MEMORANDUM
April
13,
2006
SUBJECT:
Science
Chapter
on:
Environmental
Fate
Studies
and
Environmental
Fate
Assessment
of
Orthophenylphenol
FROM
A.
Najm
Shamim,
Ph.
D.,
Chemist
and
Science
Coordinator
for
Orthophenylphenol
and
its
Salts
(
Na
and
K)
Regulatory
Management
Branch
II
Antimicrobials
Division
(
7510C)

To:
Rebecca
Miller,
CRM
for
OrthophenolPhenol
and
its
Salts
(
Na
and
K)
Regulatory
Management
Branch
II
Antimicrobials
Division
(
7510C)

Thru:
Mark
Hartman,
Chief
Regulatory
Management
Branch
II
Antimicrobials
Division
(
7510C)

Environmental
Fate
Science
Chapter
and
Fate
Assessment
on
Orthophenylphenol
is
submitted
for
Reregistration
Eligibility
Decision
(
RED).
EXECUTIVE
SUMMARY
Orthophenylphenol
is
stable
and
persistent
in
abiotic
aqueous
medium
at
pHs
5,
7
and
9.
It
degrades
completely
in
14
days
when
exposed
to
sunlight
and
is
therefore,
photolytically
unstable
in
neutral
aqueous
medium.
When
exposed
to
UV
light
(
253.7
nm),
it
degrades
into:
phenyl
benzoquinone,
pehnylhydroquinone,
and
2­
hydroxy
benzofuran.
Its
half
life
is
(
measured
against
hydroxyl
radical)
14
hours
and
is
unstable
in
the
atmosphere.
It
has
a
high
KOC
value
of
10,000
and
is
immobile
in
soils
and
is
likely
to
remain
on
the
soil
surfaces.
It
is
not
likely
to
migrate
into
ground
water.
Its
major
degradation
pathway
appears
to
be
through
biodegradation
under
aerobic
and
anaerobic
conditions.
The
observed
half
lives
vary
from
a
few
hours
to
three
weeks.
Hence,
even
though
it
is
likely
to
stay
on
soil
surfaces,
it
biodegrades
under
aerobic
and
anaerobic
soil
conditions.
Thus
it
is
not
likely
to
contaminate
surface
water
(
drinking
water).
Sodium
salt
of
OPP,
is
applied
as
wood
treatment
(
antisapstian)
has
been
shown
to
leach
out
up
to
58%
within
first
day
after
treatment
highest
leach
rate:
71
µ
g//
cm2
/
day
on
day
one)
and
up
to
82
%
within
14
days
after
treatment
(
maximum
application
rate
is
4%
of
SOPP).

APPENDIX
FOR
ENVIRONMENTAL
FATE
CHAPTER
Environmental
Fate
Science
and
Transport
For
2­
Phenylphenol
and
its
Salts
(
Na
and
K)

Registrants
submitted
hydrolysis
study
for
environmental
fate
data
requirements.
In
addition
recently
a
leaching
study
on
the
treated
wood
(
non­
pressure
treatment,
antisapstian
use)
was
also
submitted
and
has
been
used
for
fate
risk
assessment.
However,
in
order
to
conduct
a
reasonably
complete
fate
and
transport
assessment,
the
Agency
conducted
an
open
literature
search.
Most
of
the
fate
studies
reported
in
this
chapter
are
abstracted
from
the
Hazardous
Substance
Database
(
HSDB).
These
are
summarized
below:

1.
Abiotic
Degradation
1.1
Hydrolysis.
A
30­
day
hydrolysis
study
of
Carbon
­
14
(
radiolabeled)
OPP,
based
on
Office
of
Pesticide
Programs'
guidelines
161­
1,
was
submitted
in
1996
by
the
registrants.
The
study
was
carried
out
under
buffered
and
abiotic
conditions
at
pHs
5,
7
and
9
(
and
at
a
temperature
of
25
o
C).
The
concentration
of
OPP
decreased:
8.8
%
at
pH
5;
6.8%
at
pH
7
and
6.3%
at
pH
9
at
the
end
of
thirty
day
period.
Therefore,
OPP
is
hydrolytically
stable
and
may
be
persistent
under
abiotic
conditions
in
acidic
and
basic
aqueous
solutions.
(
MRID#:
439942).
This
is
an
acceptable
study
and
fulfils
guidelines
requirements.
SJ.
Gonsior,
1996,
The
Environmental
Chemistry
Research
Laboratory,
The
Dow
Chemical
Company,
Study
ID#:
ES
3034)

