Document ID: EPA-HQ-OPP-2002-0280-0002
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2002-10-02T04:00Z

Page
1
of
14
UNITED
STATES
ENVIRONMENTAL
PROTECTION
AGENCY
WASHINGTON,
D.
C.
20460
OFFICE
OF
PREVENTION,
PESTICIDES
AND
TOXIC
SUBSTANCES
January
31,
2002
MEMORANDUM
FROM:
Kathryn
Boyle,
CoChair
IIFG
and
Kerry
Leifer,
CoChair
IIFG
TO:
Robert
Forrest,
Chief
Minor
Use,
Inerts,
and
Emergency
Response
Branch
SUBJECT:
November
13,
2001
and
December
18,
2001
Meeting
of
the
IIFG
Decision
Memo
Please
find
attached
the
Inert
Ingredient
Focus
Group
recommendations
for
the
inert
ingredients
associated
with
the
"weathered
materials"
grouping.
Page
2
of
14
INERT
INGREDIENT
FOCUS
GROUP
MEETING
November
13,
2001
and
December
18,
2001
Chemical
Name:
Several,
see
below.

Category:
Weathered
materials.

CAS
Reg.
No.:
Several,
see
below.

PC
Code:
Several,
see
below.

Introduction:

There
were
two
meetings
of
the
Inert
Ingredient
Focus
Group
to
discuss
the
"weathered
materials"
grouping.
The
first
was
held
on
November
13,
2001,
and
the
second
on
December
18,
2001.
Focus
Group
members
in
attendance
at
both
meetings
were:
Kathryn
Boyle
(RD),
Kerry
Leifer
(RD),
Michael
Doherty
(HED),
Pauline
Wagner
(HED),
Diana
Locke
(HED),
Sid
Abel
(EFED),
and
Mark
Perry
(SRRD).
Robert
Forrest
(RD),
Tom
Brennan
(HED),
Henry
Craven
(EFED),
and
Larry
Schnaubelt
(SRRD)
were
present
for
the
November
13
meeting
only.
Kelly
O'Rourke
(HED)
attended
only
the
December
18
meeting.
The
presenters
were:
Kathryn
Boyle
(RD)
and
Sid
Abel
(EFED).
The
Executive
Secretary
for
the
November
13
meeting
was
Linda
Gerber
(RD).
Also
in
attendance
at
the
November
13
meeting
were:
John
Redden
(RD),
Jeanie
McAndrew
(RD),
Christina
Jarvis
(RD),
and
Carol
Christensen
(HED).
Jeanie
McAndrew
also
attended
the
December
18
meeting.

At
both
meetings
the
available
information
on
various
weathered
materials
were
discussed
to
determine
if
sufficient
information
were
available
to
make
tolerance
reassessment
decisions
assessment
on
the
various
materials
and
to
make
the
determination
as
to
whether
the
various
materials
should
be
classified
as
List
4A
or
List
4B
substances.
The
available
information
consisted
of
information
retrieved
from
various
websites,
such
as,
°EPA(
www.
epa.
gov),
°CDC(
www.
atsdr.
cdc.
gov/
toxprofiles/),
°NIOSH,(
www.
cdc.
gov/
niosh/
ipcsneng/
neng0000.html)
and
(www.
cdc.
gov/
niosh/
npg/
npg.
html)
°
TOXNET
(
www.
toxnet.
nlm.
nih.
gov.),
Page
3
of
14
°NTP(
ntp­
server.
niehs.
nih.
gov.),
°Firstgov(
www.
firstgov.
gov/),
°IARC(
www.
iarc.
fr/)

Additional
information
included
parts
of
the
FDA
GRAS
assessment
of
sodium
silicoaluminate..
Also,
SAR
(structure­
activity­
relationship)
assessments
as
performed
by
OPPT
were
available
for
some
of
the
oxides
and
silicates.

Three
handouts
were
provided
at
the
meeting
on
the
13th:
(1)
a
listing
of
the
substances
for
which
there
are
existing
tolerance
exemptions;
(2)
a
short
summary
dividing
the
substances
into
15
groups
for
discussion
purposes;
and
(3)
the
following
description/
explanation
of
weathered
materials.

Description
of
Weathered
Materials
Weathered
materials
is
the
term
that
the
Agency
is
using
to
describe
a
group
of
substances
that
could
also
be
referred
to
as
rocks
and
minerals.
Generally,
weathered
materials
are
decayed
or
weathered
rocks
that
are
mostly
unrefined,
i.
e.,
not
altered
or
manufactured
by
man.
When
referring
to
weathered
materials
as
mostly
unrefined,
the
Agency
is
including
the
mechanical
grinding
of
larger
rocks
into
smaller
pieces
that
are
essentially
the
same,
but
not
the
chemical
or
physical
alteration
of
the
rock
into
a
different
substance.

