shift
from
organophosphorous
insecticides
to
pyrethoids
appears
to
be
ending
the
water
column
toxicity,
but
it
is
causing
toxicity
to
sediment
dwelling
organisms.
The
CRWQCB
predicted
this
problem
in
a
report
published
in
2003.

Response
to
CRWQCB
Comment
4:
The
EFED
has
been
working
with
the
PWG
to
obtain
sediment
toxicity
data
and
to
strengthen
its
environmental
fate
and
ecotox
database
for
many
years.
Concern
for
both
acute
and
chronic
risk
to
benthic
organisms
has
been
identified
in
the
EFED's
Science
Chapter;
all
RQs
exceed
the
acute
and
chronic
LOCs
for
every
scenario
considered.

CRWQCB
Comment
5:
The
USEPA
needs
to
complete
a
cumulative
environmental
risk
assessment
of
the
pyrethroids.
It
is
noted
that
the
pyrethroids
have
a
common
mode
of
action
and
exposure
to
multiple
pyrethroids
in
surface
waters
is
likely.

Response
to
CRWQCB
Comment
5:
Please
refer
to
the
Agency's
response
to
SWRCB
comment
6
and
the
Reregistration
Eligibility
Decision
for
Cypermethrin.

CRWQCB
Comment
6:
The
draft
assessment
indicates
that
there
is
a
potential
risk
 
toxicity
to
sediment
dwelling
organisms
in
urban
creeks
is
documented
and
widespread
 
and
cypermethrin
contributes
to
this
adverse
impact.
The
CRWQCB
is
concerned
about
the
limited
analysis
of
outdoor
urban
cypermethrin
use.

Response
to
CRWQCB
Comment
6:
Please
refer
to
the
Reregistration
Eligibility
Decision
for
Cypermethrin.

CRWQCB
Comment
7:
The
Board
encouraged
California
agencies
and
provided
financial
support
for
research
on
urban
uses
of
pyrethroids.
They
shared
the
information
with
the
EPA;
however,
some
important
findings
were
not
included
in
the
assessment.
The
CRWQCB
attached
abstracts
and
several
publications
with
information
immediately
relevant
to
cypermethrin's
environmental
risk.
It
includes
sediment
toxicity
test
to
Hyalella
azteca
which
has
documented
in
at
least
15
Northern
California
creeks.

Response
to
CRWQCB
Comment
7:
The
EFED/
OPP
appreciates
the
fact
that
the
CRWQCB
has
shared
the
data
with
the
EFED/
OPP.
Please
see
the
Agency's
Response
to
CRWQCB
Comment
12
and
Comment
13.
8
CRWQCB
Comment
8:
Request
a
full
six
phase
public
participation
process
for
cypermethrin.
The
Board
provides
various
reasons
to
support
this
request.

Response
to
CRWQCB
Comment
8:
Please
refer
to
the
Reregistration
Eligibility
Decision
for
Cypermethrin.

CRWQCB
Comment
9:
Request
to
use
the
Water
Quality
Criteria
(
WQC),
developed
by
the
Department
of
Fish
and
Game,
for
cypermethrin
in
accordance
with
USEPA
guidance
and
available
aquatic
toxicity
data.
Cypermethrin
Risk
Assessment,
ppb
Waters
Criterion
Method,
ppb
Freshwater
acute
0.14­
0.39
0.002
(
1
h)
Freshwater
chronic
0.069­
0.14
(
Unable
to
calc,
<
0.002)(
4
days)
Saltwater
acute
0.00457­
0.95
(
Unable
to
calculate)
Saltwater
chronic
0.000781­
0.34
(
Unable
to
calculate)
Saltwater
includes
estuarine/
marine.

Response
to
CRWQCB
Comment
9:
It
was
observed
that
the
WQC
were
incomplete,
while
the
risk
assessment
toxicity
reference
values
were
available.
At
this
time,
the
methodology
described
in
the
EFED's
guidelines
for
a
deterministic
risk
assessment,
call
for
the
use
of
toxicity
reference
values,
not
WQC.

CRWQCB
Comment
10:
Most
states,
including
California,
have
narrative
WQC
in
addition
to,
and
in
the
absence
of
numeric
criteria.
For
example,
for
San
Francisco
Bay,
it
is
as
follows:
 
Population
and
community
ecology
 
"
All
waters
shall
be
maintained
free
of
toxic
substances
in
concentrations
that
are
lethal
to
or
that
produce
significant
alterations
in
population
of
community
ecology
or
receiving
water
biota.
In
addition,
the
health
and
life
history
characteristics
of
aquatic
organisms
in
waters
affected
by
controllable
water
quality
factors
shall
not
differ
significantly
from
those
for
the
same
waters
in
areas
unaffected
by
controllable
water
quality
factors."
 
Sediment
 
"
Controllable
water
quality
factors
shall
not
cause
a
detrimental
increase
in
the
concentrations
of
toxic
pollutants
in
sediments
or
aquatic
life."
 
Toxicity
 
"
All
water
shall
be
maintained
free
of
toxic
substances
in
concentrations
that
are
lethal
to
or
that
produce
other
detrimental
responses
in
aquatic
organisms.
The
health
and
life
history
characteristics
of
aquatic
organisms
in
waters
affected
by
controllable
water
quality
factors
shall
not
differ
significantly
from
those
for
the
same
waters
in
areas
unaffected
by
controllable
water
quality
factors.

Response
to
CRWQCB
Comment
10:
The
decision
to
advance
cypermethrin
for
consideration
in
establishing
a
Water
Quality
Criteria
(
WQC)
lies
within
the
purview
of
USEPA
Office
of
Water
(
OW).
The
OPP
stands
ready
to
collaborate
with
the
OW
within
the
confines
of
Confidential
Business
Information
(
CBI).
9
CRWQCB
Comment
11:
According
to
these
narratives
and
in
accordance
with
the
Federal
CWA's
statement
of
national
policy
"
that
the
discharge
of
toxic
pollutants
in
toxic
amounts
is
prohibited."
Arguments
such
as
the
invertebrates
are
resilient
and
their
population
may
possibly
reintroduces
themselves
again
in
time,
or
diminished
invertebrate
diversity
may
not
be
important
for
the
ecosystem
integrity
do
not
agree
with
the
Clean
Water
Act,
nor
its
costly
compliance
requirements.

Response
to
CRWQCB
Comment
11:
Please
see
the
Agency
response
to
CRWQCB
Comment
10.

CRWQCB
Comment
12:
There
are
sediment
toxicity
data
for
Hyalella
azteca
available.
For
cypermethrin,
the
toxicity
is
as
follows:
average
sediment
10
day
LC50
(
µ
g/
g
organic
carbon)
is
0.38.

Response
to
CRWQCB
Comment
12:
The
EFED
is
aware
of
this
toxicity
endpoint
from
the
Maund
et
al.
(
2002)
paper.
In
fact,
the
data
from
this
open
literature
study
had
already
been
submitted
to
the
Agency
prior
to
publication
(
MRID
44074402
and
44074406).
However,
rather
than
use
the
average
sediment
10­
day
LC50
(
µ
g/
g
organic
carbon),
the
EFED
used
the
most
sensitive
10­
day
LC50
(
3.6
µ
g/
kg
sediment)
to
determine
risk
to
aquatic
benthic
invertebrates
in
the
risk
assessment.

CRWQCB
Comment
13:
The
Board
appreciates
the
EPA
efforts
and
the
consultation
with
the
Office
of
Water
to
come
up
with
the
equilibrium
partitioning
approach.
However,
now
that
there
are
toxicity
data
available
that
can
be
used
in
the
assessment,
they
request
that
the
analysis
be
revised
to
reflect
actual
potential
toxicity.

Response
to
CRWQCB
Comment
13:
Toxicity
data
were
used
to
evaluate
acute
risk
to
benthic
invertebrates
exposed
to
cypermethrin
in
the
sediment
based
on
what
was
considered
to
be
the
most
appropriate
and
sensitive
available
data
(
as
stated
above
in
the
Agency's
Response
to
CRWQCB
Comment
12).
However,
the
LC50'
s
were
based
only
on
concentrations
of
cypermethrin
in
bulk
sediment.
EFED
also
estimates
risk
to
benthic
invertebrates
resulting
from
exposure
to
cypermethrin
in
pore
water.
Therefore,
the
equilibrium
partitioning
approach
had
to
be
employed
in
this
instance
because
toxicity
data
based
on
pore
water
concentrations
were
not
available;
in
one
study
pore
water
concentrations
were
not
measured
(
MRID
44074402),
and
in
the
other
the
concentrations
were
below
the
LOD
(
MRID
44074406).
The
EFED
recognizes
that
additional
sediment
toxicity
data
with
LC50'
s
based
on
both
sediment
and
pore
water
concentrations
have
been
submitted
by
the
PWG
for
use
in
this
assessment.
However,
these
data
are
currently
under
review
and
may
be
incorporated
at
a
later
date
if
deemed
appropriate.

CRWQCB
Comment
14:
The
risk
assessment
does
not
include
estimates
of
urban
uses
of
cypermethrin.
Probably,
they
are
the
major
uses
nationally.
In
California,
200,000
pounds
of
cypermethrin
active
ingredient
were
used
in
2004
(
almost
all
in
urban
areas).
Based
on
data
from
the
California
Department
of
Pesticide
Regulation,
they
know
that
more
than
95%
of
the
cypermethrin
occurs
in
urban
areas
(
almost
all
in
structural
pest
control,
and
some
quantities
in
landscaping
and
for
control
of
regulated
pests).
10
Response
to
CRWQCB
Comment
14:
Please
refer
to
the
Reregistration
Eligibility
Decision
for
Cypermethrin
and
the
Agency's
response
to
CRWQCB
comment
21.

CRWQCB
Comment
15:
Most
common
reported
used
labels
indicate
that
cypermethrin
may
be:
 
Sprayed
in
a
band
around
the
exterior
of
the
structure
to
control
nuisance
insects
such
as
ants.
 
Injected
into
the
ground
(
to
control
termites).
 
Sprayed
in
building
interiors
to
control
cockroaches,
fleas,
ants,
and
other
insects.

Response
to
CRWQCB
Comment
15:
As
indicated,
only
the
first
of
these
uses
has
a
high
potential
to
be
washed
into
urban
creeks.

CRWQCB
Comment
16:
Cypermethrin
labels
are
mostly
applied
by
professionals
and
specify
application
rates;
however,
they
do
not
specify
application
frequencies.
Based
on
interviews,
it
appears
that
monthly
applications
are
typical.

Response
to
CRWQCB
Comment
16:
The
number
of
applications
influences
the
amount
of
cypermethrin
that
may
reach
nearby
bodies
of
water.
Please
refer
to
the
Reregistration
Eligibility
Decision
for
Cypermethrin
for
additional
details.

CRWQCB
Comment
17:
The
environmental
risk
assessment
should
use
all
available
scientific
data.
For
example,
the
ECOTOX
database
was
not
used.
The
CRWQCB
has
also
submitted
key
relevant
literature
from
their
own
files.

Response
to
CRWQCB
Comment
17:
Data
submissions
are
always
welcome.
The
latest
version
of
the
EFED
risk
assessment
included
the
ECOTOX
database.

CRWQCB
Comment
18:
The
aquatic
toxicity
data
set
is
incomplete.
It
is
important
that
all
data
gaps
be
filled,
not
only
the
ones
listed
in
the
EFED
data
request,
and
that
the
EPA
obtain
all
aquatic
toxicity
data
necessary
to
develop
water
quality
criteria
in
accordance
with
USEPA
methods.

Response
to
CRWQCB
Comment
18:
EFED
required
data
under
the
authority
of
FIFRA.
Please,
refer
to
the
Agency's
response
to
CRWQCB
comment
10
and
the
Reregistration
Eligibility
Decision
for
Cypermethrin
for
additional
details.

CRWQCB
Comment
19:
The
EPA
should
ensure
that
practical
methods
for
commercial
laboratories
are
developed
and
made
widely
available
in
a
timely
manner.

Response
to
CRWQCB
Comment
19:
It
is
OPP's
understanding
that
new
methods
have
recently
been
developed
by
the
pesticide
registrants.
11
CRWQCB
Comment
20:
The
EPA
or
the
registrant
should
conduct
surveillance
monitoring
of
the
nation's
surface
water
(
including
sediment)
for
pesticides,
with
pyrethroids
a
priority,
and
in
this
case,
cypermethrin.

Response
to
CRWQCB
Comment
20:
Surveillance
monitoring
is
one
possible
outcome
of
reregistration
activities.
Please
refer
to
the
Reregistration
Eligibility
Decision
for
Cypermethrin
for
additional
details.

CRWQCB
Comment
21:
The
EPA
did
not
consider
urban
runoff
in
its
water
quality
modeling.
They
indicate
that
modeling
should
address
the
following
considerations:
 
Washoff
from
urban
areas
is
probably
substantially
greater
than
from
agricultural
fields.
 
Particle
erosion
rates
for
urban
land
uses
have
been
shown
in
the
literature
to
correlate
with
the
amount
of
impervious
surface
in
the
watershed
(
reference
provided).
 
Standard
buildup
and
washoff
equations
for
sediments
on
urban
impervious
surfaces
are
available
and
widely
used
in
urban
modeling
tools
(
e.
g.
Hydrological
Simulation
Program
 
Fortran
[
HSPF],
and
Stormwater
Management
Model
[
SWMM].
 
To
complete
the
urban
runoff
modeling,
the
EPA
can
use
simplified
scenarios,
just
as
it
does
for
agricultural
runoff
modeling.
For
example,
a
simplified
model
could
be
developed
for
an
urban
watershed
with
relatively
high
impervious
surface
area,
and
then
evaluated
in
a
range
of
climatic
conditions.
 
Suggest
two
websites
to
select
a
watershed
case
study.
They
also
provide
a
website
with
weather
data.

Response
to
CRWQCB
Comment
21:
One
of
the
risk
assessment
goals
of
the
Office
of
Pesticide
Programs
(
OPP)
is
to
estimate
pesticide
exposure
through
all
significant
routes
of
exposure
in
both
rural
and
urban
areas.
For
aquatic
ecological
exposure
assessments
for
pesticides
which
have
urban
uses,
OPP
assumes
separate
routes
for
exposure
for
indoor
and
for
outdoor
uses.
For
indoor
uses
that
may
result
in
pesticide
residues
in
wastewater
(
treatments
to
insects,
pets,
clothing,
etc.),
it
is
assumed
that
wash
water
containing
pesticide
residue
flows
into
a
building
drain
and
passes
through
a
sanitary
sewer
and
publicly
owned
treatment
works
(
POTW)
before
being
discharged
to
surface
water.
For
outdoor
urban
uses
(
applications
to
home
lawns,
gardens,
parks,
etc.),
it
is
assumed
that
runoff
water
from
rain
and/
or
lawn
watering
may
remove
pesticide
to
storm
sewers
and
then
directly
to
surface
water.
Simulation
of
each
of
these
routes
of
exposure
is
important
to
the
overall
assessment.
OPP
has
developed
methods
and
carried
out
assessments
for
indoor
uses
which
ultimately
discharge
through
a
POTW
to
surface
water,
but
has
made
less
progress
in
estimating
discharges
resulting
from
urban
outdoor
uses.
Where
applicable,
monitoring
data
from
urban
areas,
such
as
that
collected
by
the
USGS
NAWQA
program
and
others,
are
regularly
included
in
OPP
risk
assessments.
Estimating
pesticide
in
runoff
from
urban
areas
through
computer
simulation
modeling
has
proven
more
difficult.
12
Developing
methods
for
modeling
aquatic
ecological
pesticide
exposure
in
urban
areas
is
difficult
due
to
lack
of
a
model
specifically
developed
to
simulate
pesticide
fate
and
transport
in
a
complex
urban
landscape.
Data
for
model
input
(
pesticide
application
amount
and
timing;
physical
representation
of
the
urban
landscape,
storm
sewer
and
receiving
water
configuration)
and
for
model
calibration
(
past
history
of
flow
and
pesticide
concentrations)
is
also
generally
unavailable.
OPP
is
aware
that
pesticide
aquatic
simulations
have
been
performed
by
the
EPA
Office
of
Water
(
OW)
and
has
discussed
the
technical
feasibility
of
their
methodology
for
national­
scale
assessments
required
under
FIFRA.
The
OW
modeling
efforts
have
been
extremely
time­
consuming
requiring
collection
of
specific
use
information
and
extensive
data
for
parameterization
for
the
simulated
watershed.
OPP
has
identified
limitations
and
deficiencies
in
existing
models
and
data
as
part
of
the
methods­
development
process.
These
include
the
following:
 
OPP
conducts
national­
level
exposure/
risk
assessments
for
pesticide
registration.
Supporting
models
need
to
be
flexible
enough
to
simulate
large
numbers
of
sites
nationally.
Simulations
of
a
single
site
for
which
there
may
be
existing
data
would
be
unlikely
to
provide
useful
information
for
a
national
registration.
Local,
sitespecific
exposure
assessments
are
only
performed
for
endangered
species
risk
assessments.
 
Many
urban
runoff
models
were
designed
primarily
as
water
quantity
rather
than
water
quality
models
and
do
not
have
water
quality
modeling
capabilities
sophisticated
enough
to
simulate
pesticide
fate
and
transport
(
e.
g.
HEC2,
SWMM).
Models
that
simulate
pesticides
need
components
to
handle
runoff
and
leaching
as
well
as
chemical
degradation,
dissipation,
volatilization
and
adsorption/
desorption
for
both
the
land
and
the
water
components
of
the
model.
 
