Document ID: EPA-HQ-OPP-2006-0338-0011
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2006-04-26T04:00Z

Page
1
of
36
UNITED
STATES
ENVIRONMENTAL
PROTECTION
AGENCY
WASHINGTON,
D.
C.
20460
OFFICE
OF
PREVENTION,
PESTICIDES
AND
TOXIC
SUBSTANCES
February
27,
2006
Memorandum:

SUBJECT:
Didecyl
Dimethyl
Ammonium
Chloride
(
DDAC):
Occupational
and
Residential
Exposure
Assessment
for
the
Reregistration
Eligibility
Decision
Document.

FROM:
Matthew
Lloyd,
Industrial
Hygienist
Reregistration
Branch
 
RRB1
Health
Effects
Division
(
HED)
(
7509C)

THROUGH:
Whang
Phang,
Branch
Senior
Scientist
Reregistration
Branch
 
RRB1
Health
Effects
Division
(
HED)
(
7509C)

TO:
Tracy
Lantz,
Regulatory
Management
Branch
Antimicrobials
Division
(
AD)
(
7510C)

PC
Code:
069149
DP
Barcode:
D326896
The
attached
assessment
is
the
occupational
and
residential
exposure
and
risk
estimates
for
DDAC
to
support
AD's
reregistration
eligibility
decision
(
RED)
document.
This
exposure
assessment
was
based
on
the
toxicity
endpoints
selected
by
AD.
The
data
analysis
included
in
this
assessment
was
prepared
by
Versar,
Inc.
under
the
supervision
of
HED.
Page
2
of
36
Table
of
Contents
Executive
Summary...................................................................................................................................................................................
3
1.0
Occupational
and
Residential
Exposure/
Risk
Assessment
............................................................................................................
6
1.1
Purpose......................................................................................................................................................................
6
1.2
Criteria
for
Conducting
Exposure
Assessments...................................................................................................
6
1.3
Summary
of
Hazard
Concerns
for
DDAC...........................................................................................
6
1.4
Incident
Reports.....................................................................................................................................................
10
1.5
Summary
of
Physical
and
Chemical
Properties
of
DDAC................................................................................
11
1.6
Summary
of
Use
Patterns
and
Formulations
.....................................................................................................
11
1.6.1
End­
Use
Products
.................................................................................................................
11
1.6.2
Registered
Use
Categories
and
Sites...................................................................................
11
1.6.3
Application
Methods
............................................................................................................
12
2.0
Occupational
Exposures
and
Risks.................................................................................................................................................
12
2.1
Occupational
Handler
Exposures
and
Risks......................................................................................................
12
2.1.1
Data
and
Assumptions
for
Handler
Exposure
Scenarios
................................................
14
2.1.1.1
Assumptions
for
Handler
Exposure
Scenarios
.............................................................
14
2.1.1.2
Exposure
Data
for
Handler
Exposure
Scenarios
.........................................................
15
2.1.1.3
DDAC
Inhalation
Handler
Exposure
Scenarios
..........................................................
15
2.1.2
DDAC
Handler
Exposure
and
Assessment
.......................................................................
16
2.1.2.1
DDAC
Handler
Exposure
and
Risk
Calculations........................................................
16
2.1.2.2
DDAC
Risk
Summary.....................................................................................................
17
2.1.3
Cancer
DDAC
Handler
Exposure
and
Risk
Assessment.................................................
19
2.1.4
Summary
of
Risk
Concerns
and
Data
Gaps
for
Occupational
Handlers......................
19
2.1.4.1
Summary
of
Risk
Concerns.............................................................................................
19
2.1.4.2
Summary
of
Data
Gaps
...................................................................................................
20
2.1.5
Recommendations
For
Refining
Occupational
Handler
Risk
Assessment....................
20
2.2
Occupational
Postapplication
Exposures
and
Risks
.........................................................................................
20
2.2.1
Occupational
Postapplication
Exposure
Scenarios..........................................................
20
2.2.2
Data/
Assumptions
for
Postapplication
Exposure
Scenarios
...........................................
21
2.2.3
Occupational
Postapplication
Exposure
and
Risk
Estimates
.........................................
22
2.2.4
Occupational
Postapplication
Exposure
and
Risk
Estimates
for
Cancer
.....................
25
2.2.5
Summary
of
Occupational
Postapplication
Risk
Concerns
and
Data
Gaps.................
25
2.2.6
Recommendations
for
Refining
Occupational
Postapplication
Risk
Assessment
........
25
3.0
Residential
and
Other
Non­
Occupational
Exposures
and
Risks
................................................................................................
25
3.1
Residential
Handler
Exposures
and
Risks..........................................................................................................
25
3.1.1
DDAC
Dermal
Handler
Exposure
Scenarios....................................................................
26
3.1.2
Data
and
Assumptions
for
Handler
Exposure
Scenarios
................................................
27
3.1.3
Residential
Handler
Exposure
and
Risk
Estimates..........................................................
27
3.1.4
Residential
Handler
Exposure
and
Risk
Estimates
for
Cancer......................................
31
3.1.5
Summary
of
Risk
Concerns
and
Data
Gaps
for
Handlers
..............................................
32
3.1.6
Recommendations
for
Refining
Residential
Handler
Risk
Assessment.........................
32
3.2
Residential
Postapplication
Exposures
and
Risks
.............................................................................................
32
3.2.1
Residential
Postapplication
Exposure
Scenarios..............................................................
32
3.2.2
Data
and
Assumptions
for
Residential
Postapplication
Exposure
Scenarios...............
33
3.2.3
Residential
Postapplication
Exposure
and
Risk
Estimates
.............................................
34
3.2.4
Residential
Postapplication
Exposure
and
Risk
Estimates
for
Cancer
.........................
35
3.2.5
Summary
of
Residential
Postapplication
Risk
Concerns
and
Data
...............................
36
Gaps.........................................................................................................................................................................
36
3.2.6
Recommendations
for
Refining
Residential
Postapplication
Risk
Assessments...........
36
List
Of
Appendices
Appendix
A
 
DDAC
Occupational
Handler
Risk
Calculations
Appendix
B
 
DDAC
Agricultural
and
Residential
Handler
Risks
Page
3
of
36
Executive
Summary
DDAC
(
Group
I
Quat
Cluster)
is
a
group
of
structurally
similar
quaternary
ammonium
compounds
("
quats").
Most
of
the
registered
uses
of
DDAC
are
classified
as
antimicrobial
uses
and
will
be
assessed
by
the
Antimicrobial
Division
in
EPA=
s
Office
of
Pesticide
Programs.
This
document
is
the
occupational
and
residential
exposure
assessment
for
DDAC
from
its
use
as
a
plant
growth
regulator.
In
this
document,
the
Agency
presents
the
results
of
its
review
of
the
potential
human
health
effects
of
occupational
and
residential/
non­
occupational
exposure
to
DDAC.

Toxicological
endpoints
were
selected
for
short
term
dermal,
short­
and
intermediate­
term
inhalation,
and
incidental
oral
exposures
to
DDAC.
There
is
a
significant
potential
for
exposure
in
a
variety
of
occupational
agricultural
and
commercial
settings,
as
well
as
in
residential
settings.
Therefore,
risk
assessments
are
required
for
occupational
and
residential
handlers,
as
well
as
for
occupational
and
residential
postapplication
exposures
that
can
occur
as
a
result
of
DDAC
use.

The
use
patterns
of
DDAC
can
range
from
short­
term
through
intermediate­
term
exposure
durations.
Endpoints
were
selected
to
address
each
of
these
durations.
DDAC
exposures
are
expected
to
occur
to
both
occupational
and
residential
users.
The
Agency
selected
a
short­
term
dermal
endpoint
for
DDAC
based
on
adverse
dermal
effects
rather
than
systemic
toxicity.
The
short­
term
dermal
NOAEL
was
2
mg/
kg/
day
and
the
LOAEL
was
6
mg/
kg/
day,
based
on
increased
clinical
and
gross
findings
of
the
skin
(
erythema,
edema,
exfoliation,
excoriation,
and
ulceration).
No
intermediate­
or
long­
term
dermal
endpoints
were
identified
for
DDAC.
The
short­
and
intermediate­
term
inhalation
and
short­
term
incidental
oral
risk
assessments
for
DDAC
were
based
on
a
NOAEL
of
10
mg/
kg/
day,
which
was
chosen
from
a
prenatal
developmental
toxicity
study
in
rats.
The
LOAEL
(
20
mg/
kg/
day)
was
based
largely
on
increased
incidence
of
skeletal
variations
in
females.
Long­
term
inhalation
exposure
to
DDAC
(
i.
e.,
greater
than
6
months)
is
not
expected
based
on
the
use
pattern
of
currently
registered
products.
No
cancer
endpoint
was
identified.

The
level
of
concern
(
LOC)
for
occupational
and
non­
occupational
DDAC
dermal
and
inhalation
exposures
is
a
margin
of
exposure
(
MOE)
of
less
than
100.
The
MOE
was
based
on
10x
for
interspecies
extrapolation,
and
10x
for
intraspecies
variability.
For
calculating
dermal
exposure
risk,
no
body
weight
is
needed
for
the
dermal
endpoint,
since
no
systemic
dose
is
calculated
(
i.
e.­
the
NOAEL
of
0.15
µ
g/
cm2
is
used
for
risk
assessment).
Since
the
endpoint
is
female
specific,
the
weight
of
60
kilograms
is
used
in
the
assessment.
This
represents
the
average
body
weight
of
an
adult
female.

DDAC
is
formulated
as
a
soluble
concentrate,
emulsifiable
concentrate,
ready­
to­
use
solution,
pressurized
liquid,
wettable
powder,
and
water
soluble
packet.
There
are
many
end­
use
products
that
contain
DDAC,
and
each
label
could
not
be
reviewed
to
determine
the
formulationtype
and
the
registered
uses.
Additionally,
the
Master
Label
does
not
indicate
the
formulation
types
that
have
been
registered
for
individual
use­
patterns.
As
a
conservative
approach,
this
chapter
will
assume
that
when
used
as
a
growth
regulator,
DDAC
may
be
formulated
as
a
liquid
Page
4
of
36
concentrate,
a
water
dispersible
granular,
and
a
wettable
powder.

In
occupational
settings,
DDAC
is
applied
with
several
types
of
application
equipment
B
including
low­
pressure
handwand
sprayers,
handgun
sprayers
(
high
pressure
handwand),
watering
cans,
and
pump­
trigger
sprayers.
DDAC
dermal
exposures
and
risks
were
not
estimated
for
occupational
handler
exposures.
Instead,
dermal
exposures
and
risks
will
be
mitigated
using
default
personal
protective
equipment
requirements
based
on
the
toxicity
of
the
end­
use
product.
To
minimize
dermal
exposures,
the
minimum
PPE
required
for
mixers,
loaders,
and
others
exposed
to
end­
use
products
containing
concentrations
of
DDAC
that
result
in
classification
of
category
I
or
II
for
skin
irritation
potential
will
be
long­
sleeve
shirt,
long
pants,
shoes,
socks,
chemical­
resistant
gloves,
and
chemical­
resistant
apron.
The
minimum
PPE
required
for
mixers,
loaders,
and
others
exposed
to
end­
use
products
containing
concentrations
of
DDAC
that
result
in
classification
of
category
III
for
skin
irritation
potential
will
be
long­
sleeve
shirt,
long
pants,
shoes,
socks,
and
chemical­
resistant
gloves.
Once
diluted,
if
the
concentration
of
DDAC
in
the
diluted
solution
would
result
in
classification
of
toxicity
category
IV
for
skin
irritation
potential,
then
the
chemical­
resistant
gloves
and
chemical­
resistant
apron
can
be
eliminated
for
applicators
and
others
exposed
to
the
dilute.
Note
that
chemical­
resistant
eye
protection
will
be
required
if
the
end­
use
product
is
classified
as
category
I
or
II
for
eye
irritation
potential.

