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Unified
Agenda
Executive
Orders
Current
Laws
and
Regulations
Category
for
Persistent,
Bioaccumulative,
and
Toxic
New
Chemical
Substances
[Federal
Register:
November
4,
1999
(Volume
64,
Number
213)]
[Notices]
[Page
60194­
60204]
From
the
Federal
Register
Online
via
GPO
Access
[wais.
access.
gpo.
gov]
[DOCID:
fr04no99­
64]

­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­

­­­­­­­­­­­­­


ENVIRONMENTAL
PROTECTION
AGENCY
[OPPTS­
53171A;
FRL­
6097­
7]

Category
for
Persistent,
Bioaccumulative,
and
Toxic
New
Chemical
Substances
AGENCY:
Environmental
Protection
Agency
(EPA).

ACTION:
Policy
statement.

­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­

­­­­­­­­­­­­­


SUMMARY:
EPA
groups
new
chemical
substances
with
similar
structural
and
toxicological
properties
into
categories
to
facilitate
premanufacture
assessment
and
regulation.
These
groupings
enable
both
Toxic
Substances
Control
Act
(TSCA)
section
5(
a)(
1)
Premanufacture
Notice
(PMN)
submitters
and
EPA
reviewers
to
benefit
from
accumulated
data
and
decisional
precedents
and
have
streamlined
the
process
for
Agency
review
of
and
regulatory
follow­
up
on
new
chemical
substances.
Consistent
with
TSCA
section
26(
c),
which
allows
EPA
action
under
TSCA
with
respect
to
categories
of
chemical
substances
or
mixtures,
EPA
is
issuing
this
policy
statement
regarding
a
category
of
persistent,
bioaccumulative,
and
toxic
(PBT)
new
chemical
substances.

DATES:
This
document
will
become
effective
January
3,
2000.

FOR
FURTHER
INFORMATION
CONTACT:
For
general
information
contact:
Christine
Augustyniak,
Associate
Director,
Environmental
Assistance
Division
(7408),
Office
of
Pollution
Prevention
and
Toxics,
Environmental
Protection
Agency,
401
M
St.,
SW.,
Washington,
DC
20460;
telephone
numbers:
202­
554­
1404
and
TDD:
202­
554­
0551;
email
address:
TSCA­
Hotline@
epa.
gov.
For
technical
information
contact:
Kenneth
Moss,
Chemical
Control
Division
(7405),
Environmental
Protection
Agency,
401
M
St.,
SW.,
Washington,
DC
20460;
telephone
number:
202­
260­
3395;
fax
number:
202­
260­
0118;
e­
mail
address:
moss.
kenneth@
epa.
gov.

SUPPLEMENTARY
INFORMATION:
On
October
5,
1998
(63
FR
53417)
(FRL­
5571­
6),
EPA
published
a
Federal
Register
notice
soliciting
comments
on
proposed
criteria
for
identifying
PBT
chemical
substances
and
their
supporting
scientific
rationale.
This
policy
statement
responds
to
comments
on
the
proposed
criteria
for
identifying
PBT
new
chemical
substances
and
their
supporting
scientific
rationale.
Please
consult
the
October
5,
1998
(63
FR
53417)
Federal
Register
notice
for
further
information
on
the
TSCA
new
chemicals
program.
The
docket
control
[[
Page
60195]]

number
for
this
document
is
OPPTS­
53171A.

I.
General
Information
A.
Does
This
Document
Apply
to
Me?

You
may
be
potentially
affected
by
this
document
if
you
are
or
may
in
the
future
be
a
submitter
of
a
PMN
under
TSCA.
Potentially
affected
entities
may
include,
but
are
not
limited
to
the
following:

­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­

­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­


Examples
of
Potentially
Category
NAICS
Code
SIC
Codes
Affected
Entities
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­

­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­

Chemical
manufacturers
or
importers
325,
32411
28,
2911
Anyone
who
plans
to
manufacture
or
import
a
new
chemical
substance
(as
defined
in
TSCA
Section
3)

for
a
non­
exempt
commercial
purpose
is
required
to
provide
the
EPA
with
a
PMN
at
least
90
days
prior
to
the
activity.
Any
TSCA
chemical
substance
that
is
not
on
the
TSCA
Inventory
is
classified
as
a
new
chemical.
New
chemical
substances
submitted
by
chemical
manufacturers
or
importers
as
PMNs
and
which
are
determined
by
EPA
to
meet
the
PBT
criteria
described
here
may
be
subject
to
regulatory
controls
under
TSCA
section
5(
e).
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­

­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­


This
listing
is
not
intended
to
be
exhaustive,
but
rather
provides
a
guide
for
readers
regarding
entities
likely
to
be
affected
by
this
document.
Other
types
of
entities
not
listed
above
could
also
be
affected.
The
four­
digit
Standard
Industrial
Classification
(SIC)
codes
or
the
six­
digit
North
American
Industrial
Classification
System
(NAICS)
codes
have
been
provided
to
assist
you
and
others
in
determining
whether
or
not
this
document
might
apply
to
certain
entities.
To
determine
whether
you
or
your
business
is
affected
by
this
document,
you
should
carefully
examine
the
applicability
provisions
in
40
CFR
720.22.
If
you
have
any
questions
regarding
the
applicability
of
this
document
to
a
particular
entity,
consult
the
technical
person
listed
in
the
``FOR
FURTHER
INFORMATION
CONTACT''
section.

B.
How
Can
I
Get
Additional
Information,
Including
Copies
of
This
Document
and
Other
Related
Documents?

1.
Electronically.
You
may
obtain
copies
of
this
document
from
the
EPA
Internet
Home
Page
at
http://
www.
epa.
gov/.
On
the
Home
Page
select
``Laws
and
Regulations''
and
then
look
up
the
entry
for
this
document
under
the
``Federal
Register
­
Environmental
Documents.
''
You
can
also
go
directly
to
the
``Federal
Register''
listings
at
http://
www.
epa.
gov/
fedrgstr/.
To
access
information
about
the
TSCA
New
Chemicals
Program,
go
directly
to
the
Home
Page
for
the
New
Chemicals
Program,
within
the
Office
of
Pollution
Prevention
and
Toxics,
at
http://
www.
epa.
gov/
opptintr/
newchms/.
2.
In
person.
The
Agency
has
established
an
official
record
for
this
document
under
docket
control
number
OPPTS­
53171A.
The
official
record
consists
of
the
documents
specifically
referenced
in
this
document,
any
public
comments
received
during
an
applicable
comment
period,
and
other
information
related
to
this
document,
including
any
information
claimed
as
Confidential
Business
Information
(CBI).
This
official
record
includes
the
documents
that
are
physically
located
in
the
docket,
as
well
as
the
documents
that
are
referenced
in
those
documents.
The
public
version
of
the
official
record
does
not
include
any
information
claimed
as
CBI.
The
public
version
of
the
official
record,
which
includes
printed,
paper
versions
of
any
electronic
comments
submitted
during
an
applicable
comment
period,
is
available
for
inspection
in
the
TSCA
Nonconfidential
Information
Center,
Rm.
NE
B­
607,
Waterside
Mall,
401
M
St.,
SW.,
Washington,
DC.
The
Center
is
open
from
12
noon
to
4
p.
m.,
Monday
through
Friday,
excluding
legal
holidays.
The
telephone
number
of
the
Center
is
202­
260­
7099.
3.
By
phone.
If
you
need
additional
information
about
this
document,
you
may
also
contact
the
person
identified
in
the
``FOR
FURTHER
INFORMATION
CONTACT''
section.

II.
Background
A.
Overview
of
the
PMN
Process
Under
section
5(
a)
of
TSCA,
persons
must
notify
EPA
at
least
90
days
before
manufacturing
or
importing
a
new
chemical
substance
for
non­
exempt
purposes.
A
new
chemical
substance,
as
defined
in
section
3(
9)
of
TSCA,
is
any
chemical
substance
(as
defined
by
section
3(
2))
that
is
not
included
on
the
Inventory
compiled
under
section
8(
b)
of
TSCA.
Section
5
of
TSCA
gives
EPA
90
days
to
review
a
PMN
(also
referred
to
as
a
``section
5
notice'').
However,
the
review
period
can
be
extended
under
TSCA
section
5(
c)
for
good
cause;
it
may
also
be
suspended
voluntarily
by
the
mutual
consent
of
EPA
and
the
PMN
submitter.
During
the
review
period,
EPA
may
take
action
under
TSCA
section
5(
e)
or
(f)
to
prohibit
or
limit
the
production,
processing,
distribution
in
commerce,
use,
and
disposal
of
new
chemical
substances
that
raise
health
or
environmental
concerns.
If
EPA
has
not
taken
action
under
TSCA
section
5(
e)
or
(f),
the
PMN
submitter
may
manufacture
or
import
the
new
chemical
substance
when
the
review
period
expires.
No
later
than
30
days
after
the
PMN
submitter
initiates
manufacturing
or
importing,
it
must
provide
EPA
with
a
notice
of
commencement
of
manufacture
or
import.
Section
8(
b)
of
TSCA
provides
that,
upon
receipt
of
such
a
notice,
EPA
must
add
the
substance
to
the
TSCA
Inventory.
Thereafter,
other
manufacturers
and
importers
may
engage
in
activities
involving
the
new
substance
without
submitting
a
PMN,
unless
the
Agency
has
used
its
Significant
New
Use
Rule
(SNUR)
authority
under
TSCA
section
5(
a)(
2)
to
designate
a
use
of
a
chemical
substance
as
a
``significant
new
use.
''
Section
5(
a)(
1)(
B)
of
TSCA
would
then
require
persons
to
submit
a
Significant
New
Use
Notice
(SNUN)
to
EPA
at
least
90
days
before
they
manufacture,
import,
or
process
the
substance
for
the
use
designated
as
significant.
The
required
SNUN
provides
EPA
with
the
opportunity
to
evaluate
the
intended
use,
and
if
necessary,
to
prohibit
or
limit
that
activity
before
it
occurs.

