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3 
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. Selection per se is not an indicator of a 

chemical's carcinogenic potential. The interpretive conclusions presented in this TechnicaLReport are based 

only on the ~esults 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. 

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, NIEHS, P.O. Box 12233, MD El-02, Research Triangle Park, NC 27709 (919-541-3419). 

Listings of all 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. 
NT~ TECHN~'CAL ~.E~O~T 

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]Research Tr~a~glle ~ark~ NC ~77~ 

May ~7 

NT~ 1fir 4~ 

NEH Publication No. ~7-3375 

U.~o ~E]PA~TMENT OF HEALTH AND ]I~IUiYJIAN SE~V]ICE$ 

]Public Hea~h Service 

National ]Institutes o~ Health . 
2 t-Butylhydroquinone, NTP TR 459 

CONTRIBUTORS 

National Toxicology Program 

Evaluated and interpreted results and reported findings " 

K.M. Abdo, Ph.D., Study Scientist 

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

D.A. Bridge, B.S. 

J.R. Bucber, Ph. D. 

L.To Burka, Ph.D. 

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

J.R~ Harley, D.V.M. . 

J.K. Haseman, Ph.D. 

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

J.H. Roycroft, Ph.D. 

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

D.B. Waiters, Ph.D. 

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

Southern Research Institute 

Conducted 13-week, 2-Year, and long-term studies, 

evaluated pathology findings 

J.D. Prejean, Ph.D., principal Investigator 

D~R, Farnell, D.V.M., Ph.D. 

J.E. Heath, D.V.M. 

R.H. James, M.S. 

C. Lindamood, Ph.D. 

Experimental Pathology Laboratories, Inc. 

Provided pathology quality assurance 

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

S. Botts, D.V.M., Ph.D. 

K. Yoshitomi, .D.V.M., Ph.D. 

Dynamac Corporation 

Prepared quality assurance audits 

S. Brecber, Ph.D., Principal Investigator 

Analytical Sciences, Inc. ~ Provided statistical analyses 

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

N.G. Mintz, B.S. 

S. Rosenblum, M.S. 

NTP Pathology Working Group 

Evaluated slides~ prepared pathology report bn rats 

(9 January 1995) 

J.C. Seely, D.V.M., Chairperson 

PATHCO, Inc. ~ 

S. Botts, D.v.M., Ph.D. 

ExperimentalPathology Laboratories, Inc. 

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

National Toxicology Program 

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

National Toxicology Program 

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

National Toxicology Program 

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

National Toxicology Program 

B. Short, D.V.M., Ph.D. 

SmithKiine-Beecham 

Evaluated slides, prepared pathology report on mice 

(24 February 1994) 

P.K. Hildebrandt, D.V.M., Chairperson 

PATHCO, Inc. 

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

National Toxicology Program 

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

National Toxicology Program 

J. Leininger, D.V.M, Ph.D. 

ChemiCal Industry Institute of Toxicology 

J. Mahler, D.V.M. 

National Toxicology Program 

C. Morris, D.V.M., M.S., Observer 

R.P.S. 

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

National Toxicology Program 

K. Yoshitomi, D.V.M., Ph. D. 

Experimental Pathology Laboratories, Inc. 

Biotechnical Services, Inc. 

Prepared Technical Report 

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

J.R. Carlton, B.A. 

L.M. Harper, B.S. 

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

D.C. Serbus, Ph.D. -
C@I TEHT5 

AI]~STI~ACT ............................................................. 5 

E~I?LAHATJ~OH OF LE~LSOF E~E~CE OF C~C~OGE~C AC~ ............. ~ 

~C~C~ ~PO~TS ~W S~CO~E ............................... ~0 

S~~Y O~ ~C~C~ ~PORTS ~W S~CO~E CO~S .......... H 

~ODUC~OH ......................................................... ~3 

~ ~ S ~ ~ODS ............................................... 2~ 

~TS ............................................................... 33 

D~SCUSS~OH ~ COHCLUS~OHS ............................................ ~ 

~~HCES ........................................................... ~ 

.A~.~x A Sun~n~ary of Lesions ~n Male ]~s ~n the ]Long-tern FFeee¢~ St~dly 

o~' t-Buty~hydroqu~none ...................... , ................... 71 

~ ~ S~n~ary o~ Lesions ~n Febrile RaN ~n the lL~ng-ter~ Feed Stagy 

o~ t-~atyH~y~roqa~aone .......................................... ~29 

A~r~wx C S~ary of Lesions ~n l~,lIa~e I~ce ~n the 2-Year Feed Stagy 

o~ t-~u~y~hy~roquinone .......................................... ~1 

A.~v~ D Sununary of Lesions in ~en~e Mice ~n the 2-Ye~- Yee~l Steely 

of t-~uty~hydroqu~none ........................................... 2~.~ 

A~D~x E Genetic.Toxicology , ............................................ ~. 

A~I~NDIX Y Organ We~gh~ ~n~ Organ-We~ght-to-~y-We~ht ~m .................. ~73 

A.I~NDIx G ~en~ato~ogy ~nd C~n~c~ Chenfis~ry ~esu~ ............................ ~7~ 

A~PENWX H Repro~uctfive Tissue Evaluations, Estro~s Cycle CharacteH~atflon~ 

and Terato~ogy ......................... . ..................... 2~ 

C~e~nica~ Characterization and Dose For~n~atio~ St~ie~ ................... 2~5 

A~PE~DD~ J Feed ~n~ Co~npoun~ Co~se~npfio~ h~ ~e L~ng-~erm~ ~ 2-Year F~¢~ S~e~ 

off t-~e~yHhy~ro~e~no~e .......................... •................ 3H 

A~D~X ~ ~ngre~en~s, HatHent Con~s~fion, and Coa~nant ~ve~ 

~n HI[~-~..~7 ~a~ and ~ouse ~l~a~fion ................................... 3~17 

~~L 5enfineR An~m~a~ ~'ogran~ ......................................... 32~ 
4 t-Butylhydroquinone, NTP TR 459 
ABSTRACT 

OH 

t-~Lr~%~YD~OQU~IONE 

CAS No. 1948-33-0 

Chemical Formula: C10H1402 Molecular Weight: 166.22 

Synonyms: Tert-butyl-hydroquinone; 2-(l,l-dimethylethyl)-l,4-benzenediol; tert-butyl-l,4-benzenediol; mono-tertiary-butylhydroquinone; 

2-(1,1-dimethyl)hydroquinone; TBHQ; MTBHQ 

Trade Names: Sustane; Tenox TBHQ; Banox 20BA 

t-Butylhydroquinone is used as an antioxidant in 

cosmetic products such as lipsticks, eye shadows, 

perfumes, blushers, and skin care preparations at 

concentrations ranging from 0.1% to 1.0%; the 

chemical is also used at concentrations up to 0.02% in 

oils, fats, and meat products to prevent rancidity, and 

as a polymerization inhibitor for various polyunsaturated polyesters (CIR, 1986). t-Butylhydroquinone 

was nominated for toxicity and carcinogenicity testing 

by the Food and Drug Administration. Toxicology 

and carcinogenicity studies were conducted in F344/N 

rats and B6C3F 1 mice. Mice were exposed to t-butylhydroquinone (99% pure) in feed for 13 weeks or 

2 years. For rats, exposure to t-butylhydroquinone 

began in utero and continued through lactation. After 

weaning, pups were fed diets containing the same 

levels of t-butylhydroquinone as those given to their 

respective dams for 13 weeks or for up to 30 months. 

The oral route of administration was selected for these 

studies because t-butylhydroquinone is used as a food 

additive and human exposure occurs predominantly 

through this route. In addition to the oral route of 

exposure, rats were exposed prenatally because 

perinatal exposure to butylated hydroxytoluene (a 

structurally related chemical) induced hepatocellular 

neoplasms in rats. Genetic toxicology studies were 

conducted in Salmonella typhimurium and cultured 

Chinese hamster ovary cells in vitro and in mouse 

bone marrow cells in vivo. 

In the perinatal exposure phase of the 13-week study, 

groups of 10 female rats (Fo) were fed 0, 2,500, 

5,000, 10,000, 20,000, or 40,000 ppm t-butylhydroquinone from 2 weeks prior to cohabitation until the 

F 1 pups were weaned. F 0 females exposed to 20,000 

or 40,000 ppm did not litter. The number of pup 

deaths in the 5,000 and 10,000 ppm groups was 

greater than that in the control group, and the average 

number of surviving pups per litter in the 10,000 ppm 

group was less than that in the control group. Mean 

body weights of pups exposed perinatally to 5,000 or 

10,000 ppm were lower than that of the controls at the 

time of weaning. , 

Groups of 10 male and 10 female F 1 rats continued to 

receive diets containing 0, 2,500, 5,000, or 

10,000 ppm t-butylhydroquinone for 13 weeks following weaning. These dietary levels corresponded 

to approximately 200, 400, or 800 mg t-butylhydroquinone/kg body weight (males) or 200, 400, or 

750 mg/kg (females) per day. All rats survived to the 

end of the study. The final mean body weights of 

males and females in the 5,000 and 10,000 ppm 

groups were significantly lower than those of the 

controls, as was the mean body weight gain of males 

exposed to 10,000 ppm. However, interpretation of 

these findings was complicated by the significantly 
6 

lower initial mean body weights of the 10,000 ppm 

•groups. Differences in initial body weights were due 

to in utero exposure to t-butylhydroquinone. Feed 

consumption by exposed groups of rats was lower 

than that by controls at week 2, and feed consumption 

by 5,000 and 10,000 ppm males and 10,000 ppm 

females was slightly lower than that by controls at the 

end of the study. Hair discoloration in all exposed 

groups of rats, except females exposed to 2,500 ppm, 

was the only clinical observation considered related to 

chemical exposure. The mean spermatid count, 

spermatid heads per testis, and spermatid heads per 

gram of testis were significantly decreased in males 

exposed to 5,000 ppm. Theestrons cycles of females 

exposed to 2,500 or 5,000 ppm were significantly 

longer than that of the controls. There were no 

biologically significant changes inclinical pathology 

parameters or in organ weights. 

Increased incidences of hyperplasia of the nasal 

respiratory epithelium were observed in males 

exposed to 5,000 ppm and males and females exposed 

to 10,000 ppm, and an increased incidence of nasal 

.exudate was observed in males in the 10,000 ppm 

group. Increased incidences of pigmentation were 

observed in the spleen of male and female rats 

exposed to 5,000 or 10,000 ppm. Based on lower 

final mean body weights and decreased feed consumption in males and females exposed to 10,000 ppm 

t-butylhydroquinone, exposure concentrations selected 

for the long-term rat study were. 1,250, 2,500, and 

5,000 ppm. 

13-WEEK STUDY IN MICE ' 

Groups of 10 male and 10 female mice were fed diets 

containing 0, 2,500, 5,000, 10,000, 20~000, or 

40,000 ppm t-butylhydroquinone for 13 weeks. These 

dietary levels corresponded to approximately 440, 

880, 1,950, 4,000, and 8,400 mg t-butylhydro-

' quinone/kg body weight (males) or 500, 1,100, 2,200, 

4,600, and 9,000 mg/kg body weight (females) per 

day. There were no exposure-related deaths. Final 

mean body weights and body weight gains of males 

and females exposed to 10,000, 20~000, or 

40,000 ppm were significantly less than those of the 

controls. Feed consumption by exposed mice appeared to be similar to that by controls, but there was 

excessive scatter of feed by mice exposed to 10,000, 

20,000, or 40,000 ppm. Therefore, feed consumption 

t-Butylhydroquinone, NTP TR 459 

by male and female mice in these groups was likely 

less than that by controls. Significant increases in • 

segmented neutrophil counts occurred at week 3 and 

at the end of the study in females exposed to 

10,000 ppm and males and females exposed to 20,000 

or 40r000 ppm. Left caudal, left epididymis, and left 

testis weights of males exposed, to 10,000 or 

40,000 ppm were generally significantly lower than 

those of the controls. The estrous cycle of females 

exposed to 40,000 ppm was significantly longer than 

that of the control group. There were no biologically 

significant differences in organ weights. 

Increased incidences and severities of mucosal ~ . 

hyperplasia were observed in the forestomach of 

males exP0Sgd I to 20,000 or 40,000 ppm and in 

females exposed to 10,000, 20,000, or 40,000 ppm, 

and increased incidences of inflammation were observed in the nose and skin of males and females 

exposed to 10,000, 20,000, or 40,000 ppm. Increased incidences of hyperplasia also occurred in the 

skin of males and females eXPosedto 10,000, 20,000, 

or 40,000 ppm. Based on lower final mean body 

weights, increased incidences of inflammation of the 

nose and skin, increased incidences of forestomach 

mucosal hyperplasia, and increased severity of 

nonneoplastic lesions observed in mice exposed to 

I0,000, 20,000, or 40,000 ppm, exposure concentrations selected for the 2-year study were 1,250, 

2,500, and 5,000 ppm. 

, , i~ 

LONG-TERM STUDY IN RATS 

In the perinatal exposure phase of the long-term 

study, groups of 60 female Fo rats were fed diets ., 

containing 0, 1,250, 2,500, or 5,000 ppm t-butylhydroquinone, beginning 2 weeks prior to cohabitation and continuing until Fi pups were weaned. 

Following weaning, groups of 70 male and 70 female 

F~ rats continued to receive diets .containing 0, 1,250, 

or 5,000 ppm, and groups of 68 male and 68 female 

rats continued to receive diets containing 2,500 ppm. 

The duration of dosing in feed was 123 weeks postweaning for males and 129 weeks for females. These 

exposure concentrations resulted in daily doses of 

approximately 50, 100, and 200 mg t-butylhydroquinone/kg body weight (males) or 60, 120, and 

240 mg/kg (females). Ten male and ten female 

F1 rats from each exposure group were evaluated at 

3 months. 
t-l~u~ylhyc~roqu~none, ~ TII~ 459 7 

Sgrvi~,a~, Body Weights, Feed Consumpaon, 

and Clinical Findings 

Survival of females exposed to 5,000 ppm was significantly greater than that of the control group. The 

mean body weights of males and females exposed to 

5,000 ppm were generally less than those of the 

controls throughout the study. Feed consumption by 

exposed groups was similar to that by controls. 

Clinical findings of hair discoloration in exposed 

groups of males and females were considered to be 

related to chemical exposure. 

Pathelegy Findings 

No increased neoplasm incidences in male or female 

rats were attributed to t-butylhydroquinone exposure. 

The incidences of mammary gland fibroadenoma and 

fibroadenoma or adenoma (combined) were significantly decreased in males exposed to !,250 ppm and 

in all exposed groups of females; and combined incidences of mammary gland fibroadenoma, adenoma, or 

carcinoma were significantly decreased in all groups 

of exposed females. The decreases occurred with 

significant negative trends. Incidences of renal cysts 

and inflammation were generally increased in exposed 

groups of male fats. 

2-Y~ S~r~_r~v ~ l~icz 

Groups of 60 male and 60 female mice received 0, 

1,250, 2,500, or 5,000 ppm t-butylhydroquinone in 

feed for 104 to 105 weeks. These exposure concentrations resulted in daily doses of approximately 150, 

300, or 600 mg t-butylhydroquinone/kg body weight 

(males) or 150, 300, or 700 mg/kg (females). As 

many as 10 males and 10 females from each exposure 

group were evaluated at 15 months. 

Sun, i~,al, Bedy Weig1~ts, 

and Feed Censumpaon 

Survival of all exposed groups of males and females 

was similar to that of the control groups.. Mean body 

weights of the 5,000 ppm groups were generally 

lower than those of the control groups from week 13 

until the end of the study. Feed consumption by 

exposed groups of males and females was similar to 

that by the controls. There were"no biologically 

significant differences in clinical pathology parameters 

between control and exposed groups of mice. 

F'aghelegy Findings 

No increased incidences Of neoplasms, or nonneoplastic lesions in male or female mice were considered to be related to t-butylhydroquinone exposure. 

(~ENET~IC ~O~,A[COLOGY 

t-Bntylhyclroqninone was not mntagenic in any of four 

strains of Salmonella typhimurium, with or without 

liver $9 metabolic .activation enzymes. It did, however, induce sister chromatid exchanges and chromosomal aberrations in cultured Chinese hamster ovary 

cells in the presence, but not the absence, of S9. No 

increase in the frequency of micronucleated erythrocytes was observed in bone marrow of male mice 

treated with t-butylhydroquinone. 

CONCLUS]IONS 

Under the conditions of this long-term feed study, 

there was no evidence of carcinogenic activity* of 

t-butylhydroquinone in male or female F344/N rats 

exposed to 1,250, 2,500, or 5,000 ppm. Under the 

conditions of this 2-year feeds study, there .was no 

evidence of carcinogenic activity of t-bntylhydroquinone in male or female B6C3F~ mice exposed to 

1,250, 2,500, or 5,000 ppm. 

Exposure of rats to t-butylhydroquinon e in feed 

resulted in decreased incidences of mammarY gland 

neoplasms in males and females. 

Explanation of Levels of Evidence of Carcinogenic Activity is on page 9. A summary of the Technical Reports Review Subcommittee 

comments and the public discussion on this Technical Report appears on page 11. 
8 rt-Butyihydroquinone, NTP TR 459 

Summary of the Long-tern and 2-Year Carcinogenesis and Genetic Toxicology Studies 

of t-Butylhydroquinone 

Male 

F344/N Rats 

Doses 0, 1,250, 2,500, or 

5,000 ppm 

(approximately 50, 100, 

or 200 mg/kg per day) 

~Body weights 5,000 ppm group less 

than controls 

Survival rates 8/60, 7/60, 1/58, 14/60 

Nonneoplastic effects None 

Neoplastic effects None 

Decreased incidences Mammary gland: 

fibroadenoma (10/60, 

4/60, 4/58, 7/60); 

fibroadenoma or 

adenoma (11/60, 4/60, 

5/58, 7/60) 

No evidence 

carcinogenic activity 

Level of evidence of 

Genetic toxicology 

Salmonella typhimurium gene mutations: 

Sister chromatid exchanges 

Cultured Chinese.hamster ovary cells in vitro: 

Chromosomal aberrations 

Cultured Chinese hamster ovary cells in vitro: 

Micronucleated erythrocytes 

Mouse bone marrow/n vivo: 

Female Male Female 

F344/N Rats B6C3F~ Mice B6C3F~ Mice 

0, 1,250, 2,500, or 0, 1,250,2,500, or 0, 1,250, 2,500, or " " 

5,000 ppm 5,000 ppm 5,000 ppm 

(approximately 60, 120, (approximately 150, (approximately 150, 

or 240 mg/kg per day) 300, or 600 mg/kg per 300, or 700 mg/kg per 

day) day) 

5,000 ppm group less 5,000 ppm group less 5;000ppnigroupless 

than controls ~ than controls than controls . 

10/60, 11/60, 16/58, 39/50, 46/50, 38/51, 38151, 35/52i 40151, 

17/60 42/51 43154 : 

None "None : None ~. 

None None None 

Mammary gland: None None 

fibroadenoma (43/60, 

33/60, 34/58, 27/60); 

fibroadenom~i, adenoma, 

or carcinoma (48/60, 

34/60, 34/58, 30/60) 

No evidence No evidence No evidence 

Negative with and without $9 in strains TA97, TA98, 

TA100, and TA102 • 

Positive with $9; negative without $9 

. 

Positive with $9; negative without $9 

Negative 

/ 
t-Buty]hydroquinone, blT]~ TR 459 9 

EX~?LANAT~ON O~ LEVELS OF EVIDENCE OF CA~C]I~TOG~i~r~C ACT~VqlT~f 

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. P6sitive 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 (dear 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 majo( 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. 

o 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. 

o 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. 

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

neoplasms that may be chemical related. 

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

malignant or benign neoplasms. 

o 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 long-term carcinogenesis studies in laboratory animals, especially for those evaluations that may be on the borderline 

between two adjacent levels. These considerations should include: 

o adequacy of the experimental design and conduct; 

o occurrence of common versus uncommon neoplasia; 

o progression (or lack thereoO from benign to malignant neoplasia as well as from preneoplastic to neoplastic lesions; 

o 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; 

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

o latency in tumor induction; 

o multiplicity in site-specific neoplasia; 

o metastases; 

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

in another sex or species); 

o presence or absence of dose relationships; 

o statistical significance of the observed tumor increase; 

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

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

o structure-activity correlations; and 

o in some cases, genetic toxicology. 
10 t-Butylhydroquinone, NTP TR 459 

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 t-butylhydroquinone on 

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

governmental agency. In this capeeity, 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 

University of Wisconsin Medical School 

Madison, WI 

Thomas L. Goldsworthy, Ph.D. 

Department of Environmental Pathology and Toxicology 

Chemical Industry Institute of Toxicology 

Research Triangle Park, NC 

Meryl H. Karol, Ph.D. 

Department of Environmental Occupational Health 

University of Pittsburgh 

Pittsburgh, PA 

Curtis D. Klaassen, Ph.D. 

Department of Pharmacology and Toxicology 

University of Kansas Medical Center 

Kansas City, KS 

Claudia S. Miller, M.D., Principal Reviewer 

University of Texas Health Sciences Center 

San Antonio, TX 

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

Department of Pathology 

Northwestern University Medical School 

Chicago, IL 

Irma Russo, M.D. 

Fox Chase Cancer Center 

Philadelphia, PA 

Louise Ryan, Ph.D. 

Division of Biostatistics 

Dana-Farber Cancer Institute 

Boston, MA 

Robert E. Taylor, M.D., Ph.D. 

Department of Pharmacology 

Howard University College of Medicine 

Washington, DC 

Mary Jo Vodicnik, Ph.D., Principal Reviewer 

University of Indiana 

Indianapolis, IN 

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

National Cancer Institute 

Frecleriek, MD 
t-Butylhydroquinone, NTP TR 459 11 

SUMMARY OF TECHNICAL REPORTS 

On 20 June 1995, the draft Technical Report on the 

toxicology and carcinogenesis studies of t-butylhydroquinone received public review by the National 

Toxicology Program's Board of Scientific Counselors' 

Technical Reports Review Subcommittee. The review 

meeting was held at the National Institute of 

Environmental Health Sciences, Research Triangle 

Park, NC. 

Dr. K.M. Abdo, NIEHS, introduced the toxicology 

and carcinogenesis studies of t-butylhydroquinone by 

discussing the uses of the chemical and rationale for 

study, describing the experimental design, reporting 

on survival and body weight effects, and commenting 

on compound-related nonneoplastic lesions in male 

and female rats and mice. The proposed conclusions 

were that there was no evidence of carcinogenic 

activity of t-butylhydroquinone in male or female 

F344/N rats or in male or female B6C3F 1 mice. 

Dr. Vodicnik, a principal reviewer, agreed with the 

proposed conclusions. She complimented the staff on 

the comprehensive review of the literature while 

recommending that a reference to a flawed study be 

deleted. Dr. Miller suggested the reference be kept 

but with the limitations of the study noted in the text 

(see page 19). 

Dr. Reddy, the second principal reviewer, agreed 

with the proposed conclusions. He inquired as to 

whether the splenic pigmentation was hemosiderin or 

whether this could be the compound or lipofuscin. 

Dr. J.R. Hailey, NIEHS, said some stains for 

hemosiderin and, perhaps, lipofuscin would be done 

(see page 46). 

REVIEW SUBCOMMITTEE COMMENTS 

Dr. Reddy asked whether the nephropathy in male 

rats was associated with increased levels of 

ct2~-globulin. Dr. Hailey responded that a minor 

contribution could not be ruled out absolutely, but 

there was no evidence in the subchronic or chronic 

studies that this protein played a significant role. 

Dr. Miller, the third principal reviewer, agreed with 

the proposed conclusions. She thought a comparison 

of the t-butylhydroquinone dose levels used in rats and 

mice and those found in a typical human diet would 

be useful for the reader (see page 13). 

Dr. W. Faber, Eastman Chemical Company, 

commended the NTP on a well conducted study. He 

stated that the possible effect of t-butylhydroquinone 

on the male and female reproductive systems seemed 

rather tenuous given the lack of a clear dose-response 

relationship as well as lack of findings in the 

teratology and multigeneration studies. He said the 

mention of t-butylhydroquinone as being structurally 

related to hydroquinone and butylated hydroxytoluene, which are described as carcinogenic 

chemicals, should be clarified to indicate these 

chemicals are carcinogenic in experimental animals. 

Dr. Miller moved that the Technical Report on 

t-butylhydroquinone be accepted with the revisions 

discussed and with the conclusions as written for male 

and female rats and mice, no evidence of carcinogenic 

activity. Dr. Reddy seconded the motion, which was 

accepted unanimously with 10 votes. 
13 

INTRODUCTION 

CHa OH 

ON 

t-BUTYLHYDROQUINONE 

CA$ No. 1948-33-0 

Chemical Formula: C10H1402 Molecular Weight: 166,22 

Synonyms: Tert-butyl-hydroquinone; 2-(1,l-dimethylethyl)-l,4-benzenediol; tert-butyl-l,4-benzendiol; mono-tertiary-butylhydroquinone; 

2-(1,l-dimethyl)hydroquinone; TBHQ; MTBHQ 

Trade Names: Sustane; Tenox TBHQ; Banox 20BA 

CHEMICAL AND t-butylhydroquinone were imported in 1983 (USITC, 

1984). More recent information was not available. PHYSICAL PROPERTIES According to the National Occupational Exposure t-Butylhydroquinone is a white to light tan crystalline Survey, a total of 18,167 workers were potentially solid with a very slight but characteristic odor and a exposed to this chemical. Of this total, 3,687 were 

melting point of 126.5" to 128.5 ° C. It is soluble in females (NIOSH, 1990). ethanol (60%), ethyl acetate (60%), propylene glycol 

(30%), and to a lesser extent in fats and oils (5% in t-Butylhydroquinone is used as an antioxidant in. 

lard at 50 ° C, 10% in cottonseed oil, corn oil, or cosmetic products such as lipsticks, eye shadows, soybean oil, and 5% in safflower oil at 25* C). perfumes, blushers, and skin care preparations at 

t-Butylhydroquinone is only slightly soluble in water concentrations ranging from 0.1% to 1.0%; the 

(less than 1% at 25 * C) (Sims and Fioriti, 1980). chemical is also used at concentrations of up to 0.02 % 

in oils, fats, and meat products to prevent rancidity 

and as a polymerization inhibitor for various polyunsaturated polyesters (CIR, 1986). PRODUCTION~ USEr 

AND HUMAN EXPOSURE t-Butylhydroquinone is permitted for use in any food 

t-Butylhydroquinone can be prepared by acid- at a maximum level of 200 mg t-butylhydroquinone/ 

catalyzed alkylation of hydroquinone with either iso- kg fat or oil content of the food (21 CFR § 172.185), 

butylene or t-butanol (Kirk-Othmer, 1981; CIR, and the entire United States population is potentially 

1986). exposed. Based on the actual usage of t-butylhydroquinone and its typical level in food, the potential 

The public portion of the Toxic Substances Control daily intake using actual body weights of individuals 

Act (TSCA) Inventory of Chemicals in Commerce surveyed has been estimated to be 0.42 mg t-butyllists two manufacturers of t-butylhydroquinone. One hydroquinone per day (0.008 mg t-butylhydroquinone 

manufacturer reported production ,ranging from per kg body weight per day) (Flamm et al., 1982). 

100,000 to 1,000,000 pounds in 1977. No production 

data were provided for the other manufacturer The amount of t-butylhydroquinone approved for use ' 

(USEPA, 1985). The U.S. International Trade as a polymerization inhibitor in cross-linked polyesters 

Commission reported that 47,983 pounds of resins used as articles or components of articles 
- - : - . _ .. ?. .-~ -~ _ ~ .... r~_~ . . . . . ~ 2 ~ ~ ~-~ .~ ~ . . . . . . . . 

14 

intended for use in contact with food is limited to less 

than or equal to 0.01% by weight of finished resin 

(21 CFR §177.2420). Based on the toxicology data 

available, the Cosmetic Ingredient Review Expert 

Panel concluded that t-butylhydroquinone may be 

safely used as a cosmetic ingredient at concentrations 

not to exceed 0.1% (CIR, 1991). 

ABSORPTION, DISTRIBUTION, 

METABOLISM, AND EXCRETION 

Experimental Animals 

Orally administered t-butylhydroquinone is rapidly 

absorbed and excreted primarily in the urine as a 

sulfate conjugate and a glucuronide; small amounts 

are excreted as unchanged t-butylhydroquinone. Rats 

given single oral doses ranging from 0.1 to 0.4 g/kg 

body weight eliminated 65% to 95%. of the administered dose in the urine in 3 to 4 days as 

4-O-sulfate (57% to 80%), .unchanged t-butylhydroquinone (4%~.to 12%), and 4-O-glucuronide (4%) 

(Astill et al., 1975). Dogs given a single oral dose of 

0. I g/kg eliminated virtually all of the dose in the 

urine in 4 days as 4-O-sulfate (69% to 85%), 

4-O-glucur0nide (24% to 31%), and unchanged 

t-butylhydroquinone (3 %) (Astill ei al., 1975). 

Rats receiving single oral doses .(0.015 to 0.92 g/kg) 

of ~-butylhydroquinone radiolabeled at carbons 2, 3, 

5, and 6 eliminated 82% to 88% of the label in urine, 

2% to 6% in the feces, and less than 0.1% as CO2; 

less than 0.2% of the radiolabel remained in the body 

after 4 days (Astill and Roudabush, 1973). Because 

the amount of t-butylhydroquinone eliminated as CO2 

was minimal, the authors concluded that t-butylhydroquinone was not catabolized via intermediary 

metabolic pathways. The proportion of metabolic 

compounds !n the urine of dogs fed diets with up to 

0,5% t-butylhydroquinone for 2 years remained 

unchanged throughout the study. However, in rats 

given up. to 0.5 % t-butylhydroquinone in the diet for 

20 months, the proportion of g!ucuronide was 

somewhat elevated. Residues in liver, kidney, brain, 

and fat from rats in the 0.16% and 0.5% dose groups 

in the long-term study were negligible, suggesting that 

t-butylhydroquinone does not.accumulate in the body 

with prolonged exposure (Astill et al., 1975). 

3.t-Butyl ~hydroxyanisole undergoes oxidative 

demethylation to t-butylhydroquinone by the 

t-Butylhydr0quinone, NTP TR 459 

cytochrome P4~0 system in vivo in dogs, rats, and man 

(Astill et al., 1962; Verhagen et al., 1989), and 

in vitro in rat liver microsomes (Rahimthula et al., 

1982; Armstrong and Wattenberg, 1985). t-Butylhydroquinone is subsequently oxidized to 2-t-butyl 

(1,4)paraquinone. The conversion of t-butylhydro: 

quinone to 2-t-butyl-(1,4)paraquinone is substantially ~. 

accelerated by prostaglandin H synthetase and 

lipoxygenase (Schilderman et al., 1993). 

Humans 

Human male volunteers administered a single dose 

(2 mg/kg) of t-butylhydroquinone in high-fat :food 

(30% corn oil) excreted 95% to 103% of the dose in 

the urine in 2 to 3 days as 4-O-sulfate (73% to 88%); 

4-O-glucuronid6 (15% to 22%), and unchanged 

t-butylhydroquin0ne (less than 1%). Human male 

volunteers administered single doses (1 to 2 mg/kg) of 

t-butylhydroquinone in low-fat food (10% corn oil) 

eliminated 18 % to 51% of the dose in urine in 2 to 

3 days as 4-O-sulfate (18% to 51%), 4-O-glucuronide 

(0% tO6 %), and unchanged t-butylhydroquinone (less 

than 1%) (Astill et al., 1975). These results in human 

volunteers suggest that absorption of t-butylhydroquin0ne from high-fat diets is much greater than from 

low-fat diets. The glucuronide and sulfate derivatives 

of t-butylhydroquinone have also been identified by 

EI-Rashidy and Niazi (1983) as metabolitcs of 

butylated hydroxyanisole in humans. The results in 

rats, dogs, and human volunteers suggest that these 

species metabolize ~-butylhydroquinone in a similar 

manner. ~ - 

BIOCHEMICAL EFFECTS. •. 

Experimental Animals 

Feeding t-butylhydroquinone (up to 0.5 % in the diet) 

to dogs for.2 years and to Sprague-Dawley rats for 

20 months did not produce any significant changes in 

hepatic enzyme activities. No hepatic enlargement 

and no proliferation of hepatic smooth-surface 

endoplasmic reticulum were observed (Asti!l et al., 

1975). However, there was ~significant liver 

enlargement in Wistar rats receiving 0.5 % t-butylhydroquinone in feed for 6 days~ followed .by a basal 

diet for 24 hours, but there was no concomitant 

increase in the activities of .hepatic microsomal 

monooxygenase enzymes (Kawano et al., 1981). 

t-Butylhydroquinone (100 raM) administered daily by 

gavage for 5 days to CD-1 mice caused an elevation 
t-l~uty]hydroquinorae,~ TR 459 

of glutathione transferase activity in the glandular 

stomach. The enzyme activity levels in the lung or 

kidney of CD-1 mice were unchanged (De Long 

et al., 1985). 

t-Butylhydroquinone inhibited the biosyntheses of 

prostaglandins E~ and E~ by the microsomal fraction 

of bovine seminal vesicles (Boehme and Branen, 

1977). Astill and Mulligan (1977) studied the effect 

of the edible stabilizers propyl gallate, butylated 

hydroxyanisole, butylated hydroxytoluene, and 

t-butylhydroquinone on. intragastric N-nitrosamine 

formation. Following a 12-hour fasting period, 

groups of 10 Sprague-Dawley rats were administered 

single doses of 125 mg sodium nitrite/kg body weight 

via gastric intubation in 2.5 % (w/v) aqueous solution 

and 1,000 mg dimethylamine/kg body weight in 20% 

aqueous solution, followed immediately by the test 

compound in doses of 25, 75, or 225 mg/kg in corn 

oil. Sodium ascorbate (200 mg/kg) in 4% (w/v) 

aqueous solution was used as a positive control. The 

vehicle control group of ten animals was administered 

corn oil. The indices of N-nitrosamine formation 

48 hours after dosing were the activities of serum 

glutamic-oxaloacetic transaminase (GOT), glutamicpyruvic transaminase (GPT), ornithine 

carbamoyltransferase (OCT), and the extent of hepatic 

necrosis. The nitrosamine-forming mixture alone 

induced extensive hepatic necrosis and 4-, 19-, and 

24-fold increases in serum OCT, GPT, and GOT 

activities, respectively. Ascorbate completely 

suppressed enzyme induction, t-Butylhydroquinone 

administered at a dose level of 225 mg/kg gave 60 % 

protection against hepatic necrosis and appreciably 

suppressed increases in enzyme activities. 

Administered at dose levels of 25 and 75 mg/kg, 

t-butylhydroquinone had no observable significant . 

effect on the nitrosamine-forming system. The gross 

liver damage observed in the rats exposed to the 

nitrosamine-forming system was absent in the corn oil 

control group. 

t-Butylhydroquinone appears to be a strong inactivator 

of phage DNA as well as a potent inducer of 

7-hydroxy-8-oxo-2'-deoxyguanosine in vitro 

(Schilderman et al., 1993). The latter compound is an 

oxidative DNA damage product resulting from C8 

oxidation of deoxyguanosine, t-Butylhydroquinone 

induced excess production of superoxide anion in rat 

liver microsomes. Excess superoxide induces injury 

~S 

of the hepatocyte plasma membranes (Bergmaun 

et al., 1992). 

ffff~ma~$ 

No information on the biochemical effects of t-butylhydroquinone in humans was found in a search of the 

available literature. 

~GY~C~T~ 

~rper~mental Anien~ls 

The reported oral LD~0 for t-butylhydroquinone 

ranges from 480 to 1,000 mg/kg for rats (Epstein 

et al., 1967; Astill et al., 1975) and is 1,000 mg/kg 

for mice (RTECS, 1983). 

Compounds structurally related to t-butylhydroquinone (butylated hydroxyanisole and butylated 

hydroxytoluene) have been shown to induce lung 

lesions and increased prothrombin time (Takahashi 

and Hiraga, 1978). No lung lesions were observed in 

CRL:CD-1 male mice 5 days after administration of 

a single intraperitoneal injection of 62.5, 125, 250, or 

500 mg t-butylhydroquinone/kg body weight. 

However, the two highest doses were lethal 

(Krasavage and O'Donohue, 1984). Intraperitoneal 

injections of 50, 100, or 150 mg/kg as a 10% solution 

in acetone:soy oil (1:10 v/v) did not increase 

prothrombin time or cause hemorrhagic death in male 

albino rats [CRL:COB CD(SD)BR] (Krasavage, 

1984). 

t-Butylhydroquinonc fed to rats (sex and strain not 

specified) at a concentration of 1% in the diet for 

22 days caused a slight depression in body weight 

gain, but did not cause death or pathologic alterations 

(Astill et al., 1975). 

Fischer rats receiving 1% t-butylhydroquinone in the 

diet (as a 4% solution in corn oil) developed 

hyperplasia of the basal cell layer in the forestomaeh 

epithelium (Nera et al., 1984). Similar lesions were 

observed in Wistar rats consuming a diet containing 

2% t-butylhydroquinone for 28 days (Altmann et al., 

1985). Twice-weekly applications of 1 mL/kg hair 

dye formulation containing a 1:1 mixture of 0.3% 

t-butylhydroquinone with 6 % hydrogen peroxide for 

13 weeks to the abraded skin of male and female New 

Zealand rabbits did not cause any compound-related 

toxicity (Burnett et al., 1976). Data collected in this 
16 t-Butyihydroquinone, NTP TR 459 

study included clinical pathology (complete blood 

count, methemoglobin concentration, fasting blood 

sugar, blood urea nitrogen, alkaline phosphatase, 

serum glutamic-oxaloacetic transaminase, urine color, 

urine pH, urine albumin, urine glucose, and occult 

blood), relative liver, kidney, adrenal, heart, thyroid, 

spleen, and brain weights, observations of gross 

abnormalities, and histopathology. 

Application of 0.1 mL hydrophilic ointment containing 1% or 5% t-butylhydroquinone to a 3.2 cm 2 

area of the skin of black guinea pigs 5 days per week 

for 13 weeks caused a weak depigmentation at the 

application site in females, but not in males. A 

similarly applied dose of 0.1% did not cause depigmentation in either males or females (CIR, 1991). 

Humans 

t-Butylhydroquinone may be a skin irritant in humans. 

In patch testing, five out of 1,096 patients with facial 

dermatitis were shown to be allergic to t-butylhydroquinone present in their cosmetics (White et al., 

1984). A 71-year-old woman who for 15 years was 

observed to have dermatitis at various body sites was 

found to be allergic to t-butylhydroquinone (Calnan, 

1981). Of a total of 271 subjects exposed to lipstick 

products containing 0.054%, 0.11%, 0.14%, or 

0.15% t-butylhydroquinone by weight, only one 

subject exposed to the product containing 0.14 % had 

intense erythema, suggesting a nonspecific irritant 

effect (CIR, 1986). 

REPRODUCTIVE 

AND DEVELOPMENTAL TOXICITY 

Experimental Animals 

t-Butylhydroquinone produced no teratogenic effects 

when given to pregnant Sprague-Dawley rats at 

concentrations of 0.125 %, 0.25 %, or 0.5 % in the diet 

from days 6 to 16 of gestation. Mean body weights 

and feed consumption of treated dams were similar to 

those of the controls. Average numbers of corpora 

lutea, implantation sites, viable fetuses, and 

resorptions and fetal body weights, mortality, and sex 

ratio were not affected at any dose. No external 

anomalies were observed in the 849 fetuses examined. 

Half of these fetuses were examined for soft-tissue 

abnormalities, and three were found to be abnormal. 

Of these three, one was from the control group and 

two were from a single litter in the 0.5 % group. The 

abnormalities observed were low body weight and 

hydrocephalus (in the control and 0.5% groups) and 

transposition of a major blood vessel (in the 0.5% 

group) (Krasavage, 1977). 

A diet containing 0 % or 0.5 % t-butylhydroquinone 

was fed to groups of 15 male and 15 female 

Sprague-Dawley rats for three successive generations 

(Astill et al., 1975). Rats were mated to produce two 

litters per generation, with the next generation 

selected from weanlings of the second litter. Littering 

throughout the study produced 2,090 rats. The 

following parameters were assessed: gonadal 

functions, estrus cycles, mating, conception rates, 

gestation rates, parturition, , and lactation; 

measurements of these parameters in the treated group 

were similar to those in the control group. Slight 

increases in F~ pup weights were observed; however, 

no similar effect was produced in a second experiment 

designed to investigate these results. No difference 

between the treated and control groups was observed 

when the Fa pups were examined grossly for skeletal 

muscle and soft tissue abnormalities. The F~a groups 

were maintained on their diets for 11 months, then 

sacrificed. Electron microscopic examination of the 

livers of some animals indicated no abnormalities 

(Astill et al., 1975). The doses used in these 

reproductive studies may have been too low to 

adequately determine the potential of t-butylhydroquinone to have an effect on reproduction or to cause 

fetal malformations. 

Humans 

No information on the reproductive and 

developmental toxicity of t-butylhydroquinone in 

humans was located in a search of the available 

literature. 

CARCINOGENICITY 

Experimental Animals 

t,Butylhydroquinone at concentrations of 0%, 

0.016%, 0.05%, 0.16%, or 0.5% in the diet was fed 

to groups of 55 male and 55 female Sprague-Dawley 

rats for up to 20 months. No differences in growth 

rate, feed intake and/or utilization, mortality, clinical 

chemistry, hematology, urinalysis, organ weights, or 

histopathology were observed between control and 
t-Butylhydroquinone, NTP TR 459 17 

treated groups at any time during the study (Terhaar 

and Krasavage, 1968a). 

Diets containing 5 % unheated or heated cottonseed oil 

solutions of 0.02%, 0.10%, or 0.50% t-butylhydroquinone were fed to groups of 15 male and 15 female 

Sprague-Dawley rats for 6 months (Astill et al., 

1975). In this study, the temperature of cottonseed oil 

for heated diets was raised over a 1-hour period to 

375 ° F, and this temperature was maintained for 

3 hours. Growth rate, feed utilization, mortality, 

organ weights, hematology, clinical chemistry, and 

urinalysis parameters were measured, and gross and 

microscopic evaluations on 27 organs were made. 

The three deaths in the 0.50% group were not 

considered to be related to t-butylhydroquinone. No 

compound-related effects on body weight, feed 

utilization, hematology, urinalysis, or histopathology 

were observed. There were slight increases in the 

relative weights of the testes and liver of male rats in 

the 0.50% t-butylhydroquinone/heated oil group and 

in the relative weights of the liver of female rats in the 

0.20% and 0.50% t-butylhydroquinone/heated oil 

groups (Astill et al., 1975). 

These studies were considered inadequate for 

evaluating the carcinogenicity of t-butylhydroquinone 

for three reasons: t-butylhydroquinone was not tested 

at the maximum tolerated dose (previous short-term 

studies have shown that SpragueoDawley rats can 

tolerate a dose of 1% t-butylhydroquinone); the 

duration of the studies was inadequate for 

carcinogenicity testing; and only 17 animals survived 

to the end of the Terhaar and Krasavage (1968a) 

study. 

Groups of four male and four female beagle dogs 

were fed diets containing 0.05%, 0.15%, or 0.5% 

t-butylhydroquinone for 2 years (Astill et al., 1975). 

Eight males and eight females served as controls. No 

compound-related effects on hematology, clinical 

chemistry, or urinalysis parameters were observed at 

weeks 12, 26, 52, 78, and 104 of the study. No 

compound-related changes (gross or microscopic) 

were noted in any of the tissues examined. 

Recent studies have demonstrated that t-butylhydroquinone has a promoting effect on chemically induced 

tumors. The combined treatment with t-butylhydroquinone (1% in feed), sodium nitrite (0.3% in 

drinking water) and/or sodium ascorbate (1% in feed) 

increased the thickness of mucosae of the 

forestomach, glandular stomach, and esophagus of 

4-week-old male F344/N rats following 4 to 6 weeks 

of treatment (Kawabe et al., 1994; Yoshida et al., 

1994). In a multi-organ carcinogenesis model, 

t-butylhydroquinone (1% in the diet) significantly 

increased the incidences of esophageal papillary 

hyperplasia or nodular hyperplasias and papillomas, 

as well as forestomach papillomas, but significantly 

decreased the multiplicity of colon adenocarcinomas 

in male F344/N rats (Hirose et al., 1993). Tumors in 

this study were initiated by pretreatment with 

N-methyl-N'-nitro-N-nitrosoguanidine (100 mg/kg), 

N-ethyl-N-hydroxyethyl nitrosamine (750 mg/kg), 

N-methylbenzyl nitrosamine (two subcutaneous 

injections of 0.5 mg/kg), and 1,2-dimethyl hydrazine 

(40 mg/kg). 

F344/N rats given 1% t-butylhydroquinone in the diet 

had decreased numbers and smaller sized diethyl 

nitrosamine-initiated preneoplastic liver foci 

(glutathione S-transferase placental form positive foci) 

than did the positive controls (Hasegawa et al., 1992). 

Mammary gland neoplasm development was reduced 

in female Sprague-Dawley rats fed diets containing 

0.8% t-butylhydroquinone for 51 weeks following 

initiation with dimethylbenz(a)anthracene. However, 

in the same study, the incidence of induced ear duct 

tumors was not affected by t-butylhydroquinone 

treatment (Hirose et al., 1988). Six-week-old male 

F344/N rats treated with N-butyl-N-(4-hydroxybutyl)- 

nitrosamine for 4 weeks then fed diets containing 

2% t-butylhydroquinone had greater incidences of 

urinary bladder papillary or nodular hyperplasia than 

those in controls receiving N-butylN-(4-hydroxybutyl)nitrosamine only (Tamano et al., 

1987). 

t-Butylhydroquinone is structurally related to 

hydroquinone, butylated hydroxyanisole, and 

butylated hydroxytoluene. In a 2-year carcinogenicity 

study, 25 or 50 mg hydroquinone/kg body weight 

administered by gavage was carcinogenic to F344/N 

rats, causing increased incidences of renal tubule cell 

adenomas in males and mononuclear cell leukemia in 

females. Hydroquinone at doses of 50 or 100 mg/kg 

administered by gavage was carcinogenic to female 

B6C3F~ mice causing an increased incidence of 

hepatocellular neoplasms (NTP, 1989). 
18 t-Butyihydroquinone,. NTP TR 459 

In 2-year carcinogenicity studies, butylated hydroxytoluene at concentrations of 3,000 or 6,000 ppm in 

feed was not carcinogenic .to male or female F344/N 

rats or B6C3F~ mice. There was a significant increase 

in the incidence of lung neoplasms .in 3,000 ppm 

female mice, but not in 6,000 ppm females; because 

there was no significant dose-related positive trend, 

this increase could not be clearly related to butylated 

hydroxytoluene exposure. (NCI, 1979). No evidence 

of carcinogenicity was observed in male or female 

B6C3F~ mice fed diets containing 200, 1,000,. or 

5,000 ppm butylated hydroxytoluene .for 96 weeks, 

followed by a basal diet for an additional 8 weeks 

(Shirai et al., 1982). No carcinogenic effects were 

observed in male or female Wistar rats fed diets 

containing 0.25 % or 1% butylated hydroxytoluene for 

up to I04 weeks (Hirose et al., 1981). Hepatocellular. 

neoplasms were induced in Wistar rats exposed 

beginning, in utero tobutylated hydroxytoluene (Olsen 

et al.,~ 1983). The carcinogenicity of butylated 

hydroxytoluene has been previously investigated in 

Wistar rats (Hirose et al., 1981) and B6C3F t mice 

(Shirai et al., 1982). Butylated hydroxytoluene 

administered in concentrations of up. to 10,000 ppm 

(rats) and 6,000 ppm (mice) in feed did not produce 

carcinogenic effects. These studies were performed 

on one generation and were terminated at 108 weeks, 

while in the Olsen et al. (1983) study, the exposure 

began, in utero and continued throughout lactation, 

weaning, and adulthood. ' 

Male and female F344/N .rats fed diets containing 

0.5%:or 2% butylated hydroxyanisole for 104 weeks 

followed by a.basal diet for an additional 8 weeks had 

chemical-related increased incidences of squamous 

cell carcinoma of the forestomach. The incidences of 

.these neoplasms in the 2% groups of males and 

females were significantly higher than those in the 

controls (Ito et al., 1982). Feeding butylated 

hydroxyanisole to male F344/N rats at a concentration 

of 2% for 13 weeks caused proliferation of the 

forestomach epithelium.: The rats recovered from 

these effects following 1 week on a basal diet (Iverson 

et al., 1985). 

GENETIC TOXICOLOGY 

t-Butylhydroquinone was not mutagenic in 

Salmonella typhimurium gene mutation assays 

performed with or without liver $9 activation enzymes 

(Bonin and Baker, 1980; Hageman et al., 1988; 

.Matsuoka et al., 1990; Zeiger et al., i992). 

Additionally, it did not produce mitotic gene 

conversion or mutations, with or without $9, in 

Saccharomyces cerevisiae (Rogers et al., 1992). In 

cultured mammalian cells, no induction of mutations 

was noted at the. HGPRT locus of Chinese hamster 

V79 lung cells incubated with primary hepatocytes 

after treatment with 0.17 to 3.4 #g t-butylhydro, 

quinone/mL medium (Rogers et al., 1992). However, 

oxidative damage was detected in single-strand phage 

PhiX 174 DNA (Schilderman et al., 1993) and 

double-strand phage PhiX 174 relaxed form DNA (Li 

and Trush, 1994) exposed to t-butylhydroquinone in 

the presence of micromolar concentrations of Cu ÷ ÷. 

No consistent induction of sister chromatid exchanges 

was observed in. Chinese hamster V79 lung cells 

treated with t-butylhydroquinone, with or without $9 

(Rogers et al,, 1992), but a significant increase in the 

frequency of chromosomal aberrations was reported 

in Chinese hamster cells treated with 2.5 to 50 #g/mL 

without $9 (Phillips et al., 1989; Matsuoka et al., 

1990) or 20 to .40 #g/mL in the presence .of $9 

(Matsuoka et al., 1990). The addition of catalase to 

the hamster cell cultures without $9 resulted in a 

substantial decrease in the frequency of t-butylhydroquinone-induced chromosomal aberrations (Phillips 

et al., 1989), thus indicating that generation of H202 

played a role in the observed induction of 

chromosomal damage. Because t-butylhydroquinone 

autooxidizes in solution to t-butylquinone, forming 

superoxide and H202, . the mutagenic effects that are 

observed in-cells exposed to t-butylhydroquinone are 

most likely the indirect result of the release of 

oxidative byproducts within the cell, Experiments 

with various radical scavengers provided evidence 

suggesting that either singlet oxygen or a singlet 

oxygen-like entity (possibly a copper-peroxide 

complex) rather than free hydroxyl radicals was 

responsible for DNA damage in phage induced by 

phenolic compounds such as t-butylhydroquinone (Li ._ 

and Trush, 1994). 

In vivo, dose-related increases in sister chromatid 

exchanges were induced in bone marrow cells of male 

Swiss albino mice given single intraperitoneal 

injections of 0.5 to 200 mg/kg t-butylhydroquinone 

dissolved in corn oil (Muldaerjee et al., 1989); the 

lowest effective dose in this experiment was 2 mg/kg. 

Induction of chromosomal aberrations (breaks, gaps, 
t-SulTlhydroquinone, NT/? TS ~59 

centric fusions, and other abnormalities) was reported 

in bone marrow cells of male mice administered a 

single intraperitoneal dose of 200 mg/kg t-butylhydroquinone or daily gavage doses of 2 mg/kg for 30 days 

(Giri et al., 1984); bone marrow analysis was 

performed 24 hours after the final dosing. Because 

the authors included gaps in their analyses and did not 

present the individual classifications of the 

abnormalities scored, and because for the acute dosing 

experiment a 24-hour post-treatment harvest time is 

inappropriate (12 to 17 hours is preferable), these 

results require independent verification. 

Much of the data obtained from studies with 

metabolites of t-butylhydroquinone derive from 

studies of the parent compound (butylated 

hydroxyanisole) and concern identification of 

metabolic pathways, investigations of oxygen radical 

scavengers or catalase inhibitors on-particular 

endpoints of metabolism, and tumor initiating 

properties of various butylated hydroxyanisole metabolites. One of the most active metabolites appears 

to be t-butylquinone, which is generated in redox 

cycling reactions with t-butylhydroquinone. Neither 

of these compounds is active in many of the standard 

in vitro mutagenicity assays, t-Butylquinone did not 

induce gene conversions or reverse mutations in 

Saccharomyces cerevisiae, nor did it induce HGPRT 

gene mutations or sister chromatid exchanges in V79 

cells (Rogers et al., 1992). However, it has been 

shown to be mutagenic in S. typhimurium strains 

TA98 and TA100 over a limited dose range (10 to 

50 #g/plate) and to induce DNA damage in repairdeficient strains of Bacillus subtilis; both responses 

were obtained in the absence of $9 activation (Mizuno 

et al., 1988). There is one report describing induced 

DNA damage in the forestomach cells of male rats. 

~9 

In this experiment, single strand breakswere detected 

by alkaline elution in the DNA of forestomach 

squamous epithelial cells harvested from Fischer 344 

rats 3 hours after the rats received 4 mL of 0.001% or 

0.00001% (approximately 0:22 or 0.0022 mg/kg) 

t-butylquinone in corn oil by gavage (Morimoto et al., 

1991). 

In summary, t-butylhydroquinone and the oxidized 

metabolite, t-butylquinone, showed limited evidence 

of mutagenicity, primarily in mammalian cell systems 

sensitive to the detection of oxygen radical-induced 

DNA damage. 

~UDY ]~ATIIOHALE 

t-Butylhydroquinonewas nominated for toxicity and 

carcinogenicity testing by the Food and Drug Administration because of the potential for increased use 

of t-butylhydroquinone as a substitute for the phenolic 

antioxidants butylated hydroxyanisole and butylated 

hydroxytoluene; previous carcinogenicity studies 

supporting the safe use of t-butylhydroquinone were 

not considered adequate because the maximum 

tolerated dose was not tested, the studies were of short 

duration, and survival within the studies was poor. 

t-Butylhydroquinone is also structurally similar to 

carcinogenic chemicals such as hydroquinone and 

butylated hydroxyanisole. The oral route of 

administration was selected for these studies because 

t-butylhydroquinone is used as a food additive and 

human exposure occurs predominantly through this 

route. In addition to the oral route of exposure, rats 

were exposed in utero because butylated hydroxytoluene (a structurally related chemical) induced 

hepatocellular neoplasms in rats exposed in utero. 
20 t-Butylhydroquinone, NTP TR 459 
21 

MATEIi IAL ANII MIET © $ 

]I~OCU~.E1V~ENT AND 

CHAI~.ACTEI~JZAT]ION 

OF ~-~UT~L~ROQU~INONE 

t-Butylhydroquinone was obtained in two lots (187-1 

and 1089-1) from U.O.P., Inc., (Des Plaines, IL). 

Lot 187-1 was used in the 13-week, long-term, and 

2-year studies. Lot 1089-1 was used in the long-term 

and 2-year studies. Identity, purity, and stability 

analyses were conducted by the analytical chemistry 

laboratory, Midwest Research Institute (Kansas City, 

MO) (Appendix I). Reports on analyses performed in 

support of the t-butylhydroquinone studies are on file 

at the National Institute of Environmental Health 

Sciences (NIEHS). 

Each lot of the chemical, a fine beige powder, was 

identified as t-butylhydroquinone by infrared, ultraviolet/visible, and nuclear magnetic resonance spectroscopy. The purity of each lot was determined by 

elemental analyses, Karl Fischer water analysis, 

functional group titration, thin-layer chromatography, 

and high-performance liquid chromatography. Elemental analyses for carbon and hydrogen were in 

agreement with the theoretical values for t-butylhydroquinone. Karl Fischer water analysis indicated less 

than 0.4% water for lot 187-1 and 0.16% water for lot 

1089-1. Functional group titration indicated a purity 

of 99.6% ± 0.5% for lot 187-1 and 99.1% ± 0.4% 

for lot 1089-1. Thin-layer chromatography of 

lot 187-1 indicated a major spot and two trace impurities using one system and a major spot, one minor 

impurity, and one trace impurity using a second 

system. For lot 1089-1, both thin-layer chromatography systems indicated a major spot, one minor 

impurity, and one trace impurity. High-performance 

liquid chromatography of lot 187-1 indicated a major 

peak and one impurity peak with an approximate area 

of 0.13% relative to the major peak. High-performance liquid chromatography of lot 1089-1 indicated 

a major peak and no impurities with. peak 'areas 

greater than 0.1% relative to the major peak. Additional high-performance liquid chromatography 

analyses using a linear gradation in the solvent system 

resolved additional impurities with peak areas of 0.3 % 

to 0.4% relative to the major peak in lots 187-1 and 

1089-1. Lot 1089-1 and lot 187-1 were concomitantly 

analyzed by the same high-performance liquid 

chromatography method used for the initial purity 

analyses. The overall purity for each lot was 99%. 

Stability studies of the bulk chemical, performed by 

the analytical chemistry laboratory using high-performance liquid chromatography, indicated that t-butylhydroquinone was stable as a bulk chemical when 

stored for 2 weeks, protected from light, at temperatures up to 60 ° C. To ensure stability, the chemical 

was stored at room temperature in sealed containers, 

protected from light. Stability was monitored 9 weeks 

after the beginning of the 13-week studies and within 

30 days after the end of the studies. For the longterm and 2-year studies, stability was monitored at 

approximately 4-month intervals and within 30 days 

after the end of the studies. No degradation of the 

bulk chemical was detected. 

~EIPAIRATI~ON AND ANAL~S]~S 

OF ~I3~oSE ~O~qI.ILAT~ONg 

The dose formulations for the 13-week, long-term, 

and 2-year studies were prepared weekly (Table I1). 

Homogeneity and stability analyses of the dose 

formulations were conducted by the analytical chemistry laboratory using high-performance liquid chromatography. Homogeneity was confirmed, and the 

stability of the dose formulations was confirmed for at 

least 3 weeks when stored in sealed containers in the 

dark at 5 ° C. During the 13-week, long-term, and 

2-year studies, the dose formulations were stored in 

sealed containers in the dark at 5 ° C for no longer 

than 3 weeks. 

Periodic analyses of the dose formulations of t-butylhydroquinone were conducted at the study laboratory 

using high-performance liquid chromatography. For 

the 13-week studies, dose formulations were analyzed 

at the beginning, in the middle, and at the end of the 
22 

studies (Table 12). During the long-term and 2-year 

studies, dose formulations were analyzed approximately every 8 weeks (Table 13). Of the dose 

formulations used in the 13-week studies, 98% 

(43/44) were within 10% of thetarget concentration 

with no value greater than 16% from the target 

concentration. In the long-term studies, 219 of the 

220 dose formulations used for rats and 185 of the 

186 dose formulations used for mice wcrc within 10% 

of the target concentration. Results of periodic 

rcfcrcc analyses performed by the analytical chemistry 

laboratory agreed with the results obtained by the 

study laboratory (Table 14). 

13-WEEK RAT STUDY 

The 13-week study was performed to evaluate the 

cumulative toxic effects of t-butylhydroquinone with " 

exposure to the chemical beginning in utero and to 

determine the appropriate doses to be used in the 

long-term study. 

Male and female F344/N rats (F o generation) were 

obtained from Taconic Farms (Germantown, N¥). 

" On receipt, the rat~ were 38 days old. Animals were 

quarantined for 19 days. Females were 57 days old 

on the first day of the study and 71 days old on the 

first day of cohabitation. Before initiation of the 

study, five male and five female rats were randomly 

selected for parasite evaluation and gross observation 

for evidence of disease: 

Males acquired for the reproductive toxicity phase 

were used for breeding purposes only and were not 

considered part of the study. Groups of 10 female 

rats (F 0 generation) were fed diets containing 0, 

~2,500, 5,000, 10,000, 20,000, or 40,000 ppm t-butylhydroquinone for approximately 6 weeks. Feed was 

available ad libitum for F 0 females from 2 weeks prior 

to cohabitation until weaning of the F 1 pups. Water 

was available ad libitum. During cohabitation~ two F 0 

females were housed with one breeder male; F 0 

females were housed individually when pregnancy 

was confirrned. Clinical findings, body weights, 'and 

feed consumption were recorded weekly for F 0 

females during the first 2 weeks of the study (prior to 

cohabitation); clinical findings and body weights were 

also recorded weekly during lactation. Details of the 

study design and animal maintenance are summarized 

in Table 1. 

t-Butylhydroquinone,,NTP TR 459 

During cohabitation, vaginal smears were taken daily 

from breeder females to determine the presence of 

sperm. Rats that did not litter by day 25 were killed 

and uteri were stained with ammonium sulfide and 

examined for implantation sites. After parturition, 

pups were examined and the number and sex of pups 

and the litter weight were recorded. On day 4 postpartum, litters were randomly culled to a maximum of 

eight rat pups per litter; pup weights were recorded on 

days 4, 11, 18, and 28. Pups were weaned on 

day 28. 

Male and female F344/N rats for the 13-week base 

study were offspring (F 1 generation) of the breeders 

from the perinatal phase of the study. Rats were 

approximately 34 days old: on the first day of the 

study. At the end of the study, serologic analyses 

were performed on five male and five female control 

(F 1 generation) rats using the protocols of the NTP 

Sentinel Animal Program (Appendix L). 

Groups of 10 male and 10 female F i rats were fed 

diets containing 0, 2,500, 5,000, or 10,000 ppm 

t-butylhydroquinone for 13 weeks after weaning. (No 

F 1 offspring resulted from F 0 females fed diets 

containing 20,000 or 40,000 ppm, so these exposure 

levels were not used in the 13-week rat study.) Feed 

and water were available ad libitum. Rats were 

housed five per cage. Clinical findings were recorded 

and the animals were weighed initially, weekly, and 

at the end of the study; feed consumption was recorded as an average of grams per animal per day. 

Details of the study design and animal maintenance 

are summarized in Table I. ' 

Blood was collected at week 13 from core study (F 1) 

rats for selected hematology, clinical chemistry,: and 

coagulation analyses. Additionally, clinical pathology " 

analyses were performed on special groups of 10 male 

and 10 female F 1 rats fed diets containing 0, 2,500, 

5,000, or 10,000 ppm t-butylhydroquinone for 

3 weeks after weaning. Selected hematology and 

clinical chemistry parameters were measured for these 

animals on day 5 and at week 3. ~ 

For clinical pathology analyses, rats were anesthetized 

with CO 2 and bled from the retroorbital sinus.. Blood 

for hematology was collected in a tube containing 

ethylenediaminetetraacetic acid (EDTA); blood for 

clinical chemistry parameters was collected in a tube 
t-Butylhydroqu~none, NT~ T~ 459 23 

without anticoagulant; blood for coagulation analyses 

was collected in a plastic .syringe containing 3.8% 

sodium citrate. Hematology determinations were 

performed on whole blood using an Ortho ELT-8 

analyzer (Ortho Instruments, Westwood, MA). 

Leukocyte and .reticulocyte counts, erythrocyte counts 

and morphologies, and differential counts were 

determined from blood smears by light microscopy. 

Clinical chemistry parameters were determined using 

a Roche Cobas Fara chemistry analyzer (Roche 

Diagnostics Systems, Inc., Montclair, NJ). Parameters evaluated are listed in Table 1. 

At the end of the study, samples from 0, 2,500, 

5,000, and 10,000 ppm F 1 rats were collected for 

sperm motility and vaginal cytology evaluations. The 

parameters evaluated are listed in Table 1. Methods 

used were those described in the NTP's Technical 

Protocol for Sperm Morphology and Vaginal 

Cytology Evaluation in Toxicity Testing for Rats and 

Mice (NTP, 1987). For 7 consecutive days prior to 

scheduled terminal sacrifice, the vaginal vaults of the 

females were moistened with saline, if necessary, and 

samples of vaginal fluid and cells were stained. 

Relative numbers of leukocytes, nucleated epithelial 

cells, and large squamous epithelial cells were determined and used to ascertain estrous cycle stage (i.e., 

diestrus, proestrus, estrus, and metestrus). Male rats 

and mice were evaluated for sperm count and motility. 

The right testis and right epididymis were isolated and 

weighed. The tail of the epididymis (cauda epididymis) was then removed from the epididymal body 

(corpus epididymis) and weighed. Test yolk (rats)or 

modified Tyrode's buffer (mice) was applied to slides 

and a small incision was made at the distal border of 

the canda epididymis. The sperm 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 sperm motility estimates, each right cauda epididymis was placed in 

buffered saline solution. Cauda were finely minced, 

and the tissue was incubated in the saline 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 by 

removing the tunica albuginea and homogenizing the 

left testis in phosphate-buffered saline containing 10% 

dimethyl sulfoxide. Homogenization-resistant spermatid nuclei were counted with a hemacytometer, 

A necropsy was performed on all core study F 1 

animals. The heart, right kidney, liver, lungs, right 

testis, and thymus were weighed. Tissues for microscopic examination were fixed and preserved in 10% 

neutral buffered formalin, processed and trimmed, 

embedded in paraffin, sectioned to a thickness of 5 to 

6 #m, and stained with hematoxylin and eosin. A 

complete histopathologic examination was performed 

on all control and 10,000 ppm rats. Additionally, the 

following tissues from selected exposure groups were 

examined: the nose of all exposed groups of male rats 

and 5,000 ppm female rats; the spleen of 5,000 and 

10,000 ppm male rats and all exposed groups of 

female rats; the mesenteric lymph node of 5,000 ppm 

female rats; and the kidneys of 2,500 and 10,000 ppm 

female rats. Table 1 lists the tissues and organs 

routinely examined. 

The 13-week study was performed to evaluate the 

cumulative toxic effects of t-butylhydroquinone and to 

determine the appropriate doses to be used in the 

2-year study. 

Male and female B6C3F I mice were obtained from 

Taconic Farms (Germantown, NY). On receipt, the 

mice were approximately 29 days old, and the mice 

were quarantined for 13 days. Mice were approximately 42 days old on the first day of the study. Prior 

to the start of the 13-week study, five male. and 

five female mice were randomly selected for parasite 

evaluation and gross observation for evidence of 

disease. At the end of the study, serologic analyses 

were performed on five male and five female sentinel 

mice using the protocols of the NTP Sentinel Animal 

Program (Appendix L). 

Groups of 10 male and 10 female mice were fed diets 

containing 0, 2,500, 5,000, 10,000, 20,000, or 

40,000 ppm t-butylhydroquinone for 13 weeks. Feed 

and water were available ad libitum. Mice were 

housed five per cage. Clinical findings were recorded 

and the animals were weighed initially, weekly, and 

at the and of the study; feed consumption was 

recorded as an average of grams per animal per day. 
24 

Details of the study design and animal maintenance 

are summarized inTable 1. 

Blood was collected at week 13 from core study (F1) 

mice for selected hematology, clinical chemistry, and 

coagulation analyses. Additionally, clinical pathology 

analyses were performed on special groups Of 10 male 

and 10 female F 1 mice fed diets containing 0, 2,500, 

.5,000, or 10,000 ppm t-butylhydroquinone for 

3 weeks after weaning. Selected. hematology and 

clinical chemistry .parameters were measured for these 

~animals on day 5 and at week 3. 

For clinical pathology analyses, mice were anesthetized with CO 2 and bled from the retroorbital sinus. 

Clinical pathology parameters were measured as 

described for.the 13-week rat study .and the parameters evaluated are listed in Table 1. 

At the end of the study, samples from 0, 2,500, 

10,000, and 40,000 ppm mice were collected for 

sperm motility and vaginal cytology evaluations. The 

parameters evaluated are listed in Table 1. Methods 

used were those described for the 13-week rat study. 

A necropsy was performed on all core study animals. 

The heart, right kidney, liver, lungs, right testis, and 

thymus were weighed. Tissues for microscopic 

examination were fixed and preserved in 10 % neutral 

buffered formalin, processed and trimmed, embedded 

in paraffin, sectioned to a thickness of 5 to 6 #m, and 

.stained with hematoxylin and eosin. A complete 

histopa~ologic examination was performed on all 

control and 40,000 ppm mice. Additionally, the nose, 

skin,, and forestomach of all exposed groups of male 

and female mice were examined. Table 1 lists the 

tissues and organs routinely, examined.. 

. 

LONG-TERM RAT STUDY 

Study Design 

Males acquired for the pcrinatal phase of the study 

were used for breeding purposes only. Groups of 

60 female F 0 rats wcrc fed diets containing 0, 1,250, 

2,500, or 5,000 ppm t-butylhyd~oquinonc, bcgilming 

2 weeks prior to cohabitation and continuing until 

F 1 pups wcrc weaned. 

• 

Following weaning, groups of as many as 70 male 

and 70 female F 1 rats were fed diets containing 0, 

1,250, 2,500, or 5,000 ppm for 30 months or until the . 

t-Butylhydroquinone, NTP TR~459 

survival rate in atiy exposure group was less than 

20%. Ten male and 10 female F 1 rats were evaluated 

at 3 months. ' 

Source and Specification of Animals 

Female F344/N F 0 rats were obtained ~from Taconic 

Farms (Germantown, NY). On receipt, the animals 

were approximately 31 days 01d. Males and females 

were quarantined for 18 days and were approximately , 

49 days old on the first day they were given dosed 

feed. Before the start of the study, 10 male and 

10 female F 0 rats were selected for parasite evaluation 

and gross observation of disease. Serology samples 

for viral screening were collected from 10 F 0 f6males 

at the end of the reproductive phase of the study~ The 

health of the animals was monitored during the study 

according to theprotocols of the NTP Sentinel Animal 

Program (Appendix L). r. 

Male and female F344/N F 1 rats were offspring 

(F 1. generation) of the breeders from the perinatal 

phase and were approximately 35 days old on the first 

, 

day of exposure through feed. Pups from the F 1 . 

generation not selected for study were used for 

parasite evaluation and gross observation of disease. • 

. 

Animal Maintenance 

During quarantine, breeder males were housed 

individually and F 0 females .were housed two per 

cage. During cohabitation, one breeder male was 

housed with two F 0 females. F 0 females were housed 

individually for the remainder of the study. F 1 rats 

.were housed five per cage.. Feed and water were 

a~ailable ad libitum to F 0 and F 1 rats. Feed consumption was not measured during the pgrinatal phase 

of the study, but was measured every 4 weeks by cage 

for F 1 rats; additionally, control feed consumption:by 

F 1 rats was measured weekly for the first 1.3 weeks of 

the study. Cages were changed twice weekly and 

racks were generally rotated once every 2, weeks l 

Further details of animal maintenance are given in 

Table 1. Information on feed composition and 

contaminants is provided in Appendi x K: ' 

• . ~ . ~ 

:-

C l n c a l i i Examinations and Pathology. ~

During the perinatal phase of the study, clinical 

findings and body weights were recorded for females 

weekly during cohabitation and .on the first day of 

dosing. F 1 rats were observed twice daily. Clinical 
t-ll~uty]hydroquinone, NTP TR 459 

findings for F 1 rats were recorded at the beginning of 

the long-term study, once weekly for the first 

13 weeks, and monthly thereafter. Additionally, 

clinical fmdings were recorded for F 1 rats on lactation 

days 4, 11, 18, and 28. As many as 10 male and 

10 female rats were evaluated for hematology alterations at 3 months using the hematology methods 

described for the 13-week study. The parameters 

evaluated are listed in Table 1. 

A complete necropsy and microscopic examination 

were performed on all F 1 rats. At the 3-month 

interim evaluation, the right kidney, liver, right 

epididymis, and right testis were weighed. At 

necropsy, all organs and tissues were examined for 

grossly visible lesions, and all major tissues were 

fixed and preserved in 10% neutral buffered formalin, 

processed and trimmed, embedded in paraffin, 

sectioned to a thickness of 5 to 6/zm, and stained with 

hematoxylin and eosin for microscopic examination. 

For all paired organs (i.e., adrenal gland, kidney, 

ovary), samples from each organ are examined. 

Tissues examined microscopically are listed in 

Table 1. 

Microscopic evaluations were completedby the study 

laboratory pathologist, and the pathology data were 

entered into the Toxicology Data Management System. ~ The slides, paraffin blocks, and residual wet 

tissues were sent to the NTP Archives for inventory, 

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

individual animal data records, and pathology tables 

were evaluated by an independent quality assessment 

laboratory. The individual animal records and tables 

were compared for accuracy, the slide and tissue 

Counts were verified, and the histotechnique was 

'evaluated. For the long-term rat study, a quality 

assessment pathologist reviewed ~the following organs: 

bone marrow (females), clitoral gland, forestomach 

(males), kidney (males), liver, mammary gland, nose, 

pituitary gland, preputial gland, spleen, and thyroid 

gland (males). 

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 diagnoses 

made by the laboratory and quality assessment pathologists. Representative histopathology ~lides containing examples of lesions related to chemical 

i 25 

administration, examples of disagreements in diagnoses between the laboratory and quality assessment 

pathologists, or lesions of general interest were 

presented by the chairperson to the PWG for review. 

The PWG consisted of the quality assessment pathologist and other pathologists experienced in rodent 

toxicologic pathology. This group examined the 

tissues without any knowledge of dose groups or 

previously rendered diagnoses. When the PWG 

consensus differed from the opinion of the laboratory 

pathologist, the diagnosis was changed. Thus, the 

final diagnoses represent a consensus of quality 

assessment pathologists, the PWG chairperson, and 

PWG. Details of these review procedures have been 

described, in part, by Maronpot and Boorman (1982) 

and Boorman et al. (1985). For subsequent analyses 

of the pathology data, the diagnosed lesions for each 

tissue type were evaluated separately or combined 

according to the guidelines of McConnell et al. 

(1986). 

2oYEArMouse 

Study Design 

Groups of 60 male and 60 female mice were fed diets 

containing 0, 1,250, 2,500, or 5,000 ppm for 104 to 

105 weeks. As many as i0 male and 10 female mice 

were evaluated at 15 months. 

Source and Specification of Animals 

BtC3F 1 mice were obtained from Taconic Farms 

(Germantown, NY) and were approximately 32 days 

old on receipt~ Mice were quarantined for 12 days 

and were approximately 44 days old on the first day 

of exposure. Before the initiation of the study, five 

male and five female mice were selected for parasite 

evaluation and gross observation of disease. Serology 

samples were collected for viral screening. The 

health of the animals was monitored during the study 

according to the protocols of the NTP Sentinel Animal 

Program (Appendix L). 

Anhrm~ Maintenance 

Mice were housed individually. Feed and water were 

available ad libitum. Feed consumption per cage was 

measured every 1 to 6 weeks up to week 17 and 

monthly thereafter. Cages were changed twice 

weekly and racks were generally rotated every 

2 weeks. Further details of animal maintenance are 
26 : t-Butylhydroquinone, NTP TR 459 

given in Table 1. Information on feed composition 

and contaminants is provided in Appendix K. 

Clinical Examinations and Pathology 

Mice were observed twice daily. Clinical findings 

were recorded at the beginning of the 2-year study, 

once weeldy for the first 12 (females) or 13 (males) 

weeks, and monthly thereafter. As many as 10 male 

and 10 female mice were evaluated for hematology 

alterations at 15 months using the methods described 

for the 13-week study. The parameters evaluated are 

listed in Table 1. 

A complete necropsy and microscopic examination 

were performed on all mice. At 15-month interim 

evaluations, the right kidney, liver, right epididymis, 

and right testis were weighed. At necropsy, all 

organs and tissues were examined for grossly visible 

lesions, and all major tissues were fixed and preserved 

in 10% neutral buffered formalin, processed and 

trimmed, embedded in paraffin, sectioned to a thickness of 5 to 6 #m, and stained with hematoxylin and 

eosin for microscopic examination. For all paired 

organs (i.e., adrenal gland, kidney, ovary), .samples 

from each organ are examined. Tissues examined 

microscopically are listed in Table 1. 

Microscopic evaluations were completed by the study 

laboratory pathologist, and the pathology data were 

entered into the Toxicology Data Management 

System. The microscopic slides, paraffin blocks, and 

residual wet tissues were sent to the NTP Archives for 

inventory, slide/block match, and wet tissue audit. 

The slides, individual animal data records, and 

pathology tables were evaluated bY an independent 

quality assessment laboratory. The individual animal 

records and tables were compared for accuracy, the 

Slide and tissue counts were verified, and the histotechnique was evaluated. The following organs were 

'reviewed in mice: liver, harderian gland, and thyroid 

gland (females). 

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 diagnosis 

made by the laboratory and quality assessment pathologists. Representative histopathology slides containing examples of lesions related to chemical administration, examples of disagreements in diagnoses 

between the laboratory and quality assessment pathologists, or lesions of general interest were presented by 

the chairperson to the PWG .for review. The PWG 

consisted of the quality assessment pathologist and 

other pathologists experienced in rodent toxicologic 

pathology. This group examined the tissues without 

any knowledge of dose groups or previously rendered 

diagnoses. When the PWG consensus differed'from 

the opinion of the laboratory pathologist, the diagnosis 

was changed. Thus,' the final diagnoses represent a 

consensus of quality assessment pathologists,' the 

PWG chairperson, and the PWG. Details of these 

review procedures have been described, in part, by 

Maronpot and Boorman (1982) and Boorman et al. 

(1985). For subsequent analyses of the pathology 

data, the diagnosed lesions for each tissue type were 

evaluated separately or combined according to the 

guidelines of McConnell et al. (1986). 

STATISTICAL METHODS ~. 

Survival Analyses 

The probability of survival was estimated by the 

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 natural causes were not censored. Statistical analyzes for 

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 AI, A4, BI, B4, Ci, C5, DI, 

and D5 are given as the number of animals bearing 

such lesions at a specific anatomic site and the number 

of animals with that site examined microscopically. 

For Calculation of statistical significance, the incidences of most neoplasms (Tables A3, B3, C3, and 

D3) and all nonneoplastic lesions are given as the 

numbers of animals affected at each site examined 

microscopically. However, when macroscopic 

examination was required to dete~t neoplasms in 

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

mammary gland, and skin)before microscopic evaluation, or when neoplasms had multiple potential sites 

of occurrence (e.g., leukemia Or lymphoma), the 
t-Su~yHhy~roqu~none, NT~ TR 4~9 27 

denominators consist of the number of animals on 

which a necropsy was performed. Tables A3, B3, 

C3, and D3 also give the survival-adjusted neoplasm 

. rate for each group and each site-specific 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 risks (Kaplan and Meier, 1958). 

An~llysfis ~ Neop~m ~nc~e~c~ 

-The majority of neoplasms in these studies were 

considered to be incidental to the cause of death or not 

rapidly lethal. Thus, the primary statistical method 

used was logistic regression analysis, which assumed 

that the 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 prevalence was modeled as a logistic function 

of chemical exposure and time. Both linear and 

quadratic terms in time were incorporated initially, 

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 of dose. This method of 

adjusting for intercurrent mortality is the prevalence 

analysis of Dinse and Lagakos (1983), further described and illustrated by Dinse and Haseman (1986). 

When neoplasms are incidental, this comparison of the 

time-specific neoplasm prevalences also provides a 

comparison of the time-specific neoplasm incidences 

(McKnight and Crowley, 1984). 

In addition to logistic regression, other methods of 

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, and the Fisher exact test and the CochranArmitage trend test (Armitage, 1971; Gart et al., 

1979), procedures based on the overall proportion of 

neoplasm-bearing animals. 

Tests of significance included pairwise comparisons of 

each exposed group with controls and a test for an 

overall dose-related trend. Continuity-corrected tests 

were used in the analysis of neoplasm incidence, and 

reported P values are one sided. The procedures 

described in the preceding paragraphs were also used 

to evaluate selected nonneoplastic lesions. For further 

discussion of these statistical methods, refer to 

Haseman (1984). 

An~ys~ o~ Nonneop~st~c Lesic~ ~ci~cnc~ 

Because all nonneoplastic lesions in this study were 

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 nonneoplastic 

lesion prevalence was modeled as a logistic function 

of chemical exposure and time. For lesions detected 

at the interim evaluation, the Fisher exact test, a 

procedure based on the overall proportion of affected 

animals, was used. 

Ar~ysis o~ Continuous V~ri~lb~es 

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

control groups in the analysis of continuous variables. 

Organ and body weight data, which have approximately normal distributions, were analyzed using the 

parametric multiple comparison procedures of.Dunnett 

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

clinical chemistry, spermatid, and epididymal 

spermatozoa, which have typically skewed distributions, were analyzed using the nonparametric 

multiple comparison methods of Shirley (1977) and 

Dunn (1964). Jonckheere's test (Jonckheere, 1954) 

was used to assess the significance of the dose-related 

trends and to determine whether a trend-sensitive test 

(Williams' or Shirley's test) was more appropriate for 

pairwise 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 

identified by the outlier test of Dixon and Massey 

(1951) were examined by NTP personnel, and 

implausible values were eliminated from the analysis. 

Average severity values were analyzed for significance using the Mann-Whitney 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 was used to bring the data into 

closer conformance with a normality assumption. 

Treatment effects were investigated by applying a 

multivariate analysis of variance (Morrison, 1976) to 

the transformed data to test for simultaneous equality 

of measurements across exposure levels. 

Dam and pup data from the in utero phases of the rat 

13-week and long-term studies were analyzed using 
28 

the variance test for homogeneity of the binomial 

distribution (Snedec0r and Cochran, 1980). Baseline 

maternal body weight data, litter averages for percent 

mortality, and pup body weights were analyzed using 

Bartlett's test of homogeneity of variances (Sokal and 

Rohlf, 1981) and the analysis of variance (Snedecor 

and Cochran, 1980) when appropriate .[i.e., if 

Bartlett's test was not significant (P>0.05)]. If the 

analysis of variance was significant, Dunnett's test 

was used to identify the statistical significance of 

individual groups. If the analysis of variance was not 

appropriate [i.e., Bartlett's test was significant 

(Pg0.05)], the Kruskal-Wallis test (Sokaland Rohlf, 

1981) was used when 75 % or fewer ties were present; 

when more than 75 % ties were present, the Fisher 

exact test was used. In cases where the KruskalWallis test was statistically significant (P~0.05), 

Dunn's method of multiple comparisons was used to 

identify statistical significance of individual groups. 

Natural delivery parameters involving discrete data 

were evaluated using the Kruskal-Wallis test. 

Historical Control Data 

Although the concurrent control group is always the 

first and most appropriate control group used for 

evaluation, historical control data can be helpful in the 

overall assessment of neoplasm incidence .in certain 

instances. Consequently, for B6C3F 1 mice, neoplasm 

incidences from the NTP historical control database 

(updated yearly) are included in this NTP report for 

neoplasms appearing to show compound-related 

effects during two-year studies. There are no studies 

of 30-month duration in the NTP historical control 

database for comparison to findings ,in the long-term 

F344/N rat studies. 

QUALITY ASSURANCE METHODS 

The 13-week, long-term, and 2-year studies were 

conducted in compliance with Food and Drug 

Administration Good Laboratory Practice Regulations 

(21 CFR, Part 58). In addition, as records from the 

long-term and.2-year studies were submitted to the 

NTP Archives, these studies were audited retrospectively by an independent quality assurance contractor. 

Separate audit~ covering completeness and accuracy 

of the pathology data, pathology specimens, final 

pathology tables, and a draft of this NTP Technical 

Report were conducted. Audit procedures and 

findings are presented in the reports and are on file at 

NIEHS. The audit findings were reviewed and 

t-Butylhydroquin0ne, NTP TR 459 

assessed by NTP staff, so all comments had been 

resolved or were otherwise addressed during the 

preparation of this Technical Report. 

GENETIC TOXICOLOGY " 

The genetic toxicity of t-butylhydroquinone was 

assessed by testing the ability of the chemical to 

induce mutations in Salmonella typhimurium and 

cultured Chinese hamster ovary cells. The protocols 

for these studies and the results are given in 

Appendix E. ~ 

. 

The genetic toxicity studies of t-butylhydroquinone 

are part of a larger effort by the NTP to develop a 

database that would permit the evaluation of carcinogenicity in experimental animals from the structure 

and responses of the chemical in short-term in vitro 

and in vivo genetic toxicity tests. These genetic 

toxicity tests were originally developed to study 

mechanisms of chemically induced DNA damage and 

to predict carcinogenicity in animals, based on the 

electrophilic theory of chemical carcinogenesis and 

the somatic mutation theory (Miller and Miller, 1977; 

Straus, 1981; Crawford, 1985). 

There is a strong correlation between a chemical's 

potential electrophilicity (structural alert to DNA 

reactivity), mutagenicity in Salmonella, and carcinogenicity in rodents. The combination of electrophili-. 

city and Salmonella mutagenicity is highly correlated 

with the induction of carcinogenicity in rats and mice 

and/or at multiple tissue sites (Ashby and Tennant, 

1991). Other in vitro genetic toxicity tests do not 

correlate well with rodent carcinogenicity ~ (Tennant 

et al., 1987; Zeiger et al., 1990), although these other 

tests can provide information on the types of DNA 

and chromosome effects that can be induced by the 

chemical being investigated. Data from NTP studies : - .

show that a positive response in Salmonella is currently the most predictive in vitro test for rodent 

carcinogenicity (89% of the Salmonella mutagens 

were rodent carcinogens), and that there is no complementarity among the in vitro genetic toxicity tests. 

That is, no battery of tests that included the 

Salmonella tes~ improved the predictivity of the 

Salmonella test alone. The predictivity for carcinogenicity of a positive response in bone marrow 

chromosome aberration or micronucleus tests is not 

yet defined. 
t-Butylhydroquinone, NTP T~ 459 29 

TABLE 1 

Experimental Design and Materials and Methods in the Feed Studies of t-Buty~hydroqu~none 

13-Week Studies ' Long-Term Rat and 2-If ear:Mouse Studies 

Study Laboratory 

Southern Research Institute (Birmingham, AL) Southern Research Institute (Birmingham, AL) 

Strain and Species 

Rats: F344/N Rats: F344/N 

Mice: B6C3F~ Mice: B6C3F~ 

Animal Source 

Taconic Farms (Germantown, NY) Taconic Farms (Germantown, NY) 

Time Held Before Studies 

Rats: Fo - 19 days Rats: 1% - 18 days 

F~ - No quarantine F~ - No quarantine 

Mice: 13 days Mice: 12 days 

Average Age When Studies Began 

Rats: Fo : 57 days Rats: Fo'-49days 

F~ - 34 days F~- 35 days 

Mice: 42 days Mice: 44days 

Date of First Dose 

Rats: Fo - 6 September 1988 Rats: E~- 13November 1989 

F~ - 21 November 1988 F~- 29 January 1990 

Mice: 5 December 1988 Mice: 29 November 1989 

Duration of Dosing 

Rats: F o - Approximately 10 weeks Rats: Fo - Approximately 12 weeks 

F~ - 87-89 days (clinical pathology study F l rats) F~ - Interim evaluation - 92 days (males) 

93-94 days (core study F~ rats) or 93 days (females) 

Mice: 87-88 days (clinical pathology study mice) Terminal sacrifice - 123 weeks (males) or 129 weeks 

93-95 days (core study mice) (females) 

Mice: 104 to 105 weeks 

Date of Last Dose 

Rats: E~- 16-18 November 1988 Rats: Fo - 31 January 1990 

Ft- 15-17 February 1989 " F~ - 30 April 1990 (interim evaluation F~ males) 

(clinical pathology study F~ rats) 1 May 1990 (interim evaluation Ft females) 

21-22 February 1989 (core study F~ rats) 3 June 1992 (core study Ft males) 

Mice: 1-2 March 1989 (clinical pathology study mice) 14-15 July 1992 (core study F~ females) 

7-9 March 1989 (core Study mice) Mice: 27-28 February 1991 (interim evaluation) 

25-27 November 1991 (core study males) 

2-4 December 1991 (core study females) 

Necropsy Dates 

Rats: F~ - 21-22 February 1989 Rats: F~ - Interim evaluation 

Mice: 7-9 March 1989 30 April (males) or 1 May (females) 1990 

Terminal sacrifice 

3 June (males) or 14-15 July (females) 1992 

Mice: Interim evaluation 

27 (males) or 28 (females) February (1991) 

Terminal sacrifice 

25-27 November (males) or 2-4 December (females) 

1991 
30 t - B u t y i h y d r o q u i n o n e , N T P T R ' 4 5 9 

TABLE 1 

E x p e r i m e n t a l D e s i g n a n d M a t e r i a l s a n d M e t h o d s in the Feed Studies of t-Butylhydroquinone (continued) 

13-Week Studies. 

Average Age at Necropsy 

Rats: F, - 121-123 days (clinical pathology study rats) 

127-128 days (core study rats) 

Mice: 129-130 days (clinical pathology study mice) 

135-137 days (core study mice) 

Size of Study Groups 

Rats: Fo generation - 10 females 

F~ generation 

Core study - I0 males and 10 females 

Clinical pathology study - 10 males and 10 females 

Mice: Core study - 10 males and 10 females 

Clinical pathology study - 10 males and 10 females 

Method of Distribution 

Animals were distributed randomly into groups of approximately 

equal initial mean body weights. • " 

Animals per Cage 

Rats: Fo -two females with one breeder male during 

cohabitation, then one female with litter per cage 

F~ -.five per cage . 

Mice: five per cage 

Method of Animal Identification 

Rats: Breeder females and pups identified by tail tattoo 

Mice: Toeclip 

Diet 

NIH-07 open formula mash diet (Zeigler Brothers, Inc., 

Gardners, PA), available ad libitum 

• 

Water Distribution 

Tap water (Birmingham, AL, municipal supply) via automatic 

watering system (Edstrom Industries, Waterford, WI); available 

ad libitum 

Cages 

Poly~arbonate (Lab Products, Inc., Maywood, NJ); changed 

twice weekly, except (rats only) between day 18 of gestation until 

completion of de!ivery 

Bedding 

SaniChip (P.J. Murphy Forestry Products, Corp., Montville, 

NJ); changed twice weekly, except (rats only) between day 18 of 

gestation until completion of delivery 

Rack Filters 

Reemay ® spun-bonded polyester (Andico, Birmingham, AL); 

changed once every 2 weeks, except (rats only) between day 18 

of gestation until completion of delivery 

Long-Term Rat and 2-Year Mouse Studies 

Rats: F~ - 127-128 days (interim evaluation rats) 

128 weeks (males) or i34 weeks (females) 

Mice: Interim evaluation - 72 weeks 

Core study - 110 weeks (males) or 111 weeks (females) 

Rats: Fo - 60 females 

Fi - 68-70 males and 68-70 females 

Mice: 60 males and 60 females 

Same as 13-week studies 

Rats: Fo - two females with one breeder male during 

cohabitation, then one female with litter per cage 

Fi - five per cage 

Mice: one per cage 

Tail tattoo 

Same as 13-week studies 

Same as 13-week studies 

Same as 13-week studies 

Same as 13-week studies 

Same as 13-week studies 
t - B u t y l h y d r o q u i n o n e , N T P T R 459 3~ 

TABLE 1 

Experlmenta~ Design and 1V~ateriaHs and Methot~s in the ~'eed Studies of t-~uty~hy~roqu~none (continued) 

13-Week Studies 

Racks 

Stainless steel (Lab Products, Inc., Maywood, NJ); changed once 

every 2 weeks, except (rats only) between day 18 of gestation 

until completion of delivery 

Animal Room Environment 

Temperature: 18.7" C to 24.2* C 

Relative humidity: 35.8 %-79.3 % 

Fluorescent light: 12 hours/day 

Room air: minimum of I0 changes per hour 

Doses 

Rats: Fo - O, 2,500, 5,000, 10,000, 20,000, or 40,000 ppm 

F~ - O, 2,500, 5,000, or 10,000 ppm 

Mice: O, 2,500, 5,000, 10,000, 20,000, or 40,000 ppm 

Type and Frequency of Observation 

Rats: Fo : Observed twice daily. Body weights and clinical 

findings were recorded weekly for breeder females during 

cohabitation and weekly for breeder females and pups 

during lactation. Feed consumption was recorded weekly 

for breeder females prior to cohabitation. 

Fm- Observed twice daily. For core study animals, 

clinical findings were recorded and the animals were 

weighed initially, weekly, and at the end of the study; 

feed consumption was recorded as an average of grams 

per animal per day. 

Mice: Observed twice daily. Clinical findings were recorded 

and the animals were weighed initially, weekly, and at the 

end of the study; feed consumption was recorded as an 

average of grams per animal per day. 

Method of Sacrifice 

Anesthetized with CO2 followed by exsanguination 

Necropsy 

A necropsy was performed on all core study F~ rats and on all 

core study mice. Organs weighed were the heart, right kidney, 

liver, lungs, right testis, and thymus. 

Long-Term Rat and 2-Year Mouse Studies 

Same as 13-week studies 

Temperature: 16.7" C to 29.1" C 

Relative humidity: 15.8 %-86.1% 

Fluorescent light: 12 hours/day 

Room air: minimum of 10 changes per hour 

Rats: Fo and Fi -0, 1,250, 2,500, or 5,000 ppm 

Mice: O, 1,250, 2,500, or 5,000 ppm 

Rats: Fo- Clinical findings and body weights recorded for 

females on the first day of the study and weekly prior to 

cohabitation. Feed consumption measured for breeder 

females weekdays through day 10 prior to cohabitation. 

Fm - Clinical findings and body weights recorded 

individually on lactation days 4, 11, 18, and 28; at the 

start of the long-term study; once weekly for the first 

13 weeks; and every 4 weeks thereafter. Body weights 

recorded on all surviving animals at the end of the study. 

Feed consumption measured monthly for exposed 

groups; feed consumption measured weekly for the first 

13 weeks for animals receiving 0 ppm. 

Mice: Observed twice daily. Clinical findings and body 

weights recorded on day 1, weekly for the first 

12 (females) or 13 (males) weeks, then monthly, at the 

interim evaluation, and the end of the study. Feed 

consumption measured per animal every 1-6 weeks up to 

week 17 and monthly thereafter. 

Same as 13-week studies 

A necropsy was performed on all F 1 rats and on all mice. At the 

3-month (rats) and 15-month (mice) interim evaluations, the right 

kidney, liver, right epididymis, and right testis were weighed. 
32 t-Butylhydroquinone, NTP TR 459 

TABLE I 

Experimental Design and Materials and Methods in the Feed Studies of t-Butylhydroquinone (continued) 

13-Week Studies 

C~inical Pathology 

Blood was collected for hematology, clinical chemistry, and 

coagulation analyses from the retroorbital sinus of core rats and 

mice at the end of the studies. Blood was collected from the 

retroorbital sinus of special study rats and mice on day 5 and at 

week 3 for hematology and clinical chemistry analyses. 

Hematology: Hematocrit level, hemoglobin concentration, 

erythrocyte count, reticulocyte count, nucleated erythrocyte 

count, mean cell volume, mean cell hemoglobin, mean cell 

hemoglobin concentration, platelet count, and leukocyte count 

and differential. 

Clinical Chemistry: Blood urea nitrogen, creatinlne, total 

protein, albumin, alkaline phosphatase, creatine kinase, sorbitol 

dehydrogenase, and bile acids. 

Coagulation: Thromboplastin time and activated partial 

thromboplastin time~ 

Sperm Motility and Vaginal Cytology Evaluation 

Sperm and vaginal fluid samples were evaluated in 0, 2,500, 

5,000, and 101000 ppm F~ rats and in 0, 2,500, 10,000, and 

40,000 ppm mice at the end of the studies. The parameters 

evaluated in males were sperm count and motility. The right 

cauda, right epididymis, and right testis were weighed. Vaginal 

fluid samples were collected for up to 7 consecutive days prior to 

the end of the studies for vaginal cytology evaluations. The 

parameters evaluated in females were relative frequency of 

estrous stages and estrous cycle length. 

Histopathology 

Complete histopathologic examinations were performed on all 

control F~ rats and mice, 10,000 ppm F~ rats, and 40,000 ppm 

mice. In addition to gross lesions, tissue masses, and associated 

lymph nodes, the tissues examined included: adrenal gland, bone 

and marrow, brain, clitoral gland, esophagus, gallbladder (mice 

only), heart (with aorta), larg e intestine (cecum, colon, rectum), 

kidneys, liver, lungs and mainstem bronchi, lymph nodes 

(mandibular and mesenteric), mammary gland, nasal cavity and 

turbinates, ovaries, pancreas, parathyroid gland, pituitary gland, 

preputial gland, prostate gland, saliyary gland, skeletal muscle, 

skin, small intestine (duodenum, jejunum, ileum), spinal cord and 

sciatic nerve, spleen, stomach (forestomach and glandular 

stomach), testis with epididymis and seminal vesicle, thymus, 

thyroid gland, trachea, urinary bladder, and uterus. Additionally, 

the following tissues from selected exposure groups were 

examined: the nose of all exposed groups of male rats, 

5,000 ppm female rats, and all exposed groups of male and 

female mice; the spleen of 5,000 and 10,000 ppm male rats and 

all exposed groups of female rats; the mesenteric lymph node of 

5,000 ppm female rats; the kidneys of 2,500 and 10,000 ppm 

female rats; and the skin and forestomach of all exposed groups 

of male and female mice. 

Long-Term Rat and 2-Year Mouse Studies 

At 3 months (rats) or 15 months (mice), blood was collected from 

the retroorbital sinus of as many as 10 male and 10 female rats 

and mice. 

Hematology:. Hematocrit level, hemoglobin concentration, 

erythrocyte count, reticulocyte count, nucleated erythrocyte 

count, mean cell volume, mean cell hemoglobin, mean cell 

hemoglobin concentration, platelet count, and leukocyte count 

and differential. 

None 

Complete histopathologic examinations were performed on all Fi 

rats and on all mice. In addition to gross lesions, tissue masses 

and associated lymph node~, the tissues examined included: 

adrenal glands, bone (including marrow), brain, clitoral gland, • 

' 

esophagus, gallbladder (mice only), heart (with aorta), kidneys, 

large intestine (cecum, colon, rectum), liver, lungs and mainstem 

bronchi, lymph nodes (mandibular and mesenteric), 'mammary 

gland, nasal cavity and turbinates, ovaries, pancreas, parathyroid 

glands, pituitary gland, preputial gland, prostate gland, salivary 

gland, .skin, small intestine (duodenum, jejunum, ileum), spinal 

cord and sciatic nerve, spleen, stomach (forestomach and 

glandular stomach), testis with epididymis and seminal vesicle 

thymus, thyroid gland, trachea, urinary bladder, and uterus. 
33 ! 

10,000 ppm groups at weaning were lower than that 

vzr v of the control. 

In the perinatal exposure phase of the 13-week study, 

t-butylhydroquinone did .not affect gestation length, All F1 rats survived to the end of the study (Table 2). 

the average number of pups born per litter, or the The final mean body weights of males and females in 

number of dams with stillborn pups for dams exposed the 5,000 and 10,000 ppm groups were significantly 

,to 2,500, 5,000, or 10,000 ppm (Table H2); dams lower than those of the controls, as was the mean 

exposed to 20,000 or 40,000 ppm did not litter. The body weight gain of males in the 10,000 ppm group. 

number of pup deaths in the 5,000 and 10,000 ppm However, interpretation of these findings was compligroups was greater than that in the control group, and cated by the significantly lower initial mean body 

the average number of surviving pups per litter in the weights observed in 10,0t30 ppm groups. Differences 

10,000 ppm group was lower than that in the control in initial mean body weights were due to in utero 

group. Mean body weights of pups in the 5,000 and exposure to t-butylhydroquinone. 

TABLE 2 

Survival, Mean Body Weights, and Feed Consumption of ~a~s in the ~3-Week Feed Study 

of t-~utyihydroquinone 

Final Weight 

Mean Body Weight b (g) Relative Feed 

Dose Survival a Initial c Final Change to Controls Consumption d 

(ppm) (%) Week2 Week 13 

Male 

0 10/10 96 ± 5 328 5:6 232 ± 4 17.0 14.6 

2,500 10/10 92 ± 3 325 ::1:3 233 ± 3 99 15.8 15.7 

5,000 10/10 86 ± 4 307 ± 7* 221 ± 6 93 14.2 13.8 

10,000 10/10 69 ± 3** 279 ± 5** 210 ± 5** 85 10.8 13.8 

Female 

0 10/10 82 ± 3 199 ± 5 117 ± 4 11.4 12.6 

2,500 10/10 81 ± 3 198 ± 3 117 ± 3 99 11.3 12.4 

5,000 10/10 78 ± 3 185 ± 2** 108 ± 2 93 10.9 12.7 

10,000 10/10 64 ± 2** 175 ± 3** 111 ± 3 88 9.2 10.6 

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

** Ps:0.01 

a Number of animals surviving/number initially in group 

b Weights and weight changes are given as mean ± standard error. 

c Differences in initial body weights were due to in utero exposure of treated groups to t-butylhydroquinone. 

d Feed consumption is expressed as grams of feed consumed per animal per day. 
34 t-Butyihydroquinone, NTP TR 4~9 

Feed consumption by exposed groups was lower than 

that by controls at week 2, and, feed consumption by 

5,000 and 10,000 ppm males and 10,000 ppm females 

was slightly lower than that consumed by controls 

at the end of the study. Dietary levels of 2,500, 

5,000, and 10,000 ppm delivered daily doses of 

approximately 200, 400, and 800 mg t-butylhydroquinone/kg body weight to males and 200, 400, and 

750 mg/kg to females. Hair discoloration was 

observed in all exposed groups of rats, with the 

exception of 2,500 ppm females; this was the only 

clinical observation considered to be related to 

chemical exposure. 

