Proposed
Rule
on
Conventional
Pesticides
(
40
CFR
Part
158)

May
3­
4,
2005
Holiday
Inn
Rosslyn
1900
N.
Fort
Myer
Drive
Arlington,
VA
22209
Environmental
Fate
and
Effects
Division
Environmental
Fate
Data
Requirements
Office
of
Pesticide
Programs
U.
S.
Environmental
Protection
Agency
May
4,
2005
3
Purpose
of
Fate
and
Transport
Assessments

Where
and
how
does
the
pesticide
move
in
the
environment
 
major
routes
of
dissipation.


How
long
will
it
persist?


What
degradation
products
are
produced
and
in
what
quantities?


How
much
parent
and/
or
degradate
is
likely
to
reach
ground
water
and/
or
surface
water?
4
Laboratory
Studies:

Degradation

835.2120
Hydrolysis

835.2240
Photodegradation
in
Water

835.2410
Photodegradation
on
Soil

835.2370
Photodegradation
in
Air
5
Laboratory
Studies
Metabolism

835.4100
Aerobic
Soil
Metabolism

835.4200
Anaerobic
Soil
Metabolism

835.4400
Anaerobic
Aquatic
Metabolism

835.4300
Aerobic
Aquatic
Metabolism
6
Laboratory
Studies
Mobility
and
Bioaccumulation

835.1240
Batch
Equilibrium

835.1230
Soil
Column
Leaching

835.1410
Laboratory
Volatility

850.1730
Accumulation
in
Fish
7
Field
Studies

835.8100
Field
Volatility

835.6100
Terrestrial
Field
Dissipation

835.6200
Aquatic
Field
Dissipation

835.6300
Forest
Field
Dissipation

850.1950
Bioaccumulation
in
Aquatic
Non­

Target
Organisms

835.7100
Prospective
Groundwater
Monitoring
8
Summary

No
new
tests

Codify
current
practices

Evolving
science,
FIFRA,
FQPA

Peer
review
and
public
participation
on
significant
changes

Clarify
test
notes

Update
"
required"
versus
"
conditionally
required"

based
on
risk
assessment
experience
9
Review
of
Laboratory
Fate
Studies
10
Hydrolysis
Studies
[
835.2120]


Purpose:
To
establish
the
significance
of
chemical
hydrolysis
as
a
route
for
degradation
of
a
pesticide
and
to
identify
the
hydrolytic
products
formed.


What
happens
to
the
pesticide
under
acidic,
neutral,
and
alkaline
environments?


Required
(
R)
for
all
use
patterns
except
indoor
where
it
is
conditionally
required
(
CR)
11
What's
Changed?


Proposed
to
be
conditionally
required
(
CR)

for
indoor
uses

May
be
required
to
support
products
for
indoor
uses
for
which
environmental
exposure
is
likely

Longstanding
practice
PHOTODEGRADATION
Aqueous
Photolysis
(
835.2240)

Soil
Photolysis
(
835.2410)

Air
Photolysis
(
835.2370)
13
Purpose
of
Photodegradation
Studies

Potential
to
degrade
in
water,
soil,
or
air
when
exposed
to
sunlight

Data
on
the
identity,
formation,
and
persistence
of
photoproducts
14
What's
Changed?


Photodegradation
in
Water
 
Proposed
new
test
note
 
"
Not
required
when
the
electronic
absorption
spectra,
measured
at
pHs
5,

7,
and
9,
of
the
chemical
and
its
hydrolytic
products,
if
any,
show
no
absorption
or
tailing
between
290
and
800
nm."

 
Longstanding
practice

Photodegradation
on
Soil
 
Proposed
R
for
terrestrial
and
forestry
uses
Previously
was
CR
 
Longstanding
practice
15
What's
Changed?


Photodegradation
in
Air
 
Adding
conditional
requirement
for
greenhouse,

forestry,
and
residential
outdoor
uses
 
New
test
note
 
"
In
view
of
methodological
difficulties
with
the
study,
prior
consultation
with
the
Agency
regarding
the
protocol
is
recommended
before
the
test
is
performed."
16
Soil
and
Aquatic
Metabolism
Studies
Aerobic
Soil
Metabolism
(
835.4100)

Anaerobic
Soil
Metabolism
(
835.4200)

Anaerobic
Aquatic
Metabolism
(
835.4400)

Aerobic
Aquatic
Metabolism
(
835.4300)
17
Purpose:
To
Provide
Information
On...

­
Microbial
degradation
in
soil
and
water
systems
­
Measure
rate
transformation
of
parent
compound
­
Provide
information
on
the
formation/
decline
of
degradation
products
­
Exposure
model
inputs
18
What's
Changed
for
Aerobic
Soil
Metabolism?


Expanded
to
require
for
aquatic
food
and
nonfood
crop
uses
for
aquatic
sites
that
are
intermittently
dry

Conditionally
required

Presented
to
the
SAP
in
1994
19
When
is
the
Anaerobic
Soil
Metabolism
Study
Required
and
What's
Changed?


Required
(
R)
for
all
terrestrial
uses

Missing
from
current
CFR
due
to
a
printing
error
20
What's
Changed
for
Anaerobic
Aquatic
Metabolism?


Proposed
required
(
R)
for
terrestrial
uses

Advances
in
ecological
risk
assessment
and
drinking
water
assessments
21
What's
Changed
for
Aerobic
Aquatic
Metabolism?