B.
History
Since
1979,
EPA
has
reviewed
over
30,000
TSCA
section
5
submissions
for
new
chemical
substances.
During
the
intervening
years,
EPA
has
implemented
various
initiatives
which
have
enabled
the
Agency
to
review
a
greater
number
of
new
chemicals
more
[[
Page
60196]]

efficiently.
In
1988,
for
example,
EPA's
Office
of
Toxic
Substances
(now
the
Office
of
Pollution
Prevention
and
Toxics)
first
used
its
accumulated
experience
to
group
chemical
substances
with
similar
physicochemical,
structural,
and
toxicological
properties
into
working
categories
(USEPA,
1988,
see
Unit
VI.
8.).
These
categories,
including
the
subject
one
for
PBT
chemical
substances,
are
developed
by
EPA
based
on
available
data
and
experience
reviewing
PMNs
on
similar
substances.
Such
groupings
enable
both
PMN
submitters
and
EPA
reviewers
to
benefit
from
the
accumulated
data
and
decisional
precedents
and
facilitates
the
assessment
of
new
chemical
substances.
PBT
chemical
substances
possess
characteristics
of
persistence
(P)
in
the
environment,
accumulation
in
biological
organisms
(bioaccumulation
(B)),
and
toxicity
(T)
that
make
them
priority
pollutants
and
potential
risks
to
humans
and
ecosystems.
Prominent
examples
of
PBT
chemical
substances
include
the
insecticide
DDT
and
polychlorinated
biphenyls
(PCBs).
Establishment
of
a
PBT
category
alerts
potential
PMN
submitters
to
possible
assessment
or
regulatory
issues
associated
with
PBT
new
chemicals
review.
It
also
provides
a
vehicle
by
which
the
Agency
may
gauge
the
flow
of
PBT
chemical
substances
through
the
TSCA
New
Chemicals
Program
and
measure
the
results
of
its
risk
screening
and
risk
management
activities
for
PBT
new
chemical
substances;
as
such,
it
is
a
major
element
in
the
Agency's
overall
strategy
to
further
reduce
risks
from
PBT
pollutants.
As
described
in
the
Federal
Register
notice
of
October
5,
1998
(63
FR
53417),
development
of
the
TSCA
new
PBT
chemicals
policy
has
occurred
in
coordination
with
U.
S.
national,
U.
S./
Canada
binational,
and
international
efforts
to
identify
and
control
the
environmental
release
of
persistent
organic
pollutants
(POPs).
The
proposed
TSCA
PBT
category
has
been
provided
to
the
Criteria
Expert
Group
(CEG)
established
at
the
first
session
of
the
Intergovernmental
Negotiating
Committee
(INC)
for
an
International
Legally
Binding
Instrument
for
Implementing
International
Action
on
Certain
Persistent
Organic
Pollutants,
in
accordance
with
the
mandate
given
by
the
Governing
Council
of
the
United
Nations
Environment
Programme
(UNEP)
in
paragraph
9
of
its
decision
19/
13
C
(http://
irptc.
unep.
ch/
pops/
gcpops<
INF>­</
INF>
e.
html).
The
CEG
is
an
open­
ended
technical
working
group
with
a
mandate
to
present
to
the
INC
proposals
for
science­
based
criteria
and
a
procedure
for
identifying
additional
POPs
as
candidates
for
future
international
action.
The
CEG
is
to
incorporate
criteria
pertaining
to
persistence,
bioaccumulation,
toxicity
and
exposure
in
different
global
regions
and
should
take
into
account
the
potential
for
regional
and
global
transport,
including
dispersion
mechanisms
for
the
atmosphere
and
the
hydrosphere,
migratory
species,
and
the
need
to
reflect
possible
influences
of
marine
transport
and
tropical
climates.
At
its
first
meeting,
October
26­
30,
1998
in
Bangkok,
the
CEG
recommended
that
the
INC
consider
developing
a
provision
encouraging
countries
and
regions
to
include
in
their
new
chemicals
schemes
elements
relating
to
development
and
introduction
of
new
chemical
POPs.
The
U.
S.
described
its
proposed
TSCA
new
chemicals
program
policy
for
the
category
of
PBT
new
chemicals,
and
the
full
text
of
the
October
5,
1998
Federal
Register
notice
was
distributed
to
all
delegations
as
a
Conference
Room
Paper.
The
CEG's
recommendation
was
accepted
at
the
second
meeting
of
the
INC
(January
25­
29,
1999
in
Nairobi)
and
the
INC
will
consider
it
further
in
its
deliberations.
This
policy
statement
is
important
in
our
new
chemical
assessment
and
TSCA
regulatory
programs,
and
represents
the
first
formal
statement
of
national
policy
regarding
new
chemical
``persistent
organic
pollutants.
''
Under
our
domestic
program,
the
policy
statement
provides
guidance
criteria
for
persistence,
bioaccumulation,
and
toxicity
for
new
chemicals
and
advises
the
industry
about
our
regulatory
approach
for
chemicals
meeting
the
criteria.
Internationally,
the
Federal
Register
notice
of
October
5,
1998
(63
FR
53417)
alerted
the
parties
involved
in
negotiation
of
the
POPs
Convention
to
the
need
for
inclusion
of
a
new
chemicals
provision
in
the
Convention.
The
issuance
of
the
final
policy
statement
will
reaffirm
US
leadership
on
this
issue
and
serve
as
a
model
for
other
countries
in
taking
steps
to
discourage
the
introduction
of
POPs
as
new
chemicals
and
pesticides.

III.
Discussion
of
Final
Policy
Statement
and
Response
to
Comments
Today's
policy
statement
adopts
the
criteria
and
testing
strategy
of
the
Federal
Register
notice
of
October
5,
1998
(63
FR
53417),
with
minor
revisions.
The
Agency
reviewed
and
considered
all
comments
received
on
the
October
5,
1998
(63
FR
53417)
notice.
A
complete
copy
of
all
comments
received
is
available
in
the
public
docket
for
this
document.
A
discussion
of
the
policy
statement,
including
a
summary
of
significant
comments
and
the
Agency's
response
follows:

A.
Pigments
Comment
1­
Pigments.
Commenters
suggested
that
EPA
not
identify
pigments
as
bioaccumulators
and
were
concerned
that
testing
could
end
up
being
expensive
for
pigments,
which
are
persistent
by
design.
Response.
EPA
assesses
PMN
chemical
substances
for
PBT
attributes
on
a
chemical­
by­
chemical
basis,
regardless
of
whether
or
not
they
fall
into
a
chemical
use
category
such
as
pigments.
Not
all
pigments
are
the
same
and
a
precise
definition
of
the
term
``pigment''
is
not
available.
As
a
result,
EPA
does
not
have
general
``pigments''
or
``dyes''
assessment
categories;
there
are,
however,
more
specifically
described
categories
of
dyes
or
pigments
that
have
been
described
by
EPA
(e.
g.,
acid
or
amphoteric
dyes,
dichlorobenzidine­
based
pigments,
and
others;
see
categories
document
at
http://
www.
epa.
gov/
opptintr/
newchms/
chemcat.
htm).
Moreover,
the
fact
that
a
substance
is
``persistent
by
design''
by
itself
is
not
a
sufficient
basis
for
identifying
a
PBT
new
chemical
substance.
Persistence
is
only
one
of
three
criteria
used
to
identify
a
chemical
as
PBT.
When
combined
with
a
potential
to
bioaccumulate,
toxicity
concern,
and
sufficient
release
to
the
environment
to
result
in
potential
risk
or
significant
exposure,
pigments
may
be
of
concern,
whether
or
not
they
are
persistent
by
design.
If
a
PMN
chemical
is
persistent
by
design,
and
becomes
subject
to
testing
requirements
by
EPA,
it
would
be
counterproductive
to
test
initially
for
persistence,
but
rather
to
address
the
``B''
and
``T''
criteria
instead.

B.
Ready
Biodegradability
Testing
Comment
2­
Ready
biodegradability
testing.
Commenters
suggested
that
EPA
avoid
the
use
of
strict
pass/
fail
criteria
for
ready
biodegradability
of
poorly
water­
soluble
substances.
Response.
Poor
water
solubility
does
not
necessarily
lead
to
inability
to
pass
a
ready
biodegradability
test,
as
amply
demonstrated
by
the
fact
that
many
fats,
oil,
petroleum
hydrocarbons,
etc.
easily
pass
ready
biodegradability
tests.
While
strict
OECD
(Organization
for
Economic
Co­
operation
and
Development)
pass/
fail
criteria
are
given
in
the
OPPTS
Ready
Biodegradability
test
guidelines
(see
http://
www.
oecd.
org//
ehs/
test/
degrad.
htm
and
Testing
Strategy
for
PBT
Chemical
Substances,
Unit
IV.
B.
of
this
document),
the
Agency
recognizes
the
limitations
in
applying
such
criteria
[[
Page
60197]]

rigidly
given
that
many
substances
of
concern
as
potential
PBTs
are
unlikely
to
pass
ready
biodegradability
tests.
A
variety
of
critical
aspects
beyond
the
pass/
fail
result
will
be
considered
when
evaluating
potential
new
chemical
PBTs
or
when
testing
decisions
are
made
about
specific
PMN
substances.
These
more
critical
aspects
include
those
related
to
chemical
structure
(e.
g.,
degree
of
branching)
and
bioavailability
(e.
g.,
uptake
of
a
substance
by
fish
or
microorganisms),
and
their
influence
on
both
biodegradation
and
bioaccumulation.

C.
Bioconcentration
Factor
and
Kow
Comment
3­
Bioconcentration
factor.
Commenters
requested
clarification
on
how
bioconcentration
factor
(BCF)
will
be
estimated
using
calculations
based
on
octanol­
water
partition
coefficient.
Response.
The
octanol­
water
partition
coefficient
(Kow)
is
correlated
with
the
potential
for
a
chemical
to
bioaccumulate
in
organisms;
the
BCF
can
be
predicted
from
log
Kow,
via
computer
programs
based
on
structure
activity
relationship
(SAR).
The
Agency
process
for
predicting
bioaccumulation
factors
(BAFs)
and
BCFs,
along
with
literature
references,
is
described
in
some
detail
in
the
proposed
rule
for
lowering
of
reporting
thresholds
for
certain
PBT
toxic
chemicals
subject
to
reporting
under
section
313
(Toxic
Release
Inventory,
or
TRI)
of
the
Emergency
Planning
and
Community
Right­
toKnow
Act
(EPCRA)
of
1986
(January
5,
1999
(64
FR
688)
(FRL­
6032­
3),
see
page
704).
Comment
4­
Log
Kow
and
low
solubility
chemicals.
Commenters
suggested
that
the
October
5,
1998
(63
FR
53417)
Federal
Register
notice
identified
methods
for
calculating
log
Kow
that
are
not
appropriate
for
organic
pigments,
which
are
insoluble
in
octanol.
They
wanted
to
know
how
EPA
handles
low
octanol
or
water
soluble
chemicals.
Response.
EPA
believes
that
the
methods
cited
in
the
October
5,
1998
(63
FR
53417)
Federal
Register
notice
for
experimental
measurement
of
the
octanol/
water
partition
coefficient
(Kow),
or
SAR
to
predict
Kow,
are
appropriate,
and
the
results
of
either
can
then
be
used
to
predict
the
Fish
BCF.
Chemicals
are
unlikely
to
be
accorded
special
treatment
in
the
new
chemicals
review
process
solely
because
of
low
solubility
in
octanol
or
water
alone.
The
test
guidelines
(OPPTS
830.7570
or
830.7560)
cited
in
the
October
5,
1998
(63
FR
53417)
Federal
Register
notice
are
viewed
as
the
most
appropriate
for
measuring
Kow,
and
alternatively,
the
shake­
flask
method
(OPPTS
830.7550
test
guideline)
or
the
new
``slow­
stir''
method
currently
under
development
by
the
OECD,
can
be
used.
However,
if
the
chemical
manufacturer
still
views
these
methods
as
inappropriate
for
a
given
chemical,
it
would
be
advisable
to
proceed
to
more
definitive
testing
to
address
bioaccumulation
potential
(i.
e.,
the
Fish
BCF
study).
This
approach
can
be
applied
to
other
testing
endpoints
as
well;
for
example,
based
on
physicochemical
properties
of
a
particular
PMN
chemical
substance,
a
company
might
forgo
a
lower
tier
acute
Daphnia
toxicity
study
in
favor
of
the
chronic
study
because
it
would
yield
the
best
information
for
the
screening
level
risk
assessment.
Comment
5­
Use
of
octanol
solubility
data
alone.
Commenters
wanted
to
know
if
octanol
or
fat
solubility
data
can
be
used
before
determining
which
chemical
substances
have
the
potential
for
bioaccumulation.
Response.
By
itself,
solubility
in
octanol
(as
a
surrogate
for
fat)
is
not
a
good
predictor
of
potential
bioaccumulation
in
fish.
Kow
is
correlated
with
the
potential
for
a
chemical
to
bioaccumulate
in
organisms;
the
bioconcentration
factor
(BCF)
can
be
predicted
from
log
Kow,
via
SAR.
Kow
is
a
coefficient
which
serves
as
a
surrogate
for
the
partitioning
of
chemicals
between
water
and
fat,
and
cannot
be
accurately
estimated
via
separate
determinations
of
solubility
in
pure
octanol
and
water
(i.
e.,
by
calculating
the
ratio
of
the
pure­
solvent
solubilities)
(Sijm
et
al.,
1999,
see
Unit
VI.
1.).
The
Agency
uses
and
recommends
the
use
of
computer
models
to
predict
Kow
where
there
are
no
measured
data.

