NTP TECHNICAL REPORT

ON THE

TOXICOLOGY AND CARCINOGENESIS

STUDIES OF TETRAFLUOROETHYLENE

(CAS NO. 116-14-3)

IN F344/N RATS AND B6C3F1 MICE

(INHALATION STUDIES)

NATIONAL TOXICOLOGY PROGRAM

P.O. Box 12233

Research Triangle Park, NC 27709

April 1997

NTP TR 450

NIH Publication No. 97-3366

U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES

Public Health Service

National Institutes of Health
FOREWORD

The National Toxicology Program (NTP) is made up of four charter agencies of the U.S. Department of Health and

Human Services (DHHS): the National Cancer Institute (NCI), National Institutes of Health; the National

Institute of Environmental Health Sciences (NIEHS), National Institutes of Health; the National Center for

Toxicological Research (NCTR), Food and Drug Administration; and the National Institute for Occupational

Safety and Health (NIOSH), Centers for Disease Control. In July 1981, the Carcinogenesis Bioassay Testing

Program, NCI, was transferred to the NIEHS. The NTP coordinates the relevant programs, staff, and resources

from these Public Health Service agencies relating to basic and applied research and to biological assay

development and validation.

The NTP develops, evaluates, and disseminates scientific information about potentially toxic and hazardous

chemicals. This knowledge is used for protecting the health of the American people and for the primary prevention

of disease.

The studies described in this Technical Report were performed under the direction of the NIEHS and were

conducted in compliance with NTP laboratory health and safety requirements and must meet or exceed all

applicable federal, state, and local health and safety regulations. Animal care and use were in accordance with the

Public Health Service Policy on Humane Care and Use of Animals. The prechronic and chronic studies were

conducted in compliance with Food and Drug Administration (FDA) Good Laboratory Practice Regulations, and

all aspects of the chronic studies were subjected to retrospective quality assurance audits before being presented

for public review.

These studies are designed and conducted to characterize and evaluate the toxicologic potential, including

carcinogenic activity, of selected chemicals in laboratory animals (usually two species, rats and mice). Chemicals

selected for NTP toxicology and carcinogenesis studies are chosen primarily on the bases of human exposure, level

of production, and chemical structure. The interpretive conclusions presented in this Technical Report are based

only on the results of these NTP studies. Extrapolation of these results to other species and quantitative risk

analyses for humans require wider analyses beyond the purview of these studies. Selection per se is not an

indicator of a chemical's carcinogenic potential.

These NTP Technical Reports are available for sale from the National Technical Information Service,

U.S. Department of Commerce, 5285 Port Royal Road, Springfield, VA 22161 (703-487-4650). Single copies of

this Technical Report are available without charge while supplies last from NTP Central Data Management,

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published NTP reports and ongoing studies are also available from NTP Central Data Management. The

Abstracts and other study information for 2-year studies are also available at the NTP's World Wide Web site: 

http//ntp-server.niehs.nih.gov.
NTP TECHNICAL REPORT

ON THE

TOXICOLOGY AND CARCINOGENESIS

STUDIES OF TETRAFLUOROETHYLENE

(CAS NO. 116-14-3)

IN F344/N RATS AND B6C3F1 MICE

(INHALATION STUDIES)

NATIONAL TOXICOLOGY PROGRAM

P.O. Box 12233

Research Triangle Park, NC 27709

April 1997

NTP TR 450

NIH Publication No. 97-3366

U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES

Public Health Service

National Institutes of Health
2 Tetrafluoroethylene, NTP TR 450

CONTRIBUTORS

National Toxicology Program NTP Pathology Working Group

Evaluated and interpreted results and reported findings Evaluated slides, prepared pathology report on rats

J.H. Roycroft, Ph.D., Study Scientist

G.A. Boorman, D.V.M., Ph.D.

D.A. Bridge, B.S.

J.R. Bucher, Ph.D.

L.T. Burka, Ph.D.

R.E. Chapin, Ph.D.

J.R. Hailey, D.V.M.

J.K. Haseman, Ph.D.

G.N. Rao, D.V.M., Ph.D.

R.C. Sills, D.V.M., Ph.D.

G.S. Travlos, D.V.M.

D.B. Walters, Ph.D.

K.L. Witt, M.S., Oak Ridge Associated Universities

Battelle Pacific Northwest Laboratories

Conducted 16-day, 13-week, and 2-year studies,

 evaluated pathology findings

B.J. Chou, D.V.M., Ph.D., Principal Investigator

J.R. Decker, B.S.

S.L. Grumbein, D.V.M., Ph.D.

P.W. Mellick, D.V.M., Ph.D.

H.A. Ragan, D.V.M.

S.E. Rowe, D.V.M., M.S.

R.B. Westerberg, Ph.D.

Experimental Pathology Laboratories, Inc.

Provided pathology quality assurance

J.F. Hardisty, D.V.M., Principal Investigator

E.T. Gaillard, D.V.M., M.S.

Dynamac Corporation

Prepared quality assurance audits

S. Brecher, Ph.D., Principal Investigator Prepared Technical Report

Analytical Sciences, Inc.

Provided statistical analyses

R.W. Morris, M.S., Principal Investigator

N.G. Mintz, B.S.

S. Rosenblum, M.S.

(2 February 1993)

M.A. Stedham, D.V.M., M.S., Chairperson

Pathology Associates, Inc.

J.M. Cullen, V.M.D., Ph.D.

North Carolina State University

M.R. Elwell, D.V.M., Ph.D.

National Toxicology Program

E.T. Gaillard, D.V.M., M.S.

Experimental Pathology Laboratories, Inc.

J.R. Hailey, D.V.M.

National Toxicology Program

C.C. Shackelford, D.V.M., M.S., Ph.D.

National Toxicology Program

R.C. Sills, D.V.M., Ph.D.

National Toxicology Program

Evaluated slides, prepared pathology report on mice

(3 June 1993)

M.A. Stedham, D.V.M., M.S., Chairperson

Pathology Associates, Inc.

G.A. Boorman, D.V.M., Ph.D.

National Toxicology Program

R. Cattley, M.S., V.M.D., Ph.D.

Chemical Industry Institute of Toxicology

R.A. Herbert, D.V.M., Ph.D.

National Toxicology Program

E.T. Gaillard, D.V.M., M.S.

Experimental Pathology Laboratories, Inc.

A. Radovsky, D.V.M., Ph.D.

National Toxicology Program

D.D. Sharpnack, D.V.M., M.S.

National Institute for Occupational Safety and Health

R.C. Sills, D.V.M., Ph.D.

National Toxicology Program

W.M. Witt, D.V.M., Ph.D.

National Center for Toxicological Research

Biotechnical Services, Inc.

S.R. Gunnels, M.A., Principal Investigator

L.M. Harper, B.S.

T.A. King-Hunter, B.S.

D.C. Serbus, Ph.D.

S.M. Swift, B.S.
3

CONTENTS

ABSTRACT ................................................................................. 5

EXPLANATION OF LEVELS OF EVIDENCE OF CARCINOGENIC ACTIVITY ................... 12

TECHNICAL REPORTS REVIEW SUBCOMMITTEE .......................................... 13

SUMMARY OF TECHNICAL REPORTS REVIEW SUBCOMMITTEE COMMENTS ............... 14

INTRODUCTION ............................................................................ 15

MATERIALS AND METHODS ............................................................... 21

RESULTS ................................................................................... 33

DISCUSSION AND CONCLUSIONS ........................................................... 69

REFERENCES .............................................................................. 75

APPENDIX A Summary of Lesions in Male Rats in the 2-Year Inhalation Study

of Tetrafluoroethylene ......................................................... 79

APPENDIX B Summary of Lesions in Female Rats in the 2-Year Inhalation Study

of Tetrafluoroethylene ......................................................... 125

APPENDIX C Summary of Lesions in Male Mice in the 2-Year Inhalation Study

of Tetrafluoroethylene ......................................................... 165

APPENDIX D Summary of Lesions in Female Mice in the 2-Year Inhalation Study

of Tetrafluoroethylene ......................................................... 209

APPENDIX E Genetic Toxicology ............................................................ 253

APPENDIX F Organ Weights and Organ-Weight-to-Body-Weight Ratios ......................... 255

APPENDIX G Hematology, Clinical Chemistry, and Urinalysis Results ............................ 263

APPENDIX H Reproductive Tissue Evaluations and Estrous Cycle Characterization ................ 273

APPENDIX I Chemical Characterization and Generation of Chamber Concentrations .............. 277

APPENDIX J Ingredients, Nutrient Composition, and Contaminant Levels 

in NIH-07 Rat and Mouse Ration ............................................... 299
4 Tetrafluoroethylene, NTP TR 450

APPENDIX K Sentinel Animal Program ...................................................... 303

APPENDIX L H-ras Codon 61 Mutation Spectra in Hepatocellular Neoplasms From B6C3F 1 Mice

Exposed to Tetrafluoroethylene for 2 Years ....................................... 307
C C

F F

F F

5

ABSTRACT

TETRAFLUOROETHYLENE

CAS No. 116-14-3

Chemical Formula: C2F4 Molecular Weight: 100.02

Synonyms: Perfluoroethylene; tetrafluoroethene; 1,1,2,2-tetrafluoroethylene; TFE

Tetrafluoroethylene is used in the production o f sure. Absolute and relative kidney weights of al l

polytetrafluoroethylene (Teflon®) and other polymers. exposed groups of males were significantly greate r

Tetrafluoroethylene was nominated by the Nationa l than those of the controls, as were those of females in

Cancer Institute for toxicity and ca rcinogenicity studies the 2,500 and 5,000 ppm gro ups. The absolute kidney

based on the potential for human exposure to th e weight of females exposed to 1,250 ppm was als o

chemical due to the large production volume and on the significantly greater than that of the controls. Th e

lack of adequate data for tetrafluoroethylene in th e relative liver weights of all exposed groups of male s

literature. Male and female F344/N rats and B6C3F 1 and the absolute liver weights of males in the 625 and

mice were exposed to tetrafluoro ethylene (98% to 99% 2,500 ppm groups were significantly greater than those

pure) by whole body inhalation exposure for 16 days, of the controls. Increased incidences of renal tubul e

13 weeks, or 2 years. Genetic toxicity studies wer e degeneration occurred in males and females exposed to

conducted in mouse peripheral blood erythrocytes. 625 ppm or greater; this lesion was located predomi16-DAY STUDY IN RATS

Groups of five male and five female F344/N rats were

exposed to 0, 312, 625, 1,250, 2,500, or 5,000 pp m

tetrafluoroethylene by inhalation for 6 hours per day ,

5 days per week for a total of 12 exposures during a

16-day period. All rats survived to the end of th e Groups of five male and five female B6C3F mice

study. The final mean body weights and body weight were exposed to 0, 312, 625, 1,250, 2,500, o r

gains of males and females exposed to 5,000 pp m 5,000 ppm tetrafluoroethylene by inhalation fo r

were significantly less than those of the controls. The 6 hours per day, 5 days per week for a total o f

mean body weight gain of females exposed t o 12 exposures during a 16-day period. All mic e

2,500 ppm was also significantly less than that of the survived to the end of the study. Final mean bod y

controls. There were no exposure-related clinica l weights and body weight gains of all exposed groups

findings in male or female rats. There were no signifi- of mice were similar to those of the controls. Ther e

cant differences in hematology parameters that wer e were no exposure-related clinical findings in male o r

considered to be related to tetrafluoroethylene expo - female mice. There were no significant differences in

nantly at the corticomedullary junction. The severit y

of degeneration increased with increasing exposur e

concentration and was slightly greater in males tha n

females.

16-DAY STUDY IN MICE

1
6 Tetrafluoroethylene, NTP TR 450

hematology parameters that were considered to b e

related to tetrafluoroethylene exposure. The absolute

and relative liver weights of females exposed t o

5,000 ppm were significantly greater than those of the

controls, as was the absolute kidney weight of females

in that group and the absolute liver weight of females

in the 2,500 ppm group. Renal tubule karyomegal y

was observed in male and female mice in the 1,250 ,

2,500, and 5,000 ppm groups, and the severity of this

lesion increased with increasing exposure concentra -

tion. Karyomegaly was located predominantly in th e

inner renal cortex.

13-WEEK STUDY IN RATS

Groups of 10 male and 9 or 10 female F344/N rat s estrous cycle lengths were not considered to b e

were exposed to 0, 312, 625, 1,250, 2,500, o r exposure related. Incidences of karyomegaly of th e

5,000 ppm tetrafluoroethylene by inhalation fo r renal tubule epithelial cells in male and female mic e

6 hours per day, 5 days per week, for 13 weeks. Al l exposed to 1,250 ppm or greater were significantl y

rats survived to the end of the study. The final mea n greater than those in the controls. Karyomegaly wa s

body weight and body weight g ain of males exposed to similar to that observed in the 16-day study and wa s

5,000 ppm were significantly less than those of th e observed primarily in the inner renal cortex.

controls, as was the mean body weight gain of females

in this exposure group. There we re no clinical findings

attributed to exposure to tetrafluoroethylene .

Exposure of rats to tetrafluoroethylene resulted in a

concentration-dependent normocytic, normochromic ,

nonresponsive anemia consistent with a secondar y

hypoproliferative anemia. An exposure concentrationdependent proteinuria also occurred, consistent wit h

renal tubule degeneration observed histopathologically.

The absolute and relative liver weights of all exposed

groups of males and of females in the 5,000 pp m

group were significantly greater than those of th e

controls. The absolute and relative right kidne y

weights of males and females expo sed to 1,250 ppm or

greater and of females in the 625 ppm group were also

significantly greater than those of the controls. There

were no differences in sperm morphology or vagina l

cytology parameters between control and expose d

groups of rats. Incidences of renal tubule degeneration

in males exposed to 625 ppm or greater and in females

exposed to 2,500 or 5,000 ppm were significantl y

greater than those in the controls. Renal lesions were

similar to those observed in the 16-day study and were

located predominantly at the cortic omedullary junction.

13-WEEK STUDY IN MICE

Groups of 10 male and 10 female B6C3F 1 mice were

exposed to 0, 312, 625, 1,250, 2,500, or 5,000 pp m

tetrafluoroethylene by inhalation for 6 hours per day ,

5 days per week, for 13 weeks. All mice survived t o

the end of the study. Final mean body weights an d

body weight gains of all exposed groups of male an d

female mice were generally similar to those of th e

controls. There were no clinical findings that wer e

considered to be related to tetrafluoroethylene expo -

sure. Exposure of mice to tetrafluoroethylene resulted

in a concentration-dependent normocytic, normochromic, nonresponsive anemia, consistent with a secondary hypoproliferative anemia, and in polyuria .

Differences in sperm morphology parameters an d

2-YEAR STUDY IN RATS

Groups of 60 male rats were exposed to 156, 312, or

625 ppm and groups of 60 female r ats were exposed to

312, 625, or 1,250 ppm tetrafluoroethylene b y

inhalation for 6 hours per day, 5 days per week, fo r

104 weeks, with an observation period of 11 day s

following the final exposure. Ten male and ten female

rats from each exposure group were evaluated a t

15 months for organ weights and clinical pathology.

Survival, Body Weights, 

and Clinical Findings

Survival rates of males in the 625 ppm group and o f

all exposed groups of females were significantly les s

than those of the controls. Mean body weights o f

males exposed to 625 ppm were lower than those o f

the controls from week 81 until the end of the study ,

and the mean body weight of 1,250 ppm females was

slightly lower than that of the controls at the end of the

study. The only clinical finding associated wit h

exposure to tetrafluoroethylen e was opacity of the eyes

in exposed groups of female rats; this change wa s

observed microscopically as cataracts.
Tetrafluoroethylene, NTP TR 450 7

Hematology, Clinical Chemistry, 

and Urinalysis

At the 15-month interim evaluation, there were n o

differences in hematology, clinical chemistry, o r

urinalysis parameters that were considered to b e

related to tetrafluoroethylene exposure.

Pathology Findings

The absolute and relative kidney weights of male s

exposed to 625 ppm and females exposed t o

1,250 ppm and the absolute kidney weight of females

exposed to 625 ppm were significantly greater tha n

those of the controls at the 15-month interim evalua -

tion. At 15 months, renal tubule hyperplasia wa s

observed in one male exposed to 312 ppm and on e

male and one female exposed to 625 ppm; oncocyti c

hyperplasia was observed in one female exposed t o

1,250 ppm. At the end of the study, incidences o f

renal tubule adenoma were greater in males an d

females exposed to 312 ppm or greater than those i n

the controls. This exposure-related increase was confirmed by examination of step sections (extende d

evaluations). At the end of the study, the incidences of

renal tubule hyperplasia in males exposed to 625 ppm

and females exposed to 1,250 ppm were significantly

greater than those in the controls. The incidences o f

renal tubule adenoma and renal tubule adenoma o r

carcinoma (combined) in the extended evaluations and

in the standard and extended evalu ations (combined) in

the 1,250 ppm female group and the 625 ppm mal e

group were significantly greater than those in th e

controls, and the incidences occurred with significant

positive trends. Oncocytic hyperplasia was observed

at the end of the study in one male exposed to 312 ppm

and in three females exposed to 1,250 ppm. A t

15 months and at the end of the study, the incidences

of renal tubule degeneration in all exposed groups o f

males and in females in the 6 25 and 1,250 ppm groups

were greater than those in the controls. Renal tubul e

degeneration was similar to that observed in th e

13-week study and was located predominantly at th e

corticomedullary junction. The severity of nephrop -

athy generally increased with increasing exposur e

concentration in male rats at 15 months and 2 years.

The absolute and relative liver weights of females i n

the 1,250 ppm group and the absolute liver weight of

females exposed to 625 ppm were significantly greater

than those of the controls at the 15-month interi m

evaluation. At 2 years, the incide nces of hepatocellular

carcinoma and hepatocellular adenoma or carcinom a

(combined) in males exposed to 312 ppm, the inci -

dences of hepatocellular adenoma and adenoma o r

carcinoma (combined) in females in all expose d

groups, and the incidences of hepatocellular carcinoma

in females exposed to 312 or 625 ppm were signifi -

cantly greater than those in the controls. Also a t

2 years, the incidence of hemangiosarcoma in females

exposed to 625 ppm was signifi cantly greater than that

in the controls. In all exposed groups of males, th e

incidences of clear cell foci at 15 months were greater

than those in the controls; at 2 years, the incidences of

eosinophilic foci in all exposed groups of males an d

the incidences of basophilic and mixed cell foci i n

males in the 312 and 625 ppm groups were greate r

than those in the controls. The incidences of mixe d

cell foci at 15 months in females exposed to 625 o r

1,250 ppm and at 2 years in females exposed t o

1,250 ppm were also significan tly greater than those in

the controls. At the end of the 2-year study, increased

incidences of cystic degeneration occurred in the liver

of all exposed groups of males, and increased inci -

dences of hepatic angiectasis were observed in exposed

groups of females.

Incidences of mononuclear cell leukemia in male s

exposed to 156 ppm and in all exposed groups o f

females were significantly greater than those in th e

controls.

Incidences of cataracts in females exposed t o

1,250 ppm were greater than those in the controls a t

the end of the 2-year study.

At the end of the study, there were slight increases in

the incidences of testicular interstitial cell adenoma in

rats exposed to 312 or 625 ppm.

2-YEAR STUDY IN MICE

Groups of 58 male and 58 female B6C3F 1 mice were

exposed to 0, 312, 625, or 1,250 ppm tetrafluoro -

ethylene by inhalation for 6 hours per day, 5 days per

week, for 95 to 96 weeks. Ten male and ten femal e

mice from each exposure group were evaluated a t

15 months for organ weights.
8 Tetrafluoroethylene, NTP TR 450

Survival, Body Weights, 

and Clinical Findings

The survival rates of all exposed groups of males and

females were significantly less than those of th e

controls. Because of the reduced survival due t o

exposure-related liver neoplasms, the study wa s

terminated during week 96. Mean body weights o f

exposed groups of males and females were generall y

similar to those of the contro ls, except at the end of the

study, when they were somewhat less than those of the

controls. There were no clinical findings related t o

tetrafluoroethylene exposure.

Pathology Findings

At the 15-month interim evaluation, there were n o

differences in absolute o r relative kidney, liver, or lung

weights between exposed and control groups of mice.

At the end of the study, the incidences of multifoca l

coagulative necrosis of the liver were increased i n

males in the 625 and 1,250 ppm groups. Also at th e

end of the study, females in all exposed groups ha d

greater incidences of hematopoiet ic cell proliferation in

the liver than the controls. Angiectasis occurred in all

exposed groups of males and females at 15 month s

and at the end of the study. At the 15-month interi m

evaluation, hemangiosarcomas were observed in three

males exposed to 1,250 ppm and in one female ex -

posed to 312 ppm. The incidences of hemangiosar -

coma in all exposed groups of male s and females at the

end of the study were significantly greater than thos e

in the controls and exceeded the historical chambe r

control ranges. Also at the end of the study, th e

incidences of hemangioma in males and female s

exposed to 312 ppm and in males exposed to 625 ppm

were also significantly greater than those in the con -

trols and exceeded the range in historical chambe r

controls. At 15 months, hepatocellular adenomas and

carcinomas occurred in control males and all exposed

groups of males and femal es. Females exposed to 625

or 1,250 ppm had significantly greater incidences o f

eosinophilic foci than the controls at the 15-mont h

interim evaluation. At the end of the study, the inci -

dences of eosinophilic foci in males exposed to 625 or

1,250 ppm and in females exposed to 312 or 625 ppm

were significantly greater tha n those in the controls. In

male and female mice, increased inc idences of a variety

of hepatocellular neoplasms, including adenomas ,

multiple adenomas, carcinomas, and multiple carci -

nomas, were considered related to tetrafluoroethylene

exposure.

At the end of the study, the incidences of histiocyti c

sarcoma (all organs) in all exposed groups of male s

and females were significantly greater than those in the

controls and exceeded the historical control ranges for

all organs. The greatest incidences of histiocyti c

sarcomas were observed in the live r and lung, but these

neoplasms were also observed in the spleen, lymp h

nodes, bone marrow, and kidney.

Significantly increased incidences of renal tubul e

dilatation (males) and karyomegaly (males and fe -

males), located predominantly in the inner cortex, were

observed in mice exposed to 625 or 1,250 ppm a t

15 months. At the end of the study, the increase d

incidences of dilatation and karyomegaly in all ex -

posed groups of males and of karyomegaly i n

1,250 ppm females were generally significant.

Incidences of hematopoietic cell proliferation in th e

spleen of all exposed groups of males and female s

were significantly greater than those in the controls at

the end of the study. Additionally, the severity of this

lesion increased with increasing exposure concentra -

tion.

GENETIC TOXICOLOGY

No increases in the frequency of micronucleate d

erythrocytes were observed in peripheral blood sam -

ples obtained from male and female mice at the end of

the 13-week inhalation study of tetrafluoroethylene.

CONCLUSIONS

Under the conditions of these 2-y ear inhalation studies,

there was clear evidence of carcinogenic activity* of

tetrafluoroethylene in male F344/N rats based o n

increased incidences of renal t ubule neoplasms (mainly

adenomas) and hepatocellular neoplasms. There was

clear evidence of carcinogenic activity of tetrafluoroethylene in female F344/N rats based on increase d

incidences of renal tubule neoplasms, liver hemangiosarcomas, hepatocellular neoplasms, and mononuclear

cell leukemia. There was clear evidence of carcinogenic activity of tetrafluoroethylene in male an d

female B6C3F mice based on increased incidences of 1

liver hemangiomas and hemangiosarcomas, hepatocellular neoplasms, and histiocytic sarcomas.
Tetrafluoroethylene, NTP TR 450 9

Slight increases in the incidences of mononuclear cell of kidney nephropathy in males, and increased inci -

leukemia and testicular interstitial cell adenomas i n dences of liver angiectasis and cataracts in females .

male rats may have been related to exposure to tetra- Exposure of mice to tetrafluoroethylene resulted i n

fluoroethylene. increased incidences of hematopoietic cell proliferation

Exposure of rats to tetrafluoroethylene resulted i n females, renal tubule dilatation in males, renal tubule

increased incidences of renal tubule hyperplasia an d karyomegaly in males and females, and splenic hemadegeneration in males and females, increased severity topoietic cell proliferation in males and females.

of the liver in females, liver angiectasis in males an d

___________

* Explanation of Levels of Evidence of Carcinogenic Activity is on page 12. A summary of the Technical Reports Review Subcommittee

comments and the public discussion on this Technical Report appears on page 14.
10 Tetrafluoroethylene, NTP TR 450

Summary of the 2-Year Carcinogenesis and Genetic Toxicology Studies of Tetrafluoroethylene

Male Female Male Female

F344/N Rats F344/N Rats B6C3F1 Mice B6C3F1 Mice

Exposure

Concentrations

0, 156, 312, or 625 ppm 0, 312, 625, or 0, 312, 625, or 0, 312, 625, or

1,250 ppm 1,250 ppm 1,250 ppm

Body Weights 625 ppm group lower 1,250 ppm group Exposed groups lower Exposed groups lower

than controls slightly lower than than controls at end of than controls at end of

controls at end of study study study

Survival Rates 17/50, 12/50, 17/50, 28/50, 16/50, 15/50, 38/48, 11/48, 2/48, 36/48, 4/48, 6/48, 4/48

1/50 (2 years) 18/50 (2 years) 1/48 (22 months) (22 months)

Nonneoplastic

Effects

Kidney (renal tubule): Kidney (renal tubule): Liver: angiectasis Liver: hematopoietic

hyperplasia (single hyperplasia (single (0/48, 6/48, 10/48, cell proliferation (3/48,

sections - 1/50, 1/50, sections - 1/50, 3/50, 13/48) 19/48, 13/47, 15/47);

1/50, 6/50; single and 6/50, 12/50; single and Kidney (renal tubule): angiectasis (1/48, 9/48,

step sections - 7/50, step sections - 3/50, dilatation (0/48, 4/48, 6/47, 4/47)

11/50, 7/50, 24/50); 6/50, 11/50, 25/50); 16/48, 36/48); Kidney (renal tubule): 

 degeneration (2/50, degeneration (0/50, karyomegaly (1/48, karyomegaly (0/48,

20/50, 50/50, 49/50); 0/50, 35/50, 46/50) 2/48, 10/48, 28/48) 0/48, 0/47, 38/48)

severity of nephropathy Liver: angiectasis Spleen: hematopoietic Spleen: hematopoietic

(2.3, 1.9, 2.7, 3.5) (0/50, 9/50, 9/50, cell proliferation cell proliferation

14/50) (14/48, 32/48, 41/46, (18/48, 39/48, 41/46,

Eye: cataracts (15/50, 42/46) 41/47)

4/50, 10/50, 45/50)
Tetrafluoroethylene, NTP TR 450 11

Summary of the 2-Year Carcinogenesis and Genetic Toxicology Studies of Tetrafluoroethylene (continued)

Male Female Male Female

F344/N Rats F344/N Rats B6C3F1 Mice B6C3F1 Mice

Neoplastic Effects Kidney (renal tubule): Kidney (renal tubule): Liver: hemangioma Liver: hemangioma

adenoma (single adenoma (single (0/48, 10/48, 5/48, (0/48, 5/48, 2/47,

sections - 0/50, 0/50, sections - 0/50, 3/50, 2/48); 1/47);

6/50, 3/50; single and 1/50, 3/50; single and hemangiosarcoma hemangiosarcoma

step sections - 2/50, step sections - 0/50, (0/48, 21/48, 27/48, (0/48, 27/48, 27/47,

4/50, 9/50, 13/50); 3/50, 3/50, 8/50); 37/48); hemangioma 34/47); hemangioma

carcinoma (single carcinoma (single or hemangiosarcoma or hemangiosarcoma

sections - 1/50, 0/50, sections - 0/50, 0/50, (0/48, 26/48, 30/48, (0/48, 31/48, 28/47,

2/50, 0/50; single and 0/50, 2/50; single and 38/48); hepatocellular 35/47); hepatocellular

step sections - 1/50, step sections - 0/50, carcinoma (11/48, carcinoma (4/48,

1/50, 2/50, 0/50); 0/50, 0/50, 3/50); 20/48, 33/48, 26/48); 28/48, 22/47, 20/47);

adenoma or carcinoma adenoma or carcinoma hepatocellular hepatocellular

(single sections - 1/50, (single sections - 0/50, adenoma or carcinoma adenoma or carcinoma

0/50, 6/50, 3/50; 3/50, 1/50, 5/50; (26/48, 34/48, 39/48, (17/48, 33/48, 29/47,

single and step sections single and step sections 35/48) 28/47)

- 3/50, 5/50, 9/50, - 0/50, 3/50, 3/50, Hematopoietic system Hematopoietic system

13/50) 10/50) (all organs): (all organs): 

Liver: hepatocellular Liver: histiocytic sarcoma histiocytic sarcoma

carcinoma (1/50, 1/50, hemangiosarcoma (0/48, 12/48, 7/48, (1/48, 21/48, 19/47,

10/50, 3/50); (0/50, 0/50, 5/50, 7/48) 18/48)

hepatocellular 1/50); hepatocellular

adenoma or carcinoma adenoma (0/50, 4/50,

(4/50, 7/50, 15/50, 5/50, 6/50);

8/50) hepatocellular

carcinoma (0/50, 4/50,

9/50, 2/50);

hepatocellular

adenoma or carcinoma

(0/50, 7/50, 12/50,

8/50)

Mononuclear cell

leukemia: (16/50,

31/50, 23/50, 36/50)

Uncertain

Findings

Mononuclear cell None None None

leukemia: (34/50,

43/50, 38/50, 31/50)

Testis: interstitial cell

adenoma (39/50,

40/50, 48/50, 47/50)

Level of Evidence

of Carcinogenic

Activity

Clear evidence Clear evidence Clear evidence Clear evidence

Genetic Toxicology

Micronucleated erythrocytes

Mouse peripheral blood in vivo: Negative
12 Tetrafluoroethylene, NTP TR 450

EXPLANATION OF LEVELS OF EVIDENCE OF CARCINOGENIC ACTIVITY

The National Toxicology Program describes the results of individual experiments on a chemical agent and notes the strength of the evidence for

conclusions regarding each study. Negative results, in which the study animals do not have a greater incidence of neoplasia than control animals, do

not necessarily mean that a chemical is not a carcinogen, inasmuch as the experiments are conducted under a limited set of conditions. Positive results

demonstrate that a chemical is carcinogenic for laboratory animals under the conditions of the study and indicate that exposure to the chemical has the

potential for hazard to humans. Other organizations, such as the International Agency for Research on Cancer, assign a strength of evidence for

conclusions based on an examination of all available evidence, including animal studies such as those conducted by the NTP, epidemiologic studies,

and estimates of exposure. Thus, the actual determination of risk to humans from chemicals found to be carcinogenic in laboratory animals requires a

wider analysis that extends beyond the purview of these studies.

Five categories of evidence of carcinogenic activity are used in the Technical Report series to summarize the strength of the evidence observed in each

experiment: two categories for positive results (clear evidence and some evidence); one category for uncertain findings (equivocal evidence); one

category for no observable effects (no evidence); and one category for experiments that cannot be evaluated because of major flaws (inadequate

study). These categories of interpretative conclusions were first adopted in June 1983 and then revised in March 1986 for use in the Technical Report

series to incorporate more specifically the concept of actual weight of evidence of carcinogenic activity. For each separate experiment (male rats,

female rats, male mice, female mice), one of the following five categories is selected to describe the findings. These categories refer to the strength of

the experimental evidence and not to potency or mechanism.

• Clear evidence of carcinogenic activity is demonstrated by studies that are interpreted as showing a dose-related 

(i) increase of malignant neoplasms, (ii) increase of a combination of malignant and benign neoplasms, or (iii) marked increase of benign

neoplasms if there is an indication from this or other studies of the ability of such tumors to progress to malignancy.

• Some evidence of carcinogenic activity is demonstrated by studies that are interpreted as showing a chemical-related increased incidence

of neoplasms (malignant, benign, or combined) in which the strength of the response is less than that required for clear evidence.

• Equivocal evidence of carcinogenic activity is demonstrated by studies that are interpreted as showing a marginal increase of neoplasms

that may be chemical related.

• No evidence of carcinogenic activity is demonstrated by studies that are interpreted as showing no chemical-related increases in

malignant or benign neoplasms.

• Inadequate study of carcinogenic activity is demonstrated by studies that, because of major qualitative or quantitative limitations,

cannot be interpreted as valid for showing either the presence or absence of carcinogenic activity.

When a conclusion statement for a particular experiment is selected, consideration must be given to key factors that would extend the actual boundary

of an individual category of evidence. Such consideration should allow for incorporation of scientific experience and current understanding of longterm carcinogenesis studies in laboratory animals, especially for those evaluations that may be on the borderline between two adjacent levels. These

considerations should include:

• adequacy of the experimental design and conduct;

• occurrence of common versus uncommon neoplasia;

• progression (or lack thereof) from benign to malignant neoplasia as well as from preneoplastic to neoplastic lesions;

• some benign neoplasms have the capacity to regress but others (of the same morphologic type) progress. At present, it is impossible to

identify the difference. Therefore, where progression is known to be a possibility, the most prudent course is to assume that benign

neoplasms of those types have the potential to become malignant;

• combining benign and malignant tumor incidence known or thought to represent stages of progression in the same organ or tissue;

• latency in tumor induction;

• multiplicity in site-specific neoplasia;

• metastases;

• supporting information from proliferative lesions (hyperplasia) in the same site of neoplasia or in other experiments (same lesion in

another sex or species);

• presence or absence of dose relationships;

• statistical significance of the observed tumor increase;

• concurrent control tumor incidence as well as the historical control rate and variability for a specific neoplasm;

• survival-adjusted analyses and false positive or false negative concerns;

• structure-activity correlations; and

• in some cases, genetic toxicology.
Tetrafluoroethylene, NTP TR 450 13

NATIONAL TOXICOLOGY PROGRAM BOARD OF SCIENTIFIC COUNSELORS

TECHNICAL REPORTS REVIEW SUBCOMMITTEE

The members of the Technical Reports Review Subcommittee who evaluated the draft NTP Technical Report on tetrafluoroethylene on December 5,

1995, are listed below. Subcommittee members serve as independent scientists, not as representatives of any institution, company, or governmental

agency. In this capacity, subcommittee members have five major responsibilities in reviewing NTP studies:

• to ascertain that all relevant literature data have been adequately cited and interpreted,

• to determine if the design and conditions of the NTP studies were appropriate,

• to ensure that the Technical Report presents the experimental results and conclusions fully and clearly,

• to judge the significance of the experimental results by scientific criteria, and

• to assess the evaluation of the evidence of carcinogenic activity and other observed toxic responses.

Arnold L. Brown, M.D., Chairperson Irma Russo, M.D.

University of Wisconsin Medical School Fox Chase Cancer Center

Madison, WI Philadelphia, PA

Gary P. Carlson, Ph.D., Principal Reviewer Louise Ryan, Ph.D., Principal Reviewer

School of Health Sciences Division of Biostatistics

Purdue University Dana-Farber Cancer Institute

West Lafayette, IN Boston, MA

Thomas L. Goldsworthy, Ph.D. Robert E. Taylor, M.D., Ph.D.

Department of Experimental Pathology and Toxicology Department of Pharmacology

Chemical Industry Institute of Toxicology Howard University College of Medicine

Research Triangle Park, NC Washington, DC

Robert LeBoeuf, Ph.D. Frederick L. Tyson, Ph.D.

Corporate Professional and Regulatory Services St. Mary's Hospital and Medical Center

Human Safety Department Cancer Research Institute

The Procter & Gamble Company Grand Junction, CO

Cincinnati, OH

Janardan K. Reddy, M.D., Principal Reviewer*

Department of Pathology Frederick, MD

Northwestern University Medical School

Chicago, IL

Jerrold M. Ward, D.V.M., Ph.D. *

National Cancer Institute

___________

* Did not attend
14 Tetrafluoroethylene, NTP TR 450

SUMMARY OF TECHNICAL REPORTS REVIEW SUBCOMMITTEE COMMENTS

On 5 December 1995, the draft Technical Report on the numbers of clinical pathology measurements appeared to

toxicology and carcinogenesis studies of tetrafluoroethy- be decreased from past reports and, in view of the types

lene received public review by the National Toxicology of lesions seen, wondered why. Dr. Roycroft responded

Program's Board of Scientific Counselors' Technical that, in actuality, there were more mea-surements; in

Reports Review Subcommittee. The review meeting was addition to standard time points and collections at

held at the National Institute of Environmental Health 13 weeks, clinical pathology analyses were performed on

Sciences, Research Triangle Park, NC. animals killed at 15 months. Dr. Carlson said a sentence

Dr. J.H. Roycroft, NIEHS, introduced the toxicology and for terminating the mouse study early. Dr. Roycroft

carcinogenesis studies of tetrafluoroethylene by describ- agreed.

ing the uses of the chemical, describing the experimental

design, reporting on survival and body weight effects,

and commenting on compound-related neoplasms and

nonneoplastic lesions in male and female rats and mice.

Dr. R.C. Sills, NIEHS, presented data from ongoing

molecular biology studies characterizing the H-ras

codon 61 mutation spectra in hepatocellular neoplasms

from control B6C3F mice and mice exposed to tetra- 1

fluoroethylene for 2 years. Data were also presented

comparing the mutation profiles of hepatocellular neoplasms from the current study with those from the NTP

study of tetrachloroethylene. The proposed conclusions

for the 2-year studies were clear evidence of carcinogenic activity in male and female F344/N rats and male

and female B6C3F mice. 1

Dr. Ryan, a principal reviewer, agreed with the proposed

conclusions. She inquired as to whether short-burst, high

exposures had been considered in the study design as

being more similar to a typical occupational exposure.

Dr. Roycroft replied that this regimen had not been

considered; the 6-hour-per-day, 5-day-per-week design

used was similar to continuous exposure in a workplace

situation. Dr. Ryan asked whether there was information

on the degree of human exposure encountered through

spills or leaks. Dr. Roycroft noted that tetrafluoroethylene is produced and maintained in closed-capture

systems, no occupational exposure limits have been

established, and no information on spills or leaks has

been found.

Dr. Carlson, the second principal reviewer, agreed with

the proposed conclusions. He observed that the 

needed to be added to the Abstract regarding the reason

Dr. Reddy, the third principal reviewer, was unable to

attend the meeting but had submitted his review, which

Dr. L.G. Hart, NIEHS, read into the record. Dr. Reddy

agreed with the proposed conclusions and found the

report acceptable.

There was some discussion about the mixing of rats and

mice in exposure chambers. Dr. Goldsworthy asked if

hormonal alterations were seen. Dr. Roycroft said that

hormone measurements were not made, but if a chemical

to be studied was known to affect hormone levels, then

separate housing might have to be considered.

Dr. G.N. Rao, NIEHS, noted that rats and mice are

produced in the same rooms so each species is

accustomed to the other's presence; he pointed out that

each inhalation chamber is by itself a room, and within

the chamber, rats and mice are not side by side in cages,

but rather in racks. This provides more efficient and

economical use of available space. Dr. LeBoeuf

commended the NTP for the molecular biology studies

evaluating the H-ras activation profiles and noted the

usefulness of such studies for risk assessment purposes.

Dr. Ryan moved that the Technical Report on tetrafluoroethylene be accepted with the revisions discussed

and with the conclusions as written for male and female

rats and male and female mice, clear evidence of

carcinogenic activity. Dr. Carlson seconded the motion,

which was accepted unanimously with seven votes.
C C

F F

F F

15

INTRODUCTION

TETRAFLUOROETHYLENE

CAS No. 116-14-3

Chemical Formula: C2F4 Molecular Weight: 100.02

Synonyms: Perfluoroethylene; tetrafluoroethene; 1,1,2,2-tetrafluoroethylene; TFE

CHEMICAL AND PHYSICAL

PROPERTIES

Tetrafluoroethylene is a colorless, odorless gas with

a melting point of 142.5 C, a boiling point of

76.3 C, a specific gravity of 1.52 at 76 C, a

vapor density of 3.87, and a vapor pressure of

428.4 mm Hg. It is insoluble in water. Tetrafluoroethylene is a highly flammable gas that reacts with

oxidants and has a flash point of less than 0 C and

an autoignition temperature of 188 C. The lower

explosion limit of the chemical is 10% v/v and the

upper explosion limit is 50% v/v. Tetrafluoroethylene can dimerize under appropriate temperature

and pressure conditions to a stable perfluorocyclobutene and polymerizes easily in the absence of

inhibitors or in the presence of heat or oxygen

(IARC, 1979; Bretherick, 1985; Weast, 1985;

NFPA, 1986; Material Safety Data Sheet

Collection, 1993; HSDB, 1995).

PRODUCTION, USE,

AND HUMAN EXPOSURE

Tetrafluoroethylene is generally produced by the

pyrolysis of chlorodifluoromethane or trifluoro-

 

methane (IARC, 1979; Hawley, 1981; Material

Safety Data Sheet Collection, 1993). Although

tetrafluoroethylene was reported to the United States

International Trade Commission for the year 1992,

there was no estimate of the annual production

(USITC, 1994). The most recent estimated United

States annual production figure of 28 million pounds

was reported in 1978. Virtually all of the tetrafluoroethylene produced in the United States is used

in the synthesis of Teflon®, one of several polytetrafluoroethylene polymers (Kennedy, 1990). Because

of its chemical properties, tetrafluoroethylene is

produced and maintained in closed-capture systems. 

For this reason, human exposure would be primarily

through leakage from these systems or through

contact with one of several decomposition products

of high-temperature processing or pyrolysis of

Teflon® and other polymers (Kennedy, 1990). 

According to the National Occupational Exposure

Survey, 14,963 male and 325 female workers were

potentially exposed to tetrafluoroethylene from the

years 1981 to 1983 (NIOSH, 1990). Currently, no

occupational exposure limits have been established. 

There were no reports in the literature of the

detection of tetrafluoroethylene in ambient air,

drinking water, or wastewater, and the chemical is

not known to occur naturally.
16 Tetrafluoroethylene, NTP TR 450

ABSORPTION, DISTRIBUTION,

METABOLISM, AND EXCRETION

Experimental Animals

Dilley et al. (1974) reported the urinary excretion of

fluoride ion following a 30-minute exposure of

Sprague-Dawley rats to 3,500 ppm tetrafluoroethylene by inhalation. A significant increase in

fluoride excretion occurred on days 6, 13, and 14

following exposure. Urinary creatinine, potassium,

and volume were significantly increased following

exposure to tetrafluoroethylene. Increased urinary

fluoride was observed in male rats and hamsters

exposed to 100 to 2,500 ppm tetrafluoroethylene by

inhalation for 2 weeks; however, urinary fluoride

concentrations returned to normal upon cessation of

exposure (Kennedy, 1990). Male and female rats

and hamsters exposed to 200 to 2,000 ppm tetrafluoroethylene by inhalation for 18 weeks displayed

an exposure-related increase in urinary fluoride

(Kennedy, 1990). Ding et al. (1980) exposed

rabbits to 1,000 ppm tetrafluoroethylene for 60

minutes via a face mask and determined alveolar

absorption to be 6.76%. Animals were evaluated

during exposure and for a period of up to 75 minutes

after exposure ended. The lung, bone, and kidney

had the highest fluoride content of the sites

examined.

As a part of an investigation of tetrafluoroethyleneinduced nephrotoxicity, Odum and Green (1984)

demonstrated that liver slices from Wistar rats

metabolized tetrafluoroethylene to S-(1,1,2,2-tetrafluoroethyl)glutathione. The reaction was catalyzed

by both microsomal and cytosolic glutathione

S-transferases, with the rate of formation with microsomal fractions occurring at four times the rate with

cytosol fractions. These same authors also identified

the cysteinylglycine and cysteine conjugates of

tetrafluoroethylene in bile from rats exposed to

6,000 ppm tetrafluoroethylene for 6 hours. Oral

administration of the cysteine conjugate [ S-(1,1,2,2--

tetrafluoroethyl)- L-cysteine] to rats caused renal

damage identical to that caused by tetrafluoroethylene. Cytochrome P oxidation did not appear 450

to be involved in tetrafluoroethylene metabolism.

Cysteine conjugates of the nephrotoxins hexachlorobutadiene, tetrafluoroethylene, and hexafluoropropane, together with those of trichloroethylene and perchloroethylene, have been chemically

synthesized, and a relationship between their structures, nephrotoxicity, and mutagenicity in vitro has

been determined (Green and Odum, 1985). All of

the conjugates had a marked effect on the uptake of

both the organic anion p-aminohippuric acid and the

cation tetraethylammonium bromide into rat kidney

slices, suggesting activation of the conjugates in the

slices to a toxic species which interferes with ion

transport. This observation is consistent with the

known nephrotoxicity of hexachlorobutadiene,

tetrafluoroethylene, and hexafluoropropene in vivo. 

Each of the conjugates was found to be metabolized

by rat kidney slices and by semi-purified rat kidney

-lyase to pyruvate, ammonia, and an unidentified

reactive metabolite (postulated at that time to be a

thiol). When semi-purified -lyase was used,

stoichiometric amounts of pyruvate and ammonia

were produced. Although all of the conjugates were

activated by -lyase and had a similar effect on ion

transport, their mutagenicity differed markedly. The

conjugates of hexachlorobutadiene,

trichloroethylene, and tetrachloroethylene were

mutagenic in the Ames bacterial mutation assay

when activated by rat kidney S9. Metabolic

cofactors were not required, suggesting that

activation was due to the enzyme -lyase. In the

same assay, conjugates of tetrafluoroethylene and

hexafluoropropene were not mutagenic either in the

presence or absence of rat kidney S9 and cofactors. 

With a limited number of cysteine conjugates, a clear

distinction was identified between the conjugates of

fluoroalkenes that were similarly nephrotoxic but not

mutagenic. The mutagenicity of the cysteine

conjugate of hexachlorobutadiene is consistent with

the known renal carcinogenicity of this chemical.

Since the initial observations by Odum and Green

(1984), a number of laboratories have investigated

the in vitro and in vivo metabolism of nephrotoxic

haloalkenes (including tetrafluoroethylene) and their

cysteine conjugates in order to determine the mechanism of haloalkene-induced nephrotoxicity. The

bioactivation of the haloalkenes likely begins with

glutathione conjugation in the liver. These conjugates are primarily excreted via the bile in the small

intestine, where biliary and intestinal peptidases

degrade them to cysteine- S-conjugates which may be
Tetrafluoroethylene, NTP TR 450 17

reabsorbed from the small intestine. Glutathione isolated proximal tubule cells from Wistar rat

conjugates released into the general circulation from kidneys were incubated with 100 μmol of

the liver are hydrolyzed to the cysteine- S-conjugates tetrafluoroethylene-cysteine conjugates or

by renal peptidases and are bioactivated by renal mercapturic acid and other chloro- and bromofluoro

-lyase to unstable, reactive thiols. Commandeur compounds, tetrafluoroethylene compounds were

et al. (1988) administered tetrafluoroethylene- more toxic, as evidenced by their ability to inhibit

mercapturic acid intraperitoneally to Wistar rats at -methylglucose uptake by the cells (Boogaard

doses of 50 μmol/kg body weight or greater. After et al., 1989). The cytotoxicity induced by both

48 hours, nephrotoxicity, but not liver toxicity, tetrafluoroethylene compounds was inhibited by

ensued, as evidenced by increased blood urea nitro- aminooxyacetic acid; however, only the toxicity

gen, urinary protein and glucose, and relative kidney induced by tetrafluoroethylene-mercapturic acid

weights. Excretion of difluoroacetic acid was dose could be inhibited by probenecid, suggesting that the

related, represented 10% of the dose of 50 μmol/kg two tetrafluoroethylene compounds are transported

body weight, and occurred primarily during the first by a different carrier system. Tetrafluoroethylene

24 hours. Difluoroacetic acid, pyruvate, hydrogen cysteine accumulated in the proximal tubule cells on

sulfide, and thiosulfate were formed during in vitro exposure to either tetrafluoroethylene-cysteine conjumetabolism of the tetrafluoroethylene-cysteine gate or tetrafluoroethylene-mercapturic acid

conjugate by rat renal cytosol. Difluoroacetic acid (Boogaard et al., 1989). Commandeur et al. (1989)

formation was inhibited by aminooxyacetic acid, a demonstrated that the tetrafluoroethylene-cysteine

-lyase inhibitor, which points to a -lyase conjugate may be bioactivated in the rat kidney and,

dependency for its formation. This suggests that the to a lesser extent, in the rat liver to electrophilic

tetrafluoroethylene-cysteine conjugate is bioactivated thioacylating reactive intermediates, probably thito a significant extent to difluorothionacyl fluoride onacetyl fluorides, which are the putative reactive

and is subsequently metabolized to difluoroacetic intermediates for tetrafluoroethylene-induced

acid (Commandeur et al., 1988). Male Wistar rats nephrotoxicity.

were also injected with 50 μmol tetrafluoroethylenecysteine conjugate/kg body weight. After 48 hours,

4% of the dose was excreted as the corresponding

mercapturic acid. In order to evaluate the enzymatic

activation or deactivation of various halogenated

cysteine conjugates and mercapturic acids, rat liver

and kidney cytosol (activation) and microsomes

(deactivation) were incubated with the

tetrafluoroethylene-cysteine conjugates and

mercapturic acid or various chloro- and bromofluoro

cysteine conjugates and mercapturic acids. 

Tetrafluoroethylene-cysteine conjugate incubated

with -lyase or tetrafluoroethylene-mercapturic acid

with N-deacetylase demonstrated a greater activation

activity with kidney cytosol than with liver. In

addition, tetrafluoroethylene-cysteine conjugates and

mercapturic acids demonstrated greater activity than

chloro- or bromofluoro compounds. Deactivation as

evidenced by N-acetyltransferase activity (microsomes) was greater with the chloro- and bromofluoro

compounds than with tetrafluoroethylene conjugates

or mercapturic acid. Deactivation activity was

greatest with renal microsomes for both tetrafluoroethylene compounds (Commandeur et al., 1991). 

The same laboratory also demonstrated that when

A number of studies have demonstrated that the

tetrafluoroethylene-cysteine conjugate and tetrafluoroethylene-derived thionacetyl fluorides affect

rat and rabbit kidney macromolecules. Using

isolated rat kidney mitochondria, Hayden and

Stevens (1990) demonstrated that

tetrafluoroethylene-cysteine conjugate was a good

substrate for the mitochondrial -lyase, inhibited

ADP-stimulated respiration (primarily stage III), was

covalently bound to macromolecules (blocked by

aminooxyacetic acid), and was metabolized by

mitochondria. Rabbit renal proximal tubules

incubated with 25 μmol tetrafluoroethylene-cysteine

conjugate produced similar results, including a

sevenfold increase in lipid peroxidation (Groves

et al., 1993). Although the majority of binding in rat

mitochondria is associated with the protein fraction,

Hayden et al. (1992) have shown that significant

binding occurs in the lipid fraction, and the major

phospholipid adduct is the thioamide adduct of

phosphatidylethanolamine.

Harris et al. (1992) administered 110 mmol

tetrafluoroethylene-cysteine conjugate intraperito-
18 Tetrafluoroethylene, NTP TR 450

neally to male Fischer rats. After 1 hour, kidneys

were removed, and cytosolic, microsomal, and mitochondrial fractions were obtained. The single, stable

amino acid adduct formed with renal protein was

N-(difluorothioacetyl)lysine. Urine taken from

bladders at necropsy was analyzed for metabolites. 

Mercapturic acids, dihaloacetic acids, and inorganic

fluoride were present, as in previously reported

studies. In a similar experiment, Hayden et al.

(1991a) intraperitoneally administered 30 mg

tetrafluoroethylene-cysteine conjugate/kg body

weight to male Sprague-Dawley rats. The resulting

kidney toxicity showed a good correlation with

metabolite binding in that difluorothioamide adducts

and toxicity were localized to the medullary ray,

which contains the S3C and S3M segments of the

proximal tubule. Cell death occurred only in cells

containing adducts.

Protein adducts such as N-acetyl-N-(difluorothionacetyl)lysine (Hayden et al., 1991b) from rat renal

subcellular fractions and N-(difluorothionoacetyl)-S-(1,1,2,2-tetrafluoroethyl)- L-cysteine

(Commandeur et al., 1989) from rat renal and liver

subcellular fractions have been isolated. Bruschi

et al. (1993) have demonstrated that as many as five

mitochondrial proteins are modified following intraperitoneal injection of male F344/N rats with 30 mg

tetrafluoroethylene-cysteine conjugate/kg body

weight; modification also occurs at the time of

formation of the N-acetyl-N-(difluorothionacetyl)

lysine adduct. Two of the proteins have been identified as the heat shock proteins HSP60 (P1 protein)

and HSP70-like protein (mortalin). HSP70 and

HSP70 mRNA are increased in porcine renal epithelial cell cultures when tetrafluoroethylene-cysteine

conjugate is added (Chen et al., 1992). Lock and

Schnellmann (1990), using in vitro studies with rat

renal mitochondrial or cytosolic preparations, have

demonstrated that the addition of

tetrafluoroethylene-cysteine conjugate inhibits lipoyl

dehydrogenase and glutathione reductase activity,

respectively.

Humans

No studies on the absorption, distribution, metabolism, or excretion of tetrafluoroethylene by humans

were found in the available literature (National 

Library of Medicine, 1995).

TOXICITY

Experimental Animals

Sakharova and Tolgskaya (1977) reported LC 50

values of 31,000 to 32,000 ppm for rats;

35,000 ppm for mice; and 28,000 ppm for guinea

pigs following 4-hour inhalation exposures to

tetrafluoroethylene. Kennedy (1990) reported a

similar 4-hour LC of 28,500 ppm for hamsters. 50

Zhemerdei (1958) reported that the lowest

concentration of tetrafluoroethylene that caused

mortality in rabbits was 40,000 ppm.

Odum and Green (1984) exposed male Wistar rats to

tetrafluoroethylene for 6 hours at concentrations of

1,000, 2,000, 3,000, 4,000, and 6,000 ppm to evaluate the potential renal toxicity of the compound. 

Blood urea nitrogen values, urine volume and urinary

excretion of glucose, and alkaline phosphatase and

-glutamyltranspeptidase activities were

significantly increased in rats exposed to 4,000 or

6,000 ppm. These changes are indicative of renal

tubule damage. Histopathologic evaluations of the

kidneys were conducted on rats in the control and

6,000 ppm groups. All exposed rats exhibited

marked renal necrosis involving the pars recta of the

proximal tubules. In addition, there were intertubule

calcified deposits in the medulla. The noobservable-effect level for kidney toxicity was

2,000 ppm. As in previously discussed studies, oral

exposure to tetrafluoroethylene-cysteine conjugate

caused renal damage identical to that observed

following exposure to tetrafluoroethylene via

inhalation.

A number of industry-sponsored studies with tetrafluoroethylene have been conducted but not

published. Kennedy (1990) has provided a brief

review of some of these studies. Because few

repeated-exposure studies with tetrafluoroethylene

are presented in the available published literature,

several of the studies are summarized here. Syrian

hamsters and male Crl:CD rats were exposed to

tetrafluoroethylene for 6 hours per day, 5 days per

week, for 2 weeks at exposure concentrations of 0,

100, 500, 1,000, and 2,500 ppm. Some of the

animals were evaluated at the end of the exposure

period, and the remaining animals were evaluated

following a 14-day recovery period. No clinical

signs of toxicity were observed in either species. 

There were no significant differences in hamster
Tetrafluoroethylene, NTP TR 450 19

absolute or relative organ weights (liver or kidney) at because these products are mixtures of a number of

either evaluation period. After the tenth exposure, chemical vapors and particulates, and any observable

absolute and relative kidney and liver weights were effects cannot be solely attributed to the inhalation of

significantly increased in rats exposed to 2,500 ppm tetra-fluoroethylene monomer.

tetrafluoroethylene; however, following the recovery

period, kidney and liver weights were similar to

those of the control group. Exposure-related kidney

lesions in rats exposed to 2,500 ppm were

characterized by swelling of the tubular epithelial

cells and dilation of the tubular lumen. Sparse

cellular degeneration was observed and localized to

the juxtamedullary cortex. No significant lesions

were apparent following the 14-day recovery period. 

No significant histopathologic changes were

observed in tetrafluoroethylene-exposed hamsters

after the tenth exposure; however, following the

14-day recovery period, testicular atrophy was

observed in the 2,500 ppm group. This effect

consisted of degeneration and sloughing of germinal

epithelial cells, resulting in an absence or reduction

in the number of mature sperm in both the testes and

epididymides, and the presence of degenerative germ

cells sloughed into the lumen of the epididymal

ducts. These effects were noted less frequently in

animals exposed to lower concentrations.

Kennedy (1990) summarized the results of a study in

which male and female rats and hamsters were exposed to 200, 600, or 2,000 ppm tetrafluoroethylene

for 6 hours per day, 5 days per week, for 18 weeks. 

Hamsters appeared to be less affected than rats in

that there was no reduction in the rate of weight gain

in any exposed group of hamsters, while rats

exposed to 2,000 ppm exhibited a reduction in the

rate of weight gain. Additionally, toxic nephrosis

associated with the straight portions of the proximal

convoluted tubules was observed in rats exposed to

600 or 2,000 ppm tetrafluoroethylene. This was

accompanied by increased urine volume and urine

fluoride concentrations and decreased urine

creatinine concentrations. The effects were more

pronounced in female rats than in male rats. No

effects on the kidneys of exposed groups of hamsters

were observed; however, testicular atrophy similar to

that reported in the 14-day study in male Syrian

hamsters and Crl:CD rats was observed.

Although a number of animal studies have been

performed with pyrolysis products of tetrafluoroethylene polymers, they are not reported here

Humans

Epidemiological studies relative to exposure to tetrafluoroethylene alone were not found in the literature

(National Library of Medicine, 1995). Although

monomeric tetrafluoroethylene is generally

considered an irritant to the eyes and respiratory

tract, there is a paucity of firm toxicologic data. 

There are considerable data in the literature on

human exposure to pyrolysis products of

tetrafluoroethylene polymers. However, those

studies are not considered here because toxic effects

from exposure to the polymer fumes cannot be

attributed solely to inhalation of tetrafluoroethylene

monomer. Following exposure to pyrolysis products

of tetrafluoroethylene, influenza-like symptoms

commonly referred to as “polymer-fume fever” do

occur. The symptoms include fever, chills,

headaches, dizziness, nausea, weakness, cough, and

rigor-like shaking of the limbs (IARC, 1979;

Gosselin et al., 1984; Material Safety Data Sheet

Collection, 1993; Patty's Industrial Hygiene and

Toxicology, 1994). The symptoms are transient if

the oxygen supply to the subject is increased and the

subject is removed from the contaminated environment.

S-(1,1,2,2-tetrafluoroethyl)- L-cysteine and other

cysteine and glutathione conjugates such as

S-(1,2-di-chlorovinyl)glutathione, S-(1,2-dichlorovinyl)-L-cysteine, S-(1,2,3,4,4-pentachlorobutadienyl)-Lcysteine, and S-(2-chloro1,1,2-trifluoroethyl)-L-cysteine were found to be toxic to

human proximal tubule cells in culture, as indicated

by the release of lactate dehydrogenase (Chen et al.,

1990). Aminooxyacetic acid protected the cells from

the toxicity of all the conjugates and inhibited the

covalent binding of the sulfur-containing metabolites

to cellular macromolecules and thus prevented cell

death.

REPRODUCTIVE 

AND DEVELOPMENTAL TOXICITY

No information on the reproductive or

developmental toxicity of tetrafluoroethylene in
20 Tetrafluoroethylene, NTP TR 450

experimental animals or in humans was found in a and females. (NTP, 1986). In the same inhalation

search of the available literature (National Library of study, mice exposed to 100 or 200 ppm for 2 years

Medicine, 1995). developed increased incidences of hepatocellular

females).

CARCINOGENICITY

No information on the carcinogenicity of tetrafluoroethylene in experimental animals or in humans was

found in a search of the available literature (National

Library of Medicine, 1995). Tetrachloroethylene,

which is structurally similar to tetrafluoroethylene,

produced hepatocellular carcinomas in male and

female B6C3F1 mice (NCI, 1977). Male mice were

administered 450 or 900 mg tetrachloroethylene/kg

body weight in corn oil by gavage for 11 weeks, then

550 or 1,100 mg/kg for 67 weeks. Female mice

were administered 300 or 600 mg/kg tetrachloroethylene in corn oil by gavage for 11 weeks, then

400 or 800 mg/kg for 67 weeks. Exposure of male

and female F344/N rats to 200 or 400 ppm

tetrachloroeth-ylene by inhalation for 2 years

resulted in increased incidences of renal tubule

adenoma or adenocarcinoma in males and increased

incidences of mononuclear cell leukemia in males

adenoma (males) and carcinoma (males and

GENETIC TOXICOLOGY

Kennedy (1990) reported that tetrafluoroethylene

was not mutagenic in Salmonella typhimurium with

or without metabolic activation.

Cysteine conjugates of tetrafluoroethylene were not

mutagenic in the Salmonella assay, with or without

rat kidney S9 (Green and Odum, 1985).

The structurally similar tetrachloroethylene was not

mutagenic in Salmonella (Haworth et al., 1983),

gave equivocal results in the mouse lymphoma

mutagenicity assay with L5178Y mouse lymphoma

cells (Myhr et al., 1990), and did not induce sister

chromatid exchanges or chromosomal aberrations in

cultured Chinese hamster ovary cells (Galloway

et al., 1987); 

all these tests were conducted with and without nomination was based on the potential for human

Aroclor-induced liver S9 enzymes. exposure to the chemical due to the large production

tetrafluoroethylene. Inhalation was chosen as the

STUDY RATIONALE

Tetrafluoroethylene was nominated to the NTP by

the National Cancer Institute for testing following a

review of related monomers and polymers. The

volume and on the lack of adequate test data for

route of exposure because human exposure occurs

primarily via this route. Sixteen-day, 13-week, and

2-year whole body inhalation studies were performed

in male and female F344/N rats and B6C3F mice. 1
21

MATERIALS AND METHODS

PROCUREMENT 

AND CHARACTERIZATION 

OF TETRAFLUOROETHYLENE

Tetrafluoroethylene was obt ained from SCM Specialty

Chemicals (Gainesville, FL) in one lot (10271), which

was used for the identity and pur ity analyses conducted

by the analytical chemistry laboratory, Midwes t

Research Institute (Kansas City, MO) (Appendix I) .

Tetrafluoroethylene was also obtained from IC I

Americas, Inc. (Bayonne, NJ), in five lots. The study

laboratory assigned a lot number to each shipment of

as many as 12 cylinders. Lot 12017 -8 was used during

the 16-day studies and during most of the 13-wee k

studies; lot 12017-77 was used during the remainde r

of the 13-week studies; and lots 12438-6, 12438-79 ,

and 12438-92 were used during the 2-year studies .

Identity and purity analyses were also conducted by the

study laboratory on each lot used during the studies .

Reports on analyses performed in support of th e

tetrafluoroethylene studies are on file at the Nationa l

Institute of Environmental Health Sciences (NIEHS).

Each lot of the chemical, a color less gas, was identified

as tetrafluoroethylene by the analytical chemistry o r

study laboratory using infrared spectroscopy and th e

purity of each lot was determined by gas chromatography. Gas chromatography of lot 10271 indicated one

major peak and one impurity with an area of 0.1 %

relative to the major peak. In addition, analysis fo r

d-limonene, which is added to tetrafluoroethylene as a

stabilizer, was conducted by the analytical chemistr y

laboratory using gas chromatography and indicate d

0.03% ± 0.00% d-limonene. Gas chromatograph y

conducted by the study laboratory for each cylinder of

each lot used during the studies indicated tha t

perfluorocyclobutane was present at concentration s

less than or equal to 462 ppm (0.05%) for the 16-day

studies and 2,604 ppm (0.26%) for the 13-wee k

studies. During the 2-year studies, gas chromatogra -

phy indicated peaks for perfluorocyclobutane wit h

areas less than or equal to 1.21% relative to the major Because tetrafluoroethylene is a gas at room temperapeak. Gas chromatography conducted by the stud y ture, the generation and delivery system incorporate d

laboratory for each cylin der of each lot used during the gas distribution under regulated pressure with indi -

13-week studies indicate d that d-limonene was present vidual adjustment and monitoring of the chemical flow

at concentrations less than or equal to 2,837 pp m

(0.28%). During the 2-year studies, gas chromatography of lots 12438-6, 12438-79, and 12438-92 indi -

cated peaks for d-limonene with areas less than o r

equal to 0.56% relative to the major peak. The manufacturer indicated that the following impurities wer e

also present at concentrations less than or equal t o

1.7 ppm: trifluoroethylene, methylene fluoride, vinyl

fluoride, and vinylidene fluoride. The overall purity of

lots 12017-8, 12017-77, and 12438-92 was deter -

mined to be greater than 99%. The overall purity o f

lots 12438-6 and 12438-79 was determined to b e

greater than 98%.

The manufacturer indicated that tetrafluoroethylen e

would be stable for up to 1 year when stored in th e

original containers at room temperature. To ensur e

stability, the bulk chemical was stored in the origina l

metal cylinders at 10 to 22 C. Stability was monitored during the 13-week and 2-year studies using gas

chromatography. The relative concentrations o f

perfluorocyclobutane were expected to increase due to

the slow dimerization of tetrafluoroethylene; therefore,

the gas cylinders were monitored for this dimer as well

as for d-limonene during the 2-year studies. Tw o

cylinders from lot 12438-6 contained higher concentrations of these compounds t han canisters from the same

lot that were analyzed earlier in the studies. One o f

these two cylinders, which contained 1.21 %

perfluorocyclobutane and 0.56% d-limonene, was

replaced immediately after gas chromatographi c

analysis was performed; it is not known if the dime r

formed in the canister due to degradation o f

tetrafluoroethylene or was present as an impurity a t

receipt. Stability was generally considered acceptable

throughout the studies.

VAPOR GENERATION 

AND EXPOSURE SYSTEM
22 Tetrafluoroethylene, NTP TR 450

rate to each chamber. Tetrafluoroethylene was take n Uniformity of exposure concentrations within eac h

directly from the cylinder in which it was shipped and chamber was acceptable, and relative standar d

was metered to each exposu re chamber. A sample line deviations were less than 5%.

was included downstream from each gas cylinder .

Stainless-steel chambers designed at Battelle Pacifi c The persistence of tetrafluoroethylene in th e

Northwest Laboratories were used for all studie s 1,250 ppm exposure chamber after shutting off th e

(Figure I3). system was monitored without animals before th e

the 2-year studies. The concentration of tetrafluoro -

VAPOR CONCENTRATION MONITORING

The concentrations of tetrafluoroethylene wer e

monitored using an on-line gas chromatograph, an d

samples were drawn and analyzed from each exposure

chamber, the control chamber, the exposure suite, and

an on-line standard. Summaries of the chambe r

concentrations during the studies are presented i n

Tables I1 through I3. The monthly mean exposur e

concentrations for the 2-year studies are presented i n

Figures I7 through I15; all were within 10% of th e

acceptable concentration range.

CHAMBER ATMOSPHERE

CHARACTERIZATION

The time for the exposure concentration to build up to

90% of the final exposure concentration (T ) used for 90

all studies was 12 minutes. During the 16-day studies,

T90 was approximately 12 minutes and T10 (the time

for the exposure concentration to decay to 10% of the

exposure concentration) was approximately 9 minutes

with and without animals in the chambers. During the

13-week studies, T90 was 11 minutes with animals i n

the chambers and ranged from 11 to 14 minute s

without animals; T10 ranged from 9 to 11 minutes with

and without animals in the chambers. During th e

2-year studies, T ranged from 8 to 10 minute s 90

without animals in the chambers and from 10 t o

16 minutes with animals present; T10 ranged from 7 to

9 minutes without animals and from 9 to 12 minute s

with animals. The T90 value was not affected by th e

presence of animals.

Uniformity of tetrafluoroethylene concentration in the

exposure chambers was measured using on-line ga s

chromatography before each of the studies, onc e

during the 16-day and 13-week studies, and approxi -

mately every 3 months during the 2-year studies .

2-year studies began and with animals present during

ethylene in the exposure chamber fell rapidly to les s

than 1% of the beginning concentration withi n

20 minutes. Tetrafluoroethylene concentrations in the

building exhaust and room air were also monitore d

during all studies.

Information supplied by the manufacturer indicate d

that all cylinders contained d-limonene as a stabilizer.

d-Limonene and perfluorocyclobutane are less volatile

than tetrafluoroethylene and c oncentrate in the cylinder

as the tetrafluoroethylene is removed. Cylinder usage

was regulated to minimize concentrations of thes e

chemicals in the exposure chambers; a maximum o f

80% of the tetrafluoroethylene in each cylinder wa s

used. Gas chromatography of chamber samples an d

cylinder headspace in used and unused cylinders wa s

conducted for d-limonene and perfluorocyclobutane .

The results indicated that tetrafluoroethylene wa s

stable during generation and in the exposure chambers

and that perfluorocyclobutane was not formed i n

significant quantities by the generation system. 

16-DAY STUDIES

Male and female F344/N rats and B6C3F 1 mice were

obtained from Frederick Cancer Research Facilit y

(Frederick, MD). On receipt, the rats and mice wer e

approximately 4 weeks old. Anim als were quarantined

for 11 days (rats) or 12 days (mice) and wer e

approximately 6 weeks old on the first day of th e

studies. Groups of five male and five female rats and

mice were exposed to tetrafluoroethylene at concen -

trations of 0, 312, 625, 1,250, 2,500, and 5,000 ppm.

The animals were exposed for 6 hours plus T 90

(12 minutes) per day, 5 days per week for 12 exposure

days during a 16-day period. Feed was availabl e

ad libitum except during exposure periods, and water

was available ad libitum. Rats and mice were housed

individually. Clinical findings were recorded tw o

times during each exposure day for rats and mice. The

animals were weighed on days 1, 8, and 15 and a t
Tetrafluoroethylene, NTP TR 450 23

necropsy. Details of the study design and anima l Groups of 10 male and 10 female rats and mice were

maintenance are summarized in Table 1. exposed to tetrafluoroethylene at concentrations of 0,

At the end of the 16-day studies, blood was collected rat assigned to the 2,500 ppm group was missexed and

from the retroorbital (rats) or supraorbital (mice) sinus discarded at week 6.) The animals were exposed fo r

for hematology analyses. Rats and mice wer e 6 hours plus T (12 minutes) per day, 5 days pe r

anesthetized with CO . Blood for hematology deter - week, for 13 weeks (excluding holidays). Feed wa s 2

minations was placed in tubes containing potassiu m available ad libitum except during exposure periods ,

EDTA as the anticoagula nt. Analyses were performed and water was available ad libitum. Rats and mice

with an Ortho ELT-8/ds hematology analyzer (Ortho were housed individually. Clinical findings wer e

Instruments; Westwood, MA). Leukocyte differential recorded once weekly for rats and mice. The animals

counts were determined by light microscopi c were weighed prior to the start of the studies an d

examination of blood films stained with Wright - weekly thereafter. Details of the study design an d

Giemsa. Reticulocyte counts were determined by light animal maintenance are summarized in Table 1.

microscopy using smears stained supravitally wit h

New Methylene Blue and a Miller disc for reticulocyte

quantitation. Hematology parameters measured ar e

listed in Table 1.

A necropsy was performed on all rats and mice. The

brain, heart, left and right kidneys, liver, lung, righ t

testis, and thymus were weighed. Histopathologi c

examinations were performed on all control an d

5,000 ppm rats and mice. Selected organs wer e

examined to a no-effect level in groups of animal s

exposed to lower concentrations of tetrafluoroethylene.

Table 1 lists the tissues and organs examined.

13-WEEK STUDIES

The 13-week studies were conducted to evaluate th e

cumulative toxic effects of repeated exposure t o

tetrafluoroethylene and to determine the appropriat e

exposure levels to be used in the 2-year studies.

Male and female F344/N rats and B6C3F 1 mice were

obtained from Taconic Farms, Inc. (Germantown ,

NY). On receipt, rats and mice were approximatel y

4 weeks old. Animals were quarantined for 12 day s At the end of the 13-week studies, samples wer e

(rats) or 14 days (mice) and were approximatel y collected for sperm morphology and vaginal cytology

6 weeks old on the first day of the studies. Before the evaluations on rats and mice exposed to 0, 312, 1,250,

studies began, five male and five female rats and mice and 5,000 ppm. The parameters evaluated are listed in

were randomly selected for parasite evaluation an d Table 1. Methods used were those described in th e

gross observation for evidence of disease. At the end NTP's sperm morphology and vaginal cytolog y

of the studies, serologic analyses were performed o n evaluations protocol (NTP, 1984). For 7 consecutive

five male and five female sentinel rats and mice using days prior to scheduled terminal sacrifice, the vaginal

the protocols of the NTP Sentinel Animal Progra m vaults of the females were moistened with saline, i f

(Appendix K). necessary, and samples of vaginal fluid and cells were

312, 625, 1,250, 2,500, or 5,000 ppm. (One femal e

90

At the end of the 13-week studies, blood was collected

from the retroorbital (rats) or supraorbital (mice) sinus

for hematology analyses. Rats and mice wer e

anesthetized with CO . Hematology determination s 2

were analyzed as described for the 16-day study .

Fourteen days (rats) or 10 days (mice) before the end

of the studies, rats and mice were placed in metabolism

cages (with access to water but not food) for a 16-hour

urine collection. Four days before the end of th e

studies, rats were again placed in metabolism cage s

and were deprived of water for 16 hours to determine

urine concentrating ability; urine was expressed from

the bladders of all rats, and urine was collected for the

following 4 hours while water deprivation continued .

Specific gravity was determined on an A/ O

refractometer; urine glucose was determined using an

Abbott VP glucose oxidase methodology (Abbot t

Laboratories, Abbott Park, IL); urine protein wa s

determined by a Coomassie blue reaction; and fluoride

was measured using an ion-specific electrode .

Hematology and urinalysis parameters measured ar e

listed in Table 1.

stained. Relative numbers of leukocytes, nucleate d

epithelial cells, and large squamous epithelial cell s
24 Tetrafluoroethylene, NTP TR 450

were determined and used to ascertain estrous cycl e 95 to 96 weeks (mice). Following the last day o f

stage (i.e., diestrus, proestrus, estrus, and metestrus). exposure, rats were observed for approximatel y

Male animals were evaluated for sperm morphology , 11 days before necropsy. Ten ma le and ten female rats

count, and motility. The right testis and righ t and mice from each group were evalu ated at 15 months

epididymis were isolated and weighed. The tail of the for alterations in hematology, clinical chemistry, an d

epididymis (cauda epididymis) was then removed from urinalysis parameters (rats only) and organ weight s

the epididymal body (corpu s epididymis) and weighed. (rats and mice).

Test yolk (rats) or modified Tyrod e's buffer (mice) was

applied to slides and a small incision was made at the

distal border of the cauda epididymis. The sper m

effluxing from the incision were dispersed in the buffer

on the slides, and the numbers of motile and nonmotile

spermatozoa were counted for five fields per slide by

two observers. Following completion of sper m

motility estimates, each right cauda epididymis wa s

placed in buffered saline solution. Caudae were finely

minced, and the tissue was incubated in the salin e

solution and then heat fixed at 65 C. Sperm density

was then determined microscopically with the aid of a

hemacytometer. To quantify spermatogenesis,

testicular spermatid head count was determined b y

removing the tunica albuginea and homogenizing th e

left testis in phosphate-b uffered saline containing 10%

dimethyl sulfoxide. Homogenization-resistan t

spermatid nuclei were counted with a hemacytometer.

A necropsy was performed on all animals. The brain,

heart, right kidney, liver, lung, right testis, and thymus

were weighed. Tissues for microscopic examinatio n

were fixed and preserved in 10% neutral buffere d

formalin, processed and trimmed, embedded i n

paraffin, sectioned to a thickness of 5 to 6 μm, an d

stained with hematoxylin and eosin. A complet e

histopathologic examination was performed on al l

control and 5,000 ppm rats and mice and on selecte d

organs from rats and mice exposed to lower concen -

trations. Table 1 lists the tissues and organ s

examined.

2-YEAR STUDIES

Study Design

Groups of 60 male rats were exposed to tetrafluoro -

ethylene at concentrations of 0, 156 , 312, and 625 ppm

for 6 hours plus T (12 minutes) per day, 5 days pe r 90

week, for 104 weeks. Groups of 60 female rats an d

58 male and female mice were exposed t o

tetrafluoroethylene at concentrations of 0, 312, 625 ,

and 1,250 ppm for 6 hours plus T (12 minutes) per 90

day, 5 days per week, for 104 weeks (female rats) o r

Source and Specification of Animals

Male and female F344/N rats and B6C3F 1 mice were

obtained from Simonsen Laborat ories (Gilroy, CA) for

use in the 2-year studies. Rats and mice were quarantined for 15 days before the beginning of the studies .

Five male and five female rats and mice were randomly

selected for parasite evaluation and gross observation

of disease. Rats and mice were approximately 7 weeks

old at the beginning of the studies. The health of th e

animals was monitored during the studies according to

the protocols of the NTP Sentinel Animal Progra m

(Appendix K).

Animal Maintenance

Rats and mice were housed individually. Feed wa s

available ad libitum except during exposure periods ,

and water was available ad libitum. Chambers and

cages were rotated weekly. Further details of anima l

maintenance are provided in Table 1. Information on

feed composition and contaminants is provided i n

Appendix J.

Clinical Examinations and Pathology

All animals were observed twice daily. Clinica l

findings were recorded monthly until the last 13 weeks

(rats) or 5 weeks (mice), when they were recorde d

twice monthly. Animals were weighed prior to th e

start of the studies, weekly for the first 13 weeks, and

monthly thereafter, until the last 13 weeks (rats) o r

5 weeks (mice), when they were weighed ever y

2 weeks.

Ten male and ten female rats and mice per exposur e

group were designated for interim evaluation a t

15 months. Two weeks before the scheduled evaluation, designated rats were placed in metabolism cages

for a 16-hour urine collection. One week later, mal e

and female rats were again placed in metabolism cages

for a urine concentrating study. Rats were deprived of

water for 16 hours, and urine was expressed from the

bladders of the animals; urine was then collecte d

during the next 6 hours for a u rine concentrating study.
Tetrafluoroethylene, NTP TR 450 25

At the 15-month interim evaluation, blood was take n pathologists, or lesions of general interest wer e

from the retroorbital plexu s of rats for hematology and presented by the chairperson to the PWG for review .

clinical chemistry analyses. The methods used wer e The PWG consisted of the quality assessmen t

those described for the 13-week studies, and parame- pathologist and other pathologists experienced i n

ters measured are listed in Table 1. rodent toxicologic pathology. This group examine d

A complete necropsy and microscopic examinatio n previously rendered diagnoses. When the PW G

were performed on all rats and mice. At the 15-month consensus differed from the opinion of the laboratory

interim evaluation, the right kidney, liver, and lun g pathologist, the diagnosis was changed. Thus, th e

were weighed. At necropsy, all organs and tissue s final diagnoses represent a consensus of contracto r

were examined for grossly visible lesions, and al l pathologists, the PWG chairperson, and the PWG .

major tissues were fixed and preserved in 10% neutral Details of these review procedures have bee n

buffered formalin, processed and trimmed, imbedde d described, in part, by Maronpot and Boorman (1982)

in paraffin, sectioned to a thickness of 5 to 6 μm, and and Boorman et al. (1985). For subsequent analyses

stained with hematoxylin and eosin for microscopi c of the pathology data, the diagnosed lesions for eac h

examination. For all paire d organs (i.e., adrenal gland, tissue type were evaluated separately or combine d

kidney, ovary), samples from each organ were exam - according to the guidelines of McConnell et al. (1986).

ined. For extended evaluation of renal proliferativ e

lesions, kidneys were st ep sectioned at 1 mm intervals,

and six to ten additional sections were obtained fro m

each kidney. Tissues examined microscopically ar e

listed in Table 1.

Microscopic evaluations were completed by the study

laboratory pathologist, and the pathology data wer e

entered into the Toxicology Data Management System.

The slides, paraffin blocks, and residual wet tissue s

were sent to the NTP Archives for inventory ,

slide/block match, and wet tissue audit. The slides ,

individual animal data records, and pathology table s

were evaluated by an independent quality assessment

laboratory. The individual animal records and table s

were compared for accuracy, the slide and tissu e

counts were verified, and the histotechnique wa s

evaluated. For the 2-year rat and mouse studies, a

quality assessment pathologist reviewed the following

organs: adrenal medulla, kidney, liver, and splee n

(male rats); eye, kidney, liver, and spleen (female rats);

kidney, liver, and spleen (male mice); and harderia n

gland, liver, and spleen (female mice).

The quality assessment report and the reviewed slides

were submitted to the NTP Pathology Working Group

(PWG) chairperson, who reviewed the selected tissues

and addressed any inconsistencies in the diagnose s

made by the laboratory and quality assessmen t

pathologists. Representative histopathology slide s

containing examples of lesions related to chemica l

administration, examples of disagr eements indiagnoses

between the laboratory and quality assessmen t

the tissues without any knowledge of dose groups o r

STATISTICAL METHODS

Survival Analyses

The probability of survival was estimated by th e

product-limit procedure of Kaplan and Meier (1958 )

and is presented in the form of graphs. Animals found

dead of other than natural causes were censored from

the survival analyses; animals dying from natura l

causes were not censored. Statistical analyses fo r

possible dose-related effects on survival used Cox' s

(1972) method for testing two groups for equality and

Tarone's (1975) life table test to identify dose-related

trends. All reported P values for the survival analyses

are two sided.

Calculation of Incidence

The incidences of neoplasms or nonneoplastic lesions

as presented in Tables A1, A5, B1, B5, C1, C5, D1 ,

and D5 are given as the number of animals bearin g

such lesions at a specifi c anatomic site and the number

of animals with that site examined microscopically .

For calculation of statistical significance, th e

incidences of most neoplasms (Ta bles A3, B3, C3, and

D3) and all nonneoplastic lesions are given as th e

numbers of animals affected at each site examine d

microscopically. However, when macroscopi c

examination was required to detect neoplasms i n

certain tissues (e.g., harderian gland, intestine ,

mammary gland, and skin) before microscopi c

evaluation, or when neoplasms had multiple potential

sites of occurrence (e.g., leukemia or lymphoma), the
26 Tetrafluoroethylene, NTP TR 450

denominators consist of the number of animals o n

which a necropsy was performed. Tables A3, B3, C3,

and D3 also give the survival-adjusted neoplasm rate

for each group and each site-specifi c neoplasm, i.e., the

Kaplan-Meier estimate of the neoplasm incidence that

would have been observed at the end of the study in the

absence of mortality from all other competing risk s

(Kaplan and Meier, 1958).

Analysis of Neoplasm Incidences animals, was used.

For those neoplasms considered incidental in thes e

studies, the primary statistical method used wa s

logistic regression analysis, which assumed that th e

diagnosed neoplasms were discovered as the result of

death from an unrelated cause and thus did not affect

the risk of death. In this approach, neoplasm preva -

lence was modeled as a logistic function of chemica l

exposure and time. Both linear and quadratic terms in

time were incorporated initial ly, and the quadratic term

was eliminated if the fit of the model was not significantly enhanced. The neoplasm incidences of exposed

and control groups were compared on the basis of the

likelihood score test for the regression coefficient o f

dose. This method of adjusting for intercurrent mortality is the prevalence analysis of Dinse and Lagako s

(1983), further described and illustrated by Dinse and

Haseman (1986). When neop lasms are incidental, this

comparison of the time-specific neoplasm prevalences

also provides a comparison of the time-specific neo -

plasm incidences (McKnight and Crowley, 1984).

In addition to logistic regression, other methods o f

statistical analysis were used, and the results of these

tests are summarized in the appendixes. These methods include the life table test (Cox, 1972; Tarone ,

1975), appropriate for rapidly lethal neoplasms, an d

the Fisher exact test and the Cochran-Armitage trend

test (Armitage, 1971; Gart et al., 1979), procedure s

based on the overall proportion of neoplasm-bearin g

animals.

Tests of significance includ ed pairwise comparisons of

each exposed group with controls and a test for a n

overall dose-related trend. Continuity-corrected tests

were used in the analysis of neoplasm incidence, an d

reported P values are one sided. The procedure s

described in the preceding paragraphs were also used

to evaluate selected nonneoplastic lesions. For further

discussion of these statistical methods, refer t o

Haseman (1984).

Analysis of Nonneoplastic Lesion Incidences

Because all nonneoplastic lesions in this study wer e

considered to be incidental to the cause of death or not

rapidly lethal, the primary statistical analysis used was

a logistic regression analysis in which nonneoplasti c

lesion prevalence was modeled as a logistic function of

chemical exposure and time. For lesions detected a t

the interim evaluation, the Fisher exact test, a proce -

dure based on the overall proportion of affecte d

Analysis of Continuous Variables

Two approaches were employed to assess the significance of pairwise comparisons between exposed an d

control groups in the analysis of continuous variables.

Organ and body weight data, which have approxi -

mately normal distributions, were analyzed using th e

parametric multiple comparis on procedures of Dunnett

(1955) and Williams (1971, 1972). Hematology ,

clinical chemistry, spermatid, and epididymal spermatozoa data, which have typically skewed distributions,

were analyzed using the nonparametric multipl e

comparison methods of Shirley (1977) and Dun n

(1964). Jonckheere's test (Jon ckheere, 1954) was used

to assess the significance of the d ose-related trends and

to determine whether a trend-sensitive test (Williams'

or Shirley's test) was more appropriate for pairwis e

comparisons than a test that does not assume a monotonic dose-related trend (Dunnett's or Dunn's test) .

Prior to statistical analysis, extreme values identifie d

by the outlier test of Dixon and Massey (1951) wer e

examined by NTP personnel, and implausible value s

were eliminated from the analysis. Average severit y

values were analyzed for significance using the MannWhitney U test (Hollander and Wolfe, 1973). Because

the vaginal cytology data are proportions (the proportion of the observation period that an animal was in a

given estrous stage), an arcsine transformation wa s

used to bring the data into closer conformance with a

normality assumption. Tr eatment effects were investigated by applying a multivariate analysis of varianc e

(Morrison, 1976) to the transformed data to test fo r

simultaneous equality of measurements across expo -

sure levels.

Historical Control Data

Although the concurrent control group is always th e

first and most appropriate control group used fo r

evaluation, historical control data can be helpful in the

overall assessment of neoplasm incidence in certai n
Tetrafluoroethylene, NTP TR 450 27

instances. Consequently, neoplasm incidences fro m this NTP Technical Report were conducted. Audi t

the NTP historical control database, which is updated procedures and findings are presented in the report s

yearly, are included in the NTP reports for neoplasms and are on file at NIEHS. The audit findings wer e

appearing to show compound-related effects. reviewed and assessed by NTP staff, so all comments

QUALITY ASSURANCE METHODS

The 13-week and 2-year studies were conducted i n

compliance with Food and Drug Administration Good

Laboratory Practice Regulations ( 21 CFR, Part 58). In

addition, as records from the 2-year studies wer e

submitted to the NTP Archives, these studies wer e

audited retrospectively by an independent qualit y

assurance contractor. Separate audits covering com -

pleteness and accuracy of the pathology data, pathology specimens, final pathology tables, and a draft of

had been resolved or were otherwise addressed during

the preparation of this Technical Report.

GENETIC TOXICOLOGY

The genetic toxicity of tetrafluoroethylene was as -

sessed by testing the ability of the chemical to induce

increases in the frequency of micronucleated erythrocytes in peripheral blood samples obtained from male

and female mice at the end of the 13-week study. The

protocol for this study and the results are given i n

Appendix E.
28 Tetrafluoroethylene, NTP TR 450

TABLE 1

Experimental Design and Materials and Methods in the Inhalation Studies of Tetrafluoroethylene

16-Day Studies 13-Week Studies 2-Year Studies

Study Laboratory

Battelle Pacific Northwest Laboratories Battelle Pacific Northwest Laboratories Battelle Pacific Northwest Laboratories

(Richland, WA) (Richland, WA) (Richland, WA)

Strain and Species

Rats: F344/N Rats: F344/N Rats: F344/N

Mice: B6C3F1 Mice: B6C3F1 Mice: B6C3F1

Animal Source

Frederick Cancer Research Facility (Frederick, Taconic Farms, Inc. Simonsen Laboratories

MD) (Germantown, NY) (Gilroy, CA)

Time Held Before Studies

Rats: 11 days Rats: 12 days 15 days

Mice: 12 days Mice: 14 days

Average Age When Studies Began

6 weeks 6 weeks 7 weeks

Date of First Exposure

Rats: 30 September 1985 Rats: 25 March 1986 Rats: 23 June 1988

Mice: 1 October 1985 Mice: 27 March 1986 Mice: 9 June 1988

Duration of Exposure

6 hours plus T90 (12 minutes) per day, 5 days 6 hours plus T (12 minutes) per day, 5 days 6 hours plus T (12 minutes) per day, 5 days

per week, for 16 days per week, for 13 weeks per week, for 104 weeks (rats) (followed by an

90 90

observation period of approximately 11 days),

or 95 to 96 weeks (mice)

Date of Last Exposure

Rats: 15 October 1985 Rats: Rats:

Mice: 16 October 1985 24 June 1986 (males) 15-month interim evaluation

25 June 1986 (females) 17-18 September 1989

Mice: terminal sacrifice

26 June 1986 (males) 14 June 1990

25 June 1985 (females) Mice:

15-month interim evaluation

6-7 September 1989

terminal sacrifice

4-5 April 1990

Necropsy Dates

Rats: 16 October 1985 Rats: Rats:

Mice: 17 October 1985 24 June 1986 (males) 15-month interim sacrifice

25 June 1986 (females) 18-19 September 1989

Mice: terminal sacrifice

27 June 1986 (males) 25 June 1990 (males)

26 June 1986 (females) or 26-27 June 1990 (females)

Mice:

15-month interim sacrifice

7-8 September 1989

terminal sacrifice

5 April 1990 (males)

or 6 April 1990 (females)
Tetrafluoroethylene, NTP TR 450 29

TABLE 1

Experimental Design and Materials and Methods in the Inhalation Studies of Tetrafluoroethylene (continued)

16-Day Studies 13-Week Studies 2-Year Studies

Average Age at Necropsy

8 weeks 19 weeks Rats:

15-month interim evaluation - 71 weeks

terminal sacrifice - 111-112 weeks

Mice:

15-month interim evaluation - 72 weeks

terminal sacrifice - 102 weeks

Size of Study Groups

5 males and 5 females 10 males and 10 females 15-Month interim evaluation:

(one rat assigned to the 2,500 ppm female 10 males and 10 females

group was determined to be missexed and was Terminal sacrifice:

discarded during week 6) 50 males and 50 females (rats)

or 48 males and 48 females (mice)

Method of Distribution

Animals were distributed randomly into Same as 16-day studies Same as 16-day studies

groups of approximately equal initial mean

body weight.

Animals per Cage

1 1 1

Method of Animal Identification

Toe clips and placement within cage unit Same as 16-day studies Rats: Tail tattoos and placement within

cage unit

Mice: Toe clips and placement within cage

unit

Diet

NIH-07 pelleted feed (Zeigler Brothers, Inc., Same as 16-day studies Same as 16-day studies

Gardners, PA); available ad libitum, except

during exposure periods

Maximum Storage Time for Feed

120 days post-milling Same as 16-day studies Same as 16-day studies

Water

Tap water (Richland municipal supply) via Same as 16-day studies Same as 16-day studies

automatic watering system (Edstrom

Industries; Waterford, WI); available

ad libitum

Cages

Stainless steel (Hazleton Systems, Inc., Same as 16-day studies Stainless steel (Lab Products, Inc., Harford

Aberdeen, MD), changed weekly Division, Aberdeen, Md), changed weekly

Bedding/Cage Board

Techsorb®, Shepherd Specialty Papers, Inc. Same as 16-day studies Same as 16-day studies

(Kalamazoo, MI), used during non-exposure

periods, 7 days per week
30 Tetrafluoroethylene, NTP TR 450

TABLE 1

Experimental Design and Materials and Methods in the Inhalation Studies of Tetrafluoroethylene (continued)

16-Day Studies 13-Week Studies 2-Year Studies

Chamber Air Supply Filters

Duct pre-filter, dual and single HEPA Same as 16-day studies Single HEPA (Flanders Filters, Inc., San

(American Air Filter, Louisville, KY); checked Rafael, CA) and charcoal (RSE, Inc., New

biannually Baltimore, MI); changed before the studies

began and once yearly thereafter

Chambers

Stainless steel (Hazleton Systems, Inc., Stainless steel (Hazleton Systems, Inc., Stainless steel (Lab Products, Inc., Harford

Aberdeen, MD); changed weekly Aberdeen, MD); changed weekly Division, Aberdeen, MD); changed weekly

Chamber Environment

Temperature: 22.3 23.2 C Temperature: 23.1 23.7 C Temperature: 24.1 24.5 C

Relative humidity: 52.7% 55.4% Relative humidity: 56.1% 60.5% Relative humidity: 53% 58%

Room fluorescent light: 12 hours/day Room fluorescent light: 12 hours/day Room fluorescent light: 12 hours/day

Chamber air changes: 15/hour Chamber air changes: 15/hour Chamber air changes: 15/hour

Exposure Concentrations

0, 312, 625, 1,250, 2,500, or 5,000 ppm 0, 312, 625, 1,250, 2,500, or 5,000 ppm Rats:

males - 0, 156, 312, or 625 ppm

females - 0, 312, 625, or 1,250 ppm

Mice:

0, 312, 625, or 1,250 ppm

Type and Frequency of Observation

All animals were observed twice daily. All animals were observed twice daily. All animals were observed twice daily. 

Clinical findings were recorded two times each Clinical findings were recorded once weekly Clinical findings were recorded monthly until

exposure day. All animals were weighed on for rats and mice. The animals were weighed the last 13 weeks (rats) or 5 weeks (mice),

days 1, 8, 15, and at necropsy. before the studies began and weekly thereafter. when they were recorded twice monthly. 

Animals were weighed before the studies

began, weekly for the first 13 weeks, and

monthly thereafter, until the last 13 weeks

(rats) or 5 weeks (mice) when they were

weighed every 2 weeks.

Method of Sacrifice

Anesthetization with sodium pentobarbital Anesthetization with CO followed by Anesthetization with CO followed by

followed by exsanguination exsanguination exsanguination

2 2

Necropsy

Necropsy performed on all animals. Organs Necropsy performed on all animals. Organs Necropsy performed on all animals. Organs

weighed were brain, heart, left and right weighed were brain, heart, right kidney, liver, weighed at the 15-month interim evaluation

kidneys, liver, lung, right testis, and thymus. lung, right testis, and thymus. were the right kidney, liver, and lung.
Tetrafluoroethylene, NTP TR 450 31

TABLE 1

Experimental Design and Materials and Methods in the Inhalation Studies of Tetrafluoroethylene (continued)

16-Day Studies 13-Week Studies 2-Year Studies

Clinical Pathology

Blood was collected from all animals from the Blood was collected from all animals from the At the 15-month interim evaluation, blood was

retroorbital (rats) or supraorbital (mice) sinus retroorbital (rats) or supraorbital (mice) sinus taken from the retroorbital plexus of rats for

for hematology analyses. for hematology analyses. Fourteen days (rats) hematology and clinical chemistry analyses. 