Models
used
for
simulating
pesticide
use
in
agricultural
areas
(
e.
g.
PRZM,
GLEAMS,
SWRRBWQ,
EPIC/
APEX,
SWAT,
etc)
typically
do
not
include
features
needed
to
simulate
urban
areas.
Urban
settings
include
impermeable
surfaces;
storm
sewer
networks;
pumping
stations;
temporary
holding
ponds;
individual,
small­
scale
lawn
irrigation
systems;
and
experience
multiple,
relatively
small
temporally
and
spatially
variable
applications
that
are
not
simulated
in
agricultural
models.
 
Some
commonly
used
models
need
extensive
monitoring
data
for
calibration
(
e.
g.
HSPF
included
in
the
OW
BASINS
platform)
and
therefore
can
only
be
used
to
simulate
sites
and
pesticides
for
which
extensive
flow
and
pollutant
data
has
been
collected
in
advance.
This
type
of
model
cannot
be
used
to
simulate
unmonitored
sites
or
pesticides.
 
Homeowner
application
data
is
not
readily
available
and
is
difficult
to
estimate
with
any
degree
of
confidence.
Estimates
of
the
pesticide
application
area
and
rate
as
well
as
its
temporal
and
spatial
distribution
are
needed
to
simulate
pesticide
in
runoff
in
an
urban
area.
 
Unlike
scenario
sites
for
agricultural
simulations;
representative,
high­
exposure,
urban
watersheds
and
water
bodies
that
can
be
used
in
national­
scale,
pesticide
exposure
assessments
in
urban
landscapes
have
not
been
developed.
Receiving
water
bodies
developed
for
use
in
simulating
aquatic
ecological
exposure
of
pesticides
used
in
agricultural
scenarios
were
designed
based
on
USDA
farm
13
pond
construction
guidelines.
These
guidelines
were
used
in
the
mid­
1900s
to
design
and
build
hundreds
of
thousands
of
rural
water
bodies.
These
agricultural
modeling
sites
represent
a
common
feature
in
rural
areas.
 
It
is
likely
that
pesticide
runoff
in
urban
areas
is
impacted
by
inadvertent
application
of
lawn­
care
products
to
impermeable
surfaces
(
driveways,
sidewalks
or
road
surfaces
adjacent
to
lawns).
Crack
and
crevice
applications
are
specifically
designed
to
be
applied
to
these
hard
surfaces.
Data
on
deposition/
degradation/
resuspension
and
washoff
from
impermeable
surfaces
are
not
available.

OPP
has,
and
continues,
to
consult
with
other
offices
within
EPA
as
well
as
other
federal,
state
and
local
agencies
on
available
tools
and
methodologies
for
assessing
aquatic
exposure
from
urban/
suburban
pesticide
use.
However,
until
such
time
as
a
reasonable
modeling
approach
which
is
appropriate
for
a
national­
scale
risk
assessment
is
developed,
OPP
will
continue
to
rely
predominantly
on
available
monitoring
data
for
characterizing
aquatic
exposure
from
urban
runoff.
Risk
assessments
indicate
that
these
data
provide
estimates
of
a
lower
bound
of
potential
exposure.

CRWQCB
Comment
22:
The
negative
temperature
coefficient
of
the
synthetic
pyrethroids,
in
this
case,
cypermethrin,
needs
to
be
addressed.
Many
of
the
nation's
surface
waters
have
a
low
temperature,
compared
to
the
laboratory
temperature.

Response
to
CRWQCB
Comment
22:
The
EFED
is
aware
that
pyrethroids
have
exhibited
a
negative
temperature
coefficient
of
toxicity
and
would
consider
incorporating
evidence
that
substantiates
this
behavior
if
such
data
become
available
for
cypermethrin.
However,
at
this
time,
acceptable
substantive
data
are
not
available
for
quantitative
use
in
this
risk
assessment.

CRWQCB
Comment
23:
Request
that
EPA,
as
part
of
the
Interagency
Ecological
Program,
evaluate
the
potential
that
cypermethrin
may
be
a
contributor
to
the
sudden
decline
in
San
Francisco
Bay
 
Delta
fisheries.
This
is
also
addressed
in
one
of
the
supporting
documents.

Response
to
CRWQCB
Comment
23:
The
suggested
type
of
analysis
is
beyond
the
scope
of
this
national
screening­
level
risk
assessment.

CRWQCB
Comment
24:
The
Board
recognizes
that
the
EPA
has
addressed
the
issue
of
synergism
of
PBO
with
pyrethroids;
however,
it
is
not
fully
acknowledged
in
this
risk
assessment.
They
indicate
that
they
are
aware
of
a
study
not
yet
published,
of
the
potential
synergism
of
a
pyrethroid
and
PBO
in
the
overlying
water.
They
ask
that
the
issue
be
addressed.

Response
to
CRWQCB
Comment
24:
The
toxicity
of
pyrethroids
and
PBO
is
considered
in
the
individual
risk
assessments
of
the
pyrethroids,
according
to
the
data
available.
Dr.
Weston
was
contacted
on
Jan.
5,
2006
regarding
two
forthcoming
papers.
The
first,
to
be
published
in
Environmental
Toxicology
&
Chemistry,
deals
with
the
14
occurrence
of
PBO
alone,
and
indicates
little
potential
for
synergism.
The
second,
which
has
yet
to
be
submitted
for
publication,
indicates
some
potential
for
synergism
from
mosquito
spraying
of
PBO
with
pyrethrins.
Typically,
the
cypermethrin
products
employed
for
agricultural
uses
that
bring
major
exposure
to
wildlife
do
not
contain
PBO.

CRWQCB
Comment
25:
The
risk
management
should
be
implemented
including
exceedances
of
water
quality
criteria
and
non
compliance
with
NPDES
permits.
The
risk
benefit
standards
of
FIFRA
require
the
EPA
to
ensure
that
pesticides
are
used
in
such
a
manner
that
mitigation
under
the
Clean
Water
Act
is
minimal
or
unnecessary.
The
EPA
should
not
leave
states
and
municipalities
in
non­
compliances
or
needing
to
prepare
and
implement
costly
TMDLs.

Response
to
CRWQCB
Comment
25:
Please
refer
to
the
Reregistration
Eligibility
Decision
for
Cypermethrin.

CRWQCB
Comment
26:
The
EPA
should
prohibit
outdoor
cypermethrin
use
in
urban
areas.
There
are
numerous
alternatives
to
cypermethrin
to
control
pests
around
structures
(
refers
to
document
EcoWise
IPM
Certification
Program).

Response
to
CRWQCB
Comment
26:
CASQA
also
recommend
to
phase
out
cypermethrin's
outdoor
uses.
Please
refer
to
the
Reregistration
Eligibility
Decision
for
Cypermethrin.

CRWQCB
Comment
27:
Without
modeling,
it
is
not
possible
to
know
the
potential
of
these
chemicals
to
reach
the
surface
waters
(
runoff
is
unknown).

Response
to
CRWQCB
Comment
27:
Please,
refer
to
the
Agency's
response
to
CRWQCB
comment
21
for
information
about
the
feasibility
of
an
urban
model
at
this
time.

CRWQCB
Comment
28:
Should
the
EPA
be
unwilling
to
accept
the
Board's
recommendation
to
phase
out
the
aboveground
outdoor
urban
uses
of
cypermethrin,
then
they
recommend
limiting
the
uses
to
spot
treatments
and
they
offer
a
definition
of
spot
treatment.

Response
to
CRWQCB
Comment
28:
Please
refer
to
the
Reregistration
Eligibility
Decision
for
Cypermethrin.

CRWQCB
Comment
29:
The
EPA
should
require
the
implementation
of
control
measures
for
pre­
construction
termiticide
applications
to
prevent
cypermethrin
runoff
from
construction
sites.
They
offer
the
following
"
best
management
practices:"
(
abbreviated)
 
Limit
the
area
to
be
treated
to
only
that
can
be
treated
during
a
normal
working
shift
and
backfilled
with
untreated
soil
by
the
end
of
the
work
shift.
 
Treated
areas
shall
be
covered
as
soon
as
practicable.
Backfill
and
covering
must
keep
rain
and
runoff
from
contacting
treated
soil.
15
 
On­
grade
spraying
should
not
be
conducted
during
sustained
high
wind.
 
Application
should
not
commence
within
24
hours
of
a
predicted
storm
event.
 
Surface
termiticide
application
is
not
allowed
within
50
feet
of
any
down­
gradient
waterway
if
there
is
no
vegetative
buffer.

Response
to
CRWQCB
Comment
29:
Please
refer
to
the
Reregistration
Eligibility
Decision
for
Cypermethrin.

CRWQCB
Comment
30:
They
question
if
the
EPA
should
allow
cypermethrin
in
swimming
pool
systems.
They
were
unable
to
determine
if
the
cypermethrin
is
in
contact
with
the
water
of
the
pool.
The
risk
assessment
did
not
assess
this
use.
If
a
pool
is
emptied,
usually
happens
every
several
years,
the
discharge
would
go
to
the
sewer
system,
controlling
such
discharges
is
near
impossible.

Response
to
CRWQCB
Comment
30:
Please
refer
to
the
Reregistration
Eligibility
Decision
for
Cypermethrin.

CRWQCB
Comment
31:
The
following
loose
subjects
were
also
mentioned:
 
Risk
Management
must
ensure
that
safer
alternatives
will
be
used.
 
Cost­
Benefit
analysis
should
include
state
and
municipal
compliance
cost.
 
Labels
should
be
modified
to
inform
the
users
of
the
hazard
to
aquatic
organisms.
 
Labels
should
limit
the
number
of
applications
per
year.
 
Labels
should
preclude
applications
prior
to
rain
events.

Response
to
CRWQCB
Comment
31:
Please
refer
to
the
Reregistration
Eligibility
Decision
for
Cypermethrin.

Comments
Supporting
Document
i
CDFG:
The
document
is
entitled
"
Hazard
Assessment
of
the
Synthetic
Pyrethroid
Insecticides
Bifenthrin,
Cypermethrin,
Esfenvalerate
and
Permethrin
in
the
Sacramento­
San
Joaquin
River
System"
It
provides
information
about
environmental
fate
and
toxicity
of
cypermethrin.
It
also
provides
use
information
of
the
chemical
in
California
and
Water
Quality
Criteria.
The
interim
freshwater
final
acute
value
was
0.003
µ
g/
L.
The
interim
freshwater
criterion
continuous
concentration
for
cypermethrin
was
0.002
µ
g/
L.
Calculation
of
saltwater
final
chronic
value
requires
paired
acute­
chronic
tests
from
fish,
and
invertebrate,
and
an
acutely
sensitive
saltwater
species.
No
monitoring
in
the
Sacramento­
San
Joaquin
River
system
was
available.

Response
to
Supporting
Document
i
CDFG:
These
data
are
cited
elsewhere
in
the
comments
also.
The
water
quality
criteria
were
developed
by
the
California
Department
of
Fish
and
Game
(
DFG),
not
the
EPA.
The
dataset
is
incomplete
(
no
saltwater
data).
It
is
noticeable
that
the
document
is
a
hazard
assessment
of
synthetic
pyrethroids
and
there
is
no
monitoring
data
in
the
Sacramento­
San
Joaquin
River
system.
16
Supporting
Document
ii,
Comment
UP3P,
Moran,
K,
TDC
Environmental,
"
Sources
of
Pyrethroids
in
Urban
Runoff":
This
poster
consists
of
several
bits
of
information.
 
Eight
pyrethroids
have
been
identified
as
priority
chemicals,
causing
widespread
toxicity
to
sediment
dwelling
organisms
(
Hyallela
azteca)
in
urban
creeks
draining
to
the
San
Francisco
Bay­
Delta
Estuary.
These
chemicals
have
a
variety
of
uses
and
a
wide
range
of
toxicities.
 
From
2001
to
2003
the
sales
of
pyrethroids
doubled
in
the
Bay
area,
while
three
chemicals
account
for
most
of
the
toxic
equivalents
applied:
bifenthrin,
cyfluthrin
and
cypermethrin.
 
Of
the
outdoor
pyrethroid
applications,
72%
correspond
to
structural
professional,
8%
to
other
professional,
and
20%
are
non­
reported.
They
may
include
underground
applications.
 
Since
pyrethroids
are
applied
to
impervious
surfaces,
they
indicate
that
washoff
fractions
are
greater.
 
Their
conclusion
is
that
the
eight
pyrethroids
are
priority
chemicals.
Outdoor
pest
control
should
be
the
top
priority
for
regulatory
agencies.
Need
to
obtain
better
fate
information.
Less
toxic
pyrethroids
have
higher
application
rates
and
substituting
one
pyrethroid
for
another
may
not
be
the
answer.

Response
to
Supporting
Document
ii:
This
poster
contains
information
and
conclusions
that
are
stated
elsewhere
in
this
comment
document.
The
comments
are
discussed
separately.

Supporting
Document
iii,
Comment
Moran,
UP3P
Project:
Pesticides
in
Urban
Surface
Water,
Urban
Pesticides
Use
Trends
Annual
Report
2005,
Prepared
by
San
Francisco
Estuary
Project
(
SFEP).
This
is
one
of
three
reports.
It
involved
several
pesticides.
The
pyrethroids
studied
were
beta­
cyfluthrin,
bifenthrin,
cyfluthrin,
cypermethrin,
deltamethrin,
esfenvalerate,
lambda­
cyhalothrin
and
permethrin
(
note,
the
pyrethrins
were
also
included).
 
The
general
trend
was
away
from
the
OP's
and
into
the
synthetic
pyrethroids.
 
Permethrin
and
carbaryl
were
labeled
for
pet
applications.
 
Urban
use
of
pyrethroids,
malathion,
fipronil,
pyrethrins
and
PHMB
increased
from
2001
to
2003.
Pyrethroids,
fipronil,
pyrethrins
and
perhaps
malathion
are
replacing
diazinon
and
chlorpyrifos
in
the
urban
pesticide
use
market.
 
Control
of
pests
around
buildings
by
professional
pest
control
operators
is
the
major
urban
use
of
pyrethroids.
 
Tralomethrin
is
now
formulated
into
non
aerosol
consumer
products
with
outdoor
uses.
Soon,
it
will
have
the
potential
to
contribute
to
surface
water
impacts
like
other
pyrethroids.
 
The
use
of
beta­
cyfluthrin
grew
significantly
in
2003.
 
In
2003,
at
least
half
of
California
pesticide
use
was
in
urban
areas.
As
a
mitigation
recommendation,
it
was
stated
to
target
structural
use
areas
of
pyrethroids.
And
conduct
surveillance
monitoring
of
California
urban
surface
water
(
including
sediment).
17
Response
to
Supporting
Document
iii:
This
document
also
provides
other
pieces
of
information
that
helps
to
put
the
pyrethroids
and
pyrethrins
in
context,
related
to
the
urban
uses.
Cypermethrin
is
noticeably
absent
in
the
lists.
It
may
be
important
to
follow
the
recommendation
to
do
surveillance
monitoring
of
California
urban
surface
waters
and
sediments.
Please
refer
to
the
Reregistration
Eligibility
Decision
for
Cypermethrin
for
additional
details.

Supporting
to
Document
iv,
Comment
Oros
and
Werner
(
UP3P):
Pyrethroid
Insecticides:
An
Analysis
of
Use
Patterns,
Distributions,
Potential
Toxicity
and
Fate
in
Sacramento­
San
Joaquin
Delta
and
Central
Valley.
This
report
constitutes
an
analysis
of
the
use
patterns,
distributions,
potential
toxicity
and
fate
in
the
Sacramento­
San
Joaquin
Delta
and
Central
Valley,
written
by
Oros
and
Werner.
It
is
an
extensive
report
that
puts
together
the
current
knowledge
of
the
potential
role
of
pyrethroid
insecticides
in
the
pelagic
organism
decline
in
the
upper
San
Francisco
estuary
(
Suisun
Bay
and
the
Sacramento­
San
Joaquin
Delta).
Only
some
of
the
conclusions
are
provided
here.

Concludes
that
there
are
uses
of
concern:
 
irrigation
return­
flows
from
row
and
orchard
crops
during
summer
months
 
spraying
of
orchards
during
the
winter
dormant
season
 
releasing
agricultural
tailwater
from
rice
fields
during
the
late
spring
and
early
summer
 
urban
areas
applications
on
hard
surfaces
that
occur
year­
round
Studies
have
shown
that
aquatic
and
benthic
species
of
concern
are
present
during
these
events
(
see
above).
Pyrethroids
can
be
found
in
surface
waters
and
sediments
from
agricultural
areas.
There
are
no
urban
storm
water
data
to
report
on
the
upper
San
Francisco
estuary
and
the
Central
Valley
Field;
studies
are
needed.

Response
to
Supporting
Document
iv:
While
three
of
the
uses
of
concern
are
agricultural
related,
it
appears
that
the
city
of
San
Francisco
would
like
to
highlight
the
last
one
of
the
uses
of
concern:
urban
areas
applications
on
hard
surfaces
that
occur
yearround
Responses
to
comments
related
to
the
issue
appear
in
this
document
elsewhere.

Supporting
Document
v:
Amweg,
E.
L.,
et
al.
(
2006)
"
Pyrethroid
Insecticides
and
Sediment
Toxicity
in
Urban
Creeks
from
California
and
Tennessee."
Environ.
Sci.
Technol.
In
press,
ASAP
article.
Web
release
date
January
31,
2006.
Urban
creeks
in
Sacramento,
California,
and
Nashville,
Tennessee
were
tested
on
up
to
four
occasions
for
pesticide
residues
in
sediments,
and
aquatic
toxicity
was
determined
by
acute
toxicity
tests
using
the
amphipod
Hyallela
azteca.