D.
Environmental
Half­
Life
Comment
6­
Calculation
of
half­
life.
Commenters
wanted
to
know
how
half­
life
is
calculated
in
the
review
of
PBT
new
chemicals.
Response.
Multimedia
fate
models
like
the
Environmental
Quality
Criteria
(EQC)
model
(Mackay
et
al.,
1996,
see
Unit
VI.
2.)
require
compartmental
half­
lives
for
air,
water,
soil
and
sediment,
which
cannot
necessarily
be
interpreted
as
half­
lives
for
any
specific
process
such
as
biodegradation.
Data
on
air
half­
lives
for
input
to
models
would
be
either
measured
or
derived
from
the
Atmospheric
Oxidation
Program
(AOP
or
AOPWIN)
or
similar
methodology.
Studies
by
Boethling
et
al.
(1995,
see
Unit
VI.
3.)
and
Federle
et
al.
(1997,
see
Unit
VI.
4.)
suggest
that
half­
lives
in
bulk
soil
may
be
assumed
for
screening
purposes
to
be
about
the
same
as
for
surface
water,
and
that
sediment
half­
lives
may
be
assumed
to
be
3­
4
times
longer.
EPA's
current
suggested
approach
to
finding
water
half­
life
is
to
use
the
Ultimate
Survey
Model
(USM)
in
the
EPI
BIOWIN
program
(Boethling
et
al.,
1994,
see
Unit
VI.
5.).
Estimation
of
bulk
compartment
half­
lives
from
USM
model
data
requires
several
assumptions,
including
that
(1)
biodegradation
is
the
only
significant
fate
process
in
water,
soil,
sediment;
(2)
water
and
soil
half­
lives
are
the
same;
and
(3)
sediment
is
dominated
by
anaerobic
conditions
and
therefore
sediment
half­
life
is
four
times
longer
than
water
half­
life.

E.
Computer
Models
and
the
Use
of
Models
vs.
Actual
Data
Comment
7­
Use
of
models
vs.
actual
data.
Commenters
support
the
use
of
the
Mackay/
EQC
model,
but
stressed
the
importance
of
having
a
process
for
using
actual
data
in
place
of
the
model.
Response.
This
is
a
reasonable
suggestion.
The
EQC
model
is
based
on
the
fugacity
approach
and
subsequently
applied
to
numerous
environmental
processes.
It
uses
an
``evaluative
environment''
in
which
environmental
parameters
such
as
bulk
compartment
dimensions
and
volumes
(e.
g.,
total
area,
volume
of
soil
and
sediment,
etc.)
are
standardized,
so
that
overall
persistence
for
chemicals
with
different
properties
and
rates
of
transformation
may
be
compared
on
an
equal
basis.
In
general,
measured
values
of
toxicity,
chemical
properties,
compartmental
transformation
half­
lives,
etc.,
provided
the
data
are
of
acceptable
quality,
are
preferred
over
those
that
are
predicted
or
estimated
via
a
model
or
computer
program.
Comment
8­
Modeling
of
air
releases.
Commenters
noted
that
the
October
5,
1998
(63
FR
53417)
Federal
Register
notice
considered
only
biodegradation
and
aqueous
hydrolysis
and
asked
about
fate
of
a
chemical
upon
release
to
air.
They
suggested
that
EPA
estimate
atmospheric
oxidation
using
AOPWIN.
Response.
Although
the
testing
strategy
for
this
policy
statement
focuses
on
biodegradability,
all
relevant
transport
and
transformation
processes
will
be
considered
in
evaluating
the
potential
for
a
PMN
substance
to
behave
as
a
PBT.
Transformation
processes
not
mentioned
in
the
Federal
Register
notice
but
which
may
be
important
for
specific
PMN
substances
include
atmospheric
oxidation
and
photolysis,
photolysis
in
water,
and
redox
transformations
(of
which
there
are
various
types)
in
water,
soil,
and
sediment.
Although
EPA
believes
that
for
most
organic
chemicals,
biodegradation
in
water,
soil,
and
sediment
will
be
the
most
important
[[
Page
60198]]
transformation
process,
each
suspected
PBT
chemical
substance
will
be
evaluated
on
its
use
and
disposal
patterns.
Clearly
the
atmosphere
is
an
important
environmental
medium,
and
is
especially
relevant
where
a
substance
is
emitted
directly
to
the
atmosphere
or
transported
there
via
volatilization
or
aerosolization.
We
know
by
deduction
that
it
is
only,
or
at
least
chiefly,
through
the
atmosphere
that
POPs
like
dioxins
and
Polychlorinated
biphenyls
(PCBs)
reach
remote
locations,
and
it
will
be
an
important
factor
in
determining
the
ultimate
fate
of
many
PMN
substances
as
well.
It
is
through
multimedia
fate
models
such
as
EQC
that
atmospheric
fate
will
be
considered
in
developing
an
overall
prediction
of
environmental
persistence
for
suspected
PBT
substances.
Where
measured
data
are
not
available,
appropriate
estimation
methods
such
as
that
in
the
AOPWIN
program
will
be
used
to
generate
screening­
level
estimates
of
atmospheric
half­
lives.

F.
Use
of
``Weight
of
Evidence''
and
Professional
Judgment
Comment
9­
Laboratory
vs.
field
behavior
of
chemicals.
Commenters
indicated
that
EPA
needs
to
incorporate
any
differences
between
lab
and
field
behavior
of
chemicals
into
its
analysis
of
new
chemical
substances,
acknowledge
the
limitations
of
screeninglevel
biodegradation
tests,
and
acknowledge
the
value
of
using
professional
judgment
when
interpreting
data
from
extended
(>
60
day)
degradation
studies.
Response.
EPA
recognizes
that
laboratory
tests
at
best
provide
a
snapshot
of
expected
environmental
behavior,
which
ideally
is
studied
in
the
field.
But
since
field
testing
is
nearly
always
impractical
for
PMN
chemical
substances,
it
is
necessary
to
conduct
laboratory
tests
and
to
apply
scientific
judgment
in
extrapolating
from
lab
to
field.
EPA
similarly
acknowledges
the
limitations
of
ready
biodegradability
and
other
screening
tests
as
indicators
of
ultimate
environmental
behavior.
Finally,
it
is
well
known
that
even
this
policy
statement's
higher
tier
(Testing
Tiers
2
and
3)
environmental
fate
guidelines,
despite
being
designed
to
provide
test
conditions
closer
to
those
expected
in
the
field,
become
less
reliable
when
tests
are
run
for
longer
than
the
maximum
duration
specified
in
the
guidelines.
EPA
will
give
appropriate
weight
to
these
and
other
complexities
in
its
assessments.
Comment
10­
``Check
the
box''
vs.
``weight
of
evidence.
''
Commenters
noted
that
the
TSCA
PMN
requirements
for
PBT
chemicals
look
more
like
``check­
the­
box''
than
``weight
of
evidence''
and
wanted
to
know
how
EPA
will
make
professional
judgment
and
use
SAR
and
assessment
methods
to
identify
PBT
new
chemicals.
Response.
These
tools
(professional
judgment,
SAR,
computer
models,
assessment
methods,
etc.)
would
be
applied
to
potential
PBT
chemical
substances
in
the
same
way
they
are
applied
to
any
other
chemical
substance
in
the
PMN
review
process.
Using
predictive
tools
(in
the
absence
of
test
data)
and
professional
judgment,
EPA
leans
towards
a
``reasonable
worst
case''
when
there
is
lack
of
chemicalspecific
data.
Industry
always
has
the
option
of
assisting
and
enhancing
the
Agency's
determinations
by
submitting
scientifically
valid
test
data.
There
are
a
number
of
existing
documents
describing
the
PMN
process
and
the
critical
role
played
by
SAR
and
professional
judgment
in
that
process,
including
the
Chemistry
Assistance
Manual
for
Premanufacture
Notification
Submitters
(USEPA,
1997,
see
Unit
VI.
6.)
and
parts
of
the
report
on
the
joint
U.
S./
European
Union
study
that
evaluated
the
predictive
power
of
the
SAR
(USEPA,
1994,
see
Unit
VI.
7.).
EPA
believes
that,
where
no
or
insufficient
actual
toxicity
data
exist
upon
which
to
base
a
decision,
toxicity
estimates
generated
by
SARs
and
other
predictive
techniques
may
constitute
sufficient
evidence
to
be
used
in
human
health
and
environmental
hazard
and
environmental
fate
assessment
as
components
in
certain
risk
determinations
under
TSCA
(see
also
the
Federal
Register
of
December
1,
1993
(58
FR
63507)
for
a
similar
statement
related
to
meeting
section
313
listing
criteria
under
EPCRA
of
1986).
Comment
11­
Implement
PBT
policy
within
risk
assessment
framework.
Commenters
suggested
that
EPA
risk
management
decisions
should
not
be
made
solely
on
hazard
information;
these
PBT
criteria
should
be
implemented
within
a
risk
assessment
framework.
They
indicated
that
toxicity
has
been
largely
overlooked
in
the
PBT
scheme
and
no
criteria
have
been
provided
for
toxicity.
Commenters
suggested
that
EPA
needs
to
take
into
account
P
and
B
and
T
before
requiring
further
testing
or
identifying
a
chemical
as
a
``true''
PBT,
and
asked
whether
persistence
and
log
Kow
would
be
sufficient
to
determine
that
a
PBT
PMN
chemical
substance
may
pose
a
significant
risk.
Commenters
also
suggest
that
EPA
should
except
non­
toxic
and
low
exposure/
release
substances
from
consideration
under
this
category
and
were
concerned
that
the
current
proposed
criteria
do
not
consider
any
health
and
safety
benefits
of
a
PBT
chemical
substance.
Response.
New
chemicals
identified
as
potential
PBT
chemicals
are
assessed
on
a
case­
by­
case
basis.
Section
5(
e)
of
TSCA
authorizes
EPA
to
control
commercial
activities
involving
a
new
chemical
substance
for
which
available
information
is
insufficient
to
permit
a
reasoned
evaluation
of
potential
health
and
environmental
effects
if
EPA
determines
either
(1)
that
the
manufacture
(including
import),
processing,
distribution
in
commerce,
use,
or
disposal
of
the
substance
may
present
an
unreasonable
risk
of
injury
to
health
or
the
environment
(``risk­
based''
finding),
or
(2)
that
the
substance
is
or
will
be
produced
in
substantial
quantities,
and
such
substance
either
enters
or
may
reasonably
be
anticipated
to
enter
the
environment
in
substantial
quantities
or
there
is
or
may
be
significant
or
substantial
human
exposure
to
the
substance
(``exposure­
based''
finding).
The
restrictions
under
TSCA
section
5(
e)
are
imposed
pending
the
development
of
the
test
data
or
other
information
needed
to
evaluate
the
new
substance's
health
or
environmental
effects.
EPA
draws
on
information
and
data
submitted
with
the
PMN
form,
other
information
available
to
the
Agency,
and
modeling
(e.
g.,
exposure,
release,
SAR,
etc.).
The
Agency
will
consider
P
and
B
and
T,
individually
and
together,
and
exposure
in
making
risk­
based
judgments.
Risk,
specific
to
the
PMN
substance
as
well
as
its
risk
relative
to
substitutes
currently
on
the
market,
is
predicted
as
a
function
of
the
potential
hazard
of
the
substance
and
the
expected
exposure.
In
other
instances,
as
discussed
in
the
October
5,
1998
(63
FR
53417)
Federal
Register
notice,
during
PMN
review
EPA
may
determine
that
a
new
substance
will
be
produced
in
substantial
quantities
and
``may
reasonably
be
anticipated
to
enter
the
environment
in
substantial
quantities
or
there
is
or
may
be
significant
or
substantial
human
exposure
to
the
substance,
''
and
that
the
available
information
is
insufficient
to
determine
the
effects
of
the
substance.
For
such
exposure­
based
determinations
on
suspected
PBT
new
chemicals,
EPA
will
use
a
case­
by­
case
approach
for
making
findings
by
applying
considerations
beyond
P
and
B
(i.
e.,
toxicity
or
physical/
chemical
properties),
and
consider
P
and
B
aspects
as
factors
which
might
argue
for
regulatory
action
under
TSCA
section
5(
e)
at
lower
levels
of
production
or
exposure/
release
than
are
described
in
the
general
guidelines
for
the
new
chemicals
program's
[[
Page
60199]]

