CANCER
ASSESSMENT
DOCUMENT
EVALUATION
OF
THE
CARCINOGENIC
POTENTIAL
OF
LINDANE
PC.
Code:
009001
Final
Report
November
29,
2001
CANCER
ASSESSMENT
REVIEW
COMMITTEE
HEALTH
EFFECTS
DIVISION
OFFICE
OF
PESTICIDE
PROGRAMS
ii
DATA
PRESENTATION:
Suhair
Shallal,
Toxicologist
DOCUMENT
PREPARATION:
Sanjivani
Diwan,
Executive
Secretary
COMMITTEE
MEMBERS
IN
ATTENDANCE:
(Signature
indicates
concurrence
with
the
assessment
unless
otherwise
stated).

Karl
Baetcke
William
Burnam
Marion
Copley
Kerry
Dearfield
Vicki
Dellarco
Virginia
Dobozy
Richard
Hill
Yiannakis
Ioannou
Tim
McMahon
Nancy
McCarroll
Esther
Rinde
Jess
Rowland
Joycelyn
Stewart
Clark
Swentzel
Linda
Taylor
Yin­
Tak­
Woo
NON­
COMMITTEE
MEMBERS
IN
ATTENDANCE
(Signature
indicates
concurrence
with
the
pathology
report
and
statistical
analysis
of
data,
respectively)
John
M.
Pletcher,
Pathology
Consultant
Lori
Brunsman,
Statistical
Analysis
ii
CONTENTS
ExecutiveSummary.............................................................
.iii
I.
Introduction...............................................................
..
1
II.
BackgroundInformation
...................................................
1
III.
Evaluation
of
Carcinogenicity
...............................................
2
1.
CombinedChronicToxicity&
CarcinogenicityStudyinCD­
1Mice..............
2
2.
CarcinogenicityStudyinAgouti,
PseudoAgoutiandBlackMice................
7
3.
NTPCarcinogenicityStudyinB6C3F1Mice
...............................
8
4.
CarcinogenicityStudyinWistarRats
....................................
11
5.
NTPChronicToxicity&
CarcinogenicityStudyinOsborne­
MendelRats.........
13
IV.
Toxicology............................................................
14
1.
Metabolism
.......................................................
14
2.
Mutagenicity
......................................................
15
3.
StructureActivityRelationship.........................................
16
4.
SubchronicandchronicToxicity
.......................................
16
5.
ModeofActionStudies
..............................................
18
V.
Committee'sAssessmentoftheWeight­
of­
theEvidence
..........................
19
VI.
ClassificationofCarcinogenicPotential
.......................................
22
VII.
QuantificationofCarcinogenicPotential.......................................
22
V.
Bibliography...........................................................
23
LINDANE
CANCER
ASSESSMENT
DOCUMENT
FINAL
REPORT
iii
EXECUTIVE
SUMMARY
Lindane
(gamma
isomer
of
hexachlorocyclohexane,
 
­HCH)
has
been
previously
classified
by
the
Cancer
Assessment
Group
of
the
Office
of
Research
and
Development
(CAG/
ORD,
1985)
as
a
group
"B2/
C"
carcinogen
based
on
an
increased
incidence
of
mouse
liver
tumors.
In
1993,
the
RfD/
Peer
Review
Committee
(1993)
determined
that
the
mouse
carcinogenicity
data
were
inadequate
because
of
major
deficiencies
associated
with
the
available
studies.
The
Toxicology
Endpoint
Selection
(TES)
Committee
concluded
that
a
new
carcinogenicity
study
in
mice
was
needed
to
make
a
determination
of
the
carcinogenic
potential
of
lindane
(
TES,
1994).

On
May30,
2001,
the
Cancer
Assessment
ReviewCommittee
(CARC)
of
the
Health
Effects
Division
(HED)
of
the
Office
of
Pesticide
Programs
met
to
evaluate
the
carcinogenic
potential
of
lindane.
At
this
meeting,
the
CARC
could
not
make
a
determination
of
the
carcinogenic
potential
of
lindane
because
the
NTP
studies
were
limited
in
value
and
it
was
uncertain
if
the
study
on
Agouti,
Pseudoagouti
and
Black
mice
with
limited
data
could
be
used
for
regulatory
purposes.
In
addition,
the
CARC
was
informed
that
new
histopathology
data
would
be
submitted.
The
Committee
also
requested
additional
information
including
results
of
a
90­
day
subchronic
range­
finding
study
in
CD1
mice,
an
earlier
RfD
Committee
report
and
analyses
of
the
older
studies
on
lindane.

At
the
September
13,
2001
meeting,
the
Committee
reevaluated
all
the
available
information/
data
including
the
old
and
the
newly
gathered
information
that
was
previously
not
available
for
review.
[A
list
of
CARC
members
who
attended
one
or
both
meetings
on
lindane
is
presented
on
page
#
i.
These
meetings
were
held
jointly
by
teleconference
with
Pesticide
Management
Regulatory
Agency
(PMRA),
HealthCanada,
Canada].
The
chronic
toxicity/
carcinogenicitystudies
were
conducted
using
5
different
strains
of
mice
and
two
strains
of
rats.
The
dietary
doses
administered
in
these
studies
were
as
follows:

·

CD­
1
mice
(50/
sex/
dose):
0,
10,
40,
or
160
ppm.
for
78
weeks
(0,
1.3,
5.2,
and
21
mg/
kg/
day
for
males
and
0,
1.
8,
7.
1,
and
26.
8
mg/
kg/
day
for
females,
respectively).


Female
Agouti,
Pseudoagouti
and
Black
mice
(36­
96
animals
per
strain):
0
or
160
ppm.
for
24
months

B6C3F1
mice
(50
/sex/
dose):
0,
80
or
160
ppm
for
80
weeks

Wistar
rats
(50/
sex/
dose):
0,
1,
10,
100,
or
400
ppm
for
2
years
(
0,
0.05,
0.47,
4.81,
and
19.66
mg/
kg/
day
for
males
and
0,
0.06,
0.59,
6.00,
and
24.34
mg/
kg/
day
for
females,
respectively).


Osborne­
Mendel
rats
(50/
sex/
dose):
For
males:
320
or
640
ppm
for
38
weeks
and
160
or
320
ppm
for
the
remaining
42
weeks.
For
females:
320
or
640
ppm
for
2
weeks
and
160
or
320
ppm
for
49
weeks
then
for
the
remaining
29
weeks
the
dose
was
lowered
to
80
or
160
ppm.
Matched
controls
consisted
of
10/
sex.
LINDANE
CANCER
ASSESSMENT
DOCUMENT
FINAL
REPORT
iv
The
CARC
concluded
that
lindane
was
carcinogenic
only
to
female
CD­
1
mice
based
on
the
following:

!
CD­
1
female
mice
had
significant
increasing
trends,
and
significant
differences
in
the
pair­
wise
comparisons
of
the
160
ppm(
26.8
mg/
kg/
day)
dose
group
with
the
controls,
for
lung
alveolarbronchiolar
adenomas
and
combined
adenomas/
carcinomas,
all
at
p
<
0.
05.
The
incidence
of
lung
adenomas
was
slightly
outside
the
historical
control
range.
However,
the
increased
incidence
of
carcinomas
was
not
dose­
dependent
and
the
tumor
response
was
variable.
Lindane
was
not
carcinogenic
to
male
mice.
The
dosing
at
the
highest
level
was
adequate
and
not
excessive
based
on
increased
incidences
of
centrilobular
hepatocellular
hypertrophy
and
eosinophilic
foci
of
cellular
alteration
in
males
and
a
slight
increase
in
bronchiolar­
alveolar
adenomas
in
females.

!
At
160
ppm,
both
the
treated
female
Agouti
and
Pseudoagouti
mice
had
an
increase
in
benign
lung
adenomas;
the
treated
Agouti
mice
also
had
an
increased
incidence
of
liver
adenomas.
No
statistical
analyses
of
tumor
data
were
conducted.
There
was
no
increase
in
the
incidence
or
decrease
in
latency
period
for
liver
tumors
in
Black
and
Pseudoagouti
strains
of
mice.
There
was
evidence
of
increased
liver
weights
and
an
increased
incidence
of
Clara
cell
hyperplasia
in
Agouti
and
Black
strains
of
mice.
However,
the
study
was
conducted
on
few
animals,
only
a
single
dose
and
sex
were
tested,
no
statistical
analyses
of
tumor
data
were
presented
and
the
results
of
the
study
were
not
adequately
reported.
The
Committee
concluded
that
although
the
liver
effects
appear
to
suggest
that
a
dose
of
160
ppm
was
adequate,
additional
dose
groups
could
have
provided
confirmatory
information.

!
The
CARC
could
not
assess
the
carcinogenicity
of
lindane
in
B6C3F1
male
and
female
mice
because
the
data
reporting
was
inadequate
and
there
were
no
indications
of
toxicity
in
high
dose
females.
Moreover,
the
use
of
only
10
mice
per
sex
for
the
control
group
compromised
the
usefulness
of
the
study.

The
Committee
concluded
that
the
increased
incidence
of
lung
tumors
in
female
mice
of
three
strains
was
treatment­
related
because
the
statistically
significant
increase
in
lung
adenomas
in
female
CD­
1
mice
was
corroborated
with
the
increase
in
lung
tumors
in
two
genetically
susceptible
strains
of
mice.
Although
there
is
some
evidence
of
liver
tumor
induction
in
these
genetically
susceptible
strains
of
mice,
no
evidence
of
liver
tumors
was
noted
in
CD­
1
mice.
Nevertheless,
the
evidence
of
hepatotoxicity
(increased
liver
weight,
hypertrophy
and
increased
incidence
of
liver
foci
in
both
sexes)
and
promoting
activity,
indicates
t
hat
t
he
liver,
in
addition
to
lung
is
a
major
target
organ
of
toxicity.

!
The
CARC
determined
that
lindane
was
not
carcinogenic
to
male
and
female
Wistar
rats
and
the
results
of
the
study
in
Osborne
Mendel
rats
were
difficult
to
interpret
and
were
not
useful
in
determining
the
carcinogenic
potential
of
lindane
in
that
strain
of
rat.

!
The
results
of
a
battery
of
acceptable
mutagenicity
assays
indicate
that
lindane
has
a
low
LINDANE
CANCER
ASSESSMENT
DOCUMENT
FINAL
REPORT
v
concern
for
mutagenicity.
These
studies
satisfy
pre­
1991
FIFRAguideline
requirements.
The
Committee
recommended
that
the
dominant
lethal
assay
be
repeated
to
determine
if
there
is
a
genetic
component
to
the
reproductive
(germ
cell)
effects
reported
for
lindane.

!
The
technical
HCH
and
the
alpha­
isomer
are
classified
as
category
"B2"
(probable
human
carcinogen).
The
beta­
isomer
is
classified
as
a
group
"C
"(
possible
human
carcinogen)
while
the
delta
and
epsilon
isomers
are
classified
as
group
"D"
(not
classifiable
as
to
human
carcinogenicity)
.

!
No
mechanistic
studies
were
submitted
to
support
the
mode
of
action
for
lung
tumor
induction
in
mice.

In
accordance
with
the
EPADraft
Guidelines
for
Carcinogen
Risk
Assessment
(July,
1999),
the
CARC
classified
lindane
into
the
category
"Suggestive
evidence
of
carcinogenicity,
but
not
sufficient
to
assess
human
carcinogenic
potential"
because
lindane
caused
an
increased
incidence
of
benign
lung
tumors
in
female
mice
only.
The
Committee
further
recommended
that
quantification
of
human
cancer
risk
is
not
required.
LINDANE
CANCER
ASSESSMENT
DOCUMENT
FINAL
REPORT
1
Cl
Cl
Cl
Cl
Cl
Cl
I.
INTRODUCTION
Lindane
(gamma
isomer
of
hexachlorocyclohexane,
 
­HCH)
was
previously
classified
by
the
Cancer
Assessment
Group
of
the
ORD
(1985)
as
a
group
"B2/
C"
carcinogen
based
on
an
increased
incidence
of
mouse
liver
tumors;
the
calculated
unit
risk
(
Q1*)
was
1.
1
(mg/
kg/
day)
­1
human
equivalents.
The
other
isomers
of
hexachlorocyclohexane
are
classified
in
IRIS.
Technical
HCH
and
the
alpha­
isomer
are
classified
as
"B2",
probable
human
carcinogens.
The
beta­
isomer
is
classified
as
"C",
possible
human
carcinogen.
The
delta
and
epsilon
isomers
are
classified
as
D,
not
classifiable
as
to
human
carcinogenicity.