Hematology: hematocrit; hemoglobin

concentration; erythrocyte, reticulocyte,

nucleated erythrocyte, and platelet counts;

mean cell volume; mean cell hemoglobin;

mean cell hemoglobin concentration; and

leukocyte count and differentials

or 10 days (mice) before the end of the studies, Two weeks prior to the scheduled evaluation,

animals were placed in metabolism cages (with designated rats were placed in metabolism

access to water but not food) for a 16-hour cages for a 16-hour urine collection. One

urine collection. Four days before the end of week prior to the evaluation, rats were again

the studies, rats were again placed in placed in metabolism cages and were deprived

metabolism cages and were deprived of water of water for 16 hours; urine was expressed

for 16 hours; urine was expressed from the from the bladders of all rats, and urine was

bladders of all rats, and urine was collected for collected for the following 6 hours while water

the following 4 hours while water deprivation deprivation continued.

continued.

Hematology: hematocrit; hemoglobin concentration; erythrocyte, reticulocyte,

concentration; erythrocyte and platelet counts; nucleated erythrocyte, and platelet counts;

mean cell volume; mean cell hemoglobin; mean cell volume; mean cell hemoglobin;

mean cell hemoglobin concentration; and mean cell hemoglobin concentration; and

leukocyte count and differentials leukocyte count and differentials

Urinalysis: fluoride, glucose, and protein Clinical chemistry: urea nitrogen, creatinine,

concentrations; volume; and specific gravity sodium, potassium, chloride, calcium, and

Hematology: hematocrit; hemoglobin

phosphorus concentrations

Urinalysis: glucose and protein

concentrations; volume; and specific gravity

Histopathology

Complete histopathology was performed on Complete histopathology was performed on Complete histopathology was performed on all

rats and mice exposed to 0 or 5,000 ppm. In rats and mice exposed to 0 or 5,000 ppm. In control and exposed rats and mice. In addition

addition to gross lesions and tissue masses, the addition to gross lesions and tissue masses, the to gross lesions and tissue masses, the tissues

tissues examined included: adrenal gland, tissues examined included: adrenal gland, examined included: adrenal gland, brain,

brain, clitoral gland, esophagus, eye (if grossly brain, clitoral gland, esophagus, gallbladder clitoral gland, esophagus, femur, gallbladder

abnormal), gallbladder (mice only), heart, (mice only), heart, large intestine (cecum, (mice only), heart, large intestine (cecum,

large intestine (cecum, colon, rectum), small colon, rectum), small intestine (duodenum, colon, rectum), small intestine (duodenum,

intestine (duodenum, jejunum, ileum), kidney, jejunum, ileum), kidney, larynx, liver, lungs, jejunum, ileum), kidney, liver, lungs, lymph

larynx, liver, lungs, lymph nodes (bronchial, lymph nodes (bronchial, mandibular, nodes (bronchial, mandibular, mediastinal,

mandibular, mediastinal, mesenteric), mediastinal, mesenteric), mammary gland, mesenteric), mammary gland, muscle (thigh),

mammary gland, nose, ovaries, pancreas, nose, ovaries, pancreas, parathyroid gland, nose, oral cavity (larynx and pharynx),

parathyroid gland, pituitary gland, preputial pituitary gland, preputial gland, prostate gland, ovaries, pancreas, parathyroid gland, pituitary

gland, prostate gland, salivary gland, skin, salivary gland, skin, spleen, sternebrae gland, preputial gland, prostate gland, salivary

spleen, sternebrae (including marrow), (including marrow), stomach (forestomach and gland, skin, spleen, sternebrae (including

stomach (forestomach and glandular), testis, glandular), testis, thymus, thyroid gland, marrow), stomach (forestomach and

thymus, thyroid gland, trachea, urinary trachea, urinary bladder, and uterus. glandular), testis, thymus, thyroid gland,

bladder, and uterus. Additionally, the kidney Additionally, the following organs were trachea, urinary bladder, and uterus.

of all other exposed groups of male and female examined in lower exposure groups: the

rats and mice was examined, as was the kidney of all exposed groups of male and

pancreas of male and female rats exposed to female rats and mice (except female rats

2,500 ppm. exposed to 312 ppm); the cecum of 625 ppm

male rats; the eye and mandibular lymph node

of 2,500 ppm female rats; and the thymus and

lung of 625 ppm male mice.
32 Tetrafluoroethylene, NTP TR 450

TABLE 1

Experimental Design and Materials and Methods in the Inhalation Studies of Tetrafluoroethylene (continued)

16-Day Studies 13-Week Studies 2-Year Studies

Sperm Morphology and Vaginal Cytology

None At terminal sacrifice, sperm samples were None

collected from all male animals in the 0, 312,

1,250, and 5,000 ppm groups for sperm

morphology evaluations. The parameters

evaluated included sperm morphology,

concentration, and motility. The right cauda,

right epididymis, and right testis were weighed. 

Vaginal samples were collected for up to

7 consecutive days prior to the end of the

studies from all females exposed to 0, 312,

1,250, or 5,000 ppm for vaginal cytology

evaluations. The parameters evaluated

included the relative frequency of estrous

stages and estrous cycle length.
33

RESULTS

RATS

16-DAY STUDY

All rats survived to the end of the study (Table 2). 

The final mean body weights and body weight gains

of males and females exposed to 5,000 ppm were

significantly less than those of the controls. The

mean body weight gain of females exposed to

2,500 ppm was also significantly less than that of

the control group. There were no exposure-related

clinical findings in male or female rats.

There were no significant differences in hematology

parameters that were considered to be related to

 

tetrafluoroethylene exposure (Table G1). Absolute

and relative left and right kidney weights of all

exposed groups of males were significantly greater

than those of the controls (Table F1), as were those

of females in the 2,500 and 5,000 ppm groups. The

absolute left and right kidney weight of females

exposed to 1,250 ppm was also significantly greater

than that of the controls. All exposed groups of

males had significantly greater relative liver weights

than the controls; males in the 625 and 2,500 ppm

groups also had greater absolute liver weights than

the controls. Other organ weight differences were

not considered to be related to chemical exposure.

TABLE 2

Survival and Body Weights of Rats in the 16-Day Inhalation Study of Tetrafluoroethylene

Exposure Mean Body Weight (g) Final Weight b

Concentration Survival Initial Final Change Relative to Controls a

(ppm) (%)

Male

0 5/5 120 ± 3 167 ± 4 48 ± 1

312 5/5 121 ± 2 176 ± 4 55 ± 3 105

625 5/5 122 ± 1 172 ± 3 50 ± 3 103

1,250 5/5 119 ± 1 165 ± 1 46 ± 1 99

2,500 5/5 119 ± 1 162 ± 2 43 ± 2 96

5,000 5/5 116 ± 2 143 ± 3** 27 ± 2** 86

Female

0 5/5 98 ± 1 126 ± 3 28 ± 2

312 5/5 104 ± 2* 131 ± 2 27 ± 2 104

625 5/5 97 ± 2 125 ± 3 28 ± 2 99

1,250 5/5 103 ± 1 131 ± 3 28 ± 3 104

2,500 5/5 100 ± 2 119 ± 4 19 ± 3* 94

5,000 5/5 99 ± 1 113 ± 2* 14 ± 1** 89

* Significantly different (P 0.05) from the control group by Williams’ or Dunnett’s test

** P 0.01

Number of animals surviving at 16 days/number initially in group a

Weights and weight changes are given as mean ± standard error. b
34 Tetrafluoroethylene, NTP TR 450

Increased incidences of renal tubule degeneration epithelium, characterized by epithelial cells with

occurred in males and females exposed to 625 ppm basophilic cytoplasm, enlarged vesicular nuclei, and

or greater (Table 3). The severity of these lesions slightly increased numbers of mitotic figures. The

increased with increasing exposure concentration and increased kidney weights were associated with the

was slightly greater in males than in females. Renal renal lesions. Histopathologic examination revealed

lesions occurred predominantly in the inner cortical no chemical-related lesions in the livers of exposed

tubular epithelial cells at the junction of the cortex male or female rats.

and medulla. Degeneration was characterized by

inner cortical tubules that contained lumenal debris

and were lined by cells with vacuolated or eosinophilic cytoplasm. Other tubule epithelial cells had

occasional dark pyknotic nuclei and shrunken,

eosinophilic cytoplasm. Associated with renal

tubule degeneration was regeneration of renal

cortical tubule 

Exposure Concentration Selection Rationale: Based

on the lack of overt toxicity following exposure of

male and female rats to 5,000 ppm for 16 days, the

13-week exposure concentrations selected were 0,

312, 625, 1,250, 2,500, and 5,000 ppm.

TABLE 3

Incidences of Nonneoplastic Lesions of the Kidney in Rats in the 16-Day Inhalation Study

of Tetrafluoroethylene

0 ppm 312 ppm 625 ppm 1,250 ppm 2,500 ppm 5,000 ppm

Male

Number Examined Microscopically 5 5 5 5 5 5

Renal Tubule, Degeneration 0 0 5** (1.0) 5** (1.4) 5** (2.0) 5** (3.0) a b

Female

Number Examined Microscopically 5 5 5 5 5 5

Renal Tubule, Degeneration 0 0 3 (1.0) 5** (1.2) 5** (1.8) 5** (3.2)

** Significantly different (P 0.01) from the control group by the Fisher exact test

Number of animals with lesion a

Average severity grade of lesions in affected rats: 1=minimal; 2=mild; 3=moderate; 4=marked b
Tetrafluoroethylene, NTP TR 450 35

13-WEEK STUDY

All rats survived to the end of the study (Table 4); one

rat in the 2,500 ppm female group was missexed and

was removed from the study. The final mean bod y

weight and body weight gain of males and the mea n

body weight gain of females exposed to 5,000 pp m

were significantly less than those of the controls .

There were no clinical findings attributed to exposure

to tetrafluoroethylene.

The hematology and clinical chemistry data for rats in

the 13-week study are presented in Table G2. Exposure to tetrafluoroethylene caused a concentration -

dependent anemia, evidenced by decreased hematocrit

values, hemoglobin concentrations, and erythrocyt e

counts in all exposed groups of males and in female s

exposed to 5,000 ppm. There were no changes in the

mean cell volume values of exposed groups of rats ,

indicating the erythrocytes were normocytic. There 

were minimal decreases of the mean cell hemoglobi n

concentration in males exposed to 1,250 ppm o r

greater; this did not occur in exposed female rats .

Decreases in mean cell hemoglobin concentration s

without alterations in mean cell volumes have bee n

related to the early stages of iron deficiency. Because

the mean cell hemoglobin concentration values o f

exposed groups of male ra ts were well within a normal

physiological range and no changes occurred in ex -

posed groups of females, the significance of the mean

cell hemoglobin concentration alterations was con -

sidered questionable and the erythrocytes were characterized as normochromic. There were no increases in

reticulocyte counts to indi cate a bone marrow response

to the anemia. Therefore, the anemia would b e

characterized as normocytic, normochromic, an d

nonresponsive. Normocytic, normochromic ,

nonresponsive anemias have been related to selective

suppression of erythropoiesis in a variety of disorders

and may be due to decreased erythropoietin 

TABLE 4

Survival and Body Weights of Rats in the 13-Week Inhalation Study of Tetrafluoroethylene

Exposure Mean Body Weight (g) Final Weight b

Concentration Survival Initial Final Change Relative to Controls a

(ppm) (%)

Male

0 10/10 116 ± 3 328 ± 5 212 ± 3

312 10/10 117 ± 2 337 ± 5 220 ± 4 103

625 10/10 115 ± 2 339 ± 4 225 ± 3 103

1,250 10/10 114 ± 2 330 ± 4 216 ± 4 101

2,500 10/10 113 ± 2 327 ± 4 214 ± 4 100

5,000 10/10 115 ± 3 299 ± 6** 184 ± 4** 91

Female

0 10/10 91 ± 2 185 ± 6 94 ± 4

312 10/10 97 ± 3 196 ± 3 99 ± 3 106

625 10/10 93 ± 2 195 ± 5 102 ± 5 105

1,250 10/10 95 ± 2 192 ± 4 97 ± 3 104

2,500 9/9 89 ± 4 177 ± 7 88 ± 4 95

5,000 10/10 94 ± 2 174 ± 4 80 ± 3* 94

* Significantly different (P 0.05) from the control group by Williams' or Dunnett's test

** P 0.01

Number of animals surviving at 13 weeks/number initially in group a

Weights and weight changes are given as mean ± standard error. b
36 Tetrafluoroethylene, NTP TR 450

elaboration, bone marrow suppression, or defectiv e group were also significantly greater than those of the

iron metabolism. controls. The absolute and relative heart weights o f

males exposed to 1,250, 2,500, or 5,000 ppm wer e

A concentration-dependent proteinuria occurred in all

exposed groups of male rats and in females exposed to

2,500 or 5,000 ppm. Proteinuria could be related t o

glomerular or renal tubule injury and is consistent with

the renal tubule degeneration observed histo -

pathologically. However, the renal injury did no t

appear to affect the ability of the kidney to concentrate

the urine, as evidenced by appropriate increases i n

urine specific gravity in response to a wate r

concentration test. There was a concentration -

dependent increase of urinary fluoride excretion in all

exposed groups of male and female rats, consisten t

with metabolism and excretion of tetrafluoroethylene.

A possible polyuria, evidenced by increased 16-hou r

urine volumes, occurred in males in the 5,000 pp m

group and in all exposed groups of females.

The absolute and relative liver weights of all exposed

groups of males and of females in the 5,000 pp m

group were significantly greater than those of th e

controls (Table F2). The absolute and relative righ t

kidney weights of males and females exposed t o

1,250 ppm or greater and of females in the 625 ppm 

generally significantly greater than those of th e

controls. Other organ weight differences were no t

considered to be related to chemical exposure.

There were no differences in sperm morpholog y

parameters or in the length of estrous cycles betwee n

control and exposed groups of rats (Tables H1 an d

H2).

Incidences of renal tubule degeneration in male s

exposed to 625 ppm or gre ater and in females exposed

to 2,500 or 5,000 ppm were significantly greater than

those in the controls (Table 5). The renal lesions ,

which were similar to those observed in the 16-da y

study, increased in severity with exposur e

concentration and were slightly more severe in male s

than females. Renal lesions were observed at th e

junction of the cortex and medulla and involved inner

cortical tubules. Degeneration was characterized b y

inner cortical tubules that were dilated, containe d

lumenal debris, and had occasional pyknotic nuclei .

Associated with degeneration was regeneration ,

characterized by renal tubule epithelial cells that were

lined by cells with basophilic cytoplasm havin g

pleomorphic 

TABLE 5

Incidences of Nonneoplastic Lesions of the Kidney in Rats in the 13-Week Inhalation Study

of Tetrafluoroethylene

0 ppm 312 ppm 625 ppm 1,250 ppm 2,500 ppm 5,000 ppm

Male

Number Examined Microscopically 10 10 10 10 10 10

Renal Tubule, Degeneration 0 0 10** (1.0) 10** (1.0) 10** (2.0) 10** (2.0) a b

Female

Number Examined Microscopically 10 — 10 10 9 10 c

Renal Tubule, Degeneration 0 0 0 9** (1.0) 10** (2.0)

** Significantly different (P 0.01) from the control group by the Fisher exact test

Number of animals with lesion a

Average severity grade of lesions in affected rats: 1=minimal; 2=mild; 3=moderate; 4=marked b

Kidney not examined at this exposure concentration c
Tetrafluoroethylene, NTP TR 450 37

nuclei with large, prominent nucleoli, a slightl y concentration was selected, in part, based on th e

increased number of mitotic figures, and varyin g number of chambers to be used in this inhalatio n

degrees of karyomegaly. The inc reased kidney weights study. When possible in inhalation studies, males and

were associated with the renal lesions . females of a species for each concentration are housed

Histopathologically, there were no chemical-relate d in the same chamber. When it is obvious that the same

lesions in the livers of male or female rats exposed to exposure concentration will cause more severe effects

tetrafluoroethylene. in one sex of the same species, space is sought i n

chambers housing the other species. In the presen t

Exposure Concentration Selection Rationale: Exposure concentrations for the 2-year rat study in male s

were based on kidney effects. Although the severit y

and incidence of kidney lesions were identical for male

rats exposed to 625 or 1,250 ppm, the absolute an d

relative kidney weights of males e xposed to 1,250 ppm

were significantly greater than those of the controls .

Therefore, the highest exposure concentration selected

was 625 ppm, which was expected to cause minima l

toxicity in the kidney following 2 years of exposure.

Although kidney effects were the main toxicologi c

consideration for exposure concentration selection i n

the 2-year study in female rats, the highest exposure 

study, concentrations selected for the 2-year mous e

study were 312, 625, and 1,250 ppm. At the time o f

selection of concentrations for the mouse study, it was

believed that female rats could tolerate exposure t o

2,500 ppm with minimal toxic effects. However, i t

was decided that an additional chamber solely fo r

female rats could not be justified economically ;

therefore, female rats were housed in the sam e

chambers as mice. In addition, because of th e

increased absolute and relative kidney weights o f

females exposed to 625 ppm or greater (even in th e

absence of histopathologic effects), it was believe d

that toxicity might occur at 625 or 1,250 ppm .

Therefore, because there was additional space in th e

mouse chambers, 1,250 ppm was selected as th e

highest exposure concentration for the 2-year study in

female rats.
38 Tetrafluoroethylene, NTP TR 450

2-YEAR STUDY

Survival

Estimates of 2-year surv ival probabilities for male and

female rats are shown in Table 6 and in the Kaplan -

Meier survival curves (Figure 1). The survival rates of

males in the 625 ppm g roup and of all exposed groups

of females were significantly less than those of th e

controls.

Body Weights and Clinical Findings

Mean body weights of males exposed to 625 ppm were

lower than those of the con trols from week 81 until the

end of the study; the mean body weights of male s

exposed to 156 or 312 ppm and of females exposed to

312 or 625 ppm were similar to those of 

the controls throughout the study (Figure 2 an d

Tables 7 and 8). Mean body weights of female s

exposed to 1,250 ppm were slightly lower than those

of the controls at the end of the study; the final mean

body weight of this group was 91% that of th e

controls. The only clinical finding associated wit h

exposure to tetrafluoroethylene was opacity of one or

both eyes in exposed groups of female rats; thi s

change was observed microscopically as cataracts.

Hematology, Clinical Chemistry, 

and Urinalysis

At the 15-month interim evaluation, no differences in

hematology, clinical chemistry, or urinalysis param -

eters were considered to be related to tetrafluoro -

ethylene exposure (Table G3).
Tetrafluoroethylene, NTP TR 450 39

TABLE 6

Survival of Rats in the 2-Year Inhalation Study of Tetrafluoroethylene

0 ppm 156 ppm 312 ppm 625 ppm

Male

Animals initially in study 60 60 60 60

15-Month interim evaluation 10 10 10 10 a

Moribund 27 34 32 48

Natural deaths 6 4 1 1

Animals surviving to study termination 17 12 17 1

Percent probability of survival at end of study 34 24 34 2

b

Mean survival (days) 665 644 665 609 c

Survival analyses P<0.001 P=0.216 P=0.829 P<0.001 d

0 ppm 312 ppm 625 ppm 1,250 ppm

Female

Animals initially in study 60 60 60 60

15-Month interim evaluation 10 10 10 10 a

Accidental death 0 0 0 1

a

Moribund 21 33 31 25

Natural deaths 1 1 4 6

Animals surviving to study termination 28 16 15 18 e

Percent probability of survival at end of study 56 32 30 37

Mean survival (days) 694 642 651 620

Survival analyses P=0.034 P=0.008 P=0.007 P=0.014

Censored from survival analyses a

Kaplan-Meier determinations b

Mean of all deaths (uncensored, censored, and terminal sacrifice) c

The result of the life table trend test (Tarone, 1975) is in the control column, and the results of the life table pairwise comparisons (Cox, 1972) with d

the controls are in the exposed group columns.

Includes one animal that died during the last week of the study e
40 Tetrafluoroethylene, NTP TR 450

FIGURE 1

Kaplan-Meier Survival Curves for Male and Female Rats Administered Tetrafluoroethylene

by Inhalation for 2 Years
Tetrafluoroethylene, NTP TR 450 41

FIGURE 2

Growth Curves for Male and Female Rats Administered Tetrafluoroethylene

by Inhalation for 2 Years
42 Tetrafluoroethylene, NTP TR 450

TABLE 7

Mean Body Weights and Survival of Male Rats in the 2-Year Inhalation Study of Tetrafluoroethylene

Weeks 0 ppm 156 ppm 312 ppm 625 ppm

on Av. Wt. No. of Av. Wt. Wt. (% of No. of Av. Wt. Wt. (% of No. of Av. Wt. Wt. (% of No. of

Study (g) Survivors (g) controls) Survivors (g) controls) Survivors (g) controls) Survivors

1 126 60 126 100 60 126 100 60 125 99 60

2 176 60 177 101 60 179 102 60 176 100 60

3 203 60 204 101 60 207 102 60 202 100 60

4 230 60 231 100 60 234 102 60 229 100 60

5 250 60 251 100 60 255 102 60 250 100 60

6 267 60 267 100 60 271 102 60 266 100 60

7 284 60 285 100 60 289 102 60 283 100 60

8 298 60 299 100 60 303 102 60 297 100 60

9 310 60 312 101 60 317 102 60 310 100 60

10 324 60 327 101 60 329 102 60 323 100 60

11 329 60 334 102 60 336 102 60 331 101 60

12 339 60 343 101 60 347 102 60 340 100 60

13 346 60 350 101 60 353 102 60 346 100 60

17 375 60 381 102 60 384 103 60 377 101 60

21 398 60 406 102 60 408 103 60 402 101 60

25 415 60 422 102 60 424 102 60 420 101 60

29 430 60 436 101 60 439 102 60 436 101 60

33 443 60 451 102 60 454 102 60 448 101 60

37 451 60 462 102 60 465 103 60 456 101 60

41 455 60 464 102 60 469 103 60 461 101 60

45 461 60 473 103 60 477 104 60 465 101 60

49 464 59 478 103 60 484 104 60 475 102 60

53 465 59 478 103 59 485 104 60 472 101 59

57 476 58 485 102 59 492 103 60 479 101 59

61 483 58 489 101 59 497 103 59 480 99 59

65 482 48 489 102 48 499 104 49 477 99 49 a

69 486 48 492 101 47 504 104 49 484 100 47

73 481 47 490 102 45 501 104 49 472 98 47

77 484 45 488 101 43 496 102 49 468 97 42

81 482 43 485 101 41 493 102 45 447 93 39

85 483 41 490 101 38 495 103 42 433 90 33

89 477 39 485 102 30 479 100 36 423 89 22

91 479 36 485 101 29 481 101 31 419 88 17

93 476 35 477 100 29 478 101 30 409 86 14

95 471 34 479 102 26 475 101 28 399 85 11

97 463 31 473 102 24 469 101 23 390 84 9

99 456 27 462 102 21 464 102 21 389 85 6

101 448 24 449 100 17 462 103 20 372 83 4

103 454 19 452 99 13 450 99 20 359 79 3

Mean for weeks

1-13 268 270 101 273 102 268 100

14-52 432 441 102 445 103 438 101

53-103 473 479 101 484 102 434 92

Interim evaluation occurred during week 65. a
Tetrafluoroethylene, NTP TR 450 43

TABLE 8

Mean Body Weights and Survival of Female Rats in the 2-Year Inhalation Study of Tetrafluoroethylene

Weeks 0 ppm 312 ppm 625 ppm 1,250 ppm

on Av. Wt. No. of Av. Wt. Wt. (% of No. of Av. Wt. Wt. (% of No. of Av. Wt. Wt. (% of No. of

Study (g) Survivors (g) controls) Survivors (g) controls) Survivors (g) controls) Survivors

1 102 60 102 100 60 102 100 60 101 99 60

2 121 60 121 100 60 121 101 60 119 99 59

3 132 60 132 100 60 133 101 60 130 99 59

4 143 60 144 100 60 143 100 60 140 98 59

5 151 60 151 101 60 152 101 60 149 99 59

6 159 60 161 101 60 161 101 60 158 99 59

7 163 60 165 101 60 166 102 60 163 100 59

8 171 60 173 101 60 174 101 60 170 100 59

9 174 60 175 101 60 178 102 60 176 101 59

10 178 60 179 101 60 183 103 60 179 101 59

11 183 60 184 101 60 188 103 60 185 101 59

12 186 60 189 102 60 192 103 60 190 102 59

13 189 60 192 102 60 195 103 60 193 102 59

17 201 60 203 101 60 207 103 60 203 101 59

21 209 60 214 102 60 218 104 60 213 102 59

25 220 60 222 101 60 229 104 60 223 101 59

29 229 60 232 101 60 238 104 60 232 101 59

33 236 60 239 101 60 248 105 60 238 101 59

37 245 60 245 100 59 253 104 60 243 99 59

41 252 60 255 101 59 265 105 60 251 100 59

45 262 60 266 102 59 279 106 60 262 100 59

49 263 60 270 103 59 282 107 60 262 100 59

53 281 60 287 102 59 300 107 59 279 100 59

57 290 60 298 103 59 307 106 58 291 100 57

61 302 60 305 101 58 315 104 58 297 98 57

65 301 59 309 103 58 318 106 58 300 100 55 a

69 307 48 315 103 46 318 104 45 303 99 43

73 302 47 310 103 46 316 105 44 296 98 42

77 314 47 320 102 44 329 105 42 305 97 39

81 319 46 322 101 40 328 103 41 306 96 38

85 331 45 330 100 35 335 101 37 313 95 34

89 330 44 333 101 29 333 101 34 309 94 28

91 333 43 333 100 28 333 100 33 313 94 25

93 330 41 333 101 26 326 99 33 310 94 24

95 333 40 336 101 25 330 99 31 308 93 23

97 332 39 337 101 24 339 102 25 312 94 21

99 325 38 339 104 23 339 104 24 312 96 20

101 336 33 334 100 21 344 102 20 311 93 19

103 333 30 323 97 20 340 102 19 304 91 19

Mean for weeks

1-13 158 159 101 161 102 158 100

14-52 235 238 101 247 105 236 100

53-103 318 321 101 326 103 304 96

Interim evaluation occurred during week 65. a
44 Tetrafluoroethylene, NTP TR 450

Pathology and Statistical Analyses

This section describes the statistically significant o r

biologically noteworthy changes in the incidences o f

mononuclear cell leukemia and of neoplasms and/o r

nonneoplastic lesions of the kidney, liver, eye, testis ,

and mammary gland. Summaries of the incidences of

neoplasms and nonneoplastic lesions, individua l

animal tumor diagnoses, statistical analyses of primary

neoplasms that occurred with an incidence of at leas t

5% in at least one animal group, and historica l

incidences for the neoplasms mentioned in this section

are presented in Appendix A for male rats an d

Appendix B for female rats.

Absolute and relative lung weights of exposed groups

of rats were similar to those of the controls at th e

15-month interim evaluation (Table F3), and no lung

lesions related to tetrafluoroethylene exposur e

occurred.

Kidney: At the 15-month interim evaluation, th e

absolute and relative right kidney weights of male s

exposed to 625 ppm and females exposed t o

1,250 ppm were significantly greater than those of the

controls (Table F3). Additionally, the absolute kidney

weight of females exposed t o 625 ppm and the relative

kidney weight of males exposed to 312 ppm wer e

significantly greater than those of the controls.

At 15 months, renal tubule hyperplasia was observed

in one male exposed to 312 ppm and in one mal e

exposed to 625 ppm. At the end of the study, th e

incidences of renal tubule hyperplasia in male s

exposed to 625 ppm and of renal tubule adenoma i n

males exposed to 312 ppm were significantly greate r

than those in the controls (Tables 9, A3, and A5). The

combined incidence of renal tubule adenoma o r

carcinoma in males exposed to 312 or 625 pp m

exceeded the range in historical controls from 2-yea r

NTP inhalation studies (Tables 9 and A4a).

At 15 months, renal tubule hyperplasia was observed

in one female exposed to 625 ppm. At the end of the

study, the incidence of renal tubule hyperplasia in 

females in the 1,250 ppm group was significantl y

greater than that in the controls (Tables 9 and B5); the

incidences of renal tubule adenoma and renal tubul e

adenoma or carcinoma (combined) in females exposed

to 1,250 ppm were also greater than those in th e

controls (Tables 9 and B3), and the incidence s

occurred with significant trends. The incidences o f

renal tubule adenoma or carcinoma (combined) i n

females exposed to 312 or 1,250 ppm exceeded th e

range in historical controls (Tables 9 and A4a).

Initially, a single hematoxylin- and eosin-staine d

section of each kidney was prepared. Primaril y

because of the increased incidences of renal tubul e

hyperplasia, adenomas, and carcinomas that wer e

observed in some groups in the standard evaluation of

the 2-year studies, additional step sections of kidne y

were prepared from the remaining formalin-fixe d

tissues of interim evaluation an d 2-year study rats. Six

to ten additional kidney sections taken at 1-m m

intervals were prepared for each male and female .

Additional males and females with focal hyperplasia or

adenomas and one 156 ppm male with a carcinom a

were identified among rats exposed for 2 years. Th e

incidences of these proliferative le sions in standard and

extended evaluations are presented in Table 9.

At the 2-year extended evaluations and combine d

standard and extended evaluations, males in th e

625 ppm group and females in the 1,250 ppm grou p

had significantly greater incidences of renal tubul e

hyperplasia, renal tubule adenoma, and renal tubul e

adenoma or carcinoma (combined) than the control s

(Tables 9 and A3). In the combined standard an d

extended evaluations, the incidences of renal tubul e

hyperplasia in females exposed to 625 ppm and renal

tubule adenoma in males exposed to 312 ppm wer e

also significantly greater than those in the controls .

The incidences renal tubul e adenoma in females and of

renal tubule adenoma or carcinoma (combined) i n

males and females occurred with significant positiv e

trends in the extended and combined standard an d

extended evaluations.
Tetrafluoroethylene, NTP TR 450 45

TABLE 9

Incidences of Neoplasms and Nonneoplastic Lesions of the Kidney in Rats in the 2-Year Inhalation Study

of Tetrafluoroethylene

0 ppm 156 ppm 312 ppm 625 ppm

Male

15-Month Interim Evaluation

Number Examined Microscopically 10 10 10 10

Single Sections (Standard Evaluation)

Nephropathy 10 (1.8) 10 (1.8) 10 (1.6) 10 (2.4) a b

Renal Tubule, Degeneration 1 (1.0) 8** (1.0) 10** (2.0) 10** (3.0)

Renal Tubule, Hyperplasia 0 0 1 (1.0) 1 (1.0)

Renal Tubule, Carcinoma 0 0 0 1

Step Sections (Extended Evaluation)

Renal Tubule, Hyperplasia 0 0 1 (1.0) 0

2-Year Study

Number Examined Microscopically 50 50 50 50

Single Sections (Standard Evaluation)

Nephropathy 49 (2.3) 50 (1.9) 50 (2.7) 50 (3.5)

Renal Tubule, Degeneration 2 (1.0) 20** (1.1) 50** (2.3) 49** (3.6)

Renal Tubule, Hyperplasia 1 (1.0) 1 (1.0) 1 (4.0) 6* (1.3)

Renal Tubule, Hyperplasia, Oncocytic 0 0 1 (1.0) 0

Renal Tubule, Adenoma 0 0 6* 3

Renal Tubule, Carcinoma 1 0 2 0

Renal Tubule, Adenoma or Carcinoma 1 0 6 3

c

Step Sections (Extended Evaluation)

Renal Tubule, Hyperplasia 7 10 7 18**

Renal Tubule, Adenoma 2 4 3 11**

Renal Tubule, Carcinoma 0 1 0 0

Renal Tubule, Adenoma or Carcinoma 2 5 3 11**

Single and Step Sections (Combined)

Renal Tubule, Hyperplasia 7 11 7 24**

Renal Tubule, Adenoma 2 4 9* 13**

Renal Tubule, Carcinoma 1 1 2 0

Renal Tubule, Adenoma or Carcinoma 3 5 9 13**

(continued)
46 Tetrafluoroethylene, NTP TR 450

TABLE 9

Incidences of Neoplasms and Nonneoplastic Lesions of the Kidney in Rats in the 2-Year Inhalation Study

of Tetrafluoroethylene (continued)

0 ppm 312 ppm 625 ppm 1,250 ppm

Female

15-Month Interim Evaluation

Number Examined Microscopically 10 10 10 10

Single Sections (Standard Evaluation)

Nephropathy 8 (1.0) 9 (1.0) 9 (1.2) 10 (1.0)

Renal Tubule, Degeneration 0 0 10** (2.0) 10** (2.6)

Renal Tubule, Hyperplasia 0 0 1 (1.0) 0

Renal Tubule, Hyperplasia, Oncocytic 0 0 0 1 (1.0)

Renal Tubule, Adenoma 0 0 0 1

Mixed Tumor, Malignant 0 0 0 1

Step Sections (Extended Evaluation)

Renal Tubule, Hyperplasia 0 1 0 4*

Renal Tubule, Adenoma 0 0 0 2

2-Year Study

Number Examined Microscopically 50 50 50 50

Single Sections (Standard Evaluation)

Nephropathy 48 (1.7) 46 (1.5) 48 (1.7) 47 (2.0)

Renal Tubule, Degeneration 0 0 35** (1.3) 46** (2.0)

Renal Tubule, Hyperplasia 1 (2.0) 3 (1.7) 6 (1.2) 12** (1.8)

Renal Tubule, Hyperplasia, Oncocytic 0 0 0 3 (1.0)

Renal Tubule, Adenoma 0 3 1 3

Renal Tubule, Carcinoma 0 0 0 2

Renal Tubule, Adenoma or Carcinoma 0 3 1 5** d

Step Sections (Extended Evaluation)

Renal Tubule, Hyperplasia 2 3 7 17**

Renal Tubule, Adenoma 0 0 2 5*

Renal Tubule, Carcinoma 0 0 0 1

Renal Tubule, Adenoma or Carcinoma 0 0 2 5*

Single Sections and Step Sections (Combined)

Renal Tubule, Hyperplasia 3 6 11* 25**

Renal Tubule, Adenoma 0 3 3 8**

Renal Tubule, Carcinoma 0 0 0 3

Renal Tubule, Adenoma or Carcinoma 0 3 3 10**

* Significantly different (P 0.05) from the control group by the Fisher exact test (15-month interim evaluation) or the logistic regression test (2-year

study)

** P 0.01

Number of animals with lesion a

Average severity grade of lesion in affected animals: 1=minimal; 2=mild; 3=moderate; 4=marked b

Historical incidence for 2-year NTP inhalation studies with chamber control groups at all labs (mean ± standard deviation): 6/652 (0.9% ± 1.3%); c

range, 0%-4%. Historical incidence for 2-year NTP inhalation studies with chamber control groups at Battelle Pacific Northwest Laboratories: 

5/347 (1.4% ± 1.5%); range, 0%-4%

Historical incidence at all labs: 2/650 (0.3% ± 0.8%); range, 0%-2%. Historical incidence at Battelle Pacific Northwest Laboratories: 2/346 d

(0.6% ± 1.0%); range, 0%-2%
Tetrafluoroethylene, NTP TR 450 47

Renal tubule hyperplasia, as defined in the presen t cuboidal epithelium (Plate 6) and often had bot h

study, was distinguished from regenerative epithelia l basophilic and eosinophilic cells lining adjacent areas

changes commonly seen as a part of nephropathy and of the same tubule. At 15 months, renal tubul e

was considered a preneoplastic lesion. Renal tubul e degeneration was easily detected; however, in th e

hyperplasia, adenoma, and carcinoma constitute a 2-year study, it was sometimes obscured by th e

morphologic continuum. Hyperplasia was generally a presence of concurrent nephropathy. The location o f

focal, minimal to mild lesion consisting of tubules that the renal tubule degeneration at the corticomedullar y

were dilated to 1.5 to 2 times the normal diameter and junction was the primary feature which distinguishe d

were lined by increased numbers of tubule epithelia l this lesion from chronic progressive nephropathy .

cells, which partially or totally filled the tubule lumen Also lacking in tetrafluoroethylene-induced rena l

(Plate 1). Cells within hyperplastic lesions varie d tubule degeneration, but present in chronic progressive

slightly in size and sometimes stained more basophilic nephropathy, were thickened basement membranes ,

than normal cells, but otherwise appeared similar t o interstitial fibrosis, inflammatory infiltrates, an d

normal tubule epithelial cells. Renal tubule adenomas prominent protein casts in dilated tubules throughout

were larger, discrete lesions, ranging from greater than the cortex and medulla.

five tubule diameters to 1 mm or mor e in size (Plate 2).

Cells within adenomas were mildly to moderatel y The severity of nephropathy generally increased wit h

pleomorphic, sometimes had vacuolated cytoplasm , increasing exposure concentration in male and female

and tended to form complex patterns, particularl y rats at 15 months and 2 years, although the increase in

microtubular structures. Renal tu bule carcinomas were exposed female rats was not as pronounced. Thes e

differentiated from adenomas in that they usually were increases were observed at the end of the 2-year study

larger and less discrete and had a more prominen t in males exposed to 312 or 625 ppm and in female s

vascular supply and more anaplasia and cellular atypia exposed to 1,250 ppm.

(Plate 3). Renal tubule cell carcinoma was characterized by vesiculate nuclei with prominent nucleoli and Liver: The absolute and relative liver weights o f

increased numbers of mitotic figures (Plate 4). females in the 1,250 ppm group and the absolute liver

weight of females exposed to 625 ppm wer e

Oncocytic hyperplasia was observed at the end of the

study in one male exposed to 312 ppm and in thre e

females exposed to 1,250 ppm (Tab les 9, A5, and B5).

This lesion was characterized by individual tubules or

small clusters of tubules that were somewhat dilate d

and totally filled by large polygonal cells wit h

abundant brightly eosin ophilic granular cytoplasm and

small, centrally located, basophilic nuclei (oncocytes).

These lesions are thought to arise from the dista l

tubule epithelium.

At 15 months and at the end of the study, the inci -

dences of renal tubule degeneration in all expose d

groups of males and in females in the 625 an d

1,250 ppm groups were greater than those in th e

controls (Tables 9, A5, and B5). Renal tubul e

degeneration was similar to that observed in th e

13-week study. Degeneration was characterized b y

dilatation of renal tubule epithelial cells and wa s

located predominantly at the corticomedullary junction

(Plates 5 and 6). Dilated tubules sometimes contained

eosinophilic debris and/or proteinaceous fluid in their

lumens. The tubules were lined by flattened t o

significantly greater than those of the controls at th e

15-month interim evaluation (Table F3). A t

15 months, all exposed groups of males had signifi -

cantly greater incidences of clear cell foci than th e

controls; females exposed to 625 or 1,250 ppm ha d

significantly greater incidences of mixed cell foci than

the controls (Tables 10, A5, and B5). At the end o f

the study, the incidences of eosinophilic foci in al l

exposed groups of males and of mixed cell foci an d

basophilic foci in males exposed to 312 or 625 pp m

were significantly greater than those in the controls, as

was the incidence of mixed cell foci in female s

exposed to 1,250 ppm. The incidences of hepatocel -

lular carcinoma and hepatocellular adenoma o r

carcinoma (combined) in males exposed to 312 pp m

were significantly greater than those in the controls at

the end of the study (Tables 10 and A3). At 2 years,

the incidences of hepatocell ular adenoma and adenoma

or carcinoma (combined) in all exposed groups o f

females were significantly greater than those in th e

controls, and the incidences occurred with significant

positive trends (Tables 10 and B3). Additionally ,

females exposed to 312 or 625 ppm had significantly
48 Tetrafluoroethylene, NTP TR 450

greater incidences of hepatoc ellular carcinoma than the discrete aggregates of often enlarged hepatocytes, and

controls at 2 years. The combined incidence o f the lobular pattern of the liver was generally retained.

hepatocellular neoplasms in each exposed group o f Hepatocellular adenomas consisted of nodules o f

males and females exceeded the historical contro l hepatocytes which compressed adjacent hepati c

ranges in chamber controls from 2-year NT P parenchyma and lacked the normal lobular an d

inhalation studies (Tables 10, A4b, and B4b). Also at sinusoidal pattern (Plate 7). Hepatocellula r

2 years, the incidence of hemangiosarcoma in females carcinomas consisted of solid sheets of hepatocytes or

exposed to 625 ppm was significantly greater than in trabeculae, three or more cells thick (Plate 8) .

the controls. The incidence of liver hemangiosarcoma Neoplastic hepatocytes were anaplastic, with promi -

in 625 ppm females exceeded the historical range for nent nuclei containing one or more nucleoli an d

hemangiosarcomas in all organs in control female rats variable amounts of cytoplasm. Hemangiosarcoma s

from NTP 2-year inhalation studies (Table 10), an d were malignant vascular neoplasms characterized b y

liver hemangiosarcomas have not been observed i n irregular, vascular spaces filled with erythrocyte s

historical control females. (Plate 9) and lined by variable numb ers of pleomorphic

Hepatocellular foci are considered potential preneo -

plastic lesions. Hepatocellular foci were relatively 

endothelial 

TABLE 10

Incidences of Neoplasms and Nonneoplastic Lesions of the Liver in Rats in the 2-Year Inhalation Study

of Tetrafluoroethylene

0 ppm 156 ppm 312 ppm 625 ppm

Male

15-Month Interim Evaluation

Number Examined Microscopically 10 10 10 10

Basophilic Focus 6 4 7 4

a

Clear Cell Focus 4 10** 9* 10**

Cystic Degeneration 0 1 3 0

Eosinophilic Focus 1 0 0 1

Mixed Cell Focus 0 2 2 2

Hepatocellular Adenoma 0 0 1 0

Hepatocellular Carcinoma 0 0 0 1

2-Year Study

Number Examined Microscopically 50 50 50 50

Basophilic Focus 22 19 33* 29**

Clear Cell Focus 7 8 11 3

Eosinophilic Focus 3 18** 22** 19**

Cystic Degeneration 17 39** 35** 32**

Mixed Cell Focus 5 5 16** 13**

Hepatocellular Adenoma 3 6 8 5

Hepatocellular Carcinoma 1 1 10** 3

Hepatocellular Adenoma or Carcinomab

Overall rate 4/50 (8%) 7/50 (14%) 15/50 (30%) 8/50 (16%) c

Adjusted rate 16.3% 34.4% 62.1% 100.0% d

Terminal rate 2/17 (12%) 3/12 (25%) 9/17 (53%) 1/1 (100%) e

First incidence (days) 624 600 617 572

Logistic regression test P=0.025 P=0.223 P=0.003 P=0.112 f

(continued)
Tetrafluoroethylene, NTP TR 450 49

TABLE 10

Incidences of Neoplasms and Nonneoplastic Lesions of the Liver in Rats in the 2-Year Inhalation Study

of Tetrafluoroethylene (continued)

0 ppm 312 ppm 625 ppm 1,250 ppm

Female

15-Month Interim Evaluation

Number Examined Microscopically 10 10 10 10

Angiectasis 0 1 0 0

Basophilic Focus 9 9 10 10

Clear Cell Focus 0 2 3 3

Eosinophilic Focus 0 5* 2 0

Mixed Cell Focus 0 1 6** 4*

2-Year Study

Number Examined Microscopically 50 50 50 50

Angiectasis 0 9** 9** 14**

Basophilic Focus 41 38 41 37

Clear Cell Focus 10 3 12 9

Eosinophilic Focus 1 4 5* 4

Mixed Cell Focus 12 14 16 18*

Hepatocellular Adenoma 0 4* 5** 6**

Hepatocellular Carcinoma 0 4* 9** 2

Hepatocellular Adenoma or Carcinomag

Overall rate 0/50 (0%) 7/50 (14%) 12/50 (24%) 8/50 (16%)

Adjusted rate 0.0% 36.3% 65.4% 37.8%

Terminal rate 0/28 (0%) 5/16 (31%) 9/15 (60%) 5/18 (28%)

First incidence (days) — 583 668 677 h

Logistic regression test P=0.001 P=0.002 P<0.001 P<0.001

Hemangiosarcomai

Overall rate 0/50 (0%) 0/50 (0%) 5/50 (10%) 1/50 (2%)

Adjusted rate 0.0% 0.0% 19.5% 5.0%

Terminal rate 0/28 (0%) 0/16 (0%) 0/15 (0%) 0/18 (0%)

First incidence (days) — — 589 703

Logistic regression test P=0.182 — P=0.025 P=0.435

* Significantly different (P 0.05) from the control group by the Fisher exact test (15-month interim evaluation) or the logistic regression test (2-year

study)

** P 0.01

Number of animals with lesion a

Historical incidence for 2-year NTP inhalation studies with chamber control groups at all labs (mean ± standard deviation): 28/653 b

(4.3% ± 2.9%); range, 2%-9%. Historical incidence for 2-year NTP inhalation studies with chamber control groups at Battelle Pacific Northwest

Laboratories: 11/347 (3.2% ± 2.3%); range, 2%-8%

Number of animals with neoplasm per number of animals with liver examined microscopically c

Kaplan-Meier estimated neoplasm incidence at the end of the study after adjustment for intercurrent mortality d

Observed incidence in animals surviving until the end of the study e

In the control column are the P values associated with the trend test. In the exposed group columns are the P values corresponding to pairwise f

comparisons between the controls and that exposed group. The logistic regression test regards neoplasms in animals dying prior to terminal kill as

nonfatal.

Historical incidence at all labs: 10/650 (1.5% ± 2.0%); range, 0%-6%. Historical incidence at Battelle Pacific Northwest Laboratories: 7/346 g

(2.0% ± 2.3%); range, 0%-6%

Not applicable; no neoplasms in animal group h

Historical incidence for all organs at all labs: 2/653 (0.3% ± 0.8%); range, 0%-2% (incidence in liver: 0/650) i
50 Tetrafluoroethylene, NTP TR 450

cells. Occasionally, hemangiosarcomas metastasized to end of the 2-year study (0 ppm, 15/50; 312 ppm, 4/50;

the lung. 625 ppm, 10/50; 1,250 ppm, 45/50; Table B5).

At the end of the 2-year study, increased incidences of normal organization of lens filters, with swelling,

hepatic cystic degeneration occurred in all exposed vacuolization, and mineralization.

groups of males, and increased incidences of hepatic

angiectasis were observed in exposed groups of females

(Tables 10, A5, and B5). Cystic degeneration was

characterized by multifocal dilated areas with cysts

containing fluid, fibrin, and/or erythrocytes; these lesions

occur spontaneously in aging rats at low incidences but

are common following chemical exposure to a

hepatocarcinogen. Hepatic angiectasis was characterized

by multifocal, dilated, blood-filled sinusoids with

prominent lining endothelial cells; these lesions are

sometimes associated with hepatocellular neoplasms.

Mononuclear Cell Leukemia: Incidences of mononuclear cell leukemia in males exposed to 156 ppm and

in all exposed groups of females were significantly

greater than those in the controls (Tables 11, A3, and

B3), and the incidences occurred with significant positive

trends in males and females. The incidence of this

neoplasm in male controls exceeded the historical range Mammary Gland: At 2 years, the incidences of

for all types of leukemia in 2-year NTP inhalation studies fibroadenoma in the mammary gland of exposed female

(Tables 11 and A4c), as did the incidences in males rats were decreased (22/50, 11/50, 9/50, 7/50;

exposed to 156 or 312 ppm. However, the incidence in Table B3). Fibroadenomas are the most common benign

females exposed to 0 ppm was within the historical neoplasm of the mammary gland in the female F344/N

control range (Tables 11 and B4c), and the incidences in rat. In other studies, decreases in the incidence of this

females exposed to 312 or 1,250 ppm exceeded that neoplasm have been associated with decreases in body

range. weights; however, in the present study, the decreases are

Eye: The incidence of cataracts in females exposed to significance of these decreased incidences is uncertain.

1,250 ppm was greater than that in the controls at the 

Cataracts were characterized by a disruption of the

Testis: At the end of the study, there was a slight

increase in the incidences of interstitial cell adenoma in

rats exposed to 312 or 625 ppm (39/50, 40/50, 48/50,

47/50; Table A3). At 15 months, there were no increases

in the incidences of interstitial cell hyperplasia or

adenoma. Interstitial cell hyperplasia and adenomas are

very common in F344/N rats, and nearly all rats will

develop such proliferative lesions if allowed to complete

their natural life span. It is uncertain whether the slightly

increased incidences of interstitial cell adenoma were

related to tetrafluoroethylene exposure, although the

control incidence is within the historical control range for

2-year NTP inhalation studies with chamber controls

(450/655; mean ± standard deviation, 68.7% ± 8.7%;

range, 54%-83%).

not related to body weight changes. The biological
Tetrafluoroethylene, NTP TR 450 51

TABLE 11

Incidences of Mononuclear Cell Leukemia in Rats in the 2-Year Inhalation Study of Tetrafluoroethylene

0 ppm 156 ppm 312 ppm 625 ppm

Male

Mononuclear Cell Leukemia (All Organs)a

Overall rate 34/50 (68%) 43/50 (86%) 38/50 (76%) 31/50 (62%) b

Adjusted rate 81.5% 95.3% 91.9% 100.0% c

Terminal rate 10/17 (59%) 10/12 (83%) 14/17 (82%) 1/1 (100%) d

First incidence (days) 509 351 413 509

Life table test P<0.001 P=0.016 P=0.231 P<0.001 e

Logistic regression test P=0.064N P=0.020 P=0.254 P=0.079N e

0 ppm 312 ppm 625 ppm 1,250 ppm

Female

Mononuclear Cell Leukemia (All Organs)f

Overall rate 16/50 (32%) 31/50 (62%) 23/50 (46%) 36/50 (72%)

Adjusted rate 43.7% 76.5% 65.1% 82.6%

Terminal rate 8/28 (29%) 7/16 (44%) 6/15 (40%) 11/18 (61%)

First incidence (days) 621 468 469 372

Life table test P<0.001 P<0.001 P=0.008 P<0.001

Logistic regression test P<0.001 P<0.001 P=0.105 P<0.001

Historical incidence for 2-year NTP inhalation studies with chamber control groups at all labs (mean ± standard deviation): 356/655 a

(54.4% ± 8.8%); range, 34%-66%. Historical incidence for 2-year NTP inhalation studies with chamber control groups at Battelle Pacific

Northwest Laboratories: 195/348 (56.0% ± 8.7%); range, 38%-66%

Number of animals with neoplasm per number of animals necropsied b

Kaplan-Meier estimated neoplasm incidence at the end of the study after adjustment for intercurrent mortality c

Observed incidence in animals surviving until the end of the study d

In the control column are the P values associated with the trend test. In the exposed group columns are the P values corresponding to pairwise e

comparisons between the controls and that exposed group. The life table test regards neoplasms in animals dying prior to terminal kill as being

(directly or indirectly) the cause of death. The logistic regression test regards these neoplasms as nonfatal. A negative trend or a lower incidence in

an exposure group is indicated by N.

Historical incidence at all labs: 262/653 (40.1% ± 7.2%); range, 30%-54%. Historical incidence at Battelle Pacific Northwest Laboratories: f

146/348 (42.0% ± 7.2%); range, 30%-54%
52 Tetrafluoroethylene, NTP TR 450

MICE

16-DAY STUDY

All mice survived to the end of the study (Table 12) .

Final mean body weights and body weight gains of all

exposed groups of mice were similar to those of th e

controls. There were no exposure-related clinica l

findings in male or female mice.

There were no significant differences in hematolog y

parameters that were considered to be related t o

tetrafluoroethylene exposure (Tabl e G4). The absolute

and relative liver weights of females exposed t o

5,000 ppm were significantly greater than those of the

controls, as were the absolute ki dney weight of females

in that group and the absolute liver weight of females

in the 2,500 ppm group (Table F4). Other differences

in organ weights were not considered to be related t o

chemical exposure.

Renal tubule karyomegaly was observed in male mice

exposed to 1,250 or greater, in females in the 2,50 0

and 5,000 ppm groups, and in one female exposed to

1,250 ppm; the severity of this lesion increased wit h

increasing exposure concentration (Table 13). Karyomegaly of renal tubule cells was observed primarily in

the inner renal cortex and was characterized by nuclei

that were enlarged, pleomorphic, an d vesicular and that

had prominent nucleoli. In the areas with karyo -

megaly, individual tubule epithelial cells had pyknotic

nuclei consistent with minimal to mild scattere d

necrosis.

Exposure Concentration Selection Rationale: Based on

the lack of overt toxicity foll owing exposure of mice to

5,000 ppm for 16 days, exposure concentration s

selected for the 13-week study were 0, 312, 625 ,

1,250, 2,500, and 5,000 ppm.

TABLE 12

Survival and Body Weights of Mice in the 16-Day Inhalation Study of Tetrafluoroethylene

Exposure Mean Body Weight (g) Final Weight b

Concentration Survival Initial Final Change Relative to Controls a

(ppm) (%)

Male

0 5/5 22.4 ± 0.3 25.3 ± 0.2 3.0 ± 0.3

312 5/5 22.6 ± 0.7 25.5 ± 0.7 2.9 ± 0.3 101

625 5/5 22.2 ± 0.5 24.8 ± 0.6 2.6 ± 0.4 98

1,250 5/5 21.5 ± 0.7 24.8 ± 1.2 3.4 ± 0.6 98

2,500 5/5 21.8 ± 0.7 25.7 ± 0.5 3.9 ± 0.2 102

5,000 5/5 21.8 ± 1.0 25.2 ± 1.0 3.4 ± 0.3 100

Female

0 5/5 18.8 ± 0.7 20.8 ± 0.6 2.0 ± 0.6

312 5/5 18.8 ± 1.2 20.8 ± 1.1 2.0 ± 0.3 100

625 5/5 18.8 ± 0.3 20.9 ± 0.3 2.1 ± 0.1 101

1,250 5/5 18.2 ± 1.0 21.0 ± 0.8 2.7 ± 0.5 101

2,500 5/5 18.9 ± 0.6 21.5 ± 0.7 2.6 ± 0.5 104

5,000 5/5 18.2 ± 0.4 21.3 ± 0.6 3.1 ± 0.5 103

Number of animals surviving at 16 days/number initially in group a

Weights and weight changes are given as mean ± standard error. Differences from the control group were not significant by Williams' or Dunnett's b

test.
Tetrafluoroethylene, NTP TR 450 53

TABLE 13

Incidences of Kidney Lesions in Mice in the 16-Day Inhalation Study of Tetrafluoroethylene

0 ppm 312 ppm 625 ppm 1,250 ppm 2,500 ppm 5,000 ppm

Male

Number Examined Microscopically 5 5 5 5 5 5

Renal Tubule, Karyomegaly 0 0 0 5** (1.0) 5** (1.2) 5** (2.4) a b

Female

Number Examined Microscopically 5 5 5 5 5 5

Renal Tubule, Karyomegaly 0 0 0 1 (1.0) 5** (2.0) 5** (3.0)

** Significantly different (P 0.01) from the control group by the Fisher exact test

Number of animals with lesion a

Average severity grade of lesions in affected mice: 1=minimal; 2=mild; 3=moderate; 4=marked b
54 Tetrafluoroethylene, NTP TR 450

13-WEEK STUDY

All mice survived to the end of the study (Table 14) .

Males in the 1,250, 2,500, and 5,000 ppm groups had

significantly lower initial mean body weights than the

controls; however, final mean body weights and body

weight gains of all exposed groups of male and female

mice were generally similar to those of the controls .

There were no clinical findings that were considere d

related to tetrafluoroethylene exposure.

The hematology and urinalysis data for mice in th e

13-week inhalation study of tetrafluoroethylene ar e

presented in Table G5. A normocytic, normochromic,

nonresponsive anemia, similar to that observed in the

13-week rat study, occurred in males exposed t o

2,500 ppm and in male s and females in the 5,000 ppm

groups. The anemia was evidenced by minima l

decreases of hematocrit values, hemoglobi n

concentrations, and erythrocyte counts. There were 

no alterations of mean cell volume or mean cel l

hemoglobin concentration; thus, the erythrocytes were

normocytic and normochromic. The lack of a bon e

marrow response was evidenced by the absence of an

increase in reticulocyte counts.

A concentration-dependent polyuria, evidenced b y

increased 16-hour urine vo lumes, occurred in male and

female mice exposed to 2,500 or 5,000 ppm. Th e

increased urine volumes were accompanied b y

decreased urine specific gravity values; these findings

are consistent with increased water consumption o r

lack of urine concentrating ab ility of the kidney. There

was a concentration-dependent increase of urinar y

fluoride excretion in all exposed groups of male an d

female mice, consistent wi th metabolism and excretion

of tetrafluoroethylene. No biologically significan t

differences in organ weights were observed.

TABLE 14

Survival and Body Weights of Mice in the 13-Week Inhalation Study of Tetrafluoroethylene

Exposure Mean Body Weight (g) Final Weight b

Concentration Survival Initial Final Change Relative to Controls a

(ppm) (%)

Male

0 10/10 25.5 ± 0.3 33.6 ± 0.6 8.2 ± 0.5

312 10/10 24.9 ± 0.3 32.4 ± 0.3 7.4 ± 0.3 96

625 10/10 25.0 ± 0.4 33.6 ± 0.7 8.6 ± 0.5 100

1,250 10/10 24.0 ± 0.2** 33.3 ± 0.6 9.3 ± 0.4 99

2,500 10/10 24.8 ± 0.2** 32.6 ± 0.3 7.9 ± 0.4 97

5,000 10/10 24.0 ± 0.2** 31.6 ± 0.5* 7.6 ± 0.4 94

Female

0 10/10 20.2 ± 0.3 28.8 ± 0.8 8.7 ± 0.7

312 10/10 20.0 ± 0.2 28.5 ± 0.7 8.4 ± 0.6 99

625 10/10 20.1 ± 0.4 27.8 ± 0.9 7.7 ± 0.8 96

1,250 10/10 19.7 ± 0.1 27.5 ± 0.6 7.8 ± 0.6 95

2,500 10/10 19.9 ± 0.2 27.8 ± 0.7 7.9 ± 0.6 96

5,000 10/10 19.9 ± 0.1 26.3 ± 0.4 6.4 ± 0.4 91

* Significantly different (P 0.05) from the control group by Williams’ or Dunnett’s test

** P 0.01

Number of animals surviving at 13 weeks/number initially in group a

Weights and weight changes are given as mean ± standard error. b
Tetrafluoroethylene, NTP TR 450 55

Differences in sperm morphology parameters an d tubule epithelial cells. The severity of the kidne y

estrous cycle length were not considered to be related lesions was slightly more pronounced in males than in

to chemical administration (Tables H3 and H4). females.

Incidences of karyomegaly of the renal tubule epithe- ExposureConcentration Selection Rationale: Based on

lial cells in male and female mice exposed t o the incidence and severity of kidney lesions in mal e

1,250 ppm or greater were significantly greater tha n and female mice exposed to 2,500 or 5,000 pp m

those in the controls (Table 15). As in the 16-da y tetrafluoroethylene, the absence of kidney lesions i n

study, the renal changes were observed primarily in the mice exposed to 625 ppm, and the absence of kidney

inner renal cortex. Karyomegaly was characterized by weight effects in exposed groups of mice, exposur e

nuclei that were enlarged, pleomorphic, and vesicular concentrations selected for the 2-year mouse stud y

and had large, hyperchromatic, prominent nucleoli. In were 312, 625, and 1,250 ppm. The highes t

areas of karyomegaly, there was minimal cytomegaly concentration (1,250 ppm) was expected to caus e

and scattered necrosis of individual minimal toxicity in the 2-year study.

TABLE 15

Incidences of Nonneoplastic Lesions of the Kidney in Mice in the 13-Week Inhalation Study

of Tetrafluoroethylene

0 ppm 312 ppm 625 ppm 1,250 ppm 2,500 ppm 5,000 ppm

Male

Number Examined Microscopically 10 10 10 10 10 10

Karyomegaly 0 0 0 10** (2.8) 10** (2.8) 10** (3.0) a b

Female

Number Examined Microscopically 10 10 10 10 10 10

Karyomegaly 0 0 0 10** (1.8) 10** (2.8) 10** (2.2)

** Significantly different (P 0.01) from the control group by the Fisher exact test

Number of animals with lesion a

Average severity grade of lesions in affected mice: 1=minimal; 2=mild; 3=moderate; 4=marked b
56 Tetrafluoroethylene, NTP TR 450

2-YEAR STUDY

Survival

Estimates of 2-year surv ival probabilities for male and

female mice are shown in Table 16 and in the KaplanMeier survival curves (Figure 3). The survival rates of

all exposed groups of males and females wer e

significantly less than those of the controls. Because

of the reduced survival, the study was terminate d

during week 96.

Body Weights and Clinical Findings

Mean body weights of exposed groups were generally

similar to those of the controls except at the end of the

study, when they were somewhat lower; however, the

number of exposed mice surviving at the end of th e

study was considerably less than the number o f

controls surviving (Tables 17 and 18 and Figure 4) .

There were no clinical findings related t o

tetrafluoroethylene exposure.

TABLE 16

Survival of Mice in the 2-Year Inhalation Study of Tetrafluoroethylene

0 ppm 312 ppm 625 ppm 1,250 ppm

Male

Animals initially in study 58 58 58 58

15-Month interim evaluation 10 10 10 10 a

Moribund 6 24 26 27

Natural deaths 4 13 20 20

Animals surviving to study termination 38 11 2 1

Percent probability of survival at end of study 79 23 4 2

b

Mean survival (days) 647 561 554 548 c

Survival analyses P<0.001 P<0.001 P<0.001 P<0.001 d

Female

Animals initially in study 58 58 58 58

15-Month interim evaluation 10 10 10 10 a

Accidental death 0 0 1 0

a

Moribund 8 28 26 27

Natural deaths 4 16 15 17

Animals surviving to study termination 36 4 6 4

Percent probability of survival at end of study 75 8 13 8

Mean survival (days) 643 597 587 560

Survival analyses P<0.001 P<0.001 P<0.001 P<0.001

Censored from survival analyses a

Kaplan-Meier determinations b

Mean of all deaths (uncensored, censored, and terminal sacrifice) c

The result of the life table trend test (Tarone, 1975) is in the control column, and the results of the life table pairwise comparisons (Cox, 1972) with d

the controls are in the exposed group columns.
Tetrafluoroethylene, NTP TR 450 57

FIGURE 2

Growth Curves for Male and Female Rats Administered Tetrafluoroethylene

by Inhalation for 2 Years
58 Tetrafluoroethylene, NTP TR 450

TABLE 17

Mean Body Weights and Survival of Male Mice in the 2-Year Inhalation Study of Tetrafluoroethylene

Weeks 0 ppm 312 ppm 625 ppm 1,250 ppm

on Av. Wt. No. of Av. Wt. Wt. (% of No. of Av. Wt. Wt. (% of No. of Av. Wt. Wt. (% of No. of

Study (g) Survivors (g) controls) Survivors (g) controls) Survivors (g) controls) Survivors

1 24.1 58 24.0 100 58 24.0 100 58 23.8 99 58

2 26.6 58 26.7 100 58 26.9 101 58 26.9 101 57

3 27.4 58 27.7 101 58 27.7 101 58 27.8 102 57

4 27.7 58 28.2 102 58 28.5 103 58 28.3 102 57

5 29.0 58 29.8 103 58 29.8 103 58 29.9 103 57

6 29.7 58 30.5 103 58 30.7 103 58 30.7 103 57

7 30.2 58 30.8 102 58 31.3 104 58 31.6 105 57

8 30.9 58 31.9 103 57 31.9 103 58 32.2 104 57

9 31.8 58 32.6 103 57 33.0 104 58 32.9 104 57

10 32.3 58 33.1 103 57 33.6 104 58 33.4 103 57

11 32.9 58 33.7 102 57 34.3 104 58 34.2 104 57

12 33.6 58 34.5 103 55 34.6 103 58 34.6 103 57

13 33.4 58 34.2 102 55 34.1 102 58 34.7 104 57

14 35.2 58 35.9 102 55 35.8 102 58 36.2 103 57

18 37.0 58 37.9 102 55 38.4 104 58 38.1 103 57

22 39.1 58 39.3 101 55 39.7 102 58 39.7 102 57

26 41.3 58 41.9 102 55 42.3 102 58 41.5 101 57

30 43.6 58 44.0 101 55 44.5 102 58 43.4 100 57

34 45.3 58 45.9 101 55 45.8 101 58 44.7 99 57

38 46.3 58 46.9 101 55 46.8 101 58 45.5 98 56

42 46.2 58 46.6 101 55 46.6 101 58 45.7 99 56

46 48.1 58 48.1 100 55 47.3 98 58 47.1 98 55

50 48.5 58 49.0 101 55 48.2 99 58 48.2 99 55

54 48.7 58 48.5 100 55 47.9 98 56 48.2 99 54

58 48.4 58 48.9 101 55 48.3 100 56 49.1 101 53

62 49.5 58 49.3 100 55 48.5 98 54 49.4 100 53

66 49.0 47 48.1 98 45 47.6 97 41 49.3 101 43 a

70 50.2 46 49.1 98 43 47.8 95 40 49.5 99 41

74 50.5 46 49.3 98 40 47.9 95 37 49.0 97 41

78 50.1 45 49.7 99 33 48.8 97 28 48.8 97 34

82 50.8 44 49.5 97 29 49.6 98 22 46.8 92 26

86 49.8 42 48.0 96 23 48.3 97 16 46.1 93 18

90 49.9 41 45.9 92 17 47.9 96 9 44.6 89 7

92 49.6 40 44.9 91 15 46.5 94 6

94 49.2 38 44.7 91 12

Mean for weeks

1-13 30.0 30.6 102 30.8 103 30.8 103

14-52 43.1 43.6 101 43.5 101 43.0 100

53-94 49.6 48.0 97 48.1 97 48.1 97

Interim evaluation occurred during week 66. a
Tetrafluoroethylene, NTP TR 450 59

TABLE 18

Mean Body Weights and Survival of Female Mice in the 2-Year Inhalation Study of Tetrafluoroethylene

Weeks 0 ppm 312 ppm 625 ppm 1,250 ppm

on Av. Wt. No. of Av. Wt. Wt. (% of No. of Av. Wt. Wt. (% of No. of Av. Wt. Wt. (% of No. of

Study (g) Survivors (g) controls) Survivors (g) controls) Survivors (g) controls) Survivors

1 19.3 58 19.2 100 58 19.1 99 58 19.2 100 58

2 21.6 58 21.7 101 58 21.6 100 58 21.6 100 58

3 22.2 58 22.3 101 58 22.2 100 58 21.8 98 58

4 22.6 58 22.4 99 58 22.5 100 58 22.6 100 58

5 23.9 58 24.0 100 58 23.9 100 58 24.1 101 58

6 24.4 58 24.8 102 58 24.6 101 58 24.8 102 58

7 25.1 58 25.0 100 58 25.3 101 58 25.1 100 58

8 25.3 58 25.7 102 58 25.6 101 58 25.4 100 58

9 26.2 58 26.2 100 58 26.4 101 58 26.3 100 58

10 26.8 58 26.9 100 58 26.9 100 58 26.8 100 58

11 27.1 58 27.3 101 58 27.5 102 58 27.3 101 58

12 27.3 58 28.1 103 58 27.5 101 58 27.6 101 58

13 27.8 58 27.9 100 58 27.5 99 58 27.7 100 58

14 29.2 58 29.4 101 58 29.6 101 58 29.1 100 58

18 30.7 58 30.9 101 58 32.2 105 58 30.5 99 58

22 34.3 58 34.0 99 58 34.6 101 58 33.3 97 56

26 36.2 58 36.6 101 58 37.1 103 58 34.4 95 56

30 38.0 58 39.0 103 58 39.7 105 58 37.0 97 56

34 40.2 58 40.5 101 58 41.9 104 58 38.3 95 56

38 41.7 58 42.6 102 58 43.7 105 58 39.8 95 56

42 43.1 58 43.4 101 58 44.1 102 58 41.8 97 56

46 45.0 58 45.2 100 58 46.0 102 58 44.0 98 56

50 45.7 58 46.0 101 58 47.2 103 58 44.2 97 56

54 47.1 58 47.7 101 58 48.7 103 58 45.8 97 55

58 48.0 57 49.6 103 58 49.8 104 58 47.3 99 55

62 51.0 57 51.3 101 58 52.1 102 58 49.5 97 55

66 50.9 47 50.6 99 44 51.1 100 48 48.8 96 45 a

70 51.8 47 50.7 98 44 50.9 98 43 49.1 95 42

74 51.6 46 50.4 98 43 49.8 97 40 48.7 94 39

78 51.9 45 51.8 100 38 51.6 99 35 49.5 95 35

82 52.0 44 50.7 98 35 49.4 95 31 48.3 93 28

86 50.7 41 48.8 96 32 50.0 99 22 47.1 93 17

90 49.6 38 45.7 92 20 48.2 97 18 41.4 84 10

92 50.9 37 43.8 86 14 49.2 97 13 41.3 81 7

94 50.5 37 50.8 101 7 40.1 79 4

Mean for weeks

1-13 24.6 24.7 100 24.7 100 24.6 100

14-52 38.4 38.8 101 39.6 103 37.2 97

53-94 50.5 49.2 97 50.1 99 46.4 92

Interim evaluation occurred during week 66. a
60 Tetrafluoroethylene, NTP TR 450

FIGURE 4

Growth Curves for Male and Female Mice Administered Tetrafluoroethylene

by Inhalation for 2 Years
Tetrafluoroethylene, NTP TR 450 61

Pathology and Statistical Analyses

This section describes the statistically significant o r

biologically noteworthy changes in the incidences o f

histiocytic sarcoma and of neoplasms and/or nonneoplastic lesions of the liver, kidney, and spleen. Sum -

maries of the incidences of neo plasms and nonneoplastic lesions, individual animal tumor diagnoses, statistical analyses of primary neoplasms that occurred with

an incidence of at least 5% in at least one anima l

group, and historical incidences for the neoplasm s

mentioned in this section are presented in Appendix C

for male mice and Appendix D for female mice.

At the 15-month interim evaluation, absolute an d

relative lung weights of exposed groups of mice were

similar to those of the controls (Table F6), and no lung

lesions related to tetrafluoroethylene exposure oc -

curred.

Liver: At the 15-month interim evaluation, absolut e

and relative liver weights of exposed groups of mic e

were similar to those of the controls (Table F6). A t

15 months and at the end of the study, vascular neo -

plasms and nonneoplastic lesi ons occurred in the livers

of exposed male and female mice. At the 15-mont h

interim evaluation, hemangiosarcomas occurred i n

three males exposed to 1,250 ppm and in one femal e

exposed to 312 ppm (Tables 19, C1, and D1). At the

end of the study, the incidences of hemangioma i n

males and females exposed to 312 ppm and in male s

exposed to 625 ppm were significantly greater tha n

those in the controls (Tables 19, C3, and D3); th e

incidences of hemangioma in all exposed groups o f

males and in females exposed to 312 or 625 pp m

exceeded the range in hist orical chamber controls from

2-year NTP inhalation studies (Tables 19, C4a, an d

D4a). The incidences of hemangiosarcoma in al l

exposed groups of males and females were signifi -

cantly greater than those in the controls and exceeded

the historical control ranges. The incidences occurred

with a significant positive trend in males and females.

Multiple hemangiomas occurred in all exposed groups

of males and females except females in the 1,250 ppm

group, and multiple hemangiosarcomas occurred in all

exposed groups of males and females.

Hemangiomas are benign, vascular neoplasms characterized by dilated vascular spaces (Plate 10), with a n

increase in the number of neoplastic endothelial cell s

(Plate 11). Hemangiosarc omas are malignant vascular

neoplasms characterized by large, irregular, cavernous

spaces filled with erythrocytes and masses of fibri n

(Plate 12) and lined by variable numbers of pleomorphic endothelial cells which form fronds, solid sheets

(Plate 13), or vascular channels around and withi n

extensive areas of thrombosis and necrosis. Although

there were high incidences of hepatic hemangiosarcomas in all groups of exposed mice, incidences of thi s

neoplasm in other organs were low. Hemangiosarcomas were observed in the lung, mesentery, pancreas ,

ovary, bone marrow, and subcutaneo us tissues of a few

mice exposed to tetrafluoroethylene, and all of thes e

mice had hepatic hemangiosarcomas. It was not clear

whether the few extra-hepa tic hemangiosarcomas were

metastases or whether they arose concomitantly i n

extra-hepatic sites. There were no hemangiosarcomas

in the liver or in other organs of control mice.

At 15 months and at the end of the studies, increased

incidences of angiectasis occurred in all expose d

groups of males and females (Tables 19, C5, and D5).

Angiectasis is charact erized by dilated vascular spaces

of sinusoids in which the endothelial cells are normal

in morphology and number, and the lesion is com -

monly observed following exposure to a hepato -

carcinogen.

At 15 months, hepatocellular adenomas and carci -

nomas occurred in all control and exposed groups o f

males, but only in exposed groups of female s

(Tables 19, C1, and D1). Additionally, the incidences

of eosinophilic foci were significantly greater i n

females exposed to 625 or 1,250 ppm than in th e

controls (Tables 19 and D5). At the end of the study,

the incidence of hepatocellular adenoma in female s

exposed to 625 ppm was signifi cantly greater than that

in the controls and exceeded the historical contro l

range from 2-year NTP inhalation studies. Multipl e

hepatocellular adenomas occurred in all control an d

exposed groups of males and females, and the inci -

dences in exposed females were significantly 
62 Tetrafluoroethylene, NTP TR 450

TABLE 19

Incidences of Neoplasms and Nonneoplastic Lesions of the Liver in Mice in the 2-Year Inhalation Study

of Tetrafluoroethylene

0 ppm 312 ppm 625 ppm 1,250 ppm

Male

15-Month Interim Evaluation

Number Examined Microscopically 10 10 10 10

Angiectasis 0 1 5* 2

a

Eosinophilic Focus 0 0 3 0

Necrosis, Coagulative, Multifocal 1 1 0 1

Hemangiosarcoma 0 0 0 3

Hepatocellular Adenoma 6 2 4 1

Hepatocellular Adenoma, Multiple 1 0 2 0

Hepatocellular Carcinoma 2 4 2 2

2-Year Study

Number Examined Microscopically 48 48 48 48

Angiectasis 0 6** 10** 13**

Eosinophilic Focus 1 6 7* 7*

Necrosis, Coagulative, Multifocal 4 3 13* 11*

Hemangioma 0 10** 5* 2

b

Hemangioma, Multiple 0 7** 2 1

Hemangiosarcoma 0 21** 27** 37** c

Hemangiosarcoma, Multiple 0 16** 17** 18**

Hemangioma or Hemangiosarcoma 0 26** 30** 38**

Hepatocellular Adenoma 17 17 12 20

Hepatocellular Adenoma, Multiple 6 6 7 7

Hepatocellular Carcinoma 11 20** 33** 26**

Hepatocellular Carcinoma, Multiple 4 9** 9** 6*

Hepatocellular Adenoma or Carcinoma 26 34** 39** 35** d

(continued)
Tetrafluoroethylene, NTP TR 450 63

TABLE 19

Incidences of Neoplasms and Nonneoplastic Lesions of the Liver in Mice in the 2-Year Inhalation Study

of Tetrafluoroethylene (continued)

0 ppm 312 ppm 625 ppm 1,250 ppm

Female

15-Month Interim Evaluation

Number Examined Microscopically 10 10 10 10

Angiectasis 0 4* 2 1

Eosinophilic Focus 0 1 4* 5*

Hemangiosarcoma 0 1 0 0

Hepatocellular Adenoma 0 2 3 2

Hepatocellular Adenoma, Multiple 0 0 0 1

Hepatocellular Carcinoma 0 3 1 3

2-Year Study

Number Examined Microscopically 48 48 47 47

Angiectasis 1 9* 6 4

Eosinophilic Focus 5 13* 12** 7

Hematopoietic Cell Proliferation 3 19** 13 15**

Hemangioma 0 5* 2 1

e

Hemangioma, Multiple 0 1 1 0

Hemangiosarcoma 0 27** 27** 34** f

Hemangiosarcoma, Multiple 0 8** 12** 15**

Hemangioma or Hemangiosarcoma 0 31** 28** 35**

Hepatocellular Adenoma 15 17 20* 15

Hepatocellular Adenoma, Multiple 1 7** 9** 7**

Hepatocellular Carcinoma 4 28** 22** 20**

Hepatocellular Carcinoma, Multiple 0 5** 7** 7**

Hepatocellular Adenoma or Carcinoma 17 33** 29** 28** g

* Significantly different (P 0.05) from the control group by the Fisher exact test (15-month interim evaluation), the logistic regression test (2-year

study, nonneoplastic lesions and benign neoplasms), or the life table test (2-year study malignant neoplasms and combined incidences, benign and

malignant)

** P 0.01

Number of animals with lesion a

Historical incidence for 2-year NTP inhalation studies with chamber control groups at all labs (mean ± standard deviation): 2/947 (0.2% ± 0.7%); b

range, 0%-2%. Historical incidence for 2-year NTP inhalation studies with chamber control groups at Battelle Pacific Northwest Laboratories: 

1/448 (0.2% ± 0.7%); range, 0%-2%

Historical incidence at all labs: 12/947 (1.3% ± 1.7%); range, 0%-6%. Historical incidence at Battelle Pacific Northwest Laboratories: 2/448 c

(0.5% ± 0.9%); range, 0%-2%

Historical incidence at all labs: 358/947 (37.8% ± 12.5%); range, 11%-60%. Historical incidence at Battelle Pacific Northwest Laboratories: d

186/448 (41.5% ± 9.2%); range, 30%-60%

Historical incidence at all labs: 1/937 (0.1% ± 0.5%); range, 0%-2%. Historical incidence at Battelle Pacific Northwest Laboratories: 0/446 e

Historical incidence at all labs: 5/937 (0.5% ± 1.0%); range, 0%-3%. Historical incidence at Battelle Pacific Northwest Laboratories: 2/446 f

(0.5% ± 0.9%); range, 0%-2%

Historical incidence at all labs: 200/937 (21.3% ± 11.9%); range, 3%-54%. Historical incidence at Battelle Pacific Northwest Laboratories: g

95/446 (21.3% ± 14.8%); range, 6%-54%
64 Tetrafluoroethylene, NTP TR 450

increased compared to the controls. The incidences of hematopoietic cell proliferation of the liver than th e

hepatocellular carcinoma in all exposed groups o f controls, and the increases in females exposed to 312

males and females were significant ly greater than those or 1,250 ppm were significant (Tables 19 and D5) .

in the controls and exceeded the historical contro l Both coagulative multifocal necrosis an d

ranges (Tables 19, C4a, and D4a). hematopoietic cell proliferation are often associate d

with malignant neoplasms in the liver of mice.

Multiple hepatocellular carcinomas occurred in al l

groups of males, including controls. However, i n

female mice, multiple hepatocellular carcinomas were

observed only in the exposed groups. The combine d

incidences of hepatocellular adenomas and carcinomas

in exposed males and females were significantl y

greater than those in the controls and exceeded th e

historical control ranges. The incidences in males and

females occurred with significant positive trends .

Hepatocellular adenomas consisted of nodules o f

hepatocytes that compressed adjacent liver paren -

chyma and lacked the normal lobular and sinusoida l

pattern (Plate 14). Hepatocellular carcinomas con -

sisted of solid sheets of hepatocytes or trabeculae ,

three or more cells thick (Plate 15). Neoplasti c

hepatocytes were anaplastic, with prominent nucle i

containing one or more nucleoli and variable amounts

of cytoplasm. Frequently, carcinomas had multipl e

foci of necrosis, hemorrhage, and thrombi. Also at the

end of the study, females exposed to 312 or 625 ppm

had significantly greater incide nces of eosinophilic foci

than the controls (Tables 19 and D5).

At 15 months, coagulative multifocal necrosis of th e cells were observed, and neoplastic cells were als o

liver occurred in one control male , one male exposed to present in vascular spaces. Many mice with histiocytic

312 ppm, and one male exposed to 1,250 pp m sarcomas had cytoplasmic eosinophilic droplets i n

(Tables 19 and C5). At the end of the study, inci - renal tubule epithelial cells; this is consistent wit h

dences of coagulative multifocal necrosis wer e other studies in which an association between rena l

significantly greater in males exposed to 625 o r tubule hyaline droplet and lysozyme accumulation i n

1,250 ppm than in the controls. Also at the end of the mice with histiocytic sarcomas has been demonstrated.

study, all exposed groups of females had greate r

incidences of 

Hematopoietic System: At the end of the study, th e

incidences of histiocytic sarcoma (all organs) in al l

exposed groups of males and females were signifi -

cantly greater than those in the controls (Tables 20 ,

C3, and D3). The incidences of histiocytic sarcoma in

all exposed groups of male and female mice exceeded

the historical control ranges for all organs (Tables 20,

C4b, and D4b). Although the incidences of thi s

neoplasm were increased in exposed groups of males

and females, females had higher incidences than males.

The highest incidences of histiocytic sarcoma wer e

observed in the liver and lung, and lower incidence s

were observed in the spleen, lymph nodes, bon e

marrow, and kidney. The neoplastic histiocytic cell s

infiltrated the liver diffusely, but sometimes forme d

nodular patterns (Plate 16). Marked variations in the

size and shape of the neoplastic cells and nuclei an d

the high cytoplasmic-to-nuclear ratio wer e

distinguishing characteristics. Neoplastic cells ha d

abundant eosinophilic cytoplasm, and nuclei wer e

hyperchromatic and sometimes bean shaped (Plate 17).

Occasional giant cells were present. In the lung ,

marked perivascular infiltrate s of neoplastic histiocytic
Tetrafluoroethylene, NTP TR 450 65

TABLE 20

Incidences of Histiocytic Sarcoma in Mice in the 2-Year Inhalation Study of Tetrafluoroethylene

0 ppm 312 ppm 625 ppm 1,250 ppm

Male

Liver 7/48 (15%) 7/48 (15%) a0/48 (0%) 12/48 (25%)

Lung 0/48 (0%) 7/48 (15%) 4/48 (8%) 3/48 (6%)

Spleen 0/48 (0%) 2/48 (4%) 1/46 (2%) 2/46 (4%)

Mesenteric Lymph Node 0/47 (0%) 4/42 (10%) 1/41 (2%) 2/40 (5%)

Bone Marrow 0/48 (0%) 1/48 (2%) 1/47 (2%) 2/47 (4%)

Kidney 0/48 (0%) 3/48 (6%) 3/48 (6%) 2/48 (4%)

All Organsb

Overall rate 0/48 (0%) 12/48 (25%) 7/48 (15%) 7/48 (15%) a

Adjusted rate 0.0% 47.8% 35.1% 65.8% c

Terminal rate 0/38 (0%) 1/11 (9%) 0/2 (0%) 0/1 (0%) d

First incidence (days) — 513 415 527 f

Life table test P<0.001 P<0.001 P<0.001 P<0.001 e

Logistic regression test P=0.100 P<0.001 P=0.039 P=0.004 e

Female

Liver 1/48 (2%) 21/48 (44%) 19/47 (40%) 18/47 (38%)

Lung 1/48 (2%) 16/48 (33%) 13/47 (28%) 13/47 (28%)

Uterus 1/48 (2%) 0/48 (0%) 0/45 (0%) 0/47 (0%)

Spleen 1/48 (2%) 7/48 (15%) 8/46 (17%) 9/47 (19%)

Mesenteric Lymph Node 1/43 (2%) 6/40 (15%) 7/41 (17%) 6/43 (14%)

Bone Marrow 0/48 (0%) 6/48 (13%) 5/46 (11%) 4/47 (9%)

Kidney 1/48 (2%) 7/48 (15%) 4/47 (9%) 3/47 (6%)

All Organsg

Overall rate 1/48 (2%) 21/48 (44%) 19/47 (40%) 18/48 (38%)

Adjusted rate 2.1% 77.6% 51.3% 78.2%

Terminal rate 0/36 (0%) 1/4 (25%) 0/6 (0%) 1/4 (25%)

First incidence (days) 400 429 457 484

Life table test P<0.001 P<0.001 P<0.001 P<0.001

Logistic regression test P=0.015 P<0.001 P<0.001 P<0.001

Number of animals with neoplasm per number of animals examined microscopically a

Historical incidence for 2-year NTP inhalation studies with chamber control groups at all labs (mean ± standard deviation): 6/950 (0.6% ± 1.2%); b

range, 0%-4%. Historical incidence for 2-year NTP inhalation studies with chamber controls at Battelle Pacific Northwest Laboratories: 2/450

(0.4% ± 0.9%); range, 0%-2%.

Kaplan-Meier estimated neoplasm incidence at the end of the study after adjustment for intercurrent mortality c

Observed incidence in animals surviving until the end of the study d

In the control column are the P values associated with the trend test. In the exposed group columns are the P values corresponding to pairwise e

comparisons between the controls and that exposed group. The life table test regards neoplasms in animals dying prior to terminal kill as being

(directly or indirectly) the cause of death. The logistic regression test regards these lesions as nonfatal.

Not applicable; no neoplasms in animal group f

Historical incidence at all labs: 26/941 (2.8% ± 3.1%); range, 0%-10%. Historical incidence at Battelle Pacific Northwest Laboratories: 14/447 g

(3.1% ± 3.0%); range, 0%-8%
66 Tetrafluoroethylene, NTP TR 450

Kidney: At the 15-month interim evaluation, absolute

and relative kidney weights of exposed groups of male

and female mice were similar to those of the controls

(Table F6). Significantly increased incidences of renal

tubule dilatation and karyomegaly were observed in male

mice exposed to 625 or 1,250 ppm at 15 months

(Tables 21 and C5). At the end of the study, the

increased incidences of these lesions in exposed groups

of males were generally significant. These increased

incidences were considered to be related to exposure to

tetrafluoroethylene. The severity of renal tubule

dilatation was slightly increased at the end of the study in

males exposed to 1,250 ppm. Karyomegaly was similar

to that observed in the 13-week study and was most 

prominent in the inner renal cortex (Plates 18 and 19).

Dilated renal tubules were filled with eosinophilic

amorphous material and were lined by flattened epithelium (Plates 20 and 21). Karyomegaly in renal tubule

cells was characterized by nuclei that were enlarged,

pleomorphic, and vesicular and had large, prominent,

hyperchromatic nucleoli (Plate 20). At 15 months,

karyomegaly was present in females exposed to 625 or

1,250 ppm, but at the end of the study, this lesion was

observed only in females in the 1,250 ppm group.

Tubule dilatation was not present in female mice at

15 months or at the end of the study. At the interim

evaluation, tubule changes were more clearly 

TABLE 21

Incidences of Nonneoplastic Lesions of the Kidney in Mice in the 2-Year Inhalation Study

of Tetrafluoroethylene

0 ppm 312 ppm 625 ppm 1,250 ppm

Male

15-Month Interim Evaluation

Number Examined Microscopically 10 10 10 10

Renal Tubule, Dilatation 0 0 6** (1.0) 10** (1.2) a b

Renal Tubule, Karyomegaly 0 0 4* (1.0) 10** (1.0)

2-Year Study

Number Examined Microscopically 48 48 48 48

Renal Tubule, Dilatation 0 4** (1.0) 16** (1.0) 36** (1.4)

Renal Tubule, Karyomegaly 1 (1.0) 2 (1.0) 10** (1.0) 28** (1.0)

Female

15-Month Interim Evaluation

Number Examined Microscopically 10 10 10 10

Renal Tubule, Karyomegaly 0 0 10** (1.0) 10** (2.0) c

2-Year Study

Number Examined Microscopically 48 48 47 48

Renal Tubule, Karyomegaly 0 0 0 38** (1.8) c

* Significantly different (P 0.05) from the control group by the Fisher exact test (15-month interim evaluation) or the logistic regression test (2-year

study)

** P 0.01

Number of animals with lesion a

Average severity grade of lesion in affected mice: 1=minimal; 2=mild; 3=moderate; 4=severe b

Results of a special review c
Tetrafluoroethylene, NTP TR 450 67

defined; however, by the end of the study, the changes associated with the presence of malignant neoplasms in

were sometimes obscured by concurrent age-related the livers of affected mice.

background lesions (i.e., inflammation). Karyomegaly

was located in the tubules in the inner renal cortex.

Spleen: Incidences of hematopoietic cell proliferation in

all exposed groups of males and females were signifi- No increases in the frequency of micronucleated

cantly greater than those in the controls at the end of the normochromatic erythrocytes were observed in peripheral

study (Tables 22, C5, and D5). Additionally, the severity blood samples obtained from male and female mice at the

of this lesion increased with increasing exposure concen- end of the 13-week inhalation study of tetrafluoroethylene

tration. Hematopoietic cell proliferation was frequently (Table E1).

GENETIC TOXICOLOGY

TABLE 22

Incidences of Nonneoplastic Lesions of the Spleen in Mice in the 2-Year Inhalation Study

of Tetrafluoroethylene

0 ppm 312 ppm 625 ppm 1,250 ppm

Male

15-Month Interim Evaluation

Number Examined Microscopically 10 10 10 10

Hematopoietic Cell Proliferation 2 (2.0) 4 (2.0) 5 (1.6) 3 (1.7) a b

2-Year Study

Number Examined Microscopically 48 48 46 46

Hematopoietic Cell Proliferation 14 (2.1) 32* (2.7) 41** (2.9) 42** (3.0)

Female

15-Month Interim Evaluation

Number Examined Microscopically 10 10 10 10

Hematopoietic Cell Proliferation 2 (1.5) 4 (1.8) 4 (1.5) 3 (2.0)

2-Year Study

Number Examined Microscopically 48 48 46 47

Hematopoietic Cell Proliferation 18 (2.1) 39** (2.8) 41** (2.9) 41** (2.9)

* Significantly different (P 0.05) from the control group by the logistic regression test

** P 0.01

Number of animals with lesion a

Average severity grade of lesion in affected mice: 1=minimal; 2=mild; 3=moderate; 4=severe b
PLATE 1

Kidney of a male F344/N rat exposed to 312 ppm tetrafluoroethylene by inhalation

for 2 years. Hyperplasia is focal. Note that the renal tubule is lined by increased

numbers of tubule epithelial cells, which totally fill the tubule lumen. H&E; 33×

PLATE 2

Renal tubule adenoma in the kidney of a male F344/N rat exposed to 625 ppm

tetrafluoroethylene by inhalation for 2 years. Note the adenoma is greater than five

renal tubules in diameter and neoplastic cells are mildly pleomorphic and tend to form

irregular clusters. H&E; 33×

PLATE 3

Renal tubule carcinoma in the kidney of a female F344/N rat exposed to

1,250 ppm tetrafluoroethylene by inhalation for 2 years. Note the carcinoma is

much larger, less discrete, and has a more prominent vascular supply than the

adenoma in Plate 2. H&E; 6.6×

PLATE 4

Higher magnification of Plate 3. Note neoplastic cells are arranged in irregular

clusters and are characterized by vesiculate nuclei with prominent nucleoli and

increased mitotic figures (arrow). H&E; 100×
PLATE 5

Renal tubule degeneration (arrows) in a male F344/N rat exposed to 625 ppm

tetrafluoroethylene by inhalation for 2 years. Degeneration is characterized by

dilatation of renal tubules in the cortex near the corticomedullary junction, with or

without eosinophilic debris and/or proteinaceous fluid in their lumens. H&E; 5×

PLATE 6

Higher magnification of Plate 5 at the corticomedullary junction. Degeneration is

characterized by dilatation of renal tubules with or without eosinophilic debris and/or

proteinaceous fluid in their lumens. The renal tubules are lined by cuboidal

epithelium. H&E; 66×
PLATE 7

Hepatocellular adenoma in the liver of a female F344/N rat exposed to 312 ppm

tetrafluoroethylene by inhalation for 2 years. Note the hepatocellular adenoma

caused compression of the adjacent liver parenchyma (arrows), and the adenoma

lacks normal lobular architecture. H&E; 16×

PLATE 8

Hepatocellular carcinoma from a male F344/N rat exposed to 312 ppm

tetrafluoroethylene by inhalation for 2 years. The high magnification shows the

trabecular pattern, three or more cells thick. Note the prominent mitotic figures

(arrow). H&E; 66×

PLATE 9

Hemangiosarcoma in the liver of a female F344/N rat exposed to 625 ppm

tetrafluoroethylene by inhalation for 2 years. Note the irregular, vascular spaces

(arrow) containing variable numbers of erythrocytes. This hemangiosarcoma

metastasized to the lung. H&E; 33×
PLATE 10

Hemangioma (arrows) in the liver (L) of a male B6C3F1 mouse exposed to

312 ppm tetrafluoroethylene by inhalation for 2 years. H&E; 6.6×

PLATE 11

Higher magnification of Plate 10 showing the dilated sinusoids with an increased

number of neoplastic endothelial cells (arrows). H&E; 66×

PLATE 12

Hemangiosarcoma in the liver of a male B6C3F1 mouse exposed to 1,250 ppm

tetrafluoroethylene by inhalation for 2 years. Note the large, irregular, cavernous

spaces filled with erythrocytes (arrows). H&E; 5×

PLATE 13

Higher magnification of Plate 12, showing sheets of anaplastic, pleomorphic,

endothelial cells that efface the liver parenchyma with only a few hepatocytes

remaining (arrows). H&E; 80×
PLATE 14

Hepatocellular adenoma in the liver of a male B6C3F1 mouse exposed to

1,250 ppm tetrafluoroethylene by inhalation for 2 years. Note the hepatocellular

adenoma caused compression of the adjacent liver parenchyma (arrows), and the

adenoma lacks normal lobular architecture. H&E; 10×

PLATE 15

Hepatocellular carcinoma from a male B6C3F1 mouse exposed to 1,250 ppm

tetrafluoroethylene by inhalation for 2 years. The high magnification shows the

trabecular pattern, three or more cells thick. Note the prominent mitotic figures

(arrows). H&E; 80×

PLATE 16

Histiocytic sarcoma in the liver of a male B6C3F1 mouse exposed to 1,250 ppm

tetrafluoroethylene by inhalation for 2 years. Note the nodular (arrows) and

infiltrative (arrowheads) nature of the neoplastic cells between hepatic plates. H&E;

25×

PLATE 17

Higher magnification of Plate 16. Note the neoplastic cells have abundant

eosinophilic cytoplasm and nuclei are hyperchromatic and sometimes bean-shaped. 

H&E; 100×
PLATE 18

Kidney of a male B6C3F1 mouse exposed to 1,250 ppm tetrafluoroethylene for

2 years. Compare to kidney from a control mouse in Plate 19. Renal tubule

dilatation (arrows) and karyomegaly were most prominent at the junction between

the cortex (C) and medulla (M). H&E; 5×

PLATE 19

Kidney from a male B6C3F1 mouse exposed to filtered air for 2 years. Note the

lack of tubular dilatation at the junction between the cortex (C) and medulla (M). 

H&E; 5×

PLATE 20

Higher magnification of Plate 18 at the corticomedullary junction. Note the dilated

renal tubules are filled with eosinophilic amorphous material and lined by flattened

epithelium (arrows). Karyomegaly in renal tubule cells was characterized by nuclei

that were enlarged and had prominent nucleoli (arrowhead). Compare with kidney

from a control mouse in Plate 21. H&E; 66×

PLATE 21

Higher magnification of Plate 19. Note the lack of tubular dilatation and

karyomegaly. H&E; 66×
68 Tetrafluoroethylene, NTP TR 450
69

DISCUSSION AND CONCLUSIONS

Tetrafluoroethylene was evaluated for toxicity an d Exposure concentration-related renal lesions similar to

carcinogenicity in 16-day, 13-week, and 2-year studies those observed in the 16-day study were observed i n

in male and female F344/N rats and B6C3F 1 mice, male rats exposed to 625 ppm or greater and in female

with whole body inhalation as the route of exposure. ratsin the 2,500 and 5,000 ppm groups. These lesions

were considered mild at most. As with exposed rats ,

In the 16-day studies, there were no exposure-relate d

deaths, clinical findings, or effects on hematologi c

parameters. Mean body weights of male and femal e

rats exposed to 5,000 ppm were lower than those o f

the controls. Absolute kidney weights of all exposed

groups of male rats, female rats ex posed to 1,250 ppm,

and female mice exposed to 5,000 ppm were greate r

than those of controls. Relative liver weights of al l

exposed groups of male rats and of female mic e

exposed to 5,000 ppm were also greater than those of

the controls; however, there were no histopathologi c

effects in the liver. There were exposure concentra -

tion-related effects on the kidneys of exposed rats and

mice, although the effects were different between th e

species. In rats, the kidney lesion (renal tubule degeneration) was located predominantl y in the inner cortical

tubule epithelial cells at the junction of the cortex and

medulla and was observed in male and female rat s

exposed to 625 ppm or greater. This lesion has been

observed previously in rats exposed to tetrafluoro -

ethylene and other halogenated compounds and is well

documented in the literature. In mice, the lesion wa s

characterized as renal tubule karyomegaly; however, it

was also located primarily in the inner renal cortex.