Proposed
required
(
R)
for
terrestrial
and
forestry
uses

Advances
in
ecological
risk
assessment
and
drinking
water
assessments
22
Mobility
Studies
Batch
Equilibrium
(
835.1240)

Soil
Column
Leaching
(
835.1230)
23
Purpose

Will
give
an
indication
of
how
fast
a
dissolved
compound
will
move
relative
to
the
movement
of
water

Describes
the
distribution
of
pesticide
between
water
and
soil
at
equilibrium

Needed
for
inputs
to
exposure
models

No
changes
are
proposed
24
Laboratory
Volatility
(
835.1410)
25
Purpose
of
the
Laboratory
Volatility
Studies
and
What's
Changed

Determine
amount
and
rate
of
volatilization
under
controlled
conditions

When
Required
 
Conditionally
required
(
CR)
for
terrestrial
and
greenhouse
uses
 
not
required
when
vapor
pressure
<
10­
6
mmHg

No
changes
are
proposed
26
Laboratory
Studies
of
Pesticide
Accumulation
in
Fish
850.1730
27
Purpose
of
the
Accumulation
in
Fish
Study

Determine
if
pesticide
residues
accumulate
in
fish
used
as
human
food
sources

Determine
the
extent
of
pesticides
in
edible
portions
of
such
fish

Data
provides
information
on
ecological
food
chain
exposure
28
What's
Changed?


Clarified
test
note
about
conditions
for
when
the
study
is
required
29
Integrating
Fate
Data
Integrating
Fate
Data
Building
a
Conceptual
Model
30
The
Conceptual
Model

Hypothesis
developed
using
assumptions
derived
from
the
laboratory
data

Since
lab
studies
evaluate
specific
fate
and
transport
properties
individually,
they
allow
for
the
development
of
a
conceptual
model
that
includes
only
those
processes
that
are
significant.
31
The
Conceptual
Model

Field
studies
provide
the
primary
mechanism
for
testing
and
refining
the
hypothesis.


Field
studies
give
site­
specific
information
on
the
fate
and
transport
of
a
pesticide
and
its
degradates
under
actual
use
conditions.
32
Field
Studies

835.6100
Terrestrial
Field
Dissipation

835.6200
Aquatic
(
sediment)
Dissipation

835.6300
Forestry
Dissipation

835.6400
Combination
and
Tank
Mixes

850.1950
Accumulation
in
Aquatic
Nontarget
Organisms
33
Important

Dissipation
in
the
field
is
NOT
the
same
as
degradation
of
the
pesticide
in
individual
laboratory
studies

Dissipation
in
the
field
results
from
interaction
of
multiple
processes
at
work
in
the
entire
soil
and/
or
water
system
34
Dissipation
can
result
from
any
one
process
or
combination
of
the
following
processes 

Applied
Pesticide
Foliar
Interception
&
Dissipation
Washoff
Plant
Uptake
Volatilization
Transformations
microbial
chemical
Sorption
/

Retention
Leaching
Surface
Runoff
Lateral
Flow
Spray
Drift
Tile
Drainage
35
How
Do
We
Use
Field
Studies?


Data
from
field
studies
can
provide
more
realistic
estimates
of
the
persistence
and
transport
of
an
active
ingredient
and
its
degradates

Can
reduce
potential
overestimation
of
exposure
and
risk
and
can
confirm
assumptions
of
low
levels
of
toxic
degradates

Results
can
be
used
to
propose
scenario­
specific
effective
risk
mitigation
36
Terrestrial
Field
Dissipation
(
835.6100)
37
What's
Changed?


Expanded
conditional
requirement
to
include
aquatic
sites
that
are
intermittently
dry

Merged
with
the
long­
term
field
dissipation
study

Added
independent
laboratory
validation
of
analytical
methods
38
Aquatic
Field
Dissipation
Studies
(
835.6200)


Similar
scientific
issues
as
the
terrestrial
field
dissipation
study

Required
for
pesticides
with
aquatic
uses

Conditionally
required
(
CR)
for
terrestrial
uses
based
on
potential
for
aquatic
exposure
and
if
pesticide
residues
have
the
potential
for
persistence,
mobility,

non­
target
aquatic
toxicity,
or
bioaccumulation
39
What's
Changed?


Expanded
conditional
requirement
to
include
terrestrial
uses

Clarified
conditions
for
when
study
is
required

Added
independent
laboratory
validation
of
analytical
methods
40
Forestry
Dissipation
(
835.6300)
41
What's
Changed?


Changed
from
"
required"
to
"
conditionally
required"


Added
independent
laboratory
validation
of
analytical
methods
42
Field
Volatility
(
835.8100)
43
Field
Accumulation
in
Aquatic
Non­
Target
Organisms
(
850.1950)
44
Prospective
Groundwater
Monitoring
(
835.7100)
45
PGW
Study

Generally
triggered
by
drinking
water
concern
(
FQPA)


Conditionally
required
(
CR)
for
terrestrial
and
forestry
uses
46
Summary

No
new
tests

Codify
current
practices

Evolving
science,
FIFRA,
FQPA

Peer
review
and
public
participation
on
significant
changes

Clarify
test
notes

Update
"
required"
versus
"
conditionally
required"

based
on
risk
assessment
experience