In
1993,
the
RfD/
Peer
Review
Committee
determined
that
the
mouse
carcinogenicity
data
were
insufficient
because
of
major
deficiencies
associated
with
all
available
studies.
The
TES
committee
concluded
that
a
new
carcinogenicity
study
in
mice
was
needed
to
make
a
determination
of
the
carcinogenic
potential
of
lindane
(TES,
1994).

On
May
30,
2001,
the
HED
Cancer
Assessment
Review
Committee
(CARC)
of
the
Health
Effects
Division
(HED)
of
the
Office
of
Pesticide
Programs
met
to
evaluate
the
carcinogenic
potential
of
lindane.
At
this
meeting,
the
CARC
could
not
make
a
determination
of
the
carcinogenic
potential
of
lindane
because
the
NTP
studies
were
limited
in
value
and
the
published
study
on
Agouti,
Pseudoagouti
and
Black
mice
could
not
be
used
for
regulatory
purposes.
The
Committee,
therefore,
requested
additional
information
including
results
of
a
90­
day
subchronic
range­
finding
studyin
CD­
1
mice,
an
earlier
RfD
Committee
report
and
analyses
of
the
older
studies
on
lindane.
At
the
September
13,
2001
meeting,
the
Committee
met
to
reevaluate
the
carcinogenic
potential
of
lindane
based
on
the
available
old
and
new
information/
data.
At
this
meeting,
information/
data
were
presented
by
Dr.
Suhair
Shallal
of
Reregistration
Branch
4.
These
data
included
a
new
mouse
carcinogenicity
study
in
CD­
1
mice
submitted
by
the
registrant,
a
published
study
in
Agouti,
Pseudoagouti
and
Black
mice,
NCI
studies
in
B6C3F1
mice
and
Osborne­
Mendel
rats
and
a
2­
year
chronic/
carcinogenicity
study
in
Wistar
rats.
In
addition,
carcinogenicity
and
genetic
toxicology
data
on
structurally­
related
compounds
were
presented.

II.
BACKGROUND
INFORMATION
Lindane
(PC.
Code
is
009001
and
CAS
Number
is
58­
89­
9)
is
a
broad­
spectrum
organochlorine
compound
used
on
a
wide
range
of
soil­
dwelling
and
plant­
eating
(phytophagous)
insects.
Its
chemical
structure
is
provided
below.

Figure
1.
Chemical
Structure
of
 
­HCH
LINDANE
CANCER
ASSESSMENT
DOCUMENT
FINAL
REPORT
2
The
technical
HCH
consists
of
 
­isomer:
65­
67%
,
 
­isomer:
11­
13%,

­isomer:
13­
15%
,
 
­isomer:
3­
5%,
 
­isomer:
4­
6%
and
other
isomers:
<1%.
Lindane
is
a
­
isomer
(1   
2   
3
4 ,
5 ,
6  
hexachlorocyclohexane).
The
other
isomers
are:
 
­isomer
(1   
2   
3
4 ,
5 ,
6  
hexachlorocyclohexane);
 
­isomer
(1   
2
3   
4 ,
5 ,
6  
hexachlorocyclohexane);
 
­isomer
(1   
2   
3   
4 ,
5 ,
6  
hexachlorocyclohexane)
and
 
­isomer:
(1   
2   
3   
4 ,
5 ,
6  
hexachlorocyclohexane).

Worldwide,
lindane
is
commonly
used
on
a
wide
variety
of
crops,
in
warehouses,
in
public
health
to
control
insect­
borne
diseases,
and
(with
fungicides)
as
a
seed
treatment.
Lindane
is
also
presently
used
in
lotions,
creams,
and
shampoos
for
the
control
of
lice
and
mites
(scabies)
in
humans;
these
pharmaceutical
uses
are
regulated
by
FDA.
In
the
U.
S.,
the
only
registered
food/
feed
use
is
seed
treatment
for
field
and
vegetable
crops.

Lindane
may
be
found
in
formulations
with
a
host
of
fungicides
and
insecticides.
Labels
for
products
containing
the
chemical
must
bear
the
Signal
Word
WARNING.
Some
formulations
of
lindane
are
classified
as
Restricted
Use
Pesticides
(RUP),
and
as
such
may
only
be
purchased
and
used
by
certified
pesticide
applicators.
Lindane
is
no
longer
manufactured
in
the
U.
S.,
and
most
agricultural
and
dairy
uses
have
been
canceled
because
of
concerns
about
its
potential
carcinogenicity.

III.
EVALUATION
OF
CARCINOGENICITY
STUDIES
1.
Combined
Chronic
Toxicity/
Carcinogenicity
Study
with
Lindane
in
CD­
1
Mice
Reference:
Lindane,
carcinogenicity
study
by
dietary
administration
to
CD­
1
mice
for
78
weeks
(2000),
final
report
(vols.
1­
4).
Huntingdon
Life
Sciences
Ltd.,
Woolley
Road,
Alconbury,
Huntingdon,
Cambridgeshire,
PE28
4HS,
England,
Report
no.
00
3512,
Huntingdon
Life
Sciences
Project
identity
no.
CIL/
021,
MRID
45291402.

Experimental
Design
Lindane
(99.78%
a.
i.,
batch
no.
HLS
96/
1)
was
administered
to
groups
of
50
Crl:
CD­
1
®

(ICR)
BR
mice/
sex/
dose
in
the
diet
at
concentrations
of
0,
10,
40,
or
160
ppm.
The
test
diets
were
given
for
78
weeks.
The
concentrations
of
10,
40,
or
160
ppm
resulted
in
mean
daily
compound
intakes
for
males
of
1.
3,
5.
2,
and
21
mg/
kg/
day
and
for
females
of
1.8,
7.1,
and
27
mg/
kg/
day,
respectively.

Discussion
of
Tumor
Data
Tumor
Analyses
As
shown
in
Table
1.
there
was
no
statistically
significant
increase
in
tumors
in
male
mice
(Brunsman,
2001).
The
incidence
of
liver
tumors
was
not
statistically
significant
in
either
male
or
female
CD­
1
mice(
Table
1).

Table
1.
CD­
1
Mice­
Male
and
Female
Liver
Tumor
Rates
+
and
Exact
Trend
Test
and
Fisher's
LINDANE
CANCER
ASSESSMENT
DOCUMENT
FINAL
REPORT
3
Exact
Test
Results
(p
values)­
(Brunsman
2001)

ppm
0
10
40
160
0
10
40
160
mg/
kg/
day
0
1.
3
5.2
20.5
0
1.8
7.
1
26.8
Males
females
Tumor
Type
Liver
Tumor
Adenoma
%
p
=
10
a
/48
(21)
0.1730
10/
46
(22)
0.5570
9/
43
(21)
0.5962
13/
46
(28)
0.2752
0/
47
(0)
0.2567
0/
45
(0)
1.000
0/
47
(0)
1.000
1
a
/48
(2)
0.5053
Carcinoma
%
p
=
4/
48
(8)
0.4046
1/
46
(2)
0.1943
1/
43
(2)
0.2167
2
b
/46
(4)
0.3592
No
carcinomas
were
observed
in
females
Combined
%
p
=
13/
48
(27)
0.1817
11/
46
(24)
0.4543
10/
43
(23)
0.4304
15/
46
(33)
0.3594
+
Number
of
tumor
bearing
animals/
Number
of
animals
examined,
excluding
those
that
died
before
week
53.
a
First
adenoma
observed
in
males
at
week
67,
dose
0
ppm;
First
adenoma
observed
in
females
at
week
80,
dose
160
ppm
b
First
carcinoma
observed
in
males
at
week
53,
dose
10
ppm;
no
carcinomas
were
observed
in
females.

Note:
Significance
of
trend
denoted
at
control.
Significance
of
pair­
wise
comparison
with
control
denoted
at
dose
level.

If
*
,
then
p
<
0.05.
If
**
,
then
p
<
0.01.

Treatment
for
up
to
78
weeks
with
lindane
resulted
in
a
statistically
significant
increase
in
the
incidence
of
bronchiolar­
alveolar
adenomas
and
an
increased
incidence
of
carcinomas
in
female
Crl:
CD­
1
mice;
however,
the
increased
incidence
of
carcinomas
was
not
dosedependent
and
tumor
response
was
variable.
Female
mice
had
significant
increasing
trends
and
significant
differences
in
the
pair­
wise
comparisons
of
the
160
ppm
dose
group
with
the
controls
for
lung
alveolar­
bronchiolar
adenomas
and
combined
adenomas/
carcinomas,
all
at
p
<
0.
05
(Table
2a).
The
incidence
of
pulmonary
adenomas
in
the
control
group
was
at
the
low
end
of
the
range
in
historical
controls
(6%)
and
the
incidence
in
females
administered
the
high
dose
(23%)
was
slightly
outside
of
the
high
end
of
the
range
for
the
historical
controls
(6%­
19%)
(MRID
45291402).

.

Table
2a.
Male
and
Female
Lung
Alveolar­
Bronchiolar
Tumor
Rates
+
and
Exact
Trend
Test
and
Fisher's
Exact
Test
Results
(p
values)­
Initial
Diagnosis
(Brunsman,
2001)
LINDANE
CANCER
ASSESSMENT
DOCUMENT
FINAL
REPORT
4
ppm
0
10
40
160
0
10
40
160
mg/
kg/
day
0
1.
3
5.2
20.5
0
1.8
7.
1
26.8
males
females
Tumor
Type
Lung
Alveolar­
Bronchiolar
Tumors
Adenoma
%
p
=
16
a
/49
(33)
0.0270*
n
15/
48
(31)
0.5278
11/
49
(22)
0.1830
8/
48
(17)
0.0554
3
a
/48
(6)
0.0274
*
7/
46
(15)
0.1412
7/
47
(15)
0.1497
11/
48
(23)
0.0200
*

Carcinoma
%
p
=
0/
49
(0)
0.3138
1/
48
(2)
0.4948
3
b
/49
(6)
0.1211
0/
48
(0)
1.0000
1/
48
(2)
0.4361
2
b
/46
(4)
0.4839
2/
47
(4)
0.4920
1/
48
(2)
0.7526
Combined
%
p
=
16/
49
(33)
0.0186*
n
16/
48
(33)
0.5574
14/
49
(29)
0.4134
8/
48
(17)
0.0554
4/
48
(8)
0.0389
*
8/
46
(17)
0.1573
9/
47
(19)
0.1080
12/
48
(25)
0.0264
*

a
first
adenoma
observed
in
males
at
week
33,
dose
0
ppm
and
in
females
at
week
44,
dose
0
ppm
b
first
carcinoma
observed
males
at
week
65,
dose
40
ppm
and
in
females
at
week
53,
dose
10
ppm
n
Negative
trend
Note:
Significance
of
trend
denoted
at
control.
Significance
of
pair­
wise
comparison
with
control
denoted
at
dose
level
If
*
,
then
p
<
0.05.
If
**
,
then
p
<
0.01.

A
new
report
on
the
results
of
resectioning
of
lungs
of
female
mice
was
later
submitted
by
the
Registrant
(MRID
45470601).
The
results
showed
the
presence
of
two
additional
pulmonary
adenomas
in
the
controls
and
two
in
the
high
dose
group.
The
number
of
pulmonary
adenomas
and
combined
adenomas/
carcinomas
in
Group
4
remained
still
statistically
significant
(Table
2b),
and
was
biologically
significant,
being
well
above
the
historical
control
range
for
this
strain
of
mouse.
The
incidence
in
the
controls
and
in
the
two
intermediate
dose
groups
was
within
the
historical
control
range
(6%­
19%)
for
pulmonary
adenomas
in
CD­
1
females.
It
is,
however,
difficult
to
compare
old
tumor
data
versus
the
combined
analyses
based
on
the
old
and
new
findings
without
knowing
the
exact
procedure
involved
in
resectioning
the
lungs
and
why
resectioning
of
the
lung
tissue
was
necessary.
Therefore,
without
judging
the
validity
of
the
new
sectioning
versus
the
original
report,
the
end
results
appear
to
be
the
same.