In
California
12
of
15
creeks
tested
were
toxic
on
at
least
one
sampling
occasion,
and
sediment
pyrethroid
concentrations
were
sufficient
to
explain
the
observed
toxicity
in
most
cases.
Bifenthrin
was
likely
responsible
for
the
majority
of
the
toxicity
at
most
sites
(
since
it
is
highly
toxic).
18
On
the
other
hand,
none
of
the
sediments
collected
from
the
12
Tennessee
creeks
were
toxic,
and
pyrethroids
were
rarely
detectable.
Total
pyrethroid
units
(
TU)
in
all
Nashville
creeks
were
consistently
below
levels
expected
to
cause
toxicity
to
Hyallela
azteca.

Precipitation
in
Nashville
(
119
cm/
yr)
is
far
above
that
of
Sacramento
(
46
cm/
yr),
and
it
occurs
year­
round.
Other
regional
differences
are
possibly
attributable
in
types
of
residential
development,
and
pesticide
use
practices.
It
is
noted
that
Sacramento
does
not
meter
water
use,
but
uses
flat
rate
pricing,
which
may
be
a
factor
contributing
to
excessive
landscape
watering
and
a
greater
potential
for
pesticide
transport
to
surface
water
bodies.
Furthermore,
in
Sacramento,
the
urban
runoff
was
served
by
storm
drain
systems.
In
Nashville,
runoff
reached
the
creeks
by
flowing
across
ground
surfaces
for
considerable
surfaces.

Response
to
Supporting
Document
v:
The
results
of
this
study
show
that
the
problem
of
pyrethroid
contamination
may
not
be
"
widely
spread,"
as
it
is
indicated
in
numerous
comments.
Two
cities
of
similar
size
in
different
locations
yield
contrasting
results
making
the
interpretation
of
the
data
very
difficult.
It
is
rather
localized
and
dependent
on
factor
still
to
be
determined.
The
EFED/
OPP
will
continue
to
gather
information
as
it
becomes
available,
and
investigating
the
extent
to
which
this
problem
is
site
specific
or
more
general
across
pyrethroid
usage
area.

Supporting
Document
vi:
Amweg,
E.
L.,
D.
P.
Weston,
N.
M.
Ureda
(
2005)
"
Use
and
Toxicity
of
Pyrethroid
Pesticides
in
the
Central
Valley,
California,
USA,"
Environ.
Toxicol.
And
Chem.
24(
15):
1300.
This
is
a
corrected
manuscript
of
a
previously
published
article.
The
paper
describes
how
they
were
able
to
determine
the
acute
sediment
toxicity
values
for
various
synthetic
pyrethroids
found
in
sediments
in
California.
These
are
estimates
of
LC50
to
the
amphipod
Hyalella
azteca.
Growth
was
inhibited
typically
at
levels
below
the
LC50.
The
results
were
as
follows:
Bifenthrin
=
0.52
µ
g/
goc;
cyfluthrin
=
1.08
µ
g/
goc;
cypermethrin
=
0.38
µ
g/
goc;
deltamethrin
=
0.79
µ
g/
goc;
esfenvalerate
=
1.54
µ
g/
goc;
lambda­
cyhalothrin
=
0.45
µ
g/
goc;
and
permethrin
=
10.83
µ
g/
goc.

Response
to
Supporting
Document
vi:
The
toxicity
value
reported
in
this
study
for
cypermethrin
appears
to
come
from
a
previously
published
paper
(
Maund
et
al.
2002).
Please
refer
to
the
Agency's
response
to
CRWQCB
comment
12
and
13.

Supporting
Document
vii:
Weston,
D.
P.,
et
al.
(
2005)
"
Aquatic
Toxicity
Due
to
Residential
Use
of
Pyrethroid
Insecticides,"
Environ.
Sci.
Technol.
39(
24):
9778­
9784;
Samples
were
taken
from
a
typical
suburban
development
in
Roseville,
Sacramento,
California.
Nearly
all
creek
sediments
collected
caused
toxicity
to
the
amphipod
Hyalella
azteca,
and
about
half
the
samples
caused
nearly
complete
mortality.
Bifenthrin
was
identified
as
the
primary
cause
of
the
toxicity,
with
contributions
of
cyfluthrin
and
cypermethrin.
The
sources
of
the
pyrethroids
are
structural
pest
control
by
professional
applicators
and/
or
homeowners
use
of
insecticides,
particularly
lawn
care
products.
The
authors
believe
that
Roseville
is
unlikely
to
be
unique
and
that
other
communities
may
be
19
affected
similarly
with
water
and
sediment
contamination.
The
authors
used
LC50
values
for
individual
pyrethroids
from
the
Supporting
Document
vi.

Response
to
Supporting
Document
vii:
This
is
one
of
various
documents
by
Dr.
Weston's
team.
Their
contribution
is
appreciated.
The
EFED
was
working
on
the
issue
prior
to
the
publication
of
the
documents.
Sediment
toxicity
and
new
mobility
data
had
been
required
to
the
PWG.
These
data
have
been
received
and
are
currently
in
review.

Supporting
Document
viii:
Medina,
M.
et
al.
(
2002)
"
Age­
and
sex­
related
variations
in
sensitivity
to
the
pyrethroid
cypermethrin
in
the
marine
copepod
Acartia
tonsa
Dana"
Arch.
Environ.
Contam.
Toxicol.
42(
1):
17­
22.
This
report
examines
the
use
of
the
calanoid
copepod
Acartia
tonsa
Dana
in
the
ecological
hazard
assessment
of
chemicals
released
in
the
environment.
It
represents
an
essential
link
in
plankton
food
incorporation.
Cypermethrin
is
used
to
treat
ectoparasite
infestations
of
salmon.

Acute
effects
of
the
chemical
were
assessed
using
the
calanoid
copepod
Acartia
tonsa.
Acartia
tonsa
has
been
used
in
hazard
assessments
of
chemicals
in
the
marine
environment,
using
acute
tests,
and
sex
ratio
of
1:
1.
In
this
study
it
was
shown
that
naupliar
stages
were
28
times
more
sensitive
to
cypermethrin
than
adults
after
96
hours
of
exposure,
with
LC50'
s
of
0.005
µ
g/
L
and
0.142
µ
g/
L,
respectively.

Significant
differences
in
sensitivity
between
the
sexes
were
also
found
during
the
first
24
hours
of
exposure,
during
which
males
were
around
twice
as
sensitive
as
females.
After
24
hours,
the
difference
was
not
significant.
One
possible
explanation
is
that
there
is
faster
depuration
for
females
through
egg
production.

They
conclude
that
the
standard
toxicity
analysis
with
Acartia
tonsa
are
unsatisfactory.
It
is
noted
that
these
studies
are
conducted
with
cypermethrin
in
saltwater
and
the
concentration
of
cypermethrin
is
higher
at
the
beginning
of
the
study
and
lower
at
the
end.
They
average
the
values
to
state
the
concentration
in
the
exposure
vessel.

Response
to
Supporting
Document
viii:
This
study
contains
some
useful
information
for
further
characterizing
ecological
hazard;
however,
more
sensitive
data
were
already
incorporated
and
used
to
determine
risk
to
estuarine/
marine
invertebrates.
Therefore,
adequate
protection
has
been
given
to
this
taxonomic
group
based
on
the
best
available
data,
and
the
inclusion
of
this
study
would
not
affect
the
conclusions
of
this
risk
assessment.

Supporting
Document
ix:
Maund,
S.
J.
et
al.
(
2002)
"
Partitioning,
Bioavailability,
and
Toxicity
of
the
Pyrethroid
Insecticide
Cypermethrin
in
Sediments,"
Environ.
Toxicol.
Chem.
21(
1):
9­
15.
In
this
publication,
the
authors
investigate
the
partitioning,
bioavailability
and
toxicity
of
cypermethrin
in
water­
sediment
systems.
They
found
that
cypermethrin
was
rapidly
adsorbed,
with
an
overall
mean
KOC
of
350,000
and
99%
adsorption
occurred
in
24
hours.
For
1%
OM,
Koc
=
238,000;
3%
OM,
it
was
302,000,
and
13%
OM,
it
was
177,000.
Measured
desorption
KOC`
s
were
similar
in
magnitude
to
the
adsorption
ones
(
somewhat
higher).
20
The
bioavailability
was
measured
via
body
burden
of
Daphnia
magna
and
Chironomus
tentans.
Mean
biota
sediment
accumulation
factors
(
BSAF's),
that
is,
the
concentration
of
the
organism
as
a
proportion
of
the
concentration
in
the
sediment
decreased
with
increasing
organic
carbon
content.
The
BSAF
values
were
0.31,
0.14
and
0.08
for
Daphnia
magna
and
0.63,
0.19
and
0.08
for
C.
tentans
in
1,
3
and
13%
OC
sediments,
respectively.

The
10­
day
LC50s
of
cypermethrin
were
3.6,
18,
and
32
mg/
Kg
for
H.
azteca
and
13,
67,
and
62
mg/
Kg
for
C.
tentans
in
1,
3
and
13%
OC
sediments,
respectively.
Predictions
of
aqueous
concentrations
at
the
LC50
in
sediments
(
based
on
KOC)
compared
well
to
each
other
and
to
the
effect
concentrations
from
studies
in
water
alone,
suggesting
that
equilibrium
partitioning
theory
could
be
used
reasonably
to
predict
and
normalize
the
toxicity
of
cypermethrin
across
sediments
of
differing
OC
content.

Response
to
Supporting
Document
ix:
Please
refer
to
the
Agency's
response
to
CRWQCB
comment
12
and
13.

Supporting
Document
x,
EcoWise:
Standards
for
IPM
Certification
in
Structural
Pest
Management
for
Structural
Pest
Control
Board
Branch
2
Licenses:
These
are
standards
adopted
as
a
pilot
in
the
nine
San
Francisco
Bay
Area
counties
and
Sacramento
County.
Overseers:
Association
of
Bay
Area
Governments
(
ABAG),
the
Sacramento
Stormwater
Program
and
Natural
Resources
Defense
Council
(
NRDC).
 
The
pilot
program
will
certify
an
IPM
service
within
a
pest
control
company
or
branch
office.
 
Certify
Branch
2
field
representatives
and
operators
through
a
written
exam.
Each
company
or
branch
office
must
employ
at
least
one
certified
individual
to
oversee
its
IPM
service.
 
Companies
or
branch
offices
submit
an
application
with
a
written
IPM
protocol
for
specific
pests
and
get
provisionally
certified.
 
Within
a
year,
applicants
must
perform
20
IPM
service
visits
for
at
least
7
different
costumers
or
sites.
These
visits
must
be
overseen
by
the
company's
certified
IPM.
Practitioner
must
follow
standards,
and
record
the
required
information
on
appropriate
forms.
 
After
the
required
service
visits,
a
certification
program
evaluator
will
review
their
record
and
perform
field
evaluations
to
determine
if
applicants
qualify
for
full
certification.
The
certification
program
manager
will
make
the
final
decision
on
granting
certification.
 
The
certification
must
be
renewed
after
3
years.
Individuals
must
complete
27
approved
continuing
IPM
education
hours
every
3
years.
 
The
program
includes
general
pests,
but
no
fumigants
or
termiticides.
 
The
program
emphasizes
3
fundamental
elements:
o
Pest
prevention
seeks
to
suppress
the
pest
reproduction,
access,
shelter/
habitat.
Management
practices
include
education
to
the
costumer,
prevention
of
the
pest.
21
o
Integration
of
multiple
management
and
tools,
such
as
providing
the
costumer
mechanical
and
physical
controls
(
traps,
physical
barriers),
and
o
Systems
approach.
 
Attachment
A
is
a
"
prototype"
materials
list,
which
is
a
list
of
"
reduced
risk"
(
to
humans
and
the
environment)
pesticides.
 
Sometimes,
a
"
non­
safe"
pesticide
is
needed.
This
is
also
recorded.
 
The
Pest
Management
Professional
(
PMP)
establishes
a
partnership
with
the
costumer,
records
a
detailed
history
about
the
pest
problem,
and
inspects
the
property.
Then
the
PMP
prepares
a
written
list/
map
and
identifies
the
pest
and
proceeds
to
discuss
the
findings
with
the
costumer.
The
PMP
provides
the
costumer
with
information
about
IPM
and
develops
a
written
site­
specific
plan.
Finally,
the
PMP
provides
inspection
records
and
recommendations,
and
for
ongoing
accounts,
periodic
monitoring
program.
 
There
is
a
record
keeping
standard,
records
should
have
sufficient
detail
to
be
understood
and
audited
and
demonstrate
compliance
with
the
standards
of
IPM
Certification.
Records
must
be
kept
for
at
least
3
years,
and
be
available
for
inspection
and
reproduction
during
normal
business
hours,
by
authorized
representatives.
Copies
of
inspection
records
must
be
provided
to
the
costumers,
with
the
recommendation,
within
a
week
after
each
visit.

Response
to
Supporting
Document
x:
This
is
an
appealing
approach
to
the
use
of
pesticides.
The
City
of
San
Francisco
appears
to
have
gone
a
long
way
towards
the
use
of
fewer
and
safer
chemicals.
Nevertheless,
the
Agency
would
be
interested
in
which
approach
the
city
has
used
for
termiticides.
Please
refer
to
the
Reregistration
Eligibility
Decision
for
Cypermethrin
for
additional
details.

CASQA
 
California
Stormwater
Quality
Association
Comment
1:
CASQA
is
composed
of
stormwater
quality
management
organizations
and
individuals,
including
cities,
counties,
special
districts,
industries,
and
consulting
firms
throughout
the
state,
it
was
formed
in
1989.

Response
to
CASQA
Comment
1:
This
comment
is
informative
and
requires
no
response.

CASQA
Comment
2:
It
is
concerned
with
cypermethrin
and
other
pyrethroids
in
that
they
pose
a
significant
risk
to
water
quality
in
urban
and
suburban
areas.
Recent
evidence
shows
that
cypermethrin
and
other
pyrethroids
are
found
in
urban
creeks.
They
are
particularly
concerned
for
the
following
reasons:
 
Cypermethrin
is
used
primarily
in
urban
areas.
 
Recent
investigations
of
sediments
in
more
than
15
Northern
California
urban
creeks
found
pyrethroids,
including
cypermethrin
in
almost
every
sample.
 
The
same
studies
have
shown
widespread
toxicity
to
sediment­
dwelling
organisms
in
California
urban
surface
water
sediments.
Cypermethrin
is
a
significant
contributor
to
the
identified
toxicity.
 
The
State
of
California
is
proposing
listing
several
creeks
as
impaired
by
pyrethroids
as
part
of
the
USEPA
mandated
CWA
§
303(
d)
listing
process.
22
Response
to
CASQA
Comment
2:
These
comments
are
also
concerns
common
to
the
CRWQCB
and
SWRCB.
Please,
refer
to
the
Agency's
response
to
SWRCB
comments
1
and
8.

CASQA
Comment
3:
CASQA
generally
supports
the
Regional
Water
Board's
comments,
but
emphasizes
the
following
items:
 
Implement
risk
management
measures
to
ensure
that
cypermethrin,
when
used
according
to
the
label,
does
not
interfere
with
the
CWA
compliance.
 
Prohibit
aboveground
outdoor
cypermethrin
use
in
urban
areas
 
Require
controls
to
prevent
cypermethrin
runoff
from
preconstruction
termiticide
applications.
 
Complete
a
cumulative
environmental
risk
assessment
for
the
pyrethroids.
 
Complete
an
"
alternative
assessment"
that
considers
alternative
pesticides
and
low­
risk
pest
control
methods.
 
Complete
a
"
cluster
assessment"
for
problematic
outdoor
urban
insecticide
applications.
 
Provide
another
opportunity
for
public
participation
in
the
cypermethrin
reregistration
process
prior
to
the
reregistration
elegibility
decidion.
The
proposed
truncated
public
comment
period
is
too
short
and
omits
critical
steps.
Given
the
complexity
and
importance
of
this
regulatory
action,
the
EPA
should
extend
the
reregistration
process.

Response
to
CASQA
comment
3:
For
comment
about
a
cumulative
environmental
risk
assessment,
please,
refer
to
the
Agency's
response
to
SWRCB
comment
6.
For
additional
details,
please
refer
to
the
Reregistration
Eligibility
Decision
for
Cypermethrin.

CASQA
Comment
4:
For
termiticides,
they
offer
suggestions
that
would
be
required
in
the
label
and
that
they
indicate
are
best
management
practices.
 
For
stormwater
protection,
the
preferred
application
of
liquid
termiticide
is
soil
injection
near
the
structure
foundation.
 
If
soil
injection
is
not
possible,
then,
limit
the
size
of
the
treated
area
to
a
work
shift.
 
Treated
area
should
be
backfilled
prior
to
the
onset
of
precipitation
(
rain).
 
Any
treated
area
that
has
the
potential
to
come
into
contact
with
stormwater
should
be
covered.
 
On
grade
spraying
should
not
be
conducted
during
gusty
winds.
 
Application
should
not
commence
within
24­
hours
of
predicted
precipitation
event.
 
During
the
rainy
season,
termiticide
application
should
not
be
allowed
within
50
ft
of
any
down
gradient
storm.

Response
to
CASQA
Comment
4:
Please
refer
to
the
Reregistration
Eligibility
Decision
for
Cypermethrin.
23
CSJESD
 
City
of
San
José
Environmental
Services
Department
Comment
1:
The
state
that
San
José
is
the
tenth
largest
city
in
the
U.
S.,
with
approximately
28,000
storm
drain
inlets.
The
purpose
of
the
City's
Urban
Runoff
Program
is
to
prevent
pollution
from
entering
the
storm
sewer
system
and
waterways
to
protect
the
health
of
the
South
San
Francisco
Bay
watershed.