exposure­
based
policy
(USEPA,
1988,
USEPA,
1989,
see
Unit
VI.
8.
and
9.).
Overall,
companies
are
not
being
prevented
from
developing
and
using
new
substances
that
are
judged
to
be
potential
PBT
chemicals,
but
EPA
may
require
certain
controls
(e.
g.,
limiting
the
release
of
the
PMN
chemical
to
the
environment)
or
testing
as
a
result
of
its
assessments.
In
order
to
be
so
identified
as
a
PBT
new
chemical
based
on
a
riskbased
finding,
all
three
criteria
must
be
satisfied.
The
Agency
has
adopted
a
1
to
3rating
system
for
each
of
P,
B,
and
T.
If
chemical
has
a
low
Kow
(i.
e.,
``B1,
''
with
BCF
estimated
as
less
than
1,000),
the
B1
rating
does
not
support
the
new
chemical's
identification
as
a
potential
``PBT
chemical.
''
For
example,
some
surfactants
could
be
P3B1T3;
they
are
highly
persistent
in
the
environment
and
chronically
toxic
to
organisms,
but
with
low
bioaccumulation
potential.
However,
Agency
action
may
still
be
taken
under
TSCA
on
chemicals
not
meeting
all
of
the
PBT
criteria,
if
they
otherwise
meet
the
risk
or
exposurebased
elements
of
TSCA
section
5(
e).
Similarly,
calcium
would
also
not
be
considered
a
PBT
chemical,
as
it
would
be
ranked
P3B3T1;
it
is
persistent
in
the
environment,
it
bioaccumulates,
but
it
is
not
considered
toxic.
Although
the
Agency
does
not
promote
the
environmental
discharge
of
more
persistent
materials,
the
environmental
``desirability''
of
a
given
chemical
often
depends
on
a
balance
of
various
factors,
including
toxicity
and
ability
of
the
chemical
to
bioaccumulate.
Like
the
previous
surfactant
example,
the
Agency
may
nonetheless
take
action
on
a
P3B3T1
chemical
(not
calcium
per
se),
most
likely
under
its
exposure­
based
authority.
The
toxicity
rating
for
a
PBT
chemical
applies
to
repeated
exposures
which
result
in
human
or
environmental
toxicity,
including,
for
example,
systemic
toxicity,
mutagenic
damage,
reproductive
toxicity,
or
developmental
toxicity.
An
example
of
this
is
chronic
toxicity
towards
aquatic
organisms
of
organotins
from
contaminated
marine
environments,
which
ultimately
resulted
in
the
regulation
of
use
of
tributyl
tin
in
marine
anti­
fouling
paints.
Repeated
exposures
result
from
a
PBT
chemical
after
it
has
been
released
into
the
environment,
usually
via
contaminated
water,
sediments,
or
food.
The
classic
PBT
problems
(i.
e.,
PCBs
and
Dichloro
diphenyl
trichloroethane
(DDT))
have
been
associated
with
food
chain
contamination.

G.
Scientific
Justification
for
PBT
Technical
Criteria
Comment
12­
Support
for
lower
threshold
criteria
for
``P''
and
``B.
''
Commenters
believed
that
there
is
little
precedent,
scientific
justification,
evidence
or
data
to
support
the
lower
regulatory
threshold
of
bioaccumulation
factor
of
1,000
and
environmental
persistence
of
2
months.
They
suggested
that
EPA
needs
a
rationale
for
these
criteria
beyond
``...
are
characterized
by
a
tendency
to
accumulate
in
organisms.
''
Response.
There
is
no
``bright
line''
that
clearly
identifies
a
bioaccumulation
factor
of
1,000
or
a
half­
life
of
2
months
as
the
best
bioaccumulation
or
persistence
criterion
from
a
scientific
perspective.
However,
it
is
not
accurate
to
state
that
there
is
no
precedent
or
basis
for
using
these
values.
As
outlined
in
EPA's
recent
proposal
to
lower
the
reporting
thresholds
for
PBT
chemicals
that
are
subject
to
reporting
under
section
313
of
EPCRA
(64
FR
688;
January
5,
1999),
similar
values
have
been
proposed
by
several
authorities,
including
the
Ontario,
Canada
Ministry
of
Environment
and
Energy
(MOEE)
for
its
Candidate
Substances
List
for
Bans
or
Phaseouts
(MOEE,
1992,
see
Unit
VI.
10.);
the
Canadian
initiative
for
Accelerated
Reduction/
Elimination
of
Toxics
(ARET)
(ARET,
1995
and
ARET,
1994,
see
Unit
VI.
11.
and
12.);
the
International
Joint
Commission
(IJC)
's
Great
Lakes
Water
Quality
Agreement
(GLWQA)
(IJC,
1993,
see
Unit
VI.
13.);
and
the
United
Nations
Economic
Commission
for
Europe
Convention
on
Long­
Range
Transboundary
Air
Pollution
(UNECE­
LRTAP),
which
did
adopt
2
months
as
the
persistence
criterion
of
record
for
water
(UNECE­
LRTAP,
1998,
see
Unit
VI.
14.).
In
determining
the
thresholds
for
this
policy
statement,
EPA
concluded
that
it
would
be
appropriate
to
reflect
the
levels
of
concern
that
the
various
PBT
chemicals
presented,
based
on
the
differing
degrees
to
which
the
chemicals
persist
and
bioaccumulate.
The
Agency
ultimately
chose
to
adopt
a
two­
tier
approach,
and
to
establish
two
separate
thresholds
to
reflect
the
chemicals'
varying
potentials
to
persist
and
bioaccumulate,
as
well
as
to
reflect
the
Agency's
belief
that
the
different
levels
of
regulatory
action
under
TSCA
are
warranted
for
the
two
tiers.
As
discussed
in
detail
in
the
preamble
to
the
mentioned
EPCRA
proposed
rule,
EPA
found
that
generally
the
criteria
selected
by
various
U.
S.
and
international
regulatory
bodies
for
either
persistence
or
bioaccumulation
clustered
around
two
values.
For
persistence
in
water,
soil,
and
sediment,
the
criteria
were
grouped
around
half­
lives
of
1
to
2
months
and
6
months,
and
for
persistence
in
air,
either
2
or
5
days.
Bioaccumulation
criteria
were
grouped
around
BAF/
BCF
values
of
1,000
and
5,000.
The
preamble
to
the
EPCRA
proposed
rule
states
``Bearing
in
mind
that
one
of
Congress'
articulated
purposes
for
EPCRA
section
313
was
to
provide
local
communities
with
relevant
information
on
the
release
and
other
waste
management
activities
of
chemicals
in
their
community
that
may
present
a
hazard,
EPA
determined
that
the
criteria
that
were
most
consistent
with
these
purposes
were,
for
persistence,
half­
lives
of
2
months
for
water,
sediment,
and
soil,
and
2
days
in
air,
and
for
bioaccumulation,
bioaccumulation/
bioconcentration
factor
values
of
1,000
or
greater''
(64
FR
692;
January
5,
1999).
EPA
is
making
a
similar
determination
for
the
PBT
new
chemicals
policy
under
TSCA.
The
PMN
process
is
one
of
EPA's
cornerstone
Pollution
Prevention
programs
and
plays
a
critical
gatekeeper
role
in
making
sure
that
all
new
chemical
substances
do
not
present
unreasonable
risks
when
they
are
commercialized.
Given
this,
and
the
uncertainty
which
often
accompanies
Agency
review
of
a
PMN
chemical
substance
due
to
lack
of
data,
the
TSCA
new
chemicals
program
is
and
must
be
conservative
by
nature,
which
suggests
that
a
half­
life
shorter
than
6
months
and
a
BCF
criterion
lower
than
5,000­­
values
that
were
selected
solely
or
primarily
to
isolate
substances
already
widely
acknowledged
to
be
POPs
are
appropriate
for
regulatory
scrutiny
of
new
chemicals
under
TSCA.
Note
that
the
CEG,
at
the
October
26­
30,
1998
Bangkok
meeting
described
in
Unit
II.
B.
of
this
document,
developed
indicative
numerical
values
as
bracketed
criteria
text
which
included
persistence
of
2
vs.
6
months
in
water
and
log
Kow
of
4
vs.
5
(equivalent
to
a
BCF
of
approximately
1,000
vs.
5,000,
respectively).
A
series
of
PMNs
submitted
to
EPA
in
1990
(Zeeman
et
al.,
1999,
see
Unit
VI.
15.)
illustrates
(1)
why
EPA
believes
that
the
persistence
criterion
for
bioaccumulating
substances
in
soil,
water,
or
sediment
should
be
set
substantially
lower
than
6
months;
and
(2)
that
concern
for
potential
exposures
to
persistent
and
bioaccumulative
toxics
must
extend
beyond
the
UNEP's
12
widely
acknowledged
POPs.
The
substances
in
question
were
alkylated
diphenyls,
for
which
EPA
expected
discharge
to
receiving
streams
and
rivers.
The
submitter
supplied
data
on
use
and
disposal,
aquatic
toxicity,
and
[[
Page
60200]]