The mean spermatid count, spermatid heads per testis, 

and spermatid heads per gram of testis were significantly decreased in F~ males exposed to 5,000 ppm; 

the estrous cycles of F~ females exposed to 2,500 or 

5,000 ppm were significantly longer than that of the 

controls (Table H1). Exposure to t-butylhydroquinone for 13 weeks did not produce morphologic 

changes in reproductive organs. 

Serum bile acid levels, were generally significantly 

increased in 5,000 and 10,000 ppm male and female 

rats at day 5, at week 3, and at the end of the study • 

(Table G1). Serum alanine aminotransferase activity 

levels were increased at day 5 in females exposed to 

10,000 ppm, at week 3 in males and females exposed 

to 2,500, 5,000, or 10,000 ppm, and at the end of the 

study in males receiving 2,500 ppm. However, 

because the increases observed in these two parameters were marginal, and since histopathologic 

evaluation did not reveal evidence of liver toxicity, 

these marginal increases were not considered to be 

biologically significant changes. Differences in 

absolute and/or relative organ weights of control and 

exposed groups of rats were observed (Table F1). 

However, these organ weight differences were associated with histopathologic lesions and in many cases 

were secondary to lower body weights of exposed 

groups. Therefore, they were not considered clearly 

related to t-butylhydroquinone exposure. 

Increased incidences of hyperplasia of the ~nasal 

respiratory epithelium were observed in. males exposed to 5,000 ppm and males and females exposed to 

10,000 ppm, andan increased incidence of nasal 

. exudate was observed in males in the i0,000 ppm 

group (Table 3)~. The hyperplasia ~vas of minimal 

severity and primarily involved an increase in the 

number of goblet cells along the nasal septum and 

medial aspect of the nasoturbinates. In a few male 

rats, there was also a mild nasal exudate composed of 

degenerated neutrophils and eosinophilic proteinaceous material. These nasal lesions suggest a mild 

irritant effect of t-butylhydroquinone possibly resulting from inhalation and/or aspiration .of the dosed 

feed. Increased incidences of splenic pigmentation 

were observed in males and females exposed to 5,000 

or 10,000 ppm, and incidences of atrophy of the red 

pulp were observed in these groups of females 

(Table 3). Because the pigment was golden brown 

and present within the phagocytic cells, it was considered to be hemosiderin. Atrophy of the splenic red 

pulp was characterized as a decrease in the number of 

hematopoietic cells. While the pathogenesis of these 

minimal changes was not determined, the biological 

significance is at most minimal because the bone 

marrow and hematologic parameters were normal. 

There was an exposure-related decrease in the incidences of renal mineralization in female rats 

(Table 3). Normally, a slight amount of mineral is 

observed near the corticomedullary junction in all 

females at 13 weeks. The pathogenesis of the observed decrease in this mineral is uncertain, although 

changes in feed and water consumption and decreased 

estrogen levels may affect mineral accumulation in the 

kidney. 

Dose Selection Rationale: Based on lower final mean 

body weights and decreased feed consumption in 

males and females exposed to 10,000 ppm t-butylhydroquinone, exposure concentrations selected for 

the long-term rat study were 1,250, 2,500, and 

5,000 ppm. 
~-~y~y~ro~no~e~~ T~ ~0~ 35 

T~ ~ 

~c~e~ces o~ ~e~ec~e~ Ho~eo~s~s~c ~es~o~s ~ 

o~ ~-~n~y~y~ro~no~e 

~ ~ ~e ~-V~ee~ Feed ~n~y 

0 ~pn~ ~,~ pp~ ~,~ ~ ~0,000 ppn~ 

M,~ge 

Nosc a 

Exudate b 

Nasal Respiratory 

Epithelial Hyperplasia 

10 

0 

0 

10 

0 

0 

10 

0 

5* (1.0) ¢ 

10 

4* 

10"* (1.7) 

Spleen 

Pigmentation 

10 

0 

10 

1 (1.0) 

10 

3 (1.0) 

10 

5* (1.0) 

F~m~ 

Nose 

Nasal Respiratory 

Epithelial Hypegplasia 

10 

0 

_d 

--

10 

0 

10 

7** (1.0) 

Spleen 

Red Pulp, Atrophy 

Pigmentation 

10 

0 

0 

10 

0 

5* (1.0) 

10 

8** (1.8) 

8 °* (1.1) 

10 

10"* (1.8) 

10"* (1.3) 

Kidney 

Mineralization 

10 

10 (2.0) 

10 

10 (1.9) 

10 

6 (1.3) 

10 

4** (1.2) 

* Significantly different (P~0.05) from the control group by the Fisher exact test 

** P~0.01 

a Number of animals with organ examined microscopically 

b Number of animals with lesion 

c Average severity grade of lesions in affected rats: 1 •minimal; 2=mild; 3ffimoderate; 4ffimarked 

d Organ not examined at this exposure level 
3~ 

LONG-TERM STUDY 

Survival 

Estimates of survival probabilities for male and female 

rats are shown in Table 4 and in the Kaplan-Meier 

survival curves in Figure 1. Survival of females in 

the 5,000 ppm group was significantly greater than 

that of the control group. Males were, killed at 

week 123 (28 months) post-weaning and females at 

week 129 (30 months) post-weaning. 

Body Weights, Feed and Compound 

Consumption, and Clinical Findings 

Mean body weights of 5,000 ppm groups were 

generally lower than those of the control groups 

TABLE 4 

t:Butylhydroquinone, NTP TR 4~9 

throughout the study. (Tables 5 and 6 and Figure 2). 

Feed consumption by exposed groups, of males and 

females was similar to that by the controls (Tables J 1 

and J2). Dietary levels of 1,250, 2,500, or 

5,000 ppm t-butylhydroquinone resulted in daily doses 

of approximately 50, 100, or 200 mg/kg body weight 

(males) or 60, 120, or 240 mg/kg (females). Clinical 

findings of hair discoloration in exposed groups of 

males and females were considered to be related to 

chemical exposure. , 

Hematology 

Results of hematology assays in all exposed groups of 

males and females were similar to those in the control 

groups (Table G2). 

Survival of Rats in the Long-Term Feed Study of t-Butylhydroquin0ne 

Male 

Animals initially in study 

3-Month interim evaluation 

Missexed a 

Moribund 

Natural deaths 

Animals surviving to study termination 

Percent probability of survival at the end of the study b 

Mean survival (days) e 

Survival analysis d 

Female 

Animals initially in study 

3-Month interim evaluation 

Missexed a 

Moribund 

Natural deaths 

Animals surviving to study termination 

Percent probability of survival at the end of the study 

Mean survival (days) 

Survival analysis 

a Censored from survival analyses 

b Kaplan-Meier determinations 

0 ppm 1,250 ppm " 2,500 ppm 5,000 ppm 

70 70 70 70 

10 10 I0 10 

0 0 2 0 

48 51 50 42 

4 2 7 4 

8 7 1 14 

13 12 2 23 

621 612 590 629 

Pf0.300N P=0.856 P=0.07/5 P=0.361N 

70 70 70 70 

10 10 10 10 

0 0 2 0 

40 41 33 36 

10 8 9 7 

10 . 11 16 17 

17 18 28 ~28 

636 663 678 693 

P=0.01q7N P=0.564N P=0.063N P=0.030N 

, . 

Mean of all deaths (censored, uncensored, and terminal s~crifice) 

d The result of the life table trend test (Tarone, 1975) is in the control column, and the results Of the life ~able pairwise comparisons 

(Cox, 1972) with the controls are in the exposed columns. A negative trend or a lower mortality in an exposure group is indicated by N. 

c 
t-~utylhydroquinone, NTF TR ,~$9 37 

1.0{ 

0.9-

0.7-

, ,, : 

. i ................................................................. ~ ............................ ' , 

0.6 - ................................................ i .................................................. 

O 

0.5-

0.4-

O 

0.3-

0.2-

0.! 

.... MALE RATS 

[] 0 ppm 

O 1,250 ppm 

A 2,500 ppm 

[] 5,000 ppm 

0.0 1'~ ~ 45, ~ . 60 75 

WEEKS ON STUDY 

90 105 120 135 

1.0[] 

0,9 ......... 

0.8 ........ 

0.7 ........ 

0.6 ........ 

O 

0off ........ 

0.4 ........ 

0 

0,~ 

0.! 

.... 

.... 

F EMAL E RAT S 

[] 0 ppm 

o 1,250 ppm 

A 2,500 ppm 

[] 5,000 ppm 

0.~! 0 1'~ ~ ~.~ 60 75' 

WEEKS ON STUDY 

90 105 120 13.5 

~F~G~ ~. 

~aplan-1~/~eier Sur~ival Curves for 1~v~ale and Female Rats Administered t-~utylhydroquinone 

~n the Long-Term Feed Stndy 
38 .' t-Butylhydroquinone, NTP TR.459 

TABLE 5 

Mean Body Weights and Survival of Male Rats in the Long-Term Feed Study of t-Butylhydroquinone 

Weeks - ~ 0 until • I,~0 unto 2.S00 unto S.000 nnm 

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) Surv/vors 

1 99 7O 106 108 70 102 103 70 91 92 7O 

2 141 70 148 105 70 141 99 70 127 9O 7O 

3 175 70 181 104 70 174 99 70 157 9O 70 

4 209 7O 213 102 70 206 99 70 188 90. 7O 

5 a 233 7O 237 102 70 232 99 68 217 93 7O 

6 267 70. 266 100 70 260 97 68 244 91 70 

7 283 70 284 100 70 277 98 68 261 92 70 

8 299. 7O 298 100 70 294 98 68 275 92 7O 

9 313 7O 311 100 70 307 98 68 287 92 70 

10 316 7O 319 101 70 320 • 101 68 . 299 95 70 

11 324 7O 324 100 70 323 100 68 3O4 94 70 

12 344 7O 342 100 70 337 98 68 318 92 7O 

13 356 7O 348 98 70 343 97 68 320 9O 70 

17 b 379 6O 37O 98 60 366 96 58 346 91 60 

21 40O 6O 391 98 60 379 95 58 358 89 60 

25 413 6O 408 99 60 399 97 58 376 91 6O 

29 4~19 6O 416 99 60 408 97, 58 386 92 60 

33 428 60 425 99 60 . 417 97 58 392 92 6O 

37 437 6O 435 100 60 430 98 58 4O2 92 6O 

41 450 6O 445 99 60 437 . 97 58 416 92 6O 

45 452 6O 450 100 59 439 97 58 415 92 6O 

49 444 6O 448 101 59 440 99 58 415 94 6O 

53 468 6O 466 100 59" 457 98 58 431 92 60 

57 468 59 468 100 57 462 99 58 435 93 6O 

61 467 59 468 100 57 463 99 57 440 94 6O 

65 470 59 471 100 57 463 99 57 44O 94 59 

69 468 57 472 101 56 463 99 55 437 93 59 

73 472 56 471 100 56 459 97 53 433 92 57 

77 463 55 463 100 56 458 99 52 438 95 55 

81 464 52 466 101 51 458 99 47 436 94 53 

85 462 51 470 102 49 ' 457 99 45 429 93 52 

89 455 51 457 lOl 49 455, 100 40 425 93 51 

93 458. 46 451 98 47 456 100 35 419 92 44 

97 455 39 452 99 40 453 100 32 421 92 39 

101 447 35 444 99 32 443 99 25 421 94 34 

105 440 28 435 99 23 430 98 21 409 93 3O 

109 420 21 421 100 2O 414 99 16 412 98 25 

113 429 13 427 100 13 420 98 10 395 92 i9 

117 428 10 422 99 11 4O0 94 6 397 93 15 

121 417 8 4O2 97 9 359 86 5 386 93 14 

Mean for weeks 

1-13 258 260 101 ' 255 99 238 92 

14-52 425 "421 99 413 97 390 92 

53-121 453 451 16O 443 98 422 93 

a Two rats in the 2,500 ppm group were missexed. These animals were removed from study during week 4.. 

b Interim evaluation occurred during week 14. • 
t-I~u~yHhydr~uinone, HTP T~,~9 39 

T~L~ 6 

I~ean ]Body Weights ~nd Surviw~ o~ Female ~ in ~he Long-Terns Feed Study o~ t-~u~ylhydr~u~none 

Weeks O ~.um 1.250 qpm ~~ 2.500 qnm 5.~C~ qum 

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 

! 

I 92 70 97 105 70 93 101 70 83 91 70 

2 121 70 124 103 70 120 100 70 110 91 70 

3 135 70 137 101 70 134 99 70 125 92 70 

4 147 70 148 101 70 143 98 70 134 92 70 

5 a 159 , 70 159 100 70 155 97 68 146 92 70 

6 171 70 168 98 70 162 95 68 154 90 70 

7 177 70 174 98 70 170 96 68 161 91 70 

8 181 70 178 99 70 174 96 68 165 92 70 

9 186 70 184 99 70 180 97 68 173 93 70 

10 176 70 181 103 70 183 104 68 176 100 70 

11 193 70 192 99 70 187 97 68 181 94 70 

12 196 70 194 99 70 188 96 68 181 92 70 

13 198 70 194 98 70 191 97 68 184 93 70 

17 b 203 60 203 100 60 197' 97 58 188 93 60 

21 224 60 212 95 60 205 92 58 200 89 60 

25 222 60 216 97 60 212 96 58 203 91 60 

29 229 60 222 97 60 217 94 57 210 91 60 

33 231 60 227 98 60 219 95 57 210 91 60 

37 232 60 ' 230 99 60 223 96 57 213 92 60 

41 240 60 238 99 60 231 97 57 219 92 60 

45 248 58 246" 99 60 239 96 57 227 91 60 

49 257 58 256 100 60 244 95 57 232 90 60 

53 264 58 263 100 60 247 94 ~ 57 236 90 60 

57 279 57 277 99 60 264 95 57 246 88 60 

61 285 55 285 100 60 269 94 57 257 90 60 

65 292 55 291 100 • 60 274 94 56 263 90 60 

69 301 55 299 99 58 282 94 56 265 88 60 

73 309 54 301 98 57 286 93 55 270 87 59 

77 315 54 311 99 56 297 94. 55 274 87 59 

81 323 51 319 99 55 300 93 55 278 86 59 

85 327 49 325 100 53 308 94 54 282 87 57 

89 333 48 327 98 52 309 93 52 287 86 54 

93 342 43 339 99 48 316 93 50 290 85 50 

97 348 42 343 99 43 325 93 45 299 86 46 

101 347 39 346 100 40 329 95 43 301 87 43 

105 345 35 347 100 37 333 96 42 303 88 42 

109 341 31 354 104 32 329 97 39 300 88 40 

113 337 24 350 104 29 337 I00 30 301 89 37 

117 348 18 355 102 22 337 97 27 309 89 33 

121 341 16 353 104 18 335 98 24 315 92 27 

Mean for weeks 

1-13 164 164 100 160 98 152 93 

14-52 232 228 98 221 95 211 91 

53-121 321 321 100 304 95 282 88 

a Two rats in the 2,500 ppm group were missexed. These animals were removed from study during week 4. 

b Interim evaluation occurred during week 14. 
40 t-Butylhydroquinone, NTP TR 459 

500 - i ~ i i i ! ! 

i ! ~_ ~eme~'.e~... i i 

.o.. ............. i ............. j.......... ~~,~~-6-~~~~i,~-~.0 ~~"m~--: ...... ~................ 

~ ,~ooo ~ ~ qooo~e~e, ~ ,0o ................ ~....8.~.~..o.o ....... ~....... ~ ........ ~ ............... ~................ ~....., .......... ~:~oo~ .............. 

~ ~o~ ~ ~ ~ ~ ~ ~ ~ 

~ o . ..:: ................ ~ ................ ~............... ~................ ~ ................ : ..............~... .......... O 350-

N ~ ..... r..; ............................................................................. ........................ ~......... :..~ .................... 

~ . ::' 

~ .... ~.... ......... . ............... : .................... . ..................................................... : ............................... :.... 

0 ~. ~ ~ ........................................................... -........................................................... : ................................. 

Z 

< 

w 

150- • 0 ppm 

0 0 1,250ppm 

A 2,500 ppm 100- El. S, O00 ppm, 

• ; 50 ; i , . ! 

0 15 30 4.,5 60 75 90 105 120 1.35 • 

WEEKS ON STUDY 

500. 

450 ........................................................ : .......... i ................................................................................ 

400 .................................................................................. : ................ : ................................................. 

< : :

0 ~o ................ ~. ............... ................ ~ ! .......... .-..-.i- ............... i ................ i, ,o_~o.~: ... ' ..............

,, o o ~oo ................ ; ............... ~................................ ; . ,. ~ .@~.~..~.-.---~..~.o. D .= .B.o.... ~................ , ' 0 ~ ~ ~ ~T&&;~nBU ~ :: ~ I 

2~0 ~ ~ am~oo~- ~ ~ ~ I ................ ~ ............... ~................ ~ o~ ............... ~................................ ~................. ==................ I ~ ..e~~ ~ ~ :: ~ ,I 

~ooJ~....... ~;,.~.~.~.~_ ................ ~ ................ ; ............... ~........ ~ ~ ~ ~ ~ .~ -~ ~ ~ ~ ~] I 

,~ot.. ~ ..... ~ ............... ~................ ~.............. ...~ ............... ~................ ~.. • oppm / ...... I 

I~ :: ~ :: ~ ~ ~ o 1,2S0 ppm / I 

,ooE~ . :: ~ ~ ~ ~ 2,s00 ppm / I 

P .......... r ....................................................... ...... I 

~°v ~, : ; ; I 0 15 30 ~ 60 75 90 105 120 135 

WEEKS OH STUDY 

FIGURE 2 

Growth Curves for Male and Female Rats Administered t-Butylhydroquinone 

in the Long-Term Feed Study 
~ ....................... 

t-~u~y~hydroquirtone, NT~ T~ 459 

Paehology and Sta~s~cal Analyses 

This section describes the statistically significant or 

biologically noteworthy changes in the incidences of 

neoplasms and/or nonneoplastic lesions of the thyroid 

gland, testis, mammary gland, pituitary gland, kidney, 

nose, spleen, and other organs. Summaries of the 

incidences of neoplasms and nonneoplastic lesions, 

individual animal tumor diagnoses, and statistical 

analyses of primary neoplasms that occurred with an 

incidence of at least 5 % in at least one animal group 

are presented in Appendix A for male rats and 

Appendix B for female rats. 

Thyroid gland: At the end of the long-term study, 

follicular cell carcinomas were observed in three 

5,000 ppm male rats and a follicular cell adenoma was 

observed in one 1,250 ppm male and one 2,500 ppm 

male (Table A1). However, the overall trend in 

neoplasm incidence was not significantly increased, 

and no thyroid gland hyperplasia was present in any 

group of male or female rats (Tables A4 and B4). At 

the 3-month interim evaluation, ultimobranchial cysts 

were found in one 1,250 ppm male and three 

5,000 ppm males. These marginal effects were not 

considered to be chemical related (Table A4). 

Testis: The incidences of testicular adenoma in 

exposed groups of males occurred with a statistically 

significant positive trend (0 ppm, 55/60; 1,250 ppm, 

49/60; 2,500 ppm, 56/57; 5,000 ppm, 59/60; 

Table A3). This marginal effect was not considered 

to be chemical related. This is a neoplasm that 

typically occurs in male rats at 2 years of age and was 

observed in all control and exposed rats at terminal 

sacrifice. The increase was attributed to slightly 

improved survival in the 5,000 ppm group. 

Mammary gland: Significantly decreased incidences 

of fibroadenoma and of fibroadenoma, adenoma, or 

carcinoma (combined) occurred in all exposed groups 

of females, and incidences of fibroadenoma and of 

fibroadenoma or adenoma (combined) were significantly decreased in 1,250 ppm males and marginally 

decreased in other exposed groups of males (Tables 9, 

A3, and B3). The incidences of dilatation of the 

mammary gland were significantly decreased in 

5,000. ppm males, and marginally decreased in 

2,500 ppm males than in controls. In females, the 

incidence of mammary gland dilatation was greater in 

the group exposed to 1,250 ppm than in the control 

group (Tables 9 and B4). Mammary gland neoplasms 

occurred earlier in the male and female control groups 

than in exposed groups. Fibroadenomas of the 

mammary gland are benign neoplasms which occur 

spontaneously at a high rate in female F344/N rats, 

and while not generally considered life threatening, 

the large size of these neoplasms often necessitates 

removal of the animal from the study. 
42 t-Butylhydroquinon~ NTP TR 459 

TABLI~ 9 

Incidences of Neoplasms and Nonneoplastic Lesions of the Mammary Gland in Rats 

in the Long-Term Feed Study of t-Butyihydroquinone 

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

Male 

Number Examined Microscopically 57 57 56 58 

Dilatation a 23 (2.0) b 24 (2.2) 17 (2.4) 10"* (1.7) 

Hyperplasia 7 (2.4) 4 (2.0) 5 (2.2) 6 (1.7) 

Fibroadenoma 

Overall rate ¢ 10/60 (17%) 4/60 (7%) 4/58 (7%) 7/60 02%) 

Adjusted rated 72.0% 40.7% 24.8% 40.2% 

Terminal ratee . 5/8 (63%) 2/7 (29%) 0/1 (0%) 5/14 (36%) 

First incidence (days) _ 381 786 619 708 

Logistic regression test t P=0.195N P=0.033N P=0.183N P-0.107N 

Adenoma 

Overall rate 1/60 (2%) 0/60 (0%) 1/58 (2%) 0/60 (0%) 

Fibroadenoma or Adenoma 

Overall rate 11/60 (18%) 4/60 (7%) 5/58 (9%) 7/60 (12%) 

Adjusted rate 72~6% 40.7% 43.6% 40.2% 

Terminal rate 5/8 (63%) 2/7 (29%) 0/1 (0%) 5/14 (36%) 

First incidence (days) 381 786 619 708 

Logistic regression test P=0.145N P=0.022N P=0.213N P=0.076N 

(continued) 
c 

t-~u~y~hy~roqu~none, ~ TI~ 459 ~ 

TA~L~ 9 

]Incidences o~ Neop~sn~s and Nonneop~mfic Lesions of ~he M~n~ry G~ ~n ~s 

in the Long-Terra ~¢ee~l Stady o~' t-~uty~y~rroqu~none (continued) 

0 ppm 1,2S0 ppm 2,S~ ppm ~,~0 ppm 

Female 

Number Examined Microscopically 60 59 58 60 

Dilatation 37. (2.1) 48* (2.1) 39 (2.3) 34 (2.0) 

Hyperplasia 12 (2.3) 6 (2.3) 11 (2.2) 15 (2.3) 

Fibroadenoma 

Overall rate 43160 (72%) 33/60 (55%) 34/58 (59%) 27/60 (45%) 

Adjusted rate 100.0% 96.6% 86.0% 74.4% 

Terminal rate 10/10 (100%) 10/11 (91%) 11/16 (69%) 9/17 (53%) 

First incidence (days) 418 537 600 596 

Logistic regression test P < 0.00IN P=0.006N P=0.009N P < 0.00IN 

Adenoma 

Overall rate 3/60 (5%) 0/60 (0%) 1/58 (2%) 2/60 (3%) 

Adjusted rate 9.9% 0.0% 2.9% 8.6% 

Terminal rate 0/10 (0%) 0/11 (0%) 0/16 (0%) 1/17 (6%) 

First incidence (days) 613 --g 774 807 

Logistic regression test P =0.562N P=0.133N P =0.345N P =0.503N 

Carcinoma 

Overall rate 8/60 (13%) 6/60 (10%) 2/58 (3%) 4/60 (7%) 

Adjusted rate 29.3% 35.4% 10.8% 10.5% 

Terminal rate 1/10 (10%) 3/11 (27%) 0/16 (0%) 0/17 (0%) 

First incidence (days) 540 640 890 690 

Logistic regression test P = 0.073N P = 0.345N P = 0.042N P = 0.177N 

Fibroadenoma, Adenoma, or Carcinoma 

Overall rate 48/60 (80%) 34/60 (57%) 34/58 (59%) 30/60 (50%) 

Adjusted rate 100.0% 96.6% 86.0% 76.3 % 

Terminal rate 10/10 (100%) 10/11 (91%) 11/16 (69%) 9/17 (53%) 

First incidence (days) 418 537 600 596 

Logistic regression test P <0.001N P <0.00IN P < 0.001N P <0.001N 

* Significantly different (P~0.05) from the control group by the logistic regression test 

** P~0.01 

a Number of animals with lesion 

b Average severity grade of lesion in affected animals: 1 =minimal; 2--mild; 3--moderate; 4=marked 

Number of animals with neoplasm per number of animals necropsied 

d Kaplan-Meier estimated neoplasm incidence at the end of the study after adjustment for intercurrent mortality 

e Observed incidence in animals surviving until the end of the study 

f In the control column are the P values associated with the trend test. In the exposure group columns are the P values corresponding to 

pairwise comparisons between the controls and that exposure group. The logistic regression test regards lesions in animals dying prior to 

terminal kill as nonfatal. A negative trend or a lower incidence in an exposure group is indicated by N. 

g Not applicable; no neoplasm in animal group 
44 t-Butylhydroqu:inone, NTP TR 459 

Pituitary gland: The incidences of~pars: distalis gland and incidences of hyperplasia and carcinoma 

adenoma and adenoma or carcinoma (combined) in were not decreased in the 5,000 ppm group. 

males in the 5,000 ppm group were significantly less Addition,~lly, there is a known positive correlation of 

than those in the controls (Tables 10 and A3): How- pituitary gland neoplasms with body weight, The 

ever, hyperplasia, adenoma, and carcinoma represent decrease in adenomas in this study may have been 

a morphological and biological continuum in the related to the decreased mean body weight of the 

progression of proliferative lesions of the pituitary 5,000 ppm group. , ,, 

TABLE 10 

Incidences of Neoplasms and Nonneoplastic Lesions of the Pituitary Gland (Pars Distalis) 

in Male Rats in the Long-Term Feed Study of t-Butyihydroquinone 

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

• ' "4 

Long-Term Study 

Number Examined Microscopically 60 58 57 60 

Hyperplasia, Focal a. 10 (2.2) b 8 (1.9) 8 (1.6) 14 (2.2) 

Adenoma 

Overall rate ¢ 19/60 (32%) • 16/58 (28%) 17/57 (30%) 6/60 (10%) 

Adjusted rate d 63.8 % 80.0% 100.0% 30.2% 

Terminal ratee 2/8 (25%) 4/6 (67%) 1/1 (100%) 3/14 (21%) 

First incidence (days) _ 528 562 , 562 668 

Logistic regression test r P=0.003N P=0.410N P--0,573 P--0.002N 

. 

Carcinoma 

Overall rate 0/60 (0%) 1/58 (2%) 1/57 (2%) 1/60 (2%) 

Adjusted rate 0~0% 5.5% 4.2% 2.1% 

Terminal rate 0/8 (0%) 0/6 (0%) 0/I (0%) 0/14 (O%) 

First incidence (days) ~-g 766 725 627 

Logistic regression test P=0.388 4. P=0.488 P=0.473 P=0.491 

Adenoma or Carcinoma 

Overall rate 19/60 (32%) 17/58 (29%) 18/57 (32%) 7/60 (12%) 

Adjusted rate 63.8% 81.1% 100.0% 31.6% 

Terminal rate 2/8 (25 %) • 4/6 (67%) 1/1 (100%) 3/14 (21%) 

First incidence (days) - 528 562 -562- 627 

Logistic regression test P=0.005N P=0.494N P=0.487 P=0.006N 

Number of animals with lesion 

Average severity grade of lesion in affected animals: 1 =minimal; 2ffimild; 3ffimoderate; 4=marked 

Number of animals with neoplasm per number of animals with pituitary gland examined microscopically 

Kaplan-Meier estimated neoplasm incidence at the end of the study after adjustment for intercurrent mortality 

Observed incidence in animals surviving until the end of the study 

In the control column are the P values associated with the trend test. In the exposure group columns are the P values corresponding to 

pairwise comparisons between the controls and that exposure group. The logistic regression test regards lesions in animals dying prior to, 

terminal kill as nonfatal. A negative trend or a lower incidence in anexposure group is indicated by N. 

Not applicable; no neoplasm in animal group 
t-~u~y~hydroquinone, NT~ TR 459 45 

Kidney: In the long-term study, there was a slight with the most severe (moderate to marked) nephropincrease in the incidences of cysts and suppurative athy. While this finding may suggest a slight exacerinflammation in the kidney of male rats (Tables 11 bation of the nephropathy by t-butylhydroquinone, the 

and A4). The development of a progressive nephrop- nephropathy severity grades in the controls and in the 

athy in aging F344/N rats (especially males) is well 5,000 ppm males were not markedly different 

documented. A spectrum of morphological changes (Table 11). It is not clear whether t-butylhydrois identified as part of the nephropathy, including quinone exposure contributed to these marginal 

marked dilatation (cysts) of renal tubules and occa- increases. Additionally, the incidence and severity of 

sional suppurative inflammation within renal tubule renal mineralization were slightly decreased in males 

lumina. In the present study, these changes were and females. 

observed in kidneys of control and exposed animals 

TABLE 1 ~ 

lIncidences of Nonneopl~sfic Lesions of ~he ~I(ddney in ]~a~ in ~he Long-Term l~eed S~udy 

of t-~utylhydroquinone 

0 ppm 1,250 ppm 2,500 ppm 5,~00 ppm 

Male 

Number Examined Microscopically 60 60 58 60 

Cyst a - 2 (3.0) b 3 (3.0) 7* (2.9) 11"* (3.0) 

Inflammation, Suppurative 9 (1.0) 8 (1.0) 9 (1.3) 20* (1.2) 

Mineralization 12 (1.7) 3** (2.3) 2** (2.0) 1"* (1.0) 

Nephropathy 60 (2.6) 60 (2.6) 58 (2.4) 60 (2.8) 

Transitional Epithelium, 

Hyperplasia 13 (1.4) 12 (1.6) 11 (2.3) 21 (1.5) 

Female 

Number Examined Microscopically 60 60 57 60 

Cyst 0 1 (4.0) 0 2 (3.0) 

Inflammation, Suppurative 2 (2.0) 1 (1.0) 0 0 

Mineralization 57 (2.4) 56 (2.4) 44* (2.0) 48* (1.6) 

Nephropathy 37 (1.7) 38 (1.8) 37 (1.6) 39 (1.8) 

* Significantly different (Pg0.05) from the control group by the logistic regression test • 

** Pg0.01 

a Number of animals with lesion 

b Average severity grade in affected animals: 1 =minimal; 2=mild; 3=moderate; 4=marked 
,86 

Nose: At the 3-month interim evaluation, goblet cell 

hyperplasia occurred in the nose of male rats exposed 

to 5,000 ppm (Tables 12 and A4). This lesion was 

observed in one exposed female at 3 months 

(Table B4), and was morphologically similar to .the 

lesion (epithelial hyperplasia) in rats exposed to 

t-butylhydroquinone for 13 weeks (Table 3). Incidences of goblet cell hyperplasia were not significantly increased in males at the end of the study 

(Tables 12 and A4). The increased incidences at 

earlier time points may have resulted from direct 

contact of the chemical with the nasal mucosa during 

feeding. 

Spleen: The incidences of splenic pigmentation 

(hemosiderin) were increased in exposed groups of 

males and females at the 3-month interim evaluation 

(Tables 12, A4, and B4) and the severity increased 

TABLE 12 

t-Butylhydroquinone, NTP TR 459 

with increasing exposure concentrations in females. 

This finding is similar to results from the 13-week 

study (Table 3). Increased incidences of pigmentation 

(hemosiderin, confirmed with Prussian Blue stain) 

were also observed in exposed groups of females at 

the end of the study (Tables 12 and B4), while the 

incidence and severity of pigmentation in exposed 

groups of males were similar to those of the controls 

(Table A4). ~ Although the incidence differences 

between the female control group and the exposed 

female groups at the end of the long-term study were 

slight, the change was consistently observed at earlier 

time points (3-month interim evaluation and 13-week 

study) as well. As at earlier time points, however, 

other changes corroborating an anemia were not 

observed. The pathogenesis of this change remains 

uncertain, and the biological significance was 

considered minimal. 

Incidences of Nonneoplastic Lesions of the Nose and Spleen of Rats in the Long-Term Feed Study 

of t-Butylhydroquinone 

Male 

3-Month Interim Evaluation 

Nose a 

Goblet Cell Hyperplasia b 

Spleen 

Pigmentation, Hemosiderin 

Long-Term Study 

Nose 

Goblet Cell Hyperplasia 

Female 

3-Month Interim Evaluation 

Spleen 

Pigmentation, Hemosiderih 

Long-Term Study 

Spleen 

Pigmentation, Hemosiderin 

• 0 ppm 1,250 ppm 2,500 ppm 5,000 ppm 

10 I0 I0 I0 

0 0 0 7** (I.0) c 

10 10 10 10 

0 0 3 (l.0i 5* (l.0) 

60 6O 58 6O 

5 (1.2) 3 (1.3) 9 (1.1) 13 (1.1) 

10 10 10 10 

5 (1.2) 7 (1.4) 8 (1.3) 10" (1.8) 

60 60 57 60 

24 (2.4) 27 (2.5) 33 (2.4) 41"* "(2.4) 

* Significantly different (PsO.05) from the control group by the Fisher exact test 

** Significantly different (P~O.OI) from the control group by the Fisher exact test O-month interim evaluation) or the logistic regression test 

(long-term study) 

a Number of animals with organ examined microscopically 

b Number of animals with lesi6n 

c Average severity grade in affected animals: 1 =minimal; 2=mild; 3ffimoderate; 4ffimarked 
~-~y~y~roq~inone, NTIS. T~ ~9 

Other Organs: There were a number of decreased 

incidences of nonneoplastic lesions in various organs 

of male and female rats. In male rats, decreased 

incidences included:adrenal medulla, hyperplasia 

(0 ppm, 26/60; 1,250 ppm, 22/60; 2,500 ppm, 15/58; 

5,000 ppm,. 12/60; Table A4);liver, cystic 

degeneration (23/60, 16/60, 11/58, 5/60; Table A4); 

liver, bile duct hyperplasia (52/60, 49/60, 43/58, 

25/60; Table A4); preputial gland, chronic 

inflammation (26/60, 16/60, 18/58, 12/60; Table A4); 

and prostate gland, inflammation (36/60, 39/60, 40/ 

58, 23/60; 

Table A4). In exposed groups of females, the 

incidence of hepatocellular cytoplasmic vacuolization 

was decreased (14/60, 14/60, 9/58, 3/50; Table B4). 

In general, these nonneoplastic lesions often occur 

spontaneously and usually represent relatively 

insignificant changes within the individual organs or 

tissues. While the potential contribution of t-butylo 

hydroquinone and/or body weight reductions as causal 

factors of these effects remains undetermined, the 

biological importance of the decreases are considered 

minimal. 
48 t-Butylhydroquinone, NTP TR 459 

MICE . 20,000, and 40,000 ppm groups. Therefore, it is 

13-WEEK S rcI Y likely that feed consumption, by male and female mice 

One female in each .of the 10,000 and 40,000.ppm in these groups was less than that by controls. 

groups died before the end of the-study, but the deaths Dietary levels of 21500, 5,000, 10,000, 20,000, and 

were not considered to be related to t-butylhydro- 40,000 ppm delivered daily doses of approximately 

quinone exposure (Table 13). Final mean body 440, 880, 1,950, 4,000, and 8,400 mg t-butylhydroweights and body weight gains of. male and female quinone/kg body weight to males and 500, 1,100, 

mice in the 10,000, 20,000, and 40,000 ppm groups 2,200, 4,600, and 9,000 mg/kg tofemales. Clinical 

were significantly lower than those of the control observations of alopecia and hair discoloration were 

groups. Feed consumption by exposed groups attributed to exposure to t-butylhydroquinone; because 

appeared to be similar to that by controls, but there of feed spillage, these observations might have been 

was excessive scatter of feed by mice in the 10,000, due to dermal exposure to t-butylhydroquinone. 

TABLE 13 

Survival, Mean Body Weights, and Feed Consumption of Mice in the 13-Week Feed Study 

of t-Butylhydroquinone 

Final Weight 

Mean Body Weight b (g) Relative Feed 

Dose Survival a Initial Final Change to Controls Consumption c 

(ppm) (%) Week2 Week 13 

Male 

0 10/10 23.1 ± 0.3 32.4 ± 1.6 9.4 ± 1.7 5.0 4.5 . 

2,500 10/10 23.0 ± 0.4 32.4 ± 0.7 9.4 ± 0.5 100 5.2 4.6 

5,000 10/10 22.7 ± 0.3 31.6 ± 0.5 8.9 ± 0.4 97 6.0 4.3 

10,000 10/10 23.4 ± 0.3 29.5 ± 0.4* 6.0 ± 0.2** 91 6.3 4.4 

20,000 10/10 22.9 ± 0.3 26.6 ± 0.4** 3.7 ± 0.2** 82 8.0 3.8 

40,000 10/10 22.4 ± 0.2 22.9 ± 0.5** 0.6 ± 0.6** 71 6.4 4.3 

Female 

0 10/10 18.3 ± 0.4 29.5 ± 0.6 11.2 ± 0.4 5.8 4.2 

2,500 10/10 17.7 ± 0.4 28.7 ± 0.6 11.0 ± 0.6 97 6.7 4.7 

5,000 10/10 17.5 ± 0.4 28.3 ± 0.8 10.7 ± 1.0 96 6.6 4.4 

10,000 9/100 17.6 ± 0.1 24.0 ± 0.4** 6.3 ± 0.4** 81 6.5 3.9 

20,000 10/10 17.5 ± 0.5 21.6 ± 0.4** 4.1 ± 0.5** 73 7.4 3.8. 

40,000 9/10 e 17.8 ± 0.2 19.8 ± 0.5** 2.0 ± 0.4~* 67 6.0 4.6 

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

** Pg0.01 

a Number of animals surviving/number initially in group 

b Weights and weight changes are given as mean ± standard error. Subsequent calculations are based on animals surviving to the e~d Of the 

study. 

Feed consumption is expressed as grams of feed consumed per animal per day. 

d Week of death: 8 (accidental death) 

e Week of death: 4 (accidental death) 

c 
t-Buty~hydroquinone, NT~ TS ,~59 49 

Significant increases in segmented neutrophil counts 

occurred at week 3 and at the end of the study in the 

20,000 and 40,000 ppm groups of males and females 

and in the 10,000 ppm female group (Table G3); this 

was the only clinical pathology change that was 

related to chemical exposure. Other. clinical pathology changes were attributed to dehydration from 

weight loss or were considered to be otherwise 

unrelated. There were no biologically significant 

differences in organ weights (Table F3). 

I_eft caudal, left epididymis, and left testis weights of 

males exposed to 10,000 or 40,000 ppm were generally significantly lower than those of the controls 

(Table H4). The estrous cycle of females exposed to 

40,000 ppm was significantly longer than that of the 

controls. Additionally, no lesions were observed in 

the reproductive system of exposed groups of mice; 

thus, differences in reproductive parameters were 

considered to be secondary to body weight changes. 

Increased incidences of mucosal hyperplasia were 

observed in the forestomach of male mice exposed to 

20,000 or 40,000 ppm and in female mice exposed to 

10,000, 20,000, or 40,000. The severity of this 

lesion also increased with increasing exposure concentration (Table 14). This change was characterized 

by a slight focal to multifocal increased thickness of 

the squamous epithelium of the forestomach. Probable contributors to this effect include chemical 

irritation and reduced mechanical action of feed in the 

forestomach due to decreased feed consumption in the 

10,000, 20,000, and 40,000 ppm groups. Increased 

incidences of inflammation occurred in the nose and 

skin of males and females exposed to 10,000, 20,000, 

or 40,000 ppm (Table 14). Nasal changes involved 

all areas of the nasal cavity and consisted of suppurative inflammation with. serous exudation. Changes 

in the skin included a minimal to mild chronic inflammation and increased thickening of the epithelium 

(hyperplasia), including the keratin layer. Both nasal 

(inhalation or aspiration) and skin (contamination of 

bedding from feed spillage) lesions were likely associated with an irritant effect of t-butylhydroquinone. 

Dose Selection Rationale: Based on lower final mean 

body weights, increased incidences of inflammation of 

the nose and skin, increased incidences of forestomach mucosal hyperplasia, and increased severity 

of nonneoplastic lesions observed in mice exposed to 

10,000, 20,000, or 40,000 ppm, exposure concen-. 

trations selected for the 2-year study were 1,250, 

2,500, and 5,000 ppm. 
50 t-Butylhydroquinone, NTP TR 459 

TABLE 14 

Incidences of Selected Nonneoplastic 

of t-Butylhydroquinone 

Lesions in Mice in the 13-Week Feed Study •., 

0 ppm 2,500 ppm $,000 ppm. 10,000 ppm 20,000 ppm 40,000 ppm . • 

Male 

Nose a 

Inflammation, Suppurative b 

10 

0 

I0 

0 

10 

0 

10 

6** (1.3) c , . 

10 

10"* (2.1) 

10 

10"* (2.6) 

Forestomach 

Mucosal Hyperplasia • 

10 

6 (1.o) 

10 

"6 

, 

(i13) 

10 

7 (1.6) 

10 

5 (1.6) 

10 

10" (2.2) 

iO 

10" (2.5) 

Skin 

Inflammation, Chronic 

Epithelial Hyperplasia . 

10 

0 

0 

10 

0 

0 

10 

0 

0 

10 

10"* (1.5) 

8** (1.0) 

10 

10"* (1.8) 

10"* (1.4) 

10 

10"* (1.9) 

10"* (2.0) 

Female 

Nose 

Inflammation, Suppurative 

10 

0 

10 

0 

10 

0 

10 

10"* (1.8) 

10 

10"* (2.1) 

10 

10"* (3.0) 

Forcstomach 

Mucosal Hyperplasia 

10 

3- (1.0) 

I0 

4 (I.0) 

I0 

6 (1.3) 

I0' : " 

9** (2.0) 

I0 

8** 

.-

(2.6) 

10 

10"* (2.9) 

Skin . 

Inflammation, Chronic 

Epithelial Hyperplasia 

10: 

1 

.0 

(1 ~0) 

10 

I. 

1 

(1.0) 

(1.0) 

10 

5 

2 

(1.0) 

(1.0) 

10 

8** 

8** 

0..4) 

(1.0) 

10 

10"* (1.9) 

10'* (1.7) 

10 

10"* (2.0) 

10"* (2.0) 

* Significantly differem (P~0.05) from the control group by the Fisher exact test 

** P~0.01 

a Number of animals with organ examined microscopically 

b Number of animals with lesion 

c Average severity grade of lesions in affected mice: 1 -- minimal; 2 ffi mild; 3 ffi moderate; 4 ffi marked 
t-ll~u~y~hyflroqu~none, ~ T~ ~$~ ~ 

2o~fE~ ~3~ru~ 

S~ival 

Estimates of 2-year survival probabilities for male and 

female mice are shown in Table 15 and in the KaplanMeier survival curves (Figure 3). Survival of males 

and females in all exposed groups was similar to that 

of the control groups. 

~@ ~e~gg~s, Feed and C~mp~un~ 

Consumpt~, ~ Cl~n~c~ ~n~ngs 

Mean body weights of males and females in the 

5,000 ppm groups were generally lower than those of 

the controls from week 13 until the end of the study 

(Figure 4 and Tables 16 and 17). Feed consumption 

by exposed groups of males and females was 

T~L~ 15 

generally, similar to that by controls (Tables J3 and 

J4). Dietary levels of 1,250, 2,500, or 5,000 ppm 

t-butylhydroquinone resulted in daily doses of 

approximately 150, 300, or 600 mg/kg body weight 

(males) or 150, 300, or 700 mg/kg (females). There 

were no clinical findings in exposed groups of male or 

female mice considered to be related to chemical 

exposure. 

~'em~.~olo~3, 

The reticulocyte count in males in the 5,000 ppm 

group was greater than that in the control group 

(Table G3). There were no other biologically 

significant differences in hematology parameters 

between control and exposed groups of mice. 

Surv~v~fl ot Mice ~n ~the 2-~fe~r ~eed ~udy ot t-~u~ylhydlr~t~qu~one 

0 ppn~ 1,~0 ppn~ 2,~I~ ppn~ 5,~ ppm 

Male 

Animals initially in study 

15-Month interim evaluation a 

Accidental death a 

Moribund 

Natural deaths 

Animals surviving to study termination 

Percent probability of survival at the end of the study b 

Mean survival (days) c 

Survival anaiysis d 

Female 

Animals initially in study 

15-Month interim evaluation a 

Moribund 

Natural deaths 

Animals surviving to study termination 

Percent probability of survival at the end of the study 

Mean survival (days) 

Survival analysis 

a Censored from survival analyses 

b Kaplan-Meier determinations 

60 60 60 60 

10 I0 9 9 

1 0 0 0 

6 3 7 7 

4 1 6 2 

39 46 38 42 

80 92 75 82 

711 721 700 701 

P=0.780 P=0.143N P = 0.(~t4 P= 1.0~0N 

60 60 60 60 

9 8 9 6 

11 7 6 6 

2 10 5 5 

38 e 35 40 43 e 

75 67 78 80 

699 689 706 695 

P=0.348N Pffi0.571 Pffi0.767N Pffi0.663N 

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

d 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 the controls are in the exposed columns. A negative trend or a lower mortality in an exposure group is indicated by i~l. 

e Includes one animal that died during the last week of the study 
52 t-Butylhydroquinone~ NTP TR 459 

1.0 

0.9 

0 0.8-

0 

MALE MICE 

0.7 ..... I 

• 

O 

0 ppm 

i,250 ppm 

~ 2,500 ppm 

[] S,000 ppm 

11.6 • 

i 

18 

• 

i 

50 45 60 78 ~0 lOft 120 

WEEKS ON STUDY 

1.0, 

0.9, 

O 0.8- ] ................. 

~ -, 

O 

FEMALE MICE 0.7- m 0ppm 

O 1,250 ppm 

~ 2,500 ppm 

[] 5,000 ppm 

0 ,'~ ~'o 45 6o 78 ,o ,08 ,20 

WEEKS ON STUDY, 

FIGURE 3 

KaplanoMeier Survival Curves for Male and Female Mice Adm|n|stered t-Butylhydroquinone 

in Feed for 2 Years ..... 
- -

t-~u~ylhydroquinone, NTP T~ 459 53 

60 ~, ~ ! 

! : :

: 

ss ........................................................ ~ ..................................... ~ ................. i ..................................... 

• i ~ ~ ~ a ~ -nno ~ 130 . ~ :: :DO 

~ ~0 ................... ~............ ~.....~ ................. !...o..~..~..~..~..~..~.i~..~..~..~..R.~..~...~ .................. 

• =~ ~ • ~ n~oOboOO~°°oO°o~ ~ 

= ..................~ ............... ~..o..o..a...~...~ ............ ~.................. ~................. ~.................. ~.................. o ~. " ~ ~a ~ s ~ ~ ~ g • 

~~ ~, ~ _ ~ ~.~ o ~..i............... ~... ~................. ~.................. ~................ 

e ~ u ~. ~ ........................... 

~ ~5 ............... ~ ............... ; ................. ~.................. ~.................. ~.................. :.................. .:.................. 

~ ~ ~ • . ................ ............................................................................................................. 

~ ~ ~ ~ ~ ~ ~ 

~ ~. ~ ............. ~.................. i ................. i .................. ~.................. i ......... ~ ~m .... 

~ ~ ~ ~ ~ 0 t,250ppm 

~ ; :: :: ~ ~ 2,500 ppm 

~0. 0 5,O00ppm 

~5 ~ ~ ; , 0 t5 ". 30 ~ 60 75 9 105 - 120 

WEEKSON STUDY 

60. ~ i i 

! : O0 : ! 0 : 0 

~ ................... : .................. : ................. : .................. ~ .............. ~;~~~.~..~..~--rg-~ ................. 

i i i ~t~ui i -=~ 

~0 ................... , .................. ~................. .!~~~~o ............ ~.~..~..o.~..o.~-.~-..~ ................. 

~ : 

0 ~ ........................ ..... .......... ~.................. ;....~ ....... o.p.~..~ .............................................................. ~ ~ ~ ~ Z , ;. ~ ; ~ ~ 

~ .................. ~............... ~..~..~ ........ ~.................. ~.................. ~.................. ~.................. ~.................. 

0 

la,.I • ~ ~ o~ ~ ~ ~ • ~ ~ ~ ~ ~ ~ ~ 

~s~ .................. ;~ ...... ~ .................. ;.................. ~.................. ~................. ~.................. ~.................. p -

0 / O:~ 

:: Z 

~E .... ;/ ....... ~.................. ~................. ~.................. ~.................. ~......... ~ ~.~s,.~ ...... 

zo ~ ........... :: :: ~ ~ :: A 2,500 ppm 

~ 5,000 ppm 

15 :~ ~ 

0 1 ~ 50 ~ 60 75 90 1~ 120 

WEEKS ON STUDY 

]~'~GUgE 4 

Growth Carves for 1V~ale and Ferule l~ice Administered t-Buty~ydroquinone 

~ Feed for 2 Years 
.~4 tTButylhydroquinone , NTP TR 459 

TABLE 16 

Mean Body Weights and Survival of Male Mice in the 2-Year Feed Study of t-Butylhydroquinone 

Weeks 0 uum 1.250 uum 2.500 umn 5.000 uum 

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 23.7 23.5 99 

2 25.4 25.3 100 

3 26.7 26.3 99 

5 28.4 28.0 99 

6 30.0 29.6 99 

7 31.1 30.7 99 

8 31.3 31.0 99 

9 32.3 32.1 99 

10 33.1 32.9 99 

11 34.2 33.6 98 

12 35.4 34.2 97. 

13 36.6 35.6 97 

17 38.8 38.3 99 

21 39.4 39.6 101 

25 41.9 41.3 99 

29 44.4 43.3 98 

33 44.9 44.4 99 

37 45.0 43.9 98 

41 46.1 44.9. 97 

45 48.1 46.5 97 

49 49.7 48.8 98 

53 50.8 49.3 97 

57 51.1 6O .50.0 98 

61 51.5 6O 50.1 97 

65 51.5 6O 49.8 97 

69 a 51.9 50 49.9 96 

73 51.8 50 • 49.8 96 

77 52.7 50 51.0 97 

81 52.6 49 51.0 97 

85 52.4 49 50.8 97 

89 52.6 47 50.5 96 

93 ~ 51.4 46 50.0 97 

97 51.4 43 49.6 97 

I01 49.9 41 48.2' 97 

• . 

Mean for weeks 

1-13 30.7 30.2 98 

14-52 44.3 43.4 98 

53-101 51.7 50.0 97 

60 23.4 99 6O 23.0 97 

60 25.3 100 60 24.7 97 

60 26.3 99 6O 25.8 97 

60 28.2 99 6O 27.5 97 

60 29.7 99 6O 29.2 97 

60 30.3 97 6O 29.8 96 

60 30.7 98 6O 30.0 96 

60 31.7 98 6O 30.5 94 

60 32.8 99 6O 30.8 93 

60 33.4 98 6O 31.9 93 

60 34.5 98 - 6O 32.8 93 

60 35.2 96 6O 33.4 91 

60 38.0 98 6O 35.4 91 

60 39.2 100 6O 36.7 93 

60 40.9 98 6O 38.3 91 

60 43.1 97 6O 40.2 91 59 

60 44.2 98 6O 40.9 91 59 

60 43.6 97 6O 40.6 9O 59 

60 45.0 98 • 6O 41.2 89 59 

60 46.5 97. 6O 43.4 9O 59 

60 48.6 98 6O 45~8 92 59 

60 49.2 97 6O 46.3 91 59 

60 49.8 98. 6O 47.5 93 59 

60 49.6 96 59 47.3 92 59 

60 49.2 96 59 46.9 91 59 

50 49.7 96. 50 47.4 91 50 

50 49.8 96 50 47.6 92 50 

50 50.3 95. 49 48.4 92 50 

50 50.2 95 47 48.1 91 50 

50 50.5 96 ,, 47 47.4 91 49 

49 50.3 96 46 47.8 91 46 

48 49.1 96: 46 48.0 93 44 

47 49.4 96 41 47.3 92 44 

47 49.4 99 40 47.8 96 42 

30.1 98 29.1 95 

43.2 98 40.3 91 

49.7 96 47.5 92 

a Interim evaluation occurred during week 66. ~ 
t-~n~hy~ro~u~none, HT~ T~ ,~ $$ 

T~L~ 17 

Mean ~y We~gh~ ~n~ Snr~,~Vei o~' Fen~e I~,~ice in ~he 2-~e~r Fee~:l S~n~y o~' t~l~n~ylhy~ro~.~nino~e 

Weeks 0 ~pm L~ . ~.5~ qpm 5.~0 e.~m 

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 17.7 60 17.9 101 60 17.8 101 6O 17.8 101 (60 

2 20.1 60 20.4 102 60 20.2 101 60 20.1 100 6O 

3 21.5 60 21.6 101 60 21.3 " 99 6O 20.9 97 60 

4 22.8 60 23.1 101 60 22.9 100 6O 22.6 99 6O 

5 24.0 60 24.1 100 60 23.9 100 6O 23.7 99 6O 

6 24.9 60 25.2 101 60 25.0 100 6O 24.5 98 6O 

7 26.0 60 26.3 101 : 60 26.2 101 6O 25.2 97 6O 

8 27.4 (60 27.7 101 60 27.4 100 (60 26.1 95 6O 

9 27.9 60 27.9 100 60 27.5 99 6O 26.6 95 6O 

10 28.3 60 28.5 101 (60 28.0 99 6O 26.7 94. 6O 

11 28.9 60 29.3 101 60 28.8 1~0 6O 27.5 95 60 

12 30.3 60 30.5 101 60 30.0 99 6O 28.3 93 60 

13 30.9 60 30.9 100 60 30.3 98 6O 28.7 93 59 

17 33.9 60 34.9 103 60 34.1 101 6O 31.8 94 59 

21 36.0 60 36.2 101 60 35.6 99 6O 33.6 93 59 

25 " 37.1 60 37.1 100 60 ~35.6 96 6O 32.8 88 59 

29 38.5 60 39.2 102 60 38.0 99 60 35.1 91 59 

33 39.9 60 40.8 102 60 39.8 100 (60 36.7 92 59 

37 39.9 60 40.8 102 60 39.9 100 6O 36.5 92 59 

41 41.5 60 42.1 101 60 41.2 99 60 37.7 91 59 

45 43.2 60 44.3 103 60 43.4 101 59 39.0 90 58 

49 46.4 60 47.6 103 60 46.5 100 59 41.9 90 58 

53 48.5 59 49.5 102 59 48.7 • 100 59 43.5 90 58 

57 50.2 59 51.4 102 59 50.5 I01 59 44.9 89 58 

61 51.3 59 52.9 103 58 51.6 101 59 45.6 89 57 

65 52.3 59 53.2 102 58 51.9 99 59 46.6 89 56 

69 a 52.6 49 53.7 102 49 52.7 100 49 46.8 89 5O 

73 53.9 49 55.4 103 47 54.3 101 49 47.9 89 50 

77 55.4 49 56.0 101 47 54.9 99 49 48.3 87 5O 

81 55.5 48 56.8 102 46 55.1 99 47 49.0 88 49 

85 56.2 46 56.9 101 46 55.7 99 47 49.6 88 49 

89 56.0 44 57.8 103 44 55.5 99 46 49.7 89 49 

93 56.1 42 57.9 103 42 55.7 99 46 49.6 88 48 

97 55.1 40 57.0 103 40 54.7 99 44 49.0 89 48 

101 54.5 39 55.8 102 39 54.2 99 43 48.6 89 47 

Mean for weeks 

1-13 25.4 25.6 101 25.3 100 24.5 96 

14-52 39.6 40.3 102 39.3 99 36.1 91 

53-101 53.7 54.9 102 53.5 100 47.6 89 

a Interim evaluation occurred during week 66. 
" 56 

Pathology and Statistical Analyses 

This section describes'the statistically significant or 

biologically noteworthy changes in the incidences of 

neoplasms and/or nonneoplastic lesions .of the liver 

and thyroid gland. Summaries of. the incidences of 

neoplasms 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 animal group, and historical inci: 

dences for the neoplasms mentioned in this section are 

presented in Appendix C for male mice and 

Appendix D for female mice. • 

Liver: The absolute liver weights of all exposed 

groups of males were greater than that of the controls 

(Table F4), although the differences were not statistically significant. Absolute liver weigh~ of exposed 

groups of females were similar to that of the controls. 

The incidences of hepatocellular adenoma and hepatocellular adenoma or carcinoma (combined) in females 

administered 1,250 ppm were significantly greater , 

than those in the control group (Tables 18 and D3), 

although the incidence of hepatocellular neoplasms 

occurred with a significant negative trend. Incidences 

of hepatocellular neoplasms in exposed groups of 

males generally decreased with increasing exposure 

concentration (Tables 18 and C3). The incidences of 

hepatocellular adenoma or carcinoma (cOmbined) in 

control and exposed groups of males and females 

t-Butylhydroquin0ne, NTPTR459 

were within the historical control range for. mice from 

NTP 2-year feed 'studies (males, 10%-68~;.females, 

3%-56%; Tables 18, C4a; and D4a). Incidences of 

nonneoplasfic lesions of the liver observed in exposed. 

groups of.males and ..females were siniilar to the 

incidences observed in the control groups (Tables 18, 

C5 and D5). There is a high rate of spontaneously 

occurring liver neoplasms ~ in ~mice (particularly in 

males), and a positive correlation with body weights 

has been demonstrated (Seilkop, 1995). 

Thyroid gland: The incidences of follicular cell 

adenoma in exposed groups of females were greater 

than that in the controls (0 ppm; 1/51; 1~250 ppm, 

,3/51; 2,500 ppm, 2/50; 5,000 ppm, 5/54;. Table D3); 

however, the differences were not Statistically significant, and the incidences did not exceed the historical 

control range for 2-year NTP feed studies (0 % to 9 %; 

Table D4b)., Incidences of follicular cell hyperplasia 

in exposed groups of females were greater than those 

in controls at the end of the 2-y~hr study (12/51, 

19/51, 24/50, 24/54; Table D5), although, the 

severity of the hyperplasia in exposed groups was 

similar to that in the controls. This lesion was not 

observed at the 15-month interim e~,aluation. 

Additionally, significant increases of thyroid follicular 

cell proliferative lesions did not Occur in female mice 

at the end of the 2-year study. Therefore, these 

marginal increases were not considered related to 

t-butylhydroquin.0ne exposure. 
¢-~u~ylhy~ro~none, NTI~ T~ ~ ~7 

. 

h~c~ences o~ Hepatocd~r Neop~ fin I~fice ~n the 2-Year Feed Stn~y o~,S-~tyihy~ro~h~one 

0 ppm L2~O p~m 2,~]~ ~pm $,OOO ppm 

Mane 

~5-Month ~nterhn Ewlu~fion 

Adenoma 

Overall rate a 1/10 (10%) 1/10 (10%) : 1/9 (I1%) 0/9 (0%) 

Carcinoma 

Overall rate 0/10 (0%) .0/10 (0%) 0/9 (0%) 1/9 (11%) 

2-Year Study. 

Number Examined Microscopically 50 50 51 51 

Basophilic Focus b 3 2 2 5 

Clear Cell Focus 6 7 7 4 

Eosinophilic Focus 8 5 5 4 

Mixed Cell Focus 5 8 4 7 

Adenoma 

Overall rate 28/50 (56%) 22/50 (44%) 22/51 (43%) 14/51 (27%) 

Adjusted rate c 60.6% 47.8% 53.2% 31.7% 

Terminal rate d 21/39 (54%) 22/46 (48%) 19/38 (50%) 12/42 (29%) 

First incidence (days) 595 727 (T) 409 630 

Logistic regression test e P--0.004N P=0.144N' P =0.147N P=0.004N 

Carcinoma 

Overall rate 8/50 (16%) 11/50 (22%) 12/51 (24%) 8/51 (16%) 

Adjusted rate 19.1% 22.8% 26.0% 17.6% 

Terminal rate 6/39 (15%) 9/46 (20%) 6/38 (16%) 5/42 (12%) 

First incidence (days) 619 619 409 615 

Logistic regression test P=0.370N Pffi0.248 P=0.342 P=0.585N 

Adenoma or Carcinoma f 

Overall rate 31/50 (62%) ,28/50 (56%) 29/51 (57%) 17/51 (33%) 

Adjusted rate 65.8% 58.3% 63.8% 37.7% 

Terminal rate 23/39 (59%) 26/46 (57%) 22/38 (58%) 14/42 (33%) 

First incidence (days) 595 619 409 615 

Logistic regression test P--0.002N P=0.369N Pffi0.341N P--0.004N 

(continued) 
58 

c 

t-But~lhydroquinone, NIT TR 459 

TABLE 18 ' ~ " 

Incidences of Hepatocellular Neoplasms in Mice in the 2-Year Feed Study of t-Butylhydroquinone (continued) 

Female 

l$-Month Interim Evaluation 

Adenoma 

Overall rate 

Carcinoma 

Overall rate 

2-Year Study 

Number Examined Microscopically 

Basophilic Focus 

Clear Cell Focus 

Eosinophilic Focus 

Mixed Cell Focus 

Adenoma 

Overall rate 

Adjusted rate 

Terminal rate 

First incidence (days) . 

Logistic regression test 

Carcinoma 

Overall rate 

Adjusted rate 

Terminal rate 

First incidence (days) 

Logistic regression test 

Adenoma or Carcinoma g 

Overall rate 

Adjusted rate 

Terminal rate 

First incidence (days) 

Logistic regression test 

(T) Terminal sacrifice 

0 ppm 1,250 ppm 

0/9 (0%) 0/8 (0%). 

0/9 (0%) 1/8 (13%) 

• 

51 52 

2 1 

0 0 

7 14 

1 3 

9/51 (18%) 20/52 (38%) 

22.7% 51.0% 

8/38 (21%) 16/35 (46%) 

582 598 

P=0.027N P=0.011 

8/51 (16%) 8/52 (15%) 

18.4% 19.2% 

4/38 (I 1%) 4/35 (I 1%) 

461 469 

Pffi0.357N Pf0,559N 

17/51 (33%) 28/52 (54%) 

38.9% 64.7% 

12/38 (32%) 20/35 (57%) 

461 469 

Pffi0.010N P =0.025 

.2,500 ppm ' 

: 

I/9 (11%) 

0/9 (0%) , 

51 

1 

2 

I0 ~ 

2 

16/51 (31%) 

37.1% 

13/40 (33%) 

555 

P=0.096 

8151 (16%) 

17.6% 

4/40 (10%) 

548 

P=0.592 

23/51 (45%) 

48.8% 

16/40 (40%) 

548 

Pffi0.155 

5,000 ppm 

0/6 (0%) 

0/6 (0%) 

, . 

54 

2 

12 

1 

5/54 (9%) 

11.6% 

5/43 (12%) 

734 (T) 

Pffi0.146N 

5154 (9%) 

11.6% 

5/43 (12%) 

734 (T) 

Pffi0.240N 

10/54 (19%) 

23.3% 

10/43 (23%) 

734 (T) 

P--0.064N 

a Number of animals with neoplasm per number of animals with liver examined microscopically 

b Number of animals with lesion 

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 exposure group columns are the P values corresponding to 

pairwise comparisons between the controls and that exposure group. The logistic regression test regards lesions in animals dying prior to 

terminal kill as nonfatal. A negative trend or a lower incidence in an exposure group is indicated by N. 

f Historical incidence for 2-year NTP feed studies with untreated control groups (mean ± standard deviation): 509/1,316 

(38.7% ± 13.9%); range, 10%-68% 

g Historical incidence: 260/1,312 (19.8% ± 12.8%); range, 3%-56% 
t-l~uty~hydroquinorae, ~ T~ 4~9 

C.~ENII~T~C ~OX~ICOLOG~ 

t-Butylhydroquinone (3 to 3,333 #g/plate) was tested 

for induction of mutations in Salmonella typhiraurium 

strains TA97, TA98, TA100, and TA102 with and 

without induced rat or hamster liver $9 (Zeiger et al., 

1992; Table El). No mutagenicity was detected in 

any of the strain/activation combinations. No induction of sister chromatid exchanges (Table E2) or 

chromosomal aberrations (Table E3) was noted in 

cultured Chinese hamster ovary cells treated with 

t-butylhydroquinone in the absence of $9 activation. 

However, in the presence of $9, positive dose-related 

responses were obtained in both these in vitro cytogenetic assays. The response obtained in the chromosomal aberrations test was particularly strong, and up 

to 90% of treated ceils showed multiple chromosomal 

$9 

aberrations at the higher doses (200 to 249 pg/mL). 

These positive results in cultured Chinese hamster 

ovary cells may have resulted from the generation of 

superoxide and H202 within the cell from the autooxidation of t-butylhydroquinone to t-butylquinone 

and the further generation of oxidative byproducts, 

thereby indirectly producing chromosome breakage 

(Phillips et al., 1989). In contrast to the positive 

results obtained in the in vitro assays for .chromosome 

damage, results of an in vivo bone marrow micronucleus test were clearly negative (Table E4). No 

significant increase in the number of micronucleated 

erythrocytes was observed in male mice treated with 

three intrapedtoneal injections of up to 300 mg 

t-butylhydroquinone/kg body weight. 
60 t-Butylhydroquinone, NTP TR 459 
~ 6~ 

AND C©MCLU$ ©M$ 

t-Butylhydroquinone, a white to light tan crystalline 

solid, is primarily used as an antioxidant in fats, oils, 

and foods containing high fat concentrations, and in a 

large number of cosmetic preparations (CIR, 1986). 

t-Butylhydroquinone was nominated for toxicity and 

carcinogenicity testing by the Food and Drug 

Administration because of the potential for its increased use, its structural relationship to carcinogenic 

chemicals such as hydroquinone, butylated hydroxytoluene, and butylated hydroxyanisole, and because of 

the lack of adequate t-butylhydroquinone carcinogenicity studies. Toxicology and carcinogenicity 

studies were conducted in F344/N rats and B6C3F~ 

mice. Mice were exposed to the chemical in the feed 

for 13 weeks or 2 years. In the 13-week and longterm rat studies, dams were exposed to t-butylhydroquinone in feed beginning 2 weeks prior to 

cohabitation through weaning. Following weaning, 

pups selected for study were given dosed feed for 

13 weeks or for 127 weeks (males) or 133 weeks 

(females). The oral route of administration was used 

because human exposure to the food additive occurs 

predominantly via this route. In addition, perinatal 

exposure was studied because butylated hydroxytoluene (a structurally related chemical) induced 

hepatocellular neoplasms in rats exposed in this 

manner. 

Three chemicals structurally related to t-butylhydroquinone (hydroquinone, butylated hydroxytoluene, 

and butylated hydroxyanisole) were found to be 

carcinogenic to rats and/or mice. Hydroquinone (25 

or 50 mg/kg body weight) given by gavage for 

2 years was carcinogenic to F344 rats, causing 

increased incidences of renal tubule cell adenomas in 

males and mononuclear cell leukemia in females. 

Hydroquinone (50 or 100 mg/kg) administered 

similarly was carcinogenic to female mice, causing an 

increased incidence of hepatocellular neoplasms (Kari 

et al., 1992). Butylated hydroxytoluene administered 

in feed for up to 2 years at concentrations up to 

10,000 ppm was not carcinogenic to rats and mice 

(NCI, 1979; Hirose et al., 1981; Shirai et al., 1982). 

However, in utero exposure to butylated hydroxytoluene induced hepatocellular neoplasms in rats 

(Olsen et al., 1983). Feeding butylated hydroxyanisole to male F344 rats at a concentration of 2 % for 

13 weeks caused proliferation of the forestomach 

epithelium, which was a reversible effect following 

removal of the chemical from their diet (Iverson, 

et al., 1985). Butylated hydroxyanisole administered 

in feed at concentrations of up to 2 % for 2 years 

caused an increase in the incidence of squamous cell 

carcinoma of the forestomach in male and female 

F344 rats (Ito et al., 1982). 

Exposure concentrations greater than 10,000 ppm 

were not used in the 13-week rat study because dams 

exposed to 20,000 or 40,000 ppm did not litter. The 

inability to litter was likely due to lower mean body 

weights of the dams. Additionally, the average 

number of surviving pups per litter was less in dams 

exposed to 10,000 ppm than in control dams, and 

pups born to dams exposed to 5,000 or 10,000 ppm 

had lower mean body weights than pups born to 

control dams. These results were similar to those 

observed in an earlier reproductive study that examined three generations of Sprague-Dawley rats 

exposed to 5,000 ppm t-butylhydroquinone in feed 

(Terhaar and Krasavage, 1968b; Krasavage and 

Terhaar, 1970; Krasavage, 1977). There was a slight 

increase in pup mortality and a decrease in feed 

consumption, with a subsequent decrease in the pup 

body weight. 

All male and female F~ rats exposed to 0, 2,500, 

5,000, or 10,000 ppm t-butylhydroquinone in feed for 

13 weeks survived to the end of the study. Decreased 

feed consumption might account for lower mean body 

weight gains of male rats exposed to 10,000 ppm and 

lower final mean body weights of F~ male and female 

rats exposed to 5,000 or 10,000 ppm. As in the 

present 13-week study, Astill et al. (1975) reported 

that 10,000 ppm t-butylhydroquinone given to rats for 

22 days caused a decrease in mean body weights, but 

had no effect on survival. 
62 

At various time points there were increases in serum 

bile acid levels and serum alanine aminotransferase 

activity levels in male and female rats exposed to 

t-butylhydroquinone. Such increases are generally 

associated with liver toxicity. However, because the 

increases observed in these two parameters were 

marginal, and since histopathologic evaluation did not 

reveal any evidence of liver toxicity, these marginal 

increases were not considered to be biologically 

significant. No biologically significant changes in 

clinical chemistry parameters were. observed in 

Sprague-Dawley rats exposed.to 10,000 ppm t-butylhydroquinone in feed for 3 weeks or to 5,000 ppm 

t-butylhydroquinone in feed for 20 months (Terhaar 

and Krasavage, 1968a; Astill et al., 1975). 

The effect of t-butylhydroquinone on reproductive 

parameters in rats included significantly lower mean 

spermatid counts, spermatid heads, per testis, and 

spermatid heads per gram of testis only in males 

exposed to .5,000 ppm (the mid-dose). The estrous 

cycles of females exposed to 2,500 or 5,000 ppm 

were significantly longer than that of the control. The 

number of females with estrous cycles that were of 

unclear duration or were longer than 12 days was 

increased in the 10,000 ppm group. Together, these 

data suggest that t-butylhydroquinone has an as yet 

undefined effect on the female reproductive system. 

Histopathologic changes observed in rats exposed to 

5,000 or 10,000 ppm t-butylhydroquinone in the 

13-week study included increased incidences of nasal 

• respiratory epithelial hyperplasia, nasal exudate 

(males only), splenic pigmentation, splenic atrophy of 

the red pulp (females only), and kidney mineralization 

(females only). Since there was no other evidence of 

anemia, the cause for the observed splenic changes is 

not clear~ In previous studies, the noses of rats exposed to 5,000 ppm t-butylhydroquinone for as long 

as 20 months were not examined (Astill et al., 1975). 

However, the authors did examine the spleen and 

bone marrow in addition to other organs and did not 

find any chemical-related changes. Administration of 

hydroquinone (50 mg/kg body weight per day, 5 days 

per week, for 13 weeks) caused a regenerative anemia 

and myelotoxicity in female rats (NTP, 1989). 

Hydroquinone caused a decrease in hematocrit levels, 

hemoglobin concentrations, and erythrocyte counts. 

t-Butylhydroquinone,NTP TR459 

In the 13-week mouse study, there were no chemicalrelated deaths. Although feed consumption data 

indicate that consumption by exposed groups Was 

similar to that by control male and female mice, 

excessive scatter of feed by mice in the 10,000, 

20,000, and 40,000 ppm groups was observed. This 

in turn may have contributed to the lower mean body 

weights of mice in these exposure groups. .; 

The effect of t-butylhydroquinone on reproductive 

parameters in mice included generally lower caudal, 

epididymis, and testis weights in males exposed to 

10,000 or 40,000 ppm than in controls. The estrous 

cycle of female mice exposed to 40,000 ppm was 

significantly longer than that of the controls. Reproductive organ weight and estrous cycle data were 

different only in exposure groups that had corresponding significantly lower mean body weights. Based on 

previous studies (Chapin et al., 1993), the body 

weight differences can account for these reproductive 

effects. This is also supported by the lack of differenee in sperrnatogenesis efficiency. .. 

Chemical-related histopathologic effects were gener: 

ally observed in the nose and skin (inflammation) and 

the forestomach (hyperplasia ofmucosal epitheliums 

of 10,000, 20,000, and 40,000 ppm mice. The 

effects were attributed to the direct irritating action of 

t-butylhydroquinone on these tissues. Increased 

segmented neutrophflcounts in these exposure groups 

may have been a response to these inflammatory 

effects. Proliferative forestomach lesions have not 

been reported in other studies of t-butylhydroquinone 

in mice. However, proliferative forestomach lesions 

have been reported in mice exposed to hydroquinone 

and rats exposed to t-butylhydroquinone and butylated 

hydr0xyanisole. Epithelial hyperplasia of the fore~- 

stomach occurred in mice dosed with 400 mg hydroquinone/kg body weight per day, 5 days per week for 

13 weeks (NTP, 1989). Hyperplasia of.the forestomach was reported in male F344 rats exposed to 

2,000 ppm butylated hydroxyanisole (a structurally 

related chemical) in feed for 13 weeks (Iverson et al., 

1985) and Fischer rats exposed to 1,000 ppm t-butyl: 

hydroquinone in feed for 28 days (Nera et aL, 1984). 

Similar lesions were observed in Wistar rats exposed 

to 2,000 ppm t-butylhydroquinone in feed for 28 days 

(Altmann et al., 1985). . 

.,. 
t-~u~ylhy~roquinone, NTP T~ 459 ~3 

Although hyperplasia of the pulmonary pneumocytes 

was observed in mice treated with butylated hydroxytoluene (a structurally related chemical) (Marino and 

Mitchell, 1972; Witschi and Saheb, 1974; Saheb and 

Witschi, 1975), no chemical-related lesions were 

observed in the lungs of rats or mice in the present 

13-week studies. Mizutani et al. (1982) have demonstrated the possibility that phenolic antioxidants can 

only exert toxic effects if the hydroxyl group of the 

antioxidants is hindered by a methyl group at the 

4-position and an ortho-alkyl group on the phenolic 

ring. Since t-butylhydroquinone does not have the 

methyl group at the 4-position, it would not be expected to undergo metabolic transformation to an active 

lung toxicant, which may explain the lack of lung 

lesions in the present studies. 

Based on lower final mean body weights, increased 

incidences of inflammation of the nose. and skin, 

increased incidences of forestomach epithelial hyperplasia, and increased severity of nonneoplastic lesions 

observed in mice exposed to 10,000, 20,000, or 

40,000 ppm, the exposure concentrations selected for 

the 2-year mouse study were 1,250, 2,500,. and 

5,000 ppm. 

In the long-term (rats) and 2-year (mice) studies, rats 

and mice were exposed to 1,250, 2,500, or 

5,000 ppm t-butylhydroquinone in feed. Based on the 

lower mean body weights in male and female rats and 

mice exposed to 5,000 ppm and on the presence of 

chemical-related kidney lesions in rats, the doses 

selected for the long-term and 2-year studies were 

considered adequate for evaluating the carcinogenic 

potential, of t-butylhydroquinone. 

In the long-term rat study, t-butylhydroquinone was 

not carcinogenic to male or female rats exposed to 

1,250, 2,500, or 5,000 ppm in feed, as evidenced by 

the absence of chemical-related increased neoplasm 

incidences at any site. However, the incidence of 

mammary gland neoplasms in exposed groups.of male 

and female rats and of pituitary gland neoplasms in 

exposed groups of males were decreased. The 

decreased incidences of these neoplasms may be 

related to mean body weight decreases of exposed 

groups of rats. This observation is supported by 

Seilkop (1995), who found positive relationships 

between body weight and pituitary gland neoplasms in 

male and female rats and mammary gland neoplasms 

in female rats. 

Nonneoplastic lesions observed in male rats exposed 

to t-butylhydroquinone included increased incidences 

of cysts and suppurative inflammation in the kidney. 

These increased incidences in rats were probably 

related to t-butylhydroquinone exposure. Hydroquinone was nephrotoxic to rats administered 25 or 

50 mg/kg body weight for up to 2 years; the chemical 

caused increased severities of nonneoplastic renal 

lesions in males and females and increased incidences 

of nonneoplastic cortical lesions in males (Kari et al., 

1992). 

Mild regenerative anemia was observed in female rats 

administered 50 mg hydroquinone/kg body weight per 

day, 5 days per week for as long as 2 years. This 

anemia was characterized by decreases in hematocrit 

levels, hemoglobin concentrations, and erythrocyte 

counts (Kari, et al., 1992). 

In the 2-year mouse study, t-butylhydroquinone did 

not cause carcinogenic effects in male or female mice 

exposed to 1,250, 2,500, or 5,000 ppm, nor did the 

chemical cause increased incidences of nonneoplastic 

lesions. 

CONCLUSIONS 

Under the conditions of this long-term feed study, 

there was no evidence of carcinogenic activity* of 

t-butylhydroquinone in male or female F344/N rats 

exposed to 1,250, 2,500, or 5,000 ppm. Under the 

conditions of this 2-year feed study, there was no 

evidence of carcinogenic activity of t-butylhydroquinone in male or female B6C3F~ mice exposed to 

1,250, 2,500, or 5,000 ppm. 

Exposure of rats to t-butylhydroquinone in feed 

resulted in decreased incidences of mammary gland 

neoplasms in males and females. 

~ Explanation of Levels of Evidence of Carcinogenic Activity is on page 9. A summary of the Technical Reports Review Subcommittee 

comments and the public discussion on this Technical Report appears on page I 1. 
64 " " t-Butylhydroquinone, NTP TR 459 
]I dE]XE]X I C]E5 

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t-Butylhydroquinone, NT~ T~ 459 69 

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TABLE A1 

TABLE ~ 

TABLE A3 

TABLE A4 

....... ~s~4~- ~;.~.-~ -~.~ ::~ . . . . . . . . . . . > ........ ~-~_ .................. 

7~ 

I 

A]~]S~X~ A 

5UX[b~I~,,A11~,.~O~ ~5~©tq'5 ]ZX ~A~ ~,.A%5 

~X T]~...~ ~©XG,.=T~:IX.I~,,'~I: ]F'1S~B 5T~J]]~" 

', O~ ~B~TY~IY~O@I.,JIIHOIW~..~ 

Sa~nmary of the ~nc~ence o~ Heop~sms ~a ~a~e ~ats 

~n the ~ng-Te~ Feed Ste~y o~ t-~ety~y~ro~u~none ........................ 

~vi~a~ A~a~ ~or ~at~oHo~ o~ ~a~e ~a~ 

~n the ~ag-Te~ ~ee~ Stagy o~ ~-~ty~y~ro~a~ne ........................ 

Stat~t~ca~ Analysis of ~a~ Neop~m~s in ~a~e ~a~ 

~n the ~ng-Te~ ~ee~ Stagy of t-~aty~y~ro~u~none ........................ 

S~a~ o~ t~e ~nc~ence o~ Nonn~p~t~c L~o~ ~ ~e ~a~ 

~n the ~ong-~e~ ~e~ Study o~ t-~aty~y~o~a~aoa~ .................... ~... 

72 

77 

I~3 

~2~ 

I 

i~ 

! 
72 t-Butylhydroquinone, NTP TR 459 

TABLE A1 

Summary of the Incidence of Neoplasms in Male Rats in the Long-Term Feed Study of t-Butylhydroquinone a 

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

I , 

Disposition Summary 

Anhnals initially in study 

3-Month interim evaluation 

Early deaths 

Moribund 

Natural deaths 

Survivors 

Terminal sacrifice 

Missexed 

70 

10 

48 

4 

8 

0 

70 

10 

51 

2 

,7 

0 

70 

10 

50 

7 

1 

2 

70 

10 

42 

4 

14 

0 

Animals examined microscopically 70 70 68 70 

Systems Examined At 3 Months With No Neoplasms Observed 

Alimentary System 

Cardiovascular System 

Endocrine System 

General Body System 

Genital System 

Hematopoietic System 

Integumentary System 

Musculoskeletal System 

Nervous System 

Respiratory System 

Special Senses System 

Urinary System 

Long-Term Study 

Alimentary System 

Intestine large, colon 

Leiomyosarcoma 

Intestine large, rectum 

Carcinoma 

Intestine large, cecum 

Intestine small, duodenum 

Intestine small, jejunum 

Carcinoma 

Intestine small, ileum 

Leiomyoma 

Liyer 

Hepatocellular carcinoma 

Hepatocellular adenoma 

Histiocytic sarcoma 

Lciomyosarcoma, metastatic, intestine large, 

colon 

Osteosarcoma, metastatic, mesentery 

, 

(58) (58) (58) (60) 

1 (2%) -. 

(59) (6o) (58) 

1 (2%) 

(59) 

(~O) 

(~O) 

(~) 

(58) 

(60) 

(60) 

(58) 

(58) 

(57) 

(6o) 

(6o) 

(60) 

i (2~) 

(~O) (59) (58) (59) 

(~) 

1 (2~) 

(60) (58) (6o) 

2 (3%) 

4 (7%) 4 (7%) 3 C5%) 

1 (2%) 

I (2~) 

.1 (2%) 
l 

_ . . . . . - - ...... .~ ~: ~,--~ -~ ~ .... ~r ............................... ~ 

t-~u~:ynhydroquinone, NT~ T~ ~ 73 

TABLE A~ 

gu~nm~ry of the ~Inc~ence o? Heo#~s~s 

Long- Term Study (continued) 

Alimentary System (cominued) 

Mesentery 

Histiocytic sarcoma 

Leiomyosarcoma, metastatic, intestine large, 

colon 

Osteosarcoma 

Schwannoma malignant 

Oral mucosa 

Squamous cell carcinoma 

Squamous cell papilloma 

Pancreas 

Leiomyosarcoma, metastatic, intestine large, 

colon 

Acinus, adenoma 

Salivary glands 

Carcinoma 

Fibrosarcoma, metastatic, skin 

Stomach, forestomach 

Squamous cell papilloma 

Stomach, glandular 

Tongue 

Squamous cell carcinoma 

Squamous cell papilloma 

Tooth 

Odontoma 

Cardiovascular System 

Heart 

Schwannoma malignant 

Endocrine System 

Adrenal cortex 

Adenoma 

Adrenal medulla 

Pheochromocytoma malignant 

Pheochromocytoma benign 

Pheochromocytoma benign, multiple 

Islets, pancreatic 

Adenoma 

Carcinoma 

Pituitary gland 

Pars distalis, adenoma 

Pars distalis, carcinoma 

Thyroid gland 

C-cell, adenoma 

C-cell, carcinoma 

Follicular cell, adenoma 

Follicular cell, carcinoma 

in Mane ~ 

0 ppm 

(20) 

1 (5%) 

1 (5%) 

(1) 

1 (100%) 

(60) 

3 (5%) 

(60) 

(60) 

(60) 

(I) 

1 (100%) 

(I) 

(60) 

1 (2%) 

(60) 

1 (2%) 

(60) 

1 (2 %) 

13 (22 %) 

I (2%) 

(60) 

5 (8%) 

1 (2%) 

(60) 

19 (32%) 

(60) 

5 (8%) 

in ~the Long-Tern Feed S*udy o~ t-~u*yahy~roquinone (continued) 

1,250 ppm 2,500 ppm 5,000 ppm 

(11) (7) (16) 

1 (9%) 

I (14%) 

(2) (2) 

1 (50%) 2 (I00%) 

1 (50%) 

(59) (58) (60) 

1 (2%) 

I (2%) 

(60) (58) (60) 

1 (2%) 

I (2%) 

(60) (58) (59) 

1 (2%) I (2%) 

(60) (58) (60) 

(2) (I) (4) 

2 (50%) 

(2) (I) 

I (50%) 

(60) (58) (60) 

• (60) (58) (60) 

1 (2%) 

(6~ (58) (6o) 

3 (5%) 1 (2%) 3 (5%) 

' 16 (27%) 11 (19%) 11 (18%) 

4 (7%) 4 (7%) I (2%) 

(59) (58) (6o) 

2 (3%) I (2%) 3 (5%) 

(58) (57) (60) 

16 

1 

(28%) 

(2%) 

17 (30%) 

I (2%) 

6 

1 

00%) 

(2%) 

(60) (58) (60) 

2 (3%) 2 (3%) 4 (7%) 

1 (2%) 2 (3%) 

1 (2%) I (2%) 

(5%) 

[ 

, : 
74 • t-Butylhydroquinone, NTP TR 459 

TABLE A1 .... 

Summary of the Incidence of Neoplasms in Male Rats in the Long-Term Feed Study of t-Butylhydroquinone (continued) . 

Long-Term Study (continued) 

General Body System 

Peritoneum 

Genital System 

Preputial gland 

Adenoma 

Carcinoma 

Carcinoma, multiple 

Prostate 

Adenoma 

Seminal vesicle 

Leiomyosarcoma, metastatic, intestine large, 

colon 

Testes 

Bilateral, interstitial cell, adenoma 

Interstitial cell, adenoma 

Hematopoietic System 

Bone marrow 

Lymph node ' 

Mediastinal, osteosarcoma, metastatic, " 

mesentery 

Lymph node, mandibular 

Carcinoma, metastatic, Zymbal's gland 

' Fibrosarcoma, metastatic, skin 

Lymph node, mesenteric 

Hemangioma 

Spleen 

Fibroma 

Histiocytic sarcoma 

Leiomyosarcoma, metastatic, intestine large, 

colon 

Osteosarcoma, metastatic, mesentery 

Sarcoma 

Thymus 

Thymoma malignant 

Integumentary System " 

Mammary gland 

Adenoma 

Fibroadenoma 

Fibroadenoma, multiple 

Skin 

Basal cell carcinoma 

Keratoacanthoma 

Keratoacanthoma, multiple 

Squamous cell papilloma 

Squamous cell papilloma, multiple 

Trichoepithelioma 

0 ppm 

(1) 

(6o) 

5 (8%) 

2 (3%) 

(6O) 

2 (3%) 

(6O) 

(6O) 

42 (70%) 

13 (22%) 

(6o) 

(33) 

(~) 

(60) 

(60) 

2 (3%) 

1 (2%) 

1 (2%) 

(58) 

(57) 

1 (2%) 

9 (16%) 

1 (2%) 

(60) 

1 (2%) 

3 (5%) 

1 (2%) 

2 (3 %) 

2 (3%) 

1,250 ppm 

(60) 

3 (5%) 

2 (3%) 

(6~0 

2 (3%) ...... 

(6~D 

I (2%) 

(60) 

4O (67%) 

9 (15%) 

(60) .,, 

(36) 

(6o) 

(58) " 

(60) 

1 (2%) 

1(2~) 

(55) 

(57) 

4 (7%) 

(6O) 

.4 (7%) 

1 (2%) 

1 (2%). 

1. (2%) 

2,500 ppm 

(1) 

(58) 

6 (10%) 

1 (2%) 

1 (2%) 

(58) 

1 (2%) 

(58) 

(57) 

45 (79%) 

11 (19%) 

(58) 

(34) 

1 (3%) 

(58) 

I (2%) 

(57) 

(58) 

1 (2%) 

1 (2%) 

(54) 

(56) 

1 (2%) 

4 (7%) 

(57) 

4 (7%) 

5,000 ppm 

(3) 

(60) 

3 (5%) 

5 (8%). 

(60).. 

I (2%) 

(60) _. 

(60) 

50 (83%) 

9 (15%) 

(6O) 

(35) 

(60) 

1 (2%) .. 

•(60) 

1 (2%) 

(6o) 

i (2%) 

(56) 

1 (2%) 

(58) 

~, (1o%) 

1 (2%) 

(6O) 

4 (7%) ,, 

2 (3%) 

1 (2%) 
.--,: ~ , :=,a, . ....... - ..... ~ = ~ , ~ . ~ w ~ ~ ' ? - ~ ' ~ - ' ~ : ~ : ~ -" : -- .~ ...... ~ y ~ - - : ~ 

t-Buiylhydroquinone, 1~ TR ,~$9 75 

TABLE A1 

Summary of the ~Incldenceof Neo#~srns in M~de ~ts in the Long-Term Feed Study of t-~utyihydroquinone (continued) 

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

Long-Term Study (continued) 

Integumentary System (continued) 

Skin (continued) (60) (60) (57) (60) 

Sebaceous gland, adenoma 1 (2%) 1 (2%) . 

Subcutaneous tissue, fibroma 3 (5%) 8 (13%) 6 (11%) 6 (10%) 

Subcutaneous tissue, fibroma, multiple 1 (2%) 

Subcutaneous tissue, fibrosarcoma 1 (2%) 1 (2%) 1 (2%) 1 (2%) 

Subcutaneous tissue, hemangioma 1 (2%) 

Subcutaneous tissue, hemangiosarcoma 1 (2%) 

Subcutaneous tissue, schwannoma benign 1 (2%) 

Subcutaneous tissue, schwannoma malignant 1 (2%) 1 (2%) 

Musculoskeletal System 

Bone (60) (60) (58) (6o) 

Osteosarcoma 1 (2%) 

Skeletal muscle (2) (2) 

Leiomyosarcoma, metastatic, intestine large, 

colon 1 (50%) 

Osteosarcoma, metastatic, mesentery I (50%) 

Nervous System 

Brain (60) (6o) (58) (60) 

Astrocytoma malignant 1 (2%) 1 (2%) 

Oligodendroglioma malignant l (2%) 

Spinal cord (2) (3) (1) (1) 

Respiratory System 

Lung (60i (6O) (58) (60) 

Alveolar/bronchiolar adenoma 3 (5%) 2 (3%) 1 (2%) 1 (2%) 

Alveolar/bronchiolar carcinoma 1 (2%) 

Carcinoma, metastatic, salivary glands 1 (2%) 

Histiocytic sarcoma 1 (2%) 

Squamous cell carcinoma, metastatic, oral 

mucosa 1 (2%) 

Nose (60) (60) (58) (60) 

Squamous cell carcinoma I (2%) 

Squamous cell papilloma 1 (2%) 

Pleura (1) 

Special Senses System 

Ear (1) (1) 

Squamous cell papilloma 1 (lOO%) 

Eye (4) (2) (1) (2) 

Carcinoma, metastatic, salivary glands 1 (100%) 

Zymbal's gland (2) (1) (3) (4) 

Adenoma 1 (25%) 

Carcinoma 2 (100%) 1 (1oo%) 3 (100%) 3 (75%) 

I 

i 

l: 

i 

i 

,. 

: 

.: 

~ (: 

I i 

i 
76 t-Butylhydroquinone, NTP TR.459 

TABLE A1 ~ 

Summary of the Incidence of Neoplasms in Male Rats in the Long-Term Feed Study of t-Butyihydroquinone (continued) 

0 ppm 1,250 ppm 

Long-Term Study (continued) 

Urinary System 

Kidney (6O) (60) 

Lipoma I (2%) 

Osteosarcoma, metastatic, mesentery 

Renal tubule, adenoma 2 (3%) 

Transitional epithelium, carcinoma i (2%) 

Urinary bladder (60) (6~ 

Papilloma 

Systemic Lesions 

Multiple organs b ' (60) (60) 

Histiocytic sarcoma 1 (2%) 

Leukemia mononuclear 39 (65%) 47 (78%) 

Lymphoma malignant I (2%) 

Mesotbelioma malignant 1 (2%) 

Neoplasm Summary 

Total animals with primary neoplasms c 60 59 

Total primary neoplasms 207 185 

Total animals with benign neoplasms 60 56 

Total benign neoplasms . 148 .125 

Total animals with malignant neoplasms 51 53 

Total malignant neoplasms 59 60 

Total animals with metastatic neoplasms .1 

Total metastatic neoplasms 6 

a Number of animals examined microscopically at the site and the number of animals with neoplasm 

b Number of animals with any tissue examined microscopically 

c Primary neoplasms: all neoplasms except metastatic neoplasms ........ 

2,500 ppm 

(58) ,. 

1 (2%) 

1 (2%) 

(58) 

I (2%)~ 

(58) 

40 (69%) 

1 (2%) 

57 

178 

56 

120 

50 

58 

5 

11 

5,000 ppm 

(~) 

1 (2%) 

(6O) ' 

I (2%) 

(60) 

32 (53%) 

3 (5%) 

60 

179 

59 

120 

47 

59 

2 

2 
~ ~ ~ . ~ 

¢-ll~u~y~hy~ro~.~uinone, .t~I'I? ~ ~1~ 77 

TALE A2 

]l~lividua] An~n~ ql'~m~r lPatho~osy o~ t~'~e II~ i~ the Lons-Ter~n Feed Stagy ot~ t-~uty~hy~roqu~none: 0 pp~ 

3445555556666666666666666 i 

Humber of Days on Study 8890234561122456677777889 

19 ,9.0844638826297834444774 [

I 

0000000000000000000000000 

Carcass ~D Humber 5216444231204003521125002 

9460846077563175085878592 

Alimentary System 

Esophagus + + + + + + + + + + + + + + + + + + + + + + + + + 

Intestine large, colon +++++++++++++++M+++M+++÷ + 

Intestine large, rectum + + + + + + + + + + + + + + + + +M+ ++ + + + + 

Intestine large, cecum + + + + + + + + + + + + + + + + + + + + + + + + + 

Intestine small, duodenum + + + + + + + + + + + + + + + + + + + + + + + + + 

Intestine small, jejunum + + + + + + + + + + + + + + + + +'+ + + + + + + + 

Intestine small, ileum + + + + + + + + + + + + + + + + + + + + + + + + + 

Liver + + + + + + + + + + + + + + + + + + + + + + + + + 

Hepatucellular adenoma X 

Histiocyti¢ sarcoma X 

Mesentery + + ++ + + + + + + + 

Histiocyti¢ sarcoma X 

Schwannoma malignant X 

Oral mucosa + 

Squamous cell carcinoma X 

Pancreas + + + + + + + + + + + + + + + + + + + + + + + + + 

Acinus, adenoma 

Salivary glands + + + + + + + + + + + + + + + + + + + + + + + + + 

Stomach, forestomaeh + + + + + + + + + + + + + + + + + + + + + + + + + 

Stomach, glandular + + + + + + + + + + + + + + + + + + + + + + + + + 

Tongue 

Squamous cell carcinoma i 

Tooth 

Cardiovascular System 

Blood vessel +++++++++++++++++++~+++++ 

Heart +++++++++++++++++++++++++ 

Schwannoma malignant X 

Endocrine System i

Adrenal cortex + + + + + + + + + + + + + + + + + + + + + + + + + [ 

Adcnoma 

Adrenal medulla + + + + + + + + + + + + + + + + + + + + + + + + + 

Pheochromocytoma malignant 

Phcochromocytoma benign X X 

Pheochromocytoma benign, multiple 

Islets, pancreatic + + + + + + + + + + + + + + + + + + + + + + + + + 

Adenoma X 

Carcinoma 

Parathyroid gland + + + + + + + + + + + + + + + + + + + + + + + + + 

Pituitary gland + + + + + + + + + + + + + + + + + + + + + + + + + 

Pars distalis, adenoma X X XX X X X 

Thyroid gland + + + + + + + + + + + + + + + + + + + + + + + + + 

C-cell, adenoma 

+: Tissue examined microscopically M: Missing tissue X: Lesion present 

A: Autolysis precludes examination I: Insufficient tissue Blank: Not examined 
78 i;Butyihydroquinone, NTP TR459 

TABLE A2 ., 

Individual Animal Tumor Pathology of Male Rats in the Long-Term Feed Study of t-Butylhydroquinone: -0 ppm (continued) 

7777777777777777777777788 

Number of Days on Study 0001123335555556778888900 ., 

4580990680227891445666578 

000000000~0000000000000000 

Carcass ID Number 3411452513234303352235500 

4940~75669236;~:103814193 I 228 

Alimentary System 

Esophagus + + + + + + + + + + + +,+ + + + + + + + + + + + + 

Intestine large, colon + + + + + + + + + + + + + + + + + + + + + + + + + 

Intestine large, rectum + + + + + + + + + + + + + + + + + + + + + + + ~'+ 

Intestine large, cecum + + + + + + + +.+ + +. +' + + + + + + + + + + + + + 

Intestine Small, duodenum + + + + + ÷ + + + + +~ + + + + + + + + + + + .+ + + 

Intestine small, jejunum + + ~ + + + + + + + + + + +~ + + + + ~.+ + + + + 

Intestine small, ileum + + + + + + + + + + + + + + + + + + + + + + + + + 

Liver + + + +' + + + + + + + +. + + + + +" + + + + + + + + 

Hepatocellular adenoma X X -: 

Histiocytic sarcoma 

Mesentery + + + + + 

Histiocytic sarcoma 

Schwannoma malignant 

Oral mucosa 

Squamous cell carcinoma 

Pancreas + + +~+ + + + + + + + + + + + + + + + + + + + + + 

Acinus, adenoma 

Salivary glands + + ++ + + + + + + + + + + + + + + + + + + + + + 

Stomach, forestumach +, + +. + + +'+ + + + + + + + + + + + + + + + + + + 

Stomach, glandular + + + +. ++ + + + + + + + + + + + + + + + + + + + 

Tongue + 

Squamous cell carcinoma ~ X ' ~ " ,~ 

Tooth 

Cardiovascular System ., 

Blood vessel + + + + + + + + + + + + + + + + + + + + + + + + + 

Heart + + + + + + + + + + + + + + + + +'+ + + + + + + + 

Schwannoma malignant 

Endocrine System .. 

Adrenal cortex 

Adenoma X 

Adrenal medulla 

Pheochromocytoma malignant 

Pheochromocytoma benign X XX X X X .XX~X 

Pheochromocytoma benign, multiple 

Islets, pancreatic + + + + + + + + + + + + + + + + + + + + + + + + + 

Adenoma X X 

Carcinoma 

Parathyroid gland ~++++MM++ ++÷++++M++ + ++ +M+ 

Pituitary gland +++++++++++++++++++++++++ 

Pars distalis, adenoma XX XX X X XXX. 

Thyroid gland + + + + + + + + + + + + + + + + + + + + + + + + + 

C-cell, adenoma X X X XX 
_ 

---- ~ ...... ~ = ~ ~ :~ ..... ~ ~ ------~..~ ~ , 

,t-Butynhy~roqufnone, N'~ 'I~ 4~9 79 

TABLE A2 

]~nd~vfdaa9 Aa~r~ Tumor ~atho~ogy of I~I~e ~at~ fin the ~I~t~ag-Tea'~ Feed Stagy o~ e-~ty]~y~r~t~ao~e: 0 ppm (continued) 

8888888888 

Number of Days on Study 2355555555 

4177777777 

0 0 0 0 0 0 0 0 0 0 Total i 

Carcass ~D Number 5 0.1 1 1 3 4 4 4 5 Tissues/ ! 

3 4 1 2 3 9 0 2 5 7 ~mors i

! 

Alimentary System i i 

Esophagus + + + + + + + + + + 

Intestine large, colon + + + + + + + + + + 58 

Intestine large, rectum • .+ + + + + + + + + + 59 

Intestine large, cecum + + + + + + + + + + 6O 

Intestine small, duodenum + + + + + + + + + + 60 

Intestine small, jejunum + + + + + + + + + + 6O 

Intestine small, ileum + + + + + + + + + + 6O 

Liver + + + + + + + + + + 6O 

Hepatoeellular adenoma X 4 

Histiocytic sarcoma 1 

Mesentery + + + + 20 

Histiocytic sarcoma 1 

Schwannoma malignant 1 

Oral mueosa 1 

Squamous cell carcinoma 1 

Pancreas + +++ +++ + + + 60 

Acinus, adenoma X X X 3 

Salivary glands + + + + + + + + + + 60 

Stomach, forestomaeh + + + ÷ + + ~+ + + 60 

Stomach, glandular + + + + + + + + + + 60 

Tongue 1 

Squamous cell carcinoma 1 

Tooth 1 

Cardiovascular System 

Blood vessel + + + + + + + + + + 60 

Heart + + + + + + + + + + 60 

Schwannoma malignant 1 

Endocrine System 

Adrenal cortex + + + + + + + + + + 60 

Adenoma 1 

Adrenal medulla + + + + + + + + + + 60 

Pheochromocytoma malignant 1 

Pheochromoeytoma benign ,XX 13 

Pheochromoeytoma benign, multiple X 1 

Islets, pancreatic +++++~++++ 60 

Adenoma X X 5 

Carcinoma X 1 

Parathyroid gland +M++++++~+ 55 

Pituitary gland + + + + + + + + + + 60 

Pars distalis, adenoma X X X 19 

Thyroid gland + + + + + + + + + + 60 

C-cell, adenoma 5 
80 t-Butylhydroquinone, ~NTP TR 4S9 

TABLE A2 

Individual Animal Tumor Pathology of Male Rats in the Long-Term'Feed Study of t-Butylhydroquinone: ,Oppm (continued) 

3445555556666.666666666666 

Number of Days on Study 889023456112"245667777788"9 

1990844638826297834444774 

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 521644423 1204003521125002 ~' 

9460846077563175085878592 ~ . 

. . 

