EPA/635/R-13/107

Preliminary Materials

www.epa.gov/iris

Preliminary Materials for the Integrated Risk Information System (IRIS)

Toxicological Review of tert-Butyl Alcohol (tert-Butanol)

[CASRN 75-65-0]

July 2013

NOTICE

This document is comprised of preliminary materials, consisting of a literature search strategy, 

evidence tables, and exposure-response arrays. This information is distributed solely for the 

purpose of pre-dissemination review under applicable information quality guidelines. It has not 

been formally disseminated by EPA. It does not represent and should not be construed to represent 

any Agency determination or policy. It is being circulated for review of its technical accuracy and 

science policy implications.

National Center for Environmental Assessment

Office of Research and Development

U.S. Environmental Protection Agency

Washington, DC
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

ii DRAFT—DO NOT CITE OR QUOTE

DISCLAIMER

This document is comprised of preliminary materials for review purposes only. This 

information is distributed solely for the purpose of pre-dissemination review under applicable 

information quality guidelines. It has not been formally disseminated by EPA. It does not represent 

and should not be construed to represent any Agency determination or policy. Mention of trade 

names or commercial products does not constitute endorsement or recommendation for use.
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

iii DRAFT—DO NOT CITE OR QUOTE

CONTENTS

PREFACE........................................................................................................................................................ v

1. DRAFT LITERATURE SEARCH STRATEGY .............................................................................................. 1-1

1.1. Literature Search and Screening Strategy for tert-Butanol .......................................................... 1-1

1.2. List of References Based on Search Strategy for tert-Butanol...................................................... 1-5

1.2.1. Primary Sources of Health Effects Data............................................................................. 1-5

1.2.2. Not Primary Source of Health Effects Data, but Kept as Additional Resources.............. 1-13

1.2.3. Kept for Possible Further Review .................................................................................... 1-17

2. PRELIMINARY EVIDENCE TABLES AND EXPOSURE-RESPONSE ARRAYS............................................... 2-1

2.1.Data Extraction: Preparation of Preliminary Evidence Tables and Exposure-Response 

Arrays............................................................................................................................................ 2-1

2.2.Kidney Effects................................................................................................................................ 2-3

2.3.Thyroid Effects............................................................................................................................ 2-13

2.4.Reproductive, Developmental, and Neurodevelopmental Effects............................................. 2-16

2.5.Central Nervous System (CNS) Effects........................................................................................ 2-25

2.6.Other Systemic Effects (Body Weight, Liver, and Urinary Bladder)............................................ 2-28

2.7.Genotoxic Effects........................................................................................................................ 2-37
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

iv DRAFT—DO NOT CITE OR QUOTE

TABLES

Table 1-1. Database search strategy for tert-butanol............................................................................... 1-3

Table 1-2. Summary of additional search strategies for tert-butanol ...................................................... 1-4

Table 2-1. Evidence pertaining to kidney effects in animals following oral exposure to tertbutanol............................................................................................................................. 2-3

Table 2-2. Evidence pertaining to kidney effects in animals following inhalation exposure to tertbutanol............................................................................................................................. 2-9

Table 2-3. Evidence pertaining to thyroid effects in animals following oral exposure to tertbutanol........................................................................................................................... 2-13

Table 2-4. Evidence pertaining to reproductive effects in animals following exposure to tertbutanol........................................................................................................................... 2-16

Table 2-5. Evidence pertaining to developmental effects in animals following exposure to tertbutanol........................................................................................................................... 2-18

Table 2-6. Evidence pertaining to neurodevelopmental effects in animals following exposure to 

tert-butanol.................................................................................................................... 2-21

Table 2-7. Evidence pertaining to CNS effects in animals following exposure to tert-butanol.............. 2-25

Table 2-8. Evidence pertaining to effects on body weight in animals following oral exposure to 

tert-butanol.................................................................................................................... 2-28

Table 2-9. Evidence pertaining to liver effects in animals following oral exposure to tert-butanol ...... 2-30

Table 2-10. Evidence pertaining to liver effects in animals following inhalation exposure to tertbutanol........................................................................................................................... 2-33

Table 2-11. Evidence pertaining to urinary bladder effects in animals following oral exposure to 

tert-butanol.................................................................................................................... 2-34

Table 2-12. Evidence pertaining to genotoxic effects of tert-butanol in vitro and in vivo studies......... 2-37

FIGURES 

Figure 1-1. Literature search approach for tert-butanol. ......................................................................... 1-2

Figure 2-1. Exposure response array of kidney effects in rats and mice following oral exposure 

to tert-butanol. .............................................................................................................. 2-11

Figure 2-2. Exposure-response array of kidney effects in rats and mice following subchronic 

inhalation exposure to tert-butanol. ............................................................................. 2-12

Figure 2-3. Exposure-response array of thyroid follicular cell effects in rats and mice following 

chronic oral exposure to tert-butanol. .......................................................................... 2-15

Figure 2-4. Exposure-response array of reproductive, developmental and neurodevelopmental 

effects following oral exposure to tert-butanol. ........................................................... 2-23

Figure 2-5. Exposure-response array of reproductive and developmental effects following 

inhalation exposure to tert-butanol. ............................................................................. 2-24

Figure 2-6. Exposure-response array of body weight, liver effects, and urinary bladder effects 

following oral exposure to tert-butanol. ....................................................................... 2-36
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

v DRAFT—DO NOT CITE OR QUOTE

PREFACE 

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This document presents the draft literature search strategy, preliminary evidence tables, 

and preliminary exposure-response arrays for tert-butyl alcohol (henceforth referred to as tertbutanol) prepared under the auspices of EPA’s Integrated Risk Information System (IRIS) Program. 

This material is being released for public viewing and comment prior to a public meeting, providing 

an opportunity for the IRIS Program to engage in early discussions with stakeholders and the public 

on data that may be used to identify adverse health effects and characterize exposure-response 

relationships. 

The draft literature search strategy, preliminary evidence tables, and preliminary exposureresponse arrays are responsive to the National Research Council (NRC) 2011 report Review of the 

Environmental Protection Agency’s Draft IRIS Assessment of Formaldehyde. The literature search 

strategy, which describes the processes for identifying scientific literature, screening studies for 

consideration, and selecting studies for inclusion in evidence tables, is responsive to NRC 

recommendations regarding systematic review of the scientific literature. In addition, NRC 

recommendations for standardized presentation of key study data are addressed in the preliminary 

evidence tables and preliminary exposure-response arrays. 

EPA welcomes all comments on the draft literature search strategy, preliminary evidence 

tables, and preliminary exposure-response arrays, such as remarks on the following:

• the clarity and transparency of the materials; 

• the approach for identifying pertinent studies;

• the selection of studies for data extraction to preliminary evidence tables and exposureresponse arrays; 

• any methodological considerations that could affect the interpretation of or confidence 

in study results; and

• any additional studies published or nearing publication that may provide data for the 

evaluation of human health hazard or exposure-response relationships.

The preliminary evidence tables and exposure-response arrays should be regarded solely as 

representing the data on each endpoint that have been identified as a result of the draft literature 

search strategy. They do not reflect any conclusions as to hazard identification or dose-response 

assessment. After obtaining public input and conducting additional study evaluation and data 

integration, EPA will revise these materials to support the hazard identification and dose-response 

assessment in a draft Toxicological Review.
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

1-1 DRAFT—DO NOT CITE OR QUOTE

1. DRAFT LITERATURE SEARCH STRATEGY

1.1. L

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chemical-specific search was conducted in four online scientific databases in December, 2012, and 

January, 2013, using the keywords and limits described in Table 1-1. After electronically 

eliminating duplicates from the citations retrieved through these databases, 2,907 unique citations 

were identified. An additional seven citations were obtained using additional search strategies 

described in Table 1-2. 

The resulting 2,410 citations were scr

t

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ert

ed using the title, abstract, and/or full text for 

pertinence to examining the health effects of -butanol exposure. A total of 2,226 references 

were identified as not being pertinent and were excluded from further consideration (see Figure 1-

1 for the exclusion categories). A total of 106 references were identified as primary sources of 

health effects data and were considered for data extraction to evidence tables and exposureresponse arrays (see Section 1.2.1). A total of 60 references were considered pertinent, but not as 

primary sources of health effects data (e.g., ADME studies), and kept as additional resources for 

development of the Toxicological Review (see Section 1.2.2). A total of 18 references did not 

provide enough material to evaluate pertinence (e.g., foreign language), and were reserved for 

further possible review (see Section 1.2.3). 

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Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

1-2 DRAFT—DO NOT CITE OR QUOTE

1 

2 

Database Searches 

(see Table 1 for keywords and limits)

(After duplicates removed electronically by HERO)

n = 2,907

Pubmed

n = 1,512

Web of Science

n = 462

Toxline

(incl. TSCATS)

n = 931

TSCATS 2

n = 2

Combined Dataset 

(After all duplicates removed)

n = 2,410

Additional Search Strategies 

(see Table 2-1 for methods and results)

n = 7

Excluded (not pertinent)

80 Biodegradation/environmental fate

75 Chemical analysis/fuel chemistry

1,143 Other chemical/ non-tert-butanol

86 Method of detection/exposure and 

biological monitoring

624 Methodology/solvent

62 Not relevant exposure paradigms (e.g., 

dermal, eye irritation, etc.)

39 Not relevant species/matrix (e.g., 

amphibians, fish, etc.)

40 Abstract only/comment

25 Book chapter/section

15 General review papers 

22 Society abstracts

14 QSAR

1 Unpublished data subsequently published

Kept for Possible Further Review

18 Foreign language

Primary Sources of Health Effects 

Data

4 Human health effects studies 

(including one case report)

37 Animal toxicology studies

22 Genotoxicity studies

43 Other studies involving direct 

administration of chemical, including 

mechanistic studies

Manual Screening For Pertinence

(Title/Abstract/Full Text)

Not Primary Source of Health Effects 

Data, but Kept As Additional 

Resource

17 Reviews, editorials

8 Health effects assessments by others

29 Toxicokinetic studies (not including PBTK)

6 PBTK modeling studies

Figure 1-1. Literature search approach for tert-butanol. 
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

1-3 DRAFT—DO NOT CITE OR QUOTE

1 Table 1-1. Database search strategy for tert-butanol 

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3 

Database 

(Search Date) Keywords Limits

PubMed

(12/20/2012) 

t-butanol OR 75-65-0[rn] OR “tbutyl hydroxide” OR “2-methyl-2-

propanol” OR “trimethyl carbinol” 

OR “t-butyl alcohol” OR tertbutanol OR "tert-butyl alcohol" 

OR tert-butyl alcohol[mesh]

None

Web of Science

(12/20/2012) 

Topic = (t-butanol OR 75-65-0 OR 

"t-butyl hydroxide" OR "2-methyl2-propanol" OR "trimethyl 

carbinol" OR "t-butyl alcohol" OR 

"tert-butanol" OR "tert-butyl 

alcohol") 

Refined by: Research Areas = (cell biology OR

respiratory system OR microscopy OR

biochemistry molecular biology OR

gastroenterology hepatology OR public 

environmental occupational health OR oncology 

OR physiology OR cardiovascular system 

cardiology or toxicology OR life sciences 

biomedicine other topics OR hematology OR

pathology OR neurosciences neurology OR

developmental biology) 

Toxline 

(includes 

TSCATS)

(1/11/2013) 

t-butanol OR 75-65-0 [rn] OR tbutyl hydroxide OR 2-methyl-2-

propanol OR trimethyl carbinol OR 

t-butyl alcohol OR tert-butanol OR 

tert-butyl alcohol OR tert-butyl 

alcohol

Not PubMed 

TSCATS2

(1/4/2013) 

75-65-0 None 
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

1-4 DRAFT—DO NOT CITE OR QUOTE

1 Table 1-2. Summary of additional search strategies for tert-butanol

Approach used Source(s)

Date

performed

Number of additional citations 

identified

Manual search 

of citations 

from reviews

Review article: McGregor, D. 

(2010). Tertiary-butanol: A 

toxicological review. Crit Rev 

Toxicol 40(8): 697-727. 

1/2013 5 citations

Review article: Chen, M. (2005). 

Amended final report of the safety 

assessment of t-butyl alcohol as 

used in cosmetics.” Int J Toxicol 

24(2): 1-20.

1/2013 2 citations

Manual search 

of citations 

from reviews 

conducted by 

other 

international

and federal 

agencies

IPCS (International Programme on 

Chemical Safety) (1987a). 

Butanols: Four isomers: 1-butanol, 

2-butanol, tert-butanol, isobutanol 

[WHO EHC]. Geneva, Switzerland: 

World Health Organization.

1/2013 None

OSHA (Occupational Safety & 

Health Administration). (1992). 

Occupational safety and health 

guideline for tert-butyl alcohol. 

Cincinnati, OH: National Institute 

for Occupational Safety and 

Health.

1/2013 None

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Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

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1 1.2. List of References Based on Search Strategy for tert-Butanol

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Citations for excluded references are not listed here, but can be found on the Health and 

Environmental Research Online (HERO) Web site (http://hero.epa.gov/tert-Butanol). 

1.2.1. Primary Sources of Health Effects Data

Data from citations in bold are displayed in Section 2. See Section 2.1 for a description of 

the process of selecting these studies for evidence tables and exposure-response arrays. 

Human health effects studies

1) Edwards, EK, Jr; Edwards, EK. (1982). Allergic reaction to tertiary butyl alcohol in a 

sunscreen. Cutis 29: 476-478.

2) Johanson, G; Nihlen, A; Lof, A. (1995). Toxicokinetics and acute effects of MTBE and ETBE in 

male volunteers. Toxicol Lett 82/83: 713-718. 

3) Laire, G; Viaene, MK; Veulemans, H; Masschelein, R; Nemery, B. (1997). Nocturnal oxygen 

desaturation, as assessed by home oximetry, in long-term solvent-exposed workers. Am J 

Ind Med 32: 656-664. 

4) Prah, JD; Goldstein, GM; Devlin, R; Otto, D; Ashley, D; House, D; Cohen, KL; Gerrity, T. (1994). 

Sensory, symptomatic, inflammatory, and ocular responses to and the metabolism of methyl 

tertiary butyl ether in a controlled human exposure experiment. Inhal Toxicol 6: 521-538. 

Animal toxicology studies

1) Acharya, S; Mehta, K; Rodrigues, S; Pereira, J; Krishnan, S; Rao, CV. (1995). 

