National Cancer Institute 

CARCINOGENESIS 

Technical Report Series 

No. 68 

1978 

BIOASSAY OF 

HEXACHLOROETHANE 

FOR POSSIBLE CARCINOGENICITY 

CAS No. 67-72-1 

NCI-CG-TR-68 

U.S. DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE 

Public Health Service 

National Institutes of Health 

BIOASSAY OF
 

HEXACHLOROETHANE
 

FOR POSSIBLE CARCINOGENICITY
 

Carcinogenesis Testing Program
 

Division of Cancer Cause and Prevention
 

National Cancer Institute
 

National Institutes of Health
 

Bethesda, Maryland 20014
 

U.S. DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE
 

Public Health Service
 

National Institutes of Health
 

DHEW Publication No. (NIH) 78-1318
 

REPORT ON THE BIOASSAY OF HEXACHLOROETHANE
 

FOR POSSIBLE CARCINOGENICITY
 

CARCINOGENESIS TESTING PROGRAM
 

DIVISION OF CANCER CAUSE AND PREVENTION'
 

NATIONAL CANCER INSTITUTE, NATIONAL INSTITUTES OF HEALTH
 

FOREWORD: This report presents the results of the bioassay of hexachloroethane conducted for the Carcinogenesis Testing Program, Division of Cancer Cause and Prevention, National Cancer Institute (NCI),
 

National Institutes of Health, Bethesda, Maryland. This is one of a
 

series of experiments designed to determine whether selected environmental chemicals have the capacity to produce cancer in animals.
 

Negative results, in which the test animals do not have a greater
 

incidence of cancer than control animals, do not necessarily mean
 

the test chemical is not a carcinogen because the experiments are
 

conducted under a limited set of circumstances. Positive results
 

demonstrate that the test chemical is carcinogenic for animals under
 

the conditions of the test and indicate a potential risk to man. The
 

actual determination of the risk to man from animal carcinogens requires a wider analysis.
 

CONTRIBUTORS: This bioassay of hexachloroethane was conducted by
 

Hazleton Laboratories America, Inc., Vienna, Virginia, initially under
 

direct contract to the NCI and currently under a subcontract to Tracor
 

Jitco, Inc., prime contractor for the NCI Carcinogenesis Testing Program.
 

The experimental design was determined by the NCI Project Officers, Dr. J. Η. Weisburger (1,2) and Dr. E. K. Weisburger (1). The
 

principal investigators for the contract were Dr. Μ. Β. Powers (3),
 

Dr. R. W. Voelker (3), Dr. W. A. Olson (3,4) and Dr. W. M. Weatherholtz (3). Chemical analysis was performed by Dr. C. L. Guyton (3,
 

5) and the analytical results were reviewed by Dr. N. Zimmerman (6);
 

the technical supervisor of animal treatment and observation was Ms.
 

K. J. Petrovics (3).
 

Histopathologic examinations were performed by Dr. R. H. Habermann (3) and Dr. D. R. Patterson (3) and reviewed by Dr. R. W. Voelker
 

(3) at the Hazleton Laboratories America, Inc., and the diagnoses
 

included in this report represent the interpretation of these pathologists. Histopathology findings and reports were reviewed by Dr. R.
 

L. Schueler (7).
 

Compilation of individual animal survival, pathology, and summary tables was performed by EG&G Mason Research Institute (8); the
 

statistical analysis was performed by Mr. W. W. Belew (6) and Dr. J.
 

iii
 
R. Joiner (7), using methods selected for the Bioassay Program by Dr.
 

J. J. Gart (9).
 

This report was prepared at METREK, a Division of The MITRE Corporation (6) under the direction of the NCI. Those responsible for
 

this report at METREK are the project coordinator, Dr. L. W. Thomas
 

(6), the task leader, Dr. M. R. Kornreich (6), the senior biologist,
 

Ms. P. Walker (6), and the technical editor, Ms. P. A. Miller (6).
 

The final report was reviewed by members of the participating organizations .
 

The statistical analysis was reviewed by members of the Mathematical Statistics and Applied Mathematics Section of the NCI: Dr.
 

J. J. Gart (9), Mr. J. Nam (9), Dr. H. M. Pettigrew (9), and Dr. R.
 

E. Tarone (9).
 

The following other scientists at the National Cancer Institute
 

were responsible for evaluating the bioassay experiment, interpreting
 

the results, and reporting the findings: Dr. K. C. Chu (1), Dr. C.
 

Cueto, Jr. (1), Dr. J. F. Douglas (1), Dr. D. G. Goodman (1), Dr. R.
 

A. Griesemer (1), Dr. H. A. Milman (1), Dr. T. W. Orme (1), Dr. R. A.
 

Squire (1,10), and Dr. J. Μ. Ward (1).
 

1.	 Carcinogenesis Testing Program, Division of Cancer Cause and
 

Prevention, National Cancer Institute, National Institutes of
 

Health, Bethesda, Maryland.
 

2.	 Now with the Naylor Dana Institute for Disease Prevention, American Health Foundation, Hammon House Road, Valhalla, New York.
 

3.	 Hazleton Laboratories America, Inc., 9200 Leesburg Turnpike,
 

Vienna, Virginia.
 

4.	 Now with the Center for Regulatory Services, 2347 Paddock Lane,
 

Reston, Virginia.
 

5.	 Now with Rhodia, Inc., 23 Belmont Drive, Somerset, New Jersey.
 

6.	 The MITRE Corporation, METREK Division, 1820 Dolley Madison
 

Boulevard, McLean, Virginia.
 

7.	 Tracor Jitco, Inc., 1776 East Jefferson Street, Rockville,
 

Maryland.
 

8.	 EG&G Mason Research Institute, 1530 East Jefferson Street,
 

Rockville, Maryland.
 

iv
 
9.	 Mathematical Statistics and Applied Mathematics Section, Biometry
 

Branch, Field Studies and Statistics Program, Division of Cancer
 

Cause and Prevention, National Cancer Institute, National Institutes of Health, Bethesda, Maryland.
 

10.	 Now with the Division of Comparative Medicine, Johns Hopkins
 

University, School of Medicine, Traylor Building, Baltimore,
 

Maryland.
 

SUMMARY
 

A bioassay for possible carcinogenicity of technical-grade hexachloroethane was conducted using Osborne-Mendel rats and B6C3F1 mice.
 

Hexachloroethane in corn oil was administered by gavage, at either of
 

two dosages, to groups of 50 male and 50 female animals of each species. The chemical was administered 5 days a week, cyclically for 44
 

of 78 weeks in rats and continuously for 78 weeks in mice, followed
 

by an observation period of 33 or 34 weeks for rats and 12 or 13 weeks
 

for mice. The high and low time-weighted average dosages of hexachloroethane were, respectively, 423 and 212 mg/kg/day for male and female
 

rats and 1179 and 590 mg/kg/day for male and female mice. For each
 

species, 20 animals of each sex were placed on test as vehicle controls. These animals were gavaged with pure corn oil at the same rate
 

as the high dose group of the same sex. Twenty animals of each sex
 

were placed on test as untreated controls for each species. These
 

animals were not intubated.
 

A statistically significant association between increased dosage
 

and accelerated mortality was observed in male and female rats but not
 

in mice of either sex.
 

Toxic tubular nephropathy was observed in all groups of treated
 

animals.
 

Statistical evaluation of the incidences of hepatocellular carcinomas revealed a significant positive association between hexachloroethane administration and tumor incidence in both male and female
 

mice. No statistical significance was attributed to the incidence of
 

any neoplasm in rats of either sex.
 

No evidence was provided for the carcinogenicity of the compound
 

in Osborne-Mendel rats. It is concluded that: under the conditions of
 

this bioassay, hexachloroethane was carcinogenic in B6C3F1 mice, inducing hepatocellular carcinomas in both sexes.
 

vii
 

TABLE OF CONTENTS
 

Page
 

I. INTRODUCTION 1
 

II. MATERIALS AND METHODS 3
 

A. Chemicals 3
 

B. Dosage Preparation 4
 

C. Animals 4
 

D. Animal Maintenance 5
 

E. Gastric Intubation 6
 

F. Selection of Initial Dose Levels 6
 

G. Experimental Design 8
 

H. Clinical and Histopathologic Examinations 11
 

I. Data Recording and Statistical Analyses 13
 

III. CHRONIC TESTING RESULTS: RATS 18
 

A. Body Weights and Clinical Observations 18
 

B. Survival 20
 

C. Pathology 22
 

D. Statistical Analyses of Results 23
 

IV. CHRONIC TESTING RESULTS: MICE 29
 

A. Body Weights and Clinical Observations 29
 

B. Survival 29
 

C. Pathology 32
 

D. Statistical Analyses of Results 33
 

V. DISCUSSION 41
 

VI. BIBLIOGRAPHY 43
 

APPENDIX A SUMMARY OF THE INCIDENCE OF NEOPLASMS IN
 

RATS TREATED WITH HEXACHLOROETHANE A-l
 

APPENDIX Β SUMMARY OF THE INCIDENCE OF NEOPLASMS IN
 

MICE TREATED WITH HEXACHLOROETHANE B-l
 

APPENDIX C SUMMARY OF THE INCIDENCE OF NONNEOPLASTIC
 

LESIONS IN RATS TREATED WITH HEXACHLOROETHANE C-l
 

APPENDIX D SUMMARY OF THE INCIDENCE OF NONNEOPLASTIC
 

LESIONS IN MICE TREATED WITH HEXACHLOROETHANE D-l
 

ix
 
LIST OF ILLUSTRATIONS
 

Figure Number 

1 GROWTH CURVES FOR HEXACHLOROETHANE CHRONIC 

STUDY RATS 19 

SURVIVAL COMPARISONS OF HEXACHLOROETHANE 

CHRONIC STUDY RATS 21 

GROWTH CURVES FOR HEXACHLOROETHANE CHRONIC 

STUDY MICE 30 

SURVIVAL COMPARISONS OF HEXACHLOROETHANE 

CHRONIC STUDY MICE 31 

LIST OF TABLES 

Table Number Page 

DESIGN SUMMARY FOR OSBORNE-MENDEL RATS— 

HEXACHLOROETHANE GAVAGE EXPERIMENT 

DESIGN SUMMARY FOR B6C3F1 MICE—HEXACHLOROETHANE GAVAGE EXPERIMENT 10 

ANALYSES OF THE INCIDENCE OF PRIMARY TUMORS 

AT SPECIFIC SITES IN MALE RATS TREATED WITH 

HEXACHLOROETHANE WHICH SURVIVED AT LEAST 52 

WEEKS 24 

ANALYSES OF THE INCIDENCE OF PRIMARY TUMORS 

AT SPECIFIC SITES IN FEMALE RATS TREATED 

WITH HEXACHLOROETHANE 26 

ANALYSES OF THE INCIDENCE OF PRIMARY TUMORS 

AT SPECIFIC SITES IN MALE MICE TREATED WITH 

HEXACHLOROETHANE 34 

ANALYSES OF THE INCIDENCE OF PRIMARY TUMORS 

AT SPECIFIC SITES IN FEMALE MICE TREATED 

WITH HEXACHLOROETHANE 36 

ANALYSES OF THE INCIDENCE OF PRIMARY TUMORS 

AT SPECIFIC SITES IN MALE MICE TREATED WITH 

HEXACHLOROETHANE WHICH SURVIVED AT LEAST 41 

WEEKS 39 
LIST OF TABLES (Concluded) 

Table Number Page 

Al SUMMARY OF THE INCIDENCE OF NEOPLASMS IN 

MALE RATS TREATED WITH HEXACHLOROETHANE A-3 

A2 SUMMARY OF THE INCIDENCE OF NEOPLASMS IN 

FEMALE RATS TREATED WITH HEXACHLOROETHANE A-7 

Bl SUMMARY OF THE INCIDENCE OF NEOPLASMS IN 

MALE MICE TREATED WITH HEXACHLOROETHANE B-3 

B2 SUMMARY OF THE INCIDENCE OF NEOPLASMS IN 

FEMALE MICE TREATED WITH HEXACHLOROETHANE B-6 

CI SUMMARY OF THE INCIDENCE OF NONNEOPLASTIC 

LESIONS IN MALE RATS TREATED WITH HEXACHLOROETHANE C-3 

C2 SUMMARY OF THE INCIDENCE OF NONNEOPLASTIC 

LESIONS IN FEMALE RATS TREATED WITH HEXACHLOROE THANE C-10 

Dl SUMMARY OF THE INCIDENCE OF NONNEOPLASTIC 

LESIONS IN MALE MICE TREATED WITH HEXACHLOROETHANE D-3 

D2 SUMMARY OF THE INCIDENCE OF NONNEOPLASTIC 

LESIONS IN FEMALE MICE TREATED WITH HEXACHLOROE THANE D-7 

xi
 

I. INTRODUCTION
 

Hexachloroethane (NCI No. C04604), a chlorinated alkane with a
 

wide variety of uses, was selected for bioassay by the National Cancer
 

Institute because of its structural similarity to chloroform, a compound which has been found to induce hepatomas in NLC mice (Rudali,
 

1967).
 

The Chemical Abstracts Service (CAS) Ninth Collective Index
 

(1977) name for this compound is hexachloro-ethane. It is also known
 

as carbon hexachloride, perchloroethane, ethylene hexachloride, and
 

Avlothane® 

.
 

Hexachloroethane is used as a veterinary anthelmintic for control
 

of liver and stomach flukes in domestic animals (Farm Chemicals Handbook, 1976). It is also used as a solvent, a camphor substitute in
 

®
 the preparation of Celluloid , a rubber vulcanizing accelerator, a
 

retarding agent in fermentation, and in explosives, pyrotechnics, and
 

smoke devices (Hawley, 1971; Windholz, 1976).
 

Specific production figures for hexachloroethane are not available; however, the inclusion of the compound in the 1977 Directory of
 

Chemical Producers, U.S.A. (Stanford Research Institute, 1977) implies
 

an annual production in excess of 1000 pounds or $1000 in value.
 

The risk of exposure to hexachloroethane is greatest for workers
 

in the chemical, rubber, plastics, pharmaceutical and explosives
 

The CAS registry number is 67-72-1,
 
industries, and for those persons using the compound for veterinary
 

purposes. The risk of inhaling hexachloroethane vapor in industrial
 

settings is minimal because the compound is a solid with a relatively
 

low vapor pressure (Irish, 1967); consequently, exposure would occur
 

primarily through dermal contact or ingestion.
 

The major physiological effect of hexachloroethane is depression
 

of the central nervous system. Ingestion of the compound results in
 

severe injury to the mucous membranes and often in liver necrosis
 

(Gosselin et al., 1976).
 
II. MATERIALS AND METHODS
 

A. Chemicals
 

One batch of technical-grade hexachloroethane was purchased from
 

Aldrich Chemical Company by Hazleton Laboratories America, Inc.,
 

Vienna, Virginia. The purity of the compound was determined at
 

Hazleton Laboratories, using gas-liquid chromatography (GLC) total-


area analysis and melting point tests. The initial GLC analysis
 

showed five peaks; one, hexachloroethane, accounted for almost 99
 

percent of the total area while the other four accounted for approximately 1 percent of the total area. Additional analyses were performed one and two years after the initiaal analyses. In the second
 

analysis by GLC, hexachloroethane accounted for over 98 percent of
 

the total area and in the third GLC analysis, the hexachloroethane
 

peak accounted for almost 100 percent of the total area. It was
 

concluded that these determinations of hexachloroethane purity by GLC
 

agreed favorably with the vendor's stated purity of 98 percent and
 

that the chemical was stable under the laboratory storage conditions.
 

In the literature it is indicated that hexachloroethane sublimes
 

at 187°C. In an open capillary the test material began to melt at
 

183.5°C and all the material sublimed at 188.0°C. In a sealed capillary, a melting point of 184.7° to 185.3°C was obtained. The narrow
 

melting point range indicated a material of high purity.
 

Throughout this report the term hexachloroethane is used to
 

represent this technical-grade material.
 

3
 
.	 Dosage Preparation
 

®
 Fresh solutions of hexachloroethane in Duke's corn oil (S. F.
 

Sauer Company, Richmond, Virginia) were prepared weekly, sealed, and
 

stored in dark bottles at 24°C. These hexachloroethane solutions
 

were considered generally stable for 10 days under the indicated
 

storage conditions. The concentration of hexachloroethane in the
 

corn oil was 10 percent for the rat bioassay and 10 to 12 percent for
 

the mouse bioassay.
 

C.	 Animals
 

Two animal species, rats and mice, were used in the carcinogenicity bioassay. The Osborne-Mendel rat was selected on the basis of a
 

comparative study of the tumorigenic responsiveness to carbon tetrachloride of five different strains of rats (Reuber and Glover, 1970).
 

The B6C3F1 mouse was selected because it has been used by the NCI for
 

carcinogenesis bioassays and has proved satisfactory in this capacity.
 

Rats and mice of both sexes were obtained through contracts with
 

the Division of Cancer Treatment, National Cancer Institute. The
 

Osborne-Mendel rats were procured from the Battelle Memorial Institute, Columbus, Ohio, and the B6C3F1 mice were obtained from the
 

Charles River Breeding Laboratories, Inc., Wilmington, Massachusetts.
 

Upon receipt, animals were quarantined for at least 10 days, observed
 

for visible signs of disease or parasites, and assigned to the various
 

dosed and control groups.
 
D. Animal Maintenance
 

All animals were housed by species in temperature- and humidity-


controlled rooms. The temperature range was 20° to 24°C and the
 

relative humidity was maintained between 45 and 55 percent. The air
 

conditioning system in the laboratory provided filtered air at a rate
 

of 12 complete changes of room air per hour. Fluorescent lighting
 

was provided on a 12-hour-daily cycle. The rats were individually
 

housed in suspended galvanized-steel wire-mesh cages with perforated
 

floors. Mice were housed by sex in groups of ten in solid-bottom
 

polypropylene cages equipped with filter tops. Sanitized cages with
 

fresh bedding (Sanichips , Pinewood Sawdust Company, Moonachie, New
 

Jersey) were provided once each week for mice. Rats received sanitized cages with no bedding with the same frequency. Food hoppers
 

were changed and heat-sterilized once a week for the first 10 weeks
 

and once a month thereafter. Fresh heat-sterilized glass water botties were provided three times a week. Food (Wayne Lab-Blox meal,
 

Allied Mills, Inc., Chicago, Illinois) and water were available ad
 

libitum.
 