A
mineral
is
a
naturally­
occurring,
inorganic
solid
substance
characterized
by
a
definite
chemical
composition
or
a
range
of
chemical
compositions
and
by
a
specific,
regular
architecture
of
the
atoms
that
make
it
up.
Simply
put,
minerals
are
chemicals
arranged
in
an
orderly
regular
pattern
to
form
a
substance
that
cannot
be
separated
mechanically,
i.
e.,
by
crushing,
into
different
substances.
Quartz,
a
very
common
mineral,
is
made
of
the
basic
elements
silicon
and
oxygen.
By
simply
crushing
the
quartz,
silicon
and
oxygen
cannot
be
separated;
but
crushed
finely,
quartz
is
a
major
component
of
the
sand
found
at
the
beach
or
in
the
soil
around
our
homes.
Some
minerals
can
be
seen
with
the
naked
eye
especially
in
coarse
grain
rocks,
but
others
need
magnifying
glasses
or
powerful
microscopes
to
be
seen.
There
are
several
thousand
minerals,
each
with
characteristic
chemical
and
physical
properties.

Minerals
are
the
building
blocks
of
rocks.
Minerals
can
be
combined,
aggregated,
in
a
great
variety
of
patterns
just
as
bricks
may
make
up
a
walkway
in
an
infinite
array
of
schemes.
Rocks
are
not
as
uniquely
defined
by
their
properties
as
minerals
because
of
the
immense
number
of
ways
the
thousands
of
minerals
can
be
combined.
The
major
divisions
of
rocks
are
igneous
(formed
from
cooling
magmas),
sedimentary
(formed
from
the
settling,
cementing
and
compacting
of
eroding
igneous
and
metamorphic
rock),
and
metamorphic
(igneous
or
sedimentary
rock
that
has
undergone
change
due
to
heat
and
pressure).
Weathered
materials
are
derived
from
these
major
groups.

Rocks
are
"weathered"
by
a
twofold
process,
mechanical
weathering
(the
physical
Page
4
of
14
breakdown,
grinding,
of
the
rocks
into
smaller
pieces),
and
chemical
weathering
(the
breaking
of
the
chemical
bonds
between
elements).
Both
processes
operate
together,
each
assisting
the
other
in
the
slow
progress
of
decomposing
the
rock
to
materials
such
as
sands
and
clays
or
dissolving
the
rock
altogether
as
happens
when
water
flows
over
limestone.
The
smaller
the
rock
pieces,
the
greater
the
surface
area,
the
faster
the
breakdown.
Over
great
periods
of
time,
the
weathering
of
rocks
may
become
the
great
deposits
of
weathered
minerals
that
are
mined
or
become
part
of
the
soils
in
the
gardens
that
are
around
our
homes.

The
conditions
(climate)
under
which
this
weathering
occurs
can
determine
the
minerals
formed.
Feldspar
of
granite
(an
igneous
rock)
may
decay
to
form
kaolinite,
a
common
mineral
and
in
its
pure
form,
a
raw
material
for
everyday
pottery
and
china.
Under
certain
climatic
conditions,
kaolinite
will
dissolve
leaving
a
solid
residue
called
gibbsite.
Gibbsite
makes
up
the
great
deposits
of
bauxite,
the
earthy
ore
known
as
the
major
source
of
extractable
aluminum.
Phosphate
rocks
(marine
shale
and
limestones
enriched
in
phosphate
–
both
sedimentary
rocks)
are
the
major
raw
materials
of
the
fertilizer
industry,
but
are
also
components
of
the
natural
soils
along
the
coastal
plain
of
the
major
continents.

The
remnants
of
rock
are
all
around
us
in
our
daily
life:
they
are
the
materials
in
and
of
the
earth.
We
are
exposed
to
them
in
a
variety
of
ways
every
day.
It
is
the
decay
and
weathering
of
rocks
that
give
us
the
soils
in
which
we
grow
our
food
and
the
ore
deposits
that
provide
the
materials
of
everyday
life.

Ecotoxicity,
and
Environmental
Fate
and
Effects:

This
presentation
was
performed
by
Sid
Abel.

EFED's
hazard
characterization
was
based
on
the
fact
that
all
of
these
substances
are
naturally
occurring.
Since
these
are
naturally
occurring
substances,
no
adverse
environmental
effects
are
anticipated.

Toxicology
Data
This
presentation
was
performed
by
Kathryn
Boyle
(RD)
based
on
the
information
contained
in
the
previously
mentioned
websites.
A
brief
summation
of
the
available
information(
see
below)
was
given
for
each
of
the
groups.
If
available,
the
CAS
Reg.
No.
is
given
in
parenthesis.
Comments
made
during
the
discussion
that
pertained
only
to
a
specific
group
are
in
italics
below.
Current
List
classification
is
also
in
(italics).

1.
Calcium
carbonate
(471­
34­
1)
(4A):
The
weathered
materials
would
be:
chalk,
marble,
calcite
(13397­
26­
7),
limestone
(1317­
65­
3)(
4A),
magnesium­
lime,
and
could
even
include
oyster
shells
and
calcareous
shale.
Also
includes
dolomite
(16389­
88­
1)(
4A)
which
is
calcium
magnesium
carbonate.
­
No
concerns
identified
Page
5
of
14
2.
Carbon
in
various
forms:
Includes
carbon,
graphite
(7782­
42­
5)(
4A),
and
activated
charcoal
(7440­
44­
0).
­
Activated
charcoal
is
not
pure
carbon.
It
is
not
absorbed,
but
can
adsorb
other
drugs
and
chemicals
on
its
surface
­
Carbon
RED
1991
examined
carbon
and
graphite,
but
did
not
include
activated
charcoal.