In the 13-week studies, there were no exposure-related An exposure concentration-dependent normocytic ,

deaths or clinical findings. Mean body weight gains of normochromic, nonresponsive anemia occurred i n

male and female rats exposed to 5,000 ppm wer e exposed rats and mice in the 13-week studies .

marginally reduced. Although there were no treat - Normocytic, normochromic, nonresponsive anemia s

ment-related lesions in the livers of exposed rats o r have been related to selective suppression of erythromice, absolute and rel ative liver weights of female rats poiesis in a variety of chronic disorders and may b e

exposed to 5,000 ppm and all exposed groups of male related to decreased erythropoietin elaboration, bon e

rats were significantly increased. Absolute and relative marrow suppression, or defective iron metabolis m

kidney weights of male rats exposed to 1,250 ppm or (Jain, 1986). Because there was histopathologi c

greater and females exposed to 625 ppm or greate r evidence of exposure concentration-dependent rena l

were significantly increased. Absolute and relativ e lesions in male and female rats and mice, the anemi a

kidney weights of exposed mice were not significantly would be consistent with a second ary hypoproliferative

different from those of the controls. 

mice exposed to 1,250 ppm or greater in the 13-week

study also developed kidney lesions similar to thos e

observed in mice at 16 days, and these lesions wer e

slightly more severe in males than in females. A

concentration-related proteinuria occurred in al l

exposed groups of rats with kidney lesions. Protein -

uria could be related to either glomerular or proximal

tubule renal injury and, in the present study, would be

consistent with the renal tubule degeneration observed

morphologically. Polyuria occurred in exposed mic e

and probably in rats and could be re lated to a variety of

conditions, including overdrinking, osmotic diuresis ,

damage to the proximal and/or distal portions of th e

renal tubule, and alterations of metabolism or kidne y

response to antidiuretic hormone (Finco, 1989). Based

on an appropriate response to a water concentratio n

test (rats only), the ability of the kidney to concentrate

the urine was not compromised, indicating that th e

pituitarykidney ADH axis was intact and that ther e

was no medullary washout (which could occur wit h

conditions such as long-term overhydration o r

hyperadrenocorticism). Therefore, the renal damag e

observed morphologically, although different for rats

and mice, would appear to involve primarily th e

proximal convoluted tubules.
70 Tetrafluoroethylene, NTP TR 450

anemia, possibly related to altered erythropoieti n and 400 ppm tetrachloroeth ylene, a structurally related

production/metabolism in the kidney. compound (NTP, 1986). In addition, incidences o f

In the 2-year study, survival was reduced in male rats female rats exposed to tetrachloroethylene.

exposed to 625 ppm and in all exposed female rats .

Mean body weights of exposed rats were generall y Considerable effort has been expended in the pas t

similar to those of the controls until the end of th e 10 years investigating the mechanism o f

study, at which time mean body weights were lower in tetrafluoroethylene-induced renal proximal tubul e

males in the 625 ppm group and females in th e toxicity, primarily in rats (Odum and Green, 1984 ;

1,250 ppm group than in the controls. These reduc - Boogaard et al., 1989; Commandeur et al., 1989;

tions reflected the mean body weights of a very small Hayden et al., 1991a,b), and that induced by othe r

number of surviving rats. The only exposure-relate d halogenated compounds. Tetrafluoroethylene i s

clinical finding was eye opacity in female rats, whic h conjugated in the liver with glutathione and sub -

upon histological examination was determined to b e sequently excreted via the bile to the small intestine ,

cataracts. At the 15-month interim evaluation, relative where biliary and intestinal peptidases degrade them to

kidney weights of male rats exposed to 312 o r cysteine-S-conjugates which may be reabsorbed from

625 ppm and absolute kidney and liver weights o f the small intestine. Glutathione conjugates release d

females exposed to 625 or 1,250 ppm were signifi - into the general circulation from the liver are als o

cantly greater than those of the controls. hydrolyzed to cysteine-S-conjugates by renal pepti -

dases, where they are bioactivated by renal -lyase to

The renal toxicity noted in male and female rats in the

13-week study was exacerbated in the 2-year study in

that exposure to tetrafluoroethylene caused increase d

incidences of neoplasms and nonneoplastic lesions of

the kidney in rats. As in the 13-week studies, rena l

tubule degeneration was associated with the proximal

tubules at the corticomedullary junction, and th e

incidence was significantly increased at 15 months and

2 years. The only difference between the two tim e

points was that the renal lesions were generally mor e

severe and more numerous after 2 years.

Additional sections of the kidney were taken to further

evaluate the renal proliferative effects. These sections

did detect additional proliferative lesions and generally

confirmed the findings of the single sections .

Exposure to tetrafluoroethylene caused significantl y

increased incidences of hyperplasia at 15 months and

2 years in male and female rats. In the combine d

extended and standard evaluations, the incidences o f

renal tubule adenoma or carcinoma (combined) wer e

significantly increased, with positive trends in exposed

males and females. Because these neoplasms, whic h

are considered uncommon, occurred consistently an d

because the incidences increased with increasin g

exposure concentration, the neoplasms are considered

to have been caused by tetrafluoroethylene exposure .

Similarly, increased incidences of renal tubul e

hyperplasia, adenoma, and carcino ma in male rats have

been reported following inhalation exposure to 20 0

karyomegaly were significantly increased in male and

unstable reactive thiols. The tetrafluoroethylen e

cysteine conjugate, S-(1,1,2,2-tetrafluoroethyl) -

L-cysteine, and tetrafluoroethylene mercapturic aci d

have been shown to cause renal damage in vivo

identical to that caused by tetrafluoroethylene and t o

have greater enzyme activation activity than severa l

chlorinated or brominated compounds; additionally ,

exposure to these compounds causes thei r

accumulation in the proximal tubule cells

(Commandeur et al., 1989). Like tetrafluoroethylene,

they are not mutagenic. The tetrafluoroethylen e

cysteine conjugate has also been shown to cause death

to cultured human proximal tubule cells, as indicate d

by the release of lactate dehydrogenase. Toxicity and

binding to macromolecules in human renal cells can be

prevented with aminooxyacetic acid, a known -lyase

inhibitor; this process has also been demonstrated for

rat renal cells (Chen et al., 1990). In rats, the cysteine

conjugate is further bioactivated in the kidney and, to

a lesser extent, in the liver to a difluorothionacety l

fluoride, the putative reactive metabolite fo r

tetrafluoroethylene-induced nephrotoxicity. The

thionacetyl fluorides cause mitochondrial dysfunction

by inhibiting adenosine diphosphate-stimulate d

respiration, increasing lipid peroxidation, modifyin g

mitochondrial proteins (HSP60 and HSP70), an d

inhibiting lipoyl dehydrogenase; by binding t o

macromolecules; and by forming protein an d

phospholipid adducts. The difluorothioamide adduc t

has been shown to cause nephrotoxicity in th e
Tetrafluoroethylene, NTP TR 450 71

proximal tubule. Considering the similarity in effects oral route of exposure. Hepatic angiectasis, characterand location of renal lesions in the present 2-yea r ized by multifocal, dilated, blood-filled sinusoids with

inhalation studies and the metabolism and toxicit y prominent lining endothelial cells, was observed i n

studies reported in the literature, similar metabolite s exposed groups of female rats. This lesion is some -

and common mechanisms may be involved in th e times associated with hepatocellular neoplasms .

carcinogenic response in the kidney of tetrafluoro - Cystic degeneration of the liver occurs at a low inci -

ethylene-exposed animals. dence in aging rats; however, following exposure o f

Although no liver lesions were observed in th e shown to be increased. In fact, the incidences of cystic

13-week studies, exposure to tetrafluoroethylene fo r degeneration in exposed groups of male rats wer e

2 years caused increased incidences of nonneoplasti c significantly greater than the control group incidence.

lesions and uncommon neoplasms of the liver in rats;

these neoplasmsinclude hemangiosarcomas, which have The incidence of mononuclear cell leukemia in mal e

not been observed previously in chamber control rats rats exposed to 156 ppm was significantly greater than

from 2-year NTP inhalation studies. Hepatocellula r in controls. In males, interpretation of the increase d

foci (including clear cell, eosinophilic, and mixed cell) incidence of mononuclear cell leukemia is complicated

were observed in rats at the 15-month interim evalua- by reduced survival in rats exposed to 625 ppm an d

tion. At 2 years, the incidences of eosinophilic an d the fact that the control incidence exceeded the previmixed cell foci were significantly increased in exposed ous historical chamber contr ol range. The incidence of

male rats and slightly increased in exposed female rats. mononuclear cell leukemia in male rats exposed t o

At 15 months, one male exposed to 312 ppm had a 312 ppm, although not significantly greater than tha t

hepatocellular adenoma and one male exposed t o in the control group, also exceeded the previou s

625 ppm had a hepatocellular carcinoma. At the end historical range. Whether this response in male rat s

of the 2-year study, male rats in the 312 ppm grou p was caused by tetrafluoroethylene exposure is uncer -

had significantly increased inc idences of hepatocellular tain. However, there was a significant increase in the

carcinoma and hepatocellular adenoma or carcinom a incidence of mononuclear cell leukemia in all exposed

(combined); in females, the incidences of hepatocel - groups of female rats. The incidence of mononuclear

lular adenoma and hepatocellular adenoma or carci - cell leukemia in female controls from the present study

noma (combined) in all exposed groups and th e was within the historical control range. The increased

incidences of hepatocellular carcinoma in the 312 and incidence of mononuclear cell leukemia in female rats

625 ppm groups were significantly greater than those is considered to have been caused by exposure t o

in the controls. There were no adenomas or carci - tetrafluoroethylene. Exposure to tetrachloroethylen e

nomas in control females. The incidences of hepato - for 2 years (NTP, 1986) also caused an increase in the

cellular adenoma or carcinoma (combined) occurre d incidence of mononuclear cell leukemia in male an d

with positive trends in exposed males and females , female F344/N rats exposed to 200 or 400 ppm.

even though the 8% incidence in the control male rats

in the present study exceeds the previous highes t At 15 months, there were no increases in the incidence

incidence of 4% for inhalation chamber controls. The of interstitial adenoma or interstitial cell hyperplasia .

fact that fewer hepatocellular neoplasms occurred i n At the end of the 2-year study, there was a slight bu t

male and female rats expos ed to the highest concentra- statistically significant increase in the incidence o f

tions (625 ppm for males, 1,250 ppm for females) than interstitial cell adenoma in the testes of rats exposed to

in rats exposed to lower con centrations may be a result 312 or 625 ppm. It is uncertain whether these in -

of reduced survival. Also, the highest exposur e creased incidences of adenomas were due to tetra -

concentration for males was half that for females. fluoroethylene exposure; however, there was a similar

Exposure to tetrafluoroethylene also caused heman - interstitial cell adenomas in F344/N rats exposed t o

giosarcomas of the liver in female rats. These uncom- 200 or 400 ppm tetrachloroethylene for 2 years (NTP,

mon liver neoplasms have not been observed previ - 1986).

ously in male or female chamber controls from 2-year

NTP inhalation studies or in untreated controls by any

rats to hepatocarcinogens, the incidence has bee n

slight but significant increase in the incidence o f
72 Tetrafluoroethylene, NTP TR 450

Exposure to tetrafluoroethylene for 2 years caused a Although exposure to 100 or 200 ppm tetrachloro -

significant increase in the incidence of cataracts i n ethylene for 2 years caused increased incidences o f

female rats exposed to 1,250 ppm. The lesion wa s hepatocellular adenoma and carcinoma in male an d

characterized by a disruption of the normal organiza- female mice, there were no exposure-related increases

tion of lens fibers, with swelling, vacuolization, an d in hemangioma or hemangi osarcoma incidences (NTP,

mineralization. 1986). However, chronic inhalation exposure to vinyl

In the 2-year mouse study, survival was reduced in all giosarcomas and hepatocellular adenomas and carci -

exposed male and female mice to the extent that th e nomas in several strains of rats, mice, and hamster s

study was terminated at week 96. The reduction i n (IARC, 1979, 1987). More importantly, a number of

survival was considered to be the result of exposure - epidemiologic studies have shown that worker s

related neoplasms of the liver. Mean body weights of exposed to vinyl chloride have higher mortality rate s

exposed mice were generally similar to those o f and a high incidence of neoplasms in the liver, brain ,

controls except at the end of the study, where survival lung, and lymphatic and hematopoietic systems, al l

was significantly decreased. attributed to vinyl chloride exposure. Neoplasm s

observed in the liver of these workers include hemanAs observed in the 2-year rat study, exposure of mice

to tetrafluoroethylene caused significant increases i n

the incidences of nonneopl astic lesions and uncommon

neoplasms of the liver in mice at 15 months an d

2 years. Exposure to tetrafluoroethylene cause d

hemangiomas in the liver of mal e and female mice, and

multiple hemangiomas were observed in males an d

females. These uncommon neoplasms were no t

observed in control mice. Hemangiosarcomas caused

by exposure to tetrafluoroethylene were observed a s

early as 15 months in males in the 1,250 ppm grou p

and females in the 312 ppm group. Hemangiosarco -

mas occurred with statistically significant incidence s

and with a positive trend in all groups of expose d

males and females. The inc idences of multiple hemangiosarcomas were significant in all exposed groups of

males and females. In a few males and females, th e

hemangiosarcomas metastasized to the lung. Hemangiosarcomas were not observed in male or femal e

control mice. The incidences of hemangioma o r

hemangiosarcoma (combined) we re also highly significant and occurred with a positive trend for expose d

groups of males and females. Hemangiomas an d

hemangiosarcomas are uncommon neo-plasms in mice

in studies using such routes as fee d or dosed water, and

the historical incidences of these neoplasms in un -

treated mice from 2-year NTP feed and dosed wate r

studies are similar to those for inhalation chambe r

control mice. The rarity of these neoplasms furthe r

accentuates the striking results of the present study .

These uncommon neoplasms probably had a signifi -

cant effect on the surviv al of mice in the present study.

chloride (chloroethylene) has caused heman -

giosarcomas and hepatocellular adenomas and carci -

nomas. Liver neoplasms caused by vinyl chlorid e

exposure in laboratory anim als and humans are similar

to those observed in rats and mice exposed t o

tetrafluoroethylene.

Angiectasis, eosinophilic foci, and coagulative multifocal necrosis of the liver were observed at 15 months

and were significantly increased in incidence an d

severity at 2 years. The incidences of hepatocellula r

adenoma or carcinoma (combined) were increased i n

all exposed groups of male mice and were signifi -

cantly greater in all exposed groups of female mic e

than in the control group. Many animals had multiple

adenomas or carcinomas. In all exposed groups, th e

incidences of multiple adenomas and multiple carci -

nomas in female mice and mu ltiple carcinomas in male

mice were significantly increased. A number of th e

carcinomas in exposed males and females, but onl y

one carcinoma in each of the male and female control

groups, metastasized to the lung. Incidences o f

hepatocellular adenoma, carcinoma, and adenoma o r

carcinoma (combined) in contr ol male and female mice

were within the historical ranges in chamber contro l

mice from 2-year NTP inhalation studies. Th e

increased incidences of these neoplasms in expose d

male and female mice were considered to be exposure

related. A low frequency (15%) of H- ras codon 61

mutations was observed in tetrafluoroethylene-induced

hepatocellular neoplasms when compared to th e

frequency in neoplasms in controls (59%) or i n

spontaneous liver neoplasms of B6C3F mice (56%) 1

(Appendix L). This frequency is similar to tha t

detected in liver neoplasms in B6C3 F1 mice exposed to
Tetrafluoroethylene, NTP TR 450 73

tetrachloroethylene (24%) (Anna et al., 1994). females, and the increased incidences of bot h

Although a few neoplasms in the tetrachloroethylen e nonneoplastic lesions were considered to be related to

study were found to have a K-ras mutation, none were exposure to tetrafluoroethylene. The effect o f

found in neoplasms in the tetrafluoroethylene study . tetrafluoroethylene exposure on the kidney of mice is

These data indicate that these two hepatocellula r very similar to the effects of exposure to 100 o r

carcinogens induce liver neoplasms via a ras- 200 ppm tetrachloroethylene for 2 years (NTP, 1986),

independent pathway. in that tetrachloroethylene caused increased incidences

The incidence of histiocytic sarcoma was markedl y causing increased incidences of kidney neoplasms.

increased in exposed male mice and significantl y

increased in all female mice, although not in a n

exposure concentration-related manner. Among mice

with any histiocytic sarcomas, histiocytic sarcoma s

were present in the liver of all animals and in the lung

of many animals. The spleen, lymph nodes, bon e

marrow, and kidney were also affected. Combine d

with the hepatocellular adenomas and carcinomas ,

hemangiomas, and hemangio sarcomas, the presence of

histiocytic sarcomas in exposed mice compromise d

liver function, ultimately leading to the death of th e

mice.

In the 13-week mouse study, renal tubule karyomegaly,

accompanied by a polyuria, occurred in male an d

female mice exposed to 1,250 ppm or greater and was

the only consideration for exposure concentratio n

selection for the 2-year study. Although there were no

kidney neoplasms in exposed groups of mice as were

observed in the 2-year rat study, there wer e

significantly increased incidences of renal tubul e

dilatation in exposed males and renal tubule karyo -

megaly, located in the tubules in the inner cortex, i n

males and females. These lesions were observed a t

15 months as well as at the end of the study. I n

general, only the incidences of these lesions increased

over the course of the study, while the severitie s

remained essentially uncha nged; in fact, the severity of

karyomegaly was similar to that observed in th e

13-week study at the same exposure concentration .

Although these lesions were observed in all expose d

groups of males at the end of the study, incidences of

karyomegaly were observed only in 1,250 pp m

females; however, this group had a high incidence. As

in the 13-week study, males were affected more tha n

of karyomegaly in male and female mice withou t

CONCLUSIONS

Under the conditions of these 2-y ear inhalation studies,

there was clear evidence of carcinogenic activity* of

tetrafluoroethylene in male F344/N rats based o n

increased incidences of renal t ubule neoplasms (mainly

adenomas) and hepatocellular neo-plasms. There was

clear evidence of carcinogenic activity of

tetrafluoroethylene in female F344/N rats based o n

increased incidences of renal tubule neoplasms, live r

hemangiosarcomas, hepatocellular neoplasms, an d

mononuclear cell leukemia. There was clear evidence

of carcinogenic activity of tetrafluoroethylene in male

and female B6C3F1 mice based on increase d

incidences of liver hemangiomas an d

hemangiosarcomas, hepatocellular neoplasms, an d

histiocytic sarcomas.

Slight increases in the incidences of mononuclear cell

leukemia and testicular interstitial cell adenomas i n

male rats may have been related to exposure t o

tetrafluoroethylene.

Exposure of rats to tetrafluoroethylene resulted i n

increased incidences of renal tubule hyperplasia an d

degeneration in males and females, increased severity

of kidney nephropathy in males, and increase d

incidences of liver angiectasis and cataracts in females.

Exposure of mice to tetrafluoroethylene resulted i n

increased incidences of hematop oietic cell proliferation

of the liver in females, liver angiectasis in males an d

females, renal tubule dilatation in males, renal tubule

karyomegaly in males and females, and spleni c

hematopoietic cell proliferation in males and females.

___________

* Explanation of Levels of Evidence of Carcinogenic Activity is on page 12. A summary of the Technical Reports Review Subcommittee comments

and the public discussion on this Technical Report appears on page 14.
74 Tetrafluoroethylene, NTP TR 450
75

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79

APPENDIX A

SUMMARY OF LESIONS IN MALE RATS

IN THE 2-YEAR INHALATION STUDY

OF TETRAFLUOROETHYLENE

TABLE A1 Summary of the Incidence of Neoplasms in Male Rats 

in the 2-Year Inhalation Study of Tetrafluoroethylene .................................. 81

TABLE A2 Individual Animal Tumor Pathology of Male Rats

in the 2-Year Inhalation Study of Tetrafluoroethylene .................................. 86

TABLE A3 Statistical Analysis of Primary Neoplasms in Male Rats

in the 2-Year Inhalation Study of Tetrafluoroethylene .................................. 108

TABLE A4a Historical Incidence of Renal Tubule Neoplasms

in Chamber Control Male F344/N Rats .............................................. 115

TABLE A4b Historical Incidence of Hepatocellular Neoplasms 

in Chamber Control Male F344/N Rats .............................................. 115

TABLE A4c Historical Incidence of Mononuclear Cell Leukemia

in Chamber Control Male F344/N Rats .............................................. 116

TABLE A5 Summary of the Incidence of Nonneoplastic Lesions in Male Rats

in the 2-Year Inhalation Study of Tetrafluoroethylene .................................. 117
80 Tetrafluoroethylene, NTP TR 450
Tetrafluoroethylene, NTP TR 450 81

TABLE A1

Summary of the Incidence of Neoplasms in Male Rats in the 2-Year Inhalation Study of Tetrafluoroethylene a

0 ppm 156 ppm 312 ppm 625 ppm

Disposition Summary

Animals initially in study 60 60 60 60

15-Month interim evaluation 10 10 10 10

Early deaths

Moribund 27 34 32 48

Natural deaths 6 4 1 1

Survivors

Terminal sacrifice 17 12 17 1

Animals examined microscopically 60 60 60 60

15-Month Interim Evaluation

Alimentary System

Intestine large, colon (10) (10) (10) (10)

Polyp adenomatous 1 (10%) 

Intestine small, duodenum (10) (10) (10) (10)

Liver (10) (10) (10) (10)

Hepatocellular carcinoma 1 (10%) 

Hepatocellular adenoma 1 (10%) 

Mesentery (2) (2) (4)

Endocrine System

Pituitary gland (10) (9) (10) (10)

Pars distalis, adenoma 2 (20%) 3 (33%) 1 (10%) 4 (40%) 

Pars distalis, adenoma, multiple 1 (10%) 

Pars intermedia, adenoma 1 (10%) 

Thyroid gland (10) (10) (10) (10)

Follicular cell, adenoma 1 (10%) 

Genital System

Epididymis (10) (10) (10) (10)

Preputial gland (10) (10) (10) (10)

Carcinoma 1 (10%) 

Testes (10) (10) (10) (10)

Bilateral, interstitial cell, adenoma 7 (70%) 5 (50%) 10 (100%) 9 (90%) 

Interstitial cell, adenoma 2 (20%) 2 (20%) 1 (10%) 

Integumentary System

Skin (10) (10) (10) (10)

Subcutaneous tissue, sarcoma 1 (10%) 

Respiratory System

Lung (10) (10) (10) (10)

Alveolar/bronchiolar carcinoma 1 (10%) 
82 Tetrafluoroethylene, NTP TR 450

TABLE A1

Summary of the Incidence of Neoplasms in Male Rats in the 2-Year Inhalation Study of Tetrafluoroethylene (continued)

0 ppm 156 ppm 312 ppm 625 ppm

15-Month Interim Evaluation (continued)

Urinary System

Kidney (10) (10) (10) (10)

Renal tubule, carcinoma 1 (10%) 

Urinary bladder (10) (10) (10) (10)

Transitional epithelium, papilloma 1 (10%) 

Systemic Lesions

Multiple organs (10) (10) (10) (10) b

Leukemia mononuclear 1 (10%) 

Mesothelioma malignant 1 (10%) 

Systems Examined With No Neoplasms Observed

Cardiovascular System

General Body System

Hematopoietic System

Musculoskeletal System

Nervous System

Special Senses System

2-Year Study

Alimentary System

Intestine large, colon (50) (50) (50) (50)

Intestine large, cecum (50) (50) (50) (50)

Intestine small, duodenum (50) (50) (50) (50)

Intestine small, jejunum (48) (47) (49) (50)

Intestine small, ileum (49) (49) (50) (50)

Liver (50) (50) (50) (50)

Hepatocellular carcinoma 1 (2%) 1 (2%) 10 (20%) 3 (6%) 

Hepatocellular adenoma 2 (4%) 3 (6%) 5 (10%) 4 (8%) 

Hepatocellular adenoma, multiple 1 (2%) 3 (6%) 3 (6%) 1 (2%) 

Hepatocholangioma 1 (2%) 

Mesentery (15) (11) (18) (14)

Hepatocellular carcinoma, metastatic, liver 1 (7%) 

Pancreas (50) (50) (50) (50)

Hepatocellular carcinoma, metastatic, liver 1 (2%) 

Acinus, adenoma 2 (4%) 1 (2%) 1 (2%) 

Pharynx (1) 

Palate, squamous cell carcinoma 1 (100%) 

Salivary glands (50) (50) (50) (50)

Stomach, forestomach (50) (50) (50) (50)

Stomach, glandular (50) (50) (50) (50)

Tongue (1) (1) (1)

Squamous cell papilloma 1 (100%) 1 (100%) 
Tetrafluoroethylene, NTP TR 450 83

TABLE A1

Summary of the Incidence of Neoplasms in Male Rats in the 2-Year Inhalation Study of Tetrafluoroethylene (continued)

0 ppm 156 ppm 312 ppm 625 ppm

2-Year Study (continued)

Cardiovascular System

Heart (50) (50) (50) (50)

Schwannoma NOS 1 (2%) 

Endocrine System

Adrenal cortex (50) (50) (50) (50)

Adenoma 2 (4%) 

Adrenal medulla (50) (50) (50) (50)

Ganglioneuroma 1 (2%) 

Pheochromocytoma malignant 2 (4%) 1 (2%) 

Pheochromocytoma complex 1 (2%) 

Pheochromocytoma benign 15 (30%) 8 (16%) 8 (16%) 6 (12%) 

Bilateral, pheochromocytoma benign 4 (8%) 3 (6%) 1 (2%) 4 (8%) 

Islets, pancreatic (50) (50) (50) (50)

Adenoma 3 (6%) 1 (2%) 1 (2%) 2 (4%) 

Carcinoma 1 (2%) 5 (10%) 1 (2%) 1 (2%) 

Parathyroid gland (50) (50) (50) (49)

Pituitary gland (50) (49) (49) (49)

Pars distalis, adenoma 39 (78%) 37 (76%) 35 (71%) 23 (47%) 

Pars intermedia, adenoma 1 (2%) 

Thyroid gland (50) (50) (50) (50)

C-cell, adenoma 7 (14%) 8 (16%) 5 (10%) 4 (8%) 

C-cell, carcinoma 2 (4%) 1 (2%) 4 (8%) 1 (2%) 

Follicular cell, adenoma 1 (2%) 1 (2%) 

General Body System

None 

Genital System

Epididymis (50) (50) (50) (50)

Preputial gland (50) (50) (50) (49)

Adenoma 1 (2%) 3 (6%) 5 (10%) 2 (4%) 

Carcinoma 3 (6%) 3 (6%) 1 (2%) 4 (8%) 

Bilateral, carcinoma 1 (2%) 

Prostate (50) (50) (50) (50)

Seminal vesicle (50) (50) (50) (50)

Testes (50) (50) (50) (50)

Bilateral, interstitial cell, adenoma 35 (70%) 37 (74%) 40 (80%) 42 (84%) 

Interstitial cell, adenoma 4 (8%) 3 (6%) 8 (16%) 5 (10%) 

Hematopoietic System

Bone marrow (50) (50) (50) (50)

Lymph node (11) (17) (16) (17)

Lymph node, bronchial (45) (50) (46) (47)

Lymph node, mandibular (50) (49) (49) (46)

Lymph node, mesenteric (50) (50) (50) (50)

Lymph node, mediastinal (49) (47) (48) (46)

Spleen (50) (50) (50) (50)

Thymus (49) (47) (47) (45)
84 Tetrafluoroethylene, NTP TR 450

TABLE A1

Summary of the Incidence of Neoplasms in Male Rats in the 2-Year Inhalation Study of Tetrafluoroethylene (continued)

0 ppm 156 ppm 312 ppm 625 ppm

2-Year Study (continued)

Integumentary System

Mammary gland (33) (36) (41) (34)

Adenoma 1 (3%) 

Carcinoma 1 (3%) 1 (2%) 

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

Skin (49) (50) (50) (50)

Basosquamous tumor benign 2 (4%) 1 (2%) 

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

Squamous cell carcinoma 1 (2%) 1 (2%) 

Squamous cell papilloma 1 (2%) 1 (2%) 

Subcutaneous tissue, fibroma 3 (6%) 1 (2%) 1 (2%) 

Subcutaneous tissue, fibrosarcoma 1 (2%) 1 (2%) 

Subcutaneous tissue, hemangiosarcoma 1 (2%) 

Subcutaneous tissue, neurofibroma 1 (2%) 1 (2%) 

Subcutaneous tissue, neurofibrosarcoma 1 (2%) 

Subcutaneous tissue, sarcoma 1 (2%) 

Musculoskeletal System

Bone (50) (50) (50) (50)

Osteosarcoma 1 (2%) 

Nervous System

Brain (50) (50) (50) (50)

Meningioma NOS 1 (2%) 

Respiratory System

Larynx (50) (50) (50) (50)

Lung (50) (50) (50) (50)

Alveolar/bronchiolar adenoma 1 (2%) 2 (4%) 1 (2%) 

Carcinoma, metastatic, kidney 1 (2%) 

Chordoma, metastatic, uncertain primary site 1 (2%) 1 (2%) 

Hepatocellular carcinoma, metastatic, liver 1 (2%) 

Nose (50) (50) (50) (50)

Trachea (50) (50) (50) (50)

Special Senses System

Zymbal's gland (1) 

Carcinoma 1 (100%) 

Urinary System

Kidney (50) (50) (50) (50)

Bilateral, renal tubule, adenoma 1 (2%) 

Renal tubule, adenoma 5 (10%) 3 (6%) 

Renal tubule, carcinoma 1 (2%) 2 (4%) 

Transitional epithelium, papilloma 1 (2%) 

Urinary bladder (49) (50) (50) (50)

Transitional epithelium, papilloma 3 (6%) 
Tetrafluoroethylene, NTP TR 450 85

TABLE A1

Summary of the Incidence of Neoplasms in Male Rats in the 2-Year Inhalation Study of Tetrafluoroethylene (continued)

0 ppm 156 ppm 312 ppm 625 ppm

2-Year Study (continued)

Systemic Lesions

Multiple organs (50) (50) (50) (50)

Leukemia mononuclear 34 (68%) 43 (86%) 38 (76%) 31 (62%) 

Mesothelioma malignant 5 (10%) 1 (2%) 2 (4%) 1 (2%) 

Neoplasm Summary

Total animals with primary neoplasmsc

15-Month interim evaluation 10 9 10 10

2-Year study 49 49 50 49

Total primary neoplasms

15-Month interim evaluation 16 12 13 18

2-Year study 177 175 194 149

Total animals with benign neoplasms

15-Month interim evaluation 10 9 10 10

2-Year study 49 48 50 49

Total benign neoplasms

15-Month interim evaluation 14 12 12 14

2-Year study 126 117 127 106

Total animals with malignant neoplasms

15-Month interim evaluation 2 1 4

2-Year study 39 46 48 35

Total malignant neoplasms

15-Month interim evaluation 2 1 4

2-Year study 51 57 66 43

Total animals with metastatic neoplasms

2-Year study 1 1 1 2

Total metastatic neoplasms

2-Year study 1 1 1 3

Total animals with malignant neoplasms

 of uncertain primary site

2-Year study 1 1

Total animals with uncertain neoplasms-

 benign or malignant

2-Year study 1 1

Total uncertain neoplasms

2-Year study 1 1

Number of animals examined microscopically at the site and the number of animals with neoplasm a

Number of animals with any tissue examined microscopically b

Primary neoplasms: all neoplasms except metastatic neoplasms c
86 Tetrafluoroethylene, NTP TR 450

TABLE A2

Individual Animal Tumor Pathology of Male Rats in the 2-Year Inhalation Study of Tetrafluoroethylene: 0 ppm 

3 3 4 5 5 5 5 5 5 5 5 6 6 6 6 6 6 6 6 6 6 6 6 7 7

Number of Days on Study 3 7 8 0 2 5 5 8 9 9 9 2 3 3 4 5 6 7 7 7 8 9 9 0 0

6 1 9 9 5 5 9 8 1 3 4 4 2 5 9 9 4 4 7 9 6 0 1 1 2

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

Carcass ID Number 2 5 5 1 5 3 5 2 4 5 4 4 0 2 5 0 4 1 2 4 3 0 2 3 3

0 2 6 3 0 0 3 8 3 9 8 4 7 3 4 6 7 6 6 1 6 4 7 3 4

Alimentary System 

Esophagus + + + + + + + + + + + + + + + + + + + + + + + + +

Intestine large, colon + + + + + + + + + + + + + + + + + + + + + + + + +

Intestine large, rectum + + + + + + + + + + + + + + + + + + + + + A + + +

Intestine large, cecum + + + + + + + + + + + + + + + + + + + + + + + + +

Intestine small, duodenum + + + + + + + + + + + + + + + + + + + + + + + + +

Intestine small, jejunum + + + + + + A + + + + + + + + + + + + + + + + + +

Intestine small, ileum + + + + + + + + + + + + + + + + + + + + + A + + +

Liver + + + + + + + + + + + + + + + + + + + + + + + + +

Hepatocellular carcinoma X

Hepatocellular adenoma X

Hepatocellular adenoma, multiple

Mesentery + + +

Pancreas + + + + + + + + + + + + + + + + + + + + + + + + +

Pharynx +

Palate, squamous cell carcinoma X

Salivary glands + + + + + + + + + + + + + + + + + + + + + + + + +

Stomach, forestomach + + + + + + + + + + + + + + + + + + + + + + + + +

Stomach, glandular + + + + + + + + + + + + + + + + + + + + + + + + +

Tongue

Squamous cell papilloma

Tooth + +

Cardiovascular System 

Blood vessel

Heart + + + + + + + + + + + + + + + + + + + + + + + + +

Endocrine System 

Adrenal cortex + + + + + + + + + + + + + + + + + + + + + + + + +

Adrenal medulla + + + + + + + + + + + + + + + + + + + + + + + + +

Pheochromocytoma malignant

Pheochromocytoma benign X X X X X X X X

Bilateral, pheochromocytoma benign X

Islets, pancreatic + + + + + + + + + + + + + + + + + + + + + + + + +

Adenoma

Carcinoma X

Parathyroid gland + + + + + + + + + + + + + + + + + + + + + + + + +

Pituitary gland + + + + + + + + + + + + + + + + + + + + + + + + +

Pars distalis, adenoma X X X X X X X X X X X X X X X X X

Pars intermedia, adenoma X

Thyroid gland + + + + + + + + + + + + + + + + + + + + + + + + +

C-cell, adenoma

C-cell, carcinoma

Follicular cell, adenoma

General Body System 

None

+: Tissue examined microscopically M: Missing tissue X: Lesion present

A: Autolysis precludes examination I: Insufficient tissue Blank: Not examined
Tetrafluoroethylene, NTP TR 450 87

TABLE A2

Individual Animal Tumor Pathology of Male Rats in the 2-Year Inhalation Study of Tetrafluoroethylene: 0 ppm (continued)

7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7

Number of Days on Study 0 0 0 0 1 1 2 2 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

5 7 8 9 5 6 1 7 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Total

Carcass ID Number 4 1 3 1 2 2 0 2 0 0 0 1 1 1 1 1 2 3 3 3 4 4 4 5 5 Tissues/

6 2 7 1 5 4 9 1 1 3 8 4 5 7 8 9 9 1 2 9 0 2 5 1 7 Tumors

Alimentary System 

Esophagus + + + + + + + + + + + + + + + + + + + + + + + + + 50

Intestine large, colon + + + + + + + + + + + + + + + + + + + + + + + + + 50

Intestine large, rectum + + + + + + + + + + + + + + + + + + + + + + + + + 49

Intestine large, cecum + + + + + + + + + + + + + + + + + + + + + + + + + 50

Intestine small, duodenum + + + + + + + + + + + + + + + + + + + + + + + + + 50

Intestine small, jejunum + + + + + A + + + + + + + + + + + + + + + + + + + 48

Intestine small, ileum + + + + + + + + + + + + + + + + + + + + + + + + + 49

Liver + + + + + + + + + + + + + + + + + + + + + + + + + 50

Hepatocellular carcinoma 1

Hepatocellular adenoma X 2

Hepatocellular adenoma, multiple X 1

Mesentery + + + + + + + + + + + + 15

Pancreas + + + + + + + + + + + + + + + + + + + + + + + + + 50

Pharynx 1

Palate, squamous cell carcinoma 1

Salivary glands + + + + + + + + + + + + + + + + + + + + + + + + + 50

Stomach, forestomach + + + + + + + + + + + + + + + + + + + + + + + + + 50

Stomach, glandular + + + + + + + + + + + + + + + + + + + + + + + + + 50

Tongue + 1

Squamous cell papilloma X 1

Tooth 2

Cardiovascular System 

Blood vessel + 1

Heart + + + + + + + + + + + + + + + + + + + + + + + + + 50

Endocrine System 

Adrenal cortex + + + + + + + + + + + + + + + + + + + + + + + + + 50

Adrenal medulla + + + + + + + + + + + + + + + + + + + + + + + + + 50

Pheochromocytoma malignant X X 2

Pheochromocytoma benign X X X X X X X 15

Bilateral, pheochromocytoma benign X X X 4

Islets, pancreatic + + + + + + + + + + + + + + + + + + + + + + + + + 50

Adenoma X X X 3

Carcinoma 1

Parathyroid gland + + + + + + + + + + + + + + + + + + + + + + + + + 50

Pituitary gland + + + + + + + + + + + + + + + + + + + + + + + + + 50

Pars distalis, adenoma X X X X X X X X X X X X X X X X X X X X X X 39

Pars intermedia, adenoma 1

Thyroid gland + + + + + + + + + + + + + + + + + + + + + + + + + 50

C-cell, adenoma X X X X X X X 7

C-cell, carcinoma X X 2

Follicular cell, adenoma X 1

General Body System 

None 
88 Tetrafluoroethylene, NTP TR 450

TABLE A2

Individual Animal Tumor Pathology of Male Rats in the 2-Year Inhalation Study of Tetrafluoroethylene: 0 ppm (continued)

3 3 4 5 5 5 5 5 5 5 5 6 6 6 6 6 6 6 6 6 6 6 6 7 7

Number of Days on Study 3 7 8 0 2 5 5 8 9 9 9 2 3 3 4 5 6 7 7 7 8 9 9 0 0

6 1 9 9 5 5 9 8 1 3 4 4 2 5 9 9 4 4 7 9 6 0 1 1 2

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

Carcass ID Number 2 5 5 1 5 3 5 2 4 5 4 4 0 2 5 0 4 1 2 4 3 0 2 3 3

0 2 6 3 0 0 3 8 3 9 8 4 7 3 4 6 7 6 6 1 6 4 7 3 4

Genital System 

Epididymis + + + + + + + + + + + + + + + + + + + + + + + + +

Preputial gland + + + + + + + + + + + + + + + + + + + + + + + + +

Adenoma

Carcinoma

Prostate + + + + + + + + + + + + + + + + + + + + + + + + +

Seminal vesicle + + + + + + + + + + + + + + + + + + + + + + + + +

Testes + + + + + + + + + + + + + + + + + + + + + + + + +

Bilateral, interstitial cell, adenoma X X X X X X X X X X X X X X X X X

Interstitial cell, adenoma X

Hematopoietic System 

Blood

Bone marrow + + + + + + + + + + + + + + + + + + + + + + + + +

Lymph node + + + + + +

Lymph node, bronchial + + + + + M + + + + + + M + + M + + + + + + + + +

Lymph node, mandibular + + + + + + + + + + + + + + + + + + + + + + + + +

Lymph node, mesenteric + + + + + + + + + + + + + + + + + + + + + + + + +

Lymph node, mediastinal + + + + + + + + + + + + + + M + + + + + + + + + +

Spleen + + + + + + + + + + + + + + + + + + + + + + + + +

Thymus + + + + + + + + + + + + + + + + M + + + + + + + +

Integumentary System 

Mammary gland M + + M M + M + + + + + + + M + + + M + + M + + +

Fibroadenoma

Skin + + + + + + + + + + + + + + + + + + + M + + + + +

Basosquamous tumor benign

Keratoacanthoma X

Squamous cell carcinoma

Squamous cell papilloma

Subcutaneous tissue, fibroma X X

Subcutaneous tissue, neurofibroma X

Musculoskeletal System 

Bone + + + + + + + + + + + + + + + + + + + + + + + + +

Nervous System 

Brain + + + + + + + + + + + + + + + + + + + + + + + + +

Respiratory System 

Larynx + + + + + + + + + + + + + + + + + + + + + + + + +

Lung + + + + + + + + + + + + + + + + + + + + + + + + +

Carcinoma, metastatic, kidney X

Nose + + + + + + + + + + + + + + + + + + + + + + + + +

Trachea + + + + + + + + + + + + + + + + + + + + + + + + +

Special Senses System 

Eye + + + + + + + + + + + + + + + + + + + +
Tetrafluoroethylene, NTP TR 450 89

TABLE A2

Individual Animal Tumor Pathology of Male Rats in the 2-Year Inhalation Study of Tetrafluoroethylene: 0 ppm (continued)

7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7

Number of Days on Study 0 0 0 0 1 1 2 2 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

5 7 8 9 5 6 1 7 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Total

Carcass ID Number 4 1 3 1 2 2 0 2 0 0 0 1 1 1 1 1 2 3 3 3 4 4 4 5 5 Tissues/

6 2 7 1 5 4 9 1 1 3 8 4 5 7 8 9 9 1 2 9 0 2 5 1 7 Tumors

Genital System 

Epididymis + + + + + + + + + + + + + + + + + + + + + + + + + 50

Preputial gland + + + + + + + + + + + + + + + + + + + + + + + + + 50

Adenoma X 1

Carcinoma X X X 3

Prostate + + + + + + + + + + + + + + + + + + + + + + + + + 50

Seminal vesicle + + + + + + + + + + + + + + + + + + + + + + + + + 50

Testes + + + + + + + + + + + + + + + + + + + + + + + + + 50

Bilateral, interstitial cell, adenoma X X X X X X X X X X X X X X X X X X 35

Interstitial cell, adenoma X X X 4

Hematopoietic System 

Blood + 1

Bone marrow + + + + + + + + + + + + + + + + + + + + + + + + + 50

Lymph node + + + + + 11

Lymph node, bronchial + + + + + M M + + + + + + + + + + + + + + + + + + 45

Lymph node, mandibular + + + + + + + + + + + + + + + + + + + + + + + + + 50

Lymph node, mesenteric + + + + + + + + + + + + + + + + + + + + + + + + + 50

Lymph node, mediastinal + + + + + + + + + + + + + + + + + + + + + + + + + 49

Spleen + + + + + + + + + + + + + + + + + + + + + + + + + 50

Thymus + + + + + + + + + + + + + + + + + + + + + + + + + 49

Integumentary System 

Mammary gland M + + + + + + M + + M + M + M M + M M + + + + M M 33

Fibroadenoma X X 2

Skin + + + + + + + + + + + + + + + + + + + + + + + + + 49

Basosquamous tumor benign X X 2

Keratoacanthoma X X 3

Squamous cell carcinoma X 1

Squamous cell papilloma X 1

Subcutaneous tissue, fibroma X 3

Subcutaneous tissue, neurofibroma 1

Musculoskeletal System 

Bone + + + + + + + + + + + + + + + + + + + + + + + + + 50

Nervous System 

Brain + + + + + + + + + + + + + + + + + + + + + + + + + 50

Respiratory System 

Larynx + + + + + + + + + + + + + + + + + + + + + + + + + 50

Lung + + + + + + + + + + + + + + + + + + + + + + + + + 50

Carcinoma, metastatic, kidney 1

Nose + + + + + + + + + + + + + + + + + + + + + + + + + 50

Trachea + + + + + + + + + + + + + + + + + + + + + + + + + 50

Special Senses System 

Eye + + + + + + + + + + + + + + + + + + + + + + + + + 45
90 Tetrafluoroethylene, NTP TR 450

TABLE A2

Individual Animal Tumor Pathology of Male Rats in the 2-Year Inhalation Study of Tetrafluoroethylene: 0 ppm (continued)

3 3 4 5 5 5 5 5 5 5 5 6 6 6 6 6 6 6 6 6 6 6 6 7 7

Number of Days on Study 3 7 8 0 2 5 5 8 9 9 9 2 3 3 4 5 6 7 7 7 8 9 9 0 0

6 1 9 9 5 5 9 8 1 3 4 4 2 5 9 9 4 4 7 9 6 0 1 1 2

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

Carcass ID Number 2 5 5 1 5 3 5 2 4 5 4 4 0 2 5 0 4 1 2 4 3 0 2 3 3

0 2 6 3 0 0 3 8 3 9 8 4 7 3 4 6 7 6 6 1 6 4 7 3 4

Urinary System 

Kidney + + + + + + + + + + + + + + + + + + + + + + + + +

Renal tubule, carcinoma X

Urinary bladder + + + + + + + + + + + + + + + + + + + I + + + + +

Systemic Lesions 

Multiple organs + + + + + + + + + + + + + + + + + + + + + + + + +

Leukemia mononuclear X X X X X X X X X X X X X X X X X X X

Mesothelioma malignant X X X X
Tetrafluoroethylene, NTP TR 450 91

TABLE A2

Individual Animal Tumor Pathology of Male Rats in the 2-Year Inhalation Study of Tetrafluoroethylene: 0 ppm (continued)

7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7

Number of Days on Study 0 0 0 0 1 1 2 2 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

5 7 8 9 5 6 1 7 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Total

Carcass ID Number 4 1 3 1 2 2 0 2 0 0 0 1 1 1 1 1 2 3 3 3 4 4 4 5 5 Tissues/

6 2 7 1 5 4 9 1 1 3 8 4 5 7 8 9 9 1 2 9 0 2 5 1 7 Tumors

Urinary System 

Kidney + + + + + + + + + + + + + + + + + + + + + + + + + 50

Renal tubule, carcinoma 1

Urinary bladder + + + + + + + + + + + + + + + + + + + + + + + + + 49

Systemic Lesions 

Multiple organs + + + + + + + + + + + + + + + + + + + + + + + + + 50

Leukemia mononuclear X X X X X X X X X X X X X X X 34

Mesothelioma malignant X 5
92 Tetrafluoroethylene, NTP TR 450

TABLE A2

Individual Animal Tumor Pathology of Male Rats in the 2-Year Inhalation Study of Tetrafluoroethylene: 156 ppm 

3 4 4 4 5 5 5 5 5 5 5 5 5 5 5 6 6 6 6 6 6 6 6 6 6

Number of Days on Study 5 5 7 9 0 2 3 5 5 8 8 9 9 9 9 0 0 1 1 2 2 5 5 5 6

1 0 0 4 9 9 3 5 5 1 9 2 4 4 4 0 4 2 6 1 7 2 3 9 4

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

Carcass ID Number 7 5 5 4 4 3 5 2 4 3 6 7 2 3 4 6 4 6 6 3 2 6 2 3 3

3 0 3 6 1 7 2 8 4 9 0 8 9 0 8 1 3 7 4 1 7 2 2 6 4

Alimentary System 

Esophagus + + + + + + + + + + + + + + + + + + + + + + + + +

Intestine large, colon + + + + + + + + + + + + + + + + + + + + + + + + +

Intestine large, rectum + + + + + + + + + + + + + + + + + + + + + + + + +

Intestine large, cecum + + + + + + + + + + + + + + + + + + + + + + + + +

Intestine small, duodenum + + + + + + + + + + + + + + + + + + + + + + + + +

Intestine small, jejunum + + + + A A + + + + + + + + + + + A + + + + + + +

Intestine small, ileum + + + + A + + + + + + + + + + + + + + + + + + + +

Liver + + + + + + + + + + + + + + + + + + + + + + + + +

Hepatocellular carcinoma X

Hepatocellular adenoma X X

Hepatocellular adenoma, multiple

Hepatocholangioma

Mesentery + + + + +

Pancreas + + + + + + + + + + + + + + + + + + + + + + + + +

Acinus, adenoma

Salivary glands + + + + + + + + + + + + + + + + + + + + + + + + +

Stomach, forestomach + + + + + + + + + + + + + + + + + + + + + + + + +

Stomach, glandular + + + + + + + + + + + + + + + + + + + + + + + + +

Tongue

Squamous cell papilloma

Tooth +

Cardiovascular System 

Heart + + + + + + + + + + + + + + + + + + + + + + + + +

Schwannoma NOS X

Endocrine System 

Adrenal cortex + + + + + + + + + + + + + + + + + + + + + + + + +

Adrenal medulla + + + + + + + + + + + + + + + + + + + + + + + + +

Pheochromocytoma complex

Pheochromocytoma benign X X X X

Bilateral, pheochromocytoma benign X

Islets, pancreatic + + + + + + + + + + + + + + + + + + + + + + + + +

Adenoma

Carcinoma X

Parathyroid gland + + + + + + + + + + + + + + + + + + + + + + + + +

Pituitary gland + + + + I + + + + + + + + + + + + + + + + + + + +

Pars distalis, adenoma X X X X X X X X X X X X X X X X X X X

Thyroid gland + + + + + + + + + + + + + + + + + + + + + + + + +

C-cell, adenoma X X X X

C-cell, carcinoma

General Body System 

None

Genital System

Epididymis + + + + + + + + + + + + + + + + + + + + + + + + +

Preputial gland + + + + + + + + + + + + + + + + + + + + + + + + +

Adenoma

Carcinoma X X

Prostate + + + + + + + + + + + + + + + + + + + + + + + + +
Tetrafluoroethylene, NTP TR 450 93

TABLE A2

Individual Animal Tumor Pathology of Male Rats in the 2-Year Inhalation Study of Tetrafluoroethylene: 156 ppm (continued)

6 6 6 6 6 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7

Number of Days on Study 6 8 8 9 9 0 0 0 1 1 1 1 3 3 3 3 3 3 3 3 3 3 3 3 3

4 1 6 1 8 0 2 5 1 5 6 6 0 3 3 3 3 3 3 3 3 3 3 3 3

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Total

Carcass ID Number 5 3 4 6 3 7 7 6 6 7 3 3 7 2 2 2 4 5 5 5 6 6 7 7 8 Tissues/

5 2 7 5 5 6 2 9 3 9 3 8 0 1 5 6 9 1 7 9 6 8 4 7 0 Tumors

Alimentary System 

Esophagus + + + + + + + + + + + + + + + + + + + + + + + + + 50

Intestine large, colon + + + + + + + + + + + + + + + + + + + + + + + + + 50

Intestine large, rectum + + + + + + + + + + + + + + + + + + + + + + + + + 50

Intestine large, cecum + + + + + + + + + + + + + + + + + + + + + + + + + 50

Intestine small, duodenum + + + + + + + + + + + + + + + + + + + + + + + + + 50

Intestine small, jejunum + + + + + + + + + + + + + + + + + + + + + + + + + 47

Intestine small, ileum + + + + + + + + + + + + + + + + + + + + + + + + + 49

Liver + + + + + + + + + + + + + + + + + + + + + + + + + 50

Hepatocellular carcinoma 1

Hepatocellular adenoma X 3

Hepatocellular adenoma, multiple X X X 3

Hepatocholangioma X 1

Mesentery + + + + + + 11

Pancreas + + + + + + + + + + + + + + + + + + + + + + + + + 50

Acinus, adenoma X X 2

Salivary glands + + + + + + + + + + + + + + + + + + + + + + + + + 50

Stomach, forestomach + + + + + + + + + + + + + + + + + + + + + + + + + 50

Stomach, glandular + + + + + + + + + + + + + + + + + + + + + + + + + 50

Tongue + 1

Squamous cell papilloma X 1

Tooth + 2

Cardiovascular System 

Heart + + + + + + + + + + + + + + + + + + + + + + + + + 50

Schwannoma NOS 1

Endocrine System 

Adrenal cortex + + + + + + + + + + + + + + + + + + + + + + + + + 50

Adrenal medulla + + + + + + + + + + + + + + + + + + + + + + + + + 50

Pheochromocytoma complex X 1

Pheochromocytoma benign X X X X 8

Bilateral, pheochromocytoma benign X X 3

Islets, pancreatic + + + + + + + + + + + + + + + + + + + + + + + + + 50

Adenoma X 1

Carcinoma X X X X 5

Parathyroid gland + + + + + + + + + + + + + + + + + + + + + + + + + 50

Pituitary gland + + + + + + + + + + + + + + + + + + + + + + + + + 49

Pars distalis, adenoma X X X X X X X X X X X X X X X X X X 37

Thyroid gland + + + + + + + + + + + + + + + + + + + + + + + + + 50

C-cell, adenoma X X X X 8

C-cell, carcinoma X 1

General Body System 

None 

Genital System 

Epididymis + + + + + + + + + + + + + + + + + + + + + + + + + 50

Preputial gland + + + + + + + + + + + + + + + + + + + + + + + + + 50

Adenoma X X X 3

Carcinoma X 3

Prostate + + + + + + + + + + + + + + + + + + + + + + + + + 50
94 Tetrafluoroethylene, NTP TR 450

TABLE A2

Individual Animal Tumor Pathology of Male Rats in the 2-Year Inhalation Study of Tetrafluoroethylene: 156 ppm (continued)

3 4 4 4 5 5 5 5 5 5 5 5 5 5 5 6 6 6 6 6 6 6 6 6 6

Number of Days on Study 5 5 7 9 0 2 3 5 5 8 8 9 9 9 9 0 0 1 1 2 2 5 5 5 6

1 0 0 4 9 9 3 5 5 1 9 2 4 4 4 0 4 2 6 1 7 2 3 9 4

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

Carcass ID Number 7 5 5 4 4 3 5 2 4 3 6 7 2 3 4 6 4 6 6 3 2 6 2 3 3

3 0 3 6 1 7 2 8 4 9 0 8 9 0 8 1 3 7 4 1 7 2 2 6 4

Genital System (continued)

Seminal vesicle + + + + + + + + + + + + + + + + + + + + + + + + +

Testes + + + + + + + + + + + + + + + + + + + + + + + + +

Bilateral, interstitial cell, adenoma X X X X X X X X X X X X X X X X X

Interstitial cell, adenoma X

Hematopoietic System 

Blood +

Bone marrow + + + + + + + + + + + + + + + + + + + + + + + + +

Lymph node + + + + + + + + + +

Lymph node, bronchial + + + + + + + + + + + + + + + + + + + + + + + + +

Lymph node, mandibular + + + + + + + + + + + + + + + + + + + + + + + + +

Lymph node, mesenteric + + + + + + + + + + + + + + + + + + + + + + + + +

Lymph node, mediastinal + + + + + + + + + + + + + + + + + + M + + + + + +

Spleen + + + + + + + + + + + + + + + + + + + + + + + + +

Thymus + + + + + + + + + + + + + + + M + + M + + + + + +

Integumentary System 

Mammary gland + + M + + + M + + + + M + M M + M + M + + + + + +

Carcinoma

Fibroadenoma

Skin + + + + + + + + + + + + + + + + + + + + + + + + +

Subcutaneous tissue, fibroma

Musculoskeletal System 

Bone + + + + + + + + + + + + + + + + + + + + + + + + +

Osteosarcoma

Nervous System 

Brain + + + + + + + + + + + + + + + + + + + + + + + + +

Respiratory System 

Larynx + + + + + + + + + + + + + + + + + + + + + + + + +

Lung + + + + + + + + + + + + + + + + + + + + + + + + +

Alveolar/bronchiolar adenoma

Chordoma, metastatic, uncertain

 primary site 

Nose + + + + + + + + + + + + + + + + + + + + + + + + +

Trachea + + + + + + + + + + + + + + + + + + + + + + + + +

Special Senses System 

Eye + + + + + + + + + + + + + + + + + +

Harderian gland

Urinary System 

Kidney + + + + + + + + + + + + + + + + + + + + + + + + +

Urinary bladder + + + + + + + + + + + + + + + + + + + + + + + + +

Transitional epithelium, papilloma X

Systemic Lesions 

Multiple organs + + + + + + + + + + + + + + + + + + + + + + + + +

Leukemia mononuclear X X X X X X X X X X X X X X X X X X X X X

Mesothelioma malignant
Tetrafluoroethylene, NTP TR 450 95

TABLE A2

Individual Animal Tumor Pathology of Male Rats in the 2-Year Inhalation Study of Tetrafluoroethylene: 156 ppm (continued)

6 6 6 6 6 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7

Number of Days on Study 6 8 8 9 9 0 0 0 1 1 1 1 3 3 3 3 3 3 3 3 3 3 3 3 3

4 1 6 1 8 0 2 5 1 5 6 6 0 3 3 3 3 3 3 3 3 3 3 3 3

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Total

Carcass ID Number 5 3 4 6 3 7 7 6 6 7 3 3 7 2 2 2 4 5 5 5 6 6 7 7 8 Tissues/

5 2 7 5 5 6 2 9 3 9 3 8 0 1 5 6 9 1 7 9 6 8 4 7 0 Tumors

Genital System (continued)

Seminal vesicle + + + + + + + + + + + + + + + + + + + + + + + + + 50

Testes + + + + + + + + + + + + + + + + + + + + + + + + + 50

Bilateral, interstitial cell, adenoma X X X X X X X X X X X X X X X X X X X X 37

Interstitial cell, adenoma X X 3

Hematopoietic System 

Blood 1

Bone marrow + + + + + + + + + + + + + + + + + + + + + + + + + 50

Lymph node + + + + + + + 17

Lymph node, bronchial + + + + + + + + + + + + + + + + + + + + + + + + + 50

Lymph node, mandibular + + + + + + + + + + + + + + M + + + + + + + + + + 49

Lymph node, mesenteric + + + + + + + + + + + + + + + + + + + + + + + + + 50

Lymph node, mediastinal + + + + + M + + M + + + + + + + + + + + + + + + + 47

Spleen + + + + + + + + + + + + + + + + + + + + + + + + + 50

Thymus + + M + + + + + + + + + + + + + + + + + + + + + + 47

Integumentary System 

Mammary gland + M M + + M M + + + + M + + + + + + + M + + M + + 36

Carcinoma X 1

Fibroadenoma X X 2

Skin + + + + + + + + + + + + + + + + + + + + + + + + + 50

Subcutaneous tissue, fibroma X 1

Musculoskeletal System 

Bone + + + + + + + + + + + + + + + + + + + + + + + + + 50

Osteosarcoma X 1

Nervous System 

Brain + + + + + + + + + + + + + + + + + + + + + + + + + 50

Respiratory System 

Larynx + + + + + + + + + + + + + + + + + + + + + + + + + 50

Lung + + + + + + + + + + + + + + + + + + + + + + + + + 50

Alveolar/bronchiolar adenoma X 1

Chordoma, metastatic, uncertain 

 primary site X 1

Nose + + + + + + + + + + + + + + + + + + + + + + + + + 50

Trachea + + + + + + + + + + + + + + + + + + + + + + + + + 50

Special Senses System 

Eye + + + + + + + + + + + + M + + + + + + + + + + + + 42

Harderian gland + 1

Urinary System 

Kidney + + + + + + + + + + + + + + + + + + + + + + + + + 50

Urinary bladder + + + + + + + + + + + + + + + + + + + + + + + + + 50

Transitional epithelium, papilloma X X 3

Systemic Lesions 

Multiple organs + + + + + + + + + + + + + + + + + + + + + + + + + 50

Leukemia mononuclear X X X X X X X X X X X X X X X X X X X X X X 43

Mesothelioma malignant X 1
96 Tetrafluoroethylene, NTP TR 450

TABLE A2

Individual Animal Tumor Pathology of Male Rats in the 2-Year Inhalation Study of Tetrafluoroethylene: 312 ppm 

4 5 5 5 5 5 5 5 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

Number of Days on Study 1 3 4 5 6 7 7 8 1 1 1 1 1 2 2 3 3 3 3 3 5 6 6 6 7

3 8 7 9 4 5 6 1 4 4 6 7 7 1 7 1 2 2 5 8 8 3 4 4 4

1 2 2 2 2 1 1 1 2 2 1 1 1 2 2 2 1 2 2 2 2 2 2 2 1

Carcass ID Number 9 1 2 2 1 9 8 9 2 3 9 8 8 0 2 0 9 2 2 3 1 0 0 3 9

6 9 2 9 3 5 9 8 0 8 2 1 7 7 5 6 4 4 7 5 8 3 4 4 3

Alimentary System 

Esophagus + + + + + + + + + + + + + + + + + + + + + + + + +

Intestine large, colon + + + + + + + + + + + + + + + + + + + + + + + + +

Intestine large, rectum + + + + + + + + + + + + + + + + + + + + + + + + +

Intestine large, cecum + + + + + + + + + + + + + + + + + + + + + + + + +

Intestine small, duodenum + + + + + + + + + + + + + + + + + + + + + + + + +

Intestine small, jejunum + + + + + + + + + + + + + + + + + + + + + A + + +

Intestine small, ileum + + + + + + + + + + + + + + + + + + + + + + + + +

Liver + + + + + + + + + + + + + + + + + + + + + + + + +

Hepatocellular carcinoma X X X X

Hepatocellular adenoma X

Hepatocellular adenoma, multiple

Mesentery + + + + + + + + +

Pancreas + + + + + + + + + + + + + + + + + + + + + + + + +

Acinus, adenoma

Salivary glands + + + + + + + + + + + + + + + + + + + + + + + + +

Stomach, forestomach + + + + + + + + + + + + + + + + + + + + + + + + +

Stomach, glandular + + + + + + + + + + + + + + + + + + + + + + + + +

Tooth

Cardiovascular System 

Blood vessel +

Heart + + + + + + + + + + + + + + + + + + + + + + + + +

Endocrine System 

Adrenal cortex + + + + + + + + + + + + + + + + + + + + + + + + +

Adenoma

Adrenal medulla + + + + + + + + + + + + + + + + + + + + + + + + +

Pheochromocytoma malignant X

Pheochromocytoma benign X X X X

Bilateral, pheochromocytoma benign X

Islets, pancreatic + + + + + + + + + + + + + + + + + + + + + + + + +

Adenoma

Carcinoma

Parathyroid gland + + + + + + + + + + + + + + + + + + + + + + + + +

Pituitary gland + + + + + + + + + + + + + + + + + + + + + + + + +

Pars distalis, adenoma X X X X X X X X X X X X X X X X X

Thyroid gland + + + + + + + + + + + + + + + + + + + + + + + + +

C-cell, adenoma X

C-cell, carcinoma X

Follicular cell, adenoma X

General Body System 

None

Genital System 

Epididymis + + + + + + + + + + + + + + + + + + + + + + + + +

Preputial gland + + + + + + + + + + + + + + + + + + + + + + + + +

Adenoma X X X X

Carcinoma X

Bilateral, carcinoma X

Prostate + + + + + + + + + + + + + + + + + + + + + + + + +
Tetrafluoroethylene, NTP TR 450 97

TABLE A2

Individual Animal Tumor Pathology of Male Rats in the 2-Year Inhalation Study of Tetrafluoroethylene: 312 ppm (continued)

6 6 6 6 6 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7

Number of Days on Study 7 7 8 9 9 2 2 2 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

4 7 8 1 3 3 6 9 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

2 1 1 2 2 2 1 2 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 2 Total

Carcass ID Number 2 8 9 1 1 3 8 0 8 8 9 9 0 0 0 0 1 1 1 1 2 2 3 3 3 Tissues/

8 6 1 7 2 7 8 5 2 5 0 7 0 1 2 8 1 4 5 6 3 6 0 1 3 Tumors

Alimentary System 

Esophagus + + + + + + + + + + + + + + + + + + + + + + + + + 50

Intestine large, colon + + + + + + + + + + + + + + + + + + + + + + + + + 50

Intestine large, rectum + + + + + + + + + + + + + + + + + + + + + + + + + 50

Intestine large, cecum + + + + + + + + + + + + + + + + + + + + + + + + + 50

Intestine small, duodenum + + + + + + + + + + + + + + + + + + + + + + + + + 50

Intestine small, jejunum + + + + + + + + + + + + + + + + + + + + + + + + + 49

Intestine small, ileum + + + + + + + + + + + + + + + + + + + + + + + + + 50

Liver + + + + + + + + + + + + + + + + + + + + + + + + + 50

Hepatocellular carcinoma X X X X X X 10

Hepatocellular adenoma X X X X 5

Hepatocellular adenoma, multiple X X X 3

Mesentery + + + + + + + + + 18

Pancreas + + + + + + + + + + + + + + + + + + + + + + + + + 50

Acinus, adenoma X 1

Salivary glands + + + + + + + + + + + + + + + + + + + + + + + + + 50

Stomach, forestomach + + + + + + + + + + + + + + + + + + + + + + + + + 50

Stomach, glandular + + + + + + + + + + + + + + + + + + + + + + + + + 50

Tooth + 1

Cardiovascular System 

Blood vessel + + 3

Heart + + + + + + + + + + + + + + + + + + + + + + + + + 50

Endocrine System 

Adrenal cortex + + + + + + + + + + + + + + + + + + + + + + + + + 50

Adenoma X X 2

Adrenal medulla + + + + + + + + + + + + + + + + + + + + + + + + + 50

Pheochromocytoma malignant 1

Pheochromocytoma benign X X X X 8

Bilateral, pheochromocytoma benign 1

Islets, pancreatic + + + + + + + + + + + + + + + + + + + + + + + + + 50

Adenoma X 1

Carcinoma X 1

Parathyroid gland + + + + + + + + + + + + + + + + + + + + + + + + + 50

Pituitary gland + + + + + + + + + + M + + + + + + + + + + + + + + 49

Pars distalis, adenoma X X X X X X X X X X X X X X X X X X 35

Thyroid gland + + + + + + + + + + + + + + + + + + + + + + + + + 50

C-cell, adenoma X X X X 5

C-cell, carcinoma X X X 4

Follicular cell, adenoma 1

General Body System 

None 

Genital System 

Epididymis + + + + + + + + + + + + + + + + + + + + + + + + + 50

Preputial gland + + + + + + + + + + + + + + + + + + + + + + + + + 50

Adenoma X 5

Carcinoma 1

Bilateral, carcinoma 1

Prostate + + + + + + + + + + + + + + + + + + + + + + + + + 50
98 Tetrafluoroethylene, NTP TR 450

TABLE A2

Individual Animal Tumor Pathology of Male Rats in the 2-Year Inhalation Study of Tetrafluoroethylene: 312 ppm (continued)

4 5 5 5 5 5 5 5 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

Number of Days on Study 1 3 4 5 6 7 7 8 1 1 1 1 1 2 2 3 3 3 3 3 5 6 6 6 7

3 8 7 9 4 5 6 1 4 4 6 7 7 1 7 1 2 2 5 8 8 3 4 4 4

1 2 2 2 2 1 1 1 2 2 1 1 1 2 2 2 1 2 2 2 2 2 2 2 1

Carcass ID Number 9 1 2 2 1 9 8 9 2 3 9 8 8 0 2 0 9 2 2 3 1 0 0 3 9

6 9 2 9 3 5 9 8 0 8 2 1 7 7 5 6 4 4 7 5 8 3 4 4 3

Genital System (continued)

Seminal vesicle + + + + + + + + + + + + + + + + + + + + + + + + +

Testes + + + + + + + + + + + + + + + + + + + + + + + + +

Bilateral, interstitial cell, adenoma X X X X X X X X X X X X X X X X

Interstitial cell, adenoma X X X X X X X

Hematopoietic System 

Bone marrow + + + + + + + + + + + + + + + + + + + + + + + + +

Lymph node + + + + + + + +

Lymph node, bronchial + + + + + + + + + + + + + + + + + + + M + M + + +

Lymph node, mandibular + + + + + + + + + + + + + + + + + + + + + + + + +

Lymph node, mesenteric + + + + + + + + + + + + + + + + + + + + + + + + +

Lymph node, mediastinal + + + + + + M + + + + + + + + + + + + + + M + + +

Spleen + + + + + + + + + + + + + + + + + + + + + + + + +

Thymus + + M + + + + + + + + + + + + + + + + + M + + + +

Integumentary System 

Mammary gland M + + + + + M + + + + + + + + M + + + M + M + + +

Carcinoma X

Fibroadenoma

Skin + + + + + + + + + + + + + + + + + + + + + + + + +

Keratoacanthoma X

Squamous cell carcinoma

Subcutaneous tissue, fibrosarcoma X

Subcutaneous tissue, hemangiosarcoma X

Subcutaneous tissue, neurofibroma

Subcutaneous tissue,

 neurofibrosarcoma X 

Musculoskeletal System 

Bone + + + + + + + + + + + + + + + + + + + + + + + + +

Skeletal muscle

Nervous System 

Brain + + + + + + + + + + + + + + + + + + + + + + + + +

Meningioma NOS

Respiratory System 

Larynx + + + + + + + + + + + + + + + + + + + + + + + + +

Lung + + + + + + + + + + + + + + + + + + + + + + + + +

Alveolar/bronchiolar adenoma X

Hepatocellular carcinoma, metastatic,

 liver

Nose + + + + + + + + + + + + + + + + + + + + + + + + +

Trachea + + + + + + + + + + + + + + + + + + + + + + + + +

Special Senses System 

Eye + + + + + + + + + + + + + + + + + + + + + + +

Zymbal's gland

Carcinoma
Tetrafluoroethylene, NTP TR 450 99

TABLE A2

Individual Animal Tumor Pathology of Male Rats in the 2-Year Inhalation Study of Tetrafluoroethylene: 312 ppm (continued)

6 6 6 6 6 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7

Number of Days on Study 7 7 8 9 9 2 2 2 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

4 7 8 1 3 3 6 9 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

2 1 1 2 2 2 1 2 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 2 Total

Carcass ID Number 2 8 9 1 1 3 8 0 8 8 9 9 0 0 0 0 1 1 1 1 2 2 3 3 3 Tissues/

8 6 1 7 2 7 8 5 2 5 0 7 0 1 2 8 1 4 5 6 3 6 0 1 3 Tumors

Genital System (continued)

Seminal vesicle + + + + + + + + + + + + + + + + + + + + + + + + + 50

Testes + + + + + + + + + + + + + + + + + + + + + + + + + 50

Bilateral, interstitial cell, adenoma X X X X X X X X X X X X X X X X X X X X X X X X 40

Interstitial cell, adenoma X 8

Hematopoietic System 

Bone marrow + + + + + + + + + + + + + + + + + + + + + + + + + 50

Lymph node + + + + + + + + 16

Lymph node, bronchial M + + + + + + M + + + + + + + + + + + + + + + + + 46

Lymph node, mandibular + + + + + + + + + + + + + + + + + M + + + + + + + 49

Lymph node, mesenteric + + + + + + + + + + + + + + + + + + + + + + + + + 50

Lymph node, mediastinal + + + + + + + + + + + + + + + + + + + + + + + + + 48

Spleen + + + + + + + + + + + + + + + + + + + + + + + + + 50

Thymus + + + + M + + + + + + + + + + + + + + + + + + + + 47

Integumentary System 

Mammary gland M + M + M + + + + + + + + + + + M + + + + + + + + 41

Carcinoma 1

Fibroadenoma X X 2

Skin + + + + + + + + + + + + + + + + + + + + + + + + + 50

Keratoacanthoma 1

Squamous cell carcinoma X 1

Subcutaneous tissue, fibrosarcoma 1

Subcutaneous tissue, hemangiosarcoma 1

Subcutaneous tissue, neurofibroma X 1

Subcutaneous tissue, 

 neurofibrosarcoma 1

Musculoskeletal System 

Bone + + + + + + + + + + + + + + + + + + + + + + + + + 50

Skeletal muscle + 1

Nervous System 

Brain + + + + + + + + + + + + + + + + + + + + + + + + + 50

Meningioma NOS X 1

Respiratory System 

Larynx + + + + + + + + + + + + + + + + + + + + + + + + + 50

Lung + + + + + + + + + + + + + + + + + + + + + + + + + 50

Alveolar/bronchiolar adenoma X 2

Hepatocellular carcinoma, metastatic, 

 liver X 1

Nose + + + + + + + + + + + + + + + + + + + + + + + + + 50

Trachea + + + + + + + + + + + + + + + + + + + + + + + + + 50

Special Senses System 

Eye + + + + + + + + + + + + + + + + + + + + + + + + + 48

Zymbal's gland + 1

Carcinoma X 1
100 Tetrafluoroethylene, NTP TR 450

TABLE A2

Individual Animal Tumor Pathology of Male Rats in the 2-Year Inhalation Study of Tetrafluoroethylene: 312 ppm (continued)

4 5 5 5 5 5 5 5 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

Number of Days on Study 1 3 4 5 6 7 7 8 1 1 1 1 1 2 2 3 3 3 3 3 5 6 6 6 7

3 8 7 9 4 5 6 1 4 4 6 7 7 1 7 1 2 2 5 8 8 3 4 4 4

1 2 2 2 2 1 1 1 2 2 1 1 1 2 2 2 1 2 2 2 2 2 2 2 1

Carcass ID Number 9 1 2 2 1 9 8 9 2 3 9 8 8 0 2 0 9 2 2 3 1 0 0 3 9

6 9 2 9 3 5 9 8 0 8 2 1 7 7 5 6 4 4 7 5 8 3 4 4 3

Urinary System 

Kidney + + + + + + + + + + + + + + + + + + + + + + + + +

Bilateral, renal tubule, adenoma X

Renal tubule, adenoma X X

Renal tubule, carcinoma X

Urinary bladder + + + + + + + + + + + + + + + + + + + + + + + + +

Systemic Lesions 

Multiple organs + + + + + + + + + + + + + + + + + + + + + + + + +

Leukemia mononuclear X X X X X X X X X X X X X X X X X X

Mesothelioma malignant
Tetrafluoroethylene, NTP TR 450 101

TABLE A2

Individual Animal Tumor Pathology of Male Rats in the 2-Year Inhalation Study of Tetrafluoroethylene: 312 ppm (continued)

6 6 6 6 6 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7

Number of Days on Study 7 7 8 9 9 2 2 2 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

4 7 8 1 3 3 6 9 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

2 1 1 2 2 2 1 2 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 2 Total

Carcass ID Number 2 8 9 1 1 3 8 0 8 8 9 9 0 0 0 0 1 1 1 1 2 2 3 3 3 Tissues/

8 6 1 7 2 7 8 5 2 5 0 7 0 1 2 8 1 4 5 6 3 6 0 1 3 Tumors

Urinary System 

Kidney + + + + + + + + + + + + + + + + + + + + + + + + + 50

Bilateral, renal tubule, adenoma 1

Renal tubule, adenoma X X X 5

Renal tubule, carcinoma X 2

Urinary bladder + + + + + + + + + + + + + + + + + + + + + + + + + 50

Systemic Lesions 

Multiple organs + + + + + + + + + + + + + + + + + + + + + + + + + 50

Leukemia mononuclear X X X X X X X X X X X X X X X X X X X X 38

Mesothelioma malignant X X 2
102 Tetrafluoroethylene, NTP TR 450

TABLE A2

Individual Animal Tumor Pathology of Male Rats in the 2-Year Inhalation Study of Tetrafluoroethylene: 625 ppm 

3 4 4 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 6 6 6 6 6 6

Number of Days on Study 6 5 8 0 1 2 2 3 4 5 5 7 7 7 8 8 9 9 9 0 0 0 1 1 1

1 5 1 9 0 3 5 1 4 5 9 1 2 2 3 6 0 3 4 3 4 8 1 6 7

3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

Carcass ID Number 4 1 4 1 3 1 0 2 0 5 0 0 3 4 6 0 3 3 0 5 4 3 4 2 0

3 3 9 8 9 0 7 9 2 9 5 6 0 8 0 3 3 8 1 5 6 7 0 8 8

Alimentary System 

Esophagus + + + + + + + + + + + + + + + + + + + + + + + + +

Intestine large, colon + + + + + + + + + + + + + + + + + + + + + + + + +

Intestine large, rectum + + + + + + + + + + + + + + + + + + + + + + + + +

Intestine large, cecum + + + + + + + + + + + + + + + + + + + + + + + + +

Intestine small, duodenum + + + + + + + + + + + + + + + + + + + + + + + + +

Intestine small, jejunum + + + + + + + + + + + + + + + + + + + + + + + + +

Intestine small, ileum + + + + + + + + + + + + + + + + + + + + + + + + +

Liver + + + + + + + + + + + + + + + + + + + + + + + + +

Hepatocellular carcinoma X

Hepatocellular adenoma X X

Hepatocellular adenoma, multiple X

Mesentery + + + + +

Hepatocellular carcinoma, metastatic,

 liver

Pancreas + + + + + + + + + + + + + + + + + + + + + + + + +

Hepatocellular carcinoma, metastatic,

 liver

Acinus, adenoma

Salivary glands + + + + + + + + + + + + + + + + + + + + + + + + +

Stomach, forestomach + + + + + + + + + + + + + + + + + + + + + + + + +

Stomach, glandular + + + + + + + + + + + + + + + + + + + + + + + + +

Tongue

Tooth + +

Cardiovascular System 

Blood vessel + + +

Heart + + + + + + + + + + + + + + + + + + + + + + + + +

Endocrine System 

Adrenal cortex + + + + + + + + + + + + + + + + + + + + + + + + +

Adrenal medulla + + + + + + + + + + + + + + + + + + + + + + + + +

Ganglioneuroma X

Pheochromocytoma benign X X

Bilateral, pheochromocytoma benign X

Islets, pancreatic + + + + + + + + + + + + + + + + + + + + + + + + +

Adenoma

Carcinoma X

Parathyroid gland M + + + + + + + + + + + + + + + + + + + + + + + +

Pituitary gland + + + + + + + + + + + + + + + + + + + + + + + + +

Pars distalis, adenoma X X X X X X X X X

Thyroid gland + + + + + + + + + + + + + + + + + + + + + + + + +

C-cell, adenoma X

C-cell, carcinoma

General Body System 

Tissue NOS +
Tetrafluoroethylene, NTP TR 450 103

TABLE A2

Individual Animal Tumor Pathology of Male Rats in the 2-Year Inhalation Study of Tetrafluoroethylene: 625 ppm (continued)

6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 7 7 7 7 7

Number of Days on Study 1 1 2 2 2 3 3 3 3 3 3 5 6 6 6 7 8 8 9 9 0 1 2 3 3

7 7 1 6 6 0 2 2 9 9 9 2 3 3 8 4 8 8 1 5 2 2 1 0 3

3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 Total

Carcass ID Number 1 5 1 5 5 2 2 3 0 1 2 4 0 5 4 3 2 2 3 1 5 3 1 2 2 Tissues/

2 0 4 4 8 0 3 4 9 5 7 5 4 6 2 2 5 6 6 9 7 5 1 1 4 Tumors

Alimentary System 

Esophagus + + + + + + + + + + + + + + + + + + + + + + + + + 50

Intestine large, colon + + + + + + + + + + + + + + + + + + + + + + + + + 50

Intestine large, rectum + + + + + + + + + + + + + + + + + + + + + + + + + 50

Intestine large, cecum + + + + + + + + + + + + + + + + + + + + + + + + + 50

Intestine small, duodenum + + + + + + + + + + + + + + + + + + + + + + + + + 50

Intestine small, jejunum + + + + + + + + + + + + + + + + + + + + + + + + + 50

Intestine small, ileum + + + + + + + + + + + + + + + + + + + + + + + + + 50

Liver + + + + + + + + + + + + + + + + + + + + + + + + + 50

Hepatocellular carcinoma X X 3

Hepatocellular adenoma X X 4

Hepatocellular adenoma, multiple 1

Mesentery + + + + + + + + + 14

Hepatocellular carcinoma, metastatic, 

 liver X 1

Pancreas + + + + + + + + + + + + + + + + + + + + + + + + + 50

Hepatocellular carcinoma, metastatic, 

 liver X 1

Acinus, adenoma X 1

Salivary glands + + + + + + + + + + + + + + + + + + + + + + + + + 50

Stomach, forestomach + + + + + + + + + + + + + + + + + + + + + + + + + 50

Stomach, glandular + + + + + + + + + + + + + + + + + + + + + + + + + 50

Tongue + 1

Tooth 2

Cardiovascular System 

Blood vessel + + + + + + + + + 12

Heart + + + + + + + + + + + + + + + + + + + + + + + + + 50

Endocrine System 

Adrenal cortex + + + + + + + + + + + + + + + + + + + + + + + + + 50

Adrenal medulla + + + + + + + + + + + + + + + + + + + + + + + + + 50

Ganglioneuroma 1

Pheochromocytoma benign X X X X 6

Bilateral, pheochromocytoma benign X X X 4

Islets, pancreatic + + + + + + + + + + + + + + + + + + + + + + + + + 50

Adenoma X X 2

Carcinoma 1

Parathyroid gland + + + + + + + + + + + + + + + + + + + + + + + + + 49

Pituitary gland + + + + + + + + + + + + + + + + + + + + + + + + M 49

Pars distalis, adenoma X X X X X X X X X X X X X X 23

Thyroid gland + + + + + + + + + + + + + + + + + + + + + + + + + 50

C-cell, adenoma X X X 4

C-cell, carcinoma X 1

General Body System 

Tissue NOS 1
104 Tetrafluoroethylene, NTP TR 450

TABLE A2

Individual Animal Tumor Pathology of Male Rats in the 2-Year Inhalation Study of Tetrafluoroethylene: 625 ppm (continued)

3 4 4 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 6 6 6 6 6 6

Number of Days on Study 6 5 8 0 1 2 2 3 4 5 5 7 7 7 8 8 9 9 9 0 0 0 1 1 1

1 5 1 9 0 3 5 1 4 5 9 1 2 2 3 6 0 3 4 3 4 8 1 6 7

3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

Carcass ID Number 4 1 4 1 3 1 0 2 0 5 0 0 3 4 6 0 3 3 0 5 4 3 4 2 0

3 3 9 8 9 0 7 9 2 9 5 6 0 8 0 3 3 8 1 5 6 7 0 8 8

Genital System 

Epididymis + + + + + + + + + + + + + + + + + + + + + + + + +

Preputial gland + + + + + + + + + + + + + + + + + + + + + + + + +

Adenoma X

Carcinoma X X X

Prostate + + + + + + + + + + + + + + + + + + + + + + + + +

Seminal vesicle + + + + + + + + + + + + + + + + + + + + + + + + +

Testes + + + + + + + + + + + + + + + + + + + + + + + + +

Bilateral, interstitial cell, adenoma X X X X X X X X X X X X X X X X X X

Interstitial cell, adenoma X X X X

Hematopoietic System 

Bone marrow + + + + + + + + + + + + + + + + + + + + + + + + +

Lymph node + + + + + +

Lymph node, bronchial + M + + + + + + + + + + + + + + + + + + + + + M +

Lymph node, mandibular + + + + + M + + + + + + + + + + M + + + + + + + +

Lymph node, mesenteric + + + + + + + + + + + + + + + + + + + + + + + + +

Lymph node, mediastinal + + + + + + + + + + + + + + + + + + + + + + + + M

Spleen + + + + + + + + + + + + + + + + + + + + + + + + +

Thymus + + + M + + + + + + + + + + + + + + + + + + + + +

Integumentary System 

Mammary gland + M M M M + M M M + + + + M + + + M M + M + + + +

Adenoma X

Fibroadenoma

Skin + + + + + + + + + + + + + + + + + + + + + + + + +

Basosquamous tumor benign

Keratoacanthoma

Squamous cell papilloma

Subcutaneous tissue, fibroma X

Subcutaneous tissue, fibrosarcoma X

Subcutaneous tissue, sarcoma

Musculoskeletal System 

Bone + + + + + + + + + + + + + + + + + + + + + + + + +

Nervous System 

Brain + + + + + + + + + + + + + + + + + + + + + + + + +

Respiratory System 

Larynx + + + + + + + + + + + + + + + + + + + + + + + + +

Lung + + + + + + + + + + + + + + + + + + + + + + + + +

Alveolar/bronchiolar adenoma X

Chordoma, metastatic, uncertain

 primary site 

Nose + + + + + + + + + + + + + + + + + + + + + + + + +

Trachea + + + + + + + + + + + + + + + + + + + + + + + + +

Special Senses System 

Eye + + + + + + + + + + + + + + + + +
Tetrafluoroethylene, NTP TR 450 105

TABLE A2

Individual Animal Tumor Pathology of Male Rats in the 2-Year Inhalation Study of Tetrafluoroethylene: 625 ppm (continued)

6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 7 7 7 7 7

Number of Days on Study 1 1 2 2 2 3 3 3 3 3 3 5 6 6 6 7 8 8 9 9 0 1 2 3 3

7 7 1 6 6 0 2 2 9 9 9 2 3 3 8 4 8 8 1 5 2 2 1 0 3

3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 Total

Carcass ID Number 1 5 1 5 5 2 2 3 0 1 2 4 0 5 4 3 2 2 3 1 5 3 1 2 2 Tissues/

2 0 4 4 8 0 3 4 9 5 7 5 4 6 2 2 5 6 6 9 7 5 1 1 4 Tumors

Genital System 

Epididymis + + + + + + + + + + + + + + + + + + + + + + + + + 50

Preputial gland + + + + + + + + M + + + + + + + + + + + + + + + + 49

Adenoma X 2

Carcinoma X 4

Prostate + + + + + + + + + + + + + + + + + + + + + + + + + 50

Seminal vesicle + + + + + + + + + + + + + + + + + + + + + + + + + 50

Testes + + + + + + + + + + + + + + + + + + + + + + + + + 50

Bilateral, interstitial cell, adenoma X X X X X X X X X X X X X X X X X X X X X X X X 42

Interstitial cell, adenoma X 5

Hematopoietic System 

Bone marrow + + + + + + + + + + + + + + + + + + + + + + + + + 50

Lymph node + + + + + + + + + + + 17

Lymph node, bronchial + + + + + + + + + + + + M + + + + + + + + + + + + 47

Lymph node, mandibular + + + + + + M + + M + + + + + + + + + + + + + + + 46

Lymph node, mesenteric + + + + + + + + + + + + + + + + + + + + + + + + + 50

Lymph node, mediastinal + + + M + + + + M + + + + + + + + + + + + M + + + 46

Spleen + + + + + + + + + + + + + + + + + + + + + + + + + 50

Thymus + + + M + + + + + + + + + + + + + + M + M M + + + 45

Integumentary System 

Mammary gland + + + + + M + + + + M M + M + + + M + + + + + + + 34

Adenoma 1

Fibroadenoma X 1

Skin + + + + + + + + + + + + + + + + + + + + + + + + + 50

Basosquamous tumor benign X 1

Keratoacanthoma X 1

Squamous cell papilloma X 1

Subcutaneous tissue, fibroma 1

Subcutaneous tissue, fibrosarcoma 1

Subcutaneous tissue, sarcoma X 1

Musculoskeletal System 

Bone + + + + + + + + + + + + + + + + + + + + + + + + + 50

Nervous System 

Brain + + + + + + + + + + + + + + + + + + + + + + + + + 50

Respiratory System 

Larynx + + + + + + + + + + + + + + + + + + + + + + + + + 50

Lung + + + + + + + + + + + + + + + + + + + + + + + + + 50

Alveolar/bronchiolar adenoma 1

Chordoma, metastatic, uncertain 

 primary site X 1

Nose + + + + + + + + + + + + + + + + + + + + + + + + + 50

Trachea + + + + + + + + + + + + + + + + + + + + + + + + + 50

Special Senses System 

Eye + + + + + + + + + + + + + + + + + + + + + + + + + 42
106 Tetrafluoroethylene, NTP TR 450

TABLE A2

Individual Animal Tumor Pathology of Male Rats in the 2-Year Inhalation Study of Tetrafluoroethylene: 625 ppm (continued)

3 4 4 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 6 6 6 6 6 6

Number of Days on Study 6 5 8 0 1 2 2 3 4 5 5 7 7 7 8 8 9 9 9 0 0 0 1 1 1

1 5 1 9 0 3 5 1 4 5 9 1 2 2 3 6 0 3 4 3 4 8 1 6 7

3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

Carcass ID Number 4 1 4 1 3 1 0 2 0 5 0 0 3 4 6 0 3 3 0 5 4 3 4 2 0

3 3 9 8 9 0 7 9 2 9 5 6 0 8 0 3 3 8 1 5 6 7 0 8 8

Urinary System 

Kidney + + + + + + + + + + + + + + + + + + + + + + + + +

Renal tubule, adenoma

Transitional epithelium, papilloma

Urinary bladder + + + + + + + + + + + + + + + + + + + + + + + + +

Systemic Lesions 

Multiple organs + + + + + + + + + + + + + + + + + + + + + + + + +

Leukemia mononuclear X X X X X X X X X X X X X X X X X

Mesothelioma malignant X
Tetrafluoroethylene, NTP TR 450 107

TABLE A2

Individual Animal Tumor Pathology of Male Rats in the 2-Year Inhalation Study of Tetrafluoroethylene: 625 ppm (continued)

6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 7 7 7 7 7

Number of Days on Study 1 1 2 2 2 3 3 3 3 3 3 5 6 6 6 7 8 8 9 9 0 1 2 3 3

7 7 1 6 6 0 2 2 9 9 9 2 3 3 8 4 8 8 1 5 2 2 1 0 3

3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 Total

Carcass ID Number 1 5 1 5 5 2 2 3 0 1 2 4 0 5 4 3 2 2 3 1 5 3 1 2 2 Tissues/

2 0 4 4 8 0 3 4 9 5 7 5 4 6 2 2 5 6 6 9 7 5 1 1 4 Tumors

Urinary System 

Kidney + + + + + + + + + + + + + + + + + + + + + + + + + 50

Renal tubule, adenoma X X X 3

Transitional epithelium, papilloma X 1

Urinary bladder + + + + + + + + + + + + + + + + + + + + + + + + + 50

Systemic Lesions 

Multiple organs + + + + + + + + + + + + + + + + + + + + + + + + + 50

Leukemia mononuclear X X X X X X X X X X X X X X 31

Mesothelioma malignant 1
108 Tetrafluoroethylene, NTP TR 450

TABLE A3

Statistical Analysis of Primary Neoplasms in Male Rats in the 2-Year Inhalation Study of Tetrafluoroethylene

0 ppm 156 ppm 312 ppm 625 ppm

Adrenal Medulla: Benign Pheochromocytoma

Overall rate 19/50 (38%) 11/50 (22%) 9/50 (18%) 10/50 (20%) a

Adjusted rate 60.0% 44.2% 33.4% 52.8% b

Terminal rate 6/17 (35%) 2/12 (17%) 4/17 (24%) 0/1 (0%) c

First incidence (days) 588 594 576 481

Life table test P=0.282 P=0.280N P=0.058N P=0.083 d

Logistic regression test P=0.108N P=0.090N P=0.024N P=0.180N d

Cochran-Armitage test P=0.040N d

Fisher exact test P=0.063N P=0.022N P=0.038N d

Adrenal Medulla: Benign, Complex, or Malignant Pheochromocytoma

Overall rate 20/50 (40%) 12/50 (24%) 9/50 (18%) 10/50 (20%)

Adjusted rate 63.6% 49.8% 33.4% 52.8%

Terminal rate 7/17 (41%) 3/12 (25%) 4/17 (24%) 0/1 (0%)

First incidence (days) 588 594 576 481

Life table test P=0.331 P=0.305N P=0.039N P=0.087 

Logistic regression test P=0.078N P=0.123N P=0.015N P=0.151N

Cochran-Armitage test P=0.023N

Fisher exact test P=0.066N P=0.013N P=0.024N

Kidney (Renal Tubule): Adenoma (Single Sections)

Overall rate 0/50 (0%) 0/50 (0%) 6/50 (12%) 3/50 (6%)

Adjusted rate 0.0% 0.0% 25.7% 18.4%

Terminal rate 0/17 (0%) 0/12 (0%) 3/17 (18%) 0/1 (0%)

First incidence (days) — — 627 617 e

Life table test P<0.001 — P=0.015 P=0.032

Logistic regression test P=0.015 — P=0.015 P=0.097 

Cochran-Armitage test P=0.047

Fisher exact test — P=0.013 P=0.121

Kidney (Renal Tubule): Adenoma (Step Sections)

Overall rate 2/50 (4%) 4/50 (8%) 3/50 (6%) 11/50 (22%)

Adjusted rate 10.8% 24.9% 10.2% 85.3%

Terminal rate 1/17 (6%) 2/12 (17%) 0/17 (0%) 0/1 (0%)

First incidence (days) 721 555 614 572

Life table test P<0.001 P=0.217 P=0.506 P<0.001

Logistic regression test P<0.001 P=0.259 P=0.492 P<0.001 

Cochran-Armitage test P=0.002

Fisher exact test P=0.339 P=0.500 P=0.007

Kidney (Renal Tubule): Adenoma (Single and Step Sections)

Overall rate 2/50 (4%) 4/50 (8%) 9/50 (18%) 13/50 (26%)

Adjusted rate 10.8% 24.9% 33.3% 87.7%

Terminal rate 1/17 (6%) 2/12 (17%) 3/17 (18%) 0/1 (0%)

First incidence (days) 721 555 614 572

Life table test P<0.001 P=0.217 P=0.029 P<0.001

Logistic regression test P<0.001 P=0.259 P=0.024 P<0.001 

Cochran-Armitage test P<0.001

Fisher exact test P=0.339 P=0.026 P=0.002
Tetrafluoroethylene, NTP TR 450 109

TABLE A3

Statistical Analysis of Primary Neoplasms in Male Rats in the 2-Year Inhalation Study of Tetrafluoroethylene (continued)

0 ppm 156 ppm 312 ppm 625 ppm

Kidney (Renal Tubule): Adenoma or Carcinoma (Single Sections)

Overall rate 1/50 (2%) 0/50 (0%) 6/50 (12%) 3/50 (6%)

Adjusted rate 2.8% 0.0% 25.7% 18.4%

Terminal rate 0/17 (0%) 0/12 (0%) 3/17 (18%) 0/1 (0%)

First incidence (days) 649 — 627 617

Life table test P=0.004 P=0.543N P=0.049 P=0.094

Logistic regression test P=0.052 P=0.497N P=0.055 P=0.270 

Cochran-Armitage test P=0.114

Fisher exact test P=0.500N P=0.056 P=0.309

Kidney (Renal Tubule): Adenoma or Carcinoma (Step Sections)

Overall rate 2/50 (4%) 5/50 (10%) 3/50 (6%) 11/50 (22%)

Adjusted rate 10.8% 28.4% 10.2% 85.3%

Terminal rate 1/17 (6%) 2/12 (17%) 0/17 (0%) 0/1 (0%)

First incidence (days) 721 555 614 572

Life table test P<0.001 P=0.123 P=0.506 P<0.001

Logistic regression test P<0.001 P=0.151 P=0.492 P<0.001

Cochran-Armitage test P=0.004

Fisher exact test P=0.218 P=0.500 P=0.007

Kidney (Renal Tubule): Adenoma or Carcinoma (Single and Step Sections)

Overall rate 3/50 (6%) 5/50 (10%) 9/50 (18%) 13/50 (26%)

Adjusted rate 13.3% 28.4% 33.3% 87.7%

Terminal rate 1/17 (6%) 2/12 (17%) 3/17 (18%) 0/1 (0%)