The rats dosed with hexachloroethane and both the vehicle and
 

untreated controls were housed in the same room with rats intubated
 

with 3-sulfolene (77-79-2) and iodoform (75-47-8).
 

The hexachloroethane-dosed and all control mice were housed in
 

the same room as mice intubated with allyl chloride (107-05-1),
 

*	 .
 

CAS registry numbers are given in parentheses.
 
chloroform (67-66-3), chloropicrin (76-06-2), dibromochloropropane
 

(96-12-8), 1,2-dibromoethane (106-93-4), 1,2-dichloroethane (107-06­

2 ), 1,1-dichloroethane (75-34-3), 3-sulfolene (77-79-2), trichloroethylene (79-01-6),iodoform (75-47-8), methylchloroform (71-55-6),
 

1,1,2-trichloroethane (79-00-5), tetrachloroethylene (127-18-4),
 

1,1,2,2-tetrachloroethane (79-34-5), carbon disulfide (75-15-0),
 

trichlorofluoromethane (75-69-4), and carbon tetrachloride (56-23-5).
 

Ε. Gastric Intubation
 

Intubation was performed for five consecutive days per week on
 

a mg/kg of body weight basis, utilizing the most recently observed
 

group mean body weight as a guide for determining the dose. Mean
 

body weights for each group were recorded at weekly intervals for the
 

first 10 weeks and at monthly intervals thereafter. All animals of
 

one sex within a treated group received the same dose. Animals were
 

gavaged with hexachloroethane solutions under a hood to minimize extraneous exposure of other animals and laboratory personnel to the
 

chemical.
 

F.	 Selection of Initial Dose Levels
 

In order to establish the estimated maximum tolerated dosages of
 

hexachloroethane for administration to treated animals in the chronic
 

studies, subchronic toxicity tests were conducted with both rats and
 

mice. Animals of each species were distributed among six groups,
 

each consisting of five males and five females. Hexachloroethane
 

mixed with corn oil was introduced by gavage to five of the six rat
 
groups at dosages of 178, 316, 562, 1000, and 1780 mg/kg/day and five
 

of the six mouse groups at dosages of 316, 562, 1000, 1780, and 3160
 

mg/kg/day. The sixth group of each species served as a control group,
 

receiving only the corn oil by gavage. Intubation was performed 5
 

days per week for 6 weeks, followed by a 2-week observation period to
 

detect any delayed toxicity.
 

A dosage inducing no mortality and resulting in a depression in
 

mean group body weight of approximately 20 percent relative to controls was to be selected as the initial high dose. When weight gain
 

criteria were not applicable, mortality data alone were utilized.
 

At a level of 562 mg/kg/day all the male and female rats survived to the end of the 8-week period. Some rats survived dosages of
 

1000 mg/kg/day, but all rats receiving dosages of 1780 mg/kg/day died
 

before the 8 weeks were over. Mean body weight gain of male and female rats receiving dosages of 316 mg/kg/day or less was similar to
 

that of controls. At 1000 mg/kg/day mean body weight depression was
 

38 percent for male rats and 18 percent for female rats. The initial
 

dosage used in the chronic bioassay for both high dose males and females was 500 mg/kg/day.
 

All male mice survived dosages of 1000 mg/kg/day or less and all
 

female mice survived dosages of 1780 mg/kg/day or less. However, at
 

doses of 3160 mg/kg/day four out of five male mice and three out of
 

five female mice died. Mean body weight gain in mice receiving
 
dosages of 1000 mg/kg/day or less (except in the group of female mice
 

receiving 562 mg/kg/day) was similar to that of controls. Mean body
 

weight gain was substantially depressed in mice receiving dosages of
 

3160 mg/kg/day. The initial high dose selected for the chronic bioassay was 1000 mg/kg/day for both male and female mice.
 

G. Experimental Design
 

The experimental design parameters for the chronic study (species, sex, group size, dosages administered, duration of treated and
 

untreated observation periods, and the time-weighted average dosages)
 

are summarized in Tables 1 and 2.
 

The untreated control and all treated rats were approximately 6
 

weeks old at the time the experiment began. The vehicle control rats
 

were approximately 8 weeks older than the other rat groups and were
 

started on test 6 weeks before the others. The vehicle control animals were approximately 8 weeks old when they received their first
 

intubation. The doses utilized throughout the 78-week intubation
 

period for both male and female rats were 250 and 500 mg/kg/day.
 

Throughout this report rats receiving the former dosage are referred
 

to as the low dose groups while those receiving the latter dosage are
 

referred to as the high dose groups. In week 23 intubation ceased
 

for all treated animals for 1 week, followed by 4 weeks of dose
 

administration. This pattern of cyclic administration was maintained
 

for the remainder of the dosing period. After the period of compound
 
TABLE 1
 

DESIGN SUMMARY FOR OSBORNE-MENDEL RATS
 

HEXACHLOROETHANE GAVAGE EXPERIMENT
 

TIME-WEIGHTED 

INITIAL HEXACHLORO­ OBSERVATION PERIOD AVERAGE DOSAGE 

GROUP ETHANE TREATED UNTREATED OVER A 78-WEEK 

SIZE DOSAGEa (WEEKS) (WEEKS) PERIODb 

MALE
 

UNTREATED CONTROL 20 0 112 0
 

VEHICLE CONTROL 20 0 78 33 0
 

LOW DOSE 50 250 22 212
 

250c 44 12
 

0 34
 

HIGH DOSE 50 500 22 423
 

500° 44 12
 

0 34
 

FEMALE
 

UNTREATED CONTROL 20 0 112 0
 

VEHICLE CONTROL 20 0 78 33 0
 

LOW DOSE 50 250 22 212
 

250C 44 12
 

0 34
 

HIGH DOSE 50 500 22 423
 

500° 44 12
 

0 34
 

aDoses, given in mg/kg body weight, were administered by gavage 5 consecutive
 

days per week.
 

b Σ(dosage X weeks received)
 Time-weighted average dosage =
 78 weeks
 

c,
 

These dosages were cyclically administered with a pattern of 1 dose-free
 

week followed by 4 weeks of dosing at the indicated levels.
 
MALE
 

UNTREATED CONTROL
 

VEHICLE CONTROL
 

LOW DOSE
 

HIGH DOSE
 

FEMALE
 

UNTREATED CONTROL
 

VEHICLE CONTROL
 

LOW DOSE
 

HIGH DOSE
 

TABLE 2
 

DESIGN SUMMARY FOR B6C3F1 MICE
 

HEXACHLOROETHANE GAVAGE EXPERIMENT
 

INITIAL HEXACHLORO­ OBSERVATION PERIOD 

GROUP ETHANE TREATED UNTREATED 

SIZE DOSAGEa (WEEKS) (WEEKS) 

20 90
 

20 78 12
 

50 500 8
 

600 70
 

0 13
 

50 1000 8
 

1200 70
 

0 13
 

20 90
 

20 78 13
 

50
 500 8
 

600 70
 

0 13
 

50 1000 8
 

1200 70
 

0 13
 

TIME-WEIGHTED
 

AVERAGE
 

DOSAGEb
 

590
 

1179
 

590
 

1179
 

Doses, given in mg/kg body weight, were administered by gavage 5 consecutive
 

days per week.
 

Σ(dosage X weeks received)
 Time-weighted average dosage =
 Σ(weeks receiving chemical)
 

10
 
administration the animals were observed for an additional 33 or 34
 

weeks.
 

The vehicle control and treated mice were approximately 5 weeks
 

old at the time they were started on test while the untreated control
 

mice were approximately 6 weeks old. The vehicle control and treated
 

mice shared the same median date of birth while the untreated control
 

mice were approximately 7 weeks older. Therefore, the untreated
 

controls were placed on test approximately 6 weeks earlier than the
 

other groups. The doses initially administered to male and female
 

mice were 500 and 1000 mg/kg/day. Throughout this report those mice
 

initially receiving the former dosage are referred to as the low dose
 

groups while those receiving the latter dosage are referred to as the
 

high dose groups. In week 9 the low and high doses were increased to
 

600 and 1200 mg/kg/day and these doses were utilized for the remainder of the dosing period. After the dosing period the animals were
 

observed for 12 or 13 weeks.
 

H. Clinical and Histopathologic Examinations
 

Animals were weighed immediately prior to initiation of the
 

experiment. From the first day, all animals were inspected daily
 

for mortality. Body weights, food consumption, and data concerning
 

appearance, behavior, signs of toxic effects, and incidence, size,
 

and location of tissue masses were recorded at weekly intervals for
 

the first 10 weeks and at monthly intervals thereafter. The presence
 

11
 
of tissue masses was determined by observation and palpation of each
 

animal.
 

A necropsy was performed on each animal regardless of whether it
 

died, was killed when moribund, or was sacrificed at the end of the
 

bioassay. The animals were euthanized by exsanguination under sodium
 

pentobarbital anesthesia, and were immediately necropsied. The histopatologic examination consisted of gross and microscopic examination
 

of major tissues, organs, or gross lesions taken from sacrificed
 

animals and, whenever possible, from animals found dead.
 

Slides were prepared from the following tissues: subcutaneous
 

tissue, lungs and bronchi, trachea, bone marrow, spleen, lymph nodes,
 

thymus, heart, salivary gland, liver, gallbladder and bile duct
 

(mice), pancreas, esophagus, stomach, small intestine, large intestine, kidney, urinary bladder, pituitary, adrenal, thyroid, parathyroid, testis, prostate, brain, muscle, tunica vaginalis, uterus,
 

mammary gland, and ovary.
 

Tissues for which slides were prepared were preserved in 10 percent buffered formalin, embedded in paraffin, sectioned, and stained
 

with hematoxylin and eosin prior to microscopic examination. An
 

occasional section was subjected to special staining techniques for
 

more definitive diagnosis.
 

A few tissues were not examined for some animals, particularly
 

for those that died early. Also, some animals were missing, cannibalized, or judged to be in such an advanced state of autolysis as to
 

12
 
preclude histopathologic interpretation. Thus, the number of animals
 

for which particular organs, tissues, or lesions were examined microscopically varies and does not necessarily represent the number of
 

animals that were placed on experiment in each group.
 

I. Data Recording and Statistical Analyses
 

Pertinent data on this experiment have been recorded in an automatic data processing system, the Carcinogenesis Bioassay Data System
 

(Linhart et al., 1974). The data elements include descriptive information on the chemicals, animals, experimental design, clinical observations, survival, body weight, and individual pathologic results, as
 

recommended by the International Union Against Cancer (Berenblum,
 

1969). Data tables were generated for verification of data transcription and for statistical review.
 

These data were analyzed using the statistical techniques
 

described in this section. Those analyses of the experimental results
 

that bear on the possibility of carcinogenicity are discussed in the
 

statistical narrative sections.
 

Probabilities of survival were estimated by the product-limit
 

procedure of Kaplan and Meier (1958) and are presented in this report
 

in the form of graphs. Animals were statistically censored as of the
 

time that they died of other than natural causes or were found to be
 

missing; animals dying from natural causes were not statistically
 

censored. Statistical analyses for a possible dose-related effect on
 

survival used the method of Cox (1972) for testing two groups for
 

13
 
equality and used Tarone's (1975) extensions of Cox's methods for
 

testing a dose-related trend. One-tailed P-values have been reported
 

for all tests except the departure from linearity test, which is only
 

reported when its two-tailed P-value is less than 0.05.
 

The incidence of neoplastic or nonneoplastic lesions has been
 

given as the ratio of the number of animals bearing such lesions at a
 

specific anatomic site (numerator) to the number of animals in which
 

that site was examined (denominator). In most instances, the denominators included only those animals for which that site was examined
 

histologically. However, when macroscopic examination was required
 

to detect lesions prior to histologic sampling (e.g., skin or mammary
 

tumors), or when lesions could have appeared at multiple sites (e.g.,
 

lymphomas), the denominators consist of the numbers of animals necropsied.
 

The purpose of the statistical analyses of tumor incidence is to
 

determine whether animals receiving the test chemical developed a significantly higher proportion of tumors than did the control animals.
 

As a part of these analyses, the one-tailed Fisher exact test (Cox,
 

1970, pp. 48-52) was used to compare the tumor incidence of a control
 

group to that of a group of treated animals at each dose level. When
 

results for a number of treated groups, k, are compared simultaneously
 

with those for a control group, a correction to ensure an overall
 

significance level of 0.05 may be made. The Bonferroni inequality
 

(Miller, 1966, pp. 6-10) requires that the P-value for any comparison
 

14
 
be less than or equal to 0.05/k. In cases where this correction was
 

used, it is discussed in the narrative section. It is not, however,
 

presented in the tables, where the Fisher exact P-values are shown.
 

The Cochran-Armitage test for linear trend in proportions, with
 

continuity correction (Armitage, 1971, pp. 362-365), was also used.
 

Under the assumption of a linear trend, this test determined if the
 

slope of the dose-response curve is different from zero at the
 

one-tailed 0.05 level of significance. Unless otherwise noted, the
 

direction of the significant trend was a positive dose relationship.
 

This method also provides a two-tailed test of departure from linear
 

trend.
 

A time-adjusted analysis was applied when numerous early deaths
 

resulted from causes that were not associated with the formation of
 

tumors. In this analysis, deaths that occurred before the first
 

tumor was observed were excluded by basing the statistical tests on
 

animals that survived at least 52 weeks, unless a tumor was found at
 

the anatomic site of interest before week 52. When such an early
 

tumor was found, comparisons were based exclusively on animals that
 

survived at least as long as the animal in which the first tumor was
 

found. Once this reduced set of data was obtained, the standard procedures for analyses of the incidence of tumors (Fisher exact tests,
 

Cochran-Armitage tests, etc.) were followed.
 

When appropriate, life-table methods were used to analyze the
 

incidence of tumors. Curves of the proportions surviving without an
 

15
 
observed tumor were computed as in Saffiotti et al. (1972). The week
 

during which animals died naturally or were sacrificed was entered as
 

the time point of tumor observation. Cox's methods of comparing
 

these curves were used for two groups; Tarone's extension to testing
 

for linear trend was used for three groups. The statistical tests for
 

the incidence of tumors which used life-table methods were one-tailed
 

and, unless otherwise noted, in the direction of a positive dose
 

relationship. Significant departures from linearity (P < 0.05, two-


tailed test) were also noted.
 

The approximate 95 percent confidence interval for the relative
 

risk of each dosed group compared to its control was calculated from
 

the exact interval on the odds ratio (Gart, 1971). The relative risk
 

is defined as ρ t /ρc where ρt is the true binomial probability of the
 

incidence of a specific type of tumor in a treated group of animals
 

and ρ c is the true probability of the spontaneous incidence of the
 

same type of tumor in a control group. The hypothesis of equality
 

between the true proportion of a specific tumor in a treated group
 

and the proportion in a control group corresponds to a relative risk
 

of unity. Values in excess of unity represent the condition of a
 

larger proportion in the treated group than in the control.
 

The lower and upper limits of the confidence interval of the
 

relative risk have been included in the tables of statistical analyses. The interpretation of the limits is that in approximately 95
 

percent of a large number of identical experiments, the true ratio
 

16
 
of the risk in a treated group of animals to that in a control group
 

would be within the interval calculated from the experiment. When
 

the lower limit of the confidence interval is greater than one, it
 

can be inferred that a statistically significant result (a P < 0.025
 

one-tailed test when the control incidence is not zero, Ρ < 0.050
 

when the control incidence is zero) has occurred. When the lower
 

limit is less than unity but the upper limit is greater than unity,
 

the lower limit indicates the absence of a significant result while
 

the upper limit indicates that there is a theoretical possibility
 

of the induction of tumors by the test chemical which could not be
 

detected under the conditions of this test.
 

17
 
III. CHRONIC TESTING RESULTS:
 

A. Body Weights and Clinical Observations
 

Distinct dose-related depression in mean body weight was evident
 

in male rat groups (Figure 1). For female rats, low dose and control
 

groups exhibited similar growth patterns, but mean body weight of
 

high dose rats was slightly depressed relative to the other female
 

rat groups. Fluctuations in the growth curve may be due to mortality;
 

as the size of the group diminishes, the mean body weight may be subject to wide variations.
 

During the first year of the study the incidence of observed
 

clinical signs was slightly increased in the treated rats when
 

compared to the untreated controls. The signs observed with the most
 

frequency were hunched appearance; reddened, squinted or lacrimating
 

eyes; and abdominal urine stains. The incidences of these signs were
 

comparable between low and high dose animals; however, the high dose
 

females showed a higher frequency of abdominal urine staining from
 

week 4 until termination of the bioassay. During the second year of
 

the study, behavior and appearance were comparable between treated
 

and control animals.
 

Respiratory abnormalities were observed in all groups during the
 

latter part of the first year. The incidence of respiratory symptoms
 

increased at gradual and comparable rates for all groups during the
 

last six months of the study. Clinical observations associated with
 

aging in laboratory rats were noted in comparable numbers of treated
 

18
 
TIME ON TEST (WEEKS) 

FIGURE 1 

GROWTH CURVES FOR HEXACHLOROETHANE CHRONIC STUDY RATS 

I9 
and untreated controls during the second year. These signs included:
 

sores on the tail or other parts of the body, alopecia, discolored or
 

rough fur, eye discharge or red crust around the eyes and palpable
 

nodules and/or tissue masses. Isolated, apparently spontaneous observations noted in several treated rats included transient tremors,
 

vaginal discharge and ataxia.
 