Administration of subtoxic doses of t-butyl alcohol and trichloroacetic acid to male 

Wistar rats to study the interactive toxicity. Toxicol Lett 80: 97-104.

2) Acharya, S; Mehta, K; Rodriguez, S; Pereira, J; Krishnan, S; Rao, CV. (1997). A 

histopathological study of liver and kidney in male Wistar rats treated with subtoxic 

doses of t-butyl alcohol and trichloroacetic acid. Exp Toxicol Pathol 49: 369-373.

3) ARCO (ARCO Chemical Company). (1992). Initial submission: letter submitting preliminary 

results from subchronic toxicity studies of tertiary butyl alcohol in rats and mice dated 

10/14/92 and attachments. (88930000018). Newton Square, PA: Arco Chemical Company.

4) Atrens, D; van der Reest, A; Balleine, B; Menéndez, J; Siviy, S. (1989). Effects of ethanol and 

tertiary butanol on blood glucose levels and body temperature of rats. Alcohol 6: 183-187. 

5) Belknap, JK; Deutsch, CK. (1982). Differential neurosensitivity to three alcohols and 

phenobarbital in C57BL/6J and DBA/2J mice. Behav Genet 12: 309-317. 

6) Bellin, SI; Edmonds, HL, Jr. (1976). The use of tert-butanol in alcohol dependence studies. 

Proc West Pharmacol Soc 19: 351-354. 
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

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1 7) Billitti, JE; Faulkner, BC; Wilson, BW. (2005). Absence of acute testicular toxicity of 

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methyl-tert butyl ether and breakdown products in mice. Bull Environ Contam 

Toxicol 75: 228-235. 

8) Cirvello, JD; Radovsky, A; Heath, JE; Farnell, DR; III, LC. (1995). Toxicity and carcinogenicity 

of t-butyl alcohol in rats and mice following chronic exposure in drinking water. Toxicol Ind 

Health 11: 151-165. 

9) Daniel, MA; Evans, MA. (1982). Quantitative comparison of maternal ethanol and 

maternal tertiary butanol diet on postnatal development. J Pharmacol Exp Ther 222: 

294-300.

10)Dow Chemical Co (Dow Chemical Company). (1992). Letter submitting multiple studies on 

multiple chemicals required for docket opts-82036 with attachments (sanitized).

11)Dow Chemical Co (Dow Chemical Company). (1994). Animal toxicity experiments with ethyl 

alcohol, tertiary butyl alcohol, and stoddard's solvent with cover letter dated 03/28/94. 

(sanitized). (8694000270S). Midland, MI. 

12)Eastman Kodak Company. (1963). Toxicity report (summary) of t-butyl alcohol with cover 

letter dated 02/15/94. Rochester, New York: Eastman Kodak Company.

13)Faulkner, TP; Wiechart, JD; Hartman, DM; Hussain, AS. (1989). The effects of prenatal 

tertiary butanol administration in CBA/J and C57BL/6J mice. Life Sci 45: 1989-1995. 

14) Feller, DJ; Crabbe, JC. (1991). Effect of alcohols and other hypnotics in mice selected for 

differential sensitivity to hypothermic actions of ethanol. J Pharmacol Exp Ther 256: 947-

953. 

15)Grant, KA; Samson, HH. (1981). Development of physical dependence on t-butanol in 

rats: An examination using schedule-induced drinking. Pharmacol Biochem Behav 

14: 633-637.

16)Grant, KA; Samson, HH. (1982). Ethanol and tertiary butanol induced microcephaly in 

the neonatal rat: Comparison of brain growth parameters. Neurobehav Toxicol 

Teratol 4: 315-321. 

17)GSRI (Gulf South Research Institute). (1979a). Repeated dose test of t-butanol (c55367) in 

B6C3F1 mice and Fischer 344 rats with cover letter dated 031594. (86940000173). Orleans 

Parrish, LA.

18)GSRI (Gulf South Research Institute). (1979b). Subchronic test of t-butanol (c55367) in 

B6C3F1 mice and Fischer 344 rats in drinking water with cover letter dated 031594. 

(86940000172). Orleans Parish, LA.

19)Hard, GC; Bruner, RH; Cohen, SM; Pletcher, JM; Regan, KS. (2011). Renal 

histopathology in toxicity and carcinogenicity studies with tert-butyl alcohol 

administered in drinking water to F344 rats: A pathology working group review and 

re-evaluation. Regul Toxicol Pharmacol 59: 430-436. 
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

1-7 DRAFT—DO NOT CITE OR QUOTE

1 20) Lindamood, C; Farnell, D; Giles, H; Prejean, J; Collins, J; Takahashi, K; Maronpot, R. (1992). 

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Subchronic toxicity studies of t-butyl alcohol in rats and mice. Fundam Appl Toxicol 19: 91-

100. 

21) Lyondell Chemical Co. (Lyondell Chemical Company). (2003). An oral gavage reproductive 

and developmental toxicity screening in rats. (Document Control Number: 88030000222).

22)Lyondell Chemical Co. (Lyondell Chemical Company). (2004). Reproductive and 

developmental toxicity screening test in rats by oral gavage. (Document Control 

Number: 89-040000106).

23)Mccomb, J; Goldstein, D. (1979a). Additive physical dependence: evidence for a 

common mechanism in alcohol dependence. J Pharmacol Exp Ther 210: 87-90.

24)Mccomb, J; Goldstein, D. (1979b). Quantitative comparison of physical dependence on 

tertiary butanol and ethanol in mice: Correlation with lipid solubility. J Pharmacol 

Exp Ther 208: 113-117. 

25)Nelson, BK. (1986). Developmental neurotoxicology of in utero exposure to industrial 

solvents in experimental animals. Neurotoxicology 7: 441-447.

26)Nelson, BK; Brightwell, WS; Khan, A; Burg, JR; Goad, PT. (1989). Lack of selective 

developmental toxicity of three butanol isomers administered by inhalation to rats. 

Fundam Appl Toxicol 12: 469-479. 

27)Nelson, BK; Brightwell, WS; Khan, A; Shaw, PB; Krieg, EF, Jr; Massari, VJ. (1991). 

Behavioral teratology investigation of tertiary-butanol administered by inhalation to 

rats. Pharmacopsychoecologia 4: 1-7. 

28)Nelson, BK; Brightwell, WS; Krieg, EF, Jr. (1990). Developmental toxicology of industrial 

alcohols: A summary of 13 alcohols administered by inhalation to rats. Toxicol Ind Health 6: 

373-387. 

29)NTP (National Toxicology Program). (1995). Toxicology and carcinogenesis studies of 

t-butyl alcohol (CAS no 75-65-0) in F344/N rats and B6C3F1 mice (drinking water 

studies) (pp. 1-305). Research Triangle Park, NC.

30)NTP (National Toxicology Program). (1997). NTP technical report on toxicity studies 

of t-butyl alcohol (CAS no 75-65-0) administered by inhalation to F344/N rats and 

B6C3F1 mice. Research Triangle Park, NC.

31)Palmer, AA; Mckinnon, CS; Bergstrom, HC; Phillips, TJ. (2002). Locomotor activity responses 

to ethanol, other alcohols, and GABA-A acting compounds in forward- and reverse-selected 

FAST and SLOW mouse lines. Behav Neurosci 116: 958-967. 

32) Siviy, SM; Atrens, DM; Jirasek, M; Holmes, LJ. (1987). Effects of ethanol and tertiary-butanol 

on energy expenditure and substrate utilization in the rat. Alcohol 4: 437-442. 

33)Snell, D. (1980). Impairment of avoidance behavior following short-term ingestion of 

ethanol, tertiary-butanol, or pentobarbital in mice. Psychopharmacology 69: 53-57. 
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

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1 34)Takahashi, K; Lindamood, C; Maronpot, R. (1993). Retrospective study of possible 

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alpha-2 mu-globulin nephropathy and associated cell proliferation in male Fischer 

344 rats dosed with t-butyl alcohol. Environ Health Perspect 101: 281-285. 

35)Thurman, RG; Winn, K; Urquhart, B. (1980). Rat brain cyclic AMP levels and 

withdrawal behavior following treatment with t-butanol. Adv Exp Med Biol 126: 271-

281.

36)Williams, TM; Borghoff, SJ. (2001). Characterization of tert-butyl alcohol binding to 

"alpha"2u-globulin in F-344 rats. Toxicol Sci 62: 228-235.

37)Wood, J; Laverty, R. (1979). Physical dependence following prolonged ethanol or tbutanol administration to rats. Pharmacol Biochem Behav 10: 113-119. 

Genotoxicity studies

1) Abbondandolo, A; Bonatti, S; Corsi, C; Corti, G; Fiorio, R; Leporini, C; Mazzaccaro, A; Nieri, R; 

Barale, R; Loprieno, N. (1980). The use of organic solvents in mutagenicity testing. DNA 

Repair 79: 141-150. 

2) ARCO (ARCO Chemical Company). (1994a). Evaluation of test article t-butyl alcohol 

99.9% (MRI #635) and arconol (MRI #636) for mutagenic potential employing the 

l5178Y TK+/- mutagenesis assay w/cover letter dated 03/24/94. (TSCATS/451796). 

3) ARCO (ARCO Chemical Company). (1994b). In vitro evaluation of t-butyl alcohol 

99.9% to produce sister chromatid exchanges in chinese hamster ovary cells with 

cover letter dated 03/24/1994. (8EHQ86940000254). Newton Square, PA.

4) ARCO (ARCO Chemical Company). (1994c). In vitro evaluation of t-butyl alcohol - arconol 

batch a209411 to produce sister chromatid exchanges in chinese hamster ovary cells with 

cover letter dated 03/24/1994. (8EHQ86940000261). Newton Square, PA.

5) ARCO (ARCO Chemical Company). (1994d). Microtox analysis of various alcohols with cover 

letter dated 05/05/94. (TSCATS/451912).

6) ARCO (ARCO Chemical Company). (1994e). Salmonella/mammalian-microsome 

preincubation mutagenicity assay with t-butyl alcohol with cover letter dated 

03/24/1994. (8EHQ86940000253). Newton Square, PA.

7) Barilyak, IR; Kozachuk, SY. (1988). Investigation of the cytogenetic effect of a number of 

monohydric alcohols on rat bone marrow cells. Cytol Genet 22(2): 51-54. 

8) Brooks, TM; Meyer, AL; Hutson, DH. (1988). The genetic toxicology of some hydrocarbon 

and oxygenated solvents. Mutagenesis 3: 227-232. 

9) Clark, JB. (1953). The mutagenic action of various chemicals on micrococcus aureus. Proc 

Okla Acad Sci 34:114-118.

10)Dickey, FH; Cleland, GH; Lotz, C. (1949). The role of organic peroxides in the induction 

of mutations. PNAS 35: 581-586. 
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

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1 11)Henry, B; Grant, SG; Klopman, G; Rosenkranz, HS. (1998). Induction of forward mutations at 

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the thymidine kinase locus of mouse lymphoma cells: Evidence for electrophilic and nonelectrophilic mechanisms. Mutat Res 397: 313-335.

12)Jimenez, J; Longo, E; Benitez, T. (1988). Induction of petite yeast mutants by 

membrane-active agents. Appl Environ Microbiol 54: 3126-3132. 

13)McGregor, D; Cruzan, G; Callander, R; May, K; Banton, M. (2005). The mutagenicity 

testing of tertiary-butyl alcohol, tertiary-butyl acetate and methyl tertiary-butyl 

ether in Salmonella typhimurium. Mutat Res 565: 181-189. 

14)McGregor, DB; Brown, A; Cattanach, P; Edwards, I; Mcbride, D; Caspary, WJ. (1988). 

Responses of the L5178Y tk+/tk- mouse lymphoma cell forward mutation assay II: 18 

coded chemicals. Environ Mol Mutagen 11: 91-118. 

15) Microbiological Associates. (1994). Salmonella/ Mammalian-microsome Plate Incorporation 

Mutagenicity Assay (Ames Test) of T-butanol with Cover Letter dated 03219. 

(TSCATS/442300).

16)Sgambato, A; Iavicoli, I; De Paola, B; Bianchino, G; Boninsegna, A; Bergamaschi, A; 

Pietroiusti, A; Cittadini, A. (2009). Differential toxic effects of methyl tertiary butyl 

ether and tert-butanol on rat fibroblasts in vitro. Toxicol Ind Health 25: 141-151. 

17)Tang, G; Wang, J; Zhuang, Z. (1997). [Cytotoxicity and genotoxicity of methyl tertbutyl ether and its metabolite to human leukemia cells]. Zhonghua Yufang Yixue 

Zazhi 31: 334-337.

18) Williams-Hill, D; Spears, CP; Prakash, S; Olah, GA; Shamma, T; Moin, T; Kim, LY; Hill, 

CK. (1999). Mutagenicity studies of methyl-tert-butylether using the Ames tester 

strain TA102. Mutat Res 446: 15-21. 

19)Yamaguchi, T. (1980). Activation with catalase of mutagenicity of hydroperoxides of some 

fatty acids and hydrocarbons. Agric Biol Chem 44: 1989-1991. 

20)Yuan, Y; Wang, HF; Sun, HF; Du, HF; Xu, LH; Liu, YF; Ding, XF; Fu, DP; Liu, KX. (2007). 

Adduction of DNA with MTBE and TBA in mice studied by accelerator mass 

Spectrometry. Environ Toxicol 22: 630-635. 

21) Zeiger, E; Anderson, B; Haworth, S; Lawlor, T; Mortelmans, K. (1992). Salmonella 

mutagenicity tests: V Results from the testing of 311 chemicals. Environ Mol Mutagen 19: 2-

141.

22)Zeiger, E; Anderson, B; Haworth, S; Lawlor, T; Mortelmans, K; Speck, W. (1987). 

Salmonella mutagenicity tests: III. Results from the testing of 255 chemicals. Environ 

Mutagen 9: 1-109.

Other studies involving direct administration of tert-butanol, including mechanistic studies

1) Aarstad, K; Zahlsen, K; Nilsen, OG. (1985). Inhalation of butanols: changes in the cytochrome 

P-450 enzyme system. Arch Toxicol 8: 418-421. 
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

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1 2) Adachi, K; Wakabayashi, T; Popinigis, J. (1991). Effects of alkyl alcohols and related 

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chemicals on rat liver structure and function II Some biochemical properties of ethanol-, 

propanol- and butanol-treated rat liver mitochondria. Pathol Int 41: 414-427. 