First incidence (days) 649 555 614 572

Life table test P<0.001 P=0.224 P=0.060 P<0.001

Logistic regression test P<0.001 P=0.281 P=0.057 P<0.001

Cochran-Armitage test P=0.002

Fisher exact test P=0.357 P=0.061 P=0.006

Liver: Hepatocellular Adenoma

Overall rate 3/50 (6%) 6/50 (12%) 8/50 (16%) 5/50 (10%)

Adjusted rate 14.1% 32.0% 43.1% 100.0%

Terminal rate 2/17 (12%) 3/12 (25%) 7/17 (41%) 1/1 (100%)

First incidence (days) 632 600 638 572

Life table test P=0.004 P=0.127 P=0.082 P=0.018

Logistic regression test P=0.103 P=0.193 P=0.065 P=0.240 

Cochran-Armitage test P=0.352 

Fisher exact test P=0.243 P=0.100 P=0.357 

Liver: Hepatocellular Carcinoma

Overall rate 1/50 (2%) 1/50 (2%) 10/50 (20%) 3/50 (6%)

Adjusted rate 2.6% 3.4% 41.3% 18.8%

Terminal rate 0/17 (0%) 0/12 (0%) 5/17 (29%) 0/1 (0%)

First incidence (days) 624 652 617 590

Life table test P=0.003 P=0.710 P=0.005 P=0.113 

Logistic regression test P=0.053 P=0.756N P=0.004 P=0.301 

Cochran-Armitage test P=0.149 

Fisher exact test P=0.753N P=0.004 P=0.309 
110 Tetrafluoroethylene, NTP TR 450

TABLE A3

Statistical Analysis of Primary Neoplasms in Male Rats in the 2-Year Inhalation Study of Tetrafluoroethylene (continued)

0 ppm 156 ppm 312 ppm 625 ppm

Liver: Hepatocellular Adenoma or Carcinoma

Overall rate 4/50 (8%) 7/50 (14%) 15/50 (30%) 8/50 (16%)

Adjusted rate 16.3% 34.4% 62.1% 100.0%

Terminal rate 2/17 (12%) 3/12 (25%) 9/17 (53%) 1/1 (100%)

First incidence (days) 624 600 617 572

Life table test P<0.001 P=0.137 P=0.004 P=0.003

Logistic regression test P=0.025 P=0.223 P=0.003 P=0.112 

Cochran-Armitage test P=0.140 

Fisher exact test P=0.262 P=0.005 P=0.178 

Mammary Gland: Fibroadenoma, Adenoma, or Carcinoma

Overall rate 2/50 (4%) 2/50 (4%) 3/50 (6%) 2/50 (4%)

Adjusted rate 10.4% 12.7% 14.2% 11.1%

Terminal rate 1/17 (6%) 1/12 (8%) 2/17 (12%) 0/1 (0%)

First incidence (days) 715 698 627 523

Life table test P=0.117 P=0.580 P=0.491 P=0.229 

Logistic regression test P=0.386 P=0.598 P=0.463 P=0.631 

Cochran-Armitage test P=0.569 

Fisher exact test P=0.691N P=0.500 P=0.691N

Pancreatic Islets: Adenoma

Overall rate 3/50 (6%) 1/50 (2%) 1/50 (2%) 2/50 (4%)

Adjusted rate 15.3% 5.6% 5.9% 20.5%

Terminal rate 2/17 (12%) 0/12 (0%) 1/17 (6%) 0/1 (0%)

First incidence (days) 705 705 733 (T) 626

Life table test P=0.248 P=0.433N P=0.324N P=0.182 

Logistic regression test P=0.463 P=0.400N P=0.339N P=0.521 

Cochran-Armitage test P=0.475N

Fisher exact test P=0.309N P=0.309N P=0.500N

Pancreatic Islets: Carcinoma

Overall rate 1/50 (2%) 5/50 (10%) 1/50 (2%) 1/50 (2%)

Adjusted rate 3.4% 31.5% 5.9% 3.0%

Terminal rate 0/17 (0%) 3/12 (25%) 1/17 (6%) 0/1 (0%)

First incidence (days) 690 664 733 (T) 593

Life table test P=0.432 P=0.049 P=0.730 P=0.587 

Logistic regression test P=0.550N P=0.059 P=0.744 P=0.768 

Cochran-Armitage test P=0.313N

Fisher exact test P=0.102 P=0.753N P=0.753N

Pancreatic Islets: Adenoma or Carcinoma

Overall rate 4/50 (8%) 6/50 (12%) 2/50 (4%) 3/50 (6%)

Adjusted rate 18.2% 35.3% 11.8% 22.9%

Terminal rate 2/17 (12%) 3/12 (25%) 2/17 (12%) 0/1 (0%)

First incidence (days) 690 664 733 (T) 593

Life table test P=0.202 P=0.192 P=0.375N P=0.144 

Logistic regression test P=0.525 P=0.228 P=0.387N P=0.553 

Cochran-Armitage test P=0.278N

Fisher exact test P=0.370 P=0.339N P=0.500N
Tetrafluoroethylene, NTP TR 450 111

TABLE A3

Statistical Analysis of Primary Neoplasms in Male Rats in the 2-Year Inhalation Study of Tetrafluoroethylene (continued)

0 ppm 156 ppm 312 ppm 625 ppm

Pituitary Gland (Pars Distalis): Adenoma

Overall rate 39/50 (78%) 37/49 (76%) 35/49 (71%) 23/49 (47%)

Adjusted rate 94.9% 91.1% 84.5% 86.1%

Terminal rate 15/17 (88%) 9/12 (75%) 10/16 (63%) 0/0

First incidence (days) 336 351 559 361

Life table test P=0.042 P=0.213 P=0.514N P=0.003

Logistic regression test P=0.002N P=0.500N P=0.290N P=0.014N

Cochran-Armitage test P<0.001N

Fisher exact test P=0.478N P=0.301N P=0.001N

Preputial Gland: Adenoma

Overall rate 1/50 (2%) 3/50 (6%) 5/50 (10%) 2/49 (4%)

Adjusted rate 5.9% 25.0% 15.6% 6.0%

Terminal rate 1/17 (6%) 3/12 (25%) 1/17 (6%) 0/1 (0%)

First incidence (days) 733 (T) 733 (T) 538 523

Life table test P=0.099 P=0.182 P=0.104 P=0.228 

Logistic regression test P=0.393 P=0.182 P=0.099 P=0.523 

Cochran-Armitage test P=0.428 

Fisher exact test P=0.309 P=0.102 P=0.492 

Preputial Gland: Carcinoma

Overall rate 3/50 (6%) 3/50 (6%) 2/50 (4%) 4/49 (8%)

Adjusted rate 15.6% 10.0% 4.9% 13.9%

Terminal rate 2/17 (12%) 0/12 (0%) 0/17 (0%) 0/1 (0%)

First incidence (days) 708 494 538 481

Life table test P=0.152 P=0.552 P=0.515N P=0.077 

Logistic regression test P=0.481 P=0.656 P=0.500N P=0.471 

Cochran-Armitage test P=0.409 

Fisher exact test P=0.661N P=0.500N P=0.489 

Preputial Gland: Adenoma or Carcinoma

Overall rate 4/50 (8%) 6/50 (12%) 6/50 (12%) 6/49 (12%)

Adjusted rate 21.2% 32.5% 18.1% 19.0%

Terminal rate 3/17 (18%) 3/12 (25%) 1/17 (6%) 0/1 (0%)

First incidence (days) 708 494 538 481

Life table test P=0.035 P=0.211 P=0.350 P=0.023

Logistic regression test P=0.355 P=0.295 P=0.369 P=0.354 

Cochran-Armitage test P=0.337 

Fisher exact test P=0.370 P=0.370 P=0.357 

Skin: Keratoacanthoma

Overall rate 3/50 (6%) 0/50 (0%) 1/50 (2%) 1/50 (2%)

Adjusted rate 14.7% 0.0% 2.2% 5.3%

Terminal rate 2/17 (12%) 0/12 (0%) 0/17 (0%) 0/1 (0%)

First incidence (days) 686 — 575 632

Life table test P=0.579N P=0.184N P=0.326N P=0.598

Logistic regression test P=0.356N P=0.165N P=0.309N P=0.609N

Cochran-Armitage test P=0.296N

Fisher exact test P=0.121N P=0.309N P=0.309N
112 Tetrafluoroethylene, NTP TR 450

TABLE A3

Statistical Analysis of Primary Neoplasms in Male Rats in the 2-Year Inhalation Study of Tetrafluoroethylene (continued)

0 ppm 156 ppm 312 ppm 625 ppm

Skin: Squamous Cell Papilloma or Keratoacanthoma

Overall rate 4/50 (8%) 0/50 (0%) 1/50 (2%) 2/50 (4%)

Adjusted rate 19.0% 0.0% 2.2% 8.9%

Terminal rate 2/17 (12%) 0/12 (0%) 0/17 (0%) 0/1 (0%)

First incidence (days) 686 — 575 617

Life table test P=0.525 P=0.112N P=0.197N P=0.375

Logistic regression test P=0.452N P=0.095N P=0.186N P=0.629N

Cochran-Armitage test P=0.373N

Fisher exact test P=0.059N P=0.181N P=0.339N

Skin: Squamous Cell Papilloma, Keratoacanthoma, or Squamous Cell Carcinoma

Overall rate 5/50 (10%) 0/50 (0%) 2/50 (4%) 2/50 (4%)

Adjusted rate 23.5% 0.0% 7.7% 8.9%

Terminal rate 2/17 (12%) 0/12 (0%) 0/17 (0%) 0/1 (0%)

First incidence (days) 686 — 575 617

Life table test P=0.552 P=0.071N P=0.233N P=0.421

Logistic regression test P=0.401N P=0.056N P=0.236N P=0.550N

Cochran-Armitage test P=0.263N

Fisher exact test P=0.028N P=0.218N P=0.218N

Skin: Squamous Cell Papilloma, Keratoacanthoma, Benign Basosquamous Tumor, or Squamous Cell Carcinoma

Overall rate 7/50 (14%) 0/50 (0%) 2/50 (4%) 3/50 (6%)

Adjusted rate 32.3% 0.0% 7.7% 12.6%

Terminal rate 3/17 (18%) 0/12 (0%) 0/17 (0%) 0/1 (0%)

First incidence (days) 686 — 575 617

Life table test P=0.527 P=0.029N P=0.092N P=0.301 

Logistic regression test P=0.369N P=0.019N P=0.095N P=0.529N

Cochran-Armitage test P=0.211N

Fisher exact test P=0.006N P=0.080N P=0.159N

Skin (Subcutaneous Tissue): Fibroma

Overall rate 3/50 (6%) 1/50 (2%) 0/50 (0%) 1/50 (2%)

Adjusted rate 11.3% 5.6% 0.0% 2.6%

Terminal rate 1/17 (6%) 0/12 (0%) 0/17 (0%) 0/1 (0%)

First incidence (days) 635 705 — 571

Life table test P=0.430N P=0.420N P=0.150N P=0.700N

Logistic regression test P=0.224N P=0.343N P=0.122N P=0.346N

Cochran-Armitage test P=0.200N

Fisher exact test P=0.309N P=0.121N P=0.309N

Testes: Adenoma

Overall rate 39/50 (78%) 40/50 (80%) 48/50 (96%) 47/50 (94%)

Adjusted rate 92.5% 97.3% 100.0% 100.0%

Terminal rate 14/17 (82%) 11/12 (92%) 17/17 (100%) 1/1 (100%)

First incidence (days) 489 470 413 418

Life table test P<0.001 P=0.101 P=0.081 P<0.001

Logistic regression test P<0.001 P=0.361 P=0.009 P=0.003

Cochran-Armitage test P=0.004

Fisher exact test P=0.500 P=0.007 P=0.020
Tetrafluoroethylene, NTP TR 450 113

TABLE A3

Statistical Analysis of Primary Neoplasms in Male Rats in the 2-Year Inhalation Study of Tetrafluoroethylene (continued)

0 ppm 156 ppm 312 ppm 625 ppm

Thyroid Gland (C-cell): Adenoma

Overall rate 7/50 (14%) 8/50 (16%) 5/50 (10%) 4/50 (8%)

Adjusted rate 31.8% 37.3% 21.6% 20.6%

Terminal rate 3/17 (18%) 3/12 (25%) 2/17 (12%) 0/1 (0%)

First incidence (days) 707 533 631 571

Life table test P=0.283 P=0.286 P=0.437N P=0.128 

Logistic regression test P=0.348N P=0.386 P=0.438N P=0.636 

Cochran-Armitage test P=0.152N

Fisher exact test P=0.500 P=0.380N P=0.262N

Thyroid Gland (C-cell): Carcinoma

Overall rate 2/50 (4%) 1/50 (2%) 4/50 (8%) 1/50 (2%)

Adjusted rate 11.8% 8.3% 18.4% 3.8%

Terminal rate 2/17 (12%) 1/12 (8%) 2/17 (12%) 0/1 (0%)

First incidence (days) 733 (T) 733 (T) 658 617

Life table test P=0.204 P=0.623N P=0.307 P=0.508 

Logistic regression test P=0.403 P=0.623N P=0.291 P=0.754 

Cochran-Armitage test P=0.500N

Fisher exact test P=0.500N P=0.339 P=0.500N

Thyroid Gland (C-cell): Adenoma or Carcinoma

Overall rate 8/50 (16%) 9/50 (18%) 9/50 (18%) 5/50 (10%)

Adjusted rate 36.7% 44.3% 37.2% 23.7%

Terminal rate 4/17 (24%) 4/12 (33%) 4/17 (24%) 0/1 (0%)

First incidence (days) 707 533 631 571

Life table test P=0.105 P=0.263 P=0.433 P=0.073 

Logistic regression test P=0.530N P=0.357 P=0.420 P=0.577 

Cochran-Armitage test P=0.204N

Fisher exact test P=0.500 P=0.500 P=0.277N

Urinary Bladder: Papilloma

Overall rate 0/49 (0%) 3/50 (6%) 0/50 (0%) 0/50 (0%)

Adjusted rate 0.0% 14.8% 0.0% 0.0%

Terminal rate 0/17 (0%) 1/12 (8%) 0/17 (0%) 0/1 (0%)

First incidence (days) — 600 — —

Life table test P=0.509N P=0.085 — —

Logistic regression test P=0.354N P=0.113 — —

Cochran-Armitage test P=0.308N

Fisher exact test P=0.125 — —

All Organs: Mononuclear Cell Leukemia

Overall rate 34/50 (68%) 43/50 (86%) 38/50 (76%) 31/50 (62%)

Adjusted rate 81.5% 95.3% 91.9% 100.0%

Terminal rate 10/17 (59%) 10/12 (83%) 14/17 (82%) 1/1 (100%)

First incidence (days) 509 351 413 509

Life table test P<0.001 P=0.016 P=0.231 P<0.001

Logistic regression test P=0.064N P=0.020 P=0.254 P=0.079N

Cochran-Armitage test P=0.108N

Fisher exact test P=0.028 P=0.252 P=0.338N
114 Tetrafluoroethylene, NTP TR 450

TABLE A3

Statistical Analysis of Primary Neoplasms in Male Rats in the 2-Year Inhalation Study of Tetrafluoroethylene (continued)

0 ppm 156 ppm 312 ppm 625 ppm

All Organs: Malignant Mesothelioma

Overall rate 5/50 (10%) 1/50 (2%) 2/50 (4%) 1/50 (2%)

Adjusted rate 15.0% 3.8% 9.5% 2.3%

Terminal rate 1/17 (6%) 0/12 (0%) 1/17 (6%) 0/1 (0%)

First incidence (days) 489 664 674 525

Life table test P=0.248N P=0.154N P=0.253N P=0.278N

Logistic regression test P=0.076N P=0.089N P=0.222N P=0.062N

Cochran-Armitage test P=0.093N

Fisher exact test P=0.102N P=0.218N P=0.102N

All Organs: Benign Neoplasms

Overall rate 49/50 (98%) 48/50 (96%) 50/50 (100%) 49/50 (98%)

Adjusted rate 100.0% 100.0% 100.0% 100.0%

Terminal rate 17/17 (100%) 12/12 (100%) 17/17 (100%) 1/1 (100%)

First incidence (days) 336 351 413 361

Life table test P<0.001 P=0.130 P=0.365 P<0.001

Logistic regression test P=0.460 P=0.529N P=0.894 P=0.759N

Cochran-Armitage test P=0.500 

Fisher exact test P=0.500N P=0.500 P=0.753N

All Organs: Malignant Neoplasms

Overall rate 39/50 (78%) 46/50 (92%) 48/50 (96%) 35/50 (70%)

Adjusted rate 87.9% 97.8% 98.0% 100.0%

Terminal rate 12/17 (71%) 11/12 (92%) 16/17 (94%) 1/1 (100%)

First incidence (days) 489 351 413 481

Life table test P<0.001 P=0.025 P=0.087 P<0.001

Logistic regression test P=0.035N P=0.030 P=0.009 P=0.042N

Cochran-Armitage test P=0.075N

Fisher exact test P=0.045 P=0.007 P=0.247N

All Organs: Benign or Malignant Neoplasms

Overall rate 49/50 (98%) 49/50 (98%) 50/50 (100%) 49/50 (98%)

Adjusted rate 100.0% 100.0% 100.0% 100.0%

Terminal rate 17/17 (100%) 12/12 (100%) 17/17 (100%) 1/1 (100%)

First incidence (days) 336 351 413 361

Life table test P<0.001 P=0.105 P=0.365 P<0.001

Logistic regression test P=0.655N P=0.769N P=0.894 P=0.759N

Cochran-Armitage test P=0.617 

Fisher exact test P=0.753N P=0.500 P=0.753N

(T)Terminal sacrifice

Number of neoplasm-bearing animals/number of animals examined. Denominator is number of animals examined microscopically for adrenal gland, kidney, liver, a

pancreatic islets, pituitary gland, preputial gland, testes, thyroid gland, and urinary bladder; for other tissues, denominator is number of animals necropsied.

Kaplan-Meier estimated neoplasm incidence at the end of the study after adjustment for intercurrent mortality b

Observed incidence at terminal kill c

Beneath the control incidence are the P values associated with the trend test. Beneath the exposed group incidence are the P values corresponding to pairwise d

comparisons between the controls and that exposed group. The life table test regards neoplasms in animals dying prior to terminal kill as being (directly or indirectly)

the cause of death. The logistic regression test regards these lesions as nonfatal. The Cochran-Armitage and Fisher exact tests compare directly the overall incidence

rates. For all tests, a negative trend or a lower incidence in an exposure group is indicated by N.

Not applicable; no neoplasms in animal group e
Tetrafluoroethylene, NTP TR 450 115

TABLE A4a

Historical Incidence of Renal Tubule Neoplasms in Chamber Control Male F344/N Rats a

Incidence in Controls

Study Adenoma Carcinoma Adenoma or Carcinoma

Historical Incidence at Battelle Pacific Northwest Laboratories

o-Chlorobenzalmalononitrile (CS-2) 1/50 0/50 1/50

Acetonitrile 1/48 0/48 1/48

-Chloroacetophenone 1/49 0/49 1/49

Epinephrine Hydrochloride 0/50 0/50 0/50

Ethyl Chloride 0/50 0/50 0/50

Hexachlorocyclopentadiene 0/50 0/50 0/50

Ozone 2/50 0/50 2/50

Total 5/347 (1.4%) 0/347 (0%) 5/347 (1.4%)

Standard deviation 1.5% 1.5%

Range 0%-4% 0%-4%

Overall Historical Incidence

Total 6/652 (0.9%) 0/652 (0%) 6/652 (0.9%)

Standard deviation 1.3% 1.3%

Range 0%-4% 0%-4%

Data as of 12 May 1995 a

TABLE A4b

Historical Incidence of Hepatocellular Neoplasms in Chamber Control Male F344/N Rats a

Incidence in Controls

Study Adenoma Carcinoma Adenoma or Carcinoma

Historical Incidence at Battelle Pacific Northwest Laboratories

o-Chlorobenzalmalononitrile (CS-2) 2/50 2/50 4/50

Acetonitrile 0/48 1/48 1/48

-Chloroacetophenone 1/49 0/49 1/49

Epinephrine Hydrochloride 1/50 0/50 1/50

Ethyl Chloride 0/50 1/50 1/50

Hexachlorocyclopentadiene 1/50 0/50 1/50

Ozone 2/50 0/50 2/50

Total 7/347 (2.0%) 4/347 (1.2%) 11/347 (3.2%)

Standard deviation 1.6% 1.6% 2.3%

Range 0%-4% 0%-4% 2%-8%

Overall Historical Incidence

Total 20/653 (3.1%) 8/653 (1.2%) 28/653 (4.3%)

Standard deviation 2.8% 1.5% 2.9%

Range 0%-8% 0%-4% 2%-9%

Data as of 12 May 1995 a
116 Tetrafluoroethylene, NTP TR 450

TABLE A4c

Historical Incidence of Mononuclear Cell Leukemia in Chamber Control Male F344/N Rats a

Study Incidence in Controls

Historical Incidence at Battelle Pacific Northwest Laboratories

o-Chlorobenzalmalononitrile (CS-2) 29/50

Acetonitrile 29/48

-Chloroacetophenone 29/50

Epinephrine Hydrochloride 19/50

Ethyl Chloride 33/50

Hexachlorocyclopentadiene 29/50

Ozone 27/50

Total 195/348 (56.0%)

Standard deviation 8.7%

Range 38%-66%

Overall Historical Incidence

Total 356/655 (54.4%)

Standard deviation 8.8%

Range 34%-66%

Data as of 12 May 1995; includes data for lymphocytic, monocytic, and undifferentiated cell type leukemias a
Tetrafluoroethylene, NTP TR 450 117

TABLE A5

Summary of the Incidence of Nonneoplastic Lesions in Male Rats in the 2-Year Inhalation Study 

of Tetrafluoroethylene a

0 ppm 156 ppm 312 ppm 625 ppm

Disposition Summary

Animals initially in study 60 60 60 60

15-Month interim evaluation 10 10 10 10

Early deaths

Moribund 27 34 32 48

Natural deaths 6 4 1 1

Survivors

Terminal sacrifice 17 12 17 1

Animals examined microscopically 60 60 60 60

15-Month Interim Evaluation

Alimentary System

Intestine large, cecum (10) (10) (10) (10)

Fibrosis 1 (10%) 

Liver (10) (10) (10) (10)

Basophilic focus 6 (60%) 4 (40%) 7 (70%) 4 (40%) 

Clear cell focus 4 (40%) 10 (100%) 9 (90%) 10 (100%)

Degeneration, cystic 1 (10%) 3 (30%) 

Eosinophilic focus 1 (10%) 1 (10%) 

Hepatodiaphragmatic nodule 1 (10%) 1 (10%) 1 (10%) 

Mixed cell focus 2 (20%) 2 (20%) 2 (20%) 

Regeneration 1 (10%) 

Bile duct, hyperplasia 7 (70%) 9 (90%) 6 (60%) 3 (30%) 

Serosa, fibrosis 1 (10%) 

Mesentery (2) (2) (4)

Fat, hemorrhage 1 (50%) 

Fat, necrosis 1 (50%) 2 (100%) 3 (75%) 

Pancreas (10) (10) (10) (10)

Basophilic focus 2 (20%) 

Hyperplasia 1 (10%) 

Acinus, atrophy 4 (40%) 7 (70%) 2 (20%) 4 (40%) 

Stomach, glandular (10) (10) (10) (10)

Mineralization 1 (10%) 

Cardiovascular System

Heart (10) (10) (10) (10)

Cardiomyopathy 10 (100%) 10 (100%) 10 (100%) 10 (100%)

Endocrine System

Adrenal cortex (10) (10) (10) (10)

Hyperplasia 1 (10%) 2 (20%) 1 (10%) 2 (20%) 

Adrenal medulla (10) (10) (10) (10)

Hyperplasia 3 (30%) 1 (10%) 

Pituitary gland (10) (9) (10) (10)

Pars distalis, hyperplasia 6 (60%) 3 (33%) 4 (40%) 7 (70%) 

Thyroid gland (10) (10) (10) (10)

C-cell, hyperplasia 4 (40%) 6 (60%) 5 (50%) 6 (60%) 

Number of animals examined microscopically at the site and the number of animals with lesion a
118 Tetrafluoroethylene, NTP TR 450

TABLE A5

Summary of the Incidence of Nonneoplastic Lesions in Male Rats in the 2-Year Inhalation Study 

of Tetrafluoroethylene (continued)

0 ppm 156 ppm 312 ppm 625 ppm

15-Month Interim Evaluation (continued)

Genital System

Preputial gland (10) (10) (10) (10)

Inflammation, chronic active 3 (30%) 8 (80%) 7 (70%) 6 (60%) 

Testes (10) (10) (10) (10)

Atrophy 1 (10%) 

Interstitial cell, hyperplasia 2 (20%) 4 (40%) 1 (10%) 

Hematopoietic System

Bone marrow (10) (10) (10) (10)

Hyperplasia, reticulum cell 1 (10%) 1 (10%) 

Lymph node, mandibular (10) (8) (10) (10)

Hemorrhage 1 (10%) 

Lymph node, mesenteric (10) (10) (10) (10)

Inflammation, chronic active 1 (10%) 

Lymph node, mediastinal (10) (10) (10) (10)

Hemorrhage 2 (20%) 1 (10%) 2 (20%) 1 (10%) 

Spleen (10) (10) (10) (10)

Developmental malformation 2 (20%) 1 (10%) 

Capsule, fibrosis 1 (10%) 

Integumentary System

Mammary gland (5) (7) (4) (5)

Galactocele 1 (20%) 

Skin (10) (10) (10) (10)

Inflammation, chronic active 1 (10%) 1 (10%) 

Respiratory System

Larynx (10) (10) (10) (10)

Inflammation, chronic active 4 (40%) 5 (50%) 5 (50%) 7 (70%) 

Metaplasia, squamous 1 (10%) 

Mineralization 6 (60%) 8 (80%) 8 (80%) 9 (90%) 

Lung (10) (10) (10) (10)

Hemorrhage 10 (100%) 10 (100%) 10 (100%) 10 (100%)

Metaplasia, osseous 1 (10%) 

Alveolar epithelium, hyperplasia 1 (10%) 2 (20%) 3 (30%) 

Urinary System

Kidney (10) (10) (10) (10)

Cyst 1 (10%) 

Nephropathy 10 (100%) 10 (100%) 10 (100%) 10 (100%)

Renal tubule, degeneration 1 (10%) 8 (80%) 10 (100%) 10 (100%)

Renal tubule, hyperplasia 1 (10%) 1 (10%) 
Tetrafluoroethylene, NTP TR 450 119

TABLE A5

Summary of the Incidence of Nonneoplastic Lesions in Male Rats in the 2-Year Inhalation Study 

of Tetrafluoroethylene (continued)

0 ppm 156 ppm 312 ppm 625 ppm

15-Month Interim Evaluation (continued)

Systems Examined With No Lesions Observed

General Body System

Musculoskeletal System

Nervous System

Special Senses System

2-Year Study

Alimentary System

Intestine large, colon (50) (50) (50) (50)

Mineralization 1 (2%) 2 (4%) 1 (2%) 

Parasite metazoan 2 (4%) 1 (2%) 3 (6%) 

Intestine large, rectum (49) (50) (50) (50)

Parasite metazoan 3 (6%) 1 (2%) 2 (4%) 

Intestine large, cecum (50) (50) (50) (50)

Inflammation, suppurative 1 (2%) 

Parasite metazoan 2 (4%) 1 (2%) 

Intestine small, duodenum (50) (50) (50) (50)

Necrosis 1 (2%) 

Intestine small, ileum (49) (49) (50) (50)

Inflammation, chronic active 1 (2%) 1 (2%) 

Mineralization 1 (2%) 

Peyer's patch, inflammation, granulomatous 1 (2%) 

Liver (50) (50) (50) (50)

Angiectasis 3 (6%) 2 (4%) 3 (6%) 

Basophilic focus 22 (44%) 19 (38%) 33 (66%) 29 (58%) 

Clear cell focus 7 (14%) 8 (16%) 11 (22%) 3 (6%) 

Congestion 1 (2%) 

Cyst 1 (2%) 

Degeneration, cystic 17 (34%) 39 (78%) 35 (70%) 32 (64%) 

Eosinophilic focus 3 (6%) 18 (36%) 22 (44%) 19 (38%) 

Fatty change 5 (10%) 3 (6%) 4 (8%) 5 (10%) 

Fibrosis 1 (2%) 

Hepatodiaphragmatic nodule 2 (4%) 2 (4%) 3 (6%) 4 (8%) 

Hyperplasia 1 (2%) 

Mineralization 1 (2%) 

Mixed cell focus 5 (10%) 5 (10%) 16 (32%) 13 (26%) 

Necrosis, focal 1 (2%) 

Regeneration 3 (6%) 4 (8%) 1 (2%) 

Thrombosis 1 (2%) 

Bile duct, hyperplasia 44 (88%) 43 (86%) 44 (88%) 42 (84%) 

Centrilobular, necrosis 3 (6%) 1 (2%) 1 (2%) 

Mesentery (15) (11) (18) (14)

Inflammation, suppurative 2 (13%) 

Fat, hemorrhage 1 (7%) 3 (17%) 1 (7%) 

Fat, necrosis 11 (73%) 11 (100%) 16 (89%) 12 (86%) 
120 Tetrafluoroethylene, NTP TR 450

TABLE A5

Summary of the Incidence of Nonneoplastic Lesions in Male Rats in the 2-Year Inhalation Study 

of Tetrafluoroethylene (continued)

0 ppm 156 ppm 312 ppm 625 ppm

2-Year Study (continued)

Alimentary System (continued)

Pancreas (50) (50) (50) (50)

Basophilic focus 4 (8%) 1 (2%) 4 (8%) 

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

Acinus, atrophy 32 (64%) 25 (50%) 31 (62%) 20 (40%) 

Duct, concretion 1 (2%) 

Stomach, forestomach (50) (50) (50) (50)

Acanthosis 2 (4%) 1 (2%) 2 (4%) 5 (10%) 

Diverticulum 2 (4%) 1 (2%) 2 (4%) 

Infiltration cellular, mast cell 1 (2%) 1 (2%) 

Mineralization 1 (2%) 2 (4%) 3 (6%) 

Necrosis 6 (12%) 4 (8%) 1 (2%) 6 (12%) 

Stomach, glandular (50) (50) (50) (50)

Mineralization 1 (2%) 3 (6%) 4 (8%) 13 (26%) 

Necrosis 5 (10%) 3 (6%) 3 (6%) 

Tongue (1) (1) (1)

Epithelium, hyperplasia 1 (100%)

Tooth (2) (2) (1) (2)

Dysplasia 2 (100%) 2 (100%) 1 (100%) 2 (100%)

Cardiovascular System

Blood vessel (1) (3) (12)

Mineralization 1 (100%) 2 (67%) 3 (25%) 

Aorta, mineralization 1 (100%) 3 (100%) 12 (100%)

Heart (50) (50) (50) (50)

Cardiomyopathy 46 (92%) 44 (88%) 43 (86%) 48 (96%) 

Mineralization 1 (2%) 2 (4%) 4 (8%) 

Atrium, thrombosis 2 (4%) 3 (6%) 1 (2%) 1 (2%) 

Endocrine System

Adrenal cortex (50) (50) (50) (50)

Hyperplasia 16 (32%) 13 (26%) 21 (42%) 17 (34%) 

Hypertrophy 4 (8%) 4 (8%) 5 (10%) 4 (8%) 

Vacuolization cytoplasmic 2 (4%) 

Adrenal medulla (50) (50) (50) (50)

Hyperplasia 21 (42%) 21 (42%) 23 (46%) 26 (52%) 

Islets, pancreatic (50) (50) (50) (50)

Hyperplasia 1 (2%) 1 (2%) 

Parathyroid gland (50) (50) (50) (49)

Hyperplasia 1 (2%) 3 (6%) 7 (14%) 25 (51%) 

Pituitary gland (50) (49) (49) (49)

Thrombosis 1 (2%) 

Pars distalis, angiectasis 1 (2%) 

Pars distalis, hyperplasia 4 (8%) 3 (6%) 4 (8%) 8 (16%) 

Thyroid gland (50) (50) (50) (50)

C-cell, hyperplasia 22 (44%) 24 (48%) 35 (70%) 20 (40%) 

Follicular cell, hyperplasia 2 (4%) 2 (4%) 

General Body System

None 
Tetrafluoroethylene, NTP TR 450 121

TABLE A5

Summary of the Incidence of Nonneoplastic Lesions in Male Rats in the 2-Year Inhalation Study 

of Tetrafluoroethylene (continued)

0 ppm 156 ppm 312 ppm 625 ppm

2-Year Study (continued)

Genital System

Epididymis (50) (50) (50) (50)

Granuloma sperm 1 (2%) 

Thrombosis 1 (2%) 

Preputial gland (50) (50) (50) (49)

Hyperplasia 1 (2%) 1 (2%) 

Inflammation, chronic active 10 (20%) 8 (16%) 10 (20%) 14 (29%) 

Inflammation, granulomatous 1 (2%) 

Duct, ectasia 1 (2%) 1 (2%) 

Prostate (50) (50) (50) (50)

Inflammation, chronic active 2 (4%) 1 (2%) 

Inflammation, suppurative 1 (2%) 

Seminal vesicle (50) (50) (50) (50)

Inflammation, suppurative 1 (2%) 

Mineralization 2 (4%) 1 (2%) 

Testes (50) (50) (50) (50)

Atrophy 2 (4%) 2 (4%) 2 (4%) 

Interstitial cell, hyperplasia 8 (16%) 10 (20%) 6 (12%) 8 (16%) 

Hematopoietic System

Bone marrow (50) (50) (50) (50)

Thrombosis 1 (2%) 

Lymph node (11) (17) (16) (17)

Iliac, pigmentation 1 (6%) 

Lumbar, hemorrhage 2 (12%) 

Pancreatic, edema 1 (6%) 

Renal, edema 2 (12%) 

Renal, hemorrhage 1 (6%) 

Renal, pigmentation 1 (6%) 

Lymph node, bronchial (45) (50) (46) (47)

Hemorrhage 1 (2%) 

Lymph node, mandibular (50) (49) (49) (46)

Hemorrhage 2 (4%) 

Infiltration cellular, plasma cell 2 (4%) 5 (10%) 2 (4%) 

Lymph node, mesenteric (50) (50) (50) (50)

Edema 1 (2%) 

Hemorrhage 1 (2%) 2 (4%) 

Lymph node, mediastinal (49) (47) (48) (46)

Hemorrhage 3 (6%) 1 (2%) 3 (7%) 

Inflammation, granulomatous 1 (2%) 1 (2%) 

Spleen (50) (50) (50) (50)

Congestion 1 (2%) 

Developmental malformation 2 (4%) 3 (6%) 1 (2%) 4 (8%) 

Fibrosis 9 (18%) 14 (28%) 11 (22%) 6 (12%) 

Hematopoietic cell proliferation 1 (2%) 1 (2%) 2 (4%) 

Infiltration cellular, lipocyte 1 (2%) 

Capsule, fibrosis 1 (2%) 1 (2%) 

Thymus (49) (47) (47) (45)

Hemorrhage 1 (2%) 
122 Tetrafluoroethylene, NTP TR 450

TABLE A5

Summary of the Incidence of Nonneoplastic Lesions in Male Rats in the 2-Year Inhalation Study 

of Tetrafluoroethylene (continued)

0 ppm 156 ppm 312 ppm 625 ppm

2-Year Study (continued)

Integumentary System

Mammary gland (33) (36) (41) (34)

Galactocele 1 (3%) 1 (2%) 

Inflammation, chronic active 1 (3%) 1 (3%) 

Skin (49) (50) (50) (50)

Acanthosis 1 (2%) 

Fibrosis 1 (2%) 

Hemorrhage 1 (2%) 

Hyperkeratosis 1 (2%) 1 (2%) 1 (2%) 

Inflammation, chronic active 9 (18%) 4 (8%) 4 (8%) 4 (8%) 

Necrosis 1 (2%) 

Prepuce, edema 1 (2%) 

Musculoskeletal System

Bone (50) (50) (50) (50)

Hyperostosis 1 (2%) 1 (2%) 1 (2%) 

Cranium, fibrous osteodystrophy 1 (2%) 1 (2%) 3 (6%) 17 (34%) 

Femur, fibrous osteodystrophy 1 (2%) 1 (2%) 3 (6%) 19 (38%) 

Sternum, developmental malformation 1 (2%) 

Nervous System

Brain (50) (50) (50) (50)

Compression 12 (24%) 11 (22%) 9 (18%) 6 (12%) 

Hemorrhage 1 (2%) 1 (2%) 

Respiratory System

Larynx (50) (50) (50) (50)

Inflammation, chronic active 10 (20%) 9 (18%) 8 (16%) 12 (24%) 

Metaplasia, squamous 1 (2%) 1 (2%) 1 (2%) 

Mineralization 36 (72%) 38 (76%) 36 (72%) 33 (66%) 

Lung (50) (50) (50) (50)

Congestion 1 (2%) 

Hemorrhage 9 (18%) 5 (10%) 3 (6%) 8 (16%) 

Inflammation, chronic active 1 (2%) 

Mineralization 1 (2%) 1 (2%) 3 (6%) 12 (24%) 

Thrombosis 1 (2%) 1 (2%) 

Alveolar epithelium, hyperplasia 5 (10%) 4 (8%) 3 (6%) 3 (6%) 

Nose (50) (50) (50) (50)

Inflammation, suppurative 5 (10%) 3 (6%) 4 (8%) 7 (14%) 

Thrombosis 2 (4%) 1 (2%) 

Nasolacrimal duct, inflammation, chronic 

 active 1 (2%) 

Olfactory epithelium, degeneration 1 (2%) 

Respiratory epithelium, hyperplasia 1 (2%) 

Respiratory epithelium, metaplasia, squamous 2 (4%) 

Trachea (50) (50) (50) (50)

Metaplasia, squamous 1 (2%) 1 (2%) 

Mineralization 1 (2%) 2 (4%) 1 (2%) 
Tetrafluoroethylene, NTP TR 450 123

TABLE A5

Summary of the Incidence of Nonneoplastic Lesions in Male Rats in the 2-Year Inhalation Study 

of Tetrafluoroethylene (continued)

0 ppm 156 ppm 312 ppm 625 ppm

2-Year Study (continued)

Special Senses System

Eye (45) (42) (48) (42)

Cataract 3 (7%) 4 (8%) 

Degeneration 1 (2%) 4 (8%) 

Cornea, inflammation, chronic active 1 (2%) 4 (10%) 

Cornea, mineralization 1 (2%) 2 (4%) 7 (17%) 

Retina, atrophy 3 (7%) 2 (5%) 5 (10%) 2 (5%) 

Harderian gland (1) 

Hypertrophy 1 (100%) 

Urinary System

Kidney (50) (50) (50) (50)

Developmental malformation 1 (2%) 

Infarct 3 (6%) 

Mineralization 1 (2%) 3 (6%) 4 (8%) 

Nephropathy 49 (98%) 50 (100%) 50 (100%) 50 (100%)

Pelvis, dilatation 1 (2%) 

Renal tubule, degeneration 2 (4%) 20 (40%) 50 (100%) 49 (98%) 

Renal tubule, hyperplasia 1 (2%) 1 (2%) 1 (2%) 6 (12%) 

Renal tubule, hyperplasia, oncocytic 1 (2%) 

Urinary bladder (49) (50) (50) (50)

Hemorrhage 1 (2%) 

Inflammation, suppurative 1 (2%) 

Transitional epithelium, hyperplasia 1 (2%) 
124 Tetrafluoroethylene, NTP TR 450
125

APPENDIX B

SUMMARY OF LESIONS IN FEMALE RATS

IN THE 2-YEAR INHALATION STUDY

OF TETRAFLUOROETHYLENE

TABLE B1 Summary of the Incidence of Neoplasms in Female Rats 

in the 2-Year Inhalation Study of Tetrafluoroethylene .................................. 127

TABLE B2 Individual Animal Tumor Pathology of Female Rats

in the 2-Year Inhalation Study of Tetrafluoroethylene .................................. 132

TABLE B3 Statistical Analysis of Primary Neoplasms in Female Rats

in the 2-Year Inhalation Study of Tetrafluoroethylene .................................. 150

TABLE B4a Historical Incidence of Renal Tubule Neoplasms

in Chamber Control Female F344/N Rats ............................................. 157

TABLE B4b Historical Incidence of Liver Neoplasms 

in Chamber Control Female F344/N Rats ............................................. 157

TABLE B4c Historical Incidence of Mononuclear Cell Leukemia

in Chamber Control Female F344/N Rats ............................................. 158

TABLE B5 Summary of the Incidence of Nonneoplastic Lesions in Female Rats

in the 2-Year Inhalation Study of Tetrafluoroethylene .................................. 159
126 Tetrafluoroethylene, NTP TR 450
Tetrafluoroethylene, NTP TR 450 127

TABLE B1

Summary of the Incidence of Neoplasms in Female Rats in the 2-Year Inhalation Study of Tetrafluoroethylene a

0 ppm 312 ppm 625 ppm 1,250 ppm

Disposition Summary

Animals initially in study 60 60 60 60

15-Month interim evaluation 10 10 10 10

Early deaths

Accidental death 1

Moribund 21 33 31 25

Natural deaths 1 1 4 6

Survivors

Died last week of study 1

Terminal sacrifice 28 15 15 18

Animals examined microscopically 60 60 60 60

15-Month Interim Evaluation

Endocrine System

Pituitary gland (10) (10) (10) (10)

Pars distalis, adenoma 1 (10%) 2 (20%) 1 (10%) 

Genital System

Clitoral gland (10) (10) (10) (10)

Adenoma 1 (10%) 

Carcinoma 1 (10%) 

Uterus (10) (10) (10) (10)

Polyp stromal 2 (20%) 1 (10%) 

Hematopoietic System

Bone marrow (10) (10) (10) (10)

Histiocytic sarcoma 1 (10%) 

Integumentary System

Mammary gland (10) (10) (10) (10)

Fibroadenoma 1 (10%) 

Respiratory System

Lung (10) (10) (10) (10)

Histiocytic sarcoma, metastatic, bone marrow 1 (10%) 

Urinary System

Kidney (10) (10) (10) (10)

Mixed tumor malignant 1 (10%) 

Renal tubule, adenoma 1 (10%) 

Systemic Lesions

Multiple organs (10) (10) (10) (10) b

Histiocytic sarcoma 1 (10%) 
128 Tetrafluoroethylene, NTP TR 450

TABLE B1

Summary of the Incidence of Neoplasms in Female Rats in the 2-Year Inhalation Study of Tetrafluoroethylene (continued)

0 ppm 312 ppm 625 ppm 1,250 ppm

15-Month Interim Evaluation (continued)

Systems Examined With No Neoplasms Observed

Alimentary System

Cardiovascular System

General Body System

Musculoskeletal System

Nervous System

Special Senses System

2-Year Study

Alimentary System

Intestine large, colon (50) (50) (49) (50)

Intestine large, rectum (50) (50) (49) (50)

Sarcoma stromal, metastatic, uterus 1 (2%) 

Intestine large, cecum (50) (50) (49) (50)

Hemangiosarcoma, metastatic, liver 1 (2%) 

Intestine small, duodenum (49) (50) (49) (50)

Intestine small, jejunum (50) (50) (47) (49)

Hemangiosarcoma, metastatic, liver 1 (2%) 

Intestine small, ileum (50) (49) (48) (49)

Liver (50) (50) (50) (50)

Hemangiosarcoma 5 (10%) 1 (2%) 

Hepatocellular carcinoma 4 (8%) 6 (12%) 2 (4%) 

Hepatocellular carcinoma, multiple 3 (6%) 

Hepatocellular adenoma 3 (6%) 4 (8%) 5 (10%) 

Hepatocellular adenoma, multiple 1 (2%) 1 (2%) 1 (2%) 

Sarcoma 1 (2%) 

Mesentery (6) (4) (4) (6)

Leiomyosarcoma, metastatic, uterus 1 (17%) 

Pancreas (50) (50) (49) (50)

Salivary glands (50) (50) (50) (50)

Adenoma 1 (2%) 

Stomach, forestomach (50) (50) (48) (50)

Squamous cell carcinoma 1 (2%) 

Stomach, glandular (50) (50) (49) (50)

Hemangiosarcoma, metastatic, liver 1 (2%) 

Tongue (2) (2) (1)

Squamous cell papilloma 2 (100%) 

Cardiovascular System

Heart (50) (50) (50) (50)

Schwannoma NOS 1 (2%) 

Endocrine System

Adrenal cortex (50) (50) (50) (50)

Hemangiosarcoma, metastatic, liver 1 (2%) 

Leiomyosarcoma, metastatic, uterus 1 (2%) 

Adrenal medulla (50) (50) (50) (50)

Pheochromocytoma benign 4 (8%) 1 (2%) 2 (4%) 5 (10%) 
Tetrafluoroethylene, NTP TR 450 129

TABLE B1

Summary of the Incidence of Neoplasms in Female Rats in the 2-Year Inhalation Study of Tetrafluoroethylene (continued)

0 ppm 312 ppm 625 ppm 1,250 ppm

2-Year Study (continued)

Endocrine System (continued)

Islets, pancreatic (50) (50) (49) (50)

Adenoma 1 (2%) 

Carcinoma 1 (2%) 

Parathyroid gland (48) (49) (49) (47)

Adenoma 1 (2%) 

Pituitary gland (50) (50) (49) (50)

Pars distalis, adenoma 43 (86%) 34 (68%) 36 (73%) 34 (68%) 

Pars distalis, carcinoma 1 (2%) 

Thyroid gland (50) (50) (50) (50)

C-cell, adenoma 5 (10%) 9 (18%) 5 (10%) 2 (4%) 

C-cell, carcinoma 2 (4%) 2 (4%) 3 (6%) 2 (4%) 

Follicular cell, carcinoma 1 (2%) 

General Body System

Tissue NOS (1)

Abdominal, fat, hemangiosarcoma, metastatic, 

 tissue NOS 1 (100%)

Genital System

Clitoral gland (49) (49) (50) (48)

Adenoma 6 (12%) 6 (12%) 2 (4%) 

Carcinoma 1 (2%) 1 (2%) 2 (4%) 2 (4%) 

Ovary (50) (50) (50) (50)

Granulosa-theca tumor benign 1 (2%) 1 (2%) 

Hepatocellular carcinoma, metastatic, liver 1 (2%) 

Uterus (50) (50) (50) (50)

Leiomyosarcoma 1 (2%) 1 (2%) 

Polyp stromal 5 (10%) 4 (8%) 4 (8%) 5 (10%) 

Polyp stromal, multiple 1 (2%) 1 (2%) 

Sarcoma stromal 1 (2%) 1 (2%) 

Vagina (1) (1) (1)

Polyp 1 (100%) 1 (100%)

Hematopoietic System

Bone marrow (50) (50) (50) (50)

Histiocytic sarcoma 1 (2%) 

Lymph node (3) (7) (7) (13)

Iliac, osteosarcoma, metastatic, bone 1 (8%) 

Lymph node, bronchial (50) (50) (50) (48)

Lymph node, mandibular (48) (49) (50) (50)

Lymph node, mesenteric (50) (50) (50) (50)

Leiomyosarcoma, metastatic, uterus 1 (2%) 

Lymph node, mediastinal (49) (49) (49) (45)

Spleen (50) (50) (49) (50)

Thymus (47) (48) (49) (48)
130 Tetrafluoroethylene, NTP TR 450

TABLE B1

Summary of the Incidence of Neoplasms in Female Rats in the 2-Year Inhalation Study of Tetrafluoroethylene (continued)

0 ppm 312 ppm 625 ppm 1,250 ppm

2-Year Study (continued)

Integumentary System

Mammary gland (50) (50) (50) (50)

Adenoma 1 (2%) 1 (2%) 1 (2%) 

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

Carcinoma, multiple 1 (2%) 

Fibroadenoma 17 (34%) 10 (20%) 8 (16%) 5 (10%) 

Fibroadenoma, multiple 5 (10%) 1 (2%) 1 (2%) 2 (4%) 

Skin (50) (50) (50) (50)

Basosquamous tumor malignant 1 (2%) 1 (2%) 

Keratoacanthoma 2 (4%) 1 (2%) 

Squamous cell papilloma 1 (2%) 1 (2%) 

Subcutaneous tissue, fibroma 1 (2%) 

Subcutaneous tissue, neurofibroma 1 (2%) 

Subcutaneous tissue, sarcoma 1 (2%) 1 (2%) 1 (2%) 

Musculoskeletal System

Bone (50) (50) (50) (50)

Vertebra, osteosarcoma 1 (2%) 

Vertebra, sarcoma 1 (2%) 

Nervous System

Brain (50) (50) (50) (50)

Astrocytoma NOS 1 (2%) 1 (2%) 

Respiratory System

Larynx (50) (50) (50) (50)

Lung (50) (50) (50) (50)

Alveolar/bronchiolar adenoma 1 (2%) 

Alveolar/bronchiolar carcinoma 1 (2%) 

Carcinoma, metastatic, mammary gland 1 (2%) 

Carcinoma, metastatic, pituitary gland 1 (2%) 

Carcinoma, metastatic, thyroid gland 1 (2%) 1 (2%) 

Hemangiosarcoma, metastatic, liver 3 (6%) 

Hepatocellular carcinoma, metastatic, liver 2 (4%) 

Leiomyosarcoma, metastatic, uterus 1 (2%) 

Osteosarcoma, metastatic, bone 1 (2%) 

Sarcoma, metastatic, bone 1 (2%) 

Sarcoma, metastatic, liver 1 (2%) 

Nose (50) (50) (50) (50)

Trachea (50) (50) (50) (50)

Special Senses System

Eye (50) (50) (50) (50)

Zymbal's gland (1) (1)

Adenoma 1 (100%) 
Tetrafluoroethylene, NTP TR 450 131

TABLE B1

Summary of the Incidence of Neoplasms in Female Rats in the 2-Year Inhalation Study of Tetrafluoroethylene (continued)

0 ppm 312 ppm 625 ppm 1,250 ppm

2-Year Study (continued)

Urinary System

Kidney (50) (50) (50) (50)

Leiomyosarcoma, metastatic, uterus 1 (2%) 

Renal tubule, adenoma 3 (6%) 1 (2%) 3 (6%) 

Renal tubule, carcinoma 2 (4%) 

Urinary bladder (49) (50) (50) (49)

Sarcoma stromal, metastatic, uterus 1 (2%) 

Transitional epithelium, papilloma 2 (4%) 

Systemic Lesions

Multiple organs (50) (50) (50) (50)

Histiocytic sarcoma 1 (2%) 

Leukemia mononuclear 16 (32%) 31 (62%) 23 (46%) 36 (72%) 

Mesothelioma malignant 1 (2%) 

Neoplasm Summary

Total animals with primary neoplasmsc

15-Month interim evaluation 1 4 3 3

2-Year study 49 50 49 48

Total primary neoplasms

15-Month interim evaluation 2 4 3 4

2-Year study 121 123 121 118

Total animals with benign neoplasms

15-Month interim evaluation 1 3 3 3

2-Year study 46 43 43 40

Total benign neoplasms

15-Month interim evaluation 1 3 3 3

2-Year study 93 75 72 68

Total animals with malignant neoplasms

15-Month interim evaluation 1 1 1

2-Year study 21 41 35 42

Total malignant neoplasms

15-Month interim evaluation 1 1 1

2-Year study 27 47 49 49

Total animals with metastatic neoplasms

15-Month interim evaluation 1

2-Year study 2 3 8 3

Total metastatic neoplasms

15-Month interim evaluation 1

2-Year study 6 4 9 7

Total animals with uncertain neoplasms-

 benign or malignant

2-Year study 1 1 1

Total uncertain neoplasms

2-Year study 1 1 1

Number of animals examined microscopically at the site and the number of animals with neoplasm a

Number of animals with any tissue examined microscopically b

Primary neoplasms: all neoplasms except metastatic neoplasms c
132 Tetrafluoroethylene, NTP TR 450

TABLE B2

Individual Animal Tumor Pathology of Female Rats in the 2-Year Inhalation Study of Tetrafluoroethylene: 0 ppm 

4 4 4 5 5 6 6 6 6 6 6 6 6 6 6 6 7 7 7 7 7 7 7 7 7 

Number of Days on Study 3 8 8 5 8 2 2 4 4 6 7 8 9 9 9 9 0 0 0 1 2 2 3 3 3

3 1 1 4 1 1 6 8 9 3 7 5 2 3 8 9 2 7 7 4 1 6 4 4 4

1 0 1 1 1 1 0 0 0 0 1 0 0 0 0 0 0 0 1 0 1 0 0 0 0

Carcass ID Number 0 7 1 0 1 2 9 9 9 7 1 8 8 6 9 7 9 6 1 6 1 9 6 6 6

2 3 5 7 2 0 9 3 2 1 7 0 3 3 4 0 5 7 8 6 3 8 1 2 4

Alimentary System 

Esophagus + + + + + + + + + + + + + + + + + + + + + + + + +

Intestine large, colon + + + + + + + + + + + + + + + + + + + + + + + + +

Intestine large, rectum + + + + + + + + + + + + + + + + + + + + + + + + +

Intestine large, cecum + + + + + + + + + + + + + + + + + + + + + + + + +

Intestine small, duodenum + + + + + + + + + + + + + + + + + + + + + + + + +

Intestine small, jejunum + + + + + + + + + + + + + + + + + + + + + + + + +

Intestine small, ileum + + + + + + + + + + + + + + + + + + + + + + + + +

Liver + + + + + + + + + + + + + + + + + + + + + + + + +

Mesentery + + + +

Leiomyosarcoma, metastatic, uterus X

Pancreas + + + + + + + + + + + + + + + + + + + + + + + + +

Salivary glands + + + + + + + + + + + + + + + + + + + + + + + + +

Stomach, forestomach + + + + + + + + + + + + + + + + + + + + + + + + +

Squamous cell carcinoma

Stomach, glandular + + + + + + + + + + + + + + + + + + + + + + + + +

Tongue +

Squamous cell papilloma X

Cardiovascular System 

Heart + + + + + + + + + + + + + + + + + + + + + + + + +

Schwannoma NOS

Endocrine System 

Adrenal cortex + + + + + + + + + + + + + + + + + + + + + + + + +

Leiomyosarcoma, metastatic, uterus X

Adrenal medulla + + + + + + + + + + + + + + + + + + + + + + + + +

Pheochromocytoma benign X X

Islets, pancreatic + + + + + + + + + + + + + + + + + + + + + + + + +

Parathyroid gland + + + + + + + + + M + + + + M + + + + + + + + + +

Adenoma X

Pituitary gland + + + + + + + + + + + + + + + + + + + + + + + + +

Pars distalis, adenoma X X X X X X X X X X X X X X X X X X X X X

Thyroid gland + + + + + + + + + + + + + + + + + + + + + + + + +

C-cell, adenoma X

C-cell, carcinoma

General Body System 

None

+: Tissue examined microscopically M: Missing tissue X: Lesion present

A: Autolysis precludes examination I: Insufficient tissue Blank: Not examined
Tetrafluoroethylene, NTP TR 450 133

TABLE B2

Individual Animal Tumor Pathology of Female Rats in the 2-Year Inhalation Study of Tetrafluoroethylene: 0 ppm (continued)

7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7

Number of Days on Study 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4

0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 Total

Carcass ID Number 6 6 7 7 7 8 8 8 8 8 9 9 9 9 0 0 0 0 0 0 1 1 1 1 1 Tissues/

5 8 2 6 9 2 4 5 8 9 0 1 6 7 0 1 4 5 8 9 0 1 4 6 9 Tumors

Alimentary System 

Esophagus + + + + + + + + + + + + + + + + + + + + + + + + + 50

Intestine large, colon + + + + + + + + + + + + + + + + + + + + + + + + + 50

Intestine large, rectum + + + + + + + + + + + + + + + + + + + + + + + + + 50

Intestine large, cecum + + + + + + + + + + + + + + + + + + + + + + + + + 50

Intestine small, duodenum + + + + + + + + + + + + + M + + + + + + + + + + + 49

Intestine small, jejunum + + + + + + + + + + + + + + + + + + + + + + + + + 50

Intestine small, ileum + + + + + + + + + + + + + + + + + + + + + + + + + 50

Liver + + + + + + + + + + + + + + + + + + + + + + + + + 50

Mesentery + + 6

Leiomyosarcoma, metastatic, uterus 1

Pancreas + + + + + + + + + + + + + + + + + + + + + + + + + 50

Salivary glands + + + + + + + + + + + + + + + + + + + + + + + + + 50

Stomach, forestomach + + + + + + + + + + + + + + + + + + + + + + + + + 50

Squamous cell carcinoma X 1

Stomach, glandular + + + + + + + + + + + + + + + + + + + + + + + + + 50

Tongue + 2

Squamous cell papilloma X 2

Cardiovascular System 

Heart + + + + + + + + + + + + + + + + + + + + + + + + + 50

Schwannoma NOS X 1

Endocrine System 

Adrenal cortex + + + + + + + + + + + + + + + + + + + + + + + + + 50

Leiomyosarcoma, metastatic, uterus 1

Adrenal medulla + + + + + + + + + + + + + + + + + + + + + + + + + 50

Pheochromocytoma benign X X 4

Islets, pancreatic + + + + + + + + + + + + + + + + + + + + + + + + + 50

Parathyroid gland + + + + + + + + + + + + + + + + + + + + + + + + + 48

Adenoma 1

Pituitary gland + + + + + + + + + + + + + + + + + + + + + + + + + 50

Pars distalis, adenoma X X X X X X X X X X X X X X X X X X X X X X 43

Thyroid gland + + + + + + + + + + + + + + + + + + + + + + + + + 50

C-cell, adenoma X X X X 5

C-cell, carcinoma X X 2

General Body System 

None 
134 Tetrafluoroethylene, NTP TR 450

TABLE B2

Individual Animal Tumor Pathology of Female Rats in the 2-Year Inhalation Study of Tetrafluoroethylene: 0 ppm (continued)

4 4 4 5 5 6 6 6 6 6 6 6 6 6 6 6 7 7 7 7 7 7 7 7 7

Number of Days on Study 3 8 8 5 8 2 2 4 4 6 7 8 9 9 9 9 0 0 0 1 2 2 3 3 3

3 1 1 4 1 1 6 8 9 3 7 5 2 3 8 9 2 7 7 4 1 6 4 4 4

1 0 1 1 1 1 0 0 0 0 1 0 0 0 0 0 0 0 1 0 1 0 0 0 0

Carcass ID Number 0 7 1 0 1 2 9 9 9 7 1 8 8 6 9 7 9 6 1 6 1 9 6 6 6

2 3 5 7 2 0 9 3 2 1 7 0 3 3 4 0 5 7 8 6 3 8 1 2 4

Genital System

Clitoral gland + + + + + + + + + + + + + + + + + M + + + + + + +

Adenoma X X

Carcinoma

Ovary + + + + + + + + + + + + + + + + + + + + + + + + +

Uterus + + + + + + + + + + + + + + + + + + + + + + + + +

Leiomyosarcoma X

Polyp stromal X X X

Polyp stromal, multiple

Vagina +

Polyp X

Hematopoietic System 

Bone marrow + + + + + + + + + + + + + + + + + + + + + + + + +

Histiocytic sarcoma

Lymph node + + +

Lymph node, bronchial + + + + + + + + + + + + + + + + + + + + + + + + +

Lymph node, mandibular + + + + + + + + M + + + + + + + + + + + + + + + +

Lymph node, mesenteric + + + + + + + + + + + + + + + + + + + + + + + + +

Leiomyosarcoma, metastatic, uterus X

Lymph node, mediastinal + + + + + + + + + + + + + + + + + + + + + + + + +

Spleen + + + + + + + + + + + + + + + + + + + + + + + + +

Thymus + M + + + + + + + + + + + + + + + + + + M + + M +

Integumentary System 

Mammary gland + + + + + + + + + + + + + + + + + + + + + + + + +

Adenoma

Carcinoma X X

Fibroadenoma X X X X X X X X X

Fibroadenoma, multiple X X X X X

Skin + + + + + + + + + + + + + + + + + + + + + + + + +

Keratoacanthoma X

Subcutaneous tissue, sarcoma X

Musculoskeletal System 

Bone + + + + + + + + + + + + + + + + + + + + + + + + +

Vertebra, sarcoma X

Nervous System 

Brain + + + + + + + + + + + + + + + + + + + + + + + + +

Respiratory System 

Larynx + + + + + + + + + + + + + + + + + + + + + + + + +

Lung + + + + + + + + + + + + + + + + + + + + + + + + +

Leiomyosarcoma, metastatic, uterus X

Sarcoma, metastatic, bone X

Nose + + + + + + + + + + + + + + + + + + + + + + + + +

Trachea + + + + + + + + + + + + + + + + + + + + + + + + +

Special Senses System 

Ear +

Eye + + + + + + + + + + + + + + + + + + + + + + + + +
Tetrafluoroethylene, NTP TR 450 135

TABLE B2

Individual Animal Tumor Pathology of Female Rats in the 2-Year Inhalation Study of Tetrafluoroethylene: 0 ppm (continued)

7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7

Number of Days on Study 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4

0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 Total

Carcass ID Number 6 6 7 7 7 8 8 8 8 8 9 9 9 9 0 0 0 0 0 0 1 1 1 1 1 Tissues/

5 8 2 6 9 2 4 5 8 9 0 1 6 7 0 1 4 5 8 9 0 1 4 6 9 Tumors

Genital System 

Clitoral gland + + + + + + + + + + + + + + + + + + + + + + + + + 49

Adenoma X X X X 6

Carcinoma X 1

Ovary + + + + + + + + + + + + + + + + + + + + + + + + + 50

Uterus + + + + + + + + + + + + + + + + + + + + + + + + + 50

Leiomyosarcoma 1

Polyp stromal X X 5

Polyp stromal, multiple X 1

Vagina 1

Polyp 1

Hematopoietic System 

Bone marrow + + + + + + + + + + + + + + + + + + + + + + + + + 50

Histiocytic sarcoma X 1

Lymph node 3

Lymph node, bronchial + + + + + + + + + + + + + + + + + + + + + + + + + 50

Lymph node, mandibular + + + + + + + + + + + + + + + + M + + + + + + + + 48

Lymph node, mesenteric + + + + + + + + + + + + + + + + + + + + + + + + + 50

Leiomyosarcoma, metastatic, uterus 1

Lymph node, mediastinal + + + + + + + + + + + + + + + + M + + + + + + + + 49

Spleen + + + + + + + + + + + + + + + + + + + + + + + + + 50

Thymus + + + + + + + + + + + + + + + + + + + + + + + + + 47

Integumentary System 

Mammary gland + + + + + + + + + + + + + + + + + + + + + + + + + 50

Adenoma X 1

Carcinoma X 3

Fibroadenoma X X X X X X X X 17

Fibroadenoma, multiple 5

Skin + + + + + + + + + + + + + + + + + + + + + + + + + 50

Keratoacanthoma X 2

Subcutaneous tissue, sarcoma 1

Musculoskeletal System 

Bone + + + + + + + + + + + + + + + + + + + + + + + + + 50

Vertebra, sarcoma 1

Nervous System 

Brain + + + + + + + + + + + + + + + + + + + + + + + + + 50

Respiratory System 

Larynx + + + + + + + + + + + + + + + + + + + + + + + + + 50

Lung + + + + + + + + + + + + + + + + + + + + + + + + + 50

Leiomyosarcoma, metastatic, uterus 1

Sarcoma, metastatic, bone 1

Nose + + + + + + + + + + + + + + + + + + + + + + + + + 50

Trachea + + + + + + + + + + + + + + + + + + + + + + + + + 50

Special Senses System 

Ear 1

Eye + + + + + + + + + + + + + + + + + + + + + + + + + 50
136 Tetrafluoroethylene, NTP TR 450

TABLE B2

Individual Animal Tumor Pathology of Female Rats in the 2-Year Inhalation Study of Tetrafluoroethylene: 0 ppm (continued)

4 4 4 5 5 6 6 6 6 6 6 6 6 6 6 6 7 7 7 7 7 7 7 7 7

Number of Days on Study 3 8 8 5 8 2 2 4 4 6 7 8 9 9 9 9 0 0 0 1 2 2 3 3 3

3 1 1 4 1 1 6 8 9 3 7 5 2 3 8 9 2 7 7 4 1 6 4 4 4

1 0 1 1 1 1 0 0 0 0 1 0 0 0 0 0 0 0 1 0 1 0 0 0 0

Carcass ID Number 0 7 1 0 1 2 9 9 9 7 1 8 8 6 9 7 9 6 1 6 1 9 6 6 6

2 3 5 7 2 0 9 3 2 1 7 0 3 3 4 0 5 7 8 6 3 8 1 2 4

Urinary System 

Kidney + + + + + + + + + + + + + + + + + + + + + + + + +

Leiomyosarcoma, metastatic, uterus X

Urinary bladder + + + + + + + + M + + + + + + + + + + + + + + + +

Systemic Lesions 

Multiple organs + + + + + + + + + + + + + + + + + + + + + + + + +

Histiocytic sarcoma

Leukemia mononuclear X X X X X X X X
Tetrafluoroethylene, NTP TR 450 137

TABLE B2

Individual Animal Tumor Pathology of Female Rats in the 2-Year Inhalation Study of Tetrafluoroethylene: 0 ppm (continued)

7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7

Number of Days on Study 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4

0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 Total

Carcass ID Number 6 6 7 7 7 8 8 8 8 8 9 9 9 9 0 0 0 0 0 0 1 1 1 1 1 Tissues/

5 8 2 6 9 2 4 5 8 9 0 1 6 7 0 1 4 5 8 9 0 1 4 6 9 Tumors

Urinary System 

Kidney + + + + + + + + + + + + + + + + + + + + + + + + + 50

Leiomyosarcoma, metastatic, uterus 1

Urinary bladder + + + + + + + + + + + + + + + + + + + + + + + + + 49

Systemic Lesions 

Multiple organs + + + + + + + + + + + + + + + + + + + + + + + + + 50

Histiocytic sarcoma X 1

Leukemia mononuclear X X X X X X X X 16
138 Tetrafluoroethylene, NTP TR 450

TABLE B2

Individual Animal Tumor Pathology of Female Rats in the 2-Year Inhalation Study of Tetrafluoroethylene: 312 ppm 

2 4 4 4 5 5 5 5 5 5 5 5 5 5 5 5 5 6 6 6 6 6 6 6 6

Number of Days on Study 4 1 6 6 1 2 3 5 6 6 7 7 8 8 8 9 9 0 1 1 1 2 3 4 5

7 3 8 8 7 3 7 7 5 5 4 4 1 3 8 4 7 0 7 8 8 5 8 9 3

2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 3

Carcass ID Number 9 7 5 8 4 7 5 7 5 7 4 6 9 9 8 5 7 6 8 6 6 7 5 9 0

2 2 2 8 8 9 5 6 0 1 4 5 0 1 1 4 4 9 7 1 7 0 8 7 0

Alimentary System 

Esophagus + + + + + + + + + + + + + + + + + + + + + + + + +

Intestine large, colon + + + + + + + + + + + + + + + + + + + + + + + + +

Intestine large, rectum + + + + + + + + + + + + + + + + + + + + + + + + +

Sarcoma stromal, metastatic, uterus X

Intestine large, cecum + + + + + + + + + + + + + + + + + + + + + + + + +

Intestine small, duodenum + + + + + + + + + + + + + + + + + + + + + + + + +

Intestine small, jejunum + + + + + + + + + + + + + + + + + + + + + + + + +

Intestine small, ileum + + + + + + + + + + + + + + + + + + + + + + + + +

Liver + + + + + + + + + + + + + + + + + + + + + + + + +

Hepatocellular carcinoma X

Hepatocellular adenoma

Hepatocellular adenoma, multiple

Mesentery + + +

Pancreas + + + + + + + + + + + + + + + + + + + + + + + + +

Pharynx +

Salivary glands + + + + + + + + + + + + + + + + + + + + + + + + +

Adenoma X

Stomach, forestomach + + + + + + + + + + + + + + + + + + + + + + + + +

Stomach, glandular + + + + + + + + + + + + + + + + + + + + + + + + +

Tooth +

Cardiovascular System 

Heart + + + + + + + + + + + + + + + + + + + + + + + + +

Endocrine System 

Adrenal cortex + + + + + + + + + + + + + + + + + + + + + + + + +

Adrenal medulla + + + + + + + + + + + + + + + + + + + + + + + + +

Pheochromocytoma benign X

Islets, pancreatic + + + + + + + + + + + + + + + + + + + + + + + + +

Carcinoma X

Parathyroid gland + + M + + + + + + + + + + + + + + + + + + + + + +

Pituitary gland + + + + + + + + + + + + + + + + + + + + + + + + +

Pars distalis, adenoma X X X X X X X X X X X X X X X X

Pars distalis, carcinoma

Thyroid gland + + + + + + + + + + + + + + + + + + + + + + + + +

C-cell, adenoma X X

C-cell, carcinoma X

Follicular cell, carcinoma

General Body System 

None

Genital System 

Clitoral gland + + + + + + + + + + + + + + + + + + + + + + + M +

Adenoma X

Carcinoma

Ovary + + + + + + + + + + + + + + + + + + + + + + + + +

Uterus + + + + + + + + + + + + + + + + + + + + + + + + +

Leiomyosarcoma X

Polyp stromal

Polyp stromal, multiple X

Sarcoma stromal X
Tetrafluoroethylene, NTP TR 450 139

TABLE B2

Individual Animal Tumor Pathology of Female Rats in the 2-Year Inhalation Study of Tetrafluoroethylene: 312 ppm

(continued)

6 6 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7

Number of Days on Study 7 9 0 0 0 2 2 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

5 1 1 4 7 2 3 0 0 4 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5

2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 Total

Carcass ID Number 5 6 9 4 9 4 5 5 8 9 4 5 6 6 7 7 7 8 8 8 8 8 9 9 9 Tissues/

3 0 3 5 5 2 9 6 5 4 3 7 3 8 3 5 7 0 2 3 4 6 6 8 9 Tumors

Alimentary System 

Esophagus + + + + + + + + + + + + + + + + + + + + + + + + + 50

Intestine large, colon + + + + + + + + + + + + + + + + + + + + + + + + + 50

Intestine large, rectum + + + + + + + + + + + + + + + + + + + + + + + + + 50

Sarcoma stromal, metastatic, uterus 1

Intestine large, cecum + + + + + + + + + + + + + + + + + + + + + + + + + 50

Intestine small, duodenum + + + + + + + + + + + + + + + + + + + + + + + + + 50

Intestine small, jejunum + + + + + + + + + + + + + + + + + + + + + + + + + 50

Intestine small, ileum A + + + + + + + + + + + + + + + + + + + + + + + + 49

Liver + + + + + + + + + + + + + + + + + + + + + + + + + 50

Hepatocellular carcinoma X X X 4

Hepatocellular adenoma X X X 3

Hepatocellular adenoma, multiple X 1

Mesentery + 4

Pancreas + + + + + + + + + + + + + + + + + + + + + + + + + 50

Pharynx 1

Salivary glands + + + + + + + + + + + + + + + + + + + + + + + + + 50

Adenoma 1

Stomach, forestomach + + + + + + + + + + + + + + + + + + + + + + + + + 50

Stomach, glandular + + + + + + + + + + + + + + + + + + + + + + + + + 50

Tooth 1

Cardiovascular System 

Heart + + + + + + + + + + + + + + + + + + + + + + + + + 50

Endocrine System 

Adrenal cortex + + + + + + + + + + + + + + + + + + + + + + + + + 50

Adrenal medulla + + + + + + + + + + + + + + + + + + + + + + + + + 50

Pheochromocytoma benign 1

Islets, pancreatic + + + + + + + + + + + + + + + + + + + + + + + + + 50

Carcinoma 1

Parathyroid gland + + + + + + + + + + + + + + + + + + + + + + + + + 49

Pituitary gland + + + + + + + + + + + + + + + + + + + + + + + + + 50

Pars distalis, adenoma X X X X X X X X X X X X X X X X X X 34

Pars distalis, carcinoma X 1

Thyroid gland + + + + + + + + + + + + + + + + + + + + + + + + + 50

C-cell, adenoma X X X X X X X 9

C-cell, carcinoma X 2

Follicular cell, carcinoma X 1

General Body System 

None 

Genital System 

Clitoral gland + + + + + + + + + + + + + + + + + + + + + + + + + 49

Adenoma X X X X X 6

Carcinoma X 1

Ovary + + + + + + + + + + + + + + + + + + + + + + + + + 50

Uterus + + + + + + + + + + + + + + + + + + + + + + + + + 50

Leiomyosarcoma 1

Polyp stromal X X X X 4

Polyp stromal, multiple 1

Sarcoma stromal 1
140 Tetrafluoroethylene, NTP TR 450

TABLE B2

Individual Animal Tumor Pathology of Female Rats in the 2-Year Inhalation Study of Tetrafluoroethylene: 312 ppm

(continued)

2 4 4 4 5 5 5 5 5 5 5 5 5 5 5 5 5 6 6 6 6 6 6 6 6

Number of Days on Study 4 1 6 6 1 2 3 5 6 6 7 7 8 8 8 9 9 0 1 1 1 2 3 4 5

7 3 8 8 7 3 7 7 5 5 4 4 1 3 8 4 7 0 7 8 8 5 8 9 3

2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 3

Carcass ID Number 9 7 5 8 4 7 5 7 5 7 4 6 9 9 8 5 7 6 8 6 6 7 5 9 0

2 2 2 8 8 9 5 6 0 1 4 5 0 1 1 4 4 9 7 1 7 0 8 7 0

Hematopoietic System 

Blood

Bone marrow + + + + + + + + + + + + + + + + + + + + + + + + +

Lymph node + + +

Lymph node, bronchial + + + + + + + + + + + + + + + + + + + + + + + + +

Lymph node, mandibular + + + + + + + + + + + + + M + + + + + + + + + + +

Lymph node, mesenteric + + + + + + + + + + + + + + + + + + + + + + + + +

Lymph node, mediastinal + + M + + + + + + + + + + + + + + + + + + + + + +

Spleen + + + + + + + + + + + + + + + + + + + + + + + + +

Thymus + M M + + + + + + + + + + + + + + + + + + + + + +

Integumentary System 

Mammary gland + + + + + + + + + + + + + + + + + + + + + + + + +

Carcinoma X

Fibroadenoma X X X X X

Fibroadenoma, multiple X

Skin + + + + + + + + + + + + + + + + + + + + + + + + +

Subcutaneous tissue, fibroma

Subcutaneous tissue, sarcoma X

Musculoskeletal System 

Bone + + + + + + + + + + + + + + + + + + + + + + + + +

Nervous System 

Brain + + + + + + + + + + + + + + + + + + + + + + + + +

Astrocytoma NOS X

Respiratory System 

Larynx + + + + + + + + + + + + + + + + + + + + + + + + +

Lung + + + + + + + + + + + + + + + + + + + + + + + + +

Alveolar/bronchiolar carcinoma

Carcinoma, metastatic, pituitary

 gland 

Carcinoma, metastatic, thyroid gland

Nose + + + + + + + + + + + + + + + + + + + + + + + + +

Trachea + + + + + + + + + + + + + + + + + + + + + + + + +

Special Senses System 

Eye + + + + + + + + + + + + + + + + + + + + + + + + +

Harderian gland

Urinary System 

Kidney + + + + + + + + + + + + + + + + + + + + + + + + +

Renal tubule, adenoma X

Urinary bladder + + + + + + + + + + + + + + + + + + + + + + + + +

Sarcoma stromal, metastatic, uterus X

Systemic Lesions 

Multiple organs + + + + + + + + + + + + + + + + + + + + + + + + +

Leukemia mononuclear X X X X X X X X X X X X X X X X

Mesothelioma malignant X
Tetrafluoroethylene, NTP TR 450 141

TABLE B2

Individual Animal Tumor Pathology of Female Rats in the 2-Year Inhalation Study of Tetrafluoroethylene: 312 ppm

(continued)

6 6 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7

Number of Days on Study 7 9 0 0 0 2 2 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

5 1 1 4 7 2 3 0 0 4 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5

2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 Total

Carcass ID Number 5 6 9 4 9 4 5 5 8 9 4 5 6 6 7 7 7 8 8 8 8 8 9 9 9 Tissues/

3 0 3 5 5 2 9 6 5 4 3 7 3 8 3 5 7 0 2 3 4 6 6 8 9 Tumors

Hematopoietic System 

Blood + 1

Bone marrow + + + + + + + + + + + + + + + + + + + + + + + + + 50

Lymph node + + + + 7

Lymph node, bronchial + + + + + + + + + + + + + + + + + + + + + + + + + 50

Lymph node, mandibular + + + + + + + + + + + + + + + + + + + + + + + + + 49

Lymph node, mesenteric + + + + + + + + + + + + + + + + + + + + + + + + + 50

Lymph node, mediastinal + + + + + + + + + + + + + + + + + + + + + + + + + 49

Spleen + + + + + + + + + + + + + + + + + + + + + + + + + 50

Thymus + + + + + + + + + + + + + + + + + + + + + + + + + 48

Integumentary System 

Mammary gland + + + + + + + + + + + + + + + + + + + + + + + + + 50

Carcinoma 1

Fibroadenoma X X X X X 10

Fibroadenoma, multiple 1

Skin + + + + + + + + + + + + + + + + + + + + + + + + + 50

Subcutaneous tissue, fibroma X 1

Subcutaneous tissue, sarcoma 1

Musculoskeletal System 

Bone + + + + + + + + + + + + + + + + + + + + + + + + + 50

Nervous System 

Brain + + + + + + + + + + + + + + + + + + + + + + + + + 50

Astrocytoma NOS 1

Respiratory System 

Larynx + + + + + + + + + + + + + + + + + + + + + + + + + 50

Lung + + + + + + + + + + + + + + + + + + + + + + + + + 50

Alveolar/bronchiolar carcinoma X 1

Carcinoma, metastatic, pituitary 

 gland X 1

Carcinoma, metastatic, thyroid gland X 1

Nose + + + + + + + + + + + + + + + + + + + + + + + + + 50

Trachea + + + + + + + + + + + + + + + + + + + + + + + + + 50

Special Senses System 

Eye + + + + + + + + + + + + + + + + + + + + + + + + + 50

Harderian gland + 1

Urinary System 

Kidney + + + + + + + + + + + + + + + + + + + + + + + + + 50

Renal tubule, adenoma X X 3

Urinary bladder + + + + + + + + + + + + + + + + + + + + + + + + + 50

Sarcoma stromal, metastatic, uterus 1

Systemic Lesions 

Multiple organs + + + + + + + + + + + + + + + + + + + + + + + + + 50

Leukemia mononuclear X X X X X X X X X X X X X X X 31

Mesothelioma malignant 1
142 Tetrafluoroethylene, NTP TR 450

TABLE B2

Individual Animal Tumor Pathology of Female Rats in the 2-Year Inhalation Study of Tetrafluoroethylene: 625 ppm 

3 3 4 4 4 5 5 5 5 5 5 5 5 6 6 6 6 6 6 6 6 6 6 6 6

Number of Days on Study 6 8 6 7 7 0 3 3 4 8 8 8 8 0 0 1 2 5 5 6 6 6 7 7 7

3 7 9 7 8 4 4 6 4 1 7 7 9 7 8 1 5 2 3 4 8 8 2 4 7

4 3 3 4 3 3 3 3 4 4 3 4 4 3 3 4 3 4 3 4 3 3 3 4 3

Carcass ID Number 0 6 7 1 8 7 6 7 1 1 9 0 1 6 7 0 9 1 6 0 6 8 9 1 9

3 9 9 0 5 3 5 7 1 9 2 0 2 2 4 4 6 5 1 1 4 4 4 4 8

Alimentary System 

Esophagus + + + + + + + + + + + + + + + + + + + + + + + + +

Intestine large, colon + + + + + + + + + + + + + + + + + + + + + + + + +

Intestine large, rectum + + + + + + + + + + + + + + + I + + + + + + + + +

Intestine large, cecum + + + + + + + + + + + + + + + + + + + + + + + + +

Intestine small, duodenum + + + + + + + + + + + + + + + + + + + + + + + + +

Intestine small, jejunum + + + + + + + A + + + + + + + + + + + + + + + + +

Intestine small, ileum + + + + + + + A + + + + + + + + + + + + + + + + +

Liver + + + + + + + + + + + + + + + + + + + + + + + + +

Hemangiosarcoma X X

Hepatocellular carcinoma X

Hepatocellular carcinoma, multiple

Hepatocellular adenoma

Hepatocellular adenoma, multiple

Sarcoma

Mesentery + +

Pancreas + + + + + + + + + + + + + + + + + + + + + + + + +

Salivary glands + + + + + + + + + + + + + + + + + + + + + + + + +

Stomach, forestomach + M + + + + + + + + + + + + + + + + + + + + + + +

Stomach, glandular + M + + + + + + + + + + + + + + + + + + + + + + +

Tongue

Cardiovascular System 

Heart + + + + + + + + + + + + + + + + + + + + + + + + +

Endocrine System 

Adrenal cortex + + + + + + + + + + + + + + + + + + + + + + + + +

Hemangiosarcoma, metastatic, liver

Adrenal medulla + + + + + + + + + + + + + + + + + + + + + + + + +

Pheochromocytoma benign X

Islets, pancreatic + + + + + + + + + + + + + + + + + + + + + + + + +

Adenoma

Parathyroid gland + + + + + + + + + + + + + + + + + + + + + + + + +

Pituitary gland + + + + + + + + + + + + + + + + + + + + + + + + +

Pars distalis, adenoma X X X X X X X X X X X X X X X X X

Thyroid gland + + + + + + + + + + + + + + + + + + + + + + + + +

C-cell, adenoma X X

C-cell, carcinoma

General Body System 

None

Genital System 

Clitoral gland + + + + + + + + + + + + + + + + + + + + + + + + +

Adenoma

Carcinoma X

Ovary + + + + + + + + + + + + + + + + + + + + + + + + +

Granulosa-theca tumor benign X

Hepatocellular carcinoma, metastatic,

 liver

Uterus + + + + + + + + + + + + + + + + + + + + + + + + +

Polyp stromal

Vagina +
Tetrafluoroethylene, NTP TR 450 143

TABLE B2

Individual Animal Tumor Pathology of Female Rats in the 2-Year Inhalation Study of Tetrafluoroethylene: 625 ppm

(continued)

6 6 6 6 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7

Number of Days on Study 8 9 9 9 0 1 2 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

5 8 8 9 2 6 9 3 3 3 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5

3 3 3 3 3 4 4 3 3 4 3 3 3 3 3 3 3 3 3 3 3 3 4 4 4 Total

Carcass ID Number 8 7 8 7 8 0 1 6 9 1 6 6 7 7 8 8 8 8 9 9 9 9 0 0 2 Tissues/

8 5 1 0 2 8 8 6 3 7 3 8 1 6 0 3 6 7 0 1 7 9 5 6 0 Tumors

Alimentary System 

Esophagus + + + + + + + + + + + + + + + + + + + + + + + + + 50

Intestine large, colon + + + + + A + + + + + + + + + + + + + + + + + + + 49

Intestine large, rectum + + + + + + + + + + + + + + + + + + + + + + + + + 49

Intestine large, cecum + + + + + A + + + + + + + + + + + + + + + + + + + 49

Intestine small, duodenum + + + + + A + + + + + + + + + + + + + + + + + + + 49

Intestine small, jejunum + + A + + A + + + + + + + + + + + + + + + + + + + 47

Intestine small, ileum + + + + + A + + + + + + + + + + + + + + + + + + + 48

Liver + + + + + + + + + + + + + + + + + + + + + + + + + 50

Hemangiosarcoma X X X 5

Hepatocellular carcinoma X X X X X 6

Hepatocellular carcinoma, multiple X X X 3

Hepatocellular adenoma X X X X 4

Hepatocellular adenoma, multiple X 1

Sarcoma X 1

Mesentery + + 4

Pancreas + + + + + A + + + + + + + + + + + + + + + + + + + 49

Salivary glands + + + + + + + + + + + + + + + + + + + + + + + + + 50

Stomach, forestomach + + + + + A + + + + + + + + + + + + + + + + + + + 48

Stomach, glandular + + + + + + + + + + + + + + + + + + + + + + + + + 49

Tongue + + 2

Cardiovascular System 

Heart + + + + + + + + + + + + + + + + + + + + + + + + + 50

Endocrine System 

Adrenal cortex + + + + + + + + + + + + + + + + + + + + + + + + + 50

Hemangiosarcoma, metastatic, liver X 1

Adrenal medulla + + + + + + + + + + + + + + + + + + + + + + + + + 50

Pheochromocytoma benign X 2

Islets, pancreatic + + + + + A + + + + + + + + + + + + + + + + + + + 49

Adenoma X 1

Parathyroid gland + M + + + + + + + + + + + + + + + + + + + + + + + 49

Pituitary gland + + + + + A + + + + + + + + + + + + + + + + + + + 49

Pars distalis, adenoma X X X X X X X X X X X X X X X X X X X 36

Thyroid gland + + + + + + + + + + + + + + + + + + + + + + + + + 50

C-cell, adenoma X X X 5

C-cell, carcinoma X X X 3

General Body System 

None 

Genital System 

Clitoral gland + + + + + + + + + + + + + + + + + + + + + + + + + 50

Adenoma X X 2

Carcinoma X 2

Ovary + + + + + + + + + + + + + + + + + + + + + + + + + 50

Granulosa-theca tumor benign 1

Hepatocellular carcinoma, metastatic, 

 liver X 1

Uterus + + + + + + + + + + + + + + + + + + + + + + + + + 50

Polyp stromal X X X X 4

Vagina 1
144 Tetrafluoroethylene, NTP TR 450

TABLE B2

Individual Animal Tumor Pathology of Female Rats in the 2-Year Inhalation Study of Tetrafluoroethylene: 625 ppm

(continued)

3 3 4 4 4 5 5 5 5 5 5 5 5 6 6 6 6 6 6 6 6 6 6 6 6

Number of Days on Study 6 8 6 7 7 0 3 3 4 8 8 8 8 0 0 1 2 5 5 6 6 6 7 7 7

3 7 9 7 8 4 4 6 4 1 7 7 9 7 8 1 5 2 3 4 8 8 2 4 7

4 3 3 4 3 3 3 3 4 4 3 4 4 3 3 4 3 4 3 4 3 3 3 4 3

Carcass ID Number 0 6 7 1 8 7 6 7 1 1 9 0 1 6 7 0 9 1 6 0 6 8 9 1 9

3 9 9 0 5 3 5 7 1 9 2 0 2 2 4 4 6 5 1 1 4 4 4 4 8

Hematopoietic System 

Bone marrow + + + + + + + + + + + + + + + + + + + + + + + + +

Lymph node + + + +

Lymph node, bronchial + + + + + + + + + + + + + + + + + + + + + + + + +

Lymph node, mandibular + + + + + + + + + + + + + + + + + + + + + + + + +

Lymph node, mesenteric + + + + + + + + + + + + + + + + + + + + + + + + +

Lymph node, mediastinal + + + + + + + + + + + + + + + + + + + + + M + + +

Spleen + + + + + + + + + + + + + + + + + + + + + + + + +

Thymus + + + + + + + + + + + + + + + + + + + + + M + + +

Integumentary System 

Mammary gland + + + + + + + + + + + + + + + + + + + + + + + + +

Adenoma

Carcinoma X X

Carcinoma, multiple

Fibroadenoma X X X X

Fibroadenoma, multiple

Skin + + + + + + + + + + + + + + + + + + + + + + + + +

Basosquamous tumor malignant

Squamous cell papilloma

Subcutaneous tissue, sarcoma X

Musculoskeletal System 

Bone + + + + + + + + + + + + + + + + + + + + + + + + +

Nervous System 

Brain + + + + + + + + + + + + + + + + + + + + + + + + +

Respiratory System 

Larynx + + + + + + + + + + + + + + + + + + + + + + + + +

Lung + + + + + + + + + + + + + + + + + + + + + + + + +

Alveolar/bronchiolar adenoma

Carcinoma, metastatic, mammary gland X

Hemangiosarcoma, metastatic, liver X X

Hepatocellular carcinoma, metastatic, liver X

Sarcoma, metastatic, liver

Nose + + + + + + + + + + + + + + + + + + + + + + + + +

Trachea + + + + + + + + + + + + + + + + + + + + + + + + +

Special Senses System 

Eye + + + + + + + + + + + + + + + + + + + + + + + + +

Zymbal's gland

Adenoma

Urinary System 

Kidney + + + + + + + + + + + + + + + + + + + + + + + + +

Renal tubule, adenoma X

Urinary bladder + + + + + + + + + + + + + + + + + + + + + + + + +

Transitional epithelium, papilloma X

Systemic Lesions 

Multiple organs + + + + + + + + + + + + + + + + + + + + + + + + +

Leukemia mononuclear X X X X X X X X X X X X X X
Tetrafluoroethylene, NTP TR 450 145

TABLE B2

Individual Animal Tumor Pathology of Female Rats in the 2-Year Inhalation Study of Tetrafluoroethylene: 625 ppm

(continued)

6 6 6 6 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7

Number of Days on Study 8 9 9 9 0 1 2 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

5 8 8 9 2 6 9 3 3 3 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5

3 3 3 3 3 4 4 3 3 4 3 3 3 3 3 3 3 3 3 3 3 3 4 4 4 Total

Carcass ID Number 8 7 8 7 8 0 1 6 9 1 6 6 7 7 8 8 8 8 9 9 9 9 0 0 2 Tissues/

8 5 1 0 2 8 8 6 3 7 3 8 1 6 0 3 6 7 0 1 7 9 5 6 0 Tumors

Hematopoietic System 

Bone marrow + + + + + + + + + + + + + + + + + + + + + + + + + 50

Lymph node + + + 7

Lymph node, bronchial + + + + + + + + + + + + + + + + + + + + + + + + + 50

Lymph node, mandibular + + + + + + + + + + + + + + + + + + + + + + + + + 50

Lymph node, mesenteric + + + + + + + + + + + + + + + + + + + + + + + + + 50

Lymph node, mediastinal + + + + + + + + + + + + + + + + + + + + + + + + + 49

Spleen + + + + + A + + + + + + + + + + + + + + + + + + + 49

Thymus + + + + + + + + + + + + + + + + + + + + + + + + + 49

Integumentary System 

Mammary gland + + + + + + + + + + + + + + + + + + + + + + + + + 50

Adenoma X 1

Carcinoma X 3

Carcinoma, multiple X 1

Fibroadenoma X X X X 8

Fibroadenoma, multiple X 1

Skin + + + + + + + + + + + + + + + + + + + + + + + + + 50

Basosquamous tumor malignant X 1

Squamous cell papilloma X 1

Subcutaneous tissue, sarcoma 1

Musculoskeletal System 

Bone + + + + + + + + + + + + + + + + + + + + + + + + + 50

Nervous System 

Brain + + + + + + + + + + + + + + + + + + + + + + + + + 50

Respiratory System 

Larynx + + + + + + + + + + + + + + + + + + + + + + + + + 50

Lung + + + + + + + + + + + + + + + + + + + + + + + + + 50

Alveolar/bronchiolar adenoma X 1

Carcinoma, metastatic, mammary gland 1

Hemangiosarcoma, metastatic, liver X 3

Hepatocellular carcinoma, metastatic, liver X 2

Sarcoma, metastatic, liver X 1

Nose + + + + + + + + + + + + + + + + + + + + + + + + + 50

Trachea + + + + + + + + + + + + + + + + + + + + + + + + + 50

Special Senses System 

Eye + + + + + + + + + + + + + + + + + + + + + + + + + 50

Zymbal's gland + 1

Adenoma X 1

Urinary System 

Kidney + + + + + + + + + + + + + + + + + + + + + + + + + 50

Renal tubule, adenoma 1

Urinary bladder + + + + + + + + + + + + + + + + + + + + + + + + + 50

Transitional epithelium, papilloma X 2

Systemic Lesions 

Multiple organs + + + + + + + + + + + + + + + + + + + + + + + + + 50

Leukemia mononuclear X X X X X X X X X 23
146 Tetrafluoroethylene, NTP TR 450

TABLE B2

Individual Animal Tumor Pathology of Female Rats in the 2-Year Inhalation Study of Tetrafluoroethylene: 1,250 ppm 

0 3 3 4 4 4 4 5 5 5 5 5 5 5 5 5 5 6 6 6 6 6 6 6 6

Number of Days on Study 0 7 7 3 3 6 8 0 0 1 3 3 7 7 7 8 9 0 0 1 2 2 2 2 3

6 2 8 3 9 1 1 4 9 8 1 8 2 6 9 3 4 3 8 0 1 1 4 8 5

4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4

Carcass ID Number 6 7 5 4 6 3 3 7 5 5 5 7 3 2 2 6 6 3 6 6 6 6 4 8 5

4 7 2 6 5 5 2 6 1 3 6 1 6 8 4 0 8 9 6 2 1 3 7 0 4

Alimentary System 

Esophagus + + + + + + + + + + + + + + + + + + + + + + + + +

Intestine large, colon + + + + + + + + + + + + + + + + + + + + + + + + +

Intestine large, rectum + + + + + + + + + + + + + + + + + + + + + + + + +

Intestine large, cecum + + + + + + + + + + + + + + + + + + + + + + + + +

Hemangiosarcoma, metastatic, liver

Intestine small, duodenum + + + + + + + + + + + + + + + + + + + + + + + + +

Intestine small, jejunum + + + + + A + + + + + + + + + + + + + + + + + + +

Hemangiosarcoma, metastatic, liver

Intestine small, ileum + + + + + + + + + + + + + + + + + + + + + + + + +

Liver + + + + + + + + + + + + + + + + + + + + + + + + +

Hemangiosarcoma

Hepatocellular carcinoma

Hepatocellular adenoma

Hepatocellular adenoma, multiple

Mesentery + + + +

Pancreas + + + + + + + + + + + + + + + + + + + + + + + + +

Salivary glands + + + + + + + + + + + + + + + + + + + + + + + + +

Stomach, forestomach + + + + + + + + + + + + + + + + + + + + + + + + +

Stomach, glandular + + + + + + + + + + + + + + + + + + + + + + + + +

Hemangiosarcoma, metastatic, liver

Tongue

Cardiovascular System 

Heart + + + + + + + + + + + + + + + + + + + + + + + + +

Endocrine System 

Adrenal cortex + + + + + + + + + + + + + + + + + + + + + + + + +

Adrenal medulla + + + + + + + + + + + + + + + + + + + + + + + + +

Pheochromocytoma benign X X X

Islets, pancreatic + + + + + + + + + + + + + + + + + + + + + + + + +

Parathyroid gland + + + + + M M + + + + + + + M + + + + + + + + + +

Pituitary gland + + + + + + + + + + + + + + + + + + + + + + + + +

Pars distalis, adenoma X X X X X X X X X X X X X X

Thyroid gland + + + + + + + + + + + + + + + + + + + + + + + + +

C-cell, adenoma X

C-cell, carcinoma

General Body System 

Tissue NOS

Abdominal, fat, hemangiosarcoma,

 metastatic, tissue NOS

Genital System 

Clitoral gland + + + + + + + + + + M + + + + + + + + + + + + + M

Carcinoma X

Ovary + + + + + + + + + + + + + + + + + + + + + + + + +

Granulosa-theca tumor benign X

Uterus + + + + + + + + + + + + + + + + + + + + + + + + +

Polyp stromal X X X

Sarcoma stromal X

Vagina +

Polyp X
Tetrafluoroethylene, NTP TR 450 147

TABLE B2

Individual Animal Tumor Pathology of Female Rats in the 2-Year Inhalation Study of Tetrafluoroethylene: 1,250 ppm