General Body System 

Peritoneum , , 

Genital System 

Epididymis + + + + + + + + + + + + + + + + + + + + + + + + + 

Preputial gland + + + + + + + + + + + + + ~ + + + + + + + + + + + 

Adenoma X X 

Carcinoma X X 

Prostate + + + + + + + + + + + + + + + + + + + + +~ + + + 

Adenoma + ÷ ÷ + + + + + + ÷ ÷ ÷ ÷ ÷ + ÷ ÷ ÷ ÷ ÷ ÷ ÷ ÷ + ÷ 

Testes 

Seminal vesicle 

+ + + + + + + + + + ÷ + + ÷ ÷ + ÷ + + + ÷ + ÷ ÷ ÷ 

Bilateral, interstitial cell, adenoma X XX X XXX XXX X X 

Interstitial cell, adenoma XXX X X X X X X • 

Hematopoietic System 

Bone marrow + + + ~+ + + + + + + + + + ÷ ÷ + ÷ + ÷ + ÷ ÷ ÷ + 

Lymph node ÷ ++÷+ ÷ ÷++ ÷ ÷÷+ 

Lymph node, mandibular + + + + + + + + + + + + + + + + + ÷ + ÷ ÷ ÷ + +'+ 

Lymph node, mesenteri¢ ++ + + + +++ + + + + + + + + + + ++ + + ++ + 

Spleen + + ++++ + ++++ + + ~++ + ++ + + ~ + + + 

Fibroma 

Histiocytic sarcoma X 

Sarcoma - , . 

Thymus + + +++ + + + +++++~÷÷ + ++ ÷+ + + + + . , • 

Integumentary System 

Mammary gland + + + + + + + + + + + +M+ + + + +M+ + +M + + 

Adenoma X 

Fibroadenoma X 

Fibroadcnoma, multiple • 

Skin + + + + + + + + + + + ~ + + + + + + + + + + + + + 

Basal cell carcinoma 

Kcratoacanthoma X 

Kcratoacamhoma, multiple X 

Squamous cell papilloma 

Trichoepithelioma 

Sebaceous gland, adenoma X 

Subcutaneous tissue, fibroma 

Subcutaneous tissue, fibroma, multiple 

Subcutaneous tissue, fibrosarcoma 

Subcutaneous tissue, hemangioma 

Subcutaneous tissue, hemangiosarcoma X 

Subcutaneous tissue, schwannoma benign 

Musculoskeletal System 

Bone + + + + + + + + + + + + + + + + + + + + + + + + + 
; . . . . . . . . . . . . . ~ .......... ~:_ ~-~:~-. _-- ~:.~i~.~.~.,~.~~,,~.~-~ ~--? : ~ : ~ ~ , ,a~7-r~:-___~..~ ~ _ 

t-l~uty~hydroqu~none, NT]F T~ ~9 

TABLE A~ 

]Individu~ Anhnsi 'Tu~nor ]Ps~ho~ogy o~ l~/lIa~e ]l~ in ~he Long-Tern Feed ~udy o~' ~-~u[y~hydroqu[none: ~ O ppn~ (continued) 

. . . . 7777777777777777777777788 

NmberofDaysonStudy 0001123335555556778888.900 

4580990680227891445666578 

0000000000000000000000 O00 

Carc~s~N~ber 34114525 I 3234303352235500. 

4940756692361038141931228 

~nerai ~y Syste~ ......... 

Peritoneum 

. ~ 

Genital System 

Epididymis + + + + + + + + + + + + + + + + + + + + + + + + + 

Preputial gland . + + + + + + + + + + + + + + + + + + + + + + + + + 

Adenoma X 

Carcinoma 

Prostate + + ~ + + + + + + + + + + + + + + + + + + + + + + 

Adenoma 

Seminal vesicle + + + + + + + + + + + + + + + + + + + + + + + + + 

Testes + + + + + + + + + + + + + + + +.+ + + + + + + + + 

Bilateral, interstitial cell, adenoma XXXXXX XXXXXX XXX XXXXX 

Interstitial ceil, adenoma x× x x 

Hematopoietic System 

Bone marrow + + + + + + + + + + + + + ~ + + + + + + + + + + + 

Lymph node ++ ++ +++ ++++ ++ + + 

Lymph node, mandibular + + + + + + + + + + + + + + + + + + + + + + + + + 

Lymph node, mesenteric + ~+ + + + + + + + + + + + + + + + + + + + + + + 

Spleen + + + + + + + + + + + + + + + + + + + + + + + + + 

Fibroma X 

Histiocytic sarcoma 

Sarcoma X 

Thymus + + + + + + + + + + + + + + + + + + + + + + + +M 

~ntegumenta~ Cyste ~- 

Mammary gland 

o .~, + + + + + + + + + + + + + + + + + + + + + + + + + 

Adenoma 

Fibroadenoma X X X X 

Fibroadenoma, multiple 

Skin + + + + + + + + + + + + + + + + + + + + + + + + + 

Basal cell carcinoma X 

Keratoacanthoma 

Keratoacanthoma, multiple 

Squamous cell papilloma X 

Trichoepithelioma X X 

Sebaceous gland, adenoma 

Subcutaneous tissue, fibroma X 

Subcutaneous tissue, fibroma, multiple X 

Subcutaneous tissue, fibrosarcoma 

Subcutaneous tissue, hemangioma 

Subcutaneous tissue, hemangiosarcoma 

Subcutaneous tissue, schwarmoma benign X 

Muscul0skele~al System 

Bone + + + + + + + + + + + + + + + + + + + + + + + + + 
82 t-ButYlhydroquinone; NTP TR 459 

TABLE A2 " 

Individual Animal Tumor Pathology of Male Rats in the Long-Term Feed Study of t-Butylhydroquinon~: '0 ppm (cohtinued) 

8888888888 

NumberofDaysonStudy 2 3 5 5 5 5 5 5 5 5 ': : 

4177777777 

0000000000 ~tal 

Carc~sIDNumber 5011134445 Tis~es/ 

3412390257 • ' ~mors 

Genera Body System 

Peri~neum + 1 

Genital System 

Epididymis + + + + + + + + + + .; 

Preputial gland + + + + + + + + + + 

Adenoma X X 

Carcinoma 

Prostate + + + + ++ + + + + 6O 

Adenoma X X 2 

Seminal vesicle + + + + + + + + + + 6O 

Testes + + + + + + + + + + 6O 

Bilateral, interstitial cell, adenoma XXXXXXXXXX 42 

Interstitial cell, adenoma 13 

Hematopoietic System 

Bone marrow + + +-+ + + + + + + 

Lymph node ++ + ++ 33 

Lymph node, mandibular + + + + + + + + + + 6O 

Lymph node, mesent6ric + + + +.+ + + +-+ + 6O 

Spleen + + + + +'+ + + + + 6O 

Fibroma X 2 

Histiocytic sarcoma 1 

Sarcoma 1 

Thymus + + +M + + +~+ + + 58. 

Integumentary 

Mamma~ gland 

System + + ++'+ + + + ~ + 57 

Adenoma 1 

Fibroadenoma X XXX' 9 

Fibroadenoma, multiple X 1 

Skin + + + + + + + + + + ~ 60 

Basal cell carcinoma 1 

Keratoacanthoma XX 3 

Keratoacanthoma, multiple 1 

Squamous cell papilloma X 2 

Trichoepithelioma 2 

Sebaceous gland, adenoma 1 

Subcutaneous tissue, fibroma X X 3 

Subcutaneous tissue, fibroma, multiple 1 

Subcutaneous tissue, fibrosarcoma X 1 

Subcutaneous tissue, hemangioma X 1 

Subcutaneous tissue, hemangiosarcoma 1 

Subcutaneous tissue, schwannoma benign 1 

Musculoskeletal System 

Bone + + + + + + + + + + 60 
.... i :a ~ ........ , - ii~ ~lp~; f ........ .... ~ .... ~ : ~ , ~ = % ~ # ~ ~ . ~ =77~ ~ 

t-Butylhydroquinon e, ~ TR 459 83 

. 

TABLE ~t~ 

~nd~vidua~.Anhn~ Tun~or ]Fatho~o~y o¢ MaZe ~ ~ the ~ng-Te~ ~eed Study o~ t-~uty~hydroqu~none: 0 ppm (continued) 

"3445555556'6666~66666666666 I 

[ 

Number of Days on Study 8890234561122456677777,88.9 

1990844638826297834444724 i 

I 

, . 

0 0"0 0 0 0 0 0 0 0 0 0 0 0 0 O0 0 0 0 0 0 0 0 0 

Carcms ~D.Number 5216444231204003521125002 

9460846077567175085878592 

Nervous System 

Brain 

Astrocytoma malignant 

Oligodcndroglioma malignant 

Peripheral nerve 

Spinal cord 

+ + + + + + + + 

X 

+ + + + + + + + + + + + + + + + + 

Respiratory System 

Lung 

Alveolar/bronchiolar adenoma 

Histiocytic sarcoma 

Nose 

Squamous cellpapilloma 

Trachea 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

X 

+ 

+ 

+ 

X 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

X 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

Special Senses System 

Eye 

Zymbal's gland 

Carcinoma 

..6 

+ 

X 

+ 

Urinary System 

Kidney 

Lipoma 

Renal tubule, adenoma 

Transitional epithelium, carcinoma 

Urethra 

• Urinary bladder 

+ 

+ 

+ 

+. 

+ 

+ 

+ 

+ 

X 

+ 

+ 

X 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ + 

. 

+ + 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

X 

+ 

Systemic Lesions 

Multiple organs 

Histiocytic sarcoma 

Leukemia mononuclear 

Lymphoma malignant 

Mesothelioma malignant 

XX 

X 

X XXXXXXXXXXXX 

i ~ 
84 t-Butylhydroquinone, NTP TR 459 

TAtaR A2 

Individual Animal~Tumor Pathology of Male Rats in the Long-Term Feed Study of t-Butylhydroquinonei 0 ppm (c~ontinued) 

7777777777777777777777788 • 

Number of Days on Study 0001123335"5 '55556778888~9~0'0 ~ 

45809906802278914456665.78 

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 3411452513234303352235500 

49407566923.61038141931228 . • . 

Nervous System 

Brain ++++ + + + + + + + + + + + + + + + + + + + + + 

Astrocytoma malignant " 

Oligodendroglioma malignant X 

Peripheral nerve + + 

Spinal cord + + 

Respiratory System 

Lung + + + + + + + + + + + + + + + + + + + + + + + + + 

Aiveolar/bronehiolar adenoma 

Histiocytic sarcoma 

Nose + + + + + + + + + + + + + + + + + + + + + + + + + 

Squamous cell papilloma X' 

Trachea + + + + + + + + + + + + + + + + + + + + + + + + + 

Special Senses System 

Eye ~ 

Zymbal's gland 

Carcinoma X 

Urinary System 

Kidney + + + + + + + + + + + + + + + + + + + + + + + + +

Lipoma 

Renal tubule, adenoma X -

Transitional epithelium, carcinoma 

Urethra 

Urinary bladder + + + + + + + + + + + + + + + + + + + + + + + + + • , 

Systemic Lesions 

Multiple organs 

Histiocytic sarcoma 

Leukemia mononuclear X XXXX 'XXXX XXXXXXXXXX X 

Lymphoma malignant 

Mesothelioma malignant 
e-~u~ynhy~amcn~e, ~ T~ ,~9 85 

T~ ~L~ 

]Ia~tv~ua~ An~aa~ Tc~mor ~a~ho~o~y o~ l~I~e Rats ~ ~he Long-Tern Feed Study o~ So~utyihy~rc~u~no~e: 0 ppm (continued) 

8888888888 

Nmber of Days on S~udy 2355555555 

4177777777 

0 0 0 0 0 0 0 0 0 0 Total 

C~reass ]~D Number 5011134445 Tissues/ 

• 3 4 .I 2 3 9 0 2 5 7 Tumors 

l~ervo~s System 

Brain + + + + + + + + + + 60 

Astrocytoma malignant 1 

Oligodendroglioma malignant 1 

Peripheral nerve 2 

Spinal cord 2 

Respiratory System 

Lung + + + + + + + + + + 60

Alveolar/bmnchiolar adenoma 3 

Histiocytic sarcoma 1 

Nose + + + + + + + + + + 60

Squamous ell papilloma 1 

Trachea + + + + + + + + + + 60

Sp~cta~ Sens~ System 

Eye + + 

Zymbal's gland 

Carcinoma 

Urha~ry ~ys~em 

Kidney + + + + + + + + + + 60 

kipoma 1 

Renal tubule, adenoma 2 

Transitional epithelium, carcinoma 1 

Urethra 1 

Urinary bladder ++~+~+++++ 0

~ys~em~c Lesions 

Multiple organs + + + + + + + + + + 60 

Histiocytie sarcoma 1 

Leukemia mononuelear X XXX 39 

Lymphoma malignant 1 

Mesothelioma malignant X 1 
86 ~ t-Butylhydroquinone, NTP TR 459 

TABLE A2 

Individual Animal Tumor Pathology: of Male Rats in the Long-Term Feed Study of t-Butylhydroquinone: 1,250 ppm 

233455~5555566666666666666 

Number of Days on Study 87963345668134556,-66678889 

934755"7424394756267872447 

000111111011 i lJ i 1. 111001000 

Carcass ID Number 97910201182022"22212790897 

54002279593 97 54088,1593733 

Alimentary System 

Esophagus 

Intestine large, colon 

Leiomyosarcoma 

Intestine large, rectum 

Intestine large, cecum 

Intestine small, duodenum 

Intestine small, jejunum 

Intestine small, ileum 

Leiomyoma 

Liver 

Hepatocellular adenoma 

Leiomyosarcoma, metastatic, • 

intestine large, colon 

Mesentery 

Leiomyosarcoma, metastatic, 

intestine large, colon 

Oral mucosa 

Squamous cell carcinoma 

Sqnamous cell papilloma 

Pancreas 

Leiomyosarcoma, metastatic, 

intestine large, colon 

Salivary glands 

Stomach, forestomach 

Stomach, glandular 

, Tongue 

+ + + + + + + + + + + + + + + + + + + + + + +~M 

+ + + M + + + + + + + + + +~+ + + + M +-+ + + + + 

+ + + + + + + + + + + ~ + + +'+ + ~ + + + + + +'+ 

+ + + + +,+ + + + + + + + + + + +M+ + + + + + + 

+ + + + + + ~ + + + + + + ~ + + + + +. +-+ + + + .+ 

+ + ~ + + + + + + + + + ~ + + + + ~ + + + + + + + 

+ + + + + + + + + + +M++ + + + +~+ + + + + + + 

+ + + + + + + + + + + + + + + + + ++ + + + + + + 

+ + + + + 

+ 

X 

+ + + + + + + + + + + + + ~ + + + + +M+ + + + + 

• 

+ + + + + + + + + + + + + + + ~ + + + + + + + + + 

÷ + + + + + + + + ~ + + + + + + + + + + + + + + + 

+ + + + + + + + + + + + + +.+ + + + + + + + + + + 

+ • 

Cardiovascular System 

Blood vessel + + + + + + + + + + +.+ + + + + + + + + + + + + +

Heart + + + + + + + + + + + + + + + + + + + + + + + + +

Endocrine System 

Adrenal cortex ~ 

Adrenal medulla 

Pheochromocytoma malignant 

Pbeochromocytoma benign 

Pbeochromocytoma benign, multiple 

Islets, pancreatic 

Adenoma 

Parathyroid gland 

Pituitary gland 

Pars distalis, adenoma 

Pars distalis, carcinoma 

Thyroid gland 

C-cell, aden0ma 

C=cell, carcinoma 

Follicular cell, adenoma 

XXX X X XX 

+++++++++++++++++++M+++++ 

++++~+++++++++++++M+M++++ 

+ + M + + + + + ,+ + + + + + + + + + + + + + + +-÷ 

X X X X 

+ + + + + + + + ÷ + + + + + + + + + + + + + + + + 

. . X 
............... -. __ --7---~-~;'~-~; 7 ~ ................ ~ : ~ - - ---- ~'~7~'7~ L ~ ~: . . . . . . ~ ~.~-.-.~--~--~-~ . ~ ~ ....... 

t-Butylhydroquinone, NT~P Tit ,~59 87 

TABLE A2 

~ndividua~ Anhna~ Tumor Pathology of MINe ll~ts in the Loug-Tern~ Feed Study of t-ll~utynhydroqu~none: 1,250 ppm 

(continued) , 

6677777777777777777777888 

Number of Days on Study 99000222233"34446666788013 

7728822590004451568366840 

11.00001100010000111100110 

Carcass ~D Number 0198871078807988101299209 

4341592886862242701667918 

Alimentary System 

Esophagus + + + + + + + + + + + + + + + + + + + + + + + + + 

Intestine large, colon + + + + + + + + + + + + + + + + + + + + ++ + + + 

Leiomyosarcoma 

Intestine large, rectum + + + + + + + + + + + + + + + + + + + + + + + + + 

Intestine large, cecum ++++++++++++++++++++ ++++M 

Intestine small, duodenum + + + + + + + + + + + + + + + + + + + + + + + + + 

+ + + + + + + + + + + + + + + + + + + + + + + + + 

Intestine small, ileum + + + + + + + + + + + + + + + + + + + + + + + + + 

Intestine small, jejunum 

Leiomyoma 

Liver + + + + + + + + + + + + + + + + + + + + + + + + + 

Hepatocellular adenoma X X X 

Leiomyosarcoma, metastatic, 

intestine large, colon 

Mesentery + + + + + 

Leiomyosarcoma, metastatic, 

intestine large, colon 

Oral mucosa + 

Squamous cell carcinoma 

Squamous cell papilloma X 

Pancreas + + + + + + + + + + + + .+ + + +.+ + + + + + + + + 

Leiomyosarcoma, metastatic, 

intestine large, colon 

Salivary glands + + + + + + + + + + + + + + + + + + + + + + + + + 

Stomach, forestomach + + + + + + + + + + + + + + + + + + + + + + + + +

Stomach, glandular + + + + + + + + + + + + + + + + + + + + + + + + +

Tongue + 

Cardiovascular System 

Blood vessel + + + + + + + + + + + + + + + + + + + + + + + + + 

Heart + + + + + + + + + + + + + + + + + + + + + + + + +

Endocrine System 

Adrenal cortex 

Adrenal medulla 

Pheochromocytoma malignam X X 

Pheochromocytoma benign • X X X X X 

Pheochromocytoma benign, multiple X X 

Islets, pancreatic + + + + + + + + + + + + + + + + + + + + + + + + + 

Adenoma X X 

Parathyroid gland ++++M+++++M++++++++++ +M+ + 

Pituitary gland + + + + + + + + + + + + + + + + + + + + + + + + + 

Pars distalis, adenoma X X X X XX X 

Pars distalis, carcinoma X 

Thyroid gland J + + + + + + + + + + + + + + + + + + + + + + + + + 

- C-cell, adenoma 

C-cell, carcinoma 

Follicular cell, adenoma 
88 t-Butylhydroquinone, NTP TR 459 

TABLE A2 

Individual Animal Tumor Pathology of Male Rats in the Long-Term Feed Study of t-Butylhydroquinone: 1,250 ppm 

(continued) 

8888888888 

Number of Days on Study 35,55555555 

1227777777 

1 1 1 0 0 0 0 0 0 1 Total 

Carcass ID Number 1137778890 Tissues/ 

6401670315 Tumors 

Alimentary System 

Esophagus + + + + + + + + + + 59 

Intestine large, colon + + + +,+ + + + + + 58 

Leiomyosarcoma X 1' 

Intestine large, rectum + + + + + + + + + + 60 

Intestine large, cecum + + + + + + + + + + 58 

Intestine small, duodenum + + + ++ + + + + + 60 

Intestine small, jejunum + + + + + + + + + + 60 

Intestine small, ileum + + + + + + + + + + 59 

Leiomyoma X 1 

Liver + + + + + + + + + + 60 

Hepatocellular adenoma X 4 

Leiomyosarcoma, metastatic, 

intestine large, colon X 1 

Mesentery + 11 

Leiomyosarcoma, metastatic, 

intestine large, colon X 1 

Oral mu¢osa 2 

Squamous cell carcinoma 1 

Squamous cell papilloma 1 

Pancreas + + + + + + + + + + 59 

Leiomyosarcoma, metastatic, 

intestine large, colon X 1 

Salivary glands + + + + + + + + + + 60 

Stomach, forestomach + + + + + + + + + + 60 

Stomach, glandular + + + + + + + + + + 60 

Tongue 2 

Cardiovascular System 

Blood vessel + + + + + + + + + + 

Heart + + + + + + + + + + 

Endocrine System 

Adrenal cortex + + + + + + + + + + 60 

Adrenal medulla + + + + + + + + + + 60 

Pheochromoeytoma malignant X 3 

Pheochromocytoma benign XXX X 16 

Pheochromocytoma benign, multiple X X 4 

Islets, pancreatic + + + + + + + + + + 59 

Adenoma 2 

Parathyroid gland M+++++++++ .54 

Pituitary gland + + + + + + + + +M 58 

Pars distalis, adenoma X X XXX 16 

Pars distalis, carcinoma 1 

Thyroid gland + + + + + + + + + + 60 

' C-cell, adenoma X X 2 

C-cell, carcinoma 1 

Follicular cell, adenoma X 1 
~ .... . 7 i r ~ ........... , ,T, ....... ~ . "-~ % ~ .--

t-Bu~y~hy~roqu~none, NT~ T~ 4S9 89 

TA~L~ A~ 

~In~ividu~ Animal Tumor l?~ho~ogy o~ I~,~I~e :~ ~n ~:he Long-Term ~'eed S~u~y of t-Bu~y~hy~ro~u~none: ~,2S~) ~pm 

(continued) 

2334555555566666666666666 

Number~DaysonStu~ 8796334566813455 666678889 

9347557424394756267872447 

0001111110111111111001000 

Carc~s~Nmber 9791020118202222212790897 

5400227959397540881593733 

GeneralBodySystem 

None 

Genital System 

Epididymis + + + + + + + + + + + + + + + + + + + + + + + + + 

Preputial + + + + + + + + + + + + + + + + + + + + + + + + + gland 

Adenoma 

Carcinoma X 

Prostate + + + + + + + + + + + + + + + + + + + + + + + + + 

Adenoma X 

Seminal vesicle + + + + + + + + + + + + + + + + + + + + + + + + + 

Leiomyosarcoma, metastatic, 

intestine large, colon 

Testes + + + + + + + + + + + + + + + + + + + + + + + + + 

Bilateral, interstitial cell, adenoma X XX X XXXXXX 

Interstitial ceil, adenoma XXXX XX XX 

Hematopoietic System 

Bone marrow + + + + + + + + + + + + + + + + + + + + + + + + + 

+ + + + + + + + + + + + + + + + 

Lymph node, mandibular + + + + + + + + + + + + + + + + + + + + + + + + + 

Lymph node 

+ + + + + + + + + + + + +M+ + + + + + + + + + + 

Spleen + + + + + + + + + + + + + + + + + + + + + + + + + 

Fibroma X 

Leiomyosarcoma, metastatic, 

intestine large, colon 

Thymus +++++++++++++++M++I ++++ ++ 

Lymph node, mesenteric 

integumentary System 

Mammary gland M + + + + + + + + + + + + + + + + + + + + + + + M 

Fibroadenoma 

Skin + + + + ÷ + + + + + + + + + + + + ÷ + + + + + + + 

Keratoacanthoma X 

Squamous cell papilloma 

Squamous cell papilloma, multiple 

Trichoepithelioma 

Sebaceous gland, adenoma 

Subcutaneous tissue, fibroma X X 

Subcutaneous tissue, fibrosarcoma 

Musculoskeletal System 

Bone + + + + + + + + + + + + + + + + + + + + + + + + + 

Skeletal muscle +

Leiomyosarcoma, metastatic, 

intestine large, colon 

Nervous System [ 

Brain 

Astrocytoma malignant X } Peripheral nerve ++ + 

Spinal cord ++ + 
90 t-Butylhydroquinone, NTP TR 459 

TABLE A2 

IndividualAnimal Tumor Pathology 

(continued) 

NmberofD~sonSmdy 

Carc~s~Number 

General Bo~ System 

No~ • 

Genital System 

Epididymis 

Preputial gland 

Adenoma 

Carcinoma 

Prostate 

Adenoma 

Seminal vesicle 

Leiomyosarcoma, metastatic, 

intestine large, colon 

Testes 

~Bilateral, interstitial cell, adenoma 

Interstitial cell, adenoma 

Hematopoietic System 

Bone marrow 

Lymph node 

Lymph node, mandibular 

Lymph node, mesenteric 

Spleen 

Fibroma 

Leiomyosarcoma, metastatic, 

intestine large, colon 

Thymus 

Integumentary System 

Mammary gland 

Fibroadenoma 

Skin 

• Keratoacanthoma 

Squamous cell papilloma 

Squamous cell papilloma, multiple 

Trichoepithelioma 

Sebaceous gland, adenoma 

Subcutaneous tissue, fibroma 

Subcutaneous tissue, fibrosarcoma .. 

Musculoskeletal System 

Bone 

Skeletal muscle 

Leiomyosarcoma, metastatic, 

intestine large, colon 

Nervous System 

Brain 

Astrocytoma malignant 

Peripheral nerve 

.Spinal cord 

of Male Rats in the Long=Term Feed Study of t-Butylhydroquinone: 1~250 ppm 

6677777777777777777777888 

99000222233344466667880~13 

7728822590004451568366840 

1100001100010000111100110 

01988710788079881012992.09 

4341592886862242701667918 

" 

+++5-+++++++++++++5-+5-+5-5-5-5-

+5-+5-+5-++++++5-5-+++5-++5-+5-+5-

XX 

X 

++++++++++++÷+++++++++++5-

+ + + + + + + + + + + + + + + + + + + + + + + + + 

+++5-5-++5-+5-+++++5-+5-+5-5-+5-++ 

X X X X X X X X X X X X X X X X X X XX 

X 

+ + + + + +.+ + + + + + + + ~ + + + + + + + + + + 

+ + + + + + + "+ + + + + + + + 

+ + + + + + + + + + + + ++ + + + + + + + + + + + 

+5-5-5-+++++++++++++5-++++++5-

+5-++++++++5-5-5-5-5-++5-++5-+5-++ 

+ + + + + + + + + + ++ + + + M + + + I + + + + + 

+M+ + + + + + + + + + + + + + + + + + + + + + + 

X 

+ 5- + + + + + + + +. + + + + 5- + + + + + + 5- 5- 5- 5-

X X X 

X 

X X 

X 

5-++++++++++++++++++++++++ 
~ ...................... ~--~- ~-. , ~--= ~ __ 

t-Bntynhydroqu~none, ~ T~ ,~9 91 

TABL~ ~ 

]~ndlv~dua~ An~na~ 

(continued) 

Tumor lPatho~ogy of Male Rats in the Long-Term Feed Study of t-~uty~hydroquhmne: 1,250 ppm 

88+88888888 

NumberofDaysonStudy 3555555555 

1227777777 

11100 O 0001 ~tal 

Carc~s~Number 1137778890 

640167 ~ 315 

Tissues/ 

~mors 

GeneraiBodySystem 

None 

Genital System 

Epididymis 

Preputial gland 

Adenoma 

Carcinoma 

Prostate 

Adenoma 

Seminal vesicle 

Leiomyosareoma, metastatic, 

intestine large, colon 

Testes 

Bilateral, interstitial cell, adenoma 

Interstitial cell, adenoma 

+ + + + + + + + + 

+ + + + + + + + + 

X 

++++++++4+ 

X + + + + + + + + + 

X + +.+ + + + + + + 

XXXXXXXXXX 

+ 

+ 

+ 

+ 

60 

60 

3 

2 

60 

2 

60 

1 

60 

40 

9 

Hematopoietic System 

Bone marrow 

Lymph node 

Lymph node, mandibular 

Lymph node, mesenteric 

Spleen 

Fibroma 

Leiomyosarcoma, metastatic, 

intestine large, colon 

Thymus 

+ + + + + + + + + 

+++ + 

+ + + + + + + + + 

+M++++++++ 

+ +.+ + + + + + + 

X 

M+ + + + + + + + 

+ 

+ 

+ 

+ 

+ 

36 

60 

58 

60 

1 

1 

55 

Integumentary System 

Mammary gland 

Fibmadenoma 

Skin 

Keratoaeanthoma 

Squamous cell papilloma 

Squamous cell papilloma, multiple 

Triehoepithelioma 

Sebaceous gland, adenoma 

Subcutaneous tissue, fibroma 

Subcutaneous tissue, fibrosarcoma 

+ 

+ 

+ 

X 

+ 

+ 

+ 

+ + 

X 

+ + 

X 

XX 

+ 

+ 

+ 

+ 

+ + 

X 

+ + 

X 

XX 

+ 

+ 

57 

4 

60 

4 

1 

1 

1 

1 

8 

1 

Musculoskeletal System 

Bone 

Skeletal muscle 

Leiomyosarcoma, metastatic, 

intestine large, colon 

+.+ 

+ 

X 

+ + + + + + + + 60 

2 

1 

Nervous System 

Brain 

Astroeytoma malignant 

Peripheral nerve 

Spinal cord 

+ + + + + + + + + + 60 

1 

3 

3 
92 t-Butyihydroquinone, .NTP TR 459 

TABLE A2 

Individual 

(continued) 

Animal Tumor Pathology of Male Rats inthe Long-Term Feed Study of t-Butylhydroquinone: 1,250 ppm 

Number of Days on Study 

2334555555566666666666666 

879,63345668.13455666678"'8..8'9 

9347557424394756267872447 

Carcass ID Number 

0 0 0 1 1 1 1 1 1 0 1 1 1 1 1 1 1 1 1 0 0 1 0 0 

9 7 9 1 0 2 0 1 1 8 2 0 2 2 2 2 2 1 2 7 9 0 8.~,9 

5400227'959397540881593733 

0 

7 

Respiratory System 

Lung 

Alveolar/bronchiolar adenoma 

Nose 

Squamous cell carcinoma 

Trachea 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ + 

+ + 

• 

+ + 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

. . 

+ 

+ 

+ 

+ 

+ 

+ 

X 

+ 

+ 

+ 

+ 

Special Senses System 

Ear 

Squamous cell papilloma 

Eye 

Zymbal's gland 

Carcinoma 

+ 

X 

Urinary System 

Kidney 

Urethra 

Urinary bladder 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ + 

+ 

++ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

Sysiemic Lesiom 

Multiple organs 

Leukemia mononuclear X XXX X XXXXXXXXXXXXX 
- - ~ .............. ~ =~-~-~--~--~-~:: - ~ ~ - : ..... --: v 

t-~utyn~ty~troqu~none, NT~P T~ ~59 93 

-~A~LE ~ 

]Mdividua~ An~ma~ Tremor ~aiho~ogy of Male ~ats in the Long-Ter~n Feed Study of t-~uty~hydroquinone: L250 ppm 

(continued) 

6677777777777777777777888 

Number of Days on Study 99000.22223334446666"788013 

7728822590004"451568366840 

1100001100010000111100110 

Carcass ~D Number 0198871078807988101299209 

4341592886862242701667918 

]Respiratory System 

Lung + + + + + + + + + + + + + + + + + + + + + + + + + 

Alveolar/bronchiolar adenoma X X i 

Nose + + + + + + + + + + + + + + + + + + + + + + + + + 

Squamous cell carcinoma 

Trachea + + + + + + + + + + + + + + + + + + + + + + + + + 

Special Senses System 

Far + i

~ Squamous cell papilloma X 

l~ye 

Zymbal's gland 

Carcinoma 

Urinary System 

Kidney + + + + + + + + + + + + + + + + + + + + + + + + + 

Urethra 

Urinary bladder + + + + + + + + + + + + + + + + + + + + + + + + + 

Systemic L~..sions 

Multiple organs 

Leukemia mononuclear XXXXXXX XXXXXXXXX XXXXXX 
94 t-Butylhydroquinone, ,NTPTR 459 

TABLE A2 

Individual Animal Tumor Pathology of Male Rats in the Long-Term Feed,Study of t-Butylhydroquinone: 1,250 ppm 

(continued) 

8888888888 

Number of Days on Study 3555555555 

1227777777 . 

1 1 1 0:0 0 0 0 0 1' Total 

Carcass ID Number 1137778890 TiSsues/. 

6401670315 Tumors • . 

Respiratory System 

Lung + + + + + + + + + + 60 

Alve~lar/bronchiolar adenoma 2 

Nose'- + + + + + + + ÷ + + 60 

Squamous cell carcinoma 1 

Trachea + + + + + + + + + + 60 

Special Senses System 

Ear : 1 

Squamous cell papilloma 1 

Eye 2 

Zymbal's gland - 1. 

Carcinoma 1 

Urinary System 

Kidney + + + + + + + + + + .60 

Urethra 1 

Urinary bladder + + + + + + + + + + 60 

Systemic Lesions 

Multiple organs + + + + + + + + + + 60 

Leukemia mononuclear X. XXXXXX. 47 

., 
_ ...~.---.~ -----~: ~ = ,,~ *~. ~ ~ l l ~ - ~ "~ ........ ................ = : : H , ~ .............. . ~ - - - ~ =: : 

t-~u~hy~roqu~none,. NT]P '~. ~ 

TABLE A2 

]Individual Ani~nal Tu~nor ]?atho~ogy o~ ~,~age. ~s ~a the Long-Tern Feed Study o~' t-~uty~hydr~uinone:~. 2,~ ppn~ 

44445"555555555556"66666666 

Number of Days on Study 0679023356677999011124.456 

8433165522208111448950251 

, • . 

1111111111111111111111111 

Carcass ID Number 7599774585787678598659549 

88834,18597920623207211042 

Alimentary System 

Esophagus + + + + + + + + + + + + + + + + + + + + + + + + + 

Intestine large, colon + + + + + + + + + + + + + + + + + + + + + + + + + 

Intestine large, rectum + + + + + + + + + + + + + + + + + + + + + + + + + 

Carcinoma 

Intestine large, cecum + + + + + + + + + + + + + + + + + + + + + + + + + 

Intestine small, duodenum + + +-+ + + + + + + + + + + + + + + + + + + + + + 

Intestine small, jejunum + + + + + + + + + + + + + + + + + + + + + + + + + 

Carcinoma X 

Intestine small, ileum + + + + + + + + + + + + + + + + + + + + + + + + + 

Liver + + + + + + + + + + + + + + + + + + + + + + + + + 

Osteosarcoma, metastatic, mesentory X 

Mesentery + + + + 

Osteosarcoma ~ " X 

Oral mucosa +

Squamous cell carcinoma X 

Pancreas + + + + + + + + + + + + + + + + + + + + + + + + + 

Acinus, adenoma 

Salivary glands + + + + + + + + + + + + + + ~ + + + + + + + + + + 

Carcinoma X 

Fibrosarcoma, metastatic, skin X 

Stomach, forestomach + + + + + + + + + + + + + + + + + + + + + + + + + 

Squamous cell papilloma 

Stomach, glandular +'+ + + + + + + + + + + + + + + + + + + + + + + + 

Tongue 

Tooth ~ 

Odontoma 

Cardiovascular System 

Blond vessel + + + + + + + + + + + + + + + + + + + + + + + + + 

Heart + + + + + + + + + + + + + + + + + + + + + + + + ~ 

:: ̧ 

Endocrine System 

Adrenal cortex + + + + + + + + + + + + + + + + + + + + + + + + + 

Adrenal medulla + + + + + + + + + + + + + + + + + + + + + + + + + 

Pheochromocytoma malignant 

Pheochromocytoma benign X 

Pheochromocytuma benign, multiple 

Islets. pancreatic + + + + + + + + + + + + + + + + + + + + + + + + + 

Adenoma 

Parathyroid gland + + + + + + + + + + + + +M+ + + + + + + + + + + 

Pituitary gland + + + + + + + + + + + + + + + + + +M+ + + + + + 

Pars distalis, adenoma X X X X X X 

Pars distalis, carcinoma 

Thyroid gland + + + + + + + + + + + + + + + + + + + + + + + + + 

C-cell, adenoma 

Follicular cell, adenoma 

General Body System 

Peritoneum 
i96 t~Butyihydroquinone, NTP TR459 

TABLE A2 

Individual Animal Tumor Pathology of Male Rats in the Long-Term Feed Study of t-Butylhydroquinone: 2,500 ppm ~ (continued) ~ , 

666666667777'7777777777777 

Number of Days on Study 7778999912223345566677899 

3472145505990847716737625 , . 

1111211111111111111111111 ,

Carcass ID Number 4797087989468468846465746 

3543006547785276863103791 

Alimentary System 

Esophagus + + + + + + + + + + + + + + + + + + + + + + + + + 

Intestine large, colon + + + + + + + + + + + + + + + + + + + + + + + + + 

Intestine large, rectum + + + +~+ + + + + + + + + + + + + + + + + + + ~ + 

Carcinoma X 

Intestine large, cecum + + + + + + + + + + + + + + + + + + + + + + + + + 

Intestine small, duodenum + + + + + + + + + + + + + + + + + + + + + + + + + 

Intestine small, jejunum + +A + + + + + + + + + + + + + + + + + + + + + ~ 

Carcinoma 

Intestine small, ileum + + + + + + + + + + ++ + + + + + + + + + + + + + 

Liver + + + + + + + + + + + + + + + + + + + + + + + + +

Osteosarcoma, metastatic, mesentery 

Mesantery + + + 

Osteosarcoma 

Oral mucosa + 

Squamous cell carcinoma X 

Pancreas + + + + + + + + + + + + + + + + + + + + + + + + + 

Acinus, adenoma 

Salivary glands + + + + + + + + + + + + + + + + + + + + + + + + + 

Carcinoma 

Fibrosar¢oma, metastatic, skin 

Stomach. forestomach + + + + + + + + + + + + + + + + + + + + + + + +'+ 

Squamous cell papilloma X 

Stomach, glandular +++++++++-6++.+++++++++++++ 

Tongue 

Tooth + +

Odontoma X 

Cardiovascular System .

Blood vessel + + + + + + + + + + + + + + + + + + + + + + + + + 

Heart + +.+ + + + + + + + + + + + + + + + + + + + + + +

Endocrine System 

Adrenal cortex .6.6.6.6.6.6.6+.6+.6.6.6.6 .6++++++++++ 

Adrenal medulla .6.6.6.6+.6.6.6.6.6.6.6.6.6 ++++++++.6++ 

Pheochromocytoma. malignam X 

Pheochromocytoma benign X X X X X X X 

Pheochromocytoma benign, multiple XX 

Islets, pancreatic .6.6.6+.6.6.6.6.6.6.6++.6 ÷÷÷÷++÷,.6+÷÷ 

Adenoma X 

Parathyroid gland 6~.6 • .6 .6 .6 + M .6 .6 .6 .6 .6 + .6 ++.6+.6+.6.6.6.6.6' 

Pituitary gland .6+.6+.6.6++.6.6+.6.6.6 .6 .6 ÷ .6 ~ ~ + .6 + + + 

Pars distalis, adenoma XX X X XX X X 

Pars distalis, carcinoma X 

Thyroid gland .6.6.6.6+.6.6.6".6+.6.6+.6 + + + + + + + + + + + 

C-cell, adenoma X X 

Follicular cell, adenoma 

General Body System 

Peritoneum + ,. 
~:~ ~ - ~ ' ~ ' ~ y ~ ::~ - - = 7--~ ~:~-~,--

: t-l~u~y~hy~r~qu~none, NTP T~.~$~ 

TABLE A2 

~nd~vidIua~ Anhna~ '~or ~a~ho~o~y o~ M~He ~n ~he Long-Te~n~ l~'eed S~udyo~ t-~u~y~hyc~roqu~none: 2,5~ ppn~ 

(continued) 

~ g Sg~ 8 s s 

I~umber of Days on Study 01145555 

60552227 

1 1 1 1 1 1 1 1 Toml 

Carcass ~D Number ~4 6 5 5.5 6 8 6 Tissues/ 

5 4 6 4 9 5 1 9 ~mors 

Alimentary System 

Esophagus ++++++++ 58

Intestine large, colon ++++++++ 58 

Intestine large, rectum ++.++++++ 58 

Carcinoma I 

Intestine large, cecum ++++++++ 58

Intestine small, duodenum ++++++++ 58 

Intestine small, jejunum ++++++++ 57 

Carcinoma I 

Intestine small, ileum ++++++++ 58

Liver ++++.++++ 58

Osteosarcoma, metastatic, mesentery I 

Mesentery 7 

Osteosarcoma I 

Oral mucosa 2 

Squamous cell carcinoma 2 

Pancreas ++++++++ 58

Acinus, adenoma X 1 

Salivary glands ++++++++ 58

Carcinoma 1 

Fibrosarcoma, metastatic, skin 1 

Stomach, forestomach ++++++++ 58

Squamous cell papilloma 1 

Stomach, glandular ++++++++ 58 

Tongue + 1 

Tooth 2 

Odontoma 1 

Cardiovascular System 

Blond vessel + + + + + + + + 58 

Heart + + + + + + + + 58 

Endocrine System l 

Adrenal cortex + + + + + + + + 58 

I Adrenal medulla + + + + + + + + 58 I 

I Pheochromocytoma malignant 1 

Pheochromocytoma benign X X X 11 

!

I Pheochromocytoma benign, multiple X X 4 

Islets, pancreatic + + + +. + + + + 58 

Adenoma 1 

Parathyroid gland M + + + + + + + 55 

Pituitary gland + + + + + + + + 57 

Pars distalis, adenoma X X X 17 

Pars distalis, carcinoma 1 

Thyroid gland + + + + + + + + 58 

C-cell, adenoma 2 

Follicular cell, adenoma X 1 

General Body System 

Peritoneum 1 
98 t-Butylhydroquinone, NTP TR 459 

J 

TABLE A2 .. 

Individual Animal Tumor Pathology of Male Rats in the Long-Term Feed Study of t-Butylhydroquinone: 2,500 ppm. ~ 

(continued) 

4444555555555555666666666 

Number of Days on Study 0679023356677999011124456. 

8433165522208111448950251 

1111111111111111111111111 

Carcass ID Number • 7599774585787678598659549' 

8883418597920623207211042 

Genital System 

Epididymis + + + + + + + + + ÷ + + + + + + + + + + +=+ + + + 

Preputial gland + + + + + + + + + + + + + + + + + + + + + + + + + 

Adenoma X X X 

Carcinoma X 

Carcinoma, multiple 

Prostate + + + + + + + + + + + + + + + ÷ + + + + + + + + + 

Adenoma 

Seminal vesicle + + + + + + + + + + + + + + + ÷ + + + + + + + + + 

Testes + + + + + + + + + + + + + + + + + + + + + + + + +

Bilateral, interstitial cell, adenoma XX X XXXXXX XXXXXX XX. X 

Interstitial cell, adenoma X X X X X -XHematopoietic System -. 

Bone marrow + + + + + + + + + + + + + + + + + + + + + + + + + 

Lymph node ++ + ++ ++ ++ +++ +

Mediastinal, osteosarcoma, . 

metastatic, mesentery X 

Lymph node, mandibular + + + + + + + + + + + + + + + + + + + + + + +,+ + 

Fibrosarcoma, metastatic, skin X 

Lymph node, mesenteric + + + + + + + + + + + + + + + + + + + + + + ÷.+ + 

Spleen + + + + + + + + + + + + + + + + + + + +.+ + + + + 

Osteosarcoma, metastatic, mesentery X 

Sarcoma 

Thymus ++++++++++++++++ ++++++M+ + 

Integumentary System 

Mammary gland + + + +M+ + + + + + + ÷ + + + + + + + + + + + + 

Adenoma 

Fibroadenoma X 

Skin ÷ + ÷ ÷ + + + + + + + + + + + + ÷ + +.÷ + + + + + 

Keratoacanthoma X 

Subcutaneous tissue, fibroma X X X 

Subcutaneous tissue, fibrosarcoma X 

Subcutaneous tissue, schwannoma malignant X 

Musculoskeletal System ,:..

+ + ++ + + + ÷ + + ÷ + + + + + + + + + + + + + + . Bone 

Osteosarcoma ~ X . : 

+ • Skeletal muscle 

Mesothelioma malignant, metastatic, peritoneum • 

Osteosarcoma, metastatic, mesentery X "i 

Nervous System 

Brain 

Peripheral nerve 

Spinal cord 
~ =::,= ~,--~:~ _ ............ ~ , ~ - , ..................... : ~ ~ . ~ - ; ~ ~ 

g-1l~u~y~hy~roqu~none, I~ T~ 459 99 

TABLE A2 

~nd~v~ua~ 

(continued) 

An~na~ Tu~nor Pathology of l~/~a~e ~a~ in the ~ng-Te~ Feed Study of t-~utynhydroq~none: 2,500 ppm 

6666666677777777777777777 

Number of Days on Study 7778999912223345566677899 

3472145505990847716737625 

1111211111111111111111111 

Carcass ~D Number 4797087989468468846465746 

3543006547785276863103791 

~l 

I 

GenRal System 

Epididymis 

Preputial gland 

Adenoma 

Carcinoma 

Carcinoma, multiple 

Prostate 

Adenoma 

Seminal vesicle 

Testes 

Bilateral, interstitial cell, adenoma 

Interstitial cell, adenoma 

+ +M+ + + + 

+ + + 

+ + + 

+ +M+ 

XX 

+ 

+ 

+ 

X 

+ + 

+ + 

+ + 

+ + 

+ + 

XX 

+ 

+ 

X 

+ 

+ 

+ 

X 

+ 

+ 

X 

+ 

+ 

+ 

X 

+ + + + + + 

+ + + + + + 

+ + + + + + 

+ + + + + + 

+ + + + + + 

XXXXXX 

+ 

+ 

+ 

+ 

+ 

X 

+ + + + + + + + + 

+ + + + + + + + + 

+ + + + + + + + + 

X 

+ + + + + + + + + 

+ + + + + + + + + 

XXXXXXXXXX 

+ 

+ 

+ 

+ 

+ 

i~ 

Hematopoietic System 

Bone marrow 

Lymph node 

Mediastinal, osteosarcoma, 

metastatic, mesentery 

Lymph node, mandibalar 

Fibrosarcoma, metastatic, skin 

Lymph node, mesenteric 

Spleen 

Osteosarcoma, metastatic, mesentery 

Sarcoma 

Thymus 

+ + 

+ + 

+ + 

+ + 

+,+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ + 

+ + 

+ ~ 

+.+ 

+ + 

+ + 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

X 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

I 

/ 

Integumentary System 

Mammary gland 

Adenoma 

Fibroadenoma 

Skin 

Keratoacanthoma 

Subcutaneous tissue, fibroma 

Subcutaneous tissue, fibrosarcoma 

Subcutaneous tissue, schwannoma malignant 

I 

I 

+ +++++++++++++++ + + + + ++ ++ 

X XX 

++++++++++++++++++++++++ 

X X X 

Musculoskeletal System 

Bone 

• Osteosarcoma 

Skeletal muscle 

Mesothelioma malignant, metastatic, peritoneum 

Osteosarcoma, metastatic, mesentery 

+ + + + + + + + + + + + + + + + + + 

+ 

X 

+ + + + + + + 

Nervous System 

Brain 

Peripheral nerve 

Spinal cord, 
100 t-Butylhydroquinone, NTP TR459 

TABLE A2 

Individual Animal Tumor Pathology of Male Rats in the Long-Term Feed Study of t-BUtylhydr0quinone: 

(continued) 

Number of Days on Study 

Carcass ID Number 

Genital System 

Epididymis 

Preputial gland 

Adenoma 

Carcinoma 

Carcinoma, multiple 

Prostate 

Adenoma 

Seminal vesicle 

Testes 

Bilateral, interstitial cell, adenoma 

Interstitial cell, adenoma 

Hematopoietic System 

Bone marrow 

Lymph node 

Mediastinal, ostebsarcoma, 

metastatic, mesentery 

Lymph node, mandibular 

Fibrosarcoma, metastatic, skin 

Lymph node, mesenterie 

Spleen 

Osteosarcoma, metastatic,, mesentery 

•Sarcoma " 

Thymus 

Integumentary System 

Mammary gland 

Adenoma 

Fibroadenoma 

Skin 

Keratoaeanthoma 

Subcutaneous tissue, fibroma 

Subcutaneous tissue, fibrosarcoma 

Subcutaneous tissue, schwannoma malignant 

Musculoskeletal System 

Bone 

Osteosarcoma 

Skeletal muscle 

Mesothelioma malignant, metastatic, peritoneum 

Osteosarcoma, metastatic, mesentery 

Nervous System 

Brain 

Peripheral nerve 

Spinal cord 

,., 

88888888 

01145555 

60552227 

11111111 " 

46555686 

54649519 

++++++++ 

++++++++ 

X X 

++++++++ 

++++++++ 

++++++++ 

XX XXXXX 

X 

++++++++ 

++++++ 

++++++++ 

++++I+++ 

++++++++ 

+++I+MM+ 

• :: 

++++++++ 

X .~; 

++++++++ 

XX X 

++++++++ 

+++÷++++ 

2,500 ppm 

Total 

Tissues/ 

Tumors 

57 

58 

6 

"I 

1' 

58 

1 

58 

57 

45 

11 

58 

34 

I 

58 

I 

57" 

• 58 

1 

'I 

54 

56 

i 

4 

57 

4 

6 

1 

1 

58 

1 

2 

1 

1 

58 -

1 

1 
:_-~_. ~ ~ . . . . ~ : ~ ~ ~: :: ..... . ~ ~ 

~ ~~---~ ~.~-=~-~.~7--~.~- : --~.~-=~.,_ .................. ....... - - ~ ~ ~ : . . . . . . . . . . . . . . . . . . . . . . . 

¢-/~u~y~hydro~u~nOne~ ~ T~ ~.~9 aoa 

T~L~ A~ 

]Mdividu~ Axm~mma~ Tummor Fa~ho~o~y oi~ I~a~e ~at~ iu the Lo~g-Te~ Feed Study oi~ g-~uty~hydroc~uinone: 2,S~ ppm 

I 

I 

 ̧:I 

(continued) 

Number o~ Days on Stuc~y 

Carcass ~D Number 

Respiratory System 

Lung 

Alveolar/bronchiolar adenorna 

Carcinoma, metastatic, salivary glands 

Squamous cell carcinoma, metastatic, 

oral mucosa 

Nose 

Pleura 

Trachea 

Special Senses System 

Ear 

Eye 

Carcinoma, metastatic, salivary glands 

Zymbal's gland 

Carcinoma 

Urinary System 

Kidney 

Osteosarcoma, metastatic, mesentery 

Renal tubule, adenoma 

Urinary bladder 

Papilloma 

Systemic ~.sions 

Multiple organs 

Leukemia mononuclear 

Mesothelioma malignant 

4444555555555555666666666 

0679023356677999011124456 

8433165522208111448950251 

1111111111111111111111111 

7599774585787678598659549 

8883418597920623207211042 

+ + + + + + + + + + + + + + + + + + + + + + + + + 

X 

X 

X 

+ + + + + + + + + + + + + + + + + + + + + + + + + 

+ + + + + + + + + + + + + + + + + + + + + + + + + 

+ 

X 

+ 

X 

+ + + + + + + + + + + + + + + + + + + + + + + + + 

X 

+ + + + + + + + + + + + + + + + + + + + + + + + + 

X 

X X XXX X XX X X X X X X 
102 

TKBLE A2 

Individual Animal Tumor 

(continued) 

Number of Days on Study 

Carcass ID Number 

Respiratory System 

Lung 

Alveolar/bronchiolar adenoma 

Carcinoma, metastatic, salivary glands 

Squamous cell carcinoma, metastatic, 

oral mncosa 

Nose 

Pleura 

Trachea 

Special Senses System 

Ear 

Eye 

Carcinoma, metastatiC, salivary glands 

Zymbal's gland 

Carcinoma 

Urinary System 

Kidney 

Osteosarcoma, metastatic, mesentery 

Renal tubule, adenoma 

Urinary bladder 

Papilloma 

Systemic Lesions 

Multiple organs 

Leukemia mononuclear 

Mesothelioma malignant 

. 

• t-Butyihydroquinone, NTP TR 459 

Pathology of Male Rats iil the Long-Term Feed Study of t-Butylhydroquinone: 2,500 ppm 

6666666677777"777777777"777 

7778999912223345566677899 . 

3472145505990847716737625 

11.1121111111!111111111111 

4797087989468468846463746 

3343006547783276863,103791 

+ + + + + + + + + + + + + + + + + + + + + + + + + 

+ + + + + + + + + + + + + + + + + + + + + + + + + 

+ 

+ + + + + + + + + + + + + + + + + + + -~ + + + .+ + 

+ + 

X " X. 

+ + + + + + + + + + + + + + + + + + + + + + + + + 

~X + + + + + + + + + + + + + + + + + + + + + + + + + 

. 

. 

X X X X X X X X XX X X X X X X X X X X X 

X 
I 

?= -~-'~----~-~7 :~---~----i-- ~ ~,~ : : = ~ ::. ~ : : :- :: =~-:----÷. . . . . . . . z 

t-Butylhydroquinone, N~P TR 459 

TABLE A2 

~nd~v~dua~Anhna~ Tumor Pathology o~ IV~adeRats ~n the Long-Term Feed Study of t-ButyHhydroqu~none: 2,500 ppm 

(continued) 

Number of Days on Study 

Carcass ~D Number 

Respiratory System 

Lung 

Alveolar/bronchiolar adenoma 

Carcinoma, metastatic, salivary glands 

Squamous cell carcinoma, metastatic, 

oral mucosa 

Nose 

Pleura 

Trachea 

Special Senses System 

Ear 

l~ye 

Carcinoma, metastatic, salivary glands 

Zymbal's gland 

Carcinoma 

Urinary System 

Kidney 

Osteosarcoma, metastatic, mesentery 

Renal tubule, adenoma 

Urinary bladder 

Papilloma 

Systemic Lesions 

Multiple organs 

Leukemia mononuclear 

Mesothelioma malignant 

88888888 

01145555 

60552227 

1 1 1 1 1 1 1 1 ToM 

46555686 Tissues/ 

54649519 Tumors 

++++++++ 58 

1 

1 

1 ++++++++ 58 

1 ++++++++ 58 

++++++++ 58 

1 

1 ++++++++ 58 

1 

++++++++ 58 

XX XXX 40 

1 
104 t-Butylhydroquinone, NTP TR 459 

TABLE A2 

Individual Animal Tumor Pathology of Male Rats in the Long-Term Feed Study of t-Butyihydroquinone: 5,000 ppm 

4445555566666.666666666667 

Number of Days on Study 2880235802222234444567890 

3778071931666722777585212 

2222222222222222222222222 

Carcass ID Number 4465375136245532345656264, 

2547008753463469940815570 

Alimentary System 

Esophagus + + + + + + + + + + + + + + + + +M+ + + + + + + 

Intestine large, colon + + + + + + + + + + + + + + + + + + + + + + + + + 

Intestine large, rectum + + + + + + + + + + + + + + + + + + + + +M+ + + 

Intestine large, cecum + + + + + + + + + + + + + + + ~ + + + + + + + + + 

Intestine small, duodenum + + + + + + + + + + + + + + + + + + + + + + + + +

Intestine small, jejunum + + + + + + + + + + + + + + + + + + + + + + + + +

Intestine small, ileum + + + + + + ++ + + + + + + + + + + + + + + + + +

Liver + + + + + + + + + + + + + + + + + + + + +.+ + + +

Hepatoceilular carcinoma 

Hepatocellular adenoma 

Mesothelioma malignant, metastatic, peritoneum 

Mesentery + + +++ + +

Pancreas ! + + + + + + ÷ + + + + + + + + + + + + + + + + + + 

+ + + + + + + + + + + + + + + + + + + + + + + + + 

+ + + + + + + + + + + + + + + + + + + + + + + + + Salivary glands 

Stomach, forestomach 

Squamous cell papilloma X 

Stomach, glandular + + + + + + + + + + + + + + + + + + + + + + + + + 

Tongue + 

Sqnamous cell papilloma X 

Tooth 

Cardiovascular System 

Blood + + + + + + + + + + + + + + + + + + + + + + + + + vessel + + + + + + + + + + + + + + + + + + + + + + + + + Heart 

Endocrine System + + + + + + + + + + + + + + + + + + + + + + + + + Adrenal cortex 

Adenoma + + + + + + + + + + + + + + + + + + + + + + + + + Adrenal medulla 

Pheochromocytoma malignant 

Pheochromocytoma benigu X X X X 

Pheochromocytoma benign, multiple 

Islets, pancreatic + + + + + + + + + + + + + + + + + + + H + + + + + 

Adenoma 

Parathyroid gland + + + + + + + + + + + + + + + + + + +M+ + + + + 

+ + + + + + + + + + + + + + + + + + + + + + + + + Pituitary gland 

Pars distalis, adenoma X 

Pars distalis, carcinoma X ++++++++++++++++ +++++++ ~ ÷ Thyroid gland 

C-cell, adenoma XX 

C-cell, carcinoma 

Follicular cell, carcinoma 

General Body System 

Peritoneum + + 
7: 

;?:~ ~:~'~:~'~ " ~,'~--'---~-S-~ ~ - ~ - ~ __ _:: : ~ ................ "~'z~z:~ . . . . . , 

t-~uty]hydroquinone, NTP Tg 459 ~05 

TABLE A2 

~Mdivhtua~ Anhn~ Tumor ~atho~ogy of Mate ~ats in the Long-Term Feed Study of t-~uty~hydroquinone: 5,~)~ ppm 

(continued) 

7777777777777777888888888 

Number of Days on Study 0013333445667788000135555 

2890009550673366678097777 

2222222222222222222222222 

Carcass ~D Number 4152456223533623236611111 

7191362782214907380132456 

Alimentat V System i Esophagus + + + M + + + + + + + + + + + + + + + + + + + + + 

Intestine large, colon + + + + + + + + + + + + + + + + + + + + + + + + + 

Intestine large, rectum + + + + + + + + + + + + + + + + + + + + + + + + + 

+ + + + + + + + +'+ + + + + + + + + + + 

Intestine small, duodenum + + + + + + + + + + + + + + + + + + + + + + + + +. 

Intestine large, cecum + + + + + 

Intestine small, jejunum + + + + + + + + + + + + + + + + + + + + + + + + +

Intestine small, ileum + + + + + + + + + + + + + + + + + + + + +M+ + + 

Liver + + + + + + + + + + + + + + + + + + + + + + + + + 

Hepatocellular carcinoma X X 

Hepatoccl[ular adcnoma X X 

Mesotbelioma malignant, metastatic, peritoneum X 

Mesentery + 

i 

++ + + + + + 

Pancreas + + + + + + + + + + + + + + + + + + + + + + + + + 

Salivary glands + + + + + + + + + + + + + + + + + + + + + + + + +

Stomach, forestomach + + + + + + + + + + + + + + + + + + + +I + + + + 

Squamous cell papilloma 

Stomach, glandular + + + + + + + + + + + + + + + + + + + + + + + + + 

Tongue + + 

Squamous cell papilloma 

Tooth + 

Cardiovascular System 

Blood vessel + + + + + + + + + + + + + + + + + + + + + + + + + 

Heart + + ÷ + + + + + + + + + + + + + + + + + + + + + +

Endocrine System 

Adrenal cortex + + + + + + + + + + + + + + + + + + + + + + + + + 

Adenoma X 

Adrenal medulla + + + + + + + + + + + + + + + + + + + + + + + + + 

Pbeochromocytoma malignant X 

Pbeochromocytoma benign X X X X 

Pbeochromocytoma benign, multiple 

Islets, pancreatic + + + + + + + + + + + + + + + + + + + + + + + + + 

Adenoma X X 

Parathyroid gland + + + + + + + + + + + + + + + + + + + + + + + + + 

Pituitary gland + + + + + + + + + + + + + + + + + + + + + + + + + 

Pars distalis, adenoma X X X 

Pars distalis, carcinoma 

Thyroid gland + + + + + + + + + + + + + + + + + + + + + + + + + 

C-cell, adenoma X 

C-cell, carcinoma X 

Follicular cell, carcinoma XX 

General Body System 

Peritoneum + 
106 :'t-Butylhydroquinone; NTP TR 459 

TABLE A2 

Individual 

(continued) 

Animal Tumor Pathology of Male Rats in the Long-Term Feed Studyof t-Butylhydroquinone: 

. 

5,000 ppm 

8888888888 

Number of Days on Study 5555555555 

7777777777' 

2222222222 Total 

Carcass ID Number 1122344456 

8926318956 

Tissues/ 

Tumors 

Alimentary System 

Esophagus 

Intestine large, colon 

Intestine large, rectum 

Intestine large, cecum 

Intestine small, duodenum 

Intestine small, jejunum 

Intestine small, ileum 

Liver 

Hepatocellular carcinoma 

Hepatocellular adenoma 

Mesothelioma malignant, metastatic, peritoneum 

Mesentery 

Pancreas 

Salivary glands 

Stomach, forestomach 

Squamous cell papilloma 

Stomach, glandular 

Tohgue 

Squamous cell papilloma 

'Tooth 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

X 

.. 

.. 

58 

60 

59 

60 

60 

60. 

59 

60 

2 

3 

1 

16 

60 

60 

59 

1 

60 

4 

2 

1 

Cardiovascular System 

Blood vessel 

Heart 

÷ 

+ 

+ 

+ 

+ 

+ 

~ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

Endocrine System 

Adrenal cortex + + + + + + + + + + ~0 

Adenoma 

Adrenal medulla 

Pbeochromocytoma malignant 

Pheochromocytoma benign 

Pheochromocytoma benign, multiple 

Islets, pancreatic 

Adenoma 

Parathyroid gland 

Pituitary gland 

Pars distalis, aden0ma 

Pars distalis, carcinoma 

Thyroid gland 

C-cell, adenoma 

' C-cell, carcinoma 

Follicular cell, carcinoma 

+ + + 

X 

XX 

+ + + 

+ ++ 

+ + + 

+ + + 

+ 

+ 

X 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

X 

+ 

+ 

+ 

X 

+ 

X 

+ 

X 

X 

+ 

+ 

+ 

+ 

X 

+ + 

+ + 

+M+ 

+ + 

X 

+ + 

X 

+ 

+ 

+ 

+ 

~' 

~ 

1 

~0 

3 

, .11 

1 

BO 

• . 58 

6• 

l 

- ~0 

4 

3 

• 

General Body System 

Peritoneum 

• ' : • .: 

3 

• ., 
_ 

~ ~r--~ ~ ........ ~r ........ ~ .... ~z,=~ : ~ ~ , , - ..i~ ...... ~ - - ~ ~ - - ~ ~ , 

t-~u~lhy~troquinone, NT~ ~II~ g~9 107 

i 

TABLE ~ 

~nd~v~due~ Anhn~ Tumor ~tho~ogy of M~e ~e~ in the Long-Tern ~'eed Study of t-~uty~hy~roqu~none:. 5,0~0 ppm 

(continued) 

4445555566666666666666667 

Number of Days on Study 2880235802222234444567890 

3778071931666722777585212 

2222222222222222222222222 

Carcass ~D Number 4465375136245532345656264 

2547008753463469940815570 

I Genital System 

Epididymis + + + + + + + + + + + + + + + + + + + + + + + + + 

Preputial gland + + + + + + + + + + + + + + + + + + + + + + + + + 

Adenoma 

Carcinoma X X 

Prostate + + + + + + + + + + + + + + + + + + + + + + + + + 

Adenoma 

Seminal vesicle + + + + + + + + + + + + + + + + + + + + + + + + + 

Testes + + + + + + + + + + + + + + + + + + + + + + + + + 

Bilateral, interstitial cell, adenoma .XXXXXXXXX XXXXXXXXXXX 

Interstitial cell, adenoma X XXX 

Hematopoietic System 

Bone marrow + + + + + + + + + + + + + + + + + + + + + + + + + 

Lymph node + + + ++ +++ + ++++ + 

Lymph node, mandibular + + + + + + + + + + + + + + + + + + + + + + + + +, 

Carcinoma, metastatic, Zymbal's gland X 

Lymph node, mesenteric + + + + + + + + + + + + + + + + + + + + + + + + + 

Hemangioma 

Spleen ÷ + + + + + + + + + + + + ÷ + + + + + + % + + + + 

Sarcoma X 

Thymus ÷ ÷ + + + + + + + + + + + + + + + + + + + + + + + 

Thymoma malignam 

~ntegumentary System 

Mammary gland +++M+++++++++++++++++++++ 

Fibroadenoma 

Fibroadenoma, multiple 

Skin 

Keramacanthoma X 

Squamous cell papilloma X 

Trichoepithelioma X 

Subcutaneous tissue, fibroma X 

Subcutaneous tissue, fibrosarcoma 

Subcutaneous tissue, schwannoma malignant 

Musculoskelet~l System 

Bone 

Nervous System 

Brain 

Peripheral nerve 

Spinal cord 

Respirmo~ System 

Lung 

Alveolar/bronchiolar adenoma 

Alveolar/bronchiolar carcinoma 

Nose 

Trachea 
108 t-Butylhydroquinone,~ NTP TR 459 

TABLE A2 

Individual Animal Tumor Pathology of Male Rats in the Long-Term Feed Study of t-Butylhydroquinone:. 5,000 ppm 

(continued) 

J 

777777777.7777777888888888 

Number of Days on Study 00.13333445667788000135555 

2890009550673366678097777 

2222222222222222222222222 

Carcass ID Number 4152456223533623236611111 

7191362782214907380132456 

Genital System 

Epididymis + + + + + + + + + + + + + + + + + + + + + + + + + 

Preputial gland + + + + + + + + + + + + + + + + + + + + + + + + +

Adenoma X X 

Carcinoma X X X 

Prostate + + + + + + + + + + + + + + + + + + + + + + + + + 

Adenoma 

Seminal vesicle + + + + + + + + + + + + + + + + + + + + + + + + + 

Testes + + + + + + + + + + + + + + + + + + + + + + + + +

Bilateral, interstitial cell, adenoma XXX XXXXXX X X XXXX X X X, X X X X 

.Interstitial cell, adenoma X X X 

HematopoieticSystem 

Bone marrow + + + + + + + + + + + + + + + + + + + + + + + + + 

Lymph node + + + + + + + + + + + + + + + + + + 

Lymph node, mandibular + + + + + + + +.+ + + + + + + + + + + + + + + + +

Carcinoma, metastatic, Zymbal's gland 

Lymph node, mesenteric + + + + + + + + + + + + + + + + + + + + + + + + + 

Hemangioma 

Spleen + + + + + + + + + + + + +.+ + + + + + + + + + + + 

Sarcoma 

Thymus + + + + + + + + + + + + + + + + + + + + + + + +M 

Thymoma malignant X 

Integumentary System 

Mammary gland + + + + + + + + + + + + + + +M+ + + + + + + + + 

Fibroadenoma X X 

Fibroadenoma, multiple + ÷ + + + + + + + + + + + + + + + + + + + + + + + Skin 

Keratoacanthoma X X 

Sqnamous cell papilloma X 

Trichoepithelioma 

Subcutaneous tissue, fibroma X X X 

Subcutaneous tissue, fibrosarcoma . X

Subcutaneous tissue, schwannoma malignant X 

Musculoskeletal System + + + + + + + + + + + + + + + + + + + + + + ~ + + ~ Bone 

Nervous System 

Brain ++ ++ + ++++ + + + + + + + + + + + + + + + +

Peripheral nerve + 

Spinal cord + 

Respiratory System 

Lung 

Alveolar/bronchiolar adenoma 

Alveolar/bronchiolar carcinoma X 

Nose 

Trachea 
=_~ . . . . 

....... ~:~7"7"~-~ :'--~:~'---~'~ "~-- ~: . . . . . . . . . . . . . . . . . 7 - - ...... ....... , ......... ~ ::='=~ ~ - " ~ .......... - - .... - - " 

t-~utylhydroqu~none, NTP TR 459 109 

TABLE A2 

Individual 

(continued) 

Anhnal Tu~nor Pathology of I~Ia~e ]l~ats ~n the Long-Terrn Feed Study o~ t-li~uty~hydroqu~noue: 5,0~ ppm 

8888888888 

Number of Days on Study 5555555555 

7777777777 

2 2 2 2 2 2 2 2 2 2 ToN 

Carcass ID Number 1122344456 

8926318956 

Tissues/ 

Tumors 

Genital System 

Epididymis 

Preputial gland 

Adenoma 

Carcinoma 

Prostate 

Adenoma 

Seminal vesicle 

Testes 

Bilateral, interstitial cell, adenoma 

Interstitial cell, adenoma 

+ + + + + ++ + + + 

+ + + + + + + + + + 

X 

+ + + + + +. + + + + 

X 

+ + + + + + + + + + 

+ + + + + + + + + + 

X X X X X X X X 

X X 

60 

60 

3 

5 

60 

1 

60 

60 

50 

9 

Hematopoietic System 

Bone marrow 

Lymph node 

Lymph node, mandibular 

Carcinoma, metastatic, Zymbar s gland 

Lymph node, mcscnteric 

Hemangioma 

Spleen 

Sarcoma 

Thymus 

Thymoma malignant 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ + + + 

+ 

+ + ++ 

+ + + + 

+ + + + 

MMM + 

+ + + 

+ + 

+ +++ 

+ + + 

X 

+ + + 

+ + + 

+ 

+ 

+ 

+ 

60 

35 

60 

I 

60 

1 

60 

1 

56 

1 

I : 

:: I 

; i I 

=?~ I 

Integumentary System 

Mammary gland 

Fibroadenoma 

Fibroadenoma, multiple 

Skin 

Keratoacanthoma 

Squamous cell papilloma 

Trichoepithelioma 

Subcutaneous tissue, fibroma 

Subcutaneous tissue, fibrosarcoma 

Subcutaneous tissue, schwannoma malignant 

+ 

X 

+ 

X 

+ 

+ 

+ 

X 

+ 

X 

+ 

X 

+ 

+ 

+ 

+ 

X 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

X 

+ 

X 

+ ~ 

58 

6 

1 

60 

4 

2 

1 

6 

1 

1 

Musculoskeletal System 

Bone +++++÷++%+ 

Nervous System 

Brain 

Peripheral nerve 

Spinal cord 

+ + + + + + + + + + 60 

1 

1 

Respiratory System 

Lung 

Alveolarforonchiolar adenoma 

Alveolar/bronchiolar carcinoma 

Nose 

Trachea 

+ + + + + + + + + 

+÷+÷÷%÷+%+ 

+ + ÷ +.+ + + + + 

+ 

+ 

60 

I 

1 

60 

60 
• 110 t-Butylhydroquinone, NTP TR 459 

TABLE A2 

Individual Animal Tumor Pathology of Male Rats in the Long-Term Feed Study of. t-Butylhydroquinone::5,000 ppm 

(continued) ". 

4445555566666666666666667 

Number of Days on Study 2880235802222234444567.890 

3778071 ,931666722777585212 

2222222222222222222222222 

Carcass ID Number • 446537513624553234565626.4 

2547008753463469940815570 

Special Senses System 

Eye + 

Harderian gland 

Zymbal's gland + + + 

Adenoma X 

Carcinoma X X 

Urinary System 

Kidney + + + + + + + + + + + + + + + + + ~ + + + + + + + 

Renal tubule, adenoma 

Urinary bladder + + + + + + + + + + + + + + + + + + + + + + + + + 

Papilloma 

Systemic Lesions 

Multiple organs 

Leukemia mononuclear X XX X XXX X X XXX. 

Mesothelioma malignant X X 
I 

t-Butylhydroquinone, NTF TIR ~S~ l~l 

TABLE A~ 

~ndividua~ Anhn~] T~nor ~atho~ogy oi ]~e, ~ ~n the Long-Tern~ ~'eed S~n~y o~ ~-Suty~hydro~e~one: 5,~0 ppm 

(continued) 

7777777777777777888888888 :: 

Number of Days on Study 0013333445667788000135555 

2890009550673366678097777 

2222222222222222222222222 

Carcass ~D Number 4152456223533623236611111 

7191362782214907380132456 

! Special Senses System 

Eye + 

Harderian gland 

Zymbal's gland + 

Adenoma 

Carcinoma X 

Urinary System 

Kidney 

Renal tubule, adenoma X 

Urinary bladder ÷%÷++÷+++÷+%%÷%%%%÷÷%÷÷%% 

Papilloma 

Systemic Lesiom 

Multiple organs 

Leukemia mononuclear XXXXX XXX XXX XX XX X 

Mesothclioma malignant X 
112 t-Butylhydroquinone, NTP TR 459 

TABLE A2 ' 

Individual 

(continued) 

Animal Tumor Pathology of Male Rats in the Long-Term Feed Study of t-Butylhydroquinone: $,000 ppm 

. 

Number of Days on Study 

8888888888 

5555555555 

7777777777 

Carcass ID Number 

2.222222222 

1122344456 

8926318956 

T0m! 

, Tissues/ 

Tumors 

Special Senses System 

Eye 

Harderian gland 

Zymbal's gland 

Adenoma 

Carcinoma 

+ 

Urinary System 

Kidney 

Renal tubule, adenoma 

Urinary bladder 

Papilloma 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ + 

+ + 

X 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

• 

6O 

1 

60 

1 

Systemic Lesions 

Multiple organs 

Leukemia mononuclear 

Mesothelioma malignant 

+ + + 

X 

+ + 

X 

+ + + + 

XX 

+ 60 

32 

3 
~ ~--~----:::~-:7~-'-~ _ . ~ , -~ - ~ - - - - ~ . . . ............ ~,~----.___~ : ......... ~ ~:,~ ...... , . . . . . . - . _..~,,, ~ 

t-~uty~hydroqu~none, blTIF TII~ ,~59 ~13 

TA~L~ A3 

Statistical Analysis of ]Primary Heop~asn~s in I~Ia~e ]iRat~ ~n the Long-Term Feed Study o~ t-~utynhydroqu~none 

Adrenal Medulla: ~enign Pheochromocytoma 

Overall rate a 

Adjusted rate b I Terminal ratec 

First incidence (days) I Life table test d 

Logistic regression test d 

Coehran-Armita~e test d 

Fisher exact test u 

Adrenal Medulla: I~alignant Pheochromecytoma 

Overall rate 

Adjusted rate 

Terminal rate 

First incidence (days) 

Life table test 

Logistic regression test .. 

Cochran-Armitage test 

Fisher exact test 

Adrenal Medulla: 

Overall rate 

Adjusted rate 

Terminal rate 

Benign or Malignant Pheochromecy~oma 

First incidence (days) 

Life table test 

Logistic regression test 

Cochran-Armitage test 

Fisher exact test 

Liver: Hepatocellular Adenoma 

Overall rate 

Adjusted rate 

Terminal rate 

First incidence (days) 

Life table test 

Logistic regression test 

Cochran-Armitage test 

Fisher exact test 

. 

Liver: Hepatocellular Adenoma or Carcinoma 

Overall rate 

Adjusted rate 

Terminal rate 

First incidence (days) 

Life table test 

Logistic regression test 

Cochran-Arrnitage test 

Fisher exact test 

.- ̧ 

0 ppm 1,250 ppm 2,500 ppm 5,0~0 ppm 

14160 (23 %) 20/60 (33%) 15/58 (26%) 12160 (20%) 

59.8% 85.5% 100.0% 49.8% 

2/8 (25%) 5/7 (71%) 1/1 (100%) 5[14 (36%) 

667 655 473 487 

P = 0.071N P=0.148 P=0.090 P=0.193N 

Pffi0.16IN P=0.123 P=0.224 P=0.351N 

P=0.223N 

P=0.156 P=0.458 ' P=0.412N 

1/60 (2%) 3/60 (5%) 1/58 (2%) 3/60 (5%) 

3.1% 23.8 % 5.0% 21.4% 

0/8 (0%) 1/7 (14%). 0/1 (0%) 3/14 (21%) 

710 702 738 857 (T) 

P=0.496 P=0.302 P=0.698 P=0.465 

P=.0.390 P=0.296 P=0.738 P=0.394 

P=0.313 

P=0.309 P=0.744 Pffi0.309 

14/60 (23%) 21/60 (35%) 16/58 (28%) 13/60 (22%) 

59.8% 85.9% 100.0% 55.4% 

218 (25%) 5/7 (71%) 1/1 (100%) 6/14 (43%) 

667 655 473 487 

P--0.090N P--0.113 P=0.062 P=0.239N 

P---0.210N P=0.087 P=0.159 P=0.431N 

P=0.282N 

P = 0.114 P = O. 375 P -- 0.500N 

4/(~ (7 %) 4/60 (7 %) 0/58 (0%) 3/60 (5 %) 

25.1% 23.7% 0.0% 12.7% 

1/8 (13%) 1/7 (14%) 0/1 (0%) 1/14 (7%) 

.642 697 _e 708 

P--0.223N P-0.615 P=0.170N P=0.370N 

P--0.291N P=0.631 P=0.096N P--0.463N 

P--0.322N 

P=0.641N P=0.064N P=0.500N 

4/(~ (7%) 4/60 (7%) 0/58 (0%) 5/60 (8%) 

25.1% 23.7 % 0.0 % 21.0 % 

1/8 (13%) 1/7 (14%) 0/1 (0%) 1/14 (7%) 

642 697 -- 708 

P=0.504N P=0.615 P=0.170N P=0.611N 

P=0.526 P=0.631 P=0.096N P=0.548 

P=0.479 

P=0.641N P=0.064N P=0.500 
114 t - B u t y i h y d r o q u i n o n e , N T P T R 459 

TABLE A3 ' ~' , ~. 

Statistical Analysis of Primary .Neoplasms in Male Rats in the Long-Term Feed Study of t-Butylhydroquinone (continued) t 

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

Lung: Alveolar/bronchiolar Adenoma 

Overall rate 3/60 (5%) 2/60 (3%) 1/58 (2%) 1/60 (2%) . 

Adjusted rate 10.2% 8.2% 2.4% 4.3% 

Terminal rate 0/8 (0%) 0/7 (0%) 0/1 (0%) 0/14 (0%) 

First incidence (days) • 618 708 604 773 

Life table test P=0.187N P=0.518N P=0.409N P=0.276N 

Logistic regression test P=0.201N P=0.502N P=0.294N P=0.306N 

Cochran-Armitage test P=0.202N 

Fisher exact test P=0.500N P=0.322N P=0.309N 

Lung: Alveolar/bronchiolar Adenoma or Carcinoma 

Overall rate 3/60 (5%) 2/60 (3%) 1/58 (2%) 2/60 (3%) 

Adjusted rate 10.2% 8.2% 2.4% 11.2% 

Terminal rate - 0/8 (0%) 0/7 (0%) 0/1 (0%) 1/14 (7%) 

First incidence (days) 618 708 604 773 

Life table test P=0.342N P=0.518N P=0.409N P=0.418N 

Logistic regression test P=0.399N P=0.502N P=0.294N P--0.488N 

Cochran-Armitage test P=0.406N 

Fisher exact test P=0.500N P=0.322N P=0.500N . 

Mammary Gland: Fibroadenoma 

Overall rate 10/60 (17%) 4/60 (7%) 4/58 (7%) 7/60 (12%) 

Adjusted rate 72.0% 40.7% 24.8% 40.2% 

Terminal rate 5/8 (63%) 2/7 (29%) 0/1 (0%) 5/14 (36%) 

First incidence (days) 381 786 619 708 

Life table test P=0.100N P=0.085N P=0.526N P=0.059N 

Logistic regression test P=0.195N P=0.033N P=0.183N P=0.107N 

Cochran-Armitage test P=0.350N 

Fisher exact test P=0.077N P=0.08'~N P=0.301N 

Mammary Gland: Fibroadenoma or Adenoma , ' 

Overall rate 11/60 (18%) 4/60 (7%) 5/58 (9%) 7/60 (12%) 

Adjusted rate 72.6% 40.7% 43.6% 40.2% 

Terminal rate 5/8 (63%) 2/7 (29%) 0/1 (0%) 5/14 (36%) 

First incidence (days) " 381 786 619 708 

Life table test P=0.072N P=0.055N P=0.580N P=0.039N 

Logistic regression test P=0.145N P=0.022N P=0.213N P=0.076N 

Cochran-Armitage test 

Fisher exact test 

P=0.282N 

P=0.048N P=0.10IN P=0.222N 

Pancreas: Adenoma 

Overall rate 3/60 (5%) 0/59 (0%) 1/58 (2%) 0/60 (0%) 

Adjusted rate 

Terminal rate 

37.5% 

3/8 (38%) 

0.0% 

0/7 (0%) 

25.0% 

0/1 (0%) 

0.0% 

0/14 (0%) 

First incidence (days) 857 (T) -- 852 --

Life table test P=0.050N P=0.130N P=0.599 P=0.038N 

Logistic regression test P=0.044N P=0.130N P=0.728N P=0.038N 

Cochran-Armitage test 

Fisher exact test 

P =0.087N 

P=0. !25N P=0.322N P=0.122N, 
115 

? -'-" ~ - ~ ~ 7 ~ @ ~ , , ~ __ = .............. ~ ~-~--'~ • - - ___~ . . . . . . . --~ __~ ~ .......... - --~__~ ~ . . . . . 

t:II~utylhydroquinone, NTP. TR 459 

TABLE A3 

Statistical Analysis of lPr~nary Neop~snas ~n M~e Rats ~n the Long-Term l~'eed Study of t-Suty~hydroquinone continued) 

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

Pancreatic ~slets: Adenoma 

Overall rate 

Adjusted rate 

Terminal rate . 

First incidence (days) 

Life table test 

Logistic regression test 

Coehran-Armitage test i Fisher exact test I 

I 

Pancreatic Islets: Adenoma or Carcinoma 

Overall rate 

Adjusted rate 

Terminal rate 

First incidence (days) 

Life table test 

Logistic regression test 

Cochran-Armitage test 

Fisher exact test 

Pituitary Gland (Pars Distalis): Adenoma 

Overall rate 

Adjusted rate 

Terminal rate 

First incidence (days) 

Life table test 

Logistic regression test 

Cochran-Armitage test 

Fisher exact test : 

Htuitary Gland (Pars Distalis): Adenoma or Carcinoma 

Overall rate 

Adjusted rate 

Terminal rate 

First incidence (days) 

Life table test 

Logistic regression test 

Cochran-Armitage test 

Fisher exact test 

Preputial Gland: Adenoma 

Overall rate 

Adjusted rate 

Terminal rate 

First incidence (days) 

Life table test 

Logistic regression test 

Cochran~Armitage test 

Fisher exact test 

5/60 (8%) 

32.5% 

1/8 (13%) 

667 

P=O.220N 

P = 0.280N 

P=0.319N 

6/60 (10%) 

42.1% 

2/8 (25%) 

667 

P=0.130N 

P =0.175N 

P=0.212N 

19/60 (32%) 

63.8 % 

2/8 (25%) 

528 

P=O.002N 

P = O.003N 

P=0.003N 

19/60 (32%) 

63.8 % 

2/8 (25 %) 

528 

P=O.004N 

P=O.005N 

P=O.006N 

5/60 (8 %) 

31.1% 

2/8 (25%) 

528 

P=0.228N 

P=0.358N 

Pffi0.386N 

2/59 (3%) 

7.6% 

0/7 (0%) 

697 

P=0.246N 

P = 0.230N 

P=0.226N 

2/59 (3%) 

7.6% 

0/7 (0%) 

697 

P=0.163N 

P=0.142N 

P=0.142N 

16/58 (28%) 

80.0% 

4/6 (67%) 

562 

P=O.468N 

P=O.410N 

P=0.389N 

17/58 (29%) 

81.1% 

4/6 (67%) 

562 

P=0.539N 

P=0.494N 

P=O.469N 

3/60 (5%) 

20.0% 

0/7 (0%) 

766 

P=0.401N 

P--0.369N 

P=O.359N 

1/58 (2%) 3/60 (5%) 

5.3% 15.9% 

0/1 (0%) 1/14 (7%) 

744 708 

P=0.297N P=0.208N 

P = 0.173N P = 0.287N 

P=0.11 IN P=0.359N 

1/58 (2%) 3/60 (5%) 

5.3% 15.9% 

0/1 (0%) 1/14 (7%) 

744 708 

P =0.269N P=0.112N 

P=0.117N P=0.170N 

P=O.062N P=0.245N 

17/57 (30%) 6/60 (!0%) 

100.0% 30.2% 

1/1 (100%) 3/14 (21%) 

562 668 

P=0.241 P=O.002N 

P=0.573 P=0.002N 

P=O.494N P=0.003N 

18/57 (32%) 7/60 (12%) 

100.0% 31.6% 

1/1 (100%) 3/14 (21%) 

562 627 

P=0.188 P=O.004N 

P=0.487 P=O.006N 

P=0.575N P=O.007N 

6/58 (10%) 3/60 (5%) 

100.0% 18.4% 

I/1 (100%) 2/14 (14%) 

526 786 

P=0.133 P=0.205N 

P=0.436 P=0.312N 

P =0.476 P =0.359N 
116 t-Butylhydroquinone, NTP TR 459 

TABLE A3 , . . 

Statistical Analysis of Primary Neoplasms in Male Rats in the Long-Term Feed Study of t-Butylhydroquinone (continued) 

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

Preputial Gland: Carcinoma 

Overall rate .. 

Adjusted rate 

2/60 (3%) 

3.6% 

2/60 (3%) 

7.9% 

2/58 (3%) 

6.0% 

5/60 (8%) 

18.4% 

Terminal rate 

First incidence (days) 

018 (0%) 

381 

017 (0%) 

467 

0/1 (0%) 

604 

1/14(7%) 

520 

Life table test Pffi0.169 Pffi0.667 P=0.625 P=0.287 

Logistic regression test Pffi0.098 Pffi0.614N P=0.622N P=0.200 

Cochran-Armitage test P=0.115 

Fisher exact test P=0.691N P=0.678 P=0.219 

Preputial Gland: Adenoma or Carcinoma 

Overall rate 7/60 02%) 5/6O (8%) 7/58 (12%) 8/60 (13%) 

Adjusted rate 33.6% 26.3% 100.0% 34.2% 

Terminal rate 2/8 (25%) 0/7 (0%) 1/1 (100%) 3/14 (21%) 

First incidence (days) . 381 467 526 520 

Life table test P--0.541N Pffi0.435N P=0.228 P=0.529N 

Logistic regression test Pffi0.355 P=0.373N Pffi0~609 P=0.556 

Cochran-Armitage test P=0.350 

Fisher exact test Pffi0.381N P=0.585 P=0.500 

Skin: Keratoacanthoma 

Overall rate 4/60 (7%) 4/60 (7%) 4/58 (7%) 4/60 (7%) 

Adjusted rate 28.6% 18.8% 44.8% 15.5% 

Terminal rate 2/8 (25%) 017 (0%) 0/I (0%) 1/14 (7%) 

First incidence (days) 667 634 535 647 

Life table test P=0.406N P=0.612 P=0.268 P=0.516N 

Logistic regression test P=0.538N P=0.632 P=0.517 P=0.616N 

Cochran-Armitage test P=0.567 

Fisher exact test P=0.641N P=0.622 Pf0.641N 

Skin: Squamous Cell Papilloma or Keratoacanthoma 

Overall rate 6/60 (1o%) 6/60 00%) 4/58 (7%) 6/60 (10%) 

Adjusted rate 45.1% 42.0% 44.8% 24.2% 

Terminal rate 3/8 (38%) 2/7 (29%) 0/I (0%) 2/14 (14%) 

First incidence (days) 667 634 535 647 

Life table test P--O.297N Pffi0.573 P-0.424 Pffi0.423N 

Logistic regression test P--0.468N Pffi0.606 P=0.543N Pffi0.566N 

Cochran-Armitage test P=0.533N 

Fisher exact test Pffi0.619N P=0.393N P=0.619N 

Skin: Trichoepithelioma or Basal Cell Carcinoma ' .. 

Overall rate 3/6O (5%) 1/6o (2%) 0/58 (0%) 1/60 (2%) 

Adjusted rate 16.5% 6.3% 0.0% 2~0% 

Terminal rate O/8 (O%) 0/7 (0%) 011 (0%) 0/14 (0%) 

First incidence (days) 759 773 -- 626 

Life table test P=0.171N Pffi0.328N P-0.179N P--0.240N 

Logistic regression test P=0.197N Pffi0.313N P--0.168N P=0.298N 

CochrawArmitage test P=0.202N 

Fisher exact test Pffi0:309N P=0.128N P--0.309N 
:::~:~-~--~,~-~--~.~-~_~ :~ --.................. ~ ............ .:~,,;............ .... :~: := ::::: .... , 

t-~u~yihydroquinone, ~ TI~ 459 H7 

TABLE A3 

S~t~s~ic~ An~ys~s.o~ ~?r'~m~ry Neoplasms in MIMe ~a~s ira the Long-Term Feed Sturdy of t-l~utyihyc~roquinone (continued) 

0 ppm 1,250 ppm 2,500 ppm 5,~ ppm 

Skin: Squemous Cell ~?apHioma, ~eratoacanthoma, Trichoepithelioma, or Basal Cell Carcinoma 

Overall rate 8/60 (13%) 7/60 (12%) 4•58 (7%) 7/60 (12%) 

Adjusted rate 50.3% 45.6% 44.8% 25.7% 

Terminal rate 3/8 (38%) 2/7 (29%) 0/1 (0%) 2/14 (14%) 

First incidence (days) 667 634 535 626 

l Life table test P=0.216N P=0.556N P=0.599N P=0.308N 

Logistic regression test P=0.363N P=0.521N P=0.320N P=0.454N 

Cochran-Armitage test Pf0,420N 

Fisher exact test P=0,500N P=0.198N P=0.500N 

Skin (Subcutaneous Tissue): Fibroma 

Overall rate 4/60 (7 %) 8/60 (13%) 6158 (I0%) 6160 (10%) 

Adjusted rate 30.0% 61.8% 26.7% 26.7% 

Terminal rate 1/8 (13%) 4/7 (57%) 0/I (0%) 2114 (14%) 

First incidence (days) 761 619 619 642 

Life table test P =0.434N P=0.146 P=0.143 P=0.574 

Logistic regression test P=0.491 P=0,161 P=0,274 P=0,448 

Cochran-Armitage test P=0,439 

Fisher exact test P=0.181 P=0.350 P=0,372 

Skin (Subcutaneous Tissue): Fibroma or ~brosarcoma 

Overall rate 5/60 (8%) 9/60 (15%) 7/58 (12%) 7/60 (12%) 

Adjusted rate 40.0 % 63.3 % 28.2 % 29,3 % 

Terminal rate 2/8 (25%) 4/7 (57%) 0/1 (0%) 2/14 (14%) 

First incidence (days) 761 619 562 642 

Life table test P=0.412N P=0.151 P=0.106 P=0.605 

Logistic regression test P=0.491 P=0.173 P=0.282 P=0.470 

Coehran-Armitage.test P =0.443 

Fisher exact test P =0.197/ P=0.357 P=0.381 

Testes: Adenoma 

Overall rate 55160 (92%) 49/60 (82%) 56/57 (98%) 59/60 (98%) 

Adjusted rate 100.0% 100.0% 100.0% 100.0% 

Terminal rate 8/8 (100%) 7/7 (100%) 1/1 (100%) 14/14 (100%) 

First incidence (days) 489 535 464 487 

Life table test P=0.346N P=0.3~9N P=0.019 P=0.306N 

Logistic regression test P=0.009 P=0.116N P =0.054 P=0.104 

Cochran-Armitagc test P=0.013 

Fisher exact test P=0.089N P=0.116 P=0.103 

Thyroid Gland (C-cell): Adenoma 

Overall rate 5/60 (8%) 2/60 (3%) 2/58 (3%) a/60 (7%) 

Adjusted rate 25.2% 22.9% I0.9% 17.6% 

Terminal rate 0/8 (0%) I/7 (14%) 0/I (0%) 2/14 (14%) 

First incidence (days) 730 831 691 603 

Life table test P=0.357N P=0.246N P=0.382N P=0.355N 

Logistic regression test P--0.478N P=0.221N P=0.311N P=0.473N 

Cochran-Armitage test P--0.521N 

Fisher exact test P=0.219N P=0.234N P=0.500N 
118 t-Butylhydroquinone, NTP TR 459 

TA~I~', A3 ~, 

Statistical Analysis of Primary Neoplasms in Male Rats in the Long'Term Feed Study of t-Butylhydroquinone (continued) 

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

Thyroid Gland (C-cell): Adenoma or Carcinoma 

Overall rate 5/60 (8%) 3/6O (5%) 2/58 (3%) 6/6O (1o%) 

Adjusted rate 25.2 % 24.7% 10,9% 26,5% 

Terminal rate 0/8 (0%) 1/7 (14%) 0/1 .(0%) 3/14 (21%) 

First incidence (days) 730 667 691 603 

Life table test P=0.545 P=0,391N P=0.382N P=0.575N 

Logistic regression test P=0.404 P=0,368N P=0.311N P=0.536 

Cochran-Armitage test P=0,361 

Fisher exact test P=0,359N P=0,234N P=0.560 • 

Thyroid Gland (Follicular Cell): Carcinoma 

Overall rate 0160 (0%) 0/60 (O%) 0/58 (0%) 3/60 (5%) 

Adjusted rate 0,0% 0,0% 0,0% 18,8% 

Terminal rate 0/8 (0%) 0/7 (0%) 0/I (0%) 1/14 (7%) 

First incidence (days) -- - - 810 

Life table test P=0,053 -- P-~0.237 

Logistic regression test P=0,031 -- P=0.179 

Cochran-Armitage test P=0,OI2 

Fisher exact test P=0,122 

Thyroid Gland (Follicular Cell): Adenoma or Carcinoma 

Overall rate 0/60 (0%) 1/60 (2%) 1/58 (2%) 3/60 (5%) 

Adjusted rate 0,0% 14,3% 12,5% 18,8% 

• Terminal rate 018 (0%) I17 (14%) 011 (0%) I114 (7%) 

First incidence (days) -- 857 (T) 806 810 

Life table test P=0,174 P=0,473 P=0,419 P=0,237 

Logistic regression test P=0.113 P=0,473 P =0,423 P=O, 179 

Cochran-Armitage test P=0.055 

Fisher exact test P=0.500 P=0.492 P=0.122 

Zymbal's Gland: Carcinoma 

Overall rate 2/60 (3%) 1/60 (2%) 3/58 (5%) 3/60 (5%) 

Adjusted rate 9.9% 1.9% 16.3% 7.8% 

Terminal rate 0/8 (0%) 0/7 (0%) 0/1 (0%) 0/14 (0%) 

First incidence (days) - 500 554 642 487 

Life table test P=0,339 P=0,493N P=0,369 P=0,527 

Logistic regression test P=0,284 P=O,462N P=0.495 P=0.483 

Cochran-Armitage test P=0.302 

Fisher exact test P=0.500N P=0,484 P=0,560 

Zymbal's Gland: Adenoma or Carcinoma 

Overall rate 2/60 (3%) 1/60 (2%) 3/58 (5%) 4/60 (7%) 

Adjusted rate 9.9% 1.9% 16.3% 10.4% 

Terminal rate 0/8 (0%) 0/7 (0%) 0/l (0%) 0/14 (0%) 

First incidence (days) 560 554 642 487 

Life table test P=0.197 P=0.493N P=0.369 P=0.366 

Logistic regression test P=0.149 P=0.462N P=0.495 P=0.321 

Cochran-Armitage test P=0.163 

Fisher exact test P=0.500N P=0.484 P=0.340 
._ --~o,~_,.~: ~ ~ _ _ _ ~ ~ , .~__ ~ - - ~ . .~ ~ - ~ - - - - - ~ ....... ,,_,, .... __ 

,t-~uty~hydroqu~none, N'~ T~ 4~9 H9 

T~L~ A3 

St~tLstica~ An~dysL~ o~ l?r~ra~ry Heop~s ~n I~Ia~e ~i~ ~n the Long-Tern Feed Study o~ t-Buty~hydroqulnone (continued) 

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

All Organs: Mononuclear Cell Leukemia 

Overall rate 39/60 (65%) 47/60 (78%) 40/58 (69%) 32/60 (53%) i 

Adjusted rate 87.2% 97.2% 100.0% 75.2% 

Terminal rate 4/8 (50%) 6/7 (86%) 1/1 (100%) 6/14 (43%) 

First incidence (days) 534 394 464 423 

Life table test P=0.035N Pffi0.148 P=0.053 P=0.085N 

Logistic regression test P =0.034N P=0.039 P=0.347 P=0.168N 

Cochran-Armitage test P =0.031N 

Fisher exact test P = 0.078 P = 0.397 P = 0.133N 

i 

All Organs: Malignant IV~esothelioma 

Overall rate 1/60 (2%) 0/60 (0%) I158 (2%) 3160 (5%) 

Adjusted rate 12.5 % 0.0% 6.3% 7.2% 

Termhial rate 1/8 (13%) 0/7 (o%) o/i (0%) o/14 (0%) 

First incidence (days) 857 ('13 - - 761 626 

Life table test P=0.151 P=0.527N P=0.53g P=0.366 

Logistic regression test P=0.103 P=0.527N P=0.676 P=0.306 

Coehran-Armitage test Pffi0.097 

Fisher exact test P=0.5OON P=0.744 P=0.309 

All Organs: Benign Neoplasms 

Overall rate 60/60 (100%) 56/60 (93%) 56/58 (97%) 59/60 (98%) 

Adjusted rate 100.0% 1oo.o% lOO.O% lOO.O% 

Terminal rate 8/8 (100%) 7/7 (100%) 1/1 (100%) 14/14 (100%) 

First incidence (days) 381 535 464 487 

Life table test Pf0.149N P=0.492N P=0.056 P=0.154N 

Logistic regression test P=0.450N P=0.100N P=0.282N P=0.354N 

Cochran-Armitage test P=0.578 

Fisher exact test P=0.059N P=0.239N P=0.500N 

All Organs: Malignant Neoplasms , 

Overall rate 51160 (85 %) 53/60 (88%) 50/58 (86%) 47/60 (78%) 

Adjusted rate 95.5 % 97.8% 100.0% 91.2% 

Terminal rate 6/8 (75 %) 6/7 (86%) 1/1 (100%) 10/14 (71%) 

First incidence (days) 381 289 464 423 

Life table test P=0.092N Pffi0.363 P=0.054 P=0.123N 

Logistic regression test P =0.150N P=0.394 Pf0.565N P=0.249N 

Cochran-Armitage test Pffi0.131N 

Fisher exact test P=0.395 P--0,530 P=0.240N 
120 t-Butylhydroquinone, NTP TR 459 

TAnLE: A3 

Statistical, Analysis of Primary Neoplasms in Male Rats in the Long-Term Feed Study of t-Butylhydroquinone (continued) 

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

All Organs: Benign or Malignant Neoplasms 

Overall rate 50/60 (100%) 59/60 (98%) 57/58 (98%) 50/60 (100%) 

Adjusted rate 1 50.0 % 100.0% 100.0% 100.0% 

Terminal rate 818 (100%) 7/7 (100%) 1/1 (100%) 14/14 (100%) 

First incidence (days) 381 289 464 423 

Life table test P=0.155N P=0.467 P=0.046 P=0.180N 

f Logistic regression test P = 0.673N P=0.773N P=0.404N --

Cochran-Armitage test P = 0.595 

Fisher exact test P=0.500N P=0.492N P= 1.000N 

(T)Terminal sacrifice . 

a Number of neoplasm-bearing animals/number of animals examined. Denominator is number of animals examined microscopically for adrenal gland, liver, 

lung, pancreas, pancreatic islets, pituitary gland, preputial gland, testes, and thyroid gland; for other tissues, denominator is number of animals necropsied. 

b Kaplan-Meier estimated neoplasm incidence at the end of the study after adjustment for intercurrent mortality 

c Observed incidence at terminal kill 

0 Beneath the control incidence are the P values associated with the trend test. Beneath the exposure group incidence are the P values corresponding to 

pairwise comparisons between the controls and that exposure 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. 

e Not applicable; no neoplasms in animal group 

f Value of statistic cannot be computed. 
121 

:: - .~-~==,~:~:~_ ~_~_~ . . . . . . . . . . . . . . . . . .. ::.,.: : ............................ :::: :::: ...... ~. =:.:---- =_.==~ 

t-~uD,~hydroquinone, NTIF TIR ,~59 

TA~L~ A4 

Sun~ansry o1~ the ~[ncidence o~ Nonneop~stic ]Lesions in 1V~de ]iR~ in the Long-Terzn Feed Study o~ t-~utyihydroquinone a i 

0 ppm ~,2~0 ppm 2,~00 ppm 5,000 ppm 

I 

I 

Disposition Sunnnary 

Animals initially in study 

3-Month interim evaluation 

Early deaths 

Moribund 

Natural deaths 

Survivors 

Terminal sacrifice 

Missexed 

70 

10 

48 

4 

8 

0 

70 

10 

51 

2 

7 

0 

70 

10 

50 

7 

1 

2 

70 

10 

42 

4 

14 

0 

• 

Animals examined microscopically 70 70 68 70 

3-Month ffnter~m ~valuat~an 

Alimentary System 

Intestine large, colon 

Parasite memzoan 

Intestine large, rectum 

Parasite metazoan 

Intestine small, ileum 

Hyperplasia, lymphoid 

Liver 

Hcpatodiaphragmatic nodule 

Inflammation, subacute 

Bile duct, hyperplasia 

Pancreas 

Atrophy 

Stomach, forestomach 

Hypcrplasia 

(10) 

(10) 

1 (10%) 

(10) 

(10) 

1 (10%) 

(I0) 

I (10%) 

(10) 

(10) 

(10) 

(10) 

1 (10%) 

(10) 

1 ( 10 % ) 

(10) 

' (10) 

1 00%) 

(10) 

(10) 

(10) 

(10) 

I (10%) 

(10) 

(I0) 

(10) 

I (10%) 

(10) 

(10) 

(1o) 

2 (2O%) 

1 (10%) 

(10) 

2 (20%) 

(10) 

Cardiovascular System 

Heart 

Cardiomyopathy 

(10) 

2 (20%) 

(10) 

4 (40%) 

(10) 

2 (20%) 

(10) 

2 (20%) 

Endocrine System 

Adrenal cortex 

Accessory adrenal cortical nodule 

Islets, pancreatic 

Hyperplasia 

Pituitary gland 

Pars intermedia, cyst 

Thyroid gland 

Ectopic thymus 

Ultimobranchial cyst 

(I0) 

I (10%) 

(10) 

(10) 

(10) 

I (10%) 

1 (10%) 

(I0) 

(10) 

I (10%) 

(10) 

(I0) 

I (10%) 

(I0) 

(10) 

(9) 

1 (11%) 

(10) 

(I0) 

1 00%) 

(10) 

(10) 

(10) 

3 (30%) 

a Number of animals examined microscopically at the site and the number of animals with lesion 
122 t-Butylhydroquinone, NTP TR 459 

TABLE A4 

Summary of the Incidence ,of Nonneoplasti c Lesions in Male Rats in the Long-Term Feed Study of t-Butylhydroquinone 

(continued) 

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

3-Month Interim Evaluation (continued) 

Genital System 

Prostate (10) 

Inflammation, suppurative 

Testes (I0) 

Seminiferous tubule, atrophy 

(I0) 

2 (20%) 

(10) 

1 (10%) 

(IO) 

I (10%) 

(I0) 

(I0) 

(10) .. 