3) Anderson, RA, Jr; Reddy, JM; Joyce, C; Willis, BR; Van der Ven, H; Zaneveld, LJD. (1982). 

Inhibition of mouse sperm capacitation by ethanol. Biol Reprod 27: 833-840.

4) Beaugé, F; Clement, M; Nordmann, J; Nordmann, R. (1981). Liver lipid disposal following tbutanol administration to rats. Chem Biol Interact 38: 45-51. 

5) Beaugé, F; Fleuret, C; Barin, F; Nordmann, R. (1984). Brain membrane disordering after 

acute in vivo administration of ethanol, isopropanol or t-butanol in rats. Biochem 

Pharmacol 33: 3591-3595. 

6) Bhattacharyya, SN; Mandal, PC. (1986). Reactions of hydroxyalkyl radicals with uracil. J 

Chem Soc Faraday Trans I 82(7): 2103-2110. 

7) Blanck, O; Fowles, J; Schorsch, F; Pallen, C; Espinasse-Lormeau, H; Schulte-Koerne, E; Totis, 

M; Banton, M. (2010). Tertiary butyl alcohol in drinking water induces phase I and II liver 

enzymes with consequent effects on thyroid hormone homeostasis in the B6C3F1 female 

mouse. J Appl Toxicol 30: 125-132. 

8) Borghoff, SJ; Prescott, JS; Janszen, DB; Wong, BA; Everitt, JI. (2001). alpha2u-Globulin 

nephropathy, renal cell proliferation, and dosimetry of inhaled tert-butyl alcohol in 

male and female F-344 rats. Toxicol Sci 61: 176-186. 

9) Breese, GR; Coyle, S; Towle, AC; Mueller, RA; Mccown, TJ; Frye, GD. (1984). Ethanol-induced 

locomotor stimulation in rats after thyrotropin-releasing hormone. J Pharmacol Exp Ther 

229: 731-737. 

10)Candura, SM; Balduini, W; Costa, LG. (1991). Interaction of short chain aliphatic alcohols 

with muscarinic receptor-stimulated phosphoinositide metabolism in cerebral cortex from 

neonatal and adult rats. NeuroToxicology 12(1): 23-32. 

11)Cederbaum, AI; Cohen, G. (1980). Oxidative demethylation of t-butyl alcohol by rat liver 

microsomes. Biochem Biophys Res Commun 97: 730-736 

12)Cederbaum, AI; Qureshi, A; Cohen, G. (1983). Production of formaldehyde and acetone by 

hydroxyl-radical generating systems during the metabolism of tertiary butyl alcohol. 

Biochem Pharmacol 32: 3517-3524. 

13)Chapin, RE; Breese, GR; Mueller, RA. (1980). Possible mechanisms of reduction of plasma 

luteinizing hormone by ethanol. J Pharmacol Exp Ther 212: 6-10.

14)Deñola, NL; Quiming, NS; Catabay, AP; Saito, Y; Jinno, K. (2008). Effects of alcohols on CE 

enantioseparation of basic drugs with native gamma-CD as chiral selector. J Sep Sci 31: 

2701-2706.

15)Hagman, M; Eriksson, T; Kitson, KE. (1993). Similar effects of ethanol and tert-butanol on 

amino acid concentrations in rat serum and liver. Alcohol Clin Exp Res 17: 299-303. 
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

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1 16)Hard, G. (2001). Expert evaluation of renal effects of tert-butyl alcohol in rats and mice. 

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Report to Lyondell Chemical Company. (12 pp.). Lyondell Chemical Company.

17)Hard, G. (2005). Comments on the NTP toxicity and carcinogenicity study in rats with tertbutyl alcohol (TBA). Report to Lyondell Chemical Company. (12 pp.). Lyondell Chemical 

Company.

18)Kolls, JK; Xie, J; Lei, D; Greenberg, S; Summer, WR; Nelson, S. (1995). Differential effects of in 

vivo ethanol on LPS-induced TNF and nitric oxide production in the lung. Am J Physiol 268: 

L991-L998.

19)Kötter, K; Jin, S; Klein, J. (2000). Inhibition of astroglial cell proliferation by alcohols: 

Interference with the protein kinase C-phospholipase D signaling pathway. Int J Dev 

Neurosci 18: 825-831. 

20)Kötter, K; Klein, J. (1999). Ethanol inhibits astroglial cell proliferation by disruption of 

phospholipase D-mediated signaling. J Neurochem 73: 2517-2523.

21)Kozlosky, J; Bonventre, J; Cooper, K. (2012). Methyl tert butyl ether is anti-angiogenic in 

both in vitro and in vivo mammalian model systems. J Appl Toxicol. 

22)Krasowski, M; Harrison, N. (2000). The actions of ether, alcohol and alkane general 

anaesthetics on GABAA and glycine receptors and the effects of TM2 and TM3 mutations. Br 

J Pharmacol 129: 731-743.

23) Lasner, M; Roth, LG; Chen, CH. (1995). Structure-functional effects of a series of alcohols on 

acetylcholinesterase-associated membrane vesicles: elucidation of factors contributing to 

the alcohol action. Arch Biochem Biophys 317: 391-396. 

24) Logan, B; Laverty, R. (1987). Comparative effects of ethanol and other depressant drugs on 

membrane order in rat synaptosomes using ESR spectroscopy. Alcohol Drug Res 7: 11-24. 

25) Lyon, R; McComb, J; Schreurs, J; Goldstein, D. (1981). A relationship between alcohol 

intoxication and the disordering of brain membranes by a series of short-chain alcohols. J 

Pharmacol Exp Ther 218: 669-675.

26) Malila, A. (1978). Intoxicating effects of three aliphatic alcohols and barbital on two rat 

strains genetically selected for their ethanol intake. Pharmacol Biochem Behav 8: 197-201. 

27) Martin, JV; Bilgin, NM; Iba, MM. (2002). Influence of oxygenated fuel additives and their 

metabolites on the binding of a convulsant ligand of the "gamma"-aminobutyric acid(A) 

(GABA(A)) receptor in rat brain membrane preparations. Toxicol Lett 129: 219-226. 

28) Martin, JV; Iyer, SV; Mcilroy, PJ; Iba, MM. (2004). Influence of oxygenated fuel additives and 

their metabolites on "gamma"-aminobutyric acid(A_ (GABA(A)) receptor function in rat 

brain synaptoneurosomes. Toxicol Lett 147: 209-217. 

29) McGregor, D; Hard, GC. (2001). Renal tubule tumor induction by tertiary-butyl alcohol. 

Toxicol Sci 61: 1-3. 
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

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1 30) Melgunov, VI; Jindal, S; Belikova, MP. (1988). Short-chain alkanols and the functional 

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efficiency of the Ca pump in the sarcoplasmic reticulum of rabbit skeletal muscles. FEBS Lett 

227: 157-160.

31)Oenfelt, A; Hellberg, S; Wold, S. (1986). Relationships between induction of anesthesia and 

mitotic spindle disturbances studied by means of principal component analysis. Mutat Res 

174: 109-113.

32) Sanchis-Segura, C; Pastor, R; Aragon, CM. (2004). Opposite effects of acute versus chronic 

naltrexone administration on ethanol-induced locomotion. Behav Brain Res 153(1): 61-67.

33) Strubelt, O; Deters, M; Pentz, R; Siegers, CP; Younes, M. (1999). The toxic and metabolic 

effects of 23 aliphatic alcohols in the isolated perfused rat liver. Toxicol Sci 49: 133-142.

34)Tanii, H; Zhang, XP; Ohyashiki, T. (1995). In-vitro influences of alcohols on mouse 

synaptosomes, and structure-activity-relationships. Arch Tox 69(9): 617-623. 

35)Thomas, M; Boura, AL; Vijayakumar, R. (1980). Prostaglandin release by aliphatic alcohols 

from the rat isolated lung. Clin Exp Pharmacol Physiol 7: 373-381. 

36)Thore, A; Baltscheffsky, H. (1965). Inhibitory effects of lower aliphatic alcohols on electron 

transport phosphorylation systems. II. Secondary, tertiary, and di-alcohols. Acta Chem 

Scand 19: 1600-1606. 

37)Videla, LA; Fernández, V; de Marinis, A; Fernández, N; Valenzuela, A. (1982). Liver 

lipoperoxidative pressure and glutathione status following acetaldehyde and aliphatic 

alcohols pretreatments in the rat. Biochem Biophys Res Commun 104: 965-970. 

38)Wakabayashi, T; Adachi, K; Popinigis, J. (1991). Effects of alkyl alcohols and related 

chemicals on rat liver structure and function. I. Induction of two distinct types of 

megamitochondria. Acta Pathol Jpn 41:405-413. 

39)Wallgren, H; Nikander, P; von Boguslawsky, P; Linkola, J. (1974). Effects of ethanol, tert. 

butanol, and clomethiazole on net movements of sodium and potassium in electrically

stimulated cerebral tissue. Acta Physiol Scand 91: 83-93. 

40)Walum, E; Peterson, A. (1983). Acute toxicity testing in cultures of mouse neuroblastoma 

cells. Acta Pharmacol Toxicol 52 Suppl 2: 100-114. 

41)Westcott, JY; Murphy, RC. (1983). The interaction of ethanol and exogenous arachidonic 

acid in the formation of leukotrienes and prostaglandin D2 in mastocytoma cells. 

Prostaglandins 26: 223-239.

42)Westcott, JY; Murphy, RC. (1985). Effect of alcohols on arachidonic acid metabolism in 

murine mastocytoma cells and human polymorphonuclear leukocytes. Biochim Biophys 

Acta 833: 262-271.

43)Yamaki, K; Yoshino, S. (2009). Inhibition of IgE-induced mast cell activation by ethyl 

tertiary-butyl ether, a bioethanol-derived fuel oxygenate. J Pharm Pharmacol 61: 1243-

1248.
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

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1 1.2.2. Not Primary Source of Health Effects Data, but Kept as Additional Resources

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Reviews, editorials

1) Caprino, L; Togna, G. (1998). Potential health effects of gasoline and its constituents: A 

review of current literature (1990-1997) on toxicological data [Review]. Environ Health 

Perspect 106: 115-125. 

2) Cederbaum, A. (1989). Oxygen radical generation by microsomes: Role of iron and 

implications for alcohol metabolism and toxicity [Review]. Free Radic Biol Med 7: 559-567. 

3) Chen, M. (2005). Amended final report of the safety assessment of t-butyl alcohol as used in 

cosmetics [Review]. Int J Toxicol 24 Suppl 2: 1-20.

4) CIRE (Cosmetic Ingredient Review Expert panel). (1989). Final report on the safety 

assessment of tert butyl alcohol. 8: 627-642. 

5) de Peyster, A. (2010). Ethyl t-butyl ether: Review of reproductive and developmental 

toxicity [Review]. Birth Defects Res B Dev Reprod Toxicol 89: 239-263. 

6) Dick, RB; Ahlers, H. (1998). Chemicals in the workplace: Incorporating human 

neurobehavioral testing into the regulatory process. Am J Ind Med 33: 439-453. 

7) ECETOC (European Centre for Ecotoxicology and Toxicology of Chemicals). (1997). Methyl 

tert-butyl ether (MTBE) health risk characterisation. (Technical Report No. 72). Brussels, 

Belgium.

8) Gleizes, V. (1988). Evaluation of the risks due to the use of monoalcohols in the workplace. 

Facultâe de Mâedecine Broussais. 

9) Hutcheon, DE; Arnold, JD; ten Hove, W; III, BJ. (1996). Disposition, metabolism, and toxicity 

of methyl tertiary butyl ether, an oxygenate for reformulated gasoline [Review]. J Toxicol 

Environ Health 47: 453-464.

10)Izzotti, A; D'Agostini, F; Bagnasco, M; Scatolini, L; Rovida, A; Balansky, RM; Cesarone, CF; De 

Flora, S. (1994). Chemoprevention of carcinogen-DNA adducts and chronic degenerative 

diseases. 54: 1994s-1998s. 

11)Kool, HJ; van Kreijl, CF; Zoeteman, BCJ; Tardiffd, RG. (1982). Toxicology assessment of 

organic compounds in drinking water. Crit Rev Environ Sci Tech 12: 307-357. 

12) McGregor, D. (2006). Methyl tertiary-butyl ether: studies for potential human health 

hazards [Review]. Crit Rev Toxicol 36: 319-358.

13) McGregor, D. (2006). Tertiary-butanol: A toxicological review [Review]. Crit Rev Toxicol 40: 

697-727. 

14) Mennear, J. (1997). Carcinogenicity studies on MTBE: critical review and interpretation. 

Risk Anal 17: 673-681. 
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

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1 15) Mersch-Sundermann, V; Schneider, U; Klopman, G; Rosenkranz, HS. (1994). SOS induction in 

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Escherichia coli and Salmonella mutagenicity: A comparison using 330 compounds 

[Review]. Mutagenesis 9: 205-224.

16) Sidhu, KS. (1992). Regulation of environmental contaminants in drinking water state 

methods and problems. J Am Coll Toxicol 11: 331-340. 

17) Skalko, RG. (1993). Reproductive and Developmental Toxicity of the Components of 

Gasoline. Environ Health Perspect 101: 143-149. 

Health effects assessments by others

1) ACGIH (American Conference of Governmental Industrial Hygienists). (2012). tert-Butanol. 

In Documentation of the threshold limit values and biological exposure indices (7th ed.). 

Cincinnati, OH.

2) Criteria Group for Occupational Standards. (1984). Scientific basis for Swedish occupational 

standards. V. 2-Butanol, isobutanol, tert-butanol. Arbete och Hälsa 44(1984): 98-105. 

3) DECOS (Dutch Expert Committee on Occupational Standards). (1994). 1-, 2- and t-Butanol: 

Health based recommended occupational exposure limit 14: 94. 

4) IPCS (International Programme on Chemical Safety). (1987a). Butanols: Four isomers: 1-

butanol, 2-butanol, tert-butanol, isobutanol [WHO EHC]. Geneva, Switzerland: World Health 

Organization.

5) IPCS (International Programme on Chemical Safety). (1987b). tert-Butanol. Geneva, 

Switzerland: World Health Organization.

6) National Board of Labour Protection. (1982). Tert-butyl alcohol. Register of safety 

information of chemical products. 