. Survival
 

The estimated probabilities of survival for male and female rats
 

in the control and hexachloroethane-dosed groups are shown in Figure
 

2.
 

For male rats the Tarone test indicated a significant (P < 0.001)
 

association between increased dosage and accelerated mortality.
 

Thirty-eight percent (19/50) of the high dose and 48 percent (24/50)
 

of the low dose males survived at least 90 weeks, compared to 70 percent (14/20) of the untreated controls, and, despite the sacrifice of
 

seven rats in week 60, 55 percent (11/20) of the vehicle controls.
 

For female rats mortality was significantly increased in the
 

dosed groups compared to the untreated groups. The actual survival,
 

however, was adequate for statistical analysis of late-developing
 

tumors as 48 percent (24/50) of the high dose, 54 percent (27/50) of
 

the low dose, 70 percent (14/20) of the vehicle control, and 70 percent (14/20) of the untreated control rats survived until the end of
 

the test.
 

20
 
FIGURE 2

 

SURVIVAL COMPARISONS OF HEXACHLOROETHANE CHRONIC STUDY RATS 

2I 
C. Pathology
 

Histopathologic findings on neoplasms in rats are summarized in
 

Appendix A (Tables Al and A2); findings on nonneoplastic lesions are
 

summarized in Appendix C (Tables C1 and C2).
 

Each of the tumor types detected has been encountered previously
 

as a spontaneous lesion in Osborne-Mendel rats and no appreciable
 

difference in frequency was noted between the control and treated
 

rats.
 

With the exception of certain renal lesions, inflammatory,
 

degenerative, and proliferative lesions seen in control and treated
 

rats were similar in number and kind to those naturally occurring
 

lesions found in aged rats. In addition to the chronic inflammatory
 

lesions of the kidney seen in control and treated animals, toxic tubular nephropathy was associated with compound exposure. The lesion
 

occurred in 22/49 (45 percent) low dose males, 33/50 (66 percent)
 

high dose males, 9/50 (18 percent) low dose females, and 29/49 (59
 

percent) high dose females and was characterized by degeneration,
 

necrosis, and the presence of large hyperchromatic regenerative epithelial cells. Overlying the tubular lesions were chronic interstitial nephritis and fibrosis, focal pyonephritis, tubular ectasia,
 

cast formation, and focal glomerulosclerosis. Renal tubular-cell
 

adenomas were found in four low dose male rats.
 

In conclusion, there is no histopathologic evidence that hexachloroethane is carcinogenic in Osborne-Mendel rats under the
 

22
 
conditions of this experiment. Toxic tubular nephropathy was present
 

in rats of both sexes at both dose levels, but not in the control
 

rats.
 

D. Statistical Analyses of Results
 

The results of the statistical analyses of tumor incidence in
 

rats are summarized in Tables 3 and 4. The analysis for every type
 

of tumor that was observed in more than 5 percent of any of the
 

hexachloroethane-dosed groups of either sex is included. Because of
 

the high early mortality in the high dose males, the statistical
 

analyses for males (Table 3) are based exclusively upon rats which
 

survived at least 52 weeks.
 

For male rats the Cochran-Armitage test indicated a significant
 

(P = 0.048) positive association between dosage and the incidence of
 

interstitial-cell tumors of the testis. The Fisher exact tests, however, were not significant. Renal tubular-cell adenomas, found in
 

four low dose male rats, were not statistically significant.
 

For female rats a significant negative association between dosage and the incidence of pituitary chromophobe adenomas was indicated
 

by the Cochran-Armitage test. The Fisher exact tests, however, were
 

not significant under the Bonferroni criterion.
 

Based upon these results there was no conclusive statistical
 

evidence that hexachloroethane was a carcinogen in Osborne-Mendel
 

rats.
 

23
 
___ 

TABLE 3
 

ANALYSES OF THE INCIDENCE OF PRIMARY TUMORS AT
 

SPECIFIC SITES IN MALE RATS TREATED WITH HEXACHLOROETHANE
 

WHICH SURVIVED AT LEAST 52 WEEKSa
 

TOPOGRAPHY: MORPHOLOGY
 

Kidney: Tubular-Cell Adenoma
 

 Valuesc
 

Departure from Linear Trend
 

Relative Risk (Vehicle Control)
 

Lower Limit
 

Upper Limit
 

Weeks to First Observed Tumor
 

Pituitary: Chromophobe Adenoma
 

 Values0
 

Relative Risk (Vehicle Control)
 

Lower Limit
 

Upper Limit
 

Weeks to First Observed Tumor
 

Thyroid: Follicular-Cell Adenoma or
 

Follicular-Cell Carcinomab
 

 Values0
 

Relative Risk (Vehicle Control)d
 

Lower Limit
 

Upper Limit
 

Weeks to First Observed Tumor
 

VEHICLE
 

CONTROL
 

0/18(0.00)
 

N.S.
 

 = 0.023
 

2/18(0.11)
 

N.S.
 

105
 

2/18(0.11)
 

N.S.
 

—
 

—
 

111
 

LOW
 

DOSE
 

4/37(0.11)
 

N.S.
 

Infinite
 

0.473
 

Infinite
 

86
 

4/32(0.13)
 

N.S.
 

1.125
 

0.184
 

11.543
 

104
 

3/36(0.08)
 

N.S.
 

0.750
 

0.097
 

8.370
 

92
 

HIGH
 

DOSE
 

0/29(0.00)
 

N.S.
 

0/24(0.00)
 

N.S.
 

0.000
 

0.000
 

3.735
 

5/28(0.18)
 

N.S.
 

1.607
 

0.305
 

15.499
 

60
 
TABLE 3 (CONCLUDED)
 

VEHICLE LOW HIGH 

TOPOGRAPHY: MORPHOLOGY CONTROL DOSE DOSE 

Testis: Interstitial-Cell Tumorb 0/18(0.00) 0/36(0.00) 3/29(0.10) 

 Valuesc 

 = 0.048 N.S. N.S. 

Relative Risk (Vehicle Control)d Infinite 

Lower Limit 0.391 

Upper Limit Infinite 

Weeks to First Observed Tumor 109 

Treated groups received time-weighted average doses of 212 or 423 ppm in feed.
 

Number of tumor-bearing animals/number of animals examined at site (proportion) .
 

"The probability level for the Cochran-Armitage test is given beneath the incidence of tumors
 

in the control group when Ρ < 0.05; otherwise, not significant (N.S,) is indicated. The probability level for the Fisher exact test for the comparison of a treated group with the control
 

group is given beneath the incidence of tumors in the treated group when Ρ < 0.05; otherwise,
 

not significant (N.S.) is indicated. For both Cochran-Armitage and Fisher exact tests a
 

negative designation (N) indicates a lower incidence in the treated group(s) than in the
 

control group.
 

The 95% confidence interval on the relative risk of the treated group to the control group,
 

"The probability level of the test for departure from linear trend is given beneath the control
 

group when Ρ < 0.05.
 
___ 

TABLE 4
 

ANALYSES OF THE INCIDENCE OF PRIMARY TUMORS AT
 

SPECIFIC SITES IN FEMALE RATS TREATED WITH HEXACHLOROETHANEa
 

TOPOGRAPHY -.MORPHOLOGY
 

Kidney: Hamartoma*b
 

 Valuesc
 

Relative Risk (Vehicle Control)
 

Lower Limit
 

Upper Limit
 

Weeks to First Observed Tumor
 

Pituitary: Chromophobe Adenoma
 

 Valuesc
 

Relative Risk (Vehicle Control)
 

Lower Limit
 

Upper Limit
 

Weeks to First Observed Tumor
 

Thyroid: Follicular-Cell Adenoma or
 

Follicular-Cell Carcinomab
 

 Valuesc
 

Relative Risk (Vehicle Control)
 

Lower Limit
 

Upper Limit
 

Weeks to First Observed Tumor
 

VEHICLE
 

CONTROL
 

0/20(0.00)
 

N.S.
 

7/20(0.35)
 

 = 0.021(N)
 

89
 

2/20(0.10)
 

N.S.
 

Ill
 

LOW
 

DOSE
 

0/50(0.00)
 

N.S.
 

—
 

—
 

—
 

15/50(0.30)
 

N.S.
 

0.857
 

0.405
 

2.169
 

89
 

3/47(0.06)
 

N.S.
 

0.638
 

0.080
 

7.284
 

112
 

HIGH
 

DOSE
 

3/49(0.06)
 

N.S.
 

Infinite
 

0.255
 

Infinite
 

112
 

6/46(0.13)
 

 = 0.045(N)
 

0.373
 

0.124
 

1.149
 

112
 

3/47(0.06)
 

N.S.
 

0.638
 

0.080
 

7.284
 

109
 

*This is considered to be a benign form of the malignant mixed tumor of the kidney and consists
 

of proliferative lipocytes, tubular structures, fibroblasts, and vascular spaces in varying
 

proportions.
 
___ 

TABLE 4 (CONCLUDED)
 

VEHICLE LOW HIGH 

TOPOGRAPHY: MORPHOLOGY CONTROL DOSE DOSE 

Mammary Gland: Fibroadenoma 6/20(0.30) 13/50(0.26) 9/50(0.18) 

 Valuesc N.S. N.S. N.S. 

Relative Risk (Vehicle Control)d 0.867 0.600 

Lower Limit 0.371 0.229 

Upper Limit 2.463 1.828 

Weeks to First Observed Tumor 106 57 94 

Ovary: Granulosa-Cell Tumor 1/20(0.05) 4/48(0.08) 0/49(0.00)
 

 Valuesc N.S. N.S. N.S.
 

Relative Risk (Vehicle Control)d 1.667 0.000
 

Lower Limit — 0.182 0.000
 

Upper Limit — 80.314 7.624
 

Weeks to First Observed Tumor 111 111
 

Treated groups received time-weighted average doses of 212 or 423 mg/kg by gavage.
 

Number of tumor-bearing animals/number of animals examined at site (proportion) .
 

The probability level for the Cochran-Armitage test is given beneath the incidence of tumors
 

in the control group when Ρ < 0.05; otherwise, not significant (N.S.) is indicated. The
 

probability level for the Fisher exact test for the comparison of a treated group with the
 

control group is given beneath the incidence of tumors in the treated group when Ρ < 0.05;
 

otherwise, not significant (N.S.) is indicated. For both Cochran-Armitage and Fisher exact
 

tests a negative designation (N) indicates a lower incidence in the treated group(s) than
 

in the control group.
 

The 95% confidence interval on the relative risk of the treated group to the control group.
 
To provide additional insight into the possible carcinogenicity
 

of this compound, 95 percent confidence intervals on the relative
 

risk have been estimated and entered in the tables based upon the observed tumor incidence rates. In all of the intervals shown in Tables 3 and 4, the value one is included: this indicates the absence
 

of statistically significant results. It should also be noted that
 

all of the confidence intervals have an upper limit greater than one,
 

indicating the theoretical possibility of tumor induction in rats by
 

hexachloroethane that could not be established under the conditions
 

of this test.
 

28
 
IV. CHRONIC TESTING RESULTS: MICE
 

A. Body Weights and Clinical Observations
 

No distinct dose-related depression in mean body weight was
 

evident in males or females (Figure 3). Fluctuations in the growth
 

curve may be due to mortality; as the size of the group diminishes,
 

the mean body weight may be subject to wide variations.
 

There was no evidence of compound effect with regard to physical
 

appearance or behavior of the treated mice during the first 34 weeks
 

of the study. Signs often observed in group-housed laboratory mice,
 

particularly males, were observed at a comparable rate in all groups.
 

These signs included sores on the body and/or extremities, a hunched
 

appearance, localized alopecia, external genital irritation, and
 

rough or stained fur.
 

A hunched or thin appearance was observed with greater frequency
 

in the treated groups from week 38 until termination of the bioassay
 

in week 91. The incidence of palpable nodules, tissue masses, or
 

swollen areas was slightly greater in the treated mice than in the
 

controls.
 

B. Survival
 

The estimated probabilities of survival for male and female mice
 

in the control and hexachloroethane-dosed groups are shown in Figure
 

4.
 

For both male and female mice there was no significant positive
 

association between dose and mortality. For males the survival was
 

29
 
TIME ON TEST (WEEKS) 

FIGURE 3 

GROWTH CURVES FOR HEXACHLOROETHANE CHRONIC STUDY MICE 

30 
TIME ON TEST (WEEKS) 

FIGURE 4 

SURVIVAL COMPARISONS OF HEXACHLOROETHANE CHRONIC STUDY MICE 

3I 

-0.0 
unexpectedly low in the control groups and the low dose group as only
 

25 percent (5/20) of the vehicle control, 5 percent (1/20) of the untreated control, and 14 percent (7/50) of the low dose mice survived
 

until the end of the test, compared to 58 percent (29/50) of the high
 

dose mice.
 

There were adequate numbers of females at risk from late-


developing tumors as 68 percent (34/50) of the high dose, 80 percent
 

(40/50) of the low dose, 80 percent (16/20) of the vehicle control,
 

and 85 percent (17/20) of the untreated control mice survived until
 

the end of the test.
 

C. Pathology
 

Histopathologic findings on neoplasms in mice are summarized in
 

Appendix Β (Tables Bl and B2); findings on nonneoplastic lesions are
 

summarized in Appendix D (Tables Dl and D2).
 

Hepatocellular carcinomas occurred in 1/18 (6 percent) male
 

untreated controls, 3/20 (15 percent) male vehicle controls, 15/50
 

(30 percent) low dose males, 31/49 (63 percent) high dose males, 0/18
 

untreated control females, 2/20 (10 percent) vehicle control females,
 

20/50 (40 percent) low dose females, and 15/49 (31 percent) high dose
 

females.
 

Microscopically, the hepatocellular carcinomas varied greatly in
 

appearance. Some contained well-differentiated hepatic cells that
 

had a relatively uniform arrangement of the cords and others had very
 

anaplastic liver cells with large hyperchromatic nuclei, often with
 

32
 
inclusion bodies and with vacuolated pale cytoplasm. Arrangement of
 

the neoplastic liver cells varied from short, stubby cords to nests
 

of hepatic cells and occasionally pseudo-acinar formation. Mitotic
 

figures were often present. The hepatic neoplasms occurring in the
 

control mice were not different in appearance from those seen in the
 

hexachloroethane-dosed animals.
 

Toxic nephropathy occurred in 49/50 (98 percent) low dose males,
 

47/49 (96 percent) high dose males, 50/50 (100 percent) low dose
 

females, and 45/49 (92 percent) high dose females. Microscopically,
 

the nephropathy was characterized by degeneration of convoluted
 

tubule epithelium at the junction of the cortex and medulla. Some
 

affected tubules contained hyalin casts. Occasionally the damaged
 

cells were replaced by enlarged dark staining regenerative tubular
 

epithelium. At this stage, the kidney often showed infiltration of
 

inflammatory cells, fibrosis, and calcium deposition.
 

Results of this histopathologic examination indicate that hexachloroethane was carcinogenic, causing an increased incidence of
 

hepatocellular carcinomas in male and female mice. This chemical
 

also caused toxic nephropathy in mice of both sexes.
 

D. Statistical Analyses of Results
 

The results of the statistical analyses of tumor incidence in
 

mice are summarized in Tables 5 and 6. The analysis for every type
 

of tumor that was observed in more than 5 percent of any of the
 

hexachloroethane-dosed groups of either sex is included.
 

33
 
TABLE 5
 

ANALYSES OF THE INCIDENCE OF PRIMARY TUMORS AT
 

SPECIFIC SITES IN MALE MICE TREATED WITH HEXACHLOROETHANE2
 

u>
 

-P­
TABLE 5 (CONCLUDED)
 

Treated groups received time-weighted average doses of 590 or 1179 mg/kg by gavage.
 

Number of tumor-bearing animals/number of animals examined at site (proportion).
 

The probability level for the Cochran-Armitage test is given beneath the incidence of tumors
 

in the corresponding control group when P<0.05; otherwise, not significant (N.S.) is indicated. The probability level for the Fisher exact test for the comparison of a treated
 

group with the pooled vehicle control group (*) or the matched vehicle control group (**)
 

is given beneath the incidence of tumors in that treated group when P<0.05; otherwise, not
 

significant (N.S.) is indicated. For both Cochran-Armitage and Fisher exact tests a negative
 

designation (N) indicates a lower incidence in the treated group(s) than in the control group.
 

The 95% confidence interval on the relative risk of the treated group to the control group.
 

The probability level of the test for departure from linear trend is given beneath the control
 

group when Ρ < 0.05.
 

35 
00 

MATCHED
 

VEHICLE
 

CONTROL
 

1/20(0.05)
 

N.S.
 

—
 

—
 

—
 

—
 

91
 

2/20(0.10)
 

N.S.
 

 = 0.028
 

90
 

TOPOGRAPHY:MORPHOLOGY
 

Lung: Alveolar/Brochiolar Adenoma or
 

Alveolar/Bronchiolar Carcinomab
 

 Valuesc
 

Relative Risk (Pooled Vehicle Control)d
 

Lower Limit
 

Upper Limit
 

Relative Risk (Matched Vehicle Control)d
 

Lower Limit
 

Upper Limit
 

Weeks to First Observed Tumor
 

Liver: Hepatocellular Carcinoma
 

 Valuesc
 

Departure from Linear Trend
 

Relative Risk (Pooled Vehicle Control)d
 

Lower Limit
 

Upper Limit
 

Relative Risk (Matched Vehicle Control)
 

Lower Limit
 

Upper Limit
 

Weeks to First Observed Tumor
 

TABLE 6
 

ANALYSES OF THE INCIDENCE OF PRIMARY TUMORS AT
 

SPECIFIC SITES IN FEMALE MICE TREATED WITH HEXACHLOROETHANEa
 

POOLED
 

VEHICLE
 

CONTROL
 

2/60(0.03)
 

N.S.
 

90
 

2/60(0.03)
 

 < 0.001
 

 = 0.002
 

90
 

LOW
 

DOSE
 

1/50(0.02)
 

N.S.
 