In
all
occupational
handler
scenarios,
inhalation
MOEs
exceed
100
at
baseline
(
i.
e.,
no
respirator)
and
are
not
of
concern.
Since
no
dermal
endpoint
for
systemic
toxicological
effects
was
selected,
no
dermal
doses
were
estimated.
Dermal
and
inhalation
risks
were
not
combined
because
the
dermal
endpoint
(
adverse
dermal
effects)
is
different
from
the
inhalation
endpoint
(
developmental
effects).

DDAC
can
be
used
on
ornamental
crops
in
greenhouse
and
outdoor
occupational
settings.
As
a
result,
individuals
can
potentially
be
exposed
by
working
in
areas
that
have
been
previously
treated.
There
is
concern
about
the
kinds
of
exposures
one
can
encounter
in
the
workplace
after
DDAC
is
applied
to
ornamentals.
The
following
occupational
postapplication
risks
are
of
concern
until:

$
day
63
for
all
crops
and
all
postapplication
activities,
assuming
400
gallons
are
applied
per
acre,

$
day
57
for
all
crops
and
all
postapplication
activities,
assuming
200
gallons
are
applied
per
acre,

$
day
50
for
all
crops
and
all
postapplication
activities,
assuming
100
gallons
are
applied
per
acre.

$
Inhalation
exposures
are
thought
to
be
negligible
in
outdoor
postapplication
scenarios,
since
DDAC
has
low
vapor
pressure,
and
the
dilution
factor
in
an
outdoor
environment
is
considered
infinite.
In
addition,
under
the
Worker
Protection
Standard
for
Agricultural
Pesticides
B
WPS
B
(
40
CFR
170)
greenhouses
must
be
appropriately
ventilated
(
ventilation
criteria
are
provided
in
section
2.2.1)
following
pesticide
applications
so
that
postapplication
inhalation
exposures
are
minimal.
As
such,
inhalation
postapplication
Page
5
of
36
exposures
are
not
considered
in
this
assessment.

It
has
been
determined
that
there
is
a
potential
for
exposure
in
residential
settings
during
the
application
process
for
homeowners
who
use
products
containing
DDAC.
There
is
also
a
potential
for
exposure
from
entering
DDAC­
treated
areas,
such
as
home
gardens
and
greenhouses
that
could
lead
to
exposures
scenarios.
Risk
assessments
have
been
completed
for
both
residential
handler
and
postapplication
scenarios.

The
NOAEL's
for
residential
handler
risks
are
based
on
80%
TGAI
(
4
µ
g/
cm2).
When
the
end­
use
product
is
formulated
with
10%
or
less
of
DDAC,
one
scenario
for
residential
handlers
is
of
concern.
Mixing/
loading/
applying
liquid
concentrates
with
a
hose­
end
sprayer
is
of
concern
for
ornamental
plants
at
the
0.034
lb
ai/
gal
rate
with
an
MOE
of
68.
When
the
end­
use
product
is
formulated
with
more
than
10%
DDAC,
the
dermal
risks
for
residential
handlers
are
of
concern
for
all
DDAC
residential
handler
scenarios
where
data
are
available
(
MOEs
<
1).
The
short­
term
inhalation
risks
for
residential
handlers
are
not
of
concern
for
any
residential
uses
of
DDAC.

Short­
term
MOEs
were
calculated
for
adults
performing
tasks
in
home
greenhouses
and
gardens
following
applications
of
DDAC.
Cancer
risks
were
not
calculated,
since
no
toxicological
endpoint
for
cancer
was
selected.
In
residential
settings,
HED
does
not
use
restricted­
entry
intervals
or
other
mitigation
approaches
to
limit
postapplication
exposures,
because
they
are
viewed
as
impractical
and
not
enforceable.
As
such,
risk
estimates
on
the
day
of
application
are
the
key
concern.
In
the
assessment
for
residential
postapplication
exposure,
there
are
risk
concerns
for
DDAC
as
currently
used
in
a
residential
environment
(
MOEs
<
1).
Page
6
of
36
1.0
Occupational
and
Residential
Exposure/
Risk
Assessment
1.1
Purpose
DDAC
(
Group
I
Quat
Cluster)
is
a
group
of
structurally
similar
quaternary
ammonium
compounds
("
quats")
that
are
characterized
by
having
a
positively
charged
nitrogen
covalently
bonded
to
two
alkyl
group
substituents
(
at
least
one
C8
or
longer)
and
two
methyl
substituents.
In
finished
form,
these
quats
are
salts
with
the
positively
charged
nitrogen
(
cation)
balanced
by
a
negatively
charged
molecule
(
anion).
The
anion
for
the
quats
in
this
cluster
is
chloride
or
bromide.
Most
of
the
registered
uses
of
DDAC
are
classified
as
antimicrobial
uses
and
will
be
assessed
by
the
Antimicrobial
Division
in
EPA=
s
Office
of
Pesticide
Programs.

This
document
is
the
occupational
and
residential
exposure
assessment
for
DDAC
from
its
use
as
a
plant
growth
regulator.
In
this
document,
the
Agency
presents
the
results
of
its
review
of
the
potential
human
health
effects
of
occupational
and
residential/
nonoccupational
exposure
to
DDAC.

1.2
Criteria
for
Conducting
Exposure
Assessments
An
occupational
and/
or
residential
exposure
assessment
is
required
for
an
active
ingredient
if
(
1)
certain
toxicological
criteria
are
triggered
and
(
2)
there
is
a
potential
for
exposure
to
handlers
(
mixers,
loaders,
applicators)
during
use
or
to
persons
entering
treated
sites
or
exposed
to
vapors
after
application
is
complete.
Toxicological
endpoints
were
selected
for
short­
term
dermal,
short­
and
intermediate­
term
inhalation,
and
incidental
oral
exposures
to
DDAC.
There
is
a
significant
potential
for
exposure
in
a
variety
of
occupational
agricultural
and
commercial
settings
as
well
as
in
residential
settings.
Therefore,
risk
assessments
are
required
for
occupational
and
residential
handlers
as
well
as
for
occupational
and
residential
postapplication
exposures
that
can
occur
as
a
result
of
DDAC
use.

1.3
Summary
of
Hazard
Concerns
for
DDAC
The
toxicological
endpoints
used
to
complete
the
occupational
and
residential
risk
assessment
were
based
on
the
best
professional
judgement
of
EPA
toxicologists.
Adverse
effects
were
identified
at
durations
of
exposure
ranging
from
short­
term
(
up
to
30
days)
to
intermediateterm
durations
(>
30
days
up
to
6
months)
and
long­
term
durations
(>
6
months).
No
cancer
endpoint
was
identified;
therefore,
cancer
risks
were
not
assessed.

DDAC
is
a
plant
growth
regulator.
The
use
patterns
can
range
from
short­
term
through
intermediate­
term
exposure
durations.
Endpoints
were
selected
to
address
each
of
these
durations
of
exposure.
DDAC
exposures
are
expected
to
occur
to
both
occupational
and
residential
users.

Dermal
Route
Page
7
of
36
No
short­
or
intermediate­
term
dermal
endpoint
for
systemic
effects
was
selected
for
DDAC,
since
no
systemic
effects
were
identified
at
the
limit
dose
of
1000
mg/
kg/
day
of
a
diluted
end
use
product
containing
0.13%
active
ingredient
(
ai).
However,
a
short­
term
dermal
endpoint
was
identified
for
DDAC
based
on
adverse
dermal
effects.
The
short­
term
dermal
NOAEL
was
2
mg/
kg/
day
which
is
equivalent
to
0.15
µ
g/
cm2)
was
determined
from
a
LOAEL
of
6
mg/
kg/
day
based
on
increased
clinical
and
gross
findings
of
the
skin
(
erythema,
edema,
exfoliation,
excoriation,
and
ulceration).
The
Agency
did
not
select
intermediate­
or
long­
term
dermal
endpoints
for
DDAC.

Inhalation
Route
The
short­
and
intermediate­
term
inhalation
risk
assessment
for
DDAC
is
based
on
an
NOAEL
of
10
mg/
kg/
day,
derived
from
a
prenatal
developmental
toxicity
study
in
rats.
The
oral
LOAEL
(
20
mg/
kg/
day)
was
based
largely
on
increased
incidence
of
skeletal
variations
in
females.
Long­
term
inhalation
exposure
to
DDAC
(
i.
e.,
greater
than
6
months)
is
not
expected
for
current
registered
uses.
It
was
assumed
that
inhalation
absorption
is
equivalent
to
oral
absorption
(
i.
e.­
100%).

Incidental
Oral
Route
The
short­
term
incidental
oral
risk
assessment
for
DDAC
is
based
on
a
NOAEL
of
10
mg/
kg/
day,
derived
from
a
prenatal
developmental
toxicity
study
in
rats.
The
LOAEL
(
20
mg/
kg/
day)
was
based
largely
on
increased
incidence
of
skeletal
variations
in
females,
and
the
FQPA
factor
was
1x.

Level
of
Concern
(
LOC)

The
level
of
concern
(
LOC)
for
occupational
and
non­
occupational
DDAC
dermal
and
inhalation
exposures
is
an
MOE
of
less
than
100.
The
MOE
was
based
on
10x
for
interspecies
extrapolation,
and
10x
for
intraspecies
extrapolation.

Body
Weight
For
calculating
dermal
exposure,
body
weight
was
not
needed
for
the
dermal
endpoint,
since
no
systemic
dose
was
calculated.
Section
3.1.1
contains
a
detailed
description
of
this
logic.
Since
the
toxicological
endpoint
for
inhalation
is
female­
specific,
a
body
weight
of
60
kilograms
is
used
in
the
assessment.
This
represents
the
average
body
weight
of
an
adult
female.

Aggregation
The
dermal
and
inhalation
margins
of
exposure
were
not
combined
for
the
DDAC
risk
assessment
because
the
toxicity
endpoints
for
the
dermal
and
inhalation
routes
of
exposure
were
Page
8
of
36
based
on
different
toxicological
effects.

Cancer
No
cancer
endpoint
was
identified.

Acute
Toxicity
DDAC
is
corrosive
and
is
of
moderate
acute
toxicity
by
oral,
dermal,
or
inhalation
routes
of
exposure.
DDAC
is
a
severe
eye
irritant.
DDAC
is
a
weak
dermal
sensitizer.
The
acute
toxicity
data
for
DDAC
are
summarized
below
in
Table
1
(
USEPA,
2006).

Table
1.
Acute
Toxicity
Profile
for
DDAC
Guideline
No.
Study
Type
MRID
#(
S).
Results
Toxicity
Category
81­
1
Acute
Oral
41394404
LD50
(
 
)
=
331mg/
kg;
LD50(
 
)
=
238mg/
kg;
LD50
(
combined)
=
262
mg/
kg
II
81­
2
Acute
Dermal
42053801
LD50
(
 
)
=
3140mg/
kg;
LD50
(
 
)
=
2730mg/
kg;
LD50
(
combined)
=
2930
mg/
kg
III
81­
3
Acute
Inhalation
00145074
LC50
=
between
0
­
0.7mg/
L
II
81­
4
Primary
Eye
Irritation
41394404
Severe
eye
irritant
I
81­
5
Primary
Skin
Irritation
41891405
Severe
dermal
irritant
I
81­
6
Dermal
Sensitization
00160084
Slight
sensitization
Page
9
of
36
Table
2.
Toxicological
Endpoints
of
Concern
for
DDAC
Exposure
Scenario
Dose
Used
in
Risk
Assessment
(
mg/
kg/
day)
Target
MOE/
UF,
Special
FQPA
SF
for
Risk
Assessment
Study
and
Toxicological
Effects
NOAEL
(
developmental)
=
10
mg/
kg/
day
FQPA
SF
=
1
UF
=
100
(
10x
inter­
species
extrapolation,
10x
intraspecies
variation)
Prenatal
Developmental
Toxicity
­
Rat
MRID
41886701
LOAEL
=
20
mg/
kg/
day
based
on
increased
incidence
of
skeletal
variations.
Acute
Dietary
(
Females
13­
50)

Acute
RfD
=
0.1
mg/
kg/
day
(
for
Females
age
13­
50)

NOAEL
=
10
mg/
kg/
day
FQPA
SF
=
1
UF
=
100
(
10x
inter­
species
extrapolation,
10x
intraspecies
variation
Chronic
Toxicity
Study
­
Dog
MRID
41970401
LOAEL
=
20
mg/
kg/
day
based
on
decreased
total
cholesterol
levels
in
females.
Chronic
Dietary
(
general
population)

Chronic
RfD
=
0.1
mg/
kg/
day
Non­
Dietary
Exposures
Incidental
Oral
Short­
Term
NOAEL
(
developmental)
=
10
mg/
kg/
day
Target
MOE
=
100
(
10x
inter­
species
extrapolation,
10x
intra­
species
variation)
FQPA
SF
=
1
Prenatal
Developmental
Toxicity
­
Rat
MRID
41886701
LOAEL
=
20
mg/
kg/
day
based
on
increased
incidence
of
skeletal
variations.