7) NRC (National Research Council). (1996). Spacecraft maximum allowable concentrations for 

selected airborne contaminants. Volume 2: 412.

8) OSHA (Occupational Safety & Health Administration). (1992). Occupational Safety and 

Health Guideline for tert-butyl alcohol. Cincinnati, OH: National Institute for Occupational 

Safety and Health (NIOSH). 

Toxicokinetic studies (excluding physiologically-based toxicokinetic [PBTK] modeling studies) 

1) Amberg, A; Rosner, E; Dekant, W. (1999). Biotransformation and kinetics of excretion of 

methyl-tert-butyl ether in rats and humans. Toxicol Sci 51: 1-8. 

2) Amberg, A; Rosner, E; Dekant, W. (2000). Biotransformation and kinetics of excretion of 

ethyl tert-butyl ether in rats and humans. Toxicol Sci 53: 194-201. 

3) Amberg, A; Rosner, E; Dekant, W. (2001). Toxicokinetics of methyl tert-butyl ether and its 

metabolites in humans after oral exposure. Toxicol Sci 61: 62-67. 
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

1-15 DRAFT—DO NOT CITE OR QUOTE

1 4) ARCO (ARCO Chemical Company). (1983). Toxicologist's report on metabolism and 

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pharmacokinetics of radiolabeled TBA 534 tertiary butyl alcohol with cover letter dated 

03/24/1994. (8EHQ86940000263). Newton Square, PA.

5) Baker, RC; Sorensen, SM; Deitrich, RA. (1982). The in vivo metabolism of tertiary butanol by 

adult rats. Alcohol Clin Exp Res 6: 247-251.

6) Benson, J; Barr, E; Krone, J. (2001). MTBE inhaled alone and in combination with gasoline 

vapor: uptake, distribution, metabolism, and excretion in rats. Res Rep Health Eff Inst 102: 

73-94. 

7) Benson, JM; Tibbetts, BM; Barr, EB. (2003). The uptake, distribution, metabolism, and 

excretion of methyl tertiary-butyl ether inhaled alone and in combination with gasoline 

vapor. J Toxicol Environ Health A 66: 1029-1052. 

8) Bermudez, E; Willson, G; Parkinson, H; Dodd, D. (2012). Toxicity of methyl tertiary-butyl 

ether (MTBE) following exposure of Wistar Rats for 13 weeks or one year via drinking 

water. J Appl Toxicol 32: 687-706. 

9) Bernauer, U; Amberg, A; Scheutzow, D; Dekant, W. (1998). Biotransformation of 12C- and 2-

13C-labeled methyl tert-butyl ether, ethyl tert-butyl ether, and tert-butyl alcohol in rats: 

identification of metabolites in urine by 13C nuclear magnetic resonance and gas 

chromatography/mass spectrometry. Chem Res Toxicol 11: 651-658. 

10)BioResearch (BioResearch Laboratories). (2000). Pharmacokinetics of methyl-t-butyl ether 

and tert-butyl alcohol in male and female fischer 344 rats after single and repeated 

inhalation (nose-only) exposure to mtbe (final report). (TSCATS/412947).

11)Ehrig, T; Bohren, KM; Wermouth, B; Von Wartburg, JP. (1988). Degradation of aliphatic 

alcohols by human liver alcohol dehydrogenase: effect of ethanol and pharmacokinetic 

implications. Alcohol Clin Exp Res 12: 789-794. 

12) Faulkner, T; Hussain, A. (1989). The pharmacokinetics of tertiary butanol in C57BL/6J mice. 

Res Comm Chem Pathol Pharmacol 64: 31-39. 

13)Gadberry, MG; Carlson, GP. (1994). 2-Butanol metabolism by rat hepatic and pulmonary 

cytochromes P450. Toxicol Lett 74: 203-209. 

14)Gaillard, D; Derache, R. (1965). Metabolism of different alcohols present in alcoholic 

beverages, in rats. Trav Soc Pharm Montpellier 25: 51-62. 

15)Groth, G; Freundt, KJ. (1994). Inhaled tert-butyl acetate and its metabolite tert-butyl alcohol 

accumulate in the blood during exposure. Hum Exp Toxicol 13: 478-480. 

16)Hong, JY; Wang, YY; Bondoc, FY; Lee, M; Yang, CS; Hu, WY; Pan, J. (1999). Metabolism of 

methyl tert-butyl ether and other gasoline ethers by human liver microsomes and 

heterologously expressed human cytochromes P450: Identification of CYP2A6 as a major 

catalyst. Toxicol Appl Pharmacol 160: 43-48. 
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

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1 17)Hong, JY; Yang, CS; Lee, M; Wang, YY; Huang, WQ; Tan, Y; Patten, CJ; Bondoc, FY. (1997). 

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Role of cytochromes P450 in the metabolism of methyl tert-butyl ether in human livers. 

Arch Toxicol 71: 266-269. 

18)Kamil, IA; Smith, JN; Williams, RT. (1953). Studies in detoxication: 46. The metabolism of 

aliphatic alcohols the glucuronic acid conjugation of acyclic aliphatic alcohols. Biochemistry 

53: 129-136. 

19) Lee, CW; Mohr, SN; Weisel, CP. (2001). Toxicokinetics of human exposure to methyl 

tertiary-butyl ether (MTBE) following short-term controlled exposures. J Expo Sci Environ 

Epidemiol 11: 67-78. 

20) Miller, MJ; Ferdinandi, ES; Klan, M; Andrews, LS; Douglas, JF; Kneiss, JJ. (1997). 

Pharmacokinetics and disposition of methyl t-butyl ether in Fischer-344 rats. J Appl Toxicol 

17: S3-S12. 

21)Nihlen, A; Lof, A; Johanson, G. (1995). Liquid/air partition coefficients of methyl and ethyl tbutyl ethers, t-amyl methyl ether, and t-butyl alcohol. J Expo Anal Environ Epidemiol 5: 573-

582. 

22)Nihlen, A; Lof, A; Johanson, G. (1998a). Controlled ethyl tert-butyl ether (ETBE) exposure of 

male volunteers: I Toxicokinetics. Toxicol Sci 46: 1-10.

23)Nihlen, A; Lof, A; Johanson, G. (1998b). Experimental exposure to methyl tertiary-butyl 

ether: I Toxicokinetics in humans. Toxicol Appl Pharmacol 148: 274-280. 

24)Nihlen, A; Lof, G; Johanson, G. (1997). Liquid/air partition coefficients of methyl and ethyl tbutyl ethers, t-amyl methyl ether, and t-butyl-alcohol. J Clean Technol, Environ Toxicol, 

Occup Med 6: 205-213. 

25)Nihlen, A; Sumner, SCJ; Lof, A; Johanson, G. (1999). 13C2-labeled methyl tert-butyl ether: 

toxicokinetics and characterization of urinary metabolites in humans. Chem Res Toxicol 12: 

822-830. 

26)Poet, TS; Valentine, JL; Borghoff, SJ. (1997). Pharmacokinetics of tertiary butyl alcohol in 

male and female Fischer 344 rats. Toxicol Lett 92: 179-186. 

27)Prah, J; Ashley, D; Blount, B; Case, M; Leavens, T; Pleil, J; Cardinali, F. (2004). Dermal, oral, 

and inhalation pharmacokinetics of methyl tertiary butyl ether (MTBE) in human 

volunteers. Toxicol Sci 77: 195-205. 

28)Turini, A; Amato, G; Longo, V; Gervasi, PG. (1998). Oxidation of methyl- and ethyl-tertiarybutyl ethers in rat liver microsomes: role of the cytochrome P450 isoforms. Arch Toxicol 72: 

207-214. 

29)Vainiotalo, S; Riihimäki, V; Pekari, K; Teräväinen, E; Aitio, A. (2007). Toxicokinetics of 

methyl tert-butyl ether (MTBE) and tert-amyl methyl ether (TAME) in humans, and 

implications to their biological monitoring. J Occup Environ Hyg 4: 739-750. 
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

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1 PBTK modeling studies 

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1) Borghoff, S; Murphy, J; Medinsky, M. (1996). Development of physiologically based 

pharmacokinetic model for methyl tertiary-butyl ether and tertiary-butanol in male Fisher344 rats. Fundam Appl Toxicol 30: 264-275. 

2) Borghoff, S; Parkinson, H; Leavens, T. (2010). Physiologically based pharmacokinetic rat 

model for methyl tertiary-butyl ether; comparison of selected dose metrics following 

various MTBE exposure scenarios used for toxicity and carcinogenicity evaluation. 

Toxicology 275: 79-91. 

3) Kim, D; Andersen, ME; Pleil, JD; Nylander-French, LA; Prah, JD. (2007). Refined PBPK model 

of aggregate exposure to methyl tertiary-butyl ether. Toxicol Lett 169: 222-235.

4) Leavens, T; Borghoff, S. (2009). Physiologically based pharmacokinetic model of methyl 

tertiary butyl ether and tertiary butyl alcohol dosimetry in male rats based on binding to 

alpha2u-globulin. Toxicol Sci 109: 321-335. 

5) Nihlen, A; Johanson, G. (1999). Physiologically based toxicokinetic modeling of inhaled ethyl

tertiary-butyl ether in humans. Toxicol Sci 51: 184-194. 

6) Rao, HV; Ginsberg, GL. (1997). A physiologically-based pharmacokinetic model assessment 

of methyl t-butyl ether in groundwater for a bathing and showering determination. Risk 

Anal 17: 583-598. 

1.2.3. Kept for Possible Further Review

Foreign language

1) Anon. (1987). Criteria for proposed 1987 short-term exposure limits. Sangyo Igaku 29: 416-

433.

2) Apel, YA. (1968). Information on the toxicology of some intermediate products in the 

production of isoprene rubber. Sbornik Nauchnykh Trudov. Severo osetinskii 

Gosudarstvennyi i Meditsinskii Institut 5: 87-88.

3) Astrand, I; Ovrum, P; Lindqvist, T; Hultengren, M. (1976). Exposure to butyl alcohol: Uptake 

and distribution in man. Scand J Work Environ Health 2: 165-175.

4) Barthelmess, A; Elkabarity, A. (1962). Chemically induced multipolar mitoses. Part 3. 

Protoplasma 54: 455-475.

5) BASF. (1994). Letter from BASF Corp to U.S. EPA regarding submission of health and safety 

data subject to 8d reporting with attachments, dated 05/05/94 (sanitized). Note: studies 

are in german.

6) Brusewitz, S; Criteria Group for Occupational Standards; Wennberg, A. (1984). Butanol och 

butylacetat. Arbete och Hälsa 13: 1-45.

7) Brusewitz, S; Wennberg, A. (1984). Criteria document for setting exposure limits for butanol 

and butyl acetate. Arbete och Hälsa 171.
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

1-18 DRAFT—DO NOT CITE OR QUOTE

1 8) Consejo Interamericano de Seguridad. (1996). tert-Butyl alcohol. 

2 

3 

4 

5 

6 

7 

8 

9 

10

11

12

13

14

15

16

17

18

19

20

9) Conso, F; Mignâee, C. (1984). Monohydric alcohols other than ethyl alcohol. Encyclopƒedie 

Mƒedico Chirurgicale Intoxications 101. 

10)Damgard Nielsen, G; Kragh Hansen, M; Molhave, L. (1982). Toxicological evaluation of a 

number of substances that may pollute the workplace air. (pp. 16-18). Denmark. 

11)De Laat, J; Maouala-Makata, P; Dore, M. (1996). Rate constants for reactions of ozone and 

hydroxyl radicals with several phenyl-ureas and acetamides. Environ Technol 17: 707-716. 

12)DFG (Deutsche Forschungsgemeinschaft). (1995). 2-Amino-2-methyl-1-propanol. In MAK 

value documentations. Weinheim, Germany: Wiley-VCH. 

13)Henschler, D. (1984). Harmful industrial substances - Toxicological and medical basis for 

the establishment of maximum permissible concentrations. Verlag Chemie. 

14)INRS (Institut national de recherche et de sécurité). (1992). [Pentanols].

15)Noda, T. (1994). [Teratogenicity of organotin compounds]. Seikatsu Eisei 38: 139-156.

16)Rozengart, E. V. (1969). The effect of aliphatic alcohols on the anticholinesterase efficacy of 

certain organophosphorus compounds. Biokhimiya 34: 813-815.

17)Weese, H. (1928). Comparative studies of the efficacy and toxicity of the vapors of lower 

aliphatic alcohols. Arch Exp Pathol Phar 135:118-130.

18)Yamamoto, I; Haseba, T; Kurosu, M; Watanabe, T. (1992). [Allosterism of acidic alcohol 

dehydrogenase (class III ADH) of mouse liver and its role in alcohol metabolism]. Nippon 

Ika Daigaku Zasshi 59: 136-144.
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

2-1 DRAFT—DO NOT CITE OR QUOTE

2. PRELIMINARY EVIDENCE TABLES AND

EXPOSURE-RESPONSE ARRAYS

1 

2 

3 

4 

5 

6 

7 

8 

9 

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

2.1. Data Extraction: Preparation of Preliminary Evidence Tables and 

Exposure-Response Arrays 

The 106 references identified as primary sources of health effects data were considered for 

data extraction to evidence tables and exposure-response arrays. References were first collated 

with respect to exposure route, exposure duration, and type of endpoint, to identify those most 

pertinent for evaluating the human health effects from chronic oral or inhalation exposure to tertbutanol. As a result, data from 73 studies with one or more of the following characteristics were

not extracted into evidence tables or exposure-response arrays:

• The study involved dermal exposure;

• The study only involved acute or short-term exposures (less than 90 days/13 weeks), and it 

was not conducted in the context of immune, neurological, developmental, or reproductive 

toxicity;

• The data in the study only included endpoints related to possible mechanisms of toxicity; 

• The study’s endpoints did not exhibit responses in any of the 106 available references. 

Data from the 33 remaining references were prepared in preliminary evidence tables. No 

studies were excluded based on study quality considerations, so as to allow for public input on 

methodological considerations that could affect the interpretation of or confidence in each study’s 

results. With regard to noncancer effects, health effect endpoints that were consistently affected in 

chronic or subchronic studies were included in the evidence tables. All data demonstrating 

carcinogenic effects were included. Supporting data that provide mechanistic information for each 

selected endpoint were also included. For each included endpoint, all studies reporting data on that 

endpoint are included regardless of the reported level or statistical significance of the response.