Hematopoietic System 

Lymph node 

Mediastinal, hemorrhage 

Mediastinal, hyperplasia, lymphoid 

Renal, hemorrhage 

Lymph node, mesenteric 

Hemorrhage 

Spleen 

PigmentatiOn; hemosiderin 

Thymus 

Hemorrhage 

(10) 

(10) 

(10) 

(1) 

I (100%) 

1 (100%) 

(10) 

I (10%) 

(10) 

(lO) 

(2) 

2 (100%) 

(10) 

(~0) 

3 (30%) 

(1o) 

3 (30%) 

(10) 

(lO) 

5 (50%) 

rio) 

1 (1o%) 

Respiratory System 

Lung 

Inflammation, subacute 

Alveolar epithelium, hyperplasia 

Nose 

Goblet cell, hyperplasia 

(I0) 

4 (40%) 

3 (30%) 

(1o) 

(lO) 

5 (50%) 

I (10%) 

(lO) 

(10) 

7 (70%) 

I (10%) 

.(10) 

(lO) 

. 7 (70%) 

3 (30%) 

(lO) 

7 (70%) 

Urinary System 

Kidney 

Mineralization 

Nephropathy 

(10) 

i (I0%) 

5 (50%) 

(10) 

l (10%) 

5 (50%) 

(10) 

4 (40%) 

(10) 

6 (60%) 

Systems Examined With No Lesions Observed 

General Body System 

Integumentary System 

Musculoskeletal System 

Nervous System 

Special Senses System 

T¢gn stray 

Alimentary System 

Intestine large, colon 

Edema 

Parasite metazoan 

Intestine large, rectum 

Edema 

Hemorrhage 

Parasite metazoan 

(58) 

7 (12%) 

(59) - • • 

2 (3%) 

5 (8%) 

(58) 

6 00%) 

(60) 

(58) 

1 (2%) 

3 (5%) 

(58) 

1 (2%) 

1 (2%) 

(60) 

1 (2%) 

2 (3%) 

(59) 

1 (2%) 

1 (2%) 

8 04%) 
:::. : ~ -~:~-::- ~ . ~ , ~ ~ ..... ~ ..-.~ ......... ~ .... - - ................. = ........ ==~-~ . . . . 

t-Buty~hydroquinone, N'~ TR 459 123 

TABL$~ A4 

Summary o~ the ][nctdence.6f Nonneopl~stic Lesions in Male Rats in the Long-Term Feed Study of t-~uty~hydroquinone 

(continuod) 

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

Lol~g-Te~ S~,tdy (continued) 

Alimentary System (continued) 

Intestine large, cecum (60) (58) (58) (60) 

Edema 3 (5%) 2 (3%) 3 (5%) 3 (5%) 

Parasite metazoan 1 (2%) 2 (3%) 3 (5%) 

Intestine small, duodenum (60) (60) (58) (60) 

Epithelium, hyperplasia 2 (3%) 4 (7%) 

Intestine small, jejunum (60) (60) (57) (60) 

Metaplasia, osseous 1 (2%) 

Epithelium, hyperplasia 1 (2%) 1 (2%) 

Intestine small, ileum (60) (59) (58) (59) 

Ulcer 1 (2%) 

Liver (60) (60) (58) (60) 

Angieetasis 10 (17%) 1 (2%) 4 (7%) 7 (12%) 

Basophilie focus. 7 (12%) 3 (5%) 2 (3%) 7 (12%) 

Clear cell focus 1 (2%) 3 (5%) 1 (2%) 5 (8%) 

Degeneration, cystic 23 (38%) 16 (27%) 11 (19%) 5 (8%) 

Eosinophilic focus 10 (17%) 4 (7%) I (2%) 4 (7%) 

Eosinophilic focus, multiple 1 (2%) 

Fibrosis 1 (2%) 1 (2%) 1 (2%) 

Hematopoietic cell proliferation " ' 1 (2%) 1 (2%) 

Hemorrhage 1 (2%) 

Hepatodiaphragmatic nodule 7 (12%) 7 (12%) 4 (7%) 8 (13%) 

Inflammation, subacute 1 (2%) 

Mixed cell focus 2 (3%) 2 (3%) 

Necrosis, focal 8 (13%) 6 (10%) 3 (5%) 2 (3%) 

Thrombosis 1 (2%) 3 (5%) I (2%) 

Bile duct, cyst 2 (3%) 

Bile duct, hyperplasia 52 (87%) 49 (82%) 43 (74%) 25 (42%) 

Centrilobular, atrophy 1 (2%) 

Centrilobular, fibrosis l (2%) 

Centrilobular, necrosis 2 (3%) 1 (2%) 2 (3%) 

Hepatoeyte, vacuolization cytoplasmic 6 (10%) 4 (7%) 7 (12%) 3 (5%) 

Kupffer cell, hyperplasia 1 (2%) 

Kupffer ceil, pigmentation 11 (18%) 18 (30%) 8 (14%) 10 (17%) 

Mesentery (20) (11) (7) (16) 

Accessory spleen 1 (5%) 3 (27%) 4 (25%) 

Fat, necrosis 16 (80%) 7 (64%) 6 (86%) 13 (81%) 

Pancreas (60) (59) (58) (60) " 

Atrophy 15 (25%) 19 (32%) 12 (21%) 15 (25%) 

Acinus, cytoplasmic alteration 3 (5%) 1 (2%) 1 (2%) 4 (7%) 

Acinus, hyperplasia, focal 2 (3%) 3 (5%) 2 (3%) 2 (3%) 

Salivary glands (60) (60) (58) (60) 

Atrophy 1 (2%) 

Stomach, forestomach (60) (60) (58) (59) 

Edema 9 (15%) 4 (7%) 5 (9%) 6 (10%) 

Erosion 2 (3%) 

Hyperplasia 8 (13%) 6 (10%) 9 (16%) 12 (20%) 

Ulcer 8 (13%) 1 (2%) 3 (5%) 7 (12%) 

Mucosa, 'hyperplasia 1 (2%) 1 (2%) 

I 

I 

! 

I 
12A t-Butylhydroquinone, NTP TR 459 

TABLE A4 -

Summary of the Incidence of Nonneoplastic Lesions in Male Rats in the Long-Term Feed Study of t-Butyihydroquinone 

(conhnued) 

Long-Term Study (continued) 

Alimentary System (continued) 

Stomach, glandular 

Edema 

Erosion 

Mineralization 

Ulcer 

Tongue 

Epithelium, hyperplasia 

Cardiovascular System 

Blood vessel 

Hypertrophy 

Inflammation, subacum 

Mineralization 

Thrombosis 

Heart 

Cardiomyopathy 

Mineralization 

Necrosis 

Thrombosis 

Endocardium, hyperplasia 

Schwann cell, hyperplasia 

Endocrine System 

Adrenal cortex 

Accessory adrenal cortical nodule 

Degeneration, cystic 

Degeneration, fatty 

Hemorrhage 

Hyperplasia, focal 

Hypertrophy, focal 

Necrosis 

Adrenal medulla 

Hyperplasia 

Islets, pancreatic 

Hyperplasia 

Parathyroid gland 

Hyperplasia 

Pituitary gland 

Nuclear alteration 

Pars distalis, angiectasis 

Pars distalis, cyst 

Pars distalis, cyst, hemorrhagic 

Pars distalis, hyperplasia, focal 

Pars intcrmcdia, angiectasis 

Pars intcrmedia, cyst 

Thyroid gland 

Ultimobranchial cyst 

C-ceil, hyperplasia 

Follicle, cyst 

0 ppm 

(60) 

1 (2%) 

l (2%) 

l (2%) 

3 (5%) 

(i) 

(60) 

• I (2%) 

I (2%) 

(60) 

40 (67%) 

I (2%) 

6 (I0%) 

I (2%) 

(60) 

17 (28%) 

9 (15%) 

1 (2%) 

4 (7%) 

6 (10%) 

1 (2%) 

(60) 

26 (43%) -

(6O) 

3 (5%) 

(55) 

6 (11%) 

(60) 

4 (7%) 

6 (10%) 

1 (2%) 

10 (17%) 

1 (2%) 

(60) 

1 (2%) 

9 (15%) 

I (2%) 

1,250 ppm 

(60) 

i (2%) 

3 (5%) 

2 (3%) 

3 (5%) 

(2) 

2 (100%) 

(~O) 

3 (5%) 

I (2%) 

1 (2%) 

(60) 

39 (65%) 

l (2%) 

(13%) 

(2%) 

(60) 

I0 (17%) 

I (2%) 

lO 07%) 

2 (3%) 

5 (8%) 

(~0) 

22 (37%) 

(59) 

(54) 

8 (15%) 

(58) 

2 (3%) 

3 (5%) 

8 (14%) 

I (2%) 

6 (10%) 

(60) 

1 (2%) 

8 03%) 

3 (5%) 

2,500 ppm 5,000 ppm 

(58) (60) 

3 (5%) 3 (5%) 

2 (3%) i (2%) 

5 (9%) 

3 (5%) 

(i) (4) 

i (100%) 2 (50%) 

(58) (60) 

1 (2%) 4 (7%) 

I (2%) 

1 (2%) 

I (2%) 

(58) (60) 

35 (60%) 37 (62%) 

4 (7%) 

(~) 

12 (21%) 13 (22%) 

(58) 

8 (14%) (12%) 

(3%) 

2 (3%) (5%) . 

2 (3%) (3%) 

(58) (60) 

15 (26%) 12 (20%) 

(58) (60) 

2 (3%) I (2%) 

(55) (58) 

7 (13%) 9 (16%) 

(57) (60) 

1 (2%) 

1 (2%) 

4 (7%) 7 (12%) 

1 (2%) 

8 (14%) 14 (23%) 

2 (4%) .1 (2%) 

4 (7%) 2 (3%) 

(58) (60) 

I (2%) 5 (8%) 

9 (16%) 7 02%) 

I (2%) 
125 

i 

: :-: :~.:~i ~ -C~. , C ~ . ~ - ~ . ~ ,~ = ............ ~ ~ :=_ ~ .................. . .......... ~ ........ 

t-~utylhydroquinone, NTP T~ 459 

TABLE A4 

Sunm~ary of the l~ncidence of Nonneop~astic Lesions in IV~a~e Rats ira the Long-Term Feed Study of t-~utyUhydroquinone 

(continued) 

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

/~,~ng-Te~r~ra S~dy (continued) 

General Body System 

None 

I 

I 

Genital System 

Epididymis (60) (60) (57) (60) 

Atypia cellular 27 (45%) 26 (43%) 28 (49%) 25 (42%) 

Granuloma sperm 1 (2%) 

Preputial gland (60) (60) (58) (60) 

Cyst 3 (5%) 3 (5%) 4 (7%) 4 (7%) 

Hyperplasia 3 (5%) 2 (3%) 4 (7%) 2 (3%) 

Inflammation, chronic 26 (43%) 16 (27%) 18.(31%) 12 (20%) 

Inflammation, suppurative 3 (5%) 7 (12%) 3 (5%) 5 (8%) 

Prostate (60) (60) (58) (60) 

Cyst 1 (2%) 

Fibrosis 3 (5%) 1 (2%) 

Inflammation, chronic 5 (8%) 1 (2%) 

Inflammation, suppurative 36 (60%) 39 (65%) 40 (69%) 23 (38%) 

Epithelium, hyperplasia 11 (18%) 10 (17%) 6 (10%) 8 (13%) 

Testes (60) (60) (57) (60). 

Interstitial cell, hyperplasia 4 (7%) 7 (12%) 6 (11%) 3 (5%) 

Seminiferous tubule, atrophy 7 (12%) 5 (8%) 2 (4%) 5 (8%) 

I 

Hematopoietic System 

Bone marrow 

Hyperplasia 

Infiltration cellular, histiocyte 

Myelofibrosis 

Lymph node 

Deep cervical, hyperplasia, lymphoid 

Iliac, hemorrhage 

Inguinal, hyperplasia, lymphoid 

Mediastinal, congestion 

Mediastinal, hemorrhage 

Mediastinal, hyperplasia, lymphoid 

Mediastinal, pigmentation 

Pancreatic, ectasia 

Pancreatic, hyperplasia, plasma cell 

Pancreatic, pigmentation 

Renal, ectasia 

Renal, hemorrhage 

Renal, hyperplasia, lymphoid 

Renal, pigmentation 

Lymph node, mandibular 

Ectasia 

Hemorrhage 

Hyperplasia, lymphoid 

Hyperplasia, plasma cell 

Pigmentation 

(60) 

6 (10%) 

4 (7%) 

(33) 

1 (3%) 

2 (6%) 

3 (9%) 

1 (3%) 

13 (39%) 

9 (27%) 

1 (3%) 

8 (24%) 

(60) 

3 (5%) 

2 (3%) 

11 (18%) 

6 (10%) 

(60) 

5 (8%) 

8 (13%) 

(36) 

1 (3%) 

2 (6%) 

1 (3%) 

14 (39%) 

1 (3%) 

3 (8%) 

1 (3%) 

8 (22%) 

(60) 

8 (13%) 

7 (12%) 

1 (2%) 

3 (5%) 

(58) 

2 (3%) 

(34) 

3 (9%) 

1 (3%) 

17 (50%) 

4 (12%) 

1 (3%) 

1 (3%) 

8 (24%) 

(58) 

7 (12%) 

2 (3%) 

10 (17%) 

1 (2%) 

7 (12%) 

(60) 

7 (12%) 

2 (3 %) 

2 (3%) 

(35) 

1 (3%) 

2 (6%) 

3 (9%) 

2 (6%) 

16 (46%) 

1 (3%) 

3 (9%) 

2 (6%) 

2 (6%) 

7 (20%) 

(60) 

6 (10%) 

3 (5%) 

17 (28%) 

5 (8%) 
126 :i2Butylhydroquinone, NTP TR 459 

TABLE A4 . 

Summary of the Incidence of Nonneoplastic Lesions in Male Rats in the Long-Term Feed Study of t-Butylhydroquinone 

(continued) 

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

Long-.Term Study (continued) 

Hematopoietie System (continued) ... 

Lymph node, mesenteric (60) (58) (57) (6O) 

Ectasia 7 (12%) 1 (2%) 7 (12%) 10 (17%) 

Hemorrhage 1 (2%) 2 (3%) 1 (2%) 2 (3%) 

Hyperplasia, lymphoid 3 (5%) 1 (2%) I0 (18%) 6 (10%) . , . 

Pigmentation I (2%) 

Spleen (60) (60) (58) (60) 

Congestion i (2%) 

• Fibrosis 21 (35%) • 20 (33%) 9 (16%) 13 (22%) 

Hematopoietic cell proliferation 7 (12%) 6 (10%) 3 (5%) 8 (13%) 

Metaplasia, lipocyte i (2%) 

Necrosis 

.. ' Pigmentation, hemosiderin 

2 (3%) 

13 (22%) 

2 (3%) 

9 (15%) 

3 (5%) 

II (19%) 12. (20%) 

Lymphoid follicle, atrophy i (2%) . - • 

Red pulp, ,atrophy 

Thymus (58) 

1 (2%) 

(55) (54) (56) 

- : 

Ectopic parathyroid gland 1 (2%) 2 (4%) 

Integumentary System 

Mammary gland (57) (57) (56) (58) 

Dilatation 23 (40%) 24 (42%) 17 (30%) I0 (17%) . . 

• Galactocele 5 (9%) 4 (7%) 1 (2%) 2 (3%) 

Hyperplasia 7 (12%) 4 (7%) 5 (9%) 6 (10%) 

Skin (6o) (60) (57) (60) 

Cyst epithelial inclusion 2 (3%) 1 (2%) 1 (2%) 1 (2%) 

Hemorrhage 1 (2%) ,. 

Hyperkeratosis I (2%) 2 (4%) I (2%) 

Inflammation, chronic 1 (2%) 2 (4%) 

Ulcer 1 (2%) I (2%) 

Epidermis, hyperplasia 1 (2%) I (2%) I (2%) (2%) , 

Subcutaneous tissue, thrombosis (2%) . 

• 

Musculoskeletal System 

Bone (6o) (6O) (58) (60) • 

Fibrous osteodystrophy 6 (lO%) 5 (8%) 5 (9%) 7 (12%). 

Hyperostosis 1 (2%) I (2%) 

Femur, osteopetrosis l (2%) 2 (3%) I (2%) 

Nervous System 

Brain 

Atrophy: 

._ 

Giiosis 

(60) 

12 (20%) 

(60) 

8 (13%) 

(58) 

8 04%) 

1 (2%) 

(60) 

3 (5%) 

Hemorrhage 

Hydrocephalus 

Necrosis 

2 (3%) 

4 (7%) 

1 (2%) 

1 (2%) 

3 (5%) 

1 (2%) 

4 (7%) 

1 (2%) 

1 (2%) 
I 

~:-=.~:~-~-~,~_.~.__~ ~ ...... ~ ............ ~ .... ~, ~ ::~-~,~_ .... ~_:,~.~ .......... :~ .......... ~_..~.~ .... _~ , ........ 

~-I~mylhy~ro~:~uinone,~ T~ ~9 ~27 

T~L~ A4 

Summary o~ the ~ncide~ce o~ ~onneopl~ic ~esio~s in ~aie ~a~s in the Long-Tern Feed Study o~ t-~uty~hydroquinone 

(continued) 

0 ppm 1,250 ppm ~,500 ppm 5,000 ppm 

Long-Ten S~dy (continued) 

Respiratory System 

Lung (60) (60) (58) (60) 

Congestion 2 (3%) 

Edema 1 (2%) 1 (2%) 

Hemorrhage 3 (5%) 5 (8%) 2 (3%) 2 (3%) 

Infiltration cellular, histiocyte 19 (32%) 21 (35%) 10 (17%) 14 (23%) 

Inflammation, subacute 2 (3%) 1 (2%) 

Metaplasia, osseous 1 (2%) 

Mineralization 1 (2%) I (2%) 

Alveolar epithelium, hyperplasia 4 (7%) 9 (15%) 5 (9%) 7 (12%) 

Nose (60) (60) (58) (6O) 

Foreign body 6 (10%) 8 (13%) 2 (3%) 2 (3%) 

Inflamraation~ suppurative 17 (28%) 22 (37%) 15 (26%) 11 (18%) 

Goblet cell, hyperplasia 5 (8%) 3 (5%) 9 (16%) 13 (22%) 

Mucosa, hyperplasia 14 (23%) 18 (30%) 13 (22%) 10 (17%) 

Mucosa, metaplasia, squamous 8 (13%) 13 (22%) 8 (14%) 7 (12%) 

Special Senses System 

Eye (4) (2) (I) (2) 

Atrophy 2 (50%) 1 (50%) 

: ̧ [ Cataract I (25%) 1 (50%) 

Inflammation, chronic 1 (50%) 

Retina, degeneration 1 (25 %) 1 (50%) 

Urinary System 

Kidney (60) (60) (58) (6o) 

Cyst 2 (3%) 3 (5%) 7 (12%) 11 (18%) 

Developmental malformation 1 (2%) 

Inflammation, suppurative 9 (15%) 8 (13%) 9 (16%) 20 (33%)

Mineralization 12 (20%) 3 (5%) 2 (3%) 1 (2%) 

Nephropathy 60 (100%). 60 (100%) 58 (100%) 60 (100%) 

Renal tubule, accumulation, hyaline droplet I (2%) I (2%) 2 (3%) 1 (2%)

Renal tubule, atrophy 1 (2%)

Renal tubule, hypetplasia, focal 1 (2%) 

Renal tubule, necrosis 3 (5%) 1 (2%) 1 (2%) 

Renal tubule, pigmentation : 18 (30%) 26 (43%) 17 (29%) 15 (25%) 

Transitional epithelium, hyperplasia 13 (22%) 12 (20%) 11 (19%) 21 (35%)

Urinary bladder (60) (60) (58) (6O) 

Hemorrhage 1 (2%) 

Inflammation, suppurative 1 (2%) 

Transitional epithelium, hyperplasia 2 (3 %) 
128 

t-Butylhydroquinone, NTP TR 459 
- ~ -..-..~s i ~ .... -_ _~_~__~.. _ ~ - . _ _ ~ ...................... ~ ~ ~ . ~ . ~ ............. 

~2~ 

AW~EHY)~ 1~ 

SVMI/IAtlY @IF LES~OHS ~H ]~E1/IAIDtl ~A~S 

~H T}~ ]DOHGoTII]t@I BItI} S~L1DY 

O~ ~-B~JTYBHYI)~OqVIHeHtl 

~i 

I 

T~L~ S~ 

T~L~ B2 

T~LE ~3 

T~L~ ]]~ 

S~ary o~ the ~c~ence o~ I~eop~as~s ~ ~e~a~e Rats 

~a the Loag-Ter~ ~eed Study o~ ~-~aty~hy~ro~a~none ........................ 

~v~a~ An~ ~or Pat~o~o~ o~ Female RaN 

~n the ~ng-Te~ ~ee~ St~y o~ t-~aty~ydro~a~noae ........................ 

Stat~fic~ ~a~ys~ o~ ~ ~plm~s ~a ~ema~e ~ts 

~n the ~ag-Te~ ~ee~ Study o~ t-~aty~hydroqu~oae ........................ 

S~ of the ~nc~e~ce o~ ~onneop~c ~ons ~n Fe~e Rats 

~ the ~ng-Te~ ~ee~ Study o~ t-~uty~ydroqu~none ........................ 

~30 

~3~ 

~7 

~73 

I 

I 

: ̧ I 
130 t-Butylhydroquinone, NTP TR 459 

TABt,E B1 • 

Sum~nary of the Incidence of Neoplasms in Female Rats in the Long-Term Feed Study of #Butylliydroquinone a " ' 

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

Disposition Summary 

Animals initially in study 70 70 .. . 70 ' :" 

• 3-Month interim evaluation 10 I0 10 10 

Early deaths 

Moribund 40 41 33 .36 

Natural deaths I0 8 9 7 

Survivors 

Terminal sacrifice 10 11 16 17 

Missexed 0 0 2 0 

Animals examined microscopically 70 • 70 68 70 . , 

Systems Examined At 3 Months With No Neoplasms Observed 

Alimentary System 

Cardiovascular System 

Endocrine System 

General Body System 

Genital System 

Hematopoietic System 

Integumentary System 

Musculoskeletal System 

Nervous System 

Respiratory System 

Special Senses System 

Urinary System 

Long-Term Study 

Alimentary System 

Intestine large, colon 

Intestine large, rectum 

Intestine large, cecum 

Intestine small, duodenum 

Carcinnma 

(60) 

(59) 

(60) 

(59) 

(59) 

(59) 

(60) ' 

(60) 

(56) 

(57) 

(57) 

(57) 

1 (2%) 

(59) 

(59) 

(60) 

(60) 

Intestine ,,;mall, jejunum 

Carcinoma 

(59) (59) (56) 

1 (2%) 

(60) 

Intestine small, ileum 

Leiomyosarcoma 

Liver 

Hepatocellular adenoma 

Hepatocellular adenoma, multiple 

Osteosarcoma, metastatic, bone 

(60) 

(60) 

(58) 

(60) 

1 (2%) 

(57) 

1 (2%) 

(58) 

2 (3%) 

1 (2%) 

(58) 

(60) 

I 

I 

(2%) 

(2%) 

Mesentery (11) (13) (I0) (7) 

Sarcoma stromal, metastatic, uterus 

Oral mucosa 

1 (9%) 

"(I) 

Squamous cell carcinoma 

Pancreas (60) (60) 

I (100%) 

(57) (sg) 

Sarcoma stromal, metastatic, uterus 

Salivary glands 

Stomach, forestomach 

1 (2%) 

(60) 

(60) 

(60) 

(60) 

(58) 

(57) 

(6O) 

(60) 

Squamous cell papilloma 

Stomach, glandular (60) (60) 

I (2%) 

(57) (60) 
131 

~ ~ ' ~ " ~ -~ ~ - ~ ........ ~:~ 7r, ? ............ ~ 7q: ......... ............. ~ =~ ~ : . -

t~Bu~lhydroquinone, NTIP TR 459 

TABLE ~1 

SumanmT of the ]Mcidence of Neoplasms in Female ]Rats in the Long-Term Feed Study of t-~utylhydroquinone (continued) 

' 0 ppm 1,250 ppm 2,500 ppm 5,000 ppm 

Long-Term Study (continued) 

Alimentary System (continued) 

Tongue (1) (1) (4) (i) 

Sqnamous cell carcinoma I (25%) 

Squamous cell papilloma 1 (100%) I (100%) 1 (25%) 

I Cardiovascular System 

Heart (60) (60) (58) (6o) 

Sehwannoma benign 1 (2%) 1 (2%) 

I Endocrine System 

Adrenal cortex (6o) (6o) (58) (6o) 

Adenoma 4 (7%) 1 (2%) 

Adrenal medulla (6O) (6O) (58) (60) 

Pheochromocytoma malignant 1 (2%) 

Pheochromocytoma benign 2 (3%) 2 (3%) I (2%) 3 (5%) 

Islets, pancreatic (60) (59) (57) (59) 

Adenoma 2 (3%) 1 (2%) 3 (5%) 2 (3%) 

Carcinoma 1 (2%) 

Parathyroid gland (52) (55) (53) (54) 

Adenoma 2 (4%) 1 (2%) 

Carcinoma, metastatic, thyroid gland 1 (2%) 

Pituitary gland 

Pars distalis, adenoma 

Pars distalis, carcinoma 

Thyroid gland 

(60) 

26 (43%) 

2 (3%) 

(6O) 

(60) 

27 (45%) 

1 (2%) 

(6O) 

(57) 

34 

1 

(57) 

(6O%) 

(2%) 

(6O) 

28 (47%) 

3 (5%) 

(60) 

C-cell, adenoma 

C-cell, carcinoma 

7 (12%) 

1 (2%) 

7 (12%) 7 

2 

(12%) 

(4%) 

6 (10%) 

1 (2%) 

Follicular cell, adcnoma 1 (2%) 

Follicular cell, carcinoma I (2%) 1 (2%) 2 (3%) 

General Body System 

Peritoneum (i) 

Genital System 

Clitoral gland (58) (59) (58) (6o) 

Adenoma 6 (lO%) 6 (10%) 5 (9%) 6 (lO%) 

Adenoma, multiple 1 (2%) 

Carcinoma 6 (10%) 4 (7%) 5 (9%) 8 (13%) 

Ovary (6O) (6O) (57) (60) 

Carcinoma 1 (2%) 

Granulosa cell tumor malignant 1 (2%) 

Granulosa cell tumor benign 1 (2%) 1 (2%) 1 (2%) 

Uterus " (6O) (6O) (58) (60) 

Adenoma 1 (2%) 1 (2%) 

Carcinoma 1 (2%) 

Leiomyoma 1 (2%) 1 (2%) (2%) 

Polyp stromal 6 (10%) 12 (20%) (9%) 9 (15%) 

Polyp stromal, multiple 1 (2%) 

Sarcoma stromal 2 (3%) 1 (2%) (2%) 
132 t-Butylhydroquinone, NTP TR 459 

TA~I~ B1 

Summary of the Incidence of Neoplasms in Female Rats in the Long-Term Feed Study of t-Butyihydroquinone (contihued) 

Long-Term Study (continued) 

Hematopoietic System 

Bone marrow 

Lymph node 

Pancreatic, carcinoma, metastatic, ovary 

Lymph node, mandibular 

Lymph nnde, mesenteric 

Carcinoma. metastatic, ovary 

Spleen 

Hemangiosar¢oma 

Osteosarcoma, metastatic, bone 

Thymus 

Thymoma malignant 

Integumentary System 

Mammary gland 

Adenoma 

Carcinoma 

Carcinoma, multiple 

Fibroadenoma 

Fibroadenoma, multiple. 

Skin 

Basal cell carcinoma 

Keratoacanthoma 

Squamous cell papilloma 

Subcutaneous tissue, fibroma 

Subcutaneous tissue, fibroma, multiple 

Subcutaneous tissue, fibrosarcoma 

Subcutaneous tissue, hemangiosarcoma 

Subcutaneous tissue, lipoma 

Subcutaneous tissue, sarcoma 

Subcutaneous tissue, schwannoma malignant 

Musculoskeletal System 

Bone 

Osteosarcoma 

Skeletal rnuscle 

Sarcoma 

Sarcoma stromal, metastatic, uterus 

Nervous System 

Brain 

Carcinoma, metastatic, mammary gland 

Carcinoma, metastatic, pituitary gland 

Oligodendroglioma malignant 

Spinal cord 

Astrocytoma malignant 

0 ppm 

(60) 

(20) 

(59) 

(58) 

(60) 

1 (2%) 

(5~ 

(60) 

3 (5%) 

8 (13%) 

28 (47%) 

15 (25%) 

(60) 

! (2%) 

3 (5%) 

I (2%) 

1 (2%) 

(60) 

(i) 

i (100%) 

(60) 

1 (2%) 

(2) 

1,250 ppm 

(60) 

(24) 

(60) 

(6O) 

(60). 

(60) 

(59) 

6 (10%) 

16 (27%) 

17 (29%) 

(60) 

1 (2%) 

2 (3%) 

I (2%) 

(59) 

(1) 

(60) 

(2) 

2,500 ppm 

(57) 

(19) 

I (5%) 

(55) 

(55) 

I (2%) 

(57) 

1 (2%) 

(57) 

1 (2%) 

(58) 

I (2%) 

2 (3%) 

25 (43%) 

9 (16%) 

(58) 

1 (2%) 

I (2%) 

1 (2%) 

(58) 

i (2%) 

(i) 

(58) 

(3) 

5,000 ppm 

(60) 

(18) 

(60) 

(60) 

(60) 

(57) 

(60) 

2,(3%) 

3 (5%) 

I (2%) 

20 (33%) 

7 (12%) 

(60) ., 

2 (3%) 

1 (2%) 

I (2%) 

1 (2%) 

I (2%) 

I (2%) 

(60) 

(i) 

I (i00%) 

(60) 

I (2%) 

I (2%) 

(4) 

1 (25%) 

~ ~ t~ 
:;~:f::~:;-- ---- ~ : ~ - ~ ~ . . . . . . . . . . . . . . . . . . . . . . . ~ ~ --==~= ~--~--~= ...... ~ :~:~ - -

S-~uty]~yOroqu~noae, ~ TI~ ~$9 ~33 

TA~L~ ~[ 

S~n~ry o~ ~Lhe ~ci~ence o~ Neop~sn~s in Fe~e R~s in Che Long-Tern Feed S~Lu~y o~' ~-]~u~Ly~hy~r~utnone (continued). 

0 ppm 1,250 ppm 2,5~ ppm 5,~ ppm 

I ~ 

Long-Term .~udy (continued) 

Respiratory System 

Lung (60) (60) (58) (60) 

Aiveolar/bronchiolar adenoma 2 (3%) 2 (3%) 1 (2%) I (2%) 

Alveolarforonchiolar carcinoma 1 (2 %) 

Carcinoma. metastatic, ovary I (2%) 

Carcinoma, metastatic, thyroid gland ~ (2%) 

Nose (60) (60) (58) (60) 

,,, 

Special Senses System 

Zymbal's gland (1) 

Carcinoma 1 (100%) 

Urinary System 

Kidney (60) (60) (57) (60) 

Sarcoma stromal, metastatic, uterus 1 (2%) 

Renal tubule, adenoma 1 (2%) 

Urinary bladder (59) (60) (58) (59) 

Papilloma 1 (2%) 

Systemic Lesions 

Multiple organs b (60) (60) (58) (60) 

Lcukemia mononuclear 27 (45%) 33 (55%) 22 (38%) 27 (45%) 

Mesothelioma malignant I (2%) 

Neoplasm Summary 

Total animals with primary neoplasms c 59 59 56 59 

Total primary neoplasms 164 147 145 148 

Total animals with benign neoplasms 52 51 49 50 

Total benign neoplasms 112 99 100 95 

Total animals with malignant neoplasms 41 39 38 38 

Total malignant neoplasms 52 48 45 53 

Total animals with metastatic neoplasms 2 2 4 

Total metastatic neoplasms 5 5 4 

a Number of animals examined microscopically at ~he site and the number of animals with neoplasm 

b Number of animals with any tissue examined microscopically 

c Primary neoplasms: all neoplasms except metastatic neoplasms 
134 

 ̧' . 

t-Butylhydroquinone, NTP TR 459 

TABLE, B2 

Individual Animal Tumor Pathology of Female Rats in the Long-Term Feed Study of t-Butylhydroquinone: 0 ppm 

2334445555566666666677777 

Number of Days on Study 90812944477 ! 2234469901223~ 

7208170068937880910442243 

3333333333•3333.33333333333 

Carcass ID Number 5597896875566578595976767 

5799051161949645428382375 

Alimentary System 

•Esophagus + + + + + + + + + + + + +.+ + + + + + + + + + + + 

Intestinelarge, colon + + + + + + + + + + + + + + + + + + + + + + + + + 

Intestine large, rectum + + + + + + + + + + + + + + + + + + + + + + ÷ + + 

Intestine large, cecum + + + + + + + + + + + + + + + + + + + + + + + + + 

Intestine small, duodenum .+++++M+++++++++++++++ ~+ ++ 

Intestine small, jejunum + + + + + + + + + + + + + + + + + + + + + + + + + 

Intestine small, ileum + + + + + + + + + + + ~+ + + + + + + + + + + + + 

Liver + + + + + + + + + ~ + + + + + + + + + + + + + + + 

+ ++ +. + 

Sarcoma stromal, metastatic, uterus X 

Pancreas 

Mescntery 

+ + + + + + + + + + + + + + + + + + + + + + + + + 

Sarcoma stromal, metastatic, uterus X 

Salivary glands + + + + + + + +,+ + + + + + + + + + + + + + + + + 

+ + + + + + + +.+ + + + + + + + + + + + + + + + + Stomach, forestomach 

+ + + + + + + + + + + + + + + + + + + + ÷ + + + + Stomach, glandular 

Tongue 

Squamous cell papilloma " 

Cardiovascular System 

~+ + + ++ + + ++ + ~ + + ++ ++ + + + + + + + + Blood vessel 

+ + + + + + + + + + + + + ~ + + + + + + + + + + + Heart 

Endocrine System 

Adrenal + + + + + + + + + + + + + + + + + + + + + + + + + cortex 

Adenorna + + + + + + + + + + + + + + + + + + + + + + + + + Adrenal medulla 

Phcochromocytoma benign + + + + + + + + + ++ + + + + + + + + + + + + + + Islets, pancreatic 

Adcnoma X . • 

Parathyroid gland +++++++++++++++++++ ++++ +M 

Adenoma + + + + + + + + + + + + + + + + + + + + + + + + + Pituitary gland 

Pars distalis, adenoma X XX XX X X 

Pars distalis, carcinoma X 

+ + + + + + + + + + + + + + + + + + + + + + + + + Thyroid #and 

C-.ccll, adcnoma X X 

C-cell, carcinoma 

Follicular cell, carcinoma 

General Body System 

Peritoneum 

Genital System + + + + + + + + + + + + + + + + + + + + + + + + + Clitoral gland 

Adenoma X 

Carcinoma X 

+: Tissue examined microscopically M: Missing tissue X: Lesion present 

A: Autolysis precludes examination I: Insufficient tissue Blank: Not examined 
i~: =~=.~_~7=-!~-~-~.-~.~_~_~_ .................. .............. --= ~. ------ -~_ ~ ~ -~....... 

t-Butylhydroquinone, NT~P TR 459 135 

TABLE ~2 

~ndividua~ Anhna~ Tumor Pathology of l~emale Rats in the Long-Term ~'eed Study of t-Buty~hydroqulnone: 0 ppm 

(condnued) 

7777777777777778888888888 

Number of Days on Study 3356666778899990033555788 

3681556785955692801456908 

4333333333433333433344433 • 

Carcass ID Number 0786897869189686078600095 

4138602807094675074335863 

t ~ 

I Alimentary System 

Esophagus I + + + ++ + + ++ +M+ + + + + + + + + + + + + 

Intestine large, colon + + + + + + + + + + + + + + + + + + + + + + + + + 

Intestine large, rectum + +M+ + + + + + + + + + + + + + + + + + + + + + 

Intestine large, cecum + + + + + + + + + + + + + + + + + + + + + + + + + 

Intestine small, duodenum + + + + + + + + + + + + + + + + + + + + + + + + + 

Intestine small, jejunum + + + + + + + + + + + + +'+ + + + + + + + + + + + 

Intestine small, ileum + + + + + + + + + + + + + + + + + + + + + + + + + 

Liver + + + + + + + + + + + + + + + + + +~+ + + + + + + 

Mescntery + + ++ + + 

Sarcoma stromal, metastatic, uterus 

Pancreas + + + + + + + + + + + + + + + + + + + + + + + + + 

Sarcoma stromal, metastatic, uterus 

Salivary glands + + + + + + + + + + + + + + + + + + + + + + + + + 

Stomach, forestomach + + + + + + + + + + + + + + + + + + + + + + + + + 

Stomach, glandular + + + + + + + + + + + + + + + + + + + + + + + + + 

Tongue 

Squamous cell papilloma 

Cardiovascular System 

Blood vessel + + + + + + + + + + + + + + + + + + + + + + + + + 

Heart + + + + + + + + + + + + + + + + + + + + + + + + + 

[ 

Endocrine System 

Adrenal cortex + + + + + + + + + + + + + + + + + + + + + +~+ + + i 

Adenoma X X X l 

l 

Adrenal medulla + + + + + + + + + + + + + + + + + + + + + + + + + 

Phcochromocytoma benign X 

Islets, pancreatic + + + + + + + + + + + + + + + + + + + + + + + + + 

Adcnoma X 

Parathyroid gland +M+++++ ++++I + +MMM+++ +++ + + 

Adenoma XX 

Pituitary gland + + + + + + + + + + + + + + + + + + + + + + + + + 

Pars distalis, adenoma XX X XXXXXXXXXXX 

Pars distalis, carcinoma X 

Thyroid gland + + + + + + + + + + + + + + + + + + + + + + + + + 

C-cell~ adenoma X 

C-cell, carcinoma 

Follicular cell, carcinoma 

General Body System 

Peritoneum 

Genital System 

Clitoral gland + + + + + + + + + + + +M+ + + + + +M+ + + + + 

Adenoma X X 

Carcinoma X 
136 t*Butylhydroquinone, NTP TR 459 

TA~L~: B2 

Individual Animal Tumor Pathology of Female Rats in th e Long-Term Feed Study of pButylhydroquinone: 0 ppm 

(continued) 

8888888888 

Number of Days on Study 9999999999 

8888888888 

3333344444 Total 

Carcass ID Number 5789900000 Tissues/ 

2021812679. Tumors 

Alimentary System 

Esophagus + + + + + + + + + + 58 

Intestine large, colon + + + + + + + + + + 60 

Intestine large, rectum + + + + +~+ + + + 59 

Intestine large, cecum + + + + + + + + + + 6O 

Intestine small, duodenum + + + + + + + + + + 59

Intestine ,,;mall, jejunum ++M+++++++ 59 

Intestine small, ileum + + + + + + + + + + 6O

Liver • + + + ~ + + + + + + 6 0

Mesantery II 

Sarcoma stromal, metastatic, uterus 1 

Pancreas + + + + + + + + + + 6O

Sarcoma stromal, metastatic, uterus I 

Salivary glands + + + +~ + + + + + 6O 

Stomach, forestomach + + + + + + + + + + 6O

Stomach, glandular + + + + + + + + + + 0 

Tongue + 

•Sq~ua~mous cell papilloma X 

Cardiovascular System 

Blood vessel + + + + + + + + + + 

Heart + + + + + + + + + +

Endocrine System 

Adrenal cortex + + + + + + + + + + 60

Adenoma X 4 

Adrenal medulla + + + + + + + + + + 60 

Pheochromocytoma benign X 2 

Islets, pancreatic + + + + + + + + + + 60

Adenoma 2 

Parathyroid gland +M+ + + + + +M+ 52 

Adenoma 2 

Pituitary gland + + + + + + + + + + 60

Pars distalis, adenoma XX X XX 26 

Pars distalis, carcinoma 2 

Thyroid ghmd + + + + + + + + + + 60

C-cell, adenoma X XX X 7 

C-cell, carcinoma X 1 

Follicular cell, carcinoma X 1 

General Body System 

Peritoneum 

Genital System 

Clitoral gland 58 

Adenoma ,X XX 6 

Carcinoma X XXX 6 
t-~aty~hy~iroquinone, ~P T]~ 459 137 

T~LZ ~2 

~vi~i~ 

(continuefl) 

~ T~ ~o~o~.,~' ~[ F~ ~ ~ ~ ~g-T~ F~i S~ly off l-~y]~y&-o~ni~o~: # ~ 

l~Iumber of Days on Study 

23344455555'66666666677777 

9081294447712234469901223 

7208170068937880910442243 

Carcass ID Number 

33333333333333333333333-33 

5597896875566578595976767 

5799051161949645428382375 

I

l 

I 

i 

~i 

Genital System (continued) 

Ovary 

Granulosa cell tumor benign 

Uterus 

Leiomyoma 

Polyp stromal 

Polyp stromal, multiple 

Sarcoma stromal 

+ 

+ 

+ 

+ 

X 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

÷ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

X 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

X 

+ 

+ 

+ 

+ 

+ 

÷ 

Hematopoietic System 

Bone marrow 

Lymph node 

Mediastinal, mesothelioma malignant, 

metastatic, peritoneum 

Lymph node, mandibular 

Lymph node, mesenteric 

Spleen 

Hemangiosarcoma 

Thymus 

+ + + + + + + + + + + + + + +'+ + + + + + + 

++ + + +++++ 

X 

+ + + + + + + + + + + + + + + + + + + + + + 

++++++++++++++++++++++I 

+ + + + + + + + + + + + + + + + + + + + + + 

+ + + + + + + + + + + + + + + + + + + + + + 

+ + + 

++ 

+ + + 

++ + ++ 

+ + + 

[ 

i 

Integumentary System 

Mammary gland 

Adenoma 

Carcinoma 

Fibroadenoma 

Fibroadenoma, multiple 

Skin 

Basal cell carcinoma 

Subcutaneous tissue, fibroma 

Subcutaneous tissue, fibrosarcoma 

Subcutaneous tissue, lipoma 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

X 

+ 

+ 

+ 

+ 

+ 

+ 

X 

+ 

+ 

X 

+ 

X 

+ 

+ 

+ 

X 

+ 

+ 

X 

+ 

+ 

X 

+ 

+ 

+ 

+ + 

XX 

+ + 

+ 

X 

X 

+ 

X 

+ + 

XXX 

+ + 

+ 

+ 

X 

+ 

+ 

+ 

X 

+ 

+ 

+ 

+ + 

XXX 

+ + 

+ 

X 

+ 

Musculoskeletal System 

Bone 

Skeletal muscle 

Sarcoma stromal, metastatic, uterus 

+ + 

+ 

X 

+ + + + + + + + + + + + + + + + + + + + + + + 

Nervous System 

Brain 

Oligodendroglioma malignant 

Peripheral nerve 

Spinal cord 

+ + + + + + + ÷ + + + + + + + + + + + + + + + + + 

Respiratory System 

Lung 

Alveolar/bronchiolar adenoma 

Nose 

Trachea 
- - 

138 t-.Butyihydroquinone, NTP TR 459 

TABLE B2 

Individual Animal Tumor Pathology of Female Rats in the Long,Term Feed Study of t-Butylhydroquin0ne: 0 ppm 

(continued) 

7777777777777778888888888 

Number of Days on Study 3356.66677889999003355578,8 

3681556785955692801456908 

4333333333433333 ~ 333" 4 4433 

Carcass ID Number 0786897869189686078600095 

4138602807094675074335863 

Genital System (continued) 

Ovary + + + + + + + + + + + + + + + + + + + + + + + + + 

Granuk)sa cell tumor benign • X 

Uterus + + + + + + + + + + + + + + + + + + + + + + + + + 

Leiomyoma X 

Polyp stromal X X X 

Polyp stromal, multiple X 

Sarcoma stromal X 

Hematopoietic System 

Bone marrow + + + + + + + + + + + + + + + + + + +'+ + + + + +

Lymph node + + + + + + 

Mediastinal, mesothelioma malignant, 

metastatic, peritoneum 

Lymph node, mandibular + + + + + + + + + + + + + + + + + + + + + + + +. + 

+ +| + + + + + + + + + + + + + + + + + + + + + + Lymph node, mesenteric + + + + + + + + + + + + + + + + + + + + + + + + + Spleen 

Hemangiosarcoma 

Thymu[ +++++++++ ++M+I I ++ ++ ++M+ ++ 

Integumentary System 

Mammary ++++++++++++++++++++++÷÷+ gland 

Adcnoma X • 

Ca,rcinoma X X X X 

Fibroadenoma XXXX X XX XXX X X X 

Fibroadcnoma, multiple X X XX X XX 

+ + + + + + + + + + + + + + + + + + + + + + + + + Skin 

Basal cell carcinoma 

Sul_)cutancous tissue, fibroma 

Subcutaneous tissue, fibrosarcoma X 

Subcutaneous tissue, lipoma X 

Musculoskeletal System 

Bone. + + + + -/: + + + + + + + -4- + + + + + + + + + + + + 

Skeletal muscle 

Sarcoma stromal, metastatic, uterus 

Nervous System 

Brain 

Oligodendroglioma malignant 

Peripheral nerve + + 

Spinal cord + + 

Respiratory System 

Lung 

Alveolar/bronchiolar adenoma X 

Nose 

Trachea 
-:: : :--'-~ :~ : : ~:~--~-:: ~-~...... ~7-..... ~ ........... ~ - ~ .... ---~- ........... ~ .............. 

~-Bu~lhydroquinone, ~ TIR ,~59 139 

TABLE ~2 

IIn~v~ua~ 

(continued) 

Anhna~ Tumor Fatho~ogy of I~ema~e IRa, s ~n the ~ng-Term Feed Study o~ t-Buty~hy~roqu~none: 0 ppm 

8888888888 

Number of Days on Study 9999999999 

8888888888 

3333344444 Total 

Carcass ~D Number 5789900000 

2 0 2 18 12 67 9 

Tissues/ 

~mors 

Genital System (continued) 

Ovary 

Granulosa cell tumor benign 

Uterus 

Leiomyoma 

Polyp stromal 

Polyp sttromal, multiple 

Sarcoma stromal 

+ 

+ 

+ 

+ 

X 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

60 

1 

60 

1 

6 

1 

2 

I 

Hematopoietic System 

Bone marrow 

Lymph node 

Mediastinal, mesothelioma malignant, 

metastatic, peritoneum 

Lymph node, mandibular 

Lymph node, mesenterie 

Spleen 

Hemangiosarcoma 

Thymus 

++ + 

+ 

+ ++ + + + 

+ + + 

+ + + 

+ 

+ 

+ 

+ 

+ 

++ + 

+ +M+ + + + 

+ + + 

X 

+ + + 

+ 

+ 

+ 

+ 

+ 

++ 

+ 

+ + 

+ + 

+ + 

+ + 

~ 

20 

1 

59 

58 

60 

1 

56 

i 

~ntegumentary System 

Mammary gland 

Adenoma 

Carcinoma 

Fibroadenoma 

Fibroadenoma, multiple 

Skin 

Basal cell carcinoma 

Subcutaneous tissue, fibroma 

Subcutaneous tissue, fibrosareoma 

Subcutaneous tissue, lipoma 

+ 

X 

+ 

+ 

X 

+ 

+ 

X 

+ 

+ 

X 

+ 

+ + 

X 

XX 

+ + 

+ 

X 

+ 

+ + 

XXX 

+ + 

+ 

+ 

60 

3 

8. 

28 

15 

60 

1 

3 

1 

1 

Musculoskeletal System 

Bone 

Skeletal muscle 

Sarcoma stromal, metastatic, uterus 

+ + + + + + + + + + 60 

1 

I 

Nervous System 

Brain 

Oligodendroglinma malignant 

Peripheral nerve 

Spinal cord 

+ + + + 

X 

+ + + + + + 60 

1 

2 

2 

Respiratory System 

Lung 

Alvcolar/bronchiolar adcnoma 

Nose 

Trachea . . • 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

X 

+ 

+ 

+ 

+ 

+ 

60 

2 

60 

60 
140 t-Butylhydroquinone, NTP TR 459 

TAttLE B2 

Incfivi~luai Animal Tumor Pathology of Female Rats in the Long-Term Feed Study of t-Butylhydroquinone: 0 ppm 

(continued) 

233444555556666666667777.7 

Number' of Days on Study 9081294447712234469901223 

7208170068937880910442243 

3333333333333333333333333 

Carcass ID Number 5597896875566578595976767 

5799051161949645428382375 

Special Senses System 

Ear 

Eye + ÷ 

Urinary System 

Kidney + + + ÷ + + ÷ ÷ + ÷ + ÷ ÷ ÷ ÷ + + ÷ ÷ + + + + ÷ + 

Sarcoma stromal, metastatic, uterus X 

Renal tubule, adenoma 

Urinary bladder + + + + + + + + + + + + + + + + + + + + + + + + + 

Systemic Lesions 

Multiple organs 

Leukemia mononuclear XX XX X X XX X XX 

Mesothelioma malignant X 
~ - ~ ~ _ _ ~ ~ = ~ ~ ................................... ~ - .......... ~ ~ _ - : - - ~ ~ .~ -... ~ ~ ......... ..... . 

t-l~uty~hydroqutnone , NTP TR ,~59 141 

TABLE ~2 

Ilud~v~dua~ An~im~ Tumor lFatho~ogyo~ Female ~Ra~ ~n the Long-Term Feed Study o~ t-~uty~hydroqu~none: 0 ppm 

(continued) 

7777777777777778888888888 

Number of Days on Study 3356666778899990033555788 

3681556785955692801456908 

4333333333433333433344433 

Carcass ~D Number 0786897869189686078600095" 

4138602807094675074335863 

Special Senses System 

Ear + , 

Eye + + ' 

Urinary System ! 

Kidney + + + + + + + + + + + + + + + + + + + + + + + + + ~i - 

Sarcoma stromal, metastatic, uterus i 

Renal tubule, adcnoma 

Urinary bladder + + + + + + + + + + + + M + + + + + + + + + + + + i 

! 

Systemic Lesions 

Multiple organs 

Leukemia mononuclcar X XXX XXXX X X X 

Mcsothclioma malignant i -

! 

i 
142 t:Butylhydroquinone, NTP TR 459 

TABLE B2 

Individual Animal Tumor Pathology of Female Rats in the Long-Term Feed Study of t-Butylhydroquinone: 0 ppm 

(continued) 

Number of Days on Study 

Carcass ID Number 

Special Senses System 

Ear 

Eye 

Urinary System 

Kidney 

Sarcoma stromal, metastatic, uterus 

Renal tubule, adenoma 

Urinary bladder 

Systemic Lesions 

Multiple organs 

,Leukemia mononuclear 

" Mesothelioma malignant 

8888888888 

9999999999 

8888888888 

3333344444 

5789900000 

2021812679 

+ + + + + + + + + + 

X + + + + + + + + + + 

X X XXX 

Total 

Tissues/ 

Tumors 

60 

1 

1 

59 

60 

.. 27 

1 

.. 
i~~'~:~--- ~--~.-~-~:r.::~ .......................... ~=--~ ~::::~-'-~ - ~:...... ~ - ~-~ ~ __ _ 

t-I~u~y~hydroqu~none, ~ ~ ~ ~3 

T~L~ ]~2 

~[n~ua~ Anhna~ Tun~or ~e~ho~o~3, o~ Fen~e ~s~ the Long-Te~ Feed Study o~ t-~uty~hy~ro~u~none: L250 ppm 

I 

[Number of Days on Study 

4445555666666666666777777 

8893378122445566689002333 

0187763855096968937552356 

Carcass ~D Number 

4444444444444444444444444 

22336437377437444867723.66 

3139.167950580850902144203 

[ 

i 

Ai~enta~ System 

Esop~s 

In~sfinela~e,c~on 

Intesfinela~e,~cmm 

Intesfinela~e, cecm 

~sfinesmall, du~enm 

Inmsfi~sm~l,j~ 

Inm~nesmall, ileum 

Liver 

Hepat~ellularadenoma 

Mesenmry 

Pan¢~as 

S~aryglands 

S~ma~,~smmach 

S~ma~,gland~ar 

~e 

Squamousccllp~illoma 

+ 

M 

+ 

+ 

+ 

M 

M 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+++++++++ 

+++++++++ 

+++++++++ 

+++++++++ 

+++++++++ 

+++++++++ 

+++++++++ 

+++++++++ 

X 

+++++++++ 

+++++++++ 

+++++++++ 

+++++++++ 

+ 

Cardiovascular System 

Blood vessel 

Heart 

Schwannoma benign 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

Endocrine System 

Adrenal cortex 

Adenoma • 

Adrenal medulla 

Pheochromocytoma benign 

Islets, pancreatic 

Adenoma 

Parathyroid gland 

Pituitary gland 

Pars distalis, adenoma 

Pars distalis, carcinoma 

Thyroid gland 

C-cell, adenoma 

+ 

+ 

+ 

+ 

+ 

X 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ + 

+ + 

+ + 

X 

+ + 

+ + 

XX 

+ + 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ + 

+ + 

+ + 

+ + 

+ + 

XX 

+ + 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

X 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

X 

+ 

+ 

+ 

+ 

+ 

X 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ + 

+ + 

+ + 

+ + 

+ + 

XX 

+ + 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

General Body System 

None 

Genital System 

Clitoral gland 

Adenoma 

Carcinoma 

Ovary 

Grartulosa ~ell tumor malignant 

Granulosa cell tumor benign 

Uterus 

Leiomyoma 

Polyp stromai 

Sarcoma stromal 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ + 

+ + 

+ + 

XX. 

+ 

+ 

+ 

+ 

+ 

+ 

+ + 

+ + 

+ + 

XX 

+ 

X 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

X 

+ 

+ 

X 

+ 

+ 

+ 

+ 

X 

+ 

+ 

X 

+ 

+ 

X 

+ 

X 

+ 

X 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 
144 t-Butylhydroquinone, NTP TR459 

TABLE B2 

Individual Animal Tumor Pathology of Female Rats in the Long-Term Feed Study of t-Butyihydroquinone: 1,250 ppm 

(continued) 

7777777778888888888888888 

Number of Days on Study 3467889990001333456679999 

8914192596670114592330478 

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 5634265322567474255346762 

0617978868792163594624782 

Alimentary System , ,

Esophagus + + + + + + + + + + + + + + + + + + + + + + ++ + 

Intestine large, colon + + + + + + + + + + + + + + + + + + + + + + + + +

Intestine large, rectum + + + + + + + + + + + + + + + + + + + + + + + + ÷

+ + + + + + + + + + + + + + + + + + + + + + + + + ' Intestine large, cecum 

+ + + + + + + + + + + + + + + + + + + + + + + + + Intestine small, duodenum 

Intestine small, jejunum + + + + + + + + + + + + + + + + + + + + + + + + ~

Intestine small, ileum + + + + + + + + + +i+ + + + + + + + + + + + + + 

Liver + + + + + + + + + + + + + + + + + + + + + + + + + 

Hepaa3cellular adenoma % 

Mesentery +++ + + +

Pancreas + + + + + + + + + + + + + + + + + + + + + + + + + 

+ + + + + + + + + + + + + + + + + + + + + + + + + Salivary glands " 

+ + + + + + + + + + + + + + + + + + + + + + +.+ + Stomach, forestomach + + + + + + + + + + + + + + + + + + + + + + + + + Stomach, glandular 

Tongue + 

Squamous cell papilloma X 

Cardiovascular System + ++++ + + + + + + + + + + + + + + + + + + + + Blood vessel .+ + + + + + + + + + + + + + + + + + + + + + + + + Heart . : 

Schwmmoma benign X 

Endocrine System + + + + + + + + + + + + +'+ + + + + + + + + • + + Adrenal cortex 

Adenoma X + + + + + + + + + + + + + + + + + + + + + + + + ~ Adrenal medulla 

Pheochromocytuma benign 

Islets, pancreatic +M++ + + + +++++++ + + + + + + + + + + + 

Adenoma 

Parathyroid gland ++++++M++M++++++++ ++ ++M++ 

+ + + + + + + + + + + + + + + + + + + + + + + + + Pituitary gland 

Pars distalis, adenoma XX X XXXX XXXXX X X 

Pars distalis, carcinoma + + + + + + + + + + + + + + + +.+ + + + + + + + + Thyroid gland 

C-cell, adenoma X X X XXX 

General Body System ; 

None 

Genital System + + + + + + + + + + + + + + + + + + + + + + + + + Clitoral gland 

Adenoma X X XXX 

Carcinoma + + + + + + + + + + + + + + + + + + + + + + + + + Ovary 

Granulosa cell tumor malignant 

Granulosa cell tumor benign 'X • 

Uterus 

Leiomyoma X 

Polyp stromal XXX X X 

Sarcoma stromai 
I 

. 

::~= ~ = • = :: : = ~ ....... ~,,~ ~ :~:=~ ~ ~ . . . . . . . . . . lr : ...... ~ . . . . . . . . . . . = :~ ~ ...... ~ ~_.~_ ='~ --~ ~ . . . . . . . . . . . . ~ - ........ 

¢-]l~u~y~hydroquluene, HT~F TI~ ~9 

T~.g ~2 

~ndividu~ Ani~m~ T~mmor ]?atho~o[gy of Fen~e ~s in the ~ng-Te~ Feed Study of t-~uty~hydroqu~none: L250 pp~ 

(confinu~) 

8888888888 

Number of Days on Study 9999999999 

8888888888 

4444444444 Total 

Carcass ~D Humber 2345555567 Tissues/ 

7441235653 Tumors 

. . 

Alimentary System 

Esophagus + + + + + + + + + + 

+ + + + + + + + + + Intestine large, colon 59 

Intestine large, rectum +++++I ++++ 59 

Intestine large, cecum + + + + + + + + + + 6O

+ + + + + + + + + + Intestine small, duodenum 6O 

+ + + + + + + + + + 

Intestine small, ileum 58 

Intestinesmall, jejunum 59 

+ + + + + + + + + + 

Liver + + + + + + + + + + 6O

Hepatocellular adenoma 1 

Mesentery ++ + 13 

Pancreas .+ + + + + + + + + + 6O 

+ + + + + + + + + + Salivary glands 6O 

Stomach, forestomach + + + + + + + + + + 6O 

Stomach, glandular + +++ + ++ + + + 6O 

Tongue 1 

Squamous cell papilloma 1 

Cardiovascular System 

Blood vessel + + + + + + + + + + 6O

Heart + + + + + + + + + + 6O

Schwannoma benign I 

Endocrine System 

Adrenal cortex + + + + + + + + + + 60

Adenoma 1 

Adrenal medulla + + + + + + + + + + 60

Pbeochromocytoma benign XX 2 

Islets, pancreatic + + + + + + + + + + 59 

Adenoma 1 

Parathyroid gland +++M+++++M 55 

Pituitary gland + + + + + + + + + + 60 

Pars distalis, adenoma X XX X 27 

Pars distalis, carcinoma X 1 

Thyroid gland + + + + + + + + + + 60 

C-cell, adenoma 7 

General ~ody System 

None 

Genital System 

Clitoral gland + + + +M+ + + + + 59 

Adenoma 6 

Carcinoma X 4 

Ovary + + + + + + + + + + 60

Granulosa cell tumor malignant 1 

Granulosa cell tumor benign 1 

Uterus + + + + + + + + + + 60

Leiomyoma 1 

Polyp stromal X 12 

Sarcoma stromal 1 
146 t-Butylhydroquinone, NTP TR 459 

TABL,E B2 ~ , 

Individual Animal Tumor Pathology of Female Rats in the Long-Term Feed Study of tzButylhydr0quinone: 1,250ppin 

(continued) . 

444555566666666666677777 7 

Number of Days on Study 889337812244556668900233 

018776385509696893755235 6 

4444444444444444444444444 • 

Carcass ID Number 223364373774374448677236'6 

3139167950580850902144203 

, , "Hematopoietic System 

Bone marrow + + + + + + + + + + + + + + + + + + + + + + + + + 

Lymph node + + +++ + +++ + + 

Lymph node, mandibular + + + + + + + + + + + + + + + + + + + + + + + + + 

Lymph node, mesenteric + + + + + + + + + + + + + + + + + + + + + + + + ÷ 

Spleen + + + + + + + + + + + + + + + + + + + + + + + + + 

Thymus + + + + + + + + + + + + + + + + + + + + + + + + + 

. . Integmnentary System 

Mammary gland ++++M+ ++++++++++++ ++ ++ ++ +, 

Carcinoma X 

Fibroadenoma X X X X X 

Fibroadenoma, multiple X ' 

Skin ++++++.+++++++4-++++++++++ + 

Basal cell carcinoma 

Subcutaneous tissue, fibroma X ~ 

Subcutaneous tissue, fibroma, multiple 

Musculoskeletal System 

Bone + +I + + + + + ÷ + + + + + + + + + + + + + + + + 

Skeletal muscle + 

Nervons System 

Brain + + + + + ~ + + + + + + + + + + + + + + + + + ++ 

Peripheral nerve 

Spinal cord + 

Respiratory System 

Lung + + + + + + + + + + + + + + + + + + + + + + + + + 

Alveolar/bronchiolar adenoma 

Alveolar/bronchiolar carcinoma .~ 

Nose + + + + + + + + + + + + + + + + + + + + + + + + + 

Trachea + + + + + + + + + + + + + • + + + + + + + + + + ~

Special Senses System 

Ear 

Eye 

Urinary System 

Kidney + + + + + +.+ + + + + + + + + + + + + + + + + + + 

Urinary + + + + + + + + + + + + + + +.+ + + + + + + + + + bladder 

Systemic Lesions 

Multiple organs 

Leukemia mononuclear X X X XXX X XXXX XX 
_ _ 

:~:- : ~:--~-~:__ _~o~ ....... , -.- ~:, ....... ~ ~ .......... .--~ ..... ~.~, . ~:: ~ ..~ . . . . . . . . . . . _. ~ 

t-~uty~hydroquinone, NTP T~ 4S9 147 

TABLE B2 

3Individual Animal 

(continued) 

Tumor 3?ntho~ogy o~ Fern~e ~s in the Long-Term Feed Study o~ t-Butynhydroquinone: 1,250 ppm 

7777777778888888888888888 

Number of Days on Study 3467889990001333456679999 

8914192596670114592330478 

I 

I 

! 

Carcass ID Number 

Hematopoietic System 

Bone marrow 

Lymph node 

Lymph node, mandibular 

Lymph node, mesenteric 

Spleen 

Thymus 

4 ~ 44444444444444444444444 

56342653225674.74255346762 

0617978868792163594624782 

+ + + + + + + + + + + + + + + + + + + + + + + + 

+ ++ + + + ++ +++ 

+ + + + + + + + + + + + + + + + + + + + + + + ~ 

+ + + + + + + + + + + + + + + + + + + + + + + + 

+ + + + + + + + + + + + + + + + + + + + + + + + 

+ + + + + + + + + + + + + + + + + + + + + + + + 

+ 

+ 

+ 

+ 

+ 

Integumentary System 

Mammary gland 

Carcinoma 

Fibroadenoma 

Fibroadenoma, multiple 

Skin 

Basal cell carcinoma 

Subcutaneous tissue, fibroma 

Subcutaneous tissue, fibroma, multiple 

+ 

+ 

+ 

+ 

+ 

X 

+ 

+ 

+ 

X 

+ 

X 

+ 

+ 

X 

+ 

+ 

+ 

+ + 

XX 

+ + 

+ 

X 

+ 

+ 

+ 

+ + 

X 

XXX 

+ + 

X 

+ 

+ 

+ + 

XX 

+ + 

+ 

X 

X 

+ 

+ 

X 

+ 

+ 

X 

+ 

+ + 

XX 

+ + 

+ 

+ 

+ 

+ 

+ 

X 

+ 

+ 

X 

X 

+ 

X 

Musculoskeletai 

Bone 

Skeletal muscle 

System 

+ + + + + + + + + + + + + + + + + + + + + + + + + 

Nervous System 

Brain 

,Peripheral nerve 

Spinal cord 

+ + + + + + + + + + + + + + + + + + + + + + 

+ 

+ 

+ + + 

Respiratory System 

Lung 

Alveolar/bronchiolar adenoma 

Alveolar/bronchiolar carcinoma 

Nose 

Trachea 

+ 

+ 

,gr 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

X 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

-k 

-k 

+ 

+ 

+ 

+ 

+ 

+ 

Special Senses System 

Ear 

Eye 

+ 

+ 

Urinary System 

Kidney 

Urinary bladder 

Systemic Lesions 

Multiple organs 

Leukemia mononuclear XX XX XXX XXX X XXXXXX 
1,~8 ~t-Butylhydroquinone, NTP TR459 

TABLJ~ B2 

Individual Animal Tumor Patl~ology of Female Rats in the Long-Term Feed Study of t-Butylhydroquinone: 1,250 ppm 

(continued) 

8 8 88888888 

Number of Days on Study 9 9 99999999 

8 8 88888888 ,~ 

4 4 44444444 Total 

C~rc~s ID Number 2 3 45555567 Tissues/ 

7 4 41235653 Tumors 

Hematopoietic System 

Bone marrow + + + + + + + + + + 60 

Lymph node + + 24 

Lymph node. mandibular + + + + + + +~+ + + 60 

Lymph node, mesenteri¢ + + + + + + + + + + 60 

Spleen + + + + + + + + + + 60 

Thymus + + + + + + + + + + 60 

lntegmnentary System 

Mammary gland + + + + + + + + + + 59

Carcinoma X X 6 

Fibroadenoma X X X 16 

Fibroadenoma, multiple XX X XX X 17 

Skin + + + + + + + + + + 60

Basal cell carcinoma 1 

Subcutaneous tissue, fibroma 2 

Subcutaneous tissue, fibroma, multiple 1 

Musculoskeletal System 

Bone + + + + + + + + + + 59"

Skeletal muscle 

Nervons System 

Brain + + + + + + + + + + 60

Peripheral nerve 1 

2 Spinal cord 

Respiratory System + + + + + + + + +'+ Lung 

Alveolar/bronchiolar 2 adeuoma X X 

Alveolar/bronchiolar carcinoma + + + +++ + +++ Nose +++ + + + ++ + + Trachea 

Special Senses System 

Ear 

Eye 

Urinary System + + + ++ + + + + + Kidney + + + + + + + + + + Urinary bladder 

Systemic Lesions + + + + + + + + + + 60 Multiple organs 33 Leukemia mononuclear X X X 
149 

~:---~:--.~ :: ~;: ............. ~ ........... ., ~ ~ ~'~'~:~'~'~"~--?~'~ ~ ~ ........ ~--~;;=:~ ~= :::, : .......... ~ ..... 

~-~u~y~hydr~t~.~u~none, ~ T~ ~ 

TA~L~ ~ 

~m~i~vht~.u~.~ Aninn~ T~n~or P~ho~Iogy o~ Fe~n~e ]ka~s ~n ~he Long-Tern Feedl S~dly o~ ~-~uty~hy~lroquimone: 2,500 ppm 

1445666666666677777777777, 

Number o~ Days on Study 9297013455666802355667777 

7588032978167231878772244 

5555455555545455555554555 

Carcass ~ID Number 4023903244292914000119404 

1494238602037558591671904 

Alimentary System 

Esophagus + + +A + + + ++ + + + + + + + + + + + + + + + + 

Intestine large, colon + ++M++ + +++ + + + +M+ + + + + + + + + + 

Intestine large, rectum + + +A + + + + + + + + + + + + + + + + + + + + + 

Intestine large, cecum + + +M+ + + + + + + + + + + + + + + + + + + + + 

Intestine small, duodenum + + +M+ + + + + + + + + + + + + + + + + + + + + 

Carcinoma 

Intestine small, jejunum M++M+++++++++++++++++ ++++ 

Carcinoma 

Intestine small, ileum + ÷ +M+ ÷ + + + + ÷ + + + + + + + ÷ ÷ + + + + + 

Leiomyosarcoma 

Liver + + + + + ÷ ÷ ÷ + + ÷ + ÷ ÷ ÷ ÷ ÷ ÷ + ÷ ÷ ÷ + + + 

Hepatocellular adenoma 

Osteosarcoma, metastatic, bone 

Mesentery + ++ + + +

+ ' Oral mucosa 

Squamous cell carcinoma X 

Pancreas + + +M+ ÷ + + + + + + + + + + + + + + + + + + + 

Salivary glands + + + + + + + + + + + + + + + + + + + + + + + + + 

Stomach, forestomach + ÷ +M+ + + + ÷ + + + + + + + + + + + + + + + + 

Squamous cell papilloma 

Stomach, glandular + ++M+ + +++ + + + + +++ + + + + + + + + + 

Tongue + 

Squamous cell carcinoma X 

Squamous cell papilloma 

Cardiovascular System 

Blood vessel + + + + + + + + + + + + + + + + + + + + + + + + + 

Heart + + + + + + + + + + + + + + + + + + + + + + + + + 

Endocrine System 

Adrenal cortex + + + + + + + + + + + + + + + + + + + + + + + + + 

Adrenal medulla + + + + + + + + + + + + + + + + + + + + + + + + +

Pheochromocytoma benign 

Islets, pancreatic + + +M+ + + + + + + + + + + + + + + + + + + + + 

Adenoma 

Carcinoma 

Parathyroid gland + + + + + + + + + + + + + + + + + + + + +'+M+ + 

Pituitary gland + + +~+ + + + + + + + + + + + + + + + + + + + + 

Pars distalis, adenoma X XX X XXXX X .XXX 

Pars distalis, carcinoma 

Thyroid gland + + ÷A + + + + + + + + + + + + + + + + + + + + + 

C-cell, adenoma XX X X 

C-cell, carcinoma 

Follicular cell, adenoma 

Follicular cell, carcinoma 

General Body System 

None 
150 " t-Butylhydroquinone, NTP TR 459 

TABLE B2 

Individual Animal Tumor Pathology of Female Rats in the Long-Term Feed Study of t-Butylhydroquinone: 2,500ppm 

(continued) 

7777888888888888888888888 

Number of Days on Study 8889011145688899999999999 

89991677560338014888888.88 

5555554545555555544455555 

Carcass ID Number 4113339090334514199900111 

3892956742135027478968013 

Alimentary System 

Esophagus + + + + + + + + + + + + + + + + + ++++++++

+ + + + + + + + + + + + + + + + + ++++++++ Intestine large, colon 

Intestine large, rectum + + + + + + + + + + + + + + + + + ++++++++

+ + + + + + + + ++++++++ Intestine large, cecum + + + + + + + + + 

+ + + + + + + + + + + + + + + + + ++++++++ Intestine small, duodenum 

Carciuoma .

+ + + + + + + + + + + + + + + + + ++++++++ Intestine small, jejunum 

Carcinoma X 

Intestine small, ileum + + + +.+ + + + + ++ + + + + + + ++++++++ 

Leiomyosarcoma X 

+ + + + + + + + + + + ~ + + + + + ,++++++++ Liver 

Hepatocellular adenoma X, 

Osteosarcoma, metastatic, bone -X 

Mcsentery + + + +

Oral mucosa -. 

Squamous cell carcinoma + + + + + + + + + +'+ + + + + + + + + + + + + + + Pancreas + + + + + + + + + + + + + + + +'+ + + + + + ~ + + Salivary glands + + + + + + + + + + + + +-+ + + + + + + + + + + + Stomach, forestomach 

Squamous cell papilloma .X + + + + + + + + + + + + + + + + + + + + + + + + + Stomach, glandular 

Tongue + + 

Squamous cell carcinoma 

Squamous cell papilloma  ̧ X 

Cardiovascular System + + + + + + + + + + + + + + + + + + + + + + + + + Blood vessel • 

+ + + + + + + + + + + + + + + + + +.+ + + + + + + Heart 

Endocrine System + + + + + + + + + + + + + + + + + + + + + + + + + Adrenal cortex + + + + + + + + + + + + + + + + + + + + + + +.+ + Adrenal medulla 

Pheochromocytoma benign X ~ + + + + + + + + + + + + + + + + + + + + + + + + +~ Islets, pancreatic 

Adenoma X X X 

X 

Parathyroid gland M+MMM++++ ++++++++ ++ ++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + 

Carcinoma 

Pituitary gland 

Pars distalis, adenoma X X X. X X X X X X X X X X ,X X X 

X 

+ + + + + + + + +.+ + + + + + + + + + + + + ~ + + Pars distalis, carcinoma 

Thyroid gland 

C-cell, adenoma XX 

C-cell, carcinoma X

Follicular X cell, adenoma 

Follicular cell, carcinoma 

General Body System 

None 
-- ~:. -~:~ --= ....... 

t-ll~utylhydroqu]none, N'~ T~ ~S~ ]5~. 

TABLE ~2 

~ndh, idaal Aa~na~ Tan~or Fat~o]ogy o~ Female ~ats in the Long-Tern~ Feed Study o~ t-~uty~ydr~u~one: 2,5~ ppm 

(continued) 

.'" [ : 88888888 ! :

!~ Number of Days on Study 99999999 

88888888 

55555555 Total 

Carcass~Nmber 22222334 Tissues/ 

12345676 Tumors 

Alimentary System 

Esophagus + + + + + ÷ + + 57 

Intestine large, colon + + + + + + + + 56 

Inte'stinelarge, rectum + + + + + + + + 57 

Intestinaiarge, cecum + + + + + + + + 57 

Intestine small, duodenum + + + + + + + + 57 

Carcinoma X 1 I Intestine small, jejunum + + + + + + + + 56 

Carcinoma 1 i • ~ ~ 

Intestine small, ileum + + + + + + + + 57 

Leiomyosarcoma 1 , i 

~ . Liver + + + + + + + + 58 

Hep~tocellular adenoma X 2 

Osteosarcoma, metastatic, bone 1 

Mesentery 10 

Oral mucosa 1 

Squamous cell carcinoma 1 

Pancreas + + + + + + + + 57 

Salivary glands + + + + ÷ + + + 58 

Stomach, forestomach + + + + + + + + 57 

Squamous cell papilloma 1 

Stomach, glandular + + + + + + + + 57 

Tongue + 4 

Squamous cell carcinoma 1 

Squamous cell papilloma 1 

Cardiovascular System 

Blood vessel ++++++++ 58

Heart ++++++++ 58 

Endocrine System 

Adrenal cortex ++++++++ 58

Adrenal medulla ++++++++ 58

Pheochromocytoma benign 1 

Islets, pancreatic ~ ++++++++ 57 

Adenoma 3 

Carcinoma 1 

Parathyroid gland +++4++++ 53 

Pituitary gland +÷++++++ 57 

Pars distalis, adenoma XXXXX X 34 

Pars dis~alis, carcinoma 1 

Thyroid gland ++++++++ 57 

C-cell, adenoma X 7 

C-cell, carcinoma X 2 

Follicular cell, adenoma 1 

Follicular cell, carcinoma X 1 

General ~ody System 

None 
152 t-Butylhydr0quinone, NTP TR 459 

TABLE B2 

Individual Animal Tumor Pathology of Female Rats in the Long-Term Feed Study of t-Butylhydroquinone: 2,500 ppm (continuod) 

1445666666666677777777777 

Number of Days on Study 9297013455666"802355"667777 

7588032978167231878772244 

5555455555545455555554555 

Carcass 1D Number 4023903244292914000119404 

1494238602037558591671904 

Genital System 

Clitoral gland + + + + + + + + + + + ~ + + + + + + +++++++ 

Adenoma X X 

Carcinoma X 

Ovary + + +M+ + ~ + +++ + + ++ + + + +++++++ 

Carcinoma X 

Uterus + + + + + + + + + + + + + + + + + + +++++++ 

Adenoma 

Leiomyoma 

Polyp stromal 

Sarconm stromal 

Hematopoietic System 

Bone marrow + + +A + + + + + + + + + + + + + + + + + + + + + 

Lymph node +++ + +++ + ++ + 

Pancreatic, carcinoma, metastatic, ovary X 

Lymph node, mandibular +++A +++++++++++M++I ++ ++++ 

Lymph node, mesenteric M++M+M+++++++++++++++ ++++ 

Carcim~ma, metastatic, ovary X 

Spleen +++M+++++++++++++++ ++++++ 

Osteosarcoma, metastatic, bone 

Thymus + + + + + + + +.+ ÷ + + + + + + + + M + + + + + + 

Thymoma malignant 

Integumentary System 

Mammary + + ÷ ÷ ÷ ÷ ÷ + + + + + ÷ ÷ ÷ + + ÷ ÷ + + ÷ ÷ ÷ + gland 

Adenoma X 

": Carcinoma 

Fibroadenoma X X X X XX XX 

Fibroadenoma, multiple X 

+ + ~ • ÷ ÷ + + • • + ÷ • ÷ • + ÷ • • ÷ ÷ + • • ÷ Skin 

Keratoacanthoma X 

Subcutaneous tissue, fibroma 

Subcutaneous tissue, fibrosarcoma 

Musculoskeletal System 

Bone ÷ + + + ÷ ÷ ÷ + + + ÷ ÷ + ÷ ÷ + + + + + ÷ ÷ + + +

Osteosarcoma 

Skeletal muscle 

Nervous System ÷ + + ÷ + ÷ + ÷ + + + + + + ÷ + ÷ + ÷ ÷ + ÷ ÷ ÷ + Brain 

Peripheral nerve ÷ 

Spinal cord + 

Respiratory System 

Lung 

Alveolar/bronchiolar adenoma 

Carcinoma, metastatic, ovary X 

Nose 

Trachea 
::. ~ - ~ ...... , .... ~.- :7 : . =~-----~ :: =:~:__~_~-~_~.~ ..... .~:: : ~ 

~ . 

i ! 

[ 

i : 

i 

[ : 

t-I~uty~hy~roqu~none, HTP T]~ 459 1~3 I: : 

TABU ~2 

I~n~ivi~a~ An~ Tun~or ~atho~o~y o~ ~e~a~e Rats In the Long-Te~n ~ee~ St~y o~ ~-~ty~hy~roquinone: 2,5~ pp~n 

(continued) 

7777888888888888888888888 

iHIumber of Days on Study 8889011145688899999999999 

8999167756033801488888888 

5555554545555555544455555 

Carcass ~ Number 4113339090334514199900111 

38929567421_35027478968013 

Genital System 

Clitoral gland + + + + + + + + + + + + + + + + + + + + + + + + + 

Adenoma X X 

Carcinoma XX X X 

Ovary + + + + + + + + + + + + + + + + + + + + + + + + + 

Carcinoma 

Uterus + + + + + + + + + + + + + + + + + + + + + + + + + ! :! 

Adenoma X 

Leiomyoma X 

Polyp slromal X X XX 

Sarcoma stromal X 

Hematopoietic System 

[ : ! 

Bone marrow + + + + + + + + + + + + + + + + + + + + + + + + +. 

Lymph node ++ + + + + + 

Pancreatic, carcinoma, metastatic, ovary 

Lymph node, mandibular + + + + + + + + ÷ + + + + + + + + + + + + + + + + 

Lymph node, mesenteric + + + + + + + + + + + + + + + + + + + + + + + + + 

Carcinoma, metastatic, ovary I 

Spleen + + + + + + + + + + + + + + + + + + + + + + + + + 

Osteosarcoma, metastatic, bone X 

Thymus ++++++++++++"6++++++++++++ 

Thymoma malignant X 

Integumentary System 

Mammary gland + + + + + + + + + + + + + + + + + + + + + + + + + 

Adenoma 

Carcinoma X X 

Fibroadenoma XXXXXX "X XX X X X xx 

Fibroadenoma, multiple xx xx x xx 

Skin + + + + + + + + + + + + + + + + + + + + + + + + + 

Keratoacanthoma 

Subcutaneous tissue, fibroma x 

Subcutaneous tissue, fibrosarcoma x 

Musculoskeletal System 

Bone + + + + + + + + + + + + + + + + + + + + + + + + + 

Osteosareoma X 

Skeletal muscle + 

Hervous System 

Brain + + + + + + + + + + + + + + + + + + + + + + + + + 

Peripheral nerve ++ 

Spinal cord ++. 

Respiratory System 

Lung 

Alveolar/bronchiolar adenoma X 

Carcinoma, metastatic, ovary 

Nose 

Trachea 
154 t-Butylhydroquinone, NTP TR 459 

TABLE B2 

Individual Animal Tumor Pathology of Female Rats in the Long-Term Feed Study of t-Butylhydroquinone: 2,500 ppm 

(continued) 

Number' of Days on Study 

Carcass ID Number 

Genital System 

Clitoral gland 

Adenoma 

Carcim)ma 

Ovary 

Carcinoma 

Uterus 

Adenoma 

Leiomyoma 

Polyp stromal 

Sarcoma stromai 

Hematopoietic System 

Bone marrow 

Lymph node 

Pancreatic, carcinoma, metastatic, ovary 

Lymph node, mandibular 

Lymph node, mesenterie 

Carcinoma, metastatic, ovary 

Spleen 

Osteosarcoma, metastatic, bone 

Thymus 

Thymoma malignant 

Integumentary System 

Mammary gland 

Adenoma 

Carcinoma 

• "Fibroadenoma 

~:ibroadenoma, multiple 

Skin 

Keratoaeantboma 

Subcutaneous tissue, fibroma 

Subcutaneous tissue, fibrosarcoma 

Musculoskeletal System 

Bone~ 

Osteosarcoma 

Skeletal muscle 

Nervous •System 

Brain 

Peripheral nerve 

Spinal cord 

Respiratory System 

Lung 

Alveolaffbronchiolar adenoma 

Carcinoma, metastatic, ovary 

Nose 

Trachea : 

88888888 

99999999 

88888888 

55555555 

.22222334 

12345676 

++++++++ 

X 

++++++++ 

++++++++ 

++++++++ 

+ 

++++++++ 

++++++++ 

++++++++ 

++++++++ 

++++++++ 

X X X 

X + + + + + + + + 

++++++++ 

++++++++, 

++++++++ 

++++~+++ 

++++++++ 

Total 

Tissues/ 

Tumors 

58 

5 

5 

57 

1 

58 

I 

1 

5 

1 

57 

19 

l 

55 

55 

1 

57 

I 

57 

1 

58 

1 

2 

25 

9 

58 

I 

1 

1 

58 

1 

1 

58 

3 

3 

58 

1 

1 

58 

58 
: : ~ - ~ - ~ . ~__~ - - _ _ 

~ ~ - ~ --~ ~':'~~:~z'~'~-~~~'z7 ~ ....... .............. ~-,,r~-- ........ --................... ::==~:- ~ .... : .................. 

t-l~uty~hydroquinone, N'~ TR,4S9 ~SS 

TABLE ~2 

~ln~v~dua~ AnhnaU~mr~or ]Pathology o~ Female ~a~s ~n ~e ~ng-Te~ ~ee~ St~y o~ ~-~u~hy~oq~o~e: 2,500 ppm 

(confinu~) 

1445666666666677777777777 

Number of Days on Study 929701345566680235566777'7 

7588032978167231878772244 

5555455555545455555554555 

Carcass ID Number 4023903244292914000119404 

1494238602037558591671904 

Special Senses System 

Ear 

Eye 

Zymbal's gland 

Carcinoma 

Urinary System 

Kidney + + +A + + ++ + + + + + ++++ + + + + + + + + 

Urinary bladder + + + + + + + + + + + + + + + + + + + + + + + + + 

Systemic Lesions 

Multiple organs  ̧.' 

Leukemia mononuclear X X X X XX X XX X XX 

[ 
156 t-Butylhydroquin0ne, NTP TR 4~9 

TABLE: B2 

Individual Animal Tumor Pathology of Female Rats in the Long-Term Feed Study of t-Butyihydroquinone: 2,500 ppm 

(con~nued) 

7777888888888888888888888 

Number of Days on Study 8889011145688899999999999 

8999167756033801488888888 

5555554545555555544455555 

Carcass ID Number 4113339090334514199900111 

3892956742135027478968013 

Special Senses System 

Ear + 

Eye + ÷

Zymbal's gland 

Carcinoma 

Urinary System 

Kidney + + + + + + + + + + + + + + + + + + + + + + + + +

UrinaD~ + + + ÷ + + + + + + + + + + + + + + + + + + + + + b|adder 

Systemic Lesions 

Multiple organs 

Leukemia mononu¢lear XX XXX X XX X 
~?:~ ~ . . . . . . 

: ?: ~-~-~-.-~--~z~r~_--~-_~ . ~ - - ~ .............. ~ , ~ .... ~:~ ...... ~ . ~ - ~ _ ~ . ~ ..... 

~-~ty~y~ro~a~ao~e, ~ TR 459 ~57 

T~L~ ~ 

~¢~¢~aa~ A~maa~ Tumor 

(continued) 

Pathology of Fen~a~e Rats ~ the Long-Terra Fee¢~ Study of t-~uty~hyc~roquinone: 2,5~0 ppm 

I~umber of Days on Study 

88888888 

99999999 

88888888 

Carcess ~D Number 

5 

2 

1 

5 

2 

2 

5 

2 

3 

5 

2 

4 

5 

2 

5 

5 

3 

6 

5 

3 

7 

5 

4 

6 

Total 

Tissues/ 

Tumors 

I Specked Senses System 

Ear 

Eye 

Zymbal's gland 

Carcinoma 

+ 

+ 

X 

1 

3 

1 

1 

Ur~n~y System 

Kidney 

Urinary bladder 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

57 

58 I 

Systemic Lesiom 

Multiple organs 

Leukemia mononu¢iear 

+ + + + + + + + 

X 

58 

22 
.. 

158 -- t-Butylhydroquin0ne, NTP TR 459 

TAnH~ B2 -

Indivi,dual Animal Tumor Pathology of Female Rats in the Long-TermFeed Study of t-Butylhydroquinone: .- 5,000 ppm ' 

5555666666666666777777777 

Number of Days on Study 0799012234567799015577888 

I 216038830963 ~ 01520247999 

6555655555655556655566556 

Cm'eams ID Number 089816896708679 l 066810690 

8876781160751968039252205 

Alinlenl:ary System 

Esophagus + + + + + + + +-+ + + + + + + + + + + + + + + + + 

Intestine large, colon + +M+ + + + + + + + + + + + + + + + + + + + + + 

Intestine large, rectum + + + + + + +.+ + + + + + + + + + + + + + + + + + 

• 

Intestine ~arge, cecum + + + + + + + + + + + + + + + + + + + + + + + + +

Intestine small, duodenum + + + + + + + + + + + + + + + + + + + + + + ++ +

Intestine ~mall, jejunum + + + + + + + + + + +-+ + + + + + + + + + + + ÷: +

Intestine small, ileum + + + + + + + + + + + + + + + + + + + + +M÷ + + 

Liver " • + + + + + + + + + + + + + + + + + + + + + + + + + 

Hepato~ellular adenoma 

Hepatu~ellular adenoma, multiple 

Mesentery + + + 

Pancreas + + + + + + M + + + + + + + + + + + + + + + + ++ 

Salivary glands + ,+ + + + + + + + + + + + + + + + + + + + + +- + + 

+ + + + + + + + + + + + + + + + + + + + + + + + + Stomach, forestuma~h 

+ + +'+ + + + + + + + + + + + + + + + + + + + + + Stomach, glandular 

Tongue. 

,Cardiovascular System 

Blood vessel + + + + + + + + + + + + + + + + + + + + + + + + + 

Heart + + + + + + + + + + + + + + + + + + + + + + + + +

Scbwannoma benign 

Endocrine System .. " + + + + + + + + + + + + + + + + + + + + + + + + + Adrenal cortex , - +.+ + + + + + + + + + + + + + + + + + + + + + + + Adrenal m~ulla • 

PheOchromocytoma malignant 

Pheochromocytoma benign X 

+Islets, pancreatic ++++++M++++++,++++ ++ ++++ ++ 

Adenoma 

Parathyroid gland + + + +~+ + + + + M M + + + + + + ++ + + + + + M 

Adenoma 

Carcinoma, metastatic, thyroid gland + + + ÷ + + + + + + + + + + + + + + + + + + + + + Pituitary gland 

.... Pars distalis, adenoma XX XXXX X X X 

Pars distalis, carcinoma X X 

+ + + ÷ + + ÷ + + ÷ + + ÷ ÷ + ÷ + + ÷ + + ÷ + + + Thyroid gland 

C-cell, adenoma '~ X X 

C-cell, carcinoma 

Follicular cell, carcinoma X 

General Body System 

;l~one 

Genital System 

Clitoral gland 

Adenoma X 

Adenoma, multiple 

Carcinoma X X 
:~'~r'=W~'~ ~ ~'- .............. ~ ~::g~: ........ ~..~ ............... ~ ~---- 7 =~ : =: : :~ ~-~'7~2:~--%-: ~----~- .. ---~ ....... 

•vButy~hydroqu~none, I~'P TI~ ~$9 159 

T~L~ ~2 

~individua~ Anim~ Tremor ]Pathology of Ferule l~a~ ~ the Long,Term Feed Studyof t-~uty~hydroqu~none: 5,000. ppm 

(continued) 

8888888888888888888888888 

Number of Days on Study 013333445566789999999999.9 

700 I I 91568299811478888888 

556"6665555555566555555555 

Carcass ~D Number 760011986897760179777788.8 

6431698459215760792348037 

Alimentary System 

Esophagus + + + + + + + + + + + + + + + + + + + + + + + + + 

Intestine large, colon ++++++++++++++++++++++++%

Intestine large, rectum +++++I ++++++++++++++ +++++ 

Intestine large, cecum + + + + + + + + + + + + + + + + + + + + + + + +.+ 

Intestine small, duodenum + + + + + + + + + + + + + + + + + + + + + + ÷ + +

+ + + + + + + + + + + + + + + + + + + + + + + + + i Intestine small, jejunum 

Intestine small, ileum + +M+ + + + + + + + + + + + + + + + + + + + • + I 

Liver + + + + + + + + + + + + + + + + + + + + + + + + +

Hepatocellular adenoma X I Hepatocellular adenoma, multiple X 

Mesantery ++ + + i:

Pancreas + + + + + + + + + + + + + + + + + + + + + + + + +

Salivary glands + + + + + + +-+ + + + + + + + + + + + + + + + + +

+ + + + + + + + + + + + + + + + + + + + + + + ÷ + 

Stomach, glandular + + + + + + + + + + + + + + + + + + + + + + + + + 

Stomach, forestomach 

Tongue + 

Cardiovascular System 

Blood vessel + + + ++ + + + + + + + + + + + + + + + + + ~ + +

Heart + + + + + + + + + + + + + + + + + + + + + + + + +

Schwannoma benign X 

I 

Endocrine System 

Adrenal cortex + ~ + + + +'+ + + + + + + + + + + + + + + + + + + 

Adrenal medulla + +'+ + + + + + + + + + + + + + + + + + + + + + +

Pbeo~hromocytoma malignant X 

Pbeochromocytoma benign X 

Islets, pancreatic + + + + + + + + + + + + + + + + + + + + + + + + + i 

Adenoma X X 

Parathyroid gland + +++ + +++ + + + ++M+ + +M+ + + + + + + 

Adenoma X 

Carcinoma, metastatic, thyroid gland X 

Pituitary gland + + + + + + + + + + + + + + + + + + + + + + + + + 

Pars distalis, adenoma X X X X X X X X X X X X X X X~ 

Pars distalis, carcinoma X ~ 

Thyroid gland ,+ + + + + + + + + + + + + + + + + + + + + + + + +" 

C-cell, adenoma X X X 

C-cell, carcinoma X 

Follicular cell, carcinoma 

General Body System 

None 

~ GenRal System 

Clitoral gland 

Adenoma, X X X X 

Adenoma, multiple X 

Carcinoma XX XX X X 
160 t-Butyihydroquinone, NTP TR 459 

TAIR~g B2 

Individual Animal Tumor Pathology of Female Rats in the Long-Term Feed Study of t-Butylhydroquinone: 5,000 ppm 

(continu~) 

8888888888 

Number of Days on Study " 9999999999 

8888888888 

5556666666 Total 

Carcass ID Number 9990011112 Tissues/ 

3454912340 Tumors 

Alimentary System 

.Esophagus + + + + + + + + + + 60 

Intestine large, colon + + + + + + + + + + - 59 

Intestine large, rectum + + + + + + + + + + 59 

Intestine large, cecum + + + + + + + + + + 60 

Intestine small, duodenum + + + + + + + + + + 60 

Intestine small, jejunum + + + + + + + + + + 60 

Intestine small, ileum + + + + + + + + + + 58 

Liver + + + + + + + + + + 60

Hepatocellular adenoma ~I 

Hepatocellular adenoma, multiple 1 

Mesentery 7 

Pancreas +++ + + +++ + + 59

Salivary glands + + + + + + + + + + 60 

Stomach, forestomach + + + + + + + + + + 60

Stomach, glandular + + + + + + + + + + 60 

Tongue 1 

Cardiovascular System 

Blood vessel + + + + + + + + + + 60

Heart + + + + + + + + + ÷ 60 

Schwannoma benign 1 

Endocrine System 

Adrenal + + + + + + + + + + cortex 6O 

Adrenal medulla + + + ÷ + + + + + + 60 

Pheochromocytoma malignant 1 

Pheochromocytoma benign X 3 

Islets, pancreatic + + + + + + + + + + 59 

Adenoma 2 

Parathyroid gland +++M+÷++++ 4 

Adenoma l 

Carcinoma, metastatic, thyroid gland I 

Pituitary gland + + + + + + + + + + 6O 

Pars distalis, adenoma X XX X 28 

Pars distalis, carcinoma 3 

Thyroid + + + + + + ÷ + + + gland 6O 

C-cell, adenoma X 6 

C-cell, carcinoma 1 

Follicular cell, carcinoma X 2 

General Body System 

None 

Genital System 

Clitoral gland + + + + + + + + + + 60 

Adenoma X 6 

Adenoma, multiple 1 

Carcinoma S 
:::~?: _ 

~ : - ~" =~7~--~-~--~--- . . . . . . . . . . ; ..... ~=,_~ ............ ,, ....... ........... = ...... ~ - ~ ' - ~ ~ ' ~ - - - : ~ 

t-Bu~ylhydroquinone, NTP TR 459 g6~ 

TABLE ~2 

~ndividu~ Anhna~ Tumor Pathology of ]Fe~na~e ]l~_~s in the Long-Term ]Feed Study of t-~uty~hydroqu~noue: ~,~I~l~ pp~n 

(continued) 

, ,. ., 

5555666666666666777777777 

Number of Days on Study 0799012234567799015577888 

1216038830963301520247999 

6555655555655556655566556 

Carcass ID Number 0898168967086791066810690 

8876781.160751968039252205 

i Genital System (continued) 

Ovary + + + + + + + + + + + + + + + + + + + + + + + + + 

Granulosa cell tumor benign 

Uterus~ + + + + + + + + + + + + + + + + + + + + + + + + + 

Adenoma X 

Carcinoma 

Polyp stromal X X X X XX 

HematopoieticSystem 

Bone marrow + + + + + + + + + + + + + + + + + + + + + + + + + 

Lymph node +++ + +++ + ++ 

Lymph node, mandibular ÷ + + +~+ + + + + + + + + + + + + + + + + + + + 

Lymph node, mesenteric + + + + + + + + + + + + + + + + + + + + + + + + + 

Spleen + + + + + + + + + + + ÷ + + + + + + + + + + + + + 

Thymus +++++++++++++++++++++++%+ 

~ntegumentary System 

Mammary gland + + + + + + + + + + + + + + + + + + + + + + + + + 

Adenema 

Carcinoma X 

Carcinoma, multiple X 

Fibroadenoma XX XX X X 

Fibroadenoma, multiple 

Skin + ++ + + + + + + + + + + + + + + + + + + + + + + 

Squamous cell papilloma 

Subcutaneous tissue, fibroma 

Subcutaneous tissue, fibrosarcoma 

Subcutaneous tissue, hemangiosarcoma 

Subcutaneous tissue, sarcoma 

Subcutaneous tissue, schwannoma malignant 

Musculoskeletal System 

Bone + + + + + + + + + + + + + + + + + + + + + + + + + 

Skeletal muscle 

Sarcoma 

Nervous System 

Brain + + + + + + + + + + + + + + + + + + + + + + + + + 

Carcinoma, metastatic,mammary gland X 

Carcinoma, metastatic, pituitary gland 

Peripheral nerve , ÷ 

Spinal cord ÷ 

Astrocytoma malignant X 

Respiratory System 

Lung 

Alveolar/bronchiolar adenoma 

Carcinoma, metastatic, thyroid gland 

Nose 

Trachea 
162 t~Butylhydroquinone, NTP TR 459 

TABLE B2 ~ 

Individual Animal Tumor Pathology of Female Rats in the Long-Term Feed Study of t, Butylhydroquinone: 5,000 ppm 

(continued) 

Number of Days on Study 

Carcms ID Number 

Genital System (continued) 

Ovary 

Granulosa cell tumor benign 

Uterus 

Adenoma 

Carcinoma 

Polyp stromal 

Hematopoietic System 

Bone marrow 

Lymph node 

Lymph node, mandibular 

Lymph node, mesenteric 

Spleen 

Thymus 

Integumentary System 

Mammary gland 

Adenoma 

Carcinoma 

Carcinoma, multiple 

Fibroadenoma 

Fibroadenoma, multiple 

Skin 

Squamous cell papilloma 

Subcutaneous tissue, fibroma 

Subcutaneous tissue, fibrosarcoma 

Subcutaneous tissue, hemangiosarcoma 

Subcutaneous tissue, sarcoma 

Subcutaneous tissue, schwannoma malignant 

Musculoskeletal System 

Bone 

Skeletal muscle 

Sarcoma 

Nervous System 

Brain 

Carcinoma, metastatic, mammary gland 

Carcinoma, metastatic, pituitary gland 

Peripheral nerve 

Spinal cord 

Astrocytoma malignant 

Respiratory System 

Lung 

Alveolar/bronchiolar adenoma 

Carcinoma, metastatic, thyroid gland 

Nose 

Trachea 

8888888888888888888888888 

0133334455667899999999999 

7001191568299811478888888 • .. 

5566665555555566555555555 

7600119868977601797777888 

6431698459215760792348037 

++++++++++++++++++++4-++++ 

X + + + + + + + + + + + + + + + + + + + + + + + + + 

X X 

+++++++++÷++4-+++++++++++4-

+ ++ + + + + + 

++++++++4-+++4-++++++++++++ 

+ + + + + + + + + + + + + + + + + + + + + + ~ + + 

+ + + + + + + + + + + +÷ + + + + + + + + + + + + 

M++M++++++++++++ +++ +++ + ++ , , 

+ + + + + + + + + + + + + + + + + + + + + + + + + 

X 

X X 

X X-X XXX X XX.XX 

XXXX XX X 

+ + + + + + + + + + + + + + + + + + + + + + + + + 

X 

X 

X 

+ + + + + + + + + + + + + + + + + + + + + + + + + 

+ 

X 

++++++++++++++++++4-÷+++++ 

X 

+ + + ÷ + + 

X 
:~: S~-~r~-~5:~ ~-.~-~_7.;~ ................... - - . - ~ ............................ . --~ .... -- ""~----

t-Butyihydroquinone, NTP T]R 459 163 

TABLE ~2 

~In~ividua~ An~ma~ Tumor Pathology of ~'em~de Rats in the Long-Term Fee~ Study of t-~utynhydroqu~none: 5,0~0 ppm 

(continued) 

8888888888 

Number of Days on Study 9999999999 

8888888888 

5556666666 Total 

Carcass ~D Number 9990011112 Tissues/ 

3454912340 Tumors 

Genital System (continued) 

Ovary + + + + + + + + + + 60 

Granulosa cell tumor benign 1 

Uterus + + + + + + + + + + 60 

Adenoma 1 

Carcinoma X 1 

Polyp stromal X 9 

Hematopoietic System 

Bone marrow + + + + + + + + + + 60 i 

Lymph node 18 

Lymph node, mandibular + + + + + + + + + + 60~ 

Lymph node, mesenteric + + + + + + + + + + 60 

Spleen + + + + + + + + + + 60 

Thymus + + + +M+ + + + + 57 

Integumentary System 

Mammary gland + + + + + + + + + + 60 

Adenoma X 2 

Carcinoma 3 

Carcinoma, multiple 1 

Fibroadenoma X XX 20 

Fibroadenoma, multiple 7 

Skin • + + + + + + + + + 60 

Squamous cell papilloma X 2 

Subcutaneous tissue, fibroma 1 

Subcutaneous tissue, fibrosarcoma X 1 

Subcutaneous tissue, hemangiosarcoma 1 

Subcutaneous tissue, sarcoma X 1 

Subcutaneous tissue, schwannoma malignant X 1 

Musculoskeletal System 

Bone + ~ + + + + + + + + 60 

Skeletal muscle 1 

Sarcoma 1 

Nervous System 

Brain + + + + + + + + + + 60 

Carcinoma, metastatic, mammary glan~l 1 

Carcinoma, metastatic, pituitary gland 1 

Peripheral nerve 4 

Spinal cord 4 

Astrocytoma malignant 1 

Respiratory System 

Lung + + + + + + + + + + 60 

Alveolar/bronchiolar adenoma X 1 

Carcinoma, metastatic, thyroid gland 1 

Nose + + + + + + + + + +. 60 

Trachea + + + + + + + + + + 60 
164 t-BUtyihydroquinone,NTP TR 459 

TABI~ B2 - .