biodegradability.
The
submitted
environmental
fate
data
and
EPA
estimates
of
biodegradability
based
on
structural
analogs
suggested
that
half­
lives
in
water
would
be
well
below
6
months,
but
not
necessarily
lower
than
2
months.
As
a
result
of
concerns
expressed
by
EPA,
use
was
limited
to
sites
where
resulting
water
concentrations
could
be
limited
to
1
microgram
per
liter
or
less;
concomitantly,
the
submitter
was
also
informed
of
EPA's
belief
that
a
potential
for
longterm
risk
existed,
but
that
EPA
could
not
quantify
this
risk
since
assessments
typically
evaluated
releases
over
a
period
of
only
1
year.
In
1998,
results
of
monitoring
revealed
that
the
PMN
substances
had
been
found
in
fish
fillets
and
sediment
samples
from
the
receiving
stream.
If,
for
these
1990
PMNs,
EPA
were
to
have
had
in
place
the
2
month
persistence
criterion
described
in
today's
policy
statement,
further
scrutiny
under
the
new
chemicals
program
would
have
been
warranted,
and
beyond
simply
informing
the
PMN
submitter
of
the
potential
for
long­
term
risk,
the
Agency
would
likely
have
required
further
testing
to
obtain
an
experimental
value
for
environmental
persistence
of
the
chemicals.
This
in
turn
would
have
given
the
Agency
a
better
picture
of
the
behavior
of
the
chemicals
in
the
environment
and
the
environmental
half­
life
relative
to
the
2
month
value.
Comment
13­
Deny
commercialization
to
lower
threshold
PBT
chemicals.
Some
commenters
supported
exercising
the
``Precautionary
Principle''
by
not
allowing
commercialization
under
a
TSCA
5(
e)
consent
order
or
SNUR
pending
testing
of
the
PMN
chemicals
which
meet
the
P=
2
month
and
BCF=
1,000
criteria.
They
suggested
that
these
chemicals
should
be
banned
instead,
pending
the
necessary
testing.
Response.
Whereas
a
half­
life
of
2
months
and
BCF
of
1,000
can
be
justified
as
lower­
tier
cutoffs
in
a
deliberately
conservative
TSCA
new
chemicals
program
that
is
designed
to
prevent
commercialization
of
potentially
risky
substances,
it
would
not
be
appropriate
to
automatically
trigger
a
``ban
pending
testing''
at
these
cutoffs
given
the
uncertainties
about
substance
properties,
release,
and
environmental
behavior
that
normally
characterize
PMN
review.
The
Agency
believes
that
the
available
predictive
tools
and
current
knowledge
of
POPs
lend
support
for
this
two­
phased
approach
to
screening
of
PBT
chemicals
and
collection
of
information
``sufficient
to
permit
a
reasoned
evaluation
of
potential
health
and
environmental
effects''
if
EPA
makes
the
requisite
risk­
or
exposurebased
findings
under
TSCA
section
5(
e).
Comment
14­
Relationship
of
P,
B,
and
T
criteria.
Commenters
suggested
that
the
October
5,
1998
(63
FR
53417)
notice
is
inaccurate
when
it
states
that
2
months
is
adequate
for
detecting
many
long­
term
toxic
effects
as
well
as
any
tendency
for
a
substance
to
bioaccumulate
in
aquatic
organisms.
Commenters
pointed
out
that
the
persistence
criterion
is
not
related
to
detection
of
long­
term
toxicity.
Response.
The
statement
in
question
was
intended
simply
to
note
that
the
2
months
half­
life
in
water
persistence
criterion
closely
tracks
the
duration
of
long­
term
environmental
toxicity
or
bioaccumulation
tests.
If
a
new
chemical
substance
is
predicted
to
or
measurably
demonstrates
chronic
toxicity,
potential
to
bioaccumulate,
and
environmental
persistence
over
that
same
time
period
(2
months),
it
would
meet
the
minimum
TSCA
PBT
criteria.
It
is
true
that,
in
general,
half­
life
cutoffs
for
identifying
POPs
warranting
international
action
(e.
g.,
in
programs
like
UNECE­
LRTAP
and
UNEP
Global
Negotiations
on
POPs)
have
not
been
selected
based
on
the
duration
of
toxicity
or
bioaccumulation
tests.
There
are
no
cutoffs
or
``fence
lines''
for
environmental
persistence
criteria
that
emerge
as
immutable
quantities
solely
from
scientific
analysis;
the
choice
of
screening
criteria
is
a
policy
decision
guided
by
the
anticipated
scope
of
a
negotiation
or
regulatory
activity.
In
the
case
of
the
PMN
program,
2
months
represents
a
reasonable
screening
level
value
for
``persistence''
which
is
more
than
the
1­
month
period
in
a
ready
biodegradation
study
and
less
than
the
6
month
value
widely
agreed
to
internationally
(U.
S.
Canada
binational
agreement
to
control
the
discharge
or
release
of
POPs
in
the
Great
Lakes
Basin,
UNECE­
LRTAP,
North
American
Free
Trade
Agreement
Commission
for
Environmental
Cooperation
(NAFTA­
CEC),
etc.)
as
reflecting
the
persistence
of
known
POPs
chemicals
(e.
g.,
DDT,
hexachlorobenzene).
As
mentioned
in
the
previous
response,
there
is
international
support,
through
the
CEG,
for
persistence
values
of
2
or
6
months
in
water.
Comment
15­
Relationship
of
P
and
B.
Commenters
suggested
that
the
October
5,
1998
(63
FR
53417)
notice's
statement,
``Generally,
persistent
bioaccumulators
are
chemical
substances
that
partition
to
water,
sediment
or
soil
and
are
not
removed
at
rates
adequate
to
prevent
their
bioaccumulation
in
aquatic
or
terrestrial
species,
''
should
be
revised
to
reflect
that
persistence
alone
is
not
sufficient
to
cause
a
substance
to
bioaccumulate.
Response.
EPA
did
not
intend
that
the
sentence
be
read
to
mean
that
persistence
alone
is
sufficient
to
result
in
bioaccumulation.
The
point
that
was
intended
to
be
conveyed
was
that
a
certain
level
of
persistence
is
a
necessary
condition
for
bioaccumulation
to
occur.
There
are
other
conditions
that
affect
bioaccumulation,
such
as
bioavailability
and
the
metabolic
transformation
rate
in
the
target
species.
These
and
other
factors
will
be
evaluated
by
EPA
in
the
determination
of
the
PBT
concern
level
for
PMN
chemical
substances.

H.
Relationship
of
TSCA
PBT
Policy
to
Other
Agency
and
International
PBT
Initiatives
Comment
16­
Finalize
overall
Agency
multimedia
strategy
first.
Commenters
suggested
that
the
PBT
classification
criteria
being
proposed
for
TSCA
section
5(
e)
may
have
broader
application,
e.
g.,
international
or
other
Agency
PBT
initiatives,
and
may
be
used
to
establish
precedent
in
other
programs.
In
addition
to
the
TSCA
October
5,
1998
(63
FR
53417)
Federal
Register
notice,
there
have
been
three
other
notices
published
in
Federal
Register
dealing
with
(1)
the
promotion
of
voluntary
waste
minimization
efforts
to
reduce
the
generation
of
those
PBT
chemicals
which
are
found
in
hazardous
waste
regulated
under
the
Resource
Conservation
and
Recovery
Act
(RCRA)
(63
FR
60332;
November
9,
1998
(FRL­
6186­
7)),
(2)
the
Agency
draft
Multimedia
PBT
Strategy
(63
FR
63926;
November
17,
1998
(FRL­
6045­
2)),
and
(3)
the
lowering
of
reporting
thresholds
for
certain
PBT
toxic
chemicals
subject
to
reporting
under
section
313
(Toxic
Release
Inventory,
or
TRI)
of
EPCRA
of
1986
(64
FR
688;
January
5,
1999).
These
commenters
stated
that
the
TSCA
notice
is
premature,
occurring
before
adoption
of
the
overall
Agency
strategy,
and
is
inconsistent
with
other
initiatives,
domestic
and
international,
which
have
lists
of
chemicals
and
more
selective
criteria
(i.
e.,
specific
to
environmental
media,
fate
and
transformation
processes).
Commenters
recommended
that
EPA
finalize
the
Agency
strategy
first,
before
proceeding
with
the
TSCA,
RCRA,
and
TRI
actions,
and
that
there
should
be
coordination
among
them
all
with
uniform
PBT
criteria
as
part
of
the
Agency
strategy.
Response.
The
PBT
Multimedia
Strategy
formalizes
an
Agency
process
for
integration
of
program
activities
involving
these
types
of
substances.
While
the
strategy
intends
to
coordinate
Agency
PBT­
related
activities
under
its
[[
Page
60201]]