0.600
 

0.010
 

11.160
 

0.400
 

0.005
 

30.802
 

91
 

20/50(0.40)
 

 < 0.001*
 

 = 0.012**
 

12.000
 

3.140
 

100.443
 

4.000
 

1.128
 

33.077
 

85
 

HIGH
 

DOSE
 

4/49(0.08)
 

N.S.
 

2.449
 

0.366
 

26.112
 

1.633
 

0.179
 

78.704
 

91
 

15/49(0.31)
 

 < 0.001*
 

9.184
 

2.287
 

78.968
 

3.061
 

0.823
 

26.000
 

91
 
37
 

TABLE 6 (CONCLUDED)
 

TOPOGRAPHY: MORPHOLOGY 

POOLED 

VEHICLE 

CONTROL 

MATCHED 

VEHICLE 

CONTROL 

LOW 

DOSE 

HIGH 

DOSE 

Hematopoietic System: Malignant Lymphoma 8/60(0.13) 4/20(0.20) 12/50(0.24) 9/49(0.18) 

 Values N.S. N.S. N.S. N.S. 

Relative Risk (Pooled Vehicle Control) 

Lower Limit 

Upper Limit 

—__ _—_ 

— 

— 

1.800 

0.737 

4.656 

1.378 

0.509 

3.783 

Relative Risk (Matched Vehicle Control) 

Lower Limit 

Upper Limit 

— 

— 

1.200 

0.430 

4.650 

0.918 

0.300 

3.731 

Weeks to First Observed Tumor 69 72 71 68 

Treated groups received time-weighted average doses of 590 or 1179 mg/kg by gavage.
 

Number of tumor-bearing animals/number of animals examined at site (proportion).
 

The probability level for the Cochran-Armitage test is given beneath the incidence of tumors
 

in the corresponding control group when Ρ < 0.05; otherwise, not significant (N.S.) is indicated. The probability level for the Fisher exact test for the comparison of a treated
 

group with the pooled vehicle control group (*) or the matched vehicle control group (**)
 

is given beneath the incidence of tumors in that treated group when Ρ < 0.05; otherwise, not
 

significant (N.S.) is indicated. For both Cochran-Armitage and Fisher exact tests a negative
 

designation (N) indicates a lower incidence in the treated group(s) than in the control group.
 

The 95% confidence interval on the relative risk of the treated group to the control group.
 

The probability level of the test for departure from linear trend is given beneath the control
 

group when Ρ < 0.05.
 
Because of the poor survival of several of the control groups,
 

two control groups were used for statistical analyses: the vehicle
 

control group (designated in this section as the "matched" vehicle
 

control group) and a pooled vehicle control group, combining the
 

vehicle controls from the studies of hexachloroethane, trichloroethylene, and 1,1,2-trichloroethane. The pooled vehicle controls
 

were of the same strain, were housed in the same room, were all
 

intubated with corn oil, were tested concurrently for at least a
 

year, and were diagnosed by the same pathologists.
 

For both male and female mice the incidence of hepatocellular
 

carcinomas was significant. For both sexes the Cochran-Armitage test
 

showed a significant (P < 0.001) positive association between dosage
 

and incidence when comparing the dosed groups to either control group.
 

For females the departure from linear trend was significant, principally because the observed incidence was higher in the low dose group
 

than in the high dose group. For both male and female mice the
 

Fisher exact tests comparing either the low dose or the high dose to
 

the pooled control group were significant (P < 0.008). Additionally,
 

the comparisons of high dose males (P < 0.001) and low dose females
 

(P = 0.012) to the matched controls were also significant.
 

Because of the unexpectedly high mortality observed among male
 

mice in the low dose group and in both control groups, additional
 

time-adjusted analyses were conducted. In Table 7 the analysis for
 

the incidences of hepatocellular carcinomas is presented, an analysis
 

38
 
TABLE 7 

ANALYSES OF THE INCIDENCE OF PRIMARY TUMORS AT 

SPECIFIC SITES IN MALE MICE TREATED WITH HEXACHLOROETHANE 

WHICH SURVIVED AT LEAST 41 WEEKSa 

TOPOGRAPHY: MORPHOLOGY 

POOLED 

VEHICLE 

CONTROL 

MATCHED 

VEHICLE 

CONTROL 

LOW 

DOSE 

HIGH 

DOSE 

Liver: Hepatocellular Carcinoma 6/55(0.11) 3/19(0.16) 15/46(0.33) 31/48(0.65) 

 Valuesc 

 < 0.001 < 0.001 = 0.007* < 0.001* 

 < 0.001** 

Departure from Linear Trend = 0.020 

u> 

Relative Risk (Pooled Vehicle Control) 

Lower Limit 

Upper Limit 

, 

2.989 

1.203 

8.572 

5.920 

2.761 

14.905 

Relative Risk (Matched Vehicle Control) 

Lower Limit 

Upper Limit 

2.065 

0.690 

10.187 

4.090 

1.542 

18.279 

Weeks to First Observed Tumor 55 55 53 41 

Treated groups received time-weighted average doses of 590 or 1179 ppm in feed.
 

Number of tumor-bearing animals/number of animals examined at site (proportion) .
 

The probability level for the Cochran-Armitage test is given beneath the incidence of tumors in
 

the corresponding control group when Ρ < 0.05; otherwise, not significant (N.S.) is indicated.
 

The probability level for the Fisher exact test for the comparison of a treated group with the
 

pooled vehicle control group (*) or the matched vehicle control group (**) is given beneath the
 

incidence of tumors in that treated group when Ρ < 0.05; otherwise, not significant (N.S.) is
 

indicated. For both Cochran-Armitage and Fisher exact tests a negative designation (N) indicates
 

a lower incidence in the treated group(s) than in the control group.
 

The 95% confidence interval on the relative risk of the treated group to the control group.
 

The probability level of the test for departure from linear trend is given beneath the control
 

group when Ρ < 0.05.
 
based exclusively upon males which survived at least 41 weeks. Both
 

Cochran-Armitage tests, the Fisher exact comparisons of the high dose
 

to both control groups, and the Fisher exact comparison of the low
 

dose to the pooled control group were significant (P _< 0.007).
 

Based upon these results the statistical conclusion is that the
 

administration of hexachloroethane was associated with an increased
 

incidence of hepatocellular carcinomas in B6C3F1 mice.
 

40
 
V. DISCUSSION
 

There was a significant association between increased dosage
 

and accelerated mortality in rats of both sexes. The survival among
 

the high dose male rats was not considered adequate for meaningful
 

statistical analysis of the incidence of late-developing tumors.
 

Doses administered to rats were high enough to cause growth retardation in the high dose female group and both dosed male groups. Adequate numbers of animals in all mouse groups survived long enough to
 

be at risk from late-developing tumors.
 

Hepatocellular carcinomas were detected in 0/18, 2/20 (10 percent), 20/50 (40 percent), and 15/49 (31 percent) of the untreated
 

control, vehicle control, low dose, and high dose female mouse groups,
 

respectively. The Cochran-Armitage test indicated a significant positive association between dosage and the incidence of this neoplasm
 

in female mice. This association was supported by the Fisher exact
 

test using the pooled vehicle control group and by the comparison of
 

the low dose females to the matched vehicle controls. Despite the
 

relatively early appearance of tumors in the male matched vehicle
 

control group and the fact that mortality of low dose mice was higher
 

than that of high dose mice, results for male mice support those
 

found for female mice. Hepatocellular carcinomas were detected in
 

1/18 (6 percent), 3/20 (15 percent), 15/50 (30 percent), and 31/49
 

(63 percent) of the untreated control, vehicle control, low dose, and
 

high dose male mouse groups, respectively. The Cochran-Armitage test
 

41
 
indicated a significant positive association between dosage and tumor
 

incidence. This was supported by Fisher exact tests comparing the
 

high dose male mouse group to the pooled vehicle and to the matched
 

vehicle control groups and comparing the low dose male mouse group to
 

the pooled vehicle control group. No other neoplasms of significance
 

were observed in rats or mice of either sex.
 

Toxic tubular nephropathy was observed in all groups of treated
 

animals. In rats 22/49 (45 percent), 33/50 (66 percent), 9/50 (18
 

percent), and 29/49 (59 percent) of the low and high dose males and
 

low and high dose females, respectively, exhibited this lesion. The
 

incidences in mice were higher (i.e., 49/50 [98 percent], 47/49 [96
 

percent], 50/50 [100 percent], 45/49 [92 percent] of the low dose
 

males, high dose males, low dose females, and high dose females,
 

respectively).
 

No evidence was provided for the carcinogenicity of hexachloroethane in Osborne-Mendel rats. It is concluded that: under the conditions of this bioassay, hexachloroethane was carcinogenic in male and
 

female B6C3F1 mice, causing hepatocellular carcinomas.
 

42
 
VI. BIBLIOGRAPHY
 

Armitage, P., Statistical Methods in Medical Research, Chapter 14.
 

J. Wiley & Sons, New York, 1971.
 

Berenblum, I., editor, Carcinogenicity Testing. International Union
 

Against Cancer, Technical Report Series, Vol. 2. International
 

Union Against Cancer, Geneva, 1969.
 

Chemical Abstracts Service, The Chemical Abstracts Service (CAS)
 

Ninth Collective Index, Volumes 76-85, 1972-1976. American
 

Chemical Society, Washington, D.C., 1977.
 

Cox, D.R., Analysis of Binary Data, Chapters 4 and 5. Methuen and
 

Co., Ltd., London, 1970.
 

Cox, D.R., "Regression Models and Life-Tables.11 Journal of the Royal
 

Statistical Society, Series "B" 34:187-220, 1972.
 

Farm Chemicals Handbook. Meister Publishing Company, Willoughby,
 

Ohio, 1976.
 

Gart, J.J., "The Comparison of Proportions: A Review of Significance
 

Tests, Confidence Limits, and Adjustments for Stratification.11
 

International Statistical Institute Review 39:148-169, 1971.
 

Gosselin, R.E., H.C. Hodge, R.P. Smith, and M.N. Gleason, Clinical
 

Toxicology of Commercial Products, 4th edition. The Williams
 

and Wilkins Company, Baltimore, Maryland, 1976.
 

Hawley, G.G., editor. The Condensed Chemical Dictionary, 8th edition.
 

Van Nostrand Reinhold Company, New York, 1971.
 

Irish, D.D., "Aliphatic Saturated Hydrocarbons." Industrial Hygiene
 

and Toxicology, 2nd revised edition. F.A. Patty, editor. Inter-


science, New York, 1967.
 

Kaplan, E.L., and P. Meier, "Nonparametric Estimation from Incomplete
 

Observations." Journal of the American Statistical Association
 

53_: 457-481, 1958"!
 

Linhart, M.S., J.A. Cooper, R.L. Martin, N.P. Page, and J.A. Peters,
 

"Carcinogenesis Bioassay Data System." Computers and Biomedical
 

Research 7:230-248, 1974.
 

Miller, R.G., Simultaneous Statistical Inference. McGraw-Hill Book
 

Co., New York, 1966.
 

43
 
Reuber, M.D·, and E.L. Glover, "Cirrhosis and Carcinoma of the Liver
 

in Male Rats Given Subcutaneous Carbon Tetrachloride.ff

 Journal
 

of the National Cancer Institute 44:419-423, 1970.
 

Rudali, G., "A Propos de l'Activite Oncogene de Quelques Hydrocarbures
 

Halogenes Utilises en Therapeutique.11

 UICC Monograph Series 7:
 

138-143, 1967. (French).
 

Saffiotti, U., R. Montesano, A.R. Sellakumar, F. Cefis, and D.G.
 

Kaufman, "Respiratory Tract Carcinogenesis in Hamsters Induced
 

by Different Numbers of Administration of Benzo (a) Pyrene and
 

Ferric Oxide.11 Cancer Research 32:1073-1079, 1972.
 

Stanford Research Institute, 1977 Directory of Chemical Producers,
 

U.S.A. Menlo Park, California, 1977.
 

Tarone, R.E., "Tests for Trend in Life-Table Analysis." Biometrika
 

^:679-682, 1975.
 

Windholz, M., editor, The Merck Index: An Encyclopedia of Chemicals
 

and Drugs, Ninth edition. Merck and Co., Inc., Rahway, New
 

Jersey, 1976.
 

44
 
APPENDIX A
 

SUMMARY OF THE INCIDENCE OF NEOPLASMS
 

IN RATS TREATED WITH HEXACHLOROETHANE
 

TABLE Al
 

SUMMARY OF THE INCIDENCE OF NEOPLASMS [N MALE RATS
 

TREATED WITH HEXACHLOROETHANE
 

CONTROL (UNTR) 

01-1biH 

CONTROL(VEH) 

01-Ί01Μ 

ANIMALS INITIALLY IN STUD* 

ANIMALS NECfiOPSIEu 

ANIKALS EXAMINED HISTOPATBOLOGICALLY** 

20 

20 

20 

20 

20 

20 

I&TEGUMENIAPY SYSTEM
 

•SUbCUT TISSUE	 (20) (20)
 

PAPILLOMA, NOS
 

FIBROMA t (5%)
 

FIBROSARCOMA 1 (5%) 2 (10*)
 

RESPIRATORY SYSTEM
 

#LUNG (20) (20)
 

*IBROSARCOMA, METASTATIC
 

HEMATOPOIETIC SYSTEB
 

•MULTIPLE ORGANS	 U0) (20)
 

HALlGdAar LYMPHOMA, ftOS 1 (5%)
 

•SPLEEI	 U0) (20)
 

HEMANGIOMA 1 (5%)
 

^MESENTERIC L. NODE Uu) (18)
 

HEMANGIOMA 1 (6%)
 1 (5X)
 

CIRCULATORY SYSTEM
 

NONE
 

DIGESTIVE SYSTEM
 

#SALIVARY GLAND	 (18)
 (11)
 PIBHOUS HISTIOCYTOMA, METASTATIC	 1 (9%)
 

#HVER (<iO) (20)
 

aEMAiuGlOSARCOMA
 

# NUMbEK OF ANIMALS WITH TISSUE EXAMINED MICROSCOPICALLY 

* DUMBER OP ANIMALS UECROPSIED 

**EXCLUDES PARTIALLY AUTOLYZED ANIMALS 

LOW DOSE
 

01-152R
 

50
 

50
 

49
 

(50)
 

1 (2%)
 

2 (4%)
 

(49)
 

1 (2%)
 

(50)
 

(49)
 

(46)
 

(34)
 

(49)
 

1 12%\
 

HIGH DOSE
 

01-153H
 

50
 

50
 

50
 

(50)
 

(50)
 

(50)
 

(49)
 

(44)
 

(22)
 

(50)
 

A-3
 
TABLE Al (CONTINUED) 

•PANCREAS
 FlbROUS HISTIOCYTOMA, METASTATIC
 

«STOMACH
 

LEIOMYOSARCOMA
 

URINARY SYSTEM
 

«KIDNEY
 

rUbULAR-cELL ADBfcOMA
 FIBROUS HISTIOCYTOMA, METASTATIC
 

MIXfiD TUMOR, MALIGNANT
 

HAMARTOMA +
 

•URINARY bLADDER
 

TKAuSlTIOhAL-CELL CARCINOMA
 

ENDOCRINE SYSTEM
 

«PITUITARY
 

CHROMOPHOBE ADENOMA
 

•ADRENAL
 

PHLOCHROMOCYTOMA
 MIXED TUMOR, METASTATIC
 

«ThYROID
 

FOLLICULAfi-CELL ADEUOMA
 FOLLICULAR-CELL CARCINOMA
 

C-CELL ADENOMA
 

«PANCREATIC ISLETS
 

ISLET-CELL CARCINOMA
 

REPRODUCTIVE SYSTEM
 

«MAMMARY GLAND
 

SUDULLAR* CARCINOMA
 

CONTROL (UNTR)
 

U1-151M
 

(19)
 

(20)
 

(20)
 

(20)
 

1 (5%)
 

(18)
 

4 (22%)
 

(19)
 

2 (11%)
 

(20)
 

2 (10%)
 

1 (5%)
 

(19)
 

1 (5%)
 

(20)
 

CONTROL (VEH)
 

01-101M
 

(20)
 

1 (5%)
 

(20)
 

1 (5%)
 

(20)
 

1 (5*)
 

(19)
 

(19)
 

2 (11%)
 

(20)
 

1 (5%)
 

(20)
 

1 (5%)
 

1 (5%)
 

(20)
 

(20)
 

1 (5%)
 

LO»I DOSS
 

01-152B
 

(49)
 

(49)
 

(49)
 

<* (6%)
 

1 (2%)
 1 (2%)
 

(48)
 

(42)
 

4 (10%)
 

(49)
 

2 (4%)
 

1 (2%)
 

(48)
 

2 (4%)
 1 (2%)
 

(49)
 

(50)
 

HIGH DOSE
 

01-153M
 

(48)
 

(50)
 

(50)
 

(48)
 

(***)
 

(50)
 

(48)
 

5 (10%)
 

1 (2%)
 

(48)
 

(50)
 

# NUMBER OF ANIMALS WITH TISSUE EXAMINED MICROSCOPICALLY 

• NUMBER OF ANIMALS NECROPSIED 

+ THIS I S CONSIDERED TO BE A BENIGN FORM OF THE MALIGNANT MIXED TUMOR OF THE KIDNEY AND CONSISTS OF PROLIFERATIVE 

LIPOCYTES, TUBULAR STRUCTURES, FIBROBLASTS, AND VASCULAR SPACES IN VARYING PROPORTIONS. 