Individual Animal Tumor Pathology of Female Rats in the Long-Term Feed Study of t-Butylhydroquinone: 5,000 ppm 

(continued) 

5555666666666666777777777 

Number of Days on Study 0799012234567799015577888 

1216038830963'301520247999 

65556555556555,56655566556 

Carcass ID Number 0898168967086791066810690 

8876781160751968039252205 

Special Senses System 

Ear 

Eye 

Urinary System 

Kidney + ++ + + + + + + + + + + + + + + + + + + + + + +

Urinary biadder + +M+ + + + + + + + + + + + + + + + + + + + + + 

Papilloma 

Systemic Lesions 

Multiple organs 

Leukemia mononuclcar X X X XX XXX XXXXX 
t-~u~y~hydroqu~none, NTF T~t ~g9 165 

* 

TA~L~ ~2 

~ndivldu~ Auinm~ Tun~or Pathology of Fenn~e RaN in the Long-Tern~ Feed Study o~ t-~uty~hydroquinone: 5,~0 ppm 

(continued) 

8888888888888888888888888 

Number of Days o n Study 0133334455667899999999999 

7001191568299811478888888 

5566665555555566555555555 

Carcass ~D Number 7600119868977601797777888 

6431698459215760792348037 

Special Senses System 

Ear + 

Eye + 

Urinary System 

Kidney + + + + + + + + + ÷ + + + + + + + + + + + + + + + 

Urinary bladder + + + + + + + + + + + + + + + + + + + + + + + + + 

Papilloma 

Systemic Lesions 

Multiple organs 

Leukemia mononuclear X XXXXX XX X X 
,166 t-Butylhydroquinone, NTP TR 459 

TABLE B2 

Individual Animal Tumor Pathology of Female Rats in the Long-Term Feed Study of t-Butylhydroquinone: 5,000 ppm 

(continued) '. • 

8888888888 

Number of Days on Study 9999999999 

8888888888 

5556666666 • Total 

Carcass: ID Number 9990011112 Tissues/ 

3 4 5 4 912 3 4 0 Tumors 

Special ,Senses System 

Ear 

Eye 

Urinary System 

Kidney + + + + + + + + + + 60

Urinary bladder + + + + + + + + + + '~ 59 

Papilloma X 1 

Systemic Lesions 

Multiple organs . . • , 

Leukemia mononuclear X X X X 27 
I 

-~__-..=~=~r: ~.~ ........ ~--~-~-~- ~ --- .................... ~ ~ ~: .... ......... :~ ~ : ..... ::: ~:.,- : , : , ~ , ~ ~ ~............. 

trButylhy~roquinone, NTP T~ 459 ~.67 

TAnL~ 1~3 

S~fist~ca~ Analysis of ]Prhnary Neoi~mn~s ~n I~erna~e Rats ~n ~he Long-Term ~ee~ Study of t-Bu~y~hy~roqu~none 

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

• Adrenal Cortex: Adenoma 

Overall rate a 4/60 (7 % ) 1/60 (2 % ) 0/~8 (0 % ) 0/60 (0 % ) 

Adjusted rate b 25.9% 3.6% 0.0% 0.0% 

Terminal rate c 1/10 (10%) 0/11 (0%) 0/16 (0%) 0/17 (0%) 

First incidence (days) 795 795 _e _ 

Life table test d P=0.007N P=0.146N P=0.025N P=O.O19N 

Logistic regression test d P=0.010N P=O. 143N P=O.O30N P=O.024N 

Coehran-Armita~e test d ' P=0.O20N 

Fisher exact test" P = 0.182N P = 0.064N P = 0.059N 

Adrenal Medulla: Benign ~heochromocytoma 

Overall rate 2/60 (3%) 2/60 (3%) 1/58 (2%) 3/60 (5%) 

Adjusted rate 16.4% 18.2% 3.1% 12.3% 

Terminal rate 1/10 (10%) 2/11 (18%) 0/16 (0%) 1/17 (6%) 

First incidence (days) 856 898 (T) 789 750 

Life table test P=0.567N P=0.649N P=O.358N P=O.630N 

Logistic regression test P=0.568 P=0.632N P=O.410N P=0.673 

Cochran-Armitage test P=0.403 

Fisher exact test P=0.691N P=O.513N P=0.500 

Adrenal Medulla: Benign or Malignant Pheochromocytoma 

Overall rate 2/60 (3%) 2/60 (3%) 1/58 (2%) 4/60 (7%) 

Adjusted rate 16.4% 18.2% 3.1% 16.9% 

Terminal rate 1/10 (10%) 2/11 (18%) 0/16 (0%) 1/17 (6%) 

First incidence (days) 856 898 ('13 789 750 

Life table test P=0.445 P=0.649N • P=0.358N P=0.601 

Logistic regression test P=0.387 P=0.632N P=0.410N P=0.539 

Cochran-Armitage test .P=0.227 

Fisher exact test P=0.691N P=O.513N P=0.340 

Clitoral Gland: Adenoma 

Overall rate 6/58 (10%) 6/59 (10%) 5/58 (9%) 7/60 (12%) 

Adjusted rate 38.3% 23.5% 22.2% 27.0% 

Terminal rate 3/10 (30%) 0/10 (0%) 3/16 (19%) 2/17 (12%) 

First incidence (days) 579 649 661 628 

Life table test Pf0.323N P=0.515N P=O.275N P=O.375N 

Logistic regression test P=0.490N P=O.549N P=O.380N P=O.513N 

Cochran-Armitage test P=0.464 

Fisher exact test P=0.607N P=O.5OON P=0.526 

Clitoral Gland: Carcinoma 

Overall rate 6/58 (10%) 4/59 (7%) 5/58 (9%) 8/60 (13%) 

Adjusted rate 43.2% 16.0% 18.8% 29.0% 

Terminal rate 4/10 (40%) 1/10 (10%) 0/16 (0%) 2/17 (12%) 

First incidence (days) 649 666 767 750 

Life table test P=O.547N P=0.349N P=0.244N P=0.465N 

Logistic regression test P=0.403 P=0.316N P=0.332N P=O.579N 

Cochran-Armitage test P=0.258 

Fisher exact test P=0.361N P=O.500N P=0.415 
168 t-Butyihydroquinone, NTP TR 459 

TABLE B3 

Statisti, cal Analysis of Primary Neoplasms in Female Rats in the Long-Term Feed Study of t-Butylhydroquinone (continued) 

~ 0 ppm 1,250 ppm 2,500 ppm 5,000 ppm 

Clitoral Gland: Adenoma or Carcinoma 

Overall rate 12/58 (21%) 10/59 (17%) " 10/58 (17%) 14/60 (23%) 

Adjusted :rate 74.9% 35.8% 36.8% 47.4% 

Terminal rate 7/10 (70%) 1/10 (10%) ~ 3/16 (19%) ~4/17 (24%) 

First incidence (days) 579 649 661 628 

Life table test P=0,288N P =0,320N P=0. 116N P=O.248N 

Logistic n,'gression test P=0.519N P=0,309N P=0.210N P=0.402N 

Cochran-Armitage test 

Fisher exact test 

P=0.338 

P=0.389N P=O.407N~ P=0.451 

Lung: Aiveolar/bronchiolar Adenoma or Carcinoma 

Overall rate 2/60 (3 %) 3/60 (5%) 1/58 (2%) 1/60 (2%) 

Adjusted rate 14.5 % 21.9% 4.5% 5.9% 

Terminal rate 1/10 (10%) 2/11 (18%) 0/16 (0%) 1/17 (6%) 

First incidence (days) 802 831 883 898 (T) 

Life table test P=0.124N P=0.574 P=0.331N P=0.316N 

Logistic regression test P=0.144N P=0.569 P=O.389N P=O.350N 

Cochran-Armitage test P=0.282N 

Fisher exact test P=0.500 P=0.513N P=O.500N 

Mammary Gland: Fibroadenoma 

Overall rate, 43160 (72%) 33160 (55%) 34158 (59%) 27/60 (45%) 

Adjusted rate 100.0% 96.6% 86.0% 74.4% 

Terminal rate 10/10 (100%) 10/11 (91%) 11/16 (69%) 9/17 (53%) 

First incidence (days) 418 537 600 596 

Life table test P<O.001N P=0.034N P=0.004N P<0.001N 

Logistic regression test P<0.001N P=0.006N P=0.009N P<0.001N 

Cochran-Armitage test P=O.005N 

Fisher exact test P=0.044N P=O.098N P=O.OO3N 

Mammary Gland: Adenoma 

Overall rate 3/60 (5%) 0/60 (0%) 1/58 (2%) 2/60 (3%) 

Adjusted rate 9.9% 0.0% 2.9% 8.6% 

Terminal rate 0/10 (0%) 0/11 (0%) 0/16 (0%) 1/17 (6%) 

First incidence (days) 613 -- 774 807 

Life table test P=0.417N P=0.099N P=0.240N P=0.326N 

Logistic regression test P=0.562N P=0.133N P=0.345N P=0.503N 

Cochran-Armitage test P=0.557N 

Fisher exact test . P=0.122N P=0.322N P=0.500N 

Mammary' Gland: Fibroadenoma or Adenoma 

Overall rate 45/60 (75%) 33/60 (55%) 34/58 (59%) 27/60 (45%) 

Adjusted rate 100.0% 96.6% 86.0% 74.4% 

Terminal rate 10/10 (100%) 10/11 (91%) 11/16 (69%) 9/17 (53%) 

First incidence (days) 418 537 600 596 

Life table test P<O.001N P =0.O19N P=0.002N P < 0.00IN 

Logistic regression test P<O.0OIN P =0.002N P=0.003N P < O.001N 

Cochran-Arrnitage test P=O.002N 

Fisher exact test P=0.017N P=O.O45N P<O.OO1N 
± ? ~ ~ ~ 

:~;~ .~=:~ - - ~ ~ ................. : -~ ........... "= ".-~ - - - - ~ - = ~ ' ~ , m ~ . ~ ~ - ~ ~ - ~ ~ ........ ~ - ..... ~ - - ~ ; - ~ ......... ... -

e-~u~y~hydr0quinone~ NTI~ T~ 459 169 

T&BLE ~3 J 

S~at~stica~ An~ys~s o~ ]Prhnary Neo#mms in l~ema~e I~ats in the ~.~tmg-Term Feed Study o~ t-l~nty~hydroquinone (continued) 

i 

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

~1 

I~kmtmary Gland: Carcinoma 

i Overall rate 8/60 (13%) 6160 (10%) 2/58 (3%) 4160 (7%) 

Adjusted rate 29.3 % 35.4% 10.8% 10.5% 

Terminal rate 1/10 (10%) 3111 (27%) 0/16 (0%) 0117 (0%) 

First incidence (days) 540 64.0 890 690 

Life table test P=0.029N P=0.308N P=0.019N P=0.070N 

Logistic regression test P=0.073N P=0.345N P=0.042N P=0.177N 

Coehran-Armitage test P =0.105N L 

Fisher exact test P=0,389N P=0.053N P=0.181N 

I~,~nmary Gland: Adenoma or Carcinoma 

! Overall rate 10160 (17%) 6/60 (10%) 3/58 (5%) 6/60 (10%) 

Adjusted rate 34.9% 35.4% 13.4% 18.2% 

Terminal rate 1/10 (10%) 3/11 (27%) 0/16 (0%) 1/17 (6%) 

First incidence (days) 540 640 774 690 

Life table test P=0.045N P=0.153N P=0.014N P=0.064N 

Logistic regression test P =0.123N P=0.180N P=0.036N . P=0.193N 

Coehran-Armitage test P = 0.170N 

Fisher exact test P=0.211N P=0.043N P=0.211N 

Mammary Gland: ~'ibroadenoma, Adenoma, or Carcinoma 

Overall rate 48/60 (80%) 34/60 (57%) 34/58 (59%) 30/60 (50%) 

Adjusted rate 100.0% 96.6% 86.0% 76.3 % 

Terminal rate 10/10 (100%) 10/11 (91%) 11/16 (69%) 9/17 (53%) 

First incidence (days) 418 537 600 596 

Life table test P <0.001N P=0.011N P<0.001N P<0.001N 

Logistic regression test P < 0.001N P < 0.001N P < 0.001N P < 0.001N 

Cochran-Armitage test P=0.002N 

Fisher exact test P = 0.005N P = 0.01 ON P < 0.001N 

Oral Cavity (Oral Mucosa or Tongue): Squamous Cell Papilloma or Squamous Cell Carcinoma 

Overall rate 1/60 (2%) 1/60 (2%) 3/58 (5%) 0/60 (0%) 

Adjusted rate 10.0% 6.7% 9.6% 0.0% 

Terminal rate 1/10 (10%) 0/11 (0%) 1/16 (6%) 0/17 (0%) 

First incidence (days) " 898 (T) 873 425 --

Life table test P=0.296N P=0.734N P=0.403 P=0,394N 

Logistic regression test P=0.435N P=0.725N P=0.258 P=0.394N 

Cochran-Armitage test P=0.411N 

Fisher exact test P=0.752N P=0.297 P=0.500N 

Pancreatic ~slets: Adenoma 

Overall rate 2/60 (3 %) 1/59 (2%) 3/57 (5%) 2/59 (3%) 

Adjusted rate 11.2 % 1.8% 14.4% 9.8% 

Terminal rate 0/10 (0%) 0/11 (0%) 1/16 (6%) 1/17 (6%) 

First incidence (days) 661 537 816 ' 869 

Life table test P =0.487N P=0.458N P=0.660N P=0.509N 

Logistic regression test Pffi0.561 P=0.537N P=0.585 P=0.609N 

Cochran-Armitage test ~ P=0.493 

Fisher exact test P=0.506N P=0.476 P=0.684 
170 t-Butylhydroquin0ne, NTP TR 459 

TA~I~ B3 

Statistical Analysis of Primary Neoplasms in Female Rats in the Long-Term Feed Study of t-Butyihydroquinone (continued) 

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

Pancreatic Islets: Adenoma or Carcinoma 

Overall rate 2/60 (3 %) 1/59 (2%) 4/57 (7%) 2/59 (3%) 

Adjusted Fate 11.2 % 1.8% 20.1% 9.8% 

Terminal irate 0/10 (0%) 0/I1 (0%) 2/16 (13%) 1/17 (6%) 

First incidence (days) 661 537 816 869 

Life table test P=0.483N P=0.458N P=0.556 P=0.509N 

Logistic regression test P=0.561, P=0.537N P=0.445 P=0.609N 

Cochran-Armitage test P=0.469 

Fisher exact test P=0,506N P=0.315 P=0.684 

Pituitary Gland (Pars Distalis): Adenoma 

Overall rate 26/60 (43 %) 27/60 (45%) 34/57 (60%) 28/60 (47%) 

Adjusted rate ' . 80.9% 75.2% 90.7% 69.8% 

Terminal rate 5/10 (50%) 5/11 (45%) 13/16 (81%) 7/17 (41%) 

First incidence (days) 540 480 600 501 

Life table tdst P=O.083N P=O.408N P=O.410N P=0.103N 

Logistic regression test P=0.492N P=O.550N P=0.207 P=O.481N 

Cochran-Armitage test P=0.328 

Fisher exact test P=0.500 P=0.057 P=0.427 

Pituitary Gland (Pars Distalis): Carcinoma 

Overall rate 2/60 (3%) 1/60 (2%) 1/57 (2%) 3/60 (5%) 

Adjusted rate 5.0% 9.1% 6.3% 10.1% 

Terminal rate 0/10 (0%) 1/11 (9%) 1/16 (6%) 1/17 (6%) 

First incidence (days) 540 898 (T) 898 (T) 666 

Life table test P=0.457 P=0.483N P=0.418N P=0.609 

' Logistic regression ~est P=0.334 P=0.504N P=0.535N P=0.441 

Cochran-Armitage test P=0.324 

Fisher exact test P=0.500N P=O.519N P=0.500 

PitUitary Gland (Pars Distalis): Adenoma or Carcinoma ' 

Overall rate 28/60 (47%) 28/60 (47%) 35/57 (61%) 31/60 (52%) 

Adjusted rate 81.9% 79.3% 93.8% 74.0% 

Terminal rate 5/10 (50%) 6/11 (55%) 14/16 (88%) 8/17 (47%) 

First incidence (days) 540 480 600 501 

Life table test - P=O.IO3N P=0.352N P=0.337N P=0.124N 

Logistic regression test P=0.484 P=O.474N P=0.256 P=0.573 

Coehran-Armitage test P=0.245 

Fisher exact test P=O.573N P=0.079 P=0.358 

Skin (Subcutaneous Tissue): Fibroma 

Overall rate 3/60 (5%) 3/60 (5%) 1/58 (2%) 1/60 (2%) 

Adjusted rate 13.8% 13.5% 3.6% 4.2% 

Terminal rate 1/10 (10%) 1/11 (9%) 0/16 (0%) 0/17 (0%) 

First incidence (days) 540 498 816 869 

Life table test P=0.090N P=O.628N P=O.227N P=0.200N 

Logistic regression test P=0.178N P=0.643 P=O.329N P=0.313N 

Cochran-Armitage test P=0.167N 

Fisher exact test P = 0.660N P = O. 322N P = 0.309N 
~ : r-~ : ~ - ~ _-~=~-~-_.~ ,~ ................. ~ - ~ ~-~~- -~-~- -7~~--~-~-~- .... ~ ................... 

t-Butylhydroquinone, N'YP TR 459 ~7~ 

TABLE ~3 

Statistical Analysis of ~'imary Ne0p~asna s in Female Rats in the Long-Term ~eed Study of t-Suty~hydroquinone (continued) 

: 

Skin (Subcutaneous Tissue): Fibroma,.Fibrosarcoma, 

Overall rate 

Adjusted rate 

Terminal rate 

I 

I First incidence (days) 

Life table test 

Logistic regression test 

Cochran-Armitage test 

:i Fisher exact test 

Thyroid Gland (C-cell): Adenoma 

Overall rate 

Adjusted rate 

Terminal rate l 

First incidence (days) 

Life table test 

Logistic regression test 

Cochran-Armitage test 

I Fisher exact test 

Thyroid Gland (C-cell): Adenoma or Carcinoma 

Overall rate 

Adjusted rate 

Terminal rate 

First incidence (days) 

Life table test 

Logistic regression test 

Cochran-Armitage test 

Fisher exact test 

Uterus: Stromal Polyp 

Overall rate 

Adjusted rate 

Terminal rate 

First incidence (days) 

Life table test 

Logistic regression test 

Cochran-Armitage test 

Fisher exact test 

Uterus: Stromal Polyp or Stromal Sarcoma 

Overall rate 

Adjusted rate 

Terfiainal rate 

First incidence (days) 

Life table test 

Logistic regression test 

Cochran-Armitage test 

Fisher exact test 

0 ppm 

or Sarcoma 

4/60 (7%) 

" 19.9% 

1/10 (10%) 

540 

P=0.228N 

P=0.382N 

P=O.423N 

7/60 (12%) 

44.9% 

4/10 (40%) 

540 

P=O.156N 

P=0.320N 

P=O.436N 

8/60 (13 %) 

54,1% 

5/10 (50%) 

540 

P=0,160N 

P=0,325N 

P=0.492N 

7/60 (12%) 

28.7% 

1/10 (10%) 

649 

P=0.267N 

P=0.503 

P=0,534 

9/60 (15 %) 

34.9% 

1/10 (10%) 

302 

P =0.132N 

P=0.431N 

P=O.374N 

1,250 ppm 

3/60 (5%) 

13.5 % 

1/11 (9%) 

498 

P=O.450N 

P=0.505N 

P=O.500N 

7/60 (12%) 

28.1% 

0/11 (0%) 

669 

P=0.504N 

P=0,550N 

P=0.61 IN 

7/60 (12%) 

28.1% 

0/11 (0%) 

669 

P=O,393N 

P=O.427N 

P=0.500N 

12/60 (20%) 

38.8% 

1/11 (9%) 

576 

P=0,257 

P=0.167 

P=0.159 

13/60 (22%) 

40.2% 

1/11 (9%) 

576 

P=0.360 

P=0,227 

P=0.240 

2,500 ppm 

2/58 (3%) 

6.6% 

0/16 (0%) 

789 

P=O,219N 

P=0.337N 

P=0.356N 

7/57 (12%) 

21.8% 

1/16 (6%) 

649 

P=O.348N 

P=0.566N 

P=0.571 

9/57 (16%) 

32.2% 

3/16 (19%) 

649 

P=0,387N 

P=O,605N 

P=0,454 

5/58 (9%) 

/ 19.2% 

0/16 (0%) 

425 

P=0.195N 

P=0,363N 

P=O.405N 

6/58 (10%) 

24,2% 

1/16 (6%) 

425 

P=O, 123N 

P=0.304N 

P=O.316N 

5,000 ppm 

3/60 (5%) 

15.4%. 

2/17 (12%) 

869 

P=0.279N 

P=O.410N 

P=O.500N 

6/60 (10%) 

24.2% 

3/17 (18%) 

633 

P=0.208N 

P=0,351N 

P=O.500N 

7/60 (12%) 

27.6% 

3/17 (18%) 

633 

P=0.174N 

P=O.309N 

P=0.500N 

9/60 (15%) 

24.8% 

2/17 (12%) 

591. 

P=O.554N 

P=0.388 

P=0.395 

9/60 (15%) 

24.8% 

2/17 (12%) 

591 

P=0,332N 

P=0,536 

P=0.601N 
172 

C 

t-Butylhydroquinone, NTP TR 459 

TABLE B3 

Statistical Analysis of Primary Neoplasms in Female Rats in the Long-Term Feed Study of t-Butyihydroquinone (continued) 

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

All Organs: Mononudear Cell Leukemia 

Overall rate 27/60 (45 %) 33/60 (55%) 22/58 (38%) 27/60 (45%) 

Adjusted rate 76.5 % 79.3% 51.6% 63.2% 

Terminal rate 5/10 (50%) 4/11 (36%)" 2/16 (13%) 5/17 (29%) 

First incidence (days) 421 481 197 501 

Life table test P=0.039N P=0.430 P=0.064N P=0.106N 

Logistic regression test P=0.355N P=0.217 P=0.313N P=0.529N 

Coehran-Armitage test P=0.346N 

Fisher e~iet test P=0.181 P=0.277N P=0.573N 

All Organs: Benign Neoplasms 

Overall rate 52/60 (87%) 51/60 (85%) 49/58 (84%) 50/60 (83%) 

Adjusted rate 100.0% 100.0% 96.0% 95.8% 

Terminal :rate 10/10 (100%) 11/11 (100%) 14/16 (88%) 15/17 (88%) 

First incidence (days) 418 480 425 501 

Life table test P=0.005N P=0.251N P=0.021N P=0.009N 

Logistic regression test P=0.079N P=0.225N " P=0.099N P=0.085N 

Cochran-Armitage test P=0.354N 

Fisher exact test P=0.500N P=0.470N P=0.399N 

All Organs: Malignant Neoplasms 

Overall rate 41/60 (68%) 39/60 (65%) 38/58 (66%) 39/60 (65%) 

Adjusted rate 100.0% 84.9% 82.2% 82.8% 

Terminal rate I0/10 (100%) 5/11 (45%) 9/16 (56%) 10/17 (59%) 

First incidence (days) 302 481 197 501 

Life table test P=0.020N P=0.246N P=0.049N P=0.024N 

Logistic regression test P=0.360N P=0.374N P=0.439N P=0.343N 

Cochran-Armitage test P=0.412N " 

Fisher exac.t test P=0.423N P--0.448N P=0.423N 

All Organs: Benign or Malignant Neoplasms 

Overall rate 59/60 (98%) 59/60 (98%) 56/58 (97%) 59/60 (98%). 

Adjusted rate 100.0% I00.0% 98.2% 98.3% 

Terminal rate 10/I0 (100%) 11/11 (100%) 15/16 (94%) 16/17 (94%) 

First incidence (days) 302 480 197 501 

Life.table test P=0.009N P=0.283N P=0.026N P=0.016N 

Logistic regression test P=0.508N P=0.639N P=0.392N P=0.624N 

Cochran-Armitage test P=0.589N 

Fisher exact test P=0.752N P=0.487N P=0.752N 

(T)Terminal sacrifice 

a Number of neoplasm-bearing animals/number of animals examined. Denominator is number of animals examined microscopically for adrenal gland, clitoral 

gland, lung, pancreatic islets, pituitary gland, thyroid gland, anduterus; for other tissues, denominator is number of animals necropsied. b Kaplan-Meier estimated neoplasm incidence at the end of the study after adjustment for intercurrent mortality 

Observed incidence at terminal kill 

d Beneath the control incidence are the P values associated with the trend test. Beneath the exposure group incidence are the P values corresponding to 

pairwise comparisons between the consols and that exposure 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 
I 

[ 

I I 

: : 

; 

[ 

~ 

i-

: 

I 

l 

I 

1

! 

~;:~ ;i : ~ ! 

~:---~.~..--~7--~~ZW-~--~,~-~ ~ _ ~ , - . . . . . . . . - - ..... ~ . - - -, : . ~ ~ : :,. ............ :: .... : 

t-~utylhydroquinone, NTIF TIR 459 

T~L~ ~4 

Su~nn~ary o~ the ]Incidence o1~ Nonneophasfic Lesions in Female ~ats in the Long-Term Feed Study 

o~'~=~uty~hydroquinone a 

.. 

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

Disposition Summary 

Animals initially in study 

3-Month interim evaluation 

Early deaths 

Moribund 

Natural deaths 

Survivors 

Terminal sacrifice 

Missexed 

70 

10 

40 

I0 

10 

0 

70 

10 

41 

8 

I1 

0 

70 

10 

33 

9 

16 

2 

70 

10 

36 

7 

17 

0 

Animals examined microscopically 70 70 68 70 

3-Month ~n~edm E~,aluat~on 

Alimentary System 

Intestine large, rectum 

Parasite metazoan 

Liver 

Angiectasis 

Hepatodiaphragmatic nodule 

Pancreas 

Atrophy 

(10) 

(1o) 

2 (20%) 

(I0) 

(lO) 

(lO) 

(10) 

1 (10%) 

(1o) 

(10) 

1 (10%) 

(10) 

1 (10%) 

(lO) 

I (1o%) 

(10) 

1 (10%) 

1 (10%) 

(10) 

Endocrine System 

Adrenal cortex 

Accessory adrenal cortical nodule 

Hyperplasia, focal 

Pituitary gland 

Pars distalis, cyst 

Thyroid gland 

Eatopic thymus 

Ultimobranchial cyst 

(10) 

3 (30%) 

1 (10%) 

(10) 

2 (20%) 

(10) 

1 (10%) 

2 (20%) 

(lO) 

1 (lO%) 

(lO) 

1 (lO%) 

(1o) 

(lO) 

(lO) 

(lO) 

1 (10%) 

3 (30%) 

(1o) 

I (1o%) 

(lO) 

(lO) 

1 (10%) 

GenRal System 

Clitoral g~an~ 

Inflammation, chronic 

Ovary 

Cyst 

Uterus 

Hydrometra 

(lO) 

1 (10%) 

(I0) 

(10) 

1 (10%) 

(10) 

(lO) 

(1o) 

5 (50%) 

(10) 

(lO) 

1 (lO%) 

(1o) 

1 (10%) 

(10) 

(tO) 

1 (lO%) 

(1o) 

2 (20%) 

Hematopoietic System 

Bone marrow 

Inflammation, granulomatous 

Lymph node, mandibular 

Hemorrhage 

Spleen 

Pigmentation, hemosiderin 

(10) 

(10) 

2 (20%) 

(10) 

5 (50%) 

(10) 

(10) 

1 (10%) 

(10) 

7 (70%) 

(I 0) 

1 (10%) 

(10) 

2 (20%) 

(10) 

8 (80%) 

(10) 

(10) 

2 (20%) 

(10) 

10 (100%) 

Number of animals examined microscopically at the site and the number of animals with lesion 

,, 

~73 

I 
-174 t-Butyihydroquinone, NTP TR 459 

TA~L~; !!4 

Summaryof the Incidence. of Nonneoplastic Lesions in Female Rats in the .Long-Term Feed Study 

of t-Butylhydroquinone (continued) 

. 0 ppm 1,250 ppm 2,500 ppm 5,000 ppm 

J 

3-Month Interim Evaluation (continued) . • . , 

~ • 

Respiratory System 

Lung 

Infiltration cellular, histiocyte 

Inflammation, subacute 

" Alveolar epithelium, hyp~rplasia 

Nose 

Inflammation, suppurative 

Goblet cell, hypcrplasia 

Urinary System 

Kidney 

Cyst 

Mineralization 

(10) (10) .(10) (10) 

1 (10%) 

4 (40%) 1 (10%) 3 (30%) 2 (20%) 

1 (10%) 1 (10%) 1 (10%) 

(tO) (10) (10) (10) 

1 (10%) 

I (10%) 

(lo) (1o) (10) (lo) 

1 ¢10%) 

10 (100%) 10 (100%) 10 (100%) 10 (100%) 

Systems Examined With No Lesions Observed 

Cardiovascular System 

General Body System 

Integumentary System 

Musculoskeletal System 

Nervous System 

Special Senses System 

Long-Term Study 

Alimentary System 

Esophagus 

Epithelium, hyperplasia 

Intestinelarge, colon 

Edema 

. Parasite metazoan 

Ulcer 

Intestine large, rectum 

Edema 

Parasite metazoan 

Intestine large, cecum 

Edema 

Parasite metazoan 

Intestine small, duodenum 

Erosion. 

Elfithelium, hyperplasia 

Intestine sr~dl, ileum 

Inflammation,. chronic active 

Epithelium, hyperplasia 

. = 

(58) (60) '(57) (60) 

(60) 

I (2%) 

(59) (56) (59) 

1 (2%) 

6 (10%) 4 (7%) 4 (7%) 5 

1 

(8%) 

(2%) 

(59) (59) (57) (59) 

I (2%) 

2 (3%) 

(6o) 

2 (3%) 

(59) 

2 (3%) 

(6O) 

2 (3%) 

1 (2%) 

(60) 

6 (11%) 

(57) 

I (2%) 

3 (5%) 

(57) •. 

8 (14%) 

(60) 

2 (3%) 

1 (2%) 

(6o) 

I (2%) 

(6o) 

1 (2%) 

(58) 

1 (2%) 

(57) 

1 (2%) 

(58) 

I (2%) 
: =:: : ~ ~ " ~ : ~ r ~ ~ ....... ~ ~ ~ ~,-. - ~ _ . . ~ . - ,..................... 

g-~utylhydroquinone9 NT~ T]~ ,~$9 ~.75 

TASL~ ~¢ 

~mmary o~ the ]Incidence o~ Non~eo~ic 

o~ t-~uty~hyc~roqu~rao~e (continued) 

Lesion i~ Ferule ]I~a~s ~ the Long-Term Feed Study . 

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

I 

Long-Term Study (continued) 

Alimentary System (continued) 

Liver 

Angiectasis 

Basophilic focus 

Clear cell focus 

Degeneration, cystic . 

Eosinophilic focus 

Eosinophilic focus, multiple 

Hematopoietie ceil proliferation 

Hemorrhage 

Hepatodiaphragmatic nodule 

Inflammation, granulomatous 

Mixed cell focus 

Necrosis, focal 

Bile duct, cyst 

Bile duct, hyperplasia 

Centriiobular, necrosis 

Hepatocyte, vacuolization cytoplasmic 

Kupffer cell, pigmentation 

Mesentery 

Accessory spleen 

Fat, necrosis 

Pancreas 

Atrophy 

Metaplasia, hepatocyte 

Acinus, cytoplasmic alteration 

Acinus, hyperplasia, focal 

Salivary glands 

Atrophy 

Stomach, forestomach 

Edema 

Erosion 

Hyperplasia 

Ulcer 

Mucosa, hyperplasia 

Stomach, glandular 

Edema 

Erosion 

Ulcer 

Tongue 

Epithelium, hyperplasia 

(60) 

1 (2%) 

26 (43%) 

2 (3%) 

1 (2%) 

1o (17%) 

1 (2%) 

12 (2o%) 

12 (20%) 

2 (3%) 

6 (1o%) 

17 (28%) 

14 (23%) 

12 

(11 ) 

I 

9 

(60) 

20 

1 

(60) 

2 

(60) 

4 

1 

2 

5 

(60) 

1 

3 

2 

( I ) 

(2O%) 

(9%) 

(82%) 

(33%) 

(2%) 

(3%) 

(7%) 

(2%) 

(3%) 

(8%) 

(2%) 

(5%) 

(3%) 

(60) 

2 (3%) 

31 (52%) 

13 (22%) 

10 (17%) 

9 (15%) 

6 (10%) 

3 (5%) 

20 (33%) 

14 (23%) 

14 (23%) 

(13) 

1 (8%) 

12 (92%) 

(60) 

21 (35%) 

1 (2%) 

1 (2%) 

(60) 

(60) 

3 (5%) 

4 (7%) 

9 (15%) 

(60) 

I (2%) 

2.(3%) 

4 (7%) 

(1) 

(58) 

1 (2%) 

31 (53%) 

4 (7%) 

12 (21%) 

1 (2%) 

4 (7%) 

8 (14%) 

9 (16%) 

8 (14%) 

5 (9%) 

1 (2%) 

18 (31%) 

9 (16%) 

7 (12%) 

(10) 

8 (80%) 

(57) 

13 (23%) 

2 (4%) 

(58) 

I (2%) 

(57) 

4 (7%) 

I (2%) 

3 (5%) 

8 (14%) 

(57) 

2 (4%) 

6 (11%) 

1 (2%) 

(4) 

2 (50%) 

• 

• 

(60) 

I (2%) 

29 (48%) 

5 (8%) 

I (2%) 

17 (28%) 

1 (2%) 

2 (3%) 

18 (30%) ~ 

10 (17%) 

7 (12%) 

3 (5%) 

I (2%) 

24 (40%) 

I (2%) 

3 (5%) 

9 (15%). 

(7) 

2 (29%) 

.5 (7!%) 

(59) 

13 (22%) 

1 (2%) 

(60) 

(60) 

1 (2%) 

I (2%) 

2 (3%) 

5 (8%) 

(60) 

2 (3%) 

(1) 

1 (100%) 

Cardiovascular System 

Heart 

Cardiomyopathy 

Thrombosis • 

Valve, inflammation, chronic 

(60) 

28 (47%) 

3 (5%) 

i (2%) 

(60) 

32 (53%) 

3 (5%) 

(58) 

26 (45%) 

(60) 

28 (47%') 
176 toButylhydroquinone, NTP TR 459 

TABLE B4 

Summary of the Incidence of Nonneoplastic Lesions in Female Rats in the Long-Term Feed Study 

of t-Butylhydroquinone (continued) 

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

.. 

Long-Term Study (continued) 

Endocrine System 

Adrenal cortex 

Accessory adrenal cortical nodule 

Atrophy 

Degeneration, fatty 

Hemorrhage 

Hyperplasia, diffuse 

Hyperplasia, focal 

Hypertrophy, focal 

Metaplasia, osseous 

Necrosis 

Adrenal medulla 

Hyperplasia 

Islets, pancreatic 

Hyperplasia 

(60) 

11 (18%) 

1 (2%) 

9 (15%) 

1 (2%) 

3 (5%) 

3 (5%) 

9 (15%) 

(6o) 

5 

(6O) 

1 

(8%) 

(2%) 

(60) 

14 (23%) 

16 (27%) 

I (2%) 

6 (10%) 

6 (10%) 

2 (3%) 

(60) 

{{ ({8%) 

(59) 

(58) 

9 (16%) 

17 (29%) 

2 (3%) 

1 (2%) 

4 (7%) 

4 (7%) . 

I (2%) 

l (2%) 

(58) 

7 ({2%) 

(57) 

(6O) 

9 

12 

1: 

I 

2 

7" 

(60) 

7 

(59) 

(15%) 

(20%) 

(2%) 

(2%)' 

(3%) 

(12%) 

(12%) 

• 

" 

Parathyroid gland 

Hypeqflasia 

Pituitary gland 

Pars distalis, angiectasis 

Pars distalis, cyst 

Pars distalis, hyperplasia, focal 

Pars intermedia, angiectasis 

(52) 

I 

(60) 

8 

14 

9 

(2%) 

({3%) 

(23%) 

({5%) 

(55) 

(60) 

3 (5%) 

24 (40%) 

15 (25%) 

2 (3%) 

(53) 

I 

(57) 

6 

17 

1 

(2%) 

({{%) 

(30%) 

(2%) 

(54) 

• 1

(60) 

7 

19 

9 

(2%) 

({2%) 

(32%) • 

(15%) 

Pars imermedia, cyst 

Thyroid gland 

Uitimobranchial cyst 

C-cell, hyperplasia 

2 

(60) 

2 

8 

(3%) 

(3%) 

({3%) 

5 (8%) 

(60) 

9 (15%) 

4 

(57) 

1 

3 

(7%) 

(2%) 

(5%) 

3 

(60) 

I 

8 

(5%) 

(2%) 

(13%) 

Follicle, cyst I (2%) 2 (4%) I (2%) 

Follicular ceil, hyperplasia 1 (2 % ) 

General Body System 

None 

Genital System 

Clitoral gland 

Cyst 

(58) 

2 (3%) 

(59) 

7 (12%) 

(58) 

6 (1o%) 

(6o) 

5 (8%) 

Cyst, multiple 1 (2%) 

Hyperplasia 3 (5%) 6 ({0%) 3 (5%) 4 (7%) 

Inflammation, chronic 2 (3%) 2 (3%) 2 (3%) 2 (3%) 

Inflammation, suppurative 

Ovary 

2 

(60) 

(3%) 3 (5%) 

(60) • 

3 

(57) 

(5%) 1 

(60) 

(2%) 

Cyst 

Uterus 

Hydrome~ra 

Hyperplasia, cystic 

17 

(60) 

3 

4 

(28%) 

(5%) 

(7%) 

11 (18%) 

(60) 

5 (8%) 

5 (8%) 

18 

(58) 

3 

2 

(32%) 

(5%) 

(3%) 

17 

(6O) 

7 

3 

(28%) 

(12%) 

(5%) 

Cervix, hypertrophy I (2%) 
~: ,~ ~ ~ ~'-~-~-7 . . . . . ~,~ . . . . ~ ........... .- , ~ . . . . . ~ ....... ._~ .......... - ....... ~ ~ l - - ~ . _ _ ~ ........... ~ ----~ .......... 

f-I~ty~hy~r~lnene, IMP ~ ~ ~77 

TABLE ~ 

Suma~a~'y oC the ]~nc~e~ce ~C Hen~e~lle~t~© ]].,e~B~ B~ ]~e~a~e ~ats in the Loag-Te~ ~ee~ 

o~ ~-~tyHhy~Ir~l~C~e (continued) 

I 

0 pp~ 1,2.50 ppm 2,5~0 ppm I 

I 

I Long-Term SAy (continued) 

lI-llematopoietic ~ys~ 

Bone ~w 

Depletion cellular 

(~) 

I (2~) 

(~o) (57) 

1 (2%) 

Fibrosis 

Hy~lasia 1 (2%) 

~l~fion cell~ar, ~sfi~y~ 1 (2%) 

Myeiofibrosis 2 (3%) 4 (7%) 1 (2%) 

Lymph n~e (20) (24) (19) 

Hy~lasia, lymphoid 1 (4%) 

l~i~l, ecmsia 1 (5%) 

I~, hemo~hage 1 (5%) 

I~l, h~lasia, lym~oid 1 (5%) 

Medias~, ec~sia I (5%) 

M~iasfi~l, hemo~ge 3 (15%) 1 (4%) 7 (37%) 

M~iasfi~l, hy~lasia, lymp~id 1 (5%) 

Mediastinal, pigmentation 14 (70%) 9 (38%) 11 (58 %) 

Pancreatic. hemorrhage 1 (5%) 

Pancreatic, pigmentation 1 (5 %) 6 (25 % ) 4 (21% ) 

Renal, hemorrhage 

Renal, pigmentation 1 (5%) 2 (8%) 

Lymph node, mandibular 

Ectasia 

Hemorrhage 

Hyperplasia, lymphoid 

Hyperplasia, plasma cell 

(59) 

2 (3%) 

3 (5%) 

13 (22%) 

1 (2%) 

(CO) 

2 (3%) 

2 (3%) 

9 (15%) 

(55) 

4 f7%) 

3 (5%) 

14 (25%) 

Pigmentation 

Lymph node, mesenteric 

Ectasia 

Hemorrhage 

' Hyperplasia, lymphoid 

Pigmentation 

Spleen 

Fibrosis 

Hematopoietic cel ! proliferation 

Hemorrhage 

20 (34%) 

(58) 

2 (3%) 

2 (3%) 

(69) 

3 (5%) 

15 (25 % ) 

19 (32%) 

(CO) 

2 (3%) 

1 (2%) 

2 (3%) 

(6o) 

5 (8%) 

12 (20%) 

26 (47%) 

(55) 

2 (4%) 

9 (16%) 

3 (5%) 

1 (2%) 

(57) 

3 (5%) 

17 (30%) 

Hyperplasia, lymphoid 

Metaplasia. lipucyte 

Necrosis 2 (3%) 2 (4%) 

Pigmentation, hemosiderin 34 (40%) 27 (45%) 33 (58%) 

Lymphoid follicle, atrophy I (2%) i (2%) 

Red pulp, atrophy 1 (2%) 

~ntegumentm.y Sys~e~ 

Mammary gland (60) (59) (58) 

Dilatation 37 (62%) 48 (81%) 39 (67%) 

Galactocele 5 (8%) 4 (7%) 1 (2%) 

Hyperplasia 12 (20%) 6 (1o%) 11 09%) 

Inflammation, suppurative 

Study 

5,~0 ppm 

(60) 

1 (2%) 

3 (5%) 

(18) 

6 (33%) 

4 (22%) 

2 (11%) 

7 (39%) • 

(60) 

1 (2%) 

7 (12%) 

1 (2%) 

25 (42%) 

(60) 

2 (3%) 

7 (12%) 

4 (7%) 

1 (2%) 

(~) 

3 (5%) 

11 (18%) 

1 (2%) 

1 (2%) 

1 (2%) 

1 (2%) 

41 (68%) 

1 (2%) 

(6O) 

34 (57%) 

5 (8%) 

15 (25%) 

1 (2%) 
178 t-Butylhydroquinone, NTP TR 459 

TABLE B4 

Summary of the Incidence of Nonneoplastic Lesions in Female Rats in the Long-Term Feed Study 

of t-Butylhydroquinone (continued) 

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

. 

Long-Term Study (continued) 

. . 

Integumentary System (continued) 

Skin (6o) (6o) (58) (6o) 

Cyst epithelial inclusion 1 (2%) 1 (2%) 

Hyperkeratosis. 1 (2%) 

Inflammation, chronic 1 (2%) 

Ulcer 1 (2%) 1 (2%) 2 (3%) 

Epiderrnis, hyperplasia 1 (2%) 2 (3%) 2 (3%) 

Musculoskeletal System 

Bone (60) (59) (58) (60) 

Fibrous osteodystrophy i (2%) 1 (2%) 

Hyperostosis I (2%) 

Cranium, osteopetrosis 8 (13%) 9 (15%) 6 (10%) 9 (15%) 

Femur, osteopetrosis 9 (15%) 10 (17%) 6 (10%) 5 (8%) 

Skeletal muscle (1) (1) (1) (1) 

Hemorrhage 1 (1oo%) 

Nervom; System 

Brain (60) (60) (58) (6o) 

Atrophy 19 (32%) 20 (33%) 25 (43%) 22 (37%) 

Hemorrhage 1 (2%) 

Hydrocephalus 4 (7%) 1 (2%) 3 (5%) 8 (13%) 

Necrosis 1 (2%) 1 (2%) 

Respiratory System 

Lung (60) (60) (58) (6o) 

Congestion 1 (2%) 

Edema 1 (2%) 

Hemorrhage 2 (3%) 1 (2%) 1 (2%) 2 (3%) 

Infiltration cellular, histiocyte 28 (47%) 23 (38%) 30 (52%) 23 (38%) 

Inflammation, subacute 3 (5%) 

Thrombosis 1 (2%) 

Alveolar epithelium, hyperplasia 4 (7%) 4 (7%) 2 (3%) 4 (7%) 

Nose (60) (60) (58) (60) 

Foreign body 3 (5%) 3 (5%) 

Inflammation, suppurative 5 (8%) 1 (2%) I1 (19%) 3 (5%) 

Goblet cell, hyperplasia I0 (17%) 2 (3%) 3 (5%) 6 (10%) 

Mucosa, hyperplasia 5 (8%) 1 (2%) 12 (21%) I (2%) 

Mucosa, metaplasia, squamous 3 (5%) 4 (7%) 

Special Senses System 

Eye (4) (1) (3) (i) 

Cataract 3 (75%) 1 (100%) 3 (lOO%) 1 (1oo%) 

Hemorrhage I (25%) 1 (33%) 

Inflammation, chronic 1 (33%) 

Retina, degeneration 4 (100%) 1 (100%) 3 (100%) 1 (IOO%) 
179 

7 .~ ~": ~ - " ~ . ~ ~ ....... : ~,77 : : 

t-Butylhydroquinone, NT~ TR 459 

TABLE B4 

Summary of the Incidence of Nonueoplasfic Lesions in Femage Rats in the Long-Term Feed Study 

of t-~uty~hydroquinone (continued) 

0 ppm 1,250 ppm 2,500 ppm 

! 

Long-Term Study (continued) 

Urinary System 

J Kidney (6o) (6o) (57) [ Cyst 1 (2%) 

Hydronephrosis 1 (2%) 

Inflammation, chronic 1 (2%) 1 (2%) 3 (5%) 

! Inflammation,suppurative 2 (3%) 1 (2%) 

Mineralization 57 (95%) 56 (93%) 44 (77%) 

Nephropathy 37 (62%) 38 (63%) 37 (65%) 

Renal tubule, atrophy 1 (2%) 4 (7%) 

Renal tubule, cytoplasmic alteration 5 (8%) 3 (5%) 4 (7%) 

Renal tubule, dilatation 1 (2%) 

Renal tubule, necrosis 2 (3%) 1 (2%) 1 (2%) 

Renal tubule, pigmentation 15 (25%) 16 (27%) 11 (19%) 

Transitional epithelium, hyperplasia 2 (3%) 2 (3%) 6 (11%) 

Urinary bladder. (59) (60) (58) 

Transitional epithelium, hyperplasia 1 (2%) 1 (2%) 

= ̧ I 

5,000 ppm 

(6o) 

2 (3%) 

5 (8%) 

48 (80%) 

39 (65%) 

5 (8%) 

2 (3%) 

1 (2%) 

2 (3%) 

16 (27%) 

3 (5%) 

(59) ~ 

2 (3%) 
7 ---~:~:ze~+~.~-,~-~k. =~-~7 - ~ ~.::~i-~ ........ ~ , ~ ~::~ ~ ~ , ~--~,_ .... ~ ~ . A ~ --~ ~ 

I 

I 

! 

i 

T~L~ C1 

TA~L~ C2 

T~L~ C3 

T~L~ C4~a 

T~L~ C4b 

T~LE C~ 

T~L~ C5 

I 

API~EHDI~Z C 

$%T~,B,~AIk~ O~ LESI~OHS~ ~H ~'~IALE ~,~I~ICE 

~H TI~{E ~o~EA~ ~EED~ST~.YDY 

OI~ toB~T~fLH~fI[])~Oq~<]I[HOHZ 

Sumn~ry o~ t~e ~nc~dence o~ I~leop~mn~s ~n 1V~a~e 1VJI~ce 

~ ~e ~-Year Feed S~y o~ t-Su~yR~y~ro~none ........................... 

~n~ An~ ~or ~a~ho~o~ o~ ~e ~ce 

~n ~he 2-Year ~ee~ S~u~y of t-Su~y~hy~roqu~one ........................... 

S~ca~ Ana~ys~ o~ ~ary Neop~mms ~n ~a~e ~ce 

~n ~he 2-Y~ Yee~ S~u~y of t-~u~y~hy~roqu~none ............................ 

~or~ca~ ~nc~ence o~ ~epa~oce~uR~ Heopam~ ~n Un~r~e~ ~aae ~C3~1 ~ce .... 

~or~ca~ ~nc~ence of Spleen ~emang~osarco~a ~n Untr~te~ ~a~e ~C3~ ~ce ..... 

~tor~c~ ~ac~dence o~ He~g~oma and Hemang~os~co~a 

~ Untreated ~a~e ~C3~ ~ce ...................................... 

Su~a~ o~ the ~c~ence of Honneop~c ~om ~n ~a~e ~ce 

~n the 2-~ ~ee~ Study o~ t-~uty~hy~roqu~none ................... ' ........ 

~2 

~ 

20~ 

~ 

~2 

2~2 

2~3 

i 
182 t-Butylhydroquinone, NTP TR ~459 

TABLE C1 

Summary of the Incidence of Neoplasms in Male Mice in the 2-Year Feed Study of t-Butyihydroquinone a 

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

Disposition Summary 

Animals initially in study 60 60 60 60 

15-Month interim evaluation 10 10 9 9 

Early deaths 

Accidental death 1 

Moribund 6 3 7 

Natural deaths 4 1 6 

Survivors 

Terminal sacrifice 39 46 38 42 

Animals examined microscopically 60 60 

15-Month Interim Evaluation 

AlimentarySystem ..... 

Intestine ,,;mall, jejunum o0) (I0) (9) . (9) 

Liver (io) (I0) (9) (9) 

Hepatocellular carcinoma 

Hepatocellular adenoma 

" 

1 (io~) 1 (10%) 1 (II~) 

1 01%) 

Endocrine System 

Thyroid gland (io) (io) (9) (9) 

Follicular cell, adenoma 1 (11~) 

Respiratory System 

Lung (IO) (1o) (9) (9) 

Alveolarforonchiolar adenoma 1 (10%) 2 (22%) 1 (11~) 

Systemic Lesions 

Multiple organs b (10) (~o) (9) (9) 

Lymphoma malignant ~ (~1%) 

Systems Examined With No Neoplasms Observed 

Cardiovascular System 

General Body System 

Genital System 

Hematopoietic System 

Integumentary System 

Musculoskeletal System 

Nervous System 

Special Senses System 

Urinary System 
t-Su~ylhydroquinone, NTP, TR 459 ~83 

TA~L~ C1 

Summary of the Incidence of Neoplasms in Male Mice in the 2-Year Feed Study of t-l~utynhydroquinone (continued) 

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

2- Year Study 

~limentary System 

Intestine small, jejunum (50) (50) (48) (50) 

Carcinoma 1 (2%) 3 (6%) 

Intestine small, ileum (49) (49) (49) (49) 

Carcinoma 1 (2%) 

Liver (50) (50) (51) (51) 

Hemangioma 1 (2%) 

Hemangiosarcoma 1 (2%) 1 (2%) 1 (2%) 1 (2%) 

Hemangiosarcoma, multiple 2 (4%) 1 (2%) 

Hepatocellular carcinoma 5 (10%) 9 (18%) 8 (16%) 7 (14%) 

Hepatocellular carcinoma, multiple 3 (6%) 2 (4%) 4 (8%) 1 (2%) 

Hepatocellular adenoma 21 (42%) 14 (28%) 17 (33%) 11 (22%) 

Hepatocellular adenoma, multiple 7 (14%) 8 (16%) 5 (10%) 3 (6%) 

Histiocytie sarcoma 2 (4%) 

Mesentery (2) (7) (14) (1) 

Histiocytic sarcoma 1 (14%) 2 (14%) 

Pancreas (49) (50) (51) (51) 

Histiocytic sarcoma 1 (2%) 

Stomachl forestomach (49) (50) (51) (51) 

Squamous cell papilloma 1 (2%) 1 (2%) 2 (4%) 

Stomach, glandular (49) (50) (51) (50) 

Carcinoid tumor benign 1 (2%) 

Cardiovascular System 

Heart (50) (50) (51) (51) 

Hemangiosarcoma 1 (2%) 

Histiocytic sarcoma 1 (2%) 

Endocrine System 

Adrenal cortex (50) (50) (50) (51) 

Subcapsular, adenoma 1 (2%) 4 (8%) 1 (2%) 2 (4%) 

Islets, pancreatic (50) (50) (51) (51) 

Adenoma 1 (2%) 1 (2%) 2 (4%) 

Parathyroid gland (49) (46) (50) (44) 

Adenoma 1 (2%) 

Pituitary gland (46) (42) (45) (49) 

Pars distalis, adenoma I (2%) 

Thyroid gland (50) (50) (50) (51) 

Follicular cell, adenoma 1 (2%) 1 (2%) 1 (2%) 

Follicular cell, carcinoma 1 (2%) 

General Body System 

None 
184 t-Butylhydroquinone, NTP TR 459 

TABLE C1 

Summary of the Incidence of Neoplasms in Male Mice in the 2-Year Feed Study of t-Butylhydroquinone (continued) 

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

2-Year Study (continued) 

Genital System 

Epididymis (50) (50) (51) (50) 

Hemangioma 1 (2%) 

Preputial gland (50) (49) (50) (51) 

Histiocytic sarcoma 1 (2%) 

Testes (50) (50) (51) (51) 

Interstitial cell, adenoma 1 (2%) 

Hematopoietic System 

Bone marrow (50) (50) (51) (51) 

Hemangiosarcoma 1 (2%) 1 (2%) 

Histiocytic sarcoma 1 (2%) 1 (2%) 

Lymph node (3) (3) (6) (3) 

Iliac, histiocytic sarcoma 2 (33 %) 

IngUinal, histiocytic sarcoma 1 (33%) 

Mediastinal, histiocytic sarcoma 1 (33%) 1 (17%) 

Pancreatic, histic~cytie sarcoma 1 (17%) 

Renal, histiocytie sarcoma 1 (33%) 1 (17%) 

Lymph node, mandibular (48) (48) (49) (51) 

Histiocytic sarcoma 1 (2%) 

Lymph node, mesenteric (50) (48) (51) (51) 

Histiocytic sarcoma 1 (2%) 1 (2%) 

Spleen (50) (50) (51) (51) 

Hemangioma 1 (2%) 

Hemangiosarcoma 4 (8%) 1 (2%) 

Histiocytic sarcoma 1 (2%) 1 (2%) 

Thymus (44) (38) (43) (42) 

Integumentary System 

Skin (50) (50) (51) (51) 

Basal cell carcinoma 1 (2%) 

Subcutaneous tissue, hemangiosarcoma 2 (4%) 1 (2%) 1 (2%) 

Subcutaneous tissue, lipoma 1 (2%) 

Muscuh)skeletal System 

Skeletal muscle (2) (1) (1) 

Hemangiosarcoma, multiple 1 (50%) 

Histiocytic sarcoma 1 (100%) 

Nervous System 

None 

Respiratory System 

Lung (50) (48) (51) (51) 

Alveolar/bronchiolar adanoma 

Alveolar/bronchi01ar adenoma, multiple 

'A!yeolar/bronchiolar carcinoma 

Alveo!ar/bronchiolar carcinoma, multiple 

Hepatncellular carcinoma, metastatic, liver 

II (22%) 

l (2 %) 

3 (6%) 

4 (8%) 

8 (17%) 

2 (4%) 

3 (6%) 

2 (4%) 

1 (2%) 

8 (16%) 

1 (2%) 

2 .(4%) 

1 (2%) 

2 (4%) 

9 (18%) 

4 (8%) 

2 (4%) 

i (2%) 

Hepatocholangiocarcinoma, metastatic, liver 1 (2%) 
g-~u~y~hyeh'oquinone, N'~, T~ 459 ~85 

T~ Ca 

S~ary of the ]Incidence of Neopnasmsin I~I~e Mice in the 2-if ear Feed Study of t-Butynhydroquinone (continued) 

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

2-Year S~dy (continued) 

Special Senses System 

Ear (1) 

External ear, histiocytic sarcoma 1 (100%) 

Harderian gland (3) (9) (6) (3) 

Adenoma 2 (67%) 8 (89%) 4 (67%) 3 (100%) 

Carcinoma 2 (33%) 

Bilateral, adenoma 1 (33%) 

Ur~na~ System 

Kidney (50) (50) (51) (51) 

Histiocytic sarcoma I (2%) 

Systemic Lesions 

Multiple organs b (50) (50) (51 ) (51 ) 

Histiocytic sarcoma 1 (2%) 2 (4%) 1 (2%) 

Lymphoma malignant 4 (8%) 2 (4%) 6 (12%) 3 (6%) 

~T~op~asm Summary 

Total animals with primary neoplasms c 

15-Month interim evaluation 1 2 3 3 

2-Year study 39 44 42 36 

Total primary neoplgsms 

15-Month interim evaluation 1 2 4 3 

2-Year study 78 72 69 56 

Total animals with benign neoplasms 

15-Month interim evaluation 1 2 3 1 

2-Year study 33 37 31 26 

Total benign neoplasms 

15-Month interim evaluation 1 2 4 1 

2-Year study 50 48 39 34 

Total animals with malignant neoplasms 

15-Month interim evaluation 2 

2-Year study 21 23 25 19 

Total malignant neoplasms 

15-Month interim evaluation 2 

2-Year study 28 24 30 22 

Total animals with metastatic neoplasms 

2-Year study 5 1 2 1 

Total metastatic neoplasms 

2-Year study 5 1 2 1 

a Number of animals examined microscopically at the site and the number of animals with neoplasm 

b Number of animals with any tissue examined microscopically 

¢ Primary neoplasms: all neoplasms except metastatic neoplasms 
186 t-Butylhydroquinone, NTP TR 459 

TABLE C2 

Individual Animal Tumor Pathology of Male Mice in the 2-Year Feed Study of t-Butylhydroquinone: 0 ppm 

5566666677777777777777777 

Number of Days on Study 3914557801222222222222222 

959711305237777777777'7778 

0000000000000000000000000 

Carcass ID Number 3330344201600113444455550 

7936671457017080345856893 

Alimentary System 

Esophagus + + + + + + + + + + + + + + + + + + + + + + + + + 

Gallbladder +++A ++++A ++++++ +++ +++++ + + 

Intestine large, colon + + +A + + + + + + + + + + + + + + + + + + + + + 

Intestine large, rectum + + + + + + + + + + + + + + + + + + + + + + + + + 

Intestine large, cecum + + +A + + + + + + + + + + + + + + + + + + + + + 

Intestine small, duodenum + + + + + + + + + + + + + + + + + + + + + + + + + 

Intestine small, jejunum + + + + + + + + + + + + + + + + + + + + + + + + + 

Intestine small, ileum + + '+ A + + + + + + + + + + + + + + + + + + + + + 

Carcinoma 

Liver + + + + W + + + + + + + + + + + + + + + + + + + + 

Hemangioma 

Hemangiosarcoma 

Hemangiosarcoma, multiple X 

Hepatocellular carcinoma X X X X 

Hepatocellular carcinoma, multiple XX X 

Hepatocellular adenoma XX XXX XXX X X X 

Hepatocellular adenoma, multiple X X X X 

Mesentery + 

Pancreas +++++++++A ++ + +++ ++ ++ + ++ + + 

Salivary glands + + + + + + ÷ + + + + + + + + + + + + + + + + + + 

Stomach, forestomach + + + + + + + + + + + + + + + + + + + + + + + + + 

Stomach, glandular + + + + + + + + + + + + + + + + + + + + + + + +~+ /

Tooth + +++ ++ + ++++ + ~/ 

Cardiowtscular System 

Blood vessel + + + + + + + + + + + + + + + + + + + + ÷ + + + + 

Heart + + + + + + + + + + + + + + + + + + + + + + + + +

Hemangiosarcoma 

Endocrine System 

Adrenal cortex + + + + + + + + + + + + + + + + + + + + + + + + + 

Subcapsular, adenoma 

Adrenal medulla + + + + + + + + + + + + + + + + + + ÷ + + + + + + 

+ + + + + + + + + + + + + + + ÷ + ÷ + + + + + + + Islets, pancreatic 

Adenoma X 

Para~thyro~d gland + + + + + + + + + + + + + + + + + + + + + + + + + 

Pituitary gland ++++++++M++++ ++++ ++ ++ ++ + + 

Pars distalis, adenoma X 

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 
t-Butylhydroquinone, NTP, TR 459 187 

TABLE C2 

l~ndividua~ Anlma~ Tumor PathoLogy of Male Mice in the 2-'Year Feed Study of t-Buty~hydroquinone: 0 ppm (continued) 

7777777777777777777777777 

Number of Days on Study 22222222222222222"22222222 

8888888888888999999999999 

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 

Carc~s~Number 0001122225555111122233334 Tissues/ 

4891257890234456902312450 Tumors 

Alimentary System 

Esophagus + + + + + + + + + + + + + + + + + + + + + + + + + 50 

Gallbladder + + + + + + + + + + + + + + + + + + + + + + + + + 48 

Intestine large, colon + + + + + + + + + + + + + + + + + + + + + + + + + 49 

Intestine large, rectum + + + + + + + + + + + + + + + + + + + + + + + + + 50 

Intestine large, cecum + + + + + + + + + + + + + + + + + + + + + + + + + 49 

Intestine small, duodenum + + + + + + + + + + + + + + + + + + + + + + + + + 50 

Intestine small, jejunum + + + + + + + + + + + + + + + + + + + + + + + + + 50 

Intestine small, ileum + + + + + + + + + + + + + + + + + + + + + + + + + 49 

Carcinoma X 1 

Liver + + + + + + + + + + + + + + + + + + + + + + + + + 50 

Hemangioma X 1 

Hemangiosarcoma 1 

Hemangiosarcoma, multiple X 2 

Hepatocellular carcinoma X 5 

Hepatocellular carcinoma, multiple 3 

Hepatocellularadenoma X X X X. X X X X X X 21 

Hepatocellular adenoma, multiple X X X 7 

Mesentery + 2 

Pancreas + + + + + ÷ + + + + + + + + + + + + + + + + + + + 49 

Salivary glands + + + + + + + + + + + + + + + + + + + + + + + + + 50 

Stomach, forestomach + + + M + + + + + + + + + + + + + + + + + + + + + 49 

Stomach, glandular + + + M + + + + + + + + + + + + + + + + + + + + + 49 

Tooth + + + + + + + + + + + + + + + 28 

Cardiov~cular S~tem 

Bloodvessel + + + + + + + + + + + + + + + + + + + + + + + + + 50 

Heart + + + + + + + + + + + + + + + + + + + + + + + + + 50 

Hema~iosarcoma X 1 

Endocrine System 

Adrenal cortex + + + + + + + + + + + + + + + + + + + + + + + + + 50 

Subeapsular, adenoma X 1 

Adrenal medulla + + + + + + + + + + + + + + + + + + + + + + + + + 50 

Islets, pancreatic + + + + + + + + + + + + + + + + + + + + + + + + + 50 

Adenoma 1 

Parathyroid gland ++ ++++++ +M+ + + ++++++++ ++ ++ 49 

Pituitary gland + + + +I +I + + + + + + + + + + +I + + + + + + 46 

Pars distalis, adenoma 1 

Thyroid gland + + + + + + + + + + + + + + + + + + + + + + + + + 50 

Follicular cell, adenoma X 1 " 

General Body System 

None 
188 t-Butylhydroquinone, NTP TR 459 

TAfiLE C2 

Individual Animal Tumor Pathology of Male Mice in the 2-Year Feed Study of t-Butylhydroquinone: 0 ppm (continued) 

5566666677777777777777777 

Number of Days on Study 3914557801222222222222222 

9597113052377777777777778 

0000000000000000000000000 

Carcass ID Number 3330344201600113444455550 

7936671457017080345856893 

Genital System 

Coagulating gland + + 

Epididymis + + + + + + + + + + + + + + + + + + + + + + + + + 

Hemangioma 

Preputial gland + +.+ + + + + + + + + + + + + + + + + + + + + + + 

Prostate + + + + + + + + + + + + + + + + + + + + + + + + + 

Seminal vesicle + + + + + + + + + + + + + + + + + + + + + + + + +

Testes + + + + + + + + + + + + + + + + + + + + + + + + +

Hematopoietic System 

Bone marrow + + + + + + + + + + + + + + + + + + + + + + + + + 

Lymph node + 

Lymph node, mandibular M+++++++++++++++++++++ +++ 

Lymph node, mesenteric + + + + + + + + + + + + + + + + + + + + + + +.+ + 

Spleen + + + + + + + + + + + + + + + + + + + + + + + + +

. Hemangiosarcoma X X 

Thymus ++++++M+MI M++++++ +++++ +++ 

Integumentary System 

Mammary gland MMMMMMMMMMMMMMMMMMMMMMM + M 

Skin + + + + + + + + + + + + + + + + + + + + + + + + + 

Basal cell carcinoma X 

Subcutaneous tissue, hemangiosarcoma X 

Subcutaneous tissue, lipoma 

Musculoskeletal System 

Bone ++ + + + + + + + + + + + + + + + + + + + + + + +

+ + Skeletal muscle 

Hemangiosarcoma, multiple X 

Nervous System 

Brain + + + + + + + + + + + + + + + + + + + + + + + + + 

Peripheral nerve + 

Spinal cord ÷ 

Respiratory System 

Lung + + + + + + + + + + + + + + ÷ + + ÷ + + + + + + + 

Alveolar/bronchiolar adenoma X XX X X X 

Alveolar/bronchiolar adenoma, multiple 

Alveolar/bronchiolar carcinoma X X 

•. Hepatocellular carcinoma, metastatic, liver X XXX 

Hepa~ocholangiocarcinoma, metastatic, liver X 

+ + + + + + + + "-b + + + + + + + + + + + + + + + + Nose 

Trachea + + + + + + + + + + + + + + + + + + + + + + + + + 
t-~u~hydroquinone, NT]~, ~ 459 189 

T~L~ C2 

][ndlviduaH Anhn~fl Tumor lPathoaogy o~ Mane Mice in the 2-Year Feed Study ot t-~utynhydroquinone: 0 ppm (continued) 

7777777777777777777777777 

Number of Days on Study 2222222222222222222222222 

8888888888888"999999999999 

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 ~D Number 0001122225555111122233334 Tissues/ 

4 8 912 5 7 8 9 0 2 3 4 4 5 6 9 0 2 3 1 2 4 5 0 ~mors 

Genital System 

Coagulating gland + + 4 

Epididymis + + + + + + + + + + + + + + + + + + + + + + + + + 50 

Hemangioma X 1 

Preputial gland + + + + + + + + + + + + + + + + + + + + + + + + + 50 

Prostate I + ++ + + + + + ++ + + + + + + + + + + + + + + 49 

Seminal vesicle + + + + + + + + + + + + + + + + + + + + + + + + + 50 

Testes + + + + + + + + + + + + + + + + + + + + + + + + + 50 

Hematopoietic System 

Bone marrow + + + + + + + + + + + + + + + + + + + + + + + + + 50 

Lymph node + + 3 

Lymph node, mandibular + + +M+ + + + + ++ + + + ++ + + + + + + + + + 48 

Lymph node, mesenteric + + + + + + + + + + + + + + + + + + + + + + + + + 50 

Spleen + + + + + + + + + + + + + + + + + + + + + + + + + 50 

Hemangiosarcoma X X 4 

Thymus +++I ++++++++++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 2 

Skin + + + + + + + + + + + + + + + + + + + + + + + ÷ + 50 

Basal cell carcinoma I 

Subcutaneous tissue, hemangiosarcoma X 2 

Subcutaneous tissue, lipoma X 1 

Musculoskeletal System 

Bone + + + + + + + + + + + + + + + + + + + + + + + + + 50 

Skeletal muscle 2 

Hemangiosarcoma, multiple I 

Nervous System 

Brain + + + + + + + + + + + + + + + + + + + + + + + + + 50 

Peripheral nerve 1 

Spinal cord 1 

Respiratory System 

Lung + + + + + + + + + + + + + + + + + + + + + + + + + 50 

Alveolar/bronchiolar adenoma X X XX X II 

Alveolar/bronchiolar adenoma, multiple X I 

Alveolar/bronchiolar carcinoma X 3 

Hepatocellular carcinoma, metastatic, liver .4 

Hepatocholangiocarcinoma, metastatic, liver I 

Nose + + + + + + + + + + + + + + + + + + + + + + + + + 50 

Trachea + + + + + + + + + + + + + + + + + + + + + + + + + 50 
190 t-Butylhydroquinone, NTP TR 459 

TABLE C2 

Individual Animal Tumor 

Number of Days on Study 

Carca~; ID Number 

Special Seines System 

Harderian gland 

Adenoma 

Bilateral, adenoma 

Zymbal's gland 

Urinary System 

Kidney 

Urinary bladder ~ 

Systemic Lesiom 

Multiple organs 

Lymphoma malignant 

Pathology of Male Mice in the 2-Year Feed Study of t-Butylhydroquinone: 0 ppm (continued) '~ 

5566666677777777777777777 

3914557801222222222222222. 

9597113052377777777777778 

0000000000000000000000000 

3330344201600113444455550 

7936671457017080345856893 

+ 

X 

M 

+ + + + + + + + + + + + + + + + + + + + + + + + + 

+ + + + + + + + + + + + + + + + + + + + + + + + + 

X X 
t-l~u~y~hy~roqu~none, NTP, T~ 459 191 

TABLE C2 

]~ndiv~dua~ A~rnai Tumor Pathology of l~,SIale Mice ira the 2-Year Feed Study of t-~uty~hydroqulnor~e: 0 ppm (continued) . 

Number of Days on Study 

Carcass ID Number 

Special Senses System 

Harderian gland 

Adenoma 

Bilateral, adenoma 

Zymbal's gland 

Urinary System 

Kidney 

Urinary bladder 

Systemic Lesions 

Multiple organs 

Lymphoma malignant 

.. 

7777777777777777777777777 

2222222222222222222222.222 

8888888888888999999999999 

0000000000000000000000000 Toml 

0001122225555111122233334 Tissues/ 

4891257890234456902312450 Tumors 

÷ + 3 

X X 2 

1 

+ 1 

+ + + + + + + + + + + + + + + + + + + + + + + + + 50 

+ + + ~ + + + + + + + + + + + + + + + + + + + + + 50 

+ + + + + + + + + + + + + + + + + + + + + + + + + 50 

X X 4 
192 t-Butylhydroquinone, NTP TR459 

TABLE C2 

Individual Animal Tumor Pathology of Male Mice in the 2oYear Feed Study of t-Butylhydroquinone: 1,250 ppm • 

6667777777777777777777777 

Number of Days on Study 1351222222222222222222222 

9040777777777777788888888 

0000000000111111100000000 

Carcass ID Number 98976678990000111_66666789 

1292275078025867914568062 

Alimentary System 

Esophagus 

Gallbladder 

Intestine large, colon 

Intestine large, rectum 

Intestine large, cecum 

Intestine small, duodenum 

Intestine small, jejunum 

Carcinoma 

Intestine small, ileum 

Liver 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

~ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

X 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

~ 

+ 

+ 

+ 

+ 

+ 

+ 

+ + 

+M 

+ ÷ 

+ + 

+ + 

+ + 

+ + 

+ + 

+ + 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

Hemangiosarcoma 

Hepatocellular carcinoma 

Hepatocellular carcinoma, multiple 

Hepatocellular adenoma 

Hepatocellular adenoma, multiple 

Mesentery 

Histi.ocytic sarcoma 

Pancreas 

XX 

+ + + + 

X 

+ + + 

X 

X 

+ + + + 

X 

+ 

+++ 

+ + + 

X 

XX 

+ + 

+ 

+ 

X 

+ 

X 

+ 

+ + 

X 

+ + 

XX 

+ 

X ~ 

+ 

Histiocytic sarcoma 

Salivary glands 

Stomach, forestomach 

Squamous cell papilloma 

Stomach, glandular 

Carcinoid tumor benign 

~ Tooth 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ + 

+ + 

++ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ + + 

+ + + 

+ + + 

+++ 

+ 

+ 

X 

+ 

+ 

+ 

+ 

+ + + 

+ + + 

+ + + 

++++ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

Cardiovascular System 

Blood vessel 

Heart 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

Endocrine System 

AdrenaJ cortex + + + + + ÷ + + + + + + +~+ + + + + + + + + + + + 

Subcapsular, adenoma 

Adrenal medulla 

Islets, pancreatic 

Adenoma 

+ 

+ 

+ 

+ 

+ 

÷ 

+ 

+ 

X 

+ 

+ 

+ 

+ 

+ 

÷ 

+ 

+ 

÷ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

X 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

Parathyroid gland 

Pituitary gland 

Thyroid gland 

Follicular cell, adenoma 

+ + + + ÷ + + ÷ + 

+++M++++M+ 

+ + + + + + + + + 

+ 

+ 

+ + +I + + + + + + + + 

+M++M+M+MM+++ 

+ + + + + + + + + + + + 

X 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

General 

None 

Body System 
~-~ty~ydr~r~one, i~]T~, T~ 459 ~93 

T~.~ C2 

~du~ Ar~rm~ 'I1~o~ Pathology of I~5I~de I~Iice ~u the 2-Year Feed Study of t-~uty]hydroquinone: L250 ppm (continued) 

7777777777777777777777777 

Number o~ Days on Stu~ny 2222222222222222222222222 

8888899999999999999999999 

0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 Total 

Carcass ~D Number 9999277777888889000001111 Tissues/ 

3 4 5 6 0 3 4 7 8 9 1 4 7 8 9 0 3 4 6 7 9 0 2 3 4 ~mors 

Alimentary System 

Esophagus ÷ + + + + ÷ + + + + ÷ + + ÷ + + + + + + + + + + + 50 

Gallbladder + + + + + + + + + + + + + + + + + + + + + + + + + 49 

Intestine large, colon + + + + +.+ + + + + ÷ ÷ ÷ + + + + + + + + + + + + 50 

Intestine large, rectum + + + ÷ + + + + + + + + + + + + + + + + + + + + + 50 

Intestine large, cecum + + + + + + + + + + + + + + + + + + + + + + + + + 50 

Intestine small, duodenum + + + ÷ + + + + + + + + + + + + + + + + + + + + + 50 

Intestine small, jejunum + + + + + + + + + + + + + + + + + + + + + + + + + 50 

Carcinoma 1 

Intestine small, ileum +++++++++++++++++++ ++++M+ 49 

Liver + + + + + + ÷ + + + ÷ + + + + ÷ + + + ÷ ÷ + + + ÷ 50 

Hemangiosarcoma 1 

Hepatocellular carcinoma X X X X X 9 

Hepatocellular carcinoma, multiple 2 i 

Hepat0cellular adenoma XX XX X XXX X 14 i 

HepatoceHular adenoma, multiple XX XX X 8 ~ 

Mesentery + + 7 i 

Histiocytic sarcoma X 1 

Pancreas 

Histioeytic sarcoma 

+ + + + + + + + + + + + + + + + + + + + 

X 

+ + + + + 5o !

i 

Salivary glands + + + + + + + + + + + + + + + + + + + + + + + + + 50 ~ 

Stomach, forestomaeh + + + + + + + + + + + + + + + + + + + + + + + + + 50 i 

Squamous cell papilloma 1 

Stomach, glandular + + + + + + + + + + + + + + + + + + + + + -'F + + + 50 

Careinoid tumor benign X 1 ~ 

Tootli + + + + + + + + + + + + + + + 26 i 

Caniiowscular System 

Blood vessel + + + + + + + + + + + + + + + + + + + + + + + + + 50 

Heart + + + + + + + + + + + + + + + + + + + + + + + + + 50 

Endocrine System 

Adrenal cortex + + + + + + + + + + + + + + + + + + + + + + + + + 50 

Subeapsular, adenorna X X X 4 

Adrenal medulla • + + + + + + + + + + + + + + + + + + + + + + + + 50 

Islets, pancreatic + + + + + + + + + + + + + + + + + + + + + + + + + 50 

Adenoma 1 

Parathyroid gland M+M++++++++++++++++++M+++ ' 46 

Pituitary gland + + + + + + + ++ + ++ + + + + + + + ++ + + +M 42 

Thyroid gland + + + ÷ + + + + + + ÷ ÷ ÷ ÷ + + + + + + + + + + + 50 

Follicular cell, adenoma 1 

General Body System 

None 
194 -. 

t-Butylhydroquinone, NTP TR 459 

TABLE C2 

Indiviidual Animal Tumor Pathology of Male Mice in the 2-Year Feed Study of t~Butylhydroquinone: 1,250 ppm (continued) 

6667777777777777777777777 

Number of Days on Study 1351222222222222222222222 

904077777777777~ 7788888888 

0000000000"111111100000000 

Carcass ID Number 989-76.67899000011166666789 

129227507802586,.7914568062 

Genital System 

Coagulating gland 

Epididymis 

Preputial gland 

Prostate 

Seminal vesicle 

Testes 

: 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

÷ 

+ 

+ 

+ 

+ + + 

+ ++ 

+ + + 

+ + + 

+ +.+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ + 

+M+ 

+ + 

+ + 

+ + 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

Hematopoietic System 

Bone marrow + + + + + + + + + + + + + + + + + + + + + + + + + 

Hemangiosarcoma 

Histiocytic sarcoma 

Lymph node 

Inguinal, histiocytic sarcoma 

Mediastinal, histiocytic sarcoma 

Reml, histiocytic sarcoma 

Lymph node, mandibular 

Lymph node, mesenteric 

Histiocytic sarcoma 

Spleen 

HemangioSarcoma 

Histiocytic sarcoma 

Thymus 

+ + 

+ + 

+ + 

M+ 

+ 

+ 

+ 

+I 

÷ 

+ 

+ 

+ + + 

+ ~ + 

+ + + 

X 

++M+ 

+ 

+ 

+ 

'X 

+ 

+ + +,+ + + +M+ 

+ + + + + + + + 

+ + + + + + + + 

+++ ++MM++ 

+ 

+ 

+ + 

+ + 

+ + 

++ 

+ + + 

+ + + 

+ + + 

++M+ 

+ 

+ 

+ 

÷ + 

+ + 

+ + 

++. 

~te~mema~ Sy~em 

Ma~a~gland 

Skin 

S~cutaneoustissue,~ma~sa~oma 

M 

+ 

+ MM 

+ + + 

+ M 

+ + 

M 

+ 

M 

+ 

M 

+ 

M 

+ 

M 

+ 

+ M 

+ + 

M 

+ 

M 

+ 

X 

M 

+ 

M 

+ 

M 

+ 

M 

+ 

+ M 

+ + 

M 

+ 

M 

+ 

M 

+ 

M 

+ 

Mnsculoskeletal 

Bone 

Sy~em 

+ + + + + + + ~ + + + + + + + + + + + ÷ + + + + + 

Ne~ous 

Brain 

System 

+ + + + + + + + + + + + + + + + + + + + + + + + + 

Respiratory System 

Lung 

Alw:olar/bronchiolar adenoma 

Alveolar/bronchiolar adcnoma, multiple 

Al~colar/bronchiolar carcinoma 

Alw:olar/bronchiolar carcinoma, multiple 

Hcpatoccllular carcinoma, metastatic, liver 

No~e 

Trachea 

+ 

X 

+ 

+ 

+ 

+ 

+ 

+ 

X 

+ 

-+ 

+ 

+ 

+ 

+ 

X 

+ 

+ 

+ 

X 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

X 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

X 

+ 

+ 

+ 

+ 

+ 

+ + 

X 

+-+ 

+ + 

+ 

+ 

+ 

+ 

: 

+ 

+ 

+ 

+ 

+ 

+ 

X 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+, 

+ 

• 

X 

+ + 

+ + -

Special Senses System 

Harderian gland 

Adenoma 

+ + 

X . 

+ 

X 

+ 

X 

+ 

X ~ 

+ 

X 
t-Butylhydroquinone, NTP, TR 459 195 

TABLE C2 

]Individual Anhnal Tumor ]Pathology of Male Mice in the 2-Year Feed Study of t-~utylhydroqulnone: 1,250 ppm (continued) 

7777777777777777777777777 

Number of Days on Study 2222222222222222222222222 

8888899999999999999999999 

0000100000000000111111111 Total 

Carcass ID Number 9999277777888889000001111 Tissues/ 

3456034789 I 47890346790234 ~mors 

Genital System. 

Coagulating gland ÷ + + 6 

Epididymis + + + + + + + + + + + + + + + + + + + + + + + + + 50 

Preputial gland + + + + + + + + + + + + + + + + + + + + + + + + + 49 

Prostate + + + + ÷ + + + + + + + + + + + + + + + + + + + + 50 

Seminal vesicle + + + + + + + + + + + + + + + + + + + + + + + + + 50 

Testes + + + + + + + + + + + + + + + + + + + + + + + + + 50 

Hematopoietic System 

Bone marrow + + + + + + + + + + + + + + + + + + + + + + + + + 50 

Hemangiosarcoma 1 

Histiocytic sarcoma X • 1 

Lymph node + + 3 

Inguinal, histiocytic sarcoma X 1 

Mediastinal, histiocytic sarcoma X 1 

Renal, histiocytic sarcoma X 1 

Lymph node, mandibular + + + + + + + + + + + + + + + + + + M + + + + + + 48 

Lymph node, mesenteric + + + + + + + + M M + + + + + + + + + + + + + + + 48 

Histiocytic sarcoma X 1 

Spleen + + + + + + + + + + + + + ÷ + + + + + + + + + + + 50 

i Hemangiosarcoma 1 

Histiocytic sarcoma X 1 

~I Thymus + + + + + + M + M + + + + + + M + + + + + + M I M 38 

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 4 

Skin + + + + + + + + + + + + + + + + + + + + + + + + + 50 

Subcutaneous tissue, hemangiosarcoma 1 

Musculoskeletal System 

Bone + + + + + + + + + + + + + + + + + + + + + + + + + 50 

Nervous System 

Brain + + + + + + + + + ÷ + + + + + + + + + + + + + + + 50 

Respiratory System 

Lung + + + + + + + + + + + + + + + + + +,+ + + + + + 48 

Alveolar/bronchiolar adenoma X X X X 8 

Alveolar/bronchiolar adenoma, multiple X 2 

Alveolar/bronchiolar carcinoma X 3 

Alveolar/bronchiolar carcinoma, multiple X 2 

Hepatocellular carcinoma, metastatic, liver 1 

Nose + + + + + + + + + + + + + + + + + + + + + + + + + 50

Trachea + + + + + + + + + + + + + + + + + + + + + + + + + 50

Special Senses System 

Harderian gland + + + 9 

Adenoma x x X 8 
196 t-Butylhydroquinone, NTP TR 459 

T~L~ C2 

Indiviidual Animal Tumor Pathology of Male Mice in the 2-Year Feed Study of t-Butylhydroquinone: 1,250 ppm (continued) 

66,67777777777777777777777 

Number of Days on Study 1351222222222222222222222 

9040777777777777788888888 

0000000000111111100000000 

Carcass ID Number 98976678990000111666667'89 

1292275078025867914568062 

Urina]~ System • 

Kidney + + + + + + + + + + + + ~ + + + + + + ~ + + + + + 

Histiocytic sarcoma 

Urethn~ + 

Urinaq, bladder + + + + + + + + + + + + + + + + + + + + + + + + + 

Systemic Lesions 

Multiple organs 

Histiocytic sarcoma 

Lymphoma malignant X 
t-l~u~yihy~roq~none, NT~, TR ~5~ ~97 

T~L~ C2 

~n~v~e~ An~l Te~nor P~hology of Male Mice. in ~he 2-Year Feed S~u~y o~ t-~u~yihy~r~u~none: ~,250 ppn~ (continued) 

7777777777777777777777777 

Number of Days on Study 2222222222222222222222222 

8888899999999"999999999999 

0000100000000000111111111 Toml 

Carcms ~D Number 9999277777888889000001111 Tissues/ 

3456034789147890346790234 Tumors 

Ur~a~ ~m 

Kidney + + + + + + + + + + + + + + + + + + + + + + + + + 50 

Histiocyficsa~oma X 1 

U~ I 

Urina~bl~der + + + + + + + + + + + + + + + + + + + + + + + + + 50 

Systemic ~esions 

Multiple organs + + + + + + + + + + + + + + + + + + + + + + + + + 50 

Histiocytic sarcoma X 1 

Lymphoma malignant X 2 
198 t-Butylhydroquinone, NTP TR'4$9 

TABLE C2 

Individual Animal Tumor Pathology .of Male Mice in the 2-Year Feed Study of t-Butylhydroquinone: 2,500 ppm 

4555666666677777777777777 

Number of Days on Study 0245155667812222222222222 

9090947693004777777777777 

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 576733224454623345566666.6 

1110411625490538623345678 

Alimentary System 

Esophagus + + + + + + + + + + + + + + + + + + + + + + +'+ + 

Gallbladder + + + + +.+ + + + + + + + + + + + + + + + + + + + 

Intestine large, colon + + + + + + + + + + + +A + + + + + + + + + + + + 

Intestine large, rectum ++++++++ ++++A +++ ++ ++ +++ + +. 

Intestine large, cecum + + + + + + + + + + + +A + + + + + + + + + + + + 

Intestine small, duodenum +++A ++++++++A +++++ +++ ++ + + 

Intestine small, jejunum +++A ++++++++A +++++ +++ +++ + 

Carcinoma X X 

Intestine small, ileum +++A ++++++++A +++ ++ +++ +++ + 

Liver + + + + + + + + + + + + + + + + + + + + + + + +,+ 

Hemangiosarcoma X 

Hepatocellular carcinoma X X X X 

Hepatocellular carcinoma, multiple X X X 

Hepatocellular adenoma X X X X X X X 

Hepatocellular adenoma, multiple X X 

Histiocytic sarcoma X X 

Mesentery + + + + + + + 

Histiocytic sarcoma X X 

Pancre~s + + + + + + + + + + + + + + + + + + + + + + + + + 

Salivary glands + + + + + + + + + + + + + + + + + + + + + + + + + 

Stomach, forestomach + + + + + + + + + + + + + + + + + + + + + + + + + 

Squamous cell papilloma 

Stomach, glandular + + + + + + +.+ + + + + + + + + + + + + + + + + + 

Tooth + + +++ ++ ++

Cardiovascular System 

Blood vessel + + + + + + + + + + + + + + + + + + + + + + + + + 

Heart + + + + + + + + + + + + + + + + + + + + + + + + +

Histiocytic sarcoma X 

Endocrine System 

Adrenal colrtex +++++++++++++++++++++÷+++ 

Subcapsular, adenoma 

Adrenal medulla + + + + + ÷ + ÷ + + + + + + + + + + + + + + + + + 

Islets, pancreatic + + + + + + + + + + + + + + + + + + + + + ++ + +

Parathyroid gland + + + + + +M+ + + + + + + + + + + + + + + + + + 

Pituitary gland +++M+++++++++++++M+M++++M 

Thyroid gland ++++++M++++ +++++÷ ++ ++ + +++ 

Follicular cell, adenoma X 

General Body System 

Peritoneum 
t-Buty~hydroquinone, NTP, TR ~59 1~ 

TABLE C2 

]Individual Animal Tumor Pathology of Male Mice in the 2-Year Feed Study of t-~utyihydroquinone: 2,5~ ppm (continued) 

Number of Days on Study 

7.7777777777777777777777777 

22222222222222222222222222 

78888888888888899999999999 

' 

Carc~Number 

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 1 Total 

6 2 3 3 4 4 4 4 5 5 5 5 6 7 7 2 2 2 3 3 7 7 7 7 7 8 Tissues/ 

9 3 7 9 0 4 7 8 0 5 7 9 2 3 4 7 8 9 0 6 5 6 7 8 9 0 ~mors 

Alimentary System 

Esophagus 

Gallbladder 

Intestine large, colon 

Intestine large, rectum 

Intestine large, cecum 

Intestine small, duodenum 

Intestine small, jejunum 

Carcinoma 

Intestine small, ileum 

Liver 

Hemangiosarcoma 

Hepatocellular carcinoma 

Hepatocellular carcinoma, multiple 

Hepatocellular adenoma 

Hepatocellular adenoma, multiple 

Histio~ytic sarcoma 

Mesentery 

Histiocytic sarcoma 

Pancreas 

Salivary glands 

Stomach, forestomach 

Squamous~cell papilloma 

Stomach, glandular 

Tooth 

++ + + + + + + + + + + + + 

++ + + + + + + + + + + + + 

++ + + + + + + + + + + + + 

++ • + + + + + + + + + + + 

++ + + + + + + + + + + + + 

++ + + + + + + + + + + + + 

++ + + + + + + + + + + + + 

X 

++ + + + + + + + + + + + + 

++ + + + + + + + + + + + + 

+ + + + + + + + + + + + 

+ + + + + + + + + + + + 

+ + + + + + + + + + + + 

+ + + + + + + + + + + + 

+ + + + + + + + + + + + 

+ + + + + + + + + + + + 

+ + + +M+ + + + + + + 

+ + + + + + + + + + + + 

+ + + + + + + + + + + + 

X X X X 

X 

X X X X X X 

X X 

X X X X 

X 

+ + + + + + + 

++ + + + + + + ÷ + + + + + + + + + + + + + + + + + 

++ + + + + + + + + + + + + + + + + + + + + + + + + 

++ + + + + + + + + + + + + + + + + + + + + + + + + 

X ++ + + + + + + + + + + + + + + + + + + + + + + + + 

+ +++ +++ + + 

51 

51 

50 

50 

50 

49 

48 ,,, 

3 

49 

51 

I 

8 

4 

17 

5 

2 

14 

2 

51 

51 

51 

I 

51 

18 

Cardiovascular System 

Blood vessel 

Heart 

Histiocytic sarcoma 

++ + + + + + + + + + + + + + + + + + + + + + + + + 51 

++ + + + + + + + + + + + + + + + + + + + + + + + + 51 

1 

Endocrine System 

Adrenal cortex 

Subcapsular, adenoma 

Adrenal medulla 

Islets, pancreatic 

Parathyroid gland 

Pituitary gland 

Thyroid gland 

Follicular cell, adenoma 

I +++++++++++ + ++++++++ +++ ++ 51 

X 1 

+ + + + + + + + + + + + + + + + + + + + + + + + + +" 51 

++ + + + + + + + + + + + + + + + + + + + + + + + + 51 

++ + + + + + + + + + + + + + + + + + + + + + + + + 50 

+++++++++ ++I ++ +++++ + + + +I ++ 45 

++ + + + + + + + + + + + + + + + + + + + + + + + + 50 

1 

General Body System 

Peritoneum + 1 

• 
200 t-Butylhydroquinone, NTP TR 459 

TABLE C2 

Individual Animal Tumor Pathology of Male Mice in the 2-Year Feed Study of t-Butylhydroquinone: 2,500 ppm (continued) 

4555666666677777777777777 

Number of Days on Study 0245155667812222222222222 

9090947693004777777777777 

1111111111111111111111111 

Carcass, ID Number 5767332244546233455666666 

1110.4116254~90538623345678 

Genital System 

Coagulating gland + 

Epididymis + + + + + + + + + + + + + + + + + + + + + + + + + 

Preputial gland + + + + + + + + + + + + + ++++ ++ +M+ +++ 

Histiocytic sarcoma X 

Prostate + + + + + + + + + + + + + + + + + + + + + + + + + 

Seminal vesicle + + + + + + +.+ + + + + + + + + + + + + + + + + +

Testes + + + + + + + + + + + + + + + + + + + + + + + + +

Hemate,poietic System 

Bone marrow ++ + + + + + + + + + + + + + + + + + + + + + + + 

Histiocytic sarcoma X 

Lymph node + + ++ + 

Iliac, histiocytic sarcoma X X 

Mediastinal, histiocytic sarcoma X 

Pancreatic, histiocytic sarcoma X 

Renal, histiocytic sarcoma X 

Lymph node, mandibular ++ + + + + + + + + + +++++ ++~+ ++ +M+ 

Histiocytic sarcoma X 

++ + + + + + + + + + + + + + + + + + + + + + + + Lymph node, mesenteric 

"Histiocyfic sarcoma X 

Spleen ++ + + + + + + + + + + + + + + + + + + + + + + + 

Hema,ngioma 

Histiocytic sarcoma .X 

Thymus +M+ + + + + + + +M+ M+++I + +I ++ + ++ 

Integumentary System 

Mammary gland MM + MMMMMMMMM MMMMMMMMMMMMM 

++ + + + + + + + + + + + + + + + + + + + + + + + Skin 

Subcutaneous dssue, hemangiosarcoma X 

Musculoskeletal System 

Bone ++ + + + + + + + + + + + + + + + + + + + + + + +

Skeletal muscle + 

Histiocytic sarcoma X 

Ne~ous System 

B~in + + ÷ + + + + + + + + + + + + + + + + + + + + + + 

R e s p i r a t o r y S y s t e m 

Lung 

Alveolar/bronchiolar adenoma X X X 

Alveolar/bronchiolar adenoma, multiple X 

Alveolar/bronchiolar carcinoma X 

AI.veolar/bronchiolar carcinoma, multiple X 

Hepatocellular carcinoma, metastatic, liver X X 

÷÷.~ ÷ ÷ ÷ ÷ ~ ÷ ÷ ~ ÷ ÷ ~ ~ ~ ÷ • • • ÷ • • ÷ • Nose 

Trachea ++++ ++M+ + + + + ++++ ++ ++++++ + 
g-~y~hydroquinor~e, NTP, TR ~59 201 

T~Lg C2 

]Individual Anhn~ Tun~or Pathology of Male Mice in the 2-~e~r Feed Study of t-llgutyihydroquinone: 2,500 ppm (continued) 

77777777777777777777777777 

Humber of Days on Study 22222222222222222222222222 

7 g 888888888-888899999999999 

I I 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 ~tal 

Carcass ~D Number 62334444555567722233777778 Tissues/ 

93 7 9 0 4 7 8 0 5 7 9 2 3 4 7 8 9 0 6 5 6 7 8 9 0 ~mors 

~nit~ S~tem 

Coa~latinggl~d + 2 

~ s + + 4 4 + 4 4 4 + + + + + + + + + + + + + + + + + + 51 

P~iglaod + + + + + + + + + + + + + + + + + + + + + + + + + + 50 

Histi~yticsa~oma 1 

Pmsta~ + + + + + + + + + + + + + + + + + + + + + + + + + + 51 

Seminaivesicle + + + + + + + + + + + + + + + + + + + + + + + + + + 51 

~s~s + + + + + + + + + + + + + + + + + + + + + + + + + + 51 

Hematopoietic System 

Bone marrow ++ + + + + + + + + + + + + + + + + + + + + + + + + 51 

Histiocytic sarcoma 1 

Lymph node + 6 

lliac, hisfiocytic sarcoma 2 

Mediastinal, histiocytic sarcoma 1 

Pancreatic, histiocytic sarcoma IRenal, histiocytic sarcoma 1 

Lymph node, mandibular ++ + + + + I + + + + + + + + + + + + + + + + + + + 49 

Histiocytic sarcoma 1 

Lymph node, mesenteric ++ + + + + + + + + + + + + + + + + + + + + + + + + 51 

Histiocytic sarcoma 1 

Spleen ++ + + + + ++ + + + + + + + + + + + + + + + + + + 51 

Hemangioma X 1 

Histiocytic sarcoma 1 

Thymus I +++M+++++ +++++++++M+ + ++ ++ 43 

~nte~menta~System 

Ma~glaod MM M M M M M MM M M M M M M M M M M M M M M M M M 1 

Skin + + + + + + + + + + + + + + + + + + + + + + + + + + 51 

Su~u~eoustissue, hem~iosa~oma 1 

Musculoskeletal System 

Bone + + + + + + + + + + + + + + + + + + + + + + + + + + 51 

Skeletal muscle 1 

Histiocytic sarcoma 1 

Nervous System 

Brain + + + + + + + + + + + + + + + + + + + + + + + + + + 51 

Respiratory System 

Lung + + + + + + + + + + + + + + + + + + + + + + + + + + 51 

Aiveolar/bronchiolar adenoma X X X X X 8 

Alveolar/bronchiolar adenoma, multiple 1 

Alveolar/bronchiolar carcinoma X 2 

Alveolar/bronchiolar carcinoma, multiple 1 

Hepatocellular carcinoma, metastatic, liver 2 

Nose + + + +.+ + +.+ + 4 + + + + + + + + + + + + + + + + 51 

Trachea + + + + + + + + + + + + + + + + + + + + + + + + + + 50 
•202 

TABLE C2 

Individual Animal Tumor 

Number of Days on Study 

Carcass ID Number 

Special Senses System 

Harderian gland 

Adenoma 

Carcinoma 

Urinary SYStem 

Kidney 

Urinary bladder -. 

Systemic Lesions 

Multiple organs 

Histiocytic sarcoma 

Lymphoma malignant 

t-Butylhydroquinone, NTP TR 459 

Pathology of Male Mice in the 2-Year Feed Study of t-Butylhydroquinone: 2,500 ppm (continued) 

4555666666677777777777777 

0245155667812222222222.222. 

9090947693004777777777777 

1111111111111111111111111 

5767332244546233455666666 

1110411625490538623345678 

+ + 

X X 

++ + + + + + + + + + + + + + + + + + + + + + + + 

++ + + + + + + + + + + + + + + + + + + + + + + + 

X X 

x X 
t-Butylhydroquinone, NTP, TR 459 ,203 

TABLE C2 

[ndlvidua~ Animal Tumor ]Pathology of Male Mice in the 2-'Year Feed Study of t-Butylhydroquinone: 2,500 ppm (continued) 

77777777777777777777777777 

Number of Days on Study 22222222222222222222222222 

78888888888888899999999999 

111111111111111111 111111 11 Toml 

Carcass ID Number 62334444555567722233777778 Tissues/ 

93790478057923478906567890 Tumors 

Special Senses System 

Harderiangland + + + + 6 ~ 

Adenoma X X 4 

Carcinoma X X 

Urinary System 

Kidney ++ + + + + + + + + + + + + + + + + + + + + + + + + 51 

Urinary bladder ++ + + + + + + + + + + + + + + + + + + + + + + + + 51 

Systemic Lesions 

Multiple organs ++ + + + + + + + + + + + + + + + + + + + ++~ + + 51 

Histiocytic sarcoma 2 

Lymphoma malignant X X X X 6 
204 " t-Butylhydroquinone, NTP TR 459 

TABLE C2 

Individual Animal Tumor Pathology of Male Mice in the 2-Year Feed Study of t-Butylhydroquinone: ' 5,000 ppm 

1556666667777777777777777 

Number' of Days on Study • 

7891123882222222222222222 

1954580087777777777777777 

2212211221111112222222222 

Carcass ID Number 2083299308888890000001233 

4474873292456990356780335 

Alimentary System 

Esophagus ++ + + + + + + + + + + + + + + + + + + + + + + + 

Gallbladder ++ + + + + + + + + + + + + + + + + + + + + + + + 

Intestine large, colon ++ +A + + + + + + + + + + + + + + + + + + + + + 

Intestine large, rectum ++ +A + + + + + + + + + + + + + + + + + + + + + 

Intestine large, cecum ++ +A + + + + + + + + + + + + + + + + + + + + + 

Intestine small, duodenum ++ +A + + + + + + + + + + + + + + + + + + + + + 

Intestine small, jejunum ++ +A + + + + + + + + + + + + + + + + + + + + + 

Intestine small, ileum M++A +++++~+++++++++ ++ + ++ ++ 

Liver ++ + + + + + +'+ + + + + + + + + + + + + + + + + 

Hemangiosarcoma 

Hemangiosarcoma, multiple X 

Hepatocellular carcinoma X X 

Hepatocellular carcinoma, multiple X 

Hepatocellular adenoma X X X X X 

Hepatocellular adenoma, multiple 

Mesenter.¢ 

Pancreas ++ + + + + + + + + + + + + + + + + + + + + + + + 

Salivary glands ++ + + + + + + + + + + + + + + + + + + + + + + + 

Stomach, foi'estomach ++ + + + + + + + + + + + + + + + + + + + + + + + 

Squamous cell papilloma X X 

Stomach, glandular +++A +++++++++++++ + ++ + +++ + 

Tooth + ++ +++++ +++ + + 

Cardiovascular System 

Blood vessel ++++ + + +++ + +++ + + + + +++ + + + +M 

Heart ++ + + + + + + + + + + + + + + + + + + + + + + + 

Endocrine System 

Adrenal cortex ++ + + + + + + + + + + + + + ÷ + + + + + + + + + 

Subcapsular, adenoma X X 

Adrenal medulla ++ + + + + + + + + + + + + + + + + + + + + + + + 

Islets, pancreatic ++ + + + + + + + + + + + + + + + + + + + + + + + 

Adenoma X 

Parathyroid gland ++ + + + + + +M+M+M+ + + + +M+ + + + + + 

Adenoma 

Pituitary gland ++ + + + + + + + + + + + + + + + + + + + + + + + 

Thyroid gland ++ + + + + + + + + + + + + + + + + + + + + + + +

Follicular cell, carcinoma 

General Body System 

~ Tissue NOS + + -F 

Genital System 

Coagulating gland 

Epididymis 

Preputial gland 

Prostate 

Seminal vesicle 

Testes 

Interstitial cell, adenoma 
t-Buty~hydroqu~none, NTP, Tg 459 ~ 205 

TABLE C2 

~Individual Anhn~d Tumor Pathology of Mite Mice in the 2-Year Feed Study of t-Buty]hydroquinone: 5,000 ppm (continued) 

77777777777777777777777777 

Number of Days on Study 22222222222222222222222222 

78888888888888899999999999 

21111112222222222222222222 ~tal 

Carcass ~D Number 48999991122222211111233333 Tissues/ 

08025687801256712456906789- ~mors 

Alimentary System 

Esophagus ++ + + + + + + + + + + + + + + + + + + + + + + + + 51 

Gallbladder ++++++++++++++++ ++MM+++ ++ + 

Intestine large, colon ++ + + + + + + + + + + + + + + + + + + + + + + + + 50 

Intestine large, rectum ++ + + + + + + + + + + + + + + + + + + + + + + + + 50 

Intestine large, cecum ++ + + + + + + + + + + + + + + + + + + + + + + + + 50 

Intestine small, duodenum ++ + + + + + + + + + + + + +M+ + + + + + + + + + 49 

Intestine small, jejunum ++ + + + + + + + + + + + + + + + + + + + + + + + + 50

Intestine small, ileum ++ + + + + + + + + + + + + + + + + + + + + + + + + 49 

Liver ++ + + + + + + + + + + + + + + + + + + + + + + + + 51 

Hemangiosarcoma X 1 

Hemangiosarcoma, multiple 1 

Hepatocellular carcinoma X X X X X 7 

Hepatocellular carcinoma, multiple 1 

Hepatoceilular adenoma X X X XX X 11 

Hepatoeellular adenoma, multiple X X X 3 

Mesentery + 1 

Pancreas ++ + + + + + + + + + + + + + + + + + + + + + + + + 51

Salivary glands ++ + + + + + + + + + + + + + + + + + + + + + + + + 51 

Stomach, forestomach ++ + + + + + + + + + + + + + + + + + + + + + + + + 51 

Squamous cell papilloma 2 

Stomach, glandular ++ + + + ÷ + + + + + + + + + + + + + ++ + + + + + 50 

Tooth +++ ++ + +++ ++ + + 26 

Cardiovascular System 

Blood vessel ++ + + + + + + + + + + + + + + + + + + + + + + + + 50 

Heart + + + + + + + + + + + + + + + + + + + + + + + + + + 51 

Endocrine System 

Adrenal cortex ++ + + + + + + + + + + + + + + + + + + + + + + + + 51 

Subeapsular, adenoma 2 

Adrenal medulla ++ + + + + + + + + + + + + + + + + + + + + + + + + 51 

Islets, pancreatic +÷ + + + + + + + + + + + + + + + + + + + + + + + + 51 

Adenoma X 2 

Parathyroid gland ++++++++++M++++M+M++++ +++ + ~ 

Adenoma X 1 

Pituitary gland ++++I +++++++M++++++++ + ++ ++ ~ 

Thyroid gland ++ + + + + + + + + + + + + + + + + + + + + + + + + 51 

Follicular cell, carcinoma X 1 

General Body System 

Tissue NOS 3 

Genital System 

Coagulating gland + 1 

Epididymis ++ + + ÷ + + + ÷ + + + ÷ ~ ÷ + I + + + + ÷ + + + + 50 

Preputial gland ++ + + ÷ ÷ + + ÷ + + + ÷ + ÷ + + + + + ÷ ÷ + + + + 51 

Prostate + + + ++ + + + + + + + + + + + + + + + + + + + + + 51 

Seminal vesicle ++ + + + + + + + + + + + + + + + + + + + + + + + + 51 

Testes ++ + + + + + + + + + + + + + + + + + + + + + + + + 51 

Interstitial cell, adenoma X 1 
206 t-Butylhydroquinone, NTP TR 459 

TASLE C2 ...... 