(continued)

6 6 6 6 6 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7

Number of Days on Study 3 5 6 7 7 0 2 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

9 3 8 7 8 3 7 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4

4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 Total

Carcass ID Number 2 2 7 4 4 3 4 2 2 2 3 3 3 4 4 4 4 5 5 6 6 7 7 7 7 Tissues/

2 1 3 3 4 1 5 3 5 7 0 7 8 1 2 8 9 0 5 7 9 0 2 4 9 Tumors

Alimentary System 

Esophagus + + + + + + + + + + + + + + + + + + + + + + + + + 50

Intestine large, colon + + + + + + + + + + + + + + + + + + + + + + + + + 50

Intestine large, rectum + + + + + + + + + + + + + + + + + + + + + + + + + 50

Intestine large, cecum + + + + + + + + + + + + + + + + + + + + + + + + + 50

Hemangiosarcoma, metastatic, liver X 1

Intestine small, duodenum + + + + + + + + + + + + + + + + + + + + + + + + + 50

Intestine small, jejunum + + + + + + + + + + + + + + + + + + + + + + + + + 49

Hemangiosarcoma, metastatic, liver X 1

Intestine small, ileum + + + + + A + + + + + + + + + + + + + + + + + + + 49

Liver + + + + + + + + + + + + + + + + + + + + + + + + + 50

Hemangiosarcoma X 1

Hepatocellular carcinoma X X 2

Hepatocellular adenoma X X X X X 5

Hepatocellular adenoma, multiple X 1

Mesentery + + 6

Pancreas + + + + + + + + + + + + + + + + + + + + + + + + + 50

Salivary glands + + + + + + + + + + + + + + + + + + + + + + + + + 50

Stomach, forestomach + + + + + + + + + + + + + + + + + + + + + + + + + 50

Stomach, glandular + + + + + + + + + + + + + + + + + + + + + + + + + 50

Hemangiosarcoma, metastatic, liver X 1

Tongue + 1

Cardiovascular System 

Heart + + + + + + + + + + + + + + + + + + + + + + + + + 50

Endocrine System 

Adrenal cortex + + + + + + + + + + + + + + + + + + + + + + + + + 50

Adrenal medulla + + + + + + + + + + + + + + + + + + + + + + + + + 50

Pheochromocytoma benign X X 5

Islets, pancreatic + + + + + + + + + + + + + + + + + + + + + + + + + 50

Parathyroid gland + + + + + + + + + + + + + + + + + + + + + + + + + 47

Pituitary gland + + + + + + + + + + + + + + + + + + + + + + + + + 50

Pars distalis, adenoma X X X X X X X X X X X X X X X X X X X X 34

Thyroid gland + + + + + + + + + + + + + + + + + + + + + + + + + 50

C-cell, adenoma X 2

C-cell, carcinoma X X 2

General Body System 

Tissue NOS + 1

Abdominal, fat, hemangiosarcoma, 

 metastatic, tissue NOS X 1

Genital System 

Clitoral gland + + + + + + + + + + + + + + + + + + + + + + + + + 48

Carcinoma X 2

Ovary + + + + + + + + + + + + + + + + + + + + + + + + + 50

Granulosa-theca tumor benign 1

Uterus + + + + + + + + + + + + + + + + + + + + + + + + + 50

Polyp stromal X X 5

Sarcoma stromal 1

Vagina 1

Polyp 1
148 Tetrafluoroethylene, NTP TR 450

TABLE B2

Individual Animal Tumor Pathology of Female Rats in the 2-Year Inhalation Study of Tetrafluoroethylene: 1,250 ppm

(continued)

0 3 3 4 4 4 4 5 5 5 5 5 5 5 5 5 5 6 6 6 6 6 6 6 6

Number of Days on Study 0 7 7 3 3 6 8 0 0 1 3 3 7 7 7 8 9 0 0 1 2 2 2 2 3

6 2 8 3 9 1 1 4 9 8 1 8 2 6 9 3 4 3 8 0 1 1 4 8 5

4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4

Carcass ID Number 6 7 5 4 6 3 3 7 5 5 5 7 3 2 2 6 6 3 6 6 6 6 4 8 5

4 7 2 6 5 5 2 6 1 3 6 1 6 8 4 0 8 9 6 2 1 3 7 0 4

Hematopoietic System 

Bone marrow + + + + + + + + + + + + + + + + + + + + + + + + +

Lymph node + + + + + + + +

Iliac, osteosarcoma, metastatic, bone X

Lymph node, bronchial M + + + + + + + + + + + + + + + + + + + + + + + +

Lymph node, mandibular + + + + + + + + + + + + + + + + + + + + + + + + +

Lymph node, mesenteric + + + + + + + + + + + + + + + + + + + + + + + + +

Lymph node, mediastinal + + + + M + + + + M + M + + + + + + + + + + + + +

Spleen + + + + + + + + + + + + + + + + + + + + + + + + +

Thymus + + + + + + + + + M + + + + + + + + + + + + + M +

Integumentary System 

Mammary gland + + + + + + + + + + + + + + + + + + + + + + + + +

Adenoma

Carcinoma

Fibroadenoma X

Fibroadenoma, multiple X

Skin + + + + + + + + + + + + + + + + + + + + + + + + +

Basosquamous tumor malignant

Keratoacanthoma

Squamous cell papilloma

Subcutaneous tissue, neurofibroma

Musculoskeletal System 

Bone + + + + + + + + + + + + + + + + + + + + + + + + +

Vertebra, osteosarcoma X

Nervous System 

Brain + + + + + + + + + + + + + + + + + + + + + + + + +

Astrocytoma NOS X

Respiratory System 

Larynx + + + + + + + + + + + + + + + + + + + + + + + + +

Lung + + + + + + + + + + + + + + + + + + + + + + + + +

Carcinoma, metastatic, thyroid gland

Osteosarcoma, metastatic, bone X

Nose + + + + + + + + + + + + + + + + + + + + + + + + +

Trachea + + + + + + + + + + + + + + + + + + + + + + + + +

Special Senses System 

Eye + + + + + + + + + + + + + + + + + + + + + + + + +

Zymbal's gland

Urinary System 

Kidney + + + + + + + + + + + + + + + + + + + + + + + + +

Renal tubule, adenoma

Renal tubule, carcinoma

Urinary bladder + + + + + + + + + + + + + + + + + + + + + + + + +

Systemic Lesions 

Multiple organs + + + + + + + + + + + + + + + + + + + + + + + + +

Leukemia mononuclear X X X X X X X X X X X X X X X X X X X X
Tetrafluoroethylene, NTP TR 450 149

TABLE B2

Individual Animal Tumor Pathology of Female Rats in the 2-Year Inhalation Study of Tetrafluoroethylene: 1,250 ppm

(continued)

6 6 6 6 6 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7

Number of Days on Study 3 5 6 7 7 0 2 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

9 3 8 7 8 3 7 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4

4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 Total

Carcass ID Number 2 2 7 4 4 3 4 2 2 2 3 3 3 4 4 4 4 5 5 6 6 7 7 7 7 Tissues/

2 1 3 3 4 1 5 3 5 7 0 7 8 1 2 8 9 0 5 7 9 0 2 4 9 Tumors

Hematopoietic System 

Bone marrow + + + + + + + + + + + + + + + + + + + + + + + + + 50

Lymph node + + + + + 13

Iliac, osteosarcoma, metastatic, bone 1

Lymph node, bronchial + + + + M + + + + + + + + + + + + + + + + + + + + 48

Lymph node, mandibular + + + + + + + + + + + + + + + + + + + + + + + + + 50

Lymph node, mesenteric + + + + + + + + + + + + + + + + + + + + + + + + + 50

Lymph node, mediastinal + + + + M + + + + + + + + + + + + + + M + + + + + 45

Spleen + + + + + + + + + + + + + + + + + + + + + + + + + 50

Thymus + + + + + + + + + + + + + + + + + + + + + + + + + 48

Integumentary System 

Mammary gland + + + + + + + + + + + + + + + + + + + + + + + + + 50

Adenoma X 1

Carcinoma X 1

Fibroadenoma X X X X 5

Fibroadenoma, multiple X 2

Skin + + + + + + + + + + + + + + + + + + + + + + + + + 50

Basosquamous tumor malignant X 1

Keratoacanthoma X 1

Squamous cell papilloma X 1

Subcutaneous tissue, neurofibroma X 1

Musculoskeletal System 

Bone + + + + + + + + + + + + + + + + + + + + + + + + + 50

Vertebra, osteosarcoma 1

Nervous System 

Brain + + + + + + + + + + + + + + + + + + + + + + + + + 50

Astrocytoma NOS 1

Respiratory System 

Larynx + + + + + + + + + + + + + + + + + + + + + + + + + 50

Lung + + + + + + + + + + + + + + + + + + + + + + + + + 50

Carcinoma, metastatic, thyroid gland X 1

Osteosarcoma, metastatic, bone 1

Nose + + + + + + + + + + + + + + + + + + + + + + + + + 50

Trachea + + + + + + + + + + + + + + + + + + + + + + + + + 50

Special Senses System 

Eye + + + + + + + + + + + + + + + + + + + + + + + + + 50

Zymbal's gland + 1

Urinary System 

Kidney + + + + + + + + + + + + + + + + + + + + + + + + + 50

Renal tubule, adenoma X X X 3

Renal tubule, carcinoma X X 2

Urinary bladder + + M + + + + + + + + + + + + + + + + + + + + + + 49

Systemic Lesions 

Multiple organs + + + + + + + + + + + + + + + + + + + + + + + + + 50

Leukemia mononuclear X X X X X X X X X X X X X X X X 36
150 Tetrafluoroethylene, NTP TR 450

TABLE B3

Statistical Analysis of Primary Neoplasms in Female Rats in the 2-Year Inhalation Study of Tetrafluoroethylene

0 ppm 312 ppm 625 ppm 1,250 ppm

Adrenal Medulla: Benign Pheochromocytoma

Overall rate 4/50 (8%) 1/50 (2%) 2/50 (4%) 5/50 (10%) a

Adjusted rate 12.7% 3.2% 9.6% 20.4% b

Terminal rate 2/28 (7%) 0/16 (0%) 1/15 (7%) 2/18 (11%) c

First incidence (days) 698 618 653 610

Life table test P=0.136 P=0.347N P=0.577N P=0.239 d

Logistic regression test P=0.188 P=0.247N P=0.461N P=0.354 d

Cochran-Armitage test P=0.273 d

Fisher exact test P=0.181N P=0.339N P=0.500 d

Clitoral Gland: Adenoma

Overall rate 6/49 (12%) 6/49 (12%) 2/50 (4%) 0/48 (0%)

Adjusted rate 18.7% 31.4% 11.9% 0.0%

Terminal rate 4/28 (14%) 4/16 (25%) 1/15 (7%) 0/18 (0%)

First incidence (days) 648 617 733 —e

Life table test P=0.029N P=0.263 P=0.365N P=0.062N 

Logistic regression test P=0.020N P=0.382 P=0.242N P=0.046N

Cochran-Armitage test P=0.006N

Fisher exact test P=0.620N P=0.128N P=0.014N

Clitoral Gland: Adenoma or Carcinoma

Overall rate 7/49 (14%) 7/49 (14%) 4/50 (8%) 2/48 (4%)

Adjusted rate 22.1% 37.1% 19.5% 8.6%

Terminal rate 5/28 (18%) 5/16 (31%) 1/15 (7%) 1/18 (6%)

First incidence (days) 648 617 625 610

Life table test P=0.152N P=0.223 P=0.594N P=0.243N 

Logistic regression test P=0.114N P=0.333 P=0.412N P=0.180N 

Cochran-Armitage test P=0.042N

Fisher exact test P=0.613N P=0.251N P=0.084N 

Kidney (Renal Tubule): Adenoma (Single Sections)

Overall rate 0/50 (0%) 3/50 (6%) 1/50 (2%) 3/50 (6%)

Adjusted rate 0.0% 13.7% 3.3% 16.7%

Terminal rate 0/28 (0%) 1/16 (6%) 0/15 (0%) 3/18 (17%)

First incidence (days) — 574 668 734(T)

Life table test P=0.095 P=0.066 P=0.443 P=0.054 

Logistic regression test P=0.099 P=0.100 P=0.505 P=0.054 

Cochran-Armitage test P=0.165

Fisher exact test P=0.121 P=0.500 P=0.121

Kidney (Renal Tubule): Adenoma (Step Sections)

Overall rate 0/50 (0%) 0/50 (0%) 2/50 (4%) 5/50 (10%)

Adjusted rate 0.0% 0.0% 11.9% 23.0%

Terminal rate 0/28 (0%) 0/16 (0%) 1/15 (7%) 3/18 (17%)

First incidence (days) — — 733 628

Life table test P<0.001 — P=0.133 P=0.008 

Logistic regression test P<0.001 — P=0.143 P=0.013 

Cochran-Armitage test P=0.003 

Fisher exact test — P=0.247 P=0.028 
Tetrafluoroethylene, NTP TR 450 151

TABLE B3

Statistical Analysis of Primary Neoplasms in Female Rats in the 2-Year Inhalation Study of Tetrafluoroethylene (continued)

0 ppm 312 ppm 625 ppm 1,250 ppm

Kidney (Renal Tubule): Adenoma (Single and Step Sections)

Overall rate 0/50 (0%) 3/50 (6%) 3/50 (6%) 8/50 (16%)

Adjusted rate 0.0% 13.7% 14.8% 38.4%

Terminal rate 0/28 (0%) 1/16 (6%) 1/15 (7%) 6/18 (33%)

First incidence (days) — 574 668 628

Life table test P<0.001 P=0.066 P=0.057 P<0.001 

Logistic regression test P<0.001 P=0.100 P=0.076 P<0.001 

Cochran-Armitage test P=0.002

Fisher exact test P=0.121 P=0.121 P=0.003

Kidney (Renal Tubule): Adenoma or Carcinoma (Single Sections)

Overall rate 0/50 (0%) 3/50 (6%) 1/50 (2%) 5/50 (10%)

Adjusted rate 0.0% 13.7% 3.3% 27.8%

Terminal rate 0/28 (0%) 1/16 (6%) 0/15 (0%) 5/18 (28%)

First incidence (days) — 574 668 734 (T) 

Life table test P=0.012 P=0.066 P=0.443 P=0.007

Logistic regression test P=0.010 P=0.100 P=0.505 P=0.007

Cochran-Armitage test P=0.029

Fisher exact test P=0.121 P=0.500 P=0.028

Kidney (Renal Tubule): Adenoma or Carcinoma (Single and Step Sections)

Overall rate 0/50 (0%) 3/50 (6%) 3/50 (6%) 10/50 (20%)

Adjusted rate 0.0% 13.7% 14.8% 48.8%

Terminal rate 0/28 (0%) 1/16 (6%) 1/15 (7%) 8/18 (44%)

First incidence (days) — 574 668 628 

Life table test P<0.001 P=0.066 P=0.057 P<0.001

Logistic regression test P<0.001 P=0.100 P=0.076 P<0.001

Cochran-Armitage test P<0.001

Fisher exact test P=0.121 P=0.121 P<0.001

Liver: Hemangiosarcoma

Overall rate 0/50 (0%) 0/50 (0%) 5/50 (10%) 1/50 (2%)

Adjusted rate 0.0% 0.0% 19.5% 5.0%

Terminal rate 0/28 (0%) 0/16 (0%) 0/15 (0%) 0/18 (0%)

First incidence (days) — — 589 703

Life table test P=0.143 — P=0.013 P=0.400 

Logistic regression test P=0.182 — P=0.025 P=0.435 

Cochran-Armitage test P=0.242 

Fisher exact test — P=0.028 P=0.500 

Liver: Hepatocellular Adenoma

Overall rate 0/50 (0%) 4/50 (8%) 5/50 (10%) 6/50 (12%)

Adjusted rate 0.0% 22.6% 33.3% 28.2%

Terminal rate 0/28 (0%) 3/16 (19%) 5/15 (33%) 3/18 (17%)

First incidence (days) — 707 734 (T) 677

Life table test P=0.006 P=0.017 P=0.003 P=0.003

Logistic regression test P=0.004 P=0.020 P=0.003 P=0.003

Cochran-Armitage test P=0.026

Fisher exact test P=0.059 P=0.028 P=0.013
152 Tetrafluoroethylene, NTP TR 450

TABLE B3

Statistical Analysis of Primary Neoplasms in Female Rats in the 2-Year Inhalation Study of Tetrafluoroethylene (continued)

0 ppm 312 ppm 625 ppm 1,250 ppm

Liver: Hepatocellular Carcinoma

Overall rate 0/50 (0%) 4/50 (8%) 9/50 (18%) 2/50 (4%)

Adjusted rate 0.0% 20.9% 48.1% 11.1%

Terminal rate 0/28 (0%) 3/16 (19%) 6/15 (40%) 2/18 (11%)

First incidence (days) — 583 668 734 (T)

Life table test P=0.146 P=0.020 P<0.001 P=0.147 

Logistic regression test P=0.128 P=0.037 P<0.001 P=0.147 

Cochran-Armitage test P=0.309 

Fisher exact test P=0.059 P=0.001 P=0.247 

Liver: Hepatocellular Adenoma or Carcinoma

Overall rate 0/50 (0%) 7/50 (14%) 12/50 (24%) 8/50 (16%)

Adjusted rate 0.0% 36.3% 65.4% 37.8%

Terminal rate 0/28 (0%) 5/16 (31%) 9/15 (60%) 5/18 (28%)

First incidence (days) — 583 668 677

Life table test P=0.002 P<0.001 P<0.001 P<0.001

Logistic regression test P=0.001 P=0.002 P<0.001 P<0.001

Cochran-Armitage test P=0.020

Fisher exact test P=0.006 P<0.001 P=0.003

Mammary Gland: Fibroadenoma

Overall rate 22/50 (44%) 11/50 (22%) 9/50 (18%) 7/50 (14%)

Adjusted rate 55.2% 41.8% 38.1% 28.0%

Terminal rate 11/28 (39%) 5/16 (31%) 4/15 (27%) 3/18 (17%)

First incidence (days) 481 468 534 504

Life table test P=0.033N P=0.277N P=0.162N P=0.055N 

Logistic regression test P=0.003N P=0.024N P=0.009N P=0.004N

Cochran-Armitage test P=0.001N

Fisher exact test P=0.016N P=0.004N P<0.001N

Mammary Gland: Fibroadenoma or Adenoma

Overall rate 23/50 (46%) 11/50 (22%) 10/50 (20%) 8/50 (16%)

Adjusted rate 57.8% 41.8% 41.1% 32.8%

Terminal rate 12/28 (43%) 5/16 (31%) 4/15 (27%) 4/18 (22%)

First incidence (days) 481 468 534 504

Life table test P=0.050N P=0.232N P=0.196N P=0.068N 

Logistic regression test P=0.005N P=0.016N P=0.011N P=0.006N

Cochran-Armitage test P=0.002N

Fisher exact test P=0.010N P=0.005N P=0.001N

Mammary Gland: Carcinoma

Overall rate 3/50 (6%) 1/50 (2%) 4/50 (8%) 1/50 (2%)

Adjusted rate 8.9% 2.6% 18.6% 5.6%

Terminal rate 1/28 (4%) 0/16 (0%) 2/15 (13%) 1/18 (6%)

First incidence (days) 693 581 611 734 (T)

Life table test P=0.523N P=0.461N P=0.262 P=0.501N 

Logistic regression test P=0.431N P=0.318N P=0.421 P=0.461N 

Cochran-Armitage test P=0.343N

Fisher exact test P=0.309N P=0.500 P=0.309N 
Tetrafluoroethylene, NTP TR 450 153

TABLE B3

Statistical Analysis of Primary Neoplasms in Female Rats in the 2-Year Inhalation Study of Tetrafluoroethylene (continued)

0 ppm 312 ppm 625 ppm 1,250 ppm

Mammary Gland: Adenoma or Carcinoma

Overall rate 4/50 (8%) 1/50 (2%) 5/50 (10%) 2/50 (4%)

Adjusted rate 12.2% 2.6% 22.5% 11.1%

Terminal rate 2/28 (7%) 0/16 (0%) 2/15 (13%) 2/18 (11%)

First incidence (days) 693 581 611 734 (T)

Life table test P=0.522 P=0.336N P=0.226 P=0.575N 

Logistic regression test P=0.558N P=0.213N P=0.389 P=0.565N 

Cochran-Armitage test P=0.420N

Fisher exact test P=0.181N P=0.500 P=0.339N 

Mammary Gland: Fibroadenoma, Adenoma, or Carcinoma

Overall rate 24/50 (48%) 12/50 (24%) 13/50 (26%) 8/50 (16%)

Adjusted rate 59.0% 43.3% 49.8% 32.8%

Terminal rate 12/28 (43%) 5/16 (31%) 5/15 (33%) 4/18 (22%)

First incidence (days) 481 468 534 504

Life table test P=0.050N P=0.260N P=0.386N P=0.054N 

Logistic regression test P=0.004N P=0.016N P=0.037N P=0.004N

Cochran-Armitage test P=0.001N

Fisher exact test P=0.011N P=0.019N P<0.001N

Pituitary Gland (Pars Distalis): Adenoma

Overall rate 43/50 (86%) 34/50 (68%) 36/49 (73%) 34/50 (68%)

Adjusted rate 93.4% 88.4% 94.0% 88.9%

Terminal rate 25/28 (89%) 12/16 (75%) 13/15 (87%) 14/18 (78%)

First incidence (days) 481 413 387 433

Life table test P=0.177 P=0.156 P=0.074 P=0.164 

Logistic regression test P=0.270N P=0.112N P=0.253N P=0.251N 

Cochran-Armitage test P=0.063N

Fisher exact test P=0.028N P=0.096N P=0.028N

Pituitary Gland (Pars Distalis): Adenoma or Carcinoma

Overall rate 43/50 (86%) 35/50 (70%) 36/49 (73%) 34/50 (68%)

Adjusted rate 93.4% 91.3% 94.0% 88.9%

Terminal rate 25/28 (89%) 13/16 (81%) 13/15 (87%) 14/18 (78%)

First incidence (days) 481 413 387 433

Life table test P=0.186 P=0.112 P=0.074 P=0.164 

Logistic regression test P=0.248N P=0.176N P=0.253N P=0.251N 

Cochran-Armitage test P=0.052N

Fisher exact test P=0.045N P=0.096N P=0.028N

Skin: Squamous Cell Papilloma, Keratoacanthoma, or Malignant Basosquamous Tumor

Overall rate 2/50 (4%) 0/50 (0%) 2/50 (4%) 3/50 (6%)

Adjusted rate 7.1% 0.0% 11.1% 16.7%

Terminal rate 2/28 (7%) 0/16 (0%) 1/15 (7%) 3/18 (17%)

First incidence (days) 734 (T) — 702 734 (T)

Life table test P=0.136 P=0.368N P=0.470 P=0.301

Logistic regression test P=0.120 P=0.368N P=0.550 P=0.301

Cochran-Armitage test P=0.237

Fisher exact test P=0.247N P=0.691N P=0.500
154 Tetrafluoroethylene, NTP TR 450

TABLE B3

Statistical Analysis of Primary Neoplasms in Female Rats in the 2-Year Inhalation Study of Tetrafluoroethylene (continued)

0 ppm 312 ppm 625 ppm 1,250 ppm

Thyroid Gland (C-cell): Adenoma

Overall rate 5/50 (10%) 9/50 (18%) 5/50 (10%) 2/50 (4%)

Adjusted rate 16.7% 35.0% 22.7% 8.2%

Terminal rate 4/28 (14%) 1/16 (6%) 2/15 (13%) 1/18 (6%)

First incidence (days) 698 523 587 579

Life table test P=0.265N P=0.044 P=0.316 P=0.420N 

Logistic regression test P=0.169N P=0.084 P=0.487 P=0.370N 

Cochran-Armitage test P=0.086N

Fisher exact test P=0.194 P=0.630N P=0.218N

Thyroid Gland (C-cell): Carcinoma

Overall rate 2/50 (4%) 2/50 (4%) 3/50 (6%) 2/50 (4%)

Adjusted rate 7.1% 8.2% 20.0% 11.1%

Terminal rate 2/28 (7%) 1/16 (6%) 3/15 (20%) 2/18 (11%)

First incidence (days) 734 (T) 468 734 (T) 734 (T)

Life table test P=0.406 P=0.536 P=0.228 P=0.528 

Logistic regression test P=0.427 P=0.701N P=0.228 P=0.528 

Cochran-Armitage test P=0.569 

Fisher exact test P=0.691N P=0.500 P=0.691N 

Thyroid Gland (C-cell): Adenoma or Carcinoma

Overall rate 7/50 (14%) 11/50 (22%) 7/50 (14%) 4/50 (8%)

Adjusted rate 23.6% 40.6% 34.6% 19.0%

Terminal rate 6/28 (21%) 2/16 (13%) 4/15 (27%) 3/18 (17%)

First incidence (days) 698 468 587 579

Life table test P=0.365N P=0.041 P=0.215 P=0.548N 

Logistic regression test P=0.253N P=0.110 P=0.386 P=0.543N 

Cochran-Armitage test P=0.117N

Fisher exact test P=0.218 P=0.613N P=0.262N 

Uterus: Stromal Polyp

Overall rate 6/50 (12%) 5/50 (10%) 4/50 (8%) 5/50 (10%)

Adjusted rate 19.7% 24.2% 21.2% 18.2%

Terminal rate 5/28 (18%) 3/16 (19%) 2/15 (13%) 2/18 (11%)

First incidence (days) 626 583 699 439

Life table test P=0.432 P=0.405 P=0.538 P=0.489 

Logistic regression test P=0.552 P=0.569 P=0.564N P=0.568N 

Cochran-Armitage test P=0.437N

Fisher exact test P=0.500N P=0.370N P=0.500N 

Uterus: Stromal Polyp or Stromal Sarcoma

Overall rate 6/50 (12%) 6/50 (12%) 4/50 (8%) 6/50 (12%)

Adjusted rate 19.7% 26.9% 21.2% 20.8%

Terminal rate 5/28 (18%) 3/16 (19%) 2/15 (13%) 2/18 (11%)

First incidence (days) 626 583 699 439

Life table test P=0.328 P=0.270 P=0.538 P=0.348 

Logistic regression test P=0.468 P=0.456 P=0.564N P=0.582 

Cochran-Armitage test P=0.530N

Fisher exact test P=0.620N P=0.370N P=0.620N 
Tetrafluoroethylene, NTP TR 450 155

TABLE B3

Statistical Analysis of Primary Neoplasms in Female Rats in the 2-Year Inhalation Study of Tetrafluoroethylene (continued)

0 ppm 312 ppm 625 ppm 1,250 ppm

All Organs: Hemangiosarcoma

Overall rate 0/50 (0%) 0/50 (0%) 5/50 (10%) 1/50 (2%)

Adjusted rate 0.0% 0.0% 19.5% 5.0%

Terminal rate 0/28 (0%) 0/16 (0%) 0/15 (0%) 0/18 (0%)

First incidence (days) — — 589 703

Life table test P=0.143 — P=0.013 P=0.400 

Logistic regression test P=0.182 — P=0.025 P=0.435 

Cochran-Armitage test P=0.242 

Fisher exact test — P=0.028 P=0.500 

All Organs: Mononuclear Cell Leukemia

Overall rate 16/50 (32%) 31/50 (62%) 23/50 (46%) 36/50 (72%)

Adjusted rate 43.7% 76.5% 65.1% 82.6%

Terminal rate 8/28 (29%) 7/16 (44%) 6/15 (40%) 11/18 (61%)

First incidence (days) 621 468 469 372

Life table test P<0.001 P<0.001 P=0.008 P<0.001

Logistic regression test P<0.001 P<0.001 P=0.105 P<0.001

Cochran-Armitage test P<0.001

Fisher exact test P=0.002 P=0.109 P<0.001

All Organs: Benign Neoplasms

Overall rate 46/50 (92%) 43/50 (86%) 43/50 (86%) 40/50 (80%)

Adjusted rate 95.8% 97.6% 100.0% 95.1%

Terminal rate 26/28 (93%) 15/16 (94%) 15/15 (100%) 16/18 (89%)

First incidence (days) 481 413 387 433

Life table test P=0.080 P=0.016 P=0.013 P=0.057 

Logistic regression test P=0.305N P=0.546N P=0.499N P=0.360N 

Cochran-Armitage test P=0.065N

Fisher exact test P=0.262N P=0.262N P=0.074N 

All Organs: Malignant Neoplasms

Overall rate 21/50 (42%) 41/50 (82%) 35/50 (70%) 42/50 (84%)

Adjusted rate 52.7% 93.0% 84.0% 91.1%

Terminal rate 10/28 (36%) 13/16 (81%) 9/15 (60%) 14/18 (78%)

First incidence (days) 433 413 387 372

Life table test P<0.001 P<0.001 P<0.001 P<0.001

Logistic regression test P<0.001 P<0.001 P=0.005 P<0.001

Cochran-Armitage test P<0.001

Fisher exact test P<0.001 P=0.004 P<0.001
156 Tetrafluoroethylene, NTP TR 450

TABLE B3

Statistical Analysis of Primary Neoplasms in Female Rats in the 2-Year Inhalation Study of Tetrafluoroethylene (continued)

0 ppm 312 ppm 625 ppm 1,250 ppm

All Organs: Benign or Malignant Neoplasms

Overall rate 49/50 (98%) 50/50 (100%) 49/50 (98%) 48/50 (96%)

Adjusted rate 98.0% 100.0% 100.0% 98.0%

Terminal rate 27/28 (96%) 16/16 (100%) 15/15 (100%) 17/18 (94%)

First incidence (days) 433 247 387 372

Life table test P=0.021 P=0.003 P=0.004 P=0.009

Logistic regression test P=0.526N P=0.612 P=0.629 P=0.748 

Cochran-Armitage test P=0.247N

Fisher exact test P=0.500 P=0.753N P=0.500N 

(T)Terminal sacrifice

Number of neoplasm-bearing animals/number of animals examined. Denominator is number of animals examined microscopically for adrenal gland, clitoral gland, a

kidney, liver, pituitary gland, thyroid gland, and uterus; for other tissues, denominator is number of animals necropsied.

Kaplan-Meier estimated neoplasm incidence at the end of the study after adjustment for intercurrent mortality b

Observed incidence at terminal kill c

Beneath the control incidence are the P values associated with the trend test. Beneath the exposed group incidence are the P values corresponding to pairwise d

comparisons between the controls and that exposed group. The life table test regards neoplasms in animals dying prior to terminal kill as being (directly or indirectly)

the cause of death. The logistic regression test regards these lesions as nonfatal. The Cochran-Armitage and Fisher exact tests compare directly the overall incidence

rates. For all tests, a negative trend or a lower incidence in an exposure group is indicated by N.

Not applicable; no neoplasms in animal group e
Tetrafluoroethylene, NTP TR 450 157

TABLE B4a

Historical Incidence of Renal Tubule Neoplasms in Chamber Control Female F344/N Rats a

Incidence in Controls

Study Adenoma Carcinoma Adenoma or Carcinoma

Historical Incidence at Battelle Pacific Northwest Laboratories

o-Chlorobenzalmalononitrile (CS-2) 0/49 0/49 0/49

Acetonitrile 0/48 0/48 0/48

-Chloroacetophenone 0/49 0/49 0/49

Epinephrine Hydrochloride 0/50 0/50 0/50

Ethyl Chloride 0/50 0/50 0/50

Hexachlorocyclopentadiene 0/50 1/50 1/50

Ozone 1/50 0/50 1/50

Total 1/346 (0.3%) 1/346 (0.3%) 2/346 (0.6%)

Standard deviation 0.8% 0.8% 1.0%

Range 0%-2% 0%-2% 0%-2%

Overall Historical Incidence

Total 1/650 (0.2%) 1/650 (0.2%) 2/650 (0.3%)

Standard deviation 0.6% 0.6% 0.8%

Range 0%-2% 0%-2% 0%-2%

Data as of 12 May 1995 a

TABLE B4b

Historical Incidence of Liver Neoplasms in Chamber Control Female F344/N Rats a

Incidence in Controls

Study Hemangiosarcoma Adenoma Carcinoma Adenoma

or Carcinoma

Historical Incidence at Battelle Pacific Northwest Laboratories

o-Chlorobenzalmalononitrile (CS-2) 0/49 3/49 0/49 3/49

Acetonitrile 0/48 0/48 0/48 0/48

-Chloroacetophenone 0/49 0/49 0/49 0/49

Epinephrine Hydrochloride 0/50 2/50 0/50 2/50

Ethyl Chloride 0/50 0/50 1/50 1/50

Hexachlorocyclopentadiene 0/50 1/50 0/50 1/50

Ozone 0/50 0/50 0/50 0/50

Total 0/346 6/346 (1.7%) 1/346 (0.3%) 7/346 (2.0%)

Standard deviation 2.4% 0.8% 2.3%

Range 0%-6% 0%-2% 0%-6%

Overall Historical Incidence

Total 0/650 9/650 (1.4%) 1/650 (0.2%) 10/650 (1.5%)

Standard deviation 2.1% 0.6% 2.0%

Range 0%-6% 0%-2% 0%-6%

Data as of 12 May 1995 a
158 Tetrafluoroethylene, NTP TR 450

TABLE B4c

Historical Incidence of Mononuclear Cell Leukemia in Chamber Control Female F344/N Rats a

Study Incidence in Controls

Historical Incidence at Battelle Pacific Northwest Laboratories

o-Chlorobenzalmalononitrile (CS-2) 24/50

Acetonitrile 18/48

-Chloroacetophenone 27/50

Epinephrine Hydrochloride 24/50

Ethyl Chloride 20/50

Hexachlorocyclopentadiene 16/50

Ozone 17/50

Total 146/348 (42.0%)

Standard deviation 8.2%

Range 32%-54%

Overall Historical Incidence

Total 262/653 (40.1%)

Standard deviation 7.2%

Range 30%-54%

Data as of 12 May 1995; includes data for lymphocytic, monocytic, and undifferentiated cell type leukemias a
Tetrafluoroethylene, NTP TR 450 159

TABLE B5

Summary of the Incidence of Nonneoplastic Lesions in Female Rats in the 2-Year Inhalation Study 

of Tetrafluoroethylene a

0 ppm 312 ppm 625 ppm 1,250 ppm

Disposition Summary

Animals initially in study 60 60 60 60

15-Month interim evaluation 10 10 10 10

Early deaths

Accidental death 1

Moribund 21 33 31 25

Natural deaths 1 1 4 6

Survivors

Died last week of study 1

Terminal sacrifice 28 15 15 18

Animals examined microscopically 60 60 60 60

15-Month Interim Evaluation

Alimentary System

Liver (10) (10) (10) (10)

Angiectasis 1 (10%) 

Basophilic focus 9 (90%) 9 (90%) 10 (100%) 10 (100%)

Clear cell focus 2 (20%) 3 (30%) 3 (30%) 

Eosinophilic focus 5 (50%) 2 (20%) 

Hepatodiaphragmatic nodule 2 (20%) 1 (10%) 

Mixed cell focus 1 (10%) 6 (60%) 4 (40%) 

Bile duct, hyperplasia 1 (10%) 

Mesentery (2) (2) (3) (1)

Fat, necrosis 2 (100%) 2 (100%) 3 (100%) 1 (100%)

Pancreas (10) (10) (10) (10)

Metaplasia, hepatocyte 2 (20%) 

Acinus, atrophy 3 (30%) 1 (10%) 2 (20%) 3 (30%) 

Stomach, forestomach (10) (10) (10) (10)

Acanthosis 1 (10%) 

Ulcer 1 (10%) 

Cardiovascular System

Heart (10) (10) (10) (10)

Cardiomyopathy 8 (80%) 10 (100%) 9 (90%) 10 (100%)

Endocrine System

Adrenal cortex (10) (10) (10) (10)

Hyperplasia 1 (10%) 1 (10%) 1 (10%) 2 (20%) 

Hypertrophy 2 (20%) 

Parathyroid gland (10) (10) (10) (10)

Hyperplasia 1 (10%) 

Pituitary gland (10) (10) (10) (10)

Pars distalis, hyperplasia 6 (60%) 5 (50%) 8 (80%) 7 (70%) 

Thyroid gland (10) (10) (10) (10)

C-cell, hyperplasia 9 (90%) 7 (70%) 9 (90%) 9 (90%) 

Number of animals examined microscopically at the site and the number of animals with lesion a
160 Tetrafluoroethylene, NTP TR 450

TABLE B5

Summary of the Incidence of Nonneoplastic Lesions in Female Rats in the 2-Year Inhalation Study 

of Tetrafluoroethylene (continued)

0 ppm 312 ppm 625 ppm 1,250 ppm

15-Month Interim Evaluation (continued)

Genital System

Clitoral gland (10) (10) (10) (10)

Inflammation, chronic active 1 (10%) 1 (10%) 

Ovary (10) (10) (10) (10)

Cyst 1 (10%) 1 (10%) 

Hematopoietic System

Bone marrow (10) (10) (10) (10)

Hyperplasia, reticulum cell 2 (20%) 2 (20%) 3 (30%) 2 (20%) 

Lymph node (1) 

Renal, hemorrhage 1 (100%) 

Lymph node, mediastinal (8) (10) (10) (9)

Hemorrhage 3 (38%) 2 (20%) 1 (10%) 

Spleen (10) (10) (10) (10)

Developmental malformation 1 (10%) 

Respiratory System

Larynx (10) (10) (10) (10)

Inflammation, chronic active 2 (20%) 3 (30%) 5 (50%) 3 (30%) 

Metaplasia, squamous 2 (20%) 1 (10%) 1 (10%) 

Mineralization 7 (70%) 6 (60%) 10 (100%) 10 (100%)

Lung (10) (10) (10) (10)

Hemorrhage 10 (100%) 10 (100%) 10 (100%) 10 (100%)

Infiltration cellular, histiocyte 1 (10%) 1 (10%) 3 (30%) 1 (10%) 

Inflammation, chronic active 1 (10%) 

Alveolar epithelium, hyperplasia 1 (10%) 1 (10%) 2 (20%) 

Nose (10) (10) (10) (10)

Inflammation, chronic active 1 (10%) 

Special Senses System

Eye (1) 

Cataract 1 (100%) 

Retina, atrophy 1 (100%) 

Urinary System

Kidney (10) (10) (10) (10)

Nephropathy 8 (80%) 9 (90%) 9 (90%) 10 (100%)

Renal tubule, degeneration 10 (100%) 10 (100%)

Renal tubule, hyperplasia 1 (10%) 

Renal tubule, hyperplasia, oncocytic 1 (10%) 

Urinary bladder (10) (10) (10) (10)

Transitional epithelium, hyperplasia 1 (10%) 
Tetrafluoroethylene, NTP TR 450 161

TABLE B5

Summary of the Incidence of Nonneoplastic Lesions in Female Rats in the 2-Year Inhalation Study 

of Tetrafluoroethylene (continued)

0 ppm 312 ppm 625 ppm 1,250 ppm

15-Month Interim Evaluation (continued)

Systems Examined With No Lesions Observed

General Body System

Integumentary System

Musculoskeletal System

Nervous System

2-Year Study

Alimentary System

Intestine large, colon (50) (50) (49) (50)

Cyst 1 (2%) 

Parasite metazoan 4 (8%) 5 (10%) 3 (6%) 3 (6%) 

Intestine large, rectum (50) (50) (49) (50)

Diverticulum 1 (2%) 

Parasite metazoan 5 (10%) 2 (4%) 2 (4%) 6 (12%) 

Intestine large, cecum (50) (50) (49) (50)

Diverticulum 1 (2%) 

Fibrosis 1 (2%) 

Infiltration cellular, eosinophil 1 (2%) 

Parasite metazoan 1 (2%) 1 (2%) 4 (8%) 

Intestine small, duodenum (49) (50) (49) (50)

Necrosis 1 (2%) 

Liver (50) (50) (50) (50)

Angiectasis 9 (18%) 9 (18%) 14 (28%) 

Basophilic focus 41 (82%) 38 (76%) 41 (82%) 37 (74%) 

Clear cell focus 10 (20%) 3 (6%) 12 (24%) 9 (18%) 

Degeneration, cystic 1 (2%) 4 (8%) 1 (2%) 3 (6%) 

Embolus bacterial 1 (2%) 

Eosinophilic focus 1 (2%) 4 (8%) 5 (10%) 4 (8%) 

Fatty change 15 (30%) 20 (40%) 17 (34%) 10 (20%) 

Hepatodiaphragmatic nodule 3 (6%) 5 (10%) 10 (20%) 5 (10%) 

Mitotic alteration 1 (2%) 

Mixed cell focus 12 (24%) 14 (28%) 16 (32%) 18 (36%) 

Necrosis, focal 1 (2%) 2 (4%) 

Regeneration 1 (2%) 2 (4%) 3 (6%) 8 (16%) 

Bile duct, hyperplasia 9 (18%) 18 (36%) 12 (24%) 18 (36%) 

Centrilobular, necrosis 2 (4%) 2 (4%) 

Mesentery (6) (4) (4) (6)

Polyarteritis 1 (17%) 1 (25%) 

Fat, necrosis 4 (67%) 4 (100%) 4 (100%) 4 (67%) 

Pancreas (50) (50) (49) (50)

Basophilic focus 3 (6%) 1 (2%) 2 (4%) 1 (2%) 

Hyperplasia 1 (2%) 

Metaplasia 1 (2%) 

Acinus, atrophy 15 (30%) 14 (28%) 9 (18%) 9 (18%) 

Pharynx (1) 

Palate, hyperplasia 1 (100%) 
162 Tetrafluoroethylene, NTP TR 450

TABLE B5

Summary of the Incidence of Nonneoplastic Lesions in Female Rats in the 2-Year Inhalation Study 

of Tetrafluoroethylene (continued)

0 ppm 312 ppm 625 ppm 1,250 ppm

2-Year Study (continued)

Alimentary System (continued)

Stomach, forestomach (50) (50) (48) (50)

Acanthosis 4 (8%) 4 (8%) 1 (2%) 1 (2%) 

Diverticulum 1 (2%) 

Inflammation, suppurative 1 (2%) 

Mineralization 1 (2%) 

Necrosis 5 (10%) 4 (8%) 

Stomach, glandular (50) (50) (49) (50)

Mineralization 1 (2%) 1 (2%) 2 (4%) 

Necrosis 2 (4%) 1 (2%) 2 (4%) 1 (2%) 

Tongue (2) (2) (1)

Hyperplasia, squamous 1 (50%) 

Epithelium, hyperplasia 1 (50%) 1 (100%)

Cardiovascular System

Heart (50) (50) (50) (50)

Cardiomyopathy 41 (82%) 40 (80%) 40 (80%) 33 (66%) 

Embolus bacterial 1 (2%) 

Polyarteritis 1 (2%) 

Atrium, thrombosis 1 (2%) 2 (4%) 1 (2%) 

Endocrine System

Adrenal cortex (50) (50) (50) (50)

Embolus bacterial 1 (2%) 

Fibrosis 1 (2%) 

Hyperplasia 18 (36%) 11 (22%) 16 (32%) 22 (44%) 

Hypertrophy 4 (8%) 4 (8%) 3 (6%) 5 (10%) 

Metaplasia, osseous 1 (2%) 

Necrosis 1 (2%) 

Vacuolization cytoplasmic 5 (10%) 3 (6%) 4 (8%) 3 (6%) 

Adrenal medulla (50) (50) (50) (50)

Embolus bacterial 1 (2%) 

Hyperplasia 6 (12%) 9 (18%) 3 (6%) 8 (16%) 

Islets, pancreatic (50) (50) (49) (50)

Hyperplasia 1 (2%) 

Pituitary gland (50) (50) (49) (50)

Pars distalis, angiectasis 1 (2%) 

Pars distalis, hemorrhage 1 (2%) 

Pars distalis, hyperplasia 4 (8%) 8 (16%) 8 (16%) 13 (26%) 

Thyroid gland (50) (50) (50) (50)

C-cell, hyperplasia 48 (96%) 40 (80%) 41 (82%) 38 (76%) 

Follicular cell, hyperplasia 2 (4%) 1 (2%) 

General Body System

None 
Tetrafluoroethylene, NTP TR 450 163

TABLE B5

Summary of the Incidence of Nonneoplastic Lesions in Female Rats in the 2-Year Inhalation Study 

of Tetrafluoroethylene (continued)

0 ppm 312 ppm 625 ppm 1,250 ppm

2-Year Study (continued)

Genital System

Clitoral gland (49) (49) (50) (48)

Dilatation 1 (2%) 

Hyperplasia 1 (2%) 1 (2%) 1 (2%) 2 (4%) 

Inflammation, chronic active 2 (4%) 4 (8%) 7 (14%) 2 (4%) 

Duct, ectasia 1 (2%) 

Ovary (50) (50) (50) (50)

Cyst 4 (8%) 3 (6%) 2 (4%) 2 (4%) 

Uterus (50) (50) (50) (50)

Cyst 1 (2%) 1 (2%) 

Hematopoietic System

Bone marrow (50) (50) (50) (50)

Hyperplasia, reticulum cell 1 (2%) 

Myelofibrosis 3 (6%) 1 (2%) 

Lymph node (3) (7) (7) (13)

Lumbar, pigmentation 1 (14%) 

Renal, hemorrhage 1 (33%) 1 (14%) 2 (15%) 

Lymph node, bronchial (50) (50) (50) (48)

Hemorrhage 2 (4%) 

Lymph node, mandibular (48) (49) (50) (50)

Hemorrhage 1 (2%) 2 (4%) 

Infiltration cellular, plasma cell 3 (6%) 2 (4%) 

Lymph node, mesenteric (50) (50) (50) (50)

Embolus bacterial 1 (2%) 

Hemorrhage 1 (2%) 1 (2%) 

Lymph node, mediastinal (49) (49) (49) (45)

Hemorrhage 1 (2%) 3 (6%) 2 (4%) 2 (4%) 

Spleen (50) (50) (49) (50)

Angiectasis 1 (2%) 1 (2%) 

Fibrosis 1 (2%) 1 (2%) 1 (2%) 2 (4%) 

Hematopoietic cell proliferation 1 (2%) 

Infiltration cellular, lipocyte 2 (4%) 

Thymus (47) (48) (49) (48)

Cyst 1 (2%) 

Integumentary System

Mammary gland (50) (50) (50) (50)

Cyst 1 (2%) 

Hyperplasia, focal 1 (2%) 

Skin (50) (50) (50) (50)

Inflammation, chronic active 2 (4%) 4 (8%) 1 (2%) 

Musculoskeletal System

Bone (50) (50) (50) (50)

Hyperostosis 6 (12%) 14 (28%) 8 (16%) 3 (6%) 

Tibia, fracture 1 (2%) 

Turbinate, fracture 1 (2%) 
164 Tetrafluoroethylene, NTP TR 450

TABLE B5

Summary of the Incidence of Nonneoplastic Lesions in Female Rats in the 2-Year Inhalation Study 

of Tetrafluoroethylene (continued)

0 ppm 312 ppm 625 ppm 1,250 ppm

2-Year Study (continued)

Nervous System

Brain (50) (50) (50) (50)

Compression 30 (60%) 23 (46%) 20 (40%) 19 (38%) 

Embolus bacterial 1 (2%) 

Hemorrhage 2 (4%) 

Respiratory System

Larynx (50) (50) (50) (50)

Inflammation, chronic active 13 (26%) 14 (28%) 14 (28%) 21 (42%) 

Metaplasia, squamous 2 (4%) 1 (2%) 2 (4%) 4 (8%) 

Mineralization 31 (62%) 29 (58%) 31 (62%) 30 (60%) 

Lung (50) (50) (50) (50)

Hemorrhage 17 (34%) 8 (16%) 12 (24%) 5 (10%) 

Infiltration cellular, lymphocyte 1 (2%) 

Infiltration cellular, histiocyte 2 (4%) 2 (4%) 

Inflammation, chronic active 2 (4%) 3 (6%) 1 (2%) 

Metaplasia, osseous 1 (2%) 

Alveolar epithelium, hyperplasia 8 (16%) 4 (8%) 9 (18%) 6 (12%) 

Mediastinum, polyarteritis 1 (2%) 

Nose (50) (50) (50) (50)

Inflammation, chronic active 1 (2%) 

Inflammation, suppurative 1 (2%) 2 (4%) 3 (6%) 5 (10%) 

Thrombosis 1 (2%) 

Nares, inflammation, chronic active 1 (2%) 

Nasolacrimal duct, inflammation, suppurative 1 (2%) 

Special Senses System

Eye (50) (50) (50) (50)

Cataract 15 (30%) 4 (8%) 10 (20%) 45 (90%) 

Degeneration 2 (4%) 1 (2%) 3 (6%) 2 (4%) 

Hemorrhage 3 (6%) 3 (6%) 2 (4%) 3 (6%) 

Cornea, inflammation, chronic active 1 (2%) 2 (4%) 

Cornea, mineralization 1 (2%) 2 (4%) 2 (4%) 3 (6%) 

Retina, atrophy 21 (42%) 11 (22%) 15 (30%) 21 (42%) 

Retina, degeneration 33 (66%) 23 (46%) 14 (28%) 13 (26%) 

Harderian gland (1) 

Inflammation, chronic active 1 (100%) 

Urinary System

Kidney (50) (50) (50) (50)

Embolus bacterial 1 (2%) 

Hyperplasia, atypical 1 (2%) 

Nephropathy 48 (96%) 46 (92%) 48 (96%) 47 (94%) 

Papilla, necrosis 1 (2%) 

Pelvis, dilatation 1 (2%) 1 (2%) 

Renal tubule, degeneration 35 (70%) 46 (92%) 

Renal tubule, hyperplasia 1 (2%) 3 (6%) 6 (12%) 12 (24%) 

Renal tubule, hyperplasia, oncocytic 3 (6%) 

Urinary bladder (49) (50) (50) (49)

Transitional epithelium, hyperplasia 1 (2%) 1 (2%) 
165

APPENDIX C

SUMMARY OF LESIONS IN MALE MICE

IN THE 2-YEAR INHALATION STUDY

OF TETRAFLUOROETHYLENE

TABLE C1 Summary of the Incidence of Neoplasms in Male Mice 

in the 2-Year Inhalation Study of Tetrafluoroethylene ................................. 167

TABLE C2 Individual Animal Tumor Pathology of Male Mice 

in the 2-Year Inhalation Study of Tetrafluoroethylene ................................. 172

TABLE C3 Statistical Analysis of Primary Neoplasms in Male Mice 

in the 2-Year Inhalation Study of Tetrafluoroethylene ................................. 194

TABLE C4a Historical Incidence of Liver Neoplasms in Chamber Control Male B6C3F 1 Mice .......... 199

TABLE C4b Historical Incidence of Histiocytic Sarcoma in Chamber Control Male B6C3F 1 Mice ....... 200

TABLE C5 Summary of the Incidence of Nonneoplastic Lesions in Male Mice 

in the 2-Year Inhalation Study of Tetrafluoroethylene ................................. 201
166 Tetrafluoroethylene, NTP TR 450
Tetrafluoroethylene, NTP TR 450 167

TABLE C1

Summary of the Incidence of Neoplasms in Male Mice in the 2-Year Inhalation Study of Tetrafluoroethylene a

0 ppm 312 ppm 625 ppm 1,250 ppm

Disposition Summary

Animals initially in study 58 58 58 58

15-Month interim evaluation 10 10 10 10

Early deaths

Moribund 6 24 26 27

Natural deaths 4 13 20 20

Survivors

Terminal sacrifice 38 11 2 1

Animals examined microscopically 58 58 58 58

15-Month Interim Evaluation

Alimentary System

Liver (10) (10) (10) (10)

Hemangiosarcoma 3 (30%) 

Hepatocellular carcinoma 2 (20%) 4 (40%) 2 (20%) 2 (20%) 

Hepatocellular adenoma 5 (50%) 2 (20%) 2 (20%) 1 (10%) 

Hepatocellular adenoma, multiple 1 (10%) 2 (20%) 

Histiocytic sarcoma 1 (10%) 

Stomach, forestomach (10) (10) (10) (10)

Squamous cell papilloma 1 (10%) 

Hematopoietic System

Thymus (8) (9) (10) (9)

Thymoma NOS 1 (11%) 

Respiratory System

Lung (10) (10) (10) (10)

Alveolar/bronchiolar adenoma 1 (10%) 1 (10%) 

Hepatocellular carcinoma, metastatic, liver 1 (10%) 1 (10%) 

Histiocytic sarcoma 1 (10%) 

Special Senses System

Harderian gland (1) (2) (1)

Adenoma 1 (100%) 2 (100%) 1 (100%)

Systemic Lesions

Multiple organs (10) (10) (10) (10) b

Histiocytic sarcoma 1 (10%) 
168 Tetrafluoroethylene, NTP TR 450

TABLE C1

Summary of the Incidence of Neoplasms in Male Mice in the 2-Year Inhalation Study of Tetrafluoroethylene (continued)

0 ppm 312 ppm 625 ppm 1,250 ppm

15-Month Interim Evaluation (continued)

Systems Examined With No Neoplasms Observed

Cardiovascular System

Endocrine System

General Body System

Genital System

Integumentary System

Musculoskeletal System

Nervous System

Urinary System

2-Year Study

Alimentary System

Liver (48) (48) (48) (48)

Carcinoma, metastatic, harderian gland 1 (2%) 

Carcinoma, metastatic, lung 1 (2%) 

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

Hemangioma, multiple 7 (15%) 2 (4%) 1 (2%) 

Hemangiosarcoma 5 (10%) 10 (21%) 19 (40%) 

Hemangiosarcoma, multiple 16 (33%) 17 (35%) 18 (38%) 

Hepatocellular carcinoma 7 (15%) 11 (23%) 24 (50%) 20 (42%) 

Hepatocellular carcinoma, multiple 4 (8%) 9 (19%) 9 (19%) 6 (13%) 

Hepatocellular adenoma 11 (23%) 11 (23%) 5 (10%) 13 (27%) 

Hepatocellular adenoma, multiple 6 (13%) 6 (13%) 7 (15%) 7 (15%) 

Histiocytic sarcoma 12 (25%) 7 (15%) 7 (15%) 

Mesentery (2) (3) (2) (7)

Carcinoma, metastatic, lung 1 (33%) 

Hemangioma 1 (14%) 

Hemangiosarcoma 1 (14%) 

Hepatocellular carcinoma, metastatic, liver 1 (14%) 

Histiocytic sarcoma 1 (50%) 

Pancreas (48) (48) (46) (45)

Hepatocellular carcinoma, metastatic, liver 1 (2%) 

Stomach, forestomach (48) (48) (46) (46)

Squamous cell carcinoma 1 (2%) 

Squamous cell papilloma 2 (4%) 1 (2%) 1 (2%) 

Cardiovascular System

Heart (48) (48) (48) (48)

Carcinoma, metastatic, lung 1 (2%) 1 (2%) 

Endocrine System

Adrenal cortex (48) (48) (47) (48)

Adenoma 1 (2%) 1 (2%) 

Islets, pancreatic (48) (48) (46) (45)

Adenoma 1 (2%) 

Thyroid gland (48) (48) (47) (47)

Follicular cell, adenoma 3 (6%) 

Follicular cell, carcinoma 1 (2%) 
Tetrafluoroethylene, NTP TR 450 169

TABLE C1

Summary of the Incidence of Neoplasms in Male Mice in the 2-Year Inhalation Study of Tetrafluoroethylene (continued)

0 ppm 312 ppm 625 ppm 1,250 ppm

2-Year Study (continued)

General Body System

Tissue NOS (1) (2) (2) 

Carcinoma, metastatic, lung 1 (50%) 

Hemangioma 1 (50%) 

Genital System

Epididymis (48) (48) (48) (48)

Leiomyoma 1 (2%) 

Leiomyosarcoma 1 (2%) 

Hematopoietic System

Bone marrow (48) (48) (47) (47)

Hemangioma 1 (2%) 

Histiocytic sarcoma 1 (2%) 1 (2%) 2 (4%) 

Lymph node (3) (1) (2) 

Renal, histiocytic sarcoma 1 (100%) 1 (50%) 

Lymph node, bronchial (36) (36) (35) (26)

Histiocytic sarcoma 3 (8%) 1 (4%) 

Lymph node, mandibular (36) (34) (32) (34)

Histiocytic sarcoma 2 (6%) 1 (3%) 

Lymph node, mesenteric (47) (42) (41) (40)

Histiocytic sarcoma 4 (10%) 1 (2%) 2 (5%) 

Lymph node, mediastinal (30) (34) (32) (29)

Carcinoma, metastatic, lung 1 (3%) 1 (3%) 

Histiocytic sarcoma 2 (6%) 1 (3%) 

Spleen (48) (48) (46) (46)

Hemangiosarcoma 2 (4%) 

Histiocytic sarcoma 2 (4%) 1 (2%) 2 (4%) 

Thymus (43) (40) (34) (37)

Histiocytic sarcoma 1 (3%) 

Integumentary System

Skin (48) (48) (48) (48)

Subcutaneous tissue, hemangioma 1 (2%) 

Subcutaneous tissue, hemangiosarcoma 1 (2%) 1 (2%) 

Musculoskeletal System

Bone (48) (48) (48) (48)

Carcinoma, metastatic, harderian gland 1 (2%) 

Skeletal muscle (1)

Carcinoma, metastatic, lung 1 (100%)

Nervous System

Brain (48) (48) (48) (48)

Carcinoma, metastatic, harderian gland 1 (2%) 
170 Tetrafluoroethylene, NTP TR 450

TABLE C1

Summary of the Incidence of Neoplasms in Male Mice in the 2-Year Inhalation Study of Tetrafluoroethylene (continued)

0 ppm 312 ppm 625 ppm 1,250 ppm

2-Year Study (continued)

Respiratory System

Lung (48) (48) (48) (48)

Alveolar/bronchiolar adenoma 9 (19%) 7 (15%) 12 (25%) 3 (6%) 

Alveolar/bronchiolar adenoma, multiple 1 (2%) 1 (2%) 1 (2%) 2 (4%) 

Alveolar/bronchiolar carcinoma 2 (4%) 4 (8%) 3 (6%) 1 (2%) 

Carcinoma 1 (2%) 1 (2%) 

Carcinoma, metastatic, harderian gland 1 (2%) 1 (2%) 

Hemangiosarcoma, metastatic, liver 2 (4%) 2 (4%) 

Hepatocellular carcinoma, metastatic, liver 1 (2%) 7 (15%) 14 (29%) 8 (17%) 

Histiocytic sarcoma 7 (15%) 4 (8%) 3 (6%) 

Nose (48) (47) (46) (47)

Carcinoma, metastatic, harderian gland 1 (2%) 

Special Senses System

Harderian gland (6) (8) (5) (6)

Adenoma 5 (83%) 7 (88%) 4 (80%) 4 (67%) 

Carcinoma 1 (17%) 1 (13%) 1 (17%) 

Urinary System

Kidney (48) (48) (48) (48)

Carcinoma, metastatic, lung 1 (2%) 

Hemangiosarcoma, metastatic, liver 1 (2%) 

Histiocytic sarcoma 3 (6%) 3 (6%) 2 (4%) 

Urinary bladder (48) (43) (43) (42)

Systemic Lesions

Multiple organs (48) (48) (48) (48)

Histiocytic sarcoma 12 (25%) 7 (15%) 7 (15%) 

Lymphoma malignant mixed 2 (4%) 1 (2%) 1 (2%) 
Tetrafluoroethylene, NTP TR 450 171

TABLE C1

Summary of the Incidence of Neoplasms in Male Mice in the 2-Year Inhalation Study of Tetrafluoroethylene (continued)

0 ppm 312 ppm 625 ppm 1,250 ppm

Neoplasm Summary

Total animals with primary neoplasmsc

15-Month interim evaluation 6 7 6 6

2-Year study 37 44 48 46

Total primary neoplasms

15-Month interim evaluation 10 9 7 9

2-Year study 53 110 107 112

Total animals with benign neoplasms

15-Month interim evaluation 6 4 4 3

2-Year study 26 30 27 27

Total benign neoplasms

15-Month interim evaluation 8 4 5 3

2-Year study 35 48 36 35

Total animals with malignant neoplasms

15-Month interim evaluation 2 4 2 4

2-Year study 16 39 47 46

Total malignant neoplasms

15-Month interim evaluation 2 4 2 6

2-Year study 18 62 71 77

Total animals with metastatic neoplasms

15-Month interim evaluation 1 1

2-Year study 2 8 14 11

Total metastatic neoplasms

15-Month interim evaluation 1 1

2-Year study 3 12 17 20

Total animals with uncertain neoplasms-

 benign or malignant

15-Month interim evaluation 1

Total uncertain neoplasms

15-Month interim evaluation 1

Number of animals examined microscopically at the site and the number of animals with neoplasm a

Number of animals with any tissue examined microscopically b

Primary neoplasms: all neoplasms except metastatic neoplasms c
172 Tetrafluoroethylene, NTP TR 450

TABLE C2

Individual Animal Tumor Pathology of Male Mice in the 2-Year Inhalation Study of Tetrafluoroethylene: 0 ppm 

4 4 5 5 5 5 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

Number of Days on Study 5 7 3 4 9 9 1 3 5 5 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

2 5 8 1 7 7 1 9 0 0 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

Carcass ID Number 3 4 4 3 2 4 1 1 1 2 0 0 0 0 0 0 1 1 1 1 1 2 2 2 2

2 2 3 7 8 8 5 8 7 5 2 4 5 6 7 9 0 2 4 6 9 1 2 3 4

Alimentary System 

Esophagus + + + + + + + + + + + + + + + + + + + + + + + + +

Gallbladder + M M + + + A + A + + + + + + + + + + + + + + + +

Intestine large, colon + + + + + + + + A + + + + + + + + + + + + + + + +

Intestine large, rectum + + + + + + + + A I + + + + + + + + + + + + + + +

Intestine large, cecum + + M + + + A + A + + + + + + + + + + + + + + + +

Intestine small, duodenum + + A + + + + + A + + M + + + + + + + + + + + + +

Intestine small, jejunum + + A + + + + + A + + + + + + + + + + + + + + + +

Intestine small, ileum + + A + + + + + A + + + + + + + + + + + + + + + +

Liver + + + + + + + + + + + + + + + + + + + + + + + + +

Hepatocellular carcinoma X X X X X X X

Hepatocellular carcinoma, multiple X

Hepatocellular adenoma X X X X

Hepatocellular adenoma, multiple X X X X

Mesentery +

Pancreas + + + + + + + + + + + + + + + + + + + + + + + + +

Salivary glands + + + + + + + + + + + + + + + + + + + + + + + + +

Stomach, forestomach + + + + + + + + + + + + + + + + + + + + + + + + +

Squamous cell papilloma X

Stomach, glandular + + + + + + + + + + + + + + + + + + + + + + + + +

Tooth + +

Cardiovascular System 

Heart + + + + + + + + + + + + + + + + + + + + + + + + +

Endocrine System 

Adrenal cortex + + + + + + + + + + + + + + + + + + + + + + + + +

Adenoma X

Adrenal medulla + + + + + + + + + + + + + + + + + + + + + + + + +

Islets, pancreatic + + + + + + + + + + + + + + + + + + + + + + + + +

Parathyroid gland + M + + M M + M + + + + + + + M + + M M M + + + M

Pituitary gland + + + + + + + + + + + + + + + + + + + + + + + + +

Thyroid gland + + + + + + + + + + + + + + + + + + + + + + + + +

General Body System 

Tissue NOS A

Genital System 

Epididymis + + + + + + + + + + + + + + + + + + + + + + + + +

Preputial gland + + + + + + + + + + + + + + + + + + + + + + + + +

Prostate + + + + + + + + + + + + + + + + + M + + + + + + +

Seminal vesicle + + + + + + + + + + + + + + + + + + + + + + + + +

Testes + + + + + + + + + + + + + + + + + + + + + + + + +

Hematopoietic System 

Bone marrow + + + + + + + + + + + + + + + + + + + + + + + + +

Lymph node + +

Lymph node, bronchial M M M + M + + + M + + M + M + + + + + + + + + + +

Lymph node, mandibular M + M M + + + I + M + + + + + M + + + + + + + + +

+: Tissue examined microscopically M: Missing tissue X: Lesion present

A: Autolysis precludes examination I: Insufficient tissue Blank: Not examined
Tetrafluoroethylene, NTP TR 450 173

TABLE C2

Individual Animal Tumor Pathology of Male Mice in the 2-Year Inhalation Study of Tetrafluoroethylene: 0 ppm (continued)

6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

Number of Days on Study 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Total

Carcass ID Number 2 2 2 3 3 3 3 3 3 3 4 4 4 4 4 5 5 5 5 5 5 5 5 Tissues/

6 7 9 0 1 4 5 6 8 9 0 4 5 7 9 0 1 2 3 5 6 7 8 Tumors

Alimentary System 

Esophagus + + + + + + + + + + + + + + + + + + + + + + + 48

Gallbladder M + + + A + + + + + + + + + + + + + + + + + + 42

Intestine large, colon + + + + + + + + + + + + + + + + + + + + + + + 47

Intestine large, rectum + + + + + + + + + + + + + + + + + + + + + + + 46

Intestine large, cecum + + + + + + + + + + + + + + + + + + + + + + + 45

Intestine small, duodenum + + + + + + + + + + + + + + + + + + + + + + + 45

Intestine small, jejunum + + + + + + + + + + + + + + + + + + + + + + + 46

Intestine small, ileum + + + + + + + + + + + + + + + + + + + + + + + 46

Liver + + + + + + + + + + + + + + + + + + + + + + + 48

Hepatocellular carcinoma 7

Hepatocellular carcinoma, multiple X X X 4

Hepatocellular adenoma X X X X X X X 11

Hepatocellular adenoma, multiple X X 6

Mesentery + 2

Pancreas + + + + + + + + + + + + + + + + + + + + + + + 48

Salivary glands + + + + + + + + + + + + + + + + + + + + + + + 48

Stomach, forestomach + + + + + + + + + + + + + + + + + + + + + + + 48

Squamous cell papilloma X 2

Stomach, glandular + + + + + + + + + + + + + + + + + + + + + + + 48

Tooth 2

Cardiovascular System 

Heart + + + + + + + + + + + + + + + + + + + + + + + 48

Endocrine System 

Adrenal cortex + + + + + + + + + + + + + + + + + + + + + + + 48

Adenoma 1

Adrenal medulla + + + + + + + + + + + + + + + + + + + + + + + 48

Islets, pancreatic + + + + + + + + + + + + + + + + + + + + + + + 48

Parathyroid gland + M M M + + + M + + M + + M M M + + + + M + + 30

Pituitary gland + + + + + + + + + + + + + + + I + + + + + + + 47

Thyroid gland + + + + + + + + + + + + + + + + + + + + + + + 48

General Body System 

Tissue NOS + 1

Genital System 

Epididymis + + + + + + + + + + + + + + + + + + + + + + + 48

Preputial gland + + + + + + + + + + + + + + + + + + + + + + + 48

Prostate + + + + + + I + + + + + + + + + + + + + + + + 46

Seminal vesicle + + + + + + + + + + + + + + + + + + + + + + + 48

Testes + + + + + + + + + + + + + + + + + + + + + + + 48

Hematopoietic System 

Bone marrow + + + + + + + + + + + + + + + + + + + + + + + 48

Lymph node + 3

Lymph node, bronchial + M + M M + M + + + + + + + + M + + + + + + + 36

Lymph node, mandibular M M + + + M + + + M + + + + + + + M + M + + + 36
174 Tetrafluoroethylene, NTP TR 450

TABLE C2

Individual Animal Tumor Pathology of Male Mice in the 2-Year Inhalation Study of Tetrafluoroethylene: 0 ppm (continued)

4 4 5 5 5 5 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

Number of Days on Study 5 7 3 4 9 9 1 3 5 5 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

2 5 8 1 7 7 1 9 0 0 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

Carcass ID Number 3 4 4 3 2 4 1 1 1 2 0 0 0 0 0 0 1 1 1 1 1 2 2 2 2

2 2 3 7 8 8 5 8 7 5 2 4 5 6 7 9 0 2 4 6 9 1 2 3 4

Hematopoietic System (continued)

Lymph node, mesenteric + + M + + + + + + + + + + + + + + + + + + + + + +

Lymph node, mediastinal M + + + + M + + + + + I + + M + + + M + + + M + +

Spleen + + + + + + + + + + + + + + + + + + + + + + + + +

Hemangiosarcoma

Thymus + + + + + + + + + + + + + M + + + + + + + + + + +

Integumentary System 

Mammary gland M M M M M M M M M M M M M M M M M M M M + M M M M

Skin + + + + + + + + + + + + + + + + + + + + + + + + +

Musculoskeletal System 

Bone + + + + + + + + + + + + + + + + + + + + + + + + +

Nervous System 

Brain + + + + + + + + + + + + + + + + + + + + + + + + +

Respiratory System 

Larynx + + A + + + + + + + + + + + + + + + + + + + + + +

Lung + + + + + + + + + + + + + + + + + + + + + + + + +

Alveolar/bronchiolar adenoma X X X X X

Alveolar/bronchiolar adenoma,

 multiple 

Alveolar/bronchiolar carcinoma X X

Carcinoma, metastatic, harderian

 gland X 

Hepatocellular carcinoma, metastatic,

 liver

Nose + + + + + + + + + + + + + + + + + + + + + + + + +

Carcinoma, metastatic, harderian

 gland X 

Trachea + + A + + + + + + + + + + + + + + + + + + + + + +

Special Senses System 

Ear M +

Harderian gland + + + +

Adenoma X X X

Carcinoma X

Urinary System 

Kidney + + + + + + + + + + + + + + + + + + + + + + + + +

Urinary bladder + + + + + + + + + + + + + + + + + + + + + + + + +

Systemic Lesions

Multiple organs + + + + + + + + + + + + + + + + + + + + + + + + +

Lymphoma malignant mixed X X
Tetrafluoroethylene, NTP TR 450 175

TABLE C2

Individual Animal Tumor Pathology of Male Mice in the 2-Year Inhalation Study of Tetrafluoroethylene: 0 ppm (continued)

6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

Number of Days on Study 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Total

Carcass ID Number 2 2 2 3 3 3 3 3 3 3 4 4 4 4 4 5 5 5 5 5 5 5 5 Tissues/

6 7 9 0 1 4 5 6 8 9 0 4 5 7 9 0 1 2 3 5 6 7 8 Tumors

Hematopoietic System (continued)

Lymph node, mesenteric + + + + + + + + + + + + + + + + + + + + + + + 47

Lymph node, mediastinal M + M M + M M M M + + M M M + + + M + + + + M 30

Spleen + + + + + + + + + + + + + + + + + + + + + + + 48

Hemangiosarcoma X X 2

Thymus + + + M + + M + M + + + + + + + + + + + M + + 43

Integumentary System 

Mammary gland M M M M M M M M M M M M M M M M M M M M M M M 1

Skin + + + + + + + + + + + + + + + + + + + + + + + 48

Musculoskeletal System 

Bone + + + + + + + + + + + + + + + + + + + + + + + 48

Nervous System 

Brain + + + + + + + + + + + + + + + + + + + + + + + 48

Respiratory System 

Larynx + + + + + + + + + + + + + + + + + + + + + + + 47

Lung + + + + + + + + + + + + + + + + + + + + + + + 48

Alveolar/bronchiolar adenoma X X X X 9

Alveolar/bronchiolar adenoma, 

 multiple X 1

Alveolar/bronchiolar carcinoma 2

Carcinoma, metastatic, harderian 

 gland 1

Hepatocellular carcinoma, metastatic, 

 liver X 1

Nose + + + + + + + + + + + + + + + + + + + + + + + 48

Carcinoma, metastatic, harderian 

 gland 1

Trachea + + + + + + + + + + + + + + + + + + + + + + + 47

Special Senses System 

Ear 1

Harderian gland + + 6

Adenoma X X 5

Carcinoma 1

Urinary System 

Kidney + + + + + + + + + + + + + + + + + + + + + + + 48

Urinary bladder + + + + + + + + + + + + + + + + + + + + + + + 48

Systemic Lesions 

Multiple organs + + + + + + + + + + + + + + + + + + + + + + + 48

Lymphoma malignant mixed 2
176 Tetrafluoroethylene, NTP TR 450

TABLE C2

Individual Animal Tumor Pathology of Male Mice in the 2-Year Inhalation Study of Tetrafluoroethylene: 312 ppm 

0 0 0 4 4 4 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5

Number of Days on Study 4 7 7 6 6 9 0 0 1 2 3 3 3 4 4 4 5 5 6 6 7 8 9 9 9

4 5 7 2 3 5 8 9 3 2 7 7 7 1 1 1 1 2 6 9 3 6 0 3 3

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

Carcass ID Number 3 3 5 5 6 7 5 2 5 3 5 6 6 2 2 2 2 5 6 3 3 5 7 4 5

5 1 8 1 9 2 5 0 9 8 0 3 6 4 5 7 3 6 2 6 2 4 3 9 2

Alimentary System 

Esophagus + + + + + + + + + + + + + + + + + + + + + + + + +

Gallbladder + A A M + + M M A A + A + + + + + + + + A + + A +

Intestine large, colon + A A + + + + + + A + + + + + + + + + + A + + + +

Intestine large, rectum + A + + + + + + + + + + + + + + A + + + + + + + +

Intestine large, cecum + A A A + + + + + A + + + + + + A + + + A + + A +

Intestine small, duodenum + A A A + + A + A A + + + + + + A + + + A + + A +

Intestine small, jejunum + A A A + + + + + A + + + + + + A + + + A + + A +

Intestine small, ileum + A A A + + + + A A + + + + + + A + + + A + + A +

Liver + + + + + + + + + + + + + + + + + + + + + + + + +

Carcinoma, metastatic, lung X

Hemangioma X X

Hemangioma, multiple

Hemangiosarcoma X

Hemangiosarcoma, multiple X X X X X

Hepatocellular carcinoma X X X X X X X X

Hepatocellular carcinoma, multiple X X X X

Hepatocellular adenoma X X X

Hepatocellular adenoma, multiple

Histiocytic sarcoma X X X X

Mesentery +

Carcinoma, metastatic, lung X

Pancreas + + + + + + + + + + + + + + + + + + + + + + + + +

Salivary glands + + + + + + + + + + + + + + + + + + + + + + + + +

Stomach, forestomach + + + + + + + + + + + + + + + + + + + + + + + + +

Squamous cell papilloma X

Stomach, glandular + + + + + + + + + + + + + + + + + + + + + + + + +

Tooth +

Cardiovascular System 

Heart + + + + + + + + + + + + + + + + + + + + + + + + +

Carcinoma, metastatic, lung X

Endocrine System 

Adrenal cortex + + + + + + + + + + + + + + + + + + + + + + + + +

Adrenal medulla + + + + + + + + + M + + I + + + + + + + + + + I +

Islets, pancreatic + + + + + + + + + + + + + + + + + + + + + + + + +

Parathyroid gland + + + M M + + + + + + M M M + + M + M + + + M + M

Pituitary gland + M + + + + + + + + + + M + + + + + + + + M M + +

Thyroid gland + + + + + + + + + + + + + + + + + + + + + + + + +

Follicular cell, adenoma

Follicular cell, carcinoma

General Body System 

Tissue NOS +

Carcinoma, metastatic, lung X

Hemangioma
Tetrafluoroethylene, NTP TR 450 177

TABLE C2

Individual Animal Tumor Pathology of Male Mice in the 2-Year Inhalation Study of Tetrafluoroethylene: 312 ppm (continued)

5 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

Number of Days on Study 9 0 1 1 1 2 3 3 4 4 4 6 6 6 6 6 6 6 6 6 6 6 6

9 0 4 4 6 5 1 7 6 6 9 0 6 6 6 6 6 6 6 6 6 6 6

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Total

Carcass ID Number 6 3 1 4 3 4 4 4 1 5 2 3 2 2 2 4 4 4 5 6 6 6 6 Tissues/

5 0 8 3 7 2 0 7 7 3 9 3 1 6 8 4 5 6 7 0 1 4 7 Tumors

Alimentary System 

Esophagus + + + + + + + + + + + + + + + + + + + + + + + 48

Gallbladder A A + + A + + + + + + + + + + + + + + + + + + 35

Intestine large, colon + A + + + + + + + + + + + + + + + + + + + + + 43

Intestine large, rectum + A + + + + + + + + + + + + + + + + + + + + + 45

Intestine large, cecum + A + + + + + + + + + + + + + + + + + + + + + 40

Intestine small, duodenum + A + + + + + + + + + + + + + + + + + + + + + 38

Intestine small, jejunum + A + + + + + + + + + + + + + + + + + + + + + 40

Intestine small, ileum + A + + + + + + + + + + + + + + + + + + + + + 39

Liver + + + + + + + + + + + + + + + + + + + + + + + 48

Carcinoma, metastatic, lung 1

Hemangioma X 3

Hemangioma, multiple X X X X X X X 7

Hemangiosarcoma X X X X 5

Hemangiosarcoma, multiple X X X X X X X X X X X 16

Hepatocellular carcinoma X X X 11

Hepatocellular carcinoma, multiple X X X X X 9

Hepatocellular adenoma X X X X X X X X 11

Hepatocellular adenoma, multiple X X X X X X 6

Histiocytic sarcoma X X X X X X X X 12

Mesentery + + 3

Carcinoma, metastatic, lung 1

Pancreas + + + + + + + + + + + + + + + + + + + + + + + 48

Salivary glands + + + + + + + + + + + + + + + + + + + + + + + 48

Stomach, forestomach + + + + + + + + + + + + + + + + + + + + + + + 48

Squamous cell papilloma 1

Stomach, glandular + + + + + + + + + + + + + + + + + + + + + + + 48

Tooth + 2

Cardiovascular System 

Heart + + + + + + + + + + + + + + + + + + + + + + + 48

Carcinoma, metastatic, lung 1

Endocrine System 

Adrenal cortex + + + + + + + + + + + + + + + + + + + + + + + 48

Adrenal medulla + + + + + + + + + + + + + + + + + + + + + + + 45

Islets, pancreatic + + + + + + + + + + + + + + + + + + + + + + + 48

Parathyroid gland + M M M M + + + + + M M M M M + M + + + + M + 28

Pituitary gland + + + + + + + + + + + + + + + + + + + + + + + 44

Thyroid gland + + + + + + + + + + + + + + + + + + + + + + + 48

Follicular cell, adenoma X X X 3

Follicular cell, carcinoma X 1

General Body System 

Tissue NOS + 2

Carcinoma, metastatic, lung 1

Hemangioma X 1
178 Tetrafluoroethylene, NTP TR 450

TABLE C2

Individual Animal Tumor Pathology of Male Mice in the 2-Year Inhalation Study of Tetrafluoroethylene: 312 ppm (continued)

0 0 0 4 4 4 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5

Number of Days on Study 4 7 7 6 6 9 0 0 1 2 3 3 3 4 4 4 5 5 6 6 7 8 9 9 9

4 5 7 2 3 5 8 9 3 2 7 7 7 1 1 1 1 2 6 9 3 6 0 3 3

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

Carcass ID Number 3 3 5 5 6 7 5 2 5 3 5 6 6 2 2 2 2 5 6 3 3 5 7 4 5

5 1 8 1 9 2 5 0 9 8 0 3 6 4 5 7 3 6 2 6 2 4 3 9 2

Genital System 

Epididymis + + + + + + + + + + + + + + + + + + + + + + + + +

Leiomyosarcoma X

Preputial gland + + + + + + + + + + + + + + + + + + + + + + + + +

Prostate + A + + + + + + + + + + + + + + + + + + + + + + +

Seminal vesicle + A + + + + + + + + + + + + + + + + + + + + + + +

Testes + + + + + + + + + + + + + + + + + + + + + + + + +

Hematopoietic System 

Bone marrow + + + + + + + + + + + + + + + + + + + + + + + + +

Histiocytic sarcoma

Lymph node

Renal, histiocytic sarcoma

Lymph node, bronchial M M + + + + + M + + M M + + + + + M + + + + + M +

Histiocytic sarcoma X

Lymph node, mandibular + M + M + M M + + + M + + + + M M M + + + + + M I

Histiocytic sarcoma

Lymph node, mesenteric + + + + + + + + + + + M + + + + + + + + + + M I M

Histiocytic sarcoma X

Lymph node, mediastinal + + + M + + M M + + M + + + + + M M + + + + + + M

Carcinoma, metastatic, lung X

Histiocytic sarcoma

Spleen + + + + + + + + + + + + + + + + + + + + + + + + +

Histiocytic sarcoma

Thymus M + + + + + + M + + M I M + + + M + + + + + + + +

Integumentary System 

Mammary gland M M M M M + M M M M M M M M M M M M M M M M M M +

Skin + + + + + + + + + + + + + + + + + + + + + + + + +

Subcutaneous tissue, hemangioma X

Musculoskeletal System 

Bone + + + + + + + + + + + + + + + + + + + + + + + + +

Nervous System 

Brain + + + + + + + + + + + + + + + + + + + + + + + + +

Respiratory System 

Larynx + + + + + + + + + + + + + + + + + + + + + + + + +

Lung + + + + + + + + + + + + + + + + + + + + + + + + +

Alveolar/bronchiolar adenoma X X

Alveolar/bronchiolar adenoma,

 multiple 

Alveolar/bronchiolar carcinoma X

Carcinoma X

Hepatocellular carcinoma, metastatic,

 liver X X X X X X X

Histiocytic sarcoma X X X

Nose + A + + + + + + + + + + + + + + + + + + + + + + +

Trachea + A + + + + + + + + + + + + + + + + + + + + + + +
Tetrafluoroethylene, NTP TR 450 179

TABLE C2

Individual Animal Tumor Pathology of Male Mice in the 2-Year Inhalation Study of Tetrafluoroethylene: 312 ppm (continued)

5 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

Number of Days on Study 9 0 1 1 1 2 3 3 4 4 4 6 6 6 6 6 6 6 6 6 6 6 6

9 0 4 4 6 5 1 7 6 6 9 0 6 6 6 6 6 6 6 6 6 6 6

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Total

Carcass ID Number 6 3 1 4 3 4 4 4 1 5 2 3 2 2 2 4 4 4 5 6 6 6 6 Tissues/

5 0 8 3 7 2 0 7 7 3 9 3 1 6 8 4 5 6 7 0 1 4 7 Tumors

Genital System 

Epididymis + + + + + + + + + + + + + + + + + + + + + + + 48

Leiomyosarcoma 1

Preputial gland + + + + + + + + + + + + + + + + + + + + + + + 48

Prostate + + + + + + + + M + + + + + + + + + + + + + + 46

Seminal vesicle + + + + + + + + + + + + + + + + + + + + + + + 47

Testes + + + + + + + + + + + + + + + + + + + + + + + 48

Hematopoietic System 

Bone marrow + + + + + + + + + + + + + + + + + + + + + + + 48

Histiocytic sarcoma X 1

Lymph node + 1

Renal, histiocytic sarcoma X 1

Lymph node, bronchial + + I + + + + + + + + + + M + + + + M M + + M 36

Histiocytic sarcoma X X 3

Lymph node, mandibular + + + + + M + + + + + + + + + M M + + + M + + 34

Histiocytic sarcoma X X 2

Lymph node, mesenteric + + + + + + + I + + + + + + + I + + + + + + + 42

Histiocytic sarcoma X X X 4

Lymph node, mediastinal M + + + M + + + + + M + M + + M + M + M + + + 34

Carcinoma, metastatic, lung 1

Histiocytic sarcoma X X 2

Spleen + + + + + + + + + + + + + + + + + + + + + + + 48

Histiocytic sarcoma X X 2

Thymus + + + + + M + + + + + + + + + + + + M + + + + 40

Integumentary System 

Mammary gland M M M M M M M M M M M M M M M M M M M M M M M 2

Skin + + + + + + + + + + + + + + + + + + + + + + + 48

Subcutaneous tissue, hemangioma 1

Musculoskeletal System 

Bone + + + + + + + + + + + + + + + + + + + + + + + 48

Nervous System 

Brain + + + + + + + + + + + + + + + + + + + + + + + 48

Respiratory System 

Larynx + + + + + + + + + + + + + + + + + + + + + + + 48

Lung + + + + + + + + + + + + + + + + + + + + + + + 48

Alveolar/bronchiolar adenoma X X X X X 7

Alveolar/bronchiolar adenoma, 

 multiple X 1

Alveolar/bronchiolar carcinoma X X X 4

Carcinoma 1

Hepatocellular carcinoma, metastatic, 

 liver 7

Histiocytic sarcoma X X X X 7

Nose + + + + + + + + + + + + + + + + + + + + + + + 47

Trachea + + + + + + + + + + + + + + + + + + + + + + + 47
180 Tetrafluoroethylene, NTP TR 450

TABLE C2

Individual Animal Tumor Pathology of Male Mice in the 2-Year Inhalation Study of Tetrafluoroethylene: 312 ppm (continued)

0 0 0 4 4 4 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5

Number of Days on Study 4 7 7 6 6 9 0 0 1 2 3 3 3 4 4 4 5 5 6 6 7 8 9 9 9

4 5 7 2 3 5 8 9 3 2 7 7 7 1 1 1 1 2 6 9 3 6 0 3 3

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

Carcass ID Number 3 3 5 5 6 7 5 2 5 3 5 6 6 2 2 2 2 5 6 3 3 5 7 4 5

5 1 8 1 9 2 5 0 9 8 0 3 6 4 5 7 3 6 2 6 2 4 3 9 2

Special Senses System 

Eye

Harderian gland +

Adenoma X

Carcinoma

Urinary System 

Kidney + + + + + + + + + + + + + + + + + + + + + + + + +

Histiocytic sarcoma X

Urinary bladder + A + A + + + + + + + + + + + + A + A + + + + + M

Systemic Lesions 

Multiple organs + + + + + + + + + + + + + + + + + + + + + + + + +

Histiocytic sarcoma X X X X

Lymphoma malignant mixed
Tetrafluoroethylene, NTP TR 450 181

TABLE C2

Individual Animal Tumor Pathology of Male Mice in the 2-Year Inhalation Study of Tetrafluoroethylene: 312 ppm (continued)

5 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

Number of Days on Study 9 0 1 1 1 2 3 3 4 4 4 6 6 6 6 6 6 6 6 6 6 6 6

9 0 4 4 6 5 1 7 6 6 9 0 6 6 6 6 6 6 6 6 6 6 6

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Total

Carcass ID Number 6 3 1 4 3 4 4 4 1 5 2 3 2 2 2 4 4 4 5 6 6 6 6 Tissues/

5 0 8 3 7 2 0 7 7 3 9 3 1 6 8 4 5 6 7 0 1 4 7 Tumors

Special Senses System 

Eye + 1

Harderian gland + + + + + + + 8

Adenoma X X X X X X 7

Carcinoma X 1

Urinary System 

Kidney + + + + + + + + + + + + + + + + + + + + + + + 48

Histiocytic sarcoma X X 3

Urinary bladder + + + + + + + + + + + + + + + + + + + + + + + 43

Systemic Lesions 

Multiple organs + + + + + + + + + + + + + + + + + + + + + + + 48

Histiocytic sarcoma X X X X X X X X 12

Lymphoma malignant mixed X 1
182 Tetrafluoroethylene, NTP TR 450

TABLE C2

Individual Animal Tumor Pathology of Male Mice in the 2-Year Inhalation Study of Tetrafluoroethylene: 625 ppm 

3 3 4 4 4 4 4 4 4 4 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5

Number of Days on Study 6 6 1 2 3 4 4 8 8 9 0 1 1 1 1 3 3 4 4 4 4 4 4 5 5

3 8 5 0 3 6 7 4 5 7 9 6 7 8 8 1 9 1 1 1 7 8 8 1 4

2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

Carcass ID Number 7 8 5 6 5 8 5 6 3 4 7 6 4 8 8 5 3 4 5 8 7 5 7 4 5

8 2 5 2 8 7 9 1 4 1 9 4 4 1 6 6 3 0 0 4 6 1 0 2 2

Alimentary System 

Esophagus + + + + + + + + + + + + + + + + + + + + A + + + +

Gallbladder A + + A A A + + M M A + A A + + M + + + A + + A A

Intestine large, colon A + + + A + + + + + A + + + + + + + + + A + + A A

Intestine large, rectum A + + + + + I + + + A + + + + + + + + + A + + A A

Intestine large, cecum A + + + A + + + + + A + + A + + A + + + A + + A A

Intestine small, duodenum A + + + A A + + + + A A A A + + A + + + A + + A A

Intestine small, jejunum A + + A A + + + + + A A A A + + A + + + A + + A A

Intestine small, ileum A + + + A + + + + + A A A A + + A + + + A + + A A

Liver + + + + + + + + + + + + + + + + + + + + + + + + +

Hemangioma X X

Hemangioma, multiple

Hemangiosarcoma X X

Hemangiosarcoma, multiple X X X X X X

Hepatocellular carcinoma X X X X X X X X X X X X X X X X X

Hepatocellular carcinoma, multiple X X X X

Hepatocellular adenoma X

Hepatocellular adenoma, multiple X X X X

Histiocytic sarcoma X X X

Mesentery +

Histiocytic sarcoma X

Pancreas A + + + + + + + + + + + + + + + + + + + A + + + +

Salivary glands + + + + + + + + + + + + + + + + + + + + + + + + +

Stomach, forestomach A + + + + + + + + + + + + + + + + + + + A + + + +

Stomach, glandular A + + + + + + + + + + + + + + + + + + + A + + + +

Tooth + +

Cardiovascular System 

Heart + + + + + + + + + + + + + + + + + + + + + + + + +

Endocrine System 

Adrenal cortex + + + + + + + + + + + + + + + + + + + + A + + + +

Adenoma

Adrenal medulla + + + + + + + M + + + + + + + + + + + + A + + + +

Islets, pancreatic A + + + + + + + + + + + + + + + + + + + A + + + +

Parathyroid gland + M M + M I + + M M + + M + + I M M + + + M + + M

Pituitary gland A + + + + + + + + + + + + + + + I + + + + + + + +

Thyroid gland + + + + + + + + + + + + + + + + + + + + A + + + +

General Body System 

Tissue NOS + +

Genital System 

Epididymis + + + + + + + + + + + + + + + + + + + + + + + + +

Preputial gland + + + + + + + + + + + + + + + + + + + + + + + + +

Prostate A + + + + + + + + + + M + + + + + + + + A + + + +

Seminal vesicle A + + + + + + + + + + + + + + + + + + + + + + + +

Testes + + + + + + + + + + + + + + + + + + + + + + + + +
Tetrafluoroethylene, NTP TR 450 183

TABLE C2

Individual Animal Tumor Pathology of Male Mice in the 2-Year Inhalation Study of Tetrafluoroethylene: 625 ppm (continued)

5 5 5 5 5 5 5 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

Number of Days on Study 6 7 8 8 8 9 9 0 0 0 0 1 1 1 3 3 3 4 4 5 5 6 6

9 3 6 9 9 3 7 0 7 8 8 5 6 8 1 2 9 6 9 3 7 6 6

2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 Total

Carcass ID Number 4 5 8 3 6 6 4 8 7 6 7 7 6 5 3 8 5 9 7 4 6 4 4 Tissues/

9 3 8 6 5 6 8 0 4 7 1 7 3 4 8 9 7 0 3 3 0 6 7 Tumors

Alimentary System 

Esophagus + + + + + + + + + + + + + + + + + + + + + + + 47

Gallbladder + + + + + + + + + + + M M + A A + + + + + + + 31

Intestine large, colon + + + + + + + + + + + A + + + + + + + + + + + 41

Intestine large, rectum + + + + + + + + + + + + + + + I + + + + + + + 41

Intestine large, cecum + + + + + + + + + + + A A + M A + + + + + + + 36

Intestine small, duodenum + + + + + + + + + + + + A + A A + + + + + + + 34

Intestine small, jejunum + + + + + + + + + + + A A + + A + + + + + + + 34

Intestine small, ileum + + + + + + + + + + + A A + + A + + + + + + + 35

Liver + + + + + + + + + + + + + + + + + + + + + + + 48

Hemangioma X 3

Hemangioma, multiple X X 2

Hemangiosarcoma X X X X X X X X 10

Hemangiosarcoma, multiple X X X X X X X X X X X 17

Hepatocellular carcinoma X X X X X X X 24

Hepatocellular carcinoma, multiple X X X X X 9

Hepatocellular adenoma X X X X 5

Hepatocellular adenoma, multiple X X X 7

Histiocytic sarcoma X X X X 7

Mesentery + 2

Histiocytic sarcoma 1

Pancreas + + + + + + + + + + + + + + + + + + + + + + + 46

Salivary glands + + + + + + + + + + + + + + + + + + + + + + + 48

Stomach, forestomach + + + + + + + + + + + + + + + + + + + + + + + 46

Stomach, glandular + + + + + + + + + + + + + + + + + + + + + + + 46

Tooth + + 4

Cardiovascular System 

Heart + + + + + + + + + + + + + + + + + + + + + + + 48

Endocrine System 

Adrenal cortex + + + + + + + + + + + + + + + + + + + + + + + 47

Adenoma X 1

Adrenal medulla + + + + + + + + + + + + + + + + + + + + + + + 46

Islets, pancreatic + + + + + + + + + + + + + + + + + + + + + + + 46

Parathyroid gland + + + M M + + + M + M + + M + M + + + + + M + 29

Pituitary gland + + + + + + + + + + + + + + + M + + + M + + + 44

Thyroid gland + + + + + + + + + + + + + + + + + + + + + + + 47

General Body System 

Tissue NOS 2

Genital System 

Epididymis + + + + + + + + + + + + + + + + + + + + + + + 48

Preputial gland + + + + + + + + + + + + M + + + + + + + + + M 46

Prostate + + + + + + + + + + + M + + + + + + + + + + + 44

Seminal vesicle + + + + + + + + + + + + + + + + + + + + + + + 47

Testes + + + + + + + + + + + + + + + + + + + + + + + 48
184 Tetrafluoroethylene, NTP TR 450

TABLE C2

Individual Animal Tumor Pathology of Male Mice in the 2-Year Inhalation Study of Tetrafluoroethylene: 625 ppm (continued)

3 3 4 4 4 4 4 4 4 4 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5

Number of Days on Study 6 6 1 2 3 4 4 8 8 9 0 1 1 1 1 3 3 4 4 4 4 4 4 5 5

3 8 5 0 3 6 7 4 5 7 9 6 7 8 8 1 9 1 1 1 7 8 8 1 4

2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

Carcass ID Number 7 8 5 6 5 8 5 6 3 4 7 6 4 8 8 5 3 4 5 8 7 5 7 4 5

8 2 5 2 8 7 9 1 4 1 9 4 4 1 6 6 3 0 0 4 6 1 0 2 2

Hematopoietic System 

Bone marrow + + + + + + + + + + + + + + + + + + + + A + + + +

Hemangioma X

Histiocytic sarcoma X

Lymph node

Renal, histiocytic sarcoma

Lymph node, bronchial A M M + + + M + + + + + + + I + + M M + + M + + +

Lymph node, mandibular M + + + + + + + + + + + + M + M M + M M + M + + +

Histiocytic sarcoma X

Lymph node, mesenteric A + + + + + M + + + A + + + M M + + + + A + + + +

Histiocytic sarcoma

Lymph node, mediastinal A + + + + + M I + + M I M M M + M + + + + M + M +

Spleen A + + + + + + + + + + + + + + + + + + + A + + + +

Histiocytic sarcoma X

Thymus A M + + + M M M M + M + M M + + + + + + + M M M +

Integumentary System 

Mammary gland M M M M M M M M M M M M M M M M M M M M M M M M M

Skin + + + + + + + + + + + + + + + + + + + + + + + + +

Subcutaneous tissue, hemangiosarcoma

Musculoskeletal System 

Bone + + + + + + + + + + + + + + + + + + + + + + + + +

Nervous System 

Brain + + + + + + + + + + + + + + + + + + + + + + + + +

Respiratory System 

Larynx A + + + + + + + + + + + + + + + + + + + A + + + +

Lung + + + + + + + + + + + + + + + + + + + + + + + + +

Alveolar/bronchiolar adenoma X X X X X X

Alveolar/bronchiolar adenoma,

 multiple 

Alveolar/bronchiolar carcinoma X

Hemangiosarcoma, metastatic, liver X

Hepatocellular carcinoma, metastatic,

 liver X X X X X X X X X

Histiocytic sarcoma X X

Nose A + + + + + + + + + + + + + + + + + + + A + + + +

Trachea A + + + + + + + + + + + + + + + + + + + A + + + +

Special Senses System 

Eye + +

Harderian gland + + + +

Adenoma X X X
Tetrafluoroethylene, NTP TR 450 185

TABLE C2

Individual Animal Tumor Pathology of Male Mice in the 2-Year Inhalation Study of Tetrafluoroethylene: 625 ppm (continued)