Table
2b.
Lindane
­
CD­
1
Mouse
Study
Female
Lung
Alveolar­
Bronchiolar
Tumor
Rates
+
[Additional
Histopathology
PLUS
LINDANE
CANCER
ASSESSMENT
DOCUMENT
FINAL
REPORT
5
Original
Diagnoses]
and
Exact
Trend
Test
and
Fisher's
Exact
Test
Results
(p
values)­
Results
of
Re­
sectioning
(Brunsman,
2001)

Dose
(ppm)

0
10
40
160
Adenomas
5
a
/48
7/
46
7/
47
13/
48
(%)
(10)
(15)
(15)
(27)

p
=
0.0165*
0.3492
0.3644
0.0326*

Carcinomas
1/
48
2
b
/46
2/
47
1/
48
(%)
(2)
(4)
(4)
(2)

p
=
0.4361
0.4839
0.4920
0.7526
Combined
6/
48
8/
46
9/
47
14/
48
(%)
(12)
(17)
(19)
(29)

p
=
0.0235*
0.3535
0.2723
0.0384*

+
Number
of
tumor
bearing
animals/
Number
of
animals
examined,
excluding
those
that
died
before
week
44.

a
First
adenoma
observed
at
week
44,
dose
0
ppm.

b
First
carcinoma
observed
at
week
53,
dose
10
ppm.

Note:
Significance
of
trend
denoted
at
control.
Significance
of
pair­
wise
comparison
with
control
denoted
at
dose
level.
If
*
,
then
p
<
0.05.
If
**
,
then
p
<
0.01.

Non­
Neoplastic
Lesions
At
78
weeks,
there
were
increases
in
the
incidences
of
centrilobular
hepatocyte
hypertrophy
(control,
6%;
160
ppm,
30%;
p<
0.
01)
and
eosinophilic
focus/
foci
of
hepatocellular
alteration
(control,
4%;
160
ppm,
16%;
p<
0.05)
in
high­
dose
males
compared
to
the
control
group
(Table
3).
No
microscopic
liver
changes
were
seen
in
females
Table
3.
Non­
Neoplastic
Lesions
in
CD­
1
Mice
Fed
Lindane
LINDANE
CANCER
ASSESSMENT
DOCUMENT
FINAL
REPORT
6
Dose
(ppm)
0
10
40
160
0
10
40
160
mg/
kg/
day
0
1.
3
5.2
20.5
0
1.8
7.
1
26.8
males
females
centrilobular
hepatocyte
hypertrophy
3/
50
2/
50
7/
50
15/
50
0/
50
0/
50
0/
50
0/
50
eosinophilic
focus/
foci
of
hepatocyte.
alterations
2/
50
1/
50
5/
50
8/
50
0/
50
0/
50
0/
50
0/
50
lung
epithelial
hyperplasia
1/
50
1/
50
1/
50
2/
50
1/
50
0/
50
0/
50
2/
50
lung
congestion
16/
50
12/
50
16/
50
11/
50
6/
50
13/
50
8/
50
13/
50
Thyroid­
dilated
follicles
9/
49
4/
16
3/
16
14/
50
2/
50
1/
19
0/
17
3/
50
LN
Bronchial­
increased
cellularity
1/
16
0/
17
1/
15
0/
11
0/
12
1/
15
2/
15
3/
14
Adequacy
of
the
Dosing
for
Assessment
of
Carcinogenicity
There
was
no
significant
change
in
body
weight
and
the
survival
analyses
indicated
no
statistically
significant
incremental
changes
with
increasing
doses
of
lindane
in
male
or
female
mice
(Brunsman,
2001).
All
dose
groups
and
controls
had

68%
survival
at
study
termination.

Histopathologyrevealed
an
increased
incidence
of
liver
lesions
in
male
mice.
The
LOAEL
was
160
ppmfor
males
(20.5
mg/
kg/
day)
and
females
(26.8
mg/
kg/
day)
based
on
liver
hypertrophy
in
males
and
a
slight
increase
in
bronchiolar­
alveolar
adenomas
in
females.

The
doses
selected
for
the
above
chronic/
carcinogenicity
study
were
based
on
the
results
of
a
range­
finding
subchronic
toxicity
study
(MRID
45424301).
In
this
study,
lindane
(99.78%
a.
i.)
was
administered
to
10
CD­
1
mice/
sex/
dose
at
dietary
levels
of
0,
40,
80,
160,
320
ppm
(0,
5.
7,
12.2,
22.8
and
46.2
and
0,
8.9,
16.0,
32.9,
and
62.6
mg/
kg/
day
in
males
and
females,
respectively).
Body
weight
gain
was
reduced
by
27%
in
males
and
9%
in
females
at
the
highest
dose.
The
four
females
in
the
highest
dose
(320
ppm)
group
that
died
during
treatment
period
had
hepatocellular
hypertrophy
and
karyomegaly
in
the
liver
and
Clara
cell
hypertrophy
as
well
as
congestion
in
the
lungs.
These
findings
were
also
seen
in
treated
animals
in
the
160
and
320
ppm
dose
groups
that
were
sacrificed
at
study
termination;
therefore,
these
deaths
were
considered
to
be
treatment­
related.
The
early
deaths
in
the
320
ppmdose
group
indicate
that
this
dose
was
excessive.
Based
on
the
results
of
this
study
the
majority
of
the
CARC
concluded
that
the
dose
levels
of
0,
10,
40
160
ppm
selected
for
the
two­
year
carcinogenicity
study
in
mice
appeared
to
be
adequate.
However,
a
few
members
felt
that
the
animals
could
have
tolerated
a
higher
dose,
based
on
the
results
of
chronic
study.

2.
Combined
Chronic
Toxicity/
Carcinogenicity
Study
with
Lindane
in
Agouti,
Pseudoagouti
and
Black
Mice
LINDANE
CANCER
ASSESSMENT
DOCUMENT
FINAL
REPORT
7
Reference:
Wolff,
G.
L.
et
al.
Tumorigenic
responses
to
lindane
in
mice:
potentiation
by
a
dominant
mutation,
NCTR,
Jefferson,
AR
;
Carcinogenesis
8(
12):
1889­
97
(1987).

Experimental
Design
In
an
NCI
study,
three
strains
of
female
mice,
Agouti,
Pseudoagouti,
and
Black,
were
administered
lindane
at
dietary
concentrations
of
0
or
160
ppm.
Groups
of
36­
96
animals
per
strain
were
continuously
fed
treated
or
control
diets
for
up
to
24
months.
Additional
groups
of
48­
96
Agouti
and
Black
mice
were
fed
treated
or
control
diets
for
6
months
and
then
fed
control
diet
for
6
or
18
months
(recovery).

Tumor
Analysis:

No
evidence
for
an
increased
incidence
or
a
decreased
latency
of
liver
tumors
was
observed
for
the
black
strain
at
any
time
during
the
24
months
of
study
or
for
the
Pseudoagouti
strain
through
the
18
month
sacrifice.
At
18
months,
0/
34
control
and
12/
36
(33%)
of
the
treated
Agouti
mice
developed
hepatocellular
adenomas;
one
carcinoma
each
in
the
treated
and
control
groups
was
noted.
Both
the
treated
Agouti
and
Pseudoagouti
strains
had
clear
increases
in
adenomas
and
slight
increases
in
carcinomas
at
24
months.
The
incidence
rates
for
the
control
and
treated
Agouti
groups
were
9%
and
35%,
respectively,
for
adenomas
and
13%
and
17%,
respectively,
for
carcinomas.
The
incidence
rates
for
the
control
and
treated
Pseudoagouti
groups
were
5%
and
12%,
respectively,
for
adenomas
and
2%
and
5%,
respectively,
for
carcinomas.

Increases
in
Clara
cell
hyperplasia
were
noted
in
the
lung
at
all
sacrifice
intervals
for
each
strain
and
the
incidence
of
lung
tumors
was
increased
in
later
months
for
the
Agouti
and
Pseudoagouti
strains.
The
percentage
of
mice
with
Clara
cell
hyperplasia
in
the
control
and
treated
groups
was
6­
31%
and
72­
92%,
respectively,
for
the
Agouti;
6­
17%
and
50­
79%,
respectively,
for
the
Pseudoagouti;
and
0­
14%
and
56­
90%,
respectively,
for
the
Black
strain.
Lung
tumors
for
the
Agouti
strain
occurred
in
0%
of
the
control
and
17%
of
the
treated
animals
at
18
months
and
4%
of
the
control
and
19%
of
the
treat
ed
animals
at
24
months.
Lung
tumors
in
the
Pseudoagouti
strain
occurred
in
6%
of
the
controls
and
14%
of
the
treated
animals
at
24
months.
After
recovery,
the
incidences
of
Clara
cell
hyperplasia
(Agouti
and
Black
mice)
and
lung
tumors
(Agouti
mice)
remained
slightly
elevated
as
compared
with
the
controls.

Non­
neoplastic
lesions:

No
clinical
signs
of
toxicity
and
no
survival
information
were
reported.
No
apparent
effects
on
body
weights
or
food
consumption
were
observed,
but
only
limited
data
were
presented.
When
compared
with
untreated
controls
at
6
and
12
months,
benzo(
a)
pyrene
monooxygenase
activity
in
the
liver
was
increased
1.61­
1.84x
in
the
Agouti,
2.71­
2.78x
in
the
Pseudoagouti,
and
2.
07­
2.09x
in
the
Black
strains.
Liver
weights
were
increased
14.7­
31.2%
in
the
Agouti,
13.5­
22.0%
in
the
Pseudoagouti,
and
12.2­
16.4%
in
the
Black
strains
at
sacrifice
intervals
up
to
24
months.
Following
the
recovery
period,
liver
weights
of
the
treated
mice
were
similar
to
the
controls.
LINDANE
CANCER
ASSESSMENT
DOCUMENT
FINAL
REPORT
8
Adequacy
of
the
dose:

Only
two
dose
groups
were
tested
in
this
study,
0
and
160
ppm.
The
CARC
concluded
that
although
the
liver
effects
appear
to
suggest
that
a
dose
of
160
ppm
was
adequate,
additional
dose
groups
may
have
provided
confirmatory
information.
Amore
thorough
reporting
of
the
clinical
signs
would
have
been
useful
in
definitive
determination
of
adequacy
of
dose.

3.
NTP
Combined
Chronic
Toxicity/
Carcinogenicity
Study
with
Lindane
in
Mice
Reference:
NCI,
Carcinogenesis
Program,
Bethesda,
MD;
DHEWPub
#
(NIH)
77­
814,
1977.

Experimental
Design:

Groups
of
50
B6C3F1
mice/
sex
were
administered
lindane
at
dietary
concentrations
of
80
or
160
ppm
for
80
weeks
then
observed
for
an
additional
10­
11
weeks.
Matched
controls
consisted
of
10
mice/
sex.
For
statistical
analysis,
40
untreated
mice/
sex
were
pooled
fromfour
other
bioassays
of
other
test
chemicals.

Discussion
of
tumor
data:

The
incidence
of
hepatocellular
carcinoma
in
low­
dose
males
(19/
49)
was
increased
significantly
(p=
0.001)
when
compared
with
pooled
controls
(5/
49).
The
incidence
of
hepatocellular
carcinoma
in
high­
dose
male
mice
(9/
46)
was
not
significantly
different
than
the
matched
(2/
10)
or
pooled
controls.

Non­
neoplastic
lesions
The
non­
neoplastic
lesions
are
presented
in
Table
4
below.
There
were
only
slight
increases
in
liver
inflammation
in
males
and
spleen
hyperplasia
in
females.
Higher
incidences
of
microscopic
changes
in
the
uterus
and
ovaries
of
treated
mice
were
noted;
however,
no
clear
dose
response
was
found.

Table
4.
Non­
neoplastic
lesions
in
B6C3F1
male
and
female
mice
Dose
0
80
160
0
80
160
LINDANE
CANCER
ASSESSMENT
DOCUMENT
FINAL
REPORT
9
males
females
liver,
inflammation/
swelling
0/
10
0/
49
5/
46
0/
10
0/
47
0/
46
spleen,
hyperplasia
0/
10
1/
50
0/
47
0/
8
2/
49
4/
48
uterus,
hyperplasia
N/
A
0/
7
3/
44
4/
43
ovary
,
inflamation
3/
7
14/
42
10/
46
Adequacy
of
Dosing
for
Assessment
of
Carcinogenicity
Body
weight
was
unaffected
by
the
test
material.
No
food
or
water
consumption
data
was
provided.
The
CARC
concluded
that
the
use
of
pooled
controls
compromised
the
usefulness
of
the
study
and
the
available
data
were
inadequate
to
make
an
assessment
of
the
carcinogenic
potential
of
lindane.

Table
5
provides
a
comparison
of
other
available
mouse
studies
and
their
deficiencies.