A-4 
TABLE Al (CONTINUED)
 

CONTROL (UNTR) CONTROL(VEH)
 

01-151H 01-101»
 

•EPIDIDYMIS	 (20) (20)
 

FIBROUS HISTIOCYTOMA, MALIGNANT
 

MIXED TUMOR, METASTATIC
 

NERVOUS SYSTEM
 

•BRAIN	 (20) (20)
 

ASTROCYTOMA
 

SPECIAL SENSE ORGANS
 

NONE
 

MUSCULOSKELETAL SYSTEM
 

•SKELETAL MUSCLS	 (20) (20)
 

FIBROUS HISTIOCYTOMA, METASTATIC 1 i(5%)
 

BODY CAVITIES
 

•PERITONEUM	 (20) (20)
 

FIBKOUS HISTIOCYTOMA, MALIGNANT 1 <5»)
 

•TUNICA VAGINALIS	 (20) (20)
 

MESOTHELIOMA, NoS
 

ALL OTHER SYSTEMS
 

NONE
 

ANIMA.L DISPOSITION SUMMARY
 

ANIMALS INITIALLY IN STUDY 20 20
 

NATURAL DEATHd> 9 5
 MORIBUND SACRIFICE
 

SCHEDULED SACRIFICE 7
 

ACCIDENTALLY RILLED
 

TEHrtlNAL SACRIFICE 11 8
 AiMlMAL MISSING
 

 INCLUDES AUIOLYZED ANIMALS
 

# NUMBER OF ANIMALS WITH TISSUE EXAMINED MICROSCOPICALLY 

• NOflbfufi OF ANIMALS NECROPSIED 

LOW DOSE
 

01-152»
 

(50)
 

1 (2%)
 

1 (2%)
 

(49)
 

(50)
 

(50)
 

(50)
 

2 (lift)
 

h0
 

42
 

8
 

HIGH DOSE
 

01-153M
 

(50)
 

(50)
 

1 (2*)
 

(50)
 

(50)
 

(50)
 

2 (4*)
 

50
 

39
 

1
 

10
 

A-5
 
TABLE Al (CONCLUDED)
 

CONTROL (ONTR) CONTROL (VBH) LOU DOSE HIGH DOSB
 

01-151H 01-101fl Q1-152B Ot-1538
 

rUMOh SJBHARY
 

TOTAL ANIMALS WITH PRIMARY TUMORS* 10 9 17 11
 

luTAL PRIMAEi TUMORS 15 13 22 12
 

TOTAL ANIMALS WITH riENIGS TUMORS b 7 12 θ
 TOTAL tiENIGN TuflORS 10 7 14 9
 

TOTAL ANIMALS WITH MALIGNANT TUHORS 5 4 6 1
 

TOTAL MALIGNANT TUMORb 5 6 6 1
 

TOTAL ANIMALS WITH SECONDARY TUHORS# 1 2
 

TOTAL SECONDARY TUMORS 4 3
 

TOTAL ANIMALS WITH 1UMORS UNCERTAINaENIb» OR rtALIGSANT 2 2
 

1OTAL UiiCERTAIN TUMORS 2 2
 

TOTAL ANIMALS WITH TUMOKb UNCERTAIN-


PRIttARY OR M£1ASTATIC
 

TOTAL UNCERTAIN TUMORS
 

• PMlttARi TUMORS: ALL 1UMO&S EXCEPT SECONDARY TOMORS
 

* ^LCUNDARY TUTORS: METASTATIC TUMORS OR TUMORS INVASIVE INTO AN ADJACENT ORGAN
 

A-6
 
TABLE A2

 

SUMMARY OF THE INCIDENCE OF NEOPLASMS IN FEMALE 

RATS TREATED WITH HEXACHLOROETHANE 

AalMALS INITIALLY IH STUDY
 

ANIMALS N2CR0PS1SD
 

ANIMALS EXAMINE^ HISTOPATHOLOGICALLY* *
 

liSiEGUftEMTARY SYSTEM
 

•SUBCUT TISSUE
 

PIbROMA
 

FIBROSARCOMA
 

iluROUS HISTIOCYTOMA, flALIGNANT
 

RESPIRATOR* SYSTEM
 

•NASAL CAVITY
 

NLUttObLASTOKA
 

«LUNG
 

CORTICAL CARCIWOMA, METASTATIC
 

PIuROSARCOMA, METASTATIC
 

MIXED TUMOR, METASTATIC
 

HEMATOPOIETIC SYSTEM
 

#SPLEEH
 

FIBROSARCOMA, BETASTAT1C
 

HEMAMGlOSARCOaA
 

CIRCULATORY SYSTEH
 

nous
 

DIGESTIVE SYSTEM
 

•LIVER
 NEOPLASTIC NODULE
 

«PANCREAS
 

FIBROSARCOMA. METASTATIC
 

# NUMBER OP ANIMALS WITH TISSUE EXAHIN£D MICROSCOPICALLY
 

* iUMBER OP ANIMALS NECROPS1ED 

**EXCLUDES PARTIALLY AUTOLYZED ANIMALS 

CONTROL (UNTR)
 

01-151F
 

20
 

20
 

20
 

(20)
 

1 <S*)
 

(20)
 

(20)
 

1 (5*)
 

(19)
 

1 (5*)
 

1 (5%)
 

(20)
 

1 (5%)
 

(20)
 

1 (b%\
 

CONTROL(VEH)
 

01-101F
 

20
 

20
 

20
 

(20)
 

(20)
 

(20)
 

(20)
 

(20)
 

(20)
 

LOW DOSS
 

01-154F
 

50
 

50
 

50
 

(50)
 

1 (2*)
 

1 (2%)
 

(50)
 

1 (2%)
 

(50)
 

1 (2%)
 

(49)
 

(50)
 

(50)
 

HIGH DOSE
 

01-155F
 

50
 

50
 

49
 

(50)
 

(50)
 

(49)
 

1 (2%)
 

(49)
 

(49)
 

A-7 
TABLE A2 fCONTINUED)
 

CONTROL (ONTR) CONTROL (VEH) LOtf DOSE
 

01-151F 01-101F 01-154*
 

tsTOSACd (2 0) (20) (50)
 

SQUAMOUS CELL CARCINOMA 1 (5%)
 

URI&ARY SYSTEM
 

«KIDSEY	 (20) (20) (50)
 

FIBROSARCOMA, METASTATIC 1 (S%)
 MIXED TUMOR, MALIGNANT 1 (2%)
 

HAMARTOMA + 1 (5%)
 

ENDOCRINE SYSTEM
 

«PITUITARY (18) (20) (SO)
 

CHROMOPHOBE ADENOMA 8 (44%) 7 (3i>%) 15 (30%)
 

#ADR£NAL (20) (20) (SO)
 

CORTICAL CARCINOMA 1 (5%)
 

PHEOCHKOflOCYTOMA 1 (5%) 1 (2%)
 

tTHYfcOID (20) (20) (47)
 

FOLL1CULAR-CELL ADENOMA 1 (5%) 1 (i>%) 3 (6*>
 

FOLL1CULAR-CELL CARCINOMA 2 (10%) 1 (5%)
 C-C2LL ADENOMA 2 (4%)
 

tPANCREATIC ISLETS (20) (20) (SO)
 

ISLET-CELL ADENOMA 2 (4%)
 

REPRODUCTIVE SYSTEM
 

•MAMMARY GLAND	 (20) (20) (50)
 

ADENOMA, NOS 1 (5%) 1 (5%)
 ADENOCARCINOMA, iaOS 2 (10%) 2 (4%)
 

PAPILLARY ADENOCARCINOMA 1 (2%)
 FIBROADENOMA 4 (20%) 6 (30%) 13 (26%)
 

•VAGINA	 (20) (20) (SO)
 

ENDOMETRIAL STROMAL SARCOMA, MET 1 (5%)
 

*UTERUS	 (2 0) (20) (49)
 

ADENOCARCINOMA, NOS 1 (5%)
 ENDOMETRIAL STROMAL POLYP 1 (5%) 3 (6»)
 

ENDOMETRIAL STROMAL SARCOMA 1 (5%)
 

# NUMBER OF ANIMALS tfITH TISSUE EXAMINED MICROSCOPICALLY 

• NJMBER OF ANIMALS NECROPSIED 

+ THIS I S CONSIDERED TO BE A BENIGN FORM OF THE MALIGNANT MIXED TUMOR OF THE KIDNEY AND CONSISTS

LIPOCYTES, TUBULAR STRUCTURES, FIBROBLASTS, MID VASCULAR SPACES IN VARYING PROPORTIONS. 

HIGH DOSE
 

01-155F
 

(49)
 

(49)
 

3 (6%)
 

(46)
 

6 (13%)
 

1 (2%)
 

(47)
 

3 (6%)
 

1 (2%)
 

(49)
 

(50)
 

1 (2%)
 

1 (2%)
 

9 |18%)
 

(50)
 

(49)
 

1 (2%)
 

 OF PROLIFERATIVE 

A-8 
TABLE A2 (CONTINUED) 

CONTROL (UNTK) CONTROL (VEH)
 

01-151F 01-101F
 

«OVARY (19) (20)
 

GRAUULOSA-CELL TUMOR
 

NERVOUS SYSTEM
 

•bRAIN	 (20) (20)
 

OLIGODENDROGLIOMA
 

SPECIAL SENSE ORGANS
 

NOSE
 

flUSCULOSRELETAL SYSTEM
 

NONE
 

iiODY CAVITIES
 

•ttESENffifti	 (20) (20)
 

FIBROSARCOMA, METASTATIC 1 (5%)
 

ALL OTHER SYSTEMS
 

*ttJLiIPL£ ORGANS (2 0) (20)
 

FlaROUS HISTIOCYTOMA, MALIGNANT
 

ANIMAL DISPOSITION SUMMARY
 

ANIMALS INITIALLY IN STUDY 20 20
 

NATURAL DEATHS 5 6
 

XORIBUIKD SACRIFICE 1
 SCHEDULED SACRIFICE
 

ACCIDENTALLY KILLED
 

TERMINAL SACRIFICE 14 14
 

ANIMAL 1ISSING
 

 INCLUDES AUTOLYZED ANIMALS
 

# SUrtbER OF ANISALS WlTti TISSUE EXAMINED MICROSCOPICALLY 

* NUMBER OF ANIKALS NfiCROPSIED 

LOW DOSE
 

01-1i>l*F
 

(48)
 

4 (b*)
 

(50)
 

(50)
 

(50)
 

50
 

21
 

2
 

27
 

HIGH DOSE
 

01-155F
 

(49)
 

(49)
 

1 (2%)
 

(50)
 

(50)
 

SO
 

26
 

24
 

A-9
 
TABLE A2 (CONCLUDED)
 

CONTROL(UNTA) CONTROL (VEH) LOW DOSE HIGH DOSE
 0T-151F 01-101P 01-154F 01-155F
 

JMOR SUMMARY
 

TOTAL ANIMALS WITH PRIMARY TUMORS* 14 33 20
 

JLOTAL PRIMARY lUWORS 24 22 50 27
 

ΊΟΓ< ANIMALS WITrt £$ENIGN TUMORS 11 11 29 18
 

TOTAL BENIGN TIK1OKS 15 17 40 24
 

TOl'J-.L ANIMALS WITH MALIGNANT TUMORS 6 4 6 3
 

l'UTAL MALIGNANT TUMORS 8 4 b 3
 

TOTAL ANIMALS WITH SECONDARY TUMORS» 1 1 1 1
 

TOTAL SECONDARY TUMORS 5 1 1 1
 

20TAL ANIMALS WITH TUMORS UNCLRTAINbUNlGS Ufi 1ALIGxNA?IT 1 1 4
 

1'ufAL urtCLRTAia rUMORS 1 1 4
 

TOTAL ANIMALS WITH TUMORS UNCLRTAIN-


PKlSAxtY OH METASTATIC
 

TOTAL UNCERTAIN TUTORS
 

* PRIMARY TufiORS: ALL TUMORS EXCEPT SECONDARY TUMORS
 

* SECONDARY TUMORS: M^TA^TATIC TUMORS OR TUMORS INVASIVE IilTO AA ADJACENT ORGAN
 

Α-IO 
APPENDIX B
 

SUMMARY OF THE INCIDENCE OF NEOPLASMS
 

IN MICE TREATED WITH HEXACHLOROETHANE
 

TABLE B1
 

SUMMARY OF THE INCIDENCE OF NEOPLASMS IN MALE MICE
 

TREATED WITH HEXACHLOROETHANE
 

CONTROL (UNTR) CONTROL (VSH) 02-ΜΊ61 02-B151 

AwIMALS INITIALLY IS STUDY 20 20 

ANIMALS MISSING 

AVIKALS NLCKOPSIEi) 18 20 

AN1KALS EXAMINED HTSTUPATKOLOGICALLY** 17 20 

INTEGUMENTARY SYS1SM
 

*SUbCUT IISSUE (18) (20)
 

FIBROSARCOMA
 

ti^hPIKAlURY SlfSTEM
 

*LUNb (18) (20)
 

HEPATOCELLULAR CARCINOMA, MLTAST
 

ALVEOLAh/bRONCHIOLAR ADENOMA
 

ALVEGLAR/bRONCHlOLAR CARCINOMA
 

HEMATOPOIETIC SYSTEM
 

fLlVx.R (18) (20)
 

MaLIb.LYMPHOMA, HISTIOCYTIC TYPE 1 (6%)
 

CIRCULATORY SYSTEM
 

NONE
 

DIGESTIVE SYSTEM
 

tLlVLR (18) (20)
 

rihPATOCFLLULAR CARCINOMA 1 (6%) 3 (1S%)
 

htiiANGIOSAPCOHA 1 <6*>
 

#PANCK£AS (18) (20)
 

HSMANGIOSARCOMA, METASTATIC 1 (6%)
 

fSTOilACH (18) (20)
 

SyUAMOJS CELL PAPILLOMA
 

UHINAKY SYSTEM
 

. NONE _ __. . , _ _
 

t NUBbER OJP ANIMALS WITH TISSU E EXAMINED MICROSCOP1CALL* 

* MUfltUSR Of ANIMALS NECROPSIED 

**EXCLUDES PARTIALLY AUTOLYZED ANIMALS 

B-3
 

LOW DOSE
 02-M152
 

50
 

50
 

50
 

(50)
 

(50)
 

1 (2%>
 1 (2%)
 

1 (2*)
 

(50)
 

(i>0)
 

15 (30%)
 

(50)
 

(50)
 

HIGH DOSE
 02-3153
 

50
 

1
 

49
 

49
 

(49)
 

1 (2%)
 

(49)
 

2 (4%)
 

1 (2%)
 

(49)
 

(49)
 

31	 (63%)
 

1 (2%)
 

(49)
 

(49)
 

1 (2%)
 
jiAJuChlJiu S/STEft
 

«PANCREATIC ISLETS
 

ISLE!-CELL uDENuSA
 

rtEPRU^UuTIVF SYSTEM
 

#TESTIS
 

lalhfiSTlCIAL-ChLL TOM OF
 

NERVOUS SiSTEtt
 

SONL
 

bl»£,ClAL SENSE OftGANS
 

*ΗΑκυϋήΙΑ GLAND
 

Αϋ£Ν0ΛΑ, NUb
 

JSUSCULOoKJiLETAL SYSTEM
 

boDi CAVITIES
 

NONE
 

A1.L OTHER SfbI£BS
 

NONE
 

ΑΛ1ΛΑ1. DISPOSITION SUflMARY
 

ANIMaLb INITIALLY IS STUDY
 

NATURAL DEA1H(*
 

MORIBUND SACRIFICE
 

SCHEDULED SACRIFICE
 

ACCIDENTALLY KILLED
 

TERMINAL SACRIFICE
 

A^IaAL MISSING
 

o> INCLUDES AUTuLYZSD ArfiUALS
 

# NUJJbEH OF ANIfsALS WITH TISSUE

* N'JflfahK OF ANlfALS NuCROPSIED 

TABLE Bl (CONTINUED) 

CONTROL (UiiiR) CONTROL (VEH)


02-M161 02-M151


(20)
 

1 (5%)
 

(1b)
 

(18) (20)
 

(18) (20)
 

20 20
 

15
 

1 5
 

 EXAMINED MICROSCOPICALLY 

B-4
 

 LOW DOSE
 

 02-W152
 

(50)
 

(U9)
 

(50)
 

50
 

41
 

1
 

1
 

7
 

HIGH DOSE
 

02-K153
 

(4 9)
 

(48)
 

1 (2%)
 

(49)
 

1 (2%)
 

50
 

17
 

3
 

29
 

1
 
TABLE Bl (CONCLUDED)
 

CONTROL (UNTR) CONTROL(VEH) LOW DOSE HIGH DOSE
 ϋ2-θ161 02-M151 02-B152 02-M153
 

TUMOR SUMMARY
 

TOTAL ANIMALS WlTfi PRIMARY TUMORS* 3 4 17 34
 

TO1AL PRIMARY TUMORS 3 17 39
 

TOTAL ANIMALS WITH BEAlt-N TUMORS 1 1 5
 TOTAL bfiNIGN TUMORS 1 1 5
 

TOTAL ANIMALS WITH MALIGNANT TUMORS 3 3 16 33
 TOTAL MALIGNANT TUMORS 3 3 16 34
 

TOTAL ANIMALS WITH SECONDARY lUMORS* Τ 1
 

TOTAL SECONDARY TUMORS 1 1
 

TOT/.L ANIMALS WITH TUMORS UNCERTAIHBENIGS OR MALIGNANT
 

TOTAL UNCERTAIN TUMORS
 

TOTAL ANIMALS WITH TUMORS UNCERTAIN-


PrtlAAKY OK METASTATIC
 

TOTAL USCERTAIN TUMORS
 

* PRIMARY TUMORS: ALL TUMORS EXCEPT SECONDARY TUMORS
 

# SECONDARY TU.1ORS: METASTATIC TUMORS OR TUMORS INVASIVE INTO AS ADJACENT ORGAN
 

B-5 
TABLE B2
 

SUMMARY OF THE INCIDENCE OF NEOPLASMS IN FEMALE
 

MICE TREATED WITH HEXACHLOROETHANE
 

COSTROL(UNTR) 02-F161 CONTROL(VEH) 02-P151 LOW DOSE 02-P154 HIGH DOSE 02-P155 

AAiMALb INITIALLY 1-1 STUDY 

ANIMALS NECROPS1ED 

ANIUALS EXAMINED HISTOPATHOLOG1CALLY 

20 

19 

** 18 

20 

20 

20 

50 

50 

50 

50 

49 

49 

IftlrEGUMENTARY SYSTEM 

•bUbCUT TISSUE

OSTEOSARCOMA

NEUROFIBROSARCOMA

 (19)