3.
Gypsum
also
referred
to
as
natural
calcium
sulfate
(13397­
24­
5)
(4A),
plaster
of
paris
which
is
hydrated
calcium
sulfate
(26499­
65­
0),
and
calcium
sulfate
(7778­
18­
9)
(10101­
41­
4)(
4B):
­
Ingestion
of
plaster
of
paris
per
se
with
little
water
may
result
in
obstruction
with
resultant
surgical
removal
It
was
determined
that
this
type
of
ingestion
is
probably
not
a
concern
for
pesticide
products.
­
Irritant
­
Calcium
sulfate
is
the
most
common
of
the
naturally
occurring
sulfates
and
is
FDA
GRAS
­
Gypsum
is
used
to
treat
alkali
soils
Plaster
of
Paris
(total
dust),
calcium
sulfate
(total
dust),
and
gypsum
(total
dust)
Chemical
Sampling
Information
Cards
described
the
threshold
limit
value
for
all
three
chemicals
as
particulate
matter
containing
no
asbestos
and
less
than
1%
crystalline
silica.

4.
Lime
(12001­
27­
3)(
4A),
which
is
calcium
oxide
(1305­
78­
8)(
4B):
­
Dust
is
irritating
to
nose
and
throat
­
Some
inhalation
concerns
­
CaO
is
a
food
additive
(GRAS
with
no
limitations)
Can
be
purchased
for
non­
pesticidal
home
use
5.
Vermiculite
(hydrated
laminar
magnesium­
aluminum­
iron­
silicate)
(1318­
00­
9)(
4A)
There
can
be
asbestos
contamination:
Discussion
focused
on
ways
to
define
asbestos­
free
vermiculite.

After
the
first
meeting,
information
was
obtained
from
the
Schindler
Company
website
(www.
schundler.
com)
and
the
Agency's
Asbestos­
Contaminated
Vermiculite
Fact
Sheet.
Vermiculite
(a
hydrated
laminar
magnesium­
aluminum­
iron­
silicate),
like
most
other
naturallyoccurring
materials,
often
contain
a
range
of
other
minerals
including,
in
some
cases,
asbestos.
However,
it
is
known
that
only
a
few
vermiculite
deposits
contain
more
than
trace
amounts
of
asbestos.
(Example:
Libby)
EPA
has
tested
samples
of
vermiculite
to
determine
the
amounts
of
asbestos
present.
Most
samples
were
non­
detect
(no
detectable
levels
of
asbestos)
using
a
quantifiable
level
of
0.1
percent
by
weight.
The
vermiculite
industry
has
also
tested
various
vermiculite
ores
with
similar
results.

6.
Bentonite
(1302­
78­
9)(
4A)
or
Montmorillonite
Clay
(1318­
93­
0)(
4A):
Page
6
of
14
­
Practically
non­
toxic
­
Biologically
inert
when
ingested
­
Some
lung
irritation
(not
silicosis)
after
years
of
exposure
­
aka
Fuller's
earth
(8031­
18­
3)
(claylike
material
composed
primarily
of
montmorillonite);
low/
moderate
concern
(SAR)

7.
Attapulgite­
clay
(12174­
11­
7)(
4A)
(complex
metallic
(magnesium
aluminum)
silicate),
also
known
as
palygorskite:
­
Long
fibers
are
carcinogenic
(>
5
um)
when
inhaled
­
Short
fibers
are
not
carcinogenic
(<
5
um)
­
Medical
Uses
(activated
attapulgite)
­
Absorbent
in
pet
litter
­
Not
absorbed
from
GI
tract
­
has
colloidal
and
sorptive
properties
Discussion
focused
on
ways
to
check
the
fiber
size
8.
Kaolin
(1332­
58­
7)(
4A)
which
are
aluminum
silicates.
­
Inert
after
oral
administration
­
Medicinal
uses
­
Some
inhalation
concerns,
kaolinosis
­
Kaolin
RED
Kaolin
Chemical
Sampling
Information
Card
described
kaolin
as
not
classifiable
as
to
carcinogenicity,
with
the
comment
for
particulate
matter
containing
no
asbestos
and
less
than
1%
crystalline
silica
(respirable
fraction).