The tables are arranged in the order from the health effect with the most data to health effect with 

the least data, with carcinogenic effects grouped with non-carcinogenic effects in the same tissue or 

system. For each endpoint, the studies are presented beginning with subchronic studies followed 

by chronic exposures. The evidence table for all reported genotoxicity endpoints follows. The 

information in the preliminary evidence tables is displayed graphically in preliminary exposure 

response arrays. In these preliminary arrays, the doses are labeled based only on statistical 

significance as determined by the study’s authors, without consideration of biological significance. 
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

2-2 DRAFT—DO NOT CITE OR QUOTE

1 As a consequence, endpoints for which the study’s authors did not report results of statistical 

2 

3 

significance tests were not included in these preliminary arrays.
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

2-3 DRAFT—DO NOT CITE OR QUOTE

1 2.2. Kidney Effects

2 

3 

Table 2-1. Evidence pertaining to kidney effects in animals following oral 

exposure to tert-butanol

Reference and study design Results

Kidney weight (percent change as compared to control)

Lyondell Chemical Company (2004)

Sprague-Dawley rat; 

12/sex/treatment

Gavage 0, 64, 160, 400, or 

1,000 mg/kg-d 

At least 9 weeks beginning 4 weeks 

prior to mating through mating (up 

to 2 weeks), gestation, and 

lactation.

Males

Dose

(mg/kg-d)

Left absolute

Weight

Left relative

Weight

Right absolute

Weight

Right relative

Weight

0 0 0 0 0

64 +6 +8 +6 +8

160 +9 +14* +6 +11*

400 +12* +14* +14* +17*

1,000 +18* +28* +20* +31*

Females

Dose

(mg/kg-d)

Left absolute

Weight

Left relative

Weight

Right absolute

Weight

Right relative

Weight

0 0 0 0 0

64 −1 −2 +2 0

160 0 0 +1 0

400 +3 +2 +4 +2

1,000 +4 0 +7 +2

NTP (1995)

F344/N rat; 10/sex/treatment

Drinking water 0, 2.5, 5, 10, 20, 

40 mg/mL 

 M: 0, 230, 490, 840, 1,520, 

3,610a mg/kg-d 

 F: 0, 290, 590, 850, 1,560, 

3,620a mg/kg-d 

13 weeks

Males Females

Dose

(mg/kg-d)

Absolute

Weight

Relative

Weight

Dose

(mg/kg-d)

Absolute

Weight

Relative

Weight

0 0 0 0 0 0

230 +12* +19* 290 +19* +17*

490 +17* +26* 590 +16* +15*

840 +16* +32* 850 +29* +28*

1,520 +26* +54* 1,560 +39* +40*

3,610 All dead All dead 3,620 +36* +81*

4 
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

2-4 DRAFT—DO NOT CITE OR QUOTE

Table 2-1. Evidence pertaining to kidney effects in animals following oral 

exposure to tert-butanol (continued) 

Reference and study design Results

NTP (1995)

B6C3F1 mouse; 10/sex/treatment

Drinking water (0, 2.5, 5, 10, 20, 

40 mg/mL)

 M: 0, 350, 640, 1,590, 3,940, 

8,210a mg/kg-d 

 F: 0, 500, 820, 1,660, 6,430, 

11,620 a mg/kg-d 

13 weeks

Males Females

Dose

(mg/kg-d)

Absolute

weight

Relative

weight

Dose

(mg/kg-d)

Absolute

weight

Relative

weight

0 0 0 0 0 0

350 +1 +1 500 0 −3

640 +3 +2 820 −3 −1

1,590 +2 +8 1,660 +1 0

3,940 +6 +22* 6,430 +6 +15*

8,210 0 +48* 11,620 +12* +35*

NTP (1995)

F344/N rat; 60/sex/treatment 

(10/sex/treatment evaluated at 15 

months)

Drinking water (0, 1.25, 2.5, 5, or 10 

mg/mL)

 M: 0, 90, 200, or 420a mg/kg-d 

 F: 0, 180, 330, or 650a mg/kg-d 

2 years

Males Females

Dose

(mg/kg-d)

Absolute

weight

Relative

weight

Dose

(mg/kg-d)

Absolute

weight

Relative

weight

0 0 0 0 0 0

90 +4 +8 180 +8* +14*

200 +11 +15* 330 +18* +21*

420 +7 +20* 650 +22* +42*

Only animals sacrificed at 15 months were evaluated for organ weights.

Histopathology

Acharya et al. (1997; 1995)

Wistar rat; 5–6 males/treatment

Drinking water (0 or 0.5%), 0 or 575 

mg/kg-d 

10 weeks

↑ tubular degeneration, degeneration of the basement membrane of the Bowman’s 

capsule, diffused glomeruli, and glomerular vacuolation (no incidences reported)

↓ kidney glutathione (~40%)*

Lyondell Chemical Company (2004)

Sprague-Dawley rat; 

12/sex/treatment

Gavage 0, 64, 160, 400, or 1,000 

mg/kg-d 

At least 9 weeks beginning 4 weeks 

prior to mating through mating (up 

to 2 weeks), gestation, and 

lactation.

There were no changes in kidney histopathology observed.
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

2-5 DRAFT—DO NOT CITE OR QUOTE

Table 2-1. Evidence pertaining to kidney effects in animals following oral 

exposure to tert-butanol (continued) 

Reference and study design Results

NTP (1995)

F344/N rat; 10/sex/treatment

Drinking water (0, 2.5, 5, 10, 20, or 

40 mg/mL) 

 M: 0, 230, 490, 840, 1,520, 3,610a

mg/kg-d 

 F: 0, 290, 590, 850, 1,560, 3,620a

mg/kg-d 

13 weeks

Incidence (severity):

Males Females

Dose 

(mg/kg-d) Mineralization Nephropathy

Dose 

(mg/kg-d) Mineralization Nephropathy

0 0/10 7/10 (1.0) 0 10/10 (1.7) 2/10 (1.0)

230 0/10 10/10 (1.6*) 290 10/10 (2.0) 3/10 (1.0)

490 2/10 (1.5) 10/10 (2.6*) 590 10/10 (2.0) 5/10 (1.0)

840 8/10*(1.4) 10/10 (2.7*) 850 10/10 (2.0) 7/10* (1.0)

1,520 4/10*(1.0) 10/10 (2.6*) 1,560 10/10 (2.0) 8/10* (1.0)

3,610 4/10*(1.0) 7/10 (1.1) 3,620 6/10 (1.2) 7/10* (1.0)

NTP (1995)

B6C3F1 mouse; 10/sex/treatment

Drinking water (0, 2.5, 5, 10, 20, or 

40 mg/mL) 

 M: 0, 350, 640, 1,590, 3,940, 

8,210a mg/kg-d 

 F: 0, 500, 820, 1,660, 6,430, 

11,620a mg/kg-d 

13 weeks

There were no changes in kidney histopathology observed (histopathology data for the 

13-week study were not provided) 
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

2-6 DRAFT—DO NOT CITE OR QUOTE

Table 2-1. Evidence pertaining to kidney effects in animals following oral 

exposure to tert-butanol (continued) 

Reference and study design Results

NTP (1995)

F344/N rat; 60/sex/treatment 

(10/sex/treatment evaluated at 15 

months)

Drinking water (0, 1.25, 2.5, 5, 10 

mg/mL)

 M: 0, 90, 200, 420a mg/kg-d 

 F: 0, 180, 330, 650a mg/kg-d 

2 years

Incidence (severity): 

Males

Dose

(mg/kg-d)

Mineralization 

(interim)

Mineralization 

(terminal)

Linear mineralization 

(terminal)

0 1/10 (1.0) 26/50 (1.0) 0/50

90 2/10 (1.0) 28/50 (1.1) 5/50* (1.0)

200 5/10 (1.8) 35/50 (1.3) 24/50* (1.2)

420 9/10* (2.3) 48/50* (2.2) 46/50* (1.7)

Dose

(mg/kg-d)

Renal tubule 

hyperplasia 

(extended 

evaluation)

Transitional 

epithelium 

hyperplasia

Nephropathy 

severity

0 12/50 (2.3) 25/50 (1.7) 3.0

90 16/50 (2.3) 32/50 (1.7) 3.1

200 14/50 (2.2) 36/50* (2.0) 3.1

420 23/50* (2.8) 40/50* (2.1) 3.3*

Females

Dose (mg/kg-d)

Mineralizationb

Interim

Mineralizationb

Terminal

Inflammation 

(suppurative) 

incidence

0 10/10 (2.8) 49/50 (2.6) 2/50

180 10/10 (2.9) 50/50 (2.6) 3/50

330 10/10 (2.9) 50/50 (2.7) 13/50*

650 10/10 (2.8) 50/50 (2.9) 17/50*

Dose

(mg/kg-d)

Renal tubule 

hyperplasia

Transitional 

epithelium 

hyperplasia

Nephropathy 

severity

 0 0/50 0/50 1.6

180 0/50 0/50 1.9*

330 0/50 3/50 (1.0) 2.3*

650 1/50 (1.0) 17/50*(1.4) 2.9*
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

2-7 DRAFT—DO NOT CITE OR QUOTE

Table 2-1. Evidence pertaining to kidney effects in animals following oral 

exposure to tert-butanol (continued) 

Reference and study design Results

NTP (1995)

B6C3F1 mouse; 60/sex/treatment 

Drinking water (0, 5, 10, or 20 

mg/mL) 

 M: 0, 540, 1,040, or 2,070a mg/kg-d 

 F: 0, 510, 1,020, or 2,110 mg/kg-d 

2 years

No changes in kidney related histopathology observed.c

Tumors

NTP (1995)

F344/N rat; 60/sex/treatment

(10/sex/treatment evaluated at 15 

months)

Drinking water (0, 1.25, 2.5, 5, or 10 

mg/mL)

 M: 0, 90, 200, or 420a mg/kg-d 

 F: 0, 180, 330, or 650a mg/kg-d 

2 years

Male

Dose

(mg/kg-d)

Renal tubule 

adenomad

Renal tubule 

adenoma (multiple)d

Renal tubule 

adenoma or 

carcinomad

0 7/50 1/50 8/50

90 7/50 4/50 13/50

200 10/50 9/50* 19/50*

420 10/50 3/50 13/50

Results do not include the animals sacrificed at 15 months. Females did not develop 

kidney tumors.

Hard et al. (2011);

reanalysis of the slides in the NTP 

(1995) study (see above)

Male

Dose

(mg/kg-d)

Renal tubule 

adenoma

Renal tubular 

adenoma (multiple)

Renal tubule 

adenoma or 

carcinoma

0 3/50 1/50 4/50

90 9/50 3/50 13/50*

200 9/50 9/50 18/50*

420 9/50 3/50 12/50*

NTP (1995)

B6C3F1 mouse; 60/sex/treatment

Drinking water (0, 5, 10, or 20 

mg/mL)

 M: 0, 540, 1,040, or 2,070a mg/kg-d 

 F: 0, 510, 1,020, or 2,110 mg/kg-d 

2 years

No changes in kidney-related tumors
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

2-8 DRAFT—DO NOT CITE OR QUOTE

Table 2-1. Evidence pertaining to kidney effects in animals following oral 

exposure to tert-butanol (continued) 

Reference and study design Results

Additional studies potentially relevant for informing the mode of action

Williams and Borghoff (2001)

F344 rats; 4/sex

Single gavage dose: 500 mg/kg 

Males: ↑ binding of tert-butanol to α2u-globulin compared to females*

Females: no change in binding observed 

Takahashi et al. (1993)

F344 rats (M); 10/treatment

Drinking water (0, 0.25, 0.5, 1, 2 ,4% 

w/v) 

0,230,490, 840, 1,520 or 3,610a

mg/kg-d 

13 weeks

↑ in hyaline droplet accumulation (number and size) with ↑ severity for nephropathy 

(no incidence data)

Male

Dose

(mg/kg-d)

Hyaline droplet 

severity score

Hyaline crystals 

severity score

Nephropathy 

severity score

0 1 0.5 1

230 1.5 2* 2*

490 2* 3* 3*

840 2* 3* 3*

1,520 2* 3* 3*

3,610 >0.25* >0.25* 1

NTP (1995)

F344/N rat; 10/sex/treatment

Drinking water (0, 2.5, 5, 10, 20, or 

40 mg/mL) 

 M: 0, 230, 490, 840, 1,520, 3,610a

mg/kg-d 

 F: 0, 290, 590, 850, 1,560, 3,620a

mg/kg-d 

13 weeks

Accumulation of hyaline droplets:

Male

Dose

(mg/kg-d)

Hyaline 

droplet accumulation

0 0/10

230 +

e

490 ++

840 ++

1,520 ++

3,610 0/10

No information provided on females. No results from statistical tests reported.

Hard et al. (2011)

Reanalysis of the slides in the NTP 

(1995) study (see above)

Males: Confirmed accumulation of hyaline droplets increased with increasing dose-levels 

in 13 week study above. No incidence data available.

Females: not evaluated

a 1 The high-dose group had an increase in mortality. 

2 

3 

4 

5 

6 

7 

8 

9 

b Linear mineralization not observed in female rats. c Organs were not weighed in mice during the 2-year study. d Standard & extended evaluation combined. e + or ++ indicated an increased accumulation relative to controls, as reported by the authors; no additional incidence data and 

no results from statistical tests available.

* Statistically significant p ≤ 0.05 as determined by the study authors. 

Percentage change compared to control = (treated value – control value) ÷ control value × 100.