framework,
the
strategy
does
not
establish
rigid
criteria
with
respect
to
PBTs.
Program
offices
must
operate
within
the
parameters
of
their
legislative
mandates
and
established
regulatory
and
policy
frameworks.
For
some
programs
such
as
the
Toxics
Release
Inventory,
the
TSCA
New
Chemicals
Program
and
the
RCRA
National
Waste
Minimization
Plan,
actions
involving
PBTs
are
a
historical
reality
and
their
experience
has,
in
fact,
largely
shaped
the
strategy.
Therefore,
EPA
does
not
intend
to
halt
all
ongoing
work
involving
PBTs
until
the
strategy
is
``finalized.
''
With
respect
to
the
PMN
process,
it
is
important
to
understand
and
acknowledge
its
fundamental
purpose,
which
is
to
allow
EPA
to
evaluate
the
hazards,
exposures,
and
risks
of
new
chemicals,
and
the
opportunity
to
protect
against
unreasonable
risks,
if
any.
The
structure
of
that
process
and
the
tools
used
to
implement
it
flow
logically
from
its
statutory
purpose
and
suggest
that
the
category
approach
outlined
in
this
policy
statement
is
the
most
appropriate
means
of
addressing
potential
concerns
for
substances
possessing
PBT
characteristics.
It
is
EPA's
intention
that
the
strategy
be
a
living
document.
Therefore,
the
strategy
will
be
updated
based
upon
public
comment;
it
will
not
be
``finalized''
in
the
more
traditional
sense
of
a
rulemaking.
EPA
does
agree
that
consistency
is
a
laudable
goal
where
the
criteria
are
meant
to
be
used
for
similar
purposes
and
is
seriously
considering
comments
within
the
context
of
the
strategy
regarding
establishment
of
consistent
criteria
for
priority
PBTs.
Comment
17­
Carefully
communicate
lower
thresholds.
Commenters
suggested
that
EPA
should
use
only
the
environmental
persistence
of
6
months/
BCF
of
5,000
screening
levels
for
consistency
among
EPA
and
U.
S./
international
programs
and
should
carefully
communicate
proposed
lower
criteria
internationally.
Response.
As
discussed
in
the
response
to
Comment
12,
EPA
believes
that
a
lower
tier
of
2
month/
BCF
of
1,000
is
appropriate
for
risk
screening
activities
under
TSCA.
Communication
is
occurring
in
the
international
forum.
Unit
II.
B.
of
this
document
discusses
the
CEG
for
POPs,
established
under
UNEP
mandate.
At
its
first
meeting,
on
October
30,
1998
in
Bangkok,
the
CEG
recommended
that
the
INC
consider
developing
a
provision
encouraging
countries
and
regions
to
include
in
their
new
chemicals
schemes
elements
relating
to
development
and
introduction
of
new
chemical
POPs.
The
U.
S.
described
its
proposed
TSCA
new
chemicals
program
policy
for
the
category
of
PBT
new
chemicals,
and
the
full
text
of
the
October
5,
1998
(63
FR
53417)
Federal
Register
notice
was
distributed
to
all
delegations
as
a
Conference
Room
Paper.
The
CEG's
recommendation
was
accepted
at
the
second
meeting
of
the
INC
(January
25­
29,
1999
in
Nairobi)
and
the
INC
will
consider
it
further
in
its
deliberations.

I.
Testing
Strategy
Comment
18­
Toxicity
testing.
Commenters
asked
whether
toxicity
was
considered
at
each
testing
tier
or
only
in
tier
3.
It
was
not
clear
to
them
when
toxicity
testing
would
be
requested,
nor
what
results
will
be
considered
acceptable
by
the
Agency.
Response.
Each
of
P
and
B
and
T
are
weighed
in
the
Agency's
assessment.
The
testing
strategy
outlined
in
this
policy
statement
is
intended
to
build
the
case,
starting
with
testing
to
establish
persistence
and
bioaccumulation,
and
then
determining
toxicity
and
confirming
a
chemical's
status
as
a
PBT
chemical
in
tier
3.
Once
a
chemical
becomes
distributed
in
the
environment
at
low
concentrations,
the
combination
of
persistence
and
bioconcentration
in
organisms
can
result
in
residues
high
enough
to
approach
a
toxic
dose.
The
first
two
tiers
focus
on
P
and
B
because
of
the
critical
role
these
aspects
play
in
PBT
determinations
and
because
of
their
relatively
lower
cost
to
determine
P
and
B.
Thus,
chronic
toxicity
testing,
which
is
expected
to
be
the
most
expensive
testing,
is
reserved
until
tier
3
where
it
serves
to
establish
PBT
status.
Although
the
early
tier
P
and
B
testing
may
either
obviate
the
need
for
toxicity
testing
or
result
in
more
directed
and
cost­
effective
toxicity
testing,
the
need
for
toxicity
testing
is
considered
in
each
testing
tier
and
will
be
obtained
in
lower
tiers
where
needed
on
a
case­
specific
basis.
As
with
all
new
chemicals
reviewed
by
the
Agency
under
TSCA,
the
potential
toxicity
of
the
chemical
is
determined
from
test
data,
if
any,
or
by
analogy
to
structurally
similar
chemicals.
If
a
company
knows
or
suspects
prior
to
testing
that
their
chemical
is
likely
to
be
persistent
and
bioaccumulative,
consideration
should
be
given
to
conducting
chronic
toxicity
testing
in
the
first
tier.
For
any
suspected
PBT
chemicals
for
which
a
risk
finding
has
not
been
made,
but
which
meet
production,
release,
and
exposure
thresholds
under
the
Agency's
exposure­
based
policy
(USEPA,
1988,
USEPA,
1989,
see
Unit
VI.
8.
and
9.),
the
standard
screening
level
battery
of
testing
(or
an
appropriate
subset
thereof)
currently
utilized
for
exposure­
based
cases
in
the
new
chemicals
program
could
be
required
in
addition
to
PBT
testing.
Comment
19­
Equivalent
tests.
Commenters
suggested
that
all
tests
referenced
in
the
testing
strategy
should
also
state
``or
an
equivalent
test.
''
Response.
EPA
realizes
that
often
there
are
a
number
of
different
but
acceptable
means
to
providing
testing
information.
However,
EPA's
acceptance
of
a
guideline
not
specified
in
this
policy
statement
and/
or
use
of
data
generated
under
such
guidelines
depends
on
multiple
factors
including
the
specifics
of
the
test
substance,
purpose
of
the
testing,
familiarity
with
specific
procedures
and
equipment,
validation
of
the
method,
etc.
Typical
TSCA
5(
e)
consent
orders
require
that
testing
performed
pursuant
to
the
order
must
be
conducted
according
to
TSCA
Good
Laboratory
Practice
Standards
at
40
CFR
part
792
and
using
methodologies
generally
accepted
at
the
time
the
study
is
initiated.
Before
starting
to
conduct
any
such
study,
the
PMN
submitter
must
obtain
approval
of
test
protocols
from
EPA
by
submitting
written
protocols.
Published
test
guidelines
specified
in
the
Test
Strategy
section
(see
Unit
IV.
B.
of
this
document)
provide
general
guidance
for
development
of
test
protocols,
but
are
not
themselves
acceptable
protocols.

J.
Applicability
of
PBT
Criteria
to
Metals
Comment
20­
PBT
criteria
are
not
appropriate
for
metals.
Commenters
suggested
that
the
application
of
Persistence
and
Bioaccumulation
criteria
appropriate
for
organic
chemicals
does
not
make
sense
for
metals
and
metal
compounds.
They
also
suggested
that
EPA
needs
criteria
to
identify
potential
problems
generated
by
organometals.
Response.
The
approach
and
the
criteria
are
sufficiently
flexible
to
apply
to
organic
chemicals,
inorganic
metals
and
organometallics.
It
is
important
to
distinguish
between
criteria
for
identifying
potential
PBTs,
on
the
one
hand,
and
on
the
other:
(1)
the
means
of
generating
information
on
the
P,
B,
and
T
endpoints
for
comparison
to
the
criteria,
and
(2)
the
applicability
of
existing
test
guidelines
for
generating
such
information
experimentally.
EPA
understands
that
metals
are
intrinsically
not
degradable
in
the
sense
of
ultimate
degradation
of
organics
(although
they
may
undergo
biologically
as
well
as
chemically
induced
changes
in,
e.
g.,
oxidation
state),
and
therefore
are
persistent
by
definition,
but
nevertheless
may
not
be
bioaccumulative.
It
is
widely
accepted
that
elemental
metals
are
persistent
by
definition,
since
they
may
take
different
[[
Page
60202]]