5 5 5 5 5 5 5 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

Number of Days on Study 6 7 8 8 8 9 9 0 0 0 0 1 1 1 3 3 3 4 4 5 5 6 6

9 3 6 9 9 3 7 0 7 8 8 5 6 8 1 2 9 6 9 3 7 6 6

2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 Total

Carcass ID Number 4 5 8 3 6 6 4 8 7 6 7 7 6 5 3 8 5 9 7 4 6 4 4 Tissues/

9 3 8 6 5 6 8 0 4 7 1 7 3 4 8 9 7 0 3 3 0 6 7 Tumors

Hematopoietic System 

Bone marrow + + + + + + + + + + + + + + + + + + + + + + + 47

Hemangioma 1

Histiocytic sarcoma 1

Lymph node + + 2

Renal, histiocytic sarcoma X 1

Lymph node, bronchial + + + M M + + + + M + + + M + M + + + + + + + 35

Lymph node, mandibular M I I + M + + + M M + + + M + + + I M + + + + 32

Histiocytic sarcoma 1

Lymph node, mesenteric + + + + + + + + + + + + + + M + + + + + + + + 41

Histiocytic sarcoma X 1

Lymph node, mediastinal + M + + + + + + + + + + + + M + + M + + + M M 32

Spleen + + + + + + + + + + + + + + + + + + + + + + + 46

Histiocytic sarcoma 1

Thymus + + + + + + M + + + M + + + + + + + + + + + + 34

Integumentary System 

Mammary gland M M M M M M M M M M M M M M M M M M M M M M M 

Skin + + + + + + + + + + + + + + + + + + + + + + + 48

Subcutaneous tissue, hemangiosarcoma X 1

Musculoskeletal System 

Bone + + + + + + + + + + + + + + + + + + + + + + + 48

Nervous System 

Brain + + + + + + + + + + + + + + + + + + + + + + + 48

Respiratory System 

Larynx + + + + + + + + + + + + + + + + + + + + + + + 46

Lung + + + + + + + + + + + + + + + + + + + + + + + 48

Alveolar/bronchiolar adenoma X X X X X X 12

Alveolar/bronchiolar adenoma, 

 multiple X 1

Alveolar/bronchiolar carcinoma X X 3

Hemangiosarcoma, metastatic, liver X 2

Hepatocellular carcinoma, metastatic, 

 liver X X X X X 14

Histiocytic sarcoma X X 4

Nose + + + + + + + + + + + + + + + + + + + + + + + 46

Trachea + + + + + + + + + + + + + + + + + + + + + + + 46

Special Senses System 

Eye 2

Harderian gland + 5

Adenoma X 4
186 Tetrafluoroethylene, NTP TR 450

TABLE C2

Individual Animal Tumor Pathology of Male Mice in the 2-Year Inhalation Study of Tetrafluoroethylene: 625 ppm (continued)

3 3 4 4 4 4 4 4 4 4 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5

Number of Days on Study 6 6 1 2 3 4 4 8 8 9 0 1 1 1 1 3 3 4 4 4 4 4 4 5 5

3 8 5 0 3 6 7 4 5 7 9 6 7 8 8 1 9 1 1 1 7 8 8 1 4

2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

Carcass ID Number 7 8 5 6 5 8 5 6 3 4 7 6 4 8 8 5 3 4 5 8 7 5 7 4 5

8 2 5 2 8 7 9 1 4 1 9 4 4 1 6 6 3 0 0 4 6 1 0 2 2

Urinary System 

Kidney + + + + + + + + + + + + + + + + + + + + + + + + +

Hemangiosarcoma, metastatic, liver X

Histiocytic sarcoma X

Urinary bladder A + + + + + + + + + + A + + + + + + + + A + + A +

Systemic Lesions 

Multiple organs + + + + + + + + + + + + + + + + + + + + + + + + +

Histiocytic sarcoma X X X
Tetrafluoroethylene, NTP TR 450 187

TABLE C2

Individual Animal Tumor Pathology of Male Mice in the 2-Year Inhalation Study of Tetrafluoroethylene: 625 ppm (continued)

5 5 5 5 5 5 5 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

Number of Days on Study 6 7 8 8 8 9 9 0 0 0 0 1 1 1 3 3 3 4 4 5 5 6 6

9 3 6 9 9 3 7 0 7 8 8 5 6 8 1 2 9 6 9 3 7 6 6

2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 Total

Carcass ID Number 4 5 8 3 6 6 4 8 7 6 7 7 6 5 3 8 5 9 7 4 6 4 4 Tissues/

9 3 8 6 5 6 8 0 4 7 1 7 3 4 8 9 7 0 3 3 0 6 7 Tumors

Urinary System 

Kidney + + + + + + + + + + + + + + + + + + + + + + + 48

Hemangiosarcoma, metastatic, liver 1

Histiocytic sarcoma X X 3

Urinary bladder + + + + + + + + + + + + + + + A + + + + + + + 43

Systemic Lesions 

Multiple organs + + + + + + + + + + + + + + + + + + + + + + + 48

Histiocytic sarcoma X X X X 7
188 Tetrafluoroethylene, NTP TR 450

TABLE C2

Individual Animal Tumor Pathology of Male Mice in the 2-Year Inhalation Study of Tetrafluoroethylene: 1,250 ppm 

0 2 3 3 4 4 4 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5

Number of Days on Study 0 5 1 5 0 6 8 1 2 2 3 4 4 4 4 4 4 4 5 5 6 6 7 7 7

5 9 5 6 1 5 3 8 7 7 6 1 1 1 3 4 8 8 1 9 3 5 4 5 8

4 3 3 3 3 3 3 3 3 3 4 3 3 4 3 3 3 3 3 3 3 4 3 3 3

Carcass ID Number 0 7 9 5 9 9 5 7 8 9 0 6 8 0 5 7 7 8 7 7 7 0 9 9 9

3 1 1 2 0 3 4 3 7 5 2 0 3 1 5 9 0 4 6 7 2 4 8 7 4

Alimentary System 

Esophagus + + + + + + + + + + + + + + + + + + + + M + + + +

Gallbladder A + M A M M + M + + + + + + + A A M M M A M + + +

Intestine large, colon + + A A + A + + + + + + + + + M A + + A A A + + +

Intestine large, rectum + + A A + A + + + + + + + + + A A + + A A A + + +

Intestine large, cecum + + A A + A + + + + + + + + + A A + + A A A + + +

Intestine small, duodenum A + A A + A + + + + + + + + + A A + A A A A + + +

Intestine small, jejunum A + A A + A + + + + + + + + + A A + A A A A + + +

Intestine small, ileum A + A A + A + + + + + + + + + A A + A A A A + + +

Liver + + + + + + + + + + + + + + + + + + + + + + + + +

Carcinoma, metastatic, harderian

 gland X 

Hemangioma

Hemangioma, multiple

Hemangiosarcoma X X X X X X X X X X X X X

Hemangiosarcoma, multiple X X X

Hepatocellular carcinoma X X X X X X X X X

Hepatocellular carcinoma, multiple X X X X

Hepatocellular adenoma X X X X X

Hepatocellular adenoma, multiple X X X X

Histiocytic sarcoma X X X

Mesentery + +

Hemangioma

Hemangiosarcoma X

Hepatocellular carcinoma, metastatic,

 liver X

Pancreas + + + A + M + + + + + + + + + + + + + + A + + + +

Hepatocellular carcinoma, metastatic,

 liver

Salivary glands + + + + + + + + + + + + + + + + + + + + + + + + +

Stomach, forestomach + + + A + + + + + + + + + + + + + + + + A + + + +

Squamous cell carcinoma

Squamous cell papilloma

Stomach, glandular + + A A + + + + + + + + + + + + + + + + A + + + +

Tooth + + + +

Cardiovascular System 

Heart + + + + + + + + + + + + + + + + + + + + + + + + +

Carcinoma, metastatic, lung

Endocrine System 

Adrenal cortex + + + + + + + + + + + + + + + + + + + + + + + + +

Adrenal medulla + + + + + + + + + + + + + + + + + + + + + + + + +

Islets, pancreatic + + + A + A + + + + + + + + + + + + + + A + + + +

Adenoma X

Parathyroid gland + M + + + M + M M M + + + + + + + + + + + + + + +

Pituitary gland + + + + + + + + + + + + + + + + + + + + M + M + +

Thyroid gland + + + + + + + + + + + + + + + + + + + + + + + + +

General Body System 

None
Tetrafluoroethylene, NTP TR 450 189

TABLE C2

Individual Animal Tumor Pathology of Male Mice in the 2-Year Inhalation Study of Tetrafluoroethylene: 1,250 ppm

(continued)

5 5 5 5 5 5 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

Number of Days on Study 8 8 8 8 8 9 0 0 0 0 0 0 1 1 1 2 2 3 3 4 4 5 6

3 5 6 6 9 9 0 0 6 8 8 8 0 3 3 3 9 0 1 3 6 4 6

3 3 3 3 3 3 3 3 4 3 3 3 3 3 3 3 3 3 4 3 3 4 3 Total

Carcass ID Number 5 8 8 9 6 6 6 7 0 5 6 8 8 6 7 7 6 8 0 4 9 0 6 Tissues/

9 9 0 9 5 7 3 5 5 7 4 1 6 6 4 8 9 2 6 9 2 0 1 Tumors

Alimentary System 

Esophagus + + + + + + + + + + + + + + + + + + + + + + + 47

Gallbladder + + + + + A + A + M + + + M M + M + + A + A + 27

Intestine large, colon + + + + + + + A + + + + + + + + + + + + + + + 39

Intestine large, rectum + + + + + + + + + + + + + + + + + + + + + + + 40

Intestine large, cecum + + + + + + + A + + + + + + + + + + + + + + + 39

Intestine small, duodenum + + + + + + + A + + + A + + + + + + + + + + + 36

Intestine small, jejunum + + + + + + + A + + + A + A + + + + + + + A + 34

Intestine small, ileum + + + + + + + A + + + A + + + + + + + + + + + 36

Liver + + + + + + + + + + + + + + + + + + + + + + + 48

Carcinoma, metastatic, harderian 

 gland 1

Hemangioma X 1

Hemangioma, multiple X 1

Hemangiosarcoma X X X X X X 19

Hemangiosarcoma, multiple X X X X X X X X X X X X X X X 18

Hepatocellular carcinoma X X X X X X X X X X X 20

Hepatocellular carcinoma, multiple X X 6

Hepatocellular adenoma X X X X X X X X 13

Hepatocellular adenoma, multiple X X X 7

Histiocytic sarcoma X X X X 7

Mesentery + + + + + 7

Hemangioma X 1

Hemangiosarcoma 1

Hepatocellular carcinoma, metastatic, 

 liver 1

Pancreas + + + + + + + + + + + + + + + + + + + + + + + 45

Hepatocellular carcinoma, metastatic, 

 liver X 1

Salivary glands + + + + + + + + + + + + + + + + + + + + + + + 48

Stomach, forestomach + + + + + + + + + + + + + + + + + + + + + + + 46

Squamous cell carcinoma X 1

Squamous cell papilloma X 1

Stomach, glandular + + + + + + + + + + + + + + + + + + + + + + + 45

Tooth + + + 7

Cardiovascular System 

Heart + + + + + + + + + + + + + + + + + + + + + + + 48

Carcinoma, metastatic, lung X 1

Endocrine System 

Adrenal cortex + + + + + + + + + + + + + + + + + + + + + + + 48

Adrenal medulla + + + + + + + + + + + + + + + + + + + + + + + 48

Islets, pancreatic + + + + + + + + + + + + + + + + + + + + + + + 45

Adenoma 1

Parathyroid gland + + M + + + + + + I + + + + + + + + + + M M + 39

Pituitary gland + + + + + M M + + + + + + + + + + + + + + + + 44

Thyroid gland + + M + + + + + + + + + + + + + + + + + + + + 47

General Body System 

None 
190 Tetrafluoroethylene, NTP TR 450

TABLE C2

Individual Animal Tumor Pathology of Male Mice in the 2-Year Inhalation Study of Tetrafluoroethylene: 1,250 ppm

(continued)

0 2 3 3 4 4 4 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5

Number of Days on Study 0 5 1 5 0 6 8 1 2 2 3 4 4 4 4 4 4 4 5 5 6 6 7 7 7

5 9 5 6 1 5 3 8 7 7 6 1 1 1 3 4 8 8 1 9 3 5 4 5 8

4 3 3 3 3 3 3 3 3 3 4 3 3 4 3 3 3 3 3 3 3 4 3 3 3

Carcass ID Number 0 7 9 5 9 9 5 7 8 9 0 6 8 0 5 7 7 8 7 7 7 0 9 9 9

3 1 1 2 0 3 4 3 7 5 2 0 3 1 5 9 0 4 6 7 2 4 8 7 4

Genital System 

Epididymis + + + + + + + + + + + + + + + + + + + + + + + + +

Leiomyoma X

Preputial gland + + + + + + + + + + + + + + + + + + + + + + + + +

Prostate + + A A + A + + + + + + + + + + + + + + A + + + +

Seminal vesicle + + A A + A + + + + + + + + + + + + + + A + + + +

Testes + + + + + + + + + + + + + + + + + + + + + + + + +

Hematopoietic System 

Bone marrow + + + + + A + + + + + + + + + + + + + + + + + + +

Histiocytic sarcoma X X

Lymph node, bronchial M M + M M A M + M + + M + M M M + M M + I + + + +

Histiocytic sarcoma

Lymph node, mandibular + M + + + M + + M + + + + + + + M + + + M + + + +

Lymph node, mesenteric + + + A + A + + + + + + + + + + M + M M A + + + M

Histiocytic sarcoma

Lymph node, mediastinal M + + + + M + + M + I + + M + M M M M + M + + + +

Carcinoma, metastatic, lung

Histiocytic sarcoma

Spleen + + + A + + + + + + + + + + + + + + + + A + + + +

Histiocytic sarcoma X X

Thymus + + + M + A M + + + + + M + + M + + M M + + + + +

Histiocytic sarcoma X

Integumentary System 

Mammary gland M M M M M M M M M M M M M M M M M M M M M M M M M

Skin + + + + + + + + + + + + + + + + + + + + + + + + +

Subcutaneous tissue, hemangiosarcoma

Musculoskeletal System 

Bone + + + + + + + + + + + + + + + + + + + + + + + + +

Carcinoma, metastatic, harderian

 gland X 

Skeletal muscle

Carcinoma, metastatic, lung

Nervous System 

Brain + + + + + + + + + + + + + + + + + + + + + + + + +

Carcinoma, metastatic, harderian

 gland X 
Tetrafluoroethylene, NTP TR 450 191

TABLE C2

Individual Animal Tumor Pathology of Male Mice in the 2-Year Inhalation Study of Tetrafluoroethylene: 1,250 ppm

(continued)

5 5 5 5 5 5 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

Number of Days on Study 8 8 8 8 8 9 0 0 0 0 0 0 1 1 1 2 2 3 3 4 4 5 6

3 5 6 6 9 9 0 0 6 8 8 8 0 3 3 3 9 0 1 3 6 4 6

3 3 3 3 3 3 3 3 4 3 3 3 3 3 3 3 3 3 4 3 3 4 3 Total

Carcass ID Number 5 8 8 9 6 6 6 7 0 5 6 8 8 6 7 7 6 8 0 4 9 0 6 Tissues/

9 9 0 9 5 7 3 5 5 7 4 1 6 6 4 8 9 2 6 9 2 0 1 Tumors

Genital System 

Epididymis + + + + + + + + + + + + + + + + + + + + + + + 48

Leiomyoma 1

Preputial gland + + + + + + + + + + + + + + + + + + + + + + + 48

Prostate + + + + + + + + + + + + + + + + + + + + + + + 44

Seminal vesicle + + + + + + + + + + + + + + + + + + + + + + + 44

Testes + + + + + + + + + + + + + + + + + + + + + + + 48

Hematopoietic System 

Bone marrow + + + + + + + + + + + + + + + + + + + + + + + 47

Histiocytic sarcoma 2

Lymph node, bronchial M I + M + + + M + M M + + + + I + + M + + + + 26

Histiocytic sarcoma X 1

Lymph node, mandibular M M M + M + + + + + M M + + + M + + + M + M + 34

Lymph node, mesenteric + + + + + + + + + + + + + + + + + + + + M + + 40

Histiocytic sarcoma X X 2

Lymph node, mediastinal + + + + + + M M + + M M + M + + I M M + + M + 29

Carcinoma, metastatic, lung X 1

Histiocytic sarcoma X 1

Spleen + + + + + + + + + + + + + + + + + + + + + + + 46

Histiocytic sarcoma 2

Thymus + M M M + + + + + + + M + + + + + + + + + + + 37

Histiocytic sarcoma 1

Integumentary System 

Mammary gland M M M M M M M M M M M M M M M M M M M M M M M 

Skin + + + + + + + + + + + + + + + + + + + + + + + 48

Subcutaneous tissue, hemangiosarcoma X 1

Musculoskeletal System 

Bone + + + + + + + + + + + + + + + + + + + + + + + 48

Carcinoma, metastatic, harderian 

 gland 1

Skeletal muscle + 1

Carcinoma, metastatic, lung X 1

Nervous System 

Brain + + + + + + + + + + + + + + + + + + + + + + + 48

Carcinoma, metastatic, harderian 

 gland 1
192 Tetrafluoroethylene, NTP TR 450

TABLE C2

Individual Animal Tumor Pathology of Male Mice in the 2-Year Inhalation Study of Tetrafluoroethylene: 1,250 ppm

(continued)

0 2 3 3 4 4 4 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5

Number of Days on Study 0 5 1 5 0 6 8 1 2 2 3 4 4 4 4 4 4 4 5 5 6 6 7 7 7

5 9 5 6 1 5 3 8 7 7 6 1 1 1 3 4 8 8 1 9 3 5 4 5 8

4 3 3 3 3 3 3 3 3 3 4 3 3 4 3 3 3 3 3 3 3 4 3 3 3

Carcass ID Number 0 7 9 5 9 9 5 7 8 9 0 6 8 0 5 7 7 8 7 7 7 0 9 9 9

3 1 1 2 0 3 4 3 7 5 2 0 3 1 5 9 0 4 6 7 2 4 8 7 4

Respiratory System 

Larynx + + + A + A + + + + + + + + + + + + + + + + + + +

Lung + + + + + + + + + + + + + + + + + + + + + + + + +

Alveolar/bronchiolar adenoma X

Alveolar/bronchiolar adenoma,

 multiple X 

Alveolar/bronchiolar carcinoma

Carcinoma

Carcinoma, metastatic, harderian

 gland X 

Hemangiosarcoma, metastatic, liver X

Hepatocellular carcinoma, metastatic,

 liver X X X X X

Histiocytic sarcoma X

Nose + + + + + A + + + + + + + + + + + + + + + + + + +

Trachea + + A A + + + + + + + + + + + + + + + + + + + + +

Special Senses System 

Ear

Harderian gland + + +

Adenoma X X

Carcinoma X

Urinary System 

Kidney + + + + + + + + + + + + + + + + + + + + + + + + +

Carcinoma, metastatic, lung

Histiocytic sarcoma X X

Urinary bladder + + A A + A + + + + + + + + + + A + + A A + + + +

Systemic Lesions 

Multiple organs + + + + + + + + + + + + + + + + + + + + + + + + +

Histiocytic sarcoma X X X

Lymphoma malignant mixed
Tetrafluoroethylene, NTP TR 450 193

TABLE C2

Individual Animal Tumor Pathology of Male Mice in the 2-Year Inhalation Study of Tetrafluoroethylene: 1,250 ppm

(continued)

5 5 5 5 5 5 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

Number of Days on Study 8 8 8 8 8 9 0 0 0 0 0 0 1 1 1 2 2 3 3 4 4 5 6

3 5 6 6 9 9 0 0 6 8 8 8 0 3 3 3 9 0 1 3 6 4 6

3 3 3 3 3 3 3 3 4 3 3 3 3 3 3 3 3 3 4 3 3 4 3 Total

Carcass ID Number 5 8 8 9 6 6 6 7 0 5 6 8 8 6 7 7 6 8 0 4 9 0 6 Tissues/

9 9 0 9 5 7 3 5 5 7 4 1 6 6 4 8 9 2 6 9 2 0 1 Tumors

Respiratory System 

Larynx + + + + + + + + + + + + + + + + + + + + + + + 46

Lung + + + + + + + + + + + + + + + + + + + + + + + 48

Alveolar/bronchiolar adenoma X X 3

Alveolar/bronchiolar adenoma, 

 multiple X 2

Alveolar/bronchiolar carcinoma X 1

Carcinoma X 1

Carcinoma, metastatic, harderian 

 gland 1

Hemangiosarcoma, metastatic, liver X 2

Hepatocellular carcinoma, metastatic, 

 liver X X X 8

Histiocytic sarcoma X X 3

Nose + + + + + + + + + + + + + + + + + + + + + + + 47

Trachea + + + + + + + + + + + + + + + + + + + + + + + 46

Special Senses System 

Ear + 1

Harderian gland + + + 6

Adenoma X X 4

Carcinoma 1

Urinary System 

Kidney + + + + + + + + + + + + + + + + + + + + + + + 48

Carcinoma, metastatic, lung X 1

Histiocytic sarcoma 2

Urinary bladder + + + + + + + + + + + + + + + + + + + + + + + 42

Systemic Lesions 

Multiple organs + + + + + + + + + + + + + + + + + + + + + + + 48

Histiocytic sarcoma X X X X 7

Lymphoma malignant mixed X 1
194 Tetrafluoroethylene, NTP TR 450

TABLE C3

Statistical Analysis of Primary Neoplasms in Male Mice in the 2-Year Inhalation Study of Tetrafluoroethylene

0 ppm 312 ppm 625 ppm 1,250 ppm

Harderian Gland: Adenoma

Overall rate 5/48 (10%) 7/48 (15%) 4/48 (8%) 4/48 (8%) a

Adjusted rate 12.6% 35.3% 13.8% 24.7% b

Terminal rate 4/38 (11%) 2/11 (18%) 0/2 (0%) 0/1 (0%) c

First incidence (days) 597 463 447 465

Life table test P=0.047 P=0.022 P=0.100 P=0.052 d

Logistic regression test P=0.381N P=0.239 P=0.481N P=0.545N d

Cochran-Armitage test P=0.316N d

Fisher exact test P=0.379 P=0.500N P=0.500N d

Harderian Gland: Adenoma or Carcinoma

Overall rate 6/48 (13%) 8/48 (17%) 4/48 (8%) 5/48 (10%)

Adjusted rate 14.6% 42.5% 13.8% 26.6%

Terminal rate 4/38 (11%) 3/11 (27%) 0/2 (0%) 0/1 (0%)

First incidence (days) 597 463 447 465

Life table test P=0.033 P=0.016 P=0.166 P=0.058 

Logistic regression test P=0.389N P=0.230 P=0.319N P=0.487N

Cochran-Armitage test P=0.312N

Fisher exact test P=0.387 P=0.370N P=0.500N

Liver: Hemangioma

Overall rate 0/48 (0%) 10/48 (21%) 5/48 (10%) 2/48 (4%)

Adjusted rate 0.0% 53.2% 60.1% 12.3%

Terminal rate 0/38 (0%) 4/11 (36%) 1/2 (50%) 0/1 (0%)

First incidence (days) — 590 548 599 e

Life table test P=0.012 P<0.001 P<0.001 P=0.066 

Logistic regression test P=0.289N P<0.001 P=0.015 P=0.188 

Cochran-Armitage test P=0.448N

Fisher exact test P<0.001 P=0.028 P=0.247 

Liver: Hemangiosarcoma

Overall rate 0/48 (0%) 21/48 (44%) 27/48 (56%) 37/48 (77%)

Adjusted rate 0.0% 89.3% 95.6% 100.0%

Terminal rate 0/38 (0%) 9/11 (82%) 1/2 (50%) 1/1 (100%)

First incidence (days) — 522 497 401

Life table test P<0.001 P<0.001 P<0.001 P<0.001

Logistic regression test P<0.001 P<0.001 P<0.001 P<0.001

Cochran-Armitage test P<0.001

Fisher exact test P<0.001 P<0.001 P<0.001

Liver: Hemangioma or Hemangiosarcoma

Overall rate 0/48 (0%) 26/48 (54%) 30/48 (63%) 38/48 (79%)

Adjusted rate 0.0% 95.7% 100.0% 100.0%

Terminal rate 0/38 (0%) 10/11 (91%) 2/2 (100%) 1/1 (100%)

First incidence (days) — 522 497 401

Life table test P<0.001 P<0.001 P<0.001 P<0.001

Logistic regression test P<0.001 P<0.001 P<0.001 P<0.001

Cochran-Armitage test P<0.001

Fisher exact test P<0.001 P<0.001 P<0.001
Tetrafluoroethylene, NTP TR 450 195

TABLE C3

Statistical Analysis of Primary Neoplasms in Male Mice in the 2-Year Inhalation Study of Tetrafluoroethylene (continued)

0 ppm 312 ppm 625 ppm 1,250 ppm

Liver: Hepatocellular Adenoma

Overall rate 17/48 (35%) 17/48 (35%) 12/48 (25%) 20/48 (42%)

Adjusted rate 42.1% 83.5% 70.3% 71.3%

Terminal rate 15/38 (39%) 8/11 (73%) 1/2 (50%) 0/1 (0%)

First incidence (days) 452 566 485 401

Life table test P<0.001 P<0.001 P<0.001 P<0.001

Logistic regression test P=0.043 P=0.059 P=0.444N P=0.181 

Cochran-Armitage test P=0.322 

Fisher exact test P=0.584N P=0.187N P=0.338 

Liver: Hepatocellular Carcinoma

Overall rate 11/48 (23%) 20/48 (42%) 33/48 (69%) 26/48 (54%)

Adjusted rate 24.4% 63.4% 94.3% 100.0%

Terminal rate 5/38 (13%) 3/11 (27%) 1/2 (50%) 1/1 (100%)

First incidence (days) 475 462 363 315

Life table test P<0.001 P<0.001 P<0.001 P<0.001

Logistic regression test P=0.150 P=0.056 P=0.055 P=0.245 

Cochran-Armitage test P=0.001

Fisher exact test P=0.040 P<0.001 P=0.002

Liver: Hepatocellular Adenoma or Carcinoma 

Overall rate 26/48 (54%) 34/48 (71%) 39/48 (81%) 35/48 (73%)

Adjusted rate 57.4% 96.8% 100.0% 100.0%

Terminal rate 19/38 (50%) 10/11 (91%) 2/2 (100%) 1/1 (100%)

First incidence (days) 452 462 363 315

Life table test P<0.001 P<0.001 P<0.001 P<0.001

Logistic regression test P=0.236 P=0.015 P=0.289 P=0.550N

Cochran-Armitage test P=0.040

Fisher exact test P=0.070 P=0.004 P=0.045

Lung: Alveolar/bronchiolar Adenoma

Overall rate 10/48 (21%) 8/48 (17%) 13/48 (27%) 5/48 (10%)

Adjusted rate 24.7% 41.7% 76.8% 23.1%

Terminal rate 8/38 (21%) 3/11 (27%) 1/2 (50%) 0/1 (0%)

First incidence (days) 475 522 433 548

Life table test P=0.007 P=0.079 P<0.001 P=0.042

Logistic regression test P=0.297N P=0.597 P=0.324 P=0.344N

Cochran-Armitage test P=0.159N

Fisher exact test P=0.397N P=0.317 P=0.130N

Lung: Alveolar/bronchiolar Carcinoma

Overall rate 2/48 (4%) 5/48 (10%) 3/48 (6%) 2/48 (4%)

Adjusted rate 5.3% 28.4% 51.9% 20.0%

Terminal rate 2/38 (5%) 2/11 (18%) 0/2 (0%) 0/1 (0%)

First incidence (days) 666 (T) 537 548 606

Life table test P=0.014 P=0.015 P=0.004 P=0.043

Logistic regression test P=0.355 P=0.103 P=0.150 P=0.330 

Cochran-Armitage test P=0.420N

Fisher exact test P=0.218 P=0.500 P=0.692N
196 Tetrafluoroethylene, NTP TR 450

TABLE C3

Statistical Analysis of Primary Neoplasms in Male Mice in the 2-Year Inhalation Study of Tetrafluoroethylene (continued)

0 ppm 312 ppm 625 ppm 1,250 ppm

Lung: Alveolar/bronchiolar Adenoma or Carcinoma

Overall rate 12/48 (25%) 13/48 (27%) 16/48 (33%) 7/48 (15%)

Adjusted rate 29.7% 61.8% 88.8% 38.5%

Terminal rate 10/38 (26%) 5/11 (45%) 1/2 (50%) 0/1 (0%)

First incidence (days) 475 522 433 548

Life table test P<0.001 P=0.003 P<0.001 P=0.004

Logistic regression test P=0.383N P=0.218 P=0.136 P=0.537N

Cochran-Armitage test P=0.130N

Fisher exact test P=0.500 P=0.250 P=0.153N

Thyroid Gland (Follicular Cell): Adenoma

Overall rate 0/48 (0%) 3/48 (6%) 0/47 (0%) 0/47 (0%)

Adjusted rate 0.0% 23.3% 0.0% 0.0%

Terminal rate 0/38 (0%) 2/11 (18%) 0/2 (0%) 0/1 (0%)

First incidence (days) — 637 — —

Life table test P=0.345 P=0.008 — —

Logistic regression test P=0.590 P=0.020 — —

Cochran-Armitage test P=0.316N

Fisher exact test P=0.121 — —

Thyroid Gland (Follicular Cell): Adenoma or Carcinoma

Overall rate 0/48 (0%) 4/48 (8%) 0/47 (0%) 0/47 (0%)

Adjusted rate 0.0% 31.8% 0.0% 0.0%

Terminal rate 0/38 (0%) 3/11 (27%) 0/2 (0%) 0/1 (0%)

First incidence (days) — 637 — —

Life table test P=0.228 P=0.001 — —

Logistic regression test P=0.478 P=0.004 — —

Cochran-Armitage test P=0.252N

Fisher exact test P=0.059 — —

All Organs: Hemangioma

Overall rate 0/48 (0%) 11/48 (23%) 6/48 (13%) 3/48 (6%)

Adjusted rate 0.0% 54.7% 61.3% 26.9%

Terminal rate 0/38 (0%) 4/11 (36%) 1/2 (50%) 0/1 (0%)

First incidence (days) — 566 541 599

Life table test P=0.005 P<0.001 P<0.001 P=0.005

Logistic regression test P=0.311N P<0.001 P=0.011 P=0.057 

Cochran-Armitage test P=0.563N

Fisher exact test P<0.001 P=0.013 P=0.121 

All Organs: Hemangiosarcoma

Overall rate 2/48 (4%) 21/48 (44%) 27/48 (56%) 37/48 (77%)

Adjusted rate 5.3% 89.3% 95.6% 100.0%

Terminal rate 2/38 (5%) 9/11 (82%) 1/2 (50%) 1/1 (100%)

First incidence (days) 666 (T) 522 497 401

Life table test P<0.001 P<0.001 P<0.001 P<0.001

Logistic regression test P<0.001 P<0.001 P<0.001 P<0.001

Cochran-Armitage test P<0.001

Fisher exact test P<0.001 P<0.001 P<0.001
Tetrafluoroethylene, NTP TR 450 197

TABLE C3

Statistical Analysis of Primary Neoplasms in Male Mice in the 2-Year Inhalation Study of Tetrafluoroethylene (continued)

0 ppm 312 ppm 625 ppm 1,250 ppm

All Organs: Hemangioma or Hemangiosarcoma

Overall rate 2/48 (4%) 27/48 (56%) 30/48 (63%) 38/48 (79%)

Adjusted rate 5.3% 95.8% 100.0% 100.0%

Terminal rate 2/38 (5%) 10/11 (91%) 2/2 (100%) 1/1 (100%)

First incidence (days) 666 (T) 522 497 401

Life table test P<0.001 P<0.001 P<0.001 P<0.001

Logistic regression test P<0.001 P<0.001 P<0.001 P<0.001

Cochran-Armitage test P<0.001

Fisher exact test P<0.001 P<0.001 P<0.001

All Organs: Histiocytic Sarcoma

Overall rate 0/48 (0%) 12/48 (25%) 7/48 (15%) 7/48 (15%)

Adjusted rate 0.0% 47.8% 35.1% 65.8%

Terminal rate 0/38 (0%) 1/11 (9%) 0/2 (0%) 0/1 (0%)

First incidence (days) — 513 415 527

Life table test P<0.001 P<0.001 P<0.001 P<0.001

Logistic regression test P=0.100 P<0.001 P=0.039 P=0.004

Cochran-Armitage test P=0.143 

Fisher exact test P<0.001 P=0.006 P=0.006

All Organs: Benign Neoplasms

Overall rate 26/48 (54%) 30/48 (63%) 27/48 (56%) 27/48 (56%)

Adjusted rate 61.6% 100.0% 100.0% 100.0%

Terminal rate 22/38 (58%) 11/11 (100%) 2/2 (100%) 1/1 (100%)

First incidence (days) 452 463 433 401

Life table test P<0.001 P<0.001 P<0.001 P<0.001

Logistic regression test P=0.135 P=0.015 P=0.329 P=0.179 

Cochran-Armitage test P=0.520N

Fisher exact test P=0.267 P=0.500 P=0.500 

All Organs: Malignant Neoplasms

Overall rate 16/48 (33%) 39/48 (81%) 47/48 (98%) 46/48 (96%)

Adjusted rate 34.6% 94.9% 100.0% 100.0%

Terminal rate 8/38 (21%) 9/11 (82%) 2/2 (100%) 1/1 (100%)

First incidence (days) 475 462 363 315

Life table test P<0.001 P<0.001 P<0.001 P<0.001

Logistic regression test P<0.001 P<0.001 P<0.001 P<0.001

Cochran-Armitage test P<0.001

Fisher exact test P<0.001 P<0.001 P<0.001
198 Tetrafluoroethylene, NTP TR 450

TABLE C3

Statistical Analysis of Primary Neoplasms in Male Mice in the 2-Year Inhalation Study of Tetrafluoroethylene (continued)

0 ppm 312 ppm 625 ppm 1,250 ppm

All Organs: Benign or Malignant Neoplasms

Overall rate 37/48 (77%) 44/48 (92%) 48/48 (100%) 46/48 (96%)

Adjusted rate 78.6% 100.0% 100.0% 100.0%

Terminal rate 28/38 (74%) 11/11 (100%) 2/2 (100%) 1/1 (100%)

First incidence (days) 452 462 363 315

Life table test P<0.001 P<0.001 P<0.001 P<0.001

Logistic regression test P=0.012 P=0.002 P=0.171 P=0.001

Cochran-Armitage test P=0.002

Fisher exact test P=0.045 P<0.001 P=0.007

(T)Terminal sacrifice

Number of neoplasm-bearing animals/number of animals examined. Denominator is number of animals examined microscopically for liver, lung, and thyroid gland; a

for other tissues, denominator is number of animals necropsied.

Kaplan-Meier estimated neoplasm incidence at the end of the study after adjustment for intercurrent mortality b

Observed incidence at terminal kill c

Beneath the control incidence are the P values associated with the trend test. Beneath the exposed group incidence are the P values corresponding to pairwise d

comparisons between the controls and that exposed group. The life table test regards neoplasms in animals dying prior to terminal kill as being (directly or indirectly)

the cause of death. The logistic regression test regards these lesions as nonfatal. The Cochran-Armitage and Fisher exact tests compare directly the overall incidence

rates. For all tests, a negative trend or a lower incidence in an exposure group is indicated by N.

Not applicable; no neoplasms in animal group e
Tetrafluoroethylene, NTP TR 450 199

TABLE C4a

Historical Incidence of Liver Neoplasms in Chamber Control Male B6C3F 1 Micea

Incidence in Controls

Study Hemangioma Hemangiosarcoma Hepatocellular Hepatocellular Hepatocellular

Adenoma Carcinoma Adenoma

or Carcinoma

Historical Incidence at Battelle Pacific Northwest Laboratories

1,3-Butadiene 0/50 0/50 13/50 11/50 21/50

Acetonitrile 0/50 1/50 13/50 7/50 19/50

Allyl Glycidyl Ether 0/49 0/49 15/49 10/49 23/49

-Chloroacetophenone 0/50 0/50 5/50 11/50 16/50

Epinephrine Hydrochloride 0/50 1/50 10/50 12/50 20/50

Ethyl Chloride 0/50 0/50 6/50 9/50 15/50

Hexachlorocyclopentadiene 0/50 0/50 19/50 7/50 24/50

o-Chlorobenzalmalononitrile (CS-2) 1/49 0/49 4/49 14/49 18/49

Ozone 0/50 0/50 23/50 12/50 30/50

Total 1/448 (0.2%) 2/448 (0.5%) 108/448 (24.1%) 93/448 (20.8%) 186/448 (41.5%)

Standard deviation 0.7% 0.9% 13.0% 4.9% 9.2%

Range 0%-2% 0%-2% 8%-46% 14%-29% 30%-60%

Overall Historical Incidence

Total 2/947 (0.2%) 12/947 (1.3%) 200/947 (21.1%) 184/947 (19.4%) 358/947 (37.8%)

Standard deviation 0.7% 1.7% 11.6% 5.8% 12.5%

Range 0%-2% 0%-6% 4%-46% 9%-29% 11%-60%

Data as of 12 May 1995 a
200 Tetrafluoroethylene, NTP TR 450

TABLE C4b

Historical Incidence of Histiocytic Sarcoma in Chamber Control Male B6C3F 1 Micea

Study Incidence in Controls

Historical Incidence at Battelle Pacific Northwest Laboratories

1,3-Butadiene 0/50

Acetonitrile 0/50

Allyl Glycidyl Ether 0/50

-Chloroacetophenone 0/50

Epinephrine Hydrochloride 1/50

Ethyl Chloride 0/50

Hexachlorocyclopentadiene 0/50

o-Chlorobenzalmalononitrile (CS-2) 1/50

Ozone 0/50

Total 2/450 (0.4%)

Standard deviation 0.9%

Range 0%-2%

Overall Historical Incidence

Total 6/950 (0.6%)

Standard deviation 1.2%

Range 0%-4%

Data as of 12 May 1995 a
Tetrafluoroethylene, NTP TR 450 201

TABLE C5

Summary of the Incidence of Nonneoplastic Lesions in Male Mice in the 2-Year Inhalation Study 

of Tetrafluoroethylene a

0 ppm 312 ppm 625 ppm 1,250 ppm

Disposition Summary

Animals initially in study 58 58 58 58

15-Month interim evaluation 10 10 10 10

Early deaths

Moribund 6 24 26 27

Natural deaths 4 13 20 20

Survivors

Terminal sacrifice 38 11 2 1

Animals examined microscopically 58 58 58 58

15-Month Interim Evaluation

Alimentary System

Intestine large, colon (10) (9) (10) (10)

Diverticulum 1 (10%) 

Inflammation, chronic 1 (10%) 

Liver (10) (10) (10) (10)

Angiectasis 1 (10%) 5 (50%) 2 (20%) 

Basophilic focus 1 (10%) 1 (10%) 

Clear cell focus 2 (20%) 1 (10%) 

Eosinophilic focus 3 (30%) 

Fatty change 4 (40%) 1 (10%) 1 (10%) 1 (10%) 

Granuloma 1 (10%) 

Hematopoietic cell proliferation 1 (10%) 

Infarct 1 (10%) 

Infiltration cellular, mixed cell 1 (10%) 2 (20%) 

Mixed cell focus 1 (10%) 1 (10%) 3 (30%) 3 (30%) 

Necrosis, coagulative, multifocal 1 (10%) 1 (10%) 1 (10%) 

Salivary glands (10) (10) (10) (10)

Infiltration cellular, mononuclear cell 4 (40%) 2 (20%) 1 (10%) 3 (30%) 

Stomach, forestomach (10) (10) (10) (10)

Epithelium, hyperplasia 1 (10%) 

Tooth (1)

Inflammation, suppurative 1 (100%)

Endocrine System

Adrenal cortex (10) (10) (10) (10)

Capsule, hyperplasia 6 (60%) 4 (40%) 7 (70%) 2 (20%) 

Islets, pancreatic (10) (10) (10) (10)

Hyperplasia 1 (10%) 1 (10%) 

Thyroid gland (10) (10) (10) (10)

Ultimobranchial cyst 1 (10%) 

Genital System

Preputial gland (10) (10) (10) (10)

Ectasia 4 (40%) 1 (10%) 1 (10%) 

Infiltration cellular, mononuclear cell 1 (10%) 2 (20%) 1 (10%) 

Inflammation, suppurative 3 (30%) 

Number of animals examined microscopically at the site and the number of animals with lesion a
202 Tetrafluoroethylene, NTP TR 450

TABLE C5

Summary of the Incidence of Nonneoplastic Lesions in Male Mice in the 2-Year Inhalation Study 

of Tetrafluoroethylene (continued)

0 ppm 312 ppm 625 ppm 1,250 ppm

15-Month Interim Evaluation (continued)

Hematopoietic System

Bone marrow (10) (10) (10) (10)

Hyperplasia, neutrophil 1 (10%) 2 (20%) 1 (10%) 

Lymph node, mandibular (8) (3) (6) (8)

Hyperplasia, plasma cell 1 (13%) 

Spleen (10) (10) (10) (10)

Hematopoietic cell proliferation 2 (20%) 4 (40%) 5 (50%) 3 (30%) 

Infiltration cellular, polymorphonuclear 1 (10%) 

Integumentary System

Skin (10) (9) (10) (10)

Inflammation, chronic 1 (11%) 

Musculoskeletal System

Bone (10) (10) (10) (10)

Sternum, fracture healed 1 (10%) 

Nervous System

Brain (10) (10) (10) (10)

Mineralization 5 (50%) 2 (20%) 6 (60%) 

Respiratory System

Larynx (10) (10) (10) (10)

Exudate, mucopurulent 1 (10%) 

Lung (10) (10) (10) (10)

Alveolus, hemorrhage, multifocal 1 (10%) 

Urinary System

Kidney (10) (10) (10) (10)

Infiltration cellular, mononuclear cell 1 (10%) 

Inflammation, chronic active 1 (10%) 

Nephropathy 3 (30%) 3 (30%) 3 (30%) 

Bilateral, pelvis, dilatation 1 (10%) 1 (10%) 

Renal tubule, dilatation 6 (60%) 10 (100%)

Renal tubule, karyomegaly 4 (40%) 10 (100%)

Urinary bladder (10) (10) (10) (10)

Inflammation, chronic active 1 (10%) 

Systems Examined With No Lesions Observed

Cardiovascular System

General Body System

Special Senses System
Tetrafluoroethylene, NTP TR 450 203

TABLE C5

Summary of the Incidence of Nonneoplastic Lesions in Male Mice in the 2-Year Inhalation Study 

of Tetrafluoroethylene (continued)

0 ppm 312 ppm 625 ppm 1,250 ppm

2-Year Study

Alimentary System

Gallbladder (42) (35) (31) (27)

Inflammation, chronic active 1 (4%) 

Intestine small, jejunum (46) (40) (34) (34)

Peyer's patch, hyperplasia, lymphoid 1 (2%) 1 (3%) 

Intestine small, ileum (46) (39) (35) (36)

Peyer's patch, inflammation, chronic active 1 (2%) 

Liver (48) (48) (48) (48)

Angiectasis 6 (13%) 10 (21%) 13 (27%) 

Basophilic focus 1 (2%) 1 (2%) 4 (8%) 3 (6%) 

Clear cell focus 1 (2%) 

Eosinophilic focus 1 (2%) 6 (13%) 7 (15%) 7 (15%) 

Fatty change 2 (4%) 

Hematopoietic cell proliferation 1 (2%) 2 (4%) 4 (8%) 

Hemorrhage 1 (2%) 1 (2%) 

Infarct 1 (2%) 6 (13%) 2 (4%) 4 (8%) 

Infiltration cellular, mixed cell 1 (2%) 5 (10%) 3 (6%) 3 (6%) 

Mixed cell focus 2 (4%) 2 (4%) 3 (6%) 

Necrosis, coagulative, multifocal 4 (8%) 3 (6%) 13 (27%) 11 (23%) 

Thrombosis 1 (2%) 3 (6%) 

Bile duct, hyperplasia 1 (2%) 

Centrilobular, necrosis 1 (2%) 1 (2%) 

Hepatocyte, regeneration 1 (2%) 

Mesentery (2) (3) (2) (7)

Angiectasis 1 (14%) 

Fat, hemorrhage 2 (29%) 

Fat, necrosis 1 (50%) 2 (67%) 1 (50%) 3 (43%) 

Pancreas (48) (48) (46) (45)

Granuloma 1 (2%) 

Duct, ectasia 1 (2%) 

Salivary glands (48) (48) (48) (48)

Infiltration cellular, mononuclear cell 7 (15%) 7 (15%) 3 (6%) 

Stomach, forestomach (48) (48) (46) (46)

Foreign body 1 (2%) 

Granuloma 1 (2%) 1 (2%) 

Hemorrhage 1 (2%) 

Hyperplasia, squamous 1 (2%) 

Inflammation, focal 1 (2%) 

Ulcer 1 (2%) 1 (2%) 

Epithelium, hyperplasia 2 (4%) 3 (6%) 2 (4%) 3 (7%) 

Serosa, inflammation 1 (2%) 

Stomach, glandular (48) (48) (46) (45)

Foreign body 1 (2%) 

Necrosis 2 (4%) 

Tooth (2) (2) (4) (7)

Dysplasia 1 (50%) 1 (50%) 3 (43%) 

Inflammation, suppurative 1 (50%) 4 (100%) 4 (57%) 

Peridontal tissue, proliferation connective 

 tissue 1 (50%) 
204 Tetrafluoroethylene, NTP TR 450

TABLE C5

Summary of the Incidence of Nonneoplastic Lesions in Male Mice in the 2-Year Inhalation Study 

of Tetrafluoroethylene (continued)

0 ppm 312 ppm 625 ppm 1,250 ppm

2-Year Study (continued)

Cardiovascular System

Heart (48) (48) (48) (48)

Cardiomyopathy 2 (4%) 2 (4%) 

Fibrosis 1 (2%) 

Infiltration cellular, mixed cell 1 (2%) 

Atrium, thrombosis 1 (2%) 

Endocrine System

Adrenal cortex (48) (48) (47) (48)

Accessory adrenal cortical nodule 1 (2%) 

Cyst 1 (2%) 

Hyperplasia 1 (2%) 3 (6%) 

Capsule, hyperplasia 29 (60%) 26 (54%) 24 (51%) 20 (42%) 

Islets, pancreatic (48) (48) (46) (45)

Hyperplasia 2 (4%) 1 (2%) 7 (15%) 2 (4%) 

Pituitary gland (47) (44) (44) (44)

Pars distalis, cyst 1 (2%) 1 (2%) 1 (2%) 

Pars distalis, hyperplasia 1 (2%) 

Pars intermedia, hemorrhage 1 (2%) 

Thyroid gland (48) (48) (47) (47)

Ultimobranchial cyst 1 (2%) 1 (2%) 

Follicle, cyst 1 (2%) 1 (2%) 1 (2%) 

Follicular cell, hyperplasia 1 (2%) 1 (2%) 

General Body System

Tissue NOS (1) (2) (2) 

Infiltration cellular, mononuclear cell 1 (50%) 

Necrosis 1 (50%) 

Genital System

Epididymis (48) (48) (48) (48)

Granuloma sperm 1 (2%) 

Hemorrhage 1 (2%) 

Preputial gland (48) (48) (46) (48)

Atrophy 1 (2%) 

Ectasia 2 (4%) 2 (4%) 1 (2%) 

Infiltration cellular, mononuclear cell 6 (13%) 5 (10%) 7 (15%) 3 (6%) 

Inflammation, chronic 5 (10%) 5 (10%) 4 (9%) 1 (2%) 

Inflammation, suppurative 1 (2%) 4 (8%) 7 (15%) 3 (6%) 

Prostate (46) (46) (44) (44)

Hyperplasia 1 (2%) 

Inflammation, chronic 1 (2%) 

Inflammation, suppurative 1 (2%) 1 (2%) 

Seminal vesicle (48) (47) (47) (44)

Dilatation 4 (8%) 1 (2%) 2 (4%) 

Hyperplasia 1 (2%) 

Inflammation, chronic 2 (4%) 2 (4%) 

Inflammation, suppurative 1 (2%) 1 (2%) 

Testes (48) (48) (48) (48)

Atrophy, focal 1 (2%) 
Tetrafluoroethylene, NTP TR 450 205

TABLE C5

Summary of the Incidence of Nonneoplastic Lesions in Male Mice in the 2-Year Inhalation Study 

of Tetrafluoroethylene (continued)

0 ppm 312 ppm 625 ppm 1,250 ppm

2-Year Study (continued)

Hematopoietic System

Bone marrow (48) (48) (47) (47)

Hyperplasia, neutrophil 2 (4%) 1 (2%) 1 (2%) 

Lymph node (3) (1) (2) 

Iliac, hemorrhage 1 (50%) 

Iliac, hyperplasia, lymphoid 1 (33%) 

Iliac, hyperplasia, plasma cell 2 (100%) 

Iliac, pigmentation, hemosiderin 1 (50%) 

Renal, hyperplasia, lymphoid 1 (33%) 

Lymph node, bronchial (36) (36) (35) (26)

Hemorrhage 2 (6%) 

Hyperplasia, lymphoid 2 (6%) 1 (3%) 

Pigmentation, hemosiderin 1 (3%) 

Lymph node, mandibular (36) (34) (32) (34)

Congestion 1 (3%) 

Hemorrhage 1 (3%) 

Hyperplasia, histiocytic 1 (3%) 2 (6%) 

Hyperplasia, lymphoid 1 (3%) 1 (3%) 

Pigmentation, hemosiderin 2 (6%) 1 (3%) 

Lymph node, mesenteric (47) (42) (41) (40)

Hematopoietic cell proliferation 1 (2%) 1 (3%) 

Hemorrhage 1 (2%) 2 (5%) 2 (5%) 

Hyperplasia, histiocytic 2 (4%) 1 (2%) 

Hyperplasia, lymphoid 1 (2%) 2 (5%) 

Inflammation, chronic active 1 (2%) 1 (2%) 1 (3%) 

Lymph node, mediastinal (30) (34) (32) (29)

Congestion 1 (3%) 

Hematopoietic cell proliferation 1 (3%) 

Hemorrhage 3 (9%) 2 (7%) 

Hyperplasia, histiocytic 1 (3%) 2 (7%) 

Hyperplasia, lymphoid 1 (3%) 1 (3%) 

Spleen (48) (48) (46) (46)

Atrophy 1 (2%) 

Hematopoietic cell proliferation 14 (29%) 32 (67%) 41 (89%) 42 (91%) 

Hyperplasia, lymphoid 1 (2%) 

Pigmentation, melanin 2 (4%) 

Thymus (43) (40) (34) (37)

Mineralization 1 (3%) 

Integumentary System

Skin (48) (48) (48) (48)

Acanthosis 1 (2%) 

Atrophy 1 (2%) 

Inflammation, chronic 2 (4%) 4 (8%) 2 (4%) 3 (6%) 

Inflammation, suppurative 1 (2%) 

Ulcer 2 (4%) 4 (8%) 5 (10%) 

Prepuce, acanthosis 1 (2%) 2 (4%) 

Prepuce, inflammation, chronic 2 (4%) 

Prepuce, inflammation, suppurative 1 (2%) 

Prepuce, pigmentation, melanin 1 (2%) 

Prepuce, ulcer 1 (2%) 1 (2%) 

Subcutaneous tissue, congestion 1 (2%) 

Subcutaneous tissue, hemorrhage 1 (2%) 
206 Tetrafluoroethylene, NTP TR 450

TABLE C5

Summary of the Incidence of Nonneoplastic Lesions in Male Mice in the 2-Year Inhalation Study 

of Tetrafluoroethylene (continued)

0 ppm 312 ppm 625 ppm 1,250 ppm

2-Year Study (continued)

Musculoskeletal System

Bone (48) (48) (48) (48)

Fracture 1 (2%) 

Sternum, developmental malformation 2 (4%) 

Nervous System

Brain (48) (48) (48) (48)

Hemorrhage 1 (2%) 1 (2%) 

Mineralization 23 (48%) 19 (40%) 13 (27%) 24 (50%) 

Necrosis, liquifactive 2 (4%) 

Respiratory System

Larynx (47) (48) (46) (46)

Cytoplasmic alteration 1 (2%) 

Exudate, mucopurulent 2 (4%) 1 (2%) 

Hemorrhage 1 (2%) 

Metaplasia, squamous 2 (4%) 

Lung (48) (48) (48) (48)

Congestion 2 (4%) 5 (10%) 1 (2%) 

Crystals 1 (2%) 

Hemorrhage 6 (13%) 4 (8%) 2 (4%) 1 (2%) 

Infarct 1 (2%) 

Pigmentation, hemosiderin 1 (2%) 

Alveolar epithelium, hyperplasia 1 (2%) 1 (2%) 1 (2%) 

Alveolus, infiltration cellular, histiocyte 4 (8%) 5 (10%) 1 (2%) 1 (2%) 

Interstitium, infiltration cellular, mixed 

 cell 1 (2%) 

Nose (48) (47) (46) (47)

Inflammation, suppurative 1 (2%) 3 (7%) 1 (2%) 

Proliferation connective tissue, multifocal 1 (2%) 

Nasolacrimal duct, inflammation, suppurative 1 (2%) 

Respiratory epithelium, cytoplasmic 

 alteration 1 (2%) 

Respiratory epithelium, degeneration 1 (2%) 

Vomeronasal organ, hypertrophy 1 (2%) 

Trachea (47) (47) (46) (46)

Cytoplasmic alteration 1 (2%) 

Special Senses System

Eye (1) (2) 

Degeneration, diffuse 1 (50%) 

Phthisis bulbi 1 (50%) 

Retinal detachment 1 (50%) 

Cornea, inflammation, chronic 1 (50%) 

Harderian gland (6) (8) (5) (6)

Hyperplasia 1 (20%) 1 (17%) 
Tetrafluoroethylene, NTP TR 450 207

TABLE C5

Summary of the Incidence of Nonneoplastic Lesions in Male Mice in the 2-Year Inhalation Study 

of Tetrafluoroethylene (continued)

0 ppm 312 ppm 625 ppm 1,250 ppm

2-Year Study (continued)

Urinary System

Kidney (48) (48) (48) (48)

Cyst 2 (4%) 1 (2%) 1 (2%) 

Hemorrhage 1 (2%) 

Infiltration cellular, mononuclear cell 2 (4%) 1 (2%) 1 (2%) 

Inflammation, chronic active 1 (2%) 1 (2%) 

Inflammation, suppurative 2 (4%) 

Nephropathy 32 (67%) 12 (25%) 10 (21%) 16 (33%) 

Renal tubule, dilatation 4 (8%) 16 (33%) 36 (75%) 

Renal tubule, karyomegaly 1 (2%) 2 (4%) 10 (21%) 28 (58%) 

Urinary bladder (48) (43) (43) (42)

Infiltration cellular, mononuclear cell 1 (2%) 

Inflammation, chronic active 2 (4%) 1 (2%) 1 (2%) 

Inflammation, suppurative 1 (2%) 1 (2%) 
208 Tetrafluoroethylene, NTP TR 450
209

APPENDIX D

SUMMARY OF LESIONS IN FEMALE MICE

IN THE 2-YEAR INHALATION STUDY

OF TETRAFLUOROETHYLENE

TABLE D1 Summary of the Incidence of Neoplasms in Female Mice 

in the 2-Year Inhalation Study of Tetrafluoroethylene ................................. 211

TABLE D2 Individual Animal Tumor Pathology of Female Mice 

in the 2-Year Inhalation Study of Tetrafluoroethylene ................................. 216

TABLE D3 Statistical Analysis of Primary Neoplasms in Female Mice 

in the 2-Year Inhalation Study of Tetrafluoroethylene ................................. 240

TABLE D4a Historical Incidence of Liver Neoplasms 

in Chamber Control Female B6C3F 1 Mice ........................................... 244

TABLE D4b Historical Incidence of Histiocytic Sarcoma

in Chamber Control Female B6C3F 1 Mice ........................................... 245

TABLE D5 Summary of the Incidence of Nonneoplastic Lesions in Female Mice 

in the 2-Year Inhalation Study of Tetrafluoroethylene ................................. 246
210 Tetrafluoroethylene, NTP TR 450
Tetrafluoroethylene, NTP TR 450 211

TABLE D1

Summary of the Incidence of Neoplasms in Female Mice in the 2-Year Inhalation Study of Tetrafluoroethylene a

0 ppm 312 ppm 625 ppm 1,250 ppm

Disposition Summary

Animals initially in study 58 58 58 58

15-Month interim evaluation 10 10 10 10

Early deaths

Accidental death 1

Moribund 8 28 26 27

Natural deaths 4 16 15 17

Survivors

Terminal sacrifice 36 4 6 4

Animals examined microscopically 58 58 57 58

15-Month Interim Evaluation

Alimentary System

Intestine small, jejunum (10) (10) (10) (10)

Liver (10) (10) (10) (10)

Hemangiosarcoma 1 (10%) 

Hepatocellular carcinoma 3 (30%) 1 (10%) 3 (30%) 

Hepatocellular adenoma 2 (20%) 3 (30%) 1 (10%) 

Hepatocellular adenoma, multiple 1 (10%) 

Endocrine System

Adrenal medulla (10) (10) (10) (10)

Pheochromocytoma benign 1 (10%) 

Thyroid gland (10) (10) (10) (10)

Follicular cell, adenoma 1 (10%) 

Respiratory System

Lung (10) (10) (10) (10)

Alveolar/bronchiolar adenoma 1 (10%) 

Alveolar/bronchiolar adenoma, multiple 1 (10%) 

Hepatocellular carcinoma, metastatic, liver 1 (10%) 

Special Senses System

Harderian gland (1) (2)

Adenoma 1 (100%) 1 (50%) 

Bilateral, adenoma 1 (50%) 

Systemic Lesions

Multiple organs (10) (10) (10) (10) b

Lymphoma malignant mixed 1 (10%) 
212 Tetrafluoroethylene, NTP TR 450

TABLE D1

Summary of the Incidence of Neoplasms in Female Mice in the 2-Year Inhalation Study of Tetrafluoroethylene (continued)

0 ppm 312 ppm 625 ppm 1,250 ppm

15-Month Interim Evaluation (continued)

Systems Examined With No Neoplasms Observed

Cardiovascular System

General Body System

Genital System

Hematopoietic System

Integumentary System

Musculoskeletal System

Nervous System

Urinary System

2-Year Study

Alimentary System

Intestine large, colon (47) (45) (42) (40)

Sarcoma 1 (2%) 

Intestine large, cecum (47) (42) (40) (36)

Leiomyosarcoma 1 (2%) 

Sarcoma 1 (2%) 

Intestine small, duodenum (45) (39) (39) (35)

Sarcoma 1 (3%) 

Intestine small, jejunum (46) (37) (39) (35)

Intestine small, ileum (46) (39) (40) (35)

Leiomyosarcoma, metastatic, uterus 1 (3%) 

Sarcoma 1 (3%) 

Liver (48) (48) (47) (47)

Hemangioma 4 (8%) 1 (2%) 1 (2%) 

Hemangioma, multiple 1 (2%) 1 (2%) 

Hemangiosarcoma 19 (40%) 15 (32%) 19 (40%) 

Hemangiosarcoma, multiple 8 (17%) 12 (26%) 15 (32%) 

Hepatocellular carcinoma 4 (8%) 23 (48%) 15 (32%) 13 (28%) 

Hepatocellular carcinoma, multiple 5 (10%) 7 (15%) 7 (15%) 

Hepatocellular adenoma 14 (29%) 10 (21%) 11 (23%) 8 (17%) 

Hepatocellular adenoma, multiple 1 (2%) 7 (15%) 9 (19%) 7 (15%) 

Histiocytic sarcoma 1 (2%) 21 (44%) 19 (40%) 18 (38%) 

Sarcoma 1 (2%) 

Mesentery (9) (13) (7) (6)

Hemangiosarcoma 2 (15%) 

Histiocytic sarcoma 1 (11%) 1 (8%) 

Leiomyosarcoma, metastatic, uterus 1 (8%) 

Sarcoma 1 (8%) 1 (17%) 

Pancreas (48) (47) (44) (47)

Hemangiosarcoma 1 (2%) 

Histiocytic sarcoma 2 (4%) 1 (2%) 1 (2%) 

Leiomyosarcoma, metastatic, uterus 1 (2%) 

Sarcoma 1 (2%) 

Stomach, forestomach (48) (48) (47) (47)

Leiomyosarcoma, metastatic, uterus 1 (2%) 

Squamous cell papilloma 1 (2%) 1 (2%) 

Stomach, glandular (48) (48) (45) (45)

Leiomyosarcoma, metastatic, uterus 1 (2%) 

Sarcoma 1 (2%) 
Tetrafluoroethylene, NTP TR 450 213

TABLE D1

Summary of the Incidence of Neoplasms in Female Mice in the 2-Year Inhalation Study of Tetrafluoroethylene (continued)

0 ppm 312 ppm 625 ppm 1,250 ppm

2-Year Study (continued)

Cardiovascular System

Heart (48) (48) (47) (48)

Histiocytic sarcoma 1 (2%) 1 (2%) 

Endocrine System

Adrenal cortex (48) (47) (47) (47)

Adenoma 1 (2%) 

Histiocytic sarcoma 1 (2%) 3 (6%) 1 (2%) 

Capsule, adenoma 1 (2%) 

Capsule, carcinoma 1 (2%) 

Islets, pancreatic (48) (45) (44) (47)

Adenoma 1 (2%) 1 (2%) 

Pituitary gland (46) (45) (44) (46)

Histiocytic sarcoma 1 (2%) 

Pars distalis, adenoma 4 (9%) 5 (11%) 2 (5%) 6 (13%) 

Pars intermedia, adenoma 1 (2%) 

Thyroid gland (48) (48) (46) (46)

Follicular cell, adenoma 2 (4%) 1 (2%) 1 (2%) 1 (2%) 

General Body System

Tissue NOS (1) 

Sarcoma 1 (100%) 

Genital System

Ovary (47) (47) (45) (46)

Cystadenoma 2 (4%) 2 (4%) 

Hemangiosarcoma 1 (2%) 

Histiocytic sarcoma 1 (2%) 5 (11%) 4 (9%) 3 (7%) 

Luteoma 2 (4%) 

Sarcoma 1 (2%) 

Periovarian tissue, histiocytic sarcoma 1 (2%) 

Uterus (48) (48) (45) (47)

Histiocytic sarcoma 1 (2%) 

Leiomyosarcoma 1 (2%) 

Polyp stromal 1 (2%) 1 (2%) 

Cervix, granular cell tumor NOS 1 (2%) 

Hematopoietic System

Bone marrow (48) (48) (46) (47)

Histiocytic sarcoma 6 (13%) 5 (11%) 4 (9%) 

Lymph node (5) (6) (4) (6)

Axillary, histiocytic sarcoma 1 (20%) 

Iliac, histiocytic sarcoma 1 (20%) 1 (17%) 1 (25%) 1 (17%) 

Pancreatic, histiocytic sarcoma 1 (25%) 1 (17%) 

Renal, histiocytic sarcoma 1 (17%) 2 (50%) 2 (33%) 

Lymph node, bronchial (40) (36) (40) (38)

Histiocytic sarcoma 4 (11%) 6 (15%) 4 (11%) 

Sarcoma 1 (3%) 
214 Tetrafluoroethylene, NTP TR 450

TABLE D1

Summary of the Incidence of Neoplasms in Female Mice in the 2-Year Inhalation Study of Tetrafluoroethylene (continued)

0 ppm 312 ppm 625 ppm 1,250 ppm

2-Year Study (continued)

Hematopoietic System (continued)

Lymph node, mandibular (39) (35) (34) (32)

Histiocytic sarcoma 1 (3%) 3 (9%) 2 (6%) 2 (6%) 

Lymph node, mesenteric (43) (40) (41) (43)

Hemangioma 1 (2%) 

Histiocytic sarcoma 1 (2%) 6 (15%) 7 (17%) 6 (14%) 

Lymph node, mediastinal (28) (35) (35) (33)

Histiocytic sarcoma 1 (4%) 9 (26%) 9 (26%) 4 (12%) 

Spleen (48) (48) (46) (47)

Histiocytic sarcoma 1 (2%) 7 (15%) 8 (17%) 9 (19%) 

Sarcoma 1 (2%) 

Thymus (46) (42) (39) (38)

Histiocytic sarcoma 2 (5%) 2 (5%) 2 (5%) 

Integumentary System

Mammary gland (48) (46) (45) (46)

Carcinoma 1 (2%) 

Skin (47) (48) (47) (48)

Hemangioma 1 (2%) 

Squamous cell papilloma 1 (2%) 

Subcutaneous tissue, sarcoma 2 (4%) 

Musculoskeletal System

Bone (48) (48) (47) (48)

Osteosarcoma 1 (2%) 

Rib, leiomyosarcoma, metastatic, uterus 1 (2%) 

Skeletal muscle (1) 

Leiomyosarcoma, metastatic, uterus 1 (100%) 

Nervous System

Brain (48) (48) (47) (48)

Astrocytoma NOS 1 (2%) 

Histiocytic sarcoma 1 (2%) 1 (2%) 

Respiratory System

Lung (48) (48) (47) (47)

Alveolar/bronchiolar adenoma 5 (10%) 5 (11%) 3 (6%) 

Alveolar/bronchiolar adenoma, multiple 1 (2%) 1 (2%) 

Alveolar/bronchiolar carcinoma 2 (4%) 1 (2%) 

Carcinoma 1 (2%) 

Carcinoma, metastatic, mammary gland 1 (2%) 

Hemangiosarcoma, metastatic, liver 3 (6%) 

Hemangiosarcoma, metastatic, pancreas 1 (2%) 

Hepatocellular carcinoma, metastatic, liver 1 (2%) 8 (17%) 6 (13%) 4 (9%) 

Histiocytic sarcoma 1 (2%) 16 (33%) 13 (28%) 13 (28%) 

Osteosarcoma, metastatic, bone 1 (2%) 

Sarcoma 1 (2%) 

Sarcoma, metastatic, skin 1 (2%) 
Tetrafluoroethylene, NTP TR 450 215

TABLE D1

Summary of the Incidence of Neoplasms in Female Mice in the 2-Year Inhalation Study of Tetrafluoroethylene (continued)

0 ppm 312 ppm 625 ppm 1,250 ppm

2-Year Study (continued)

Special Senses System

Harderian gland (3) (6) (4) (6)

Adenoma 2 (67%) 3 (50%) 6 (100%)

Urinary System

Kidney (48) (48) (47) (47)

Histiocytic sarcoma 1 (2%) 7 (15%) 4 (9%) 3 (6%) 

Osteosarcoma, metastatic, bone 1 (2%) 

Urinary bladder (46) (43) (43) (37)

Leiomyosarcoma, metastatic, uterus 1 (2%) 

Sarcoma 1 (2%) 

Systemic Lesions

Multiple organs (48) (48) (47) (48)

Histiocytic sarcoma 1 (2%) 21 (44%) 19 (40%) 18 (38%) 

Lymphoma malignant lymphocytic 1 (2%) 

Lymphoma malignant mixed 5 (10%) 2 (4%) 2 (4%) 

Neoplasm Summary

Total animals with primary neoplasmsc

15-Month interim evaluation 2 6 5 6

2-Year study 34 47 45 46

Total Primary Neoplasms

15-Month interim evaluation 3 7 5 8

2-Year study 53 132 104 115

Total animals with benign neoplasms

15-Month interim evaluation 2 3 4 4

2-Year study 27 24 26 29

Total benign neoplasms

15-Month interim evaluation 3 3 4 4

2-Year study 37 34 34 36

Total animals with malignant neoplasms

15-Month interim evaluation 3 1 4

2-Year study 14 46 45 46

Total malignant neoplasms

15-Month interim evaluation 4 1 4

2-Year study 14 98 70 79

Total animals with metastatic neoplasms

15-Month interim evaluation 1

2-Year study 3 9 6 9

Total metastatic neoplasms

15-Month interim evaluation 1

2-Year study 4 16 6 9

Total animals with uncertain neoplasms-

 benign or malignant

2-Year study 2

Total uncertain neoplasms

2-Year study 2

Number of animals examined microscopically at the site and the number of animals with neoplasm a

Number of animals with any tissue examined microscopically b

Primary neoplasms: all neoplasms except metastatic neoplasms c
216 Tetrafluoroethylene, NTP TR 450

TABLE D2

Individual Animal Tumor Pathology of Female Mice in the 2-Year Inhalation Study of Tetrafluoroethylene: 0 ppm 

4 4 5 5 5 5 5 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 

Number of Days on Study 0 8 3 4 7 9 9 0 1 2 2 6 6 6 6 6 6 6 6 6 6 6 6 6 6

0 8 1 1 3 5 7 3 7 1 6 0 7 7 7 7 7 7 7 7 7 7 7 7 7

1 0 1 0 0 1 1 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

Carcass ID Number 1 8 0 8 7 1 0 9 7 0 6 6 5 6 6 6 6 6 6 6 7 7 7 7 7

0 9 3 2 4 4 5 4 7 0 0 4 9 1 2 3 5 6 7 9 0 1 2 3 5

Alimentary System 

Esophagus + + + + + + + + + + + + + + + + + + + + + + + + +

Gallbladder + + + + A + + + + + + A + + + + + + + + + + + + +

Intestine large, colon + + + + + + + + + + + A + + + + + + + + + + + + +

Intestine large, rectum + + + + + + + + + + + + + + + + + + + + + + + + +

Intestine large, cecum + + + + + + + + + + + A + + + + + + + + + + + + +

Leiomyosarcoma X

Intestine small, duodenum + + + M A + + + + + + A + + + + + + + + + + + + +

Intestine small, jejunum + + + + A + + + + + + A + + + + + + + + + + + + +

Intestine small, ileum + + + + M + + + + + + A + + + + + + + + + + + + +

Liver + + + + + + + + + + + + + + + + + + + + + + + + +

Hepatocellular carcinoma X X

Hepatocellular adenoma X X X X X X X X X X

Hepatocellular adenoma, multiple

Histiocytic sarcoma X

Mesentery + + + + + + + +

Histiocytic sarcoma X

Pancreas + + + + + + + + + + + + + + + + + + + + + + + + +

Salivary glands + + + + + + + + + + + + + + + + + + + + + + + + +

Stomach, forestomach + + + + + + + + + + + + + + + + + + + + + + + + +

Stomach, glandular + + + + + + + + + + + + + + + + + + + + + + + + +

Tooth +

Cardiovascular System 

Heart + + + + + + + + + + + + + + + + + + + + + + + + +

Endocrine System 

Adrenal cortex + + + + + + + + + + + + + + + + + + + + + + + + +

Histiocytic sarcoma X

Capsule, adenoma X

Capsule, carcinoma

Adrenal medulla + + + + + + + + + + + + + + + + + + + + + + + + +

Islets, pancreatic + + + + + + + + + + + + + + + + + + + + + + + + +

Adenoma

Parathyroid gland + + M + + M + + + M M + M + + M + + + M + + + + +

Pituitary gland + M + + + + + + + + I + + + + + + + + + + + + + +

Histiocytic sarcoma X

Pars distalis, adenoma X

Pars intermedia, adenoma

Thyroid gland + + + + + + + + + + + + + + + + + + + + + + + + +

Follicular cell, adenoma

General Body System 

None

+: Tissue examined microscopically M: Missing tissue X: Lesion present

A: Autolysis precludes examination I: Insufficient tissue Blank: Not examined
Tetrafluoroethylene, NTP TR 450 217

TABLE D2

Individual Animal Tumor Pathology of Female Mice in the 2-Year Inhalation Study of Tetrafluoroethylene: 0 ppm (continued)

6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

Number of Days on Study 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7

0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 Total

Carcass ID Number 7 8 8 8 8 8 9 9 9 9 9 9 9 0 0 0 0 0 1 1 1 1 1 Tissues/

8 1 4 5 6 7 1 3 5 6 7 8 9 1 2 6 7 9 1 2 3 5 6 Tumors

Alimentary System 

Esophagus + + + + + + + + + + + + + + + + + + + + + + + 48

Gallbladder + I + M + + + + + + + + + + + + + M + + A + + 42

Intestine large, colon + + + + + + + + + + + + + + + + + + + + + + + 47

Intestine large, rectum + + + + + + + + + + + + + + + + + + + + + + + 48

Intestine large, cecum + + + + + + + + + + + + + + + + + + + + + + + 47

Leiomyosarcoma 1

Intestine small, duodenum + + + + + + + + + + + + + + + + + + + + + + + 45

Intestine small, jejunum + + + + + + + + + + + + + + + + + + + + + + + 46

Intestine small, ileum + + + + + + + + + + + + + + + + + + + + + + + 46

Liver + + + + + + + + + + + + + + + + + + + + + + + 48

Hepatocellular carcinoma X X 4

Hepatocellular adenoma X X X X 14

Hepatocellular adenoma, multiple X 1

Histiocytic sarcoma 1

Mesentery + 9

Histiocytic sarcoma 1

Pancreas + + + + + + + + + + + + + + + + + + + + + + + 48

Salivary glands + + + + + + + + + + + + + + + + + + + + + + + 48

Stomach, forestomach + + + + + + + + + + + + + + + + + + + + + + + 48

Stomach, glandular + + + + + + + + + + + + + + + + + + + + + + + 48

Tooth + 2

Cardiovascular System 

Heart + + + + + + + + + + + + + + + + + + + + + + + 48

Endocrine System 

Adrenal cortex + + + + + + + + + + + + + + + + + + + + + + + 48

Histiocytic sarcoma 1

Capsule, adenoma 1

Capsule, carcinoma X 1

Adrenal medulla + + + + + + + + + + + + + + + + + + + + + + + 48

Islets, pancreatic + + + + + + + + + + + + + + + + + + + + + + + 48

Adenoma X 1

Parathyroid gland + + M M M + M M + M M M + M M M M + + + M + + 28

Pituitary gland + + + + + + + + + + + + + + + + + + + + + + + 46

Histiocytic sarcoma 1

Pars distalis, adenoma X X X 4

Pars intermedia, adenoma X 1

Thyroid gland + + + + + + + + + + + + + + + + + + + + + + + 48

Follicular cell, adenoma X X 2

General Body System 

None 
218 Tetrafluoroethylene, NTP TR 450

TABLE D2

Individual Animal Tumor Pathology of Female Mice in the 2-Year Inhalation Study of Tetrafluoroethylene: 0 ppm (continued)

4 4 5 5 5 5 5 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

Number of Days on Study 0 8 3 4 7 9 9 0 1 2 2 6 6 6 6 6 6 6 6 6 6 6 6 6 6

0 8 1 1 3 5 7 3 7 1 6 0 7 7 7 7 7 7 7 7 7 7 7 7 7

1 0 1 0 0 1 1 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

Carcass ID Number 1 8 0 8 7 1 0 9 7 0 6 6 5 6 6 6 6 6 6 6 7 7 7 7 7

0 9 3 2 4 4 5 4 7 0 0 4 9 1 2 3 5 6 7 9 0 1 2 3 5

Genital System 

Clitoral gland M M + + + + + + + + + + M + + + + + + M + M + + +

Ovary + M + + + + + + + + + + + + + + + + + + + + + + +

Cystadenoma X X

Histiocytic sarcoma X

Luteoma X

Uterus + + + + + + + + + + + + + + + + + + + + + + + + +

Histiocytic sarcoma X

Polyp stromal

Cervix, granular cell tumor NOS

Hematopoietic System 

Bone marrow + + + + + + + + + + + + + + + + + + + + + + + + +

Lymph node + + +

Axillary, histiocytic sarcoma X

Iliac, histiocytic sarcoma X

Lymph node, bronchial + + + + + + + + + + + + + + M + + + M + + + + + +

Lymph node, mandibular + + + + + M + + + M + + + M + + + + + + + + M + +

Histiocytic sarcoma X

Lymph node, mesenteric + + I + + + + + M + + + + + I + + + + + + + + + +

Histiocytic sarcoma X

Lymph node, mediastinal + + + + + + + M + + + M + + + + + M M M + M M M +

Histiocytic sarcoma X

Spleen + + + + + + + + + + + + + + + + + + + + + + + + +

Histiocytic sarcoma X

Thymus M I + + + + + + + + + + + + + + + + + + + + + + +

Integumentary System 

Mammary gland + + + + + + + + + + + + + + + + + + + + + + + + +

Carcinoma X

Skin + + + + + + + + + + + + + + + + + + + + + + + + +

Musculoskeletal System 

Bone + + + + + + + + + + + + + + + + + + + + + + + + +

Osteosarcoma X

Nervous System 

Brain + + + + + + + + + + + + + + + + + + + + + + + + +

Astrocytoma NOS X
Tetrafluoroethylene, NTP TR 450 219

TABLE D2

Individual Animal Tumor Pathology of Female Mice in the 2-Year Inhalation Study of Tetrafluoroethylene: 0 ppm (continued)

6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

Number of Days on Study 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7

0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 Total

Carcass ID Number 7 8 8 8 8 8 9 9 9 9 9 9 9 0 0 0 0 0 1 1 1 1 1 Tissues/

8 1 4 5 6 7 1 3 5 6 7 8 9 1 2 6 7 9 1 2 3 5 6 Tumors

Genital System 

Clitoral gland + + + + + + + + + + + + + M + + + + + + + + + 42

Ovary + + + + + + + + + + + + + + + + + + + + + + + 47

Cystadenoma 2

Histiocytic sarcoma 1

Luteoma X 2

Uterus + + + + + + + + + + + + + + + + + + + + + + + 48

Histiocytic sarcoma 1

Polyp stromal X 1

Cervix, granular cell tumor NOS X 1

Hematopoietic System 

Bone marrow + + + + + + + + + + + + + + + + + + + + + + + 48

Lymph node + + 5

Axillary, histiocytic sarcoma 1

Iliac, histiocytic sarcoma 1

Lymph node, bronchial M + + + M + + + M + M + + + + + + + I + M + + 40

Lymph node, mandibular M + + M + M + + + + + + + + + + M + + + M + + 39

Histiocytic sarcoma 1

Lymph node, mesenteric + + + + + + + M + + + I + + + + + + + + + + + 43

Histiocytic sarcoma 1

Lymph node, mediastinal + + + M + + M + + M + M M M M I M M M + M + + 28

Histiocytic sarcoma 1

Spleen + + + + + + + + + + + + + + + + + + + + + + + 48

Histiocytic sarcoma 1

Thymus + + + + + + + + + + + + + + + + + + + + + + + 46

Integumentary System 

Mammary gland + + + + + + + + + + + + + + + + + + + + + + + 48

Carcinoma 1

Skin M + + + + + + + + + + + + + + + + + + + + + + 47

Musculoskeletal System 

Bone + + + + + + + + + + + + + + + + + + + + + + + 48

Osteosarcoma 1

Nervous System 

Brain + + + + + + + + + + + + + + + + + + + + + + + 48

Astrocytoma NOS 1
220 Tetrafluoroethylene, NTP TR 450

TABLE D2

Individual Animal Tumor Pathology of Female Mice in the 2-Year Inhalation Study of Tetrafluoroethylene: 0 ppm (continued)

4 4 5 5 5 5 5 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

Number of Days on Study 0 8 3 4 7 9 9 0 1 2 2 6 6 6 6 6 6 6 6 6 6 6 6 6 6

0 8 1 1 3 5 7 3 7 1 6 0 7 7 7 7 7 7 7 7 7 7 7 7 7

1 0 1 0 0 1 1 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

Carcass ID Number 1 8 0 8 7 1 0 9 7 0 6 6 5 6 6 6 6 6 6 6 7 7 7 7 7

0 9 3 2 4 4 5 4 7 0 0 4 9 1 2 3 5 6 7 9 0 1 2 3 5

Respiratory System 

Larynx + + + + + + + + + + + + + + + + + + + + + + + + +

Lung + + + + + + + + + + + + + + + + + + + + + + + + +

Alveolar/bronchiolar adenoma X X

Alveolar/bronchiolar adenoma,

 multiple 

Carcinoma, metastatic, mammary gland X

Hepatocellular carcinoma, metastatic,

 liver X

Histiocytic sarcoma X

Osteosarcoma, metastatic, bone X

Nose + + + + + + + + + + + A + + + + + + + + + + + + +

Trachea + + + + + + + + + + + + + + + + + + + + + + + + +

Special Senses System 

Ear +

Harderian gland + +

Adenoma X

Urinary System 

Kidney + + + + + + + + + + + + + + + + + + + + + + + + +

Histiocytic sarcoma X

Osteosarcoma, metastatic, bone X

Urinary bladder + + + + + + + + + + + A + + + + + + + + + M + + +

Systemic Lesions 

Multiple organs + + + + + + + + + + + + + + + + + + + + + + + + +

Histiocytic sarcoma X

Lymphoma malignant mixed X X
Tetrafluoroethylene, NTP TR 450 221

TABLE D2

Individual Animal Tumor Pathology of Female Mice in the 2-Year Inhalation Study of Tetrafluoroethylene: 0 ppm (continued)

6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

Number of Days on Study 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7

0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 Total

Carcass ID Number 7 8 8 8 8 8 9 9 9 9 9 9 9 0 0 0 0 0 1 1 1 1 1 Tissues/

8 1 4 5 6 7 1 3 5 6 7 8 9 1 2 6 7 9 1 2 3 5 6 Tumors

Respiratory System 

Larynx + + + + + + + + + + + + + + + + + + + + + + + 48

Lung + + + + + + + + + + + + + + + + + + + + + + + 48

Alveolar/bronchiolar adenoma X X X 5

Alveolar/bronchiolar adenoma, 

 multiple X 1

Carcinoma, metastatic, mammary gland 1

Hepatocellular carcinoma, metastatic, 

 liver 1

Histiocytic sarcoma 1

Osteosarcoma, metastatic, bone 1

Nose + + + + + + + + + + + + + + + + + + + + + + + 47

Trachea + + + + + + + + + + + + + + + + + + + + + + + 48

Special Senses System 

Ear 1

Harderian gland + 3

Adenoma X 2

Urinary System 

Kidney + + + + + + + + + + + + + + + + + + + + + + + 48

Histiocytic sarcoma 1

Osteosarcoma, metastatic, bone 1

Urinary bladder + + + + + + + + + + + + + + + + + + + + + + + 46

Systemic Lesions 

Multiple organs + + + + + + + + + + + + + + + + + + + + + + + 48

Histiocytic sarcoma 1

Lymphoma malignant mixed X X X 5
222 Tetrafluoroethylene, NTP TR 450

TABLE D2

Individual Animal Tumor Pathology of Female Mice in the 2-Year Inhalation Study of Tetrafluoroethylene: 312 ppm 

4 4 4 4 4 5 5 5 5 5 5 5 5 5 5 5 6 6 6 6 6 6 6 6 6

Number of Days on Study 2 2 5 5 9 3 3 3 4 4 4 4 6 8 8 9 0 0 0 0 0 1 1 1 1

9 9 4 5 3 0 0 9 1 1 1 1 6 5 8 6 0 0 3 7 9 4 4 4 4

1 2 1 2 1 1 2 1 1 1 2 2 2 2 2 2 1 1 1 2 2 1 1 2 2

Carcass ID Number 9 1 8 0 9 7 1 8 7 9 1 2 0 3 0 1 7 8 8 0 2 7 9 1 2

2 2 0 5 6 6 6 7 7 4 9 3 3 1 7 3 9 2 8 6 0 5 7 1 5

Alimentary System 

Esophagus + + + + + + + + + + + + + + + + + + + + + + + + +

Gallbladder + + A A A + + A + + + + + A + M A + + + A A + + +

Intestine large, colon + + A + + + + + + + + + + + + A + + + + + A + + +

Sarcoma

Intestine large, rectum + + + + + + + + + + + + + + + + + + + + + + + + +

Intestine large, cecum + + + A A + + A + + + + + + + + + + + + + A + + +

Sarcoma

Intestine small, duodenum + + A A A + + A + + + + I + + A A + + + + M + + +

Sarcoma

Intestine small, jejunum + + A A A A + A + + + + + + + A A + + + + A + + +

Intestine small, ileum + + + A A + + A + + + + + + A A A + + + + A + + +

Leiomyosarcoma, metastatic, uterus X

Sarcoma

Liver + + + + + + + + + + + + + + + + + + + + + + + + +

Hemangioma X

Hemangioma, multiple X

Hemangiosarcoma X X X X X X X

Hemangiosarcoma, multiple X X X

Hepatocellular carcinoma X X X X X X X X X X

Hepatocellular carcinoma, multiple X X

Hepatocellular adenoma X X X X X X

Hepatocellular adenoma, multiple X X

Histiocytic sarcoma X X X X X X X X

Sarcoma

Mesentery + + + + +

Hemangiosarcoma X

Histiocytic sarcoma

Leiomyosarcoma, metastatic, uterus X

Sarcoma

Pancreas + + + + + + + + + + + + + + + + + + + + + + + + +

Histiocytic sarcoma X X

Leiomyosarcoma, metastatic, uterus X

Sarcoma

Salivary glands + + + + + + + + + + + + + + + + + + + + + + + + +

Stomach, forestomach + + + + + + + + + + + + + + + + + + + + + + + + +

Leiomyosarcoma, metastatic, uterus X

Squamous cell papilloma

Stomach, glandular + + + + + + + + + + + + + + + + + + + + + + + + +

Leiomyosarcoma, metastatic, uterus X

Sarcoma

Cardiovascular System 

Heart + + + + + + + + + + + + + + + + + + + + + + + + +

Endocrine System 

Adrenal cortex + + M + + + + + + + + + + + + + + + + + + + + + +

Adenoma X

Histiocytic sarcoma X

Adrenal medulla + + M + + + + + + + + + + + + + + + + + + + + + +

Islets, pancreatic + + I I + + + + + + + + + + + + + + + + + + + + +

Adenoma
Tetrafluoroethylene, NTP TR 450 223

TABLE D2

Individual Animal Tumor Pathology of Female Mice in the 2-Year Inhalation Study of Tetrafluoroethylene: 312 ppm

(continued)

6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

Number of Days on Study 1 1 1 3 3 3 3 3 3 4 4 4 4 4 4 4 5 5 5 6 6 6 6

4 5 8 1 6 6 8 9 9 3 4 5 6 6 6 9 1 7 9 7 7 7 7

2 1 2 2 1 2 2 1 2 1 2 2 2 2 2 2 2 1 1 1 1 2 2 Total

Carcass ID Number 2 9 3 0 7 3 2 8 0 8 1 2 1 1 2 1 2 8 9 8 8 0 1 Tissues/

9 8 0 0 8 2 4 3 4 6 4 7 0 8 6 5 2 5 3 1 9 1 7 Tumors

Alimentary System 

Esophagus + + + + + + + + + + + + + + + + + + + + + + + 48

Gallbladder + + + + + + + + + M A + + + A + + + + + + + + 36

Intestine large, colon + + + + + + + + + + + + + + + + + + + + + + + 45

Sarcoma X 1

Intestine large, rectum + + + + + + + + + + + + + + + + + + + + + + + 48

Intestine large, cecum + + + + + + + + + + A + + + A + + + + + + + + 42

Sarcoma X 1

Intestine small, duodenum + + + + + + + + + + + + + + A + + + + + + + + 39

Sarcoma X 1

Intestine small, jejunum + + + + + + + + + + A + + + A + A + + + + + + 37

Intestine small, ileum + + + + + + + + + + A + + + A + + + + + + + + 39

Leiomyosarcoma, metastatic, uterus 1

Sarcoma X 1

Liver + + + + + + + + + + + + + + + + + + + + + + + 48

Hemangioma X X X 4

Hemangioma, multiple 1

Hemangiosarcoma X X X X X X X X X X X X 19

Hemangiosarcoma, multiple X X X X X 8

Hepatocellular carcinoma X X X X X X X X X X X X X 23

Hepatocellular carcinoma, multiple X X X 5

Hepatocellular adenoma X X X X 10

Hepatocellular adenoma, multiple X X X X X 7

Histiocytic sarcoma X X X X X X X X X X X X X 21

Sarcoma X 1

Mesentery + + + + + + + + 13

Hemangiosarcoma X 2

Histiocytic sarcoma X 1

Leiomyosarcoma, metastatic, uterus 1

Sarcoma X 1

Pancreas + + + + + + + + + + + I + + + + + + + + + + + 47

Histiocytic sarcoma 2

Leiomyosarcoma, metastatic, uterus 1

Sarcoma X 1

Salivary glands + + + + + + + + + + + + + + + + + + + + + + + 48

Stomach, forestomach + + + + + + + + + + + + + + + + + + + + + + + 48

Leiomyosarcoma, metastatic, uterus 1

Squamous cell papilloma X 1

Stomach, glandular + + + + + + + + + + + + + + + + + + + + + + + 48

Leiomyosarcoma, metastatic, uterus 1

Sarcoma X 1

Cardiovascular System 

Heart + + + + + + + + + + + + + + + + + + + + + + + 48

Endocrine System 

Adrenal cortex + + + + + + + + + + + + + + + + + + + + + + + 47

Adenoma 1

Histiocytic sarcoma X X 3

Adrenal medulla + + + + + + + + + + + + + + + + + + + + + + + 47

Islets, pancreatic + + + + + + + + + + + M + + + + + + + + + + + 45

Adenoma X 1
224 Tetrafluoroethylene, NTP TR 450

TABLE D2

Individual Animal Tumor Pathology of Female Mice in the 2-Year Inhalation Study of Tetrafluoroethylene: 312 ppm

(continued)

4 4 4 4 4 5 5 5 5 5 5 5 5 5 5 5 6 6 6 6 6 6 6 6 6

Number of Days on Study 2 2 5 5 9 3 3 3 4 4 4 4 6 8 8 9 0 0 0 0 0 1 1 1 1

9 9 4 5 3 0 0 9 1 1 1 1 6 5 8 6 0 0 3 7 9 4 4 4 4

1 2 1 2 1 1 2 1 1 1 2 2 2 2 2 2 1 1 1 2 2 1 1 2 2

Carcass ID Number 9 1 8 0 9 7 1 8 7 9 1 2 0 3 0 1 7 8 8 0 2 7 9 1 2

2 2 0 5 6 6 6 7 7 4 9 3 3 1 7 3 9 2 8 6 0 5 7 1 5

Endocrine System (continued)

Parathyroid gland M + + M + M + + + M M + M + + M M M + M M M + M +

Pituitary gland + + + + + + + I + + + + + + + + + + + + + + + + +

Pars distalis, adenoma X X

Thyroid gland + + + + + + + + + + + + + + + + + + + + + + + + +

Follicular cell, adenoma

General Body System 

Tissue NOS

Sarcoma

Genital System 

Clitoral gland + + M + + + + M + + + M + M + + + + + M + + + + M

Ovary + + M + + + + + + + + + + + + + + + + + + + + + +

Hemangiosarcoma X

Histiocytic sarcoma X X X X

Sarcoma

Uterus + + + + + + + + + + + + + + + + + + + + + + + + +

Leiomyosarcoma X

Hematopoietic System 

Bone marrow + + + + + + + + + + + + + + + + + + + + + + + + +

Histiocytic sarcoma X X X X X

Lymph node + +

Iliac, histiocytic sarcoma

Renal, histiocytic sarcoma X

Lymph node, bronchial + + M M + + + M I + + + M + + + + M + + + + + + M

Histiocytic sarcoma X X X

Sarcoma

Lymph node, mandibular + + M + M + + + + + + + M + + + + M M M + + + + +

Histiocytic sarcoma X X X

Lymph node, mesenteric + + + + + I M + + + + + + + + + M + + + + + + + +

Histiocytic sarcoma X X X X

Lymph node, mediastinal + + M + + M M + + + + + + + + I M + + I M M + + +

Histiocytic sarcoma X X X X X

Spleen + + + + + + + + + + + + + + + + + + + + + + + + +

Histiocytic sarcoma X X X X X X

Sarcoma

Thymus + + M + + + + + + + + + + + I M M + + + + + + + +

Histiocytic sarcoma X X

Integumentary System 

Mammary gland + + + + + + + + + + + + + + + M + + + + + + + + I

Skin + + + + + + + + + + + + + + + + + + + + + + + + +

Musculoskeletal System 

Bone + + + + + + + + + + + + + + + + + + + + + + + + +

Rib, leiomyosarcoma, metastatic,

 uterus X

Skeletal muscle +

Leiomyosarcoma, metastatic, uterus X
Tetrafluoroethylene, NTP TR 450 225

TABLE D2

Individual Animal Tumor Pathology of Female Mice in the 2-Year Inhalation Study of Tetrafluoroethylene: 312 ppm

(continued)

6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

Number of Days on Study 1 1 1 3 3 3 3 3 3 4 4 4 4 4 4 4 5 5 5 6 6 6 6

4 5 8 1 6 6 8 9 9 3 4 5 6 6 6 9 1 7 9 7 7 7 7

2 1 2 2 1 2 2 1 2 1 2 2 2 2 2 2 2 1 1 1 1 2 2 Total

Carcass ID Number 2 9 3 0 7 3 2 8 0 8 1 2 1 1 2 1 2 8 9 8 8 0 1 Tissues/

9 8 0 0 8 2 4 3 4 6 4 7 0 8 6 5 2 5 3 1 9 1 7 Tumors

Endocrine System (continued)

Parathyroid gland + M + + + + + M M M + M + M M + + M + + + M M 25

Pituitary gland + + + + + + + + + + + M + + + + + + M + + + + 45

Pars distalis, adenoma X X X 5

Thyroid gland + + + + + + + + + + + + + + + + + + + + + + + 48

Follicular cell, adenoma X 1

General Body System 

Tissue NOS + 1

Sarcoma X 1

Genital System 

Clitoral gland + + + + + + + + + + + + + + + + + + + + + + + 42

Ovary + + + + + + + + + + + + + + + + + + + + + + + 47

Hemangiosarcoma 1

Histiocytic sarcoma X 5

Sarcoma X 1

Uterus + + + + + + + + + + + + + + + + + + + + + + + 48

Leiomyosarcoma 1

Hematopoietic System 

Bone marrow + + + + + + + + + + + + + + + + + + + + + + + 48

Histiocytic sarcoma X 6

Lymph node + + + + 6

Iliac, histiocytic sarcoma X 1

Renal, histiocytic sarcoma 1

Lymph node, bronchial + + + M + + + + + M M M + M + + + + + + + + + 36

Histiocytic sarcoma X 4

Sarcoma X 1

Lymph node, mandibular + + + M I + + + + + + + + M M I + + M + + M + 35

Histiocytic sarcoma 3

Lymph node, mesenteric + M + + + + + M M + M + + + M + + + + + + + + 40

Histiocytic sarcoma X X 6

Lymph node, mediastinal + + + + + + + + + M + + + + M I + M + + M + + 35

Histiocytic sarcoma X X X X 9

Spleen + + + + + + + + + + + + + + + + + + + + + + + 48

Histiocytic sarcoma X 7

Sarcoma X 1

Thymus + + M + + + + + + + + + + + + + + M + + + + + 42

Histiocytic sarcoma 2

Integumentary System 

Mammary gland + + + + + + + + + + + + + + + + + + + + + + + 46

Skin + + + + + + + + + + + + + + + + + + + + + + + 48

Musculoskeletal System 

Bone + + + + + + + + + + + + + + + + + + + + + + + 48

Rib, leiomyosarcoma, metastatic, 

 uterus 1

Skeletal muscle 1

Leiomyosarcoma, metastatic, uterus 1
226 Tetrafluoroethylene, NTP TR 450

TABLE D2

Individual Animal Tumor Pathology of Female Mice in the 2-Year Inhalation Study of Tetrafluoroethylene: 312 ppm