Incidental
Oral
Intermediate­
Term
NOAEL
=
10
mg/
kg/
day
Target
MOE
=
100
(
10x
inter­
species
extrapolation,
10x
intra­
species
variation)
FQPA
SF
=
1
Chronic
Toxicity
Study
­
Dog
MRID
41970401
LOAEL
=
20
mg/
kg/
day
based
on
decreased
total
cholesterol
levels
in
females.

Dermal,
Short­
term
(
formulated
product,
0.13%
ai)
No
endpoint
identified.
No
dermal
or
systemic
effects
identified
in
the
21­
day
dermal
toxicity
study
(
MRID
45656601)
up
to
and
including
the
limit
dose
of
1000
mg/
kg/
day
Dermal,
Short­
term
(
formulated
product,
6%
a.
i.)
NOAEL=
500
mg/
kg/
day
(
7750
µ
g/
cm2)
a
Target
MOE
=
100
(
10x
inter­
species
extrapolation,
10x
intra­
species
variation)
21­
day
dermal
toxicity­
guinea
pigs
MRID
41105801
LOAEL
=
1000
mg/
kg/
day,
based
on
denuded
nonvascularized
epidermal
layer.
Page
10
of
36
Table
2.
Toxicological
Endpoints
of
Concern
for
DDAC
Exposure
Scenario
Dose
Used
in
Risk
Assessment
(
mg/
kg/
day)
Target
MOE/
UF,
Special
FQPA
SF
for
Risk
Assessment
Study
and
Toxicological
Effects
Dermal,
Short­
term
(
TGAI
80%)
NOAEL(
dermal)
=
2
mg/
kg/
day
(
4.0
Fg/
cm2)
b
Target
MOE
=
100
(
10x
inter­
species
extrapolation,
10x
intra­
species
variation)
90­
day
Dermal
Toxicity
­
Rat
MRID
41305901
LOAEL
=
6
mg/
kg/
day
based
on
increased
clinical
and
gross
findings
(
erythema,
edema,
exfoliation,
excoriation,
and
ulceration)

Dermal,
Intermediate­
and
Long­
term
(
formulated
product)
No
appropriate
endpoint
identified.

Inhalation,
Short­
Term
NOAEL
=
10
mg/
kg/
day
Target
MOE
=
100
(
10x
inter­
species
extrapolation,
10x
intra­
species
variation)
c
FQPA
SF
=
1
Prenatal
Developmental
Toxicity
­
Rat
MRID
41886701
LOAEL
=
20
mg/
kg/
day
based
on
increased
incidence
of
skeletal
variations.

Inhalation,
Intermediate­
and
Long­
Term
NOAEL
=
10
mg/
kg/
day
Target
MOE
=
100
(
10x
inter­
species
extrapolation,
10x
intra­
species
variation)
c
FQPA
SF
=
1
Chronic
Toxicity
Study
­
Dog
MRID
41970401
LOAEL
=
20
mg/
kg/
day
based
on
decreased
total
cholesterol
levels
in
females.

a
Formulated­
based
dermal
endpoint
=
(
500
mg/
kg
guinea
pig
x
0.4
kg
guinea
pig
x
1000
ug/
mg)
/
25.8
cm2
area
treated
=
7,750
µ
g/
cm2
.
b
TGAI­
based
dermal
endpoint
=
(
2
mg/
kg
rat
x
0.2
kg
rat
x
1000
ug/
mg)
/
100
cm2
area
treated
=
4
µ
g/
cm2
.
C
an
additional
uncertainty
factor
of
10x
is
used
for
route
extrapolation
from
an
oral
endpoint.

1.4
Incident
Reports
The
incident
report
is
being
prepared
under
a
separate
memo
by
Jonathan
Chen,
of
the
Office
of
Pesticide
Programs.
Page
11
of
36
1.5
Summary
of
Physical
and
Chemical
Properties
of
DDAC
The
following
table
shows
physical/
chemical
characteristics
that
have
been
reported
for
DDAC.

Table
3.
Physical/
Chemical
Properties
of
DDAC
Parameter
DDAC
Molecular
Weight
362.08
Density
0.9216
g/
cm3
at
25
C
Boiling
Point
NA
Water
Solubility
Completely
soluble
Vapor
Pressure
2.33E­
11
mmHg
1.6
Summary
of
Use
Patterns
and
Formulations
1.6.1
End­
Use
Products
DDAC
(
Group
I
Quat
Cluster)
is
a
group
of
structurally
similar
quaternary
ammonium
compounds
("
quats").
It
is
used
in
agricultural,
commercial,
and
residential
settings.
DDAC
is
formulated
as
a
soluble
concentrate,
emulsifiable
concentrate,
ready­
to­
use
solution,
pressurized
liquid,
wettable
powder,
water
soluble
packet,
and
impregnated
material.
Note
that
there
are
many
end­
use
products
that
contain
DDAC
and
each
label
could
not
be
reviewed
to
determine
the
formulation­
type
and
the
registered
uses.
Also
note
that
the
Master
Label
does
not
indicate
the
formulation
types
registered
for
individual
use­
patterns.
Therefore,
as
a
conservative
approach,
this
chapter
will
assume
that
when
used
as
a
growth
regulator,
DDAC
may
be
formulated
as
a
liquid
concentrate,
a
water
dispersible
granular,
and
a
wettable
powder.

1.6.2
Registered
Use
Categories
and
Sites
An
analysis
of
the
current
labeling
and
available
use
information
was
completed
by
the
Antimicrobial
Division.
DDAC
is
registered
for
use
in
a
variety
of
occupational
and
residential
scenarios
and
thus
both
occupational
and
residential
populations
could
be
potentially
exposed
while
performing
DDAC
applications.
It
is
also
possible
for
occupational
and
residential
populations
to
be
exposed
to
DDAC
during
postapplication
time
periods.
Table
4
provides
a
summary
of
the
maximum
application
rates,
equipment,
and
amounts
handled
daily
for
registered
DDAC
uses.
Page
12
of
36
Table
4:
Summary
of
Maximum
Application
Rates
for
Registered
DDAC
Agricultural,
Commercial,
and
Residential
Uses
Crop
Target
Maximum
Application
Rate
Formulation
Application
Equipment
Amount
Handled
Daily
low­
pressure
handwand
sprayer
40
gallonsa
5
gallonsb
handgun
sprayer
(
high­
pressure
handwand)
1000
gallonsa
100
gallonsb
Hose­
end
sprayer
100
gallons
Liquid
Concentrate,
Wettable
Powder,
Water
Dispersible
Granule
watering
can
5
gallons
Ornamental
Plants
Foliage
Spray
or
Soil
Drench
0.034
lb
ai/
gal
Ready­
to­
use
liquid
pump
trigger
sprayer
1
gallon
a
 
occupational
rate
b
 
residential
rate
All
other
amounts
indicate
dual
use
rate.

1.6.3
Application
Methods
DDAC
is
applied
with
several
types
of
application
equipment
B
including
low­
pressure
handwand
sprayers,
handgun
sprayers
(
high­
pressure
handwand),
watering
cans,
and
pumptrigger
sprayers.

2.0
Occupational
Exposures
and
Risks
There
is
a
potential
for
exposure
to
DDAC
in
occupational
scenarios
from
handling
DDAC
products
during
the
application
process
(
i.
e.,
mixer/
loaders,
applicators,
and
mixer/
loader/
applicators)
and
a
potential
for
postapplication
worker
exposure
from
entering
into
areas
previously
treated
with
DDAC.
As
a
result,
risk
assessments
have
been
completed
for
occupational
handler
scenarios
as
well
as
occupational
postapplication
scenarios.

2.1
Occupational
Handler
Exposures
and
Risks
HED
uses
the
term
"
handlers"
to
describe
those
individuals
who
are
involved
in
the
pesticide
application
process.
HED
believes
that
there
are
distinct
job
functions
or
tasks
related
to
applications
and
that
exposures
can
vary
depending
on
the
specifics
of
each
task.
Job
requirements
(
e.
g.,
amount
of
chemical
to
be
used
in
an
application),
the
kinds
of
equipment
used,
the
target
being
treated,
and
the
level
of
protection
used
by
a
handler
can
cause
exposure
levels
to
differ
in
a
manner
specific
to
each
application
event.

HED
uses
exposure
scenarios
to
describe
the
various
types
of
handler
exposures
that
may
Page
13
of
36
occur
for
a
specific
active
ingredient.
The
use
of
scenarios
as
a
basis
for
exposure
assessment
is
very
common
as
described
in
the
U.
S.
EPA
Guidelines
for
Exposure
Assessment
(
U.
S.
EPA;
Federal
Register
Volume
57,
Number
104;
May
29,
1992).
Information
from
the
current
labels,
use
and
usage
information,
toxicology
data,
and
exposure
data
were
all
key
components
in
the
development
of
the
exposure
scenarios.
HED
has
developed
a
series
of
general
descriptions
for
tasks
that
are
associated
with
pesticide
applications.
Tasks
associated
with
occupational
pesticide
handlers
are
categorized
using
one
of
the
following
terms:

$
Mixers
and/
or
Loaders:
These
individuals
perform
tasks
in
preparation
for
an
application.
For
example,
prior
to
application,
mixer/
loaders
would
mix
the
DDAC
and
load
it
into
the
holding
tank
of
the
airplane
or
groundboom.

$
Applicators:
These
individuals
operate
application
equipment
during
the
release
of
a
pesticide
product
into
the
environment.
These
individuals
can
make
applications
using
equipment
such
as
airplanes
or
groundboom.

$
Mixer/
Loader/
Applicators
and
or
Loader/
Applicators:
These
individuals
are
involved
in
the
entire
pesticide
application
process
(
i.
e.,
they
do
all
job
functions
related
to
a
pesticide
application
event).
These
individuals
would
transfer
DDAC
into
the
application
equipment
and
then
also
apply
it.

A
chemical
can
produce
different
effects
based
on
how
long
a
person
is
exposed,
how
frequently
exposures
occur,
and
the
level
of
exposure.
HED
classifies
exposures
up
to
30
days
as
short­
term
and
exposures
greater
than
30
days
up
to
several
months
as
intermediate­
term.
HED
completes
both
short­
and
intermediate­
term
assessments
for
occupational
scenarios
in
essentially
all
cases,
because
these
kinds
of
exposures
are
likely
and
acceptable
use/
usage
data
are
not
available
to
justify
deleting
intermediate­
term
scenarios.
Based
on
use
data
and
label
instructions,
HED
believes
that
occupational
DDAC
exposures
may
occur
over
a
single
day
or
up
to
weeks
at
a
time
for
many
use­
patterns
and
that
intermittent
exposure
over
several
weeks
also
may
occur.
Some
applicators
may
apply
DDAC
over
a
period
of
weeks,
because
they
are
custom
or
commercial
applicators
who
are
completing
multiple
applications
for
a
number
of
different
clients.
Long­
term
handler
exposures
are
not
expected
to
occur
for
DDAC.

Other
parameters
are
also
defined
from
use
and
usage
data
such
as
application
rates
and
application
frequency.
HED
typically
completes
risk
assessments
using
maximum
application
rates
for
each
in
order
to
ensure
there
are
no
concerns
for
each
specific
use.