Table
5.
Mouse
Carcinogenicity
Studies,
their
Results
and
Deficiencies
1
Study
design/
deficiencies/
classification
Results
1.
Carcinogenicity
­
CF­
1
mouse
Walker
and
Thorpe
as
published
in
Food
Cosmetic
Toxicology
11:
433­
442,1973.

Supplementary.
Data
in
summary
tables
were
not
supported
by
individual
animal
data.
Test
material
cannot
be
validated.
Only
one
dose
level
which
produced
severe
toxicity
was
used.
Study
was
run
concurrently
with
dieldrin,
DDT,
phenobarbitone
Considered
positive
for
liver
tumors.
Males
Females
Control(
45)
BHC(
29)
Control(
44)
BHC(
29)
Adenoma
20%
38%
23%
34%
Carcinoma
4%
55%
0
34%
Total
24%
93%**
23%
69%**
[data
are
%
of
animals
with
tumor,
the
number
in­(
)
is
the
number
of
mice
per
sex
examined.]
**
P
<
0.01
study
author's
statistics.

CFl
strain
mouse,
Dose
levels
tested:
0,
400
ppm
and
beta­
BHC
for
105
to
109
weeks.

2.
Carcinogenicit
­dd
mouse
Hamada,
Yutani
and
Miya
as
published
in
GANN
64:
511­
3(
1973).

Supplementary.
Data
were
available
in
summary
form
only.
Very
small
number
(only
3
or
4)
of
animals
were
dosed
per
group.
The
survival
was
poor
and
dosing
period
was
only
32
weeks
.
Test
material
cannot
be
validated.
Study
was
run
concurrently
with
alpha,
beta
and
gamma
isomers
of
BHC.
considered
positive
Three
of
f
our
males
and
one
of
three
f
emales
receiving
pure
gamma
isomer
at
600
ppm
were
said
to
develop
"hepatoma"
or
liver
tumors.
None
of
the
controls
or
mice
dosed
with
100
or
300
ppm
developed
these
tumors.

dd
strain
mice,
dose
levels
0,
100,
300
or
600
ppm
of
gamma,
alpha
or
beta
hexachlorocyclohexane
or
crude
"BHC"
for
36
to
38
weeks.

3.
Oncogenicity
­
B6C3F1
mouse
NCI,
No.:
NCI­
CG­
TR­
14,
1977
Supplementary:
Use
of
only
10
mice
per
sex
for
the
control
group
compromised
the
usef
ulness
of
the
study.
Data
were
in
summary
tables
only.
There
were
no
indications
of
toxicity
at
high
dose.
Test
material
cannot
be
validated.
Considered
positive
at
low
dose
only.
Hepatocellular
Carcinomas
Dose
Level
Males
Females
Control
10
2(
20%)
10
0
80
ppm
49
19(
39%)
47
2(
4%)
160
ppm
46
9(
20%)
46
4(
7%)
NCI
study
conclusion
is
that
the
chemical
is
not
positive
for
liver
tumors.
Conclusion
corroborated
by
Vesselinovich
and
Carlborg.
The
CAG
of
ORD
considers
low
dose
group
positive.
Dose
levels
tested
were
0,
80
and
160
ppm
for
80
weeks
with
10
weeks
recovery.
B6C3CF
1
strain
mice.
LINDANE
CANCER
ASSESSMENT
DOCUMENT
FINAL
REPORT
10
4.
Oncogenicity
­Chbb­
NMRI
mouse
Boehringer
Sohn
Ingelheim
am
Rhein,
No
Study
No.:
February
25.
1975
Supplementary:
Insufficient
raw
data
were
used
to
support
conclusions.
There
was
no
verif
ication
of
identity
of
test
material
and
no
evidence
of
toxicity
at
high
dose
level.
No
evidence
of
liver
neoplasms.

Dose
levels
tested
0,
12.5,
25
and
50
ppm.

Chbb­
NMRI
strain
mice.

5.
Oncogenicity
­
mice
(strain
unspecified)
Ito
,
Nagasaki,
Arie,
Sughara
and
Makiura,
Nara
Medical
University
No
Study
No.:
as
published
in
J.
National
Cancer
Institute
51:
817­
826,
1972
.
Supplementary/
Invalid:
No
individual
animal
data
were
provided,
test
was
conducted
for
only
24
weeks.
There
was
no
verif
ication
of
the
test
material.
gamma
isomer
was
not
shown
to
increase
liver
tumors.
Alpha
isomer
was
positive.

Dose
levels
tested
0,
100,
250
or
500
ppm
for
24
weeks.

Strain
was
not
specified.

6.
oncogenicity
­
ICR­
JCL
mouse
Goto,
Hattori,
Miyagawa
and
Enomoto,
Gakushin
University,
as
published
in
Chemosphere
1(
6):
279­
282
1972.
No
Study
No.,
Supplementary:
No
individual
animal
data
were
available
and
there
was
no
verif
ication
of
the
test
material.
Single
dose
level
f
or
only
26
weeks.
Other
isomers
were
tested
at
the
same
time.
No
inf
ormation
on
survival
or
reactions
to
treatment
was
available.
Test
material
was
not
validated
as
lindane.
considered
positive
Liver
tumors
developed
in
5
of
10
mice
dosed
with
gamma
isomer
after
26
weeks.

Dose
level
tested:
0
and
600
ppm,
other
isomers
of
HCH
also
tested.

ICR­
JCL
strain
mouse.

7.
Carcinogenicit
­
dd
mouse
Nagasaki,
Tonrii,
Mega,
Marugami
and
Ito,
Nara
Medical
University,
as
published
in
Topics
in
Chemical
Carcinogenesis,
1972
No
Study
No.:
Supplementary:
Technical
ECCE
(mixture
of
isomers)
was
used,
not
lindane.
Data
were
available
in
summary
tables
only.
Only
males
were
tested.
"Hepatoma"
resulted
in
response
to
660
ppm
of
the
test
material
(mixture
of
isomers).

Doselevelstested:
0,
6.
6,
66and660ppm.

dd
strain
of
mice,
only
males
tested.

8.
Carcinogenicity
­
mouse
Wolff
and
colleagues.
AS
published
in
Carcinogenesis
8(
12):
1889­
1892
,
1987
Supplementary:
Data
are
in
summary
tables
only.
No
verif
ication
of
the
test
material.
Only
f
emales
tested.
Only
a
single
dose
tested.
No
data
on
clinical
observations,
body
weight
or
survival.
This
strain
may
metabolize
lindane
at
a
slower
rate
with
resulting
accumulation
in
tissue.
Considered
positive
in
two
of
three
strains
Liver
and
lung
adenomas
and
liver
carcinomas
in
"pseudoagouti"
and
"yellow"
but
not
in
black
normal
mice.

Dose
levels
tested
0
and
160
ppm.

Strains
as
indicated
above.

1
This
table
developed
by
John
Doherty
(1993
RfD
document)
has
been
slightly
modified.

5.
Carcinogenicity
Study
in
Rats
Reference:

Aymes,
S.
J.
1993.
Lindane:
Combined
carcinogenicity
and
toxicity
study
by
dietary
administration
to
Wistar
rats
for
104
weeks.
Addendum
to
final
report
(Adrenal
histopathology
­
additional
investigations).
Life
Sciences
Research,
England.
Study
No.
90/
CIL002/
0839.
June
2,
1993.
MRID
42891201.
Unpublished.
LINDANE
CANCER
ASSESSMENT
DOCUMENT
FINAL
REPORT
11
Aymes,
S.
J.
1989.
Combined
carcinogenicity
and
toxicity
study
by
dietary
administration
to
Wistar
rats
for
104
weeks.
Life
Sciences
Research,
England.
Study
No.
90/
CIL002/
0839.
November
7,
1989.
MRID
41853701.
Unpublished.

Aymes,
S.
J.
1989.
Lindane:
Combined
carcinogenicity
and
toxicity
study
by
dietary
administration
to
Wistar
rats
for
104
weeks
­
Interim
report
week
0­
26.
Life
Sciences
Research,
England.
Study
No.
88/
CIL002/
816.
March
7,
1989.
MRID
41094101.
Unpublished.

Experimental
Design
Lindane
(99.75%
a.
i.,
Lot
no.
DA433)
was
administered
in
the
diet
to
groups
of
50
male
and
50
female
Wistar
rats
at
concentrations
of
0,
1,
10,
100,
or
400
ppm
for
2
years.
Corresponding
delivered
doses
were
0,
0.
05,
0.47,
4.81,
and
19.66
mg/
kg/
day,
respectively,
for
males
and
0,
0.06,
0.59,
6.00,
and
24.34
mg/
kg/
day,
respectively,
for
females.
An
additional
15
rats/
sex/
group
were
designated
for
interim
sacrifices
at
30
days
and
26
weeks.

Discussion
of
Tumor
Data
Male
rats
were
identified
as
having
adrenal
pheochromocytomas
(Table
6).
The
percentages
of
animals
with
adrenal
tumors
in
the
0,
1,
10,
100,
and
400
ppm
groups
were
14,
16,
16,
6,
and
24%
for
benign
tumors,
respectively,
and
0,
0,
6,
8,
and
2%
for
malignant
tumors,
respectively.
Statistical
significance
was
not
reached
by
relevant
tests.

When
compared
to
historical
controls,
the
incidence
of
adrenal
pheochromocytomas
in
the
current
study
slightly
exceeded
that
of
the
historical
control
at
the
HDT
(400
ppm).
The
range
of
adrenal
pheochromocytomas
observed
in
the
historical
control
data
was
4/
50
to
11/
50
(8%
­
22%)
for
male
rats
examined
in
four
studies
conducted
in
1990.
Of
the
18
studies
in
the
historical
control
data,
6
were
performed
in
1990;
the
other
12
were
performed
between
1986
and
1988.

Non­
Neoplastic
Lesions
The
incidence
rate
of
periacinar
hepatocytic
hypertrophy
was
significantly
(p<
0.01)
increased
in
the
100
and
400
ppm
groups
with
25/
50
males
and
19/
50
females
at
100
ppm
and
in
40/
50
males
and
43/
50
females
at
400
ppmcompared
with
the
vehicle
control.
No
treatment­
related
histopathological
lesions
were
observed
in
the
spleen
or
bone
marrow.

Kidney
lesions
in
males
indicative
of
alpha
2µ
globulin
accumulation
were
observed
in
animals
treated
with

10
ppm;
but
since
this
effect
is
species
(rat)
specific,
it
was
not
considered
relevant
to
human
health
risk
assessment.

Table
6.
Percentage
(%)
of
animals
with
adrenal
pheochromocytomas
LINDANE
CANCER
ASSESSMENT
DOCUMENT
FINAL
REPORT
12
Control
(ppm)
Benign
Malignant
Both
(B
&
M)

0
14014
1
16016
10
16
6
18
100
6
8
14
400
24
2
26
Adjusted
Rates
1
0
29029
1
39039
10
33.5
15.2
38.6
100
12.1
21.4
31.0
400
52.9
2.
9
54.2
Historical
controls:
Benign­
8
to
22%
and
Malignant­
0
to
2%
1
Kaplan­
Meier
estimated
tumor
incidence
at
the
end
of
the
study
after
adjusting
for
inter­
current
mortality.

Adequacy
of
Dosing
for
Assessment
of
Carcinogenicity
CARC
concluded
that
the
doses
tested
were
considered
to
be
adequate
and
not
excessive
in
both
sexes.
This
was
based
on
decreased
survival,
decreased
body
weight
gains,
decreased
food
consumption,
and
increased
spleen
and
liver
weights
correlated
with
periacinar
hepatocyte
hypertrophy
in
both
sexes
at
the
high­
dose,
relative
to
the
controls.

Final
body
weights
of
the
high­
dose
males
were
significantly
(­
14%;
p

0.05)
less
than
the
controls.
Body
weights
and
body
weight
gains
for
the
treated
females
were
similar
to
the
controls
throughout
the
study.
Total
food
consumption
for
the
entire
study
was
similar
to
the
control
levels.

Platelet
counts
were
significantly
increased
in
males
at
100
and
400
ppm
at
week
12
and
in
males
and
females
at
week
24,
but
not
at
later
time
points.
High­
dose
males
and
females
had
significant
decreases
in
red
blood
cell
parameters
at
week
104
as
compared
with
the
controls.