Response
to
CSJESD
Comment
1:
This
comment
is
informative
and
requires
no
response.

CSJESD
Comment
2:
Studies
have
shown
that
some
registered
pesticides
can
cause
widespread
toxicity
in
local
creeks
and
urban
runoff
even
when
used
in
accordance
with
FIFRA
requirements.

Response
to
CSJESD
Comment
2:
Please,
refer
to
the
Agency's
response
to
SWRCB
comment
13.

CSJESD
Comment
3:
The
State
Water
Board
and
USEPA
have
found
many
waters
in
urban
areas
in
California
to
be
impaired,
according
to
the
CWA,
§
303(
d).
as
a
result
of
discharges
of
pesticides
registered
for
use
by
the
USEPA
under
FIFRA.
The
CWA
requires
that
the
state
adhere
to
resource­
intensive
TMDLs
for
these
waters,
which
can,
in
turn,
require
municipalities
to
implement
expensive
programs
in
hope
of
restoring
designated
uses
of
impaired
water
bodies.
This
could
be
largely
avoided
if
the
USEPA
more
proactively
employed
its
FIFRA
authority
to
reduce
the
potential
for
registered
pesticides
to
impair
surface
water
quality.

Response
to
CSJESD
Comment
3:
Please
refer
to
the
Reregistration
Eligibility
Decision
for
Cypermethrin.

CSJESD
Comment
4:
Recent
evidence
indicates
that
cypermethrin
,
as
well
as
other
pyrethroids
are
found
in
urban
creeks
at
levels
of
concern.
The
State
of
California
is
proposing
listing
several
creeks
as
impaired
by
pyrethroids
as
part
of
the
CWA
§
303(
d)
listing
process.

Response
to
CSJESD
Comment
4:
Please
refer
to
the
Reregistration
Eligibility
Decision
for
Cypermethrin.

CSJESD
Comment
5:
The
city
is
concerned
that
cypermethrin
and
other
pyrethroids
may
pose
a
significant
risk
to
water
quality
in
urban
areas
because:
 
It
is
mainly
used
in
urban
areas.
 
Recent
investigations
found
pyrethroids
in
sediments
in
more
than
15
Northern
California
urban
creeks
in
almost
every
sample.
Among
the
pyrethroids
found,
cypermethrin
was
included.
 
The
same
studies
have
shown
widespread
toxicity
to
sediment­
dwelling
organisms
in
California
urban
surface
water
sediments.
Cypermethrin
is
a
significant
contributor
to
the
identified
toxicity.
24
Response
to
CSJESD
Comment
5:
Please,
refer
to
the
Agency's
response
to
SWRCB
comment
13.

CSJESD
Comment
6:
The
City
of
San
José
supports
several
of
the
Regional
Water
Board's
comments.
Particularly,
they
mention
the
San
Francisco
Water
Quality
Control
Board
letter.

Response
to
CSJESD
Comment
6:
Please,
refer
to
the
Agency
responses
to
the
CRWQCB
comments,
that
appear
previously
in
this
report.

CSJESD
Comment
7:
They
emphasize
that
the
USEPA
should
complete
a
risk
assessment
that
includes
the
following:
 
Implementation
of
sufficient
risk
management
measures
to
ensure
that
the
use
of
cypermethrin
according
to
the
label
does
not
interfere
with
compliance
with
the
CWA.
 
Forbid
use
of
cypermethrin
above
ground
outdoor
in
urban
areas.
 
Perform
an
"
alternatives
assessment"
that
considers
low­
risk
pest
control
methods.
 
Complete
a
"
cluster
assessment"
for
problematic
outdoor
urban
insecticide
applications.
 
Provide
additional
opportunities
for
public
participation
in
the
cypermethrin
reregistration
process,
prior
to
the
reregistration
elegibility
decision.

Response
to
CSJESD
Comment
7:
Please
refer
to
the
Reregistration
Eligibility
Decision
for
Cypermethrin.

CSJESD
Comment
8:
The
USEPA
needs
to
improve
integration
of
surface
water
protection
into
its
pesticide
registration
and
regulatory
review
programs.
The
risk
benefit
standards
of
FIFRA
require
USEPA
to
ensure
that
pesticides
are
used
in
such
a
manner
that
mitigation
under
the
CWA
is
minimal
or
unnecessary.
Full
cooperation
between
the
Office
of
Water
and
the
Office
of
Pesticides
Programs
will
help
the
Agency
to
meet
this
goal.

Response
to
CSJESD
Comment
8:
Please
refer
to
the
Reregistration
Eligibility
Decision
for
Cypermethrin.

SFE
Comment
1:
The
San
Francisco
Department
of
the
Environment's
(
SFE's)
mission
is
to
improve,
enhance,
and
preserve
the
environment,
and
promote
San
Francisco's
longterm
well
being.
In
1996,
the
San
Francisco
adopted
an
Integrated
Pest
Management
(
IPM)
ordinance,
which
commits
the
City
to
a
pest
management
approach
on
its
own
property
that
minimizes
the
use
of
toxic
chemicals
and
control
pests
by
methods
that
pose
a
lower
risk
to
public
and
environmental
health.
They
strongly
believe
that
USEPA
should
use
its
registration
process
to
protect
human
health
and
prevent
environmental
problems
with
pesticides.
25
Response
to
SFE
Comment
1:
Please
refer
to
the
Reregistration
Eligibility
Decision
for
Cypermethrin.

SFE
Comment
2:
Most
use
of
cypermethrin
is
non
agricultural.
Cypermethrin
and
other
pyrethroids
are
now
the
most
commonly
used
urban
insecticides.
They
have
been
found
in
"
our
water,
our
air,
and
our
bodies,"
and
are
of
great
concern
for
their
toxicity
to
aquatic
organisms,
and
possible
human
health
effects.

Response
to
SFE
Comment
2:
Please
refer
to
the
Reregistration
Eligibility
Decision
for
Cypermethrin.

SFE
Comment
3:
Researchers
have
found
significant
toxicity
to
sediment­
dwelling
organisms
native
of
Northern
California
creeks.
The
toxicity
is
linked
to
pyrethroids.

Response
to
SFE
Comment
3:
Please,
refer
to
the
Agency's
response
to
CRWQCB
comment
2
and
the
Reregistration
Eligibility
Decision
for
Cypermethrin.

SFE
Comment
4:
If
EPA
does
not
act
immediately,
the
above
mentioned
finding
could
have
costly
regulatory
implications
to
the
City.

Response
to
SFE
Comment
4:
Please
refer
to
the
Reregistration
Eligibility
Decision
for
Cypermethrin.

SFE
Comment
5:
SFE
has
eliminated
the
use
of
pyrethroids
for
control
of
ants,
cockroaches,
and
landscape
insects
in
their
IPM
program.
They
believe
that
the
EPA
should
emphasize
alternatives
when
seeking
to
reduce
risks.

Response
to
SFE
Comment
5:
Please
refer
to
the
Reregistration
Eligibility
Decision
for
Cypermethrin.

SFE
Comment
6:
Human
health
risks:
 
6B.
Cumulative
risk
of
pyrethroids
needs
to
be
assessed
­
The
EPA
stated
that
no
determination
of
a
common
toxic
mode
of
action
has
yet
been
made.
SFE
recognizes
that
pyrethroids
are
divided
into
two
distinct
types.
This
research
is
important
because
all
pyrethroids
are
neurotoxicants,
and
several
of
them
may
be
carcinogens.
In
addition,
they
are
widely
used
in
and
around
homes.
It
is
their
view
that
EPA
should
take
the
precautionary
approach
of
assuming
cumulative
risk
exists.
o
Response
to
6B:
Please,
refer
to
the
Agency's
response
to
SWRCB
comment
6
and
the
Reregistration
Eligibility
Decision
for
Cypermethrin
for
additional
details.
SFE
Comment
7:
Environmental
risks:
 
7A.
Use
Water
Quality
Criteria
(
WQC)
to
assess
risks
to
aquatic
life
 
The
Agency
has
used
toxicity
reference
values,
based
on
the
most
sensitive
species;
however,
SFE
recommends
to
use
WQC,
like
the
ones
developed
by
the
California
Department
of
Fish
and
Game
(
DFG),
using
Office
of
Water
(
OW)
26
methods.
These
WQC
are
representative
of
a
range
of
species
that
are
exposed
to
pollutants
in
surface
waters.
If
EPA
does
not
use
the
criterion,
it
will
not
ensure
compliance
with
the
CWA,
and
will
leave
municipalities
like
San
Francisco
with
the
responsibility
for
complying
with
the
water
quality
criterion,
but
without
funding
or
regulatory
authority
to
manage
the
problem.
o
Response
to
7A:
Please,
refer
to
the
Agency's
response
to
CRWQCB
comment
10.
 
7B.
Assess
urban
runoff
risks
 
There
is
evidence
that
pyrethroid
toxicity
due
to
urban
runoff
is
higher
than
in
surface
water
receiving
agricultural
runoff.
Furthermore,
USGS
NAWQA
monitoring
data
shows
that
there
are
higher
insecticide
concentrations
in
urban
surface
waters
than
in
agricultural
surface
waters.
EPA
assumes
that
agricultural
modeling
covers
the
risk
in
urban
environments,
an
argument
that
the
SFE
considers
untenable.
Urban
runoff
modeling
is
needed.
o
Response
to
7B:
Please,
refer
to
the
Agency's
response
to
CRWQCB
comment
21.
 
7C.
The
EPA
needs
to
evaluate
cumulative
effects
of
cypermethrin
with
other
pyrethroids
and
with
synergists.
o
Response
to
7C:
The
EFED
does
not
do
cumulative
environmental
risk
assessments.
The
toxicity
of
pyrethroids
and
PBO
is
considered
in
the
individual
risk
assessments
of
the
pyrethroids
when
data
are
available;
however,
the
cypermethrin
products
employed
for
agricultural
uses
that
bring
major
exposure
to
wildlife
do
not
typically
contain
PBO.

SFE
Comment
8:
Risk
Management:
 
Restrict
above­
ground,
urban,
outdoor
uses
of
cypermethrin
 
These
applications
include
applications
around
buildings
and
applications
on
lawns
and
in
gardens.
Preconstruction
termiticide
applications
may
also
be
subject
to
washoff
if
treated
surfaces
are
not
covered
and
protected
from
rain
and
runoff
before
the
next
storm.
These
applications
have
not
been
necessary
in
San
Francisco,
which
proves
that
there
are
safer
alternatives
to
cypermethrin.
 
Complete
an
alternatives
assessment
 
Need
to
ensure
that
alternatives
for
cancelled
pesticide
uses
are
indeed
safer
for
human
health
and
the
environment.
A
cursory
alternatives
assessment
will
reveal
a
wide
range
of
effective,
safer
alternatives,
which
should
provide
the
Agency
with
solid
justification
for
restricting
the
use
for
ant
control
in
urban
areas.
 
Include
local
government
costs
in
benefit
assessment
 
The
Agency
should
consider
the
costs
that
cypermethrin
reregistration
decision
could
create,
such
as
waste
disposal
and
health
care
costs
are
potentially
significant,
they
could
change
the
outcome
of
a
benefits
assessment.
 
Label
should
limit
the
number
of
applications
per
year
 
This
applies
to
all
the
pyrethroids.
 
Labels
should
preclude
outdoor
applications
prior
to
forecasted
rain.

Response
to
SFE
Comment
8:
Please
refer
to
the
Reregistration
Eligibility
Decision
for
Cypermethrin.
27
FMC
Response
(
MRID#
467759­
01)

FMC
Comment
1:
The
Science
Chapter
notes
that
cypermethrin
and
other
pyrethroids
have
been
found
in
sediments
of
urban
streams,
possibly
resulting
from
runoff
from
lawn
care
uses.
It
is
appropriate
to
raise
the
issue
of
urban
uses
in
the
Problem
Formulation.
This
would
also
be
an
appropriate
place
to
state
that
urban
uses
will
not
be
addressed
in
the
risk
assessment.

Response
to
FMC
Comment
1:
EFED
acknowledges
that
FMC
is
correct
in
its
recommendation
about
inclusion
of
urban
issues
in
the
problem
formulation.
Perceptions
of
the
issue
have
changed
since
the
chapter
was
written.
However,
rewriting
the
problem
formulation
to
include
these
additional
issues
will
not
impact
the
risk
characterization
or
the
risk
mitigation.
The
Agency
did
raise
the
issue
of
pyrethroid
contamination
of
urban
streams
in
the
problem
formulation.
However,
at
this
point
the
Agency
is
limited
in
its
ability
to
assess
the
risk
to
these
aquatic
communities
adjacent
to
urban
developments.

FMC
Comment
2:
With
respect
to
the
paragraph
summarizing
Dr.
Weston's
work
on
urban
monitoring
III.
C.
1.
a
(
4)
a.
Residue
Monitoring
(
non­
agricultural),
the
FMC
poses
the
following
questions:
1)
How
widespread
is
this
condition
in
space
and
time?
2)
How
do
pyrethroids
get
into
the
sediments
of
urban
streams?
3)
Are
species
affected
other
than
Hyallela
azteca?

Response
to
FMC
Comment
2:
At
this
early
stage,
Dr.
Weston's
work
poses
as
many
new
questions
as
it
provides
answers.
As
cypermethrin
is
widely
used
in
urban
areas,
there
is
a
possibility
that
concentrations
in
sediments
are
widespread.
Pyrethroids
typically
get
to
surface
water
through
some
combination
of
spray
drift,
washoff
and
adsorbed
to
eroding
soil.
There
is
no
reason
at
this
time
to
expect
that
the
route
would
be
different
in
this
case.
The
work
done
by
Don
Weston
was
a
preliminary
study
to
see
if
future
research
should
be
conducted.
The
study
was
limited
to
one
urban
community
and
samples
were
generally
taken
close
to
points
of
entry
(
culvert
opening
etc).
There
was
no
attempt
to
assess
spatial
and
temporal
distribution
of
contaminants.
It
is
assumed
that
pesticides
reached
the
urban
streams
as
a
result
of
runoff
from
impermeable
surfaces
(
walkways,
streets,
etc.)
and/
or
runoff
or
erosion
from
irrigated
lawns.
Weston
did
not
specify
impacts
to
aquatic
communities.
The
studies
were
set­
up
to
evaluate
in
situ
toxicity
(
toxic
units)
of
prevalent
pyrethroids
that
were
found
in
the
sediments.

FMC
Comment
3:
Section
II.
B.
3.
Ecosystems
at
Risk.
The
FMC
contends
that
this
section
does
not
address
ecosystems
at
risk.
It
simply
reiterates
the
list
of
taxonomic
groups
"
of
potential
concern."
It
could
be
simplified
to
state
that
"
all
aquatic
and
terrestrial
organisms
could
potentially
be
exposed
to
cypermethrin."
It
does
not
state,
for
example,
the
relationship
between
aquatic
or
terrestrial
exposure,
and
proximity
to
sites
of
cypermethrin
use,
or
the
factors
that
determine
whether
exposure
will
be
dominated
by
spray
drift
or
erosion.
28
Response
to
FMC
Comment
3:
EFED
typically
does
not
address
the
relationship
between
aquatic
or
terrestrial
exposure,
but
clearly
there
are
linkages
that
could
be
explored.
Preliminary
work
by
the
PWG
would
indicate
that
exposure
in
agricultural
areas
may
be
dominated
by
spray
drift
in
some
locations
and
erosion
in
others.
Routes
of
exposure
in
urban
areas
have
yet
to
be
positively
determined.
Ecosystem
at
Risk
was
a
general
assessment
of
the
potential
for
cypermethrin
exposure
and
toxic
risk
to
aquatic
organisms.

FMC
Comment
4:
The
EPA
has
adopted
a
tiered
approach
to
conduct
aquatic
and
terrestrial
risk
assessments.
The
predicted
concentrations
reflect
the
cumulative
effect
of
numerous
conservative
assumptions
used
in
the
analysis,
for
example,
the
input
parameters
"
exaggerate"
persistence,
use
of
maximum
label
rate,
use
of
standard
pond
(
closed
system),
many
of
the
Tier
II
crop
scenarios
over­
estimate
soil
erosion,
high
spray
drift
loadings
are
assumed
with
every
event.
Many
of
these
factors
are
being
examined
by
the
PWG
at
this
time.

Response
to
Comment
4:
The
Agency's
tiered
approach
is
designed
to
estimate
exposure
at
a
few
"
high­
exposure"
sites
where
occasional
combinations
of
factors
may
produce
high
end
concentration
values.
If
high­
exposure
sites
can
be
shown
to
be
safe,
it
will
reduce
expenditure
of
Agency
resources
in
investigating
the
extent
of
lower
exposure
sites.
If
safety
cannot
be
demonstrated
at
high­
exposure
sites,
additional
work
may
need
to
be
done.
The
Agency
together
with
the
PWG
is
exploring
those
factors
that
would
lead
to
lower
concentration
values
in
some
locations.
When
PWG
completes
their
evaluation,
the
Agency
may
possibly
refine
its
assessment.

FMC
Comment
5:
These
uncertainties
impact
the
EFED's
preliminary
(
screening­
level)
aquatic
risk
assessment.

Response
to
FMC
Comment
5:
The
Agency
agrees.
This
screening
level
assessment
does
represent
exposure
at
high­
exposure
sites.
The
PWG
work
is
expected
to
give
a
distribution
of
concentration
values
for
pyrethroids
across
a
broader
range
of
sites.