Occupational
handler
exposure
assessments
are
completed
by
the
Angency
using
different
levels
of
risk
mitigation.
Typically,
HED
uses
a
tiered
approach.
The
lowest
tier
is
designated
as
the
baseline
exposure
scenario
(
i.
e.,
no
respirator).
If
risks
are
of
concern
at
baseline
attire,
then
increasing
levels
of
personal
protective
equipment
or
PPE
(
e.
g.,
respirators)
are
evaluated.
If
risks
remain
of
concern
with
maximum
PPE,
then
engineering
controls
(
e.
g.,
enclosed
cabs,
water­
soluble
packaging,
and
closed
mixing/
loading
systems)
are
evaluated.
This
approach
is
used
to
ensure
that
the
lowest
level
of
risk
mitigation
that
provides
adequate
protection
is
Page
14
of
36
selected,
since
the
addition
of
PPE
and
engineering
controls
involves
an
additional
expense
to
the
user
and
B
in
the
case
of
PPE
B
also
involves
an
additional
burden
to
the
user
due
to
decreased
comfort
and
dexterity
and
increased
heat
stress
and
respiratory
stress.

2.1.1
Data
and
Assumptions
for
Handler
Exposure
Scenarios
2.1.1.1
Assumptions
for
Handler
Exposure
Scenarios
A
series
of
assumptions
and
exposure
factors
served
as
the
basis
for
completing
the
occupational
handler
risk
assessments.
Each
assumption
and
factor
is
detailed
below
on
an
individual
basis.
The
assumptions
and
factors
used
in
the
risk
calculations
include:

$
Occupational
handler
exposure
estimates
were
based
on
surrogate
data
from:
(
1)
the
Pesticide
Handlers
Exposure
Database
(
PHED)
and
(
2)
the
Outdoor
Residential
Exposure
Task
Force
(
ORETF).

$
The
toxicological
endpoint
of
concern
for
dermal
risks
is
from
a
dermal
study;
with
the
effects
being
irritation
(
no
systemic
effects
were
observed).
Therefore,
no
dose
is
calculated
and
no
body
weight
is
used
to
complete
the
dermal
exposure
assessment.
The
toxicological
endpoint
of
concern
for
inhalation
risks
is
from
a
prenatal
developmental
toxicity
study;
with
the
effects
seen
in
females;
therefore,
the
average
body
weight
of
an
adult
female
(
i.
e.,
60
kg)
is
used
to
complete
the
inhalation
exposure
assessment.

$
Generic
protection
factors
(
PFs)
were
used
to
calculate
exposures
when
data
were
not
available.
For
example,
an
80
percent
protection
factor
was
assumed
for
the
use
of
a
respirator
equipped
with
a
quarter­
face
dust/
mist
filter.

$
Exposure
factors
used
to
calculate
daily
exposures
to
handlers
are
based
on
applicable
data,
if
available.
For
lack
of
appropriate
data,
values
from
a
scenario
deemed
similar
enough
by
the
assessor
might
be
used.
For
example,
ORETF
data
for
hose­
end
sprayers
is
used
as
a
surrogate
for
inhalation
unit
exposures
for
mixing/
loading/
applying
with
a
sprinkling
can.

$
The
Agency
typically
assumes
the
maximum
application
rates
allowed
by
labels
in
its
risk
assessments
(
see
Table
4).

$
The
average
occupational
workday
is
assumed
to
be
8
hours.

$
The
daily
areas
treated
were
defined
for
each
handler
scenario
(
in
appropriate
units)
by
determining
the
amount
that
can
be
reasonably
treated
in
a
single
day
(
e.
g.,
gallons
per
day).
When
possible,
the
assumptions
for
daily
areas
treated
are
taken
from
the
Health
Effects
Division
Science
Advisory
Committee
on
Exposure
SOP
#
9:
Standard
Values
for
Daily
Acres
Treated
in
Agriculture,
completed
in
July,
2000.
However,
no
standard
values
are
available
for
numerous
scenarios.
Assumptions
for
these
scenarios
are
based
on
Page
15
of
36
HED
estimates
and
could
be
further
refined
from
input
from
affected
sectors.

There
are
data
gaps
that
have
been
identified
for
some
DDAC
applications.
Each
is
identified
in
the
calculation
tables
and
is
also
noted
in
the
summary
of
risk
calculations.

2.1.1.2
Exposure
Data
for
Handler
Exposure
Scenarios
Exposure
analyses
were
performed
using
the
Pesticide
Handlers
Exposure
Database
(
PHED)
as
tabulated
in
the
PHED
Surrogate
Exposure
Guide
of
August
1998.
A
description
of
PHED
is
included
in
Appendix
A.
The
unit
exposures
calculated
by
PHED
generally
range
from
the
geometric
mean
to
the
median
of
the
selected
data
set.
The
assessment
of
data
quality
is
based
on
the
number
of
observations
and
the
available
quality
control
data.
While
data
from
PHED
provide
the
best
available
information
on
handler
exposures,
it
should
be
noted
that
some
aspects
of
the
included
studies
(
e.
g.,
duration,
acres
treated,
pounds
of
active
ingredient
handled)
may
not
accurately
represent
labeled
uses
in
all
cases.

Unit
exposures
values
have
been
taken
from
both
the
Pesticide
Handler
Exposure
Database
(
PHED)
and
studies
provided
by
the
Outdoor
Residential
Exposure
Task
Force
(
ORETF)
where
the
scenario
unit
exposure
values
are
more
applicable.
Appendix
A
contains
background
information
on
PHED
and
ORETF.

Once
the
data
for
a
given
exposure
scenario
have
been
selected,
the
data
are
normalized
(
i.
e.,
divided
by)
by
the
amount
of
pesticide
handled
resulting
in
standard
unit
exposures
(
milligrams
of
exposure
per
pound
of
active
ingredient
handled).
Following
normalization,
the
data
are
statistically
summarized.
The
distribution
of
exposure
for
each
body
part
(
e.
g.,
chest,
upper
arm)
is
categorized
as
normal,
lognormal,
or
"
other"
(
i.
e.,
neither
normal
nor
lognormal).
A
central
tendency
value
is
then
selected
from
the
distribution
of
the
exposure
for
each
body
part.
These
values
are
the
arithmetic
mean
for
normal
distributions,
the
geometric
mean
for
lognormal
distributions,
and
the
median
for
all
"
other"
distributions.
Once
selected,
the
central
tendency
values
for
each
body
part
are
composited
into
a
Abest
fit@
exposure
value
representing
the
entire
body.

ORETF
Handler
Studies
(
MRID
449722­
01):
A
report
was
submitted
by
the
ORETF
(
Outdoor
Residential
Exposure
Task
Force)
that
presented
data
in
which
the
application
of
various
products
used
on
turf
by
homeowners
and
lawncare
operators
(
LCOs)
was
monitored.
All
of
the
data
submitted
in
this
report
were
completed
in
a
series
of
studies.
The
study
that
monitored
LCO
exposure
scenarios
using
a
low
pressure,
high
volume
turf
handgun
(
ORETF
Study
OMA002)
is
summarized
in
Appendix
A
as
is
the
study
that
monitored
homeowner
exposures
while
using
a
hose­
end
sprayer
(
ORETF
Study
OMA004).

2.1.1.3
DDAC
Inhalation
Handler
Exposure
Scenarios
It
has
been
determined
that
exposure
to
pesticide
handlers
is
likely
during
the
occupational
use
of
DDAC
in
a
variety
of
occupational
environments.
The
anticipated
use
patterns
and
current
Page
16
of
36
labeling
indicate
several
occupational
exposure
scenarios
based
on
the
types
of
equipment
and
techniques
that
can
potentially
be
used
for
DDAC
applications.

DDAC
inhalation
exposure
was
estimated
using
PHED
or
ORETF
data.
Risks
were
calculated
by
comparing
the
inhalation
dose
to
the
short­
and
intermediate­
term
NOAEL
to
determine
the
Margin
of
Exposure
(
MOE).

DDAC
dermal
exposures
and
risks
were
not
estimated
for
occupational
handler
exposures.
Instead,
dermal
exposures
and
risks
will
be
mitigated
using
default
personal
protective
equipment
requirements
based
on
the
toxicity
of
the
end­
use
product.
To
minimize
dermal
exposures,
the
minimum
PPE
required
for
mixers,
loaders,
and
others
exposed
to
end­
use
products
containing
concentrations
of
DDAC
that
result
in
classification
of
category
I
or
II
for
skin
potential
will
be
long­
sleeve
shirt,
long
pants,
shoes,
socks,
chemical­
resistant
gloves,
and
chemical­
resistant
apron.
The
minimum
PPE
required
for
mixers,
loaders,
and
others
exposed
to
end­
use
products
containing
concentrations
of
DDAC
that
result
in
classification
of
category
III
for
skin
potential
will
be
long­
sleeve
shirt,
long
pants,
shoes,
socks,
and
chemical­
resistant
gloves.
Once
diluted,
if
the
concentration
of
DDAC
in
the
diluted
solution
would
result
in
classification
of
toxicity
category
IV
for
skin
potential,
then
the
chemical­
resistant
gloves
and
chemical­
resistant
apron
can
be
eliminated
for
applicators
and
others
exposed
to
the
dilute.
Note
that
chemical­
resistant
eye
protection
will
be
required
if
the
end­
use
product
is
classified
as
category
I
or
II
for
eye
irritation
potential.

The
quantitative
inhalation
exposure
assessment
developed
for
occupational
handlers
is
based
on
the
following
scenarios.
[
Note:
The
scenario
numbers
correspond
to
the
tables
of
risk
calculations
included
in
the
occupational
risk
calculation
aspects
of
the
appendices.]

Mixer/
Loader/
Applicators:
(
1)
Liquid
Formulations:
Low
Pressure
Handwand
Sprayer
(
ORETF
data)
(
2)
Wettable
Powder
Formulations:
Low
Pressure
Handwand
Sprayer
(
PHED
data)
(
3)
Water
Dispersible
Granules
with
Low
Pressure
Handwand
(
using
liquids
ORETF
data)
(
4)
Liquid
Formulations:
Handgun
Sprayer
(
ORETF
data)
(
5)
Wettable
Powders
with
a
Handgun
Sprayer
(
ORETF
data)
(
6)
Water
Soluble
Bags
with
Handgun
Sprayer
(
ORETF
data)
(
7)
Dry
Flowables
Concentrates
with
a
Handgun
Sprayer
(
ORETF
data)
(
8)
Liquid
Formulations:
Sprinkling
Can
(
ORETF
hose­
end
data)
(
9)
Liquid
Formulations:
Ready­
to­
Use
Pump
Trigger
Sprayer
(
ORETF
data)

2.1.2
DDAC
Handler
Exposure
and
Assessment
2.1.2.1
DDAC
Handler
Exposure
and
Risk
Calculations
Handler
risks
(
i.
e.
MOEs)
were
calculated
as
described
in
Appendix
A.
The
basic
rationale
for
these
calculations
is
that
the
daily
exposure
is
the
product
of
the
amount
of
ai
handled
per
day
times
a
unit
exposure
value.
The
MOEs
were
calculated
for
short/
intermediate
Page
17
of
36
term
dermal
and
inhalation
exposures.
These
MOEs
were
calculated
separately
because
the
dermal
and
inhalation
endpoints
were
based
upon
different
effects.
A
MOE
greater
than
100
indicates
the
risk
is
not
of
concern
for
that
scenario.

2.1.2.2
DDAC
Risk
Summary
The
short­
and
intermediate­
term
risks
for
each
inhalation
exposure
scenario
are
presented
in
Table
5
and
details
are
presented
in
Appendix
B.

Short­
and
Intermediate­
term
Inhalation
Risks
In
all
occupational
handler
scenarios,
inhalation
MOEs
are
not
of
concern
at
baseline
(
i.
e.,
no
respirator).
In
the
case
that
the
MOE
is
below
1000,
the
Agency
may
request
a
confirmatory
inhalation
toxicity
study
according
to
AD's
policy
(
oral
communication
from
Tim
Leighton).