forms
that
can
be
interconverted,
but
the
elemental
metal
itself
cannot
be
destroyed.
All
elemental
metals
therefore
meet
the
6
month
half­
life
criterion.
Given
this,
it
is
not
correct
that
EPA's
proposed
persistence
criteria
cannot
be
applied
to
metals.
It
may
be
more
accurate
to
state
that
the
persistence
criteria
are
not
themselves
very
helpful
in
screening
or
assessing
metals
and
metal
compounds
with
respect
to
the
potential
for
risk,
whether
from
direct
exposure
or
through
bioaccumulation.
Relative
to
applicability
of
test
guidelines,
the
same
level
of
judgment
will
be
brought
to
bear
such
that,
for
example,
EPA
would
not
require
ready
biodegradability
testing
for
a
metal
or
metal
salt.
(EPA
may,
however,
request
such
testing
for
organometallics,
which,
depending
on
chemical
structure,
could
still
show
significant
degradation
in
such
tests.)
EPA
understands
that
bioavailability
is
important
in
determining
the
potential
for
risk,
and
notes
that
the
same
generalization
applies
to
any
substance
whether
metallic
or
not.
Metals
and
organometallic
compounds
are
no
different
from
other
organic
chemicals
with
respect
to
the
applicability
of
the
proposed
criteria
for
identifying
persistent,
bioaccumulative,
and
toxic
substances,
except
that
Kow
determination
may
not
be
relevant
for
metals
(although
the
fish
BCF
study
is
relevant).
Similarly,
it
is
not
necessary
to
develop
different
criteria
or
assessment
strategies
for
pigments
(see
first
comments/
responses
in
this
policy
statement)
or
any
other
specific
classes
of
organics.
What
is
necessary
is
to
consider
what
is
known
about
the
behavior
of
substances
like
metals
during
the
TSCA
PMN
review
process,
both
in
the
assessment
of
whether
a
given
chemical
substance
meets
the
established
criteria
and
in
subsequent
testing
decisions.
For
any
untested
PMN
chemical
substance,
if
there
are
no
close
analogs
with
data
and
no
clear
evidence
that
available
estimation
methods
are
unreliable
for
this
or
closely
related
substances,
then
the
estimation
methods
can
be
assumed
to
apply
and
the
resulting
data
compared
to
PBT
criteria.
Put
another
way,
a
metal
or
organometallic
(or,
similarly,
a
pigment)
that
is
judged
sufficiently
persistent
and
meets
the
criteria
for
bioaccumulation
potential
and
toxicity
is
of
concern
for
``PBTness''
regardless
of
theoretical
arguments
or
generalizations.
The
key
is
how
persistence
and
bioaccumulation
potential
are
determined
in
the
PMN
process,
and
by
implication,
how
bioavailability
is
determined.
This
policy
statement
leaves
unspecified
how
EPA
intends
to
do
this,
but
the
Agency
will
consider
all
available
and
relevant
data,
and
will
use
its
professional
judgment
in
considering
issues
like
bioavailability
of
metals.
Using
lead
as
an
example,
many
processes
commonly
observed
in
the
environment
can
result
in
the
presence
of
bioavailable
(ionic)
lead
where
it
can
be
bioaccumulated
by
organisms.
These
processes
may
occur
in
soil
and
aquatic
environments
with
low
pH
and
low
levels
of
organic
matter.
Under
these
conditions,
the
solubility
of
lead
is
enhanced
and,
in
the
absence
of
sorbing
surfaces
and
colloids,
lead
ion
can
remain
in
solution
for
a
sufficient
period
to
be
taken
up
by
biota.
Lead
sorption
to
soil
organic
matter
has
been
shown
to
be
pH
dependent.
Decreasing
pH
can
lead
to
increasing
concentrations
of
lead
in
soil
and
water.
Microbial
transformations
in
soil,
water,
and
sediment
are
also
important
in
determining
the
overall
fate
of
metals
and
metal
compounds,
and
therefore
the
potential
for
formation
of
bioavailable
forms.
Metals
are
generally
taken
into
cells
by
nutrient
metal
transport
systems,
and
these
are
not
sufficiently
specific
to
completely
exclude
nonessential
metals,
some
of
which
may
be
toxic
and/
or
bioaccumulative.
In
this
situation,
nutrient
metals
can
be
displaced
from
their
binding
sites
by
undesirable,
toxic
metals,
which
then
gain
access
to
the
cell
interior
with
concomitant
exclusion
of
the
essential
metal
(Stumm
and
Morgan,
1996
see
Unit
VI.
16.).
Toxic
metal
ions
are
then
free
to
react
with
critical
enzymes
or
otherwise
disrupt
cellular
functions
if
they
reach
certain
levels.
EPA
concludes
that
under
many
environmental
conditions,
metals
and
metal
compounds
may
be
available
to
express
toxicity
and
to
bioaccumulate,
and
that
these
effects
are
not
necessarily
limited
to
metals
that
are
not
essential
nutrients.
It
is
appropriate,
therefore,
to
be
concerned
about
the
potential
for
risk
from
these
effects.
It
is
the
policy
of
the
TSCA
New
Chemicals
Program
that
if
the
metal
in
a
metal
compound
cannot
become
available
as
a
result
of
biotic
or
abiotic
processes
then
the
metal
will
not
be
available
to
express
its
toxicity,
and
by
extension,
to
bioaccumulate.
If
the
intact
metal
compound
is
not
toxic
and
the
metal
is
not
available
from
the
metal
compound,
then
such
a
chemical
would
not
be
a
strong
candidate
for
regulation
under
TSCA
section
5(
e).

IV.
Final
TSCA
New
Chemicals
Program
Policy
for
PBT
Chemical
Substances
A.
Evaluation
Criteria
and
Process
for
New
PBT
Chemical
Substances
EPA
is
adopting
the
following
specific
identification
criteria
and
associated
process
for
use
in
evaluating
new
chemical
substances.

New
Chemicals
Program
PBT
Category
Criteria
and
Process
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­

­­­­­­­­­­­­­­

TSCA
Section
5(
e)
Action
­­­­­­­­­­­­­­­­­­­­­­­

­­­­­­­­­­­­­­

5(
e)
Order
Pending
Testing/
5(
e)
Ban
Pending
Significant
New
Testing<
SUP>
2</
SUP>
Use
Rule
(SNUR)<
SUP>
1</
SUP>
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­

­­­­­­­­­­­­­­

Persistence
(transformation
half­
>
2
months........
>
6
months
life).
Bioaccumulation
(Fish
BCF
or
<gr­
thn­
eq>
1,000.
<gr­
thn­
eq>
5,000
BAF)<
SUP>
3</
SUP>.
Toxicity........................
Develop
toxicity
Develop
toxicity
data
where
data
where
necessary<
SUP>
4</
SUP>.
necessary<
SUP>
4</
SUP>
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­

­­­­­­­­­­­­­­

<SUP>
1</
SUP>
Exposure/
release
controls
included
in
order;
testing
required.
<SUP>
2</
SUP>
Deny
commercialization;
testing
results
may
justify
removing
chemical
from
``high
risk
concern''.
<SUP>
3</
SUP>
Chemicals
must
also
meet
criteria
for
MW
(<
1000)
and
cross­
sectional
diameter
(<
20A
,
or
<
20
x
10<
SUP>­
8</
SUP>
cm).
<SUP>
4</
SUP>
Based
upon
various
factors,
including
concerns
for
persistence,
bioaccumulation,
other
physical/
chemical
factors,
and
toxicity
based
on
existing
data.

Chemical
substances
suspected
as
persistent
bioaccumulators
under
the
criteria
listed
in
the
table
in
Unit
IV.
A.
of
this
document
may
need
to
undergo
testing
on
``P''
and
``B''
endpoints
which,
if
confirmed,
would
be
followed
by
appropriate
toxicity
testing
to
identify
``PBT
chemical
substances.
''
Control
action
under
TSCA
section
5(
e)
may
be
needed
in
varying
degrees,
based
upon
the
level
of
risk
concern.
Agency
control
actions
taken
under
TSCA
section
5(
e)
for
chemical
substances
meeting
these
criteria
would
be
based
upon
the
level
of
certainty
for
the
PBT
properties
of
a
PMN
substance
(e.
g.,
measured
vs.
estimated
values),
the
magnitude
of
Agency
concerns,
and
conditions
of
expected
use
and
release
of
the
chemical.
For
example,
new
chemical
substances
meeting
the
PBT
criteria
listed
under
``5(
e)
Order
Pending
Testing/
Significant
New
Use
Rule
(SNUR)
''
could
be
addressed
via
a
negotiated
consent
agreement
under
[[
Page
60203]]

which
necessary
testing
is
``triggered''
by
specific
production
limits.
While
the
PMN
submitter
would
be
allowed
to
commercialize
the
substance,
certain
controls
could
be
stipulated,
including
annual
TRI­
type
reporting
on
environmental
releases
of
the
PMN
substance
and
specific
limits
on
exposures,
releases,
or
uses.
The
``ban
pending
testing''
criteria
are
equivalent
to
those
that
have
been
used
internationally
to
identify
POPs.
For
the
chemical
substances
meeting
these
criteria,
the
concern
level
is
higher
and
the
Agency
would
look
carefully
at
any
and
all
environmental
releases.
Because
of
the
increased
concern,
more
stringent
control
action
would
be
a
likely
outcome,
up
to
a
ban
on
commercial
production
until
data
are
submitted
which
allow
the
Agency
to
determine
that
the
level
of
risk
can
be
appropriately
addressed
by
less
restrictive
measures.
The
control
actions
described
in
the
table
in
Unit
IV.
A.
of
this
document
represent
just
one
body
of
possible
decisions
and
should
not
be
considered
as
exclusive
of
other
risk
management
options.

B.
Testing
Strategy
for
PBT
Chemical
Substances
Where
EPA
is
unable
to
adequately
determine
the
potential
for
bioaccumulation,
persistence
in
the
environment,
and
toxicity
which
may
result
from
exposure
of
humans
and
environmental
organisms
to
a
possible
PBT
chemical
substance,
the
Agency
may
conclude,
pursuant
to
sections
5(
e)(
1)(
A)(
i)
and
5(
e)(
1)(
A)(
ii)(
I)
and
(II)
of
TSCA,
that
the
information
available
to
the
Agency
is
insufficient
to
permit
a
reasoned
evaluation
of
the
human
health
and
environmental
effects
of
that
PMN
substance,
that
the
manufacturing,
processing,
distribution
in
commerce,
use,
or
disposal
of
the
substance
may
present
an
unreasonable
risk
of
injury
to
human
health
or
the
environment,
and/
or
that
the
PMN
substance
will
be
produced
in
substantial
quantities
and
that
there
may
be
significant
or
substantial
human
exposure
to
the
substance
or
the
PMN
substance
may
reasonably
be
anticipated
to
enter
the
environment
in
substantial
quantities.
Accordingly,
the
Agency
may
find
it
appropriate
to
prohibit
or
otherwise
limit
the
manufacture,
import,
processing,
distribution
in
commerce,
use,
or
disposal
of
the
PMN
substance
in
the
United
States
pending
the
development
of
information
necessary
for
a
reasoned
evaluation
of
these
effects.
The
following
testing
strategy
describes
test
data
which
EPA
believes
are
needed
to
evaluate
the
persistence,
bioaccumulation,
and
toxicity
of
a
PBT
chemical
substance
for
which
EPA
has
made
the
above
described
risk
and/
or
exposure­
based
findings
under
section
5(
e)(
1)(
A)(
i)
and
(ii)
of
TSCA.
The
tests
are
tiered;
depending
upon
the
circumstances,
such
as
magnitude
of
environmental
releases,
results
of
testing,
or
SAR,
testing
could
begin
above
Tier
1
or
additional,
higher
levels
of
testing
may
be
required.
As
discussed
in
the
response
to
Comment
19
in
Unit
III.
I.
of
this
document,
testing
must
be
conducted
according
to
TSCA
Good
Laboratory
Practice
Standards
at
40
CFR
part
792
and
using
methodologies
generally
accepted
at
the
time
the
study
is
initiated.
Before
starting
to
conduct
any
such
study
under
the
terms
of
a
Consent
Order
under
TSCA
section
5(
e),
the
PMN
submitter
must
obtain
approval
of
test
protocols
from
EPA
by
submitting
written
protocols.
Published
test
guidelines
specified
in
Unit
IV.
B.
of
this
document
provide
general
guidance
for
development
of
test
protocols,
but
are
not
themselves
acceptable
protocols.
Tier
1.
If,
based
upon
available
test
data,
SAR,
and
professional
judgment,
the
Agency
identifies
a
new
chemical
substance
as
a
possible
PBT
chemical
substance,
Log
Kow
should
be
determined
experimentally,
using
either
the
liquid
chromatography
(OPPTS
830.7570
test
guideline)
or
generator
column
(OPPTS
830.7560
test
guideline)
method.
Hydrolysis
in
water
(OPPTS
835.2110
test
guideline)
should
be
determined
if,
based
upon
SAR,
susceptibility
to
hydrolysis
is
suspected.
Ready
biodegradability
should
be
determined
according
to
either
one
of
the
following
test
guidelines:
1.
Ready
biodegradability
(OPPTS
835.3110
test
guideline)
6
methods
(choose
one):
DOC
Die­
Away,
CO<
INF>
2</
INF>
Evolution,
Modified
MITI
(I),
Closed
Bottle,
Modified
OECD
Screening,
Manometric
Respirometry.
2.
Sealed­
vessel
CO<
INF>
2</
INF>
production
test
(OPPTS
835.3120
test
guideline).
If
the
measured
log
Kow
is
<
4.2
(equivalent
to
an
estimated
BCF
of
1,000)
or
if
the
test
chemical
passes
(pass
criteria
are
described
in
the
test
guidelines)
the
ready
biodegradability
test
(i.
e.,
not
persistent
in
the
environment),
no
further
PBT­
related
testing
is
required.
If
the
measured
log
Kow
is
greater
than
or
equal
to
4.2,
and
the
chemical
does
not
pass
the
ready
biodegradability
test,
no
further
testing
will
normally
be
deemed
necessary
in
tier
1;
the
Agency
would
likely
require
tier
2
testing.
If
hydrolysis
testing
is
conducted
and
results
in
a
half­
life
of
<
60
days,
further
testing
may
not
be
needed,
but
the
need
for
testing
must
be
determined
after
consideration
of
factors
specific
to
the
case,
such
as
physical/
chemical
properties,
persistence
and
bioaccumulative
qualities
of
hydrolysis
products,
and
the
nature
of
the
expected
releases.
Tier
2.
Biodegradability
should
be
determined
according
to
the
Shake­
flask
die­
away
test
(OPPTS
835.3170
test
guideline).
This
test
is
based
on
the
principle
of
aerobic
incubation
of
the
test
chemical
in
natural
water
with
and
without
suspended
sediment,
requires
a
chemicalspecific
analytical
method,
and
allows
for
the
development
of
a
firstorder
rate
constant
and
half­
life.
It
provides
information
on
persistence
that
is
relevant
to
the
natural
environment
and
is
intermediate
in
cost
between
ready
biodegradability
tests
(tier
1)
and
sediment/
water
microcosm
biodegradation
test
(tier
3).
Bioaccumulation
potential
should
be
determined
by
experimental
measurement
of
the
bioconcentration
factor
(BCF),
using
the
Fish
bioconcentration
test
(OPPTS
850.1730
test
guideline
(public
draft)).
Measured
BCF
should
be
based
on
100
percent
active
ingredient
and
measured
concentration(
s).
If
the
measured
biodegradation
half­
life
is
>
60
days
and
measured
BCF
is
>
1,000,
tier
3
testing
will
normally
be
required.
If
only
one
condition
is
met,
releases
and
exposure
are
further
considered
to
determine
if
additional
testing
is
required.
Tier
3.
Toxicity/
advanced
environmental
fate
testing.
Human
health
hazards
should
be
determined
in
the
combined
repeated
dose
oral
toxicity
with
the
reproductive/
developmental
toxicity
screening
test
(OECD
No.
422
test
guideline)
in
rats.
Other
health
testing
will
be
considered
where
appropriate.
Environmental
fate
testing
should
be
conducted
according
to
the
Sediment/
water
microcosm
biodegradation
test
(OPPTS
835.3180
test
guideline).
The
principle
of
this
method
is
the
determination
of
the
test
chemical's
fate,
including
transport
and
transformation,
in
core
chambers
containing
intact
benthic
sediment
and
overlying
site
water.
The
method
permits
more
accurate
and
reliable
extrapolation
to
natural
aquatic
environments
than
is
possible
with
lower
tier
test
methods.
Chronic
toxicity
to
fish
(rainbow
trout)
and
daphnids
should
be
determined
according
to
40
CFR
797.1600
(same
as
OPPTS
test
guideline
850.1400
(public
draft))
and
40
CFR
797.1330
(same
as
OPPTS
test
guideline
850.1300
(public
draft)),
respectively.
Additional
testing
to
evaluate
other
biota
(e.
g.,
avian,
sediment
dwelling
organisms)
or
other
effects
(e.
g.,