Significant
changes
in
clinical
chemistry
parameters
were
observed
in
high­
dose
males
and
females
during
the
first
year
of
the
study.
Inorganic
phosphorous
and
calcium
were
increased
in
males
and
females;
the
cholesterol
and
urea
were
increased
in
females;
and
the
albumin/
globulin
ratio
was
decreased
in
females.
All
parameters
were
similar
to
the
control
LINDANE
CANCER
ASSESSMENT
DOCUMENT
FINAL
REPORT
13
levels
by
week
104.

High­
dose
males
and
females
had
increased
absolute
and
relative
liver
weights
at
all
interim
sacrifices,
although
statistical
significance
was
not
always
reached.
At
study
termination,
absolute
and
relative
liver
weights
were
significantly
increased
in
high­
dose
males
and
females.
At
100
ppm,
absolute
and
relative
liver
weights
were
increased
for
both
sexes.

6.
NTP
Combined
Chronic
Toxicity/
Carcinogenicity
Study
with
Lindane
in
Rats
Reference:
NCI,
Carcinogenesis
Program,
Bethesda,
MD;
DHEWPub
#
(NIH)
77­
814,
1977.

Experimental
design:

Lindane
was
administered
in
the
diet
of
50
Osborne­
Mendel
rats/
sex/
dose
for
a
total
of
80
weeks.
Males
received
320
or
640
ppm
for
38
weeks
and
160
or
320
ppm
for
the
remaining
42
weeks.
Females
received
320
or
640
ppm
for
2
weeks
and
160
or
320
ppm
for
49
weeks;
then
for
the
remaining
29
weeks,
the
dose
was
lowered
to
80
or
160
ppm.
After
the
initial
80
week
treatment
period,
all
animals
were
observed
for
an
additional
29­
30
weeks.
Matched
controls
consisted
of
10
rats/
sex.
For
statistical
analysis
45
untreated
rats/
sex
were
pooled
from
four
other
bioassays
of
other
test
chemicals.

Discussion
of
tumor
data
As
shown
in
Table
7,
there
were
three
incidences
of
spleen
hemangioma
in
the
high­
dose
male
group
only
and
none
in
the
females.
There
were
also
increases
in
neoplastic
lesions
of
the
liver;
however,
these
were
within
the
historical
control
values
in
this
tumor
for
this
rat
strain
(0­
12%,
Goodman
et
al.
2000,
personal
communication).
Other
organs
affected
with
primary
tumors
include:
thyroid,
pituitary,
and
mammary
glands
wit
h
only
a
few
incidences
and
no
clear
dose­
response
correlation.
.

Non­
neoplastic
Lesions
Microscopic
changes
were
seen
in
the
liver
of
both
males
and
females,
including
cirrhosis,
degeneration
and
necrosis
in
a
dose
dependent
manner.
Cysts,
hyperplasia
and
atrophy
were
seen
in
the
endocrine
and
reproductive
organs
of
these
animals.

Table
7.
Tumor
data
for
Osborne­
Mendel
rats
fed
lindane
for
80
weeks
Dose
control
low
high
control
low
high
males
females
spleen
hemangioma
0/
8
0/
44
3/
44
­­­­­­­­­­
­­­­­­­­­
­­­­­­­­­
LINDANE
CANCER
ASSESSMENT
DOCUMENT
FINAL
REPORT
14
thyroid,
adenoma
carcinoma
1/
6
5/
37
0/
37
0/
8
1/
44
1/
42
0/
6
1/
37
4/
37
0/
8
1/
44
0/
42
liver,
neoplastic
nodule
0/
10
3/
45
2/
45
0/
10
4/
48
2/
45
pituitary,
adenoma
carcinoma
0/
10
0/
32
2/
35
0/
7
0/
45
2/
41
0/
10
1/
32
0/
35
0/
7
1/
45
0/
41
mammary,
adenoma
carcinoma
0/
10
0/
48
2/
49
0/
10
3/
50
1/
50
0/
10
1/
48
0/
49
1/
10
1/
50
0/
50
Adequacy
of
Dosing
for
Assessment
of
Carcinogenicity
Mean
body
weight
did
not
show
consistent
changes
from
the
administration
of
lindane.
The
CARC
concluded
that
the
use
of
pooled
controls
compromised
the
usefulness
of
the
study
and
the
available
data
were
inadequate
to
make
an
assessment
of
the
carcinogenic
potential
of
lindane.

IV.
TOXICOLOGY
1.
Metabolism
Lindane
is
distributed
to
all
organs
at
measurable
concentrations
within
a
few
hours
after
oral
administration.
The
highest
concentrations
are
found
in
adipose
tissue.
The
metabolism
of
lindane
is
initiated
through
one
of
the
following
pathways:
dehydrogenation
leading
to

HCH,
dehydrochlorination
leading
to
formation
of

PCCH,
dechlorination
leading
to
formation
of
­
tetrachlorohexene,
or
hydroxylation
leading
to
formation
of
hexachlorocyclohexanol.
Further
metabolism
leads
to
a
large
number
of
metabolites.
Volatilizalion
appears
to
be
an
important
route
of
its
dissipation
under
the
high­
temperature
conditions
oftropicalregions.
Lindane
is
converted
byenzymatic
reactions,
mainlyin
the
liver.
In
mammals,
including
humans,
lindane
is
excreted
very
rapidly
in
urine
and
feces
after
metabolic
degradation;
only
small
amounts
are
eliminated
unchanged.
The
half­
life
of
lindane
administered
to
rats
is
2­
4
days
depending
on
the
frequency
of
exposures,
single
or
repeated.

Other
metabolites
are
also
known
to
be
associated
with
lindane
exposure;
these
include
2,4,6­
trichlorophenol
and
2,
4,
5­
trichlorophenol.
Exposure
to
lindane
in
a
residential
setting
is
expected
to
be
negligible
except
for
use
as
a
lice
or
scabies
treatment.
These
uses
are
regulated
by
FDA
and
have
not
been
evaluated
in
this
document.

2.
Mutagenicity
As
part
of
the
Registration
Standard
prepared
in
1985,
the
available
literature
and
submitted
mutagenicity
studies
were
evaluated
(HED
Document
No.
004704).
Based
on
this
evaluation,
it
was
concluded
that
the
weight­
of­
the­
evidence
with
conventional
genotoxicity
testing
LINDANE
CANCER
ASSESSMENT
DOCUMENT
FINAL
REPORT
15
indicated
that
lindane
did
not
interact
with
DNA
or
interfere
with
genetic
mechanisms.
This
position
was
reiterated
in
1993
(memo
by
G.
Ghali,
1993).
Reviews
prepared
by
IARC
(1979/
1987),
IPCS
(1990)
and
ATSDR(
1999)
indicate
that
lindane
and
its
associated
isomers
have
mixed
genotoxic
potential.
In
addition,
numerous
mutagenicity
studies
have
been
evaluated
by
the
European
Commission
(EU)
in
their
draft
monograph
on
lindane
(2001).
Representative
studies
were
selected
from
the
EU
evaluation
of
lindane
since
they
were
performed
according
to
OECD
or
EPA
guidelines.
These
include:

1.
A
bacterial
mutagenicity
assay
using
Salmonella
typhimurium
with
and
without
metabolic
activation
which
was
negative
up
to
cytotoxic
doses
(5000
ug/
plate
+S9)
or
insoluble
doses
(greater
than
or
equal
to
500
ug/
plate
­S9;
greater
than
or
equal
to1500
ug/
plate
+S9
;
Oesch,
1980).

2.
An
aerobic
mammalian
cell
(V79)
gene
mutation
assay
was
negative
up
to
cytotoxic
doses
(greater
than
or
equal
to
50
ug/
mL
­S9;
greater
than
or
equal
to
250
ug/
mL+
S9);
the
compound
precipitated
at
greater
than
or
equal
to
250
ug/
mL
(Glatt,
1984).
EPA
only
received
an
anaerobic
assay
which
had
an
acceptable
aerobic
portion
(Glatt,
1985).

3.
Mammalian
cell
cytogenetic
assay
was
negative
in
CHO
cells
up
to
cytotoxic
doses
(greater
than
or
equal
to
33.2
ug/
mL
­S9;
greater
than
33.2
ug/
mL+
S9).
(Murli,
1990).

4.
UDS
in
primary
rat
hepatocytes
was
also
found
to
be
negative
up
to
cytotoxic
doses
(15
ug/
mL)
(Cifone,
1990).

There
are
no
acceptable
in
vivo
studies
but
they
are
not
necessary
to
satisfy
pre­
1991
FIFRA
guideline
requirements.
Newer
published
data
shows
that
lindane
induces
oxidative
stress
in
the
liver
of
treated
rats
(Carrion
et
al.,
2001;
Cornnejo
et
al.,
2001;
Videla
et
al.,
2000).
In
agreement
with
these
findings,
the
1999
ATSDR
review
states
that
oxidative
stress
may
be
a
possible
mechanism
of
liver
toxicity.

The
CARC
has
an
additional
concern
related
to
possible
genetic
effects
on
germinal
cells.

Although
an
old
submitted
dominant
lethal
assay
(MRID
00062657)
was
negative,
it
was
considered
unacceptable
and
not
upgradable
because
of
technical
deficiencies.
Recent
information
found
in
the
open
literature
indicates
that
topical
application
of
lindane
led
to
rapid
absorption
and
accumulation
in
rat
testes
(Suwalsky
et
al.,
2000).
The
investigators
reported
widespread
damage
to
a
"great
number"
of
Leydig
cells
after
the
application
of
1%
lindane
once
daily
for
4
consecutive
days.
These
findings
are
consistent
with
the
work
of
Walsh
and
Stocco
(2000)
showing
inhibition
of
steroidogenesis
by
reductions
in
steroidogenic
acute
regulatory
(StAR)
protein
expression
in
mouse
Leydig
cells
in
vitro.
Since
there
is
some
evidence
that
lindane
reaches
and
damages
germ
cells,
the
Committee
recommends
that
the
dominant
lethal
assay
be
repeated
to
determine
if
there
is
a
genetic
component
to
the
reproductive
(germ
cell)
effects
reported
above
for
lindane.

3.
Structure­
Activity
Relationship
LINDANE
CANCER
ASSESSMENT
DOCUMENT
FINAL
REPORT
16
Technical­
grade
hexachlorohexane
(HCH)
which
consists
of
alpha,
beta,
gamma,
delta
and
epsilon
isomers
of
HCH
is
a
carcinogen.
In
rodents
studies,
the
pure
alpha
isomer
of
HCH
has
been
found
to
induce
liver
tumors;
this
is
also
true
for
the
pure
beta
isomer
of
HCH..
These
studies
are
found
in
the
NTP,
IARC
and
IPCS
reports
on
hexachlorohexanes.
Lindane
shares
its
structure
with
at
least
four
other
isomers.
They
differ
only
with
respect
to
the
position
of
the
chlorine
atoms
in
the
alpha
or
beta
positions,
above
or
below
the
plane
of
the
hexane
ring
structure.

Structure
of
HCH
(Lindane)::


­isomer:
1   
2   
3
4 ,
5 ,
6  
hexachlorocyclohexane
Other
isomers:
 
­isomer:
1   
2   
3
4 ,
5 ,
6  
hexachlorocyclohexane
 
­isomer:
1   
2
3   
4 ,
5 ,
6  
hexachlorocyclohexane
 
­isomer:
1   
2   
3   
4 ,
5 ,
6  
hexachlorocyclohexane
 
­isomer:
1   
2   
3   
4 ,
5 ,
6  
hexachlorocyclohexane
Isomers
of
hexachlorocyclohexane
(HCH),
other
than
lindane,
have
been
classified
as
follows,
according
to
IRIS:
The
technical
HCH
and
the
alpha­
isomer
are
classified
as
B2,
probable
human
carcinogens.
The
beta­
isomer
is
classified
as
C,
possible
human
carcinogen.
The
delta
and
epsilon
isomers
are
classified
as
D,
not
classifiable
as
to
human
carcinogenicity.

Appendix
A
contains
a
summary
of
various
studies
which
examine
the
carcinogenicity
of
the
gamma
isomer
(Lindane)
alone
or
in
comparison
with
the
other
isomers.

4.
Subchronic,
and
Chronic
Toxicity
Subchronic
Toxicity
Mice
A
range­
finding
subchronic
toxicity
study
(MRID
45424301)
was
conducted
to
determine
the
doses
to
be
used
in
a
two­
year
carcinogenicity
study.
In
this
study,
Lindane
(99.
78%
a.
i.)
was
administered
to
10
CD­
1
mice/
sex/
dose
in
the
diet
at
dose
levels
of
0,
40,
80,
160,
320
ppm
(0,
5.
7,
12.2,
22.8
and
46.2
and
0,
8.9,
16.0,
32.9,
and
62.6
mg/
kg/
day
in
males
and
females,
respectively).