Short­
and
Intermediate­
term
Total
Risks
Since
no
dermal
endpoint
for
systemic
toxicological
effects
was
selected,
no
dermal
exposure
was
estimated.
Therefore,
no
combined
dermal
and
inhalation
risks
were
calculated.
Page
18
of
36
Table
5:
Short
and
Intermediate­
Term
Inhalation
Exposures
and
Risks
to
Occupational
Handlers
Exposure
Scenario
Application
Ratea
(
lb
ai/
gallon)
Area
Treated
Dailyb
(
gallons)
Baseline
Inhalation
Unit
Exposurec
(
ug/
lb
ai)
Baseline
Inhalation
Exposure
(
mg/
day)
Baseline
Inhalation
Dose
(
mg/
kg/
day)
Baseline
Inhalation
MOE
Mixer/
Loader/
Applicator
Mixing/
Loading/
Applying
(
M/
L/
A)
Liquid
Concentrates
with
Low
Pressure
(
LP)
Handwand
(
1)
0.034
40
2.7
0.0037
0.000061
160000
M/
L/
A
Wettable
Powders
(
WP)
with
LP
Handwand
(
2)
0.034
40
1100
1.5
0.025
400
M/
L/
A
Water
Dispersible
Granules
(
WDG)
with
LP
Handwand
(
liquid
concentrate
ORETF
data
as
surrogate)
(
3)
0.034
40
2.7
0.0037
0.000061
160000
M/
L/
A
Liquid
Concentrates
with
a
Handgun
Sprayer
(
4)
0.034
1000
1.5
0.051
0.00085
12000
M/
L/
A
WP
with
a
Handgun
Sprayer
(
4)
0.034
1000
64
2.2
0.036
280
M/
L/
A
WSB
with
Handgun
Sprayer
(
5)
0.034
1000
7.2
0.24
0.0041
2500
M/
L/
A
Dry
Flowables
Concentrates
(
DF)
with
a
Handgun
Sprayer
(
6)
0.034
1000
22
0.75
0.012
800
M/
L/
A
Liquids
with
a
Watering
Can
(
7)
0.034
5
17
0.0029
0.000048
210000
a
Application
rates
are
the
maximum
application
rates
determined
from
the
EPA
Master
Label
provided
for
DDAC
from
AD
b
Amount
handled
per
day
values
are
HED
estimates
of
gallons
applied
per
day
based
on
Exposure
SAC
SOP
#
9
A
Standard
Values
for
Daily
Acres
Treated
in
Agriculture,@
industry
sources,
and
HED
estimates.

c
Baseline
Inhalation:
no
respirator.

d
Baseline
inhalation
exposure
(
mg/
day)
=
application
rate
(
lb
ai/
gal
)
x
amount
handled
per
day
(
gal/
day)
x
baseline
inhalation
unit
exposure
(
µ
g/
lb
ai)
x
conversion
factor
from
µ
g
to
mg
(
0.001)

e
Baseline
inhalation
dose
(
mg/
kg/
day)
=
baseline
inhalation
exposure
(
mg/
day)
x
inhalation
absorption
factor
(
100%)
/
female
bodyweight
(
60
kg)

f
Inhalation
MOE
=
inhalation
NOAEL
(
10
mg/
kg/
day)
/
baseline
inhalation
dose
(
mg/
kg/
day)
Page
19
of
36
2.1.3
Cancer
DDAC
Handler
Exposure
and
Risk
Assessment
No
cancer
endpoints
were
identified
for
DDAC;
therefore,
cancer
risks
to
handlers
were
not
assessed.

2.1.4
Summary
of
Risk
Concerns
and
Data
Gaps
for
Occupational
Handlers
There
are
no
occupational
handler
scenarios
for
DDAC
that
have
inhalation
risks
associated
with
them
that
are
above
the
Agency's
level
of
concern
for
risk
assessments.
However,
there
are
some
occupational
handler
scenarios
for
DDAC
that
are
data
gaps
because
of
lack
of
unit
exposure
data.

2.1.4.1
Summary
of
Risk
Concerns
The
short­
and
intermediate­
term
inhalation
handler
risk
assessment
for
DDAC
indicates
no
risk
concerns
for
occupational
handler
scenarios
at
baseline
(
no
respirator).
See
Section
2.1.2.2
for
a
detailed
summary.

Three
scenarios
fall
below
an
inhalation
MOE
of
1000
at
the
maximum
level
of
mitigation,
and
the
Agency
may
request
a
confirmatory
inhalation
toxicity
study:
 
Mix/
Load/
Apply
wettable
powders
with
low
pressure
handwand
(
MOE
 
400)
 
Mix/
Load/
Apply
wettable
powders
with
handgun
sprayer
(
high
pressure
handwand)
(
MOE
 
280)
 
Mix/
Load/
Apply
dry
flowables
with
high
pressure
handwand
(
MOE
 
800)

DDAC
dermal
exposures
and
risks
were
not
estimated
for
occupational
handler
exposures.
Instead,
dermal
exposures
and
risks
will
be
mitigated
using
default
personal
protective
equipment
requirements
based
on
the
toxicity
of
the
end­
use
product.
To
minimize
dermal
exposures,
the
minimum
PPE
required
for
mixers,
loaders,
and
others
exposed
to
end­
use
products
containing
concentrations
of
DDAC
that
result
in
classification
of
category
I
or
II
for
skin
irritation
potential
will
be
long­
sleeve
shirt,
long
pants,
shoes,
socks,
chemical­
resistant
gloves,
and
chemicalresistant
apron.
The
minimum
PPE
required
for
mixers,
loaders,
and
others
exposed
to
end­
use
products
containing
concentrations
of
DDAC
that
result
in
classification
of
category
III
for
skin
irritation
potential
will
be
long­
sleeve
shirt,
long
pants,
shoes,
socks,
and
chemical­
resistant
gloves.
Once
diluted,
if
the
concentration
of
DDAC
in
the
diluted
solution
would
result
in
classification
of
toxicity
category
IV
for
skin
irritation
potential,
then
the
chemical­
resistant
gloves
and
chemical­
resistant
apron
can
be
eliminated
for
applicators
and
others
exposed
to
the
dilute.
Note
that
chemical­
resistant
eyewear
will
be
required
if
the
end­
use
product
is
classified
as
category
I
or
II
for
eye
irritation
potential.
Page
20
of
36
2.1.4.2
Summary
of
Data
Gaps
Two
data
gaps
were
identified
for
DDAC:

$
mixing/
loading/
applying
dry
flowables
using
a
low­
pressure
handwand
sprayer
(
data
for
liquid
formulations
was
used
as
a
surrogate),
and
$
mixing/
loading/
applying
liquid
concentrates
for
sprinkling
can
(
ORETF
data
for
hose­
end
sprayers
was
used
as
a
surrogate).

2.1.5
Recommendations
For
Refining
Occupational
Handler
Risk
Assessment
In
order
to
refine
this
occupational
risk
assessment,
data
on
actual
use
patterns
including
rates,
timing,
and
areas
treated
would
better
characterize
DDAC
risks.
Exposure
studies
for
many
equipment
types
that
lack
data
or
that
are
not
well
represented
in
PHED
(
e.
g.,
because
of
low
replicate
numbers
or
data
quality)
should
also
be
considered
based
on
the
data
gaps
identified
above
and
based
on
a
review
of
the
quality
of
the
data
used
in
this
assessment.

2.2
Occupational
Postapplication
Exposures
and
Risks
HED
uses
the
term
"
postapplication"
to
describe
exposures
to
individuals
that
occur
as
a
result
of
being
in
an
environment
that
has
been
previously
treated
with
a
pesticide
(
also
referred
to
as
reentry
exposure).
HED
believes
that
there
are
distinct
job
functions
or
tasks
related
to
the
kinds
of
activities
that
occur
in
previously
treated
areas.
Job
requirements
(
e.
g.,
the
kinds
of
jobs
to
cultivate
a
crop),
the
nature
of
the
crop
or
target
that
was
treated,
and
how
the
chemical
residues
degrade
in
the
environment
can
cause
exposure
levels
to
differ
over
time.
Each
factor
has
been
considered
in
this
assessment.

2.2.1
Occupational
Postapplication
Exposure
Scenarios
DDAC
can
be
used
on
ornamental
crops
in
greenhouse
and
outdoor
occupational
settings.
As
a
result,
individuals
can
potentially
be
exposed
by
working
in
areas
that
have
been
previously
treated.
HED
is
concerned
about
the
kinds
of
exposures
one
can
receive
in
the
workplace
after
DDAC
is
applied
to
ornamentals.

Since
no
toxicological
endpoint
was
identified
for
dermal
systemic
adverse
effects,
no
postapplication
occupational
exposures
and
risks
were
assessed
using
the
traditional
method
of
transfer
coefficients
specific
to
activities
performed.
Instead,
a
dermal
endpoint
was
identified
and
expressed
as
µ
g/
cm2.
Postapplication
dermal
risks
were
assessed
by:

$
converting
the
application
rate
from
lb
ai/
A
to
µ
g/
cm2;

$
using
HED=
s
default
assumption
that
20
percent
of
the
initial
application
is
available
for
transfer
on
day
0
(
i.
e.,
12
hours
after
application);

$
using
HED=
s
default
assumption
that
the
residue
dissipates
at
a
rate
of
10
percent
Page
21
of
36
per
day;

$
assuming
that
during
the
exposure
period
the
skin
repeatedly
contacts
foliar
surfaces
until
a
concentration
of
residues
on
the
hand
is
equal
to
the
concentration
of
residues
on
foliar
surfaces,
and
thereafter,
a
steady­
state
is
achieved
whereby
the
concentration
on
the
hands
remains
the
same
as
the
concentration
on
the
foliar
surfaces.

Inhalation
exposures
are
thought
to
be
negligible
in
outdoor
postapplication
scenarios,
since
DDAC
has
low
vapor
pressure
and
the
dilution
factor
in
an
outdoor
environment
is
considered
infinite.
In
addition,
under
the
Worker
Protection
Standard
for
Agricultural
Pesticides
B
WPS
B
(
40
CFR
170)
greenhouses
must
be
appropriately
ventilated
(
ventilation
criteria
are
provided)
following
pesticide
applications
so
that
postapplication
inhalation
exposures
are
minimal.
As
such,
inhalation
postapplication
exposures
are
not
considered
in
this
assessment.
However,
HED
recommends
that
WPS
ventilation
criteria
be
imposed
on
non­
WPS
applications
indoors
in
settings
such
as
an
atrium,
interiorscape,
or
other
commercial
plant
setting.
The
WPS
ventilation
requirements
are:

$
10
air
exchanges,
or
$
2
hours
of
mechanical
ventilation
(
i.
e.,
fans),
or
$
4
hours
of
passive
ventilation
(
i.
e.,
windows,
vents),
or
$
11
hours
of
no
ventilation
followed
by
1
hour
of
mechanical
ventilation,
or
$
11
hours
of
no
ventilation
followed
by
2
hours
of
passive
ventilation,
or
$
24
hours
of
no
ventilation
In
agricultural
crop
settings,
the
use
of
personal
protective
equipment
or
other
types
of
equipment
to
mitigate
postapplication
exposures
to
workers
is
not
considered
a
viable
alternative
for
the
regulatory
process.
This
is
described
in
some
detail
in
the
WPS.
Instead,
an
administrative
approach
B
a
Restricted
Entry
Interval
or
REI
B
is
used
to
mitigate
postapplication
risks
following
applications
to
crops.
The
REI
is
the
period
following
a
pesticide
application
during
which
entry
into
the
treated
area
is
restricted.
Postapplication
risk
levels
are
generally
calculated
in
the
risk
assessment
process
on
a
chemical­,
crop­,
and
activity­
specific
basis.
To
establish
REIs,
HED
considers
postapplication
risks
on
varying
days
after
application.

2.2.2
Data/
Assumptions
for
Postapplication
Exposure
Scenarios
A
series
of
assumptions
and
exposure
factors
served
as
the
basis
for
completing
the
occupational
postapplication
worker
risk
assessments.
Each
assumption
and
factor
is
detailed
below
on
an
individual
basis.

$
Maximum
application
rates
were
considered.