FMC
Comment
6:
The
EFED
said
under
"
Source
and
Intensity"
that
there
are
four
different
cypermethrin
products
(
alpha­,
beta­,
theta,
and
zeta­
cypermethrin).
The
FMC
indicates
that
the
EFED
should
state
whether
all
isomer
mixtures
will
be
treated
as
a
single
group,
or
whether
distinctions
will
be
made
among
them.
FMC
noted
that
several
trv's
were
from
beta­
cypermethrin.
This
should
be
addressed
in
the
Problem
Formulation.
The
PWG
ecological
assessment
is
expected
to
include
an
evaluation
of
the
relative
toxicity
of
the
pyrethroid
isomers.

Response
to
FMC
Comment
6:
As
a
screening
level
assessment,
the
cypermethrin
isomer
data
were
treated
as
bridging
data
(
the
registrants
requested
a
waiver
on
toxicity
studies
for
the
different
isomers).
Since,
the
range
in
cypermethrin
(
isomers)
toxicity
to
non
target
organisms
was
considered
to
be
similar
enough
(
1X
 
4X),
the
Agency
used
all
of
the
available
information
in
the
cypermethrin
RED.
29
FMC
Comment
7:
The
FMC
states
that
the
definitions
of
measures
of
effect
and
assessment
endpoints
are
confusing
(
p.
15
of
FMC
report).
They
indicate
that
measures
of
effect
are
better
defined
as
"
attributes
of
an
ecological
entity
(
the
assessment
endpoint
or
a
surrogate)
that
are
actually
measured,
and
from
which
effects
on
assessment
endpoints
are
inferred."
They
indicate
that
the
assessment
endpoints
are
at
the
population
and
community
level;
the
measures
of
effect
are
at
the
individual
level.
They
state
that
Table
3.
Summary
of
Assessment
and
Measures
of
Effect
for
Cypermethrin
is
also
inconsistent
in
its
reference
to
individuals,
populations
and
communities.

Response
to
FMC
Comment
7:
Table
3
is
not
inconsistent.
Measures
of
effect
reflect
the
parameters
evaluated
in
the
toxicity
studies
that
are
routinely
submitted
to
the
Agency
(
e.
g.,
acute
studies:
LC50,
LD50,
EC50;
Chronic
studies
reproduction
studies,
early
life
stage
studies,
full
life
cycle:
NOAEC).
The
toxicity
values
derived
from
these
laboratory
derived
measurements
of
effect
are
used
in
the
risk
assessment
in
order
to
predict
potential
risk
to
non
target
organisms
in
the
environment.
The
assessment
endpoints
represent
the
environmental
relevant
system
that
the
measures
of
effect
could
show
potential
impact.
For
example,
the
chronic
studies
that
indicate
significant
reproductive
effects
for
invertebrates(
measure
of
effect)
may
be
used
to
extrapolate
the
potential
for
a
decrease
in
invertebrate
community
diversity
(
assessment
endpoint)
and
the
secondary
effects
(
e.
g.
fish
grow)
to
organisms
that
are
dependent
upon
invertebrates
as
a
food
source.

FMC
Comment
8:
The
Conceptual
Model
is
too
generic
and
at
a
minimum
should
address
the
following
items:
 
Aquatic
exposure
scenarios
(
farm
pond
adjacent
to
treated
field)
 
Use
factors
influencing
drift,
runoff
and
erosion
 
Climate
and
soil
factors
influencing
drift,
runoff
and
erosion
 
Landscape
factors
influencing
drift,
runoff
and
erosion
 
Environmental
fate
processes
in
receiving
water
 
Partitioning
to
sediment
 
Bioavalability
and
bioaccumulation
in
water
column
and
sediment
 
Food
chain
transport
 
Direct
acute
and
chronic
effects
in
water
column
 
Direct
acute
and
chronic
effects
in
sediment,
and
 
Indirect
effects
For
each
of
these
elements,
the
conceptual
model
should
specify
assumptions
and
uncertainties
about
the
process.

Response
to
FMC
Comment
8:
The
Conceptual
Model
is
intended
to
be
relatively
general,
especially
for
a
document
as
large
and
complicated
as
a
RED.
Clarity
is
the
intent
of
the
Conceptual
Model.
However,
the
Agency
agrees
that
some
of
the
points
could
be
added
to
include
direct
acute
and
chronic
effects
in
water
column,
direct
acute
and
chronic
effects
in
sediment,
and
indirect
effects
through
food
chain
depletion
and
bioaccumulation.
However,
these
additions
would
not
ultimately
affect
the
conclusions
of
this
risk
assessment.
30
FMC
Comment
9:
Risk
in
Sediments
 
The
use
of
the
EqP
approach
depends
on
reliable
estimates
of
the
KOC.
The
PWG
and
others
are
developing
methods
to
measure
more
accurately
the
freely
dissolved
pore
water
pyrethroids,
using
SPME
(
Solid
Phase
Microextraction)
techniques.
However,
in
the
end,
the
EFED
did
not
use
the
method
described
in
the
problem
formulation
(
EqP
approach)
and
used
existing
sediment
toxicity
testing.

Response
to
FMC
Comment
9:
It
is
true
that
toxicity
data
were
used
to
evaluate
acute
risk
to
benthic
invertebrates
exposed
to
cypermethrin
in
the
sediment
based
on
the
appropriate
most
sensitive
available
data
(
as
stated
above
in
the
Agency's
Response
to
CRWQCB
Comment
12
and
13),
and
that
the
EqP
method
is
typically
used
by
the
Agency
in
the
absence
of
appropriate
sediment
toxicity
data.
However,
EFED
also
typically
estimates
risk
to
benthic
invertebrates
resulting
from
exposure
to
a
chemical
in
pore
water.
Therefore,
the
equilibrium
partitioning
approach
had
to
be
employed
in
this
instance
because
cypermethrin
toxicity
data
based
on
pore
water
concentrations
were
not
available.
In
one
study
pore
water
concentrations
were
not
measured
(
MRID
44074402),
and
in
the
other
the
concentrations
were
below
the
LOD
(
MRID
44074406).
The
EFED
recognizes
that
additional
sediment
toxicity
data
with
LC50'
s
based
on
both
sediment
and
pore
water
concentrations
have
been
submitted
by
the
PWG
for
use
in
this
assessment.
However,
these
data
are
currently
under
review
and
may
be
incorporated
at
a
later
date
if
deemed
appropriate.

FMC
Comment
10:
There
seems
to
be
no
scenario
description
(
pp.
34­
37
of
the
Science
Chapter).
The
standard
pond
scenario
assumes
a
1­
ha
pond,
2­
m
deep,
receives
drift
and
runoff/
erosion
from
a
10
ha
watershed,
consisting
entirely
of
treated
crop.
Other
assumptions,
such
as
constant
pond
volume
also
affect
the
EEC's.

Response
to
FMC
Comment
10:
The
assumptions
of
the
standard
pond
scenario
are
usually
described
in
each
risk
assessment.

FMC
Comment
11:
The
risk
to
benthic
organisms
can
be
presumed
to
be
due
to
potential
chronic
effects
rather
than
acute
effects
because
the
concentrations
in
the
pore
water
are
much
lower
than
in
the
water
column.

Response
to
FMC
Comment
11:
This
is
only
a
presumption
made
by
FMC.
Acute
effects
may
not
be
precluded
if
the
concentrations
of
cypermethrin
reach
certain
levels.
Pore
water
RQ
values
suggest
that
acute
and
chronic
risk
from
sediment
exposure
can
potentially
impact
benthic
invertebrates.

FMC
Comment
12:
The
Science
Chapter
did
not
include
quantitative
exposure
in
an
estuarine/
marine
environment.
The
standard
farm
pond
EEC's
was
used
as
surrogates
in
lieu
of
the
exposure
of
estuarine/
marine
environment.
Because
this
assumption
is
tenuous
and
largely
untested,
the
assessment
does
not
support
conclusive
statements
about
risk
to
estuarine/
marine
organisms.
31
Response
to
FMC
Comment
12:
The
standard
pond
scenario
is
currently
accepted
by
the
EFED
and
used
to
generate
EEC
values
for
estuarine/
marine
organisms.

FMC
Comment
13:
Sentences
in
III.
B.
1.
a.
Summary
of
Empirical
Data,
and
III.
B.
1.
d.
Bioaccumulation,
are
inconsistent
with
respect
to
the
characterization
of
the
bioaccumulation
and
depuration
in
fish
of
cypermethrin.

Response
to
FMC
Comment
13:
The
EFED
appreciates
the
identification
of
this
error;
however,
this
is
a
minor
error
that
does
not
compromise
the
quality,
conclusions,
or
the
integrity
of
the
risk
assessment.

FMC
Comment
14:
Data
selection:
FMC
indicates
that
the
reviewer
may
have
overlooked
a
Daphnia
magna
acute
toxicity
study
(
MRID
43293501;
Wheat
and
Evans,
1994),
with
48
hr
EC50
=
161.5
ppt
=
161.5
ng
ai/
L
[
not
µ
g
a.
i./
L
as
it
was
reported
in
the
Chapter].
This
value
is
lower
than
the
lowest
value
reported
in
the
Science
Chapter.

Response
to
FMC
Comment
14:
MRID
43293501
was
not
overlooked
in
the
document
and
was
correctly
not
used
to
calculate
risk
to
freshwater
invertebrates;
rather,
MRID
43293501
was
misclassified
in
the
RED.
The
individual
data
evaluation
record
for
the
study
indicates
that
it
was
not
scientifically
sound
because
there
was
significant
contamination
of
the
controls.
The
study
report
itself
also
states
that
the
measured
"
residues
from
the
cypermethrin
exposure 
did
not
follow
a
serial
dilution
pattern"
and
that
the
"
analysis
of
test
samples
failed
to
yield
useful
results."
Therefore,
the
study
should
have
been
classified
as
Invalid
and
should
not
have
been
discussed
in
the
RED.

FMC
Comment
15:
EFED's
rationale
to
reject
EPAIDENT
00089047
does
not
apply
to
the
calculation
of
the
NOEC
for
the
most
sensitive
endpoint
(
refer
to
p.
19
of
58
of
FMC
report).

Response
to
FMC
Comment
15:
Unfortunately
the
study
in
question
had
several
problems
that
included
the
following:
negative
control
contamination;
delivery
lines
for
treatment
1
and
2
were
switched
for
4
days;
mortality
in
2
of
the
4
replicates
for
solvent
controls
exceeded
30%;
Dissolved
oxygen
levels
were
not
maintained
above
60%
throughout
the
test.
Because
of
these
problems
the
Agency
deemed
this
study
invalid
and
has
required
that
a
new
study
be
conducted.

FMC
Comment
16:
The
chronic
NOAEC
for
waterflea
calculated
using
the
acute:
chronic
ratio
resulted
in
a
NOAEC
4­
11
fold
higher
than
measured
values.
There
is
uncertainty
in
the
applicability
of
the
acute:
chronic
ratio
method,
particularly
considering
the
large
difference
in
acute
sensitivity
of
the
two
species.

Response
to
FMC
Comment
16:
The
Agency
understands
the
uncertainty
in
calculating
a
NOAEC
using
an
acute:
chronic
ratio.
However,
the
measured
values
from
the
daphnid
life
cycle
study
were
not
acceptable
as
noted
previously.
32
FMC
Comment
17:
The
trv
for
estuarine/
marine
fish
was
0.95
µ
g
a.
i./
L
(
sheephead
minnow,
MRID
90075).
FMC
did
not
examine
the
study
44546033
that
reports
a
third
sheephead
minnow
study
because
FMC
does
not
have
access
to
this
study
(
it
was
conducted
with
beta­
cypermethrin).

Response
to
FMC
Comment
17:
EFED
defers
this
issue
to
the
SRRD.
The
responsibility
of
data
compensation
belongs
to
the
SRRD.
However,
the
value
used
by
the
Agency
is
0.95
ug
ai/
L
and
is
the
worst
case.

FMC
Comment
18:
The
acute
to
chronic
ratios
should
be
calculated
with
trv's
of
the
same
species,
if
available,
not
the
lowest
trv.

Response
to
FMC
Comment
18:
The
Agency
agrees.
However,
the
availability
of
data
on
the
same
species
or
even
genus,
is
rare.
Therefore,
the
Agency
will
use
the
best
information
that
is
available
in
order
to
make
necessary
extrapolations.
This
is
done
with
a
complete
understanding
and
acknowledgment
of
the
inherent
uncertainties.

FMC
Comment
19:
EFED
considers
data
from
water­
only
studies
with
benthic
organisms
to
be
representative
of
organisms
living
in
the
water
column.
In
the
analysis
of
effects
on
estuarine/
marine
invertebrates,
toxicity
data
from
benthic
and
open
water
species
were
combined.
Yet
in
the
analysis
of
effects
on
freshwater
invertebrates,
the
Science
Chapter
separated
toxicity
data
for
benthic
species
from
data
for
Daphnia
magna,
and
used
Daphnia
magna
as
a
surrogate
for
all
freshwater
water
column
invertebrates.
Data
from
water­
only
studies
with
freshwater
invertebrate
species
considered
to
be
benthic
were
not
used
in
the
effects
characterization
for
the
water
column.
(
Not
all
of
the
test
organisms
listed
as
benthic
in
Table
E­
4
are
actually
sediment
dwellers;
for
example,
adult
whirligigs
(
Gyrinus),
backswimmers
(
Notonecta),
water
boatmen
(
Corixa),
and
water
mites
(
Piona).)
The
segregation
of
benthic
from
water
column
species
was
not
discussed,
and
no
justification
was
presented.
By
segregating
data
from
benthic
and
water
column
species
this
assessment
deviates
from
EPA's
stated
practice
of
basing
screening
level
RQs
on
the
most
sensitive
species
in
each
category
of
organisms.
Daphnia
magna
is
in
fact
the
least
sensitive
of
the
five
freshwater
crustacean
species
for
which
water­
only
toxicity
data
are
presented
in
Appendix
E.
As
has
been
found
for
other
synthetic
pyrethroids,
amphipods
(
Gammarus
and
Hyalella)
are
substantially
more
sensitive
than
Daphnia
magna.
If
data
from
all
water­
only
toxicity
tests
with
freshwater
invertebrates
were
used
to
characterize
effects
on
water
column
species,
the
Toxicity
Reference
Value
would
have
been
0.0036
µ
g/
L
(
Hyalella
azteca,
96­
h
LC50,
p.
E­
38)
rather
than
0.42
µ
g/
L
(
Daphnia
magna,
48­
h
EC50,
p.
E­
23).
RQs
for
freshwater
invertebrates
would
have
been
approximately
100
times
greater
than
those
calculated
in
the
Science
Chapter.
Use
of
Daphnia
magna
data
to
represent
all
water
column
invertebrates
reduces
the
apparent
risk
of
cypermethrin.
Attention
is
drawn
to
it
here
for
two
reasons:
Inconsistent
application
of
data
selection
strategies
for
screening
level
assessments
leads
to
confusion
and
subjectivity
in
what
should
be
a
transparent
process.
33
Response
to
FMC
Comment
19:
The
Agency
acknowledges
that
some
of
the
species
listed
in
the
table
referring
to
Freshwater
Benthic
Invertebrates
are
not
benthic
(
e.
g.,
adult
whirligigs
(
Gyrinus),
backswimmers
(
Notonecta),
water
boatmen
(
Corixa),
and
water
mites
(
Piona)).
EFED
also
agrees
that
the
data
for
aquatic
invertebrates
would
have
been
most
transparently
separated
based
on
water
column
toxicity
(
studies
with
water­
only
systems)
data
and
sediment
toxicity
(
studies
with
water­
sediment
systems)
data.

The
two
most
important
considerations
when
selecting
toxicity
data
to
characterize
risk
to
a
specific
taxonomic
group
are
whether
the
data
are
the
most
sensitive
available
and
whether
the
exposure
scenario
under
which
the
endpoints
were
derived
are
appropriate
and
representative
of
that
group
of
organisms.
The
RED
explicitly
states
in
Appendix
E:

"
In
the
water
system
studies,
organisms
were
exposed
only
to
cypermethrin
in
overlying
water;
there
was
no
sediment
in
the
test
chamber.
Thus,
while
data
from
these
studies
provide
information
regarding
the
sensitivity
of
benthic
organisms
to
cypermethrin
in
surface
water,
no
data
from
these
studies
regarding
exposure
to
cypermethrin
in
sediment
are
available.
Therefore,
data
are
insufficient
for
use
in
quantifying
risks
to
benthic
organisms,"
and
"
studies
using
the
water­
sediment
system
more
accurately
depict
the
environmental
exposure
of
benthic
organisms
than
the
water
system
studies."

Therefore,
only
those
studies
that
exposed
sediment
dwellers
to
cypermethrin
in
a
watersediment
system
were
considered
appropriate
for
determining
risk
to
benthic
organisms.
The
only
two
studies
that
met
these
criteria
were
MRID
44074402
and
MRID
44074406.

EFED
agrees
that
it
may
be
appropriate
to
use
the
study
with
Hyallella
(
MRID
44423501)
to
characterize
risk
to
freshwater
water
column
dwelling
species
because
this
species
can
spend
time
in
both
the
water
column
and
benthos
and
because
the
study
was
conducted
in
a
water­
only
system.
However,
the
EFED
reviewer
exercised
best
professional
judgment
and
chose
the
Daphnia
measurement
endpoint
because
the
use
of
this
endpoint
allows
for
a
comparative
analysis
of
toxicity
to
most
other
chemicals.
Although
the
96­
hour
LC50
value
of
0.0036
µ
g
a.
i./
L
for
Hyalella
azteca
(
based
on
a
water­
only
system)
may
be
appropriate
for
determining
risk
to
all
freshwater
water
column
dwelling
organisms,
freshwater
invertebrate
RQs
still
exceeded
all
acute
LOCs
(
RQ
range=
0.4
­
4.8)
when
based
on
the
48­
h
EC50
value
of
0.42
µ
g
a.
i./
L
for
Daphnia
magna.
If
based
on
the
endpoint
for
Hyalella,
RQs
would
be
approximately
100
times
higher
and
range
from
49.4
to
558.3.