 1 (5%) 

 (20) (50)

 1 (2*) 

 (49) 

K£SPlf(ATORi SYSI'EK 

#LUwG

ALVEOLAH/bRONCHlOLAR ADENOMA

ALVEOLAR/bRONCHIOLAR CARCINOMA

OSTEOSARCOMA, MhTASTAlIC

NEUROFIBROSARCOMA, METASTATIC

 (18)

 1 (6*) 

 1 (6%) 

 (20) 

 1 (5*) 

(50) 

1 (2%) 

 1 (2*) 

(49) 

3 

1 

(6%) 

(2%) 

H^MAIOPQISTIC SYSTEM 

*aOLTIPLE UKGANS 

MALIG.LYMPHOMA, HISTIOCYTIC TYPE 

MALlUNAi<T LYMPHOMA, MIXED TYPE 

(19) 

1 (5%) 

(20) 

2 (10%) 

(50) 

6 (12%) 

1 (2%) 

(49) 

5 (10%) 

1 (2%) 

«SPLEEN 

MAL1G.LYMPHOMA, LYKPHOCYT1C TYPE 

MAL1G.LYMPHOMA, HISTIOCYTIC TYPE 

(18) (20) (50) (49) 

1 (2%) 

1 (2%) 

«ChRVIOAL LYMPH NODE 

G.LYMPHOMA, HISTIOCYTIC TYPE 

(18) (20) (50) 

1 (2%) 

(49) 

L. Λ ODE 

HEMANGICSARCOMA 

iALIG.LYMPHOMA, HISTIOCYTIC TYPE 

(18) (20) (50) (49) 

1 (2%) 

1 (2%) 

MALIG.LYMPHOMA, HISTIOCYTIC TYPE 

(18) (20) 

1 (5%) 

(50) (49) 

*LIV£R 

MALIG.LYMPHOMA,

MALIGNLYΜΡΗΟΊΑ,

 LYMPHOCYTIC

 HISTIOCYTIC

 TYPE 

 TYPE 

(18) (20) (50) 

1 (2%) 

2 1*%X 

(49) 

# NUIbhR OF ANIftALS WITH TISSUE EXAMINED

* alMbER OF ANIMALS NuCKOPSIED 

**EXCLUDLS PARTIALLY AUTOLYZED ANIMALS 

 MICROSCOPICALLY 

B-6
 
TABLE B2 (CONTINUED) 

CONTROL(UNTR) CONTROL(VBH) 

02-F161 02-F151 

#SfO3ACH (18) (20)
 

MALIG.LYMPHOMA, HISTIOCYTIC TYPE
 

«OVARY (18) (19)
 

MALIGNANT LYMPHOMA, MIXED TYPE
 

CIRCULATORY SYSTEM
 

DIGESTIVE SYSTEM
 

•LIVER	 (18) (20)
 

HEPATOCELLULAR CARCINOMA 2 (10%)
 

HEMANGIOSARCOMA
 

«DUODENUM (18) (20)
 

ADENOMATOUS POLYP, NOS 1 (6%)
 

URINARY SYSTEM
 

NONE
 

ENDOCRINE SYSTEM
 

tTHYKOlD (17) (20)
 FO.LLICULAR-CELL AD£UOMA 2 (12%) 2 (10%)
 

C-CELL ADENOMA
 

REPRODUCTIVE SYSTEM
 

•BAMhARY GLAND	 (19) (20)
 

ADENOCARCINOMA, NOS
 

#UT£.RUS (18) (20)
 

ADENOCARCINOMA, NOS
 ENDOMETRIAL STROMAL POLYP
 

#OVARY (18) (19)
 PAP1LLARX CYSTADENOMA, NOS
 

# NUMBER OF ANIMALS WITH TISSUE EXABIHED MICROSCOPICALLY 

• NUMBER OF ANIMALS fcECROPSIED 

'-7 

LOU DOSE
 

02-F154
 

(50)
 

(49)
 

1 (2%)
 

(50)
 

20	 (40*)
 

1 (2%)
 

(50)
 

(47)
 

1 (2*)
 

(50)
 

2 (4X)
 

(49)
 

1 (2*)
 

(49)
 

1 (2%)
 

HIGH DOSE 

02-F155 

(48)
 

(49)
 

(49)
 

15 (31*)
 

1 (2%)
 

(48)
 

<*5>
 

(49)
 

1 (2*)
 

(49)
 

1 (2%)
 

(49)
 
TABLE B2 (CONTINUED) 

CONTROL (UNTR) CONTROL (VEH) LOH DOSE HIGH DOSB
 

02-F161 Q2-F151 02-F154 02-F155
 

SiSTErt 

SfiNSE ORGAflS
 

fiUSCJLOSKJiLBrAL 

ODl CAVITIES 

BONh 

ALL OTHER SYSTEMS 

ANIMAL DISPOSITION SUBHAfci 

ANIMALS INITIAL!.* IN STUDY

NATURAL DEATHa>

SORIBUtfD SACRIFICE

SChEDULEf) SACRIFICE 

ACClDENTALLi KILLED

TsKKINAL SACRIFICE

ASIflAL MISSING 

 20

 3

 1?

 20

 4

 16

 50

 10

 40

 50 

 13 

2 

1 

34 

 INCLUDES AUTOLY&ED ANIBALS 

• NOBBLR OF ANIHALS WITH TISSUE EXABINED BICROSCOPICALLT 

* NURbER OF ANIMALS NECROPSIED 

B-8
 
TABLE B2 (CONCLUDED) 

CONTROL(ONTR) CONTROL(VBH) LOW DOSB HIGH DOSB 

02-F161 02-F151 02-F154 02-F155 

TUMOJi SUHMARY 

TOTAL ANIMALS WITH PRIMARY TUMORS* 

TOTAL PRIMARY TUHORS 

32 

40 

26 

32 

TOTAL ANIMALS WITH BENIGN TUMORS 

TOTAL BENIGN TUflORS 

Tul'AL ANIMALS WITH MALIGNANT TUHORS 

TOTAL MALIGNANT TUMORS 

31 

37 

24 

28 

TOTAL ANIhALS WITH SECONDARY TUMORS*

TOTAL SECONDARY TUMORS

 1

 1

 1 

1 

TOTAL ANIMALS WITH TUMORS UNCERTAIN3EN1GH OR MALIGNANT 

TOTAL UNCERTAIN TUMORS 

TOTAL ANIMALS WITH TUMORS UNCERTAINPRIMARY OR METASTATIC 

TOTAL UNCERTAIN TUMORS 

* PRIMARY TUMORS: ALL TUMORS EXCEPT SECONDARY TUMORS 

# SECONDARY TUilORS: METASTATIC TUHORS OR TUHORS IfcVASI?£ INTO &N ADJACENT ORGAN 

B-9
 

APPENDIX C
 

SUMMARY OF THE INCIDENCE OF NONNEOPLASTIC
 

LESIONS IN RATS TREATED WITH HEXACHLOROETHANE
 

TABLE CI

 

SUMMARY OF THE INCIDENCE OF NONNEOPLASTIC LESIONS IN MALE RATS 

TREATED WITH HEXACHLOROETHANE 

CONTROL(UBTR) 

01-151U 

COHTROL (VJBH) 

01-101B 

LOW DOSE 

01-152» 

E1GK DOSE 

01-153H 

ANIMALS 

ANIMALS 

ANIMALS 

INITIALLY IN STUDY 

NECROPSIBD 

EXAMINED HISTOPATHOLOGICALLY** 

20 

20 

20 

20 

20 

20 

50 

50 

49 

50 

50 

50 

INTEGUMENTARY SYSTEM 

*SKIS 

INFLAMMATION, 14OS (20) (20) 

1 (5%) 

(50) (50) 

RESPIRATORY SYSTEM 

ffRAcHEA 

INFLAMMATION,

INFLAMMATION,

 ACUTE 

 CliRONlL. 

(20) 

1 (5*) 

(20) 

2 (10%) 

(48) 

1 

4 (2*) 

(81) 

(49) 

1 (2*) 

MINERALIZATION 

INFLAMMATION, NOS 

PiaEUMOMA, ASPIRATION 

INFLAMMATION, ACUTE 

PNEUMONIA, CHRONIC MURINE 

INFLAMMATION, GRANULOMATOUS 

INFLAMMATION, PJiOGRAHULOflATOUS 

PERIARTERITIS 

CALCIFICATION, METASTATIC 

(20) 

1 

13 

1 

(5%) 

(65%) 

(5%) 

(20) 

15 

1 

(75%) 

(5%) 

1 (5*) 

(49) 

5 

1 

24 

1 

(10*) 

(2%) 

(49*) 

(2*) 

(50) 

1 

1 

25 

(2*) 

(2*) 

(50*) 

HEMATOPOIETIC SYSTEM 

#dONE MARROW 

HEMATOPOIETIC (20) (20) 

1 (5*) 

(49) (50) 

•SPLEEN 

HEMOSIDEROSIS 

HEMATOPOIESIS 

(20) 

1 

1 (5*) 

(5*) 

(20) 

1 (5*) 

(49) 

1 (2*7 3 (6*) 

(49) 

2 (4*) 

#LYKPH NODE 

HYPERPLASIA, NOS 

(20) (18) 

1 (6*) 

(46) (44) 

fSUBMANDIBULAR L.NODE 

INFLAMMATION, NOS 

(2 0) (18) (46) (44) 

1 (2*) 

# NU3buR OF ANIMALS WITH TISSUE EXAMINED MICROSCOPICALLY 

* NUMBER OF ANIMALS NECROPSIED 

**EXCLUDES PARTIALLY AUTOLYZED ANIMALS 

C-3
 
TABLE CI (CONTINUED) 

#CEBV1CAL LYMPH NODE
 

LYMPHANGIECTASIS
 

INFLAMMATION, NOS
 

INFLAMMATION, ACUTE
 

HiPERPLASIA, LYMPHOID
 

#THYMUS
 

ATROPHY, NOS
 

CIRCULATORY SYSTEM
 

fttEART
 INFLAMMATION, CHRONIC
 

CALCIFICATION, METASTATIC
 

fMYOCARDIUM
 

MINERALIZATION
 

INPLAKMATION, NOS
 

INFLAMMATION, FOCAL
 

FIBROSIS
 

FIBROSIS, FOCAL
 

DUG2NERAT1ON, tfOS
 

•ARTERY
 

fllNERALIZATION
 

IHFLAMMATIOi», isiOS
 

NECROSIS, NOS
 

HYPERPLASIA, HEMATOPOIETIC
 

•AORTA
 

MINERALISATION
 

MEDIAL CALCIFICATION
 

•CORONARY ARTERY
 

MINERALIZATION
 

•PULMONARY ARTERY
 

MINERALIZATION
 

•MJESfiiiTERIC ARTS it Υ
 

MINERALIZATION
 

PERIARTERITIS
 

MEDIAL CALCIFICATION
 

•RENAL ARTERY
 

MINERALIZATION
 

f NUMBER OF ANIMALS WITH T1SS0E


• NUMBER OF ANIMALS NECfvOPSlED
 

CONTROL (UNTR) CONTROL(VEH)
 

01-151H 01-101M
 

(20) (18)
 

1 (5%)
 

1 (5%)
 

2 (10%)
 

OZ) (11)
 1 (8%) 1 (9%)
 

(20) (20)
 

1 (5%)
 

(20) (20)
 

1 (5%)
 

1 (5%)
 

7 (35%)
 

2 (10%)
 

1 (5%)
 

(20)	 (20)
 

1 (5%)
 

1 (5%)
 

1 (5%)
 

1 (5%)
 

(20) (20)
 

1 (5%)
 

(20) (20)
 

(20) (20)
 

(20) (20)
 

1 (5%)
 

(20) (20)
 

 EXABINED MICROSCOPICALLT
 

C-4
 

LOW DOSE
 

01-152H
 

(46)
 

1 (2%)
 

5 (11%)
 

(38)
 

(49)
 

(49)
 

3 (6%)
 

10 (20%)
 

1 (2%)
 

1 (2%)
 

(50)
 

(50)
 

8 (16%)
 

(50)
 

1 (2%)
 

(50)
 

7 (14%)
 

(50)
 

5 (10%)
 

1 (2%)
 

(50)
 

1 (2*)
 

HIGH DOSE
 

01-T53M
 

(44)
 

(25)
 

(49)
 

1 (2%)
 

(49)
 

1 (2%)
 

2 (4%)
 

(50)
 

(50)
 

1 (2%)
 

(50)
 

(5 O>
 

1 (2%)
 

(50)
 

1 (2%>
 

(50)
 
TABLE CI (CONTINUED) 

CONTROL (UNTR) CONTROL(VEH)
 

01-151H 01-101H
 

DIGESTIVE SYSTEM
 

#LIVLH (20) (20)
 

HEBORRHAGE 1 (5%)
 GhA^ULOHA, HOS 1 (5%)
 PERIARTERITIS
 

POLIOSIS HEPATIS (20Χ) 3 (15%)
 

ftETAfiORPHOSlS PATTY 1 (5%)
 PuCAL CELLULAR CHANGE
 

•HEPATIC LUBJLL·	 (20) (20)
 

«hTAIORPHOSIS FATTY
 

•LIVhfi/CEaTRILOBULAR	 (20) (20)
 

NECROSIS, NOS 1 (5%)
 

METAftORPHOSIS FATTY 2 (10*)
 

•L1V.C.R/PSR I PORTAL (20) (20)
 

INPLAdMATION, ACJTb/CHRONIC 1 (5%)
 FIBROSIS 1 (i>%)
 

•LI V ER/HEPATOC iTES (20) (20)
 

FOCAL CELLULAR CHANGE
 

•BILE DOCT	 (ZO) (20)
 

DILATATION, i*US
 

INFLAMHATION, NOS 3 (15%)
 

INFLAMMATION, CHRONIC
 

HYPERPLASIA, NOS	 i> (2b%) ^ (2 5%)
 

#PANCHEAS (19) (20)
 

IMPLAMrtATION, ACUTE/CHBON1C 1 (5%)
 

PERIARTERITIS 1 (5*) 1 (5%)
 

PERIVASCULITIS
 

#PASCREAT1C DOCT (19) (20)
 

DISTENTION 1 (5%)
 

•PANCREATIC ACINUS	 (19) (20)
 

ATROPHY, NOS 1 (5%)
 

•ESOPHAGUS	 (19) (20)
 

PERFORATION. INFLAftttAlOKl
 

• NUMBER OF ANIMALS WITH TISSUE EXAMINED MICROSCOPICALLY
 

* SUflbER OF ANIMALS NECROPSIED
 

LOtf DOSE
 

01-152»
 

(49)
 

1 (2%)
 3 (6%)
 

(49)
 

(49)
 

1 (2%)
 

3 (6%)
 

(49)
 

(49)
 

3 (6%)
 

(50)
 

1 (2%)
 

1 (2%)
 

5	 O0X)
 

(49)
 

3 (6%)
 

1 (2%)
 

(*»9)
 

(49)
 

(47)
 

HIGH DOSE
 

01-t53M
 

(50)
 

2 (1%)
 

(50)
 

1 (2%)
 

(50)
 

2 {*»*)
 

(50)
 

(50)
 

1 (2%)
 

(4 8)
 

2 (4%)
 

(48)
 

(48)
 

(47)
 

1 (2%)
 

C-5 
TABLE CI (CONTINUED)
 

COMTROL(UHTR) CONTROL(VEH) LOW DOSE HIGH DOSB
 

01-151» 01-101B 01-1528 0T-153H
 

•STOMACH (20) (20) 

MINERALIZATION 1 (5%) 

ULCKR, FOCAL 1 (5%) ULCER, ACUTE 

PERIARTERITIS 

CALCIFICATION, METASTATIC 1 (5*) 

HYPERKERATOSIS 

ACANTHOSIS 

«LARGE INTESTINE (20) (18) 

MINERALIZATION 

PARASITISM 2 (11%) 

URINARY SYSTEM
 

#άΙΙ>ΝΕΪ (20) (20)
 MINERALIZATION 5 (25%)
 

PYELONEPHRITIS,, NuS
 

JLNFLABHATION, SUPPURATIVE 1 (5*)
 

INFLARMA-PION, CHROMIC 15 (75%) 14 (70%)
 

NEPHROPATHY, TOXIC
 

CALCIFICATION, HOS 3 (15%)
 

CALCIFICATION, METASTATIC 1 (5%)
 FOCAL CELLULAR CHANGE
 

fKlUNEY/PELVIS (20) (20) 

INFLAMMATION, NOS 

INFLAHMATION, ACUTE 

#JRlNAhY (20) (19) INFLAMMATION, FOCAL 

ISFLARttATION, HEMORRHAGIC 

iNFLAHilAriON, ACUTE 1 (5%) 

INFLAMMATION, ACUTE/CHRONIC 1 (5%) 

INFLACMATION, CHKOHIC 

HYPERPLASIA, EPITHELIAL 1 (5%) 

SgUAMOUS
 

•URh'JMRA	 (20) (20) 

INFLAMMATION, ACUTE (10%) 

ENDOCRINE SYSTEM 

tPHUITARY (18) (19) 

iiYPERPLASIA, 1 (5%), 

# HUMbER OF ANIMALS WITH TISSUE EXAMINED MICROSCOPICALLY
 

* *UMBhR OF AiUrtALS NELKOPSIED
 

C-6
 

(49)
 

7


2


1


1


1


1


(Ί9)
 

1


2


(49)
 

4
 

1
 

32
 

22
 

(49)
 

(48)
 

1
 

1
 

(50) 

(42)
 

3


 (14%)
 

 (4%)
 

 (2*)
 