$
Levels
of
Concern:
HED
has
established
levels
of
concern
(
LOC)
for
occupational
postapplication
risks
B
margins
of
exposure
of
less
than
100
for
occupational
dermal
risks
are
considered
of
concern.
Page
22
of
36
$
Dislodgeable
Foliar
Residues:
No
DDAC­
specific
dislodgeable
foliar
residue
(
DFR)
data
were
available.
Therefore,
this
assessment
uses
HED=
s
default
assumption
that
20
percent
of
the
application
rate
is
available
on
day
0
(
i.
e.,
12
hours
after
application)
and
the
residue
dissipates
at
a
rate
of
10
percent
per
day.

$
Application
rates
are
provided
on
the
label
only
in
terms
of
pounds
active
ingredient
per
gallon
of
spray.
No
information
is
provided
for
pounds
active
ingredient
applied
per
acre.
Postapplication
assessments
rely
on
the
amount
of
active
ingredient
applied
per
unit
area.
To
complete
the
postapplication
occupational
risk
assessment
for
DDAC,
a
rangefinder
was
used
based
on
gallons
per
acre
that
are
often
used
in
agriculture.
Risks
were
assessed
based
on
a
rangefinder
of
gallons
of
dilute
spray
that
might
be
applied
per
acre.
The
rangefinder
includes:
400
gallons
per
acre
(
as
might
be
used
in
drench
scenarios),
200
gallons
per
acre,
and
100
gallons
per
acre.

2.2.3
Occupational
Postapplication
Exposure
and
Risk
Estimates
Occupational
risks
were
calculated
using
a
Margin
of
Exposure
(
MOE),
which
is
a
ratio
of
the
daily
exposure
to
the
toxicological
endpoint
of
concern.
Postapplication
risks
diminish
over
time
because
DDAC
residues
eventually
dissipate
in
the
environment.
As
a
result,
risks
were
calculated
over
time
based
on
changing
residue
levels.
Postapplication
exposure
(
i.
e.
MOEs)
were
calculated
as
described
in
Appendix
A.

Postapplication
Risk
Summary
A
summary
of
the
postapplication
risks
are
provided
in
Table
6
and
details
are
presented
in
Appendix
B.
The
occupational
postapplication
exposure
and
risk
assessment
for
ornamental
crop
uses
of
DDAC
indicates
that
dermal
risks
are
of
concern
until:

$
day
63
for
all
crops
and
all
postapplication
activities,
assuming
400
gallons
are
applied
per
acre,

$
day
57
for
all
crops
and
all
postapplication
activities,
assuming
200
gallons
are
applied
per
acre,

$
day
50
for
all
crops
and
all
postapplication
activities,
assuming
100
gallons
are
applied
per
acre.
Page
23
of
36
Table
6:
Dermal
Risks
to
Occupational
Postapplication
Workers
Day
After
Exposure
Daily
residue
dissipation
percent
(
minus
10%
after
day
0)
Residue
Concentration
on
Skinc
(
ug/
cm2)
Dermal
MOEd
Handling
treated
ornamental
plants,
Spray
Formulation
0.034
lb
ai/
gal,
assuming
400
gallons
per
acre,
20%
initial
default
transferable
residue,
31
ug/
cm2
DFR
on
day
0.

0
(
12
hours)
0%
31
<
1
1
(
24
hours)
10%
27
<
1
10
(
days)
10%
11
<
1
20
10%
3.7
1
30
10%
1.3
3
40
10%
0.45
9
50
10%
0.16
25
60
10%
0.055
73
61
10%
0.049
81
62
10%
0.044
90
63
10%
0.04
100
Handling
treated
ornamental
plants,
Spray
Formulation
0.034
lb
ai/
gal,
assuming
200
gallons
per
acre,
20%
initial
default
transferable
residue,
15
ug/
cm2
DFR
on
day
0.

0
(
12
hours)
0%
15
<
1
1
(
24
hours)
10%
14
<
1
10
(
days)
10%
5.3
1
20
10%
1.9
2
30
10%
0.65
6
40
10%
.23
18
50
10%
0.079
51
55
10%
0.046
86
56
10%
0.042
96
57
10%
0.038
110
Page
24
of
36
Table
6:
Dermal
Risks
to
Occupational
Postapplication
Workers
Day
After
Exposure
Daily
residue
dissipation
percent
(
minus
10%
after
day
0)
Residue
Concentration
on
Skinc
(
ug/
cm2)
Dermal
MOEd
Handling
treated
ornamental
plants,
Spray
Formulation
0.034
lb
ai/
gal,
assuming
100
gallons
per
acre,
20%
initial
default
transferable
residue,
8
ug/
cm2
DFR
on
day
0.

0
(
12
hours)
0%
7.6
1
1
(
24
hours)
10%
6.9
1
10
(
days)
10%
2.7
2
20
10%
.93
4
30
10%
.32
12
40
10%
.11
35
48
10%
0.049
82
49
10%
0.044
92
50
10%
0.039
100
a
Maximum
application
rate
on
label
(
lb
ai/
gal).
b
Gallons
of
dilute
applied
per
acre
(
rangefinder).
c
Residue
concentration
available
to
be
transferred
on
day
A
t
@

=
application
rate
in
µ
g/
cm2
(
lb
ai/
gal
*
gallons/
A
*
conversion
factors
(
lb
to
µ
g
and
A
to
cm2)*
DFR
available
on
day
0
(
20%)
*
(
daily
dissipation
for
day
@

t
@)
*
percent
of
DFR
transferrable
to
skin.

d
Dermal
MOE
=
dermal
endpoint­
80%
TGAI
(
4
µ
g/
cm2)
/
residue
concentration
on
skin.
Page
25
of
36
2.2.4
Occupational
Postapplication
Exposure
and
Risk
Estimates
for
Cancer
Since
no
toxicological
endpoint
of
concern
was
identified
for
cancer,
cancer
risks
from
occupational
postapplication
exposures
were
not
assessed.

2.2.5
Summary
of
Occupational
Postapplication
Risk
Concerns
and
Data
Gaps
The
Agency
has
used
the
most
up­
to­
date
information
available
to
complete
this
postapplication
risk
assessment
for
DDAC.
A
summary
of
the
postapplication
risks
are
provided
in
Table
6.
The
occupational
postapplication
exposure
and
risk
assessment
for
ornamental
crop
uses
of
DDAC
indicates
that
risks
are
of
concern
until:

$
day
63
for
all
crops
and
all
postapplication
activities,
assuming
400
gallons
are
applied
per
acre,

$
day
57
for
all
crops
and
all
postapplication
activities,
assuming
200
gallons
are
applied
per
acre,

$
day
50
for
all
crops
and
all
postapplication
activities,
assuming
100
gallons
are
applied
per
acre.

2.2.6
Recommendations
for
Refining
Occupational
Postapplication
Risk
Assessment
To
refine
this
occupational
risk
assessment,
data
on
actual
use
patterns
including
rates,
timing,
and
the
gallons
per
acre
that
are
required
to
apply
DDAC
as
a
plant
growth
regulator
would
better
characterize
DDAC
risks.
In
addition,
DDAC­
specific
DFR
data
could
refine
exposure
and
risk
estimates.

3.0
Residential
and
Other
Non­
Occupational
Exposures
and
Risks
It
has
been
determined
there
is
a
potential
for
exposure
in
residential
settings
during
the
application
process
for
homeowners
who
use
products
containing
DDAC.
There
is
also
a
potential
for
exposure
from
entering
DDAC­
treated
areas,
such
as
home
gardens
and
greenhouses
that
could
lead
to
exposures
to
adults.
Risk
assessments
have
been
completed
for
both
residential
handler
and
postapplication
scenarios.

3.1
Residential
Handler
Exposures
and
Risks
The
Agency
uses
the
term
Ahandlers@
to
describe
those
individuals
who
are
involved
in
the
pesticide
application
process.
The
Agency
believes
that
there
are
distinct
tasks
related
to
applications
and
that
exposures
can
vary
depending
on
the
specifics
of
each
task
as
was
described
above
for
occupational
handlers
Page
26
of
36
3.1.1
DDAC
Dermal
Handler
Exposure
Scenarios
Scenarios
are
used
to
define
risks
based
on
the
U.
S.
EPA
Guidelines
for
Exposure
Assessment
(
U.
S.
EPA;
Federal
Register
Volume
57,
Number
104;
May
29,
1992).
Assessing
exposures
and
risks
resulting
from
residential
uses
is
very
similar
to
assessing
occupational
exposures
and
risks,
with
the
following
exceptions:

$
Residential
handler
exposure
scenarios
are
considered
to
be
short­
term
only,
due
to
the
infrequent
use
patterns
associated
with
homeowner
products.

$
Homeowner
handler
assessments
are
based
on
the
assumption
that
individuals
experience
irritation
based
on
hand
contact
with
DDAC.

$
Homeowner
handlers
are
expected
to
complete
all
tasks
associated
with
the
use
of
a
pesticide
product
including
mixing/
loading
if
needed
as
well
as
the
application.

$
Master
Label
use­
rates
and
use­
information
specific
to
residential
products
serve
as
the
basis
for
the
risk
calculations.

$
Area/
volumes
of
spray
or
chemical
used
in
the
risk
assessment
are
based
on
The
Agency=
s
guidance
specific
to
residential
use­
patterns.

Dermal
risks
were
estimated
by
using
the
dermal
unit
exposure
for
hands
from
PHED
for
the
application
equipment/
method
being
assessed
divided
by
the
surface
area
of
adult
hands
and
then
normalizing
for
the
amount
handled
per
day
(
application
rate
in
pounds
active
ingredient
per
gallon
times
the
gallons
handled
per
day).
The
residue
concentration
on
skin
(
µ
g/
cm2)
was
then
compared
directly
to
the
dermal
endpoint
(
NOAEL
4
µ
g/
cm2
for
a
80%
ai
formulated
product).
The
margin
of
exposure
for
the
dermal
assessment
is
less
than
100.

It
has
been
determined
that
exposure
to
pesticide
handlers
is
likely
during
the
residential
use
of
DDAC
in
indoor
(
greenhouse)
and
outdoor
while
treating
ornamentals.
The
anticipated
use
patterns
and
current
labeling
indicate
several
residential
handler
exposure
scenarios
based
on
the
types
of
equipment
and
techniques
that
can
potentially
be
used
to
make
DDAC
applications.
The
quantitative
exposure/
risk
assessment
developed
for
residential
handlers
is
based
on
these
scenarios.
[
Note:
The
scenario
numbers
correspond
to
the
tables
of
risk
calculations
included
in
the
residential
risk
calculations
in
Appendix
B].

Mixer/
Loader/
Applicators:
(
1)
Liquid
Formulations:
Low
Pressure
Handwand
(
PHED
data
for
dermal
and
ORETF
data
for
inhalation)
(
2)
Wettable
Powder
Formulations:
Low
Pressure
Handwand
(
PHED
data
for
dermal
and
inhalation)
(
3)
Dry
Flowable
Formulations:
Low
Pressure
Handwand
(
using
liquid
concentrate
Page
27
of
36
PHED
data
for
dermal
and
liquid
concentrate
ORETF
data
for
inhalation)
(
4)
Liquid
Concentrates:
Hose­
End
Sprayer
(
PHED
data
for
dermal
and
ORETF
data
for
inhalation)
(
5)
Wettable
Powder
Formulations:
Hose­
End
Sprayer
(
no
data)
(
6)
Dry
Flowable
Formulatons:
Hose­
End
Sprayer
(
no
data)
(
7)
Ready­
to­
Use
Formulations:
Hose­
End
Sprayer
(
no
data)
(
8)
Liquid
Concentrates:
Watering
Can
(
using
PHED
hose­
end
sprayer
data
for
dermal
and
ORETF
hose­
end
data
for
inhalation)

3.1.2
Data
and
Assumptions
for
Handler
Exposure
Scenarios
A
series
of
assumptions
and
exposure
factors
served
as
the
basis
for
completing
the
residential
handler
risk
assessments.
Each
assumption
and
factor
is
detailed
below.
In
addition
to
these
factors,
unit
exposure
values
were
used
to
calculate
risk
estimates.
Dermal
unit
exposure
values
were
taken
from
the
Pesticide
Handlers
Exposure
Database
(
PHED).
Both
PHED
and
the
individual
studies
are
presented
below.
[
Note:
Several
of
the
assumptions
and
factors
used
for
the
assessment
are
similar
to
those
used
in
the
occupational
assessment
presented
above.
As
such,
only
factors
that
are
unique
to
the
residential
scenarios
are
presented
below.]