In
addition,
chronic
RQs
for
freshwater
invertebrates
would
also
increase
if
the
Hyalella
measurement
endpoint
is
used.
Because
no
chronic
data
were
available
for
freshwater
invertebrates,
a
surrogate
NOAEC
toxicity
value
was
derived
to
calculate
chronic
RQs
for
this
taxonomic
group.
Previously,
the
chronic
NOAEC
estimated
for
freshwater
invertebrates
was
based
on
the
acute­
to­
chronic
ratio
method,
determined
by
using
the
acute
Daphnia
measurement
endpoint
and
the
following
mathematical
relationship:
34
Estuarine/
marine
invertebrate
LC50
(
0.00475
µ
g
a.
i./
L)
/
Estuarine/
marine
invertebrate
NOAEC
(
0.000781
µ
g
a.
i./
L)
=
Freshwater
invertebrate
LC50
(
0.42
µ
g
a.
i./
L)/
X
(
estimated
value
for
Freshwater
invertebrate
NOAEC),
where
X
=
0.069
µ
g
a.
i./
L.

Based
on
this
derived
NOAEC
for
freshwater
invertebrates,
chronic
RQs
exceeded
chronic
LOCs
and
ranged
from
0.5
to
2.8.
However,
because
a
more
sensitive
endpoint
has
now
been
identified,
a
chronic
NOAEC
can
be
estimated
for
freshwater
invertebrates
using
the
acute
Hyalella
measurement
endpoint
and
the
following
mathematical
relationship:

Estuarine/
marine
invertebrate
LC50
(
0.00475
µ
g
a.
i./
L)
/
Estuarine/
marine
invertebrate
NOAEC
(
0.000781
µ
g
a.
i./
L)
=
Freshwater
invertebrate
LC50
(
0.0036
µ
g
a.
i./
L)/
X
(
estimated
value
for
Freshwater
invertebrate
NOAEC),
where
X
=
0.00059
µ
g
a.
i./
L.

Based
on
this
newly
estimated
NOAEC
value,
chronic
RQs
for
freshwater
invertebrates
would
be
approximately
100
times
higher
and
range
from
57.6
to
325.4.
Therefore,
while
use
of
the
Daphnia
EC50
value
may
foster
a
comparative
analysis,
its
use
may
also
result
in
RQs
that
underestimate
acute
and
chronic
risk
to
freshwater
water
column
dwelling
invertebrates.

This
issue
was
also
addressed
in
the
Addendum
to
the
EFED
RED
Chapter
for
Cypermethrin.

FMC
Comment
20:
The
analysis
based
on
Daphnia
magna
leads
EFED
to
the
erroneous
conclusion
that
estuarine/
marine
invertebrates
are
substantially
more
sensitive
to
cypermethrin
than
freshwater
invertebrates.
Section
III.
C.
1.
Aquatic
Effects
Characterization
(
p.
51).
The
EFED
states
that
for
estuarine/
marine
invertebrates,
the
lowest
LC50
value
reported
is
0.00475
µ
g
a.
i./
L,
which
is
100
times
lower
than
reported
for
other
aquatic
animals.
The
FMC
states
that,
data
for
freshwater
amphipods
was
ignored
(
e.
g.
Hyalella
azteca
and
Gammarus
species),
which
are
approximately
100
times
more
sensitive
than
Daphnia
magna.
Moreover,
the
relative
sensitivities
would
be
better
represented
by
means,
medians
or
Entire
Sensitivity
Distributions.
The
EFED
statement
also
says
that
estuarine/
marine
invertebrates
are
expected
to
be
the
species
at
greatest
risk.
The
FMC
believes
that
the
statement
may
be
incorrect,
and
based
on
studies
not
yet
published,
freshwater
and
marine
invertebrates
are
approximately
equal
in
their
sensitivity
to
cypermethrin.

Response
to
FMC
Comment
20:
The
EFED
does
not
use
means,
medians,
or
Entire
Sensitivity
Distributions
in
screening­
level
risk
assessments,
but
rather,
bases
risk
conclusions
on
the
most
relevant
and
sensitive
data
available.
The
EFED
acknowledges
that
it
may
be
considered
appropriate
to
use
the
study
with
Hyallella
(
MRID
44423501)
to
characterize
risk
to
freshwater
water
column
dwelling
species
(
Please
refer
to
the
Agency's
response
to
FMC
comment
19),
and
that
based
on
such
an
analysis,
the
sensitivity
of
and
risk
to
estuarine/
marine
invertebrates
is
on
par
with
freshwater
35
invertebrates.
However,
while
the
EFED
cannot
comment
on
the
unpublished
data
mentioned
above,
the
increased
sensitivity
of
estuarine/
marine
invertebrates
does
appear
to
be
consistent
among
other
pyrethroids
and
may
be
correlated
with
osmoregulation.

FMC
Comment
21:
Even
if
marine
invertebrates
were
more
sensitive
than
freshwater
invertebrates,
the
final
part
of
the
statement
 
"
Thus,
estuarine/
marine
invertebrates
are
expected
to
be
the
species
at
greatest
risk
for
acute
effects
(
lethality)."
would
be
inappropriate
unless
accompanied
by
valid
exposure
estimates
for
the
estuarine/
marine
environments.

Response
to
FMC
Comment
21:
Please
refer
to
the
Agency's
response
to
FMC
comments
12,
19,
and
20.

FMC
Comment
22:
Laskowski
established
that
the
KOC
for
cypermethrin
is
310,000.
Use
of
the
Laskowski
(
2002)
Koc
value
in
this
calculation
and
in
PRZM/
EXAMS
would
reduce
the
estimates
of
cypermethrin
concentrations
in
pore
water.
If
this
value
is
used,
the
estimates
of
toxicity
of
Hyalella
azteca
LC50
for
Florissant
sediment
in
units
of
OC
are
as
follows:
Florissant
(
0.99%
OC)
 
Bulk
sediment
LC50
3.6
µ
g
ai/
Kg
sediment
 
OC­
normalized
LC50
364
µ
g
ai/
Kg
sed
OC)
 
Pore
Water
LC50
0.00257
µ
g
ai/
L
FMC
provides
the
values
for
Mississippi
3.1%
OC
and
Duluth
13.3%
OC.
The
results
show
that
cypermethrin
is
more
toxic
in
the
Florissant
sediment
when
represented
in
Bulk
Sediment
LC50;
however,
the
chemical
is
more
toxic
when
represented
in
units
of
OCnormalized
LC50
or
Pore
Water
LC50.

Response
to
FMC
Comment
22:
The
Agency
used
the
Koc
=
141,
700.
This
value
represents
the
average
from
Koc
=
20,800
 
328,500.
Although
the
EFED
chose
to
select
the
most
sensitive
measurement
endpoints
based
on
the
measurement
endpoints
represented
in
bulk
sediment,
RQs
for
benthic
organisms
would
still
exceed
the
acute
risk
LOCs
regardless
of
whether
they
were
calculated
using
the
most
sensitive
bulk
sediment
toxicity
values
or
the
most
sensitive
OC­
normalized
pore
water
toxicity
values.

FMC
Comment
23:
As
noted
in
the
Science
Chapter,
the
PWG
submitted
new
cypermethrin
sediment
toxicity
studies
with
benthic
organisms
to
EFED.
The
results
will
provide
a
broader
understanding
of
the
toxicity
and
bioavailability
of
pyrethroids
in
sediments.

Response
to
FMC
Comment
23:
These
studies
have
been
received
by
EFED
and
are
still
in
review.

FMC
Comment
24:
III.
C.
1
Aquatic
Effects
Characterization
(
p.
32).
It
is
stated
that
in
most
studies,
the
NOAEC
is
2­
to
3­
fold
lower
than
the
LC50
(
exception
rainbow
trout
and
bluegill
sunfish).
III.
C.
i.
a(
3)
Sublethal
Effects
(
p.
62)
The
NOAEC
values
cited
for
Bluegill
sunfish
and
Rainbow
trout
are
incorrect.
The
NOAEC
units
are
mg/
L
instead
of
µ
g/
L;
therefore
36
Rainbow
trout
LC50
=
0.8
µ
g
a.
i./
L
NOAEC
=
0.68
µ
g/
L
Bluegill
sunfish
LC50
=
2.2
µ
g
a.
i./
L
NOAEC
<
2.2
µ
g/
L
Response
to
FMC
Comment
24:
The
Agency
will
address
this
units
correction
in
an
addendum
to
the
EFED
Science
Chapter.

FMC
Comment
25:
II.
B.
3.
Ecosystems
at
Risk,
p.
12,
EFED
states
that
several
aquatic
field
studies
are
available
and
will
be
incorporated
into
the
risk
characterization.
III..
C.
1.
a.(
4)
Field
Studies,
p.
64
EFED
states
that
the
results
are
not
sufficient
for
use
in
quantitative
assessments,
but
will
be
used
qualitatively.
There
is
a
discrepancy
between
the
two
statements.
The
FMC
indicates
that
the
field
studies
are
useful
for
rounding
out
the
description
of
effects
and
for
adding
perspective
to
the
interpretation
of
standard
toxicity
data,
rather
than
the
dose­
response
relationships.
Information
such
like
comparison
of
magnitude
of
effects
on
different
species,
on
populations
as
individuals,
and
short
term
versus
long
term
impacts.

Response
to
FMC
Comment
25:
The
Agency
agrees
and
included
a
qualitative
statement
in
the
risk
assessment.
In
general
the
studies
found
that
some
species
of
invertebrates
were
impacted
and
that
opportunistic
species
increased
in
numbers.
However,
the
increase
in
biomass
of
species
that
are
not
a
viable
food
source
for
fish
was
also
mentioned.
Keystone
species
were
generally
impacted
and
the
diversity
of
communities
was
affected
in
several
cases.
Recovery
was
a
great
uncertainty.
Some
species
recolonized
the
area
within
a
few
weeks
while
others
did
not.
The
studies
looked
at
one
application.
Spatial
and
temporal
assessment
of
community
impact
and
recovery
was
not
achieved,
which
raises
more
uncertainty
as
to
the
realistic
impact
of
cypermethrin
on
aquatic
ecological
systems
over
time.

FMC
Comment
26:
III.
C.
1.
a.(
4)
Field
Studies,
p.
64.
The
EFED
stated
that
sublethal
effects
were
observed
for
8
days
following
application
(
0.0012­
0.089
lb
a.
i./
A)
and
were
attributed,
in
part
to
exposure
to
cypermethrin
from
ingestion
of
dead
and
dying
invertebrates.
The
FMC
observes
that
three
studies
show
no
sublethal
effects
at
rates
from
0.0012
to
0.089
lb
a.
i./
A.
The
study
discussed
above
is
inconsistent
with
the
other
evidence
and
additional
analyses
should
be
made
to
determine
if
food­
chain
exposure
is
plausible
(
presumed
bioconcentration).

Response
to
FMC
Comment
26:
The
Agency
agrees
that
an
evaluation
of
food
chain
exposure
would
be
beneficial.
However,
based
on
the
currently
available
data
from
Davies
and
Cook
(
1993),
the
Agency
cannot
discount
the
possiblity
that
the
sublethal
effects
(
fish
lethargy)
noted
in
the
study
were
the
result
of
the
consumption
of
cypermethrin
residues
in
dying
or
dead
invertebrates.

FMC
Comment
27:
IV.
A.
1.
b.
Sediment
Exposure
 
Acute
and
Chronic
Risk
(
p.
72).
The
EFED
indicates
that
the
acute
RQ
for
pore
water
and
chronic
RQ
from
sediment
and
pore
water
were
derived
from
a
sediment
toxicity
study
that
had
considerable
uncertainty
surrounding
it.
The
system
was
not
at
equilibrium.
FMC
considers
that
equilibrium
is
unlikely
in
a
sediment
toxicity
test
system.
Other
source
of
error
in
the
EqP
approach
is
37
the
natural
variability
of
KOC
and
sediment
organic
matter.
However,
the
FMC
believes
that
the
best
approach
is
the
EqP
approach
because
the
percent
OC
may
be
different
in
the
sediment
toxicity
study
vs.
the
PRZM/
EXAMS
run.

Response
to
FMC
Comment
27:
Equilibrium
in
the
sediment
can
be
achieved
in
the
laboratory
(>
one
month
for
pyrethroids)
and
has
been
verified
by
the
EPA
laboratory
at
Duluth,
Minnesota
(
Dave
Mount,
personal
communication).
The
Agency
will
use
actual
sediment
toxicity
tests
values
when
they
are
available.
However,
the
EqP
approach
is
an
acceptable
method
for
deriving
an
estimated
toxicity
value
(
normalized
to
organic
carbon
levels).

FMC
Comment
28:
IV.
B
Risk
Description,
p.
81.
The
EFED
says
that
there
is
the
potential
for
direct
acute
and
chronic
toxic
risk
to
aquatic
life
in
the
water
column
and
the
benthos,
as
well
as
indirect
sublethal
risk
to
fish
through
food
chain
alterations
that
can
affect
freshwater
and
estuarine/
marine
fish
year
classes.
This
potential
risk
is
predicated
on
the
data
pertaining
the
sediment
toxicity.
The
FMC
says
that
there
is
no
data
to
support
these
"
conjectures"
based
on
general
ecological
principles.

Response
to
FMC
Comment
28:
Based
on
general
ecological,
toxicological,
and
risk
assessment
principles,
the
decline
of
aquatic
invertebrate
populations
will
affect
aquatic
communities,
especially
fish
year
class
strength,
fish
species
distribution,
possible
fish
pathology,
as
well
as
the
general
energetics
of
a
balanced
system.
This
has
been
noted
from
several
field
studies
that
showed
a
decline
in
certain
invertebrate
species
(
keystone
species)
and
the
increase
in
other
opportunistic
species
followed
by
a
decline
in
fish
growth.
Given
the
available
information
for
a
screening
level
assessment,
the
Agency
has
made
assumptions
based
on
sound
scientific
principles
that
are
accepted
in
the
science
community
with
regard
to
pyrethroid
effects
on
aquatic
organisms.

FMC
Comment
29:
IV.
A.
1.
c.
Use
of
Buffer
Zones,
p.
75.
The
RQ
in
NC
changed
little
with
an
increase
of
the
buffer
zone.
In
a
CA
scenario,
the
RQ
changed
substantially.
It
is
indicated
that
the
NC
scenario
has
a
small
component
of
drift,
while
the
CA
scenario
has
a
large
component
of
drift.
The
FMC
indicated
that
the
mandated
vegetated
filter
strip
was
not
taken
into
consideration
in
the
model.
The
filter
strip
is
expected
to
decrease
the
level
of
erosion.

Response
to
FMC
Comment
29:
Maintained
buffer
strips
are
a
way
to
decrease
the
level
of
erosion,
but
it
cannot
be
quantified.

FMC
Comment
30:
At
this
time,
the
EFED
does
not
have
any
tools
to
do
quantitative
measurements
of
the
vegetated
filter
strip
to
decrease
the
level
of
erosion.

Response
to
FMC
Comment
30:
We
agree
that
unfortunately
there
are
no
models
to
measure
quantitatively
the
decrease
in
levels
of
erosion
due
to
maintained
vegetated
filter
strips
suitable
for
national
assessments.
38
FMC
Comment
31:
IV.
B.
Risk
Description,
p.
81.
The
Agency
has
identified
acute
and
chronic
risk
concerns 
includes 
aquatic
snails,
clams.
FMC
indicates
that
this
is
the
first
reference
to
mollusks
in
the
chapter.
The
toxicity
data
in
Appendix
E
do
not
support
the
conclusion
of
risk
to
snails
and
clams.
Based
on
data
for
estuarine/
marine
mollusks,
the
Science
Chapter
concluded
that
"
results
of
these
studies
indicate
that
mollusks
are
less
susceptible
than
shrimp
and
crustaceans
to
cypermethrin
toxicity
on
an
acute
basis."

Response
to
FMC
Comment
31:
Although
it
is
true
that
based
on
the
limited
data
on
a
few
oyster
species
alone
mollusks
may
be
less
susceptible
than
shrimp
and
crustaceans
to
cypermethrin
toxicity,
these
data
still
suggest
that
cypermethrin
can
be
classified
as
moderately
to
highly
toxic
to
mollusks.
However,
the
cypermethrin
database
does
not
currently
contain
toxicity
values
for
aquatic
snails,
aquatic
clams,
or
any
freshwater
mollusk,
so
it
is
not
possible
to
preclude
risk
at
this
time
to
these
organisms.
It
is
a
standard
approach
of
the
EFED
to
assess
risk
to
entire
taxonomic
groups
based
on
the
most
sensitive
toxicity
data
available.
To
a
certain
extent,
using
the
most
sensitive
data
available
helps
to
address
the
issue
of
interspecies
variability
and
the
likelihood
that
laboratory
tests
do
not
account
for
all
variables
that
could
influence
species
sensitivity
in
the
environment.
Since
the
most
sensitive
data
for
both
the
freshwater
and
estuarine/
marine
invertebrates
taxonomic
groups
suggested
the
potential
for
risk,
a
general
statement
of
risk
to
all
aquatic
invertebrates
was
made.

FMC
Comment
32:
IV.
B.
4.
Endocrine
Effects,
p.
91.
In
the
study
of
reproductive
effects
in
aquatic
invertebrates,
there
may
be
many
causes
for
the
effects,
such
as
general
toxicity
(
e.
g.
egg
mortality
or
feeding
inhibition).
Equating
those
to
reproductive
effects
is
incorrect.