 (2%)
 

 (2%)
 

 (2*)
 

 (2%)
 

 (4*)
 

(8%)
 

(2%)
 

(65%)
 

(45%)
 

(2%)
 

(2%)
 

 (7?) _
 

(50)
 

1 (2*)
 

2 (4*)
 

1 (2%)
 

1 (2%)
 

1 (2%)
 

(48)
 

(50)
 

1 (2%)
 

2 (**>
 

25 (50%)
 

33 (66%)
 

(50)
 

3 (6%)
 1 (2%)
 

(48)
 

1 (2%)
 

1 (2%)
 

2 {*%)
 1 {2%)
 

1 (2%)
 

(50) 

(44)
 
TABLE CI (CONTINUED)
 

•ADRENAL	 CORTEX
 

HEMORRHAGE
 

DEGENERATION, NuS
 

ANGIECTAS1S
 

«ADRENAL MEDULLA
 

HYPERPLASIA, FOCAL
 

•THYROID
 

CYSTIC FOLLICLES
 

FOLLICULAR CYST, NOS
 

INFLAfl^AlION, NOS
 

HYPgRPLASIA, C-CSLL
 

*PAΚATHYROID
 

HYPERPLASIA, NOS
 

REPnODUCTJV£ SYSTEM
 

#PRUSTATL·
 

MINERALIZATION
 

INFLAMMATION, FOCAL
 

INFLAMMATION, ACUTE
 

INFLAMMATION, ACUTE FOCAL
 

INFLAMMATION, ACUTE/CHRONIC
 

I^FLAKSATIu^, CHRONIC
 

*3^M1NAL VESICLE
 

INFLAMMATION, ACUTE
 

±NFLAKi1AriOii», ACUTE/CHROttlC
 

BiEsTIS
 

..H^ERALIZATiOis
 

HEMORRHAGE
 

PERIARTERITIS
 

CALCIFICATION, NOS
 

ATROPHY, aOS
 

HYPOSPERflATOGENLSlS
 

•3t>lDlD*aiS
 

MINERALIZATION
 

PERIARTERITIS
 

NECROSIS, FAT
 

SUnDER OF ANIMALS WITh TISSUE


NUIbER OF ANIMALS NECROPSIED
 

CONTROL (UNTR) COHTPOL(VEH) LOW DOSE HIGH DOSE 

01-151» 01-101M 01-152M 01-153» 

(19) (20) (I|9 ) (50) 

1 (2%) 

12 (63%) 7 (35%) 12 (24%) 12 (24%) 

2 (11%) 1 (5%) 3 (6%) 

(19) (20) (49) (50) 

1 (5%) 1 U%) 

(20) (20) (48) (48) 

4 (8%) 

1 (5%) 

1 (5%) 

2 (<*») 1 (2%) 

(10) (17) (29) (20) 

9 (90%) 2 (12%) 14 (48%) 5 (25%) 

(20) (16) (40) (33) 

1 (5%) 1 (3%) 

1 (3%) 

6 (30%) 5 (13%) 2 (6%) 

1 (5%) 1 (3%) 1 (3%) 

1 (3%) 

1 (6%) 1 (3%) 2 (6%) 

(20) (20) (50) (50) 

1 (2%) 

1 (2%) 

(20) (20) (48) (50) 

4 (20%) 5 (10%) 4 (8%) 

1 (2%) 

1 (5%) 1 (5%) 3 (6%) 

1 (2%) 

5 (25%) 1 (5%) 2 (4%) 7 (14%) 

7 (35%) 4 (20%) 15 (31%) 6 (12%) 

(20) (20) (50) (50) 

1 (2%) 

1 (5%) 

1 (5%) 

 EXAMIHED MICROSCOPICALLY 

C-7
 
TABLE CI (CONTINUED) 

CONTROL (UNTR) CONTROL (VfiH) LOW DOSE HIGH DOSS 

01-151H 01-101H 01-152S 01-153H 

NLRVOUS SYSTEM 

fBRAIN 

HYDROCEPHALUS, SOS 

HEMORRHAGE 

NECROSIS, FOCAL 

(20) (20) (49) 

(2%) 

(2%) 

(2%) 

SPECIAL SENSE ORGANS 

NONE 

MUSCULOSKELETAL SYSTEM 

•BONE 

FIBROUS OSTEODYS'lROPhY 

(20) (20) (50) (50) 

•STERNUM 

PERIARTERITIS 

(20) (20) (50) 

1 (2X) 

(50) 

BODY CAVITIES 

•MEDIASTINUM

INFLAMMATION,

AbscEss, aos 

PERIARTERITIS 

 HCUTE 

 (20) (20) (50) 

1

1

 (2%) 

 (2%) 

(50) 

1 (2%) 

•PLEURA

I&FLAMMA1ION,

INFLAMMATION,

INFLAMMATION,

 FOCAL 

 ACUTE 

 PYOGRANOLOMATOUb 

 (20) (20) (50) (50) 

1 

3 

1 

(2*) 

(6%) 

(2%) 

•PERICARDIUM

INFLAMMATION,

INFLAMMATION,

INFLAMMATION,

 HOS 

 ACUTE 

 CHRONIC FOCAL 

 (20) (20) (50) (50) 

1 

2 

1 

(2%) 

(**) 

(2%) 

•EP1CARDIUM

INFLAMMATION,

INFLAMMATION,

 FOCAL 

 ACUTE 

 (20) (20) (50) (50) 

1 

1 

(2%) 

(2%) 

•MESENTERY

PERIARTERITIS

 (20 ) 

 (5%) 

(20) 

3 Π5%> 

(50) 

3 16%) 

(50) 

2 ( 4%i 

# NUMBER OF ANIMALS HITH TISSUE EXAMINED MICROSCOPICALLY 

• NUMBER OF ANIMALS NECROPSIED 

C-8
 
TABLE CI (CONCLUDED) 

CONTROL(UNTfi) 01-151H CONTROL(VEH) 

01-IOIrt 

LOW DOSS 01-1523 HIGH DOSE 

01-153» 

ALL OTHER SYSTEMS 

•MULTIPLE ORGANS 

THORAX 

PERIARTERITIS 

PLEURAL CAVITY 

HEMORRHAGE 

INFLAMMATION, PYOGRANOLOMATOUS 

(20) 

3 (15%) 

(20) (50) (50) 

SP2LIAL MORPHOLOGY SU!L1ARY 

NO LESlOxN REPORTED 

AUTO/NBCROPSJf/HlSTO PERP 

AUTO/SECROPSY/N H1STO 

bufi OP ANIMALS WITH TISSUE EXAHINED MICROSCOPICALLY 

* *U«BJSR OF ANIMALS NECROPSIED 

C-9
 
TABLE C2

 

SUMMARY OF THE INCIDENCE OF NONNEOPLASTIC LESIONS IN FEMALE RATS 

TREATED WITH HEXACHLOROETHANE 

LOW DOSE
 

01-154P
 

50
 

50
 

50
 

(50)
 

(50)
 

(49)
 

2 (4%)
 

2 (4%)
 

(50)
 

1 (2%)
 

1 (2%)
 

32 (64%)
 

(50) 

(49)
 

1 (2%)
 

1 (2%)
 

3 (61)
 

(47)
 

HIGH DOSB
 

01-155P
 

50
 

50
 

49
 

(50)
 

(50)
 

(49)
 

1 (2%)
 

1 (2%)
 

(49)
 

1 (2%)
 29 (59%)
 

(49)
 

(49)
 

2 (4%)
 

(49)
 

ANIMALS INITIALLY IN STUDi
 

ANIMALS NECR0PS1ED
 

ANIMALS EXAMINED HISTOPATHOLOGICALLY**
 

INTEGUMENTARY SYSTEM
 

•SKIN
 

ULCER, NOS
 

•SUbCUT TISSUE
 

HLHORKHAGIC CYST
 

RESPIRATORY SYSTEM
 

tTRACHEA
 

INFLAMMATION, ACUTE
 

INFLAMMATION, CHRONIC
 

fLUNG
 

ATELECTASIS
 

INFLAMMATION, ACUTi,
 

AbSCESS, NOS
 

PNEUMONIA, CHROMIC MURINE
 

CALCIFICATION, METASTATIC
 

HEMATOPOIETIC SYSTEM
 

#bONK MARROW
 

HYPERPLASIA, HEMATOPOIETIC
 

«SPLEEN
 

INFLAMMATION, ACUTE
 

HEMOSIDEROSIS
 

HEMATOPOIESIS
 

•MANDIBULAR L. NODL·
 

luFLAMMATIOu, NOS
 

INFLAMMATION, ACUTE
 

# NUMbfiR OF ANIMALS WITH TISSUE

• aUMfcJiS OF ANIMALS t*£CROPSIED 

CONTROL (UNTR)
 

01-151F
 

20
 

20
 

20
 

(20)
 

(20)
 

(20)
 

1 (5%)
 

1 (5%)
 

(20)
 

1b (90%) 

(20)
 

(19)
 

3 (1b%)
 

(19)
 

CONTROL(VEH)
 

01-101F
 

20
 

20
 

20
 

(20)
 

1 (5%)
 

(20)
 

(20) 

(20)
 

1 (5%)
 

1 (5%)
 

18 (90%)
 

1 (5%)
 

(20)
 

4 (20%)
 

(20)
 

2 (10%>
 

(20)
 

1 (5%)
 

 EXAMINED MICROSCOPICALLY 

**EXCLUDES PARTIALLY AUTOLYZED ANIMALS 

C-IO
 
TABLE C2 (CONTINUED) 

LOW DOSE
 

01-154P
 

(47)
 

1 (2*)
 

(50)
 

(50)
 

(50)
 

1 (2*)
 

5 (10X)
 

1 (2*)
 

(50)
 

(50)
 

(50)
 

2 (4%)
 

(50)
 

1 (2*)
 

(50)
 

2 (4*)
 

(50)
 

2 (4%)
 

1 (2*)
 

HIGH DOSI
 

01-155F
 

(49)
 

1 (2*)
 

(49)
 

(50)
 

(49)
 

1 (2*)
 

2 (4%)
 

(*9)
 

1 (2*)
 

(49)
 

1 (2*)
 

(50)
 

t (2%)
 

(49)
 

(48)
 

4 (3%)
 

(4 9)
 

1 (2*)
 

1 (2*)
 

iCERVICAL LYMPH NODE
 

HYPERPLASIA, «OS
 

HYPERPLASIA, LYMPHOID
 

CIRCULATORY SYSTEM
 

•MYOCARDIUM
 

FJBROSIS
 

DEGENERATION, SOS
 

•ARTERY
 

MEDIAL CALCIFICATION
 

CALCIFICATION, METASTATIC
 

DIGEbJ'IVS SYSTEM
 

«LIVER
 

HELIOSIS riEPATIS
 

FOCAL CELLULAR CHANGE
 

ARtolJBCTASIS
 

«LIVtiR/CENTRiLOBULAR
 

NECROSIS, FOCAL
 

tLIVnit/HEPATOCYTBS
 

FOCAL CELLULAR CHANGE
 

•BILL uUCr
 

DILATATION, ΝOS
 

INFLAMMATION, CHRONIC
 

HYPERPLASIA, NOS
 

ANG1ECTASIS
 

•PANCREAS
 

INFLAMMATION, ACU1E HEMORRHAGIC
 

PERIARTERITIS
 

ATROPHY, aOS
 

«ESOPHAGUS
 

PERFORATION, INFLAMMATORY
 

«SlOrtACH
 

ULCER, FOCAL
 

INFLAMMATION, CHRONIC
 

PERIARTERITIS
 

CALCIFICATION, METASTATIC
 

COHTROi. (UHTR)
 

01-151F
 

(19)
 

1 (5*)
 

2 (11%)
 

(20)
 

1 (5*)
 

1 (5*)
 

(20)
 

(20)
 

1 (5*)
 1 (5%)
 

(20)
 

(20)
 

(20)
 

3 (15*)
 

1 (5%)
 5 (25*)
 

(20)
 

2 (10*)
 

1 (5%)
 

(19)
 

(20)
 

3 (15*)
 

CONTROL (VEH)
 

01-101F
 

(20)
 

1 (5*)
 

(20)
 

1 (5*)
 

(20)
 

1 (5%)
 

1 (5*)
 

(20)
 

1 (5*)
 

(20)
 

(20)
 

(20)
 

6 (30*)
 

1 (5*)
 

(20)
 

1 (5*)
 

(20)
 

(20)
 

1 i5*)
 

# NUrtbER OF AidISALS WITH TISSUE EXAHIMED MICROSCOPICALLY 

• NUMtfLH OF ANIMALS NjbCROPSIED 

C-ll 
TABLE C2 (CONTINUED) 

C O* 

CONTROL (11NTR) 

01-151F 

CONTROL (VEH) 

01-101F 

LOW DOSE 

01-154P 

HIGd DOSE 

01-155F 

fSMALL INTESTINE 

ULCJ&R, NOS 

(20) (20) 

1 (5%) 

(48) (48) 

*L\HGd 

NEMATODIASIS 

PARASITISM 

#LOLON 

PARASITISM 

(20) 

1 (5%) 

UO) 

(20) 

1 (5%) 

(20) 

1 (5%) 

(49) 

2 (4%) 

(49) 

(49) 

(49) 

URIwARY SYSTEM 

•KIDNEY 

MINERALIZATION 

HYDRONEPHROSIS PYELONEPHRITIS, NOS 

INFLAMMATION, ACUTE FOCAL 

INFLAMMATION, CHRONIC 

NEPHROPATHY 

NEPHROPATHY, TOXIC 

INFARCT, FOCAL 

CALCIFICATION, NOS 

(20) 

7 

8 

(35%) 

(4 0%) 

(20) 

2 (10%) 

1 (5%) 

1 (5%) 

4 (20%) 

1 (5%) 

7 (35%) 

(50) 

2 

1 

18 

9 

(4%) 

(2%) 

(36%) 

(16%) 

(49) 

20 (41%) 

29 (59%) 

1 (2%) 

«KIDNEY/PELVIS 

INFLAMMATION, &OS 

(20) (20) (50) (49) 

1 (2%) 

•URINARY BLADDER 

INFLAMMATION, CHRONIC 

(18) (20) (49) 

1 (2%) 

(4 8) 

ENDOCRINE SYSTEM 

•PITU1TAKY 

CYST, dOS 

HYPERPLASIA, CHROMOPHObE-CELL 

(18) 

(22%) 

(20) 

2 (10%) 

(50) 

2 

4 (4%) 

(8%) 

(46) 

2 (4%) 

•ADRESAL CORTEX 

DEGENERATION, NOS ANGIECTASIS 

(20) 

i> 

10 (25%) (50%) 

(20) 

6 (30%) 8 (40%) 

(50) 

10 

10 (20%) 

(20%) 

(49) 

4 (8%) 12 (24%) 

«THYROID 

CYSTIC FOLLICLES FOLLICULAR CYST, NOS HYPERPLASIA, C-CELL 

(20) 

1 

1 (5%) 

(5%) 

(20) (47) 

4 

1 

(9%) 

(2%) 

(47) 

1 (2%) 

# NUMBER

* NOMBEfi

 OF

 OF

 ANIMALS

 ANIMALS

 WITrii TISSUE

 NECROPSIED 

 EXAMINED MICROSCOPICALLY 

C-I2 
TABLE C2 (CONTINUED) 

CONTROL(UNTR) 

01-151P 

CONTROL(VEH) 

01-101F 

LOW DOSE 

01-154F 

HIGH DOSE 

01-155F 

#PAKATHYROID 

HYPERPLASIA, NOS O^) 

8 (67%) 

(18) (t9) 

3 (16%) 

(21) 

2 (10%) 

REPRODUCTIVE SYSTEM 

•VAblMA 

PROLAPSE 

(20) (20) (50) 

1 (2%) 

(50) 

«UTERUS 

HYDRO3ETRA 

(20) (49) 

4 (6%) 

(49) 

4 (8%) 

fOThRUS/aNDOrtETfllUH 

INFLAMMATION, UOS 

INPLAIMATION, ACUTE 

HYPERPLASIA, CYSTIC 

(20) 

2 (10%) 

1 (5%) 

(20) 

1 ('>%> 

(49) 

1 

1 U») 

(2%) 

(49) 

1 (2%) 

•OVARY 

CYST, NOS 

FOLLICULAR CYST, NOS 

(19) (20) (48) 

1 (2*) 

(49) 

1 (2%) 

NERVOUS SYSTEM 

HONL· 

SPECIAL SENSE ORGANS 

KUSCULOSKELETAL SYSTEM 

•SKELETAL flUSCLE 

PERIARTERITIS 

(20) (20) 

(5%) 

(50) (50) 

ύΟΏΪ CAVITIES 

•PERITONEI 

INFLAflMATION r ACUTE/CBRONIC 

*PLtURA 

INFLAMMATION, ACUTE 

1NFLA1MAI1ON, ACUTE FIBRINOUS 

INPLAgflATlOMj PYOGRANULOUATOOS 

(20) 

1 (5%) 

(20) 

(20) 

(20) 

(50) 

(50) 

3 

1 

2 

(6%) 

(23k) 

(4%) 

(50) 

(50) 

5 110%) 

# NUHBER OF ANIMALS

• NUMBER OF ANIMALS

 WITH TISSJE EXAMINED

 NECROPSIED 

 HICROSCOPICALLT 

C-13
 
TABLE C2 (CONCLUDED) 

CONTROL (UNTR)

01-151F

 CONTROL (VBH)

 01-101F

 LOW DOSE

 01-154P

 HIGH DOS» 

 01-155F 

•PERICARDIUM

INFLAMMATION, ACUTE 

INFLAMMATION, CHRONIC 

*£PICARD1UM

INFLAMMATION, ACUTE 

INFLAMMATION, ACUTE FIBRINOUS 

INFLAMMATION, CHRONIC 

•MESENTERY

PERIARTERITIS

 (20)

 (20)

 (2 0)

 Ζ (10%) 

 (20) 