(continued)

4 4 4 4 4 5 5 5 5 5 5 5 5 5 5 5 6 6 6 6 6 6 6 6 6

Number of Days on Study 2 2 5 5 9 3 3 3 4 4 4 4 6 8 8 9 0 0 0 0 0 1 1 1 1

9 9 4 5 3 0 0 9 1 1 1 1 6 5 8 6 0 0 3 7 9 4 4 4 4

1 2 1 2 1 1 2 1 1 1 2 2 2 2 2 2 1 1 1 2 2 1 1 2 2

Carcass ID Number 9 1 8 0 9 7 1 8 7 9 1 2 0 3 0 1 7 8 8 0 2 7 9 1 2

2 2 0 5 6 6 6 7 7 4 9 3 3 1 7 3 9 2 8 6 0 5 7 1 5

Nervous System 

Brain + + + + + + + + + + + + + + + + + + + + + + + + +

Histiocytic sarcoma X

Respiratory System 

Larynx + + + + + + + A + + + + + + + + + + + + + + + + +

Lung + + + + + + + + + + + + + + + + + + + + + + + + +

Carcinoma X

Hepatocellular carcinoma, metastatic,

 liver X X X X X

Histiocytic sarcoma X X X X X X X

Sarcoma

Nose + + + + + + + + + + + + + + + + + + + + + + + + +

Trachea + + + + + + + + + + + + + + + + + + + + + + + + +

Special Senses System 

Ear +

Harderian gland + +

Adenoma

Urinary System 

Kidney + + + + + + + + + + + + + + + + + + + + + + + + +

Histiocytic sarcoma X X X

Urinary bladder + + + A + + + A + + + + + + + A + + + + + A + + +

Leiomyosarcoma, metastatic, uterus X

Sarcoma

Systemic Lesions 

Multiple organs + + + + + + + + + + + + + + + + + + + + + + + + +

Histiocytic sarcoma X X X X X X X X

Lymphoma malignant lymphocytic X

Lymphoma malignant mixed
Tetrafluoroethylene, NTP TR 450 227

TABLE D2

Individual Animal Tumor Pathology of Female Mice in the 2-Year Inhalation Study of Tetrafluoroethylene: 312 ppm

(continued)

6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

Number of Days on Study 1 1 1 3 3 3 3 3 3 4 4 4 4 4 4 4 5 5 5 6 6 6 6

4 5 8 1 6 6 8 9 9 3 4 5 6 6 6 9 1 7 9 7 7 7 7

2 1 2 2 1 2 2 1 2 1 2 2 2 2 2 2 2 1 1 1 1 2 2 Total

Carcass ID Number 2 9 3 0 7 3 2 8 0 8 1 2 1 1 2 1 2 8 9 8 8 0 1 Tissues/

9 8 0 0 8 2 4 3 4 6 4 7 0 8 6 5 2 5 3 1 9 1 7 Tumors

Nervous System 

Brain + + + + + + + + + + + + + + + + + + + + + + + 48

Histiocytic sarcoma 1

Respiratory System 

Larynx + + + + + + + + + + + + + + + + + + + + + + + 47

Lung + + + + + + + + + + + + + + + + + + + + + + + 48

Carcinoma 1

Hepatocellular carcinoma, metastatic, 

 liver X X X 8

Histiocytic sarcoma X X X X X X X X X 16

Sarcoma X 1

Nose + + + + + + + + + + + + + + + + + + + + + + + 48

Trachea + + + + + + + + + + + + + + + + + + + + + + + 48

Special Senses System 

Ear 1

Harderian gland + + + + 6

Adenoma X X X 3

Urinary System 

Kidney + + + + + + + + + + + + + + + + + + + + + + + 48

Histiocytic sarcoma X X X X 7

Urinary bladder + + + + + + + + + A + + + + + + + + + + + + + 43

Leiomyosarcoma, metastatic, uterus 1

Sarcoma X 1

Systemic Lesions 

Multiple organs + + + + + + + + + + + + + + + + + + + + + + + 48

Histiocytic sarcoma X X X X X X X X X X X X X 21

Lymphoma malignant lymphocytic 1

Lymphoma malignant mixed X X 2
228 Tetrafluoroethylene, NTP TR 450

TABLE D2

Individual Animal Tumor Pathology of Female Mice in the 2-Year Inhalation Study of Tetrafluoroethylene: 625 ppm 

4 4 4 4 4 4 4 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5

Number of Days on Study 5 7 7 8 8 8 9 1 3 4 4 4 4 5 5 5 6 6 6 6 6 8 8 9

7 6 8 1 4 9 2 0 5 1 1 1 1 2 5 6 6 9 9 9 9 0 9 5

3 3 3 3 3 3 3 3 3 3 3 3 3 3 2 3 3 2 2 3 3 2 3 3

Carcass ID Number 1 3 0 0 3 2 0 1 1 0 0 2 4 3 9 4 0 9 9 2 4 9 2 1

8 4 4 0 7 3 2 7 6 1 8 6 3 9 5 8 7 2 8 4 5 1 5 1

Alimentary System 

Esophagus + + + + + + + + + + + + + + + + + + + + + + + +

Gallbladder + + M + + A + A A + + A + A + A M + A M + + + +

Intestine large, colon + + + + + + + A A + + + + A + A + + + + + + + +

Intestine large, rectum + + + + + A + A A + + + + A + A + + + + + + + +

Intestine large, cecum + + + + + A + A A + + + + A + A + + M + + + + +

Intestine small, duodenum + + A + + A + A A + + + + A + A + + + + + + + +

Intestine small, jejunum + + A + + A + A A + + + + A + A + + + + + + + +

Intestine small, ileum + + + + + A + A A + + + + A + A + + A + + + + +

Liver + + + + + + + + + + + + + + + + + + + + + + + +

Hemangioma

Hemangioma, multiple X

Hemangiosarcoma X X X X

Hemangiosarcoma, multiple X X X X

Hepatocellular carcinoma X X X X X X X

Hepatocellular carcinoma, multiple X X

Hepatocellular adenoma X X X X X

Hepatocellular adenoma, multiple X X

Histiocytic sarcoma X X X X X X X X X X X X X X X

Mesentery + + + + +

Pancreas + + + + + + + A A + + + + A + + + + + + + + + +

Histiocytic sarcoma

Salivary glands + + + + + + + + + + + + + + + + + + + + + + + +

Stomach, forestomach + + + + + + + + + + + + + + + + + + + + + + + +

Squamous cell papilloma

Stomach, glandular + + + + + + + A A + + + + + + + + + + + + + + +

Tooth

Cardiovascular System 

Heart + + + + + + + + + + + + + + + + + + + + + + + +

Histiocytic sarcoma X

Endocrine System 

Adrenal cortex + + + + + + + + + + + + + + + + + + + + + + + +

Adrenal medulla + + + + + + + + + + + + + + + + + + + + + + + +

Islets, pancreatic + + + + + + + A A + + + + + + + + + + + + + + +

Parathyroid gland + + M M + + M + + + + M + + M M + M M + M + + +

Pituitary gland + + + + + + + + M + + + + + + + + + + + + + + +

Pars distalis, adenoma

Thyroid gland + + + + + + + + A + + + + + + + + + + + + + + +

Follicular cell, adenoma

General Body System 

None

Genital System 

Clitoral gland + + + + + M M + + M + + + M + + M M + + + + + +

Ovary + + + + + + + + + + + M + + + + + + + + + + + +

Histiocytic sarcoma X X X X

Periovarian tissue, histiocytic

 sarcoma X

Uterus + + + + + + + A A + + + + + + + + + + + + + + +
Tetrafluoroethylene, NTP TR 450 229

TABLE D2

Individual Animal Tumor Pathology of Female Mice in the 2-Year Inhalation Study of Tetrafluoroethylene: 625 ppm

(continued)

5 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

Number of Days on Study 9 0 1 1 1 2 3 3 3 3 4 5 5 5 5 5 6 6 6 6 6 6 6

7 8 4 5 9 9 0 0 1 6 2 0 2 3 3 3 1 7 7 7 7 7 7

3 3 3 2 2 3 3 3 2 3 3 3 3 3 3 3 3 3 3 3 3 3 3 Total

Carcass ID Number 1 1 2 9 9 1 0 1 9 3 4 3 3 3 3 4 4 0 1 2 2 3 4 Tissues/

9 4 7 6 3 5 6 3 9 3 2 2 0 5 6 7 0 3 0 1 8 1 6 Tumors

Alimentary System 

Esophagus + + + + + + + + + + + + + + + + + + + + + + + 47

Gallbladder + + + + A + + + + + A A + + + + + + + + + + + 34

Intestine large, colon + + + + + + + + + + A + + + + + + + + + + + + 42

Intestine large, rectum + + + + + + + + + + + + + + + + + + + + + + + 42

Intestine large, cecum + + + + + + + + + + A + + + + + + + + + + + + 40

Intestine small, duodenum + + + + + + + + + + A A + + + + + + + + + + + 39

Intestine small, jejunum + + + + A + + + + + A + + + + + + + + + + + + 39

Intestine small, ileum + + + + + + + + + + A + + + + + + + + + + + + 40

Liver + + + + + + + + + + + + + + + + + + + + + + + 47

Hemangioma X 1

Hemangioma, multiple 1

Hemangiosarcoma X X X X X X X X X X X 15

Hemangiosarcoma, multiple X X X X X X X X 12

Hepatocellular carcinoma X X X X X X X X 15

Hepatocellular carcinoma, multiple X X X X X 7

Hepatocellular adenoma X X X X X X 11

Hepatocellular adenoma, multiple X X X X X X X 9

Histiocytic sarcoma X X X X 19

Mesentery + + 7

Pancreas + + + + + + + + + + + + + + + + + + + + + + + 44

Histiocytic sarcoma X 1

Salivary glands + + + + + + + + + + + + + + + + + + + + + + + 47

Stomach, forestomach + + + + + + + + + + + + + + + + + + + + + + + 47

Squamous cell papilloma X 1

Stomach, glandular + + + + + + + + + + + + + + + + + + + + + + + 45

Tooth 

Cardiovascular System 

Heart + + + + + + + + + + + + + + + + + + + + + + + 47

Histiocytic sarcoma 1

Endocrine System 

Adrenal cortex + + + + + + + + + + + + + + + + + + + + + + + 47

Adrenal medulla + + + + + + + + + + + + + + + + + + + + + + + 47

Islets, pancreatic + + A + + + + + + + + + + + + + + + + + + + + 44

Parathyroid gland M M + M M + M + M + + + + M + M M M + + + M + 27

Pituitary gland + + + + M + + M + + + + + + + + + + + + + + + 44

Pars distalis, adenoma X X 2

Thyroid gland + + + + + + + + + + + + + + + + + + + + + + + 46

Follicular cell, adenoma X 1

General Body System 

None 

Genital System 

Clitoral gland + + + + M + + + + + + + + + + + + + M + + + M 38

Ovary + + M + + + + + + + + + + + + + + + + + + + + 45

Histiocytic sarcoma 4

Periovarian tissue, histiocytic 

 sarcoma 1

Uterus + + + + + + + + + + + + + + + + + + + + + + + 45
230 Tetrafluoroethylene, NTP TR 450

TABLE D2

Individual Animal Tumor Pathology of Female Mice in the 2-Year Inhalation Study of Tetrafluoroethylene: 625 ppm

(continued)

4 4 4 4 4 4 4 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5

Number of Days on Study 5 7 7 8 8 8 9 1 3 4 4 4 4 5 5 5 6 6 6 6 6 8 8 9

7 6 8 1 4 9 2 0 5 1 1 1 1 2 5 6 6 9 9 9 9 0 9 5

3 3 3 3 3 3 3 3 3 3 3 3 3 3 2 3 3 2 2 3 3 2 3 3

Carcass ID Number 1 3 0 0 3 2 0 1 1 0 0 2 4 3 9 4 0 9 9 2 4 9 2 1

8 4 4 0 7 3 2 7 6 1 8 6 3 9 5 8 7 2 8 4 5 1 5 1

Hematopoietic System 

Blood +

Bone marrow + + + + + + + + A + + + + + + + + + + + + + + +

Histiocytic sarcoma X X X X X

Lymph node + + + +

Iliac, histiocytic sarcoma X

Pancreatic, histiocytic sarcoma X

Renal, histiocytic sarcoma X X

Lymph node, bronchial + + + + + + + + + + + + + + + M + + M + + + M +

Histiocytic sarcoma X X X X X

Lymph node, mandibular + + + + + M + M + + + + + M + + + + + M M M +

Histiocytic sarcoma X X

Lymph node, mesenteric + + + + + + + A M + + + + A + + + + + + + + + +

Hemangioma

Histiocytic sarcoma X X X X X X

Lymph node, mediastinal + + + + + + + + + M + + M M M + M + M + + M + +

Histiocytic sarcoma X X X X X X X

Spleen + + + + + + + A + + + + + + + + + + + + + + + +

Histiocytic sarcoma X X X X X X

Thymus M + + + M + + + M I + + + I + + + M + + + + + +

Histiocytic sarcoma X

Integumentary System 

Mammary gland + + M + + + + + M + + + + + + + + + + + + + + +

Skin + + + + + + + + + + + + + + + + + + + + + + + +

Hemangioma

Musculoskeletal System 

Bone + + + + + + + + + + + + + + + + + + + + + + + +

Nervous System 

Brain + + + + + + + + + + + + + + + + + + + + + + + +

Respiratory System 

Larynx + + + + + A + A A + + + + A + + + + + + + + + +

Lung + + + + + + + + + + + + + + + + + + + + + + + +

Alveolar/bronchiolar adenoma X X X

Alveolar/bronchiolar adenoma,

 multiple X 

Alveolar/bronchiolar carcinoma

Hepatocellular carcinoma, metastatic,

 liver X X X X X

Histiocytic sarcoma X X X X X X X X X X X

Nose + + + + + A + + A + + + + + + + + + + + + + + +

Trachea + + + + + + + + A + + + + A + + + + + + + + + +
Tetrafluoroethylene, NTP TR 450 231

TABLE D2

Individual Animal Tumor Pathology of Female Mice in the 2-Year Inhalation Study of Tetrafluoroethylene: 625 ppm

(continued)

5 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

Number of Days on Study 9 0 1 1 1 2 3 3 3 3 4 5 5 5 5 5 6 6 6 6 6 6 6

7 8 4 5 9 9 0 0 1 6 2 0 2 3 3 3 1 7 7 7 7 7 7

3 3 3 2 2 3 3 3 2 3 3 3 3 3 3 3 3 3 3 3 3 3 3 Total

Carcass ID Number 1 1 2 9 9 1 0 1 9 3 4 3 3 3 3 4 4 0 1 2 2 3 4 Tissues/

9 4 7 6 3 5 6 3 9 3 2 2 0 5 6 7 0 3 0 1 8 1 6 Tumors

Hematopoietic System 

Blood 1

Bone marrow + + + + + + + + + + + + + + + + + + + + + + + 46

Histiocytic sarcoma 5

Lymph node 4

Iliac, histiocytic sarcoma 1

Pancreatic, histiocytic sarcoma 1

Renal, histiocytic sarcoma 2

Lymph node, bronchial M + + + + + + + + + A + M + + + + + + + + M + 40

Histiocytic sarcoma X 6

Lymph node, mandibular + + + I M + + + + + M + + I M + + + + M + + + 34

Histiocytic sarcoma 2

Lymph node, mesenteric + M + + M + + + + + + + + + I + + + + + + + + 41

Hemangioma X 1

Histiocytic sarcoma X 7

Lymph node, mediastinal M M M + + + + + + + + + + + + M + + + + M + + 35

Histiocytic sarcoma X X 9

Spleen + + + + + + + + + + + + + + + + + + + + + + + 46

Histiocytic sarcoma X X 8

Thymus + + + + + + + + + + + + M + M + + + + + + + + 39

Histiocytic sarcoma X 2

Integumentary System 

Mammary gland + + + + + + + + + + + + + + + + + + + + + + + 45

Skin + + + + + + + + + + + + + + + + + + + + + + + 47

Hemangioma X 1

Musculoskeletal System 

Bone + + + + + + + + + + + + + + + + + + + + + + + 47

Nervous System 

Brain + + + + + + + + + + + + + + + + + + + + + + + 47

Respiratory System 

Larynx + + + + + + + + + + + + + + + + + + + + + + + 43

Lung + + + + + + + + + + + + + + + + + + + + + + + 47

Alveolar/bronchiolar adenoma X X 5

Alveolar/bronchiolar adenoma, 

 multiple 1

Alveolar/bronchiolar carcinoma X X 2

Hepatocellular carcinoma, metastatic, 

 liver X 6

Histiocytic sarcoma X X 13

Nose + + + + + + + + + + + + + + + + + + + + + + + 45

Trachea + + + + + + + + + + + + + + + + + + + + + + + 45
232 Tetrafluoroethylene, NTP TR 450

TABLE D2

Individual Animal Tumor Pathology of Female Mice in the 2-Year Inhalation Study of Tetrafluoroethylene: 625 ppm

(continued)

4 4 4 4 4 4 4 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5

Number of Days on Study 5 7 7 8 8 8 9 1 3 4 4 4 4 5 5 5 6 6 6 6 6 8 8 9

7 6 8 1 4 9 2 0 5 1 1 1 1 2 5 6 6 9 9 9 9 0 9 5

3 3 3 3 3 3 3 3 3 3 3 3 3 3 2 3 3 2 2 3 3 2 3 3

Carcass ID Number 1 3 0 0 3 2 0 1 1 0 0 2 4 3 9 4 0 9 9 2 4 9 2 1

8 4 4 0 7 3 2 7 6 1 8 6 3 9 5 8 7 2 8 4 5 1 5 1

Special Senses System 

Harderian gland + +

Urinary System 

Kidney + + + + + + + + + + + + + + + + + + + + + + + +

Histiocytic sarcoma X X X X

Urinary bladder + + + + + + + A A + + + + + + + + + + + + + + +

Systemic Lesions 

Multiple organs + + + + + + + + + + + + + + + + + + + + + + + +

Histiocytic sarcoma X X X X X X X X X X X X X X X
Tetrafluoroethylene, NTP TR 450 233

TABLE D2

Individual Animal Tumor Pathology of Female Mice in the 2-Year Inhalation Study of Tetrafluoroethylene: 625 ppm

(continued)

5 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

Number of Days on Study 9 0 1 1 1 2 3 3 3 3 4 5 5 5 5 5 6 6 6 6 6 6 6

7 8 4 5 9 9 0 0 1 6 2 0 2 3 3 3 1 7 7 7 7 7 7

3 3 3 2 2 3 3 3 2 3 3 3 3 3 3 3 3 3 3 3 3 3 3 Total

Carcass ID Number 1 1 2 9 9 1 0 1 9 3 4 3 3 3 3 4 4 0 1 2 2 3 4 Tissues/

9 4 7 6 3 5 6 3 9 3 2 2 0 5 6 7 0 3 0 1 8 1 6 Tumors

Special Senses System 

Harderian gland + + 4

Urinary System 

Kidney + + + + + + + + + + + + + + + + + + + + + + + 47

Histiocytic sarcoma 4

Urinary bladder + + + + I + + + + + + + + + + + + + M + + + + 43

Systemic Lesions 

Multiple organs + + + + + + + + + + + + + + + + + + + + + + + 47

Histiocytic sarcoma X X X X 19
234 Tetrafluoroethylene, NTP TR 450

TABLE D2

Individual Animal Tumor Pathology of Female Mice in the 2-Year Inhalation Study of Tetrafluoroethylene: 1,250 ppm 

1 1 3 4 4 4 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5

Number of Days on Study 3 4 6 6 8 8 0 0 1 1 3 4 4 4 5 5 5 6 6 6 8 8 8 8 8

5 4 6 8 4 4 7 9 3 8 6 1 1 8 2 2 5 3 5 9 0 5 6 6 6

4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4

Carcass ID Number 2 0 5 2 5 6 1 6 5 1 2 0 4 1 1 2 1 2 1 4 3 3 1 1 2

1 7 3 6 4 3 5 1 1 4 2 8 5 6 9 5 2 7 1 2 1 9 3 7 9

Alimentary System 

Esophagus + + + + + + + + + + + + + + + + + + + + + + + + +

Gallbladder A + + + + + + A A + + + + + + + M A + + A A + + +

Intestine large, colon A + + + + + + A + + + + + + + + + + + + A A + + +

Intestine large, rectum A + + + + + + + + + + + + + + I + + + + A + + + +

Intestine large, cecum A + + + + + A A A + A + + + + + + + + + A A + + +

Intestine small, duodenum A + + + + + A A + + + M + + + + + A + + A A + + +

Intestine small, jejunum A + + + + + + A A + A + + + + + + A + + A A + + +

Intestine small, ileum A + + + + + A A A + A + + + + + + A + + A A + + +

Liver A + + + + + + + + + + + + + + + + + + + + + + + +

Hemangioma

Hemangiosarcoma X X X X X X X

Hemangiosarcoma, multiple X X X X X X X X X

Hepatocellular carcinoma X X X X X X X X

Hepatocellular carcinoma, multiple X X

Hepatocellular adenoma X X X

Hepatocellular adenoma, multiple X X X

Histiocytic sarcoma X X X X X X X X

Mesentery + + +

Sarcoma

Pancreas A + + + + + + + + + + + + + + + + + + + + + + + +

Hemangiosarcoma X

Histiocytic sarcoma X

Salivary glands + + + + + + + + + + + + + + + + + + + + + + + + +

Stomach, forestomach A + + + + + + + + + + + + + + + + + + + + + + + +

Stomach, glandular A + + + + + + + + + + + + + + + + + + + A A + + +

Tooth + +

Cardiovascular System 

Heart + + + + + + + + + + + + + + + + + + + + + + + + +

Histiocytic sarcoma X

Endocrine System 

Adrenal cortex A + + + + + + + + + + + + + + + + + + + + + + + +

Histiocytic sarcoma X

Adrenal medulla A + + + + + + + + + + + + + + + + + + + M + + + +

Islets, pancreatic A + + + + + + + + + + + + + + + + + + + + + + + +

Parathyroid gland A + + + + + + + + + + + + M M + + M + M + M + + +

Pituitary gland A + M + + + + + + + + + + + + + + + + + + + + + +

Pars distalis, adenoma X

Thyroid gland A + + + + + + + + + + + + + I + + + + + + + + + +

Follicular cell, adenoma

General Body System 

None
Tetrafluoroethylene, NTP TR 450 235

TABLE D2

Individual Animal Tumor Pathology of Female Mice in the 2-Year Inhalation Study of Tetrafluoroethylene: 1,250 ppm

(continued)

5 5 5 5 5 5 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

Number of Days on Study 8 8 8 8 9 9 0 0 0 0 0 1 2 2 2 3 4 4 4 6 6 6 6

7 8 8 9 7 7 0 6 8 8 8 9 3 6 9 9 2 6 6 7 7 7 7

4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 Total

Carcass ID Number 5 1 5 3 5 5 5 4 2 3 4 6 6 4 2 3 2 3 4 3 3 4 4 Tissues/

7 8 9 2 2 6 8 9 0 7 4 4 0 8 3 8 4 0 3 4 6 0 7 Tumors

Alimentary System 

Esophagus + + + + + + + + + + + + + + + + + + + + + + + 48

Gallbladder M + + + + A M A + + + + A A + + A + + + + + + 34

Intestine large, colon + + + + + A + + + + + + A A + + A + + + + + + 40

Intestine large, rectum + + + + + A + + M + + + A A + + + + + + + + + 41

Intestine large, cecum + + + + + A A + + + + + A A + + A + + + + + + 36

Intestine small, duodenum A + + + + A + A + + + + A A + + A + + + + + + 35

Intestine small, jejunum A + + + + A + A + + + + A A + + A + + + + + + 35

Intestine small, ileum A + + + + A + + + + + + A A + + A + + + + + + 35

Liver + + + + + + + + + + + + + + + + + + + + + + + 47

Hemangioma X 1

Hemangiosarcoma X X X X X X X X X X X X 19

Hemangiosarcoma, multiple X X X X X X 15

Hepatocellular carcinoma X X X X X 13

Hepatocellular carcinoma, multiple X X X X X 7

Hepatocellular adenoma X X X X X 8

Hepatocellular adenoma, multiple X X X X 7

Histiocytic sarcoma X X X X X X X X X X 18

Mesentery + + + 6

Sarcoma X 1

Pancreas + + + + + + + + + + + + + + + + + + + + + + + 47

Hemangiosarcoma 1

Histiocytic sarcoma 1

Salivary glands + + + + + + + + + + + + + + + + + + + + + + + 48

Stomach, forestomach + + + + + + + + + + + + + + + + + + + + + + + 47

Stomach, glandular + + + + + + + + + + + + + + + + + + + + + + + 45

Tooth + 3

Cardiovascular System 

Heart + + + + + + + + + + + + + + + + + + + + + + + 48

Histiocytic sarcoma 1

Endocrine System 

Adrenal cortex + + + + + + + + + + + + + + + + + + + + + + + 47

Histiocytic sarcoma 1

Adrenal medulla + + + + + + + + + + + + + + + + + + + + + + + 46

Islets, pancreatic + + + + + + + + + + + + + + + + + + + + + + + 47

Parathyroid gland M + M + M M M M + + M M M + + M + + M + + + + 31

Pituitary gland + + + + + + + + + + + + + + + + + + + + + + + 46

Pars distalis, adenoma X X X X X 6

Thyroid gland + + + + + + + + + + + + + + + + + + + + + + + 46

Follicular cell, adenoma X 1

General Body System 

None 
236 Tetrafluoroethylene, NTP TR 450

TABLE D2

Individual Animal Tumor Pathology of Female Mice in the 2-Year Inhalation Study of Tetrafluoroethylene: 1,250 ppm

(continued)

1 1 3 4 4 4 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5

Number of Days on Study 3 4 6 6 8 8 0 0 1 1 3 4 4 4 5 5 5 6 6 6 8 8 8 8 8

5 4 6 8 4 4 7 9 3 8 6 1 1 8 2 2 5 3 5 9 0 5 6 6 6

4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4

Carcass ID Number 2 0 5 2 5 6 1 6 5 1 2 0 4 1 1 2 1 2 1 4 3 3 1 1 2

1 7 3 6 4 3 5 1 1 4 2 8 5 6 9 5 2 7 1 2 1 9 3 7 9

Genital System 

Clitoral gland M M + M + + + + + + + + + + + + + + + + M + + + +

Ovary A + + + + + + A + + + + + + + + + + + + + + + + +

Cystadenoma

Histiocytic sarcoma X X X

Uterus A + + + + + + + + + + + + + + + + + + + + + + + +

Polyp stromal X

Hematopoietic System 

Blood

Bone marrow A + + + + + + + + + + + + + + + + + + + + + + + +

Histiocytic sarcoma X X X

Lymph node + +

Iliac, histiocytic sarcoma

Pancreatic, histiocytic sarcoma

Renal, histiocytic sarcoma X X

Lymph node, bronchial + + + + M + + + + + M + M M + + + M + + + + + + +

Histiocytic sarcoma X X X

Lymph node, mandibular A + + + + M + M M + M + + + + + + M + M + M + +

Histiocytic sarcoma X X

Lymph node, mesenteric A + + + M + + + + + + + + + + + M + + + + A + + +

Histiocytic sarcoma X X X

Lymph node, mediastinal M M + + + + M M M M + M M + + M M + + + + + + + +

Histiocytic sarcoma X X X

Spleen A + + + + + + + + + + + + + + + + + + + + + + + +

Histiocytic sarcoma X X X X X X

Thymus + I + + M + + + + I + + + + + + + + + + + + + + +

Histiocytic sarcoma X X

Integumentary System 

Mammary gland + + + + + + + + + + + + + + + + + + + + + + + + +

Skin + + + + + + + + + + + + + + + + + + + + + + + + +

Squamous cell papilloma

Subcutaneous tissue, sarcoma X

Musculoskeletal System 

Bone + + + + + + + + + + + + + + + + + + + + + + + + +

Nervous System 

Brain + + + + + + + + + + + + + + + + + + + + + + + + +

Histiocytic sarcoma X
Tetrafluoroethylene, NTP TR 450 237

TABLE D2

Individual Animal Tumor Pathology of Female Mice in the 2-Year Inhalation Study of Tetrafluoroethylene: 1,250 ppm

(continued)

5 5 5 5 5 5 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

Number of Days on Study 8 8 8 8 9 9 0 0 0 0 0 1 2 2 2 3 4 4 4 6 6 6 6

7 8 8 9 7 7 0 6 8 8 8 9 3 6 9 9 2 6 6 7 7 7 7

4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 Total

Carcass ID Number 5 1 5 3 5 5 5 4 2 3 4 6 6 4 2 3 2 3 4 3 3 4 4 Tissues/

7 8 9 2 2 6 8 9 0 7 4 4 0 8 3 8 4 0 3 4 6 0 7 Tumors

Genital System 

Clitoral gland + + + + + + M M + M M + + + + + + + M + + + + 39

Ovary + + + + + + + + + + + + + + + + + + + + + + + 46

Cystadenoma X X 2

Histiocytic sarcoma 3

Uterus + + + + + + + + + + + + + + + + + + + + + + + 47

Polyp stromal 1

Hematopoietic System 

Blood + 1

Bone marrow + + + + + + + + + + + + + + + + + + + + + + + 47

Histiocytic sarcoma X 4

Lymph node + + + + 6

Iliac, histiocytic sarcoma X 1

Pancreatic, histiocytic sarcoma X 1

Renal, histiocytic sarcoma 2

Lymph node, bronchial + + + + + M M + + M + + + + + + M + + + M + + 38

Histiocytic sarcoma X 4

Lymph node, mandibular M + + + + + + M M M + M + M M + + + + + + + + 32

Histiocytic sarcoma 2

Lymph node, mesenteric + + + + + + + M + + + + + + + + + + + + + + + 43

Histiocytic sarcoma X X X 6

Lymph node, mediastinal + + + M + + M + M + + + + + + + + + M M + + + 33

Histiocytic sarcoma X 4

Spleen + + + + + + + + + + + + + + + + + + + + + + + 47

Histiocytic sarcoma X X X 9

Thymus M + + + + + + + + M + M + + M M + + M + M + + 38

Histiocytic sarcoma 2

Integumentary System 

Mammary gland M + + + + + + + + M + + + + + + + + + + + + + 46

Skin + + + + + + + + + + + + + + + + + + + + + + + 48

Squamous cell papilloma X 1

Subcutaneous tissue, sarcoma X 2

Musculoskeletal System 

Bone + + + + + + + + + + + + + + + + + + + + + + + 48

Nervous System 

Brain + + + + + + + + + + + + + + + + + + + + + + + 48

Histiocytic sarcoma 1
238 Tetrafluoroethylene, NTP TR 450

TABLE D2

Individual Animal Tumor Pathology of Female Mice in the 2-Year Inhalation Study of Tetrafluoroethylene: 1,250 ppm

(continued)

1 1 3 4 4 4 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5

Number of Days on Study 3 4 6 6 8 8 0 0 1 1 3 4 4 4 5 5 5 6 6 6 8 8 8 8 8

5 4 6 8 4 4 7 9 3 8 6 1 1 8 2 2 5 3 5 9 0 5 6 6 6

4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4

Carcass ID Number 2 0 5 2 5 6 1 6 5 1 2 0 4 1 1 2 1 2 1 4 3 3 1 1 2

1 7 3 6 4 3 5 1 1 4 2 8 5 6 9 5 2 7 1 2 1 9 3 7 9

Respiratory System 

Larynx + + + + + + + A + + + + + + + + + + + + + + + + +

Lung A + + + + + + + + + + + + + + + + + + + + + + + +

Alveolar/bronchiolar adenoma X

Alveolar/bronchiolar carcinoma

Hemangiosarcoma, metastatic, liver X

Hemangiosarcoma, metastatic, pancreas X

Hepatocellular carcinoma, metastatic,

 liver X X X

Histiocytic sarcoma X X X X X X X

Sarcoma, metastatic, skin X

Nose A + M + + + + A + + + + + + + + + + + + + + + + +

Trachea A + + + + + + + + + + + + + + + + + + + + + + + +

Special Senses System 

Harderian gland + +

Adenoma X X

Urinary System 

Kidney A + + + + + + + + + + + + + + + + + + + + + + + +

Histiocytic sarcoma X X X

Urinary bladder A + + + + M + + A + + + + + + + + + + + A A + + I

Systemic Lesions 

Multiple organs + + + + + + + + + + + + + + + + + + + + + + + + +

Histiocytic sarcoma X X X X X X X X

Lymphoma malignant mixed
Tetrafluoroethylene, NTP TR 450 239

TABLE D2

Individual Animal Tumor Pathology of Female Mice in the 2-Year Inhalation Study of Tetrafluoroethylene: 1,250 ppm

(continued)

5 5 5 5 5 5 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

Number of Days on Study 8 8 8 8 9 9 0 0 0 0 0 1 2 2 2 3 4 4 4 6 6 6 6

7 8 8 9 7 7 0 6 8 8 8 9 3 6 9 9 2 6 6 7 7 7 7

4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 Total

Carcass ID Number 5 1 5 3 5 5 5 4 2 3 4 6 6 4 2 3 2 3 4 3 3 4 4 Tissues/

7 8 9 2 2 6 8 9 0 7 4 4 0 8 3 8 4 0 3 4 6 0 7 Tumors

Respiratory System 

Larynx + + + + + + + + + + + + + + + + + + + + + + + 47

Lung + + + + + + + + + + + + + + + + + + + + + + + 47

Alveolar/bronchiolar adenoma X X 3

Alveolar/bronchiolar carcinoma X 1

Hemangiosarcoma, metastatic, liver X X 3

Hemangiosarcoma, metastatic, pancreas 1

Hepatocellular carcinoma, metastatic, 

 liver X 4

Histiocytic sarcoma X X X X X X 13

Sarcoma, metastatic, skin 1

Nose + + + + + + + + + + + + + + + + + + + + + + + 45

Trachea + + + + + + + + + + + + + + + + + + + + + + + 47

Special Senses System 

Harderian gland + + + + 6

Adenoma X X X X 6

Urinary System 

Kidney + + + + + + + + + + + + + + + + + + + + + + + 47

Histiocytic sarcoma 3

Urinary bladder + + + + + A + + + + + I M A + + + + + I + + + 37

Systemic Lesions 

Multiple organs + + + + + + + + + + + + + + + + + + + + + + + 48

Histiocytic sarcoma X X X X X X X X X X 18

Lymphoma malignant mixed X X 2
240 Tetrafluoroethylene, NTP TR 450

TABLE D3

Statistical Analysis of Primary Neoplasms in Female Mice in the 2-Year Inhalation Study of Tetrafluoroethylene

0 ppm 312 ppm 625 ppm 1,250 ppm

Harderian Gland: Adenoma

Overall rate 2/48 (4%) 3/48 (6%) 0/47 (0%) 6/48 (13%) a

Adjusted rate 5.6% 39.7% 0.0% 61.6% b

Terminal rate 2/36 (6%) 1/4 (25%) 0/6 (0%) 2/4 (50%) c

First incidence (days) 667 (T) 639 — 484 e

Life table test P<0.001 P=0.012 P=0.669N P<0.001 d

Logistic regression test P=0.009 P=0.109 P=0.669N P=0.040 d

Cochran-Armitage test P=0.078 d

Fisher exact test P=0.500 P=0.253N P=0.134 d

Liver: Hemangioma

Overall rate 0/48 (0%) 5/48 (10%) 2/47 (4%) 1/47 (2%)

Adjusted rate 0.0% 37.1% 13.0% 25.0%

Terminal rate 0/36 (0%) 0/4 (0%) 0/6 (0%) 1/4 (25%)

First incidence (days) — 541 569 667 (T)

Life table test P=0.145 P<0.001 P=0.084 P=0.091 

Logistic regression test P=0.523 P=0.024 P=0.224 P=0.091 

Cochran-Armitage test P=0.510N

Fisher exact test P=0.028 P=0.242 P=0.495 

Liver: Hemangiosarcoma

Overall rate 0/48 (0%) 27/48 (56%) 27/47 (57%) 34/47 (72%)

Adjusted rate 0.0% 100.0% 95.5% 93.5%

Terminal rate 0/36 (0%) 4/4 (100%) 5/6 (83%) 2/4 (50%)

First incidence (days) — 530 481 468

Life table test P<0.001 P<0.001 P<0.001 P<0.001

Logistic regression test P<0.001 P<0.001 P<0.001 P<0.001

Cochran-Armitage test P<0.001

Fisher exact test P<0.001 P<0.001 P<0.001

Liver: Hemangioma or Hemangiosarcoma

Overall rate 0/48 (0%) 31/48 (65%) 28/47 (60%) 35/48 (73%)

Adjusted rate 0.0% 100.0% 96.0% 96.7%

Terminal rate 0/36 (0%) 4/4 (100%) 5/6 (83%) 3/4 (75%)

First incidence (days) — 530 481 468

Life table test P<0.001 P<0.001 P<0.001 P<0.001

Logistic regression test P<0.001 P<0.001 P<0.001 P<0.001

Cochran-Armitage test P<0.001

Fisher exact test P<0.001 P<0.001 P<0.001

Liver: Hepatocellular Adenoma

Overall rate 15/48 (31%) 17/48 (35%) 20/47 (43%) 15/47 (32%)

Adjusted rate 37.2% 89.1% 93.2% 76.8%

Terminal rate 11/36 (31%) 3/4 (75%) 5/6 (83%) 2/4 (50%)

First incidence (days) 595 530 541 536

Life table test P<0.001 P<0.001 P<0.001 P<0.001

Logistic regression test P=0.090 P=0.138 P=0.016 P=0.198 

Cochran-Armitage test P=0.515 

Fisher exact test P=0.414 P=0.176 P=0.560 
Tetrafluoroethylene, NTP TR 450 241

TABLE D3

Statistical Analysis of Primary Neoplasms in Female Mice in the 2-Year Inhalation Study of Tetrafluoroethylene (continued)

0 ppm 312 ppm 625 ppm 1,250 ppm

Liver: Hepatocellular Carcinoma

Overall rate 4/48 (8%) 28/48 (58%) 22/47 (47%) 20/47 (43%)

Adjusted rate 10.8% 95.0% 87.7% 72.5%

Terminal rate 3/36 (8%) 3/4 (75%) 4/6 (67%) 1/4 (25%)

First incidence (days) 660 530 478 484

Life table test P<0.001 P<0.001 P<0.001 P<0.001

Logistic regression test P=0.042 P<0.001 P<0.001 P<0.001

Cochran-Armitage test P=0.012

Fisher exact test P<0.001 P<0.001 P<0.001

Liver: Hepatocellular Adenoma or Carcinoma

Overall rate 17/48 (35%) 33/48 (69%) 29/47 (62%) 28/47 (60%)

Adjusted rate 42.2% 100.0% 95.6% 88.6%

Terminal rate 13/36 (36%) 4/4 (100%) 5/6 (83%) 2/4 (50%)

First incidence (days) 595 530 478 484

Life table test P<0.001 P<0.001 P<0.001 P<0.001

Logistic regression test P=0.045 P<0.001 P<0.001 P=0.005

Cochran-Armitage test P=0.055 

Fisher exact test P=0.001 P=0.009 P=0.015

Lung: Alveolar/bronchiolar Adenoma

Overall rate 6/48 (13%) 0/48 (0%) 6/47 (13%) 3/47 (6%)

Adjusted rate 16.7% 0.0% 40.6% 30.2%

Terminal rate 6/36 (17%) 0/4 (0%) 2/6 (33%) 1/4 (25%)

First incidence (days) 667 (T) — 510 509

Life table test P=0.056 P=0.442N P=0.026 P=0.162 

Logistic regression test P=0.563 P=0.442N P=0.505 P=0.636N 

Cochran-Armitage test P=0.424N

Fisher exact test P=0.013N P=0.605 P=0.254N 

Lung: Alveolar/bronchiolar Adenoma or Carcinoma

Overall rate 6/48 (13%) 1/48 (2%) 8/47 (17%) 4/47 (9%)

Adjusted rate 16.7% 2.5% 49.2% 33.8%

Terminal rate 6/36 (17%) 0/4 (0%) 2/6 (33%) 1/4 (25%)

First incidence (days) 667 (T) 541 510 509

Life table test P=0.017 P=0.694N P=0.003 P=0.064 

Logistic regression test P=0.413 P=0.148N P=0.232 P=0.575 

Cochran-Armitage test P=0.565 

Fisher exact test P=0.056N P=0.370 P=0.384N 

Pituitary Gland (Pars Distalis): Adenoma

Overall rate 4/46 (9%) 5/45 (11%) 2/44 (5%) 6/46 (13%)

Adjusted rate 10.6% 55.3% 18.2% 53.0%

Terminal rate 3/36 (8%) 2/4 (50%) 0/6 (0%) 1/4 (25%)

First incidence (days) 617 585 652 565

Life table test P=0.002 P=0.018 P=0.374 P=0.002

Logistic regression test P=0.071 P=0.282 P=0.665 P=0.123 

Cochran-Armitage test P=0.352 

Fisher exact test P=0.486 P=0.360N P=0.370 
242 Tetrafluoroethylene, NTP TR 450

TABLE D3

Statistical Analysis of Primary Neoplasms in Female Mice in the 2-Year Inhalation Study of Tetrafluoroethylene (continued)

0 ppm 312 ppm 625 ppm 1,250 ppm

All Organs: Hemangioma

Overall rate 0/48 (0%) 5/48 (10%) 4/47 (9%) 1/48 (2%)

Adjusted rate 0.0% 37.1% 33.5% 25.0%

Terminal rate 0/36 (0%) 0/4 (0%) 1/6 (17%) 1/4 (25%)

First incidence (days) — 541 569 667 (T)

Life table test P=0.054 P<0.001 P=0.002 P=0.091 

Logistic regression test P=0.353 P=0.024 P=0.018 P=0.091 

Cochran-Armitage test P=0.544N

Fisher exact test P=0.028 P=0.056 P=0.500 

All Organs: Hemangiosarcoma

Overall rate 0/48 (0%) 27/48 (56%) 27/47 (57%) 34/48 (71%)

Adjusted rate 0.0% 100.0% 95.5% 93.5%

Terminal rate 0/36 (0%) 4/4 (100%) 5/6 (83%) 2/4 (50%)

First incidence (days) — 530 481 468

Life table test P<0.001 P<0.001 P<0.001 P<0.001

Logistic regression test P<0.001 P<0.001 P<0.001 P<0.001

Cochran-Armitage test P<0.001

Fisher exact test P<0.001 P<0.001 P<0.001

All Organs: Hemangioma or Hemangiosarcoma

Overall rate 0/48 (0%) 31/48 (65%) 28/47 (60%) 35/48 (73%)

Adjusted rate 0.0% 100.0% 96.0% 96.7%

Terminal rate 0/36 (0%) 4/4 (100%) 5/6 (83%) 3/4 (75%)

First incidence (days) — 530 481 468

Life table test P<0.001 P<0.001 P<0.001 P<0.001

Logistic regression test P<0.001 P<0.001 P<0.001 P<0.001

Cochran-Armitage test P<0.001

Fisher exact test P<0.001 P<0.001 P<0.001

All Organs: Histiocytic Sarcoma

Overall rate 1/48 (2%) 21/48 (44%) 19/47 (40%) 18/48 (38%)

Adjusted rate 2.1% 77.6% 51.3% 78.2%

Terminal rate 0/36 (0%) 1/4 (25%) 0/6 (0%) 1/4 (25%)

First incidence (days) 400 429 457 484

Life table test P<0.001 P<0.001 P<0.001 P<0.001

Logistic regression test P=0.015 P<0.001 P<0.001 P<0.001

Cochran-Armitage test P=0.002

Fisher exact test P<0.001 P<0.001 P<0.001

All Organs: Lymphocytic or Mixed Malignant Lymphoma

Overall rate 5/48 (10%) 3/48 (6%) 0/47 (0%) 2/48 (4%)

Adjusted rate 12.8% 18.0% 0.0% 30.0%

Terminal rate 3/36 (8%) 0/4 (0%) 0/6 (0%) 1/4 (25%)

First incidence (days) 595 530 — 608

Life table test P=0.471 P=0.348 P=0.250N P=0.377

Logistic regression test P=0.276N P=0.419N P=0.068N P=0.551N

Cochran-Armitage test P=0.115N

Fisher exact test P=0.357N P=0.030N P=0.218N
Tetrafluoroethylene, NTP TR 450 243

TABLE D3

Statistical Analysis of Primary Neoplasms in Female Mice in the 2-Year Inhalation Study of Tetrafluoroethylene (continued)

0 ppm 312 ppm 625 ppm 1,250 ppm

All Organs: Benign Neoplasms

Overall rate 27/48 (56%) 24/48 (50%) 26/47 (55%) 29/48 (60%)

Adjusted rate 64.2% 100.0% 95.0% 100.0%

Terminal rate 21/36 (58%) 4/4 (100%) 5/6 (83%) 4/4 (100%)

First incidence (days) 595 530 510 484

Life table test P<0.001 P<0.001 P<0.001 P<0.001

Logistic regression test P=0.005 P=0.319 P=0.133 P=0.016

Cochran-Armitage test P=0.290

Fisher exact test P=0.341N P=0.546N P=0.418 

All Organs: Malignant Neoplasms

Overall rate 14/48 (29%) 46/48 (96%) 45/47 (96%) 46/48 (96%)

Adjusted rate 32.3% 100.0% 100.0% 100.0%

Terminal rate 7/36 (19%) 4/4 (100%) 6/6 (100%) 4/4 (100%)

First incidence (days) 400 429 457 366

Life table test P<0.001 P<0.001 P<0.001 P<0.001

Logistic regression test P<0.001 P<0.001 P<0.001 P<0.001

Cochran-Armitage test P<0.001

Fisher exact test P<0.001 P<0.001 P<0.001

All Organs: Benign or Malignant Neoplasms

Overall rate 34/48 (71%) 47/48 (98%) 45/47 (96%) 46/48 (96%)

Adjusted rate 77.2% 100.0% 100.0% 100.0%

Terminal rate 26/36 (72%) 4/4 (100%) 6/6 (100%) 4/4 (100%)

First incidence (days) 400 429 457 366

Life table test P<0.001 P<0.001 P<0.001 P<0.001

Logistic regression test P<0.001 P<0.001 P=0.001 P<0.001

Cochran-Armitage test P<0.001

Fisher exact test P<0.001 P=0.001 P<0.001

(T)Terminal sacrifice

Number of neoplasm-bearing animals/number of animals examined. Denominator is number of animals examined microscopically for liver, lung, and pituitary a

gland; for other tissues, denominator is number of animals necropsied.

Kaplan-Meier estimated neoplasm incidence at the end of the study after adjustment for intercurrent mortality b

Observed incidence at terminal kill c

Beneath the control incidence are the P values associated with the trend test. Beneath the exposed group incidence are the P values corresponding to pairwise d

comparisons between the controls and that exposed group. The life table test regards neoplasms in animals dying prior to terminal kill as being (directly or indirectly)

the cause of death. The logistic regression test regards these lesions as nonfatal. The Cochran-Armitage and Fisher exact tests compare directly the overall incidence

rates. For all tests, a negative trend or a lower incidence in an exposure group is indicated by N.

Not applicable; no neoplasms in animal group e
244 Tetrafluoroethylene, NTP TR 450

TABLE D4a

Historical Incidence of Liver Neoplasms in Chamber Control Female B6C3F 1 Micea

Incidence in Controls

Study Hemangioma Hemangiosarcoma Hepatocellular Hepatocellular Hepatocellular

Adenoma Carcinoma Adenoma

or Carcinoma

Historical Incidence at Battelle Pacific Northwest Laboratories

1,3-Butadiene 0/49 1/49 11/49 4/49 15/49

Acetonitrile 0/49 0/49 4/49 7/49 9/49

Allyl Glycidyl Ether 0/50 0/50 1/50 5/50 6/50

-Chloroacetophenone 0/50 0/50 4/50 8/50 12/50

Epinephrine Hydrochloride 0/50 1/50 2/50 1/50 3/50

Ethyl Chloride 0/49 0/49 0/49 3/49 3/49

Hexachlorocyclopentadiene 0/49 0/49 5/49 4/49 9/49

o-Chlorobenzalmalononitrile (CS-2) 0/50 0/50 4/50 7/50 11/50

Ozone 0/50 0/50 20/50 15/50 27/50

Total 0/446 2/446 (0.5%) 51/446 (11.4%) 54/446 (12.1%) 95/446 (21.3%)

Standard deviation 0.9% 12.5% 8.1% 14.8%

Range 0%-2% 0%-40% 2%-30% 6%-54%

Overall Historical Incidence

Total 1/937 (0.1%) 5/937 (0.5%) 114/937 (12.2%) 103/937 (11.0%) 200/937 (21.3%)

Standard deviation 0.5% 1.0% 9.7% 6.7% 11.9%

Range 0%-2% 0%-3% 0%-40% 0%-30% 3%-54%

Data as of 12 May 1995 a
Tetrafluoroethylene, NTP TR 450 245

TABLE D4b

Historical Incidence of Histiocytic Sarcoma in Chamber Control Female B6C3F 1 Micea

Study Incidence in Controls

Historical Incidence at Battelle Pacific Northwest Laboratories

1,3-Butadiene 3/50

Acetonitrile 2/49

Allyl Glycidyl Ether 3/50

-Chloroacetophenone 1/50

Epinephrine Hydrochloride 1/50

Ethyl Chloride 0/49

Hexachlorocyclopentadiene 4/49

o-Chlorobenzalmalononitrile (CS-2) 0/50

Ozone 0/50

Total 14/447 (3.1%)

Standard deviation 3.0%

Range 0%-8%

Overall Historical Incidence

Total 26/941 (2.8%)

Standard deviation 3.1%

Range 0%-10%

Data as of 12 May 1995 a
246 Tetrafluoroethylene, NTP TR 450

TABLE D5

Summary of the Incidence of Nonneoplastic Lesions in Female Mice in the 2-Year Inhalation Study 

of Tetrafluoroethylene a

0 ppm 312 ppm 625 ppm 1,250 ppm

Disposition Summary

Animals initially in study 58 58 58 58

15-Month interim evaluation 10 10 10 10

Early deaths

Accidental death 1

Moribund 8 28 26 27

Natural deaths 4 16 15 17

Survivors

Terminal sacrifice 36 4 6 4

Animals examined microscopically 58 58 57 58

15-Month Interim Evaluation

Alimentary System

Intestine large, cecum (10) (10) (10) (10)

Developmental malformation 1 (10%) 

Liver (10) (10) (10) (10)

Angiectasis 4 (40%) 2 (20%) 1 (10%) 

Basophilic focus 1 (10%) 

Clear cell focus 1 (10%) 

Eosinophilic focus 1 (10%) 4 (40%) 5 (50%) 

Fatty change 1 (10%) 1 (10%) 

Hematopoietic cell proliferation 1 (10%) 

Infarct, chronic 1 (10%) 

Infiltration cellular, mixed cell 1 (10%) 4 (40%) 3 (30%) 1 (10%) 

Mixed cell focus 1 (10%) 1 (10%) 

Necrosis, coagulative, multifocal 1 (10%) 

Thrombosis 1 (10%) 

Hepatocyte, karyomegaly 1 (10%) 

Mesentery (1) (1) (1)

Fat, necrosis 1 (100%) 1 (100%) 1 (100%)

Salivary glands (10) (10) (10) (10)

Infiltration cellular, mononuclear cell 4 (40%) 3 (30%) 4 (40%) 1 (10%) 

Endocrine System

Adrenal cortex (10) (10) (10) (10)

Capsule, hyperplasia 5 (50%) 10 (100%) 5 (50%) 9 (90%) 

X-zone, vacuolization cytoplasmic 1 (10%) 2 (20%) 3 (30%) 1 (10%) 

Thyroid gland (10) (10) (10) (10)

Ultimobranchial cyst 1 (10%) 

Genital System

Clitoral gland (9) (9) (9) (9)

Ectasia 1 (11%) 

Infiltration cellular, mononuclear cell 1 (11%) 1 (11%) 

Ovary (10) (10) (10) (10)

Abscess 1 (10%) 

Cyst 1 (10%) 1 (10%) 2 (20%) 

Uterus (10) (10) (10) (10)

Endometrium, hyperplasia, cystic 4 (40%) 6 (60%) 4 (40%) 7 (70%) 

Number of animals examined microscopically at the site and the number of animals with lesion a
Tetrafluoroethylene, NTP TR 450 247

TABLE D5

Summary of the Incidence of Nonneoplastic Lesions in Female Mice in the 2-Year Inhalation Study 

of Tetrafluoroethylene (continued)

0 ppm 312 ppm 625 ppm 1,250 ppm

15-Month Interim Evaluation (continued)

Hematopoietic System

Bone marrow (10) (10) (10) (10)

Hyperplasia, neutrophil 1 (10%) 1 (10%) 1 (10%) 

Lymph node (1) 

Pancreatic, hyperplasia, lymphoid 1 (100%) 

Lymph node, mandibular (7) (4) (9) (6)

Hyperplasia, lymphoid 1 (25%) 

Lymph node, mediastinal (7) (7) (8) (3)

Hemorrhage 1 (13%) 

Hyperplasia, lymphoid 1 (13%) 

Spleen (10) (10) (10) (10)

Hematopoietic cell proliferation 2 (20%) 4 (40%) 4 (40%) 3 (30%) 

Hyperplasia, lymphoid 1 (10%) 

Infiltration cellular, polymorphonuclear 1 (10%) 

Nervous System

Brain (10) (10) (9) (10)

Mineralization 4 (40%) 1 (10%) 1 (11%) 4 (40%) 

Respiratory System

Lung (10) (10) (10) (10)

Embolus, focal 1 (10%) 

Hemorrhage 1 (10%) 1 (10%) 

Urinary System

Kidney (10) (10) (10) (10)

Infiltration cellular, mononuclear cell 2 (20%) 2 (20%) 1 (10%) 

Pelvis, infiltration cellular, mononuclear 

 cell 1 (10%) 

Renal tubule, dilatation 1 (10%) 

Renal tubule, karyomegaly 10 (100%) 10 (100%)

Urinary bladder (9) (10) (10) (9)

Hyperplasia, lymphoid 2 (22%) 1 (10%) 1 (11%) 

Systems Examined With No Lesions Observed

Cardiovascular System

General Body System

Integumentary System

Musculoskeletal System

Special Senses System
248 Tetrafluoroethylene, NTP TR 450

TABLE D5

Summary of the Incidence of Nonneoplastic Lesions in Female Mice in the 2-Year Inhalation Study 

of Tetrafluoroethylene (continued)

0 ppm 312 ppm 625 ppm 1,250 ppm

2-Year Study

Alimentary System

Gallbladder (42) (36) (34) (34)

Inflammation, chronic active 1 (2%) 

Intestine large, colon (47) (45) (42) (40)

Infarct 1 (2%) 

Mesothelium, inflammation, chronic active 2 (4%) 

Intestine large, rectum (48) (48) (42) (41)

Mesothelium, inflammation, chronic active 1 (2%) 

Intestine large, cecum (47) (42) (40) (36)

Lymphoid tissue, hyperplasia, lymphoid 1 (2%) 

Mesothelium, inflammation, chronic active 1 (2%) 

Intestine small, duodenum (45) (39) (39) (35)

Mesothelium, inflammation, chronic active 1 (2%) 

Peyer's patch, hyperplasia, lymphoid 1 (2%) 1 (3%) 

Intestine small, jejunum (46) (37) (39) (35)

Hemorrhage 1 (3%) 

Perforation 1 (2%) 

Mesothelium, inflammation, chronic active 1 (2%) 

Peyer's patch, hyperplasia, lymphoid 1 (3%) 

Intestine small, ileum (46) (39) (40) (35)

Mesothelium, inflammation, chronic active 2 (4%) 

Peyer's patch, hyperplasia, lymphoid 1 (3%) 1 (3%) 

Liver (48) (48) (47) (47)

Angiectasis 1 (2%) 9 (19%) 6 (13%) 4 (9%) 

Basophilic focus 1 (2%) 2 (4%) 

Clear cell focus 1 (2%) 

Eosinophilic focus 5 (10%) 13 (27%) 12 (26%) 7 (15%) 

Fatty change 3 (6%) 

Hematopoietic cell proliferation 3 (6%) 19 (40%) 13 (28%) 15 (32%) 

Hyperplasia, lymphoid 1 (2%) 

Infarct 2 (4%) 1 (2%) 

Infiltration cellular, mixed cell 8 (17%) 8 (17%) 9 (19%) 3 (6%) 

Inflammation, suppurative 1 (2%) 

Mixed cell focus 3 (6%) 1 (2%) 

Necrosis, coagulative, multifocal 4 (8%) 11 (23%) 8 (17%) 8 (17%) 

Thrombosis 1 (2%) 

Centrilobular, necrosis 3 (6%) 1 (2%) 

Serosa, fibrosis 1 (2%) 1 (2%) 

Mesentery (9) (13) (7) (6)

Angiectasis 1 (11%) 

Cyst 1 (8%) 

Hyperplasia, lymphoid 1 (14%) 

Mineralization 1 (14%) 

Fat, hemorrhage 1 (8%) 

Fat, necrosis 7 (78%) 8 (62%) 6 (86%) 5 (83%) 

Mesothelium, inflammation, chronic active 1 (11%) 

Pancreas (48) (47) (44) (47)

Fibrosis 1 (2%) 1 (2%) 

Infiltration cellular, lymphocyte 1 (2%) 

Inflammation, acute 1 (2%) 

Inflammation, chronic active 3 (6%) 

Acinus, atrophy 1 (2%) 1 (2%) 3 (7%) 

Acinus, vacuolization cytoplasmic 1 (2%) 

Duct, ectasia 1 (2%) 
Tetrafluoroethylene, NTP TR 450 249

TABLE D5

Summary of the Incidence of Nonneoplastic Lesions in Female Mice in the 2-Year Inhalation Study 

of Tetrafluoroethylene (continued)

0 ppm 312 ppm 625 ppm 1,250 ppm

2-Year Study (continued)

Alimentary System (continued)

Salivary glands (48) (48) (47) (48)

Infiltration cellular, mononuclear cell 19 (40%) 6 (13%) 9 (19%) 2 (4%) 

Inflammation, focal, suppurative 1 (2%) 

Stomach, forestomach (48) (48) (47) (47)

Hyperplasia, squamous 1 (2%) 

Ulcer 1 (2%) 

Epithelium, hyperplasia 4 (8%) 4 (9%) 

Serosa, inflammation, chronic active 1 (2%) 

Stomach, glandular (48) (48) (45) (45)

Mineralization 1 (2%) 

Serosa, inflammation, chronic active 1 (2%) 

Tooth (2) (3)

Dysplasia 1 (50%) 2 (67%) 

Peridontal tissue, inflammation, suppurative 1 (33%) 

Cardiovascular System

Heart (48) (48) (47) (48)

Cardiomyopathy 2 (4%) 

Polyarteritis 1 (2%) 

Endocrine System

Adrenal cortex (48) (47) (47) (47)

Cyst 1 (2%) 1 (2%) 

Degeneration, fatty 1 (2%) 

Hyperplasia 1 (2%) 1 (2%) 

Capsule, hyperplasia 45 (94%) 45 (96%) 47 (100%) 41 (87%) 

Capsule, mineralization 1 (2%) 

X-zone, vacuolization cytoplasmic 1 (2%) 1 (2%) 2 (4%) 

Adrenal medulla (48) (47) (47) (46)

Angiectasis 1 (2%) 

Islets, pancreatic (48) (45) (44) (47)

Hyperplasia 1 (2%) 

Pituitary gland (46) (45) (44) (46)

Pars distalis, angiectasis 2 (4%) 

Pars distalis, congestion 2 (4%) 2 (4%) 

Pars distalis, cyst 3 (7%) 1 (2%) 

Pars distalis, hyperplasia 6 (13%) 3 (7%) 2 (5%) 5 (11%) 

Thyroid gland (48) (48) (46) (46)

Inflammation, focal 1 (2%) 1 (2%) 

Polyarteritis 1 (2%) 

Ultimobranchial cyst 2 (4%) 2 (4%) 2 (4%) 2 (4%) 

Follicle, cyst 2 (4%) 2 (4%) 

Follicular cell, hyperplasia 2 (4%) 
250 Tetrafluoroethylene, NTP TR 450

TABLE D5

Summary of the Incidence of Nonneoplastic Lesions in Female Mice in the 2-Year Inhalation Study 

of Tetrafluoroethylene (continued)

0 ppm 312 ppm 625 ppm 1,250 ppm

2-Year Study (continued)

General Body System

None 

Genital System

Clitoral gland (42) (42) (38) (39)

Infiltration cellular, mononuclear cell 1 (2%) 1 (2%) 

Ovary (47) (47) (45) (46)

Atrophy 2 (4%) 4 (9%) 5 (11%) 2 (4%) 

Congestion 1 (2%) 2 (4%) 1 (2%) 

Cyst 13 (28%) 27 (57%) 16 (36%) 18 (39%) 

Hemorrhage 1 (2%) 

Inflammation, chronic 1 (2%) 

Metaplasia, osseous 1 (2%) 

Pigmentation, hemosiderin 1 (2%) 

Pigmentation, hemosiderin, cholesterol 1 (2%) 

Pigmentation, lipofuscin 1 (2%) 

Polyarteritis 1 (2%) 

Uterus (48) (48) (45) (47)

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

Hemorrhage 1 (2%) 

Inflammation, chronic active 1 (2%) 1 (2%) 

Inflammation, suppurative 1 (2%) 1 (2%) 

Necrosis 1 (2%) 

Endometrium, hyperplasia, cystic 23 (48%) 21 (44%) 24 (53%) 24 (51%) 

Hematopoietic System

Bone marrow (48) (48) (46) (47)

Hyperplasia, erythrocyte 2 (4%) 2 (4%) 

Hyperplasia, neutrophil 2 (4%) 1 (2%) 

Lymph node (5) (6) (4) (6)

Axillary, hyperplasia, lymphoid 1 (25%) 

Iliac, angiectasis 1 (17%) 

Iliac, hyperplasia, lymphoid 1 (17%) 1 (25%) 

Iliac, inflammation, chronic active 1 (17%) 

Lumbar, hyperplasia, lymphoid 1 (25%) 

Pancreatic, hyperplasia, histiocytic 1 (20%) 

Pancreatic, hyperplasia, lymphoid 1 (17%) 1 (17%) 

Renal, hemorrhage 1 (17%) 2 (33%) 

Renal, hyperplasia, lymphoid 1 (17%) 

Lymph node, bronchial (40) (36) (40) (38)

Congestion 1 (3%) 

Hemorrhage 1 (3%) 2 (5%) 3 (8%) 

Hyperplasia, histiocytic 1 (3%) 1 (3%) 

Hyperplasia, lymphoid 1 (3%) 5 (14%) 3 (8%) 

Hyperplasia, plasma cell 1 (3%) 1 (3%) 

Inflammation 1 (3%) 

Pigmentation, hemosiderin 1 (3%) 1 (3%) 1 (3%) 
Tetrafluoroethylene, NTP TR 450 251

TABLE D5

Summary of the Incidence of Nonneoplastic Lesions in Female Mice in the 2-Year Inhalation Study 

of Tetrafluoroethylene (continued)

0 ppm 312 ppm 625 ppm 1,250 ppm

2-Year Study (continued)

Hematopoietic System (continued)

Lymph node, mandibular (39) (35) (34) (32)

Hemorrhage 1 (3%) 1 (3%) 

Hyperplasia, histiocytic 1 (3%) 1 (3%) 

Hyperplasia, lymphoid 2 (5%) 1 (3%) 2 (6%) 1 (3%) 

Hyperplasia, plasma cell 1 (3%) 1 (3%) 

Inflammation 1 (3%) 

Lymph node, mesenteric (43) (40) (41) (43)

Angiectasis 1 (2%) 

Hemorrhage 2 (5%) 1 (3%) 3 (7%) 2 (5%) 

Hyperplasia, histiocytic 1 (2%) 1 (3%) 3 (7%) 

Hyperplasia, lymphoid 5 (13%) 4 (10%) 2 (5%) 

Hyperplasia, plasma cell 1 (2%) 

Inflammation, chronic active 2 (5%) 

Lymph node, mediastinal (28) (35) (35) (33)

Congestion 1 (3%) 2 (6%) 

Hematopoietic cell proliferation 1 (3%) 

Hemorrhage 3 (9%) 

Hyperplasia, histiocytic 2 (6%) 

Hyperplasia, lymphoid 2 (7%) 2 (6%) 4 (11%) 

Hyperplasia, plasma cell 1 (4%) 

Inflammation 1 (4%) 

Pigmentation, hemosiderin 1 (3%) 1 (3%) 

Spleen (48) (48) (46) (47)

Hematopoietic cell proliferation 18 (38%) 39 (81%) 41 (89%) 41 (87%) 

Hyperplasia, lymphoid 2 (4%) 2 (4%) 1 (2%) 

Pigmentation, melanin 1 (2%) 

Capsule, hematocyst 1 (2%) 

Thymus (46) (42) (39) (38)

Atrophy 1 (3%) 

Hyperplasia, lymphoid 1 (2%) 

Necrosis 4 (10%) 

Integumentary System

Mammary gland (48) (46) (45) (46)

Hyperplasia 1 (2%) 2 (4%) 2 (4%) 

Skin (47) (48) (47) (48)

Congestion 1 (2%) 

Musculoskeletal System

Bone (48) (48) (47) (48)

Fracture healed 1 (2%) 

Nervous System

Brain (48) (48) (47) (48)

Compression 1 (2%) 1 (2%) 1 (2%) 

Hemorrhage 1 (2%) 

Mineralization 20 (42%) 9 (19%) 14 (30%) 21 (44%) 

Ventricle, dilatation 1 (2%) 
252 Tetrafluoroethylene, NTP TR 450

TABLE D5

Summary of the Incidence of Nonneoplastic Lesions in Female Mice in the 2-Year Inhalation Study 

of Tetrafluoroethylene (continued)

0 ppm 312 ppm 625 ppm 1,250 ppm

2-Year Study (continued)

Respiratory System

Lung (48) (48) (47) (47)

Congestion 2 (4%) 1 (2%) 

Hemorrhage 2 (4%) 5 (10%) 5 (11%) 3 (6%) 

Inflammation, chronic 2 (4%) 

Pigmentation, hemosiderin 2 (4%) 3 (6%) 

Pigmentation, hemoglobin 1 (2%) 

Alveolar epithelium, hyperplasia 1 (2%) 2 (4%) 

Alveolus, infiltration cellular, histiocyte 1 (2%) 1 (2%) 2 (4%) 3 (6%) 

Interstitium, infiltration cellular, mixed 

 cell 3 (6%) 1 (2%) 

Nose (47) (48) (45) (45)

Inflammation, suppurative 1 (2%) 

Nasolacrimal duct, inflammation, suppurative 1 (2%) 

Respiratory epithelium, cytoplasmic 

 alteration 1 (2%) 

Special Senses System

Harderian gland (3) (6) (4) (6)

Hyperplasia 2 (33%) 3 (75%) 

Urinary System

Kidney (48) (48) (47) (47)

Hemorrhage 1 (2%) 

Infarct, chronic 2 (4%) 1 (2%) 

Infiltration cellular, mononuclear cell 3 (6%) 1 (2%) 4 (9%) 

Inflammation, chronic active 1 (2%) 

Metaplasia, osseous 1 (2%) 1 (2%) 

Nephropathy 1 (2%) 1 (2%) 

Pigmentation, hemosiderin 1 (2%) 1 (2%) 

Polyarteritis 1 (2%) 

Renal tubule, karyomegaly 38 (81%) 

Glomerulus, amyloid deposition 1 (2%) 

Urinary bladder (46) (43) (43) (37)

Hyperplasia, lymphoid 2 (4%) 1 (2%) 2 (5%) 

Infiltration cellular, mononuclear cell 1 (2%) 

Inflammation, chronic active 1 (2%) 

Metaplasia, squamous 1 (2%) 
253

APPENDIX E

GENETIC TOXICOLOGY

MOUSE PERIPHERAL BLOOD MICRONUCLEUS TEST PROTOCOL ....................................... 254

RESULTS ................................................................................ 254

TABLE E1 Frequency of Micronuclei in Mouse Peripheral Blood Erythrocytes

Following Treatment with Tetrafluoroethylene by Inhalation for 13 Weeks ............... 254
254 Tetrafluoroethylene, NTP TR 450

GENETIC TOXICOLOGY

MOUSE PERIPHERAL BLOOD MICRONUCLEUS TEST PROTOCOL

A detailed discussion of this assay is presented in MacGregor et al. (1990). Peripheral blood samples were obtained from male

and female B6C3F mice at the end of the 13-week study. Smears were immediately prepared and fixed in absolute methanol 1

and stained with Giemsa. Slides were scanned at 630× or 1,000× magnification using a semi-automated image analysis system

to determine the frequency of micronuclei in 10,000 normochromatic erythrocytes (NCEs) in each of 10 animals per exposure

group. The criteria of Schmid (1976) were used to define micronuclei; the minimum size limit was approximately 1/20 the

diameter of the NCE.

Log transformation of the NCE data, testing for normality by the Shapiro-Wilk test, and testing for heterogeneity of variance by

Cochran's test were performed before statistical analyses. The frequency of micronucleated cells among NCEs was analyzed by

analysis of variance using the SAS GLM procedure. The NCE data for each exposure group were compared with the concurrent

solvent control by Student's t-test.

RESULTS

No increases in the frequency of micronucleated NCEs were observed in peripheral blood samples obtained from male and

female mice at the end of the 13-week inhalation study of tetrafluoroethylene (Table E1).

TABLE E1

Frequency of Micronuclei in Mouse Peripheral Blood Erythrocytes Following Treatment

with Tetrafluoroethylene by Inhalation for 13 Weeks a

Dose Micronucleated Normochromatic Cells/

(ppm) 1,000 Normochromatic Cells

Male

0 1.15 ± 0.10

1,250 1.31 ± 0.07

2,500 1.29 ± 0.07

5,000 1.29 ± 0.06

P=0.1276b

Female

0 1.05 ± 0.08

1,250 1.04 ± 0.07

2,500 1.07 ± 0.07

5,000 1.14 ± 0.04

P=0.7150

Study was performed at USDA Western Regional Center. Data are presented as mean ± standard error. 10,000 normochromatic erythrocytes were scored for each of a

10 animals per exposure group.

Trend test, linear contrasts from analysis of variance b
255

APPENDIX F

ORGAN WEIGHTS

AND ORGAN-WEIGHT-TO-BODY-WEIGHT RATIOS

TABLE F1 Organ Weights and Organ-Weight-to-Body-Weight Ratios for Rats

in the 16-Day Inhalation Study of Tetrafluoroethylene ................................. 256

TABLE F2 Organ Weights and Organ-Weight-to-Body-Weight Ratios for Rats

in the 13-Week Inhalation Study of Tetrafluoroethylene ............................... 257

TABLE F3 Organ Weights and Organ-Weight-to-Body-Weight Ratios for Rats

at the 15-Month Interim Evaluation

in the 2-Year Inhalation Study of Tetrafluoroethylene ................................. 258

TABLE F4 Organ Weights and Organ-Weight-to-Body-Weight Ratios for Mice

in the 16-Day Inhalation Study of Tetrafluoroethylene ................................. 259

TABLE F5 Organ Weights and Organ-Weight-to-Body-Weight Ratios for Mice

in the 13-Week Inhalation Study of Tetrafluoroethylene ............................... 260

TABLE F6 Organ Weights and Organ-Weight-to-Body-Weight Ratios for Mice

at the 15-Month Interim Evaluation

in the 2-Year Inhalation Study of Tetrafluoroethylene ................................. 261
256 Tetrafluoroethylene, NTP TR 450

TABLE F1

Organ Weights and Organ-Weight-to-Body-Weight Ratios for Rats in the 16-Day Inhalation Study

of Tetrafluoroethylene a

0 ppm 312 ppm 625 ppm 1,250 ppm 2,500 ppm 5,000 ppm

n 5 5 5 5 5 5

Male

Necropsy body wt 153 ± 4 161 ± 4 160 ± 3 153 ± 1 148 ± 2 130 ± 3**

Brain

Absolute 1.702 ± 0.013 1.752 ± 0.026 1.738 ± 0.025 1.724 ± 0.012 1.686 ± 0.021 1.648 ± 0.023 

Relative 11.12 ± 0.21 10.93 ± 0.18 10.87 ± 0.31 11.27 ± 0.08 11.40 ± 0.24 12.72 ± 0.31**

Heart

Absolute 0.522 ± 0.010 0.610 ± 0.015* 0.602 ± 0.024* 0.604 ± 0.023* 0.594 ± 0.025 0.524 ± 0.014 

Relative 3.41 ± 0.08 3.80 ± 0.07 3.77 ± 0.18 3.95 ± 0.17** 4.01 ± 0.14** 4.04 ± 0.10**

L. and R. Kidneys

Absolute 1.200 ± 0.042 1.396 ± 0.037** 1.402 ± 0.031** 1.418 ± 0.017** 1.512 ± 0.038** 1.624 ± 0.049**

Relative 7.82 ± 0.15 8.70 ± 0.08** 8.75 ± 0.15** 9.27 ± 0.15** 10.21 ± 0.17** 12.51 ± 0.27**

Liver

Absolute 4.952 ± 0.289 6.094 ± 0.339 6.198 ± 0.411* 5.888 ± 0.274 6.622 ± 0.257** 5.282 ± 0.219 

Relative 32.20 ± 1.24 38.02 ± 2.08* 38.57 ± 1.92* 38.50 ± 1.87* 44.72 ± 1.60** 40.71 ± 1.49** 

Lung

Absolute 0.886 ± 0.025 1.150 ± 0.103* 1.288 ± 0.086** 1.114 ± 0.033 0.978 ± 0.051 0.926 ± 0.016 

Relative 5.79 ± 0.17 7.13 ± 0.51* 8.03 ± 0.45** 7.29 ± 0.24* 6.60 ± 0.32 7.15 ± 0.20* 

R. Testis

Absolute 1.940 ± 0.039 2.070 ± 0.027 2.055 ± 0.054 2.018 ± 0.027 2.006 ± 0.023 1.728 ± 0.063** 

Relative 12.68 ± 0.43 12.93 ± 0.35 12.85 ± 0.44 13.19 ± 0.16 13.57 ± 0.32 13.33 ± 0.48 

Thymus

Absolute 0.312 ± 0.017 0.355 ± 0.013 0.342 ± 0.019 0.313 ± 0.022 0.341 ± 0.012 0.258 ± 0.019 

Relative 2.04 ± 0.12 2.21 ± 0.06 2.13 ± 0.08 2.05 ± 0.15 2.30 ± 0.06 1.98 ± 0.12

Female

Necropsy body wt 116 ± 2 121 ± 2 115 ± 3 120 ± 2 110 ± 3 101 ± 2**

Brain

Absolute 1.656 ± 0.018 1.686 ± 0.036 1.648 ± 0.021 1.620 ± 0.030 1.620 ± 0.007 1.620 ± 0.039 

Relative 14.34 ± 0.31 13.95 ± 0.21 14.32 ± 0.23 13.57 ± 0.41 14.84 ± 0.49 16.16 ± 0.59*

Heart

Absolute 0.458 ± 0.008 0.498 ± 0.010* 0.458 ± 0.013 0.470 ± 0.014 0.464 ± 0.005 0.438 ± 0.006 

Relative 3.97 ± 0.11 4.12 ± 0.07 3.98 ± 0.11 3.93 ± 0.09 4.25 ± 0.13 4.36 ± 0.08*

L. and R. Kidneys

Absolute 1.008 ± 0.020 1.130 ± 0.021 1.082 ± 0.020 1.142 ± 0.040* 1.202 ± 0.045** 1.456 ± 0.061**

Relative 8.73 ± 0.25 9.35 ± 0.04 9.41 ± 0.27 9.54 ± 0.23 10.97 ± 0.26** 14.49 ± 0.51**

Liver

Absolute 4.016 ± 0.204 4.438 ± 0.177 4.006 ± 0.093 4.200 ± 0.245 3.986 ± 0.189 4.064 ± 0.110 

Relative 34.74 ± 1.75 36.67 ± 1.06 34.82 ± 1.05 35.08 ± 1.71 36.34 ± 1.04 40.51 ± 1.34*

Lung

Absolute 0.876 ± 0.028 0.918 ± 0.038 0.898 ± 0.038 0.984 ± 0.048 0.886 ± 0.029 0.714 ± 0.012*

Relative 7.59 ± 0.29 7.59 ± 0.28 7.83 ± 0.51 8.23 ± 0.37 8.09 ± 0.19 7.11 ± 0.11 

Thymus

Absolute 0.275 ± 0.018 0.308 ± 0.019 0.271 ± 0.012 0.274 ± 0.026 0.249 ± 0.011 0.233 ± 0.027 

Relative 2.38 ± 0.14 2.54 ± 0.11 2.36 ± 0.11 2.29 ± 0.20 2.27 ± 0.05 2.32 ± 0.26 

* Significantly different (P 0.05) from the control group by Williams' or Dunnett's test

** P 0.01

Organ weights (absolute weights) and body weights are given in grams; organ-weight-to-body-weight ratios (relative weights) are given as mg organ weight/g body a

weight (mean ± standard error).
Tetrafluoroethylene, NTP TR 450 257

TABLE F2

Organ Weights and Organ-Weight-to-Body-Weight Ratios for Rats in the 13-Week Inhalation Study

of Tetrafluoroethylene a

0 ppm 312 ppm 625 ppm 1,250 ppm 2,500 ppm 5,000 ppm

n 10 10 10 10 10 10

Male

Necropsy body wt 329 ± 5 343 ± 5 345 ± 4 333 ± 4 331 ± 4 301 ± 5**

Brain

Absolute 1.889 ± 0.011 1.913 ± 0.018 1.895 ± 0.018 1.884 ± 0.014 1.886 ± 0.016 1.866 ± 0.017 

Relative 5.75 ± 0.07 5.59 ± 0.06 5.50 ± 0.06 5.66 ± 0.05 5.71 ± 0.07 6.21 ± 0.08**

Heart

Absolute 0.875 ± 0.021 0.913 ± 0.010 0.913 ± 0.017 0.964 ± 0.027* 0.981 ± 0.035** 0.904 ± 0.019 

Relative 2.66 ± 0.05 2.67 ± 0.02 2.65 ± 0.04 2.90 ± 0.08** 2.97 ± 0.10** 3.00 ± 0.03**

R. Kidney

Absolute 2.218 ± 0.055 2.369 ± 0.044 2.372 ± 0.051 2.512 ± 0.055** 3.527 ± 0.087** 2.915 ± 0.048**

Relative 6.74 ± 0.14 6.91 ± 0.08 6.88 ± 0.11 7.54 ± 0.12** 10.66 ± 0.20** 9.68 ± 0.06**

Liver

Absolute 11.587 ± 0.337 13.125 ± 0.407** 13.494 ± 0.296** 13.829 ± 0.354** 14.825 ± 0.265** 14.398 ± 0.402**

Relative 35.19 ± 0.74 38.29 ± 0.98* 39.16 ± 0.82** 41.48 ± 0.72** 44.92 ± 1.10** 47.81 ± 1.01**

Lung

Absolute 2.008 ± 0.064 2.033 ± 0.040 2.039 ± 0.041 2.175 ± 0.106 1.895 ± 0.072 1.890 ± 0.100 

Relative 6.10 ± 0.17 5.94 ± 0.14 5.92 ± 0.12 6.56 ± 0.37 5.74 ± 0.24 6.28 ± 0.32 

R. Testis

Absolute 1.384 ± 0.023 1.412 ± 0.029 1.343 ± 0.043 1.375 ± 0.031 1.472 ± 0.019 1.417 ± 0.020 

Relative 4.21 ± 0.05 4.12 ± 0.08 3.90 ± 0.12 4.13 ± 0.10 4.45 ± 0.05* 4.71 ± 0.05**

Thymus

Absolute 0.236 ± 0.007 0.247 ± 0.014 0.256 ± 0.006 0.248 ± 0.007 0.244 ± 0.007 0.222 ± 0.006 

Relative 0.72 ± 0.02 0.72 ± 0.04 0.74 ± 0.02 0.75 ± 0.02 0.74 ± 0.02 0.74 ± 0.02 

Female

Necropsy body wt 189 ± 5 198 ± 3 197 ± 5 194 ± 4 177 ± 8 173 ± 4*

Brain

Absolute 1.755 ± 0.017 1.795 ± 0.013 1.784 ± 0.021 1.763 ± 0.018 1.716 ± 0.035 1.704 ± 0.017 

Relative 9.32 ± 0.16 9.07 ± 0.12 9.13 ± 0.25 9.08 ± 0.12 9.89 ± 0.57 9.87 ± 0.20 

Heart

Absolute 0.596 ± 0.021 0.636 ± 0.012 0.644 ± 0.011 0.633 ± 0.014 0.597 ± 0.025 0.620 ± 0.010 

Relative 3.15 ± 0.05 3.21 ± 0.04 3.28 ± 0.05 3.26 ± 0.05 3.38 ± 0.05** 3.59 ± 0.06**

R. Kidney

Absolute 1.326 ± 0.039 1.432 ± 0.028 1.485 ± 0.027* 1.583 ± 0.038** 1.710 ± 0.083** 1.877 ± 0.043**

Relative 7.01 ± 0.08 7.23 ± 0.13 7.57 ± 0.12** 8.14 ± 0.12** 9.66 ± 0.10** 10.83 ± 0.13**

Liver

Absolute 6.618 ± 0.260 6.687 ± 0.122 6.812 ± 0.114 7.044 ± 0.294 6.816 ± 0.331 7.567 ± 0.249*

Relative 34.95 ± 0.84 33.75 ± 0.43 34.79 ± 0.80 36.17 ± 1.17 38.55 ± 0.78** 43.58 ± 0.63**

Lung

Absolute 1.411 ± 0.061 1.472 ± 0.023 1.501 ± 0.046 1.399 ± 0.037 1.307 ± 0.034 1.231 ± 0.030**

Relative 7.47 ± 0.27 7.44 ± 0.12 7.64 ± 0.14 7.20 ± 0.15 7.49 ± 0.31 7.11 ± 0.11 

Thymus

Absolute 0.204 ± 0.007 0.227 ± 0.004 0.227 ± 0.005 0.217 ± 0.007 0.188 ± 0.017 0.181 ± 0.006 

Relative 1.08 ± 0.03 1.15 ± 0.02 1.16 ± 0.02 1.11 ± 0.03 1.05 ± 0.07 1.05 ± 0.04 

* Significantly different (P 0.05) from the control group by Williams' or Dunnett's test

** P 0.01

Organ weights (absolute weights) and body weights are given in grams; organ-weight-to-body-weight ratios (relative weights) are given as mg organ weight/g body a

weight (mean ± standard error).
258 Tetrafluoroethylene, NTP TR 450

TABLE F3

Organ Weights and Organ-Weight-to-Body-Weight Ratios for Rats at the 15-Month Interim Evaluation

in the 2-Year Inhalation Study of Tetrafluoroethylene a

0 ppm 156 ppm 312 ppm 625 ppm

n 10 10 10 10

Male

Necropsy body wt 490 ± 9 490 ± 10 485 ± 11 484 ± 11

R. Kidney

Absolute 1.487 ± 0.025 1.527 ± 0.045 1.592 ± 0.042 2.076 ± 0.077**

Relative 3.04 ± 0.03 3.12 ± 0.07 3.28 ± 0.05* 4.28 ± 0.11**

Liver

Absolute 15.921 ± 0.258 16.155 ± 0.558 16.323 ± 0.507 16.912 ± 0.616 

Relative 32.56 ± 0.40 32.92 ± 0.70 33.61 ± 0.50 34.96 ± 1.13 

Lung

Absolute 2.283 ± 0.160 2.354 ± 0.074 2.178 ± 0.106 2.378 ± 0.154 

Relative 4.63 ± 0.25 4.81 ± 0.14 4.49 ± 0.20 4.92 ± 0.31 

0 ppm 312 ppm 625 ppm 1,250 ppm

Female

Necropsy body wt 301 ± 8 299 ± 8 327 ± 4* 304 ± 8

R. Kidney

Absolute 0.915 ± 0.020 0.933 ± 0.019 1.051 ± 0.026** 1.178 ± 0.058**

Relative 3.04 ± 0.05 3.13 ± 0.07 3.21 ± 0.07 3.88 ± 0.16**

Liver

Absolute 8.759 ± 0.225 8.818 ± 0.239 9.922 ± 0.224** 9.785 ± 0.226**

Relative 29.08 ± 0.24 29.53 ± 0.43 30.32 ± 0.52 32.26 ± 0.52**

Lung

Absolute 1.578 ± 0.058 1.468 ± 0.060 1.560 ± 0.064 1.487 ± 0.052 

Relative 5.25 ± 0.17 4.91 ± 0.15 4.76 ± 0.17 4.90 ± 0.15 

* Significantly different (P 0.05) from the control group by Williams' or Dunnett's test

** P 0.01

Organ weights (absolute weights) and body weights are given in grams; organ-weight-to-body-weight ratios (relative weights) are given as mg organ weight/g body a

weight (mean ± standard error). 
Tetrafluoroethylene, NTP TR 450 259

TABLE F4

Organ Weights and Organ-Weight-to-Body-Weight Ratios for Mice in the 16-Day Inhalation Study

of Tetrafluoroethylene a

0 ppm 312 ppm 625 ppm 1,250 ppm 2,500 ppm 5,000 ppm

n 5 5 5 5 5 5

Male

Necropsy body wt 21.2 ± 0.4 21.2 ± 0.6 20.5 ± 0.5 20.4 ± 1.1 22.0 ± 0.7 21.2 ± 0.9

Brain

Absolute 0.440 ± 0.005 0.456 ± 0.007 0.466 ± 0.009 0.452 ± 0.005 0.454 ± 0.009 0.494 ± 0.042 

Relative 20.78 ± 0.37 21.59 ± 0.79 22.73 ± 0.39 22.28 ± 0.82 20.64 ± 0.41 23.23 ± 1.55 

Heart

Absolute 0.140 ± 0.015 0.128 ± 0.014 0.138 ± 0.007 0.124 ± 0.011 0.128 ± 0.009 0.146 ± 0.008 

Relative 6.60 ± 0.67 6.07 ± 0.72 6.74 ± 0.38 6.11 ± 0.61 5.82 ± 0.39 6.90 ± 0.38 

L. and R. Kidneys

Absolute 0.408 ± 0.007 0.420 ± 0.013 0.404 ± 0.009 0.400 ± 0.017 0.428 ± 0.026 0.446 ± 0.019 

Relative 19.26 ± 0.34 19.83 ± 0.56 19.71 ± 0.50 19.63 ± 0.52 19.43 ± 1.06 21.02 ± 0.53 

Liver

Absolute 0.988 ± 0.031 1.002 ± 0.032 0.970 ± 0.044 0.986 ± 0.031 1.078 ± 0.052 1.032 ± 0.054 

Relative 46.66 ± 1.65 47.34 ± 1.60 47.19 ± 1.25 48.48 ± 1.46 49.04 ± 2.51 48.53 ± 0.65 

Lung

Absolute 0.190 ± 0.006 0.192 ± 0.008 0.208 ± 0.004 0.184 ± 0.005 0.204 ± 0.007 0.192 ± 0.008 

Relative 8.97 ± 0.26 9.10 ± 0.53 10.16 ± 0.31 9.07 ± 0.39 9.26 ± 0.21 9.07 ± 0.34 

R. Testis

Absolute 0.197 ± 0.012 0.202 ± 0.006 0.204 ± 0.009 0.202 ± 0.013 0.202 ± 0.007 0.199 ± 0.007 

Relative 9.31 ± 0.54 9.52 ± 0.13 9.94 ± 0.37 9.85 ± 0.27 9.18 ± 0.17 9.38 ± 0.18 

Thymus

Absolute 0.044 ± 0.009 0.042 ± 0.006 0.044 ± 0.007 0.047 ± 0.009 0.045 ± 0.006 0.045 ± 0.003 

Relative 2.07 ± 0.41 1.99 ± 0.26 2.12 ± 0.33 2.27 ± 0.36 2.06 ± 0.26 2.13 ± 0.13 

Female

Necropsy body wt 16.2 ± 0.4 16.7 ± 0.8 16.1 ± 0.2 16.8 ± 0.8 17.5 ± 0.6 17.5 ± 0.5

Brain

Absolute 0.458 ± 0.007 0.458 ± 0.020 0.458 ± 0.007 0.450 ± 0.018 0.464 ± 0.010 0.456 ± 0.002 

Relative 28.33 ± 0.84 27.46 ± 0.86 28.49 ± 0.47 27.06 ± 1.79 26.55 ± 0.72 26.18 ± 0.79 

Heart

Absolute 0.104 ± 0.004 0.120 ± 0.012 0.122 ± 0.006 0.104 ± 0.002 0.122 ± 0.007 0.128 ± 0.006 

Relative 6.44 ± 0.31 7.13 ± 0.54 7.58 ± 0.34 6.24 ± 0.28 6.96 ± 0.33 7.33 ± 0.31 

L. and R. Kidneys

Absolute 0.270 ± 0.009 0.284 ± 0.015 0.276 ± 0.010 0.278 ± 0.011 0.306 ± 0.015 0.316 ± 0.009*

Relative 16.65 ± 0.24 16.97 ± 0.15 17.15 ± 0.53 16.59 ± 0.27 17.48 ± 0.72 18.10 ± 0.38 

Liver

Absolute 0.722 ± 0.025 0.786 ± 0.031 0.736 ± 0.030 0.800 ± 0.058 0.858 ± 0.045* 0.900 ± 0.047**

Relative 44.66 ± 1.87 47.12 ± 1.04 45.72 ± 1.47 47.53 ± 1.89 48.88 ± 1.28 51.36 ± 1.35**

Lung

Absolute 0.176 ± 0.009 0.178 ± 0.015 0.190 ± 0.004 0.182 ± 0.012 0.198 ± 0.011 0.184 ± 0.010 

Relative 10.90 ± 0.67 10.59 ± 0.59 11.82 ± 0.32 10.83 ± 0.48 11.34 ± 0.70 10.52 ± 0.45 

Thymus

Absolute 0.046 ± 0.003 0.054 ± 0.003 0.046 ± 0.002 0.056 ± 0.006 0.055 ± 0.004 0.063 ± 0.005*

Relative 2.83 ± 0.19 3.23 ± 0.15 2.86 ± 0.15 3.31 ± 0.21 3.15 ± 0.23 3.63 ± 0.25*

* Significantly different (P 0.05) from the control group by Williams' or Dunnett's test

** P 0.01

Organ weights (absolute weights) and body weights are given in grams; organ-weight-to-body-weight ratios (relative weights) are given as mg organ weight/g body a

weight (mean ± standard error).
260 Tetrafluoroethylene, NTP TR 450

TABLE F5

Organ Weights and Organ-Weight-to-Body-Weight Ratios for Mice in the 13-Week Inhalation Study

of Tetrafluoroethylene a

0 ppm 312 ppm 625 ppm 1,250 ppm 2,500 pm 5,000 ppm

n 10 10 10 10 10 10

Male

Necropsy body wt 36.2 ± 0.7 35.3 ± 0.5 35.9 ± 0.8 34.6 ± 0.5* 34.0 ± 0.3** 32.1 ± 0.5**

Brain

Absolute 0.464 ± 0.004 0.464 ± 0.006 0.465 ± 0.005 0.469 ± 0.002 0.464 ± 0.004 0.469 ± 0.006 

Relative 12.84 ± 0.25 13.18 ± 0.21 12.99 ± 0.27 13.58 ± 0.22* 13.64 ± 0.13* 14.64 ± 0.24**

Heart

Absolute 0.159 ± 0.004 0.157 ± 0.004 0.156 ± 0.004 0.158 ± 0.006 0.151 ± 0.005 0.145 ± 0.004 

Relative 4.39 ± 0.12 4.45 ± 0.10 4.35 ± 0.10 4.57 ± 0.15 4.43 ± 0.13 4.52 ± 0.09 

R. Kidney

Absolute 0.588 ± 0.009 0.606 ± 0.019 0.571 ± 0.017 0.573 ± 0.013 0.557 ± 0.012 0.550 ± 0.011 

Relative 16.26 ± 0.30 17.18 ± 0.44 15.89 ± 0.31 16.56 ± 0.28 16.35 ± 0.27 17.15 ± 0.24 

Liver

Absolute 1.672 ± 0.040 1.705 ± 0.047 1.687 ± 0.051 1.721 ± 0.045 1.622 ± 0.056 1.600 ± 0.049 

Relative 46.13 ± 0.61 48.31 ± 0.91 46.93 ± 0.87 49.70 ± 0.86 47.58 ± 1.32 49.86 ± 1.28*

Lung

Absolute 0.247 ± 0.004 0.242 ± 0.004 0.239 ± 0.007 0.232 ± 0.004* 0.230 ± 0.003** 0.216 ± 0.003**

Relative 6.82 ± 0.08 6.87 ± 0.07 6.65 ± 0.13 6.71 ± 0.13 6.76 ± 0.09 6.75 ± 0.17 

R. Testis

Absolute 0.117 ± 0.003 0.117 ± 0.002 0.116 ± 0.001 0.118 ± 0.001 0.114 ± 0.002 0.112 ± 0.003 

Relative 3.24 ± 0.07 3.31 ± 0.04 3.25 ± 0.06 3.41 ± 0.07 3.36 ± 0.06 3.50 ± 0.10*

Thymus

Absolute 0.032 ± 0.001 0.033 ± 0.002 0.033 ± 0.002 0.031 ± 0.001 0.031 ± 0.002 0.029 ± 0.001 

Relative 0.89 ± 0.03 0.94 ± 0.04 0.93 ± 0.06 0.90 ± 0.04 0.90 ± 0.05 0.90 ± 0.05 

Female

Necropsy body wt 31.5 ± 0.7 30.8 ± 0.8 30.9 ± 0.8 29.8 ± 0.6 30.7 ± 0.8 29.2 ± 0.5

Brain

Absolute 0.473 ± 0.004 0.468 ± 0.003 0.471 ± 0.006 0.479 ± 0.004 0.469 ± 0.005 0.474 ± 0.003 

Relative 15.07 ± 0.32 15.28 ± 0.41 15.34 ± 0.39 16.11 ± 0.25 15.36 ± 0.35 16.26 ± 0.28 

Heart

Absolute 0.131 ± 0.003 0.127 ± 0.002 0.126 ± 0.002 0.127 ± 0.002 0.127 ± 0.004 0.126 ± 0.002 