9.
Silicon
dioxide:
includes
crystalline
forms:
silica/
quartz
(14808­
60­
7),
cristobalite
(14464­
46­
1)(
3),
tridymite
(15468­
32­
3),
tripoli
(1317­
95­
9);
includes
amorphous
silica
(112926­
00­
8,
76313­
69­
5,
7631­
86­
9),
sand
(3),
diatomaceous
earth
(61790­
53­
2)(
4B),
granite,
vitreous
silica
(60676­
86­
0)(
4B)
and
silica
gel
(63231­
67­
4,
112926­
00­
8)(
4B).
­
Considered
to
be
inert
when
ingested
­
Crystalline
forms
are
carcinogenic
when
inhaled
from
occupational
sources
­
Cristobalite
is
moderate
concern
(SAR)
­
Silicosis
occurs
by
prolonged
and
extensive
exposure
to
respirable
free
crystalline
silica.
­
Food
additive/
feed
additive
Information
was
also
obtained
from
the
9
th
Report
on
Carcinogens
(revised
January
2001):
"Inhalation
of
excessive
levels
of
crystalline
silica
is
best
known
as
a
cause
of
pneumoconiosis,
an
occupational
lung
disease.
It
is
unclear
whether
the
carcinogenic
risk
of
crystalline
silica
is
because
it
is
a
traditional
carcinogen
that
interacts
with
nuclear
macromolecules
or
because
of
an
epigenetic
process
associated
with
cell
damage
and
healing."
Page
7
of
14
10.
Talc
(14807­
96­
6)(
3)
is
a
finely
powdered
magnesium
silicate
hydroxide,
also
known
as
steatite:
­
The
nonasbestiform
cosmetic
grade
was
determined
to
be
carcinogenic.
­
Talc
pneumoconiosis
­
Soapstone
(1343­
90­
4)(
4A)
is
a
granular
form
of
talc.
­
Pyrophyllite
(12269­
78­
2)(
4B)
is
a
hydrous
aluminum
silicate
with
a
structure
similar
to
that
of
talc;
it
is
a
color
additive
mixture
for
drugs
and
cosmetics
exempt
from
certification
Both
forms
of
talc
(asbestiform
and
non­
asbestiform)
have
been
proposed
for
review
for
listing
in
the
10
th
Report
on
Carcinogens.
Additional
information
was
found
on
the
NIOSH
Sampling
Guide
which
described
talc
as
"containing
no
asbestos
and
less
than
1%
quartz".
OSHA
Chemical
Sampling
Information
Cards
have
two
descriptions
of
talc
"containing
asbestos"
and
"containing
no
asbestos".
While
the
CAS
Reg.
Nos.
are
the
same,
the
descriptors
are
different,
with
the
first
being
described
as
carcinogenic,
and
the
second
being
described
as
not
classifiable
as
to
carcinogenicity,
with
the
comment
for
particulate
matter
containing
no
asbestos
and
less
than
1%
crystalline
silica
(respirable
fraction).
The
International
Chemical
Safety
Card
refers
to
"Talc
(exempt
de
silice
et
de
fibres)"

11.
Mica
(12003­
38­
2)(
4A)
(hydrated
potassium
aluminum
silicate)
and
feldspar
(potassium
aluminum
silicate)(
68476­
25­
5),
low/
moderate
concern
(SAR)
­
Pneumconiosis
The
OSHA
Chemical
Sampling
Information
Card
referred
to
a
value
for
particulate
matter
containing
no
asbestos
and
less
than
1%
crystalline
silica
(respirable
fraction).
Also,
a
different
CAS
Reg.
No.
was
referenced:
12001­
26­
2
12.
Zeolites
(3)

Zeolites
are
crystalline
alumino­
silicate
minerals
with
cage­
like
crystal
structures.
This
is
probably
the
most
extensive
family
of
minerals
in
the
earth's
crust.
(1318­
02­
1,
12173­
10­
3,
12271­
42­
0,
67240­
23­
7,
12173­
98­
7,
12445­
20­
4,
66732­
10­
3,
68652­
75­
5,
12174­
18­
4,
61027­
84­
7,
66733­
09­
3,
68989­
22­
0,
68989­
23­
1,
and
79982­
98­
2)
There
are
both
naturallyoccurring
and
synthetic
versions
of
zeolites.
Both
can
be
fibrous
or
non­
fibrous.
Terms
used
to
describe
zeolites
include
clinoptilolite,
mordenite,
and
phillipsite.
The
SAR
assessment
performed
by
OPPT
indicated
moderate
concern
for
the
68989­
22­
0
form
of
zeolite.