 (20) 

 (20) 

(50) 

(50) 

2 

1 

(50) 

1 

(«%) 

(2X) 

(2X> 

(50) 

2 

(50) 

2 

(50) 

ALL OTHER SYSTEMS 

•aOLTIPLh ORGANS (20) (20) (50) (50) 

MINERALISATION 1 (5%) 

SPECIAL MORPHOLOGY SUMMARY 

NO LESION REPORT ED

ΑϋΤΟ/NECROPSY/NO HISTO

• NUMBER OF ANIMALS WITH TISSUE LXAuINED MICROSCOPICALLY 

• NUMBER OF ANIMALS NECROPSIED 

3 8 

1 

C-14
 
APPENDIX D
 

SUMMARY OF THE INCIDENCE OF NONNEOPLASTIC
 

LESIONS IN MICE TREATED WITH HEXACHLOROETHANE
 

TABLE Dl
 

SUMMARY OF THE INCIDENCE OF NONNEOPLASTIC LESIONS IN MALE MICE
 

TREATED WITH HEXACHLOROETHANE
 

CONTROL (UNTR) 

02-B16 1 

CONTROL fVEH) 

02-M151 LOW DOSE 

02-B152 

HIGH DOSE 02-B15 3 

ANIMALS INITIALLY IN STUDY 

ANIMALS 1ISSTNG 

ANIMALS NECROPSIED 

Aal.lALS EXAMINED HISTOPATHOLOGICALLY ** 

20 

18 

17 7

20 

20 

20 

50 

50 

50 

50 

1 

4949 

INTEGUMENTARY SYSTEM 

•SKIN 

EPIDERMAL INCLUSION

INFLAMMATION, NOS 

CYST (1a) 

1 (6%) 

(20) 

1 (5%) 

(50) 

2 

(49) 

1 (2%) 

*SUtfCUT TISSUE 

ABSCESS, NOS 

(18) 

1 (6%) 

(20) 

1 (5%) 

(50) 

6 (12%) 

(49) 

1 (2%) 

RESPIRATORY SYSTEM 

INFLAMMATION, NOS (17) (19) (49) 

*

 1 (2%) 

(49) 

1 (2%) 

#LUNG 

JNPLAMMATION, ACUTE SUPPURATIVE 

PNEUMONIA, CHRONIC MURINE 

(18) (20) 

1 (5%) 

(50) 

1 

12 

(2%) 

(24%) 

(49) 

1 

2 

(2%) 

(4%) 

HEMATOPOIETIC SYSTE3 

AMYLOIDOSIS (18) 10 (56%) (19) 

6 (ό2%\ (50) 

8 

1 

(16%) 

(2%) 

(49) 

1 (2%) 

«MESENTERIC L. NODE 

INFLAMMATION, i«US 

(16) 

3 (19%) 

(19) 

3 (16*) 

(47) 

14 (30%) 

(49) 

3 (6%) 

INFLAMMAilON, NOS (10) (5 ) (26) (36) 

Τ (3%) 

LI&CLJLATORY SYSTEM 

»HEAKT 

CALCIUM DEPOSIT (18) (20) (50) (49) 

* SiURbElt OF ANIftALS WITH TISSUE EXAMINED

* NUMiiER OF AJIilALS NECROPSIED 

**EXCLUD£S PARTIALLY AUTOLYZED ANIMALS 

MICROSCOPICALLY 

D-3
 
TABLE Dl (CONTINUED) 

CONIROL(ONTR) CONTROL (VBH) LOU DOSE BIGfi DOSE 

02-W161 02-M151 02-M152 02-B15 3 

thLAft'l/ATRIUM 

ltiKOflBUS, ORGANIZED 

(18) (20) (50) 

1 (2%) 

(49) 

fKYOCARDIUfi 

FIBROSIS 

DEGENERATION, NOS 

(18) (20) (50) 

i 

1 

<*»*) 

(2%) 

(49) 

DIGESTIVE SYSTEM 

#SALIVARY GLAND (1i>) (19) (49) (48) 

CYST, NOS 1 (2%) 

AiROPHY, NOS 1 (2%) 

(18) (20) (50) (49) 

THROMBUS, ORGANIZED 1 (2%) 1 (2%) 

INFLAMMATION, NOS 1 (5*) 3 (6*> 

FIBROSIS 1 (5%) 

NECROSIS, NOS 1 (2%) 

INFARCT, NOS 1 (2*) 

AMYLOIDOSIS 1 (6%) 1 (2*) 

#LIV£.R/CENTRILOBULAR (18) (20) (50) (49) 

NECROSIS, i»US 1 (2%) 

*BlLh DUCT (18) (20) (50) (49) 

HYPERPLASIA, NOS 1 (5%) 

«PANCREAS (18) (20) (50) (49) 

CiSl, NOS t (2%) 

INFLAMMAIION, HOS 1 (5%) 

*SlOttACH (18) (20) (50) (49) 

ULCER, FOCAL 2 (4%) 

•LARGE INTESTINE (18) (20) (49) (*9) 

NEMATODIASIS 1 (5*) 

fCULON (18) (20) (49) (49) 

NEMATODIASIS 2 (4%) 

i NUBBER OF AKIHALS WITH I1SSUE EXABINED fllCROSCOPICALLY * SUiitJEft OF ANIflALS NECROPSIED 

D-4 
TABLE Dl (CONTINUED)
 

URINAR* SYSTEM
 

•KIDNEY
 

BiDRONEPHROSIS
 

LIST, NOS
 

PYELONEPHRITIS, NOS
 

INFLAMMATION, CHROAIC
 

INFLAMMATION, CHRONIC FOCAL
 NEPHROPATHY, TOXIC
 

AMYLOIDOSIS
 

CALCIUM DEPOSIT
 

tuRlSAK* BLADDER
 

INFLAMMATION, i»OS
 

ENDOCRINE SYSTEB
 

#PI3UITARY
 

INFLAMMATION, NOS
 

#r^YK01D
 

IOLLICULAR CYS1, NOS
 

REPRODUCTIVE SYSTEM
 

•PRLPUcE
 

INFLAMMATION, NOS
 

•PROSTATE
 

INFLAMMATION, NOS
 

•SEMINAL VESICLE
 

INFLAMMATION, NOS
 

•TESTIS
 

CALCIUH DEPOSIT
 

ATROPHY, NOS
 

•EPIDIDYMIS
 

GRANULOMA, SPERHATIC
 

NERVOUS SYSTLS
 

NONE
 

CONTROL (UNTR)
 

02-B161
 

(18)
 

4 (22*)
 

12 (67%)
 

9 (50*)
 

(1b)
 

4 (22*)
 

(14)
 

(16)
 

1 (6*)
 

(18)
 

(1b)
 

3 (17*)
 

(18)
 

1 (6*)
 

(18)
 

(18)
 

COHTROL(VEH)
 

02-B15!
 

(20)
 

1 (5%)
 

2 (10*)
 

16 (80*)
 

9 (45*)
 

(20)
 

1 (5*)
 

(17)
 

(18)
 

(20)
 

(20)
 

U0)
 

(20)
 

(20)
 

1 (5*)
 

LOW DOSF
 

02-B152
 

(50)
 

4 (8%)
 

6 (12%)
 

2 (4%)
 

33 (66%)
 

1 (2%)
 49	 (98%)
 

7 (14%)
 

2 (4%)
 

(49)
 

1 (2%)
 

(43)
 

(46)
 

(i>0)
 

(49)
 

(50)
 

(49)
 

2 (4%)
 

(50)
 

1 (2%)
 

HIGH DOSE
 

02-H153
 

(49)
 

2 (4%)
 

9 (18%)
 

47 (96%)
 

(48)
 

(46)
 

1 (2%)
 

(45)
 

(49)
 

(48)
 

(49)
 

(48)
 

1 (2%)
 5 (10%)
 

(49)
 

# NUMBER Of ANIMALS WITH TISSUE EXABINED ftlCROSCOPICALLI
 

• NUMBER OF ANIMALS NECROPSIED
 

D-5
 
TABLE Dl (CONCLUDED) 

CONTROL(OSTR) 

02-B161 

CONTROL(?EH) 

02-U151 

1.0 DOSE 

02-H152 

HIGH DOSE 

02-Bib3 

SPECIAL SENSE ORGANS 

•EYE 

SYNECHIA, ANTERIOR 

SYNECHIA, POSTERIOR 

(18) (20) (50) (49) 

1 

1 (2%) 

MUSCULOSKELETAL

NONE 

 SYSTEM 

BODY CAVITIES 

NONE 

ALL OTHER SYSTEMS 

LL· ORbANS 

AHYLOIDOSIS 

(18) 

(22X) 

(20) 

(5%) 

(50) 

3 (61) 

(49) 

SPECIAL ftORPHOLOGY SUMMARY 

NO LESION REPORTED 

ANIMAL MISSING/NO NECROPSY 

AUrO/NECROPSY/NO H1STO 

AUTOLYSIS/NO NECROPSY 

# NUMBER OP ANIMALS WITH TISSUE EXAMINED

• NUMbhR OP ANIMALS NECfcOPSIhb 

 MICROSCOPICALLY 

D-6
 
TABLE D2
 

SUMMARY OF THE INCIDENCE OF NONNEOPLASTIC LESIONS
 

IN FEMALE MICE TREATED WITH HEXACHLOROETHANE
 

LOW DOSS HIGH DOSE 

02-Π54 02-F155 

50 50 

50 49 

50 49 

(50) (49) 

13 (26*) 5 (10%) 

(50) (49) 

2 (4%) 

(50) (49) 

1 (<**) 

(50) (4 9) 

1 (2%) 4 (8%) 

1 (2*) 

(50) (49) 

(50) (49) 

(49) 

ANlflALS INITIALLY I* STUDY
 

ANIMALS NECROPSIED
 

ANIMALS EXAMINED HISTOPAIHOLOGICALLY**
 

INTEGUMENTARY SYSTEM 

NONE 

RESP [KATGRY SYSTEM 

«LUNG 

PNEUMONIA, CHRONIC MURINE
 

HEMATOPOIETIC SYSTEM
 

• SPLEEi»
 

HEMATOPOILSIS
 

•CERVICAL LYMPH NODE
 

INFLAMMATION, NOS
 

•MESENTERIC L. NODE
 

INFLAMMATION, NOS
 

ANGI5CTAS1S
 

CIRCULATORY SYSTEM
 

•MYOCARDIUM
 

INFLAMMATION, NOS
 

•ENDOCARDIUM
 

INFLAMMATION, NOS
 

DIGESTIVE SYSTEM
 

•SALIVARY GLAND
 

• NUPBhR OP ANIRALS WITH TISSU E

* NUMBER OF Ai.IMALS ulECROPSIED 

**LXCLUDES PARTIALLY AUTOLYZED ANIMALS 

CONTROL (ONTR)
 

02-F161
 

20
 

19
 

18
 

(18)
 

1 (6%)
 

(18)
 

(18)
 

(18)
 

(18)
 

(18)
 

(6*)
 

(18)
 

CONTROL tVEH)
 

02-P151
 

20
 

20
 

20
 

(20)
 

1
 

(20)
 

(20)
 

(20)
 

(20)
 

(20)
 

(19)
 

 EXAMINED MICROSCOPICALLY 

D-7
 
TABLE D2 (CONTINUED) 

CONTROL (UNTR) CONTROL (VEH) LOW DOSE HIGH DOSE 

02-F161 02-F151 02-F154 02-F155 

#LlVhR (18) (20) THROMBUS, ORGANIZED 

PELIOSIS HEPATIS 

AMYLOIDOSIS 

METAMORPHOSIS FATTY 1 HYPERPLASIA, NOD-JLAR 

«STOMACH (18) (20) 

HYPERKERATOSIS 

ACANTHOSIS 

UhINARY SYSTEM
 

fKIDNEY (18) (20) CYST, NOS 1 

INFLAMMATION, CHRONIC 3 

NEPtiROPATHY, TOXIC 

AMYLOIDOSIS 

ENDOCRINE SYSTEM
 

*THYROID (20) 

INFLAMMATION, NOS 1 (6%) 

HYPERPLASIA, C-CELL 

HYPERPLASIA, FOLLICULAH-CELL 

REPRODUCTIVE SYSTEM 

• UTLxtUS 

HYDROMETRA 

INFLAMMATION, i«OS 

(18) 

4 

1 

(22%) 

(6%) 

(20) 

5 

1 

#0T£K0S/ENDOKETRIUfl 

iNf LAftflATIOw, HOS 

HYPERPLASIA, CYSTIC 

(18) 

5 (28%) 

(20) 

9 

«OVAkY 

CYST, llUi 

FOLLICULAR CYST, NOS 

INFLAMBAT1ON, NOS 

(18) 

2 

1 

(11%) 

(6%) 

(19) 

6 

1 

NERVOUS SYSTEM
 

NONE
 

• :*UilBER OP ANIMALS WITH TISSUE EXAMINED MICROSCOPICALLY
 

* MUflbEh OF ANIMALS NECKOPSIED 

D-8 

 (5%) 

(5%) 

(15%) 

(25%) 

(5%) 

(<*5%) 

(32%) 

(S%) 

(i>0)

1 

1 

1 

(f>0) 

1 

1 

(i>0) 

i>0 

1 

(47) 

1

(49) 

8 

(49) 

1 

8 

(49) 

7 

4 

2 

(2%) 

(2%) 

(2%) 

(2%) 

(2%) 

(100%) 

(2%) 

 (2%) 

(16%) 

(2%) 

(1&%) 

(14%) 

(8%) 

(4%) 

(49) 

1 

(48) 

1 

(49) 

1 

45 

(45) 

1

(49) 

9 

t 

(49) 

1 

6 

(49) 

5 

2 

2 

(2%) 

(2%) 

(2%) 

(92%) 

 (2%) 

(18%) 

(2%) 

(2%) 

(12%) 

(10%) 

(4%) 
TABLE D2 (CONCLUDED) 

CONTROL (ONTR) 

02-F16 1 

CONTROL (VEH) 

02-F131 

LOW DOSB 02-F154 HIGH DOSE 

02-F155 

SPECIAL SENSE ORGANS 

NONE 

MUSCULOSKELETAL SYSTEM 

NONE 

BODY CAVITIES 

ALL OTHER SiSTEMS 

• SULTIPLE OfiGADIS 

AMiLOIDOSIS 

(19) (20) 

1 (5%) 

(SO) (49) 

SPECIAL SORFHOLOGY SUMMARY 

NO LESION REPORTED 

AUTO/N2CRUPSY/NO HISTO 

AUXOLYSIS/NO NECROPSY 

NUMBER OF ANIMALS WITH TISSUE EXAMINED MICROSCOPICALLY 

NUMuEH OF ANIKALS NECROPSIiiD 

D-9
 

Review of the Bioassay of Hexachloroethane* for Carcinogenicity
 

by the Data Evaluation/Risk Assessment Subgroup of the
 

Clearinghouse on Environmental Carcinogens
 

January 18, 1978
 

The Clearinghouse on Environmental Carcinogens was
 

established in May, 1976 under the authority of the National
 

Cancer Act of 1971 (P.L. 92-218). The purpose of the Clearinghouse is to advise on the National Cancer Institute's
 

bioassay program to identify and evaluate chemical carcinogens in the environment to which humans may be exposed. The
 

members of the Clearinghouse have been drawn from academia,
 

industry, organized labor, public interest groups, State
 

health officials, and quasi-public health and research
 

organizations. Members have been selected on the basis of
 

their experience in carcinogenesis or related fields and,
 

collectively, provide expertise in organic chemistry, biostatistics, biochemistry, toxicology, pathology, and epidemiology. Representatives of various Governmental agencies
 

participate as ad hoc members. The Data Evaluation/Risk
 

Assessment Subgroup of the Clearinghouse is charged with
 

the responsibility of providing a peer review of NCI bioassay
 

reports on chemicals studied for carcinogenicity. In this
 

context, below is the edited excerpt from the minutes of
 

the Subgroup's meeting at which Hexachloroethane was reviewed.
 

The primary reviewer agreed with the staff's conclusion
 

that Hexachloroethane was carcinogenic in the treated mice,
 under the conditions of test, but there was no evidence
 

for such an effect in the treated rats. He opined that the
 

failure to see a carcinogenic effect in the rats may have
 

been due to their early death, as evidenced by the association
 

between Increased dosage and accelerated mortality. Despite
 

the overt toxicity produced by the treatment, the primary
 

reviewer agreed with the conclusion that Hexachloroethane
 

was carcinogenic in the treated mice. He added that
 

Hexachloroethane may pose a carcinogenic risk to humans
 

and that notification of the bioassay results should be
 

given to the National Institute for Occupational Safety
 

and Health, Occupational Safety and Health Administration,
 and exposed workers. (All bioassay reports are routinely
 

sent to the relevant regulatory agencies.)
 

The secondary reviewer, also agreed with the conclusions
 

given in the report. She noted the controversy regarding
 

the Implications to humans of mouse hepatocarcincgens.
 

45
 
A Subgroup member moved that the bioassay report on
 

Hexachloroethane be accepted as written. The motion was
 

seconded and approved unanimously. (In reviewing the
 

minutes, Dr. Rowe noted that he had abstained during the
 

vote on the motion.)
 

Members Present Were:
 

Arnold Brown (Acting Chairman), Mayo Clinic
 

Lawrence Garfinkel, American Cancer Society
 

Joseph Highland, Environmental Defense Fund
 

Charles Kensler, Arthur D. Little Company
 

Verald K. Rowe, Dow Chemical, U.S.A.
 

Sheldon Samuels, Industrial Union Department, AFL-CIO
 

Louise Strong, University of Texas Health Sciences Center
 

Sidney Wolfe, Health Research Group
 

*	 Subsequent to this review, changes may have been made
 

in the bioassay report either as a result of the review
 

or other reasons. Thus, certain comments and criticisms
 

reflected in the review may no longer be appropriate.
 

46
 

DHEW Publication No. (NIH) 78-1318