Response
to
FMC
Comment
32:
The
endocrine
effects
criteria
for
a
screening
level
assessment
is
reproductive
effects.
The
Agency
is
very
aware
that
different
environmental
components
can
contribute
to
effects
on
reproduction,
but
will
use
broad
assumptions
at
this
time.
In
the
future
a
more
refined
evaluation
for
endocrine
effects
will
be
possible
as
appropriate
testing
is
developed.

FMC
Comment
33:
Section
on
endangered
and
threatened
(
listed)
species
(
IV.
B.
5.,
pp.
92­
97)
reflects
the
current
uncertainties
and
ambiguities
about
how
the
guidance
will
be
put
into
practice.
Section
IV.
B.
5.
a.
Action
Area
begins
with
the
observation
that
the
screening
level
assessment
assumes
all
listed
species
inhabit
the
pesticide
treatment
area.
This
assumption
avoids
to
define
the
action
area.
Then
it
continues
with
a
summary
of
OPP's
endangered
species
assessment
process,
rather
than
explaining
the
relevance
or
application
of
the
action
area
concept
to
the
assessment.

Response
to
FMC
Comment
33:
This
is
a
screening
level
assessment.
Specific
information
on
listed
species
is
provided
for
refined
assessments
when
identified.

FMC
Comment
34:
Section
IV.
B.
5.
b
(
Taxonomic
Groups
Potentially
at
Risk):
The
section
begins
by
noting
the
registrant's
responsibility
for
providing
data
on
the
proximity
of
listed
species
to
cypermethrin
use
sites.
The
section
then
provides
a
table
39
with
numbers
of
taxa
in
proximity
to
various
crops
in
each
state
with
no
indication
of
how
such
information
was
obtained
or
what
it
implies
to
the
assessment.
Furthermore,
it
includes
clams
and
snails,
for
which
no
RQs
were
calculated,
and
are
not
generally
sensitive
to
pyrethroids.

Response
to
FMC
Comment
34:
The
goal
of
the
analysis
for
co­
location
is
to
determine
whether
sites
of
pesticide
use
are
geographically
associated
with
known
locations
of
listed
species.
At
the
screening
level,
this
analysis
is
accomplished
using
the
LOCATES
database.
The
database
uses
location
information
for
listed
species
at
the
county
level
and
compares
it
to
agricultural
census
data
for
crop
production
at
the
same
county
level
of
resolution.
The
product
is
a
listing
of
federally
listed
species
that
are
located
within
counties
known
to
produce
the
crops
upon
which
the
pesticide
will
be
used.
For
additional
details
regarding
the
inclusion
of
clams
and
snails,
please
refer
to
the
Agency's
response
to
FMC
comment
31.

FMC
Comment
35:
In
a
section
named
"
Probit
Slope
Analysis",
a
brief
statement
about
calculation
of
the
probability
of
individual
mortality
at
the
listed
species
acute
LOC
is
introduced.
The
results
are
presented
only
for
freshwater
fish.
The
utility
of
these
calculations
is
not
apparent.

Response
to
FMC
Comment
35:
The
Probit
Analysis
is
used
to
estimate
the
chance
for
individual
effects
and
was
part
of
an
agreement
with
the
Alternative
Consultation
for
evaluating
risk
to
listed
species.
The
application
of
these
analyses
occurs
as
a
species
specific
assessment
is
advanced
to
the
determination
of
the
likelihood
of
adverse
effects.

FMC
Comment
36:
Section
IV.
B.
5.
c.
Critical
Habitat,
describes
an
approach
to
evaluate
risk
to
pesticide
effects
on
designated
critical
habitat,
based
on
screening
level
RQs.
However,
no
analysis
is
presented.

Response
to
FMC
Comment
36:
At
present,
the
information
reviewed
by
the
Agency
does
not
permit
use
of
either
analytical
approach
to
make
a
definitive
identification
of
listed
species
that
are
potentially
impacted
indirectly
or
critical
habitats
that
are
potentially
impacted
directly
by
the
use
of
pesticides.
The
screening
level
assessment
for
critical
habitat
only
provides
a
listing
of
potential
biological
features
that,
if
they
are
constituent
elements
of
one
or
more
critical
habitats,
would
be
a
potential
concern.
This
corresponds
to
the
taxa
identification
as
being
of
potential
concern
for
indirect
effects.

FMC
Comment
37:
In
many
places
of
the
Science
Chapter,
the
word
"
endangered"
appears
to
have
been
replaced
to
"
listed."
This
results
in
anomalies
such
as
"
the
Listed
Species
Act,"
p.
17.

Response
to
FMC
Comment
37:
These
minor
errors
do
not
compromise
the
quality
or
conclusions
of
the
risk
assessment,
the
results,
or
the
actual
species
in
the
list
of
endangered/
threatened
species.
The
risk
assessment
will
not
be
revised.
40
FMC
Comment
38:
Assumptions
and
Uncertainties:
Exposure
Analysis
must
be
approached
with
an
understanding
of
the
assumptions
and
limitations
of
the
model:
 
Input
parameters
may
exaggerate
persistence
(
by
means
of
safety
factors).
 
The
maximum
label
rate
is
used.
 
Standard
pond
scenario
is
very
conservative
(
it
is
closed
with
no
flow).
 
Many
PRZM/
EXAMS
combinations
overestimate
soil
erosion
and
consequently
runoff
of
chemicals
like
cypermethrin.
 
Natural
and
engineered
landscape
features
to
attenuate
and
reduce
pesticide
transport
in
runoff
and
drift
are
neglected
(
e.
g.
buffer
strips).
 
High
spray
drift
loadings
are
assumed
to
occur.

Response
to
FMC
Comment
38:
This
is
a
screening
level
assessment.
Actual
monitoring
data
are
not
available.
Models
are
used
in
an
attempt
to
assess
the
potential
for
toxic
exposure
to
non
target
organisms.
Currently
PRZM/
EXAMS
scenarios
prove
to
be
adequate
for
this
type
of
assessment.
However,
if
the
registrant
has
a
more
accurate
model
the
Agency
would
gladly
provide
it's
evaluation.

FMC
Comment
39:
IV.
C.
4.
Assumptions,
Limitations,
Uncertainties,
Strengths
and
Data
Gaps
Related
to
Effects
Assessment,
pp.
101­
102.
There
is
a
discussion
of
two
effects
analysis:
"
differences
in
the
sensitivity
of
individuals
depending
on
their
age
class,
and
differences
in
sensitivity
among
species.
In
both
cases,
the
screening
level
assessment
is
intended
to
"
err"
on
the
conservative
side.
These
are
techniques
to
account
for
species
sensitivity
differences
in
a
refined
ecological
risk
assessment.

Response
to
FMC
Comment
39:
The
Agency
agrees.

FMC
Comment
40:
The
analysis
of
the
risk
of
the
pyrethroids
to
sediment
dwelling
organisms
is
subject
to
several
other
assumptions
and
uncertainties.
The
equilibrium
partitioning
is
taken
into
account.
The
partition
coefficient
is
highly
variable
in
natural
sediments.

Response
to
FMC
Comment
40:
The
partition
coefficient
was
found
to
have
a
range
(
Koc
=
20,800
 
328,500
L/
Kg).
It
is
the
EFED's
policy
to
use
the
average
of
the
available
Koc
values
when
running
PRZM/
EXAMS
to
generate
water
column,
pore
water,
and
sediment
EECs.
Therefore,
the
Agency
used
an
average
value
when
it
derived
toxicity
values
using
the
EqP
Theory
calculations
as
well,
since
the
derived
toxicity
values
would
be
compared
to
those
EECs.

FMC
Comment
41:
In
Appendix
3,
the
FMC
provides
a
revised
Tier
1
avian
risk
assessment.
Cypermethrin
is
practically
non­
toxic
to
birds
with
all
of
the
calculated
avian
RQs
for
the
target
crops
(
cotton,
lettuce
and
pecans)
being
below
the
LOCs
for
acute
endangered
species
(
0.1).
Several
of
the
chronic
RQs
are
above
the
LOC
(
RQ
range
0.16­
2.65;
LOC=
1).
However,
since
the
chronic
toxicity
was
reported
as
greater
than
(
NOAEC>
50
mg/
Kg
diet),
the
actual
RQs
are
potentially
lower
than
those
reported.
The
refinement
was
done
by
using
actual
residue
data
from
cotton
and
lettuce
field
trials.
41
Response
to
FMC
Comment
41:
The
EFED
has
revised
the
terrestrial
risk
assessment
in
an
addendum
to
the
EFED's
Science
Chapter
to
demonstrate
that
risk
to
avian
species
from
cypermethrin
exposure
is
low.
Please,
refer
to
the
addendum
for
additional
details.

FMC
Comment
42:
The
FMC
is
also
providing
a
revised
Tier
I
risk
assessment.
Acute
RQs
are
below
the
LOCs
for
acute
high
risk
(
LOC=
0.5)
and
acute
restricted
use
(
LOC=
0.2),
except
for
the
15
g
mammal
feeding
on
short
grass
(
RQ=
0.23).
The
endangered
species
LOC
(
0.1)
is
exceeded
for
various
scenarios.
The
LOC
for
chronic
risk
(
LOC=
1)
for
all
modeled
crop
uses
and
mammalian
weight
classes
was
exceeded
based
on
dose­
based
RQs.
No
dietary
chronic
RQs
exceeded
the
chronic
risk
LOC.

Response
to
FMC
Comment
42:
The
Agency
has
revised
the
terrestrial
risk
assessment
in
an
addendum
to
the
EFED's
Science
Chapter
and
has
also
identified
acute
endangered
species
and
dose­
and
dietary­
based
chronic
LOC
exceedances
for
mammals.
A
foliar
dissipation
half­
life
based
on
measured
total
residues
on
plants
(
internal
plus
dislodgeable)
in
the
field
(
Willis
and
McDowell
1987)
was
used
to
determine
upperbound
exposure
levels
and
risk
to
terrestrial
organisms.
Please,
refer
to
the
addendum
for
additional
details.

FMC
Comment
43:
Honeybees
do
not
frequent
lettuce
or
pecans.
There
is
a
slight
risk
through
exposure
to
treated
cotton,
which
needs
proper
monitoring.
FMC
concludes
that
cypermethrin
poses
minimal
risk
to
earthworms
and
to
honeybees
when
used
according
to
label
requirements.

Response
to
FMC
Comment
43:
Please,
refer
to
the
Agency's
response
to
comment
Appendix
4
below.

FMC
Comment
44:
Avian
NOAEC
datagap.
Based
on
FMC
assessment,
chronic
RQs
ranged
from
0.020
to
0.078,
and
since
there
is
no
anticipated
risk
to
birds,
the
study
is
not
required.

Response
to
FMC
Comment
44:
Based
on
the
EFED's
analyses,
the
non­
definitive
NOAEC
value
of
>
50
ppm
could
not
be
used
to
preclude
chronic
risk
to
avian
species,
and
the
NOAEC
value
for
permethrin
was
used
to
demonstrate
low
risk
to
birds
resulting
from
cypermethrin
use.
Permethrin
data
are
considered
to
be
suitable
surrogate
data
for
cypermethrin
because
both
chemicals
are
pyrethroids,
they
are
structurally­
similar
compounds
with
similar
modes
of
action,
and
both
are
expected
to
be
of
low
chronic
toxicity
to
birds.
Based
on
the
NOAEC
for
permethrin,
there
appears
to
be
no
chronic
risk
to
birds.
Therefore,
at
this
time,
additional
avian
reproductive
studies
are
not
being
requested.
Please,
refer
to
the
addendum
for
additional
details.

FMC
Comment
45:
Three
data
gaps
were
identified
by
EFED
for
aquatic
organisms,
namely,
1)
Acute
and
chronic
freshwater
sediment,
2)
Chronic
estuarine
and
marine
sediment
and
3)
Aquatic
freshwater
invertebrate
life­
cycle
study.
The
FMC
indicates
that
the
first
two
were
addressed
through
the
PWG
and
reports
were
submitted
to
the
Agency.
42
The
third
study
was
submitted
under
EPAIDENT
00089047,
21­
day
D.
magna
toxicity
study.
It
was
listed
as
invalid
because
only
one
test
chamber
per
test
concentration
was
used
(
should
have
used
replication
for
statistical
analysis).
The
FMC
notes
that
growth
was
more
sensitive
than
reproduction
in
this
study,
based
on
measured
lengths
of
10
individuals
at
each
concentration
in
each
trial.
Thus,
EFED's
rationale
for
rejection
of
the
study
does
not
apply
for
the
calculation
of
the
NOEC
for
the
most
sensitive
endpoint.
FMC
believes
that
the
study
is
valid
and
the
data
requirement
would
be
fulfilled.

Response
to
FMC
Comment
45:
In
recent
revisions
to
the
chapter,
the
EFED
has
acknowledged
the
submission
of
studies
by
the
PWG
to
address
data
gaps
1
and
2
above.
The
submitted
studies
have
been
received
but
are
still
in
review
and
have
not
been
discussed
in
the
RED.
With
respect
to
the
third
data
gap,
it
has
been
mentioned
in
a
previous
response
that
the
study
in
question
had
several
problems
that
included
the
following:
negative
control
contamination;
delivery
lines
for
treatment
1
and
2
were
switched
for
4
days;
mortality
in
2
of
the
4
replicates
for
solvent
controls
exceeded
30%;
Dissolved
oxygen
levels
were
not
maintained
above
60%
throughout
the
test.
Because
of
these
problems
the
Agency
deemed
this
study
invalid
and
has
required
that
a
new
study
be
conducted.

FMC
Comment
46:
There
are
existing
mitigation
measures
for
crop
uses,
for
example,
the
buffer
zones
(
25
ft
for
ground
applications,
150
ft
for
aerial
applications,
450
ft
for
ULV,
a
10
foot
vegetative
buffer
strip
for
ground
boom
applications).
These
buffer
zones
and
filter
strips
mitigate
erosion
and
spray
drift.
Cypermethrin's
physical­
chemical
properties
result
in
strong
binding
to
soil
and
organic
matter,
as
a
result,
cypermethrin
exhibits
only
a
limited
expression
of
its
inherent
toxicity
to
aquatic
organisms
during
labeled
use.

Response
to
FMC
Comment
46:
Unfortunately,
there
are
no
models
to
measure
quantitatively
the
decrease
in
levels
of
erosion
due
to
maintained
vegetated
filter
strips
suitable
for
national
assessments.

FMC
Comment
47:
FMC
concludes
with
a
series
of
remarks.
Generally,
these
remarks
are
the
positive
aspects
of
cypermethrin
or
the
pyrethroids
as
a
class.
They
are
abridged
as
follows:
 
Several
issues
discussed
in
the
Science
Chapter
apply
to
synthetic
pyrethroids
as
a
class
and
are
the
subject
of
ongoing
investigation
by
the
Pyrethroid
Working
Group
(
PWG),
of
which
FMC
Corporation
is
a
member.
 
According
to
FMC,
pyrethroids,
including
cypermethrin,
are
critically
important
agricultural
and
residential
use
insecticides.
The
pyrethroid
class
of
chemistry
controls
a
wide
variety
of
pests
that
cause
direct
harm
to
people
and
agriculture.
In
aquatic
environments,
the
inherent
toxicity
observed
in
clean­
water
systems
in
the
laboratory
is
ameliorated
under
field
conditions,
since
the
bioavailability
of
cypermethrin
is
restricted
by
its
physical­
chemical
properties.
For
cypermethrin,
the
exposure
risk
to
terrestrial
species
is
generally
low.
43
 
Certain
aspects
of
the
implementation
of
standard
approaches
in
this
cypermethrin
risk
assessment
could
be
improved.
 
The
Problem
Formulation
should
be
more
specific
in
its
identification
of
ecosystems
and
organisms
at
risk,
assessment
endpoints,
and
measures
of
effects.
The
conceptual
model
is
too
generic
to
guide
the
risk
assessment.
 
Aquatic
exposure
is
estimated
using
EFED's
standard
pond
scenario,
which
is
not
described
in
the
Science
Chapter.
 
Use
of
the
equilibrium
partitioning
(
EqP)
approach
for
evaluating
the
risks
of
pyrethroids
in
sediments
is
appropriate.
This
approach
makes
several
important
assumptions
which
should
be
applied
consistently
throughout
the
assessment.
 
The
Problem
Formulation
acknowledges
recent
reports
of
cypermethrin
and
other
pyrethroids
in
sediments
of
suburban
streams,
presumably
originating
from
nonagricultural
uses
such
as
lawn
care.
FMC,
through
the
PWG,
is
aware
of
these
reports
and
will
consider
measures
to
address
specific
issues
as
they
are
raised
by
federal
and
state
regulatory
agencies.
 
The
Science
Chapter
includes
no
quantitative
estimate
of
exposure
in
estuarine/
marine
environments.
An
implicit
assumption
is
made
that
exposure
in
estuarine/
marine
environments
is
similar
to
exposure
in
farm
ponds.
Because
this
assumption
is
tenuous
and
largely
untested,
the
assessment
does
not
support
conclusive
statements
about
risk
to
estuarine/
marine
organisms.
 
Data
selection
should
be
more
accurate
and
transparent.
In
several
cases,
the
Science
Chapter
selects
and
misinterprets
toxicity
data
based
on
errors
concerning
concentration
units.
In
other
cases,
data
are
rejected
without
adequate
explanation,
or
data
from
unreliable
studies
are
used
in
the
analysis.
 