Conversions from drinking water concentrations to mg/kg-d performed by study authors.
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

2-9 DRAFT—DO NOT CITE OR QUOTE

1 Table 2-2. Evidence pertaining to kidney effects in animals following 

2 inhalation exposure to tert-butanol

Reference and study design Results

Kidney weight (percent change compared to control)

NTP (1997)

F344/N rat; 10/sex/treatment

Analytical concentration: 0, 134, 272, 542, 

1,080, or 2,101 ppm (0, 406, 824, 1,643, 3,273 

or 6,368 mg/m3 ) 6 hr/d, 5 d/wk 

13 weeks

Males Females

Dose

(mg/m3)

Absolute

weight

Relative

weight

Absolute

weight

Relative

weight

0 0 0 0 0

406 +1 +1 −4 −1

824 −2 −1 0 +1

1,643 +3 +2 +4 +4

3,273 +11* +8* +2 +2

6,368 +9.8* +9* +4 +9*

NTP (1997)

B6C3F1 mouse; 10/sex/treatment

Analytical concentration: 0, 134, 272, 542, 

1,080, or 2,101 ppm (0, 406, 824, 1,643, 3,273 

or 6,368 mg/m3

) 6 hr/d, 5 d/wk 

13 weeks

Males Females

Dose

(mg/m3)

Absolute

weight

Relative

weight

Absolute

weight

Relative

weight

0 0 0 0 0

406 −6 −4 +1 −3

824 −1 +3 +5 +9

1,643 +4 +3 +1 −2

3,273 −10 −3 0 +7

6,368 +3 +6 +3 +15*

Histopathology 

NTP (1997)

F344/N rat; 10/sex/treatment

Analytical concentration: 0, 134, 272, 542, 

1,080, or 2,101 ppm (0, 406, 824, 1,643, 3,273 

or 6,368 mg/m3 ) 6 hr/d, 5 d/wk

13 weeks 

Male

Dose

(mg/m3)

Average severity 

of chronic 

nephropathy

0 1.0

406 1.4

824 1.4

1,643 1.6

3,273 1.9

6,368 2.0

Severity categories: 1= minimal, 2= mild. No results from statistical tests 

reported

3 
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

2-10 DRAFT—DO NOT CITE OR QUOTE

Table 2-2. Evidence pertaining to kidney effects in animals following 

inhalation exposure to tert-butanol (continued)

Reference and study design Results

NTP (1997)

B6C3F1 mouse; 10/sex/treatment

Analytical concentration: 0, 134, 272, 542, 

1,080, or 2,101 ppm (0, 406, 824, 1,643, 3,273 

or 6,368 mg/m3

) 6 hr/d, 5 d/wk

13 weeks 

There were no kidney effects observed.

Additional studies potentially relevant for informing the mode of action

Borghoff et al. (2001)

F344 rat; 5/sex/treatment

Analytical concentration:0, 250, 450, 1,750 ppm 

(0,771, 1,387 or 5,395mg/m3

) 6hr/d

10 days

Males: positive trend for accumulation of protein droplets (p < 0.05), 

significant increase in accumulation of α2u-globulin at 5,394 mg/m3 as 

compared to controls (no incidence data provided)

Females: No positive staining for α2u-globulin was observed in exposed 

female rats. 

1 * Statistically significant p ≤ 0.05 as determined by study authors. 

2 

3 

4 

5 

Conversion from ppm to mg/m3 is 1 ppm = 3.031 mg/m3. 

Percentage change compared to control = (treated value – control value) ÷ control value × 100.
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

2-11 DRAFT—DO NOT CITE OR QUOTE

1 

2 

3 

4 

5 

6 

10

100

1,000

10,000

100,000 Dose (mg/kg-day)

Absolute weight; M Rat (D)

Nephropathy severity; M Rat (D)

Relative weight; M Rat (D)

Decreased glutathione; M Rat (A)

Mineralization; M Rat (D)

Absolute weight; F Rat (D)

Relative weight; F Rat (D)

Nephropathy incidence; F Rat (D)

Mineralization; F Rat (D)

Absolute weight; M Mouse (D)

Relative weight; M Mouse (D)

Relative weight; F Mouse (D)

Absolute weight; F Mouse (D)

Linear mineralization; M Rat (D)

Absolute weight; M Rat (D)

Relative weight; M Rat (D)

Transitional epithelium hyperplasia; M Rat (D)

Interim/terminal mineralization; M Rat (D)

Nephropathy severity; M Rat (D)

Renal tubular hyperplasia; M Rat (D)

Nephropathy severity; F Rat (D)

Relative weight; F Rat (D)

Absolute weight; F Rat (D)

Inflammation; F Rat (D)

Transitional epithelium hyperplasia; F Rat (D)

Interim/terminal mineralization; F Rat (D)

Renal tubule hyperplasia; F Rat (D)

Relative weight; M Rat (C)

Absolute weight; M Rat (C)

Absolute weight; F Rat (C)

Relative weight; F Rat (C)

Renal tubular adenoma or carcinoma; M Rat (B)

Renal tubular adenoma or carcinoma; M Rat (D)

Renal tubular adenoma or carcinoma; F Rat (D)

Renal tubular adenoma or carcinoma; M Mouse (D)

Renal tubular adenoma or carcinoma; F Mouse (D)

 = exposures at which the endpoint was reported statistically significant by study authors

 = exposures at which the endpoint was reported not statistically significant by study authors

× = exposures at which all animals were dead and unable to be examined for the endpoint

SUBCHRONIC CHRONIC CANCER

REPRODUCTIVE

Sources: (A) Acharya et al. (1997; 1995); (B) Hard et al. (2011)*; (C) Lyondell (2004); (D) NTP (1995) 

*: reanalysis of NTP (1995) 

Figure 2-1. Exposure response array of kidney effects in rats and mice 

following oral exposure to tert-butanol. 
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

2-12 DRAFT—DO NOT CITE OR QUOTE

1 

2 

3 

4 

5 

6 

100

1,000

10,000

Absolute weight; M Rat

Relative weight; M Rat

Absolute weight; F Rat

Relative weight; F Rat

Absolute/relative weight; M Mouse

Absolute weight; F Mouse

Relative weight; F Mouse

Concentration (mg/m3)

 = exposures at which the endpoint was reported statistically significant by study authors

 = exposures at which the endpoint was reported not statistically significant by study authors

Source: NTP (1997) 

Figure 2-2. Exposure-response array of kidney effects in rats and mice

following subchronic inhalation exposure to tert-butanol.
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

2-13 DRAFT—DO NOT CITE OR QUOTE

1 2.3. Thyroid Effects 

2 

3 

4 

Table 2-3. Evidence pertaining to thyroid effects in animals following oral 

exposure to tert-butanol

Reference and study design Results

Follicular cell hyperplasia

NTP (1995)

F344/N rat; 60/sex/treatment 

(10/sex/treatment evaluated at 15 

months)

Drinking water (0, 1.25, 2.5, 5, or 10 

mg/mL) 

 M: 0, 90, 200, or 420a mg/kg-d 

 F: 0, 180, 330, or 650a mg/kg-d

2 years

Incidenceb

Males Females

Dose

(mg/kg-d)

Follicular cell 

hyperplasia

Dose

(mg/kg-d)

Follicular cell 

hyperplasia

0 3/50 0 0/50

90 0/49 180 0/50

200 0/50 330 0/50

420 0/50 650 0/50

NTP (1995)

B6C3F1 mouse; 60/sex/treatment 

Drinking water (0, 5, 10, or 20 mg/mL) 

 M: 0, 540, 1,040, or 2,070a mg/kg-d

 F: 0, 510, 1,020, or 2,110 mg/kg-d 

2 years

Incidence (severity)

Males Females

Dose

(mg/kg-d)

Follicular cell 

hyperplasia

Dose

(mg/kg-d)

Follicular cell 

hyperplasia

0 5/60 (1.2) 0 19/58 (1.8)

540 18/59* (1.6) 510 28/60 (1.9)

1,040 15/59* (1.4) 1,020 33/59* (1.7)

2,070 18/57* (2.1) 2,110 47/59* (2.2)

Tumors

NTP (1995)

F344/N rat; 60/sex/treatment 

(10/sex/treatment evaluated at 15 

months)

Drinking water (0, 1.25, 2.5, 5, or 10 

mg/mL) 

 M: 0, 90, 200, or 420a mg/kg-d 

 F: 0, 180, 330, or 650a mg/kg-d 

2 years

Incidenceb

Dose (mg/kg-d)

Follicular cell 

adenoma

Follicular cell 

carcinoma

Male

0 2/50 2/50

90 0/49 0/49

200 0/50 0/50

420 0/50 0/50

Female

0 1/50 1/50

180 0/50 0/50

330 1/50 1/50

6,500 0/50 0/50
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

2-14 DRAFT—DO NOT CITE OR QUOTE

Table 2-3. Evidence pertaining to thyroid effects in animals following oral 

exposure to tert-butanol (continued) 

Reference and study design Results

NTP (1995)

B6C3F1 mouse; 60/sex/treatment 

Drinking water (0, 5, 10, or 20 mg/mL) 

 M: 0, 540, 1,040, or 2,070a mg/kg-d

 F: 0, 510, 1,020, or 2,110 mg/kg-d 

2 years

Incidence

Dose

(mg/kg-d)

Follicular cell 

adenoma

Mortalityadjusted rate 

(%)

Follicular cell 

carcinoma or 

adenoma

Mortalityadjusted rate

(%)

Male

0 1/60 3.6 1/60 3.6

540 0/59 0.0 0/59 0.0

1,040 4/59 10.1 4/59 10.1

2,070 1/57 5.9 2/57 8.7

Female

0 2/58 5.6 2/58 5.6

510 3/60 8.6 3/60 8.6

1,020 2/59 4.9 2/59 4.9

2,110 9/59* 19.6 9/59* 19.6

a 1 There was a significant decrease in survival in the high-dose group.

2 

3 

4 

5 

6 

7 

8 

b

Results do not include the animals sacrificed at 15 months.

* Statistically significant p ≤ 0.05 as determined by the study authors. 

Conversions from drinking water concentrations to mg/kg-d performed by study authors.
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

2-15 DRAFT—DO NOT CITE OR QUOTE

1 

2 

3 

4 

5 

6 

10

100

1,000

10,000

Hyperplasia; M mouse

Hyperplasia; F mouse

Hyperplasia; M rat

Hyperplasia; F rat

Adenoma; M mouse

Adenoma; F mouse

Adenoma; M rat

Adenoma; F rat

Dose (mg/kg-day)

NONCANCER CANCER

 = exposures at which the endpoint was reported statistically significant by study authors

 = exposures at which the endpoint was reported not statistically significant by study authors

Source: NTP (1995) 

Figure 2-3. Exposure-response array of thyroid follicular cell effects in rats 

and mice following chronic oral exposure to tert-butanol.
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

2-16 DRAFT—DO NOT CITE OR QUOTE

1 2.4. Reproductive, Developmental, and Neurodevelopmental Effects

2 

3 

Table 2-4. Evidence pertaining to reproductive effects in animals following 

exposure to tert-butanol

Reference and study design Results

Oral

Billitti et al. (2005)

CD-1 male mice; number unclear

Gavage, 0, 400, 1,000, 2,000 mg/kg

Single dose

no effect on testosterone levels in feces or serum (data not provided)

no effect on body weight (statistical tests not reported)

↑ testes weights (averaged weights in the 1,000 and 2,000 mg/kg groups 

+14% higher relative to controls; p ≤ 0.05)

higher percentage (+7%; p ≤ 0.05) of sloughing in the seminiferous 

epithelium in the control animals

Lyondell Chemical Company (2004)

Sprague-Dawley rat; 12/sex/treatment

Gavage 0, 64, 160, 400, or 1,000 mg/kg-d 

P0 Males and Females: At least 9 weeks 

beginning 4 weeks prior to mating through 

mating (up to 2 weeks), gestation, and lactation.

P0 reproductive effects

M: No effects weights of male reproductive organs or sperm observed

F:

Dose 

(mg/kg-d) 0 64 160 400 1000

Pregnancy index

91.7% 91.7% 100% 100% 91.7%

Live pups/litter response relative to control

0 −9 −11 −7 −33*

NTP (1995)

F344/N rat; 10/sex/treatment 

Drinking water (0, 2.5, 5, 10, 20, or 40 mg/mL) 

 M: 0, 230, 490, 840, 1,520, 3,610a mg/kg-d 

 F: 0, 290, 590, 850, 1,560, 3,620a mg/kg-d 

13 weeks

No significant effect on weights of male reproductive organs or sperm 

observed

No significant effect on female estrous cycle (0, −2, −4, 0, +8 % change 

relative to control)

NTP (1995)

B6C3F1 mouse; 10/sex/treatment 

Drinking water (0, 2.5, 5, 10, 20, or 40 mg/mL) 

 M: 0, 350, 640, 1,590, 3,940, 8,210a mg/kg-d 

 F: 0, 500, 820, 1,660, 6,430, 11,620a mg/kg-d 

13 weeks

No significant effect on weights of male reproductive organs or sperm 

observed

↑ length of estrous cycle

Response relative to control: 0, +5, +5, +5, +6, +28*%

4

5
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

2-17 DRAFT—DO NOT CITE OR QUOTE

Table 2-4. Evidence pertaining to reproductive effects in animals following 

exposure to tert-butanol (continued)

Reference and study design Results

Inhalation

NTP (1997)

F344/N rat; 10/sex/treatment

Analytical concentration: 0, 134, 272, 542, 

1,080, or 2,101 ppm (0, 406, 824, 1,643, 3,273 

or 6,368 mg/m3) 6 hr/d, 5 d/wk 

13 weeks

No significant effect on weights of male reproductive organs or sperm 

observed

No significant effect on female estrous cycle (0, −4, +2, +4 % change relative 

to control)

Evaluations were only performed for concentrations ≥542 ppm

NTP (1997)

B6C3F1 mouse; 10/sex/treatment

Analytical concentration: 0, 134, 272, 542, 

1,080, or 2,101 ppm (0, 406, 824, 1,643, 3,273 

or 6,368 mg/m3

) 6 hr/d, 5 d/wk 

13 weeks 

No significant effect on weights of male reproductive organs or sperm 

observed

No significant effect on female estrous cycle (0, −3, −9, −5 % change relative 

to control)

Evaluations were only performed for concentrations ≥542 ppm

1 * Statistically significant p ≤ 0.05 as determined by the study authors. 

2 

3 

4 

5 

6 

Conversions from drinking water concentrations to mg/kg-d performed by study authors.

Conversion from ppm to mg/m3 is 1 ppm = 3.031 mg/m3

. 