One
form,
erionite
(66733­
21­
9),
was
determined
to
be
carcinogenic,
by
IARC
(8
th
Annual
Report
on
Carcinogens).
Erionite
consists
of
crystals,
and
is
not
know
to
occur
in
other
than
fibrous
form.
When
administered
by
inhalation
erionite
induces
plural
mesotheliomas.
Natural
erionite
has
been
replaced
by
synthetic
non­
fibrous
zeolites.
Erionite
is
not
known
to
be
currently
in
use
in
the
US.
Page
8
of
14
13.
Refined
silicates
Refined
silicates
(both
hydrous
and
anhydrous
forms)
are
not
the
naturally
occurring
forms
of
silicate,
but
the
more
refined
chemicals
that
are
either
derived
from
the
naturally
occurring
forms
or
manufactured
specifically
through
the
reaction
of
other
chemicals
for
selling
in
commerce.
According
to
information
in
the
FDA's
GRAS
assessment
of
silicates,
there
are
at
least
30
to
40
silicate
compounds
that
could
be
consumed
by
humans.
Most
silicon
compounds
(except
potassium
and
sodium)
are
insoluble
or
only
slightly
soluble
in
water:
­
Sodium
(1344­
09­
8,
6834­
92­
0,
and
10213­
79­
3)(
4B)
forms
a
gelatinous
(very
alkaline)
mixture
in
water,
corrosive,
extreme
eye
irritant;
also
a
sodium
metasilicate
(10213­
79­
3,
13870­
28­
5,
and
15593­
82­
5)
which
is
more
caustic
than
sodium
­
Calcium
(1344­
95­
2)(
4B)
is
GRAS
with
limitations,
in
pharmaceuticals;
also
a
tricalcium
form
which
is
used
in
cement;
occurs
naturally
as
wollastonite
(13983­
17­
0)
moderate
concern
(SAR)
­
Magnesium
(14987­
04­
3,
1343­
88­
0,
13776­
74­
4,
and
1343­
90­
4)(
4B)
is
classified
as
practically
non­
toxic;
low/
moderate
concern
(SAR)
­
Sodium
aluminum
(12003­
51­
9
and
1344­
00­
9)
has
low
ecotoxicity,
negative
for
mutagenicity,
silicon
excreted
in
rats;
it
was
the
predominate
silicate
added
to
foods
in
the
US
in
1979;
low/
moderate
concern
(SAR)
­
Potassium
aluminum
(1327­
44­
2)
is
moderate
concern
(SAR)
­
Potassium
(1312­
76­
1)(
3)
­
Sodium
potassium
aluminum
(12736­
96­
8,
37244­
96­
5)(
3)
­
Aluminum
(1327­
36­
2)
is
low/
moderate
concern
(SAR);
hydrated
(1335­
30­
4)(
3)
­
Aluminum
calcium
silicate
­
Aluminum
magnesium
silicate
(1327­
43­
1)(
3)
­
Perlite
(93763­
70­
3)
(a
naturally
occurring
polysilicate/
glass)

14.
Refined
Oxides:
­
Metal
fume
fever:
produced
by
inhalation
of
metal
ions
at
high
temperatures
from
occupational
exposures
such
as
cutting
and
welding
Fumes
are
only
produced
at
high
temperatures.
Therefore,
should
not
be
a
concern
when
used
in
a
pesticide
product.
­
Zinc
(1314­
13­
2)(
4B)
is
also
known
as
C.
I.
pigment
white
4;
no
concerns
identified
in
SAR;
used
in
sunscreen
products
and
calamine
lotion;
positive
mutagenicity
results
were
reported
in
two
studies;
no
evidence
of
carcinogenicity
was
found
in
feeding
zinc
oxide
at
34.4
mg
zinc
per
day
to
rats
for
29
weeks;
in
rats
growth
is
retarded
at
1%
zinc
oxide
and
developmental
impacts
occurred
at
4000
ppm;
used
as
an
animal
feed
nutritional
supplement;
Zinc
Salts
RED
indicated
that
people
are
usually
not
exposed
to
such
large
amounts
of
zinc
through
the
diet
­
Aluminum
(1344­
28­
1)(
4B)
is
low/
moderate
(SAR)
for
health,
high
for
Page
9
of
14
ecotoxicity
(this
was
the
only
3)
­
Magnesium
(1309­
48­
4)(
4B)
is
low
concern
(SAR),
mutagenicity
studies
were
negative
­
Iron
also
known
as
rust
(1345­
25­
1,
1309­
37­
1,
1317­
61­
9
and
12259­
21­
1)(
4B)
is
low
concern
(SAR);
inhalation
if
iron
oxide
can
cause
siderosis
which
is
a
benign
condition
(takes
6
to10
years
to
get
and
can
be
slowly
cleared
from
rat
lungs;
IARC
monograph
­
not
classifiable
(Group
3)
­
Iron
magnesium
oxide
(12068­
86­
9)(
3)
­
Zinc
iron
oxide
(12063­
19­
3)(
3)

15.
Sulfur
(7704­
34­
9)
(3):
­
Used
as
a
fertilizer
or
soil
amendment
­
1991
RED
­
low
toxicity
­
EPA
designation
under
40
CFR
180.2
­
MSDS
indicates
airborne
exposure
limits
have
not
been
established.

Discussion
By
consensus,
the
group
determined
that
these
materials
are
generally,
with
some
exceptions,
low
toxicity
substances.
There
would
be
no
concerns
for
ecotoxicity,
or
for
most
dietary
or
dermal
human
exposure.
All
existing
tolerance
exemptions
can
be
reassessed.

However,
there
are
inhalation
concerns
for
some
of
these
substances.
Several
of
these
substances
have
suspected
or
documented
chronic
inhalation
exposure/
risk
issues
including
carcinogenicity,
silicosis
or
pneumoconiosis.
At
the
November
13
meeting,
the
IIFG
did
not
come
to
a
complete
conclusion
for
these
inhalation
concerns.
In
response
to
these
concerns,
Tom
Brennan
(HED)
researched
how
these
inhalation
exposure/
risk
concerns,
that
are
of
concern
in
industrial
settings,
might
translate
to
exposure/
risk
concerns
of
these
same
materials
used
as
an
inert
ingredients
in
pesticides.
His
analysis
is
summarized
in
the
paragraph
below:

Generally
mining,
processing,
packaging
and
transporting
weathered
materials
are
full
time
industrial
occupations
that
may
lead
to
daily
exposures
over
the
course
of
many
years.
These
industrial
activities
will
create
exposures
to
the
raw
(extracted)
product
as
well
as
more
refined
products.
It
is
very
likely
that
routine
worker
activities
will
create
the
possibility
of
routine
exposure
to
respirable­
sized
particles.
By
contrast,
mixing/
loading
and
applying
granular
or
dust
pesticide
products
that
have
these
same
weathered
materials
will
not
have
the
same
level
or
types
of
exposures.
The
first
major
difference
is
the
time
and
duration
of
exposure.
For
most
cases
the
pesticide
applicators
will
not
be
exposed
on
a
daily
basis.
In
fact,
it
is
much
more
likely
that
pesticide
applicators,
both
professional
operators
and
homeowners,
will
have
only
short­
term
exposures
(i.
e.,
those
occurring
for
1
day
to
a
month
–
over
a
year's
time).
Additionally,
the
applicator's
exposure
to
the
inert
ingredient
is
in
a
formulated
product
–
not
the
raw
weathered
material.
Page
10
of
14
Classification
of
an
inert
ingredient
to
List
4A
means
that
the
inert
can
be
used
in
25(
b)
deregulated
products,
without
the
need
for
acute
end­
product
toxicity
testing
for
the
Agency
to
determine
the
appropriate
labeling
language.
Thus,
List
4A
reclassification
requires
consideration
of
other
routes
of
exposure
for
the
pesticide
product.
The
List
4A
classification
would
depend
not
only
on
the
dietary
exposure,
but
also
on
the
likelihood
of
dermal
and/
or
inhalation
concerns.

There
is
various
information
from
OSHA/
NIOSH
(Occupational
Safety
and
Health
Administration/
National
Institute
for
Occupational
Safety
and
Health),
such
as
that
on
a
Chemical
Sampling
Information
Card
or
an
International
Safety
Card.
A
threshold
limit
value
(TLV)
s
is
a
limit
on
inhalation
exposure
in
the
workplace
(40
years,
usually
8
hours
per
day).
Generally
a
level
of
10
mg/
m
3
is
considered
to
be
a
nuisance
level
dust
standard,
which
implies
for
inhalation
concerns,
that
the
chemical
is
non­
toxic,
not
irritating.
TLVs
are
developed
exclusively
for
occupational
settings,
assuming
healthy
workers.
It
is
possible
that
the
general
public
could
be
more
susceptible.
IIFG
believes
that
TLVs
are
sufficient
for
use
as
benchmarks.

TLVs
and
other
endpoints
such
as
NIOSH
RELs
(recommended
exposure
limits)
or
OSHA
PELs
(permissible
exposure
limits)
were
obtained
from
various
sources
such
as
the
Chemical
Sampling
Information
Cards.
All
units
are
mg/
m
3
.
The
TWA
(time­
weighted
average)
is
usually
for
8
hours.
If
information
were
available
for
both
the
total
dust
and
the
respirable
dust,
then
the
total
dust
was
used.
(See
below)

attapulgite
not
established
bentonite
10
OSHA
PEL:
15
calcium
carbonate
10
(TWA)
NIOSH
REL:
10
(TWA)
calcium
oxide
2
NIOSH
REL:
2
calcium
silicate
NIOSH
REL:
10
(TWA)
calcium
sulfate
10
(TWA)
NIOSH
REL:
10
graphite,
natural
2
(TWA)
NIOSH
REL:
2.
5
(TWA)
graphite,
synthetic
15
(TWA)
gypsum
10
(TWA)
NIOSH
REL:
10
(TWA)
iron
oxide
not
established
kaolin
10
(TWA)
limestone
10
(TWA)
NIOSH
REL:
10
(TWA)
magnesium
oxide
10
(TWA
fume)
marble
10
(TWA)
NIOSH
REL:
10
(TWA)
mica
3
(TWA)
NIOSH
REL:
3
(TWA)
montmorillonite
not
established
perlite
10
(TWA)
sand
0.05
(TWA)
silica,
amorphous
10
silica,
amorphous,
NIOSH
REL:
6
(TWA)
diatomaceous
earth
silica,
amorphous,
NIOSH
REL:
6
(TWA)
Page
11
of
14
precipitated
and
gel
silica,
crystalline
cristobalite
0.
05
(TWA)
NIOSH
REL:
0.
05
(TWA)
silica,
crystalline
quartz
0.
1
(TWA)
NIOSH
REL:
0.
05
(TWA)
silica,
crystalline
tripoli
0.
1
(TWA)
NIOSH
REL:
0.
05
(TWA)
silica,
crystalline
tridymite
0.
05
(TWA)
NIOSH
REL:
0.
05
(TWA)
silica,
fused
0.
1
(TWA)
NIOSH
REL:
0.
05
(TWA)
silica,
quartz
NIOSH
REL:
0.05
(TWA)
soapstone
6
(TWA)
NIOSH
REL:
6
(TWA)
sodium
metasilicate
none
listed
sulfur
none
listed
talc
(asbestos
free)
2
(TWA)
NIOSH
REL:
2
(TWA)
talc
0.
1
fiber/
cc
(100
min
TWA)
vermiculite
not
established
zinc
oxide
10
(TWA)
NIOSH
REL:
5
(TWA)