No
treatment­
related
clinical
signs
were
observed.
Five
females
died
or
were
killed
during
the
treatment
period.
Four
were
in
the
highest
dose
(320
ppm)
group
and
one
from
the
control
group
was
a
humane
kill.
These
animals
presented
wit
h
no
macroscopic
changes.
Histopathology
revealed
hepatocyte
hypertrophy
and
karyomegaly
in
the
liver
and
Clara
cell
hypertrophy
and
congestion
in
the
lungs.
These
findings
were
also
seen
in
treated
animals
in
the
160
and
320
ppm
dose
groups
that
were
sacrificed
at
study
termination;
therefore,
these
deaths
were
considered
to
be
treatment­
related.
Body
weight
was
reduced
by
6%
in
males
and
was
unaffected
in
females
in
the
highest
dose
tested
(320
ppm).
Body
weight
gain
was
reduced
by
27%
LINDANE
CANCER
ASSESSMENT
DOCUMENT
FINAL
REPORT
17
in
males
and
9%
in
females.

In
a
subchronic
inhalation
toxicity
study,
Lindane
(99.6%
a.
i.,
Batch
no.
DA433)
was
administered
by
inhalation
to
groups
of
45
male
and
45
female
CD­
1
mice
at
nominal
concentrations
of
0,
0.3,
1.0,
5.0
to
10
mg/
m3
(0,
0.
1,
0.
4,
2.
0
or
4.0
mg/
kg/
6
hrs),
for
14
weeks.
Exposures
were
6
hours/
day,
5
day/
week
as
described
in
the
pilot
study.
During
the
first
five
exposures,
the
high­
dose
group
was
exposed
to
a
mean
concentration
of
9.
72
mg/
m3
(4.
0
mg/
kg/
6
hrs),
but
due
to
excessive
deaths,
the
mean
concentration
was
lowered
to
4.
94
mg/
m3
(2.
0
mg/
kg/
6
hrs).
No
exposure­
related
effects
were
noted
for
body
weight
gain,
food
consumption,
water
consumption,
or
ophthalmoscopic,
hematology,
clinical
chemist
ry,
or
urinalysis
parameters.
Bone
marrow
analysis
did
not
show
any
time­
or
concentration­
related
changes.
Brain,
kidney,
lung,
spleen,
thymus,
and
adrenal,
and
testes
weights
were
similar
between
the
treated
and
control
animals.
Liver
weights
of
females
exposed
to
5
mg/
m3
were
increased
14%
(p

0.05)
at
week
20.

Rats
In
a
subchronic
oral
neurotoxicity
study
(MRID
44781101),
groups
of
10
Crl:
CD®
BR
rats/
sex/
group
were
administered
lindane
(Batch
No.
HLS96/
1,
Purity
99.78%)
in
the
diet
for
13
weeks
at
concentrations
of
0
(control),
20,
100,
or
500
ppm.
Due
to
severe
toxic
reactions
to
treatment
at
500
ppm,
the
dose
was
reduced
to
400
ppm
on
day
11
of
treatment
thereafter.
These
doses
resulted
in
average
daily
intake
values
of
0,
1.4,
7.1,
and
28.
1
mg/
kg/
day
for
males
and
0,
1.6,
7.9,
and
30.2
mg/
kg/
day
in
females
for
0,
20,
100,
and
500/
400
ppm,
respectively.

Significant
treatment­
related
decreases
(p<
0.05
or
p<
0.01)
in
body
weight
were
observed
among
males
and
females
treated
with
500/
400
ppm
of
14%
and
23%,
respectively.
Decreases
in
body
weight
gains
(70%

and
180%

,p<
0.
01),
food
consumption
(35%

and
50%

,
p<
0.05
or
p<
0.01,
respectively),
and
food
conversion
ratios
were
observed
for
males
and
females
in
the
500
ppm
groups
compared
to
the
control
group
for
the
first
week
of
the
study.
Male
rats
tended
to
recover
from
these
effects
after
the
dose
was
lowered.
Females,
however,
did
not
exhibit
this
same
level
of
recovery
as
their
food
consumption
remained
slightly
depressed
throughout
the
remainder
of
the
study.

Females
in
the
100
ppm
group
had
significantly
decreased
body
weight
gains
(40%,
p<
0.05)
compared
to
the
control
group
during
the
first
week
of
the
study
and
this
effect
continued,
although
not
at
a
level
of
significance
throughout
the
remainder
of
the
study.
Females
in
the
100
ppm
group
had
significantly
decreased
food
consumption
(16%,
p<
0.01)
for
the
first
week
of
the
study
and
this
trend
continued
throughout
the
study.
Liver
weights
were
also
found
to
be
increased
at
500/
400
ppm
for
both
sexes;
no
additional
information
was
given.

Chronic
Toxicity
In
the
chronic
toxicity/
carcinogenicity
study
(MRID41853701),
lindane
(99.75%
a.
i.,
Lot
no.
DA433)
was
administered
in
the
diet
to
groups
of
50
male
and
50
female
Wistar
rats
at
concentrations
of
0,
1,
10,
100,
or
400
ppm
for
2
years.
Corresponding
LINDANE
CANCER
ASSESSMENT
DOCUMENT
FINAL
REPORT
18
delivered
doses
were
0,
0.
05,
0.47,
4.81,
and
19.66
mg/
kg/
day,
respectively,
for
males
and
0,
0.
06,
0.59,
6.00,
and
24.34
mg/
kg/
day,
respectively,
for
females.
An
additional
15
rats/
sex/
group
were
designated
for
interim
sacrifices
at
30
days
and
26
weeks.

Body
weights
were
slightly
less
than
the
controls
for
the
high­
dose
males
(­
6%)
and
females
(­
8%)
during
weeks
1­
5
of
the
study,
but
gradually
increased
to
within
2%
of
the
control
level
by
week
26
for
males
and
week
9­
10
for
females.

High­
dose
females
hadsignificantlydecreased
hemoglobin,
decreased
RBCcounts,
and
decreased
PCV.
These
red
cell
parameters
were
"marginally
lower"
for
high­
dose
males
(non
statistically
significant).
Platelet
counts
increased
in
mid­
and
high­
dose
males
and
females.
White
cell
counts
significantly
increased
in
mid­
dose
and
in
highdose
females
due
to
increases
in
neutrophils.

The
liver
appears
to
be
the
major
target
organ.
Kidney
lesions
in
male
rats
indicative
of
alpha
2µ
globulin
accumulation
were
observed
in
animals
treated
with

10
ppm,
but
are
not
considered
relevant
to
human
health
risk
assessment.
Absolute
kidney
weights
were
significantly
increased
in
high­
dose
males.
Absolute
and
relative
kidney
weights
increased
in
mid­
dose
males
and
high­
dose
males
and
females.
The
incidence
of
periacinar
hepatocytic
hypertrophy
was
significantly
increased
in
males
at
100
and
400
ppm
and
in
females
at
400
ppm.
This
lesion
was
not
seen
in
control
animals
of
either
sex.
No
treatment­
related
histopathological
lesions
were
observed
in
the
spleen,
adrenals,
brain,
or
thymus.
Bone
marrow
data
presentation
was
inadequate
for
assessment.

5.
Mode
of
Action
Studies
No
mode
of
action
studies
have
been
submitted
for
lindane.
There
have
been,
however,
several
published
studies
which
attempt
to
elucidate
the
initiator­
promoter
activity
of
lindane.
As
discussed
earlier
lindane
does
not
appear
to
have
a
clear
mutagenic
potential.

Lindane
may
act
as
a
promoter
as
evidenced
by
studies
with
Agouti,
Pseudoagouti
and
Black
mice.
Only
Agouti
and
Pseudoagouti
mice,
which
have
a
transformed
genotype
linked
to
tumorigenicity,
were
found
to
have
an
increased
incidence
of
liver
and
lung
tumors.
The
Black
mice
had
no
tumors
in
the
24
month
period
of
the
study.
The
Pseudoagouti
and
Black
mice
had
a
low
rate
of
spontaneous
tumor
incidence
in
the
liver
and
lung,
but
of
these
two
only
the
Pseudoagouti
responded
to
lindane.
Therefore,
lindane
appears
to
augment
the
propensity
of
these
genetically
altered
mice
to
develop
tumors.
It
has
been
suggested
that
lindane
has
a
similar
mode
of
action
to
phenobarbital,
which
also
increases
the
incidence
of
benign
tumors
in
these
mice.
As
discussed
earlier
on
page
13,
oxidative
stress
may
be
a
possible
mechanism
of
liver
toxicity.

Suggestions
have
been
made
that
the
metabolites
of
lindane
may
contribute
to
its
carcinogenic
potential.
One
major
urinary
metabolite,
2,4,6­
TCP,
is
considered
to
be
a
carcinogen.
However
studies
indicate
that
TCP
may
have
only
a
minimal
effect
on
LINDANE
CANCER
ASSESSMENT
DOCUMENT
FINAL
REPORT
19
the
overall
carcinogenic
potential
of
lindane.

V.
COMMITTEE'S
ASSESSMENT
OF
THE
WEIGHT­
OF­
THE­
EVIDENCE
1.
Carcinogenicity
The
CARCconcluded
that
lindane
is
carcinogenic
only
to
female
mice
and
is
not
carcinogenic
to
male
mice
and
male
and
female
rats.

!
CD­
1
female
mice
had
significant
increasing
trends
and
significant
differences
in
pair­
wise
comparisons
of
the
160
ppm(
26.8
mg/
kg/
day)
dose
group
with
the
controls,
for
lung
alveolar­
bronchiolar
adenomas
(23%
vs
6%
in
controls)
and
combined
adenomas/
carcinomas
(25%
vs
8%
in
controls),
all
at
p
<
0.
05;
the
incidence
of
lung
adenomas
(23%)
was
slightly
outside
the
historical
control
range
(6%­
19%).
The
increased
incidence
of
carcinomas
was
not
dosedependent
and
tumor
response
was
variable.
Lindane
was
not
carcinogenic
to
male
mice.
No
non­
neoplastic
liver
changes
were
seen
in
females.
The
majority
of
the
CARC
considered
the
dosing
to
have
been
adequate
and
not
excessive
based
on
an
increase
in
the
incidence
of
centrilobular
hepatocyte
hypertrophy
as
well
as
eosinophilic
foci
of
hepat
ocellular
alteration
in
high­
dose
males
compared
to
the
control
group;
similar
liver
findings
were
also
reported
in
a
range­
finding
subchronic
toxicity
study
in
which
early
deaths
of
four
females
were
reported
in
the
320
ppm
dose
group
indicating
that
this
dose
was
excessive.
However,
based
on
the
results
of
the
chronic
study
a
few
members
felt
that
the
animals
could
have
tolerated
a
higher
dose.

!
At
160
ppm,
both
the
treated
female
Agouti
and
Pseudoagouti
mice
had
an
increased
occurrence
of
benign
lung
tumors
(19%
vs
4%
in
controls
and
14%
vs
6%
in
controls,
respectively).
In
addition,
both
the
treated
female
Agouti
and
Pseudoagouti
mice
had
increases
in
liver
adenomas
(35%
vs
9%
in
controls
and
17%
vs
13%
in
controls,
respectively)
and
slight
increases
in
liver
carcinomas
(5%
vs
2%
in
controls
and
12%
vs
5%
in
controls)
at
24
months.
No
statistical
analyses
of
tumor
data
were
provided.
There
was
no
increase
in
incidence
or
decrease
in
latency
period
of
liver
tumors
in
Black
and
Pseudoagouti
strains
of
mice.
There
was
evidence
of
increased
liver
weights
and
increased
incidence
of
Clara
cell
hyperplasia
in
Agouti
and
Black
strains
of
mice.
Increases
in
Clara
cell
hyperplasia
were
noted
in
the
lung
at
all
sacrifice
intervals
for
each
strain
and
the
incidence
of
lung
tumors
was
increased
in
later
months
for
the
female
Agouti
and
Pseudoagouti
mice.
The
percentage
of
mice
with
Clara
cell
hyperplasia
in
the
treated
and
control
groups
was
72%­
92%
and
6%­
31%,
respectively,
for
the
Agouti;
50%­
79%
and
6%
17
respectively,
for
the
Pseudoagouti;
and
56%­
90%
and
0%­
14%,
respectively,
for
the
female
Black
mice.
However,
the
study
was
conducted
on
few
animals,
only
a
single
dose
was
tested,
no
statistical
analyses
of
tumor
data
were
presented;
and
the
results
of
the
studywere
not
adequately
reported.
The
Committee
concluded
that
although
the
liver
effects
appear
to
suggest
that
a
LINDANE
CANCER
ASSESSMENT
DOCUMENT
FINAL
REPORT
20
dose
of
160
ppm
was
adequate,
additional
dose
groups
could
have
provided
confirmatory
information.