1.2
Aqueous
Photolysis.
OPP
is
known
to
absorb
under
UV
light
with
a
maxima
at
282
nm.
When
a
neutral
aqueous
solution
of
OPP
was
exposed
to
sunlight,
it
degraded
completely
within
14
days.
When
the
same
sample
was
kept
in
darkness,
only
20%
degradation
ensued.
Under
acidic
conditions
and
when
irradiated
with
UV
light
at
253.7
nm,
OPP
degraded
forming:
phenylbenzoquinone,
phenylhydroquinone,
and
2­
hydroxybenzofuran.
OPP
is
not
likely
to
be
photolytically
stable
in
aqueous
medium.

1.3
Photooxidation
in
Air.
At
room
temperature
OPP
has
reasonably
high
vapor
pressure
(
0.002
mm
Hg)
and
in
vapor
phase
it
is
likely
to
behave
similar
to
phenol
and
interact
with
hydroxyl
radical
to
undergo
photooxidation.
Estimated
half
life
of
OPP
to
undergo
photooxidation
is
about
14
hours.
It
is
therefore,
not
likely
to
be
persistent
in
air.

2.
Biotic
Degradation
(
Abstracted
From
References
4­
12
in
This
Document)

2.1
In
a
study
it
has
been
shown
that
OPP
(
initial
concentration
of
30
mg/
L)
reached
47­
86
%
of
its
theoretical
BOD
level
in
two
weeks
when
activated
sludge
inoculum
was
100
mg/
L
level
In
an
activated
sludge
screening
test
on
OPP
with
an
initial
concentration
of
50
ppm,
it
was
observed
that
within
7
days,
the
concentration
reduced
30%
under
aerobic
conditions
(
At
the
initial
concentration
of
100
ppm
of
OPP,
and
under
aerated
lagoon
simulation
scenario,
43%
of
OPP
reduced
within
54
hours.
The
same
study
showed
that
the
initial
concentration
of
100
ppm
of
OPP
reduced
20%
in
168
hours
in
a
retention
pond
simulation
scenario.

2.2
(
C­
14
radiolabeled
OPP
was
observed
to
biodegrade
within
24
hours
in
a
non­
acclimated
sludge
from
a
river
of
Midland,
MI
up
to
50%
of
the
original
concentration.
The
sludge
was
activated
sludge
collected
from
the
municipal
wastewater
treatment
plant
in
East
Lansing,
Michigan.
The
river
water
study
was
conducted
with
water
from
the
river
in
Midland,
MI.
When
the
sludge
was
acclimated,
the
reduction
was
attained
within
3
hours.
Mineralization
of
OPP
into
14
CO2
(
50­
65%
)
occurred
in
16
days
in
the
river
water
and
48
hours
in
an
activated
sludge
2.3
In
a
study
on
OPP,
when
it
was
used
as
the
sole
carbon
source,
a
100%
biodegradation
occurred
under
aerobic
and
anaerobic
conditions
within
3
weeks
(
OPP
sample
of
10­
40
mg/
L).

2.5
Although
stable
under
abiotic
conditions
and
does
not
hydrolyze
at
pHs
5,
7
and
9,
OPP
appears
to
be
easily
biodegradable
under
aerobic
and
anaerobic
media
with
half
lives
between
a
few
hours
to
three
weeks.
In
addition
it
is
not
stable
or
persistent
in
air
and
undergoes
photooxidation
in
the
presence
of
hydroxyl
radical
with
a
half
life
of
about
14
hours.
It
is
likely
to
be
quite
immobile
in
soils
and
may
not
migrate
into
ground
water.

3.0
Bioaccumulation
Estimated
Log
KOW
of
OPP
is
3.09
and
it
is
likely
to
be
moderately
bioaccumulative
in
aquatic
organisms.
No
concrete
data
were
available
on
bioaccumulation.