Relative 4.17 ± 0.09 4.14 ± 0.09 4.10 ± 0.11 4.27 ± 0.06 4.15 ± 0.11 4.32 ± 0.11 

R. Kidney

Absolute 0.384 ± 0.005 0.382 ± 0.014 0.372 ± 0.006 0.382 ± 0.009 0.382 ± 0.011 0.379 ± 0.010 

Relative 12.22 ± 0.24 12.41 ± 0.38 12.11 ± 0.28 12.82 ± 0.19 12.46 ± 0.27 12.98 ± 0.33 

Liver

Absolute 1.475 ± 0.043 1.460 ± 0.069 1.508 ± 0.026 1.506 ± 0.052 1.503 ± 0.063 1.498 ± 0.036 

Relative 46.81 ± 0.97 47.30 ± 1.63 49.09 ± 1.28 50.44 ± 1.08 48.92 ± 1.44 51.32 ± 1.25*

Lung

Absolute 0.238 ± 0.010 0.229 ± 0.006 0.249 ± 0.005 0.226 ± 0.004 0.236 ± 0.009 0.237 ± 0.011 

Relative 7.53 ± 0.20 7.45 ± 0.17 8.10 ± 0.21 7.59 ± 0.13 7.69 ± 0.18 8.15 ± 0.44 

Thymus

Absolute 0.041 ± 0.001 0.039 ± 0.002 0.039 ± 0.002 0.039 ± 0.002 0.040 ± 0.002 0.035 ± 0.003 b c

Relative 1.29 ± 0.03 1.26 ± 0.05 1.26 ± 0.05 1.30 ± 0.06 1.30 ± 0.06 1.18 ± 0.10 b c

* Significantly different (P 0.05) from the control group by Williams' or Dunnett's test

** P 0.01

Organ weights (absolute weights) and body weights are given in grams; organ-weight-to-body-weight ratios (relative weights) are given as mg organ weight/g body a

weight (mean ± standard error).

n=9 n=8 b c
Tetrafluoroethylene, NTP TR 450 261

TABLE F6

Organ Weights and Organ-Weight-to-Body-Weight Ratios for Mice at the 15-Month Interim Evaluation

in the 2-Year Inhalation Study of Tetrafluoroethylene a

0 ppm 312 ppm 625 ppm 1,250 ppm

n 10 10 10 10

Male

Necropsy body wt 50.2 ± 1.6 50.8 ± 0.9 50.5 ± 1.6 48.5 ± 1.1

R. Kidney

Absolute 0.413 ± 0.010 0.406 ± 0.012 0.420 ± 0.013 0.413 ± 0.011 

Relative 8.26 ± 0.13 8.00 ± 0.22 8.41 ± 0.40 8.52 ± 0.15 

Liver

Absolute 2.845 ± 0.356 2.683 ± 0.231 2.455 ± 0.147 2.493 ± 0.175 

Relative 59.58 ± 10.80 53.33 ± 5.04 49.30 ± 3.64 51.70 ± 3.96 

Lung

Absolute 0.297 ± 0.013 0.316 ± 0.019 0.291 ± 0.013 0.308 ± 0.010 

Relative 5.95 ± 0.24 6.22 ± 0.36 5.77 ± 0.15 6.36 ± 0.17 

Female

Necropsy body wt 48.5 ± 1.5 50.8 ± 1.5 53.3 ± 3.0 48.3 ± 2.5

R. Kidney

Absolute 0.286 ± 0.011 0.270 ± 0.006 0.287 ± 0.009 0.278 ± 0.010 

Relative 5.96 ± 0.31 5.33 ± 0.13 5.49 ± 0.26 5.83 ± 0.21 

Liver

Absolute 1.886 ± 0.094 2.135 ± 0.173 2.210 ± 0.174 2.423 ± 0.321 

Relative 39.02 ± 1.94 42.75 ± 4.42 41.34 ± 1.80 50.96 ± 7.10 

Lung

Absolute 0.258 ± 0.006 0.283 ± 0.016 0.275 ± 0.008 0.278 ± 0.012 

Relative 5.38 ± 0.24 5.59 ± 0.30 5.31 ± 0.34 5.90 ± 0.42 

Organ weights (absolute weights) and body weights are given in grams; organ-weight-to-body-weight ratios (relative weights) are given as mg organ weight/g body a

weight (mean ± standard error). Differences from the control group were not significant by Williams' or Dunnett's test.
262 Tetrafluoroethylene, NTP TR 450
263

APPENDIX G

HEMATOLOGY, CLINICAL CHEMISTRY,

AND URINALYSIS RESULTS

TABLE G1 Hematology Data for Rats in the 16-Day Inhalation Study

of Tetrafluoroethylene ............................................................ 264

TABLE G2 Hematology and Urinalysis Data for Rats in the 13-Week Inhalation Study

of Tetrafluoroethylene ............................................................ 265

TABLE G3 Hematology, Clinical Chemistry, and Urinalysis Data for Rats

at the 15-Month Interim Evaluation

in the 2-Year Inhalation Study of Tetrafluoroethylene ................................. 267

TABLE G4 Hematology Data for Mice in the 16-Day Inhalation Study

of Tetrafluoroethylene ............................................................ 269

TABLE G5 Hematology and Urinalysis Data for Mice in the 13-Week Inhalation Study

of Tetrafluoroethylene ............................................................ 270
264 Tetrafluoroethylene, NTP TR 450

TABLE G1

Hematology Data for Rats in the 16-Day Inhalation Study of Tetrafluoroethylene a

0 ppm 312 ppm 625 ppm 1,250 ppm 2,500 ppm 5,000 ppm

Male

n 5 5 5 5 4 5

Hematocrit (%) 43.0 ± 0.3 42.4 ± 0.6 41.7 ± 0.2 42.1 ± 0.4 41.9 ± 0.3 42.6 ± 0.5

Hemoglobin (g/dL) 16.2 ± 0.2 16.0 ± 0.3 15.7 ± 0.1 15.9 ± 0.2 15.8 ± 0.2 16.0 ± 0.2

Erythrocytes (10 /μL) 7.93 ± 0.05 7.70 ± 0.14 7.67 ± 0.12 7.68 ± 0.10 7.72 ± 0.05 7.77 ± 0.10 6

Reticulocytes (per 5 oil

 immersion fields) 53.00 ± 8.56 54.40 ± 4.07 66.80 ± 8.29 70.00 ± 5.52 68.75 ± 7.22 69.20 ± 5.44

Nucleated erythrocytes

 (10 /μL) 0.01 ± 0.01 0.00 ± 0.00 0.01 ± 0.01 0.00 ± 0.00 0.00 ± 0.00 0.00 ± 0.00 3

Mean cell volume (fL) 54.2 ± 0.2 55.0 ± 0.3 54.6 ± 0.7 55.0 ± 0.6 54.3 ± 0.3 55.0 ± 0.6

Mean cell hemoglobin (pg) 20.5 ± 0.1 20.8 ± 0.2 20.5 ± 0.3 20.8 ± 0.2 20.4 ± 0.2 20.6 ± 0.2

Mean cell hemoglobin

 concentration (g/dL) 37.8 ± 0.1 37.7 ± 0.2 37.7 ± 0.1 37.8 ± 0.1 37.6 ± 0.1 37.5 ± 0.1

Platelets (10 /μL) 641.4 ± 10.3 699.4 ± 22.4 603.0 ± 74.8 677.6 ± 15.2 745.3 ± 20.3* 641.8 ± 31.4 3

Leukocytes (10 /μL) 3.66 ± 0.17 4.12 ± 0.09 4.26 ± 0.49 3.68 ± 0.35 4.20 ± 0.67 4.18 ± 0.32 3

Segmented neutrophils

 (10 /μL) 0.70 ± 0.09 0.71 ± 0.09 0.82 ± 0.16 0.70 ± 0.14 0.60 ± 0.04 0.65 ± 0.06 3

Lymphocytes (10 /μL) 2.92 ± 0.16 3.35 ± 0.03 3.38 ± 0.41 2.91 ± 0.20 3.54 ± 0.67 3.52 ± 0.34 3

Monocytes (10 /μL) 0.02 ± 0.02 0.03 ± 0.02 0.06 ± 0.04 0.07 ± 0.03 0.03 ± 0.01 0.01 ± 0.01 3

Eosinophils (10 /μL) 0.01 ± 0.01 0.04 ± 0.01 0.00 ± 0.00 0.01 ± 0.01 0.04 ± 0.02 0.00 ± 0.00 3

Female

n 5 5 5 5 5 5

Hematocrit (%) 45.6 ± 0.3 45.7 ± 0.5 45.8 ± 0.1 46.9 ± 0.4 46.6 ± 0.3 46.2 ± 0.6

Hemoglobin (g/dL) 16.8 ± 0.1 16.8 ± 0.2 16.9 ± 0.1 17.3 ± 0.1 17.2 ± 0.2 17.1 ± 0.3

Erythrocytes (10 /μL) 8.11 ± 0.18 8.16 ± 0.11 8.12 ± 0.12 8.28 ± 0.09 8.49 ± 0.14 8.34 ± 0.11 6

Reticulocytes (per 5 oil

 immersion fields) 46.00 ± 7.77 42.00 ± 5.65 32.20 ± 1.59 37.20 ± 3.09 35.00 ± 3.48 31.40 ± 1.33

Nucleated erythrocytes

 (10 /μL) 0.00 ± 0.00 0.01 ± 0.01 0.00 ± 0.00 0.01 ± 0.01 0.00 ± 0.00 0.00 ± 0.00 3

Mean cell volume (fL) 56.4 ± 1.3 56.0 ± 0.6 56.6 ± 1.0 56.8 ± 0.4 55.0 ± 0.6 55.6 ± 0.4

Mean cell hemoglobin (pg) 20.8 ± 0.5 20.6 ± 0.1 20.8 ± 0.4 20.9 ± 0.1 20.3 ± 0.2 20.5 ± 0.2

Mean cell hemoglobin

 concentration (g/dL) 36.9 ± 0.1 36.7 ± 0.2 36.9 ± 0.2 37.0 ± 0.1 36.9 ± 0.1 36.9 ± 0.2

Platelets (10 /μL) 626.8 ± 22.5 705.6 ± 17.5 626.2 ± 12.7 650.2 ± 49.6 552.2 ± 20.8 599.8 ± 14.1 3

Leukocytes (10 /μL) 4.80 ± 0.10 4.16 ± 0.46 3.96 ± 0.27 4.72 ± 0.48 4.82 ± 0.77 4.18 ± 0.44 3

Segmented neutrophils

 (10 /μL) 0.81 ± 0.10 0.70 ± 0.14 0.55 ± 0.15 0.70 ± 0.03 1.07 ± 0.22 1.08 ± 0.23 3

Lymphocytes (10 /μL) 3.86 ± 0.16 3.37 ± 0.42 3.29 ± 0.30 3.86 ± 0.41 3.68 ± 0.60 2.88 ± 0.31 3

Monocytes (10 /μL) 0.11 ± 0.02 0.08 ± 0.03 0.10 ± 0.04 0.11 ± 0.04 0.07 ± 0.02 0.18 ± 0.04 3

Eosinophils (10 /μL) 0.02 ± 0.01 0.02 ± 0.02 0.02 ± 0.01 0.05 ± 0.02 0.01 ± 0.01 0.04 ± 0.01 3

* Significantly different (P 0.05) from the control group by Dunn's test

Mean ± standard error. Statistical tests were performed on unrounded data. a
Tetrafluoroethylene, NTP TR 450 265

TABLE G2

Hematology and Urinalysis Data for Rats in the 13-Week Inhalation Study of Tetrafluoroethylene a

0 ppm 312 ppm 625 ppm 1,250 ppm 2,500 ppm 5,000 ppm

Male

Hematology

n 10 9 9 10 9 10

Hematocrit (%) 47.3 ± 0.3 45.5 ± 0.3** 45.9 ± 0.4** 44.9 ± 0.6** 44.3 ± 0.3** 44.3 ± 0.3**

Hemoglobin (g/dL) 15.8 ± 0.1 15.2 ± 0.1** 15.3 ± 0.1** 14.8 ± 0.2** 14.6 ± 0.1** 14.5 ± 0.1**

Erythrocytes (10 /μL) 9.45 ± 0.06 9.11 ± 0.07** 9.22 ± 0.09* 9.02 ± 0.12** 8.91 ± 0.08** 8.80 ± 0.07** 6

Reticulocytes (10 /μL) 91.2 ± 47.5 118.8 ± 60.3 109.9 ± 41.7 84.2 ± 44.1 116.9 ± 82.7 87.0 ± 61.2 3

Mean cell volume (fL) 50.2 ± 0.3 49.9 ± 0.2 49.7 ± 0.2 49.9 ± 0.2 49.8 ± 0.2 50.3 ± 0.2

Mean cell hemoglobin (pg) 16.7 ± 0.1 16.7 ± 0.1 16.6 ± 0.1 16.5 ± 0.2* 16.4 ± 0.1** 16.5 ± 0.1*

Mean cell hemoglobin

 concentration (g/dL) 33.4 ± 0.1 33.3 ± 0.1 33.3 ± 0.1 33.0 ± 0.3* 33.0 ± 0.1* 32.8 ± 0.1**

Platelets (10 /μL) 515.4 ± 8.6 530.1 ± 15.8 540.6 ± 23.8* 599.4 ± 21.8** 581.1 ± 10.6** 637.4 ± 12.4** 3

Leukocytes (10 /μL) 6.38 ± 0.20 6.27 ± 0.20 6.43 ± 0.27 6.59 ± 0.31 6.02 ± 0.45 6.59 ± 0.27 3

Segmented neutrophils

 (10 /μL) 1.06 ± 0.10 1.16 ± 0.11 0.89 ± 0.07 0.91 ± 0.10 0.86 ± 0.11 0.97 ± 0.08 3

Lymphocytes (10 /μL) 5.07 ± 0.18 4.82 ± 0.26 5.33 ± 0.19 5.51 ± 0.29 4.95 ± 0.38 5.39 ± 0.21 3

Monocytes (10 /μL) 0.22 ± 0.05 0.18 ± 0.04 0.16 ± 0.06 0.09 ± 0.03 0.17 ± 0.04 0.19 ± 0.05 3

Eosinophils (10 /μL) 0.04 ± 0.02 0.10 ± 0.01* 0.05 ± 0.02 0.07 ± 0.02 0.04 ± 0.02 0.04 ± 0.01 3

Urinalysis

n 10 10 10 10 10 10

Fluoride (μg/16 hr) 7.98 ± 0.37 35.68 ± 1.82** 45.87 ± 2.42** 69.91 ± 5.63** 122.41 ± 12.02** 205.45 ± 16.71**

Glucose (mg/16 hr) 0.09 ± 0.01 0.02 ± 0.00** 0.08 ± 0.02 0.04 ± 0.01 0.05 ± 0.02 2.81 ± 1.27 b b b

Protein (mg/16 hr) 14 ± 1 17 ± 1** 19 ± 1** 23 ± 2** 23 ± 1** 35 ± 2**

Volume (mL/16 hr) 24.8 ± 2.4 21.5 ± 3.1 27.0 ± 2.1 24.0 ± 2.8 28.7 ± 2.0 38.6 ± 4.5

Volume (mL)

 (concentrated) 0.9 ± 0.2 0.8 ± 0.1 0.9 ± 0.2 1.1 ± 0.2 1.2 ± 0.1 1.1 ± 0.2 b b b

Specific gravity 1.010 ± 0.001 1.014 ± 0.002 1.009 ± 0.001 1.012 ± 0.002 1.009 ± 0.001 1.009 ± 0.001

Specific gravity

 (concentrated) 1.037 ± 0.006 1.064 ± 0.001** 1.060 ± 0.002 1.058 ± 0.003* 1.055 ± 0.002 1.060 ± 0.002* b b b
266 Tetrafluoroethylene, NTP TR 450

TABLE G2

Hematology and Urinalysis Data for Rats in the 13-Week Inhalation Study of Tetrafluoroethylene (continued)

0 ppm 312 ppm 625 ppm 1,250 ppm 2,500 ppm 5,000 ppm

Female

Hematology

n 10 10 10 10 9 10

Hematocrit (%) 47.5 ± 0.4 47.3 ± 0.3 46.8 ± 0.5 47.2 ± 0.3 48.0 ± 0.7 45.3 ± 0.3**

Hemoglobin (g/dL) 15.7 ± 0.2 15.7 ± 0.2 15.6 ± 0.2 15.6 ± 0.1 15.9 ± 0.2 14.9 ± 0.1**

Erythrocytes (10 /μL) 8.67 ± 0.08 8.67 ± 0.08 8.67 ± 0.09 8.66 ± 0.05 8.79 ± 0.08 8.34 ± 0.09* 6

Reticulocytes (10 /μL) 82.8 ± 36.4 88.6 ± 22.1 71.5 ± 30.5 86.6 ± 33.0 67.2 ± 41.2 96.4 ± 33.3 3

Mean cell volume (fL) 54.9 ± 0.2 54.4 ± 0.2 54.1 ± 0.2* 54.5 ± 0.2 54.7 ± 0.3 54.5 ± 0.4 

Mean cell hemoglobin (pg) 18.1 ± 0.1 18.1 ± 0.1 17.9 ± 0.1 18.0 ± 0.1 18.0 ± 0.1 17.9 ± 0.2**

Mean cell hemoglobin

 concentration (g/dL) 33.2 ± 0.1 33.1 ± 0.2 33.3 ± 0.2 33.1 ± 0.1 33.1 ± 0.1 32.8 ± 0.1

Platelets (10 /μL) 589.0 ± 31.3 584.7 ± 11.8 571.1 ± 17.2 585.5 ± 14.3 614.4 ± 25.8 665.5 ± 19.1 3

Leukocytes (10 /μL) 6.19 ± 0.43 5.07 ± 0.15 5.55 ± 0.28 5.35 ± 0.23 5.74 ± 0.33 4.84 ± 0.26* 3

Segmented neutrophils

 (10 /μL) 0.66 ± 0.05 0.65 ± 0.09 0.86 ± 0.07 0.67 ± 0.09 0.82 ± 0.12 0.76 ± 0.06 3

Lymphocytes (10 /μL) 5.39 ± 0.43 4.26 ± 0.20 4.58 ± 0.29 4.51 ± 0.22 4.81 ± 0.33 3.95 ± 0.22* 3

Monocytes (10 /μL) 0.11 ± 0.03 0.10 ± 0.03 0.08 ± 0.02 0.13 ± 0.04 0.10 ± 0.03 0.11 ± 0.03 3

Eosinophils (10 /μL) 0.03 ± 0.02 0.05 ± 0.01 0.03 ± 0.02 0.04 ± 0.02 0.02 ± 0.01 0.02 ± 0.01 3

Urinalysis

n 10 10 10 10 8 10

Fluoride (μg/16 hr) 4.33 ± 0.17 20.71 ± 1.12** 32.30 ± 1.22** 49.86 ± 4.38** 73.80 ± 4.68** 118.76 ± 5.00** b c

Glucose (mg/16 hr) 0.12 ± 0.06 0.10 ± 0.03 0.18 ± 0.07 0.09 ± 0.02 0.21 ± 0.04** 0.06 ± 0.01

Protein (mg/16 hr) 1 ± 0 1 ± 0 1 ± 0 1 ± 0 2 ± 0** 2 ± 0**

Volume (mL/16 hr) 11.9 ± 1.5 18.1 ± 2.1* 20.0 ± 3.1* 23.3 ± 1.9** 34.3 ± 3.7** 38.5 ± 3.1**

Volume (mL)

 (concentrated) 0.5 ± 0.2 0.8 ± 0.2 0.6 ± 0.2 0.6 ± 0.2 0.4 ± 0.2 0.4 ± 0.1 b c b d e

Specific gravity 1.015 ± 0.002 1.009 ± 0.001* 1.010 ± 0.001 1.008 ± 0.001** 1.005 ± 0.001** 1.006 ± 0.000**

Specific gravity

 (concentrated) 1.049 ± 0.007 1.053 ± 0.013 1.064 ± 0.005 1.062 ± 0.012 1.079 ± 0.011 1.057 ± 0.007 b c b d e

* Significantly different (P 0.05) from the control group by Dunn's or Shirley's test

** P 0.01

Mean ± standard error. Statistical tests were performed on unrounded data. a

n=9 b

n=8 c

n=7 d

n=6 e
Tetrafluoroethylene, NTP TR 450 267

TABLE G3

Hematology, Clinical Chemistry, and Urinalysis Data for Rats at the 15-Month Interim Evaluation

in the 2-Year Inhalation Study of Tetrafluoroethylene a

0 ppm 156 ppm 312 ppm 625 ppm

Male

n 10 10 10 10

Hematology

Hematocrit (automated) (%) 44.0 ± 0.9 45.0 ± 0.7 45.0 ± 1.0 42.1 ± 0.9 

Hematocrit (manual) (%) 43.0 ± 0.8 43.5 ± 0.8 43.7 ± 0.9 41.1 ± 0.8 

Hemoglobin (g/dL) 14.1 ± 0.3 14.2 ± 0.2 14.5 ± 0.3 13.4 ± 0.3 

Erythrocytes (10 /μL) 8.37 ± 0.13 8.40 ± 0.15 8.54 ± 0.20 7.79 ± 0.26 6

Reticulocytes (10 /μL) 0.30 ± 0.03 0.30 ± 0.02 0.30 ± 0.02 0.36 ± 0.08 6

Nucleated erythrocytes (10 /μL) 0.12 ± 0.03 0.13 ± 0.02 0.09 ± 0.02 0.27 ± 0.14 3

Mean cell volume (fL) 52.7 ± 0.8 53.6 ± 0.3 52.8 ± 0.4 54.2 ± 0.9 

Mean cell hemoglobin (pg) 16.9 ± 0.3 16.9 ± 0.1 17.0 ± 0.1 17.3 ± 0.3 

Mean cell hemoglobin concentration (g/dL) 32.2 ± 0.1 31.6 ± 0.1* 32.2 ± 0.1 31.9 ± 0.1 

Platelets (10 /μL) 535.7 ± 21.9 531.8 ± 8.2 562.0 ± 16.4 520.8 ± 32.4 3

Leukocytes (10 /μL) 3.45 ± 0.83 2.89 ± 0.56 2.19 ± 0.13 3.06 ± 0.41 3

Segmented neutrophils (10 /μL) 1.76 ± 0.49 1.11 ± 0.21 0.96 ± 0.08 1.11 ± 0.12 3

Lymphocytes (10 /μL) 1.66 ± 0.35 1.74 ± 0.36 1.21 ± 0.12 1.89 ± 0.36 3

Monocytes (10 /μL) 0.01 ± 0.00 0.01 ± 0.01 0.00 ± 0.00 0.01 ± 0.01 3

Eosinophils (10 /μL) 0.02 ± 0.01 0.03 ± 0.02 0.01 ± 0.01 0.05 ± 0.01 3

Clinical Chemistry

Blood urea nitrogen (mg/dL) 18.4 ± 0.3 19.7 ± 0.7 19.3 ± 0.5 20.6 ± 0.7*

Creatinine (mg/dL) 0.63 ± 0.02 0.67 ± 0.03 0.59 ± 0.02 0.67 ± 0.02

Sodium (mEq/L) 152 ± 1 152 ± 1 151 ± 1 151 ± 1

Potassium (mEq/L) 5.2 ± 0.1 5.1 ± 0.1 5.1 ± 0.1 5.3 ± 0.1

Chloride (mEq/L) 107 ± 1 106 ± 1 107 ± 0 106 ± 1 

Calcium (mg/dL) 11.42 ± 0.15 11.48 ± 0.15 11.78 ± 0.12 11.48 ± 0.15 

Phosphorus (mg/dL) 5.9 ± 0.3 6.0 ± 0.3 6.4 ± 0.2 6.4 ± 0.2 

Urinalysis

Glucose (mg/16 hr) 1.5 ± 0.1 1.4 ± 0.1 1.0 ± 0.1** 1.0 ± 0.0**

Protein (mg/16 hr) 19 ± 2 17 ± 2 14 ± 1 27 ± 4

Volume (mL/16 hr)

 Week 63 14.7 ± 2.8 9.0 ± 0.8 8.3 ± 0.6* 12.9 ± 0.8 

 Week 64 0.7 ± 0.2 0.8 ± 0.2 1.0 ± 0.3 1.4 ± 0.3 

Specific gravity

 Week 63 1.022 ± 0.002 1.029 ± 0.001 1.026 ± 0.001 1.023 ± 0.001 

 Week 64 1.048 ± 0.006 1.045 ± 0.007 1.039 ± 0.008 1.045 ± 0.006 b b c d
268 Tetrafluoroethylene, NTP TR 450

TABLE G3

Hematology, Clinical Chemistry, and Urinalysis Data for Rats at the 15-Month Interim Evaluation

in the 2-Year Inhalation Study of Tetrafluoroethylene (continued)

0 ppm 312 ppm 625 ppm 1,250 ppm

Female

n 10 10 10 10

Hematology

Hematocrit (automated) (%) 44.4 ± 0.4 44.9 ± 0.5 44.0 ± 0.4 43.9 ± 0.5 

Hematocrit (manual) (%) 42.9 ± 0.4 43.4 ± 0.4 42.6 ± 0.4 42.9 ± 0.5 

Hemoglobin (g/dL) 14.3 ± 0.2 14.4 ± 0.2 14.1 ± 0.1 14.0 ± 0.2

Erythrocytes (10 /μL) 7.82 ± 0.07 7.95 ± 0.07 7.81 ± 0.09 7.87 ± 0.08 6

Reticulocytes (10 /μL) 0.23 ± 0.02 0.25 ± 0.01 0.25 ± 0.01 0.27 ± 0.01* 6

Nucleated erythrocytes (10 /μL) 0.09 ± 0.02 0.07 ± 0.01 0.08 ± 0.01 0.06 ± 0.01 3

Mean cell volume (fL) 56.9 ± 0.2 56.4 ± 0.2 56.3 ± 0.3 55.8 ± 0.2**

Mean cell hemoglobin (pg) 18.3 ± 0.1 18.1 ± 0.1 18.1 ± 0.1 17.8 ± 0.1**

Mean cell hemoglobin concentration (g/dL) 32.1 ± 0.2 32.0 ± 0.1 32.0 ± 0.1 32.0 ± 0.1

Platelets (10 /μL) 463.3 ± 16.9 492.4 ± 11.8 479.8 ± 12.6 491.0 ± 9.8 3

Leukocytes (10 /μL) 1.45 ± 0.18 1.51 ± 0.15 1.86 ± 0.28 1.89 ± 0.16* 3

Segmented neutrophils (10 /μL) 0.43 ± 0.06 0.47 ± 0.05 0.65 ± 0.10* 0.70 ± 0.09** 3

Lymphocytes (10 /μL) 1.00 ± 0.14 1.01 ± 0.11 1.19 ± 0.19 1.16 ± 0.12 3

Monocytes (10 /μL) 0.01 ± 0.01 0.01 ± 0.01 0.01 ± 0.01 0.01 ± 0.01 3

Eosinophils (10 /μL) 0.02 ± 0.01 0.02 ± 0.01 0.01 ± 0.01 0.02 ± 0.01 3

Clinical Chemistry

Blood urea nitrogen (mg/dL) 17.6 ± 0.8 17.4 ± 0.6 17.6 ± 0.7 17.7 ± 0.5 

Creatinine (mg/dL) 0.67 ± 0.03 0.64 ± 0.02 0.61 ± 0.02 0.62 ± 0.03 

Sodium (mEq/L) 148 ± 0 148 ± 1 148 ± 1 147 ± 1 

Potassium (mEq/L) 5.2 ± 0.1 5.1 ± 0.1 5.0 ± 0.1 5.2 ± 0.1 

Chloride (mEq/L) 100 ± 1 102 ± 1 99 ± 0 100 ± 1 

Calcium (mg/dL) 11.55 ± 0.09 11.44 ± 0.17 11.26 ± 0.12 11.18 ± 0.17 

Phosphorus (mg/dL) 6.2 ± 0.3 5.9 ± 0.4 6.0 ± 0.3 6.5 ± 0.2

Urinalysis

Glucose (mg/16 hr) 0.8 ± 0.1 0.8 ± 0.0 0.7 ± 0.1 0.8 ± 0.4

Protein (mg/16 hr) 4 ± 1 4 ± 1 5 ± 1 5 ± 1

Volume (mL/16 hr) 

 Week 63 9.6 ± 2.2 6.1 ± 0.5 7.4 ± 0.8 10.1 ± 0.7 

 Week 64 0.2 ± 0.1 0.2 ± 0.1 0.2 ± 0.1 0.2 ± 0.1

Specific gravity

 Week 63 1.019 ± 0.002 1.027 ± 0.002* 1.021 ± 0.002 1.019 ± 0.001 

 Week 64 1.038 ± 0.012 1.046 ± 0.006 1.060 ± 0.002 1.061 ± 0.007 e c e e

* Significantly different (P 0.05) from the control group by Dunn's or Shirley's test

** P 0.01

Mean ± standard error. Statistical tests were performed on unrounded data. a

n=6 b

n=5 c

n=9 d

n=3 e
Tetrafluoroethylene, NTP TR 450 269

TABLE G4

Hematology Data for Mice in the 16-Day Inhalation Study of Tetrafluoroethylene a

0 ppm 312 ppm 625 ppm 1,250 ppm 2,500 ppm 5,000 ppm

Male

n 5 5 5 5 5 5

Hematocrit (%) 44.3 ± 0.4 45.2 ± 0.9 44.4 ± 0.4 43.6 ± 0.5 43.5 ± 0.5 43.8 ± 0.3

Hemoglobin (g/dL) 17.7 ± 0.2 18.0 ± 0.4 17.6 ± 0.1 17.0 ± 0.3 17.2 ± 0.3 17.3 ± 0.2

Erythrocytes (10 /μL) 8.24 ± 0.09 8.46 ± 0.17 8.38 ± 0.06 8.14 ± 0.09 7.94 ± 0.07 8.18 ± 0.03 6

Reticulocytes (per 5 oil

 immersion fields) 29.80 ± 2.99 15.20 ± 4.53* 21.80 ± 5.03 21.40 ± 5.77 23.20 ± 4.31 24.00 ± 1.55

Nucleated erythrocytes

 (10 /μL) 0.00 ± 0.00 0.00 ± 0.00 0.00 ± 0.00 0.00 ± 0.00 0.00 ± 0.00 0.00 ± 0.00 3

Mean cell volume (fL) 53.8 ± 0.4 53.6 ± 0.6 53.0 ± 0.3 53.6 ± 0.2 55.0 ± 0.0 53.6 ± 0.2

Mean cell hemoglobin (pg) 21.4 ± 0.2 21.3 ± 0.2 21.0 ± 0.1 20.9 ± 0.2 21.7 ± 0.2 21.2 ± 0.1

Mean cell hemoglobin

 concentration (g/dL) 39.8 ± 0.3 39.9 ± 0.2 39.6 ± 0.1 39.1 ± 0.5 39.6 ± 0.4 39.6 ± 0.3

Platelets (10 /μL) 805.0 ± 39.9 782.2 ± 16.7 759.8 ± 4.1 778.0 ± 24.1 815.6 ± 70.7 799.4 ± 34.8 3

Leukocytes (10 /μL) 1.62 ± 0.26 1.54 ± 0.41 1.92 ± 0.59 1.24 ± 0.38 1.10 ± 0.30 1.90 ± 0.23 3

Segmented neutrophils

 (10 /μL) 0.48 ± 0.09 0.22 ± 0.04 0.72 ± 0.35 0.26 ± 0.08 0.17 ± 0.08 0.52 ± 0.08 3

Lymphocytes (10 /μL) 1.10 ± 0.30 1.29 ± 0.35 1.16 ± 0.26 0.92 ± 0.33 0.90 ± 0.23 1.33 ± 0.20 3

Monocytes (10 /μL) 0.04 ± 0.02 0.03 ± 0.02 0.05 ± 0.02 0.05 ± 0.03 0.03 ± 0.01 0.05 ± 0.03 3

Eosinophils (10 /μL) 0.00 ± 0.00 0.00 ± 0.00 0.00 ± 0.00 0.01 ± 0.01 0.00 ± 0.00 0.00 ± 0.00 3

Female

n 4 5 5 5 5 5

Hematocrit (%) 44.6 ± 0.7 43.8 ± 0.8 43.5 ± 0.6 43.3 ± 0.6 44.3 ± 0.3 43.3 ± 0.4

Hemoglobin (g/dL) 17.5 ± 0.3 17.2 ± 0.3 17.0 ± 0.3 17.1 ± 0.2 17.4 ± 0.1 17.0 ± 0.1

Erythrocytes (10 /μL) 8.24 ± 0.12 8.16 ± 0.15 7.95 ± 0.11 8.08 ± 0.14 8.22 ± 0.06 8.07 ± 0.07 6

Reticulocytes (per 5 oil

 immersion fields) 25.00 ± 1.91 29.00 ± 3.39 21.40 ± 3.16 15.00 ± 2.02 29.40 ± 3.72 20.20 ± 4.18

Nucleated erythrocytes

 (10 /μL) 0.00 ± 0.00 0.00 ± 0.00 0.00 ± 0.00 0.00 ± 0.00 0.00 ± 0.00 0.00 ± 0.00 3

Mean cell volume (fL) 54.3 ± 0.3 53.6 ± 0.4 54.6 ± 0.2 53.6 ± 0.2 53.8 ± 0.2 53.8 ± 0.2

Mean cell hemoglobin (pg) 21.2 ± 0.1 21.1 ± 0.2 21.4 ± 0.2 21.2 ± 0.3 21.1 ± 0.1 21.1 ± 0.1

Mean cell hemoglobin

 concentration (g/dL) 39.1 ± 0.1 39.3 ± 0.1 39.2 ± 0.2 39.6 ± 0.4 39.2 ± 0.3 39.3 ± 0.1

Platelets (10 /μL) 797.3 ± 26.7 764.4 ± 32.2 734.2 ± 25.6 775.0 ± 27.0 785.6 ± 30.2 797.6 ± 24.9 3

Leukocytes (10 /μL) 0.85 ± 0.22 0.76 ± 0.08 0.64 ± 0.13 0.94 ± 0.18 0.98 ± 0.22 0.86 ± 0.16 3

Segmented neutrophils

 (10 /μL) 0.30 ± 0.04 0.14 ± 0.03 0.24 ± 0.04 0.29 ± 0.13 0.38 ± 0.18 0.13 ± 0.02 3

Lymphocytes (10 /μL) 0.55 ± 0.21 0.62 ± 0.07 0.39 ± 0.12 0.64 ± 0.12 0.59 ± 0.07 0.72 ± 0.15 3

Monocytes (10 /μL) 0.00 ± 0.00 0.00 ± 0.00 0.01 ± 0.01 0.01 ± 0.01 0.01 ± 0.01 0.01 ± 0.01 3

Eosinophils (10 /μL) 0.00 ± 0.00 0.00 ± 0.00 0.00 ± 0.00 0.00 ± 0.00 0.00 ± 0.00 0.00 ± 0.00 3

* Significantly different (P 0.05) from the control group by Dunn's test

Mean ± standard error. Statistical tests were performed on unrounded data. a
270 Tetrafluoroethylene, NTP TR 450

TABLE G5

Hematology and Urinalysis Data for Mice in the 13-Week Inhalation Study of Tetrafluoroethylene a

0 ppm 312 ppm 625 ppm 1,250 ppm 2,500 ppm 5,000 ppm

Male

Hematology

n 10 10 10 10 10 10

Hematocrit (%) 50.6 ± 0.4 50.0 ± 0.5 50.2 ± 0.4 50.4 ± 0.7 47.9 ± 0.4** 46.3 ± 0.5**

Hemoglobin (g/dL) 17.0 ± 0.2 16.7 ± 0.1 16.7 ± 0.1 16.7 ± 0.1 16.0 ± 0.1** 15.4 ± 0.2**

Erythrocytes (10 /μL) 10.51 ± 0.10 10.35 ± 0.09 10.42 ± 0.11 10.44 ± 0.13 10.03 ± 0.08** 9.65 ± 0.14** 6

Reticulocytes (10 /μL) 70 ± 43 93 ± 45 108 ± 135 80 ± 24 75 ± 27 102 ± 115 3

Howell-Jolly bodies

 (% erythrocytes) 0.1 ± 0.0 0.0 ± 0.0 0.2 ± 0.0 0.1 ± 0. 0.1 ± 0.0 0.2 ± 0.0

Mean cell volume (fL) 48.0 ± 0.3 48.4 ± 0.2 48.1 ± 0.2 48.2 ± 0.4 47.9 ± 0.3 48.0 ± 0.4 

Mean cell hemoglobin (pg) 16.1 ± 0.1 16.2 ± 0.1 16.0 ± 0.1 16.0 ± 0.1 15.9 ± 0.1 16.0 ± 0.1

Mean cell hemoglobin

 concentration (g/dL) 33.5 ± 0.1 33.4 ± 0.2 33.3 ± 0.2 33.1 ± 0.2 33.4 ± 0.2 33.3 ± 0.1

Platelets (10 /μL) 961.6 ± 16.8 932.9 ± 20.3 969.7 ± 25.4 993.5 ± 18.9 996.2 ± 18.3 1,017.3 ± 27.7 3

Leukocytes (10 /μL) 4.15 ± 0.44 3.36 ± 0.29 3.16 ± 0.28 3.71 ± 0.31 2.89 ± 0.34 3.16 ± 0.39 3

Segmented neutrophils

 (10 /μL) 0.54 ± 0.08 0.49 ± 0.08 0.51 ± 0.12 0.67 ± 0.12 0.65 ± 0.12 0.82 ± 0.13 3

Lymphocytes (10 /μL) 3.52 ± 0.38 2.77 ± 0.25 2.57 ± 0.27 2.93 ± 0.26 2.14 ± 0.28** 2.25 ± 0.31** 3

Monocytes (10 /μL) 0.07 ± 0.02 0.07 ± 0.02 0.04 ± 0.01 0.08 ± 0.01 0.07 ± 0.01 0.05 ± 0.01 3

Eosinophils (10 /μL) 0.02 ± 0.01 0.04 ± 0.02 0.04 ± 0.01 0.04 ± 0.01 0.03 ± 0.01 0.04 ± 0.02 3

Urinalysis

n 10 10 9 10 10 10

Fluoride (μg/16 hr) 1.35 ± 0.10 19.68 ± 3.15** 18.06 ± 4.66** 25.94 ± 3.62** 56.48 ± 11.66** 66.20 ± 6.15** b c d

Glucose (mg/16 hr) 0.16 ± 0.01 0.13 ± 0.02 0.09 ± 0.02 0.13 ± 0.01 0.12 ± 0.03 0.16 ± 0.02

Protein (mg/16 hr) 1 ± 0 1 ± 0 1 ± 0 1 ± 0 2 ± 0 2 ± 0 

Volume (mL/16 hr) 2.4 ± 0.5 1.2 ± 0.3 0.8 ± 0.2 2.0 ± 0.4 5.9 ± 1.2 5.6 ± 0.8

Specific gravity 1.027 ± 0.002 1.038 ± 0.004 1.039 ± 0.004 1.025 ± 0.002 1.013 ± 0.002** 1.015 ± 0.003** b
Tetrafluoroethylene, NTP TR 450 271

TABLE G5

Hematology and Urinalysis Data for Mice in the 13-Week Inhalation Study of Tetrafluoroethylene (continued)

0 ppm 312 ppm 625 ppm 1,250 ppm 2,500 ppm 5,000 ppm

Female

n 10 10 10 10 10 10

Hematology

Hematocrit (%) 49.1 ± 0.5 48.8 ± 0.3 48.4 ± 0.3 49.5 ± 0.3 48.3 ± 0.5 47.1 ± 0.5**

Hemoglobin (g/dL) 16.4 ± 0.2 16.4 ± 0.1 16.3 ± 0.1 16.3 ± 0.1 16.2 ± 0.2 15.8 ± 0.1**

Erythrocytes (10 /μL) 10.20 ± 0.09 10.27 ± 0.07 10.16 ± 0.07 10.29 ± 0.06 10.17 ± 0.10 9.93 ± 0.11 6

Reticulocytes (10 /μL) 111 ± 40 113 ± 39 90 ± 42 108 ± 61 132 ± 51 117 ± 52 3

Howell-Jolly bodies

 (% erythrocytes) 0.1 ± 0.0 0.1 ± 0.0 0.1 ± 0.0 0.1 ± 0.0 0.1 ± 0.0 0.1 ± 0.0

Mean cell volume (fL) 48.1 ± 0.2 47.6 ± 0.3 47.7 ± 0.3 48.1 ± 0.3 47.6 ± 0.2 47.4 ± 0.3

Mean cell hemoglobin (pg) 16.1 ± 0.1 16.0 ± 0.1 16.0 ± 0.1 15.9 ± 0.1 15.9 ± 0.1 15.9 ± 0.1

Mean cell hemoglobin

 concentration (g/dL) 33.4 ± 0.2 33.7 ± 0.1 33.6 ± 0.1 33.0 ± 0.2 33.5 ± 0.2 33.6 ± 0.1

Platelets (10 /μL) 899.1 ± 24.7 893.5 ± 14.5 901.0 ± 17.2 868.1 ± 17.4 911.2 ± 20.2 945.1 ± 21.2 3

Leukocytes (10 /μL) 3.80 ± 0.25 3.18 ± 0.14* 3.17 ± 0.23* 3.36 ± 0.26 2.62 ± 0.30** 2.97 ± 0.21** 3

Segmented neutrophils

 (10 /μL) 0.59 ± 0.08 0.50 ± 0.06 0.30 ± 0.03* 0.44 ± 0.05 0.39 ± 0.09 0.42 ± 0.07 3

Lymphocytes (10 /μL) 3.11 ± 0.22 2.62 ± 0.11 2.78 ± 0.24 2.76 ± 0.21 2.15 ± 0.21** 2.41 ± 0.19** 3

Monocytes (10 /μL) 0.03 ± 0.02 0.03 ± 0.01 0.02 ± 0.01 0.07 ± 0.02 0.06 ± 0.02 0.10 ± 0.03 3

Eosinophils (10 /μL) 0.07 ± 0.02 0.03 ± 0.01 0.05 ± 0.02 0.08 ± 0.02 0.02 ± 0.01 0.04 ± 0.01 3

Urinalysis

Fluoride (μg/16 hr) 1.01 ± 0.07 7.79 ± 2.20** 12.05 ± 2.73** 8.74 ± 1.38** 19.34 ± 3.65** 23.94 ± 1.72** b b

Glucose (mg/16 hr) 0.12 ± 0.02 0.13 ± 0.02 0.12 ± 0.02 0.13 ± 0.02 0.18 ± 0.03 0.22 ± 0.02*

Protein (mg/16 hr) 0 ± 0 0 ± 0 0 ± 0 0 ± 0 0 ± 0 1 ± 0

Volume (mL/16 hr) 1.1 ± 0.2 1.2 ± 0.3 1.0 ± 0.1 1.1 ± 0.2 3.9 ± 0.8* 6.4 ± 1.0**

Specific gravity 1.025 ± 0.003 1.025 ± 0.003 1.027 ± 0.003 1.022 ± 0.002 1.012 ± 0.002** 1.008 ± 0.001**

* Statistically different (P 0.05) from the control group by Dunn's or Shirley's test

** P 0.01

Mean ± standard error; statistical tests were performed on unrounded data. a

n=9 b

n=7 c

n=5 d
272 Tetrafluoroethylene, NTP TR 450
273

APPENDIX H

REPRODUCTIVE TISSUE EVALUATIONS

AND ESTROUS CYCLE CHARACTERIZATION

TABLE H1 Summary of Reproductive Tissue Evaluations

for Male Rats in the 13-Week Inhalation Study of Tetrafluoroethylene ................... 274

TABLE H2 Summary of Estrous Cycle Characterization

for Female Rats in the 13-Week Inhalation Study of Tetrafluoroethylene ................. 274

TABLE H3 Summary of Reproductive Tissue Evaluations

for Male Mice in the 13-Week Inhalation Study of Tetrafluoroethylene .................. 275

TABLE H4 Summary of Estrous Cycle Characterization

for Female Mice in the 13-Week Inhalation Study of Tetrafluoroethylene ................. 275
274 Tetrafluoroethylene, NTP TR 450

TABLE H1

Summary of Reproductive Tissue Evaluations for Male Rats in the 13-Week Inhalation Study

of Tetrafluoroethylene a

0 ppm 312 ppm 1,250 ppm 5,000 ppm

n 10 10 10 10

Weights (g)

Necropsy body wt 329 ± 5 343 ± 5 333 ± 4 301 ± 5**

R. cauda 0.170 ± 0.004 0.175 ± 0.004 0.161 ± 0.004 0.161 ± 0.005

R. epididymis 0.472 ± 0.008 0.479 ± 0.010 0.469 ± 0.010 0.477 ± 0.009

R. testis 1.384 ± 0.023 1.412 ± 0.029 1.375 ± 0.031 1.417 ± 0.020

Epididymal spermatozoal parameters

Abnormal sperm (%) 0.680 ± 0.085 0.480 ± 0.080 0.640 ± 0.088 0.600 ± 0.107

Motility (%) 82.22 ± 1.29 80.60 ± 1.63 79.42 ± 1.96 80.21 ± 0.76

Concentration

 (10 /g cauda epididymal tissue) 452 ± 25 445 ± 21 408 ± 34 426 ± 20 6

** Significantly different (P 0.01) from the control group by Williams' test

Data are presented as mean ± standard error. Differences from the control group were not significant by Dunnett's test (organ weights) or Dunn's test (epididymal a

spermatozoal parameters).

TABLE H2

Summary of Estrous Cycle Characterization for Female Rats in the 13-Week Inhalation Study

of Tetrafluoroethylene a

0 ppm 312 ppm 1,250 ppm 5,000 ppm

n 10 10 10 10

Necropsy body wt (g) 189 ± 5 198 ± 3 194 ± 4 173 ± 4*

Estrous cycle length (days) 4.70 ± 0.21 5.10 ± 0.18 5.00 ± 0.27 5.43 ± 0.43 b c

Estrous stage (% of cycle)

Diestrus 38.6 42.9 35.7 51.4

Proestrus 14.3 12.9 11.4 21.4

Estrus 21.4 27.1 27.1 14.3

Metestrus 24.3 17.1 25.7 12.9

Unclear diagnosis 1.4 0.0 0.0 0.0

* Significantly different (P 0.05) from the control group by Williams' test

Necropsy body weight and estrous cycle length data are presented as mean ± standard error. Differences from the control group for estrous cycle length are not a

significant by Dunn's test. By multivariate analysis of variance, exposed groups do not differ significantly from the control group in the relative length of time spend

in the estrous stages.

Estrous cycle was longer than 12 days or unclear in 2 of 10 animals. b

Estrous cycle was longer than 12 days or unclear in 3 of 10 animals. c
Tetrafluoroethylene, NTP TR 450 275

TABLE H3

Summary of Reproductive Tissue Evaluations for Male Mice in the 13-Week Inhalation Study

of Tetrafluoroethylene a

0 ppm 312 ppm 1,250 ppm 5,000 ppm

n 10 10 10 10

Weights (g)

Necropsy body wt 36.2 ± 0.7 35.3 ± 0.5 34.6 ± 0.5* 32.1 ± 0.5**

R. cauda 0.016 ± 0.001 0.017 ± 0.001 0.016 ± 0.000 0.014 ± 0.000*

R. epididymis 0.049 ± 0.002 0.048 ± 0.001 0.047 ± 0.001 0.045 ± 0.002

R. testis 0.117 ± 0.003 0.117 ± 0.002 0.118 ± 0.001 0.112 ± 0.003

Epididymal spermatozoal parameters

Abnormal sperm (%) 1.100 ± 0.141 0.920 ± 0.108 1.360 ± 0.168 0.860 ± 0.116 b

Motility (%) 75.36 ± 4.15 73.56 ± 2.02 70.08 ± 1.26* 69.89 ± 2.60

Concentration

 (10 /g cauda epididymal tissue) 976 ± 134 1,010 ± 62 921 ± 72 947 ± 101 6 b

* Significantly different (P 0.05) from the control group by Williams' test (body weights), Dunnett's test (organ weights), or Dunn's test (epididymal spermatozoal

parameters)

** Significantly different (P 0.01) from the control group by Williams' test

Data are presented as mean ± standard error. a

n=8 b

TABLE H4

Summary of Estrous Cycle Characterization for Female Mice in the 13-Week Inhalation Study

of Tetrafluoroethylene a

0 ppm 312 ppm 1,250 ppm 5,000 ppm

n 10 10 10 10

Necropsy body wt (g) 31.5 ± 0.7 30.8 ± 0.8 29.8 ± 0.6 29.2 ± 0.5

Estrous cycle length (days) 4.33 ± 0.24 4.88 ± 0.23 4.56 ± 0.18 5.22 ± 0.28 b c b b

Estrous stage (% of cycle)

Diestrus 34.3 42.9 34.3 31.4

Proestrus 18.6 11.4 22.9 20.0

Estrus 28.6 30.0 22.9 27.1

Metestrus 18.6 15.7 20.0 21.4

Necropsy body weight and estrous cycle length data are presented as mean ± standard error. Differences from the control group for body weights were not significant a

by Dunnett's test. Differences from the control group for estrous cycle length are not significant by Dunn's test. By multivariate analysis of variance, exposed groups

do not differ significantly from the control group in the relative length of time spend in the estrous stages.

Estrous cycle was longer than 12 days or unclear in 1 of 10 animals. b

Estrous cycle was longer than 12 days or unclear in 2 of 10 animals. c
276 Tetrafluoroethylene, NTP TR 450
277

APPENDIX I

CHEMICAL CHARACTERIZATION AND

GENERATION OF CHAMBER CONCENTRATIONS

PROCUREMENT AND CHARACTERIZATION OF TETRAFLUOROETHYLENE ................................. 278

VAPOR GENERATION AND EXPOSURE SYSTEM ...................................................... 279

VAPOR CONCENTRATION MONITORING ........................................................... 279

CHAMBER ATMOSPHERE CHARACTERIZATION ..................................................... 279

FIGURE I1 Infrared Absorption Spectrum of Tetrafluoroethylene ................................. 281

FIGURE I2 Schematic of the Generation and Delivery System .................................... 282

FIGURE I3 Schematic of the Exposure Chambers ............................................... 283

FIGURE I4 16-Day and 13-Week Inhalation Suite ............................................... 284

FIGURE I5 2-Year Inhalation Suite ........................................................... 285

FIGURE I6 Schematic of the Concentration Monitoring System ................................... 286

TABLE I1 Summary of Chamber Concentrations in the 16-Day Inhalation Studies 

of Tetrafluoroethylene ............................................................ 287

TABLE I2 Summary of Chamber Concentrations in the 13-Week Inhalation Studies 

of Tetrafluoroethylene ............................................................ 287

TABLE I3 Summary of Chamber Concentrations in the 2-Year Inhalation Studies 

of Tetrafluoroethylene ............................................................ 288

FIGURE I7 Monthly Mean Concentrations and Standard Deviations 

in the 156 ppm Tetrafluoroethylene Male Rat Exposure Chamber 

for the 2-Year Study .............................................................. 289

FIGURE I8 Monthly Mean Concentrations and Standard Deviations 

in the 312 ppm Tetrafluoroethylene Male Rat Exposure Chamber 

for the 2-Year Study .............................................................. 290

FIGURE I9 Monthly Mean Concentrations and Standard Deviations 

in the 625 ppm Tetrafluoroethylene Male Rat Exposure Chamber 

for the 2-Year Study .............................................................. 291

FIGURE I10 Monthly Mean Concentrations and Standard Deviations 

in the 312 ppm Tetrafluoroethylene Female Rat Exposure Chamber 

for the 2-Year Study .............................................................. 292

FIGURE I11 Monthly Mean Concentrations and Standard Deviations 

in the 625 ppm Tetrafluoroethylene Female Rat Exposure Chamber 

for the 2-Year Study .............................................................. 293

FIGURE I12 Monthly Mean Concentrations and Standard Deviations 

in the 1,250 ppm Tetrafluoroethylene Female Rat Exposure Chamber 

for the 2-Year Study .............................................................. 294

FIGURE I13 Monthly Mean Concentrations and Standard Deviations 

in the 312 ppm Tetrafluoroethylene Mouse Exposure Chamber 

for the 2-Year Study .............................................................. 295

FIGURE I14 Monthly Mean Concentrations and Standard Deviations 

in the 625 ppm Tetrafluoroethylene Mouse Exposure Chamber 

for the 2-Year Study .............................................................. 296

FIGURE I15 Monthly Mean Concentrations and Standard Deviations 

in the 1,250 ppm Tetrafluoroethylene Mouse Exposure Chamber 

for the 2-Year Study .............................................................. 297
278 Tetrafluoroethylene, NTP TR 450

CHEMICAL CHARACTERIZATION AND

GENERATION OF CHAMBER CONCENTRATIONS

PROCUREMENT AND CHARACTERIZATION OF TETRAFLUOROETHYLENE

Tetrafluoroethylene was obtained from SCM Specialty Chemicals (Gainesville, FL) in one lot (10271), which was used for the

identity and purity analyses conducted by the analytical chemistry laboratory, Midwest Research Institute (Kansas City, MO). 

Tetrafluoroethylene was also obtained from ICI Americas, Inc. (Bayonne, NJ), in five lots. The study laboratory assigned a lot

number to each shipment of as many as 12 cylinders. Lot 12017-8 was used during the 16-day studies and during most of the

13-week studies; lot 12017-77 was used during the remainder of the 13-week studies; and lots 12438-6, 12438-79, and

12438-92 were used during the 2-year studies. Identity and purity analyses were also conducted by the study laboratory on each

lot used during the studies. Reports on analyses performed in support of the tetrafluoroethylene studies are on file at the

National Institute of Environmental Health Sciences.

Each lot of the chemical, a colorless gas, was identified as tetrafluoroethylene by the analytical chemistry or study laboratory

using infrared spectroscopy. The infrared spectrum for each lot was consistent with that expected for the structure of

tetrafluoroethylene (Figure I1).

The purity of lot 10271 was determined by the analytical chemistry laboratory using gas chromatography. The purity of lots

12017-8, 12017-77, 12438-6, 12438-79, and 12438-92 was determined by the study laboratory using gas chromatography. Gas

chromatography of each lot was conducted using a flame ionization detector with a nitrogen carrier gas at a flow rate of

70 mL/minute, a 60/80 Carbopack B/1% glass column, and an oven temperature program of 35 C for 5 minutes, then 35 to

200 C at 10 C per minute. 

Gas chromatography of lot 10271 indicated one major peak and one impurity with an area greater than or equal to 0.1% relative

to the major peak. In addition, analysis for d-limonene, which is added to tetrafluoroethylene as a stabilizer, was conducted by

the analytical chemistry laboratory using gas chromatography with the same system as that used for the purity analyses but with a

10% SP-2100 on 100/120 Supelcoport glass column and an oven temperature program of 50 C for 5 minutes, then 50 to

250 C at 10 C per minute. The sample contained 0.03% ± 0.00% d-limonene. Gas chromatography conducted by the study

laboratory for each cylinder of lots 12017-8 and 12017-77 indicated that perfluorocyclobutane, the most abundant dimer

produced during tetrafluoroethylene decomposition, was present at concentrations less than or equal to 462 ppm and 2,604 ppm

for the 16-day and 13-week studies, respectively. For lots 12438-6, 12438-79, and 12438-92, gas chromatography indicated

peaks for perfluorocyclobutane with areas less than or equal to 1.21% relative to the major peak. Gas chromatography

conducted by the study laboratory for each cylinder of lots 12017-8 and 12017-77 indicated that d-limonene was present at

concentrations less than or equal to 2,837 ppm for the 13-week studies. During the 2-year studies, gas chromatography of

lots 12438-6, 12438-79, and 12438-92 indicated peaks for d-limonene with areas less than or equal to 0.56% relative to the

major peak. The manufacturer indicated that trifluoroethylene, methylene fluoride, vinyl fluoride, and vinylidene fluoride were

also present as impurities at concentrations less than or equal to 1.7 ppm. The overall purities of lots 12017-8, 12017-77, and

12438-92 were determined to be greater than 99%. The overall purities of lots 12438-6 and 12438-79 were determined to be

greater than 98%.

The manufacturer indicated that tetrafluoroethylene would be stable for up to 1 year when stored in the original containers at

room temperature. To ensure stability, the bulk chemical was stored in the original metal cylinders at 10 to 22 C. Stability

was monitored during the 13-week and 2-year studies using the same gas chromatography system used for the purity analyses. 

The relative concentrations of perfluorocyclobutane were expected to increase due to the slow dimerization of tetrafluoroethylene,

and therefore the gas cylinders were monitored for this dimer as well as for d-limonene during the 2-year studies. Two cylinders

from lot 12438-6 contained higher concentrations of these compounds than canisters from the same lot that were analyzed earlier

in the studies. One of these two cylinders, which contained 1.21% perfluorocyclobutane and 0.56% d-limonene, was replaced

immediately after gas chromatographic analysis was performed; it is not known if the dimer formed in the canister due to

degradation of tetrafluoroethylene or was present as an impurity at receipt. Stability was generally considered acceptable

throughout the studies.
Tetrafluoroethylene, NTP TR 450 279

VAPOR GENERATION AND EXPOSURE SYSTEM

A diagram of the tetrafluoroethylene generation and delivery system is shown in Figure I2. Because tetrafluoroethylene is a gas

at room temperature, the system incorporated gas distribution under regulated pressure with individual adjustment and

monitoring of the chemical flow rate to each chamber. Tetrafluoroethylene was taken directly from the cylinder in which it was

shipped. The output pressure from the cylinder was regulated to 20 psi with a two-stage regulator. The gas was passed through

a main exposure pneumatic valve, a check valve, and a filter to a manifold of five (16-day and 13-week studies) or six (2-year

studies) flow meters with integral metering valves. The gas was metered to each exposure chamber through these flow meters,

which were monitored by a pressure gauge at the manifold. A three-way solenoid valve was located in the gas delivery line to

each exposure chamber. This valve and a nitrogen inlet valve just downstream from the main exposure valve allowed the system

to be purged with nitrogen at the end of each exposure period. A sample line was included downstream from each gas cylinder. 

All equipment that came in contact with the tetrafluoroethylene gas was stainless steel, polytetrafluoroethylene, Viton® (E.I.

DuPont de Nemours, Wilmington, DE), or glass.

Stainless-steel chambers designed at Battelle Pacific Northwest Laboratories were used for all studies (Figure I3). The total

volume of each chamber was 2.3 m ; the active mixing volume of each chamber was 1.7 m . The chamber was designed so that 3 3

uniform aerosol or vapor concentrations could be maintained throughout the chamber when the catch pans were in position,

provided the aerosol or vapor was uniformly mixed with dilution air before entering the chamber. A diagram of the 16-day and

13-week exposure suite is shown in Figure I4, and a diagram of the 2-year exposure suite is shown in Figure I5.

VAPOR CONCENTRATION MONITORING

A diagram of the tetrafluoroethylene concentration monitoring system used in all studies is shown in Figure I6. The

concentrations of tetrafluoroethylene were monitored using an on-line gas chromatograph with a flame ionization detector, an

80/100 Porapack Q nickel column, and a nitrogen carrier gas at a flow rate of 22 mL/minute. Samples were drawn and analyzed

from each exposure chamber, the control chamber, the exposure suite, and an on-line standard using an automatic 8-port (16-day

and 13-week studies) or 12-port (2-year studies) sample valve. Certified standards of tetrafluoroethylene in nitrogen (Byrne

Specialty Gases, Inc., Seattle, WA; MG Industries Scientific Gases, Los Angeles, CA; Phoenix Distributors, Inc., Los Angeles,

CA) were used to perform the absolute calibration of the on-line gas chromatograph and to check instrument drift throughout the

exposure periods. Summaries of the chamber concentrations during the studies are presented in Tables I1 through I3. The

monthly mean exposure concentrations for the 2-year studies are presented in Figures I7 through I15.

CHAMBER ATMOSPHERE CHARACTERIZATION

The times for the exposure concentration to build up to 90% of the final exposure concentration (T 90) and to decay to 10% of the

exposure concentration (T ) were measured in all studies with and without animals present. During the 16-day studies, T was 10 90

approximately 12 minutes and T10 was approximately 9 minutes with and without animals in the chambers. During the 13-week

studies, T90 was 11 minutes with animals in the chambers and ranged from 11 to 14 minutes without animals; T 10 ranged from 9

to 11 minutes with and without animals in the chambers. During the 2-year studies, T ranged from 8 to 10 minutes without 90

animals in the chambers and from 10 to 16 minutes with animals present; T10 ranged from 7 to 9 minutes without animals and

from 9 to 12 minutes with animals. The T value used for all studies was 12 minutes. 90

Uniformity of tetrafluoroethylene concentration in the exposure chambers was measured prior to the start of all studies, once

during the 16-day and 13-week studies, and approximately every 3 months during the 2-year studies. The concentration was

measured with and without animals present using the on-line gas chromatograph with the automatic 8-port (16-day and 13-week

studies) or 12-port (2-year studies) sample valve disabled to allow continuous monitoring from a single input line. Uniformity of

exposure concentrations in all chambers was acceptable.

The persistence of tetrafluoroethylene in the 1,250 ppm exposure chamber after shutting off the system was monitored without

animals before the 2-year studies began and with animals present during the 2-year studies. The concentration of
280 Tetrafluoroethylene, NTP TR 450

tetrafluoroethylene in the exposure chamber fell rapidly to less than 1% of the beginning concentration within 20 minutes. 

Tetrafluoroethylene concentrations in the building exhaust and room air were also monitored during all studies.

Information supplied by the manufacturer indicated that all cylinders contained d-limonene as a stabilizer. d-Limonene and

perfluorocyclobutane are less volatile than tetrafluoroethylene and concentrate in the cylinder as the tetrafluoroethylene is

removed. Cylinder usage was regulated to minimize concentrations of these chemicals in the exposure chambers; a maximum of

80% of the tetrafluoroethylene in each cylinder was used. Gas chromatography of chamber samples did not indicate any

impurities other than perfluorocyclobutane and d-limonene. Concurrent analysis of cylinder headspace and chamber samples for

perfluorocyclobutane demonstrated that chamber concentrations of perfluorocyclobutane matched those in the cylinder

headspace. The contents of selected used cylinders were analyzed for d-limonene and perfluorocyclobutane. The results

indicated that tetrafluoroethylene was stable during generation and in the exposure chambers and that perfluorocyclobutane was

not formed in significant quantities by the generation system. As expected, the headspace concentrations of d-limonene and

perfluorocyclobutane in the cylinders increased as tetrafluoroethylene was removed. 
281 Tetrafluoroethylene, NTP TR 450

FIGURE I1

Infrared Absorption Spectrum of Tetrafluoroethylene
282 Tetrafluoroethylene, NTP TR 450

FIGURE I2

Schematic of the Generation and Delivery System
283 Tetrafluoroethylene, NTP TR 450

FIGURE I3

Schematic of the Exposure Chambers
284 Tetrafluoroethylene, NTP TR 450

FIGURE I4

16-Day and 13-Week Inhalation Suite
285 Tetrafluoroethylene, NTP TR 450

FIGURE I5

2-Year Inhalation Suite
286 Tetrafluoroethylene, NTP TR 450

FIGURE I6

Schematic of the Concentration Monitoring System
Tetrafluoroethylene, NTP TR 450 287

TABLE I1

Summary of Chamber Concentrations in the 16-Day Inhalation Studies of Tetrafluoroethylene

Target Concentration Total Number of Readings Average Concentrationa

(ppm) (ppm)

Rat Chambers

312 250 312 ± 6.21

625 250 621 ± 9.66

1,250 252 1,250 ± 19.2

2,500 253 2,500 ± 33.9

5,000 255 4,990 ± 6.19

Mouse Chambers

312 250 312 ± 5.60

625 249 622 ± 9.40

1,250 252 1,260 ± 19.2

2,500 253 2,500 ± 34.1

5,000 255 4,990 ± 59.4

Mean ± standard deviation a

TABLE I2

Summary of Chamber Concentrations in the 13-Week Inhalation Studies of Tetrafluoroethylene

Target Concentration Total Number of Readings Average Concentrationa

(ppm) (ppm)

Rat Chambers

312 1,107 314 ± 9.3

625 1,106 628 ± 16

1,250 1,146 1,260 ± 40

2,500 1,154 2,520 ± 77

5,000 1,149 5,050 ± 136

Mouse Chambers

312 1,104 314 ± 9.4

625 1,103 627 ± 16

1,250 1,145 1,260 ± 35

2,500 1,153 2,520 ± 67

5,000 1,147 5,050 ± 128

Mean ± standard deviation a
288 Tetrafluoroethylene, NTP TR 450

TABLE I3

Summary of Chamber Concentrations in the 2-Year Inhalation Studies of Tetrafluoroethylene

Target Concentration Total Number of Readings Average Concentrationa

(ppm) (ppm)

Male Rat Chambers

156 6,470 155 ± 7

312 6,523 312 ± 12

625 6,533 623 ± 24

Female Rat Chambers

312 6,106 312 ± 10

625 6,146 625 ± 20

1,250 6,154 1,250 ± 43

Mouse Chambers

312 5,577 311 ± 10

625 5,619 625 ± 19

1,250 5,633 1,250 ± 42

Mean ± standard deviation a
1 Tetrafluoroethylene, NTP TR 450

FIGURE I7

Monthly Mean Concentrations and Standard Deviations

in the 156 ppm Tetrafluoroethylene Male Rat Exposure Chamber

for the 2-Year Study
Tetrafluoroethylene, NTP TR 450 2

FIGURE I8

Monthly Mean Concentrations and Standard Deviations

in the 312 ppm Tetrafluoroethylene Male Rat Exposure Chamber

for the 2-Year Study
3 Tetrafluoroethylene, NTP TR 450

FIGURE I9

Monthly Mean Concentrations and Standard Deviations

in the 625 ppm Tetrafluoroethylene Male Rat Exposure Chamber

for the 2-Year Study
Tetrafluoroethylene, NTP TR 450 4

FIGURE I10

Monthly Mean Concentrations and Standard Deviations

in the 312 ppm Tetrafluoroethylene Female Rat Exposure Chamber

for the 2-Year Study
5 Tetrafluoroethylene, NTP TR 450

FIGURE I11

Monthly Mean Concentrations and Standard Deviations

in the 625 ppm Tetrafluoroethylene Female Rat Exposure Chamber

for the 2-Year Study
Tetrafluoroethylene, NTP TR 450 6

FIGURE I12

Monthly Mean Concentrations and Standard Deviations

in the 1,250 ppm Tetrafluoroethylene Female Rat Exposure Chamber

for the 2-Year Study
7 Tetrafluoroethylene, NTP TR 450

FIGURE I13

Monthly Mean Concentrations and Standard Deviations

in the 312 ppm Tetrafluoroethylene Mouse Exposure Chamber

for the 2-Year Study
Tetrafluoroethylene, NTP TR 450 8

FIGURE I14

Monthly Mean Concentrations and Standard Deviations

in the 625 ppm Tetrafluoroethylene Mouse Exposure Chamber

for the 2-Year Study
9 Tetrafluoroethylene, NTP TR 450

FIGURE I15

Monthly Mean Concentrations and Standard Deviations

in the 1,250 ppm Tetrafluoroethylene Mouse Exposure Chamber

for the 2-Year Study
298 Tetrafluoroethylene, NTP TR 450
299

APPENDIX J

INGREDIENTS, NUTRIENT COMPOSITION,

AND CONTAMINANT LEVELS

IN NIH-07 RAT AND MOUSE RATION

TABLE J1 Ingredients of NIH-07 Rat and Mouse Ration ........................................ 300

TABLE J2 Vitamins and Minerals in NIH-07 Rat and Mouse Ration .............................. 300

TABLE J3 Nutrient Composition of NIH-07 Rat and Mouse Ration ............................... 301

TABLE J4 Contaminant Levels in NIH-07 Rat and Mouse Ration ................................ 302
300 Tetrafluoroethylene, NTP TR 450

TABLE J1

Ingredients of NIH-07 Rat and Mouse Ration a

Ingredients Percent by Weight b

Ground #2 yellow shelled corn 24.50

Ground hard winter wheat 23.00

Soybean meal (49% protein) 12.00

Fish meal (60% protein) 10.00

Wheat middlings 10.00

Dried skim milk 5.00

Alfalfa meal (dehydrated, 17% protein) 4.00

Corn gluten meal (60% protein) 3.00

Soy oil 2.50

Dried brewer's yeast 2.00

Dry molasses 1.50

Dicalcium phosphate 1.25

Ground limestone 0.50

Salt 0.50

Premixes (vitamin and mineral) 0.25

NCI, 1976; NIH, 1978 a

Ingredients were ground to pass through a U.S. Standard Screen No. 16 before being mixed. b

TABLE J2

Vitamins and Minerals in NIH-07 Rat and Mouse Ration a

Amount Source

Vitamins

A 5,500,000 IU Stabilized vitamin A palmitate or acetate

D 4,600,000 IU D-activated animal sterol 3

K3 2.8 g Menadione

d- -Tocopheryl acetate 20,000 IU

Choline 560.0 g Choline chloride

Folic acid 2.2 g

Niacin 30.0 g

d-Pantothenic acid 18.0 g d-Calcium pantothenate

Riboflavin 3.4 g

Thiamine 10.0 g Thiamine mononitrate

B12 4,000 μg

Pyridoxine 1.7 g Pyridoxine hydrochloride

Biotin 140.0 mg d-Biotin

Minerals

Iron 120.0 g Iron sulfate

Manganese 60.0 g Manganous oxide

Zinc 16.0 g Zinc oxide

Copper 4.0 g Copper sulfate

Iodine 1.4 g Calcium iodate

Cobalt 0.4 g Cobalt carbonate

Per ton (2,000 lb) of finished product a
Tetrafluoroethylene, NTP TR 450 301

TABLE J3

Nutrient Composition of NIH-07 Rat and Mouse Ration

Mean ± Standard

Nutrient Deviation Range Number of Samples

Protein (% by weight) 22.97 ± 0.81 21.7 ) 24.2 24

Crude fat (% by weight) 5.37 ± 0.32 4.60 ) 5.90 24

Crude fiber (% by weight) 3.66 ± 0.39 2.80 ) 4.20 24

Ash (% by weight) 6.62 ± 0.31 6.11 ) 7.30 24

Amino Acids (% of total diet)

Arginine 1.280 ± 0.083 1.110 ) 1.390 11

Cystine 0.308 ± 0.071 0.181 ) 0.400 11

Glycine 1.158 ± 0.048 1.060 ) 1.220 11

Histidine 0.584 ± 0.027 0.531 ) 0.630 11

Isoleucine 0.917 ± 0.033 0.867 ) 0.965 11

Leucine 1.975 ± 0.051 1.850 ) 2.040 11

Lysine 1.274 ± 0.049 1.200 ) 1.370 11

Methionine 0.437 ± 0.109 0.306 ) 0.699 11

Phenylalanine 0.999 ± 0.120 0.665 ) 1.110 11

Threonine 0.904 ± 0.058 0.824 ) 0.985 11

Tryptophan 0.218 ± 0.153 0.107 ) 0.671 11

Tyrosine 0.685 ± 0.094 0.564 ) 0.794 11

Valine 1.086 ± 0.055 0.962 ) 1.170 11

Essential Fatty Acids (% of total diet)

Linoleic 2.407 ± 0.227 1.830 ) 2.570 10

Linolenic 0.259 ± 0.065 0.100 ) 0.320 10

Vitamins

Vitamin A (IU/kg) 6,771 ± 1,915 4,180 ) 12,140 24

Vitamin D (IU/kg) 4,450 ± 1,382 3,000 ) 6,300 4

-Tocopherol (ppm) 36.12 ± 9.15 22.5 ) 48.9 10

Thiamine (ppm) 19.00 ± 2.36 16.0 ) 28.0 24

Riboflavin (ppm) 7.83 ± 0.92 6.10 ) 9.00 11

Niacin (ppm) 98.64 ± 25.51 65.0 ) 150.0 10

Pantothenic acid (ppm) 30.55 ± 3.52 23.0 ) 34.6 11

Pyridoxine (ppm) 9.11 ± 2.53 5.60 ) 14.0 11

Folic acid (ppm) 2.46 ± 0.63 1.80 ) 3.70 11

Biotin (ppm) 0.268 ± 0.047 0.190 ) 0.354 11

Vitamin B12 (ppb) 40.5 ± 19.1 10.6 ) 65.0 11

Choline (ppm) 2,991 ± 382 2,400 ) 3,430 10

Minerals

Calcium (%) 1.25 ± 0.11 1.10 ) 1.54 24

Phosphorus (%) 0.95 ± 0.032 0.890 ) 1.00 24

Potassium (%) 0.886 ± 0.063 0.772 ) 0.971 9

Chloride (%) 0.529 ± 0.087 0.380 ) 0.635 9

Sodium (%) 0.316 ± 0.033 0.258 ) 0.371 11

Magnesium (%) 0.166 ± 0.010 0.148 ) 0.181 11

Sulfur (%) 0.272 ± 0.059 0.208 ) 0.420 10

Iron (ppm) 350.5 ± 87.3 255.0 ) 523.0 11

Manganese (ppm) 92.48 ± 5.14 81.7 ) 99.4 11

Zinc (ppm) 59.33 ± 10.2 46.1 ) 81.6 11

Copper (ppm) 11.81 ± 2.50 8.09 ) 15.4 11

Iodine (ppm) 3.54 ± 1.19 1.52 ) 5.83 10

Chromium (ppm) 1.66 ± 0.46 0.85 ) 2.09 11

Cobalt (ppm) 0.76 ± 0.23 0.49 ) 1.15 7
302 Tetrafluoroethylene, NTP TR 450

TABLE J4

Contaminant Levels in NIH-07 Rat and Mouse Ration a

Mean ± Standard

Deviation Range Number of Samples b

Contaminants

Arsenic (ppm) 0.23 ± 0.17 0.05 ) 0.60 24

Cadmium (ppm) 0.09 ± 0.02 0.05 ) 0.10 24

Lead (ppm) 0.24 ± 0.18 0.10 ) 1.00 24

Mercury (ppm) 0.05 ± 0.02 0.02 ) 0.11 24

Selenium (ppm) 0.40 ± 0.20 0.16 ) 1.21 24

Aflatoxins (ppb) <5.0 23 c

Nitrate nitrogen (ppm) 16.60 ± 4.13 8.60 ) 24.0 24 d

Nitrite nitrogen (ppm) 0.20 ± 0.17 0.10 ) 0.60 24 d

BHA (ppm) 1.54 ± 0.65 0.10 ) 3.00 24 e

BHT (ppm) 1.30 ± 0.62 0.10 ) 3.00 24 e

Aerobic plate count (CFU/g) 46,404 ± 24,682 6,700 ) 120,000 24

Coliform (MPN/g) 50 ± 224 3 ) 1,100 24

Escherichia coli (MPN/g) 3 ± 0.2 3 ) 4 24

Salmonella (MPN/g) Negative 24

Total nitrosoamines (ppb) 8.05 ± 3.23 3.60 ) 16.50 24 f

N-Nitrosodimethylamine (ppb) 5.85 ± 2.71 2.60 ) 13.00 24 f

N-Nitrosopyrrolidine (ppb) 2.20 ± 1.25 0.90 ) 5.20 24 f

Pesticides (ppm)

-BHC <0.01 24

-BHC <0.02 24

-BHC <0.01 24

-BHC <0.01 24

Heptachlor <0.01 24

Aldrin <0.01 24

Heptachlor epoxide <0.01 24

DDE <0.01 24

DDD <0.01 24

DDT <0.01 24

HCB <0.01 24

Mirex <0.01 24

Methoxychlor <0.05 24

Dieldrin <0.01 24

Endrin <0.01 24

Telodrin <0.01 24

Chlordane <0.05 24

Toxaphene <0.10 24

Estimated PCBs <0.20 24

Ronnel <0.01 24

Ethion <0.02 24

Trithion <0.05 24

Diazinon <0.10 24

Methyl parathion <0.02 24

Ethyl parathion <0.02 24

Malathion 0.24 ± 0.23 0.05 ) 1.00 24

Endosulfan I <0.01 24

Endosulfan II <0.01 24

Endosulfan sulfate <0.03 24

CFU = colony forming units; MPN = most probable number; BHC = hexachlorocyclohexane or benzene hexachloride a

For values less than the limit of detection, the detection limit is given as the mean. b

No aflatoxin measurement was recorded for the lot milled on 2 October 1989. c

Sources of contamination: alfalfa, grains, and fish meal d

Sources of contamination: soy oil and fish meal e

All values were corrected for percent recovery. f
APPENDIX K

SENTINEL ANIMAL PROGRAM

METHODS ......................................................................................... 304

TABLE K1 Murine Virus Antibody Determinations for Rats and Mice 

in the 13-Week and 2-Year Studies of Tetrafluoroethylene .................................. 306
304 Tetrafluoroethylene, NTP TR 450

SENTINEL ANIMAL PROGRAM

METHODS

Rodents used in the Carcinogenesis Program of the National Toxicology Program are produced in optimally clean facilities to

eliminate potential pathogens that may affect study results. The Sentinel Animal Program is part of the periodic monitoring of

animal health that occurs during the toxicologic evaluation of chemical compounds. Under this program, the disease state of the

rodents is monitored via serology on sera from extra (sentinel) animals in the study rooms. These animals and the study animals

are subject to identical environmental conditions. The sentinel animals come from the same production source and weanling

groups as the animals used for the studies of chemical compounds.

Serum samples were collected from randomly selected rats and mice during the 13-week and 2-year studies. Blood from each

animal was collected and allowed to clot, and the serum was separated. The samples were processed appropriately and sent to

Microbiological Associates, Inc. (Bethesda, MD), for determination of antibody titers. The laboratory serology methods and

viral agents for which testing was performed are tabulated below; the times at which blood was collected during the studies are

also listed.

Method and Test Time of Analysis

RATS

13-Week Study

ELISA

Mycoplasma arthritidis Study termination

Mycoplasma pulmonis Study termination

PVM (pneumonia virus of mice) Study termination

RCV/SDA

 (rat coronavirus/sialodacryoadenitis virus) Study termination

Sendai Study termination

Hemagglutination Inhibition

H-1 (Toolan's H-1 virus) Study termination

KRV (Kilham rat virus) Study termination

2-Year Study

ELISA

M. arthritidis 22 and 24 months

M. pulmonis 22 and 24 months

PVM 6, 12, 18, 22, and 24 months

RCV/SDA 6, 12, 18, 22, and 24 months

Sendai 6, 12, 18, 22, and 24 months

Hemagglutination Inhibition

H-1 6, 12, 18, 22, and 24 months

KRV 6, 12, 18, 22, and 24 months
Tetrafluoroethylene, NTP TR 450 305

MICE

13-Week Study

Complement Fixation

LCM (lymphocytic choriomeningitis virus) Study termination

ELISA

Ectromelia virus Study termination

GDVII (mouse encephalomyelitis virus) Study termination

Mouse adenoma virus Study termination

MHV (mouse hepatitis virus) Study termination

M. arthritidis Study termination

M. pulmonis Study termination

PVM Study termination

Reovirus 3 Study termination

Sendai Study termination

Immunofluorescence Assay

EDIM (epizootic diarrhea of infant mice) Study termination

Hemagglutination Inhibition

K (papovavirus) Study termination

MVM (minute virus of mice) Study termination

Polyoma virus Study termination

2-Year Study

ELISA

Ectromelia virus 6, 12, 18, and 22 months

EDIM 22 months

GDVII 6, 12, 18, and 22 months

LCM 18 and 22 months

MVM 6 and 12 months

Mouse adenoma virus 6, 12, 18, and 22 months

MHV 6, 12, 18, and 22 months

M. arthritidis 22 months

M. pulmonis 22 months

PVM 6, 12, 18, and 22 months 

Reovirus 3 6, 12, 18, and 22 months

Sendai 6, 12, 18, and 22 months

Immunofluorescence Assay

EDIM 6, 12, 18, and 22 months

LCM 6 and 12 months

Reovirus 3 12 months

MVM 18 and 22 months

Mouse adenoma virus 22 months

Hemagglutination Inhibition

K 6, 12, 18, and 22 months

MVM 18 months

Polyoma virus 6, 12, 18, and 22 months

Results of serology tests are presented in Table K1.
306 Tetrafluoroethylene, NTP TR 450

TABLE K1

Murine Virus Antibody Determinations for Rats and Mice in the 13-Week and 2-Year Studies

of Tetrafluoroethylene

Interval Incidence of Antibody Positive Serologic

in Sentinel Animals Reaction for

13-Week Studies

Rats

Study termination 0/10 None positive

Mice

Study termination 0/10 None positive

2-Year Studies

Rats

6 Months 0/10 None positive

12 Months 0/10 None positive

18 Months 0/11 None positive

22 Months 0/2 None positive

24 Months 2/10 M. arthritidisa

Mice

6 Months 0/16 None positive

12 Months 1/16 Reovirus 3b

18 Months 0/13 None positive

22 Months 0/10 None positive

Further evaluation of samples positive for M. arthritidis by immunoblot and Western blot procedures indicated that the positive titers may be due to cross reaction a

with antibodies of nonpathogenic Mycoplasma or other agents. Only sporadic samples were positive and there were no clinical findings or histopathologic changes of

M. arthritidis infection in mice with positive titers. Accordingly, M. arthritidis-positive titers were considered to be false positives.

Negative for Reovirus 3 by Western blot; false positive b
307

APPENDIX L

H-RAS CODON 61 MUTATION SPECTRA

IN HEPATOCELLULAR NEOPLASMS

FROM B6C3F1 MICE EXPOSED

TO TETRAFLUOROETHYLENE FOR 2 YEARS

Robert C. Sills, H. Lily Hong, Joe Roycroft,

Theodora R. Devereux, and Gary A. Boorman

National Institute of Environmental Health Sciences

Research Triangle Park, North Carolina

INTRODUCTION ..................................................................................... 308

MATERIALS AND METHODS ........................................................................... 308

RESULTS .......................................................................................... 309

DISCUSSION ........................................................................................ 309

REFERENCES ....................................................................................... 310

TABLE L1 H-ras Mutations at Codon 61 in Spontaneously Occurring

and Tetrafluoroethylene-Induced Liver Neoplasms from B6C3F 1 Mice ....................... 312

TABLE L2 Frequency of K- ras Proto-oncogene Activation in Spontaneously Occurring 

and Tetrafluoroethylene-Induced Liver Neoplasms from B6C3F 1 Mice ....................... 312

TABLE L3 H-ras Mutations at Codon 61 Detected in Hepatocellular Adenomas

and Carcinomas from B6C3F 1 Mice ..................................................... 313
308 Tetrafluoroethylene, NTP TR 450

H-RAS CODON 61 MUTATION SPECTRA

IN HEPATOCELLULAR NEOPLASMS

FROM B6C3F1 MICE EXPOSED

TO TETRAFLUOROETHYLENE FOR 2 YEARS

INTRODUCTION

Liver neoplasms are commonly seen in B6C3F1 mice in 2-year inhalation studies, occurring with a typical incidence of 40% in

control males and 20% in control females. Chemical-induced neoplasms in mice have a high frequency of proto-oncogene

activation, particularly by point mutations in codon 61 of H-ras genes (Maronpot et al., 1995). The frequency of ras activation

in these neoplasms is often greater than detected in neoplasms occurring in control animals (Reynolds et al., 1987), and there is

evidence for chemical specificity in the pattern of oncogene activation (Wiseman et al., 1986; Maronpot et al., 1995). The

specific types of oncogene-activating mutations induced by a chemical carcinogen often agree with what is expected based on the

DNA adducts formed by the agent (Wiseman et al., 1986). Even for “nongenotoxic carcinogens,” the patterns of ras gene

mutations in neoplasms can give clues about the mechanism of tumorigenesis (Devereux et al., 1993; Maronpot et al., 1995).

MATERIALS AND METHODS

Liver neoplasms: Male and female B6C3F1 mice were exposed to 0, 312, 625, or 1,250 ppm tetrafluoroethylene by inhalation

for 6 hours per day, 5 days per week for 2 years. At necropsy, liver neoplasms were fixed in 10% neutral buffered formalin,

routinely processed, embedded in paraffin, sectioned to a thickness of 5 μm, and stained with hematoxylin and eosin (H&E). 

Subsequently, six unstained serial sections (10 μm thick) were prepared from paraffin blocks containing hepatocellular

adenomas or carcinomas for isolation of DNA for polymerase chain reaction (PCR)-based assays. In order to isolate adequate

amounts of DNA, liver neoplasms greater than 1 mm in diameter were identified for analysis. Based on the size criterion, a total

of 66 paraffin-embedded neoplasms were examined for genetic alterations in the H- ras gene. These included 53 neoplasms from

tetrafluoroethylene-exposed mice and 13 neoplasms from control mice. Also, 13 frozen liver neoplasms were evaluated for

H-ras and K-ras mutations. For the liver neoplasms from which frozen and paraffin-embedded tissue were available, both were

examined to confirm the results.

DNA isolation: The DNA isolation procedure is described in Marmur (1961) and in Sills et al. (1995). The paraffin-embedded

tissue was deparaffinized and rehydrated before digesting with proteinase K (Wright and Manos, 1990). The frozen tumor tissue

was digested with 10 mg/mL pronase in 1% sodium dodecyl sulfate in TNE buffer (10 mM TRIS; 150 mM NaCl; and 2 mM

EDTA disodium salt, pH 7.5). DNA was extracted with phenol and chloroform and precipitated with ethanol. DNA was

quantified by optical density at 260 nm and 200 ng/μL was used for amplification.

DNA amplification: DNA was amplified by the polymerase chain reaction (Saiki et al., 1988; Sills et al., 1995); details of the

use of nested primers are described in Devereux et al. (1991, 1993).

Restriction fragment length polymorphic identification: A “cold” method was employed to identify mutation in the H-ras gene

at codon 61 from liver neoplasms. This was based on restriction fragment length polymorphism in the DNA containing a CAA

to AAA, CTA, or CGA mutation in codon 61 of exon 2 (Sukumuar and Barbacid, 1990). The sense primer used for

amplification of exon 2 was 5 -GACATCTTAGACACAGCAGTT-3 . A restriction site for MSEI, XbaI, or TaqI enzyme (New

England Biolaboratory, Beverly, MA) is created by the presence of a C to A, A to T, or A to G mutation in the first or second

base of codon 61, respectively. By using this technique, we detected codon 61 AAA, CTA, and CGA mutations by MSEI, XbaI,

and TaqI digestion, respectively; the normal sequence (CAA) of codon 61 is not cut by these enzymes. The reaction was

incubated at 37 C (for MSEI or XbaI) or 60 C (for TaqI) for 2 hours. Fifteen μL of the mixture with bromophenol blue dye

was loaded onto the 6% acrylamide TBE gel (8 × 8 cm × 1 mm; 15 wells) (Novex, San Diego, CA). The gel was run at

100 volts for 1 hour on the Novex gel electrophoresis unit. Gels were stained with a 5 μg/mL solution of ethidium bromide for
Tetrafluoroethylene, NTP TR 450 309

20 minutes and then destained in distilled water. Ethidium bromide-stained bands were visualized using a 312 nm ultraviolet

viewing box and were photographed.

Single-strand conformational analysis: Single-strand conformation analysis (Orita et al., 1989) was performed with PCR

products into which [ - P]dATP was incorporated during the inner amplification. For the first exon of K- ras, 10% acrylamide 33

gel containing 10% glycerol and 1X TRIS-borate-EDTA buffer was electrophoresed at room temperature with constant power at

8 watts for 16 hours on a Model S2 sequencing gel electrophoresis apparatus (Bethesda Research Labs, Gaithersburg, MD). For

the second exon of H-ras, 12% acrylamide gel with 5% glycerol in 1X TRIS-borate-EDTA buffer was used at 35 watts in a 4 C

cold room for 5 hours.

RESULTS

In order to determine if the tetrafluoroethylene-induced neoplasms contained an H- ras mutation profile similar to that observed

with ``spontaneous'' neoplasms, sample groups of 29 neoplasms consisting of adenomas and carcinomas from the two highest

exposure groups, four neoplasms from the low exposure group, and 17 neoplasms from the chamber controls were evaluated by

polymerase chain reaction amplification of H-ras exon 2 followed by restriction fragment length polymorphism analysis for the

three common codon 61 mutations in the B6C3F mouse (Table L1). Single-stranded conformation polymorphism was used as 1

an alternative screening method for detection of H- and K-ras mutations in DNA from 19 neoplasms following

tetrafluoroethylene exposure and from four chamber controls (Table L2). A low frequency (9/62, 15%) of H- ras mutations was

detected in hepatocellular neoplasms when compared to the high frequency (10/17 or 59% in controls from the present study and

183/333 or 56% in historical controls) detected in spontaneous liver neoplasms from B6C3F 1 mice (Table L1). In addition, the

proportion of H-ras mutations in hepatocellular neoplasms was 1:1:1 for codon 61 AAA, CGA, and CTA mutations,

respectively, when compared to 3:6:1 for controls from the present study or 5:2:1 for spontaneous hepatocellular neoplasms in

historical controls. There were generally no differences in the mutation frequency and spectrum between exposure groups and

between benign and malignant hepatocellular neoplasms (Tables L1 and L3). K- ras mutations were not detected in

hepatocellular neoplasms following tetrafluoroethylene exposure.

DISCUSSION

The low frequency (9/62, 15%) of H-ras mutations detected in hepatocellular neoplasms following tetrafluoroethylene exposure

is similar to that reported with other nongenotoxic agents such as phenobarbital (7%), chloroform (21%), and ciprofibrate (31%)

when compared to the generally higher frequency (183/333, 56%) observed in spontaneous liver neoplasms from B6C3F 1 mice

(Fox et al., 1990; Maronpot et al., 1995). Other nongenotoxic hepatocellular carcinogens associated with low frequencies of

H-ras include hexachlorobenzene (Rumsby et al., 1992), dieldrin, (Bauer-Hofmann et al., 1992), methylclofenapate (Stanley

et al., 1994), and oxazepam (NTP, 1993). Nongenotoxic agents, by definition, are not positive in in vitro mutation assays, and

therefore the parent chemical or metabolites do not react with the DNA directly to cause mutations. Our findings of a decreased

frequency of ras mutations at codon 61 are consistent with the lack of mutagenicity in the Salmonella typhimurium assay and

suggest that tetrafluoroethylene may be acting in the liver as a nongenotoxic carcinogen. In addition, the finding of no increases

in the frequency of micronucleated erythrocytes in peripheral blood samples supports this theory.

The decreased frequency of H-ras mutations in tetrafluoroethylene-induced hepatocellular neoplasms is similar to that detected in

B6C3F mice exposed to the structurally similar tetrachloroethylene (24%) (Anna et al., 1994). Unlike the lack of K-ras 1

mutations in the tetrafluoroethylene study, a few K-ras mutations were detected in the tetrachloroethylene study. Data from the

present study support the hypothesis that the liver tumors induced by these two structurally similar hepatocellular carcinogens

may be acting via a ras-independent pathway. Recently, chlordane-induced hepatocarcinogenesis in B6C3F1 mice was shown to

be independent of ras activation (Malarkey et al., 1995). Alternate pathways such as cytotoxicity followed by enhanced cell

proliferation may also not be playing a major role in the development of hepatocellular neoplasms with tetrafluoroethylene since

at 16 days or 13 weeks, there was no evidence of hepatocellular toxicity. Furthermore, since the mutation spectrum at H- ras

codon 61 was not similar to that of spontaneous hepatocellular neoplasms, the data also argue against the theory that

tetrafluoroethylene-induced tumors may be acting by a simple promotional mechanism involving ras-mutated cells. If this was
310 Tetrafluoroethylene, NTP TR 450

the case, one would expect that a number of the hepatocellular neoplasms would have had similar mutation profiles to those of

the controls, due to the clonal expansion of spontaneously initiated cells with ras mutations.

The low frequency of H-ras mutations in the liver is consistent with the findings with various nongenotoxic carcinogens;

however, the variety of different types of neoplasms in the liver of B6C3F1 mice supports the hypothesis that a potential in vivo

genotoxic event(s) may be associated with the carcinogenesis process. The multiplicity of hepatocellular neoplasms and the

development of liver hemangiosarcomas, and the significant increase in histiocytic sarcomas in the liver suggest that

metabolizing enzymes in the liver may have produced unique tetrafluoroethylene metabolites which may have played a role,

perhaps through as yet undetected genotoxic events, in the development of the marked increase in tumors in the liver. Similar to

tetrafluoroethylene, 1,3-butadiene (Melnick et al., 1990) and vinyl chloride (Froment et al., 1994) induced hepatic

hemangiosarcomas and hepatocellular neoplasms and were both genotoxic carcinogens.

REFERENCES

Anna, C.H., Maronpot, R.R., Pereira, M.A., Foley, J.F., Malarkey, D.E., and Anderson, M.W. (1994). ras Proto-oncogene

activation in dichloroacetic acid-, trichloroethylene- and tetrachloroethylene-induced liver tumors in B6C3F1 mice. 

Carcinogenesis 15, 2255-2261.

Bauer-Hofmann, R., Buchmann, A., Mahr, J., Kress, S., and Schwarz, M. (1992). The tumour promoters dieldrin and

phenobarbital increase the frequency of c-Ha-ras wild-type, but not of c-Ha-ras mutated focal liver lesions in male C3H/He

mice. Carcinogenesis 13, 477-481.

Devereux, T.R., Anderson, M.W., and Belinsky, S.A. (1991). Role of ras protooncogene activation in the formation of

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312 Tetrafluoroethylene, NTP TR 450

TABLE L1

H-ras Mutations at Codon 61 in Spontaneously Occurring and Tetrafluoroethylene-Induced 

Liver Neoplasms from B6C3F 1 Mice

Treatment Activated H-ras Codon 61

H-ras (%) AAA CGA CTA

Control, Historical 183/333 (56%) 106/177 (60%) 50/177 (28%) 21/177 (12%) a

Control 10/17 (59%) 3/10 (30%) 6/10 (60%) 1/10 (10%)

Tetrafluoroethylene (312 ppm) 0/3 (0%) — — —

Tetrafluoroethylene (625 ppm) 6/29 (21%) 2/6 (33%) 2/6 (33%) 2/6 (33%)

Tetrafluoroethylene (1,250 ppm) 3/27 (10%) 1/3 (33%) 1/3 (33%) 1/3 (33%)

Tetrafluoroethylene (Total) 9/59 (15%) 3/9 (33%) 3/9 (33%) 3/9 (33%)

Data are presented in Maronpot et al. (1995). a

TABLE L2

Frequency of K- ras Proto-oncogene Activation in Spontaneously Occurring

and Tetrafluoroethylene-Induced Liver Neoplasms from B6C3F 1 Mice

Treatment K-ras Mutations (%)

Control, Historical 3/167 (1.8%) a

Control 0/4 (0%) b

Tetrafluoroethylene 0/19 (0%) b

Data are presented in Maronpot et al. (1995). a

Determined only for first exon of K-ras at codons 12 and 13. b
Tetrafluoroethylene, NTP TR 450 313

TABLE L3

H-ras Mutations at Codon 61 Detected in Hepatocellular Adenomas and Carcinomas from B6C3F 1 Mice

Treatment Activated H-ras Codon 61

H-ras (%) AAA CGA CTA

Controls

Hepatocellular Adenoma 5/11 (46%) 1 3 1

Hepatocellular Carcinoma 5/6 (83%) 2 3 0

Tetrafluoroethylene

Hepatocellular Adenoma 4/20 (20%) 1 2 1

Hepatocellular Carcinoma 5/39 (13%) 2 1 2