Assumptions
and
Factors:
The
assumptions
and
factors
used
in
the
risk
calculations
include:

$
Exposure
factors
used
to
calculate
daily
exposures
to
handlers
were
based
on
applicable
data
if
available.
When
appropriate
data
is
unavailable,
values
from
a
scenario
deemed
similar
might
be
used.

$
HED
typically
considers
the
maximum
application
rates
allowed
by
labels
in
its
risk
assessments.
If
additional
information
such
as
average
or
typical
rates
is
available,
these
values
also
may
be
used
to
allow
risk
managers
to
make
a
more
informed
risk
management
decision.
Average/
typical
application
rates
were
not
available
for
residential
scenarios.

$
Residential
risk
assessments
are
based
on
estimates
of
what
homeowners
would
typically
treat,
such
as
the
size
of
a
lawn
or
the
size
of
a
garden.
The
factors
used
for
the
DDAC
assessment
were
from
the
Health
Effects
Division
Science
Advisory
Committee
Policy
12:
Recommended
Revisions
to
the
Standard
Operating
Procedures
for
Residential
Exposure
Assessment
which
was
completed
on
February
22,
2001,
and
on
professional
judgement.
The
daily
volumes
handled
used
in
each
residential
scenario
are
provided
in
Table
4.

Residential
Handler
Exposure
Studies:
The
unit
exposure
values
that
were
used
in
this
assessment
were
based
on
the
Outdoor
Residential
Exposure
Task
Force
studies
and
the
Pesticide
Handler
Exposure
Database
(
PHED,
Version
1.1
August
1998)
[
Note:
PHED
and
some
ORETF
studies
are
described
above
in
Section
2.1.1.]
More
details
can
be
found
in
Appendix
A.

3.1.3
Residential
Handler
Exposure
and
Risk
Estimates
Page
28
of
36
Risks
were
calculated
using
the
Margin
of
Exposure
(
MOE)
as
described
in
Section
2.1.3.
Assessing
exposures
and
risks
resulting
from
residential
uses
is
very
similar
to
assessing
occupational
exposures
and
risks,
except
as
described
in
Section
3.1.1.

Residential
Risk
Summary
The
Agency
believes
that
the
scenarios
assessed
in
this
document
represent
worse­
case
exposures
and
risks
resulting
from
use
of
DDAC
in
residential
environments.
It
should
be
noted
that
there
were
many
other
scenarios
where
medium
to
low
PHED
quality
data
were
used
to
complete
the
assessment.
Data
quality
should
be
considered
in
the
interpretation
of
the
uncertainties
associated
with
each
risk
value
presented.

Short­
term
dermal
and
inhalation
risks
for
residential
handlers
(
intermediate­
term
exposures
are
not
likely
because
of
the
intermittent
nature
of
applications
by
homeowners)
are
presented
in
Tables
7,
8,
and
9.
When
the
end­
use
product
is
formulated
with
10%
or
less
of
DDAC,
one
scenario
for
residential
handlers
is
of
concern.
Mixing/
loading/
applying
liquid
concentrates
with
a
hose­
end
sprayer
is
of
concern
for
ornamental
plants
at
the
0.034
lb
ai/
gal
rate
with
an
MOE
of
68.
When
the
end­
use
product
is
formulated
with
more
than
10%
DDAC,
the
dermal
risks
for
residential
handlers
are
of
concern
for
all
DDAC
residential
handler
scenarios
where
data
are
available.
The
short­
term
inhalation
risks
for
residential
handlers
are
not
of
concern
for
any
residential
uses
of
DDAC.

Table
7:
Short­
term
Dermal
Risks
to
Residential
Handlers
Using
Formulations
with
10%
or
Less
DDAC
Scenario
Crop/
Target
Application
Ratea
(
lb
ai/
gal)
Quantity
Handled
per
Dayb
(
gallons/
day)
Unit
Exposure
for
Handsc
(
mg/
lb
ai)
Surface
Area
of
Adult
Handsd
(
cm2)
Estimated
Residue
Transferred
to
Skin
of
Handse
(
ug/
cm2/
day)
Dermal
MOEf
(
UF
=
100)

Mixing/
Loading
Applying
(
M/
L/
A)
Liquid
Concentrates
with
Low
Pressure
(
LP)
Handwand
(
1)
0.034
5
102
820
21
370
M/
L/
A
Wettable
Powders
(
WP)
with
LP
Handwand
(
2)
Ornamental
Plants
(
drench
or
spray)

0.034
5
229
820
47
160
Page
29
of
36
Table
7:
Short­
term
Dermal
Risks
to
Residential
Handlers
Using
Formulations
with
10%
or
Less
DDAC
Scenario
Crop/
Target
Application
Ratea
(
lb
ai/
gal)
Quantity
Handled
per
Dayb
(
gallons/
day)
Unit
Exposure
for
Handsc
(
mg/
lb
ai)
Surface
Area
of
Adult
Handsd
(
cm2)
Estimated
Residue
Transferred
to
Skin
of
Handse
(
ug/
cm2/
day)
Dermal
MOEf
(
UF
=
100)

M/
L/
A
Dry
Flowables
(
DF)
with
LP
Handwand
(
3)
0.034
5
102
820
21
370
M/
L/
A
Liquid
s
with
Hose­
end
Sprayer
(
4)
0.034
100
27.5
820
110
68
M/
L/
A
Liquids
with
a
Watering
Can
(
PHED
residential
hose­
end
data
as
surrogate)
(
8)
0.034
5
27.5
820
6
1,400
a
Application
rates
are
the
maximum
application
rates
determined
from
EPA
registered
labels
for
DDAC
b
Amount
handled
per
day
values
are
HED
estimates
of
acres,
square
feet,
or
cubic
feet
treated
or
gallons
applied
based
on
Exposure
SAC
SOP
#
9
A
Standard
Values
for
Daily
Acres
Treated
in
Agriculture,@
industry
sources,
and
HED
estimates.
c
From
residential
PHED
unit
exposures
values
for
hands
for
the
scenarios
listed.
d
From
Exposure
Factors
Handbook
e
Application
rate
(
lb
ai/
gal)
*
amount
handled
per
day
(
gal/
day)
*
dermal
unit
exposures
value
(
mg/
lb
ai)
*
conversion
factor
mg
to
µ
g
(
1000)
/
surface
area
of
adult
hands
(
cm2)
f
Dermal
MOE
=
Estimated
Residue
transferred
to
Skin
of
Hands
(
µ
g/
cm2/
day)/
Dermal
Endpoint
(
7750
µ
g/
cm2/
day)
for
6%
ai
product
Table
8:
Short­
term
Dermal
Risks
to
Residential
Handlers
Using
Formulations
with
More
than
10%
DDAC
Page
30
of
36
Scenario
Crop/
Target
Application
Ratea
(
lb
ai/
gal)
Quantity
Handled
per
Dayb
(
gallons/
day)
Unit
Exposure
for
Handsc
(
mg/
lb
ai)
Surface
Area
of
Adult
Handsd
(
cm2)
Estimated
Residue
Transferred
to
Skin
of
Handse
(
ug/
cm2/
day)
Dermal
MOEf
(
UF
=
100)

M/
L/
A
Liquid
LP
Handwand
(
ORETF
data)
(
1)
0.034
5
102
820
21
<
1
M/
L/
A
WP
with
LP
Handwand
(
2)
0.034
5
229
820
47
<
1
M/
L/
A
Water
Dispersible
Granules
(
WDG)
with
LP
Handwand
(
liquid
concentrate
ORETF
data
as
surrogate)
(
3)
0.034
5
102
820
21
<
1
M/
L/
A
Liquid
Concentrates
with
a
Hose­
end
Sprayer
(
4)
Ornamental
Plants
(
drench
or
spray)

0.034
100
27.5
820
110
<
1
M/
L/
A
Liquids
with
a
Watering
Can
(
ORETF
residential
hose­
end
data
as
surrogate)
(
8)
Ornamental
Plants
(
drench)
0.034
5
27.5
820
6
<
1
a
Application
rates
are
the
maximum
application
rates
determined
from
EPA
registered
labels
for
DDAC
b
Amount
handled
per
day
values
are
HED
estimates
of
acres,
square
feet,
or
cubic
feet
treated
or
gallons
applied
based
on
Exposure
SAC
SOP
#
9
A
Standard
Values
for
Daily
Acres
Treated
in
Agriculture,@
industry
sources,
and
HED
estimates.
c
From
residential
PHED
unit
exposures
values
for
hands
for
the
scenarios
listed.
d
From
Exposure
Factors
Handbook
e
Application
rate
(
lb
ai/
gal)
*
amount
handled
per
day
(
gal/
day)
*
dermal
unit
exposures
value
(
mg/
lb
ai)
*
conversion
factor
mg
to
µ
g
(
1000)
/
surface
area
of
adult
hands
(
cm2)
f
Dermal
MOE
=
Estimated
Residue
transferred
to
Skin
of
Hands
(
µ
g/
cm2/
day)/
Dermal
Endpoint
(
4.0
µ
g/
cm2/
day)
for
80%
TGAI
Page
31
of
36
Table
9:
Short­
term
Inhalation
Risks
to
Residential
Handlers
Scenario
Crop/
Target
Application
Ratea
(
lb
ai/
gal)
Quantity
Handled/
Treated
per
Dayb
(
gal/
day)
Baseline
Inhalation
Unit
Exposurec
(
ug/
lb
ai)
Baseline
Inhalation
Exposured
(
mg/
day)
Baseline
Inhalation
Dosee
(
mg/
kg/
day)
Inhalation
MOEf
UF
=
100)

M/
L/
A
Liquid
Concentrates
with
LP
Handwand
(
1)
0.034
5
2.7
0.00046
7.7E­
06
7,800,000
M/
L/
A
WP
with
LP
Handwand
(
2)
0.034
5
1063
0.18
0.003
20,000
M/
L/
A
WDG
LP
Handwand
(
liquid
concentrate
ORETF
data
as
surrogate)
(
3)
0.034
5
2.7
0.00046
7.7E­
06
7,800,000
M/
L/
A
Liquid
Concentrates
with
a
Hose­
end
Sprayer
(
4)
0.034
100
0.82
0.0028
0.000046
1,300,000
Loading/
Applying
Readyto
Use
Formulation
with
a
Hose­
end
Sprayer
(
7)
Ornamental
Plants
(
drench
or
spray)

0.034
100
11
0.037
0.00062
97,000
M/
L/
A
Liquids
with
a
Watering
Can
(
ORETF
residential
hose­
end
data
as
surrogate)
(
8)
Ornamental
Plants
(
drench)
0.034
5
17
0.0029
0.000048
1,300,000
a
Application
rates
are
the
maximum
application
rates
determined
from
EPA
registered
labels
for
DDAC
b
Amount
handled
per
day
values
are
HED
estimates
of
gallons
applied
per
day
based
on
Exposure
SAC
SOP
#
9
A
Standard
Values
for
Daily
Acres
Treated
in
Agriculture,@
industry
sources,
and
HED
estimates.
c
Baseline
Inhalation:
no
respirator.
d
Baseline
inhalation
exposure
(
mg/
day)
=
application
rate
(
lb
ai/
gal
)
x
amount
handled
per
day
(
gal/
day)
x
baseline
inhalation
unit
exposure
(
µ
g/
lb
ai)
x
conversion
factor
from
µ
g
to
mg
(
0.001)
e
Baseline
inhalation
dose
(
mg/
kg/
day)
=
baseline
inhalation
exposure
(
mg/
day)
x
inhalation
absorption
factor
(
100%)
/
female
bodyweight
(
kg)
f
Inhalation
MOE
=
inhalation
NOAEL
(
10
mg/
kg/
day)
/
baseline
inhalation
dose
(
mg/
kg/
day)

3.1.4
Residential
Handler
Exposure
and
Risk
Estimates
for
Cancer
Page
32
of
36
Residential
handler
cancer
risks
are
not
assessed,
since
no
toxicological
endpoint
of
concern
for
cancer
was
selected.