Individual Animal Tumor Pathology of Male Mice in the 2.Year Feed Study'of t-Butylhydroquinone: 5,000 ppm (continued) 

1556666667777.777777777777 

• Number of Days on Study 78911238-82222222222222222 

195458008777~7777777777777 

2212211221111112222222222 

Carcass ID Number 2083299308888890000001233: 

447487329245699035.6780335 

Hematopoietic System 

Bone marrow ++ + + + + + + + + + + + + + + + + + + + + + + + 

Hema~giosarcoma X 

Lymph node + + 

Lymph node, mandibular ++++++++++++++++++++++++.4 

Lymph node, mesenteric ++ + + + + + + + + + + + + + • + + + + + + + + + 

Spleen ++ + + + + + + + + + + + + + + + + ++ + + + + + 

Thymus +++÷I MI I M+++ ~+++++ ++++++ + 

Integumentary System 

"Mammary gland MMMMMMMMMMMMMMMMMMMMMMMMM 

Skin ++ + + + + + + + + + + + + + + + + + + + + + + + 

Musculoskeletal System ,, ̧ . 

Bone ++ + + + + + + + + + + + + + + + + + + + + + + +~ 

Skeletal muscle + 

Nervot~t System 

Brain ++ + + + + + + + + + + + + + + + + + + + + + + + 

Spinal cord + + 

Respiratory System 

Lung ++ + + + + + + + + + + + + + + + + + + + + + + + 

~Alveolar/bmnchiolar adenoma X X X X X 

Alveolar/bmnchiolar carcinoma X 

Alveolar/bronchiolar carcinoma, multiple X 

Hepatocellular carcinoma, metastatic, liver 

Nose ++ + ÷ + + + + + + + + + + ÷ + + + + + + + + ÷ + 

Trachea ++ + + + + + + + + + + + + + + + + + + + + + + + 

Special Senses System 

Ear -4-

External ear, histiocytic sarcoma X 

Harderian gland + 

Adenoma X 

Urinary System 

Kidney +÷ + + ÷ ÷ + ÷ + + + ÷ ÷ ÷ + ÷ ÷ + ÷ + + + + + ÷ 

Urinary bladder ÷+ + + + ÷ ÷ + + + + + ÷ + + + + + ÷ + ÷ + + ÷ + 

Systemic Lesions ,. 

Multiple organs 

Histiocytic sarcoma 

Lymphoma malignant ~: .. . , ..... 

.. ̧ 
g-~uty~hydroqu~none, NTIP, T]g 4S9 207 

TABLE C2 

~a~avaduan An~m~ Tumor I?atho~ogy of MaRe Mice ~n the 2-Ye~ Feed Study of t-~uty]hydroqu~n0rae: 5,000 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 7 

Number of Days on Study 222222222222222222222222.-22 

78888888888888899999999999 

21111112222222222222222222 Total 

Carcass ~D Number 48999991122222211111233333 Tissues/ 

08025687801256712456906789 Tumors 

Hematopoietic System 

Bone marrow ++ + +.+ + + + + + + + + + + + + + + + + + + + + + 51 if ̧ 

Hemangiosarcoma 1 

Lymph node + 3 i 

Lymph node, mandibular ++ + + + + + + + + + + + + + + + + + + + + + + +,+ 51 i

++ + + + + + + + + + + + + + + + + + + + + + + + + 

Spleen ++ + + + + + + + + + + + + + + + + + + + + + + + + 

Lymph node, mesenteric 51 i 

51 i 

Thymus +++MM+++++++++++M++++ + +M+ + 42 

~ntegumentary System 

Mammary gland MMMMMMMMMM +MMMMMMMM + MMMMMM 2 

Skin ++ + + + + + + + + + + + + + + + + + + + + + + + + 51

Mnsculoskeletal System 

Bone ++ + + + + + + + + + + + + + + + + + + + + + + + + 51 1 

Skeletal muscle 1 i 

Nervous System 

Brain ++ + + + + + + + + + + + + + + + + + + + + + + + + 51 '

Spinal cord 2 

Respiratory System 

Lung ++ + + + + + + + + + + + + + + + + + + + + + + + + 51

Alveolar/bmnchiolar adenoma X X X X 9 

Alveolar/bronchiolar carcinoma X X X 4 

Alveolar/bronchiolar carcinoma, multiple X 2 

Hepatocellular carcinoma, metastatic, liver X 1 

Nose ++ + + + + + + + + + + + + + + + + + + + + + + + + 51

Trachea ++ + + + + + + + + + + + + + + + + + + + + + + + + 51 

Special Senses System 

Ear 

External ear, histiocytic sarcoma 

Harderian gland + + 

Adenoma X X 

Urinary System 

Kidney ++ + + + + + + + + + ~ + + + + + + + + + + + + + + 

Urinary bladder ++ + + + + + + + + + + + + + + + + + + + + + + + + 51 

Systemic Lesions 

Multiple organs ++ + + + ÷ + + + + + + + + + + + + + + + + + + + + 51

Histiocytic sarcoma 1 .. ~ Lymphoma malignant X 
208 t-Butylhydroquinone, NTP TR 459 

TABLE C3 

Statistical Analysis of Primary Neoplasms in Male Mice in the 2-Year Feed Study of t-Butylhydroquinone 

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

Adrenal Cortex: Adenoma 

• Overall rate a 1/50 (2%) 4/50 (8%) 1/50 (2%) 2/51 (4%) 

Adjusted1 rate b 2.6% 8.7% 2.7% 4.8% 

Termimd rate c 1/39 (3 %) 4/46 (9%) 1/37 (3%) 2/42 (5%) 

First incidence (days) 727 (I) 727 (T) 727 (T) 727 (1) 

Life table test d P=0.592N • P=0.233 P=0.750 P=0.526 

Logistic regression test d P=0.592N P=0.233 P=0.750 P=0.526 

Coehran-Armita~e test d P=0.588N 

Fisher exact test u P=0.181 P=0.753N P=0.508 

Harderian Gland: Adenoma 

Overall rate 3/50 (6%) 8/50 (16%) 4/51 (8%) 3/51 (6%) 

Adjusted rate 7.7 % 17.4% 10.5% 7.0% 

Termiml rate 3•39 (8 %) 8/46 (17%) 4/38 (11%) 2/42 (5%) 

First incidence (days) 727 (T) 727 (T) 727 (T) 688 

Life table test P=0.331N P=0.159 P=0.486 P=0.631N 

Logistic regression test P=0.351N P=0.159 P=0.486 P=0.661N 

Cochran-Armitage test P=0.325N 

Fisher exact test P=0.100 P=0.511 P=0.652N 

Harderian Gland: Adenoma or Carcinoma 

Overall rate 3/50 (6%) 8/50 (16%) 6/51 (12%) 3/51 (6%) 

Adjusted rate 7.7% 17.4% 15.8% 7.0% 

Termimtl rate 3/39 (8%) 8/46 (17%) 6/38 (16%) 2/42 (5%) 

First inc, idence (days) 727 (T) 727 (T) 727 (T) 688 

Life table test P=0.367N P=0.159 P=0.228 P=0.631N 

Logistic regression test P=0.389N P=0.159 P=0.228 P=0.661N 

Cochran-Armitage test P=0.360N 

Fisher exact test P=0.100 P=0.254 P=0.652N 

Intestine, Small (Jejunum): Carcinoma 

Overall rate 0/50 (0%) 1/50 (2%) 3/51 (6%) 0/51 (0%) 

Adjust1 rate 0.0% 2.2% 7.3% 0.0% 

Termimd rate 0/39 (0%) 1/46 (2%) 2/38 (5%) 0/42 (0%) 

First incidence (days) __e 727 (T) 654 --

Life table test P=0.632N P=0.533 P=0.123 --

Logistic regression test P=0.628N P=0.533 P=0.124 --

Cochran-Armitage test P =0.627N 

Fisher exact test P=0.500 P=0.125 

Liver: Hepatocellular Adenoma 

Overall rate 2g/50 (56%) 22/50 (44%) 22/51 (43%) 14/51 (27%) 

Adjusted rate 

Termi~d rate 

60.6% 

21/39 (54%) 

47.8% 

22/46 (48%) 

53.2% 

19/38 (50%) 

31.7% 

12/42 (29%) 

First incidence (days) 

Life table test 

595 

P=0.005N 

727 (T) 

P=0.050N 

409 

P=0.208N 

630 

P=0.004N " 

Logistic.. regression test P=0.004N P=0.144N' P=0.147N P=0.004N 

Cochrma-Armitage test 

Fisher exact test 

P=0.003N 

P=0.159N P=0.137N P=0.003N 
t-~mynhydroquinone, NT~, TS ~9 

TABLE C3 

Stafisfic~n Ananys~s of ~'r~m~ry Neo#mms in Mane Mice in the 2-'Year Feed Study of t-~utylhydroquinone (6ontinued) 

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

Liver: Hepatocellular Carcinoma 

Overall rate 8•50 (16%) 11/50 (22%) 12/51 (24%) 8/51 (16%) 

Adjusted rate 19.1% 22.8% 26.0% 17.6% 

Terminal rate 6/39 (15%) 9/46 (20%) 6/38 (16%) 5/42 (12%) 

First incidence (days) 619 619 409 615 

Life table test ~ P=0.490N P=0.437 P=0.225 P=0.566N 

Logistic regression ~st P=0.370N P=0.248 P=0.342 P=0.585N 

Cochran-Armitage test P=0.465N 

Fisher exact test P=0.306 P=0.243 Pf0.590N 

Liver: Hepa/ocelluinr Aflenoma or Carcinoma 

Overall rate 31/50 (62%) 28/50 (56%) 29/51 (57%) 17/51 (33%) 

Adjusted rate 65.8% 58.3% 63.8% 37.7% 

Terminal rate 23/39 (59%) 26/46 (57%) 22/38 (58%) 14/42 (33%) 

First incidence (days) 595 619 409 615 

Life table test P=0.006N P=0.126N P=0.480N P=0.005N 

Logistic regression test P=0.002N P=0.369N P=0.341N Pf0.004N 

Cnchran-Armitage test P=0.002N 

Fisher exact test P = 0.342N P = 0.373N P=0.003N 

Liver: Hemangiosarcoma 

Overall rate 3/50 (6%) 1/50 (2%) 1/51 (2%) 2/51 (4%) 

Adjusted rate 7.1% 2.2% . 2.6% 4.3% 

Terminal rate 2/39 (5 %) 1/46 (2%) 1/38 (3%) 1/42 (2%) 

First incidence (days) 595 727 (T) 727 (T) 589 

Life table test P=0.471N P=0.262N P =0.317N P =0.478N 

Logistic regression test P=0.423N P=0.379N P=0.278N P=0.446N 

Cochran-Armitage test P=0.465N 

Fisher exact test P=0.309N P=0.301N Pf0.491N 

Lung: Alveolar/bronchiol~r Adenoma 

Overall rate .12/50 (24%) 10/48 (21%) 9/51 (18%) 9/51 (18%) 

Adjusted rate 28.1% 22.0% 22.1% 20.1% 

Terminal rate 9/39 (23%) 9/44 (20%) 7/38 (18%) 7/42 (17%) 

First incidence (days) 647 619 619 589 

Life table test P=0.266N P=0.304N P=0.344N P=0.272N 

Logistic regression test P=0.250N P=0.466N P=0.312N P=0.295N 

Cochran-Armitage test P=0.245N 

Fisher exact test P=0.447N P=0.294N P=0.294N 

Lung: Alveolar/bronchiolar Carcinoma 

Overall rate 3/50 (6%) 5/48 (I0%) 3/51 (6%) 6/51 (12%) 

Adjusted rate 7.0% II.0% 7.2% 13.3% 

Terminal rate 1/39 (3 %) 4/44 (9%) 1/38 (3%) 4/42 (10%) 

First incidence (days) 651 654 666 595 

Life table test P=0.242 P--0.418 P=0.648 P=0.266 

Logistic regression test P=0.279 P=0.279 P=0.630N P=0.271 

Cnchran-Armitage test P=0.252 

Fisher exact test P=0.335 P=0.652N P=0.254 
210 t-Butylhydroquinone, NTP TR 459 

TABLE C3 " ' 

Statistical Analysis of PrimaryNeoplasms in Male Mice in the 2-Year Feed Study of t-Butylhydroquinone (continued) 

'. 0 ppm 1,250 ppm 2,500 ppm 5,000 ppm 

, . 

Lung: Alveolar/bronchiolar'Adenoma or Carcinoma 

Overalll rate 15/50 (30%) 15/48 (31%) 11/51 (22%) 14/51 (27%) 

Adjusted rate 33.7% 32.4% 26.3% 30.0% 

Termir~al rate 10/39 (26%) 13/44. (30%) 8/38 (21%) 10/42 (24%) 

First incidence (days) 647 619 619 589 

Life table test P=0.394N ~ P=0.450N P=0.286N P=0.445N 

Logistic regression test P=0.371N P=0.483 P=0.237N P=0.459N 

Cochran-Armitage test P=0.361N 

Fisher exact test P=0.534 P=0.229N P=0.475N 

Spleen: Hemangiosarcoma 

Overall rate 4/50 (8%) 1/50 (2%) 0/51 (0%) 0/51 (0%) 

AdjusteA rate 9.7% 2.2% 0.0% 0.0% 

Terminal rate 3/39 (8%) 1/46 (2%) 0/38 (0%) 0/42 (0.%) 

First incidence (days) 647 727 (T) -- --

Life table test P=0.020N P=O.144N P=0.068N P=0.O60N 

Logistic regression test P=0.019N P=0.190N P=0.060N P=0.060N 

Cochran-Armitage test P=0.O19N 

Fisher exact test P=0.181N P=0.056N P=0.056N 

All Organs: Hemangiosarcoma 

Overall rate 7/50 (14%) 3/50 (6%) 2/51 (4%) 2/51 (4%) 

Adjusted rate 15.8% 6.5% 5.3% 4.3% 

Terminal rate 4/39 (10%) 3/46 (7%) 2/38 (5%) 1/42 (2%) 

First incidence (days) 595 727 (T) 727 (T) 589 

Life table test P =0.058N P=0.120N P=0.093N P=0.081N 

Logistic regression test P=0.040N P=0.242N P=0.061N P=0.055N 

Cochran-Armitage ~st P=0.052N 

Fisher exact test P=0.159N P=0.075N P=0.075N 

All Organs: Hemangioma or Hemangiosarcoma 

Overall rate 9/50 (18%) 3/50 (6%). 3/51 (6%) 2/51 (4%) 

Adjusted rate 20.6% 6.5% 7.9% 4.3% 

Terminal rate 6/39 (15%) 3/46 (7%) 3/38 (8%) 1/42 (2%) 

First incidence (days) 

Life table test 

595 

P=0.023N 

727 (T) 

P=0.041N 

727 (T) 

P=0.073N 

589 

P=0.027N 

Logistic regression test P=0.017N P=0.095N P=0.052N P=0.019N 

Cochran-Armitage test P=0.020N 

Fisher exact test P=0.061N ' P=0.056N P=0.024N 

All Organs: Malignant Lymphoma (NOS) 

Overall rate 4/50 (8%) 2/50 (4%) 6/51 (12%) 3/51 (6%) 

Adjusted rate 

Termi~ml rate 

i0.3% 

4/39 (10%) 

4.3% 

2/46 (4%) 

14.9% 

4/38 (11%) 

7.1% 

3/42 (7%) 

First incidence (days) 

Life table test 

727 (T) 

P=0.547N 

727 (T) 

P=0.264N 

673 

P=0.356 

727 (T) 

P=0.459N 

Logistic regression test P=0.568N P=0.264N P=0.353 P=0.459N 

Cochran-Armitage test 

Fisher exact test 

P=0.541N 

P=0.339N P=0.383 P=0.489N 
t-Butylhydroquinone, ~TP, TR 459 2~.1 

TABLE C3 

Stat~sticaa Ananys~.s o~ Primary Neo#mrns in. Male Mice in the 2-Year-~'eed Study of t-]~utyihydroquinone (continued) 

~I 

l

t 

I 

~ 

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

All Organs: Benign Neoplasms 

Overall rate 33/50 (66%) 38/50 (76%) 32/51 (63%) 27/51 (53%) 

Adjusted rate ~ 70.0% 79.1% 74.1% 57.4% 

Terminal rate . 25/39 (64%) 36/46 (78%) 27/38 (71%) 22/42 (52%) 

First incidence (days) ~ 595 619 409 589 

Life table test P=0.063N P=0.550N P=0.557N P=0.122N 

Logistic regression test P=O.O49N P=0.209 P=O.482N P=O. 140N 

Cochran-Armitage test P=O.O36N 

Fisher exact test P=0.189 P=0.447N P=0.128N 

All Organs: Malignant Neoplasms 

Overall rate 21/50 (42%) 23/50 (46%) 25/51 (49%) 20/51 (39%) 

Adjusted rate 47.1% 46.9% 49.9% 41.4% 

Terminal rate 16/39 (41%) 20/46 (43%) 13/38 (34%) 14/42 (33%) 

First incidence (days) 595 619 409 589 

Life table test P=0.439N P=O.488N P=0.279 P=0.427N 

Logistic regression test P=0.324N P=0.337 P=0.380 P=O.450N 

Cochran-Armitage test P=O.392N 

Fisher exact test P=0.420 P=0.306 P=O.467N 

All Organs: Benign or Malignant Neoplasms 

Overall rate 39/50 (78%) 45/50 (90%) 4M51 (84%) 37/51 (73%) 

Adjusted rate 81.2% 90.0% 86.0% 75.5% 

Terminal rate • 30/39 (77%) 41/46 (89%) 31/38 (82%) 30/42 (71%) 

First incidence (days) 595 619 409 589 

Life table test P=0.253N P=0.557N Pffi0.248 P=O.288N 

Logistic regression test P ffi O. 158N P = 0.089 P ffi 0.293 P = O. 378N 

Cochran-Armitage test P=O. 136N 

Fisher exact test P=0.086 Pffi0.289 P=0.343N 

(T)Terminal sacrifice . , 

a Number of neoplasm-bearing animals/number of animals examined. Denominator is number of animals examined microscopically for adrenal gland, liver, 

lung, and spleen; for other tissues, denominator is number of animals necropsied. 

b Kaplan-Meier estimated neoplasm incidence at the end of the study after adjuslment for intercurrent mortality 

c Observed incidence at terminal kill 

d Beneath the control incidence are the P values associated with the trend test. Beneath the exposure group incidence are the P values corresponding to 

pairwise comparisons between the controls and that exposure 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. 

e Not applicable; no neop~sms in animal group 
212 t-Butylhydroquinone, NTP TR 459 

TABLE C4a 

Historical Incidence of Hepatocellular Neoplasms in Untreated Male B6C3Fi Mice a 

Adenoma 

Incidence in Controls 

Carcinoma Adenoma 

or Carcinoma 

OveraJI Historical Incidence 

Tottl 

Standard deviation 

Ravage 

344/I,316 (26.1%) 

13.2 % 

4 % -60 % 

220/1,316 (16.7%) 

7.2 % 

3 % -29 % 

50911,316 (38.7%) 

13.9 % 

10 % -68 % 

a Data as of 17 June 1994 

TABLE C4b 

Historical Incidence of Spleen Hemangiosarcoma in Untreated Male B6C3Fi Mice a 

Incidence in Controls 

Overell Historical Incidence 

Total 

Standard deviation 

Range 

28/1,302 (2.2%) 

2.7 % 

0%-8% 

a Data as of 17 June 1994 

TABLE C4c 

Historical Incidence of Hemangioma and Hemangiosarcoma in Untreated Male B6C3F 1 Mice a, 

Hemangioma 

Incidence in Controls 

Hemanglosarcoma Hemangioma or 

Hemangiosarcoma 

Overall Historical Incidence 

Total 

Statndard deviation 

Range 

7/1,324 (0.5%) 

I. 1% 

0%-3% 

68/I,324 (5.1%) 

4. 1% 

0%-16% 

75/I ,324 (5.7%) 

3.9% 

0%-16% 

a . D~ta as of 17 June 1994 
t-Bu~nhydroqu~none, NT~, T~ 459 213 

TABLE C5 

Summary of the ]Incidence of Nonneop~ast~c Lesions ~n M~de Mice ~n the 2-~e~r ~eed S~u~y o~ t-~uty~hydroqu~none a 

0 ppm i,250 ppm 2,500 ppm 5,000 ppm 

Disposition Summary 

Animals initially in study 60 60 60 60 

15-Month interim evaluation 10 10 9 9 

Early deaths 

] Accidental death i 

Moribund 6 3 7 7 

I Natural deaths 4 1 6 2 

Survivors 

Terminal sacrifice 39 46 38 42 

Animals examined microscopically 60 60 60 60 

15-Month ffngerim Evaluation 

Alimentary System 

Liver (10) (10) (9) (9) 

Basophilic focus 2 (20%) 

Clear cell focus 2 (22%) 

Fatty change,.focal I (10%) 1 (11%) 

Hematopoietic cell proliferation 1 (11%) 

Mixed cell focus 1 (11%) 

Necrosis, focal 1 (10%) 

Mesentery (1) 

Fat, necrosis 1 (100%) 

Pancreas (10) (10) (9) (9) I

I Atrophy, focal ~ 1 (11%) 

Tooth (1) (1) (2) 

Incisor, dysplasia 1 (100%) 1 (100%) 2 (100%) 

Endocrine System 

Adrenal cortex (10) (10) (9) (9) 

Cyst 1 (10%) 

Subcapsular, hyperplasia 1 (10%) 2 (22%) 

Islets, pancreatic (10) (10) (9) (9) 

Cyst 1 (11%) 

Parathyroid gland (I0) (10) (8) (9) 

Cyst 1 (10%) 

Pituitary gland (9) (10) (8) (8) 

Cyst 1 (13%) 

Thyroid gland (I0) (10) (9) (9) 

Degeneration, cystic, focal 1 (10%) 

Fibrosis, focal 1 (10%) 

Genital System 

Preputial gland (10) (10) (9) (8) 

Degeneration, cystic 2 (20%) 1 (11%) 

Seminal vesicle (10) (10) (9) (9) 

Inflammation, chronic 1 (10%) 

Testes (10) (10) (9) (9) 

Granuloma sperm 1 (10%) 

a Number of animals examined microscopically at the site and the number of animals with lesion 
214 t-Butylhydroquinone, NTP TR, 459 

TABLE C5 

Smnnlary of theIncidence of Nonneoplastic Lesions in Male Mice in the 2-Year Feed Study of t-Butylhydroqu~inone :.. 

(continued) 

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

• 

15-Month Interim Evaluation (continued) 

Hematopoietie System 

Spleen (10) 

Hematopoietie cell proliferation 

Thymus (9) 

Cyst 

(10) 

(10) 

(9) 

(9) 

1 (11%) 

(9) 

2 (22%) 

(9) 

lnteg~anentary System 

Skin 

Alopeeia 

(10) (10) (9) (9) 

1 (11%) 

Respiratory System 

Lung 

Alveolar epithelium, hyperplasia 

(10) 

I (10%) 

(10) (9) 

1 (11%) 

(9) 

Systems Examined With No ILesions Observed 

Cardiovascular System 

General Body System 

Musculoskeletal System 

Nervous System 

Special Senses System 

Urinary System 

2-Year Study 

Alimentary System 

Intestine small, jejunum 

Perforation 

Peyer's patch, hyperplasia, lymphoid 

Intcstine small, ileum 

Peyer's patch, hyperplasia, lymphoid 

Liver 

Angieetasis 

Basophilic focus 

Clear cell focus 

Clear cell focus, multiple 

Cyst 

Eosinophilio focus 

Eosinophilic focus, multiple 

Fatty change 

Fatty change, focal 

Hematopoietie cell proliferation 

Hepatodiaphragmatic nodule 

Infiltration cellular, mixed cell 

Inflammation, focal 

Mixed cell focus 

Mixed cell focus, multiple 

Necrosis, focal 

Pigmentation, focal 

Thrombosis 

(50) 

(49) 

(50) 

2 (4%) 

3 (6%) 

4 (8%) 

2 (4%) 

7 (14%) 

1 (2%) 

1 (2%) 

6 (12%) 

I (2%) 

1.(2%) 

2 (4%) 

5 (10%) 

1 (2%) 

1 (2%) 

1 (2%) 

(50) 

2 (4%) 

(49) 

(50) 

1 (2%) 

2 (4%) 

3 (6%) 

,4 (8%) 

4 (8%) 

1 (2%) 

8 (16%)- 

1 (2%) 

8 (16%) 

I (2%) 

(48) 

1 (2%) 

1 (2%) 

(49) 

(51) 

2 (4%) 

5 (10%) 

2 (4%) 

4 (8%) 

1 (2%) 

5 (10%) 

1 (2%) 

4 (8%) 

2 (4%) 

(50) 

1 (2%) 

(49) 

1, (2%) 

(51) - • 

1 (2%) 

5 (10%) 

3 (6%) 

1 (2%) 

1 (2%) 

3 (6%) 

1 (2%) 

3 (6%) 

4 (8%) 

3 (6%) 

1 (2%) 
• t-~utylhy~troquinone, IWYP, TS 459 . -

TABLE C5 

Statuary of the Incidence of Nouneo 

(continued) 

2- ~" ear Sgudy (continued) 

Alimentary System (continued) 

Liver (continued) 

Bile duct, hyperplasia 

Centrilobular, necrosis 

Oval ceil, hyperplasia 

Mesentery 

Inflammation, chronic 

Artery, inflammation, chronic 

Fat, necrosis 

Pancreas 

Atrophy, diffuse 

Atrophy, focal 

Duct, cyst 

Stomach, forestomaeh 

Edema 

Erosion 

Inflammation, chronic 

Epithelium, hyperplasia 

Stomach, glandular 

Edema 

Erosion 

Mineralization 

Pigmentation, focal 

Epithelium, hyperplasia, cystic 

Tooth 

Incisor, dysplasia 

Cardiovmcular System 

Heart 

Inflammation, chronic, focal 

Artery, degeneration 

Artery, inflammation, chronic 

Endocrine System 

Adrenal cortex 

Accessory adrenal cortical nodule 

Cyst 

Cytoplasmic alteration, focal 

Fibrosis 

Subcapsular, hyperplasia, focal 

Islets, pancreatic 

Hyperplasia 

Parathyroid gland 

Cyst 

Pituitary gland 

Angieetasis 

Cyst 

2~5 

flastic Lesions in Male Mice in the 2-Year Feed Study of t-~utylhydroquinone 

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

(50) (50) (51) (51) 

1 (2%) 

1 (2%) 

1 (2%) 

(2) (7) ' (14) (1) 

1 (14%) 3 (21%) 

1 (50%) 1 (7%) 

5 (71%) 6 (43%) 1 (100%) 

(49) (50) (51) (51) 

1 (2%) 1 (2%) 

1 (2%) 

1 (2%) 2 (4%) 

(49) (50) (51) (51) 

1 (2%) 

1 (2%) 1 (2%) 

3 (6%)~ 2 (4%) I (2%) 

4 (8%) 2 (4%) 1 (2%) 

(49) (50) (51) (50) 

! (2%) 

I (2%) I (2%) 

l (2%) 1 (2%) 

1 (2%) 

1 (2%) 

(28) (26) (18) (26) 

28 (100%) 26 (100%) 18 (100%) 26 (100%) 

(50) (50) (51) (51) 

2 (4%) 

1 (2%) 

1 (2%) 

(50) (50) (50) (51) 

3 (6%) 1 (2%) 2 (4%) 

1 (2%) 

1 (2%) 3 (6%) 2 (4%) 

1 (2%) 1 (2%) 

5 (10%) 4 (8%) 6 (12%) 8 (16%) 

(50) (50) (51) (51) 

1 (2%) 1 (2%) 

(49) (46) (50) (44) 

2 (4%) 1 (2%) 

(46) (42) (45) (49) 

1 (2%) 

1 (2%) 2 (5%) 2 (4%) 3 (6%) 
216 t-Butylhydroquinone, NTP TR 459 

TABLE C5 

Summary of the Incidence of,Nonneoplastic Lesions in Male Mice in the 2-Year Feed Study of t-Butylhydroquinone 

(continued) 

2-Year Study (continued) 

Endocrine System (continued) 

Thyroid gland 

Degeneration, cystic, focal 

C-cell, hyperplasia 

Follicle, hypertrophy, focal 

Follicular cell, hyperplasia 

Generali Body System 

Tissue NOS 

Pelvic, inflammation, chronic 

Genital System 

Coagulating gland 

Inflammation, chronic 

Epididymis 

Sperrnatocele 

Preputial gland 

Degeneration, cystic 

Inflanumtion, chronic 

Prostate 

Inflammation, chronic, focal 

Epithelium, hyperplasia, focal 

Semimd vesicle 

Inflan~ation, chronic 

Testes 

Fibrosis 

Miner, dization, focal 

Thrombosis 

Artery, inflammation, chronic 

Germinal epithelium, degeneration 

Hematopoietic System 

Bone marrow 

Angiec.tasis 

Hyperplasia 

Myelofibrosis 

Lymph node 

Bronctdal, hyperplasia 

Iliac, hemorrhage 

Ingu~al, hyperplasia 

Inguir~l, hyperplasia, lymphoid 

Ingu~l, pigmentation 

Mediastinal, hyperplasia 

Mediastinai, hyperplasia, lymphoid 

Renal, hemorrhage 

Lymph node, mandibular 

Hype~lasia, lymphoid 

0 ppm 

(50) 

6 (12%) 

1 (2%) 

6 (12%) 

(4) 

(50) 

(50) 

22 (44%) 

8 (16%) 

(49) 

1 (2%) 

(50) 

(50) 

(50) 

l (2%) 

I (2%) 

(3) 

2 (67%) 

1 (33%) 

(48) 

1,250 ppm 

.(50) 

5 00%) 

I (2%) 

12 (24%) 

(6) 

(50) 

(49) 

28 (57%) 

5 (1o%) 

(50) 

(50) 

(50) 

1 (2%) 

1 (2%) 

(50) 

I (2%) 

(3) 

1 (33%) 

I (33%) 

1 (33%) 

l (33%) 

(48) 

1 (2%) 

2,500 ppm 5,000 ppm 

(50) (51) 

6 (12%) 6 (12%) 

6 02%) 6 (12%) 

(3) 

2 (67%) 

(2) (I) 

I (100%) 

(51) (50) 

1 (2%) 

(50) (51) 

32 (64%) 29 (57%) 

8 (16%) 5 (10%) 

(51) (51) 

I (2%) 

2 (4%) 1 (2%) 

(51) (51) 

I (2%) 

(51) (51) 

1 (2%) 

l (2%) 

l (2%) 

1 (2%) 

(51) (51) 

(6) (3) 

1 07%) 

I (17%) 

~ (17%) 

1 (1'7%) 

(49) (51) 

1 (2%) 
g-~u~yahydroquinone, NT~, T~ 4~9 ~7 

TA~ C5 

S~n~ry o~ ~he ~ci~e~ce o~ I~lonneop~mfic Les~o~s in I~le ~ce ~n ~he ~-Y~r Feed S~y o~ t-~y~y~r~o~e 

(con~) 

2- gear Study (continued) 

,' Hematopoietic System (continued) 

Lymph node, mesenteric 

Ectasia 

Hematopoietic cell proliferation 

Hemorrhage 

Hyperplasia 

Hyperplasia, histiocytic 

Hyperplasia, lymphoid 

Sp]eeli 

Accessory spleen 

Hematopoietic cell proliferation 

Hyperplasia, lymphoid 

Thymus 

Cyst 

Integumentary System 

Skin 

Aiopecia 

Inflammation, chronic, focal 

Ulcer 

Epidermis, hyperplasia, focal 

Subcutaneous tissue, edema 

Subcutaneous tissue, mineralization, focal 

Subcutaneous tissue, necrosis, focal 

1~usculoskeletal System 

Skeletal muscle 

Mineralization, focal 

Nervous System 

Brain 

Atrophy, focal 

Respiratory System 

Lung 

Congestion 

Hemorrhage 

Hyperplasia, histiocytic 

Inflammation, chronic, focal 

Thrombosis, multiple 

Alveolar epithelium, hyperplasia 

Interstitium, edema 

Mediastinum; edema 

Nose 

Inflammation, suppurative 

Mucosa, cyst 

Mucosa, polyp, inflammatory 

Mucosa, glands, dilatation, focal 

0 ppm 

(50) 

2 (4%) 

1 (2%) 

12 (24%) 

2 (4%) 

(50) 

1 (2%) 

8 (16%) 

(44) 

4 (9%) 

(50) 

I (2%) 

2 (4%) 

1 (2%) 

I (2%) 

(2) 

1 (50%) 

(5o) 

i (2%) 

(50) 

2 (4%) 

3 (6%) 

(50) 

2 (4%) 

9 (18%) 

1,2~0 ppm 

(48) ' 

2 (4%) 

11 (23%) 

I (2%) 

3 (6%) 

(50) 

12 (24%) 

2 (4%) 

(38) 

8 (21%) 

(50) 

I (2%) 

1 (2%) 

1 (2%) 

(5o) 

(48) 

i (2%) 

2 (4%) 

4 (8%) 

i (2%) 

5 (1o%) 

(5o) 

2 (4%) 

I (2%) 

18 (36%) 

2,5~0 ppm 5,~0 ppm 

(51) (51) 

2 (4%) 

9 (18%) 9 (18%) 

1 (2%) 

I (2%) 

2 (4%) l (2%) 

(51) (51) 

17 (33%) 9 (18%) 

1 (2%) I (2%) 

(43) (42) 

4 (9%) 4 (10%) 

(51) (51) 

I (2%) 

2 (4%) 1 (2%) 

I (2%) 

(i) (1) 

(51) (51) 

(51) (51) 

I (2%) 

1 (2%) 1 (2%) 

l (2%) I (2%) 

1 (2%) 

3 (6%) 9 (18%) " 

I (2%) 

I (2%) 

(51) (51) 

1 (2%) 

lO (2o%) 9 (18%) 
218 t-Butylhydroquinone, NTP TR 459 

TABLE C5 

Summm-y of the Incidence of Nonneoplastic Lesions in Male Mice in the 2-Year Feed Study of t-Butylhydroquinone 

(continued) 

0 ppm 1,250 ppm . 

2,500 ppm ,, 5,000 ppm 

2-Year Study (continued) 

Special Senses System 

Harderim~ gland 

Hyperplasia, focal 

(3) (9) 

1 (11%) 

,(6) (3) 

Urinary System 

Ki~hey 

Cyst 

Fibrosis, focal 

Hydronephrosis 

Hyperplasia, focal 

Necrosis, focal 

Nephropathy 

Pelvis, inflammation, suppurative 

Renal tubule, dilatation, diffuse 

Renal tubule, dilatation, focal 

Renal tubule, hyperplasia, focal 

Urinat3, bladder 

Calculus microscopic observation only 

Transitional epithelium, hyperplasia 

(50) 

1 (2%) 

1 (2%) 

1 (2%) 

50 (100 % ) 

1 (2%) . 

1 (2%) 

(50) 

(50) 

I (2%) 

1 (2%) 

47 (94%) 

1 (2%) 

'1 (2%) 

(50) 

1 (2%)' 

1 (2%) 

.(5i) 

~ (2%) 

48 (94%) 

(51) 

(51) 

I (2%) 

1 (2%) 

I (2%) 

50 (98%) 

I (2%) 

• 

! (2%) 

(51) 
TA~Lg D~ 

TAILS D2 

TA~L~ D3 

TA~L~ D~a 

TAnLE D~b 

TA~L~ D5 

2~.9 

AIH~EI~I~II~ K~ 

StLrM~IAI~f OF LES~©HS ~H FEI~IALE ~CE 

~H TI~Ng ~o~EA~ FEED ST~I..I~Y 

OF ~oBILITYLHYI~I~©QINIH©HE 

Summary of the Incidence of Neoplasms in Female Mice 

in the 2-Fear Feed Study of t-~utylhydroquinone ........................... 22~ 

~ndividuaa Anhna~ Tumor Pathology of ~¢ema~e Mice 

~n the 2-Year Feed Study of t-Butyghydrroquinone ........................... 226 

Statistical Analysis of ]~rhnary Neoplasms in Female Mice 

in the 2-~fear ~¢eed Study of t-Bnty~hydroqulnone ........................... 250 

~-~stor~ca~ ]Incidence of Hepatoce~nular Neoplasms in Untreated Female ~6C3F~ IV~ice ... 25~ 

Historical Incidence of Thyroid Gland (Follicular Ce~) Adenoma 

in Untreated Female ~6C3~¢ 1 Mice ..................................... 254 

Summary of the Incidence of Nonneop~astic Lesions in Female Mice 

in the 2-Year Feed Study of t-llgutyHhydroqulnone ........................... 255 
t-l~uty~hydroquinone, ~ T]~ ~S~ .22~ 

TA~L~ D1 

Sun~nary of the l~ncidence o~ Neop~asn~s in ]~enm~e Mice in the 2-if ear Yeed SCudy of t-~uty~hydroquinone a 

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

Disposition Summm'y 

Animals initially in study 

15-Month interim evaluation 

Early deaths 

Moribund sacrifice 

Natural death 

Survivors 

Died last week of study 

Terminal sacrifice 

60 

9 

11 

2 

1 

37 

60 

8 

7 

10 

35 

60 

9 

6 

5 

40 

60 

6 

6 

5 

1 

42 

Animals examined microscopically 60 60 60 60 

.~5-Mongh Ynterim ~E~,aluation 

Alimentary System 

Liver 

Hepatoeellular carcinoma 

Hepatocellular adenoma 

(9) (8) 

1 ( 13 %) 

(9) 

1 (11%) 

(6) 

Genital System 

Ovary 

Cystadenoma 

(9) (8) (9) 

1 (11%) 

(6) 

Respiratory System 

Lung 

Alveolar/bronchiolar adenoma 

(9) 

1 (11%) 

(8) (9) (6) 

Systems Examined With No Neoplasms Observed 

Cardiovascular System 

Endocrine System 

General Body System 

Hematopoietic System 

Integumentary System 

Musculoskeletal System 

Nervous System 

Special Senses System 

Urinary System • 

2-Year Study 

Alimentary System 

Gallbladder 

Intestine large, cecum 

Intestine small, duodenum 

Leiomyosarcoma 

Intestine small, jejunum 

Intestine small, ileum 

(50) 

(51) 

(51) 

(51) 

(51) 

(50) 

(50) 

(51) 

(51) 

(51) 

(47) 

(48) 

(48) 

(48) 

(47) 

(54) 

(53) 

(53) 

1 (2%) 

(53) 

(53) 
222 t-Butylhydroquinone; NTP TR 459 

TABLe; D1 

Summaryof the Incidence of Neoplasms in Female Mice in the 2-Year Feed Study of t-Butylhydroquinone (C~ntinued) -

2-Year Study (continued) 

Alimentary System (continued) 

Liver 

Here~gioma 

Hemangiosarcoma 

Hepatoblastoma 

Hepatocellular carcinoma 

Hepatoeellular carcinoma, multiple 

Hepau~cellniar adenoma 

~ Hepatocellular adenoma, multiple 

Histiocytic sarcoma 

Mesentery 

Hepatocellular carcinoma, metastatic, liver 

Histiocytic sarcoma • 

' Squamous cell carcinoma, metastatic, stomach, 

fore;stomach 

Pancreas; 

Carcinoma 

Hepatocellular carcinoma, metastatic, liver 

Salivary glands 

Sarcoma 

- Sarcoma,metastatic, skin 

Stomach, forestomaeh 

Squamous cell carcinoma 

" Squamous cell papilloma 

Stomach, glandula r 

Cardiovascular System 

None 

Endocrine System 

Adrenal cortex 

Capsule, hepatoeellular carcinoma, 

metastatic, liver 

Adrenal medulla 

Pheochromocytoma malignant 

Pheoehromoeytoma benign 

Islets, pancreatic 

Adenoma 

Pituitary gland 

Pars distalis, adenoma 

Pars distalis, carcinoma 

Pars intermedia, adenoma 

Thyroid gland 

Follicular cell, adenoma 

General Body System 

Tissue NOS 

Pelvic, hemangiosarcoma, multiple 

. , 

f-' 

0 ppm 

(51) 

1 (2%) 

7 04%) 

I (2%) 

8 (16%) 

I (2%) 

1 (2%) 

(1o) 

(51) 

(51) 

(51) 

I (2%) 

(51) 

(51) 

(51) 

I (2%) 

(51) 

1 (2%) 

(49) 

5 (10%) 

(51) 

1 (2%) 

1,250 ppm 

(52) 

1 (2%) 

8 (15%) 

11 (21%) 

9 (i7%) 

1 (2%) 

(13) 

1 (8%) 

(52) 

1 (2%) 

(52) 

I (2%) 

I (2%) 

(52) 

I (2%) 

(52) 

~2,500 ppm 5,000 ppm 

,~ 

(51) (54) 

1 (2%) 

1 (2%) 

7 (14%) 4 (7%) 

1 (2%) 1 (2%) 

11 (22%) 4 (7%) 

5 (10%) 1 (2%) 

1 (2%) 2 (4%) 

(7) (8) 

1 (14%) 

1 (14%) 

(49) (54). 

1 (2%) 

.(51) (53) 

(51) (54) 

2 (4%) 

(49). (54)~ .: ̧ 

(51) 

(51) 

1 

• (52) 

(44) 

5 

1 

(51) 

3 

(2) 

(2%) 

(11%) 

(2%) 

(6%) 

(50) 

1 (2%) 

(51) . 

1 (2%) 

(48) 

1 (2%) 

(46) 

5 (11%) 

(50) 

2 (4%) 

(1) 

1 (100%) 

(54) 

(54) 

(54) 

(49) 

4 

i 

(54) 

5 

(8%) 

(2%) 

(9%) • 
t-Buty~hydroqu~none, ~ TR 459 223 

TA~L~ D1 

Summary of the Incidence of Neopnmmsin Female Mtice in the 2-Year Feed Study o~ t-ll~utynhydroquinone(continued) 

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

2-Yes Stady (continued) 

Genital System 

Clitoral gland (51) (52) (50) (54) 

Ovary (50) (49) (47) (50) 

Cystadenoma 2 (4%) 2 (4%) 3 (6%) 2 (4%) 

Granulosa cell tumor malignant 1 (2%) 

Histiocytic sarcoma 1 (2%) 1 (2%) 1 (2%) 

Luteoma 1 (2%) 

Teratoma NOS 1 (2%) 

Uterus (51) (52) (50) (54) 

Hemangiosarcoma 1 (2%) 

Histiocytic sarcoma 1 (2%) 1 (2%) 2 (4%) 1 (2%) 

Leiomyosarcoma 1 (2%) 

Endometrium, adenoma 1 (2%) 1 (2%) 

Endometrium, carcinoma 1 (2%) 

Endometrium, polyp stromal 3 (6%) 1 (2%) 

Hematopoietic System. 

Bone marrow (51) (52) (51) (54) 

Lymph node (7) (8) (12) (9) 

Iliac, histiocytic sarcoma 1 (14%) I (8%) 

Inguinal, histiocytic sarcoma i (13%) 

Mediastinal, hepatocellular carcinoma, 

metastatic, liver I (8%) 

Mediastinal, histioeytie sarcoma I (8%) 

Renal, hisfiocytic sarcoma I (14%) 1 (8%) 

Lymph node; mandibular (48) (52) (50) (52). 

Lymph node, mesenterie (50) (48) (49) (50) 

Hepatoeellular carcinoma, metastatic, liver 1 (2%) 

Histiocytic sarcoma 1 (2%), 1 (2%) 2 (4%) 

Spleen- (51) (52) (50) (54) 

Hemangiosarcoma 1 (2%) 

Histioeytic sarcoma 1 (2%) 1 (2%) 

Thymus •(45) (51) (47) (48) 

Histioeytic sarcoma 1 (2%) 

Integumentary System 

Mammary gland (51) (51) (51) (54) 

Carcinoma 1(2%) 

Myoepithelioma 1 (2%) 

Skin (51) (52) (51) (54) 

Basal cell carcinoma I (2%) 

Squamous cell papilloma 1 (2%) 

Subcutaneous tissue, fibrosarcoma 1 (2%) 1 (2%), 

Subcutaneous tissue, histiocytic sarcoma 1 (2%) 2 (4%) 1 (2%) 1 (2%) 

Subcutaneous tissue, sarcoma 2 (4%) 2 (4%) 1 (2%) 
224 t-Butylhydroquinone, NTP TR 459 

TABLE D1 

Sumtnary of the Incidence of Neoplasms in Female Mice in the 2-Year Feed Study of t-Butylhydroquinone (cohtinued)' 

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

2-Year Study (continued) ,. 

Musculoskeletal System 

Bone (51) (52) (51) tS ) , Osteosarcoma 1 (2%) ,, Skeletal muscle (1 ) (1) (2) 

Hepatocellular carcinoma, metastatic, liver 1 (50%) 

Nervous System 

None 

Respiratory System 

Lung (51) (52) (51) (54) 

• Alveolar/bronchiolar adenoma 2 (4%) 2 (4%) 4 (8%) 3 (6%) 

Aiveolar/bronchiolar adenoma, multiple 1 (2%) 

Aiveolar/bronchiolar carcinoma 2 (4%) 1 (2%) 

Basal cell carcinoma, metastatic, skin 1 (2%) 

Hepatoblastoma, metastatic, liver 1 (2%) 

Hepatocellular carcinoma, metastatic, liver 1 (2%) 1 (2%) 4 (8%) 2 (4%) 

Histioeytie sarcoma 1 (2%) 1 (2%) 1 (2%) 

Osteosarcoma, metastatic, bone 1 (2%) 

Sarcoma, metastatic, skin 1 (2%) 

Squamous cell carcinoma, metastatic, stomach, 

forestomach 1 (2%) 

Mediastinum, squamous cell carcinoma, 

metastatic, stomach, forestomach ! (2%) 

Special Senses System 

Harderian gland (1) (6) (l .) 

Adenoma 6 (1oo%) 1 (100%) 

Carcinoma 1 (100%) 

Urinary System 

Kidney (51) (52) (50) (53) 

Histiocytic sarcoma 1 (2%) 1 (2%) 1 (2%) 

Sqnamous cell carcinoma, metastatic, stomach, 

forestomach 1 (2%) 

Urinary bladder (51) (51) (50) (53) 

Histiocytic sarcoma 1 (2%) 

Systelnic Lesions 

Multiple organs b (51) (52) (51) (54) 

Hisfiocytie sarcoma 2 (4%) 2 (4%) 3 (6%) 4 (7%) 

Lymphoma malignant 3 (6%) 9 (17%) 10 (20%) 8 (15%) 

Lymphoma malignant mixed 1 (2%) 
: ~ ~ -i 

! 

t-Su~y~hydroquinoue, NTP T~ ~L~9 :~:~ 

i 

i 

i 

TABLE D1 i : 

S~nn~ry o~ the lI~cidence o~ Neoplasms in ~¢e~m~e Mice ~ the 2-~fe~r I~¢eed Study of t-~utyihydroquinone (continued) i

! 

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

Neoplasm Summary 

Total animals with primary neoplasms ¢ 

15-Month interim evaluation 

2-Year study 

Total primary neoplasms 

15-Month interim evaluation 

2-Year study 

Total animals with benign neoplasms 

15-Month interim evaluation 

2-Year study 

Total benign neoplasms 

15-Month interim evaluation 

2-Year study 

Total animals with malignant neoplasms 

15-Month interim evaluation 

2-Year study 

Total malignant neoplasms 

15-Month interim evaluation 

2-Year study 

Total animals with metastatic neoplasms 

2-Year study 

Total metastatic neoplasms 

2-Year study 

Total animals with uncertain neoplasms --

benign or malignant 

2-Year study 

Total uncertain neoplasms 

2-Year study 

1 

32 

" 1 

46 

1 

22 

1 

25 

18 

21 

2 

2 

1 

41 

1 

61 

26 

34 

1 

22 

I 

27 

3 

6 

2 

36 

2 

71 

2 

25 

2. 

42 

22 

29 

6 

12 

33 

49 

19 

25 

22 

23 

3 

3 

1 

1 

i ̧: 

a 

b 

c 

Number of animals examined microscopically at the site and the number of animals with neoplasm 

Number of animals with any tissue examined microscopically 

Primary neoplasms: all neoplasms except metastatic neoplasms 
226 t-Butylhydroquinone, NTP TR 459 

TABLED2 

Individual Animal Tumor Pathology of Female" Mice in the 2-Year Feed Study 0f t-Buty!hydroquinone: 0 ppm 

4555 66666667777777777777 

Number of Days on Study 6568 1112677"233333333333"3 

1072 78927373444444444444 

22222 22222222222222222222 

Carcass ID Number 76864 68467578455555689999 • 

23718 96187214545678610347 

Alimentary System 

Esophagus +++++++ + + + + + + + + + + + + + + + + + + 

+ + + + + "+ + + + + + + + + + + + .+ 

+++++++ +'+ + + + + + + + + + + + + + + + +" 

Gallbladder +A+++++ 

Intestine large, colon 

Intestine large, rectum +++++++ + + + + + + + + + + + + + + + + ~ + 

+++++++ + + + + + + + + + + + + + + + + + • Intestine large, cecum 

Intestine small, duodenum +++++++ + + + + + + + + + + + + + + + + + +

+++++++ + + + + + + + + + + + + + + + + + +~ 

"+++++++ + + + + • + + + + + + + + + + + + + Intestine small, jejunum 

Intestine small, ileum .: 

Liver ++++++~ + + + + + + ~ + + + + + + + + + + + 

Hernangiosarcoma X .. 

Hepatocellular carcinoma X X ~X X 

Hepatocellular carcinoma, multiple 

Hepatocellular adenoma X X .XXX 

Hepatocellular adenoma, multiple 

Histioeytic sarcoma X 

Mesentery + + + + + +

+++++++ + + + + + + + + + + + + + + + + + + Pancreas 

+++++++ + + + + + + + + + + + + + + + + + + Salivary glands 

+++++++ + + + + + + + + + + + + + + + + + + Stomach, forestomach 

Squamous cell papilloma 

+++++++ + + + + + + + + + + + + + + + + + + Stomach, glandular • . 

Cardiovascular System 

Blood vessel +++++++ + + + + + + + "+ + + + + + + M + + +"

Heart +~+++++ + + + + + + + + + + + + + + + + + +

Endocrine System 

Adrenal +++++++ + + + + + + + + + + + + + + + + + + cortex 

Adrenal medulla +++++++ + + + + + + + + + + + + + + + + + +

Pheochromocytoma benign X 

+++++++ + + + + + + + + + + + + + + + + + + Islets, :pancreatic 

Adenoma X 

+ + + + +'+ + + + + + + + + + + + + Parath.groid gland ++++M++ 

Pituitary gland +++++++ + + + + + + + + + + + + +M+ + + + 

Pars distalis, adenoma X X X 

+++++++ ~ + + + +~ + + + + + + + + + + + + Thyroid gland 

Follicular cell, adenoma X 

General Body System 

None 

+: Tissue examined microscopically M: Missing tissue X: Lesion present 

A: Autolysis precludes examination I: Insufficient tissue Blank: Not examined 
t-Butylhydroquinone, NTP TR.459 227 

TABLE D2 

lI~dividua~ Animal Tumor ]?atho~ogy ,of ]~ema~e l~dI~ce ~ the 2-V~ear ~eed Study of t-~uty~hydroqu~no~e: O ppm (continued) i 

777 "777 ~ 77777" 77777777777777 

Number of Days on Study 33333333333333333333333333 

45555555555555666666666666 

. . . . 

22222222222223222222222222 Total i 

Carcass ~D Number ~ 4444455889990566677777788 Tissues/ I

~ : 

83467901581560924503456902 ~mors 1 

i 

Alimentary System" 

Esophagus ++ + + + + + + + + + + + + + + + + + + + + + + + + 51 

i ~: i 

Gallbladder ++ + + + + + + + + + + + + + + + + + + + + + + + + 50 i 

Intestine large, colon ++ + + + + + + + + + + + + + + + + + + + + + + + + 51 ~ 

Intestine large, rectum +++M++++++++++++++ ++++ ++÷ + 50 

Intestine large, cecum + + + + + + + + + + + +i+ + .+ + + + + + + + + + + + 51 ! 

Intestine small, duodenum ++ + • + + + + + + ~ + + + + + + + + + + + + + + + 51 [ : 

Intestine small, jejunum +,+ + + + + + + + + + + + + + + + + + + + + + + + + 51 ~ 

Intestine small, ileum + + + + + + + + + + + + + + + + + + + + + + + + + + 51 ! 

Liver ++ + + + + + + + + + + + + + + + + + + + + + + + + 51 ~ 

Hemangiosarcoma 

Hepatocellular carcinoma X X X 

1 

7 i i ) 

Hepatocellular Carcinoma, multiple 1 ! 

Hepatocellular adenoma 

Hepatocellular adenoma, multiple 

X X X 8 

1 

i 

Histiocytic sarcoma 1 i 

Mesentery + + + + ~o i ~ 

Pancreas ++ ~ + + + + + + + + + + + + + + + + + + + + + + + 51 i 

Salivary glands ++ + + + + + + + + + + + + + + + + + + + + + + + + 51 i 

Stomach, forestomach ++ + + + + + + + + + + + + + + + + + + + + + + + + 51 

Squamous cell papilloma , X 1 

Stomach, glandular ++ + + + + + + + + + +~+ + + + + + + + + + + + + + 51 : ; 

Cardiovascular System 

Blood vessel + + + + + + + + + + + + + + + + + + + + + + + + + + 50 

Heart + + + + + + + + + + + + + + + + + + + + + + + + + + 51 

Endocrine System 

Adrenal cortex ++ + + + + + + + + + + + + + + + + + + + + + + + + 51 

Adrenal medulla ++ + + + + + + + + + + + + + + + + + + + + + + + + 51 

Pheochromocytoma benign 1 

Islets, pancreatic ++ + + + + + + + + + + + + + + + + + + + + + + + + 51 

Adenoma 1 

Parathyroid gland +++M+++++MM+++++++M+ +++ ++ + 46 

Pituitary gland +++++I ++++++++++++++ +++ ++ + 4~9 

Pars distalis, adenoma X X 5 

Thyroid gland ++ ++ + + ++++ + ++ + + + + + + + + + + + + + 51 

Follicular cell, adenoma -1 

General Body System ~ 

None 
228 t-Butylhydroquinone, NTP TR 459 

TABLED2 

Individual Animal Tumor Pathology of Female Mice in the 2-Year Feed Study of t-Butylhydroquinone: 0 ppm (continued) 

3455566666667777777777777 

Number of Days on Study 6656811126772333333333333 

4107278927373444444444444 

2222222222222222222222222 

Carca~;s ID Number 7686468467578455555689999 

2371896187214545678610347 

Genital System 

Clitoral gland + + + + + + + + + + + + + + + + + + + + + + + + + 

Ovary + + + + + + + + + + + + + + + + + + + + + + + + + 

Cystadenoma X 

Histi~ocytic sarcoma X 

Luteoma 

Uterus ++ + + + + + + + + + + + + + + + + + + + + + + + 

Hemangiosarcoma 

Hisfiocytic sarcoma X 

Endometrium, adenoma 

Endometrium, carcinoma 

Hematopoietic System 

Bone marrow ++ + + + + + + + + + + + + + + + + + + + + + + + 

Lymph node + + ++ + + + 

Iliac, histiocytic sarcoma X 

Remtl, histiocytic sarcoma X 

Lymph node, mandibular ++ + + + + + + + + + + +M+ + + + + + + + + + + 

Lymph node, mesenteric +~ + + + + + + + + + + + + + + + + + + + + + + + 

Histiocytic sarcoma X 

Spleen ++ + + + + + + + + + + + + + + + + + + + + + + + 

Histiocytic sarcoma X 

Thymus +++I MMM+++I +M++++++++ +++ + 

Integumentary System 

Manmutry gland ++ + + + ++ + + + + + + ~ + + ++ + + + + + + + 

++ + + + + + + + + + + + + + + + + + + + + + + + 

Basal cell carcinoma X 

Subcutaneous tissue, histiocytic sarcoma 

Subcutaneous tissue, sarcoma X X 

Skin 

Musculoskeletal System 

Bone ++ + + + + + + + + + + + + + + + + + + + + + + + 

Skeletal muscle + 

Nervous System 

Brain ++ + + + + + + + + + + + + + + + + + + + + + + ÷ 

Spinal ~:ord + + 

Respiratory System 

Lung ÷~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ÷ ÷+ ÷ ÷ ÷ • ~ ~ ÷ • ÷ • ÷ 

Alveolar/bronchiolar adenoma 

Alveolar/bronchiolar adenoma, multiple X 

Alveolar/bronchiolar carcinoma X X 

Basal cell carcinoma, metastatic, skin X 

Hepatocellular carcinoma, metastatic, liver X 

Nose ~ ~ ÷ ÷ ÷ • ÷ ~ • • ÷ • • • • • • ÷ • • ÷ • • • • 

Trachea ÷~ ÷ ÷ ÷ ~ ~ ÷ • • ÷ • ÷ • ÷ • • ÷ • • • • ÷ ÷ •
( 

t-Butynhydroquhaone, NT]? TR 459 229 

TA~L~ D2 

lhadiv~du,~d Anhnal Tunnor ]Pathology of ]~ema~e l~ce in the 2-Year ~¢ee~ Study o~' t-~uty~hydroquhaone: 0 ppm (continued) 

77777.777777777777777777777 • 

Number of Days on Study 33333333333333333333333333 

45555555555555666666666666 [ 

22222222222223222222222222 Total 

Carcass ~D Number 94444455889990566677777788 Tissues/ 

834 67 9015815 60 92 45 03 4 5 6 9 0 2 ~mors 

Genital System i 

Clitoral gland ++ + + + + + + + + + + + + + + + + + + + + + + + + 

Ovary +++++M+++++++++++++++ +++++ 50 i 

Cystadenoma X 2 i , 

Histioeytic sarcoma 

Luteoma X 

1 

1 

!

i

i 

Uterus ++ + + + + + + + + + + + + + + + + + + + + + + + + 51 • ~ 

Hemangiosarcoma X 1 i 

Histiocytic sarcoma 1 

Endometrium, adenoma X 1 

Endometrium, carcinoma X 1 i 

i 

Hematopoietic System 

Bone marrow + + ÷ + + + + + + + + + + + + + + + + + + + + + + -I- 51 

Lymph node 7 

lilac, histiocytic sarcoma 1 

Renal, histiocytic sarcoma I 

Lymph node, mandibular +M+++++++++++++++++M++ + ++ + 48 

Lymph node, mesenteric +++++++++M++++++++ +++++ ++ + 50 

Histiocytic sarcoma 1 

Spleen ++ + + + + + + + + + + + + + + + + + + + + + + + + 51 

Histiocytic sarcoma 1 

Thymus + + + + + + + + + + + + + + + + + + + + + + + + + + 45 

Integumentary System 

Mammary gland ++ + + + + + + + + + + + + + + + + + + + + + + + + 51 

Skin ++ + + + + + + + + + + + + + + + + + + + + + + + + 51 

Basal cell carcinoma 1 

Subcutaneous tissue, histiocytie sarcoma X 1 

Subcutaneous tissue, sarcoma 2 

Musculoskeletal System 

Bone ++ + + + + + + + + + + + + + + + + + + + + + + + + 51 

Skeletal muscle 1 

Nervous System 

Brain ++ + + + + + + + + + + + + + + + + + + + + + + + + 51 

Spinal cord 2 

Respiratory System 

Lung ++ + + + + + + + + + + + + + + + + + + + + + + + + 51 

Alveolar/bronchiolar adenoma X X 2 

Alveolar/bronehiolar adenoma, multiple 1 

Alveolar/bronchiolar carcinoma 2 

Basal cell carcinoma, metastatic, skin 1 

Hepatocellular carcinoma, metastatic, liver 1 

Nose + + + + + + + + + + + + + + + ÷ + + + + + + + + + + 51 

Trachea + + + + + + + + + + + + + + + + + + + + + + + + + + 51 
230 t-Butylhydroquinone, NTP TR ~i59 

TABLE D2 

Individual AnimalTumor Pathology of Female Mice in the 2-Year Feed Study of t-Butyihydroquinone: 0 ppm (continued) 

3455566666667777777777777 

Number of Days on Study 6656811126772333333333333 

4107278927373444444444444 

2222222222222222222222222 

Carcass ID Number 7686468467578455555689999 

2371896187214545678610347 

Special Senses System 

Ear 

Lacrinud gland + 

Urinary System 

Kidney ++ + + + + + + + + + + + + + + + + + + + + + + + 

Histiocytic sarcoma X 

Urinary bladder ++ . 

+ + + + + + + + + + + + + + + + + + + + . + + + 

Systemic Lesions 

Multiple organs 

Histiocytic sarcoma X 

Lymphoma malignant X X 
: t-BuCylhydroqu~none, NTP TR 459 2,3~ 

TABLE D2 

]Indiv~dua~ An~naaH Tumor Pathology of l~emale 1V~ce ~u the 2-Year Feed Study of t-Suty~hydroqu~none:. 0 pprn (continued) 

77777777777777777777777777 

Number of Days on Study 33333333333333333333333333 

45555555555555666666666666 

222 22 2222 2 2 2 23 2 2 2 2 2 2 2 22 2 2 2 Toml 

Carcass ID Number 94444455889990566677777788 Tissues/ 

83 4 67 9015 815 60 92 45.03 4 5 6 9 02 ~mo~ 

Special Senses System 

Ear 1 

Lacrimal gland 1 

Urinary System 

Kidney +++ ++++++++++ ++++ + ++++ ++ ++ 51 

Histiocytic sarcoma 1 

Urinary bladder ++ + + + + + + + + + + + + + + + + + + + + + + + + 51 

Systemic Lesions 

Multiple organs + + + + + + + + + + + + + + + + + + +, + + + + + + + 51 

Histiocytic sarcoma X 2 

Lymphoma malignant X 3 
232 t-Butylhydroquinone, NTP TR 459 

TA~: D2 

Individual Animal Tumor Pathology of Female Mice in the 2-Year Feed Study of t-Butylhydroquinone: 1,250 ppm 

334455566666677777"7777777 

Number of Days on Study 6969069122569012233333333 

5994328233487.605944444444 

3333333333333333333333333 

CarcassID Number 5344501623531142400000123 

3042448096010554613689128 

Alimentary System 

Esophagus ++ + + + + + + + + + + + + + + + + + + + + + + + 

Gallbladder + + + + + + + + ++ +A + + + + + + + + + + + + + 

Intestine, large, colon +++ + + +'+ + + + + + +A + + + + + + + + + + + 

Intestine large, rectum ++ + + + + + + + + + + +A + + + + + + + + + + + 

Intestine: large, cecum ++ + ++ + + + ++ + +MA + + + + + + + + + + + 

Intestine small, duodenum ++ + + + + + + + + + + +A + + + + + + + + + + + 

Intestine small, jejunum ++ + + + ++ + + + + + +A + + + + +÷ + + + + + 

Intestine small, ileum ++ + + + + + + + + + + +A + + + + + + + + + + + 

Liver ++ + + + + + + + + + + + + + + + + + + + + + + + 

Hemangioma X 

Hepatocellular carcinoma X X X X X X X 

• Hepatocellular adenoma X XX X 

Hepatocellular adenoma, multiple X X X 

Histiocytic sarcoma X 

Mesentery + + +++++ + + 

Squamous cell carcinoma, metastatic, 

stomach, forestumach X 

Pancreas + + + + + + + + + + + + + + + + + + + + + + + + + 

Carcinoma 

Salivary glands ÷÷ ÷ ÷ + ÷ ÷ ÷ + + ÷ + + ÷ + ÷ + + + ÷ + ÷ ÷ + + 

Sarcoma X 

Sarcoma, metastatic, skin X 

Stomach, forestomach + + + + + + + + + + + + + + + + + + + + + + ++ + 

Sqm~ous cell carcinoma X 

Stomach, glandular + + + + + + + + + + + + + + + + + + + + + + + + + 

Tooth + +

Cardiovascular System 

Blood vessel + + + + + + + + + + + + + + + + + + + + + + + + + 

Heart + + + + + + + + + ~ + + + + + + + + + + + + + + + 

Endocrine System 

Adrena]~ cortex + + + + + + + + + + + + + + +M+ + + + + + + + + 

Adrenal medulla ++ + + + + + + + + + + + + +M+ + + + + + + + + 

Pheochromocytoma benign 

Islets~ pancreatic ÷÷ ÷ ÷ + + ÷ ÷ + ÷ + ÷ + + + + + ÷ + ÷ + ÷ + + ÷ 

Parathyroid gland +M+++++++++++ +++++++++++ + 

Pituitary gland +++M+++M+++++++MI + ++ ++ +++ 

Pars distalis, adenoma X 

Pars distalis, carcinoma X 

+ + + + ÷ ÷ + + + + + + + + + + + ÷ + + + ÷ + ÷ + Thyroid gland 

Follicular cell, adenoma X X 

General Body System 

Tissue NOS 
i L ....... : ............ =~ 

t-l~uty~hydroquinone, NT~ TR ~9 233 

TABL~ D2 

]Ind~v~duan Au~a~ Tumor ?athonogy o~' Female Mice in the 2-'~'ear Feed Study o? t-li~utylhydroqu~uoue: L250 ppm 

(continued) 

777777777777777777777777777 

Humber of Days on Study 333333333333333333333333333 

444445555555555556666666666 

333333333333333333333333333 Total 

Carcass ID Number 555550111123333452222234444 Tissues/ 

' 1 5 6 8 9 2 3 4 6 7 8 2 3 4 5 9 2 0 1 3 5 6 9 0 1 3 7 ~mors 

Alimentary System 

Esophagus + + + + +++++++ + + + + + + + + + + + + + + + + 52 

Gallbladder +M+ + +++++++ + + + + + + + + + + + + + + + + 50 

Intestine large, colon + + + + +++++++ + + + + + + + + + + + + + + + + 51 

Intestine large, rectum + + + + +++++++ + + + + + + + + + + + + + + + + 51 

Intestine large, cecum + + + + +++++++ + + + + +~+ + + + + + + + + + + 50 

Intestine small, duodenum +++ + +++++++ + + + + + + + + + + + + + + + + 51 

Intestine small, jejunum + + + + +++++++ + + + + + + + + + + + + + + + + 51 

Intestine small, ileum + + + + +++++++ + + + + + + + + + + + + + + + + 51 

Liver + + + + +++++++ +++++++++++4.++++ 52 

Hemangioma 1 

Hepatocellular carcinoma X 8 

Hepatocellular adenoma X X X X X X X II 

Hepatocellular adenoma, multiple X X X X X X 9 

Histiocytic sarcoma 1 

Mesentery + + + + 13 

Squamous cell carcinoma, metastatic, 

stomach, forestomach 1 

Pancreas +++ + + + + + + + + + + + + + + + + + + + + + + + + 52 

Carcinoma X 1 

Salivary glands +++ + + + + + + + + + + + + + + + + + + + + + + + + 52 

Sarcoma 1 

Sarcoma, metastatic, skin I 

Stomach, forestomach +++ + + + + + + + + + + + + + + + + + + + + + + + + 52 

Squamous cell carcinoma I 

Stomach, glandular +++ + + + + + + + + + + + + + + + + + + + + + + + + 52 

Tooth 2 

Cardiovascular System 

Blood vessel + + + + + + + + + + + + + + + + + + + + + + + + + + + 52-

Heart +++++++++++++++++++++++++++ 52 

Endocrine System 

Adrenal cortex +++ + ++ + + + + + + + + + + + + + + + + + + + + + 51 

Adrenal medulla +++ + + + + + + + + + + + + + + + + + + + + + + + + 51 

Pbeochromocytoma benign X I 

Islets, pancreatic ++ + + + + + + + + + + + + + + + + + + + + + + + + + 52 

Parathyroid gland +++++++++++++++M+M+++++ ++++ 49 

Pituitary gland +++++++++M+++M++M++++++M+ ++ 44 

Pars distalis, adenoma XX X X 5 

' Pars distalis, carcinoma 1 

Thyroid gland ÷ ++ + ++ ÷ ++ 4- ++ 4- 4- 4- 4. 4. 4. 4- 4- 4- I 4- 4- 4- 4- 4- .4- 4. 4- 4- 51 

Follicular cell, adenoma X 3 

General Body System 

Tissue NOS 4- 4. 
234 t-Butylhydroquinone, NTP TR 459 

TABLE D2 

Individual Animal Tumor Pathology of Female Mice in the 2-Year Feed Study of t-Butylhydroquinone: 1,250 ppm 

(continued) 

3344555666666777777777777 

Number' of Days on Study 6969069122569012233333333 

5994328233487605944444444 

3333333333333333333333333 

Carcass ID Number 5344501623531142400000123 

3042448096010554613639128 

Genital System 

Clitoral gland +++ + + + + + + + + + + + + + + + + + + + + + + 

Ovary ++++++ ++++++MM+ + +++ ++ + + ++ 

Cystadenoma X X 

Histiocytic sarcoma X 

Uterus + + + + + + + + + + + + + + + + + + + + + + + + + 

Histiocytic sarcoma X 

He~atopoietic System 

Bone marrow + + + + + + + + + + + + + + + + + + + + + + + + + 

Lymph nixie + + ++ + + 

Inguinal, histiocytic sarcoma X 

Lymph n~e, mandibular + + + + + + + + + + + + + + + + + + + + + + + + + 

Lymph nixie, mesenterie +++M+++++++++~+M+ +++ +++++ 

Lymph nnde, mediastinal + 

Spleen +++ + + + + + + + + + + + + + + + + + + + + + + 

Histi~:ytic sarcoma X 

Thymus +++M+ + + + + + + + + + + + + + + + + + + + + 

Integumentary System 

Mammary gland + + + + + + + + + + + + + + + + + + + + + + + + 

Skin ++ + + + + + + + + + + + + + + + + + + + + + + + 

Subcutaneous tissue, histiocytic sarcoma X X 

Subcutaneous tissue, sarcoma X 

Musculoskeletal System 

Bone + + + + + + + + + + + + + + + + + + + + + + + + + 

Skeletal muscle + 

.. . 

Nervous System 

Brain + + + + + + + + + + + + + + + + + + + + + + + + + 

Peripl~eral nerve + + 

Spinal cord + + + 

Respiratory System 

Lung 

Alveolar/bronchiolar 'adenoma X X 

Hepatocellular carcinoma, metastatic, liver X 

Histiocyt[c sarcoma X 

Squamous cell carcinoma, metastatic, 

stomach, forestomac h X 

Mediastinum, squamous cell carcinoma, 

~netastatic, stomach, forestomach X 

Nose 

Trachea 
t-~utylhydroquinone, NTP TR 4S9 235 

TA~L~ D2 

~ndiv~dual Anhna~ Tumor Pathologyof Female Mice ~n the 2-Xfear Feed Study of t-Buty~hydroqu~none: 1,250 ppm 

(continued) 

777777777777777777777777777 

Number of Days on Study 333333333333333333333333333 

444445555555555556666666666 

333333333333333333333333333 Total 

Carcass ~D Number 555550111123333452222234444 Tissues/ 

156892346782345920135 690137 ~mors 

Genital System 

Clitoral gland +++ + + + + + + + + + + + + + + + + + + + + + + + + 52' 

Ovary M+++++++++++++++++++++++++ + 49 

Cystadenoma 

Histiocytie sarcoma 1 ! " 

Uterus + + + + + + + + + + + + + + + + + + + + + + + + + + + 52 !i 

Histiocytic sarcoma I ~ 

Hematopoietic System 

Bone marrow +++ + + + + + + + + + + + + + + + + + + + + + + + + 52 

Lymph node + + 

Inguinal, histiocytic sarcoma 1 ~ 

• Lymph node, mandibular +++ + + + + +'+ + + + + + + + + + + + + + + + + + + 52 

Lymph node, mesenteric M+++++++++++ ++++++++M+ +++++ 48 

Lymph node, mediasdnal i 

Spleen +++ + + + + + + + + + + + + + + + + + + + + + + + + 52 

Histiocytic sarcoma 1 

Thymus +++ + + + + + + + + + + + + + + + + + + + + + + + + 51 

Integumentary System 

Mammary gland +++ + + + + + + + + + + + + + + + + + + + + + + + + 51 

Skin +++ + + + + + + + + + + + + + + + + + + + + + + + + 52 

Subcutaneous tissue, histiocytic sarcoma 2 

Subcutaneous tissue, sarcoma X 2. 

Musculoskeletal System 

Bone + ++ + + + + + + + + + + + + + + + + + + + + + + + + 52 

Skeletal muscle 1 

Nervous System 

Brain + + + + + + + + + + + + + + + + + + + + + + + + + + + 52 ' 

Peripheral nerve 2 

Spinal cord 3': ,,, 

Respiratory System 

Lung 52 

Alveolar/bronchiolar adenoma 2 

Hepatocellular carcinoma, metastatic, liver 1 

Histiocytic sarcoma 1 

Squamous cell carcinoma, metastatic, 

stomach, forestomach 1 

Mediastinum, squamous cell carcinoma, 

metastatic, stomach, forestomach 1 

Nose 52 

Trachea 52 
236 t-Butylhydroquinone, NTP TR 459 

TABLE D2 

Individual Animal Tumor Pathology 

(continued) 

Number' of Days on Study 

Carcass ID Number 

Special Senses System 

Harderian gland 

Carcinoma 

Urinary System 

Kidney 

Hisdocytic sarcoma 

Sqnamous cell carcinoma, metastatic, 

stomach, forestomach 

Urinary bladder 

Systemic Lesions 

Multiple organs 

• Histiocyfic sarcoma 

Lymphoma malignant 

Lymphoma malignant mixed 

of Female Mice in the 2-Year Feed Study of t-Butylhydroquinone: 1,250 ppm 

3344555666666777777777777 

6969069122569012233333333 

5994328233487605944444444 

3333333333333333333333333 

5344501623531142400000123 

3042448096010554613689128 

+++ + + + + + + + + + + + + + ~ + + + + + + + + 

X 

X +++ + + + + + + + + + + + + + + + + + + + + + + 

X X 

XXX X X 

X 
t-~u~ylhydroqu~none, NTI? T~ 459 237 

T~BL~ D2 

lIradividu~d Anianai Tumor lPathoiogy of ~emaie IV~I~ce in the 2-Year ~'eed Study of t-~uty~hydroqu~none: L250 ppm 

(continued) 

777777777'777777777777777777 

Number of Days on Study 333333333333333333333333,333 

444445555555555556666666666 

333333333333333333333333333 Total 

Carcass ~ Number 555550111123333452222234444 Tissues/ 

156. 892346782345920135690137 ~mo~ 

Special Senses System 

Harderian gland + 1 

Carcinoma X 1 

Urinary System 

Kidney + + + + + + + + + + + + + + + + + + + + + + + + + + + 52 

Histiocytic sarcoma 1 

Squamous cell carcinoma, metastatic, 

stomach, forestomach 1 

Urinary bladder + + + + + + + + + + + + + + + + + '+ + + + + + M + + + 51 

Systemic Lesions 

Multiple organs , ++++++++++++++++++~+++ + ++ ++ 52 

Histiocytic sarcoma 2 

Lymphoma malignant XX X X 9 

Lymphoma malignant mixed : 1 ' 
238 t-Butylhydroquinone; NTP TR 459 

TABLE: D2 

Individual Animal Tumor Pathology of Female Mice in the 2-Year Feed Study of t-Butylhydroquinone~ ~ 2;500 ppm 

2455666677777777777777777 

Number of Days on Study 854515671223333333333333"3 

8685814683444444444444445 

3344344434333333333333443 

Carcass ID Number 9810801190866666667789017 

2343927300412357890206764 

Alimentary System 

Esophagus M+++++~+++++++++ + +++ ++ + + + 

Gallbladder +A++ +A +A + ++++M++++++ + +++ + 

Intestine large, colon. +A+A +A ÷++ +++++++++ +++ + + + + 

Intestine large, rectum +A+A +A ++++++++++ + + ++ + ++ + + 

Intestine large, cecum +A+A +A +++ ++ ++++++ + ++ + + ++ + 

Intestine small, duodenum + A + A +A + + + + + + + + + + + + + + + + + + + 

Intestine small, jejunum +A+A +A + + + + + + + + + + + + + + + + + + +' 

Intestine small, ileum +A+A +A ++A ++++++++ + ++ + ++ + + 

Liver + + + + + + + + + + + + + + + + + + +. + + + + + + 

Hepatoblastoma 

Hepatocellular carcinoma X X X X X • " 

Hepatocellular carcinoma, multiple X 

Hepatocellular adenoma X X X X X 

Hepatocellular adenoma, multiple X 

Histiocytic sarcoma X 

Mesente~ry + + + + + 

Hepatocellular carcinoma, metastatic, liver X 

Histincytic sarcoma X 

Oral mucosa + 

Pancreas : +A+++A ++++++++ ++ +++ + ++ +++ 

.Hepatocellular c~rcinoma, metastatic, liver X ~ 

Salivary glands° ++ + + + + + + + + + + + + + + + + + + + + + + + 

Stomach, fo'fe~tomach + + + + + + +.+ + + + + + + + + + + + + + + + + + 

Stomach, glandular +A + + +A + + + + + + + ÷ + +~+ + + + + + + + + 

Tooth + + + • 

Cardiovascular System 

Blood vessel + + + + + + + + + + + + + + + + + + + + + + + + + 

Heart ++ + + + + + + + + + + + + + + + + + + + + + + +

Endocrine System 

Adrenal cortex + + + + +A + + + + + + + + + + + + + + + + + + + 

.o Capsule, hepatocellular carcinoma, 

metastatic, liver X 

Adrenal medulla ++ + + + + + + + + + + + +-+ + + + + + + + + + + 

/Phec~hromoc~toma malignant X 

Islets, pancreatic +A + +A + + + ++ + + + + + + + + + + + + + + 

Adenoma 

Parathyroid gland + + + + +.+ + + + + + + + + + + + + + + + + + + + 

Pituitary gland +M++I ++M++ + + + + + + + ++ + + + +I + 

Pars distalis, adenoma X 

Thyroid gland ++ + + + + + + + + + + + + + + + + + + + + + + + 

Follicular cell, adenoma X 
t-~utynhydroquinone, NTIP TR 459 239 

TABLE D2 

iKndiv~dua~ Anhna~ Tumor 1Pathology o~ lFem~de Mice in the 2-'treat Feed Study of t-Buty]hydroquiuone: 2,500 ppm, 

(continued) 

777777 77777777777777777777 

Number of Days on Study 333333 33333333333333333333 

555555 55555666666666666666 

, 33333344444333333333444444 Total 

Carcass~Nmber 7777.780011288899999900011-1 Tissues/ 

5 6 7 8 9 2 5 6 5 9 0 5 6 7 3 4 5 7 8 9 1 4 9 0 1 2 ~mors 

Alimentary System 

Esophagus +++ + + + + + + + + + + + + + + + + + + + + + + + 50 

Gallbladder +++ + + + + + + + + + + + + + + + + + + + + + + + 47 

Intestine large, colon +++ + + + + + + + + + + + + + + + + + + +.+ + + + 48 

Intestine large, rectum ++ + + + + + + + + + + + + + + + + + + + + + + + +, 48 

Intestine large, cecum +++ + + + + + + + + + + + + + + + + + + + + + + + 48 

Intestine small, duodenum ++ + + + + + + + + + + + + + + + + + + + + + + + + 48 

Intestine small, jejunum +++ + + + + + + + + + + + + + + + + + + + + + + +. • 48 

Intestine small, ileum +++ + + + + + + + + + + + + + + + + + + + + + + + 47 

Liver +++ + + + + + + + + + + + + + + + + + + + + + + + 51 

Hepatoblastoma X 1 

Hepatoeellular carcinoma X X 7 

• Hepatocellular carcinoma, multiple 1 

Hepatocellular adenoma X XXX X X . 11 

Hepatocellular adenoma, multiple X X X X 5 

Histioeytie sarcoma 1 

Mesentery + ÷ 7 

. Hepatocellular carcinoma, metastatic, liver 1 

Histiocyfi¢ sarcoma 1 

Oral mucosa 1 

Pancreas +++ + + + + + + + + + + + + + + + + + + + + + + + 49 

Hepatocellular carcinoma, metastatic, liver 1 

Salivary glands + + + + + + + + + + + + + + + + + + + + + + + + + + 51 

Stomach, forestomach + + + + + + + + + + + + + + + + + + + + + + + + + + 51 

Stomach, glandular + + + + + + + + + + + + + + + + + + + + + + + + + + 49 

Tooth + 4 

Cardiovascular System 

Blood vessel ++ + + + + + + + + + + + + + + + + + + + + + + + + 51 

Hean +++ + • + + + + + + + + + + + + + + + + + + + + + 51 

Endocrine System 

Adrenal cortex +++ + + + + + + + + + + + + + + + + + + + + + + + 50 

Capsule, hepatocellular carcinoma, 

metastatic, liver 1 

Adrenal medulla +++ + ++ + + ++ + + + + + + + + + + + + + + + + 51 

Pheoehromoeytoma malignant 1 

Islets, pancreatic +++ + + + + + + + + + + + + + + + + + + + + + + + .48 

Adenoma X 1 

Parathyroid gland +++ ++++ +M+M++++++++++++ ++ + 49 

Pituitary gland +++ + + + + + + +M+ + + + + + + + + + + + + + + 46 

Pars distalis, adenoma X X XX 5 

Thyroid gland ++++++++M++++ ++++++++ +++ ++ 50 

Follicular cell, adenoma X 2
240 t-Butylhydroquinone, NTP TR 459 

TABLE: D2 

Individual Animal Tumor Pathology 

(continued) 

Number of Days on Study 

Carcass ID Number 

General Body System 

Tissue NOS 

Pelvic, hemangiosarcoma, multiple 

Genital System 

Clitoral gland 

Ovary 

Cystadenoma 

Granulosa cell tumor malignant 

Histiocytic sarcoma 

Uterus 

Histiocytic sarcoma 

Endometrium, adenoma 

Endometrium, polyp stromal 

Hematopoietic System 

Bone marrow 

Lymph node 

Iliac, histiocytic sarcoma 

Mediastinal, hepatocellular carcinoma, 

,metastatic, liver 

Mediastinal, histiocytic sarcoma 

Renal, histiocytic sarcoma 

Lymph node, mandibular 

Lymph node, mesenteric 

Hepatocellular carcinoma, metastatic, liver 

Histiocytic sarcoma 

Lymph node, mediastinal 

Spleen 

Hemangiosarcoma 

Thymus 

Integmnentary System 

Mammary gland 

Myoepithelioma 

Skin 

Subcutaneous tissue, fibrosarcoma 

Subcutaneous tissue, histiocytic sarcoma 

Subcutaneous tissue, sarcoma 

Muscu]loskeletal System 

Bone 

Skeletal muscle 

Hepatocellular carcinoma, metastatic, liver 

Nervous System 

Brain 

of Female~Mice in the 2-Year Feed Study of t-Butylhydroquinone: 2,500 ppm 

24556666777777"77777777777 

8545156712233333333333333 

86858146834444'44444444445 

334 4344434333333333 ~333443 

9810801190866666667789017 

2343927300412357890206764 

+ 

X 

+++++++M+++++++++++ ++ ++++ 

+++++A ++M+~+++ ++++M+ ++ ++ ++ 

X 

X 

+++ + +A + + + + + + + + + + + + + + + + + + + 

X 

X 

+++ + + + + + + + + + ÷ + + + + + + + + + + + + 

++ + + ++ ++ + + 

X 

X 

X 

X 

+++ + +A + ++++++ + ++++ + + + + + + + 

++++ +A + + + ++ ++ +++ + + + +M+ + + + 

X '. 

x 

+ + 

+++++A ++++++÷++++++ ++++ ++ 

X 

+++M+A +++ + + + + + + + +M+ + + + + + + 

+++ + + + + + + + + + + + + + + + + + + + ÷ + + 

+++ + + + + + + + + + + + + + + + + + + + + + + 

X 

X 

X 

+++ + + + + + ++ + ++ + + + + + + ++ + + + + 

+ + 

X 

+ + + + + + + + + + + +' + + + + + + + + + + + + + 
t-~u~ynhy~roqu~none, NTP TS ~ 

T~LE D2 

][n~v~dl~a~ A~hm~a~ 'Tumor 

(continued) 

]Pathology o~ ~'ema~e IV~ce ~n the 2.'Y'ear ~'ee~ St~y o~' t-~uty~hy~roq~none: 2,5~ ppm 

77777777777777777777777777 

Number of Days on Study 33333333333333333333333333 

55555555555666666666666666 

33333344444333333333444444 Total 

Carcass ~D Number 77777800112888999999000111 

56789256590567345789149012 

Tissues/ 

~mors 

General ~ody System 

Tissue NOS 

Pelvic, hemangiosarcoma, multiple 

Genital System 

Clitoral gland 

Ovary 

• Cystadenoma 

Granulosa cell tumor malignant 

Histiocytic sarcoma 

Uterus 

Histiocytic sarcoma 

Endometrium, adenoma 

Endometrium, polyp stromal 

+++ 

+++ 

X 

+++ 

X 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ + 

+M+ 

+ + 

X 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

X 

+ 

X 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

X 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

X 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

50 

47 

3 

1 

I 

50 

2 

1 

3 

Hematopoietic System 

Bone marrow 

Lymph node 

Iliac, histiocytic sarcoma 

Mediastinal, hepatocellular carcinoma, 

metastatic, liver 

Mediastinal, hisfineytic sarcoma 

Renal, histiocytic sarcoma 

Lymph node, mandibular 

Lymph node, mesenteric 

Hepatocellular carcinoma, metastatic, liver 

Histio~ytic sarcoma 

Lymph node, mediastinai 

Spleen 

Hemangiosarcoma 

Thymus 

+++ + + + + + + + + + + + + + + + + + + 

+ 

+++ + + + + + + + + + + + + + + + + + + 

+++ + + + + + + + + + + + + + + + + + + 

+ + + + + + + + + + + + + + + + + + + + + 

++++++++++++++++++++++ 

+ 

+ 

+ 

+ 

+ 

+ + 

+ + 

+ + 

+ + 

+I 

+ + 

+ + 

+ + 

+ + 

++ 

51 

12 

1 

1 

49 

1 

2 

50 

1 

47 

i 

i 

i 

I ~ 

i 

i 

~ 

i ̧ ̧ 

i ~ 

i 

Integumentary System 

Mammary gland 

Myoepithelioma 

Skin 

Subcutaneous tissue, fibrosarcoma 

Subcutaneous tissue, histiocytic sarcoma 

Subcutaneous tissue, sarcoma 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

X 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

51 

1 

" 51 

1 

1 

1 

Musculoskeletal System 

Bone 

Skeletal muscle 

Hepatocellular carcinoma, metastatic, liver 

+ + + + + + + + + + + + + + + + + + + + + + + + + + 51 

2 

1 

Nervous System 

Brain + + + + + + + + + + + + + + + + + + + + + + + + + + 51 
242 t-Butylhydroquinone, NTP TR 459 

TABLE D2 

Individual Animal Tumor Pathology 

(continued) 

Number of Days on Study 1 

Carcass ID Number 

Respiratory System 

Lung 

Alveolar/bronchiolar adenoma 

AIveolar/bronchiolar carcinoma 

Hepatoblastoma, metastatic, liver 

Hepatocellular carcinoma, metastatic, liver 

Hisdocytic sarcoma 

Sarcoma, metastatic, skin 

Nose 

Trachea 

Special Senses System 

Eye 

Harderian gland 

Adenoma 

Urinary System 

Kidney 

Hisdocytic sarcoma 

Urinal./bladder 

Hisdocytic sarcoma 

Systemic Lesions 

Multiple organs 

His'tiocytic sarcoma 

Lymphoma malignant 

of Female Mice in the 2-Year Feed Study of t-Butylhydroquinone: 2,500 ppm 

2 g 55666677777777777777777 

8545156712233333333333333 

8685814683444444444444445 

3344344434333333333333443 

9810801190866666667789017 

2343927300412357890206.764 

+ ++ + + + + + + + + + + + + + + + + + + + + + + 

X X X 

X 

X - ++ + + + + + + + + + + + + + + + + + + + + + 

+++ + + + + + + + + +'+ + + + + + + + + + + + + 

+ 

X 

+++++A +++++ +++ ++ ++ + ++ ++ + + 

X 

+++++++ +++++++++M+ +++ + + + + 

X 

X X 

X X XXXX X 
t-Butylhydroquinone, NTP TR 459 2~3 

TABLE D2 

]Individual Anhn~d Tumor ~athonogy of ~'emaie Mice in the 2-Year Yeed Study of t-~utyihydroquinone: 2,500 pprn 

(continued) 

Number of Days on Study 

Carcass ~D Number 

Respiratory System 

Lung 

Alveolar/bronchiolar adenoma 

Alveolar/bronchiolar carcinoma 

Hepatoblastoma, metastatic, liver 

Hepatocellular carcinoma, metastatic, liver 

Histiocytic sarcoma 

Sarcoma, metastatic, skin 

Nose 

Trachea 

Special, Senses System 

Eye 

Harderian gland 

Adenoma 

Urinary System 

Kidney 

Histiocytic sarcoma 

Urinary bladder 

Histiocytic sarcoma 

Systemic Lesions 

Multiple organs 

Histiocytic sarcoma 

Lymphoma malignant 

77777777"777777777777777777 

33333333333333333333333333 

55555555555666666666666666 

33333344444333333333444444 Total 

77777800112888999999000111 Tissues/ 

56789256590567345789149012 Tumors 

+ + + + + + + + + + + + + + + + + + + + + + + + + + 51 

XX X X 4 

X 1 

X 1 

X 4 

1 

1 

++ + + + + + + + + + + + + + + + + + + + + + + + + '49 

+++ + + ++ +M+ + + + + + + + + + + + + + + + + 50 

÷ 

+ + + + + 

X X X X X 

+ + + + + + + + + + + + + + + + + + + + + + + + + + 50 

1 

+++ + + + + + + + + + + + + + + + + + + + + + + + 50 

1 

+ + + + + + + + + + + + + + + + + + + + + + + + + + 51 

X 3 

X X X 10 
244 t-Butyihydroquinone, NTP TR 459 

TAet~ D2 

Individual Animal Tumor Pathology.of Female Mice in the 2-Year Feed Study of t-Butylhydroquinone: 5,000 ppm 

0244567777777777777777777 

Number of Days on Study 891232002223333•3333333333 

2689891323844444444444444 

4444444444444444444444444 

Carc=~ ID Number 436"34475745222"22233345666 

3856588990145678901367346 

Alimentary system 

Esoplmgus ++ + + + + + + + + + + + + + + + + + + + + + + + 

Gallbladder +++ + + + + + + + + + + + + + + + + + + + + + + 

Intestine large, colon ++++A ++++'++ + + + + + + + + + + + + + + 

Intestine large, rectum +++ +A + + + + + + + + + + + + + + + + + + + + 

Intestine large, cecum +++ +A + + + + + + + + + + + + + + + + + + + + 

Intestine small, duodenum ++++A ++++++ + + + + + + + + + + + + + + 

I.~eiomyosarcoma X 

Intesth~e small, jejunum +++ +A + + + + + + + + + + + + +.+ + + + + + + 

Intestine small, ileum + + + + + + + + + + + + + + 

Liver +++ + + + ÷ + + + + + + + + + + + + + + + + + + 

Hemangiosarcoma X • 

Hepatocellular carcinoma X X 

HCl?atocellular carcinoma, multiple 

Hepatoceilular adenoma X X 

Hepatocellular adenoma, multiple X 

Histiocytic sarcoma X X 

Mesentery + + + +++ 

Pancreas +++ + + + + + + + + + + + + + + + + + + + + + + 

Salivary glands +++ + + + + + + + + + + + + + + + + + + + + + + 

Stomach, forestomach +++ + + + + + + + + + + + + + + + + + + + + + + 

Squamous cell papilloma 

Stomach, glandular ++.+ + + + + + + + + + + + + + + + + + + + + + + 

Tooth 

+++ +A + + + + + + 

Cardiiovascular System 

Blood vessel + + + + + + + + + + + + + + + + + + + + + + + + + 

Heart +++ + +++ + + ++ + + + + ~ + + + + + + + + + 

Endocrine System 

Adrenal cortex + + + + + + + + + + + + + ÷ ÷ ÷ ÷ + + + + + ÷ ÷ ÷

÷ ÷ ÷ + + + + ~ + ÷ ÷ ÷ 

Islets~pancreatic + + + + + + + + + + + + + ÷ + + + ÷ + + + + ÷ + ÷ 

Parathymidgland + + + + + + + + + + + + + ÷÷+M+M++++++ 

Pituitary gland + + + + + + + + + + + + + + + ÷ ÷ + + + + ÷ ÷M+ 

Pars distalis, adenoma X X 

Pars interrnedia, adenoma X 

Thyroid gland + + + + + + + + + + + + + + ÷ ÷ + ÷ ÷ ÷ ÷ ÷ ÷ + ÷ 

Follicular cell, ad~noma X X X 

Adrenal medulla + + + + + + + + + + + + + 

General Body System 

None 
t-Butylhydroquinone, NTP T~ ,~59 2,g5 

TABLE D2 

~ndiv~dua~ An~maH Tumor Pathology of Female l~ice in the 2-Year Feed Study of t-~uty~hydroquiuone: S,~ ppm 

(continued) 

77777777777777777777.777777777 

Number of Days on Study 33333333333333333333333 333333 

44455555555555555666666666666 

44444444444444444444444444444 Total 

Carcass ~D Number 667223 3 35 555 77777 344445 566678 Tissues/ 

78612257345601347924790801250 Tumors 

Alimentary System 

Esophagus +++++ + + + + + + + + + + + + + + + + + + ++++++ 54

Gallbladder +++++ + + + + + + + + + + + + + + + + + + ++++++ 54

Intestine large, colon +++++ + + + + + + + + + + + + + + + + + + ++++++ 53

Intestine large, rectum +÷÷ ~+ + + ÷ + ÷ + ÷ + + ÷ ÷ ÷ ÷ + + + + + + ++ + ++ 53

Intestine large, cecum ÷ ÷++ ÷ ÷ + ÷ + + ÷ ÷ ÷ + ÷ + ÷ ÷ + ÷ + + + ÷ ++ ÷+÷ 53 

Intestine small, duodenum +++++ + + + + + + + + + + + + + + + + + + ++++++ 53

Leiomyosareoma 1 

Intestine small, jejunum 53 +++ + + ÷ + ÷ + ÷ + ÷ ÷ + ÷ ÷ + + ÷ + + + + ÷÷+ ++ + 

Intestine small, ileum ÷÷+ ÷÷ + + + + ÷ + ÷ ÷ + ÷ ÷ + + + ÷ ÷ + ÷ + ++ + + + 53

Liver ++÷÷÷ ÷ + ÷ ÷ + ÷ ÷ ÷ + ÷ + ÷ ÷ + + + ÷ + + ++ ÷++ 54

Hemangiosarcoma 1 

Hepatocellular carcinoma X X 4 

Hepatocellular carcinoma, multiple 1 

Hepatocellular adenoma X 4 

Hepatocellular adenoma, multiple 1 

Histioeytie sarcoma 2 

Mesentery + + 8 

Pancreas ÷ ++ + ÷ + + + + + + ÷ + + ÷ + + ÷ ÷ + ÷ + + + +÷ +÷ + 54

Salivary glands +++++ + + + + + + ++ + + + + + + + +M+++++++ 53 

Stomach, forestomach ÷ +÷+ ÷ + ÷ ÷ + + + + + ÷ ÷ + ÷ ÷ ÷ + ÷ + ÷ + ÷+ ++ ÷ 54

Squamous cell papilloma X X 2 

Stomach, glandular ++++ + + + + ÷ + + ÷ ÷ + ÷ + + ÷ + ÷ + + + + ++ ÷ + + 54

Tooth + 1

Cardiovascular System 

Blood vessel +++++ + + + + + + + + + + + + + + + + + + ++++++ 54

Heart +++++ + + + ÷ + + + + + ÷ + + + + + + + + ++++++ 54

Endocrine System 

Adrenal cortex +++ + + + + + + + + + + + + + + + + + + + + + + + + + + 54

Adrenal medulla +++ + + + + + + + + + + + + + + + + + + + + + + + + + + 54

Islets, pancreatic + ++ + + + + + + + + + + + + + + + + + + + + + + + + + + 54 

Parathyroid gland +M+ + + M + + + + M + + + + + + + ++.4-++++.-I-+++ 49 

Pituitary gland + M + + + + + + + + + M + + + + + + + + ÷ + ÷++÷+M 49 

Pars distalis, adenoma X X 4 

Pars intermedia, adenoma 1 

Thyroid gland + + + + + + + + + + ÷ + + + + + + + + + + + + + + + + + + 54 

Follicular cell, adenoma X X 5 

General Hody System 

None 
246 t-Butylhydroquinone, NTP TR 459 

.. 

TABLE D2 

Individual Animal Tumor Pathology of Female Mice in the 2-Year Feed Study of t-Butylhydroquinone: 5,000 ppm 

(continued) 

02445677777777777777777 77 

Number of Days on Study 8912320022233333333333333 

2689891323844444444444444 

4444444444444444444444444 

Carcass ID Number 4363447574522222233345666 

3856588990145678901367346 

Genital System 

Clitoral gland +++++ + + + + + + + + + + + + + + + + + + ++ 

Ovary +++++ + + + + + + + + + + +I + + +M+ + ++ 

Cystadenoma 

Teratoma NOS X 

Uterus + ++++ + + + + + + + + + + + + + + + + + + ++ 

Histiocytic sarcoma X 

Leiomyosarcoma X 

Endometrium, polyp stromal X 

Hematopoietic System 

Bone marrow +++++ + + + + + + + + + + + + + + + + + + ++ 

Lymph node + + + + + +

Lymph node, mandibular +++++ + + + + +M+ + + + + + + + + + + + ++ 

+++++ + + + + + + + + + + + + + + ~ + + + + + Lymph node, mesenteric 

Histiocytic sarcoma X 

Spleen + ++ + + + + + + + + + + + + + + + + + + ++ + + 

Thymus ++M++M++ ++M+ + + + + +++++ ++ ++ 

Histiocytic sarcoma X 

.Integumentary System 

Mammary + ++ + + + + + + + + + + + + + + + + + + + + + + gland 

Carcinoma + ++ + + + + + + + + + + + + + + + + + + + + + + Skin 

Squamous cell papilloma X 

Sulx:utaneous tissue, fibrosarcoma X 

Sulx:utaneous tissue, histiocytic 

sarcoma X 

Musculoskeletal System 

Bone + ++ + + + ++ + + + + + + + + + + + + + + + + + 

Osteosarcoma X 

Nervous System +++ + + + + + + + + + + + + + + + + + + + + + + Brain 

Spinal cord + 

Respiratory System . 