At
the
December
18
meeting
the
group
discussed
using
information
such
as
TLVs
to
perform
a
screen
level
inhalation
assessment.
Kelly
O'Rourke
(HED)
developed
such
an
inhalation
screen
for
residential
exposures
for
comparison
with
TLVs.
Weathered
materials
are
oftentimes
used
as
solid
carriers
or
diluents.
Therefore,
for
these
screening
level
exposure
assessments
it
was
assumed
the
product
was
a
granular
formulation
and
that
the
weathered
material
comprised
100%
of
the
formulation.
Two
scenarios
were
considered:
broadcast
treatment
of
half
an
acre
taking
approximately
1
hour,
and
spot
treatment
of
1000
square
feet
taking
approximately
half
an
hour.
The
point
estimate
for
broadcast
treatment
is
0.
18
mg/
m
3
and
for
spot
treatment
is
0.6
mg/
m
3
.
It
was
necessary
to
convert
these
point
estimates
to
a
time
weighted
average
over
8
hours
for
comparison
to
time
weighted
averages
such
as
TLVs.
The
weighted
average
is
0.
023
mg/
m
3
for
broadcast
and
0.038
mg/
m
3
for
spot
treatment.
For
most
of
the
substances
the
estimated
weighted
averages
are
less
than
the
TLVs
by
at
least
two
orders
of
magnitude.
However,
for
some
substances
for
which
there
was
already
information
indicative
of
inhalation
concerns,
the
lowest
TLVs
(0.
05
mg/
m
3
and
0.
01
mg/
m
3
for
sand
and
various
crystalline
silicas)
are
in
the
range
of
the
estimated
weighted
averages.
Such
substances
would
not
be
considered
for
List
4A
classification.

There
was
also
a
concern
for
the
use
of
aluminum
oxide
due
to
aquatic
ecotoxicty.
According
to
the
OPPT
Chemical
Categories
Report,
soluble
salts
of
aluminum
are
known
to
be
highly
toxic
to
green
algae
and
moderately
toxic
to
fish
and
aquatic
invertebrates.
A
screening
level
assessment
was
performed
to
determine
the
maximum
application
rate
for
aluminum
oxide
to
avoid
exceeding
estimated
toxicity
endpoints
for
aquatic
organisms.
This
assessment
assumed
the
direct
application
of
a
pesticide
containing
aluminum
oxide
to
either
a
farm
pond
or
to
a
shallow
waterbody
or
wetland.
The
lowest
application
rate
that
would
not
exceed
a
level
of
concern
was
2.
1
pounds
of
aluminum
oxide
per
acre.
Aluminum
oxide
will
be
classified
as
List
4B.

IIFG
Recommendations
Page
12
of
14
By
consensus
there
were
no
objections
to
the
following:

All
existing
tolerance
exemptions
can
be
reassessed.
In
40
CFR
180.2
lime
and
sulfur.
In
40
CFR
180.1001(
c):
aluminum
oxide
,
attapulgite­
type
clay;
bentonite;
calcareous
shale;
calcite;
calcium
carbonate;
calcium
oxide;
calcium
silicate;
charcoal,
activated;
diatomite
(diatomaceous
earth);
dolomite,
granite,
graphite,
gypsum,
iron
oxide;
kaolinite­
type
clay;
magnesium
lime;
magnesium
oxide;
magnesium
silicate;
mica;
montmorillonite­
type
clay;
potassium
aluminum
silicate;
pyrophyllite;
sand;
silica,
hydrated;
soapstone;
sodium
aluminum
silicate;
sodium
metasilicate;
sodium
silicate;
talc;
vermiculite;
zeolite
(hydrated
alkali
aluminum
silicate);
and
zinc
oxide.
In
40
CFR
180.1001(
d):
graphite.
In
40
CFR
180.1001(
e):
attapulgite­
type
clay;
calcium
carbonate;
calcium
silicate,
hydrated
calcium
silicate;
calcium
sulfate;
diatomite
(diatomaceous
earth);
graphite;
iron
oxide;
kaolinite­
type
clay;
magnesium
silicate,
hydrated
magnesium
silicate;
montmorillonite­
type
clay;
silica,
hydrated
silica;
silica
aerogel
(finely
powdered
microcellular
silica
foam
having
a
minimum
silica
content
of
89.
5
%);
soapstone;
sulfur;
talc;
and
zinc
oxide.
Also
40
CFR
180.1017.

Tolerance
exemptions
maybe
established
for
those
chemicals
evaluated
for
which
there
is
not
currently
an
existing
exemption.

By
consensus
the
following
List
classifications
have
been
determined:

1.
Calcium
carbonate,
chalk,
marble,
calcite,
limestone,
magnesium
lime,
and
dolomite:
List
4A
based
on
the
fact
that
no
concerns
were
identified.

2.
Activated
charcoal:
List
4B
given
its
adsorptive
properties.
Carbon
and
graphite:
List
4A
given
the
properties
of
and
lack
of
toxicity
of
carbon.

3.
Gypsum,
plaster
of
paris,
and
calcium
sulfate:
List
4A
with
the
following
specification:
(no
asbestos,
less
than
1%
crystalline
silica).