By
segregating
toxicity
data
for
"
benthic"
freshwater
invertebrates
from
the
standard
Daphnia
magna,
the
Science
Chapter
underestimates
the
sensitivity
of
freshwater
invertebrates
to
cypermethrin.
This
also
leads
to
erroneous
conclusions
about
the
relative
sensitivity
of
freshwater
and
estuarine/
marine
invertebrate
species.
 
Due
to
a
transcription
error
regarding
test
concentration
units,
the
Science
Chapter
reaches
the
erroneous
conclusion
that
"
sublethal
effects
[
on
fish]
can
occur
at
exposure
levels
far
below
the
concentrations
that
cause
lethality."
On
the
contrary,
all
data
from
studies
with
freshwater
fish
demonstrate
that
sublethal
effects
(
such
as
loss
of
equilibrium
or
altered
swimming
behavior)
occur
at
concentrations
only
slightly
below
acute
lethal
concentrations.
 
EFED
construes
observations
of
reproductive
effects
of
cypermethrin
in
estuarine/
marine
invertebrates
as
an
indication
of
effects
on
the
endocrine
system.
Reproductive
effects
in
aquatic
invertebrates
(
and
other
taxa)
can
have
many
causes
other
than
endocrine
disruption
(
e.
g.,
egg
mortality
or
feeding
inhibition).
 
The
Science
Chapter
includes
a
description
of
"
assumptions,
limitations,
uncertainties,
strengths,
and
data
gaps"
affecting
the
assessment.
Most
of
the
assumptions
and
uncertainties
identified
are
interpreted
as
potential
causes
of
underestimation
of
risk.
Assumptions
that
lead
to
overestimation
of
risk
are
generally
ignored.
Many
implicit
assumptions
need
to
be
stated
explicitly.
 
The
PWG
and
FMC
continue
to
actively
evaluate
and
refine
potential
aquatic
risk.
Aquatic
exposure
evaluations
include
environmental­
fate
studies
and
reviews,
44
small
and
large­
scale
runoff
studies,
a
review
of
vegetative
filter
strips,
and
freshwater
and
marine
acute
and
chronic
sediment
studies
(
APPENDIX
1).
Ongoing
evaluations
include
preliminary
endangered
species
assessment,
evaluation
of
SPME
(
solid
phase
micro
extraction)
analytical
techniques
for
pore
water,
national
proximity/
vulnerability
assessments,
and
a
revised
ecological
risk
assessment.
 
FMC
contends
that
existing
mitigation
measures
are
protective.
Cypermethrin
crop­
use
labels
require
a
no­
spray
buffer
zone
distance
of
150
feet
with
a
10­
foot
vegetative
buffer
strip
for
aerial
and
25
foot
buffer
with
a
10­
foot
vegetative
buffer
strip
for
ground
boom
applications.
The
purpose
of
this
distance
is
to
mitigate
potential
spray
drift
into
water
bodies.
Buffer
zones
and
filter
strips
also
provide
mitigation
from
soil
erosion.
Cypermethrin's
physical/
chemical
properties
result
in
strong
binding
to
soil
and
organic
matter;
as
a
result,
cypermethrin
exhibits
only
a
limited
expression
of
its
inherent
toxicity
to
aquatic
organisms
during
labelled
use.
 
FMC's
revised
risk
assessment
concludes
that
cypermethrin
poses
a
minimal
risk
to
terrestrial
(
avian
and
mammalian)
species.
EFED
demonstrated
a
minimal
acute
risk,
and
a
potential
chronic
risk
to
birds
and
mammals.
However,
when
real
field
residue
data
from
cotton
and
lettuce
were
utilized
to
assess
the
risk,
there
was
minimal
risk
to
both
birds
and
mammals
with
quotients
ranging
from
0.0001
to
0.013
for
acute
and
0.013
to
0.431
for
chronic
RQs
in
birds
and
mammals
combined.
 
FMC's
revised
risk
assessment
for
honeybees
concludes
no
concern
to
honeybees
in
lettuce
or
pecans
since
honeybees
do
not
generally
frequent
these
crops
during
treatment
periods.
FMC
notes
a
slight
risk
to
honeybees
through
exposure
to
treated
cotton.
However,
mitigation
is
possible
though
appropriate
monitoring
of
cotton
fields,
i.
e.,
safe
to
use
when
honeybees
are
not
active
(
e.
g.,
at
night
or
during
non­
flowering
seasons).
 
Cypermethrin
applied
as
a
foliar
application
to
target
crops
is
not
a
risk
to
earthworms.

Response
to
FMC
Comment
47:
Comment
47
is
a
summary
of
the
comments
submitted
by
FMC.
They
have
been
responded
to
previously;
therefore,
no
additional
response
is
necessary.

FMC,
Comment
Appendix
1:
It
is
a
list
of
studies
submitted
by
the
PWG.

Response
to
Comment
Appendix
1:
The
EFED
appreciates
the
submission
of
the
list.

FMC,
Comment
Appendix
2:
It
is
a
note
that
a
review
of
aquatic
risk
assessment
is
submitted
jointly
with
Syngenta
Crop
Protection,
separately.

Response
to
Comment
Appendix
2:
EFED
acknowledges
the
information
submitted
in
the
appendix.
45
FMC,
Comment
Appendix
3:
It
is
an
assessment
of
the
potential
risk
to
birds
and
mammals
from
cypermethrin
applications.
 
FMC
indicates
that
it
provides
a
more
realistic
potential
exposure,
using
the
same
timing
than
the
one
of
PRZM/
EXAMS
model
(
e.
g.
application
interval).
 
FMC
noted
that
the
RQs
in
the
model
were
different
in
the
T­
REX
model
vs.
those
in
the
RED.
 
Assumption
1
is
that
birds
spend
100%
of
their
time
in
treated
fields.
Crocker,
et
al.,
(
2001)
provide
data
for
four
species
of
passerine
birds
in
the
U.
K.
Most
songbirds
spend
<
10%
in
crops
while
a
few
birds
spend
90%
or
more
in
crops.
 
Assumption
2,
RQs
calculated
using
LD50s
(
bolus
dose)
misrepresent
the
potential
dietary
(
dose
over
time)
toxicity
to
birds.
Birds
consume
food
items
over
many
hours
of
the
day
and
the
exposure
characteristics
are
more
similar
to
a
dietary
LC50
toxicity
test.
 
Assumption
3:
100%
of
the
avian
diet
contains
residue.
Very
few
birds
will
spend
more
than
90%
of
their
time
in
one
field.
 
Assumption
4:
Risk
to
birds
is
assessed
using
one
food
source
while
bird
diet
consists
of
a
variety
of
food
sources.
 
Assumption
5:
Even
for
a
screening
level
process,
it
is
unreasonable
to
promote
the
vegetation­
eating
scenario.
Few
birds
are
specialized
herbivores.
 
The
EFEDs
RQs
do
not
reflect
a
realistic
exposure
scenario
for
avian
species,
according
to
the
FMC.
 
The
FMC
says
that,
in
addition,
the
toxicity
reference
values
are
reported
as
greater
than
[
e.
g.
LC50
>
20,000
mg/
Kg
bw,
and
LD50
>
2000
mg/
Kg
bw.
The
RQs
are
potentially
lower.
 
After
recalculation
of
the
chronic
RQs
for
birds,
several
of
them
were
above
the
LOC
for
chronic
risk
(
range
0.16­
2.65;
LOC=
1).
 
The
chronic
toxicity
reference
value
(
trv)
was
reported
as
greater
than
for
both
mallard
duck
and
bobwhite
quail
(
NOAEC>
50
mg/
Kg
diet).
RQs
are
potentially
lower.
 
The
EFED
found
that
the
acute
RQs
for
mammals
are
below
the
LOC
for
acute
risk
(
0.5)
and
restricted
use
(
0.2),
except
for
15
g
mammal
feeding
on
shortgrass
(
RQ=
0.23).
The
endangered
species
LOC
(
0.1)
was
exceeded
in
several
scenarios
for
cotton,
lettuce
and
pecan.
 
FMC
believes
that
EFED
exaggerated
the
estimates
of
exposure
because
mammals
were
assumed
to
spend
100%
of
the
time
in
the
treated
field
and
it
was
assumed
that
100%
of
the
diet
contains
cypermethrin
residue.
 
The
chronic
risk
dose­
based
RQs
for
mammals
exceeded
the
LOC
(
1)
for
all
modeled
crop
uses
and
weight
classes
for
exposure
via
short
grass,
tall
grass
and
broadleaf
plants/
small
insects.
None
of
the
chronic
dietary
based
RQs
for
mammals
are
exceeded.
FMC
believes
that
dietary
RQs
are
more
relevant,
since
mammals
are
potentially
more
likely
to
obtain
cypermethrin
through
their
diets
over
the
longer
term
rather
than
through
single
bolus
doses.
 
FMC
believes
that
EFED's
assessment
may
be
revised
by
incorporating
the
avian
and
mammalian
RQs
using
field
residue
data.
In
this
case,
the
resulting
RQs
are
well
below
EFED's
LOC
for
both
acute
and
chronic
risks.
46
 
Birds
 
Acute
oral
RQs
range
from
0.0005
to
0.002,
and
acute
dietary
RQs
range
from
0.00005
to
0.0002.
Chronic
RQs
range
from
0.020
to
0.078
when
calculated
at
maximum
field
value
(
3.4
ppm),
obtained
from
up
to
15
applications
per
trial
residue
studies.
 
Mammals
 
Acute
RQs
range
from
0.0004
to
0.013
and
chronic
RQs
range
from
0.013
to
0.431
when
calculated
using
the
maximum
EEC
field
value
obtained
from
up
to
15
applications
per
trial
residue
studies.

Response
to
Comment
Appendix
3:
Many
of
the
comments
above
have
been
addressed
in
a
recently
completed
revised
terrestrial
risk
assessment
for
birds
and
mammals
and
in
a
number
of
responses
to
previous
comments.
In
addition,
while
FMC
contends
that
a
number
of
the
"
exaggerated"
assumptions
outlined
above
do
not
reflect
a
realistic
exposure
scenario
and
that
actual
exposure
to
terrestrial
organisms
may
be
lower
for
some
organisms,
it
is
standard
policy
of
the
EFED
to
be
as
protective
as
possible
of
the
most
sensitive/
vulnerable
species
and
endangered
species
in
screening­
level
risk
assessments
by
taking
a
conservative
approach.
Because
pesticide
regulatory
decisions
involve
potentially
widespread
uses
of
pesticides,
EFED
believes
that
conservative
assumptions
are
necessary
to
account
for
the
potential
variability
and
uncertainty
associated
with
exposure
of
a
diverse
array
of
receptors
to
pesticides
applied
to
a
wide
variety
of
use
sites
under
a
variety
of
environmental
conditions.

The
use
of
the
maximum
observed
residue
value
from
the
available
field
trials
is
not
considered
appropriate
for
generating
risk
estimates
in
the
EFED's
assessment
because
it
is
ultimately
an
estimate
representative
of
a
single
exposure
scenario
at
best
(
i.
e.,
consumption
of
lettuce
contaminated
with
cypermethrin),
whereas
it
is
likely
that
there
will
be
numerous
scenarios
in
which
exposure
estimates
may
be
well
above
this
maximum
EEC
on
lettuce.
To
account
for
potential
variability
and
uncertainty,
the
EFED's
model,
T­
REX,
calculates
EECs
and
risk
quotients
based
on
upper­
bound
residue
concentrations
as
presented
by
Hoerger
and
Kenaga
(
1972)
and
modified
by
Fletcher
et
al.
(
1994).
These
concentrations
are
determined
using
nomograms
that
relate
application
rate
of
a
pesticide
to
residues
remaining
on
dietary
items
of
terrestrial
organisms
(
based
on
the
foliar
dissipation
half­
lives
of
a
chemical).
The
exposure
estimates
in
the
EFED's
RED
for
cypermethrin
are
expected
to
be
the
most
accurate
and
conservative
estimates
available,
since
they
are
based
on
a
foliar
half­
life
that
represents
the
90%
upper
confidence
limit
of
the
mean
half­
life
for
data
from
actual
foliar
dissipation
studies
(
Willis
and
McDowell
1987).

FMC,
Comment
Appendix
4:
Assessment
of
the
potential
risk
to
honeybees
and
earthworms
from
cypermethrin
applications.
The
FMC
conducted
preliminary
risk
assessments
for
these
organisms
to
address
the
gap,
using
the
scenarios:
cotton,
lettuce
and
pecans.
 
The
EU
uses
the
hazard
quotient
(
QH)
in
a
Tier
1
risk
assessment
to
take
into
consideration
the
exposure
in
the
environment,
as
opposed
to
laboratory
toxicity
honeybee
testing.
QH
=
Application
rate
(
g
a.
i./
ha)/
Toxicity
endpoint
(
µ
g/
honeybee).
47
 
The
QH,
ORAL
=
112.4/
0.172
=
654,
moderate
toxicity;
the
QH,
CONTACT
=
112.4/
0.023
=
4,887,
extremely
high.
They
indicate
that
the
label
states
that
"
This
product
is
highly
toxic
to
bees
exposed
to
direct
treatment
or
residues
on
blooming
crops
or
weed.
Do
not
apply
this
product
or
allow
it
to
drift
to
blooming
crops
if
bees
are
visiting
the
treatment
area."
 
Cotton
and
honeybees
have
a
mutually
beneficial
relationship.
The
crop
should
be
monitored
for
honeybee
activity
prior
to
cypermethrin
application
to
avoid
unnecessary
risk.
Lettuce
is
a
self
pollinating
plant,
in
most
agricultural
fields,
minimal
exposure
of
cypermethrin
to
honeybees
occur.
Pecans
are
pollinated
by
the
wind
and
they
are
not
considered
a
food
source
by
the
honeybees,
therefore,
the
exposure
to
cypermethrin
will
also
be
minimal.
 
Cypermethrin
is
very
toxic
to
earthworms
(
LC50
=
26.09
µ
g/
cm2).
The
FMC
indicated
that
in
soil,
the
exposure
is
reduced.
In
a
2
week
study,
using
artificial
soil,
with
concentrations
ranging
from
0.1­
100
mg
a.
i./
Kg
dry
soil,
the
LC50
>
100
mg
a.
i./
Kg
dry
soil,
and
NOEC
=
100
mg
a.
i./
Kg
dry
soil.
 
Since
the
Agency
does
not
have
guidance
to
evaluate
earthworms,
the
FMC
used
the
European
Amnex
III
guideline
(
SANCO/
10329/
2002)
for
a
Tier
II
assessment.
Three
issues
were
factored
in:
the
toxicity
of
the
chemical,
the
calculation
of
the
exposure
in
the
soil,
and
the
ratio
or
hazard
quotient.
 
The
registrant
conducted
the
analysis
according
to
the
guideline,
that
states
that
when
the
log
KOW
is
>
2
(
in
this
case
it
is
6.54,
from
Laskowski,
2000),
the
LC50
is
adjusted
to
the
toxicity
of
natural
soils
by
dividing
the
endpoint
by
two.
Then,
the
corrected
LC50
=
50
mg
a.
i./
kg
dry
soil.
 
The
EECs
in
soil
are
based
on
the
application
rate
without
consideration
of
degradation,
EEC
=
application
rate,
112.4
g
a.
i./
ha
x
6
x
percentage
that
reaches
the
soil
x
factor
(
not
described).
 
The
EEC
is
0.90
mg/
Kg,
then
the
RQ
=
0.018.
It
is
below
0.5,
therefore,
no
risk
is
anticipated
following
exposure
to
cypermethrin
applied
to
soil
at
a
rate
of
6X
the
recommended
single
application
rate.

Response
to
Comment
Appendix
4:
The
EFED
has
reviewed
FMC's
"
Assessment
of
the
Potential
Risk
to
Honeybees
and
Earthworms
from
Cypermethrin
Applications."
While
the
EFED
appreciates
FMC's
attempt
to
further
characterize
risk
to
earthworms
and
honey
bees,
it
disagrees
with
the
conclusion
that
cypermethrin
poses
minimal
risk
to
earthworms
and
honeybees
if
used
according
to
the
label
requirements.
The
EFED
asserts
that
concern
for
honeybees
and
earthworms
is
warranted
because
the
evidence
currently
available
to
the
Agency
is
not
sufficient
for
precluding
risk
to
these
organisms.
For
instance,
the
studies
which
FMC
points
to
as
evidence
of
low
toxicity
to
earthworms
under
"
realistic
exposure
conditions"
(
i.
e.,
in
the
presence
of
soil)
have
not
been
submitted
or
reviewed
by
the
EFED,
whereas
the
evidence
that
suggests
high
toxicity
is
currently
available
to
the
Agency.
If
the
registrant
would
like
the
Agency
to
incorporate
the
data
into
a
future
risk
assessment,
then
the
studies
must
be
submitted
for
review.
Upon
receiving
these
data,
they
will
be
evaluated
and
addressed
during
Registration
Review.
48
For
honeybees,
FMC
assumes
that
spray
drift
to
non­
target
plants
from
agricultural
applications
is
negligible
and
only
considers
risk
to
honey
bees
actively
foraging
on
targeted
crops
or
weeds
treated
with
cypermethrin.
However,
drift
to
non­
target
plants
off­
site
could
also
pose
risks
even
if
in
relatively
low
amounts
because
the
toxicity
to
honey
bees
is
extremely
high.
In
addition,
even
if
bees
aren't
actively
foraging
during
an
application,
it
is
reasonable
to
expect
that
residues
on
plants
could
remain
high
enough
so
as
to
induce
toxic
effects
to
bees
foraging
shortly
after
application.
Given
the
timing
(
i.
e.,
the
seasons)
and
number
of
applications
of
cypermethrin,
it
appears
that
exposure
and
risk
to
honey
bees
and
non­
target
insects
is
likely.