Lung 

Alveolar/bronchiolar adenoma X X 

Hepatocellular carcinoma, metastatic, 

liver X 

Histiocytic sarcoma X 

Osteosarcoma, metastatic, bone 

Nose 

Trachea 
t-ll~utylhydroquinone, NXP TI~ 459 ~7 

TABLE D2 

3Indivldua~ An~na~ 

(continued) 

Tumor l~atho~ogy of ~emaae Mice ~n the 2-'t(earr ~eed Study of t-~utylhydroqu~none: 5,~ ppm 

•77777777777777777777777777777 

Number of Days on Study 33333333333333333333333333333 

44455555555555555666666666666 

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 1D Number • 66722333 .555577777344445 566678 

78612257345601347924790801250 

Tissues/ 

Tumors 

Genital System 

Clitoral gland 

Ovary 

Cystadenoma 

Teratoma NOS 

Uterus 

Histiocytic sarcoma 

Leiomyosarcoma 

Endometrium, polyp stromal 

+++++ + + + + + + 

+ +++++++M++ 

X 

+++++ + + + + + + 

+ 

+ 

+ + + + + + + + + + 

+++++++++++ 

X 

+ + + + + + + + + + 

+ 

+ 

++++++ 

++÷+++ 

++++++ 

54 

50 

2 

1 

54 

1 

1 

1 

Hematopoietic ~ystem 

Bone marrow 

Lymph node 

Lymph node, man~libular 

Lymph node, mesenteric 

Histiocytic sarcoma 

Spleen 

Thymus 

Histiocytic sarcoma 

+++++ 

+ 

+++++ 

+ +++I 

+++++ 

+++++ 

+ + + + + + + + + + + + + + + + + 

+ + 

+ + ++ + + + + + + + + + + + + + 

+M+M++++++++++++ 

X 

+ + + + + + + + + + + + + + + + + 

+ +M+ + + + ++ + + +M+ + +I 

+ ++++++ 

+ +M+÷++ 

+ ++++++ 

+ ++++++ 

+ ++++++ 

54 

9 

52 

50 

• 2' 

54 

48 

1 

lntegumentary System 

Mammary gland 

Carcinoma 

Skin. 

Squamous cell papilloma 

Subcutaneous tissue, fibrosarcoma 

Subcutaneous tissue, histiocytic 

sarcoma 

++ 

+~+ 

++ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

X 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+++ 

++ 

+ 

+++ 

+ ,54 

1 

54 

1 

1 

Musculoskeletal System 

Bone 

Osteosarcoma 

+ +++ + + + + + + + + + + + + + + + + + + + + ++ + ++ 54 

1 

Nervous Sys,tem 

Brain 

Spinal cord 

+ +++ + + + + + + + + + + + + + + + + 

+ 

+ + + + + + ++ + 54 

2 

Respiratory System : 

Lung 

Alveolar/bronchiolar adenoma 

Hepatocellular carcinoma, metastatic, 

liver 

Histiocytic sarcoma 

Osteosarcoma, metastatic, bone 

Nose 

Trachea 

+ 

X 

+ 

+ 

+ 

+ 

++ 

++ 

++ 

+ + 

+.+ 

+ + 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ 

+ ++ ++ 

X 

++ + ++ 

+ + + ++ 

+ 

+ 

+ 

54 

3 

2 

1 

1 

53 

54 
t-Butylhydroquinone, NTP TR 459 

TABLE D2 

Individual Animal Tumor Pathology of Female Mice inthe 2-Year Feed Study of t-Butylhydroquinone: 5,000 ppm 

(continued) 

0244567777777777777777777 

Number of Days on Study 89123200222333333333333 33 

2689891323844444444444444 

4444444444444444444444.444 

Carcass ID Number 4363447574522222233345666 

3856588990145678901.367346 

Special Senses System 

Harderian gland + 

Adenoma X 

Urinary System 

Kidney +++++ + + + + + + + + + + + + + + + + + + ++ 

Urinary lbladder +++++ + + + + + + + + + + + + + + + + + + ++ 

Systemic Lesions 

Multiple organs 

Histk~ytic sarcoma X X X 

Lymphoma malignant X X X X 

~k~ 
i 

t-~u~ynhydroquinone, N'I'P T~ 459 2,~9 ~ 

!: 

TABLE D2 

]Individual Animal Tumor Pathology o~ ~'en~ale Mice in the 2-~fear ~'eed Study o~' t-~uty~hydroquinone: S,~ ppn~ ~, (continued) 

77777777777777777777777777777 

Number of Days on Study 333333.33333333333333333 333333 

44455555555555555666666666666 

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 ~D Number 66722 333 555577777344445 566678 Tissues/ 

78612257345601347924790801250 Tumors 

Special Senses System 

Harderian gland 

Adenoma 

Urinary System 

Kidney + +++ + + + + + + + + + + + + + + + + + + ++++++ 53 

Urinary bladder + + + + + + + +'+ + + + + + + + + + + + + + M + + + + + + 53 

Systemic Lesions 

Multiple organs +++++ + + + + + + + + + + + + + + + + + + ++++++ 54 

Histiocytic sarcoma X 4 

Lymphoma malignant XX X X 8 
250 t-Butylhydroquinone, NTP TR 459 

TABLE D3 

Statistical Analysis of Primary Neoplasms in Female Mice in the.2.Year Feed Study of t-Butylhydroquinone 

0 ppm 1,250 ppm 2,500 ppm 5,000 ppm : 

Harderian Gland: Adenoma 

Overall rate a 0/51 (0%) 0/52 (0%) 6/51 (12%) 1/54 (2%) 

Adjusted rate b 0.0% 0.0% 15.0% 2.3% 

Terminal rate c 0/38 (0%) 0/35 (0%) 6/40 (15%) 1/43 (2%) 

First incidence (days) _e _ 734 (T) 734 (T) 

Life table test d P=0.294 - - P=0.020 P=0.525 

Logistic regression test a P=0.294 - - P=0.020 P=0.525 

Coch'~'an-Armita~e test d P=0.255 

Fisher exact test u ' P=0.013 P=0.514 

Harderian Gland: Adenoma or Carcinoma 

Overall rate 0151 (0%) 1/52 (2%) 6/51 (12%) 1/54 (2%) 

Adjusted rate 0.0% 2.9% 15.0% 2.3% 

'Terminal rate 0/38 (0%) 1/35 (3%) 6/40 (15%) 1/43 (2%) 

First incklenee (days) - - 734 (T) 734 (T) 734 (T) 

Life table test P=0.379 P=0.484 P=0.020 P=0.525 

Logistic regression test P=0.379 P=0.484 P=0.020 P=0.525 

Cochran-Armitage test P=0.334 

Fisher exact test P=0.505 P=0.013 P=0.514 

Liver: Hepatocellular Adenoma. 

Overall rate 9/51 (18%) 20/52 (38%) 16/51 (31%) 5/54 (9%) 

Adjusted rate 22.7 % 51.0% 37.1% 11.6% . 

Terminal rate 8/38 (21%) 16/35 (46%) 13/40 (33%) 5/43 (12%) 

First incidence (days) 582 598 555 734 (T) 

Life table test P=0.023N P = 0.008 P=0.111 P=0.135N 

Logistic regression test " P=0.027N P=0.011 P = 0.096 P=0.146N 

Cochran-Armitage test P=0.041N 

Fisher exact test P=0.016 P=0.083 P=0.165N 

Liver: Hepatocellular Carcinoma 

Overall rate 8/51 (16%) 8/52 (15%) 8/51 (16%) 5/54 (9%) 

Adjusted rate 18.4% 19.2% 17.6% 11.6% 

Terminal rate 4/38 (11%) 4/35 (11%) 4/40 (10%) 5/43 (12%) 

First incidence (days) 461 469 548 734 (T) 

Life table test. P=0.155N P=0.566 P=0.561N P=0.216N 

L0gi~tic regression test P=0.357N P =0.559N P=0.592 P =0.240N 

•Cochran-Armitage test P=O. 188N 

Fisher exact test P=0.590N P=0.607N P=0.241N 

Liver:. I-Iepatocellular Adenoma or Hepatocellular Carcinoma 

Overall rate , 17/51 (33%) 28/52 (54%) 23/51 (45%) 10/54 (19%) 

Adjusted rate 38.9 % 64.7% 48.8% 23.3% 

T6rminal rate 12/38 (32%) 20/35 (57%) 16/40 (40%) 10/43 (23%) 

First incidence (days) 461 469 548 734 (T) 

Life table-test. P=0.007N P=0.021 P=0.233 P=0,050N 

Logistic regression .test P=0.010N P=0.025 P=0.155 P=0.064N 

Coehran-Armitage test P=0.011N 

Fisher exact test P=0,028 P=0.155 P=0.065N 
t-~utylhydroquinone, NTP TR ,~59 251 

TABLE D3 

Stafistica~ Amflys~s of Primary Neop~mms ~n Female Mice in the 2-'Year Feed Study o~ t-llguty~hydroquinoue (continued) 

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

Liver: Hepatocellular Carcinoma or Hepatoblastoma 

Overall rate 8/51 (16%) 8/52 (15%) 9/51 (18%) 5/54 (9%) 

Adjusted rate 18.4 % 19.2 % 19.9% 11.6% 

Terminal rate 4/38 (11%) 4/35 (11%) 5/40 (13%) 5/43 (12%) 

First incidence (days) 461 469 548 734 (T) 

Life table test P=0.163N P=0.566 P=0.543 P=0.216N 

Logistic regression test P = 0.197N P =0.559N P=0.484 P=0.240N 

Cochran-Armitage test P=0.200N 

Fisher exact test P=0.590N P=0.500 P=0.241N 

Liver: Hepatocellular Adenoma, Hepatocellular Carcinoma, or Hepatoblastoma 

Overall rate 17/51 (33%) 28/52 (54%) 23/51 (45%) 10/54 (19%) 

Adjusted rate 38.9% 64.7% 48.8% 23.3% 

Terminal rate 12/38 (32%) 20/35 (57%) 16/40 (40%) 10/43 (23%) 

First incidence (days) 461 469 548 734 (T) 

Life table test P=0.007N P=0.021 P=0.233 P=0.050N 

Logistic regression test P=0.010N P=0.025 P=0.155 P=0.064N 

Cochran-Armitage test P =0.01 IN 

Fisher exact test P=0.028 P=0.155 P=0.065N 

Lung: Alveolar/bronchiolar Adenoma 

Overall rate 3/51 (6%) 2/52 (4%) 4/51 (8%) 3/54 (6%) 

Adjusted rate 7.9% 5.3% 10.0% 7.0% \ 

Terminal rate 3/38 (8 %) 1/35 (3%) 4/40 (10%) 3/43 (7%) 

First incidence (days) 734 (T) 706 734 (T) 734 (T) 

Life table test P=0.571N P=0.530N P=0.528 P=0.605N 

Logistic regression test P=0.567N P=0.509N P=0.528 P=0.605N 

Cochran-Armitage test P=0.528 

Fisher exact test P=0.491N P=0.500 P=0.633N 

Lung: Alveolar/bronchiolar Adenoma or Carcinoma 

Overall rate 5/51 (10%) 2/52 (4%) 5/51 (10%) 3/54 (6%) 

Adjusted rate 13.2% 5.3% 12.5% 7.0% 

Terminal rate 5/38 (13 % ) 1/35 (3%) 5/40 (13%) 3/43 (7%) 

First incidence (days) 734 (T) 706 734 (T) 734 (T) 

Life table test P=0.321N P=0.247N P=0.599N P=0.290N 

Logistic regression test P=0.311N P=0.223N P=0.599N P=0.290N 

Cochran-Armitage test P=0.381N 

Fisher exact test P=0.210N P=0.630N P=0.326N 

Ovary: Cystadenoma 

Overall rate 2/50 (4%) 2/49 (4%) 3/47 (6%) 2/50 (4%) 

Adjusted rate 5.4% 5.3% 7.9% 5.1% 

Terminal rate 2/37 (5 %) 1/34 (3%) 3/38 (8%) 2/39 (5%) 

First incidence (days) 734 (T) 654 734 (T) 734 (T) 

Life table test P=0.571N P=0.671 P=0.512 P=0.676N 

Logistic regression test P=0.586N P=0.679 P=0.512 P=0.676N 

Cochran-Armitage te~t P=0.568 

Fisher exact test P=0.684 P=0.470 P=0.691N 
-- 

-- 

-- 

252 t-Butylhydroquinone, NTP TR 459 

TABLE D3 

Statistical Analysis of Primary Neoplasms in Female Mice in the 2-Year Feed Study of t-Butylhydroquinone (continued) 

0 ppm • • : 

Pituitary Gland (Pars Distalis): Adenoma 

Overall rate 5/49 (10%) 

Adjusted rate 12.3% 

Terminal rate 3/36 (8 %) 

First incidence (days) 567 

Life table test P=0.351N 

Logistic :regression test P=0.382N 

Coehran-.Armitage test P=0.401N 

Fisher exact test 

Pituitary Gland (Pars Distalis): Adenoma or Carcinoma 

Overall rate 5/49 (10%) 

Adjusted rate 12.3 % 

Terminal rate 3/36 (8%) 

First incidence (days) 567 

Life table test P=0.310N 

Logistic :regression test " P=0.350N 

Coehran-Armitage test P=0.358N 

Fisher exact test 

Thyroid Gland (Follicular Cell): .Adenoma 

Overall rate 1/51 (2%) 

Adjusted rate 2.6% 

Terminal rate 1/38 (3%) 

First incidence (days) . 

, 734 (T) 

Life table test P=0.120 

Logistic :regression test P=0.103 

Coehran..Armitage test P=0.092 

Fisher exact test 

Uterus: Stromal Polyp 

Overall rate 0/51 (0%) 

Adjusted rate ' " 0.0% 

Terminal. rate O/38 (0%) 

First incidence (days) 

Life table test P=0.291 

Logistic regression test P=0.291 

Cochran..Armitage test P=0.262 

Fisher exact test 

All Organs: Histiocytic Sarcoma 

Overall rate 2/51 (4%) 

Adjusted rate 5.0% 

Terminal rate 1/38 (3%) 

First incidence (days) 673 

Life table test P=0.279 

Logistic regression test P=0.246 

Coehran-Armitage test P=0.238 

Fisher exact test 

• . 

1,250 ppm 

5/44(11%) 

16.1% 

5/31 (16%) 

734 (T) 

P=0.550 

P=0.554 

P=0.559 

6/44 (14%) 

18.0% 

5/31 (16%) 

598 

P=0.423 

P=0.423 

P=0.423 

3/51 (6%) 

8.0% 

2/34 (6%) 

612 

P=0.276 

P=0.300 

P =0.309 

0/52 (0%) 

0.0% 

0/35 (0%) 

.--

2•52 (4%) 

4.9% 

1i35 (3%)' 

562 • 

P=0.673 

P=0.679N 

P=0.684N 

2,500 ppm 5,000 ppm 

5/~t6 (11%) 4/49(8%) 

13.2% 10.5% 

5/38 (13%) 4/38 (11%) 

734 (T) 734 (T) 

P=0.600N P=0.465N 

P=0.593 P=0.502N 

P=0.589 P=0.500N 

5/46 (11%) 4/49 (8%) 

13.2% 10.5% 

5/38 (13%) 4/38 (11%) 

734 (T) 734 (T) 

P=0.600N P=0.465N 

P=0.593 P=0.502N 

P=0.589 P =0.500N 

2/50 (4%) 5/54 (9%) 

5.1% 11.4% 

2/39 (5%) 4/43 (9%) 

734 (T) 728 

P=0.509 P=0.137 

P=0.509 P =0.142 

P=0.492 P =0.116 

3/51 (6%) 1/54 (2%) 

7.5% 2.3% 

3/40 (8%) 1/43 (2%) 

734 (T) 734 (T) 

P=0.130 P=0.525 

P=0.130 P=0.525 

P=0.121 P=0.514 

3/51 (6%) 4/54 (7%) 

6.8% 8.5% 

1/40 (3%) 2/43 (5%) 

618 418 

P=0.526 P=0.397/ 

P=0.498 P=0.376 

P=0.500 P=0.367 
t-ll~u~y]hy~droqu~none,NTIP TII~ 4~9 2~3 

T~L~ II~3 

S~fistica] A~a~ys~s of ~hr~nary Neoplasms in ~ena~e I~,SI~ce ~n ~he 2-Year l~eed S~udy of t-~u~y~hydroqu~none (continued) 

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

All Organs: Malignant Lymphoma (Mixed or I~IOS) 

Overall rate 3/51 (6%) 9/52 (17%) ~ 10/51 (20%) 8/54 (15%) 

Adjusted rate 7.1% 22.7 % 24.3 % 18.2 % 

Terminal rate 1/38 (3%) 5/35 (14%) 9/40 (23%) 7/43 (16%) 

First incidence (days) 582 " 668 718 728 

Life table test P=0.271 P=0.061 P=0.050 P=0.150 

Logistic regression test P=0.217 P=0.063 P=0.041 P=0.122 

Cochran-Armitagetest P=0.190 

Fisher exact test P=0.065 P=0.036 P =0.119 

All Organs: Benign Neoplasms 

Overall rate 23/51 (45%) ' 26•52 (50%) 27/51 ,(53%) 19/54 (35%) 

Adjusted rate 54.3 % 63.1% 59.7 % 43.2 % 

Terminal rate 19138 (50%) 20/35 (57%) 22/40 (55%) 18/43 (42%) 

First incidence (days) 567 598 288 728 

Life table test P=0.060N P=0.244 P=0.367 P=0.137N 

Logistic regression test P =0.106N P=0.326 P=0.289 P=0.168N 

Cochran-Armitagetest P=0.131N 

Fisher exact test P=0.382 P=0.276 P=0.201N 

All Organs: Malignant Neoplasms 

Overall rate 18/51 (35%) 22/52 (42%) 22/51 (43%) 22/54 (41%) 

Adjusted rate 39.6% 47.2% 45.8% 44.8% 

Terminal rate 11/38 (29%) 11/35 (31%) 14/40 (35%) 16/43 (37%) 

First incidence (days) 461 469 548 418 

Life table test Pf0.531N P=0.249 P=0.366 P=0.460 

Logistic regression test P =0.152 P=0.279 P=0.269 P=0.352 

Cochran-Armitagetest Pffi0.367 

Fisher exact test P=0.299 P=0.272 P--0.355 

All Organs: Benign or Malignant Neoplasms 

Overall rate 33/51 (65%) 41/52 (79%) 37/51 (73%) 33/54 (61%) 

Adjusted rate 68.7% 83.7% 74.0% 65.9% 

Terminal rate 23•38 (61%) 27/35 (77%) 27/40 (68%) 26/43 (60%) 

First incidence (days) 461 469 288 82 

Life table test P=0.110N P=0.074 P=0.419 P=0.312N 

Logistic regression test P=0.206N P=0.055 P=0.258 P=0.432N 

Cochran-Armitagetest P=0.206N 

Fisher exact test P=0.084 P=0.261 P=0.429N 

(T)Terminal sacrifice 

a Number of neoplasm-bearing animals/number of animals examined. Denominator is number of animals examined microscopically for liver, lung, pituitary 

gland, thyroid gland, and uterus; for other tissues, denominator is number of animals necropsied. . 

b Kaplan-Meier estimated neoplasm incidence at the end of the study after adjustment for intereurrent mortality 

c Observed incidence at terminal kill 

d 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 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. 

e Not applicable; no neoplasms in animal group 
254 t-Butylhydroquinone, NTP TR 459 

TABLE D4a 

Historical Incidence of Hepatocellular Neoplasms in Untreated Female B6C3F 1 Mice a 

Incidence in Controls 

Adenoma "~'' Carcinoma Adenoma 

. . . . . or Carcinoma 

Overal]l Historical Incidence 

Total 194/1,312 (14.8%) 90/1,312 (6.9%) 260/1,312 (19.8%) 

Standard deviation 10.5 % 6. 1% 12.8 % .. 

Range 2%-50% 0%-20% 3 %-56% 

a Data as of 17 June 1994 

,.. 

TABLE, D4b .. 

Historical Incidence of Thyroid Gland (Follicular Cell) Adenoma in Untreated Female B6C3F 1 Mice a 

Incidence in Controls 

• 

Overalll Historical Incidence . 

Total 27/1,301 (2.1%) 

Standard deviation 2.8% 

Range 0%-9% 

a Data as of 17 June 1994 

.? 

• . 
~:, 

, g~utylhyc~roquinone, NTP T~ 4~59 2~$ 

TABLE D$ 

Sumnmry o~ the ]Incidence of Nonneopl~stic Lesions in Fen~fle Mice in the 2-Year Feed Study of t-Butyihydroquinone a 

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

Disposition Summary 

Animals initially in study 

15-Month interim evaluation 9 8 9 6 

Early deaths 

Moribund 11 7 6 6 

Natural deaths 10 5 5 

Survivors 

Died last week of study 1 I 

Terminal sacrifice 37 35 40 42 

Animals examined microscopically 

.L~-M:onfh,~nterim EvalUation 

Alimentary System 

Liver (9) (8) (9) (6) 

Mixed ceil focus 1 (13%) 1 (11%) 

Vacuolization cytoplasmic, focal 1(11%) 

Mesentery (1) 

Fat, necrosis 1 (100%) 

Pancreas (9) (8) (9) (6) 

Atrophy, focal I (11%) 

Endecrine System 

Adrenal cortex (9) (8) (9) (6) 

Accessory adrenal cortic~fl nodule 1 (11%) 

Parathyroid gland (9) (7) (9) (6) 

Hypcrplasia 1 (14%) 

Thyroid gland (9) (8) (9) (6) 

Degeneration, cystic, focal I (17%) 

Genital System 

Ovary (9) (8) (9) (6) 

Cyst 4 (44%) 1 (11%) 1 (17%) 

Uterus (9) (8) (9) • (6) 

Hydrometra 4 (44%) I (13%) 1 (11%) 2 (33%) 

Inflammation, suppurative 1 (11%) 2 (25%) 

Endometrium, hyperplasia, cystic 9 (100%) 8 (100%) 8 (89%) 6 (100%) 

Hematopoietic System 

Lymph node, mandibular (9) (8) (9) (5) 

Hypcrplasia, lymphoid I (11%) 

Spleen (9) (8) (9) (6) 

Fibrosis, focal I (13%) 

Integumentary System ' 

Skin (9) (8) (9) (6) 

Alopccia, focal 1 (11%) 

a Number of animals examined microscopically at the site and the number of animals with lesion 
256 t-Butylhydroquinone, NTP TR'~,59 

TAnLIg D5 . 

Summary of the Incidence of Nonneoplastic Lesions in Female Mice in the 2-Year Feed Study of t-Butylhydroquinone 

(continuod) 

0 ppm 

15-Month Interim Evaluation (continued) 

Respiratory System 

Lung (9) 

Alveolar epithelium, hyperplasia 

UrinmT System 

Kidney (9) 

Renal tubule, dilatation, focal 

Systems Examined With No ILesions Observed 

Cardiovascular System 

General Body System 

Musculoskeletal System 

Nervous System 

Special Senses System 

2-Year Study 

Alimentary System 

Gallbladder (5o) 

Cyst 

Intestine small, duodenum (51) 

Erosion I (2%) 

Inflammation, chronic, focal I (2%) 

Intestine small, jejunum (51) 

Perforation, chronic 

Peyer's patch, hyperplasia, lymphoid 

Intestine small, ileum (51) 

Peyer's patch, hyperplasia, lymphoid 

Liver (51) 

Angiectasis 2 (4%) 

Basophilie focus 2 (4%) 

Clear cell focus 

Eosinophilic focus (8%) 

Eosinophilic focus, multiple (6%) 

Fatty change (8%) 

Fatty change, focal (4%) 

Hematopoietic cell proliferation (6%) 

Hemorrhage, focal 

Hyperplasia, focal, lymphoid 

Infan:t (2%) 

Infiltration cellular, mixed cell (4%) 

Inflalnmation, focal (6%) 

Mineralization, focal 

Mixed cell focus (2%) 

Mixed cell focus, multiple 

Necrosis, focal (2%) 

Thrombosis (2%) 

Bile duct, cyst (2%) 

Centrilobular, necrosis (2%) 

1,250 ppm 

(8) 

(8) 

(50) 

(51) 

(51) 

(51) 

(52) 

I (2%) , 

9 (17%) 

5 (10%) 

I (2%) 

I (2%) 

1 (2%) 

t (2%) 

3 (6%) 

1 (2%) 

2,500 ppm 

(9) 

1 (11%) 

(9) 

l (11%) 

(47) 

I (2%) 

(48) 

(48) 

1 (2%) 

1 (2%) 

(47) 

1 (2%) 

(51) 

(2%) 

(4%) 

(18%) 

(2%) 

(2%) 

(2%) 

(2%) 

(2%) 

(4%) 

(2%) 

(2%) 

(2%)' 

(2%) 

(2%) 

5,000 ppm 

• , . 

: 

• . 

(6) 

(6) 

,. 

(54) 

(53) 

3 

(53) , 

(53) 

I (2%) " 

(54)-

1 (2%) 

2 (4%) 

11 (20%) 

1 (2%) 

2 (4%) 

1 (2%) 

1 (2%) 

3 (6%) 

2 (4%) 

1 (2%) 

2 (4%) 

1 (2%) 
t-~u~y~hy~roquinone, NT~ T~ 459 2~7 

TA~ D5 

gu~m~y of the ~Incidence o~ I~lonneo ~]a..~ic Le~iora~ in Fem~de l~AIice in the 2-Year Feed Study of t-~utyihydroqulnone 

(continued) 

O ppm 1,2~ ppm 2,500 ppm ~,0~0 ppm 

2" ~¢ag' S~J@ (continued) 

AHmen~ry System (continued) 

Mesentery (10) (13) (7) (8) 

Hemorrhage 1 (8%) 

Inflammation, chronic 1 (10%) 1 (8%) 3 (43%) 4 (50%) 

Fat, necrosis 8 (80%) 5 (38%) 1 (14%) 1 (13%) 

Pancreas (51) (52) (49) (54) 

Atrophy, focal 1 (2%) 2 (4%) 

Duct, cyst I (2%) 

Salivary glands (51) (52) (51) (53) 

Vaeuolization cytoplasmic 1 (2%) 

Stomach, forestomach (51) (52) (51) (54) 

Erosion 3 (6%) 1 (2%) 

Inflammation, chronic 5 (10%) I (2%) .3 (6%) 

Pigmentation, focal I (2%) 

Ulcer 1 (2%) 2 (4%) 

Epithelium, hyperplasia 5 (10%) 1 (2%) 4 (7%) 

Stomach, glandular (51) (52) (49) (54) 

Erosion 1 (2%) 1 (2%) 1 (2%) 

Inflammation, chronic 1 (2%) 

Pigmentation, focal 1 (2%) 

Ulcer (2%) 

Glands, degeneration, cystic, focal 1 (2%) 

Tooth (2) (4) (1) 

Incisor, dysplasia 2 (100%) 4 (100%) 1 (100%) 

C~rdiovescul~r System 

Blood vessel (50) (52) (51) (54) 

Mesenteric artery, inflammation, chronic 1 (2%) 

Heart (51) (52) (51) (54) 

Inflammation, chronic, focal 1 (2%) 

Thrombosis I (2%) 

Artery, inflammation, chronic 2 (4%) 

Myocardium, mineralization, focal I (2%) 

Endeerhae System 

Adrenal cortex (51) (51) (50) (54) 

Accessory adreml cortical nodule 2 (4%) 4 (8%) 1 (2%) 

Cytoplasmic alteration, focal 1 (2%) 

Hematopoietie cell proliferation 1 (2%) 

Capsule, hyperplasia 1 (2%) 

Suboapsular, hyperplasia, focal 2 (4%) 

Adrenal medulla (51) (51) (51) (54) 

Hyperplasia 1 (2%) 4 (7%) 

Islets, pancreatic (51) (52) (48) (54) 

Hyperplasia 1 (2%) 

Parathyroid gland (46) (49) (49) (49) 

Cyst 1 (2%) 
258 t:Butylhydroquinone, NTP TR 459 

TABLE D5 ' 

Summalry of the Incidence of Nonneoplastic Lesions in Female Mice in the 2-Year Feed Study of t-Butylhydroqulnone 

(continued) . . ~ 

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

2-Year Study (continued) 

Endocrine System (continued) 

Pituitary gland (49) (44) (46) (49) 

Angiectasis 2 (4%) 2 (4%) 1- (2%) 

Cyst 1 (2%) 

Pars distalis, angiectasis 1 (2%) 

Pars distalis, cytoplasmic alteration, focal 2 (4%) 3 (7%) 2 (4%) 1 (2%) 

Pars distalis, hyperplasia, focal " 3 (6%) 3 (7%) 2 (4%) 1 (2%) 

Pars intermedia, hyperplasia, focal ' l (2%) 

Thyroid gland (51) (51) (50) (54) 

Degeneration, cystic, focal 1 (2%) 

Inflammation 1 (2%) 

Inflammation, chronic, focal 1 (2%) 2 (4%) 

C-cell, hyperplasia 2 (4%) 1 (2%) 

Follicular cell, hyperplasia 12 (24%) 19 (37%) 24 (48%) 24 (44%) 

General Body System 

None 

Genital System 

Clitoral gland (51) (52) (50) (54) 

Degeneration, cystic 4 (8%) 2 (4%) 3 (6%) 

Ovary (50) (49) (47) (50) 

Angiectasis 2 (4%) 2 (4%) 3 (6%) 

Cyst 15 (30%) I0 (20%) 10 (21%) 11 (22%) 

Hemorrhage 1 (2%) 

Hyperplasia, tubular 1 (2%) 

Inflammation, suppurative 2 (4%) 2 (4%) 2 (4%) 5 (lO%) 

Thrombosis •. 1. (2%) 

Interstitial cell, hyperplasia 1 (2%) 

Uterus (51) (52) (50) (54) 

Cyst I (2%) 1 (2%) 

Hemorrhage 1 (2%) 

Hydrometra 13 (25%) 1.1 (21%) 12 (24%) 14 (26%) 

Hyl~.-rplasia, focal, histiocytie 1 (2%) 

Inflammation, suppurative 3 (6%) 3 (6%) 

Endometrium, hyperplasia, cystic 50 (98%) 52 (100%) 50 (100%) 51 (94%) 

Hematopoietic System 

Bone marrow (51) (52) (51) (54) 

Hypvrplasia 2 (4%) 

Hypvrplasia, focal, histiocytic -1 (2%) 

Myelofibrosis 1 (2%) 

Lymph node (7) (8) (12) (9) 

Hyperplasia, cystic 1 (14%) 

Iliac, hemorrhage 1 (14%) 

Iliac, hyperplasia 2 (29%) 1 (13%) I (11%) 

Inguinal, hyperplasia .. 2 (17%) 

Lumbar; hyperplasia 1 (11%) 
.t-~utylhydro~luinone, NTP, TR 459 259 

TABLE D5 

Summary of the llnddence.of Nonneop~astkLes~ons ~ ~ema~e M~ce ~n the 2-Year. Feed Study of t-~uty~hydroqu~nor~e 

(continued) 

• . 

2-Year Study (continued) 

Hematopoietic System (continued) 

Lymph Node (continued) 

Mediastinal, hyperplasia 

Mediastinal, hyperplasia, lymphoid , 

Mediastinal, inflammation, focal, suppurative 

Renal, hemorrhage 

Renal, hyperplasia 

Lymph node, mandibular 

Hemorrhage 

Hyperplasia, lymphoid 

Lymph node, mesenteric 

Amyloid deposition 

Hematopoietic cell proliferation 

Hemorrhage 

Hyperplasia 

Hyperplasia, histiocytic 

Hyperplasia, lymphoid 

Spleen 

Angiectasis 

Congestion 

Fibrosis, focal 

Hematopoietic cell proliferation 

Hemorrhage 

Hyperplasia, lymphoid 

Necrosis, focal 

Thymus 

Cyst 

Hyperplasia, histiocytic 

Hyperplasia, lymphoid 

Integumentary System 

Mammary gland 

Ectasia 

Hyperplasia 

Skin 

Alopecia, focal 

Inflammation, chronic, focal 

Ulcer 

Epidermis, hyperplasia, focal 

Subcutaneous tissue, edema 

Subcutaneous tissue, inflammation, chronic, 

focal ! 

Musculoskeletal System 

Skeletal muscle 

Inflammation, suppurative 

0 ppm :. 

(7) 

1 (14%) 

1 (14%) 

1 (14%) 

2 (29%) 

(48) 

1 (2%) 

1 (2%) 

(5O) 

I (2%) 

1 (2%) 

1 (2%) 

1 (2%) 

I (2%) 

6 (12%) 

(51) 

14 (27%) 

3 (6%) 

1 (2%) 

(45) 

1 (2%) 

1 (2%) 

(51) 

3 (6%) 

(51) 

(1) 

1 (lOO%) 

1,250 ppm 

(8) 

1 (13%) 

2 (25%) 

(52) 

2 (4%) 

(48) 

2 (4%) 

2 (4%) 

3 (6%) 

(52) 

I (2%) 

14 (27%) 

8 (15%) 

(51) 

l (2%) 

1 (2%) 

(51) 

1 (2%) 

l (2%) 

(52) 

1 (2%) . 

1 (2%) 

(1) 

1 0oo%) 

2,500 ppm 5,000 ppm 

(12) (9) • 

2 (17%) ,1 (11%) 

1 (11%) 

1 (11%) 

I (8%) 3 (33%) 

(50) (52) 

1 (2%) 

(49) (50) 

I (2%) 

I (2%) 1 (2%) 

I (2%) 

3 (6%) 1 (2%) 

(50) (54) 

I (2%) 

1 (2%) 

13 (26%) 13 (24%) 

1 (2%) 

7 (14%) 7 (13%) 

(47) (48) 

1 (2%) 1 (2%) 

1 (2%) 

(51) (54) 

(51) (54) 

1 (2%) 

1 (2%) 

I (2%) 

1 (2%) 

1 (2%) 

(2) 

l (50%) 
260 t-Butylhydroquinone, NTP TR 459 

TABLE D5 

Summary of the Incidence of Nonneoplastic Lesions in Female Mice in the 2-Year Feed Study of t-Butylhydroquinone 

(continued) 

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

2-Year Study (continued) 

Nervm~s System 

Brain (51) (52) (51) (54) 

Atrophy, focal 3 (6%) 4 (8%) I (2%) i (2%) 

Artery, meninges, inflammation, chronic I (2%) 

Me~nges, cyst I (2%) 

Respiratory System 

Lung (51) (52) (51) (54) 

Congestion 1 (2%) 

Hemorrhage l (2%) (2%). 

Hyperplasia, lymphoid 1 (2%) 

Infil•:ation cellular, mixed cell I (2%) 2 (4%) 

Inflammation, chronic, focal 1 (2%) 

Alveolar epithelium, hyperplasia 1 (2%) 1 (2%) 2 (4%) 

Inter~,/titium, inflammation, suppurative 2 (4%) i (2%) 

Mediastinum, inflammation, chronic i (2%) 

Pleura, mediasfinum, inflammation, chronic / i (2%) 1 (2%) 

Nose (51) (52) (49) (53) 

Inflammation, suppurative 1 (2%) 1 (2%) 

Mucnsa, glands, dilatation, focal 16 (31%) 27 (52%) 16 (33%) 26 (49%) 

Nasolacrimal duct, cyst I (2%) 

Trachea (51) (52) (50) (54) 

Artery, peritracheal tissue, inflammation, 

chronic I (2%) 

Special Senses System 

aye (I) 

Cornea, inflammation, chronic 1 (I00%) 

Urinary System 

Kidney (51) (52) (50) (53) 

Congestion 2 (4%) 

Cyst I (2%) 

Hydronephrosis 1 (2%) 

Hylz;rplasia, lymphoid 1 (2%) 1 (2%) 

Inflammation, chronic 2 (4%) I (2%) 

Metaplasia, focal, osseous 1 (2%) 

Nephropathy 30 (59%) 32 (62%) 35 (70%) 28 (53%) 

Arte:ry, inflammation, chronic 1 (2%) 

Renal tubule, casts 1 (2%) 

Renal tubule, dilatation, focal 1 (2%) 

Renal tubule, pigmentation 1 (2%) 

Renal tubule, pigmentation, hemoglobin I (2%) 

Urinary bladder (51) (51) (50) (53) 

Angiectasis 1 (2%) 

Hyperplasia, lymphoid 2 (4%) 
26~ 

SALMONELLA ]~,~UTAGEN~C~TY '~EST ~OTOCOL ...................................... 262 

CHiNeSE ~']~AIVlSTER OVARY CELL CYTOGENET~CS ]PROTOCOLS ............................ 262 

MOUSE ~ON~ ~/~ARROW ]~/~ICRONUCLEUS TEST PROTOCOL ............................... 263 

~LTS ............................................................... 26~ 

T~LE ~1 1V~e~agen~c~y of t-~u~y~ydroqe~none ~n Salmonella typhimurium ................ 265 

T,~L~ ~2 ~n~c~on of S~s~er Chronm~ ~ch~nges ~n Chinese ~s~er ~vary Ce~s 

by t-Bu~yl~y~ro~u~none ......................... . ................... 26~ 

T~L~ ~ ~n~uct~on of Chromosomal Aberrat~om ~n Chinese ~ster ~vary Ce~s 

by t-~uty~hy~roqu~none ............................................ 270 

TA~ ~ ~'requency of M~cronuc~e~ ~n Bone Marrow Ce~s of MaRe,Mice 

Tre~te~ with t-~uty~hydroqu~none by ~ntraper[toa~ [~ect[on .................. 27~ 

i 
262 t-Butylhydroquinone, NTP TR 459 

• 

. ,

GENETIC TOXICOLOGY 

SALMONELLA MUTAGENICITY TEST PRoTocoL 

Testing was performed as reported by Zeiger et al. (1992). t-Butylhydroquinone was sent to thetaboratory 

as a coded aliquot from Radian Corporation (Austin, TX). It was incubated with the Salmonella ~ 

typhimurium tester strains TA97, TA98, TA100, and TA102 either in buffer or $9 mix (metabolic activation 

enzymes and cofactors from Aroclor ® 1254-induced male Sprague-Dawley rat or Syrian hamster liver) for • 

20 minutes at 37 ° C. Top agar supplemented, with/-histidine and d-biotin was added, and the contents of 

the tubes were mixed and poured onto the surfaces of minimal glucose agar plates. Histidine-independent' 

mutant colonies arising on these plates were counted following 2 days incubation at 37* C. All testswere 

repeated using either the same or different $9 concentrations. 

Each trial consisted of triplicate plates of concurrent positive and negative controls and of at least five doses 

of t-butylhydroquinone. The high dose was limited by toxicity. All assays were repeated. 

In this assay, a positive response is defined as a reproducible, dose-related increase in histidine-independent . 

(revertant) colonies in any one strain/activation combination. An equivocal response is defined as an. 

increase in revertants which was not dose-related, not reproducible, or of insufficient magnitude to support 

a determination of mutagenicity. A negative response is obtained when no increase in revertantcolonies is 

observed following chemical treatment. There was no minimum percentage Or fold~increase required for a 

chemical to be judged positive or weakly • positive. • 

• 

CHINESE HAMSTER OVARY CELL CYTOGENETICS PRoToCOLS 

Testing was performed as reported by Galloway et al. (!987). t-Butylhydroquinone was sent to the 

laboratory as a coded aliquot by Radian Corporation. It was tested in cultured Chinesehamster ovary 

(CHO) cell~ for induction of sister, chromatid exchanges (SCEs) and chromosomal aberrations (Abs)both in 

the presence and absence of Aroclor 1254-induced male Sprague-Dawley rat liver $9 and cofactor mix.. 

Cultures were handled under gold lights to prevent• photolysis of bromodeoxyuridine-substituted DNA. : 

Each test consisted of concurrent solvent and positive controls and of at least three doses of • 

t-butylhydroquinone; the high dose was limited by toxicity. A single flask per dose was used, and tests 

yielding equivocal or positive results were repeated. 

"t 

Sister Chromatid Exchange Test: In the SCE test without $9, CHO Cells were incubated for 25.5 hours 

with t-butylhydroquinone in supplemented McCoy's 5A medium. Bromodeoxyuridine (BrdU) was added-. 

2 hours after culture initiation.. After 25.5 hours, the medium containing t-butylhydroquinone was removed 

and replaced with fresh medium plus BrdU and Colcemid ®, and incubation was continued for 2 hours. 

Cells were then. harvested by mitotic shake-off, fixed, and stained with Hoechst 33258 and Giemsa. In the. 

SCE test with $9, cells were incubated with t-butylhydroquinone, serum-free medium, and $9 for 2 hours. 

The medium was then removed and replaced with medium containing serum and BrdU and no 

t-butylhydroquinone, and incubation proceeded for an additional 25.5 hours, with Colcemid ® present for the 

final 2 hours..Harvesting and staining were the same as for cells treated without $9. All slides were scored 

blind and those from a single test were read by the same person. Fifty second-division metaphase cells ' 

were scored for frequency of SCEs/cell from each dose level. Because significant chemical-induced cell 

cycle delay was observed in the presence of $9, .incubation time in the second trial with $9 was lengthened 

to enstire a sufficient number of scorable. (second-division metaphase) cells. 

Statistical analyses were conductedon the slopes of the dose-response curves and the individual dose points 

(Galloway et al., 1987). An SCE frequency20% above the concurrent solvent control value was chosen as .. 
t-Butylhydroqu~none, NTP T~ ~S~ 

a statistically conservative positive response. The probability of this level of difference occurring by chance 

at one dose point is less than 0.01; the probability for such a chance occurrence at two dose points is less 

than 0.001. An increase of 20% or greater at any single dose was considered weak evidence of activity; 

increases at two or more doses resulted in a determination that the trial was positive. A significant trend 

(P < 0.005) in the absence of any responses reaching 20% above background led to a call of equivocal. 

Chramasamal Aberrations Test: In the Abs test without $9, cells were incubated in McCoy's 5A medium 

with t-butylhydroquinone for 8 hours; Colcemid ® was added and incubation continued for 2 hours. The 

cells were then harvested by mitotic shake-off, fixed, and stained with Giemsa. For the Abs test with $9, 

cells were treated with t-butylhydroquinone and $9 for 2 hours, after which the treatment medium was 

removed and the cells incubated for an additional 18 hours in fresh medium, with Colcemid ® present for the 

final 2 hours. Cells were harvested in the same manner as for the treatment without $9. The harvest time 

for the Abs test was based on the cell cycle information obtained in the SCE test; because cell cycle delay 

was anticipated in the presence of $9, the incubation period was extended beyond the normal 10 to 12 hour 

period. 

Cells were selected for scoring on the basis of good morphology and completeness of karyotype 

(21 ± 2 chromosomes). All slides were scored blind and those from a single test were read by the same 

person. Two hundred first-division metaphase cells were scored at each dose level in the trial without $9. 

Because large numbers of aberrations were observed in the cells treated in the presence of $9, fewer cells 

were scored per dose level. Cells with large numbers of aberrations are difficult to score, and the process is 

extremely arduous. Because so many aberrations were observed in almost 100% of the cells, use of a 

smaller sample size does not affect the validity of the statistical analysis of the data. Classes of aberrations 

scored included "simple" (breaks and terminal deletions), "complex" (rearrangements and translocations), 

and "other" (pulverized cells, despiralized chromosomes, and cells containing ten or more aberrations). 

Chromosomal aberration data are presented as percentage of cells with aberrations. To arrive at a statistical 

call for a trial, analyses were conducted on both the dose-response curve and individual dose points. For a 

single trial, a statistically significant (P < 0.05) difference for one dose point and a significant trend 

(P < 0.015) were considered weak evidence for a positive response; significant differences for two or more 

doses indicated the trial was positive. A positive trend in the absence of a statistically significant increaseat 

any one dose point led to an equivocal call. Ultimately, the trial calls were based on a consideration of the 

statistical analyses as well as the biological information available to the reviewers. 

i IOU E ONE MA OW I I C 01 JCL EU tOTOCOL 

Selection of doses was based upon published LDs0 information; no preliminary range-finding studies were 

~ , required. Male B6C3F~ mice received three intraperitoneal injections of/-butylhydroquinone dissolved in 

corn oil at 24-hour intervals. Up to five mice were treated per exposure group and the highest dose 

administered was 400 mg/kg. Solvem control animals received corn oil only, and the positive control mice 

received injections of 25 mg/kg cycI0Phosphamide. The mice were killed 24 hours after the final injection 

and slides were prepared from bone marrow smears obtained from the femurs. Slides were air-dried, fixed, 

and stained. Two thousand polychromatic erythrocytes (PCEs) were scored per animal for frequency of 

micronucleated cells. No animals survived in the 400 mg/kg group and only one mouse survived in the 

300 mg/kg dose group. 

The results were tabulated as the me.an of~th~ pooled results from all animals within an exposure group, plus 

or minus the standard error of the mean. The frequency of micronucleated cells among PCEs was analyzed 

by a statistical software package that tested for increasing trend over exposure groups using a one-tailed 

Cochran-Armitage trend test, followed by pairwise comparisons between each exposure group and the 
264 . t-Butylhydroquinone, NTP TR 459 

c.ontrol group (Margolin et al., 1990). In the presence of excess binomial variation, as detected by a .. 

binomial dispersion test, the binomial variance of the Cochran-Armitage test was adjusted .upward in 

proportion to the excess variation. In the micronucleus test, an individual trial is considered positive if the 

trend test P value is ~0.025 or the P value for any.single exposure group is ~0.025/n where n = the 

number of exposure groups. A final call of positive for micronucleus induction is preferably based on 

reproducibly positive trials (as noted above).. Ultimately, the final call is determined by the scientific staff 

after considering the results of statistical analyses, reproducibility of any effects observed, and the 

magnitudes of those .effects. . 

:RESULTS 

t-Butylhydroquinone (3 to 3,333 pg/plate) was tested for induction of mutations in $. typhimurium strains 

TA97, TA98, TA100, and TA102 with and without induced rat or hamster liver $9 (Zeiger et al., 1992; 

Table El). No mutagenicity was detected in any of the strain/activation combinations. No induction of 

SCEs (Table E2) or Abs (Table E3) was noted in cultured CHO cells treated with t-butylhydroquinone in 

the absence of $9 activation. However, in the presence of $9, positive dose-related responses were obtained 

in both these in vitro cytogenetic assays. The response obtained in the Abs test was particularly strong, and 

up to 90% of treated cells showed multiple Abs at the higher doses (200 to 249 pg/mL). These positive 

results in cultured CHO cells may have resulted from the generation of superoxide and H202 within the cell 

from the autooxidation of t-butylhydroquinone to't-butylquinone and the further generation of oxidative 

byproducts, thereby indirectly producing chromosome breakage (Phillips et al., 1989). In contrast to the 

positive ~results obtained in the in vitro assays for chromosome damage, results of an in vivo bone marrow 

micronucleus test were clearly negative. No significant increase in micronucleated erythrocytes was 

observed in male mice treated with three intraperitoneal injections of up to 300 mg/kg t-butylhydroquinone 

(Table E4). 

• . 
r L : : ; "" 7{ ................ 

¢-~utyahydroqu~none, ~ TR 45~ 

TA~tLS E1 

]~Iutagen~city o~ t-~uty~hydro~uinone in Salmonella typhiraudum a 

~eve~an~s/pnate b 

-$9 Strain Dose 

0tg/plate) Trial I Trial 2 

TAI~ 0 

3 

10 

33 

IO0 

166 

333 

309 ± 25.5 

319 ± 18.6 

323 ± 9.8 

267 ± 25.5 

234 ± 12.3 

128 ± 21.4 ¢ 

202 ± 12.4 

213 ± 5.8 

187 ± 9.2 

166 ± 3.6 

180 ± 7.1 

191 ± 10.0 

Trial summary 

Positive con~ol d 

Negative 

1,433 + 26.6 

Negative 

565 + 18.7 

Reve~ants/plate 

10% 

+hamster S~ 

i0% 30% ~.0% 

+rat S~ 

10% 30% 

TA102 (continued) 

0 

3 

10 

33 

loo 

333 

666 

1,0OO 

1,666 

3,333 

249 ± 11.0 

227 ± 18.5 

224 ± 10.8 

188 ± 13.5 

63 ~ 11.5 

0 ± 0.00 

122 ± 2.6 

135 ± 13.0 

127 ± 4.0 

135 ± 10.6 

129 ± 4.8 

150 ± 8.7 

331 ± 25.3 

372 ± 27.1 

348 ± 10.8 

328 ± 12.0 

200 ± 10.5 

o±o.~ 

233 + 7.1 

279 + 19.7 

238 + 16.5 

169 + 11.5 

58 + 9.1 

31 + 4.3 

189 + 3.1 

185 + 7.2 

175 + 16.3 

145 + 6.7 

143 + 4.5 

167 + 6.8 

342 + 18.5 

370 + 40.1 

363 + 25.4 

363 + 21.1 

277 ± 12.7 

22 + 3.2 ~ 

Trial summary 

Positive control 

Negative 

604 + 165.4 

Negative 

332 + 29.4 

Negative 

2,127 + 104.3 

Negative 

1,239 + 25.6 

Negative 

939 + 10.5 

Negative 

2,633 + 58.1 
266 t-Butylhydroquinone, NTP TR 459 

TABLE E1 

Mutagenicityof t-Butylhydroquinone in Salmonella typhimurium (continued) 

Revertants/plate 

-$9 

(~g/plate) Trial 1 Trial 2 Trial 3 

Strain Dose 

TA100 0 

3 

10 

33 

100 

166 

333 

666 

143 ± 6.0 

129 5:11.3 

115 :1: 1.2 

145 ± 2.5 

, 

Toxic 

Toxic 

95± 11.0 

83 ± 3.3 

98::t: 7.5 

90 5:4.8 

85 5:3.2 

• 79 5:4.4 

121 ± 10.3 

111 ::t: 11.6 

112:1:5.1 

113 5:7.9 

119 5:11.2 

106 5:3.8 

' 

. 

Trial summary 

Positive control 

Negative 

317 ± 9.3 • . 

Negative 

'394 fl:: 24.4 

Negative 

450:1:20.9 

Revertants/plate 

10% 

+hamster $9 

10% • . 10% 

+ rat S9 

30% 

TA100 (continued) 

0 

~33 

100 

333 

1,000 

1,666 

3,333 

118 ::1: 11.0 

115 ~ 4.7 

111 ~ 7.8 

101 ~ 7.7 

103 ~ 11.3 

81 ± 3.0 e 

172 5: 1.2 

127 ± 16.2 

153 ± 3.4 

128 ± 8.2 

85 ± 10.7 

o±o.~ 

108 :k 4.0 

134 ± 3.5 

140 5:10.7 

131 ± 2.2 

103 ± 7.5 

61 ± 6.4 

141 5: 10.7 

150 ± 13.2 

111 ± 14.8 

145 5:12.5 

141 ± 8.5 ' 

106:1:10.5 

Trial summary 

Positive control 

' Negative 

691:1:48.0 

Negative 

645 ::1:37.1 .. 

Negative 

553 5:18.8 

Negative 

627 ~ 22.6 
i~ ~ 

t-~u~ylhydroquinone, NT~ T~ ~$9 67 

TAnLE E~. 

MutageniciCy of t-~utylhydroquinone in Salmonella typhimurium (continued) 

Revertants/plate 

-$9 Strain Dose 

(pg/plate) Trial I Trial 2 Trial 3 Trial ,~ 

TA98 0 32 ± 2.6 22 ± 1.2 27 ± 0.9 20 ± 2.3 

3 19 :i: 1.9 25 ± 0.3 19 ± 1.0 

10 26 ± 0.7 25 ± 4.9 27 ± 0.7 21 ± 2.3 

33 24 ± 3.8 21 :i: 2.5 87 ± 5.5 16 ± 4.9 

100 24 ± 1.9 20 ± 0.6 11 ± 1.2 ¢ 14 ± 3.1 

166 30 ± 4.5 0 ± 0.0 ¢ 4 ± 2.3 ¢ 

333 Toxic 

666 Toxic 

Trial summary Negative Negative Eqtiivocal Negative 

Positive control 474 ± 22.1 505 ± 19.5 487 ± 44.2 537 ± 36.4 

Revertants/plate 

Strain Dose + hamster $9 + rat $9 

~g/plate) 10% 30% 10% 30% 

TA98 (continued) 

0 35 ± 7.8 30 ± 1.2 38 ± 3.8 38 ~ 1.9 

33 33 ± 3.8 25 ± 3.2 36 ± 2.0 40 ~ 2.6 

100 35 ± 2.0 42 ± 6.0 36 ± 3.3 34 ± 5.2 

333 26 ± 2.3 37 ± 2.5 36 ± 4.2 31 ± 3.2 

1,000 23 ± 1.8 26 ± 5.5 27 ± 0.7 15 ~ 3.5 

1,666 4±0.9 c 14±3.2 ¢ 

3,333 0 ± 0.0 ¢ Toxic 

Trial summary Negative Negative Negative Negative 

Positive control 725 ± 35.2 489 ± 16.0 197 ± 20.1 192 ± 3.2 
268 t-Butylhydroquinone, NTP TR 4~9 

,FABLE E1 

Mutagenicity of t-Butylhydroquinone in Salmonella typhimurium (continued) 

,. Revertants/plate

Strain Dose . , . - ~;~ + hamster $9 .... + rat $9 

(pg/plate) Trial 1 Trial 2 10% 30% 10% 30% . 

TA97 0 127 4- 6.7 151 4- 6.6 154 + 3.4 163 + 15.2 176 4- 18.3 223 4- 8.1 

3 155 4- 18.8 141 4- 5.9 

10 155 4- 4.9 163 4- 8.5 

33 167 4- 8.6 157 4- 3.3 158 + 6.7 228 + 3.8 192 + 7.1 198 + 6.4 

100 171'+ 4.0 163 4- 7.1 167 + 15.8-~ 218 + 19.8 . 202 + 12.2 176 + 6.8 

• .166 124 4- 11.0 

333 0 4- 0.0 c 170 + 12.5 . 150 + 6.1 181 + 7.1 146 + 23.0 

666 

1,000 140 + 7.6 • 160 + 10.3 152 + 9.7 154 + 15.4 

1,666 55 + 35.2 c 72 + 6.2 c 

3,333 0 + 0.0 c 0 + 0.0 c 

, 

Trial summary Equivocal Negative Negative Equivocal Negative Negative 

Positive control 415 4- 11.2 388 4- 27.1 620 + 34.7 368 + 24.9 617 + 4.7 454 + 25.6 

a Study performed at SRI International. The detailed protocol and these data are presented in Zeiger et al. (1992). : 

b Revertants are presented as mean + standard error from three plates. 

c Slight toxicity 

c~ The positive controls in the absence of metabolic activation were sodium azide (TA100), 9-aminoacridine (TA97), 

4-nitro-o-phenylenediamine (TA98), and mitomycin C (TA102). The positive control for metabolic activation with all strains was 

2-aminoanthracene, except 2-aminoanthracene/sterigmatocystin was used for TAI02. 

-, ." 
t-~uty~hydroquinone, ~TP TR ~$9 

T~ ]g2 

]Indaction o~ Sister Chron~atid ]Exchanges in Chinese Hamster Ovary Ce~s by t-~uty~ydroq~inone a 

I~o. of SCEs/ Relative Change 

Dose Total Chromo- No. of Chromo- SCEs/ Hrs of SC~s/ 

Compound (/~g/mL) Cells sore,s SCEs some C~ll in SrdU Chromosome b 

(%) 

Summary: Negative 

Dimethylsulfoxide 50 1,014 477 0.47 9.5 25.5 

Mitomycin-C O.OOl 50 996 566 0.56 11.3 25.5 20.80 

O.OlO 5 lO0 138 1.38 27.6 25.5 193.36 

t-Butylhydroquinone 0.5 50 1,024 441 0.43 8.8 25.5 -8.45 

1.7 50 1,020 566 0.55 11.3 ' 25.5 17.96 

5.0 50 1,029 490 0.47 9.8 25.5 1.23 

16.7 0 

P =0.062 c 

+$9 

Trial I 

Summary: Positive 

Dimethylsufoxide 50 1,029 409 0.39 8.2 25.5 

Cyclophosphamide 0.4 50 1,019 706 0.69 14.1 ; 25.5 74.31 

2.0 5 105 210 2.00 42.0 25.5 403.18 

t-Butylhydroquinone 5.0 50 1,031 494 0.47 9.9 25.5 20.55* 

16.7 50 1,016 598 0.58 12.0 25.5 48.08* 

50.0 50 1,033 603 0.58 12.1 25.5 46.86* 

166.7 0 25.5 

P<O.O01 

Trial 2 

Summary: Positive 

Dimethylsulfoxide 25 523 208 0.39 8.3 25.5 

Cyclophosphamide 0.4 25 517 278 0.53 11.1 25.5 35.20 

2.0 5 102 168 1.64 33.6 25.5 314.14 

t-Butylhydroquinone 49.8 25 514 318 0.61 12.7 25.5 55.56* 

100.5 25 516 352 0.68 14.1 30.5 d 71.53" 

150.0 25 521 359 0.68 14.4 30.5 d 73.26* 

P<0.000 

* Positive (P<0.O1) 

a Study performed at Litton Bionetics, Inc. A detailed description of the protocol is presented in Galloway et al. (1987). SCE=sister 

chromadd exchange; BrdU=bromodeoxyuridine. 

b SCEs/chromosome in treated cells versus SCEs/chromosome in solvent control cells 

Significance of SCEs/chromosome tested by the finear regression trend test vs. log of the dose 

d Because t-butylhydroquinone induced a delay in the cell division cycle, harvest time was extended to maximize the proportion of seconddivision cells available for analysis. 

c 
c 

270 t-Butyih~,dr0quinone~ NTP TR 459 

TABLE E3 

Induction of Chromosomal Aberrations in Chinese Hamster Ovary Cells by t-Butylhydroquin0ne a . 

-$9 +$9 

Dose Total • No.of Abs/. Cells with Dose Total ' No. of Abs/. Cells with 

(pg/m!~) Cell~ .Ab, s Cell . Abs (%) (#g/mL) ,. Cells • .. Abs ... Cell • Abs (%) .... 

Trial 1 

Harvest time: 10.0 hours Harvest time: 20.0 hours c 

,Summary: Negative Summary: Positive 

Dimethylsulfoxide Dimethylsulfoxide 

200 5 • 0.03 2.5 200 11 0.06 2.~0 

iMitomycin-C Cyclophosphamide 

0.25 200 37 0.19 16.0 6.25 200 43 0.22 20~0 

0.75 25 13 0.52 32.0 12.5 25 22 0.88 40.0 

t-Butylhydroquinone t-Bu~lhydroquinone 

~ 5.0 200 6 0.03 3.0 100.5 100 79 0.79 36.0* 

7.6 200 5 0.03 2.5 150.0 20 . .53 2.65 75.0" 

10.1 200 4 0.02 2.0 • " 200.0 : :10 " 36 3.60 80.0* , . , 25.2 0 '. 

P=0.410 b P<0.001' 

Trial 2 

Harvest time: 20.0 hours c 

Summary: Positive 

Dimethylsufoxide " 

100 3 0.03 2.0 

Cyclophosphamide 

6.25 100 22 0.22 18.0 

12.5 25 20 0.80 48.0 

t-Butylhydroquinone 

149.4 25 22 0.88 44..0* 

199.2 10 31 3.10 90.0* 

249.0 10 39 3.90 90.0* 

300.0 0 

P<0.001 

* Positive (P<0.05) ~' 

a Study performed at Litton Bionetics, Inc. The detailed protocol is presented in Galloway et al. (1987). Absfaberrations. 

b Significance of percent cells with aberrations tested by the linear regression trend test vs. log of the dose 

Because significant chemical-induced cell cycle delay was anticipated, incubation time prior to addition of Colcemid ® was lengthened to 

ensure sufficient metaphases for analysis. • 
~ .... 

¢-~ty~by~ro~u~noae, ~ T~ ~9 27~ 

T~LE ]~ 

~e~lue~cy o~ ~C~'~c~e~ ~ ~e I~I~'~ Ce~ ~ ~e ~ce ~t~ ,~t~ ~-~u~y~o~e 

~y ~t~ape~toae~ ~tiO~ a 

Dose (mg/~g) l~l.~e~ o~ I~I~©e ]~ic~-o~cn~.~ed ~C~.~.SI~.,~ cen~ b 

Cyclophosphamide c 

25.00 17.6 + 1.46 • 

t-Butylhydroquinone 

0.00 

9.38 

18.75 

37.50 

75.00 

150.00 

300.00 

5 

4 

5 

5 

5 

5 

1 

0.8 + 0.4~ 

0.9 + 0.43 

1.7 + 0.46 

1.3 + 0.41 

1.0 + 0.45 

1.4 + 0.19 

1.0 

P=0.367 d 

a Study performed at Environmental Health Research and Testing, Inc. 0 mgl~g is the solvent (corn oil) control. Frequency of micronuclei 

was measured in 2,000 polychromatic erythrocytes (PCEs) per mouse. 

b Data presented as mean ± standard error 

c Positive control 

d Trend test 
272 t-Butylhydroquinone, NTP TR 459 
27~ 

A~I~IEI~EX F 

AI~ 

©Ii~GAN WIEI[GI~IT~ 

©~GANoWEEG~ToT©oI~©I~YoWIEEG~T ~AT~I©S 

TABLE ~'~. 

T~L~ ~ 

T~L~ F3 

~LZ F,~ 

Grgan Weights and Grgan-We~gh~-to-~y Weight ~fios ~or ~a~s 

~n ~e ~3-~ee~ ~ee~ S~u~y of ~-~u~y~y~ro~u~none ......................... 

~rgan We~gh~ and Orga~-We~gh~-~o~y Weight ~afios for ~a~ 

a~ ~he 3-~on~h ~n~er~ Ev~ua~ion in ~he ~ng-Te~ Feed ~u~y 

o~ t-~u~y~hy~o~u~none ............................................ 

O~gan We~gh~ ~ O~gan-~e~ghg-~ody We~ ~afios ~ ~ce 

~n ~he ~3-Wee~ ~ee~ S~u~y o~ t-~u~y~hy~oqu~one ......................... 

Organ Weigh~ ~n~ Org~-Wei~-~o~y Weigh~ ~afios for ~ice 

a~ ~he ~5-~on~h ~er~ Evaluation ~n ~he 2-Y~ ~ee~ S~u~y 

o~ t-Bu~y~hy~r~u~none ............................................ 

~7~ 

27~ 

27~ 

277 
27,4 t-Bu.tylhydroquinone, NTP TR 459 

TABLE F1 

Organ Weights and Organ-Weight-to-Body-Weight Ratios for Rats in the 13-Week Feed Study 

of t-Butylhydroquinone a ; , 

0 ppm 2,500 ppm 5,000 ppm 10,000 ppm 

n 10 10 10 10 

Male 

Necropsy body wt 340 ± 7 339 ± 3 313 ± 7** 284 ± 6** 

Heart 

Absolute 0.957 ± 0.019 0.940± 0.019 0.876 ± 0.017"* 0.806 ± 0.016 *~ 

Relative 2.82 ± 0.04 2.77 ± 0.04 2.80 ± 0.04 2.84 ± 0.03 

R. Kidney 

Absolute 1.181 ± 0.034 1.252 ± 0.019 1.205 ± 0.029 1.145 ± 0.024 

Relative 3.47 ± 0.06 3.70 ± 0.06** 3.85 ± 0.05** 4.04 ± 0.04** 

Liver 

Absolute 11.950.± 0.327 14.411 ± 0.229** 12.670 ± 0.441 12.557 ± 0.338 

Relative 35.16 ± 0.67 42.52 ± 0.49** ' 40.42 ± 0.80** 44.23 ± 0.62** 

Lung 

Absolute 1.567 ± 0.060 1.274 ± 0.020** 1.246 ± 0.021"* 1.212 ± 0.013"* 

Relative 4.62 ± 0.18 3.76 ± 0.06** " 3.99 ± 0.07** 4.29 ± 0.10 

R. Testis 

Absolute 1.399 ± 0.030 1.471 ± 0.017 1.407 ± 0.016 1.392 ± 0.017 

Relative 4.12 ± 0.05 4.34 ± 0.04* 4.51 ± 0.08** 4.92 ± 0.09** 

Thymus 

Absolute 0.263 ± 0.015 0.286 ± 0.009 0.276 ± 0.018 0.251 ± 0.012 

Relative 0.78 ± 0.05 0.85 ± 0.03 0.88 ± 0.05 0.88 ± 0.04 

Female 

Necropsy body wt 201 ± 5 199 ± 3 184 ± 2** 173 ± 3** 

Heart 

- , Absolute 0.631 ± 0.013 • 0.619 ± 0.013 0.585 ± 0.014" 0.575 ± 0.011"* 

Relative 3.14 ± 0.06 3.11 ± 0.04 3.18 ± 0.05 3.33 ± 0.05* 

R. Kidney ,, 

Absolute 0.726 ± 0.014 0.717 ± 0.013 0.689 ± 0.012 0.675 ± 0.016" 

Relative 3.61 ± 0.04 3.61 ± 0.05 3.75 ± 0.06 3.91 ± 0.07** 

Liver 

Absolute 6.358 ± 0.210 6.781 ± 0.160 6.256 ± 0.096 6.743 ± 0.198 

Relative 31.53 ± 0.50 34.12 ± 0.64* 34.10 ± 0.54* 39.08 ± 1.01"* 

Lung 

Absolute 1.033 ± 0.028 0.988 ± 0.015 0.988 ± 0.037 0.929 ± 0.017"* 

Relative 5.14 ± 0.12 4.98 ± 0.10 5.37 ± 0.17 5.39 ± 0.09 

Thymus 

Absolute 0.260 ± 0.016 " 0.271 ± 0.008 0.259 ± 0.009 0.245 ± 0.006 

Relative 1.29 ± 0.07 1.36 ± 0.04 1.41 ± 0.05 1.42 ± 0.04 

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

** P~0.01 

a 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 weight (mean ::1:: standard error). 
t-Bu~ylhydroquinone, NT~ TR 459 275 

TABLE F22 

Organ Weights and Organ-Welghf-to-Body-Weigh~ 1Ratios for Rats a~ Che 3-1~'iIonth ]Interim EvaH~ion 

~n the.~.~oug-Term Feed Study of t-~utynhydroqu~none a 

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

n ,. lO lO 1o lO 

Male 

Necropsy body wt 355 ± 7 348 ± 4 338 5:7 341 5:6 

R. Epididymis 

Absolute 0.472 5:0.020 b.492 ± 0.016 0.474 ± 0.018 0.479 5:0.014 

Relative 1.33 5:0.07 1.41 5:0.05 1.40 5:0.04 1.41 5:0.04 

R. Kidney 

Absolute 1.389 d: 0.038 1.351 ± 0.032 1.396 ± 0.038 1.385 5:0.052 

Relative 3.91 ± 0.06 3.88 ± 0.10 4.14 5:0.08 4.06 5:0.10 

Liver 

.absolute 13.467 ± 0.435 13.527 ± 0.388 14.531 5:0.572 14.420 5:0.451 

Relative •37.88 ± 0.62 38.90 ± 1.17 42.95 ± 1.15"* 42.26 5: 0.86** 

R. Testis 

Absolute 1.489 ::t:'0.022 1.463 ± 0.022 1.453 ± 0.031 1.485 ± 0.022 

Relative 4.21 5:0.11 4.21 5:0.09 4.31 5:0.06 4.36 5:0.07 

~'emale 

Necropsy body wt 199 ± 2 191 ± 2** 192 ± 3** 181 ± 2** 

R. Kidney 

Absolute 0.749 ± 0.013 0.729 ± 0.012 0.728 ± 0.017 0.675 ± 0.015"* 

Relative 3.76 ± 0.07 3.82 5:0.07 3.80 ± 0.05 3.73 ± 0.07 

Liver 

Absolute 6.310 ± 0.150 6.625 ± 0.170 6.593 ± 0.162 6.255 ± 0.096 

Relative 31.70 ± 0.80 34.67 ± 0.76** 34.40 ± 0.65* 34.61 ± 0.37* 

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

** P~:0.01 • 

a 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 weight (mean ± standard error). 
276 t-Butylhydroquin0ne, NTP TR 459 

TABL]~. F3 

Organ Weights and Organ-Weight-to-Body-Weight Ratios for Mice in the 13-Week Feed Study of t-Butylhydroquinone a 

' ' 0 ppm 2,500 ppm 5,000 ppm 10,000 ppm 20,000 ppm 40,000 ppm , . 

. 

Male 

n 10 9 9 10 9 8 

Necropsy body wt 34.1 ± 0.7 31.9 ± 0.7* 32.3 ± 0.4* 30.1 ± 0.4** 27.6 ± 0.6** 23.7 ± 0.4** 

; 

Heart 

Absolute 0.143 ± 0.003 0.147 ± 0.005 0.151 ± 0.004 0.134 ± 0.003 0:127 ± 0.003** 0.113 ± 0.003** 

Relative 4.20 ± 0.07 4.60 ± 0.15" 4.67 ± 0.07* 4.46 ± 0.10" 4.60 ± 0.14" 4.75 ± 0.10"* 

R. Kidney 

Absolute 0.286 ± 0.006 0.298 ± 0.007 0.310 ± 0.006 0.268 ± 0.007 0.236 ± 0.005** 0.195 ± 0.007** 

Relative 8.41 ± 0.16 9.34 ± 0.18"* 9.58 ± 0.15"* 8.91 ± 0.16 8.54 ± 0.16 8.22 ± 0.18 

Liver 

Absolute 1.334 ± 0.040 1.448 ± 0.033 1.559 ± 0.032** 1.313 ± 0.036 1.326 ± 0.057 1.318 ± 0.033 

Relative 39.24 ± 1.19 45.45 ± 0.92** 48.19 ± 0.80** 43.68 ± 1.01"* 47.89 ± 1.40"* 55.59 ± 0.90**, 

Lung 

Absolute 0.180 ± 0.005 b 0.177 ± 0.005 0.174 5:0.005 0.175 ± 0.003 0.179:5:0.008 c 0.168 ± 0.007 .. 

Relative 5.27 ± 0.20b ~ 5.55 ± 0.16 5.39 ± 0.12 5.84 5: 0.15" 6.48 ± 0.20 **c 7.07 ± 0.27** 

R. Testis 

Absolute 0.117 5:0.002 0.119 ± 0.003 0.121 ± 0.001 0.115 ± 0.002 0.112 ± 0.003 0.105 ± 0.004** 

Relative 3.44 ± 0.07 3.74 ± 0.07* 3.74 ± 0.04* 3.83 ± 0.06** 4.08 ± 0.09** 4.44:1: 0.17"* 

Thymus 

Absolute 0.038 ± 0.003 0.039 ± 0.004 0.034 ± 0.002 c 0,030 ± 0.001" 0.031 ± 0.001 *c 0.028 ± 0.003* 

Relative 1.12 ± 0:08 1.22 ± 0.12 1.06 ± 0.05 c 1.00 ± 0.06 1.12 ± 0.04 ¢ 1.17 ± 0.13 

:. 

Female 

n 9 9 10 . 8 10 9 

Necropsy body wt 30.7 ± 0.7 28.5 ± 1.0" 28.6 ± 0.7* 24.1 ± 0.4** 22.1 ± 0.4** 20.3 ± 0.5** • 

Heart 

Absolute 0.128 ± 0.004 0.126 ± 0.004 0.129 5:0.003 0.115 ± 0.003* 0.105 ± 0.002** 0.103 ± 0.003** 

• • Relative " 4.17 ± 0.16 4.43 ± 0.16 .... 4.53 ± 0.11 4.78 ± 0.11"* 4.77 ± 0.11"* 5.10 ± 0.12"* 

R. Kidney 

Absolute 0.218 ± 0.006 0.211 ± 0.1)06 0.212 ± 0.005 0.185 ± 0.005** 0.170 ± 0.005*.* 0.160 ± 0.004** 

Relative 7.11 ± 0.26 7.44 ± 0.24 7.44 ± 0.18 7.69 ± 0.18 7.70 ± 0.14 7.91 ± 0.22* 

Liver 

Absolute 1.203 ± 0.030 1.249 ± 0.038 1.293 ± 0.025 1.030 ± 0.027** 1.051 ± 0.039** 1.237 ± 0.032 

Relative 39.22 ± 0.96 43.90 ± 1.00"* 45.43 ± 1.06"* 42.75 ± 0.54** 47.52 ± 0.93** 61.14 ± 1.73"* 

Lung 

Absolute 0.170 ± 0.008 0.166 ± 0.006 0.163 ± 0.006 0.169 ± 0.005 0.164 ± 0.005 0.150 ± 0.004. 

Relative 5.56 ± 0.32 5.82 ± 0.15 5.73 ± 0.25 7.02 ± 0.24** 7.42 ± 0.16"* 7.41 ± 0.19"* 

Thymu~ 

Absolute 0.045 :t:: 0.002 0.048 ± 0.002 e 0.044 ± 0.002 0.046 ± 0.002 0.037 ± 0.002* 0.028 ± 0.004** 

Relative 1.49 ± 0.08 1.68 ± 0.05 ¢ 1.53 ± 0.07 1.92 ± 0.09* 1.65 ± 0.06 1.34 ± 0.16 

* Significantly different (P~0,05) from the control group by Williams' or Dunnett's test 

** P~0.01 

a 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 weight (mean ± standard error). 

b n=9 

c n=:8 
t-ll~utylhydroquinone, NTP T~ ,~59 277 

TABLE ~4 

Organ Weights 

~n ~he 2-'~'e~r F

and 

eed 

Organ-Weight-to-body-Welght 

Study of t-~utyihydroquinone a 

Ratios for Mice at t h e 15-Month ~nterirn Evaluation 

• . , 

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

Male 

n 10 10 9 9 

Necropsy body wt 49.1 5:1.0 50.3 5:1.2 49.4 5:1.0 45.4 5:1.5 

R. Epididymis 

Absolute 0.051 5:0.002 0.052 5:0.003 0.050 5:0.002 0.048 5:0.002 

Relative 1.05 5:0.05 1.04 5:0.06 1.02 5:0.03 1.06 5:0.03 

R. Kidney 

Absolute 0.422 5:0.014 0.441 5:0.022 0.439 5:0.019 0.420 5:0.018 b 

Relative 8.58 5:0.14 8.76:1:0.33 8.87 5:0.21 9.29 5:0.23 b 

Liver 

Absolute 2.042 5:0.108 c 2.257 5:0.176 2.258 5:0.155 2.401 5:0.434 

Relative 41.57 5:1.39 c 45.04 5:3.74 45.42 5:2.13 55.62 5:13.39 

R. Testis 

Absolute 0.118 5:0.002 0.114 5:0.002 0.116 :t: 0.003 0.115 5:0.004 

Relative 2.42 5:0.05 2.28 5:0.06 2.36 5:0.04 2.55 5:0.09 

Female 

n 9 8 9 6 

Necropsy body wt 53.5 5:1.8 53.6 :t: 3.7 51.9 5:1.8 44.8 5:2.0 

R. Kidney 

Absolute 0.279 5:0.011 0.298 5:0.014 0.287 5:: 0.013 0.272 5:0.009 

Relative 5.24 5:0.24 5.67:5:: 0.33 5.53 5:0.19 6.12 5:0.37 

Liver 

Absolute 1.696 5:0.054 1.918 5:0.153 1.820 5:0.047 1.775 5:0.029 

Relative 31.73 5:0.67 36.11 5:2.20 35.26 5:1.03 39.88 5: 1.46"* 

** Significantly different (Pa0.01) from the control group by Williams' test 

a 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 weight (mean 5: standard error). 

b n=8 

¢ n=9 
278 t-Butylhydroquinone, NTP TR 459 
279 

~FE~rD~ CG i 

]Z-~..,~,IY~I:A~©L©~,-~ AI~]l~ CL~~CAL C]~-~..~[~5~,~.~ 

~..,,~5~.,.~1~5 

TABLE G1 

TABLE G2 

TABLE G3 

TABLE G4 

Hen~atology and Clinical Chen~Lstry Data for ~ats 

in the 13-Week ~'eed Study o~ t-~atyn~y~oqe~aoae ......................... 

~e~atonogy Data for ~a~ at the 3-Month ~nte~ Eviction 

~n the Long-Term ~eed Study o~ t-Butyahydroqu~no~e ........................ 

He~ato~o~ and C~n~c~ Chem~t~ Data ~or Mice 

~n the 13-Week ~eed Study of t-~uty~hydroqu~aon( ......................... 

Hemato]o~ Da~ for ~ce at the ~5-Month ~nter~ Evaluation 

~n the 2-Year ~eed Study of t-~utynhydroqu~none ........................... 

2~0 

2~ 

2~5 

2~9 
280 t-Butylhydroquinone, NTP TR 459 

TABLE GI 

Hematology and Clinical Chemistry Data for.Rats in the 13-Week Feed Study of t-Butylhydroquinone a 

Male 

n 

. 

Hematology 

Hcmatocrit (%) 

Day :5 

Week 3 

Week 13 

Hemoglobin (g/dL) 

Day 5 

Week 3 

Week 13 

Erythrocytes (106/pL) 

Day 5 

Week 3 

Week 13 

Reticulocytes (106//~L) 

Day 5 

. Week 3 

Week 13 

Nucleated erythrocytes (I~/~L) 

Day 5 

Week 3 

Week 13 

Mean cell volume (fL) 

Day 5 

Week 3 

Week 13 

Mean cell hemoglobin (pg) 

Day 5 

Week 3 

Week 13 

Mean cell hemoglobin concentration (g/dL) 

Day 5 

Week 3 

Weelk 13 

Platelets (103/~L) 

Day 5 

Week 3 

Week 13 

Leukocytes (103/aL) 

Day 5 

Week 3 

Week 13 

Segmented neutrophils (10J/eL) 

Day5 

Week 3 

Week 13 

Lymphocytes (103/pL) 

Day 5 

Week 3 

Week 13 

Monoeytes (103//zL) 

Day 5 

Week 3 

Week 13 

0 ppm 

10 

41.1 ± 0.5 

45.0 ± 0.7 

44.7 ± 1.0 

.14.1 5:0.2 

15.2 ± 0.2 

15.3 ±~0.3 

7.15 ± 0.10 

7.79 ± 0.12 

8.96 ± 0.20 

0.33 ± 0.04 

0.21 ± 0.03 

0.18 ± 0.02 

0.14 ± 0.04 

0.12 ± 0.03 

0.02 ± 0.01 

57.5 ± 0.3 

57,9 ± 0.4 

. 50.0 ± 0.2 

19.7 ± 0.1 

19.5 ± 0.2 

17.1 ± 0.1 

34.4 ± 0.1 

33.8 ± 0.4 

34.2 ± 0.I 

962.9 ± 9.6 

844.8 ± 38.0 

676.9 ± 23.2 

9.02 ± 0.26 

9.03 ± 0.26 

8.94 ± 0.45 

0.90 ± 0.06 

1.06 ± 0.11 

1.30 ± 0.17 

7.90 ± 0.32 

7.76 ± 0.24 

7.52 ± 0.36 

0.16 ± 0.05 

0.15 ± 0.07 

0.04 ± 0.02 

2,500 ppm 

10 

40.6 ± 0.5 

44.6 ± 0.4 

45.0 ± 0.4 

14.0 ± 0.1 

15.1 ± 0.1 

15.3 ± 0.2 

7.15 ± 0.08 

7.77± 0.05 

9.04 ± 0.09 

0.44 ± 0.04 

0.24 ± 0.03 

0.19 ± 0.01 

0.09 ± 0.02 

0.11 ± 0.03 

0.04 ± 0.02 

56.8 ± 0.2 

57.3 ± 0.3 

49.8 ± 0.3 .. 

19.5 ± 0.1 

19.4 ± 0.1 

16.9 ± 0.1 

34.4 ± 0.2 

33.8 ± 0.2 

34.0 ± O. 1 

938.6 ± 24.6 

828.9 ± 11.5 

655.7 ± 23.0 

8.37 ± 0.31 

9.01 ± 0.11 

8.96 ± 0.53 

0.87 ± 0.10 

0~80 ± 0.09 

1.11 ± 0.09 

7.36 ± 0.30 

8.12 ± 0.12 

• 7.72 ± 0.44 

0.10 ± 0.03 

0.06 ± 0.02 

0.02 ± 0.01 

5,000 ppm 

10 

41.5 ± 0.6 

44.7 ± 0.8 

44.0 ± 0.8 

14.3 ± 0.2 

15.0 ± 0.3 

14.9 ± 0.3 

7.35 ± 0. I0 

7.76 ± 0.16 

8.80 ± 0.16 

0.46 ± 0.05 

0.28 ± 0.03 

0.17 ± 0.03 

0.14 ± 0.03 

0.17 ± 0.05 

0.01 ± 0.01 

56.4 ± 0.3**

57.8 ± 0.4 

50.1 ± 0.2 

19.5 ± 0.1" 

19.4 ± 0.1 

16.9 ± 0.1 

34.4 ± 0.2 

33.6 ± 0.2 

33.8 ± 0.2 

903.7 ± 26.1" 

830.3 ± 17.0 

745.9 ± 54.6 

8.58 ± 0.32 

8.84.± 0.21 

8.50 ± 0.63 

1.01 ± 0.11 

0.96 ± 0.15 

0.92 ± 0.13 

7.39 ± 0.37 

7.69 ± 0.21 

7.48 ±'0:58 

0.11 ± 0.02 

0.09 ± 0.05 

0.01 ± 0.01 

10,000 ppm 

• 

10 

41.3 ± 0.4 

42.4 ± 0.4** 

" 44.6 5:0.3 

14.2 ~ 0.1 

14.1 ± 0.1"* 

15.2 ± 0.1 

7.40 ± 0.07 

• 7.34 ± 0.07** 

8.87 ± 0.05 

0.44 ± 0.04 

0.29 ± 0.03 

0.17 ± 0.03 

0.11 ± 0.03 

0.10 ± 0.03 

0.02 ± 0~01 

55.9 ± 0.1"* 

57.7 ± 0.5 

. 50.0 5= 0.2 

19.2 ± 0.1"* 

19.3 ± 0.2 

17.1 ± 0.1 

34,3 ± 0.1 

33.4 ± 0.3 

34.1 ± 0.I 

944.7 ± 16.2 

909.7 ± 15.6"* 

688.1 ± 9.8 

7.81 ± 0.36* 

8.30 ± 0.28 

9.44 ± 0.51 

0.80 ± 0.10 

0.90 ± 0.07 

1.38 ± 0.17 

6.89 ± 0.29 

7.29 ± 0.30 

7.95 ± 0.44 

0.08 ± 0.05 

0.04 ± 0.02 

0.00 ± 0.00 
? . . . . . = . . . . . ........ 

t-~utylhydroquinone, NTPT~ 459 

'FABLE G1 

Elemato~ogy and C~n~can Chemistry Data for ~ats in the 13-Week ~eed Study of t-~uty~hydroqu~r~one (continued) 

0 ppm 2,500 ppm 5,000 ppm 10,000 ppm 

Male (continued) 

n 10 10 10 10 

Hematology (continued) 

Eosinophils (103/~L) 

Day 5 0.03 5:0.02 0.04 ± 0.03 0.05 ± 0.02 0.04 ± 0.02 

Week 3 0.04 ± 0.02 0.02 ± 0.01 0.09 ± 0.02 0.07 ::1:: 0.03 

Week 13 0.10 ± 0.03 0.11 ± 0.05 0.10 ± 0.02 0.11 5:: 0.04 

Thromboplastin time (seconds) 

Week 13 10.63 ± 0.40 b 10.29 ::t: 0.30 c 10.96 ± 0.28 ¢ 10.21 ± 0.36 d 

Activated partial thromboplastin time (seconds) 

Week 13 19.95 ± 1.43 b 19.40 ± 1.28 b 18.29 ± 0.68 c 19.84 ± 1.09 d 

Clinical Chemistry 

Blood urea nitrogen (mg/dL) 

Day 5 23.5 ± 0.7 22.8 ± 0.3 22.0 ± 0.4 21.9 ± 0.5 

Week 3 21.1 ± 0.8 25.2 ± 0.6** 25.3 ± 0.7** 24.9 ± 0.6** 

Week 13 22.9 ± 0.4 22.1 5:0.6 22.2 ± 0.5 22.9 ± 0.3 

Creatinine (mg/dL) 

Day 5 0.51 ± 0.02 0.48 ± 0.01 0.50 ± 0.03 d 0.46 ± 0.02 b 

Week 3 0.58 ± 0.02 0.56 ± 0.03 0.58 ± 0.02 0.55 5:0.01 ' 

Week 13 0.64 ± 0.02 0.63 ± 0.02 0.68 ± 0.02 0.67 ± 0.02 

Total protein (g/dL) 

Day 5 6.3 ± 0.1 6.0 ± 0.1" 6.1 ± 0.1" 5.6 ±.0.1"* 

Week 3 6.3 5:0.1 6.4 ± 0.1 6.4 ± 0.1 6.4 ± 0.1 

Week 13 7.3 5:0.1 7.3 ± 0.1 7.4 ± 0.1 7.5 5:0.1 

Albumin (g/dL) 

Day 5 3.7 ± 0.1 3.6 ± 0.1 3.5 ± 0.0 3.3 ± 0.1"* 

Week 3 3.7 ± 0.1 3.8 ± 0.1 3.8 ± 0.1 3.8 ± 0.1 

Week 13 4.0 ± 0.1 4.2 ± 0.1 4.2 ± 0.1 4.3 ± 0.1" 

Alanine aminotransferase (IU/L) 

Week 3 43 ± 1 48 ± 1" 48 ± 1" 48 ±2" 

Week 13 51 ±2 63 ±4* 44± 1 51 ± 1 

Alkaline phosphatase (IU/L) 

Day 5 662 ± 17 603 ± 12 626 ± 20 611 ± 24 

Week 3 498 ± 9 494 ± 8 504 ± 12 496 ± 9 

Week 13 258 ±9 243 ±9 244±3 253 ±5 

Creatine kinase (IU/L) 

Day 5 722 ± 98 635 ± 55 781 ± 50 800 ± 47 

Week 3 973 ± 79 996 ± 108 925:1:48 1,054 ± 100" 

Week 13 376 ± 47 492 ± 97 399 ± 44 428 ± 39 

Sorbitol dehydrogenase (IU/L) 

Day 5 7 ±0 8 ±0 8 ±0" 8 ±0"* 

Week 3 95:1 9± 1 10± 1 10±0 

Week 13 11 ± 1 12± 1 12 ± 1 10± 1 

Bile acids (~mol/L) 

Day 5 2'1.6 ± 5.6 e 19.2 ± 3.0 b 43.7 ± 1.9 **b 74.8:1:10.6 **e 

Week 3 28.9 ± 2.8 30.8 ± 3.0 46.5 ± 5.1"* 46.2 ± 4.1"* 

Week 13 22.1 ± 3.6 21.7 ± 2.3 31.4 ± 3.7* 42.0 5: 2.2** 
282 t-Butyliiydroqt/inone, NTP TR 459 

TABLE G1 

Hematology and Clinical Chemistry Data for Rats in the 13'Week Feed Study of t-Butylhydroquinone (Continued 

0 ppm 2,500 ppm 5,000 ppm !0,000 ppm • 

Female 

n 10 10 10 10 

Hematology 

Hematocrit (%) 

Day 5 42.2 ± '0.5 42.0 ± 0.6 42.0 ± 0.4 42.3 ± 0.4 

Week 3 46.2 ± 0.5 46.3 ± 0.6 45.5 ± 0.5 45.8 ± 0.5 

Week 13 43.8 ± 0.4 43.4 ± 0.4 43.6± 0.3 42.7 ± 0.5 f 

Hemoglobin (g/dL) 

Day 5 14.7 ± 0.1 14.5 ± 0.2 14.3 ± 0.2 14.7 ± 0.1 

Week 3 15.3"± 0.2 15.3 ± 0.2 15.3 ± 0.2 . 15.2 ± 0.2 

Week 13 14.6 ± 0.1 14.3 ± 0.1 14.4 ± 0.1 14.1 ± 0.2 f 

Erythrocytes (106/#L) 

Day 5 7.45 ± 0.10 7.42 ± 0.10 7.54 ± 0.07 7.68 ± 0.09 

Week :3 7.78 ± 0.11 7.78 ± 0.08 7.73 ± 0.09 7.85 ± 0.08 

Week 13 8.28 ± 0.06 8.16 ± 0.07 8.22 ± 0.07 8.03 ± 0.11 f 

Reticulocytes (106/~L) 

Day 5 0.30 ± 0.03 0.33 ± 0.02 0.28 ± 0.04 0.27 ± 0.03 

Week 3 0.26 5:0.03 0.26 ± 0.02 0.25 ± 0.03 0.21 :5:0.02 

Week 13 0.19. ± 0.02 0.22 5:0.03 0.23 ± 0.03 0.20 ± 0.03 f 

Nucleated erythrocytes (103//~L) 

Day 5 0.12 ± 0.05 0.07 5:0.03 0.06 ± 0.03 0.07 :t: 0.03 

Week :3 0.00 ± 0.00 0.00 5:0.00 0.00:5:0.00 0.00 ± 0.00 

Week 13 0.04 ± 0.02 0.03 ± 0.02 0.06 ± 0.02 0.04 ± 0.04 f 

Mean cell volume (fL) 

Day 5 56.7 ± 0.3 56.6 ± 0.2 55.8± 0.3* 55.2 5: 0.1"* 

Week 3 59.4 ± 0.2 ' 59.5 5:0.3 58.9 ± 0.2 58.4 ± 0.3* 

Week 13 52.9 ± 0.2 53.3 ± 0.2 53.1 ± 0.2 53.0 ± 0.2 f 

Mean cell hemoglobin (pg) 

Day 5 19.7 ± 0.1 19.6 5:0.1 19.0 ± 0.3** 19.1 ± 0.1"* 

Week 3 19.7 ± 0.1 19.7 ± 0.1 19.8 ± 0.1 19.3 5:0.2 

Week 13 17.6 5:0.1 17.6 ± 0.1 17.5 ± 0.1 17.6 ± 0.1 f 

Mean cell hemoglobin concentration (g/dL) 

Day 5 34.8 ± 0.1 34.7 5:0.2 34.1 5:0.5 34.7 ± 0.2 

Week 3 33.1 ± 0.1 33.2 ± 0.2 33.6 ± 0.2 33.2 ± 0.2 

Week 13 33.3 ± 0.2 33.0 ± 0.1 33.0 ± 0.2 33.1 ± 0.2 f 

Platelets (103//~L) 

Day 5 1,036.3 ± 44.7 1,009.3 5:44.6 945.7 5:44.5 923~4 ± 40.6 

Week 3 901.6 5:25.5 959.0 ± 38.5 962.2 ± 39.1 885.0 ± 31.4 

Week 13 700.8 ± 5.8 737.4 5:6.3 715.9 ± 23.1 744.2 ± 18.9 f 

Leukocytes (103/t~L) 

Day 5 8.10 ~ 0.28 8.45 ± 0.36 8.89::t: 0.29 7.84 ± 0.35 

Week 3 8.02 ± 0.53 9.09 ± 0.23 8.81 ± 0.26 8.62 ± 0.48 

Week 13 7.53 ± 0.60 7.09 ± 0.28 7.86 ± 0.32 8.34 ± 0.47 f 

Segmented neutrophils (103//~L) • 

Day 5 0.71 5:0.09 0.78 5:0.07 0.77 5:0.10 0.89 ± 0.09 

Week 3 1.20 ± 0.12 1.10 5:0.15 0.93 ± 0.11 0.89 ± 0.08 

Week 13 1.36 ± 0.24 1.26 ± 0.14 1.23 ± 0.13 1.12 5:0.11 f 

Lymphocytes (103/#L) 

Day 5 7.25 5:0.26 7.56 ± 0.36 • 7.92 :t: 0.27 6.80 ± 0.30 

Week 3 6.33 ± 0.40 7.60 5:0.25 7.48 ± 0.31 7.30 ± 0.41 

Week 13 6.09 ± 0.42 5.71 ± 0.31 6.50:5:.0.26 ...7.03 ± 0.43 f 

Monocytes (103//xL) 

Day 5 0.10 5:0.03 0.07 5:0.02 0.07 5:0.04 0.10 5:0.04 

Week 3 0.43:5:0.10 0.37 5:0.08 0.34 5:0.08 0.39 ± 0.06 

Week 13 0.05 ± 0.02 0.04 5:0.02 0.08 5:0.03 0.10 5:0.04 f 
t-Butylhydroquinone, NTP TR 459 283 

TABLE G1 

Hematology mad Cl~nictd Chemfistry Data for Rats ~n the 13-Week Feed Study of t-Buty~hydroqu~none (continued) 

0 ppm 2,500 ppm 5,000 ppm 10,000 ppm 

Female (continued) 

n 10 

Hematology (continued) 

Eosinophils (103/~L) 

Day 5 0.08 ± 0.03 

Week 3 0.06 ± 0.02 

Week 13 0.05 ± 0.02 

Thromboplastin time (seconds) 

Week 13 9.82 ± 0.33 

Activated partial thromboplastin time (seconds) 

Week 13 20.13 ± 1.02 

Clinical Chemistry 

Blood urea nitrogen (mg/dL) 

Day 5 22.7 ± 0.5 

Week 3 22.3 ± 0.8 

Week 13 22.5 ± 0.6 

Creatinine (mg/dL) 

Day 5 0.54 ± 0.02 

Week 3 0.54 ± 0.02 

Week 13 0.72 ± 0.01 

Total protein (g/dL) 

Day 5 6.0 ± 0.1 

Week 3 6.0 ± 0.1 

Week 13 7.0 ± 0.1 

Albumin (g/dL) 

Day 5 4.0 ± 0.1 

Week 3 3.7 ± 0.1 

Week 13 4.3 ± 0.1 

Alanine aminotransferase (IU/L) 

Day 5 47 ± 2 d 

Week 3 36 ± 1 

Week 13 47 ± 3 

Alkaline phosphatase (lUlL) 

Day 5 598 ± 20 

Week 3 439 ± 11 

Week 13 254 ± 6 

Creatine kinase (IU/L) 

Day 5 1,030 ± 52 

Week 3 865 ± 94 

Week 13 261 ± 30 

Sorbitol dehydrogenase (IU/L) 

Day 5 7 ± 0 

Week 3 9 ± 0 

Week 13 15 ± 1 

Bile acids (#mol/L) 

Day 5 18.6 ± 2.0 

Week 3 26.5 ± 3.4 

Week 13 29.8 ± 3.9 

10 

0.05 ± 0.02 

0.06 ± 0.03 

0.09 ± 0.02 

9.83 ± 0.30 f 

21.19 ± 1.61 f 

21.0 ± 0.6 

25.2 ± 0.9* 

23.4 ± 0.6 

0.51 ± 0.02 

0.51 ± 0.02 

0.78 ± 0.02* 

5.8 ± 0.1 

6.2 ± 0.1" 

7.0 ± 0.1 

3.8 ± 0.1 

3.8 ± 0.1 

4.3 ± 0.1 

49 ±2 

43 ± 1"* 

46:t:1 

• 

556 ± 12 

440 ± 12 

266±9 

1,214 ± 67 

802 ± 60 

245 ± 19 

7 ±0 

9±0 

14 ± 1 

25.5 ± 2.5* 

31.5 ± 5.9 

38.4 ± 4.0 

10 10 

0.15 ± 0.03 0.07 ± 0.03 

0.07 ± 0.03 0.06 ± 0.03 

0.07 ± 0.03 0.11 ± 0.03 f 

10.24 ± 0.38 10.19 ± 0.37 

20.91 ± 0.91 20.12 ± 1.02 

21.9 ± 0.6 22.4 ± 0.7 

26.4 ± 0.9** 26.4 ± 0.8** 

21.4 ± 0.8 20.0 ± 1.0 

0.55 ± 0.02 0.57 ± 0.03 

0.48 ± 0.02 f 0.52 ± 0.02 

0.78 ± 0.02 0.79 ± 0.02 

5.9 ± 0.1 5.8 ± 0.I 

6.1 ± 0.1 6.2 ± 0.1" 

7.2 ± 0.1 7.0 ± 0.1 

3.9 ± 0.1 3.8 ± 0.1 

3.7 ± 0.1 3.9 ± 0.1" 

4.3 ::t: 0.1 4.2 ± 0.1 

50 ± 3 f 69 ± 2 **d 

39 ± 1 *f 46 ± 1 **f 

46±3 45::1:2 

535 ± 20 603 ± 17 

415 ± 8 460 ± 11 

267 ±9 257 ±7 

1,248 ± 90 1,100 ± 92 

836 ± 132 692 ± 58 

240 ± 26 274 ± 34 

7 ±0" 8 ± 1 **f 

8±0 9±0 

13 ± 1 14 ± 1 

34.5 ± 3.9** 53.1 ± 3.5 **d 

43.9 ± 5.2 *f 46.9 ± 5.0** 

36.7 ± 4.1 49.4 ± 4.6** 

* Significantly different (P~0.05) from the control group by Dunn's or Shirley's test 

** P~0.01 

a Mean ± standard error. Statistical tests were performed on unfounded data. 

b n=6 c n=7 d n=8 e n=4 f n=9 
284 t-Butylhydroquinone, NTP TR ~459 

TABLE G2 

Hematology Data for Rats at the 3-Month Interim Evaluation in the Long-.Term Feed Study oft-Butylhydroquinone a 

0 ppm 1,250 ppm 

Male 

n 10 10 

Hematocrit (%) 46.4 ± 0.3 46.9 ± 0.5 

Hemoglobin (g/dL) 15.3 ± 0.1 15.3 ± 0.1 

Erythrocytes (106/#L) . 9:03 ± 0.07 9.14 ± 0.07 

Reticulocytes (106/~L) 3 0.16 ± 0.02 0.17 ± 0.02 

Nucleated erythrocytes (10/#L) 0.00 ± 0.00 0.00 ± 0.00 

Mean (:ell volume (fL) 51.4 ± 0.3 51.4 ± 0.4 

Mean (:eli hemoglobin (pg) 16.9 ± 0.1 16.8 ± 0.I 

Mean (:ell hemoglobin : 

concentration (g/dL) 32.9 ± 0.2 32.6 ± 0.2 

Platelets (103/~L) 797.3 ± 48.7 821.9 ± 12.7 

Leukocytes (103/#L) 3 10.20 ± 0.84 10.66 ± 0.89 

Segmented neutr,o~hils (10/#L) 2.09 ± 0.22 1.93 ± 0.34 

Lymphocytes (10/#L) 7.80 ± 0.74 8.28 ± 0.59 

Atypical lymphocytes (103/#L) 0.00 ± 0.00 0.00 ± 0.00 

Monocytes (103/#L) 0.18 ± 0.05 0.31 ± 0.09 

Eosinophils (103/#L) 0.13 ± 0.03 0.15 ± 0.05 

Female 

n 9 10 

Hematocrit (%) 44.8 ± 0.4 45.4 ± 0.5 

Hemoglobin (g/dL) 15.0 ± 0.2 15.2 ± 0.1 

Erythro~ytes (106/#L) 8.41 ± 0.08 8.39 ± 0.06 

Reticulocytes (106/#L) 0.15 ± 0.01 0.14 ± 0.02 

Nucleated erythrocytes (103/#L) 0.02 ± 0.02 0.05 ± 0.02 

Mean cell volume (fL) 53.3 ± 0.4 54.2 ± 0.7 

Mean cell hemoglobin (pg) 17.8 ± 0.1 18.2- ± 0.1" 

Mean cell hemoglobin 

concentration (g/alL) 33.5 ± 0.3 33.6 ± 0.3 

• Platelets (103/#L) . 763.8 ± 27.4 823.7 ± 21.4 

Leukocytes (103/#L) 7.35 ± 0.59 6.63 ± 0.59 

Segmented neutro~phils (103/#L) 1.15 ± 0.11 1.20 ± 0.24 

Lymphocytes (I~/#L) 6.04 ± 0.53 5.18 ± 0,36 

Atypical lymphocytes (103/#L) 0.00 ± 0.00 0.00 ± 0.00 

Monocytes (103/#L) 0.12 ± 0.04 0.18 ± 0.03 

Eosinophils (103/#L) 0.06 ± 0.02 c 0.06 ± 0.02 

Significantly different (P~0.05) from the control group by Dunn's or Shirley's test 

Mean ± standard error. Statistical tests were. performed on Unrounded data. 

n=9 

n=8 

2,500 ppm 

10 

46.6 ± 0.9 

15.2 ± 0.3 

9.04 ± 0.17 

O.17 ± 0.02 

0.05 ± 0.03 

51.6 ± 0.2 

16.8 ± 0.0 

32:5 ± 0.1 

817.1 ± 33.3 

10.89 ± 1.06 

1.62 ± 0.25 

8.96 ± 0.83 

0.00 ± 0.00 

0.24 ± 0.06 

0.06 ± 0.04 

. 10 

44.5 ± 0.4 

15.1 ± 0.2 

8.39 ± 0.08 

0.13 ± 0.03 

0.04 ± 0.01 

53.0 ± 0.3 

18.0 ± 0.1 

34.0 ± 0.2 • 

819.8 ± 26.7 

7.35 ± 0.52 

1.24 ± 0.16 

5.95 ± 0.38 

0.00 ± 0.00 

0.13 ± 0.03 

0.04 ± 0.02 

5,000 ppm 

10 

45.9 ± 0.5 

15.1 ± 0.1 

9.00 ± 0.H 

0.17 ± 0.01 

0.01 ± 0.01 

51.0 ± 0.3 

16.8 ± 0.1 

32.9 ± 0.2 

759.8 ± 26.3 

10.74 ± 0.94 

1.71 ± 0.17 

8.64 ± 0.79 

0.00 ± 0.00 

0.28 ± 0.08 

0.11 ± 0.03 

10 

44.5 ± 0.4 " 

15.2 ± 0.1 

8.42 ± 0.05 

0.14 ± 0.02 

0.06 ± 0.02 

52.9 ± 0.4 

18.0 ± 0.1 

34.1 ± 0.3 

840.7 ± 15.5 b 

6.72 ± 0.43 

0.90 ± 0.13 

5.67 ± 0.38 

0.00 ± 0.00 

0.I0 ± 0.02 

0.04 ± 0.02 
t-~uty~hydroqu~none~ NTP T~ 4S9 285 

TAeL~ G3 

Hematology and CH~a~ca~ Chemistry Data ~'or IV~ce ~n the ~3-Week Yeed Study o~ t-~aty~hydroqu~aone a 

0 ppm 2,500 ppm 5,000 ppm 10,000 ppm 20,000 ppm 

I~£ale 

n 10 10 - 10 9 10 

Hematology 

Hematoerit (%) 

Day 5 45.0 ± 0.7 44.6 ± 0.8 45.9 ± 0.8 46.5 ± 1.0 45.5 ± 0.8 

Week 3 48.6 ± 0.6 47.4 ± 0.5 47.2 ± 0.6 47.3 ± 0.5 b 47.3 ± 0.7 e 

Week 13 47.7 ± 0.6 c 47.7 ± 0.5 48.6 ± 0.5 48.3 ± 0.4 d 47.9 ± 0.6 

Hemoglobin (g/dL) 

Day 5 15.2 ± 0.2 15.1 ± 0.3 15.1 ± 0.2 15.4 ± 0.3 15.1 ± 0.4 

Week 3 16.5 ± 0.2 16.1 ± 0.2 16.1 ± 0.1 16.1 ± 0.2 b 16.3 ± 0.2 e 

Week 13 16.0 ± 0.2 e 15.7 ± 0.4 16.1 ± 0.1 c 16.0 ± 0.2 16.1 ± 0.2 ¢ 

Erythrocytes (106//~L) 

Day5 9.05 ± 0.15 9.01± 0.18 9.22 ± 0.16 9.38 ± 0.20 9.21 ± 0.17 

Week 3 10.15 ± 0.15 9.92 ± 0.12 9.91 5:0.12 9.94 ± 0.09 b 10.08 ± 0.16 c 

Week 13 10.07 ± 0.12 c 10.23 ± 0.12 10.24 ± 0.12 c 10.16 ± 0.12 10.38 ± 0.12 

Reticulocytes (106//~L) 

Day 5 0.51 ± 0.08 c 0.45 5:0.08 0.62 ± 0.17 b 0.41 ± 0.08 0.59 ± 0.14 e 

Week 3 0.21 5:0.02 c 0.26 ± 0.02 c 0.19 ± 0.01 c 0.24 ± 0.02 e 0.31 ± 0.04 c 

Week 13 0.16 ± 0.06 f 0.22 ± 0.03 g 0.21 ± 0.02 h 0,21 ± 0.04 i 0.25 ± 0.04 e 

Mean cell volume (fL) 

Day 5 49.7 ± 0.3 49.6 ± 0.3 49.8 ± 0.4 49.4 ± 0.3 49.3 ± 0.3 

Week 3 47.8 ± 0.3 47.7 ::t: 0.2 47.5 ± 0.2 47.4 ± 0.3 b 47.0 ± 0.3 c 

Week 13 47.4 ± 0.8 c 46.6 ± 0.4 47.4 ± 0.5 e 47.7 ± 0.6 46.1 ± 0.4 

Mean cell hemoglobin (pg) 

Day 5 16.8 ± 0.1 16.7 ± 0.1 16.4 ± 0.1"* 16.5 ± 0.1"* 16.3 ± 0.1"* 

Week 3 16.3 ± 0.1 16.3 ::t: 0.1 16.3:5:0.1 16.2 ± 0.1 b 16.2 ± 0.1 c 

Week 13 15.9 ± 0.1 e 15.3 ± 0.3* 15.7 ± 0.1 c 15.8:5:0.1 15.5 ± 0.1 **e 

Mean cell hemoglobin concentration (g/dL) 

Day 5 33.8 ± 0.1 33.7 ± 0.2 32.9 ± 0.2* 33.2 ± 0.2 33.1 ± 0.3 

Week 3 34.1 ± 0.3 34.1 ± 0.1 34.2 ± 0.3 34.0 ± 0.2 b 34.5 ± 0.3 c 

Week 13 33.5 ± 0.5 c 32.8 ± 0.6 33.2 ± 0.4 c 33.2 ± 0.4 33.5 ± 0.4 c 

Platelets (10~/~L) 

Day 5 1,186 5:63 1,128 ::1:57 1,124 ± 61 1,224 ± 56 1,229 ± 87 

Week 3 937 ± 19 901 5:34 956 ± 34 1,001 ± 19 b 1,030 ± 47 c 

Week 13 754 ::1:58 c 796 5:39 834 ± 42 c 887 ± 63 931 ± 50* 

l.,~ukoeyt~s (10a/iLL) 

Day 5 6.17 ± 0.29 5.75 ± 0.42 5.99 ± 0.33 6,59 ± 0.38 6.56 ± 0.28 

Week 3 7.93 ± 0.38 8.36 ± 0.47 7.65:1:0.60 9,11 ± 0.30 *b 9.56 ± 0.60 *c 

Week 13 6.67 ± 0.61 c 7.31 ± 0.50 7.71 ± 0.63 c 9.82 ± 0.70* 8.30 ± 0.52 

Segmented neutrophils (I~/~L) 

Day 5 0.61 ± 0.10 0.43 ::1:0.12 0.46 ± 0.07 0,71 ± 0.11 0.73 ± 0.11 

Week 3 1.10 ± 0.14 0.90 ± 0.15 0.91 ± 0.15 1,55 ± 0.14 b 2.80 ± 0.42 **c 

Week 13 0.94 ± 0.14 e 0.77 ± 0.17 h 1.09 ± 0.15 ¢ 1.51 ± 0.21 1.85 ± 0.44* 

Lymphocytes (I~//~L) 

Day 5 5.53 ::t: 0.24 5.27 ± 0.36 5.49 ± 0.31 5.84 ± 0.33 5.77 ± 0.29 

Week 3 6.71 ± 0.29 7.41 ± 0.48 6.60 ± 0.52 7,45 ± 0.34 b 6.57 ± 0.33 e 

Week 13 5.37 ± 0.67 e 5.78 ± 0.31 h 6.49 ± 0.64 e 8.19 ± 0.55* 6.33 ± 0.18 

Eosinophils (103//~L) 

Day 5 0.02 ± 0.01 0.05 ± 0.02 0.04 ± 0.02 0.07 ± 0.02 0.03 ± 0.02 

Week 3 0.10 ± 0.04 0.07 ± 0.03 0.14 ± 0.03 0.15 ± 0.07 b 0.18 ± 0.04 c 

Week 13 0.04 ± 0.02 e 0.12 ± 0.03 h 0.14 ± 0.04 c 0.16 ± 0.05 0.13 ± 0.04 

Thromboplastin time (seconds) 

Week 13 8.01 ± 0.18 c 7.62 ± 0.17 e 7.97/± 0.20 ¢ 8.23 ± 0.31 h 8.03 5:0.23 b 

Activated partial thromboplastin time (seconds.) 