4.
Lime:
List
4A
since
agricultural
lime
is
prepared
by
calcining
materials
consisting
largely
of
calcium
carbonate
such
as
limestone,
or
oyster,
clam
or
fossil
shells.
Carbon
dioxide
is
driven
off.
Thus,
agricultural
lime
contains
the
original
impurities
in
the
starting
materials.
This
material
is
openly
available
for
purchase
in
lawn
and
garden
centers.
Calcium
oxide:
List
4B
given
the
liberation
of
heat
and
dehydration
of
tissues
possible
from
this
more
refined
material.

5.
Vermiculite:
List
4A
with
the
following
specification:
no
asbestos,
less
than
1%
crystalline
silica
6.
Bentonite,
Montmorillonite
clay,
and
Fuller's
earth
:
List
4A
based
on
the
fact
that
no
concerns
were
identified.
Page
13
of
14
7.
Attapulgite
clay:
Reclassified
to
List
4B
based
on
carcinogenic
concerns
for
fibers
greater
in
length
than
5
um.

8.
Kaolin:
List
4A
based
on
the
RED,
with
the
following
specification:
(no
asbestos,
less
than
1%
crystalline
silica
(
respirable
fraction))

9.
Crystalline
forms
of
silica/
quartz
including
cristobalite,
tridymite,
and
tripoli:
List
4B
based
on
concerns
for
carcinogenicity
when
inhaled.
Granite:
List
4B
based
on
the
fact
that
it
contains
25
to
30%
quartz.
Silica
sand
and
flours:
List
4B
based
on
the
many
forms
and
varieties
available
which
contain
crystalline
quartz
in
various
amounts
Amorphous
silica,
vitreous
silica,
and
silica
gel:
List
4A
given
that
there
are
no
carcinogenic
concerns
for
non­
crystalline
forms
of
silica/
quartz.
Diatomaceous
earth:
List
4A
when
specified
as
silica,
amorphous,
diatomaceous
earth
(less
than
1%
crystalline
silica)

10.
Talc:
List
4B
based
on
concerns
for
carcinogenicity
in
the
NTP
study
which
was
performed
with
non
asbestiform
cosmetic
grade
talc,
with
the
following
specification
(no
asbestos,
less
than
1%
crystalline
silica
(
respirable
fraction))
Soapstone:
List
4A
given
that
it
is
a
granular
form
of
talc.
Pyrophillite:
List
4B
given
its
similarities
to
talc,
and
the
lack
of
information
on
its
carcinogenicity.

11.
Mica:
List
4A
with
the
following
specification
(no
asbestos,
less
than
1%
crystalline
silica
(
respirable
fraction)).

12.
Natural
and
synthetic
zeolites:
List
4A
with
an
exclusion
for
erionite
due
to
concerns
for
carcinogenicity.

13.
Sodium
silicate
and
sodium
metasilicate:
List
4B
given
the
corrosive,
caustic
nature
of
the
chemical.
Potassium
silicate:
List
4B
given
its
similarities
to
sodium
silicate.
Calcium
silicate:
List
4A
given
the
SAR
assessment,
the
low
ecotoxicity,
and
the
role
of
calcium
in
bone­
formation.
Magnesium
silicate:
List
4A
given
the
SAR
assessment,
the
low
ecotoxicity,
and
that
magnesium
is
an
essential
nutrient.
Aluminum
silicate:
List
4A
given
the
SAR
assessment
and
the
low
ecotoxicity.
Sodium
aluminum
silicate:
List
4A
given
its
low
ecotoxicity
and
the
SAR
assessment.
Potassium
aluminum
silicate:
List
4A
given
the
SAR
assessment
and
its
similarities
to
sodium
aluminum
silicate.
Sodium
potassium
aluminum
silicate:
List
4A
given
the
above
assessments.
Aluminum
calcium
silicate:
List
4A
based
on
the
assessments
for
aluminum
and
calcium.
Aluminum
magnesium
silicate:
List
4A
based
on
the
assessments
for
aluminum
and
Page
14
of
14
magnesium.
Perlite:
List
4A
with
the
following
specification:
(no
asbestos,
less
than
1%
crystalline
silica
(
respirable
fraction)).

14.
Zinc
oxide:
List
4A
given
the
SAR
assessment,
the
RED,
and
that
zinc
is
an
essential
nutrient.
Aluminum
oxide:
List
4B
given
that
the
SAR
assessment
is
low/
moderate
for
health
and
high
for
ecotoxicity
(this
was
the
only
3)
Magnesium
oxide:
List
4A
given
the
SAR
assessment
and
that
magnesium
is
an
essential
nutrient
Iron
oxide:
List
4A
given
the
low
concern
in
the
SAR
assessment
Iron
magnesium
oxide:
List
4A
based
on
the
assessments
for
iron
oxide
and
magnesium
oxide.
Zinc
iron
oxide:
List
4A
based
on
the
assessments
for
iron
oxide
and
zinc
oxide.

15.
Sulfur:
List
4A
based
on
the
low
toxicity,
the
fact
that
it
is
metabolized
in
the
body,
and
the
RED.