!
The
incidence
of
hepatocellular
carcinoma
in
low­
dose
B6C3F1
males
(19/
49)
was
significant
(p=
0.001)
when
compared
with
that
in
pooled
controls
(5/
49).
The
incidence
of
hepatocellular
carcinoma
in
high­
dose
male
mice
(9/
46)
was
not
significantly
different
than
the
matched
(2/
10)
or
pooled
controls.
The
CARC
could
not
assess
the
carcinogenicity
of
lindane
in
B6C3F1
male
and
female
mice
because
the
data
reporting
was
inadequate,
there
were
no
indications
of
toxicity
at
the
high
dose
and
the
test
material
could
not
be
validated.
Moreover,
the
use
of
only
10
mice
per
sex
for
the
control
group
compromised
the
usefulness
of
the
study.

The
Committee
concluded
that
the
increased
incidence
of
benign
lung
tumors
in
female
CD­
1
mice
was
treatment­
related
because
the
treatment­
related
statistically
significant
increase
in
lung
adenomas
in
female
CD­
1
mice
was
correlated
with
increases
in
lung
tumors
in
two
genetically
susceptible
strains
of
mice
(Agouti
and
Pseudoagouti).
Although
there
is
some
evidence
of
liver
tumor
induction
in
these
genetically
susceptible
strains
of
mice,
there
was
no
evidence
of
liver
tumors
in
CD­
1
mice.
Nevertheless,
the
evidence
of
hepatotoxicity
(increased
incidences
of
liver
hypertrophy
and
liver
foci
in
both
sexes)
and
promoting
activity
suggests
the
liver
as
a
major
target
organ
of
toxicity.

!
The
treated
male
Wistar
rats
developed
adrenal
pheochromocytomas.
The
percentages
of
animals
with
adrenal
tumors
in
the
0,
1,
10,
100,
and
400
ppm
groups
were
14%,
16%,
16%,
6%,
and
24%
for
benign
tumors,
respectively,
and
0%,
0%,
6%,
8%,
and
2%
for
malignant
tumors,
respectively.
Statistical
significance
was
not
reached
by
relevant
tests
and
no
dose­
response
was
evident.
When
compared
to
historical
controls,
the
incidence
of
adrenal
pheochromocytomas
in
the
current
studyslightlyexceeded
that
of
the
historical
control
at
the
HDT
(400
ppm).
The
range
of
adrenal
pheochromocytomas
observed
in
the
historical
control
data
was
4/
50
to
11/
50
(8%
­
22%)
for
male
rats
examined
in
four
studies
conducted
in
1990.
Of
the
18
studies
in
the
historical
control
data,
6
were
performed
in
1990;
the
other
12
were
performed
between
1986
and
1988.
The
Committee
concluded
that
the
adrenal
tumors
in
male
rats
were
not
treatment­
related.
The
doses
tested
were
considered
to
be
adequate
and
not
excessive
in
both
sexes
based
on
decreased
survival,
decreased
body
weight
gains
and
decreased
food
consumption;
the
increased
spleen
and
liver
weights
correlated
with
increased
occurrence
of
periacinar
hepatocyte
hypertrophy
in
both
sexes
at
the
high­
dose.

!
There
were
three
spleen
hemangiomas
in
44
high­
dose
male
Osborne­
Mendel
rats
only
(0/
8
in
controls)
and
none
in
the
females.
There
were
also
non­
dose
related
increases
in
neoplastic
lesions
of
the
liver
(3/
45
and
2/
45
in
males
and
4/
48
and
2/
45
in
females
in
the
low
and
high
dose
groups
compared
to
0/
10/
sex
in
control
groups)
which
were
within
the
historical
control
values
(0%­
12%).
Other
organs
with
primary
tumors
include:
thyroid,
pituitary,
and
mammary
LINDANE
CANCER
ASSESSMENT
DOCUMENT
FINAL
REPORT
21
glands
with
only
a
few
incidences
but
there
was
no
clear
dose­
response.
Dosing
at
the
highest
level
was
considered
to
be
adequate
based
on
microscopic
changes
seen
in
the
liver
of
both
males
and
females,
including
cirrhosis,
degeneration,
necrosis
in
a
dose
dependent
manner.
Cysts,
hyperplasia
and
atrophy
were
seen
in
the
endocrine
and
reproductive
organs
of
these
animals.
Survival
of
the
animals
was
adequate
for
meaningful
statistical
analyses
of
the
incidence
of
tumors.

The
CARC
concluded
that
lindane
was
not
carcinogenic
to
male
and
female
Wistar
rats
and
that
the
results
of
the
study
in
Osborne
Mendel
rats
were
difficult
to
interpret
and
were
not
useful
in
determining
the
carcinogenic
potential
of
lindane
in
that
strain
of
rat.

2.
Mutagenicity
!
Lindane
has
been
tested
in
a
battery
of
pre­
1991
mutagenicity
assays
which
satisfies
the
guideline
requirements.
The
review
of
both
the
guideline
and
literature
studies
suggests
that
lindane
does
not
interact
with
DNAor
interfere
with
genetic
mechanisms.
However,
since
there
is
some
evidence
that
lindane
reaches
and
damages
germ
cells,
the
Committee
recommended
that
the
dominant
lethal
assay
be
repeated
to
determine
if
there
is
a
genetic
component
to
the
reproductive
(germ
cell)
effects
reported
for
lindane.

3.
Structure
Activity
Relationship
!
Isomers
of
hexachlorocyclohexane
(HCH),
other
than
lindane,
have
been
classified
for
carcinogenic
potential.
The
technical
HCH
and
the
alpha­
isomer
are
classified
as
B2,
probable
human
carcinogens.
The
beta­
isomer
is
classified
as
C,
possible
human
carcinogen.
The
delta
and
epsilon
isomers
are
classified
as
D,
not
classifiable
as
to
human
carcinogenicity.

4.
Mode
of
Action
!
The
tumor­
initiating
activity
reported
in
the
literature
has
been
discounted
due
to
the
lack
of
morphologic
alterations
in
liver
foci
after
treatment
with
lindane.
Lindane
appears
to
augment
the
propensity
of
genetically
altered
mice
to
develop
tumors.
However,
no
definitive
studies
have
established
the
mode
of
action
for
liver
tumor
induction
by
lindane.
There
is
a
suggestion
that
oxidative
stress
may
play
a
role
in
the
liver
toxicity
of
lindane.

VI.
CLASSIFICATION
OF
CARCINOGENIC
POTENTIAL
In
accordance
with
the
Agency's
Draft
Guidelines
for
Carcinogen
Risk
Assessment
(July,
1999),
the
Committee
classified
lindane
into
category:
"Suggestive
evidence
of
carcinogenicity,
but
not
sufficient
to
assess
human
carcinogenic
potential"
based
on
the
occurrence
of
benign
lung
tumors
in
one
sex
of
one
species
(i.
e.,
female
CD­
1
mice).
LINDANE
CANCER
ASSESSMENT
DOCUMENT
FINAL
REPORT
22
VII.
QUANTIFICATION
OF
CARCINOGENIC
POTENTIAL
The
Committee
recommended
that
quantification
of
human
cancer
risk
is
not
required.

VIII
BIBLIOGRAPHY
MRID
No.
CITATIONS
00160863
Koenig,
GR,
Rexroat,
MA
and
Probst,
GS
(1985)
The
effect
of
benefin
EL110
compound
54521)
on
the
induction
of
reverse
mutations
of
Salmonella
typhimirium
using
the
Ames
test.
Study
Laboratory:
Toxicology
Div
Lilly
Research
Laboratories,
Laboratory#
85624UB2598
and
850708UB
2598,
August
13,
1985.

00160865
Koenig,
GR,
Hill,
LE
and
Probst,
GS
(1985)
The
effect
of
benefin
(EL­
110,
Compound
54521)
on
the
induction
of
DNA
synthesis
in
primary
cultures
of
adult
rat
hepatocytes.
Study
Laboratory:
Toxicology
Div
Lilly
Research
Laboratories,
Laboratory#
85716UDS2598
and
850723UDS2598,
October
29,
1985.

00160866
Koenig,
G.
R.,
Oberly,
T.
J.,
Bewsey,
B.
J.,
(1985)
The
Effect
of
Benefin
EL110
Compound
54521)
onthe
Inductionof
Forward
Mutation
at
the
Thymidine
Kinase
Locus
of
L5178Y
Mouse
Lymphoma
Cells.
Toxicology
Division,
Lilly
Research
Laboratories,
Greenfield,
IN.
Laboratory
Study
Numbers
LINDANE
CANCER
ASSESSMENT
DOCUMENT
FINAL
REPORT
23
850612MLA2598
and
850724MLA2598,
October
1985.
Unpublished.

40693201
Berard,
D.
F.
(1988)
Characterization
and
Identification
of
Radioactivity
in
Urine
and
Feces
of
Rats
Dosed
with
14
C
Benefin.
Lilly
Research
Laboratories,
Greenfield,
IN.
Laboratory
Project
Id.
ABC­
0389,
April
4,
1988.
Unpublished.

40693202
Koenig,
G.
R.,
Pohland,
R.
C.
(1988)
Excretion
of
Radiocarbon
in
the
Expired
Air
of
Fischer
344
Rats
Given
a
Single
Oral
Dose
of
14
C­
Benefin
(EL­
110,
Compound
54521).
Lilly
Research
Laboratories,
Greenfield,
IN.
Laboratory
Project
Id.
R06087,
May
25,
1988.
Unpublished.

40693203
Koenig,
G.
R.,
Byrd,
T.
K.,
Pohland,
R.
C.
(1988)
Radiocarbon
Disposition
in
Fischer
344
Rats
Given
Single
Oral
Doses
of
14
C­
Benefin
(EL­
110,
Compound
54521):
Pharmacokinetics,
Excretion,
and
Residual
Tissue
Levels.
Lilly
Research
Laboratories,
Greenfield,
IN.
Laboratory
Project
Id.
R16687,
May
25,
1988.
Unpublished.

40693204
Koenig,
G.
R.,
Byrd,
T.
K.,
Pohland,
R.
C.
(1988)
Biliary
Excretion
of
Radioactivity
by
Fischer
344
Rats
Given
Single
Oral
Doses
of
14
C­
Benefin
EL110
Compound
54521).
Lilly
Research
Laboratories,
Greenfield,
IN.
Laboratory
Project
Id.
R09887
and
R23887,
May
25,
1988.
Unpublished.

40693205
Koenig,
G.
R.,
Byrd,
T.
K.,
Pohland,
R.
C.
(1988)
Tissue
Distribution
of
Radioactivity
in
Fischer
344
Rats
Given
Single
Oral
Doses
of
14
C­
Benefin
EL110
Compound
54521).
Lilly
Research
Laboratories,
Greenfield,
IN.
Laboratory
Project
Id.
R09887,
May
25,
1988.
Unpublished.

45291402.
Chase,
K.
(2000)
Lindane,
carcinogenicity
study
by
dietary
administration
to
CD­
1
mice
for
78
weeks,
final
report
(vols.
1­
4).
Huntingdon
Life
Sciences
Ltd.,
Woolley
Road,
Alconbury,
Huntingdon,
Cambridgeshire,
PE28
4HS,
England,
Report
no.
00
3512,
Huntingdon
Life
Sciences
Project
identity
no.
CIL/
021,
December
20,
2000.

42891201.
Aymes,
S.
J.
1993.
Lindane:
Combined
carcinogenicit
and
toxicity
study
by
dietary
administration
to
Wistar
rats
for
104
weeks.
Addendum
to
final
report
(Adrenal
histopathology
­
additional
investigations).
Life
Sciences
Research,
England.
Study
No.
90/
CIL002/
0839.
June
2,
1993
.
45470601
Huntingdon
Life
Sciences
Ltd.
Additional
histopathology
investigations
of
female
mouse
lung
tissues
conducted
by
Huntingdon
Life
Sciences
Ltd.,
Cambridgeshire,
England,
for
C.
I.
E.
L.
(Centre
International
Etudes
du
Lindane),
Brussels,
Belgium,
and
completed
July31,
2001
(Project
Identity
No.
CIL/
027.