3.1.5
Summary
of
Risk
Concerns
and
Data
Gaps
for
Handlers
Risks
for
all
inhalation
scenarios
were
not
of
concern
for
residential
handlers.
When
the
end­
use
product
is
formulated
with
10%
or
less
of
DDAC,
one
scenario
for
residential
handlers
is
of
concern.
Mixing/
loading/
applying
liquid
concentrates
with
a
hose­
end
sprayer
is
of
concern
for
ornamental
plants
at
the
0.034
lb
ai/
gal
rate
with
an
MOE
of
68.
However
all
residential
dermal
scenarios
were
of
concern
when
the
end­
use
product
formulation
was
more
than
10
percent.

There
are
several
data
gaps
identified
by
HED
for
residential
handlers
including:

$
mixing/
loading/
applying
dry
flowables
with
low­
pressure
handwand
sprayers
and
with
hose­
end
sprayers;

$
mixing/
loading/
applying
wettable
powders
with
hose­
end
sprayers;

$
mixing/
loading/
applying
liquid
concentrates
with
a
sprinkling
can.

3.1.6
Recommendations
for
Refining
Residential
Handler
Risk
Assessment
In
order
to
refine
this
residential
risk
assessment,
more
data
on
actual
use
patterns
including
rates,
timing,
and
areas
treated
would
better
characterize
DDAC
risks.
In
addition,
if
ORETF
hand
data
are
available
separately
from
other
dermal
data,
then
ORETF
hand
data
could
be
used
to
refine
the
dermal
exposures
and
risks.
Exposure
studies
for
many
equipment
types
that
lack
data
or
that
are
not
well
represented
in
PHED
(
e.
g.,
because
of
low
replicate
numbers
or
data
quality)
should
also
be
considered
based
on
the
data
gaps
identified
above
and
based
on
a
review
of
the
quality
of
the
data
used
in
this
assessment.

3.2
Residential
Postapplication
Exposures
and
Risks
HED
uses
the
term
Apostapplication@
to
describe
exposures
to
individuals
that
occur
as
a
result
of
being
in
an
environment
that
has
been
previously
treated
with
a
pesticide.
DDAC
can
be
used
in
many
areas
that
can
be
frequented
by
the
general
population
including
residential
areas
(
e.
g.,
home
greenhouses
and
gardens).
As
a
result,
individuals
can
be
exposed
by
entering
these
areas
if
they
have
been
previously
treated.

3.2.1
Residential
Postapplication
Exposure
Scenarios
Postapplication
exposure
scenarios
were
developed
for
each
residential
setting
where
DDAC
can
be
used.
Assessing
postapplication
exposures
and
risks
resulting
from
residential
uses
is
very
similar
to
assessing
occupational
postapplication
exposures
and
risks
(
Section
2.2),
except
in
residential
assessments
the
risks
must
not
be
of
concern
on
day
0.
Page
33
of
36
HED
relies
on
a
standardized
approach
for
completing
residential
risk
assessments
that
is
based
on
current
DDAC
labels
and
guidance
contained
in
the
following
five
documents:

$
Series
875,
Residential
and
Residential
Exposure
Test
Guidelines:
Group
B
­
Postapplication
Exposure
Monitoring
Test
Guidelines
(
V
5.4,
Feb.
1998):
This
document
provides
general
risk
assessment
guidance
and
criteria
for
analysis
of
residue
dissipation
data.

$
Standard
Operating
Procedures
for
Residential
Exposure
Assessment
(
Dec.
1997):
This
document
provides
the
overarching
guidance
for
developing
residential
risk
assessments
including
scenario
development,
algorithms,
and
values
for
inputs.

$
Science
Advisory
Council
for
Exposure
Policy
12
(
Feb.
2001):
Recommended
Revisions
To
The
Standard
Operating
Procedures
(
SOPs)
For
Residential
Exposure
Assessment:
This
document
provides
additional,
revised
guidance
for
completing
residential
exposure
assessments.

$
Overview
of
Issues
Related
to
the
Standard
Operating
Procedures
for
Residential
Exposure
Assessment
(
August
1999
Presentation
To
The
FIFRA
SAP):
This
document
provides
rationale
for
Agency
changes
in
SOPs.

Usually
HED
considers
children
of
differing
ages
as
well
as
adults
in
its
postapplication
residential
exposure
and
risk
assessments.
Only
adults
were
considered
in
the
assessment
since
the
dermal
endpoint
is
for
skin
irritation
potential.
The
sole
postapplication
residential
scenario
assessed
is
for
residential
adults.
These
individuals
are
members
of
the
general
population
that
are
exposed
to
chemicals
by
engaging
in
activities
at
their
residences
(
e.
g.,
in
home
greenhouses
or
gardens)
previously
treated
with
a
pesticide.
These
kinds
of
exposures
are
attributable
to
a
variety
of
activities
and
are
usually
addressed
by
HED
in
risk
assessments
by
considering
a
representative
activity
as
the
basis
for
the
exposure
calculation.

The
SOPs
for
Residential
Exposure
Assessment
define
several
scenarios
that
apply
to
uses
specified
in
current
labels.
These
scenarios
served
as
the
basis
for
the
residential
postapplication
assessment
along
with
the
modifications
to
them
and
the
additional
data
and
approaches
described
above.
HED
used
this
guidance
to
define
the
exposure
scenarios
that
essentially
include
dermal
exposure
to
adults
in
treated
greenhouses
and
gardens.
The
SOPs
and
the
associated
scenarios
are
presented
below:

$
Potential
residues
on
skin
from
dermal
exposure
to
treated
foliage
in
greenhouses
or
gardens.

3.2.2
Data
and
Assumptions
for
Residential
Postapplication
Exposure
Scenarios
Page
34
of
36
Assumptions
and
Exposure
Factors
A
series
of
assumptions
and
exposure
factors
served
as
the
basis
for
completing
the
residential
postapplication
risk
assessments.
The
assumptions
and
factors
used
in
the
risk
calculations
are
consistent
with
current
Agency
policy
for
completing
residential
exposure
assessments
(
i.
e.,
SOPs
for
Residential
Exposure
Assessment).
The
values
used
in
this
assessment
include:

$
There
are
many
factors
that
are
common
to
the
occupational
and
residential
postapplication
risk
assessments,
such
as
body
weights
for
adults
and
analysis
of
residue
dissipation
data,
Please
refer
to
the
assumptions
and
factors
in
Section
2.1.2
for
further
information
concerning
these
common
values.

$
Exposures
to
adults
working
in
home
greenhouses
and
gardens
have
been
addressed
using
the
latest
HED
approaches
for
this
scenario
including:
the
DFR
data
used
for
the
assessments
are
the
default
assumption
that
20
percent
of
the
application
rate
is
available
for
transfer,
since
no
DDAC­
specific
DFR
data
are
available.

$
Postapplication
residential
risks
are
based
on
maximum
application
rates
or
values
specified
in
the
SOPs
for
Residential
Exposure
Assessment.

3.2.3
Residential
Postapplication
Exposure
and
Risk
Estimates
Risks
were
calculated
using
the
Margin
of
Exposure
(
MOE)
approach,
which
is
a
ratio
of
the
skin
burden
to
the
dermal
endpoint
of
concern.
Exposures
were
calculated
by
considering
the
potential
sources
of
exposure
(
i.
e.,
DFRs
on
ornamental
plants),
then
calculating
potential
skin
residues.

Dermal
Exposure
from
Treated
Ornamental
Greenhouses
and
Gardens
(
adult)

The
approach
used
to
calculate
the
dermal
exposures
that
are
attributable
to
exposure
from
contacting
treated
gardens
is:

RC(
0)
=
AR
(
lb
ai/
A)
x
CF1
x
CF2
x
F
Where:

RC(
0)
=
Residue
concentration
transferred
to
the
surface
of
the
skin
on
day
(
t)
attributable
for
activity
in
a
previously
treated
area
(
µ
g/
cm2/
day);
AR
=
application
rate
in
lb
ai/
A
(
if
application
rate
is
lb
ai/
gal,
then
this
is
multiplied
by
the
gallons
of
dilute
applied
per
acre
to
achieve
lb
ai/
A);
CF1
=
Conversion
factor
from
pounds
to
micrograms
(
4.5E+
08);
CF2
=
Conversion
factor
from
acres
to
centimeters
squared
(
2.47E­
08);
Page
35
of
36
F
=
fraction
of
ai
available
for
transfer
on
day
0
(
20%)

Residential
Risk
Summary:

Adults
Table
10
presents
the
postapplication
MOE
values
calculated
for
adults
after
home
greenhouse
or
garden
applications
of
DDAC.
The
short­
term
dermal
MOEs
are
less
than
100
on
the
day
of
application
for
these
scenarios
and
are
of
concern.

Table
10:
Dermal
Risks
to
Residential
Postapplication
Workers
Exposure
Scenario
Formulation
Application
Ratea
(
lb
ai/
gal)
Gallons
per
Acresb
Day
After
Exposure
Default
transferable
residue
(%)
Default
DFR
on
Postapplication
Day
Zeroc
(
ug/
cm2)
Residue
Concentration
on
Skin
(
ug/
cm2)
Dermal
MOEd
Assuming
400
gallons
per
acre
Handling
Treated
Ornamental
Plants
Spray
0.034
400
0
(
12
hours)
20%
31
31
<
1
Assuming
200
gallons
per
acre
Handling
Treated
Ornamental
Plants
Spray
0.034
200
0
(
12
hours)
20%
15
15
<
1
Assuming
100
gallons
per
acre
Handling
Treated
Ornamental
Plants
Spray
0.034
100
0
(
12
hours)
20%
7.6
7.6
<
1
a
Maximum
application
rate
on
label
(
lb
ai/
gal).
b
Gallons
of
dilute
applied
per
acre
(
rangefinder).
c
Residue
concentration
available
to
be
transferred
on
day
A
t
@

=
application
rate
in
µ
g/
cm2
(
lb
ai/
gal
*
gallons/
A
*
conversion
factors
(
lb
to
µ
g
and
A
to
cm2)*
DFR
available
on
day
0
(
20%)
*
(
daily
dissipation
for
day
@

t
@)
*
percent
of
DFR
transferrable
to
skin
d
Dermal
MOE
=
dermal
endpoint­
80%
TGAI
(
4
ug/
cm2)/
residue
concentration
on
skin
3.2.4
Residential
Postapplication
Exposure
and
Risk
Estimates
for
Cancer
Residential
postapplication
cancer
risks
were
not
assessed
for
DDAC,
since
no
toxicological
endpoint
of
concern
was
selected
for
cancer.
Page
36
of
36
3.2.5
Summary
of
Residential
Postapplication
Risk
Concerns
and
Data
Gaps
Short­
term
MOEs
were
calculated
for
adults
performing
tasks
in
home
greenhouses
and
gardens
following
applications
of
DDAC.
Cancer
risks
were
not
calculated,
since
no
toxicological
endpoint
for
cancer
was
selected.
In
residential
settings,
HED
does
not
use
restricted­
entry
intervals
or
other
mitigation
approaches
to
limit
postapplication
exposures,
because
they
are
viewed
as
impractical
and
not
enforceable.
As
such,
risk
estimates
on
the
day
of
application
are
the
key
concern.

In
the
assessment
for
residential
postapplication
exposure
and
risk,
there
are
risk
concerns
for
DDAC
as
it
is
currently
used
in
a
residential
environment.

3.2.6
Recommendations
for
Refining
Residential
Postapplication
Risk
Assessments
In
order
to
refine
this
residential
assessment,
data
on
actual
use
patterns
including
rates,
timing,
and
the
kinds
of
tasks
performed
are
required
to
better
characterize
DDAC
risks.