[[
Page
60204]]

endocrine
disrupting
potential)
will
be
considered
where
appropriate.

V.
Intended
Legal
Affect
of
this
Policy
Statement
The
policy
discussed
in
this
document
provides
general
guidance
on
the
Agency's
use
of
a
category
grouping
for
PBT
new
chemical
substances
to
facilitate
the
PMN
assessment
process
for
PMN
submitters
and
EPA
reviewers.
EPA
uses
groupings
of
new
chemical
substances
with
similar
structural
and
toxicological
properties
to
allow
PMN
submitters
and
EPA
reviewers
to
benefit
from
accumulated
data
and
decisional
precedents,
as
well
as
streamlined
procedural
requirements
related
to
the
review
of
and
follow­
up
for
new
chemical
substances.
As
guidance,
the
policy
presented
in
this
document
is
not
binding
on
either
EPA
or
any
outside
parties,
and
this
document
is
not
intended,
nor
can
it
be
relied
upon,
to
create
any
rights
enforceable
by
any
party
in
litigation
with
the
United
States.
Although
this
guidance
provides
a
starting
point
for
assessing
PBT
new
chemical
substances,
EPA
will
depart
from
its
policy
where
the
facts
or
circumstances
warrant.
In
such
cases,
EPA
will
explain
why
a
different
course
was
taken.
Similarly,
outside
parties
remain
free
to
assert
that
this
policy
is
not
appropriate
for
a
specific
PMN
or
that
the
circumstances
surrounding
a
specific
PMN
demonstrate
that
this
policy
should
not
be
applied.
Although
the
Agency
has
provided
an
opportunity
for
public
comment
on
the
guidance
provided
in
this
policy
statement
and
is
likely
to
request
additional
feedback
if
changes
are
necessary
at
some
point
in
the
future,
the
Agency
may
revise,
clarify,
or
update
the
text
of
this
guidance
without
public
notice.

VI.
References
The
OPPTS
harmonized
test
guidelines
referenced
in
this
document
are
available
on
EPA's
World
Wide
Web
site
(http://
www.
epa.
gov/
OPPTS<
INF>­</
INF>
Harmonized/).
1.
Sijm,
D.
T.
H.
M.,
Schuurmann,
G.,
de
Vries,
P.
J.,
Opperhuizen,
A.
Aqueous
Solubility,
Octanol
Solubility,
and
Octanol/
Water
Partition
Coefficient
of
Nine
Hydrophobic
Dyes.
Environ.
Toxicol.
and
Chem.
18:
1109­
1117.
2.
Mackay,
D.,
Di
Guardo,
A.,
Paterson,
S.,
Cowan,
C.
E.
1996.
Evaluating
the
environmental
fate
of
a
variety
of
types
of
chemicals
using
the
EQC
model.
Environ.
Toxicol.
Chem.
15:
1627­
1637.
3.
Boethling
RS,
PH
Howard,
JA
Beauman
and
ME
Larosche.
1995.
Factors
for
intermedia
extrapolation
in
biodegradability
assessment.
Chemosphere
30:
741­
752.
4.
Federle
TW,
SD
Gasior
and
BA
Nuck.
1997.
Extrapolating
mineralization
rates
from
the
ready
CO2
screening
test
to
activated
sludge,
river
water,
and
soil.
Environ.
Toxicol.
Chem.
16:
127­
134.
5.
Boethling
RS,
Howard
PH,
Meylan
W,
Stiteler
W,
Beauman
J,
Tirado
N.
1994.
Group
contribution
method
for
predicting
probability
and
rate
of
aerobic
biodegradation.
Environ.
Sci.
Technol.
28:
459­
465.
6.
USEPA.
March,
1997.
Chemistry
Assistance
Manual
for
Premanufacture
Notification
Submitters.
EPA
744­
R­
97­
003.
Also
available
as
Premanufacture
Notification:
Chemistry
Assistance
for
Submitters,
by
Steven
C.
DeVito
and
Carol
A.
Farris
(ISBN:
0­
471­
19151­
5)
through
the
publisher,
John
Wiley
and
Sons,
at
1­
800­
225­
5945
or
the
TSCA
Hot
Line,
at
202­
554­
1404.
7.
USEPA.
March,
1994.
U.
S.
EPA/
EC
Joint
Project
on
the
Evaluation
of
(Quantitative)
Structure
Activity
Relationships.
EPA
743­
R­
94­
001.
8.
USEPA.
1988.
Letter
from
Charles
L.
Elkins
to
Geraldine
V.
Cox
(Chemical
Manufacturers
Association).
Office
of
Toxic
Substances,
USEPA
(September
22,
1988).
9.
USEPA.
1989.
Letter
from
Charles
L.
Elkins
to
Geraldine
V.
Cox
(Chemical
Manufacturers
Association).
Office
of
Toxic
Substances,
USEPA
(August
31,
1989).
10.
Ministry
of
Environment
and
Energy
for
Ontario
(MOEE).
1992.
Candidate
substances
list
for
bans
or
phase­
outs.
Report
perpared
by
the
Hazardous
Contaminants
Branch
and
the
Water
Resources
Branch,
MOEE.
Ontario,
Canada,
ISBN
0­
7729­
9764­
0.
11.
Accelerated
Reduction/
Elimination
of
Toxics
(ARET)
Secretariat.
1995.
Environment
leaders
1.
Voluntary
commitments
to
action
on
toxics
through
ARET.
March
95.
12.
Accelerated
Reduction/
Elimination
of
Toxics
(ARET)
Secretariat.
1994.
The
ARET
substance
selection
process
and
guidelines.
January
94.
13.
International
Joint
Commission
(IJC).
1993.
A
strategy
for
the
virtual
elimination
of
persistent
toxic
substances.
Vol.
1,
report
of
the
Virtual
Elimination
Task
Force
to
the
IJC.
Windsor,
Ontario,
Canada,
72
pp.
14.
United
Nations
Economic
Commission
for
Europe,
Convention
on
Long­
Range
Transboundary
Air
Pollution
(UNECE­
LRTAP).
1998.
Draft
composite
negotiating
text
for
a
protocol
on
persistent
organic
pollutants.
UNECE,
EB.
AIR/
1998/
2,
31
March
1998.
15.
Zeeman,
M.,
D
Rodier,
and
JV
Nabholz.
1999.
Chapter
2.
Ecological
Risks
of
a
New
Industrial
Chemical.
Under
TSCA.
In
Ecological
Risk
Assessment
in
the
Federal
Government
(Executive
Office
of
the
President,
National
Science
and
Technology
Council,
Committee
on
Environment
and
Natural
Resources,
Ed.).
CENR/
5­
99/
001,
May,
1999,
pp
2­
1
to
2­
30.
16.
Stumm,
W.
and
JJ
Morgan.
1996.
Aquatic
Chemistry,
3rd
ed.
New
York:
Wiley.

List
of
Subjects
Environmental
protection,
Chemical
substances,
Hazardous
substances,
Reporting
and
recordkeeping
requirements.

Dated:
October
22,
1999.

Susan
H.
Wayland,

Deputy
Assistant
Administrator
for
Prevention,
Pesticides
and
Toxic
Substances.

[FR
Doc.
99­
28888
Filed
11­
3­
99;
8:
45
am]
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CODE
6560­
50­
F
EPA
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