.Week 13 25.65 ± 0.251 27.57 ± 1.17 f 26.15 ± 1.25 j _k _ 

40,000 ppm 

10 

46.5 ± 1.2 c 

50.5 ± 1.3 b 

47.8 ± 0.9 

15.6 5:0.3 c 

17.4 ± 0.5 b 

15.9 ± 0.3 c 

• 

9.39 ± 0.23 

10.92 ± 0.29 b 

10.38 ± 0.10 ¢ 

0.68 ± o.2o b 

0.33 ± 0.04 *b 

0.25 ± 0.03 i 

49.6 ± 0.2 c . 

46.1 ± 0.4 **b 

46.1 ± 0.7 e 

16.5 ± 0.1 **e 

15.9 ± 0.1 **b 

15.3 ± 0.2 **c 

33.2 ± 0.2 b 

34.4 ± 0.1 b 

33.3 ± 0.4 c 

1,245 ± 48 

1,034 ± 20 **b 

933 ± 53 *c 

7.77 ± 0.62* 

8.74 ± 0.98 b 

7.47 ± 0.69 c 

1.00 ± 0.13 

2.91 ± 0.45 **b 

2.27 ± 0.41 **¢ 

6.60 ± 0.56 

5.70 ± 0.57 ~ 

5.11 ± 0.39 e 

0.16 ± 0.04** 

o.13 ± o.04 b 

0.08 ± 0.03 c 

7.97 ± 0.35 e 
286 t-Butylhydroquinone; NTP TR 459 

TABLE G3 

Hematology and Clinical ChemistryDatafor Mice in ithe 13-Week Feed Study of t-Butylhydroquin0ne (continued) 

0 ppm 2,500 ppm 5,000 ppm 10,000 ppm 20,000 ppm 40,000 ppm 

Male (continued) , . . 

n 8 10 8 8 ,, 9 9 

Clinical Chemistry 

Blood urea nitrogen (mg/dL) 

Day 5 30.1 ± ,1.1 27.2 ± 1.2 25.5 :t: 1.4" 25.2 ± 1.0" 2422 ± 1.3"* " 20.9 ± 1.3 **e 

Week 3 - 27.1'± 1.5 28.8 ± 1.5 c 25.4 ± 1.6 d 21.2 5: 1.0" :17.'1 ± 0.7 **b 17.0 ± 0.6 **i 

Week 13 27.5 ± 2.6 e 23.6 5:1.7 b 25.1 ::1:1.4 e 22.9 ± 0.6 19:1 ± 1.2 **e 20.3 ± 0.6 ** ' 

Creatinine (mg/dL) 

Day 5 0.34 ± 0.05! 0.38 5:0.02 h 0.43 5:0.04 i 0.34 ::1:0.04 g 0.36 ± 0.02 i 0.33 ± 0.03 f -

Week 3 0.35 5:0.02 t 0.38 ± 0.02 g 0.36 5:0.03 e 0.28 ± 0.02 h 0.33 5:0.01 h 0.34 ± 0.02 f 

Total protein (g/dL) • . _. . 

Day 5 4.9 ±0.i i 4.9 5:0.1 h 5.1 :t: 0.1 i 5.1 5:0.1 g 5.0 ± 0.1 ~ • "" 5.2 ±0.1 f - , 

Aibumin (g/dL) ' 

Day5 2.8 ~" 0.1 g 2.6 ± 0.1 h 2.8:5:: 0.1 g • 2,8 ± 0,1 f 2.9 ± 0.1 ~ 3.0 ± 0.1 f 

Alanine aminotransferase (IU/L) 

Day5 51 ±6 e 43 ±9 35±5 29 ± 5** 38 ± 4 b 37 ±.6 d 

Week 3 22 ± 2 24 ± 2 c 21 5:2 d 18::1:2 22 ± 4bl 16 ± 2 h 

Week 13 : 83 ± 41 f 175 5:93 g 111 ± 61 i 110"± 49 h : 118 ± 45 t 124 ± 22 h 

Alkaline phosphatase (IU/L) ,:, 

Day 5 161 5:6 158 5:4 154 5:6 153 5:6 149 ± 5 139 ± 4 e 

Week 3 1185:48 122 5:7 i 122 ± 7 g 95 5:2 *e : 84 5:6 **h 80 5:6 ~ 

Creatine kinase (lUlL) 

Day 5 292 ± 75 161 ± 47 ' 147 ± 30 141 ± 28 223 ± 53 150.5:28 ~ 

Sorbltoi dehydrogenase (IU/L) • 

. 

Week 3 37 ± 3! 46 ± 6 h 36 5: 2. c 37±4 34 ± 3 e 42 ± 5 f 

Week 13 30 ± 4 ,I 31 ± 2 f 34±3 I 42 ± 16 j 27 ± 4 f 271 

Bile acids (pmol/L) , 

Week 3 10.7 ± 1.3. e 7.9 ± 0.5* 7.6 5:0.4 *d 7.1 ± 0.6** 7.5 ± 0.7 *b 7.0 5:0.9 **h 

Week 13 ' 21.2 5:0.91 22.3 5:0.8 g 22.0 5:2.0 h 16.7 ::1:2.5 e 19.8 5:1.3 i 16.2 5:1.3 h 

Female 

n io 10 10 10 10 10 

Hematology 

Hematocrit (%) 

Day 5 45.2 5: 0.3• 44.6 "± 0.5 45.0 ± 0.6 45.7 ± 0.3 45,6 ± 1.2 47.9 .± 0.6** 

Week 3 46.2 ± 1.4 49.5 ± 0.9 46.4 ± 0.6 46.9 ± 0.5 48.8 ± 1.5' 46.9" ± 0.8 c 

Week 13 47.4 ± 0~4 47.4-± 0.4 48.0 5:0.4 48.9 ± 1.4 c 47.4 ± 0.4 48.5 ± 1.0 c 

Hemoglobin (g/dL) 

Day 5 15.0 ±0.1 14.9 ± 0.2 15.1 ± 0.2 15.3 ± 0.1 15.4 ± 0.4 16.2 ± 0~2"* -

Week 3 ~, 15.6 ± ,0.4 16.6 ± 0.3 15.7 ± 0.2 15.9 ± 0.2 16.9 ± 0.5 c 16.2 ± 0.2 c 

Week 13 15.7 ± 0.2 15.6 ± 0.2 15.9 ±0.1 16.2 ± 0.4 c 15.7 ± 0.2 16.3 ± 0.4 e 

Erythrocytes (106//~L) 

Day 5 9.14 ± 0.12 9.04 ± 0.13 9.24 ± 0.15 9.51 5: 0.09* 9.55 ± 0.26 10.20 ± 0.16"* 

Week 3 9.40 ± 0.27 10.15 ± 0.17"* 9.63 ± 0.09 9.98 ± 0.08* 10.60 ± 0.31"* 10.29 ± 0.15 **c 

Week 13 9.99 5:0.11 10.07 ± 0.08 10.18 ± 0.09 10.50 ± 0.32 c 10.17 ::t: 0.07 10.58 ± 0.27 c 

Reticulocytes (106//~L) 

Day 5 0.44 ± 0.05 l° 0.42 ± 0.04 c 

. 0.31 ± 0.04 e 0.42 ± 0.08 0.27 ± 0.04.* 0.22 ± 0.04** 

Week 3 0.14 ± 0.03 h 0.13 ± 0.02 I 0.15 ± 0.02 h 0.17 ± 0.03 b 0.24 ± 0.031 0.24 ± 0.04 e 

Week 13 0.20 ± 0.02 0.19 ± 0.02 b 0.18 ± 0.02 0.21 ± 0.03 c 0.28 ± 0.03* 0.29 ± 0.04 *b 
/ g-~u~y~hydroquinone, NTI? T~ ~9 ~7 

T~L~ G3 

~en~ato~ogy and C~nica~ Che~n~stry Data ~'or Mice in the ~.3-Week Feed Study o~ t-~uty~hy~roqu~none (continued). ~ 

0 ppm 2,500 ppm 5,000 ppm ~0,0~0 ppm 20,~00 ppm ,~0,000 ppm 

~¢emale (continued) 

n 10 10 10 10 10 10 

Hematology (continued) 

Mean cell volume (fL) • . 

Day 5 49.6 + 0.5 49.4 + 0.3 48.8 + 0.4 48.0 + 0.3* 47.7 + 0.2**" 47.2 + 0.4** 

Week 3 48.9 + 0.2 48.9 + 0.4 48.3 + 0.3 47.0 + 0.2** 45.9 + 0.2** 45.6 + 0.3 **c 

Week 13 47.5 + 0.2 47.0 + 0.2 47.1 + 0.3 46.4 + 0.2 **¢ 46.6"+ 0.3** 46.0 + 0.3 **¢ 

Mean cell hemoglobin (pg) 

Day 5 16.4 + 0.2 16.5 + 0.1 16.4 + 0.1 16.1 + 0.1 16.2 + 0.1 15.9 + 0.2 

Week 3 16.6 + 0.1 16.4 + 0.1 16.3 + 0.1" 15.9 + 0.1"* 15.7 + 0.1 **c 15.8 + 0.1 **c 

Week 13 15.7 + 0.1 15.5 + 0.1 15.7 + 0.1 15.4 + 0.1 ¢ 15.5 :t: 0.1 15.4 :t: 0.1 c 

Mean cell hemoglobin concentration (g/dL) • . 

Day 5 33.1 + 0.2 33.4 + 0.1 33.6 + 0.2 33.5 + 0.2 33.8 + 0.2** 33.9 + 0.2** 

Week 3 33.9 + 0.3 33.6 + 0.2 33.8 + 0.2 33.9 + 0.3 34.2 + 0.2 c 34.6 + 0.3 ¢ 

Week 13 33.1 + 0.2 32.9 + 0.1 33.2 :i: 0.2 33.1 + 0.1 c 33.2 + 0.2 33.6 + 0.2 *c 

Platelets (103//zL) 

Day 5 901.5 + 21.6 900.0 + 19.3 820.5 + 38.6 915.0 + 28.6 913.3 + 34.3 914.5 + 41.9 

Week 3 788.8 + 33.8 882.3 + 29.6 814.6 + 27.8 c 938.9 + 41.5"* 1,040.8 + 34.0** 1,158.2 + 63.7 **¢ 

Week 13 853.4 + 23.1 880.2 + 42.5 867.9 + 35.6 1,005.6 + 31.0 **c 966.7 + 26.6** 1,141.9 + 46.6 **¢ 

Leukocytes (103/#L) 

Day 5 6.91 4- 0.50 6.60 + 0.45 6.44. + 0.36 7.00 + 0.50 6.85 + 0.56 7.92 + 0.70 

Week 3 7.49 + 0.37 7.85 4- 0.66 8.08 + 0.39 8.23 + 0.37 9.67 + 1.01 10.64 + 0255 **c 

Week 13 5.67 4- 0.30 6.46 + 0.41 5.66 + 0.42 8.69 + 0.65 **c 8.88 + 0.79** 8.11 + 0.78 **c 

Segmented neutrophils (103//~L) 

Day 5 0.65 + 0.10 0.65 + 0.10 0.49 + 0.06 0.83 + 0.10 0.97 + 0.24 2.12 + 0.48** 

Week 3 0.98 + 0.17 1.11 + 0.07 1.19 + 0.14 1.61 + 0.21"* 1.76 + 0.23** 3.78 ± 0.28 **c 

Week 13 0.82 + 0.11 1.13 ± 0.13 0.87 ± 0.12 2.31 + 0.56 **c 2.14 + 0.23** 2.74 :t= 0.52 **c 

Lymphocytes (103/ttL) 

Day 5 6.13 + 0.47 5.92 + 0.44 5.85 + 0.32 6.06 + 0.43 5.77 + 0.44 5.72 + 0.82 

Week 3 6.32 + 0.22 6.59 + 0.62 6.59 + 0.32 6.51 + 0.20 7.77 + 0.82 6.66 + 0.52 c 

Week 13 4.78 + 0.23 .5.28 + 0.37 4.72 + 0.36 6.28 + 0.30 *c 6.63 + 0.63* 5.20 + 0.51 c 

Monocytes (103//~L) 

Week 13 0.01 + 0.01 0.00 + 0.00 0.01 + 0.01 0.01 + 0.01 c 0.02 + 0.01 0.02 + 0.02 c 

Eosinophils (103//~L) 

Day 5 0.11 + 0.04 0.06 4- 0.02 0.09 + 0.01 0.12 + 0.04 0.08 + 0.02 0.12 :i: 0.04 ., 

Week 3 0.18 + 0.06 0.15 + 0.04 0.32 + 0.08 0.12 + 0.04 0.11 + 0.05 0.19 + 0.06 c 

Week 13 0.07 + 0.02 0.07 + 0.03 0.06 + 0.02 O.lO + 0.03 c 0.08 + 0.03 0.II + 0.05 c 

Thromboplastin time (seconds) 

Week 13 7.85 ± 0.23 7.95 + 0.19 7.62 ± 0.28 7.60 + 0.20 7.55 + 0.18 7.56 ± 0.20 b 

Activated partial thromboplastin time (seconds) 

Week 13 29.34 + 1.32 e 27.15 4- 1.23 h 26.57 + 1.79 h 28.00 + 1.37 i 28.90 + 0.82 h 28.53 + 1.05 g 
288 t-Butylhydroquinone, NTP. TR459 

TABLE G3 . ,

Hematology and Clinical Chemistry Data for Mice in the 13-Week Feed Study of t-Butylhydroquinone (continued) 

0 ppm 2,500 ppm 5,000 ppm 10,000 ppm 20,000 ppm 40,'000 ppm 

Female (continued) 

n 10 9 10 8 9 8 

Clinical Chemistry 

Blood urea nitrogen (mg/dL) 

Day 5 20.2 5:1.6 i " 21.5 5:1.0 b 20.5 5:1.2 c 17.8 5:1.4 e 15.5 5:1.0 *e 22.5 I 

Week 3 27.9 5:1.3 e 22.9 ± 1.3" 23.3 5:1.3 *b 21.2 5:1.8 **d 16.4 5:0.7 **e • 15.8 5:'1.6 *gg 

Week 13 29.2 5:1.9 25.1 5:2.3 b 28.5 5:1.9 c 19.0 5:1.1 **e 18.1 5: 0.8** 20.6 5: 2..6"*! 

Creatinine (mg/dL) ~ 

Week 3 0.31 5: 0.03. g 0.32 5:0.03 f "0.29 5:0.02 h 0.26 5:0.02 g • 0,29 5:0,01 j 

Week 13 0.32 5:0.01 ~ 0.34 5:0.04 i 0.34 5:0.03 g 0.26 5:0.03 f 0.24 5:0.02 g .0.33 5:0.03 j 

Total protein (g/dL) 

Week 3 5.35:0.1 f -- 5.7 ± 0.1 j 5.01 5.5 5:0.1 f B 

Week 13 5.6 5:0.1 g 5.71 5.4 ::k 0.1 f - - " - 5.3 5:0.1 j 

Albumin (g/dL) . 

Week 3 3.2 5:0.0 f - - 3.5 5:0.1 j 3.01 3.4 5: 0A j 

Week 13 3,5 5:0.0 e 3.7 5:0.2 f 3.4 ::1:0.1 f 3.5 5:0.1 j 3.4 5:0.2 j 

Alanine aminotransferase (IU/L) 

Day 5 28 5:3 h 30 5:5 b 28 5:4 c 33 5:4 e 25 5:2 h 31 5:3 f 

Week 3 40 5:13 e 29±4 24 5:4 b 39 5:7 d 34 5:4 e 35 5:7 g 

Week 13 39 5:6 30 5:2 e 40 5:5 e 40 5:7 i 36::t::4 53 5:19 f 

Alkaline phosphatase (IU/L) 

Day 5 229 5: 8! 199 5:9 b 200 5:9 e 210 5:6 e 172 5:11 **e 156 5:18 **f 

Week 3 156 ± 7 t 154 5:4 i 155:5:3 e 133 5:7 *h Ill ± 7 **h 98 5:14 *j 

Week 13 92 5:4 b 103 5:5 h 110 ± 7 f 102 5:9 g 91 5:5 g 771 

Creatine kinase (IU/L) 

Day 5 160 ± 42 88 ± 16 99 5:15 152 ± 43 73 5:: 6 65 ~ I0" 

Week 3 32 5:2 f 345:8 j 39, 5:16 g 381 37 5: 8. g 421 

Week 13 "~ 41 5:6 e 60 5:26 g 38 5:3 g 301 35 5: - -

Sorbitol dehydrogenase (IU/L) 

Week 3 

Week 13 

27 5:~ 3 h 

27 ± 1 e 

23 5:2 h 

28 5:3 e 

27 ±4 b 

26 ::k 3 h 

23 ±3 

23 5:2 f 

25 5: 

30 :t: 

5 h 

4 e 

22 d: 3 g 

32:1:1 f 

Bile acids (#tool/L) ~, 

Day 5 12.3 5:0.8 g 17.2 5:1.9 i 11.3 ± 0.3 g 14.0 5:1.5 f 13.0 ± 1.5 g 18.0 I 

Week 3 9.6 5:1,1 e 9.9 ± 1.7 d 9.3 5:1.2 12.1 5:2.2 d 8.8 5: 0.8 10.5 ± 1.4 

Week 13 16.0 5:1.3 e 14.9 5:1.8 b 17.0 5:1.6 c 18.4 5:1.9 e 12.5 5: 1.4 d 13.8 ± 2.9 i 

* Significantly different (Pa0.05) from the control group by Dunn's or Shirley's test 

** Pa0,01 

a Mean 5: standard error. Statistical tests were performed on unrounded data. 

b n=8 

c n=9 ' ~ 

d n=lO 

e n=7 

f n--3 

g n=4 

h n=6 

i n=5 

J n=2 

k Not measured at this exposure level 

I n= 1; no standard error calculated , 
,~,~--~ ~ , , ~ _ ....... ~ ~ ~ :: -, 

I 

t-ll~uty]hy~roqainone, NTP TR 459 2~9 

T~L~ G4 

Hem~*o~ogy D~*e ~'or Mince ~ 

o~" t-~u~yll~ydroqu~none a 

~he ~l$-Mon*h ~n~eri~n ~v~u~tlon in ~he 2-Year Feed S~udy 

0 ppm 1,250 ppm 2,500 ppm 5,~ ppm 

Mele 

n 10 10 9 9 

Hematocrit (%) 

Hemoglobin (g/dL) 

Erythrocytes (106/~L) 

Reticulocytes (106/~L) 

Nucleated erythrocytes (103/~L) 

Mean cell volume (fL) 

Mean cell hemoglobin (pg) 

Mean cell hemoglobin 

concentration (g/dL) 

Platelets (103/~L) 

Leukoeytes (103/pL) 

Segmented neutr,o~p, hils (103//~L) 

Lymphocytes (10/~L) 

Atypical lymphgeytes (103//~L) 

Monocytes(103/~L) 

Eosinophils (I~/~L) 

45.1 5:0.4 

15.0 ± 0.1 

9.66 ± 0.08 

0.21 ::1:0.01 

0.04 ± 0.02 

46.7 ± 0.2 

15.6 ± 0.1 

33.4 ± 0.1 

1,283 ± 57 

7.84 ± 0.38 

1.46 ± 0.16 

6.13 ± 0.24 

0.00 ± 0.00 

0.12 ± 0.03 

0.13 ± 0.03 

46.2 :t: 0.8 

15.3:1:0.2 

10.08 ::i: 0.20 

0.20:1:: 0.02 

0.01 ± 0.01 

45.9 ± 0.4 

15.2 ::t: 0.1" 

33.1 ± 0.2 

1,301 5:75 

8.63 ± 0.57 

1.73 5:0.10 

6.55 ± 0.59 

0.00 ~ 0.00 

0.19 5:0.09 

0.17:1:0.03 

45.3 ± 0.4 

15.2 ± 0.1 

9.77 ± 0.12 

0.20 ± 0~02 

0.02 ± 0.01 

46.4 ± 0.2 

15.6 ± 0.1 

33.6 ± 0.2 

1,240 ± 65 

8.77:5:0.40 

1.63 ± 0.16 

6.80 ± 0.30 

0.00 ± 0.00 

0.21 ± 0.05 

0.13 5:0.05 

46.0 ± 2.2 

15.1 5:0.7 

9.92 :t: 0.74 

0.47 ± 0.15" 

0.01 ± 0.01 

47.2 ± 1.6 

15.5 ± 0.4 

32.9 ± 0.5 

1,294 ± 94 

8.21 ± 0.46 

1.54 ± 0.14 b 

6.03 ± 0.38 b 

0.00 ± 0.00 

0.19 ± 0.05 

0.10 :t: 0.04 

Female 

n 

. 

9 8 9 6 

Hematoerit (%) 

Hemoglobin (g/dL) 

Erythrocytes (106/#L) 

Retieuloeytes (106/~L) 

Nucleated erythrocytes (103/~L) 

Mean cell .volume (fL) 

Mean cell hemoglobin (pg) 

Mean cell hemoglobin 

concentration (g/dL) 

Platelets (103/~L) 

Leukocytes (103/~L) 

Segmented neutro~hils (I~/#L) 

Lymphoeytes (10°/t~L) 

Atypical lymphocytes (103//~L) 

Monocytes (103/~L) 

Eosinophils (103//~L) 

44.5 ± 0.3 

14.7 ± 0.1 

9.78:1:: 0.06 

0.19 ± 0.02 

0.00 5:0.00 

45.5 ± 0.3 

15.1:5:0.1 

33.1 ± 0.1 

1,165 ± 45 

5.51:5:0.39 

1.22 ± 0.15 

4.02 5:0.27 

0.00 ± 0.00 

0.08 ± 0.04 

0.19 ± 0.04 

45.0 ± 0.4 

14.9 ::1: 0. I 

9.97 ± 0.10 

0.24:1:0.02 

0.02 ± 0.01 

45.2:5:0.4 

15.0:1: 0. I 

33.1 :t: 0.1 

1,242 :t: 48 

5.78 ± 0.49 

1.03 :l: 0.11 

4.46 ± 0.43 

0.00 ± 0.00 

0.11 ± 0.03 

0.17 ± 0.03 

44.4 5:0.5 

14.7 ± 0.2 

9.79 ± 0.12 

0.25 ± 0.03 

0.00 ± 0.00 

45.3 5:0.3 

15.0 ± 0.1 

33.1 ::1:0.2 

1,249 ± 51 

7.00 :t: 0.45 

1.62 ± 0.15 

5.03 ± 0.36 

0.00 ± 0.00 

0.13 ± 0.05 

0.21 ± 0.05 

44.6 5:0.2 

14.9 ± 0.1 

9.97 :t:: 0.08 

0.23 ± 0.02 

0.01 ± 0.01 

44.8 ± 0.3 

14.9 ± 0.1 

33.3 ± 0.2 

1,288 ::t: 58 

6.28 ± 0.67 

1.80 ± 0.23 

4.23 ± 0.43 

0.00 ± 0.00 

0.09 ± 0.04 

0.16 ± 0.06 

* Significantly different (P~0.05) from ~he control group by Dunn's test 

a Mean ± standard error. Statistical tests were performed on unrounded data. 

b n----8 
290 t-Butylhydroquinone, NTP TR 459 
I 

i 

I 

I 

I 

I I' ' 

AIFJFJENTIJ) IIX IBI 

JRIEIFJROIINUCC1riiVIE 1rJI§§1UIE IEV AIL1UA 1riiON§9 

IE§1rJR01U§ CCYCCILIE CCIBIAJRACC1riEJRIIZA 1riiON 9 

ANTIJ) 1riEJRA TO ILOCG Y 

TABLE lffi:D. Summary of Reprodunctive Tnssune lEvanunationns anndllEstrouns Cycne Cllnaracterizationn 

for Rats inn tine :8.3-Weelk JFeedl §tundly of t-BuntyHilnydlroquninnonne ••••••••••••••••••• 292 

TABLE lHl2 Maternal Toxicity inn JF3.:841/N Rats (JF ) 0 lExposedl to t-BuntyHilnydlroquninnonne inn JFeeull 

Dunrinng tllle Perinatal 1Expos1111re IPilnase of tllne ].3-W eelk §tundly • • • • • • • • • • • • • • • • • • • • 293 

TABLE lffi3 DeveHopmental Toxicity in IF3.:841/N Rats (IF ) 1 JFonnowinng Maternnan lExposunre 

to t-ButyHinydlroquninnone inn !Feed! Dunring ltllne IPerinatan lExposunre IP'Ilnase 

of ltllne ll3-W eelk §tundly • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 293 

TABLE lffi4 §unmmary olf Reproductive Tnssune lEvanunations andllEstrouns Cyde Cllnaracterization 

lfor Mice inn tllne B-Weelk !Feed! §tundly olf t-BuntyHilnydlroquninonne ••••••••••••••••••• 
292 t-Butylhydroquinone, NTP TR459 

TABLE HI 

Summary of Reproductive Tissue Evaluations and Estrons Cycle Characterization for Rats in the 13-Week Feed Study 

of t-Butylhydroquinone a 

0 ppm , 2,500 ppm 5,000 ppm 10,000 ppm 

Male 

n I0 I0 I0 I0 

Weights (g) 

Necropsy body wt 340 + 7 339 ± 3 313 ± 7** 284 ± 6** 

L. eauda 0.138 ± 0.004 0.149 ± 0.003* 0.142 ± 0.003 0.139 ± 0.003 

.L. testis 1.48 ± 0.03 1.58 ± 0.02** 1.49 ± 0.02 1.47 ± 0.01 

L. epididymis 0.414 + 0.008 0.434 ± 0.004* 0.412 ± 0.006 0.410 ± 0.004 

Spermatid parameters. 

Spermatid heads (107/g testis) 12.45 ± 0.68 11.28 ± 0.52 10.02 ± 0.42* 11.57 ± 0.50 . 

Spermatid heads (107/testis) 18.35 ± 1.00 17.76 ± 0.72 14.89 ± 0.67* 16~96 ± 0.74 

Spermatid count (mean/10 -4 mL suspension) 

917.3 + 50.1 887.8 ± 36.2 744..3 ± 33.7* 848.0 ± 37.2 

Epididymal spermatozoal parameters 

Motility (%) 92.77 ± 0.69 91.87 ± 0.48 92.79 ± 0.39 90.91 ± 0.72 

Concentration (106/g cauda epididymal tissue) 

680.7 ±42.2 661.0 ± 39.8 632.7 ± 35.7 592.3 ± 28.5 

Female 

10 10 10 I0 

Necropsy body wt (g) 201 ± 5 199 ± 3 184 ± 2** 173 ~: 3** 

Estrous 5.00 ± 0.007 6.25 ± 0.35 **b 6A0 ± 0.34* 5.44 ± 0.27 b cycle length (days) 

Estrous stage (% of cycle) 

Diestms 49.2 50.8 43.3 56~7 

Proestrus 10.8 8.3 14.2 8.3

Es~s 32.5 32.5 32.5 27.5

Metestms 7.5 8.3 10.0 7.5

* Significantly different (P~0.05) from the control group by Williams' or Dunned' s test (organ and body weights) or Dunn's test (spermatid and epididymal 

spermatozoal parameters) 

** P~O.01 

a Dam are presented as mean ± standard error. 

b Estrous cycle was longer than 12 days or unclear in 2 of I0 animals. 
t-~u~yfhydroquinone, NT]P,T~ 459 293 

TABLE ]Hi2 

Materna~ Toxfcfty fn F3,~4/N floats (F o) Exposed to t-~utyfhydroquinone fin Feed During the lPerfnataf Exposure ~Phase 

of the 13-Week Study a 

0 ppm 2,500 ppm 5,000 ppm 10,000 ppm 20,000 ppm 40,000 ppm 

Number examined 16 16 16 16 16 16 

Number pregnant 9 (56%) 10 (63 %) 10 (63 %) 11 (69%) 0"* 0"* 

Maternal body weight (g) 

Day 1 141 ± 6 142 ± 6 141 ± 5 141 ± 6 140 ± 5 141 ± 5 

Day7 149 ± 6 152 ± 7 147 ± 5 143 ± 7** 131 ± 4** 114 ± 6** 

Day 15 161 ± 8 163 ± 7 158 ± 5 153 ± 8** 141 ± 5** 112 ± 10"* 

Duration of gestation (days) 22.9 ± 0.3 23.0 ± 0.0 23.0 ± 0.0 23.3 ± 0.5 

** Significandy different (P~0.01) from the control group 

a Data are presented as mean ± standard deviation. 

TABLE H3 

Developmental Toxicity fn F344/N ]Rats (F t) FoffowfngMaternal Exposure to t-~u~y~hydroqufuone in Feed 

Durfng the lPerinat~fl Exposure ~hase of the 13-Week Study a 

0 ppm 2,500 ppm 5,000 ppm 10,000 ppm 

Number of dams/litters examined 9 10 10 11 

Pups delivered (total) 68 106 78 92 

Pups delivered per litter 7.6 ± 3.6 10.6 ± 1.8 7.8 ± 3.4 8.4 ± 3.1 

Pups surviving 4 days (precull) 

per number of pups delivered 66/68 (97%) 105/106 (99%) 77/78 (99%) 83/92 (90%)** 

Pup weight per litter (g) 

Day 4 (precull) 6.8 ± 0.6 7.0 ± 0.7 6.6 ± 0.7 6.8 ± 0.7 b 

Pups surviving 28 days per number of pups 

selected on day 4 (postcull) 58/58 (100 %) 78/79 (99 %) 58/66 (88 %) 43/69 (62 %)** 

Pup weight per litter (g) 

Day 28 49.2 ± 5.6 50.8 ± 6.3 45.1 ~ 4.3 b 42.0 ± 3.6 c 

** Significantly different (P~0.01) from the control group 

a Data are presented as mean ± standard deviation. 

b n=9 

e n=6 
294 t-Butylhydroquinone, NTP TR 459 

TABt~: H4 

Summary of Reproductive Tissue Evaluations and Estrons Cycle Characterization for Mice in the 13-Week Feed Study 

of t-Butylhydroquinone a 

.. O.ppm 2,500 ppm i0,000 ppm " 

• 

40,000 ppm • 

Male , 

n I0 9 1o 8 

Weights (g) 

Necropsy body wt 34.1 ± 0.7 31.9 ± 0:7" 30d 5: 0.4** • 23.7 ± 0.4** 

L. canda 0.013 5:0.001 0.012. 5:0.001 0,007 5:0.001 **b 0.009 5: 0.001"* 

L. testis 0.114 5:0.003 0.109. 5:. 0.003 0.106 ± 0.002 0.101 ± 0.004** 

L. epididymis 0.042 ± 0.002 0.038 ± 0.002 0.036 5: 0.001" " 0.031 ± 0.001"* .,. 

Spermatid parameters 

Spermatid heads (107/g testis) 22.84 5:0.58 24.46 5:0.95 c 24.88 5:1.36 25.65 5:1.28 c 

Spermatid heads (107/testis) 2.60 5:0.10 2.67 5:0.11 c 2.63 5:0.13 2.61 5:0.17 c 

Spermatid count (mean/lO-' mL suspension) 

811.8 5:31.4 833.6 5:35.0 c 823.8 5:41.9 815.0 5:51.9 c 

Epididymal spermatozoal parameters 

Motility (%) 92.54 5:0.83 88.71 5: 1.17" 91.25 5:0.64 89.21 5:2.83 

Concentration (10~/g cauda epididymal tissue) 

1,732 ± 123 2,054 5:184 2,922 5:426 1,822 ± 228 

:, 

Female 

I0 10 9 9 

Necropsy body wt (g) 30.7 5:0.7 b 28.5 5:1.0 *b 24.1 ± 0.4 **d 20.3 5: 0.5** 

Estrous cycle length (days) 4.25 5:0.13 4.25 5:0.13 4.94 5:0.40 5.80 5:0.86 *e 

Estrous stage (% of cycle) 

Diesuus 31.7 33.3 27.8 44.4 

• Proestms 17.5 15.0 13.9 '14.8 

Estms 36.7 41.7 43.5 31.5 

Metestrus 14.2 9.2 14.8 9.3 

Unclear diagnosis 0.0 ,.. 

0.8 0.0 0.0 

* Significantly different (P<0.05) from the control group by Williams' or Dunnett's test (organ and body weights) or Dunn's test (spermatid and epididymal 

spermatozoal parameters) 

** P<0.01 

a Data. are presented as mean + standard error. 

b n=9 

¢ n----7 

d II----8 .. " 

e Estrous cycie was longer than 12 days or unclear in 4 o~ 9 animals. 
295 

AI EH] ZX 

CHEMICAL CHAI AC EI ZA ©H 

AHI) ] ©5E 

]~'ROCUREMENT AND CHARACTERIZATION OF t-~UTYLHYDROQUINONE ....................... 296 

]PREPARATION AND ANALYSIS OF DOSE FORMULATIONS ................................ 2~7 

'FIGURE [~ Infrared Absorption Spectrum of t-Butynhydroqu~none ....................... 298 

~'IGURE ~2 Nucaear Magnetic l~esonance Spectrum of t-Buty~hydroqu~none ................. 2~ 

TABLE ~1 Preparation and Storage of Dose Formulations an the Feed Studies 

of t-~uty~hydroqa~noae ............................................ 300 

TABLE ]~2 ~esu~ts of AnaHyses of Dose For~nuHafions Administered to Rats and l~ce 

nn the 13-Week Feed Studies of t-~uty~hydroqa~none ........................ 301 

TABLE ~3 ~es~ts of Analyses of Dose Formulations A~in~n~stered to ~ats and ~ce 

~n the brig-Term and 2-Year Yee~ Studies of t-~uty~hyd~oqu~none ............... 303 

T~LE ~4 ~esu~ of Referee Analyses of Dose ~ormunafioas Admin~tere~ to ~ats and Mice 

~n the 13-Week, brig-Term, and 2-Year ~ee~ Studies o~ t-~uty~hy~roqu~none ....... 30~ 
,296 t-Butylhydroquinone,NTP TR 459 

CHEMICAL CHARACTERIZATION AND 

DOSE FORMULATIONS 

PROCUREMENT.AND CHARACTERIZATION OF t-BUTYLHYDROQUINONE 

t-Butylhydroquinone was obtained in two lots (187-1 and 1089-1) from U.O.P., Inc., (Des Plaines, IL). 

Lot 187-1 was used in the 13-week, long-term, and 2-year studies. Lot 1089-1 was used in the long-term 

and 2-year studies. Identity, purity, and stability analyses were conducted by the analytical chemistry 

laboratory, Midwest Research Institute (Kansas City, MO). Reports on analyses performed in support of 

the t-butylhydroquinone studies are on file at the National Institute of Environmental Health Sciences 

(NIEHS). 

Each lot of the chemical, a fine beige powder, was identified as t-butylhydroquinone by infrared, 

ultraviolet/visible, and nuclear magnetic resonance spectroscopy. All spectra were consistent with the 

literature spectra (Sadtler Standard Spectra) of t-butylhydroquinone (Figures I 1 and 12). • , 

-The purity of each lot was determined by elemental analyses, Karl Fischer water analysis, functional group 

titration, thin-layer chromatography (TLC), and high-performance liquid chromatography (HPLC). 

Functional group titration was performed by dissolving samples in.methanol, water, and 1 N sulfuric acid. 

Diphenylamine indicator solution was added to the samples and the samples were titrated with 0.1 N ceric 

sulfate to a colorimetric endpoint. TLC was performed on Silica Gel 60 F-254 plates with two solvent 

systems: I) acetone:toluene:chloroform (40:35:25), and 2) toluene:acetone (95:5) with phenol as a 

reference standardl Plates were examined under visible and ultraviolet light at 254 nm and sprayed with 

first a 0:4 % methanolic solution of 2,6-dichloroquinonechloroimide and then 10 % aqueous sodium 

carbonate. HPLC was performed for lot 187-1 using a Waters Resolve C18 column with a solvent system 

containing water:acetonit~ile (90:10) with 1% glacial acetic acid at a flow rate of 1.0 mL/minute, and 

detection at 280 ran. HPLC was performed for lot 1089-1 using a WatersResolve C18 column with a 

solvent system containing water:acetonitrile (75:25) with 1% glaci~il acetic acid for 20 minutes followed by 

100% acetonitrile with 1% glacial acetic acid at a flow rate of 1.0 mL/minute, and detection at 280 rim. 

Elemental analyses for carbon and hydrogen were in agreement with the theoretical values for 

t-butylhydroquinone. Karl Fischer water analysis indicated less than 0.4% water for lot 187-1 and 0.16% 

water for lot 1089-1. Functional.group titration indicated a purity of 99.6% ± 0.5% for lot 187-1 and 

99.1% ± 0.4% for lot 1089-1. TLC of lot 187-1 indicated a major spot and two trace impurities using the 

first system and a major spot, one minor impurity, and one trace impurity using the second system. For lot 

1089-1, both TLC systems indicated a major spot, one minor impurity, and one trace impurity. HPLC of 

lot 187-1 indicated a major peak and one impurity peak with an approximate area of 0.13 % relative to the 

major peak. HPLC of lot 1089-1 indicated a major peak and no impurities with peak areas greater than 

0.1% relative to the major peak. Additional HPLC analyses were performed using a linear gradation in the 

solvent system, changing it from 90:10 to 0:100 (lot 187-1) or from 75:25 to 0:100 (lot 1089-1) over a 

20-minute period. These analyses resolved additional impurities for lots 187-1 and 1089-1 with peak areas 

of 0.3% to 0.4% relative to the major peak. Lots 1089q and 187-1 were concomitantly analyzed by the 

same HPLC method used for the initial purity analyses. The overall purity for each lot was 99%. 

Stability. studies of the bulk chemical were performed by the analytical chemistry laboratory. Stability 

studies were performed using the HPLC methods described previously for the purity analysis, but .with a 

solvent system ratio of 80:20. These studies indicated that t-butylhydroquinone was stable as a bulk 

chemical when stored for 2 weeks, protected from light, at temperatures up to 60* C. To ensure stability, 

the chemical was stored at room temperature in sealed containers, protected from light. Stability was • 

monitored 9 weeks after the beginning of the 13-week studies and within 30 days after the end of the studies 
t-Butynhy~lroquinone,NTP TR 459 2~ 

using HPLC. For the long-term and 2-year studies, stability was monitored at approximately 4-month 

intervals and within 30 days after the end of the studies using HPLC. No degradation of the bulk chemical 

was detected. 

]~.E~AIi~AT~ON AND A.NAL'YS~S OF DOSE ~'~qIJLAT~[~NS 

The dose formulations for the 13-week, long-term, and 2-year studies were prepared weekly. Formulations 

were prepared by first forming a premix of a small amount of feed and the required weight of chemical. 

This premix and additional feed were then mixed in a twin-shell blender for 15 minutes, with an intensifier 

bar used for the initial 5 minutes.. Each dose formulation was poured into a labeled, double-thickness plastic 

bag that was placed in labeled containers and protected from light. Formulations were stored for no longer 

than 21 days (13-week studies) or 18 days (long-term and 2-year studies) at 5 ° C (Table I1). 

Homogeneity analyses of the dose formulations were conducted by the analytical chemistry laboratory. 

Prior to the start of the 13-week studies, a preliminary mixing of the 2,500 ppm and 40,000 ppm dose 

formulations was performed. Triplicate samples were analyzed for homogeneity, and analytical results 

indicated that the samples were not homogeneous. The study laboratory Changed the analytical method 

slightly (samples were diluted with mobile phase instead of the MRI-recommended acetonitrile) and 2 weeks 

after the start of the 13-week studies, results from the analysis of the 2,500 ppm dose formulations were 

within 10% of the theoretical value. Prior to the start of the long-term and 2-year studies, the study 

laboratory performed homogeneity analyses on the 125 ppm dose formulation (homogeneity determinations 

had been previously performed on greater concentrations). Three samples from this dose formulation, taken 

from three different areas of the blender, were analyzed in duplicate; results of the analyses were 

unacceptable, and a remix and second analysis were performed. Results of the second analyses were within 

10 % of theoretical values. 

Stability studies of the 5,000 ppm dose formulation were conducted by the analytical chemistry laboratory. 

Samples (10 g) of the dose formulation were extracted with 100 mL of acetonitrfle and shaken for 

5 minutes. The extracts were centrifuged, and 25 mL aliquots of the extracts were mixed with 2 mL of 

internal standard solution (propiophenone, 10 mg/mL acetonitrile) and diluted to 100 mL with acetonitrile. 

Portions of the final diluted solutions were filtered (0.45/~m pore size) and analyzed using HPLC. HPLC 

was performed using a Waters ~Bondapack C18 column with a solvent system of water:acetonitrile:acetic 

acid (50:50:1) at a flow rate of 1.0 mL/minute. For the stability analysis, the 5,000 ppm formulation was 

prepared and stored for up to 21 days in the dark at room temperature, 5 ° C, or -20 ° C, or was stored for 

up to 7 daysunder animal room conditions. Stability of the 5,000 ppm formulation was confirmed for at 

least 3 weeks when stored in sealed containers in the dark at 5 ° C. A 5.3 % loss of chemical was observed 

after 2 days of storage under animal room conditions. Based on these findings, the dose formulations were 

stored in sealed containers .in the dark at 5" C for no longer than 3 weeks. 

Periodic analyses of the dose formulations of t-butylhydroquinone were conducted at the study laboratory. 

using HPLC. For the 13-week studies, dose formulations were analyzed at the beginning, in the middle, 

and at the end of the studies (Table 12). During the long-term and 2-year studies, dose formulations were 

analyzed approximately every 8 weeks (Table 13). In the 13-week studies, 98% (43/44) of the dose 

formulations used were within 10 % of the target concentration with no value greater than 16 % from the 

target concentration. In the long-term studies, 219 of the 220 dose formulations used for rats and 185 of the 

186 dose formulations used for mice were within 10% of the target concentration. Results of periodic 

referee analyses performed by the analytical chemistry laboratory agreed with the results obtained by the 

study laboratory (Table 14). 
298 t-Butylhydroquinone, NTP TR 459 

~ I ' I ' I ' l ' 

~o ~ 

X It ~ 

~= ~ ~°~ ~ 

~9 ~ ~ ~ 

~ 9 , 

~1" E 

~ II 0 ~ ~-~ 

~ 

-= .~ 

~m~ 

~o~ ~ ~ ~ ~ 

~ ~ 0 0 

~o 

~" 

, 

! 

_ 

'_ 

. ~ 

. 

~ ~ 

~ := 

~ 

= ~ 

=lAX= 

£ 

~. 

~ 

~, 

~ 

-

8 

•~.~ ~ ~ ~:~. O..1~ 

~_~-E~ 

0~ 0 0 ~ 

--~~- ~0 ~'~ ":~ ~ o ..

:~: ~~ 

~oE ~ ~ ~0 

~oo~ 

8 

o 

8 

O r,. O "~" E~" ~ o~m 

>-~ .~.E ~.. 

~Ez 

~ 

~ 

~ 

0 

•--

~-~ 

0 

0 

~ 

0 

~ ~ 0 ~ 0 ~ 0 

o 

0

,~ 

(%) NOISSII~iSNVl:II 

FIGURE I1 

Infrared Absorption Spectrum of t-Butylhydroquin~ne 

~ ? ~ 
299 t-Butylhydroquinone, NTP TR ,~59 

o 

o 

~-'~0 i= 

0 

L J~----__~ A A 

, o Z ~00~ 

~, o ~ w ~o E.~ O 

o= ~ x 

~- ~ ~ .~ -~ 

~-.~m ~ 0 ~ ~,~° ~ ~.~~.~ -~o~ ~

m~~ 

O

e~ ~~ .~ .~ .~....q ~ E X ~.~0o ~ A ~ A [ ~

-~e~ ~. ~ ~ ~ ~ ~ ~ --mOO ~ I 

J 

I 

i~ 

FIGURE ~2 

Nuclear Magnetic ~tesonance Spectrum of t-Butylhydroquinone I 

I 

! 

I 

[ ̧ = 

[ 
300 t-Butylhydroquinone, NTP TR 459 

TABLE I1 

Preparation and Storage of Dose Formulations in the Feed.Studies of t-Butylhydroquinone 

13-Week Studies 

.. 

lh'eparation 

A premix of feed and t-butythyd~o= 

quinone was prepared by mixing the 

chemical and feed in a beaker and 

stirring until a homogeneous mixture 

was obtained. The premix was then 

blended with feed in a Patterson=Kelly 

twin-shell blender with the intensifier 

bar on for 5 minutes and off for 

10 minutes. Doses were prepared 

weekly. 

Chemical Lot Number 

187-1 

Maximum Storage Time 

21 days 

Storage Conditions 

Formulations were stored in sealed 

containers in the dark at 5* C. 

Study Laboratory 

Southern Research Institute 

(Birmingham, AL) 

Referee Laboratory 

Midwest Research Institute 

(Kansas City, MO) 

Long-Term Study 

Same as 13-week studies 

187-1 and 1089-1 

18 days 

Same as 13-week studies 

Southern Research Institute 

(Birmingham, AL) 

Midwest Research Institute 

(Kansas City, MO) 

2-Y~ar Study 

Same as 13-week study 

., 

187-1 and 1089-1 

18 days 

Same as 13-week studies 

Southern Research Institute 

(Birmingham, AL) 

Midwest Research Institute 

(Kansas City, MO) 
t-l/~u~yihydro~uiraone, NTI? TR 4~9 30~ 

T~ ~I2 

~e~u~ o~ An~yses o~ Dose ~'orm~om A~:hraira~stered ~o ~ ~nd I~,tIice in the 13-Week Feed Studies 

o1~ ~-~ty~hydro~uinone a 

Date IPrepared Date Analyzed 

Target 

Concentration 

(mg/g) 

Determined 

Concentration 

(mg/g) b 

% Difference 

from Target 

15 Augus t 1988 22-23 August 1988 2.5 

2.5 

2.5 

40 

40 

40 

2.17 c'd 

2.34 c'd 

2.44 c'd 

36.0 c'd 

38. I c,d 

38.2 c'd 

- 13 

-6 

-2 

- 10 

= 5 

-4 

]I~s and Mice 

1 December 1988 2-3 December 1988 2.5 

2.5 

2.5 

2.5 

2.5 

2.5 

5 

5 

5 

5 

10 

10 

10 

20 

40 

2.60 d'e 

2.64 d'f 

2.33 d'g'h 

2.50 

2.71 

2.39 h 

4.98 

4.73 h 

5.05 

5.00 

9.58 

9.04 h 

9.68 

20.2 

38.5 

+4 

+6 

-7 

0 

+8 

-4 

0 

-5 

+ 1 

0 

-4 

- 10 

-3 

+ 1 

-4 

4 December 1988 10 9.74 -3 

12 January 1989 

• 

13 January 1989 2.5 

2.5 

2.5 

2.5 

5 

5 

5 

5 

10 

10 

10 

10 

20 

40 

2.30 

2.29 

2.18 c 

2.28 

4.50 

4.50 

4.74 

4.74 

9.56 

10.2 

9.10 

9.07 

19.2 

39.4 

-8 

-8 

- 13 

-9 

- 10 

- 10 

-5 

-5 

-4 

+2 

-9 

-9 

-4 

-2 

17 January 1989 18 January 1989 2.5 2.52 i + 1 
302 t-Butylhydroquin0ne, NTP TR 459 

TABLE I2 

Results of Analyses of Dose Formulations Administered to Rats and Mice in the 13-Week Feed Studies 

of t-Butylhydroquinone (continued) 

' Target Determined % Difference 

Date Prepared Date Analyzed Concentration Concentration from Target 

(mg/g) (mg/g) 

Rats and Mice (continued) 

9 February 1989 10 February 1989 2.5 ' ' '2:62 +5 

2.5 2.26 -10 

2.5 2.39 h -4 

2.5 2.51 h 0 

5 4.19 . -16 

5 4.84 -3 

5 5.12 +2 

5 5.02 0 

10 9.50 -5 

10 9.82 -2 

10 9.08 ' -9 

10 9.42 -6 

20 19.0 -5 

40 38.0 --5' 

13 February 1989 14 February 1989 5 4.80 i -4 

a 2.5 mg/g=2,500 ppm; 5 mg/g=5,000 ppm; 10 mg/g= 10,000 ppm; 20 mg/g=20,000 ppm; 40 mg/g=40,000 ppm 

b ,Results of duplicate analyses 

e Not used for dosing 

d Homogeneity analysis 

e Sample selection from top of twin-shell blender 

f Sample selection from middle of twin-shell blender 

g Sample selection from bottom of twin-shell blender 

h Results of triplicate analysis 

i Results of remix 

/ 
303 

..... .., .......... ,~ -

t-~u~y~hydro~none, ~ T~ ,~9 

TABLE ~I3 

~es~lts of An~ys~ of Dine Yomulafiom A~n~ered ~o ~ and Mice ~n the ~ng-Te~ 

~d 2-Yes Feed Stud~ of t-Buty~hy~oqu~none a 

Target Dete~ed % Difference 

Date ~epared Date ~yzed Concentration Concentration from Target 

(mg/g) (mg/g) b 

Rats 

6 November 1989 7 November 1989 1.25 1.14 -9 

1.25 1.14 - 9 

1.25 1.10 ¢ - 12 

2.5 2.44 -2 

2.5 2.44 -2 

2.5 2.46 -2 

5 4.87 -3 

5 4.86 -3 

5 4.85 -3 

9 November 1989 9 November 1989 • 1.25 1.22 d -2 

Rats and Mice 

20 November 1989 20-21 November 1989 1.25 1.32 +6 

1.25 1.35 +8 

1.25 1.26 + 1 

1.25 1.26 + 1 

2.5 2.54 +2 

2.5 2.55 +2 

2.5 2.62 +5 

2.5 2.66 +6 

5 5.23 +5 

5 5.14 +3 • 

5 5.20 +4 

5 5.18 +4 • 

5 5.24 +5 

5 5.12 +2 

17 January 1990 18 January 1990 1.25 1.23 -2 

1.25 1.22 -2 

1.25 1.21 -3 

1.25 1.22 -2 

2.5 2.53 + 1 

2.5 2.44 -2 

2.5 2.38 -5 

2.5 2.46 -2 

5 4.66 -7 

5 4.60 -8 

5 4.88 -2 

5 4.76 -5 

5 4.68 -6 

5 4.88 -2 
304 t-Butylhydroquinone, NTP TR 459 

TABLE I3 

Results of Analyses of Dose Formulations Administered to Rats and Mice in the Long-Term 

and 2-Year Feed Studies of t-Butylhydroquinone (continued) 

. ~,: Target Determined % Difference 

Date Prepared Date Analyzed Concentration Concentration from Target 

(mg/g) (mg/g) 

Rats and Mice (continued) 

21 March 1990 22-23 March 1990 1.25 

1.25 

1.25 

1.25 

1.25 

2.5 

2.5 

2.5 

2.5 

2.5 

5 

5 

5 

5 

5 

16 May 1990 . 17 May 1990 1.25 

1.25 

1.25 

1.25 

2.5 

2.5 

2.5 

2.5 

5 

5 

5 

5 

5 

11 July 1990 12 July 1990 1.25 

1.25 

1.25 

1.25 

2.5 

2.5 

2.5 

2.5 

5 

5 

5 

5 

5 

1;16 

1.20 

1.18 

1.17 

1.23 

2.35 

2.33 

2.25 

2.30 

2.30 

4.72 

4.64 

4.69 

4.78 

4.54 

1.26 

1.27 

1.23 

1.18 

2.44 

2.45 

2.41 

2.43 

4.77 

4.86 

5.01 

4.92 

4.61 

1.20 

1.23 

1.18 

1.18 

2.44 

2.41 

2.44 

2.31 

4.75 

4.92 

4.91 

4.96 

4.96 

• 

-7 

-6 

-6 

-2 

-6 

-7 

-10 

-8 

-8 

-6 

-7 

-6 

-4 

-9 

+1 

+2 

-2 

-6 

-2 

-2 

-4 

-3 

-5 

-3 

0 

-2 

-8 

-4 

-2 

-6 

-6 

. -2 

-4 

-2 

-8 

-5 

-2 

-2 

-1 

-1 
t-]~u~y~hydro~ufinone, NT~ T~ 459 305 

TA~L~ ~I3 

~esu~s of An~Jyses of Dose ~ormu~atio~ Administered to ~ and Mice in the Long-Te~n 

and 2-Year ~'eed Studies of t-~nty~hydro~u~nane (continued) 

Target Determined % Difference 

Date Prepared Date Analyzed Concentration Concentration from Target 

(rag/g) (mg/g) 

Rats and Mice (continued) 

5 September 1990 7 September 1990 1.25 1.24 - 1 

1.25 1.22 -2 

1.25 1.24 - 1 

1.25 1.18 -6 

2.5 2.42 -3 

2.5 2.48 - 1 

j: 2.5 2.44 -2 

2.5 2.54 +2 

5 4.86 -3 

5 4.78 -4 

5 4.89 -2 

5 5.06 +I 

5 4.96 -I 

7 November 1990 8 November 1990 1.25 1.20 -4 

1.25 1.17 -6 

1.25 1.23 -2 

1.25 1.23 -2 

2.5 2.49 0 

2.5 2.44 -3 

2.5 2.50 0 

2.5 2.41 -4 

5 5.00 0 

5 4.91 -2 

5 5.05 +1 

5 4.91 -2 

5 4.86 -3 

9 January 1991 10-11 January 1991 1.25 1.205 -4 

1.25 1.086 c - 13 

1.25 1.201 -4 

1.25 1.163 -7 

2.5 2.459 -2 

2.5 2.424 -3 

2.5 2.459 -2 

2.5 2.362 -6 

5 4.889 -2 

5 4.545 -9 

5 4.689 -6 

5 4.462 - 11 

5 4.9022 -2 

14 January 1991 14 January 1991 1.25 1.22 d -3 
• 

306 t-Butylhydroquinone, NTP TR 459 

TABLE 13 

Results of Analyses of Dose Formulations Administered to Rats and Mice in th~ Long-Term 

and 2-Year Feed Studies of t-Butylhydroquinone (continued). = , . 

' Target Determined % Difference 

Date Prepared ' Date Analyzed Concentration Concentration from Target 

' (mg/g) (mg/g) 

Rats and Mice (continued) 

26-27 February 1991 28 February 1991 1.25 

1.25 

1.25 

1.25 

2.5 

2.5 

2.5 

2.5 

5 

5 

5 

5 

5 

1 May 1991 2 May 1991 1.25. 

1.25 

1.25 

1.25 

2.5 

. 2.5 

2.5 

2.5 

5 ' 

5 

5 

5 

5 

19 June 1991 20 June 1991 1.25 

1.25 

1.25 

1.25 

2.5 

2.5 

2.5 

2.5 

5 . 

5 

5 

5 

5 

q~31 

1.24 

1.25 

1.20 

2.31 

2.45 

2.47 

2.42 

4.91 

5.07 

4.80 

4.77 

4.97 

1.28 

1.22 

1.32 

1.29 

2.59 

2.50 

2.55 

2.39 

5.05 

4.88 

5.10 

4.94 

5.08 

1.31 

1.25 

1.25 

1.33 

2.42 

2.53 

2.48 

2.45 

4.84 

4.84 

4.82 

4.97 

4.93 

+5 

-1 

0 

-4 

-8 

-2 

-1 

-3 

-2 

+1 

-4 

-5 

-1 

+2 

-2 

+6 

+3 

+4 

0 

+2 

-4 

+1 

-2 

+2 

-1 

+2 

+5 

0 

0 

+6 

-3 

+1 

-1 

-2 

-3 

-3 

-4 

-1 

-1 
............ ............. ~ . . . . . ~-~ ~ ~ ~ -~ 

t-Butylhydroquinone, N'~ TR ,~9 

TABLE L3 

~esu~s of Analyses oF Dose For~nu~afions Adn~n~sf~ered ~to ~a~ 

and 2-Year Feed S~ud~es of t-~uiy]hydroquinone (continued) 

. Target 

Date Prepared Date Analyzed Concentration 

(mglg) 

Rats and Mice (continued) 

14 August 1991 15-16 August 1991 1.25 

1.25 

1.25 

1.25 

2.5 

2.5 

2.5 

2.5 

5 

5 

5 

5 

5 

9 October 1991 10-11 October 1991 1.25 

1,25 

1.25 

1.25 

2.5 

2.5 

2.5 

2.5 

5 

5 

5 

5 

5 

20 November 1991 21-25 November 1991 1.25 

1.25 

1.25 

1.25 

2.5 

2.5 

2.5 

2.5 

5 

5 

5 

5 

5 

~nd R,~Iice in ~the Long-Tern 

Determined 

Concentration 

(m~/~) 

1.27 

1.17 

1.20 

1.21 

2.38 

2.37 

2.48 

2.25 

4.76 

4.91 

4.76 

4.83 

4.79 

1.25 

1.21 

1.22 

1.26 

2.46 

2.45 

2.50 

2.46 

4.91 

4.85 

4.85 

4.78 

4.85 

1.!9 

1.19 

1.20 

1.19 

2.42 

2.48 

2.26 

2.44 

4.95 

4.80 

4.80 

4.67 

4.78 

307 

% D|fference 

from Target 

+2 

-6 

-4 

-3 

-5 

-5 

- 1 

- 10 

-5 

-2 

-5 

-3 

-4 

0 

-3 

-2 

+ I 

-2 

-2 

0 

-2 

-2 

-3 

-3 

-4 

-3 

-5 

-5 

-4 

-5 

- 3 

-I 

- 10 

-2 

- 1 

-4 

-4 

-7 

-4 
308 t-Butylhydroquinone, NTP TR 459 

TABLE I3 

Results of Analyses of Dose Formulations Administered to Rats and Mice in the Long-Term 

and 2-Year Feed Studies of t-Butylhydroquinone (continued) 

Target Determined % Difference 

Date Prepared Date Analyzed Concentration Concentration from Target 

(mg/g) (mg/g) 

Rats (continued) 

22 January 1992 23 January 1992 1.25 1.21 -3 

1.25 1.20 -4 

1.25 1.24 - 1 

2.5 2.49 0 

2.5 2.42 -3 

2.5 2.60 +4 

5 • 5.01 0 

5 4.98 0 

5 4.90 -2 

5 5.03 + I 

18 March 1992 19 March 1992 1.25 1.25 0 

1.25 1.26 + 1 

2.5 2.52 + 1 

2.5 2.48 - 1 

5 5.03 + 1 

5 5.00 0 

5 5.01 0 

27 May 1992 28 May 1992 1.25 1.25 0 

1.25 1.26 +1 

2.5 2.47 • -1 

2.5 2.49 0 

5 4.90 -2 

5 4.86 -3 

5 5.12 +2 

22 July 1992 23 July 1992 5 4.92 -2 

a 1.25 mg/g= 1,250 ppm; 2.5 mg/g=2,500 ppm; 5 mg/g=5,000 ppm 

b Duplicate analyses 

c Not used for dosing 

d Results of rcmix 
~ ~ ~=~ ........ - , ........ _ ...... ~ ............................... 

v 

t-ll~u~ynhydrocluinone, NTP TR 459 3~ 

TABLE [4 

Results of Referee Ananyses of Dose Formulations Adm~n~stere~ to Rats and Mice ~n the 13-Week, 

Long-Term, and 2-Year ~'ee~ Studies of t-ll~uty~hydroqu~none 

Determined Concentration (mg/g) 

Target Concentration Study Referee 

Date ~a'repared (mg/g) Laboratory a Laboratory b 

13-Week Studies 

1 December 1988 2.5 2.44 2.13 

12 January 1989 5 4.74 4.68 

Long-Term Study 

Rats 

6 November 1989 1.25 1.14 1.20 

20 November 1989 5 5.14 4.53 

17 January 1990 2.5 2.53 2.20 

2-Year Study 

Mice " 

20 November 1989 5 5.14 4.53 

17 January 1990 2.5 2.53 2.20 

a Results of duplicate analyses 

b Results of triplicate analyses 
310 t-Butyihydroquinone, NTP TR 459 
3~1 

~PE~~[~ ~ 

FEED ~-~ C@I%IiI?@I.JH]I:) C©NSLr~/~PT[©N 

IN T~@-~ L©NCGoTE~.~V~ ~~ ~oYE~ FEED 5TI,.,III)]IE5 

OF ~-iBII.,.I"W ~LIRI"I"ID]ft,.O @I,.JIHOHL 

'rA~LE 51 Feed and CompoundConsumption by ]V~a~e Rats ~n the Long-Te~n ~'eed Study 

of t-~uty~hydroquinone ............................................ 312 

TABLE 52 Feed and Compound Consumption by Female Rats in the Long-Tern Feed Study 

• 

of t-Buty~hydroqu~none ............................................ 313 

'~'A~LE 53 Feed and Compound Consumption by Mane ]Mice in the 2-Year Feed Study 

of t-~uty~hydroqu~none ............................................ 314 

~'A~LE 5,~ ~ Feed and Compound Consumption by Female Mice in the 2-'Year Feed Study 

of t-~uty~hydroquinone ............................................ 315 
312 t-Butylhydroquinone, NTP TR 459 

TABLE J1 

]Teed and Compound Consumption by Male Rats in the Long-Term Feed Study of t-Butyihydroquinone a 

0 DDm 1.250 oum 2.500 u~m 5[000 unto 

Feed Body Feed Body Dose/ Feed Body , Dose/ .Feed Body Dose/ 

(g/day) b Weight (g/day) Weight Day c (g/day) Weight Day (g/day) Weight Day 

Week (0 (g) (mg/kg/day) (g) (mg/kg/day) (g) (mg/kg/day) 

1 13.9 

2 15.2 

3 16.5 

4 18.2 

5 17.4 

6 20.8 

7 17.2 

8 17.0 

9 16.9 

10 13.1 

I1 19.2 

12. 17.4 

13 - 16.8 

17 16.5 

21 16.4 

25 15.6-

29, 16.5 

33 16.4 

37r 17.4 

41 14.7 

45 • 16.5 

49. 16.9 

53 19.9 

57 14.8 

61 16.1 

65 16.3 

69 15.8 

73 15.3 

77 17.0 

81 16.6 

85 15.4 

89 15.1 

93 14.3 

97 15.4 

101 15.2 

105. 14.5 

109 15.7 

113 14.8 

117 14.0 

121 14.4 

99 

141 16.4 148 138 15.7 141 280 15.7 127 619 

175 

209 

233 

267 19.0 266 89 19.0 260 183 18.3 244 375 

283 

299 

313 

316 13.2 319 52 17.3 320 " 135 17.5 ' 299 293 

324 

344 

356 17.2 348 62 18.7 343 136 17.6 320 275 ' 

379 17.6 370 60 16.5 366 113 17.2 346 248 

40O 18.6 391 59 18.5 379 122 17.2 358 241 

413 16.5 408 51 16.0 399 100 15.9 376 211 

419 17.0 416 51 16.5 408 101 16.4 386 213 

428 17.1 425 50 17.4 417 104 16.7 392 213 

437 17.4 435 50 16.8 430 98 16.4 402 204 

450 14.8 445 42 14.5 437 83 15.2 416 182 

452 16.0 450 44 17.7 439 101 16.9 415 203 

444 17.0 448 47 • 17.2 440 98 16.0 415 193 

• 468 19.7 466 53 20.5 457 112 20.8 431 242 

468 16.2 468 43 16.6 462 90- 16.8 435 193 

467 17.0 468 45 18.2 463 98 17.7 440 202 

470 17.3 471 46 17.2 463 93 17.6 440 200 

468 16.5 472 44 16.6 463 90 16.7 437 191 

472 15.7 471 42 16.3 459 89 16.0 433 185 

463 17.6 463 47 16.3 458 • 89 16.3 438 186 

464 17.0 466 46 17.5 458 95 17.3 436 199 

462 15.7 470 42 15.1 457 83 15.1 429 176 

455 15.0 457 41 15.3 455 84 14.0 425 164 

458 14.9 451 41 15.5 456 _ 85 15.1 419 180 

455 15.5 452 43 16.5 453 91 16.0 421 190 

447 15.6 444 44 14.9 443 84 15.7 421 186 

440 15d 435 44 15.9 430 93 16:4 409 201 

420 14.3 . 421 42 14.4 414 87 14~2 412 173 

429 16.5 427 48 16.5 420 98 15.7 395 198 

428 15.5 422 46 16.7 400 104 '15.0 397 189 

417 11.5 402 36 16.1 359 112 15.5 386 200 

Mean for weeks 

1-13 16.9 258 16.5 271 85 17.7 266 183 17.3 247 390 

14-52 16.3 425 16.9 421 51 16.8 413 102 16.4 390 212 

53-121 15.6 453 15.9 452 44 16.4 443 . 93 16.2 422 192 

a Feed consumption for controls measured weekly for the first 13 weeks and monthly thereafter. 

b Grams of feed consumed per animal per day 

c Milligrams oft-butylhydroquinone consumed per kilogram body weight per day ~ 
t-Buty~hydroqu~none, NT~ TI~ ~S~ 3~3 

TABLE J2 

Feed and Co~npound Cons~pfion by Female floats in the Lo~g-Tern~ Feed Study o~' t-~uty~hydroqa~none a 

0 opn~ 1.~0 n.~q~ ~.500 n.~m 5.000 qpm 

Feed Body• Feed '~ ' ~ody Dose/ Feed Body Dose/ Feed• Body Dose/ 

(g/day) b Weight (g/day) Weight Day c (g/day) Weight Day (g/day) Weight Day 

Week (g) (g) (mg/~,/day) (g) (mg/kg/day) (g) (mg/lw,/day) 

l 10.8 92 

2 ll.3 121 12.0 124 122 12.0 120 249 ll.9 

3 ll.3 135 

4 11.6 147 

5 • ll.l 159 

6 13.7 171 12.4 168 93 12.2 162 188 ll.3 

7 11.6 177 

8 10.8 181 

9 10.7 186 

10 9.4 176 8.8 181 61 11.2 183 154 11.1 

11 11.9 193 

12 10.5 196 

13 10.2 198 10.5' 194 68 10.8 191 141 11.2 

17 10.7 203 10.5 203 65 10.4 197 133 9.8 

21 10.7 224 ll.! 212 65 10.4 205 127 10.8 

25 9.4 222 ll.O 216 64 IO.O 212 lib 9.5 

29 9.2 229 10.4 222 59 9.8 217 114 10.1 

33 10.1 231 II.O 227 60 10.4 219 118 lO.O 

37 10.9 232 ll.l 230 60 11.0 223 123 10.4 

41 lO.l 240 10.4 238 55 10.4 231 ll2 9.1 • 

45 10.8 248 ll.1 246 56 11.6 239 122 11.0 

49 11.6 257 11.8 256 57 ll.4 244 117 10.7 

53 15.3 264 15.7 263 74 14.7 247 149 14.1 

57 9.6 279 10.2 277 46 10.7 264 102 10.8 

61 11.3 285 11.4 285 50 12.0 269 ' Ill ll.2 

65 12.2 292 12.3 291 53 12.8 274 117 11.5 

69 11.6 301 11.5 299 48 11.3 282 I00 10.7 

73 12.2 309 11.9 301 49 11.5 286 101 11.0 

77 12.4 315 12.4 311 50 11.6 297 98 11.5 

81 12.3 323 12.4 319 49 12.7 300 106 ll.8 

85 11.5 327 11.9 325 46 ll.O 308 90 11.3 

89 ll.7 333 12.5 327 48 ll.9 309 96 10.9 

93 12.3 342 11.6 339 43 11.6 316 91 ll.l 

97 12.6 348 12.9 343 47 12.9 325 99 12.5 

101 12.0 347 12.8 346 46 12.0 329 91 ll.9 

105 13.0 345 13.6 347 49 12.8 333 97 12.3 ' 

109 12.5 341 13.3 354 47 12.2 329 92 12.0 

113 ll.1 337 12.3 350 44 12.8 337 95 12.4 

117 11.7 348 12.1 355 43 12.0 337 89 !1.4 

121 12.3 341 12.3 353 44 ll.l 335 83 12.0 

125 11.9 336 13.0 340 48 12.3 326 95 12.0 

110 541 

154 367 

176 316 

184 304 

188 262 

200 270 

203 235 

210 240 

210 239 

213 244 

219 207 

227 242 

232 232 

236 299 

246 219 

257 217 

263 219 

265 202 

270 204 

274 209 

278 213 

282 200 

287 190 

290 191 

299 209 

301 197 

303 203 

300 200 

301 205 

309 184 

315 190 

307 196 

Mean for weeks 

1-13 . 11.2 164 11.0 167 86 11.5 164 183 11.4 156 382 

14-52 10.4 232 10.9 228 60 10.6 221 120 10.2 211 241 

53-125 12.1 322 12.4 322 49 12.1 305 lO0 11.7 283 .. 208 

a Feed consumption for controls measured weekly for the first 13 weeks and monthly thereafter. 

b Grams of feed consumed per animal per day 

c Milligrams of t-butylhydroquinone consumed per kilogram body weight per day 
..3,14 t-Butylhydroquinone,.,NTP TR 459 

TABLE J3 

Feed and Compound Consumption by Male Mice in the 2-Year-Feed Study of t-Butyihydroquinone 

0 DDm 1.250 uDm ~.500 unto 5.000 uum 

Feed Body Feed Body Dose/ Feed Body Dose/ Feed Body Dose/ 

(g/day) a Weight (g/day) Weight Day b (g/day) Weight Day (g/day): Weight Day 

Week (g) (g) (mg/kg/day) (g) (mg/kg/day) (g) (mg/kg/day) 

1 3.9 

2 4.4 

6 3.7 

9 3.8. 

10 4.7 

13 4.8 

17 4.7 

21 4.9 

25 4.5 

29 4.6 

33 5.1 

37 4.5 " 

41 - 4..6 

45 3.7 , 

49 3.9 

53 3.9 

57 4.5 

61 4.6 

65 5.1 

69 • 4.9 

73 5.6 

77 • 4.3 

81 4.6 

85 3.9 

89 4.3 

93 3.9 

97 4.3 

I01 4.2 : 

23.7 

25.4 

30.0. 

32.3 ~ 

33.1 . 

36.6 . 

38.8 

39.4 

41.9 

44.4 

44.9 

45.0 

46.1 

48.1 

49.7 

50.8 

51.1 

51.5 

51.5 

51.9 

51.8 

52.7 

52.6 

52.4 

52.6 

51.4 

51.4 

49.9 

3.6 

4.2 

3.7 

4.0 

4.2 

4.6 

4.O 

3.8 

4.8, 

4.1 

5. I 

4.9 

4.6 

4.1 

3.8 

4.1. 

4.4 

4.7 

5.0 

4.7 

5.8 

4.5 

4.2 

3.9 

5.0 

4.4 

4.8 

4.3 

23.5 

25.3 

29.6 

32.1 

32.9 

35.6 

38.3 

39.6 

41.3 

43.3. 

44.4 

43.9 

44.9 

46.5 

48.8 

49.3 

50.0 

50.1 

' 49.8 

49.9 

49.8 

51.0 

51.0 

50.8 

50.5 

50.0 

49.6 

48.2 

191 

206 

156~ 

157 

158 

160 

130 

120 

146 

119 

144 

140 

129. 

If0 

98 

I03 

I11 

118 

126 

118 

146 

III 

102 

97 

123 

109 

122 

112 

3.3 

4.4 

4.1 

3.7 

4.4 

4.5 

4.4 

4.4 

4.8 

3.9 

5.1 

5.5 

4.4 

4.6 

4.0 

4.O 

4.6, 

5.4 

5.3 

5.2 

5.3 

4.6 

4.0 

4.3 

5.0 

4.1 

4.5 

4.1 

23.4 

25.3 

29.7 

31.7 

32.8 

35.2 

38.0 

39.2 

40.9 

43.1 

44.2 

43.6. 

45.0 

46.5 

48.6 

49.2 

49.8 

49.6 

49.2 

49.7 

49.8 

50.3 

50.2 

50.5 

50.3 

49.1 

49.4 

49.4 

• 

35[ 

433 . 

345 

294 

336 

320 

289 

280 

294 

226 

287 

314 

246 

248 

208 

203 

229 

271 

272 

260 

267 

229 

200. 

214 

249 

207 

229 

2O8 

4.3 

4.6 

4.6 

4.2 

4.2 

4.8 

4.4 

5.4 

4.7 

4.2 

5.2 

5.4 

4.4 

4.8 

4.0 

4.2 

4.8 

6.0 

5.5 

4.9 

5.0 

4.4 

4.5 

5.2 

5.4 

5.2 

4.9 

4.4 

23.0 

24.7 

29.2 

30.5 

30.8 

33.4 . 

35.4 

36.7 

38.3 

40.2 

40.9 

40.6 

41.2 

43.4 

45.8 

46.3 

47.5 

47.3 

46.9 

47.4 

47.6 

48.4 

48.1 

47.4 

47.8 

48.0 

47.3 

47.8 

932 

940 

790 

682 

675 

715 

619 

737 

607 

528 

637 

669 

528 

550 

441 

449 

503 

637 

586 

517 

526 

452 

464 

544 

565 

545 

514 

458 

Mean for weeks 

1-13 4.2 

1,1-52 4.5 

53-101 4.5 

30.2 

44.3 

51.7 

4.0 

4.4 

4.6 

29.8 

43.4 

50.0 

171 

126 

! 15 

4.1 

4.6 

4.6 

29.7 

43.2 

49.7 

347 

266 

234 

4.4 

4.7 

4.9 

28.6 

40.3 

47.5 

789 

591 

520 

a Grams of feed consumed per animal per day 

b Milligrams oft-butylhydroquinone consumed per kilogram body weight per day 
t-Bu~y~hydroquinone, NTP T~ 459 3~L5 

TABLE J~ 

Feed and Compound Conse~rnption by Feana~e ~ice ~n the 2-Year Feed Stady o~ t-~atynhydroquinone 

Q uum, 1.250 hum 2.500 qum 5.00~ p.pm 

Feed Body Feed Body Dose/ Feed Body Dose/ Feed Body Dose/ 

(g/day) a Weight (g/day) Weight Day b (g/day) Weight Day (g/day) Weight Day 

Week (g) (g) (mg/kg/day) (g) (mg/kg/day) (g) (mg/kg/day) 

2 4.4 20.1 4.3 20.4 261 3.6 20.2 445 6.1 20.1 1,520 

3 3.6 21.5 4.0 21.6 229 4.1 21.3 477 3.9 20.9 933 

6 3.0 24.9 3.2 25.2 158 3.5 25.0 353 3.0 24.5 610 

7 3.7 26.0 3.7 26.3 176 3.8 26.2 367 4.2 25.2 827 

10 3.3 28.3 3.3 28.5 146 3.7 28.0 331 4.4 26.7 821 

11 4.3 28.9 4.5 29.3 192 4.3 28.8 369 4.4 27.5 793 

17 4.0 33.9 4.2 34.9 150 4.1 34.1 303 4.1 31.8 646 

21 4.9 36.0 4.6 36.2 158 4.8 35.6 337 4.8 33.6 713 

25 3.9 37.1 4.8 37.1 161 5.1 35.6 " 359 5.1 32.8 772 

29 5.3 38.5 5.3 39.2 168 5.6 38.0 367 5.8 35.1 828 

33 4.5 39.9 5.1 40.8 157 5.3 39.8 336 4.9 36.7 669 

37 4.8 39.9 4.6 40.8 140 4.8 39.9 303 5.0 36.5 678 

41 4.7 41.5 4.8 42.1 142 5.0 41.2 305 5.2 37.7 691 

45 4.3 43.2 4.5 44.3 127 5.1 43.4 293 4.7 39.0 603 

49 4.8 46.4 4.8 47.6 127 4.8 46.5 260 4.7 41.9 562 

53 4.9 48.5 4.9 49.5 124 5.1 48.7 264 5.1 43.5 587 

57 5.2 50.2 6.0 51.4 145 5.9 50.5 291 5.6 44.9 622 

61 5.1 51.3 5.6 52.9 132 5.7 51.6 277 5.5 45.6 603 

65 5.4 52.3 5.4 53.2 127 5.4 51.9 260 5.0 46.6 532 

69 5.5 52.6 5.0 53.7 117 5.4 52.7 256 5.4 46.8 581 

73 4.3 53.9 4.8 55.4 109 4.8 54.3 220 4.8 47.9 502 

77 5.3 55.4 5.3 56.0 118 5.3 54.9 241 5.2 48.3 542 

81 4.8 55.5 4.8 56.8 107 4.9 55.1 223 5.1 49.0 524 

85 5.0 56.2 4.9 56.9 107 5.2 55.7 232 5.1 49.6 511 

89 4.9 56.0 5.1 57.8 110 5.1 55.5 230 4.9 49.7 492 

93 5.0 56.1 5.0 57.9 109 5.3 55.7' 236 5.2 49.6 527 

97 4.9 55.1 4.8 57.0 106 5.4 54.7 246 5.3 49.0 538 

101 4.8 54.5 4.9 55.8 111 5.1 54.2 235 4.7 48.6 485 

105 4.6 52.9 4.6 55.6 104 5.1 53.2 239 4.6 47.3 482 

Mean for weeks 

1-13 3.7 25.0 3.8 25.2 194 3.8 24.9 391 4.3 24.2 917 

14-52 4.6 39.6 4.7 40.3 148 5.0 39.3 318 4.9 36.1 685 

53-105 5.0 53.6 5.1 55.0 116 5.3 53.5 247 .5.1 47.6 538 

a Grams of feed consumed per animal per day 

b Milligrams of t-butylhydroquinone consumed per kilogram body weight per day 
316 t-Butylhydroquinone, NTP TR 459 

ii 
3~17 

,A.~IEH~]IX I4 

~HG]XB~]11BHTS~ HX.Y1XX.~iISHT C©B@~©5]Z'T]I©H~ 

~ C@HTA,S~I~IH,A.HT ~]B~E~5 

]ZH Hliltio®7 I~h~.TAH]I} ~Yi[O~SE ]KfkT]I©H 

T~LZ H~ ]I~r~lie~ o~ ~-~7 ]~ ~t ~o~e ~io~ ............................. 3~ 

T~ ~C~ V~ ~ ~e~ ~ ~ ~ ~ ~o~e ~io~ ..................... 3~ 

T~ ~ ~ Co~io~ o~ ~ ~ ~ ~o~e ~a~io~ ........ ............... ~9 

T~ ~44 Co~~ ~ve~ ~ ~ ~ ~ ~o~e ~o~ ....................... 3~0 
318 - t-Butylhydroquinone, NTP TR 459 

TABLE K1 

Ingredients of NIH-07 Rat and Mouse Ration a ' . 

Ingredients b Percent by Weight 

• 

G~0~nd//2yellow shelled corn 24150 

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 

.. 

a NCI, 1976; NIH, 1978 

b Ingredients were ground to pass through a U.S. Standard Screen No. 16 before being.mixed. 

TAnLE K2 

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 3 4,600,000 IU D-activated animal sterol 

2.8 g M~nadione 

d-~-Tocopheryl acetate 20,000 IU 

Choline 560.0 g Choline chloride 

Folic acid 2.2 g 

Niacin 30.0 g 

d-Pamothenic acid 18.0 g d-Calcium pantothenate 

Riboflavin 3.4 g 

Thiamine 10.0 g Thiamine mononitrate 

B12 4,000 #g 

Pyridoxine 1.7 g Pyridoxine hydrochloride 

Biotin • : 140.0 mg d-Biotin • 

Minerals 

Iron 120.0 g Iron sulfate 

Manganese 60.0g 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 

a Per ton (2,000 lb) of finished product 
g-~u~y~hydroqu~none, I~ TI~ ~$9 3~19 

TABLE ]~3 

Hutrient Composition of ~-07 ]~.at a~ Mome ~at~oa 

Mean ± Standard 

Nutrient Deviation 1~'~ber ~p~ 

Protein (% by weight) 23.6 + 0.52 22.50 - 25.20 34 

Crude Fat (% by weight) 5.30 + 0.23 4.80-5.80 34 

Crude Fiber (% by weight) 3.50 + 0.42 2.60-4.80 34 

Ash (% by weight) 6.50 + 0.22 6.12 - 7~03 34 

Amino Acids (% of total diet) 

Arginine 1.287 + 0.084. 1.100- 1.390 10 

Cystine 0.306 + 0.075 0.181 -0.400 10 

Glycine 1.160 + 0.050 1.060- 1.220 10 

Histidine 0.580 + 0.024 0.531 - 0.608 10 

Isoleucine 0.917 + 0.034 0.867 - 0.965 10 

Leucine 1.972 + 0.052 1.850 - 2.040 10 

Lysine 1.273 + 0.051 1.200- 1.370 10 

MethionJne 0.437 + 0.115 0.306 - 0.699 10 

Phenylalanine 0.994 + 0.125 0.665 - 1.110 10 

Threonine 0.896 + 0.055 0.824 - 0.985 10 

Tryptophan 0.223 + 0.160 0.107 - 0.671 10 

Tyrosine 0.677 + 0.105 0.564 - 0.794 10 

Valine 1.089 + 0.057 0.962- 1.170 10 

~ssential Fatty Acids (% of total diet) 

Linoleic 2.389 + 0.233 1.830 - 2.570 

Linolenic 0.277 + 0.036 0.210 - 0.320 

Vitamins 

Vitamin A (IU/kg) 6,725 + 1,375 4,290- 12,540 34 

Vitamin D (IU/kg) 4,450 + 1,382 3,000 - 6,300 4 

g-Tocopberol (ppm) 36.92 + 9.32 22.5 -48.9 9 

Thiamine (ppm) 18.40 + 2.50 12.0 - 25.0 34 

Riboflavin (ppm) 7.92 + 0.93 6.10 - 9.00 10 

Niacin (ppm) 100.95 + 25.92 65.0- 150.0 9 

Pantothenic Acid (ppm) 30.30 + 3.60 23.0 - 34.6 10 

Pyridoxine (ppm) 9.25 + 2.62 5.60- 14.0 10 

Folic Acid (ppm) 2.51 + 0.64 1.80 - 3.70 10 

Biotin (ppm) 0.267 + 0.049 0.19 - 0.35 10 

Vitamin B12 (PPb) 40.14 + 20.04 10.6 - 65.0 10 

Choline (ppm) 3,068 + 314 2,40O - 3,430 9 

I~Iinerals 

Calcium (%) 1.20 + 0.09 1.0O- 1.37 34 

Phosphorus (%) 0.94 ± 0.05 0.80- 1.03 34 

Potassium (%) 0.887 + 0.067 0.772 - 0.971 8 

Chloride (%) 0.526 + 0.092 0.380 - 0.635 8 

Sodium (%) 0.315 + 0.034 0.258 - 0.370 10 

Magnesium (%) 0.168 =1:0.008 0.151 - 0.180 10 

Sulfur (%) 0.274 + 0.063 0.208 - 0.420 10 

Iron (ppm) 356.2 + 90.0 255.0 - 523.0 10 

Manganese (ppm) 92.24 + 5.35 81.70 - 99.40 10 

Zinc (ppm) 58.14 +9.91 46.10 - 81.60 10 

Copper (ppm) 11.5.0 + 2.40 8.090- 15.39 10 

Iodine (ppm) 3.70 + 1.14 1.52 - 5.83 10 

Chromium (ppm) 1.71 + 0.45 0.85 - 2.09 9 

Cobalt (ppm) 0.797 + 0.23 0.490- 1.150 6 
320 t-Butylhydroquinone, NTP TR 459 

TA~L~ K4 

Contaminant Levels in NIH-07 Rat 

Contaminants 

Arsenic (ppm) 

Cadmium (ppm) 

Lead (ppm) 

Mercury (ppm) 

Selenium (ppm) c. 

Aflatoxins (ppb) e 

Nitrate nitrogen (ppm) e 

'Nitrite nitrogen (ppm) e 

BHA (ppm)~ 

BHT (ppm) I 

Aerobic plate count (CFU/g) 

Coliform (MPN/g) 

Escherichia coli (MPN/g) 

Total Nitrosoamines (ppb) g 

N-Nitrosndimethylamine (ppb) g 

N-Nitrosopyrrolidine (ppb) g 

Pesticid.~ (ppm) 

a-BHC J 

~-BHC 

¥-BHC 

8-BHC ' 

Heptachlor 

Aldrin 

Heptachlor epoxide 

DDE 

DDD 

DDT 

HCB 

Mirex 

Methoxychlor 

Dieldrin 

Endrin 

Telodrin 

Chlordane 

Toxapbene 

Estimated PCBs 

Ronnel 

Ethion 

Tr~thion 

Diazinon 

Methyl parathion 

Ethyl parathion 

Malathion 

Endosulfan I 

Endosulfan II 

Endosulfan sulfate 

and Mouse Ration a 

Mean + Standard 

Deviation b 

0.44 ± 0.21 

0.13 :t: 0.08 

0.35 ± 0.37 

0.02 ± 0.01 

0.32 ± 0.11 r 

< 5.0 

9.94 ± 5.02 

0.24 ± 0.20 

1.33 ± 0.82 

1.28 ± 0.61 

139,873 ± 169,234 

19.4 ± 22.20 

3.24 ± 1:04 

7.08 ± 2.40 

5.23 ± 1.35 

1.61 ± 1.17 

<0.01 

< 0.02 

<0.01 

<0.01 

, < 0.01 

<0.01 

< 0.01 

<0.01 

<0.01 

<0.01 

< 0.01 

<0.01 • 

< 0.05 

< 0.01 

<0.01 

<0.01 

< 0.05 

< 0.1 

<0.2 

< 0.01 

< 0.02 

< 0.05 

< 0.1 

< 0.02 

<0.02 

0.28 + 0.26 

< 0.01 

< 0.01 

< 0.03 

0.10-0.80 

0.05 -0.40 

0.10-2.10 

0.02 - 0.05 

0.02 - 0.44 

1.80 - 20.0 

0.10 - 1.00 

1.00 - 4.00 

1.00- 7.00 

4,700 - 630,000 

3.00 - 93.00 

3.00 - 9.0 

2.90 = 13.70 

2.90-9.40 

0.00 - 4.70 

<0.05 - 1.00 

Number of Samples 

34 

34 

34 

34 

33 

24 

34 

34 

33 

33 

34 

34 

34 

34 

34 

34 

31 

31 

31 

31 

31 

31 

31 

31 

31 

31 

31 

31 

31 

31 

31 

31 

31 

31 

31 

31 

31 

31 

31 

31 

31 

34 

31 

31 

31 

a CFU = colony forming units, MPN = most probable number, BHC is hexachlorocyclohexane or benzene hexachloride. 

b For values less than the limit of detection, the detection limit is given as the mean. 

No selenium measurement was recorded for the lot milled on 4 May 1990. 

d No aflatoxin measurement was recorded for the lot milled on 2 October 1989. 

• Sources of contamination: alfalfa, grains, and fish meal 

f Sources of contamination: soy oil and fish meal; no BHA or BHT measurements were recorded for the lot milled on 1 November 1989. 

g All values were corrected for percent recovery. 

c 
321 

A]P]PEIhT}]~Z. L. 

$1ZNT]II~IZL AN]~I~IAL P~©Q~A.I~I 

~T~ODS 

TABLE L~ 

............................................................. 

~urfi~e Vfirus Antibody De~ern~n~tfions for ]~ats and ~fice fin ~he ~.3-Wee~ 

Long-Term, and 2-Year Studies of t-~uty~hydro~u~none ....................... 

322 

~2~ 
322 ~t-Butylhydroquinone,i NTP TR 459 

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. 

Most serum samples were collected from sentinel, untreated, or vehicle control rats and mice. At the end of 

the 13-week studies, blood was collected from five male and five female control rats and five male and five 

female sentinel mice. During the long-term rat study, samples were collected from 10 first-generation (F0) 

females at necropsy; five male and five female sentinels at 6, 7, 12, and 13 months; one male sentinel at 

14 months (insufficient serum was collected for analysis); one male sentinel at 16 months; five male and 

five female sentinels at 18 months; three male and four female sentinels at 19 months; one male and four 

female sentinels at 24 months; four male and one female sentinels at 25 months; five vehicle control or 

untreated females at 30 months; and four vehicle control or untreated females at 31 months. During the 

2-year mouse study, samples were collected from four to five male and four to five female sentinels or 

controls at 6, 12, 18, and 24 months. Additional samples for ELISA determination of mouse hepatitis virus 

and Sendai, were taken from ten naive male sentinels at 17, 18, 19, 20, and 2.3 months. Blood from each 

animal was collected and allowed to clot, and the serum was separated. The samples were processed 

appropriately and sent to Micr0b!01ogical 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 

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 

Long-Term Study. . . ELISA 

Mycoplasma arthritidis 30, 31 months 

Mycoplasma pulmonis 30, 31 months 

PVM Fonecropsy,.6, 7, 12, 13, 16, 18, 19, 24, 25, 30, 3.1 months 

RCV/SDA Fo necropsy, 6, 7, 12, 13, 18, 19, 25, 30 months 

Sendai Fo necropsy, 6, 7, 12, 13, 16, 18, 19, 24, 25, 30, 31 months 
t-Butylhydroquinone,NT]? T~ 323 ,~$9 

Method and Test 

]i~.ATS (continued) 

]Long-Term Study (continued) 

ImmunofluorescenceAssay 

PVM 

• RCV/SDA 

Hemagglutination Inhibition .~. 

H-1 

KRV . 

1V~CE 

~3-Week Study 

ELISA 

Ectromelia virus . 

GDVII (mouse encephalomyelitis virus) 

MVM (minute virus of mice) 

Mouse adenoma virus 

MHV (mouse hepatitis virus) 

PVM 

Reovirus 3 

Sendal 

Irnmunofluorescence Assay 

EDIM 

(epizootic diarrhea of infant mice) 

LCM 

(lymphocytic choriomeningitis virus) 

Hemagglutination Inhibition 

K (papovavirus) 

Polyoma virus 

2-'~'ear Study 

ELISA 

Ectromelia virus 

EDIM 

GDVII 

LCM 

Mouse adenoma virus 

MHV 

M. arthritidis 

M. pulmonis 

PVM 

Reovirus 3 

Sendai 

~me off' Anaaysis 

31 months " 

16, 18, 19, 24, 25 months 

F0 necropsy, 6, 7, 12, 13, 16, 18, 19,. 24, 25, 30, 31 months 

Fo necropsy, 6, 7, 12, 13, 16, 18, 19, 24, 25~ 30,.31 months 

Study termination 

Study termination 

Study termination 

Study termination 

. Study termination 

Study termination 

Study termination 

Study termination 

Study termination. 

Study termination 

Study termination 

Study termination 

6, 12, 18, and 24 months 

12, and 24 months 

6, 12, 18, and 24 months 

6, 12, !8, and- 24 months 

6, 12, 18, and 24 months 

6, 12, 17, 18, 19, 20, 23, and 24 months 

24 months (females only) 

24 months (females only) 

6, 12, 18, and 24 months 

6, 12, 18, and 24 months 

6, 12, 17, 18, 19, 20, 23, and 24 months 
324 t-Butylhydroquinone, NTP TR 459 

Methofl and Test Time of Analysis 

MICE (continued) 

2-Year Study (continued) 

Immunofluorescence Assay 

EDIM 6, 18, and 24 (one female only) months 

GDVII 18, and 24 (one male only) months 

MVM 6 months 

Mouse adenoma virus 24 (one female only) months 

Reovirus 3 6 and 24 (one male and one female only) months 

Hemagglutination Inhibition 

K 6, 12, 18, and 24 months 

MVM 12, 18, and 24 months 

Polyoma virus 6, 12, 18, and 24 months 

Reovirus 3 6 months 

Results of serology tests are presented in Table L1. 
t-~uty~hydroquinone, NT]~ TIR ,~59 3~ 

TABLE L~ 

I~Iur~ne Virus Antibody Determinations for ~gs ~ I~/lI~ce ~a ~he 13-Week, Long-Terra, 

and 2-~ea~ Stu~es. of t-~uty~hydroquJnone 

Interval Incidence of.Antibody l~ositive Serologic 

in Sentinel Animals Reaction for 

13-Week Studies 

Rats 

Study termination 0/10 None 

Mice 

Study termination 0/10 None 

Long-Term Study 

Rats 

Fo necropsy 0/10 None 

6 months 0/10 None 

7 months 0/10 None 

12 months 0/10 None 

13 months 0/10 None 

16 months 0/1 None 

18 months 0/11 None 

19 months 0/7 None 

24 months 0/5 None 

25 months 0/5 None 

30 months 115 M. arthritidis a 

31 months 2/4 M. arthritidis a 

2-~gear Study 

Mice 

6 months 3/10 b Reovirus 3 

12 months 0/10 None 

17 months 0/10 None 

18 months 0/18 None 

19 months 0/10 None 

20 months 0/10 None 

23 months 0/10 None 

24 months 1/10 Mouse hepatitis virus 

a Further evaluation of samples positive for M. arthritidis by immunobiot and Western blot procedures indicated that the positive titers may 

be due to cross reaction with antibodies of nonpathogenlc Mycoplasma or other agents. Only sporadic samples were positive and there 

were no clinical findings or histopathologic changes of M. arthritidis infection in rats with positive titers. Accordingly, M. arthritidispositive titers were considered to be false positives. 

b Western blot analysis of the three sera testing positive for Reovirus 3 were negative for specific antibodies. Therefore, the low level 

ELISA and immunofluorescence assay results were considered to be nonspecific due to the lack of increasing titer and the incidence in the 

colonies in which the positive results occurred. 

DEPARTMENT OF 

HEALTH & HUMAN SERVICES 

Public Health Service 

National Toxicology Program 

Central Data Management 

P.O. Box 12233, MD El-02 

Research Triangle Park, NC 27709 

/J 

SPECIAL FOURTH-CLASS RATE 

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Penalty for Private Use o $300 

NIH Publication No. 97-3375 

May 1997