00162724.
Huntington
Research
Center
(Lindane
toxicity
study
in
beagle
dogs)
report
#3720/
70/
532,
1970
LINDANE
CANCER
ASSESSMENT
DOCUMENT
FINAL
REPORT
24
­­­­­­­­­­­­
Boehringer
C.
H.
Sohn
Ingelheim
am
Rhein.;
(Testing
of
the
substance
Lindane
for
carcinogenic
effects
in
mice
using
oral
administration­
duration
80
weeks)
translated
from
German
(1975).

­­­­­­­­­­­­
Brunsman,
L.
L.
;
Lindane:
Qualitative
Risk
Assessment
Based
On
Crl:
CD­
1
(ICR)
BR
Mouse
Dietary
Study.
Memorandum
from
Lori
Brunsman,
Science
Information
Management
Branch,
to
Suhair
Shallal,
Reregistration
Branch
4,
Health
Effects
Division,
Office
of
Pesticide
Programs,
Environmental
Protection
Agency,
dated
May
1,
2001.
HED
Doc.#
014556.

­­­­­­­­­­­­
Brunsman,
L.
L.
;
ADDENDUMTo
Lidane:
Qualitative
Risk
Assessment
Memo
of
5/
1/
2001
Based
OnAdditional
HistopathologyInvestigations
of
Female
Lung
Tissues
of
Crl:
CD­
1(
ICR)
BR
Mouse
Dietary
Study.
MemorandumfromLori
Brunsman,
Science
Information
Management
Branch,
to
Suhair
Shallal,
Reregistration
Branch
4,
Health
Effects
Division,
Office
of
Pesticide
Programs,
Environmental
ProtectionAgency,
dated
August
16,
2001.
HEDDoc.#
014652.

­­­­­­­­­­­­
Fitzhugh,
O.
G.;
Nelson,
A.
A.;
and
Frawley,
J.
P.;
The
chronic
toxicities
of
technical
benzene
hexachloride
and
its
alpha,
beta
and
gamma
isomers
J.
Pharmacol.
Expt.
Therapeutics.
100:
59
(1950)..

­­­­­­­­­­­­
Goto,
M.;
Hattori,
M.;
Miyagawa,
T.;
and
Enomoto,
M..;
Contributions
to
ecological
chemistry
II.
Hepatoma
development
in
mice
after
administration
of
HCH
isomers
in
high
dosage
Chemosphere
1(
6):
279­
282
(1972).

­­­­­­­­­­­
Hanada,
M.;
Yutani,
C.;
and
Miya,
T.;
Induction
of
hepatoma
in
mice
with
benzene
hydrochloride
GANN
64:
511­
513
(1973).

­­­­­­­­­­
Ito,
N.;
Nagasaki,
H.;
Arai,
M.;
Sugihara,
S.;
and
Makiura,
S.;
Pathologic
and
ultrastructural
studies
in
the
hepatocarcinogenicity
of
benzene
hexachlooride
in
mice
J.
NCI
51:
817­
826
(1973).

­­­­­­­­­
Ito,
N.;
Nagasaki,
H.;
et
al.;
Brief
communication:
development
of
hepatocellular
carcinomas
in
rats
treated
with
benzene
hexachloride
J.
NCI
54:
801­
805
(1975).

­­­­­­­­­­
Lindane,
Environmental
HealthCriteria
124,
IPCS,
WHO,
Geneva,
Switzerland
(1991).

­­­­­­­­­­
Nagasaki,
H.;
Tonrii,
S.;
et
al.
;
Carcinogenicity
of
Benzene
Hexachloride
(BHC)
Proc.
of
2
nd
Intern
Symp
of
Princess
Tokamatsu
Cancer
Center
Res.
Fund
in
Topics
in
Chem.
Carcino.
1972
­­­­­­­­­­­
NCI.;
NTP
Combined
Chronic
Toxicity/
Carcinogenicity
Study
with
Lindane
in
Mice.
National
Cancer
Institute,
Carcinogenesis
Program,
Bethesda,
MD;
DHEW
Pub
#
(NIH)
77­
814
(1977).
25
­­­­­­­­­­
NCI;
NTP
Combined
Chronic
Toxicity/
Carcinogenicity
Study
with
Lindane
in
Rats.
National
Cancer
Institute,
Carcinogenesis
Program,
DHEWPub
#
(NIH)
77­
814
(1977).

­­­­­­­­­­
Ortega,
P.;
Hayes,
W.
J.;
and
Durham,
W.
F.;
Pathologic
changes
in
the
liver
of
rats
after
feeding
low
levels
of
various
insecticides
A.
M.
A.
Archives
of
Pathology,
64:
614,
(1957).

­­­­­­­­­­
Thorpe
and
Walker;
The
toxicology
of
dieldrin
(HEOD).
II.
Comparitive
longt
erm
oral
toxicity
studies
in
mice
with
dieldrin,
DDT,
phenobarbitone,
betaBHC
and
gamma­
BHC
Fd.
Cosmet.
Toxicol,
11:
433­
442
(1973).

­­­­­­­­­­
Wolff,
G.
L.,
Roberts,
D.
W.,
Morrissey,
R.
L.,
Greenman,
D.
L.,
Allen,
R.
R.,
Campbell,
W.
L.,
Bergman,
H.,
Nesnow,
S.,
and
Firth,
C.
H.
1987.
Tumorigenic
responses
to
lindane
in
mice:
potentiation
by
a
dominant
mutation.
Carcinogenesis
8:
1889­
1897
(1987).
National
Center
for
Toxicological
Research,
Jefferson,
AK.

APPENDIX
A
Carcinogenicity
Studies
comparing
the
toxicity
of
gamma­
HCH
with
other
isomers
Study
#
of
animals
doses
results
for
lindane
(gamma­
HCH)
results
for
other
isomers
Carcinogenicityrat
(The
chronic
toxicities
of
technical
benzene
hexachloride
and
its
alpha,
beta
and
gamma
isomers)
published:
1950
10

/10

Wistar
rat
0,
5,
10,
50,
100,
400,
800
or
1600
ppm
of

 
,

 
,
or

 
HCH.
At
100
ppm
of

 
HCH
,
liver
wt.
incr
no
frank
liver
tumors
induced
by

 
HCH
26
CarcinogenicityRats
(Pathologic
changes
in
the
liver
of
rats
after
feeding
low
levels
of
various
insecticides)
published:
1957
6

/
6

0,
50,
100
ppm
for
8
months.
One
50
ppm

,
and
one
each
100
ppm

and

developed
centrilobular
hypertrophy,
peripheral
migration
of
basophilic
cytoplasmic
granulations
and
cytoplasmic
inclusion
bodies.

Carcinogenicity
rats
(Brief
communication:
development
of
hepatocellular
carcinomas
in
rats
treated
with
benzene
hexachloride)
published:
1975.
9
groups
of

W
rats
(Japanese
strain)
0,
500,
1000
or
1500
ppm
of

 
,


 
,

 
,
or

 
BHC

 
 
 
BHC
:
cell
hypertrophy

 
 
 
BHC:
cell
hypertrophy,
nodular
hyperplasia
(27/
41
dosed
w/


1000
ppm
for
48­
72
wks),
hepatocellular
carcinoma
(4/
29
dosed
w/

1000
ppm
for
72
wks)

  
,
,
,

 
 
 
:cell
hypertrophy
Carcinogenicity
rats
(Bioassay
of
lindane
for
possible
carcinogenicity)
NCI
(NCI­
RG­
TR
14)
1977
10

/10

Osborne
Mendel
rats
50



50


0
ppm;

320
or
640
ppm
for
38
wks,
160
or
320
ppm
for
42
wks,
then
0
ppm
for
30
wks
320
or
640
for
2
wks,
160
or
320
ppm
for
49
wks,
80
or
160
ppm
for
29
wks,
then
0
ppm
for
30
wks.
Incidence
of
liver
neoplasia
is
within
historical
control
levels
Carcinogenicity
mice
(Bioassay
of
lindane
for
possible
carcinogenicity)
NCI
(NCI­
RG­
TR
14)
1977
10

/10

BGC3F1
hybrid
mice
50

/50

0
ppm
80
or
160
ppm
for
80
wks
then
control
diet
for
10
wks
hepatocellular
carcinoma:
0
ppm
(20%),
80
ppm
(39%),
160
ppm
(20%)
27
Carcinogenicitymouse
(The
toxicology
of
dieldrin
(HEOD).
II.
Comparitive
long­
term
oral
toxicity
studies
in
mice
with
dieldrin,
DDT,
phenobarbitone,
beta­
BHC
and
gamma­
BHC)
Thorpe
and
Walker
(1973).
CF1
mice
45

/45

30

/30

0
ppm
(24/
23%)

400
ppm
(gamma­
BHC)
10
ppm
(dieldrin)
100
ppm
(DDT)
500
ppm
(phenobarbitone)
200
ppm
betaBHC

/

%
of
liver
tumors
(gamma­
BHC)
93/
69%

/

%
of
liver
tumors
(dieldrin)
100/
87%
(DDT)
77/
87
%
(phenobarbitone)
80/
75%
(beta­
BHC)
73/
43
%

Carcinogenicitymouse
(Testing
of
the
substance
Lindane
for
carcinogenic
effects
in
mice
using
oral
administrationduration
80
weeks)
translated
from
German
1975
SPF
mice
ChbbNMRI
100

/
100

50

/50

0
ppm
12.5,
25
or
50
ppm
for
80
wks
incidences
(

/


)
liver
cell
adenomas:
4/
1,
1/
1,
0/
0,
2/
0
lung
tumor:
13/
8,
10/
1,
5/
3,
6/
4
lymphosarcoma
:
5/
12,
0/
7,
1/
3,
2/
5,
respectively
Carcinogenicitymouse
(Pathologic
and
ultrastructural
studies
in
the
hepatocarcinogenic
ity
of
benzene
hexachlooride
in
mice)
published
(1973)
19
groups
(20­
40/
group)

 
,

 
,

 
or

 
BHC
at
100,
250,
or
500
ppm
and
combos
of
250
ppm
ea.
of

 
with

 
,

 
,
or

 
BHC.
Only
mice
that
were
dosed
w/

 
BHC
in
combo.
or
alone
developed
nodular
hyperplasia
and
hepatocellular
carcinoma
Carcinogenicitymouse
(Contributions
to
ecological
chemistry
II.
Hepatoma
development
in
mice
after
administration
of
HCH
isomers
in
high
dosage.
Published:
(1972).
8
groups
of
20

ICR
JCL
mice
600
ppm
of
technical
HCH
(I),

 
HCH
(II)
,


 
HCH
(III),
  
HCH
(IV),
a
mix
of

 
/

 
HCH
(V),
or
300
ppm
of

 
HCH
(IX)
5/
10
in
gp
IX
developed
liver
tumors
and
incr.
Liver
wgt.
all
of
group
I
and
II
developed
hepatomas
8/
10
in
gp
V
developed
liver
tumors
and
incr.
Liver
wgt.
28
Carcinogenicitymouse
(Carcinogenicity
of
Benzene
Hexachloride
(BHC))
published:
(1972)
4
groups
of
dd
mice
0,
6.6,
66,
660
ppm
of
technical
BHC

 
(67%),


 
(11%),

 
(15%)
or

 
(6%)
BHC
and
other
isomers
<
1%
for
24
wks
at
all
doses:

liver
wgt,
cellular
hyperplasia,
nodular
hyperplasia,
all
660
ppm
mice
developed
hepatoma
Carcinogenicitymouse
(Induction
of
hepatoma
in
mice
with
benzene
hydrochloride)
published:
(1973).
4
groups
of
dd
mice
0,
100,
300
or
600
ppm
with
crude
BHC,
or
pure

 
,

 
,
or

 
isomer
for
36­
38
wks
No
control
and
100
or
300
ppm

 
isomer
mice
developed
hepatomas
many
mice
in
crude
BHC,
or
pure

 
isomer
developed
hepatoma,

Chronic
feeding
Dogs
(Lindane
toxicity
study
in
beagle
dogs)
1970
4
group
of
4
beagles/
sex
0,
25,
50,
or
100
ppm
for
104
wks
NOAEL:
50
ppm
LOAEL:
100
ppm
liver
changes,
slight
inc
liver
wt.