Percentage change compared to control = (treated value – control value) ÷ control value × 100.
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

2-18 DRAFT—DO NOT CITE OR QUOTE

Table 2-5. Evidence pertaining to developmental effects in animals following 

exposure to tert-butanol

1 

2 

Reference and study design Results

Oral

Daniel and Evans (1982)

Swiss Webster (Cox) mouse; 15 pregnant 

dams/treatment 

Liquid diet (0, 0.5, 0.75, 1.0%, w/v) 

0 (isocaloric amounts of maltose/dextrin), 

3,324, 4,879, 6,677 mg/kg-d 

GD 6–20 

No statistical analysis was conducted on any of these data

Maternal

Percent change compared to control:

Dose

(mg/kg-d)

Body weight on 

GD 20

Body weight

gain

Number of litters 

(% pregnant 

dams)

0 0 0 11 (77%)

3,324 +2 −3 12 (80%)

4,879 −5 −19 8 (53%)

6,677 −10 −20 7 (47%)

Fetal

Percent change compared to control:

Dose

(mg/kg-d)

Number of 

neonates/litter

Fetal body weight 

on PND 2

0 0 0

3,324 −1 −7

4,879 −29 −19

6,677 −49 −38

Number of stillborn also increased with dose (3, 6, 14, and 20, respectively), 

but appropriate denominators not reported so statistical significance of this 

change could not be calculated. The high dose also caused a delay in eye 

opening and a lag in weight gain during PND 2–10 (information was only 

provided in text or figures)

Faulkner et al. (1989)

CBA/J mouse; 7 pregnant females in control, 

12 pregnant females in treated 

Gavage (10.5 mmoles/kg twice a day); 

0 (tap water), 1,556 mg/kg-d 

GD 6–18 

Maternal results not reported. 

Fetal

Percent change compared to 

control: Incidence:

Dose

(mg/kg-d)

Live 

fetuses/litter

Fetal

weight

Sternal 

variations

Skull 

variations

0 0 0 4/28 1/28

1,556 −41* −4 7/30 3/30

Sternal variations: misaligned or unossified sternebrae

Skull variations: moderate reduction in ossification of supraoccipital bone

Number of total resorptions (10 resorptions/66 implants in controls, 37/94 

implants in treated) and resorptions per litter resorptions per litter (+118%) 

increased (p < 0.05)
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

2-19 DRAFT—DO NOT CITE OR QUOTE

Table 2-5. Evidence pertaining to developmental effects in animals following 

exposure to tert-butanol (continued)

Reference and study design Results

Faulkner et al. (1989)

C57BL/6J mouse; 5 pregnant females in 

controls, 9 pregnant females treated 

Gavage (10.5 mmoles/kg twice a day) 

0 (tap water), 1,556 mg/kg-d 

GD 6–18 

Maternal results not reported. 

Fetal

Percent change compared to 

control: Incidence:

Dose

(mg/kg-d)

Live 

fetuses/litter

Fetal

weight

Sternal 

variations Skull variations

0 0 0 5/21 1/21

1,556 −58%* −4 9/16 7/16

Sternal variations: misaligned or unossified sternebrae

Skull variations: moderate reduction in ossification of supraoccipital bone

Number of total resorptions (4 resorptions/44 implants in controls, 38/68 

implants in treated) and resorptions per litter resorptions per litter (+428%) 

increased (p < 0.05)

Lyondell Chemical Company (2004)

Sprague-Dawley rat; 12/sex/treatment

Gavage 0, 64, 160, 400, or 1,000 mg/kg-d 

P0 Males and Females: At least 9 weeks 

beginning 4 weeks prior to mating through 

mating (up to 2 weeks), gestation, and 

lactation.

F1 Males and Females: 7 weeks 

(throughout gestation and lactation; 1 male 

and 1 female from each litter was treated 

themselves from PND 21-28) 

Response relative to control

Dose 

(mg/kg-d) 0 64 160 400 1000

Maternal effects

Body weight gain GD 0-20

0 −3 −4 0 −16*

Body weight gain PND 1-21

0 +3 −10 +3 +100*

F1 Reproductive effects 

0 64 160 400 1000

Viability index

96.4% 98.7% 98.2% 99.4% 74.1%*

Lactation index

100% 100% 100% 99.2% 98.8%

Sex ratio (% males)

54.4 52.3 50.9 53.4 52.1

Pup weight/litter PND 1 response relative to control

0 +6 +4 +7 −10

Pup weight PND 28 response relative to control

M: 0 +2 0 0 −12*

F: 0 0 −4 −2 −8

 1 
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

2-20 DRAFT—DO NOT CITE OR QUOTE

Table 2-5. Evidence pertaining to developmental effects in animals following 

exposure to tert-butanol (continued)

Reference and study design Results

Inhalation

Nelson et al. (1989)

Sprague-Dawley rat; 15 pregnant 

dams/treatment

Whole body inhalation

Analytical concentration: 0, 2,200, 3,510, 

5,030 ppm (0, 6,669, 10,640, 15,248 

mg/m3), 7 hr/d 

GD 1–19 

Maternal: Unsteady gait (no statistical tests reported), dose-dependent ↓ in 

body weight gain (results presented in figure only), dose-dependent ↓ in food 

consumption ranging from 7–36% depending on dose and time

Fetal

Percent change compared to control:

Dose

(mg/m3)

Number of 

live 

fetuses/litter

Resorptions 

per litter

0 0 0

6,669 0 +9

10,640 +15 −18

15,248 +8 0

Percent change compared to 

control: Incidence:

Dose

(mg/m3)

Fetal weight 

(males)

Fetal weight 

(females)

Skeletal 

variation

by litter

Skeletal 

variation

by fetus

0 0 0 10/15 18/96

6,669 −9* −9* 14/17 35/104

10,640 −12* −13* 14/14 53/103*

15,248 −32* −31* 12/12 76/83*

Skeletal variation by litter refers to the number of variations observed in the 

number of litters examined. Skeletal variation by fetus refers to the number of 

variations observed in the total number of fetuses examined. Fetuses are not 

categorized by litter.

1 * Statistically significant p ≤ 0.05 as determined by study authors. 

2 

3 

4 

5 

6 

Conversions from diet concentrations to mg/kg-d performed by study authors.

Conversion from ppm to mg/m3 is 1 ppm = 3.031 mg/m3

. 

Percentage change compared to control = (treated value – control value) ÷ control value × 100.
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

2-21 DRAFT—DO NOT CITE OR QUOTE

1 Table 2-6. Evidence pertaining to neurodevelopmental effects in animals

2 following exposure to tert-butanol

Reference and study design Results

Oral

Daniel and Evans (1982)

Liquid diet (0, 0.5, 0.75, or 1.0%, w/v); GD6–20; 

Swiss Webster (Cox) mouse; 15 pregnant 

dams/treatment; after birth half the pups were 

nursed with their treated dams and the other 

half were fostered by untreated dams who 

recently gave birth

0 (isocaloric amounts of maltose/dextrin), 

3,324, 4,879, or 6,677 mg/kg-d 

Results were presented in figures only with no comparison to control or in 

tables with only comparison between pups fostered with their maternal 

dams and those fostered with untreated dams with no indication of dose.

Results indicate 

• a dose-dependent increase in the time it took for the righting reflex 

with more time needed in animals maintained with maternal dams

• a dose-dependent decrease in open field behavior with less activity 

with pups maintained with maternal dams

• a dose-dependent decrease in rotorod performance with the pups 

from maternal dams having lower performances

• a dose-dependent decrease in the amount of time the pups were 

able to avoid a cliff with animals maintained with their maternal 

dams having less avoidance time

Grant and Samson (1982)

Surgical cannulation; male and female LongEvans rat fetus; 8 control and 12 treated

PND 4–7 (a period of brain growth) with 

consecutive daily doses of 1,440, 2,160, 600, 

and 2,690 mg/kg-d tert-butanol on PND 4, 5, 6, 

and 7, respectively (average daily dose of 1,723 

mg/kg-d)

↓ Absolute and relative brain weights 

Response relative to control (only relative data provided, but no changes 

were noted in body weight): 0, −16%*

Brain biochemical parameters included: ↓ DNA levels in the hindbrain 

(−16%*) and ↓ protein levels in the forebrain (−15%*).

Inhalation

Nelson et al. (1991)

Whole body inhalation; Sprague-Dawley rat; 15 

pregnant dams/treatment

Analytical concentration: 0, 6,000, or 12,000 

mg/m3

; 7 hr/d GD 1–19 

Data were not presented specifically by dose nor were any tables or figures 

of the data provided

Maternal toxicity was noted by decreased food consumption and body 

weight gains

Results in offspring 

• increase in rotorod performance in high-dose group (16 versus 26 

revolutions/min for controls and 3,500 mg/m3 animals, respectively)

• decreased time held on wire in the performance ascent test in the 

low-dose group (16 sec versus 10 sec for controls and 1,750 mg/m3

animals, respectively)

There were some differences in neurochemical measurements in the brain 

between control and treated offspring, but they were not related to dose

3 
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

2-22 DRAFT—DO NOT CITE OR QUOTE

Table 2-6. Evidence pertaining to neurodevelopmental effects in animals

following exposure to tert-butanol (continued)

Reference and study design Results

Nelson et al. (1991)

Whole body inhalation; adult male SpragueDawley rats (18/treatment) mated to untreated 

females

Analytical concentration: 0, 6,000, or 12,000 

mg/m3; 7 hr/d for 6 wk

Data were not presented specifically by dose nor were any tables or figures 

of the data provided

Results (generally only specified as paternally treated versus controls) in 

offspring indicate

• increase in rotorod performance (16 versus 20 revolutions/min for 

controls and 3,500 mg/m3 animals, respectively)

• decreased time in open field (less time to reach the outer circle of 

the field, 210 sec versus 115 seconds for controls and 3,500 mg/m3

animals, respectively)

There were some differences in neurochemical measurements in the brain 

between control and treated offspring, but they were not related to dose

1 * Statistically significant p ≤ 0.05 as determined by study authors. 

2 

3 

4 

5 

6 

Conversions from diet concentrations to mg/kg-d performed by study authors.

Percentage change compared to control = (treated value – control value) ÷ control value × 100.
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

2-23 DRAFT—DO NOT CITE OR QUOTE

1 

2 

3 

4 

5 

6 

7 

10

100

1,000

10,000

100,000

Dose (mg/kg-day)

Testes weight; M mouse (A)

Reproductive organs or sperm; M rat (E)

Reproductive organs or sperm; M rat (D)

Number of live pups per litter; F rat (D)

Estrous cycle length; F rat (E)

Pregnancy index; F rat (D)

Reproductive organs or sperm; M mouse (E)

Estrous cycle length; F mouse (E)

Body weight gain (gestation days 0-20); F rat (D)

Body weight gain (lactation days 1-21); F rat (D)

Pup weight per litter (postnatal day 28); M rat (D)

Pup weight per litter (postnatal day 28); F rat (D)

Viability index; M+F rat (D)

Pup weight per litter (postnatal day 1); M+F rat (D)

Sex ratio; M+F rat (D)

Neurodevelopment; M+F rat (C)

Lactation index; M+F rat (D)

Number of resorptions; M+F mouse (B)

Number of live fetuses per litter; M+F mouse (B)

Pup weight; M+F mouse (B)

Skeletal variations; M+F mouse (B)

REPRODUCTIVE DEVELOPMENTAL

Acute Sub-chronic Maternal Fetal

 = exposures at which the endpoint was reported statistically significant by study authors

 = exposures at which the endpoint was reported not statistically significant by study authors

Sources: (A) Billitti et al. (2005); (B) Faulkner et al. (1989); (C) Grant and Samson (1982); (D) Lyondell Chemical 

Company (2004); (E) NTP (1995) 

Figure 2-4. Exposure-response array of reproductive, developmental and 

neurodevelopmental effects following oral exposure to tert-butanol.
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

2-24 DRAFT—DO NOT CITE OR QUOTE

1 

2 

3 

4 

5 

6 

100

1,000

10,000

100,000

Reproductive organs or sperm; M rat (A)

Estrous cycle; F rat (A)

Reproductive organs or sperm; M mouse (A)

Estrous cycle; F mouse (A)

Body weight; M mouse (B)

Body weight; F mouse (B)

Skeletal variation; M+F mouse (B)

Number of resorptions per litter; M+F mouse (B)

Number of live pups per litter; M+F mouse (B)

Concentration (mg/m3)

REPRODUCTIVE

(Parental)

DEVELOPMENTAL

(Fetal)

 = exposures at which the endpoint was reported statistically significant by study authors

 = exposures at which the endpoint was reported not statistically significant by study authors

Sources: (A) NTP (1997); (B) Nelson et al. (1989); (C) Nelson et al. (1991) 

Figure 2-5. Exposure-response array of reproductive and developmental 

effects following inhalation exposure to tert-butanol. 
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

2-25 DRAFT—DO NOT CITE OR QUOTE

1 2.5. Central Nervous System (CNS) Effects

2 

3 

Table 2-7. Evidence pertaining to CNS effects in animals following exposure to 

tert-butanol

Reference and study design Results

Oral

Grant and Samson (1981)

Male Long-Evans rat; 4–6/treatment; 

daily intakes were estimated to be 700 to 

2,800 mg/kg depending on the treatment 

and time

Drinking water

Scheduled-induced condition (maintained 

at 80% body weight):

Treatment 1: 0.5% for 5 days, then 1% for 

60 days

Treatment 2:Drinking water stepwise 

increase with 0.25%, 0.50%, 1.0%, 2.0%, 

and 2.5% for 5 days each and 3.0%, and 

3.5% for 10 days each, then 3.0% for 40 

days 

Treatment 3: 1.0% for 5 days, 2.0% for 5 

days, then 1.0% for 5 days and 3.0% for 

90 days

Home cage condition:

Treatment 1: 80% body weight 

administered 0.5% 5 days, then 1.0% for 

90 days

Treatment 2: free access to food, 1.0% for 

5 days, 2.0% for 10 days, and 3.0% for 90 

days

Treatment 3: 80% body weight on water

After treatment, all animals were given 

water to replace t-butanol

• 5 of 15 animals treated with 3% t-butanol had to be removed from the 

experiment based on self-withdrawal and/or self-mutilation (2 died), 

trend of increased t-butanol intake and decreased food intake prior to 

removal. Symptoms were not observed with 1% t-butanol or with 

control. 

• 1 of 4 animals receiving 3.5% t-butanol self-mutilated, ceased drinking, 

and was removed from the experiment.

• 60 days of 3% t-butanol was related to moderate seizure activity 

(withdrawal scores of 9, 5, and 6).

• 90 days of 3% t-butanol had withdrawal scores of 12, 6, and 7

• At least one animal from every group had a withdrawal score of 0, and 

only animals exposed to 3% t-butanol had withdrawal scores of 6 or 

higher. Significantly higher withdrawal scores were observed in animals 

receiving greater amounts of t-butanol (Fischer’s exact p<0.002). 

• Schedule-induced conditioning resulted in greater withdrawal 

symptoms over the home cage conditions.