4.0
KOC
for
OPP
has
been
estimated
to
be
about
10,000;
this
indicates
that
OPP
is
likely
to
be
immobile
in
certain
types
of
soils
and
is
not
likely
to
move
downward
into
ground
water.

5.0
Leaching
of
SOPP
(
Sodium
Ortho
phenylphenol)
from
Treated
Wood.

5.1
A
leaching
study
was
conducted
by
registrants
on
the
wooden
blocks
treated
with
1
and
4%
solutions
of
sodium
orthophenylphenol
for
sapstain
use.
The
wooden
blocks
were
treated
with
1%
and
4%
DOWICIDE
A.
Since
the
DOWICIDE
A
contains
71.1%
actives,
actual
dosings
of
SOPP
were
0.71
and
2.84%,
respectively).
The
study
showed
that
under
experimental
conditions,
1%
and
4
%
solutions
of
SOPP
leached
52
to
58%
from
the
treated
wooden
blocks
within
the
first
day;
after
14
days,
78­
82
%
of
SOPP
leached
out
from
the
treated
wooden
blocks.
Leach
rates
were:
1%
solution
71
µ
g
SOPP/
cm2
/
day
and
for
4%
solution:
192
µ
g/
SOPP/
cm2
/
day
for
the
first
day;
after
14
days,
leach
rates
were:
0.5
to
2.0
µ
g/
cm2
/
day
for
both
solutions.
Maximum
leaching
occurred
within
the
first
day
and
attained
pseudo
equilibrium
after
14
days.
At
the
end
of
the
experiment
20­
24%
SOPP
was
extracted
from
the
wooden
blocks.
(
Orthophenylphenol:
Determination
of
the
leaching
rate
from
Wood
following
a
simulated
Sapstain
Treatment,
The
Dow
Chemical
Company,
Study
ID#:
051089,
2005,
DP
Barcode:
319656)
BIBLIOGRAPHY
MRID
#
CITATIONS
1.
439942­
01
The
Hydrolysis
of
o­
Phenylphenol
in
Buffered
Solution:
SJ
Gonsior,
1996,
Study
ID#:
ES
3034,
Performing
Lab:
The
Environmental
Chemistry
Research
Laboratory,
The
Dow
Chemical
company,
Midland,
Michigan
48674
2.
Hazard
Substances
Databank
(
HSDB),
A
Database
of
the
National
Library
of
Medicine's
TOXNET
System.

3.
AD
Memo
by:
A.
Najm
Shamim,
and
Kathryn
Montague,
2005;
Review
on
the
Determination
of
the
Leaching
Rate
of
SOPP
From
Wood
Following
A
Simulated
Sapstain
Treatment
(
DP
Bar
Code:
319656)

Note:
Citations
4
through
12
are
abstracted
from
HSDB
4.
(
K.
Verschwren,
1996;
Handbook
of
Environmental
Data
on
Organic
Chemicals,
3rd.
Edition,
Van
Nostrand,
NY,
pp
536)

5
(
RC
Gore
et
al.
J.
Assoc.
Official
Analytical
Chemists,
1971,
Volume
54,
pp
1042­
82
6
J.
Suzuki
et
al.;
Bull
Environ
Contam.
Toxicol,
1990,
Volume
45,
pp
512
and
M.

7.
Sarakha
et
al.;
Chemophere,
1989,
volume
18,
pp
1391)

8.
(
L.
Krumenacker,
1995;
Kirk­
Othmer
Encyclopedia
of
Chem.
And
Technol.,
4th
Edition,
John
Wiley,
NY,
Volume
13,
pp
1004
9.
(
W.
M
Meylan,
and
PH
Howard,
1993;
Chemosphere,
Volume
26,
pp
2293)
Another
study
identified
the
major
photoxidation
product:
phenylbenzoquinone)

10.
AW
Garrison,
1969
Analytical
Studies
of
Textile
Wastes,
Presented
to
Division
of
Drinking
Water/
Air/
Waste
Chem.
American
Chemical
Society)

11.
(
TR
Tallin,
1975;
Polytech.
Inst.,
Volume
390,
pp
107)

12.
(
SJ
Gonsior,
J.
Agri.
Food
Chem,
1984,
Volume
34,
pp
593).