• Withdrawal symptoms were considered less than those observed with 

ethanol.

4 
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

2-26 DRAFT—DO NOT CITE OR QUOTE

Table 2-7. Evidence pertaining to CNS effects in animals following exposure

to tert-butanol (continued)

Reference and study design Results

Wood and Laverty (1979)

Male Wistar rat; 12 rats/20-day 

treatment and 24 rats on time-course 

withdrawal sequence (4 rats withdrawn 

on days 4, 6, 8, 10, 12, and 14)

Liquid diet; 44–54 mmol/kg (mean 47 

mmol/kg); daily consumption was 

variable with spontaneous periods of 

abstinence in a few rats; blood alcohol 

levels 2–25 mmol/L

4–20 days

• Signs of intoxication in the 20-day study included docility and slight 

ataxia while on the diet.

• One rat out of 12 in the 20-day study spontaneously withdrew from the 

diet on Day 10, and had signs of irritability, hyperactivity, and muscular 

rigidity.

• Following removal of t-butanol after 20 days, animals initially appeared 

intoxicated. Head bobbing and paw shaking were observed 3–4 hours 

after withdrawal. Muscular rigidity, tail signs, abnormal gait, tremor, 

and irritability were apparent 5–6 hours after withdrawal.

• 4/12 treated rats had spontaneous forelimb convulsions

• 5/12 treated rats had audiogenic convulsions; resulted in 3 deaths.

• In the surviving 8/12 rats, irritability, hyperreactivity, and muscular 

rigidity were considerable at 24 hours post-withdrawaland in some 

animals lasted for up to 72 hours. 

• In the time-course group, withdrawal symptoms were seen with as little 

as 4 days of t-butanol intake. Severity rating increased with increasing 

days on the diet.

Snell and Harris (1980)

Male DBA/2J mouse; 20 mice/treatment

1.25% t-butanol via liquid diet

3,390 mg/kg-day (average)

7 days

• Shock avoidance behavior was impaired after cessation of treatment.

• Latencies for experimental group was significantly (p < 0.05) longer than 

the controls.

• One day after withdrawal, the number of trials where animals avoided 

shock was significantly (p < 0.05) greater in the control group (control: 

35/150; t-butanol: 6/150).

• Even 2 days after withdrawal, treated animals showed a significant (p < 

0.01) deficit in avoidance response measured by both latency and 

number of avoidances (control: 51/100; t-butanol: 35/100).

• At time of withdrawal, there was no difference in body temperature and 

withdrawal scores were low (0.20 ± 0.13, not significantly different from 

the control).

Body temperature

Control t-butanol

3 hours after withdrawal 37.6 ± 0.1 34.9 ± 0.4*

8 hours after withdrawal 37.4 ± 0.1 35.7 ± 0.3*

Withdrawal scores

Control t-butanol

3 hours after withdrawal 0 0.30 ± 0.21

8 hours after withdrawal 0 0.30 ± 0.15
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

2-27 DRAFT—DO NOT CITE OR QUOTE

Table 2-7. Evidence pertaining to CNS effects in animals following exposure

to tert-butanol (continued)

Reference and study design Results

Thurman et al. (1980)

Female Sprague-Dawley rat; 12–

14/treatment

Gavage; 5.7% in saline every 8 hours for 

up to 6 days

14 symptoms of withdrawal were scored according to severity on a 1–3 point 

scale (every 2 hours beginning 6-8 hours after last treatment. 

• Treatment caused a steady increase in withdrawal score (results 

presented in a figure)

Inhalation

McComb and Goldstein (1979a)

Male Swiss-Webster mouse; 14 

mice/treatment

Two 3-day cycles separated by 24 hours 

of no treatment (withdrawal reaction 

observed for 24 hours following each 

exposure period); mice were maintained 

on either a low (range 3.5–6.4 mM) or 

high (range 6.5–10.0 mM) blood alcohol 

level 

Withdrawal reaction consisted of signs of CNS hyperexcitability, including 

tremors, spontaneous convulsions, and convulsions elicited by handling

Withdrawal peak height

Low blood alcohol High blood alcohol

3 days of exposure (n=11) 0.79 ± 0.12 1.43 ±0.07

6 days of exposure (n=13) 1.49 ± 0.08 1.63 ±0.10

McComb and Goldstein (1979b)

Male Swiss-Webster mouse; 24 

mice/treatment

Mice received an initial i.p. priming dose 

of 6.8 or 10.1 mmol/kg t-butanol; tbutanol vapor concentration was 

maintained between 50 and 80 μmol/m3

for 24 hours then were steadily increased 

to maintain a constant blood alcohol level

Withdrawal was measured after 1, 3, 6 or 

9 days

• Withdrawal reaction consisted of signs of CNS hyperexcitability, 

including tremors, spontaneous convulsions, and convulsions elicited by 

handling.

• Intensity of withdrawal symptoms was related to blood levels and 

duration of exposure (results provided in figure only). 

o At mean blood levels of 5mM t-butanol (range 2.4-6.6 mM), 

severity of withdrawal reaction rose steadily through day 9. 

o At mean blood levels of 8.5 mM (range 6.8-10.7 mM) and 

above, a ceiling of withdrawal levels occurred at a height of 

approximately 1.5. 

• Peak withdrawal reactions occurred 3–5 hours after removal of tbutanol and was 4-5 times greater than with ethanol. 

1 * Statistically significant p ≤ 0.05 as determined by study authors. 

2 
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

2-28 DRAFT—DO NOT CITE OR QUOTE

1 2.6. Other Systemic Effects (Body Weight, Liver, and Urinary Bladder)

2 

3 

Table 2-8. Evidence pertaining to effects on body weight in animals following 

oral exposure to tert-butanol

Reference and study design Results

Acharya et al. (1995)

Wistar rat; 5–6 males/treatment

Drinking water (0 or 0.5%), 0 or 575 mg/kg-d 

10 weeks

Body weight in treated animals lower than controls by ~7% (p< 0.05); (results 

only provided in a figure) 

Lyondell Chemical Company (2004)

Sprague-Dawley rat; 12/sex/treatment

Gavage 0, 64, 160, 400, or 1,000 mg/kg-d 

At least 9 weeks beginning 4 weeks prior to 

mating through mating (up to 2 weeks), 

gestation, and lactation.

Percent change compared to control:

Males Females

Dose

(mg/kg-d) Body weight

Dose

(mg/kg-d) Body weight

0 0 0 0

64 −2 64 0

160 −4 160 −2

400 +2 400 +1

1,000 −7 1,000 +4

NTP (1995)

F344/N rat; 10/sex/treatment

Drinking water (0, 2.5, 5, 10, 20, or 40 mg/mL) 

 M: 0, 230, 490, 840, 1,520, 3,610a mg/kg-d 

 F: 0, 290, 590, 850, 1,560, 3,620a mg/kg-d 

13 weeks

Percent change compared to control:

Males Females

Dose

(mg/kg-d) Body weight

Dose

(mg/kg-d) Body weight

0 0 0 0

230 −4 290 +2

490 −5* 590 +1

840 −12* 850 +1

1,520 −17* 1,560 −2

3,610 All dead 3,620 −21*

NTP (1995)

B6C3F1 mouse; 10/sex/treatment

Drinking water (0, 2.5, 5, 10, 20, or 40 mg/mL) 

 M: 0, 350, 640, 1,590, 3,940, 8,210a mg/kg-d 

 F: 0, 500, 820, 1,660, 6,430, 11,620a mg/kg-d 

13 weeks

Percent change compared to control:

Males Females

Dose

(mg/kg-d) Body weight

Dose

(mg/kg-d) Body weight

0 0 0 0

350 −1 500 +3

640 +1 820 −1

1,590 −4 1,660 +4

3,940 −14* 6,430 −6

8,210 −24* 11,620 −15*

High-dose females had a significantly lower initial weight, but also had a 

significantly lower body weight gain indicating that there was some effect of 

treatment
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

2-29 DRAFT—DO NOT CITE OR QUOTE

 1 

Table 2-8. Evidence pertaining to effects on body weight in animals following 

oral exposure to tert-butanol (continued)

Reference and study design Results

NTP (1995)

F344/N rat; 60/sex/treatment 

(10/sex/treatment evaluated at 15 months)

Drinking water (0, 1.25, 2.5, 5, 10 mg/mL)

 M: 0, 90, 200, 420a mg/kg-d 

 F: 0, 180, 330, 650a mg/kg-d 

2 years

Percent change compared to control:

Males Females

Dose

(mg/kg-d) Body weight

Dose

(mg/kg-d) Body weight

0 0 0 0

90 −15 180 −2

200 −18 330 −5

420 −24 650 −21

Only animals that survived at the end of 2 years were evaluated for body 

weight. Note: statistical significance not determined by study authors.

NTP (1995)

B6C3F1 mouse; 60/sex/treatment

Drinking water (0, 5, 10, 20 mg/mL); 

 M: 0, 540, 1,040, 2,070a mg/kg-d 

 F: 0, 510, 1,020, 2,110 mg/kg-d 

2 years

Percent change compared to control:

Males Females

Dose

(mg/kg-d) Body weight

Dose

(mg/kg-d) Body weight

0 0 0 0

540 +1 510 −2

1,040 −2 1,020 −3

2,070 −1 2,110 −12

Only animals that survived at the end of 2 years were evaluated for body 

weight. Note: statistical significance not determined by study authors.

a 2 There was a significant decrease in survival in the high-dose group.

3 

4 

5 

6 

7 

* Statistically significant p ≤ 0.05 as determined by study authors. 

Conversions from drinking water concentrations to mg/kg-d performed by study authors.

Percentage change compared to control = (treated value – control value) ÷ control value × 100.
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

2-30 DRAFT—DO NOT CITE OR QUOTE

Table 2-9. Evidence pertaining to liver effects in animals following oral 

exposure to tert-butanol

1 

2 

Reference and study design Results

Liver weight

Acharya et al. (1995)

Wistar rat; 5–6 males/treatment

Drinking water (0 or 0.5%), 0 or 575 mg/kg-d 

10 weeks

No significant treatment-related effects (results were only provided in a 

figure)

Lyondell Chemical Company (2004)

Sprague-Dawley rat; 12/sex/treatment

Gavage 0, 64, 160, 400, or 1,000 mg/kg-d 

At least 9 weeks beginning 4 weeks prior to 

mating through mating (up to 2 weeks), 

gestation, and lactation.

Percent change compared to control:

Males Females

Dose

(mg/kg-d)

Absolute 

weight

Relative 

weight

Dose

(mg/kg-d)

Absolute 

weight

Relative 

weight

0 0 0 0 0 0

64 −1 0 64 −4 −4

160 −3 +1 160 −7 −5

400 −2 −1 400 +2 +1

1,000 +8 +16* 1,000 +8 +3

NTP (1995)

F344/N rat; 10/sex/treatment 

Drinking water (0, 2.5, 5, 10, 20, or 40 mg/mL) 

 M: 0, 230, 490, 840, 1,520, 3,610a mg/kg-d 

 F: 0, 290, 590, 850, 1,560, 3,620a mg/kg-d 

13 weeks

Percent change compared to control:

Males Females

Dose

(mg/kg-d)

Absolute

weight

Relative

weight

Dose

(mg/kg-d)

Absolute

weight

Relative

weight

0 0 0 0 0 0

230 −2 +4 290 +11* +9*

490 +1 +8* 590 +10* +9*

840 +5 +20* 850 +12* +11*

1,520 +8 +31* 1,560 +15* +16*

3,610 All dead All dead 3,620 +9* +41*

NTP (1995)

B6C3F1 mouse; 10/sex/treatment

Drinking water (0, 2.5, 5, 10, 20, or 40 mg/mL) 

 M: 0, 350, 640, 1,590, 3,940, 8,210a mg/kg-d 

 F: 0, 500, 820, 1,660, 6,430, 11,620a mg/kg-d 

13 weeks

Percent change compared to control:

Males Females

Dose

(mg/kg-d)

Absolute

weight

Relative

weight

Dose

(mg/kg-d)

Absolute

weight

Relative

weight

0 0 0 0 0 0

350 +2 +3 500 −1 −4

640 −1 −2 820 −5 −3

1,590 −1 +5 1,660 −8 −9*

3,940 0 +14* 6,430 −2 +6

8,210 −16 +22* 11,620 −6 +13*
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

2-31 DRAFT—DO NOT CITE OR QUOTE

1 

Table 2-9. Evidence pertaining to liver effects in animals following oral 

exposure to tert-butanol (continued)

Reference and study design Results

NTP (1995)

F344/N rat; 60/sex/treatment 

(10/sex/treatment evaluated at 15 months)

Drinking water (0, 1.25, 2.5, 5 or 10 mg/mL) 

 M: 0, 90, 200, or 420a mg/kg-d 

 F: 0, 180, 330, or 650a mg/kg-d 

2 years

Percent change compared to control:

Males Females

Dose

(mg/kg-d)

Absolute

weight

Relative

weight

Dose

(mg/kg-d)

Absolute

weight

Relative

weight

0 0 0 0 0 0

90 +2 +7 180 −14* −8

200 +8 +11 330 −3 −1

420 +1 +14* 650 −6 +9*

Only animals sacrificed at 15 months were evaluated for organ weights.

Histopathology

Acharya et al. (1997; 1995)

Wistar rat; 5–6 males/treatment

Drinking water (0, 0.5%), 0, 575 mg/kg-d 

10 weeks

↑ liver glycogen (~ 7 fold)*

↑incidence of centrilobular necrosis, vacuolation of hepatocytes, loss of 

hepatocyte architecture, peripheral proliferation, and lymphocyte 

infiltration (incidences and results of statistical tests not reported)

Lyondell Chemical Company (2004)

Sprague-Dawley rat; 12/sex/treatment

Gavage 0, 64, 160, 400, or 1,000 mg/kg-d 

At least 9 weeks beginning 4 weeks prior to 

mating through mating (up to 2 weeks), 

gestation, and lactation.

No treatment-related effects observed.

NTP (1995)

F344/N rat; 10/sex/treatment

Drinking water (0, 2.5, 5, 10, 20, or 40 mg/mL) 

 M: 0, 230, 490, 840, 1,520, 3,610a mg/kg-d 

 F: 0, 290, 590, 850, 1,560, 3,620a mg/kg-d 

13 weeks

No treatment-related effects observed (histopathology data for the 13-week 

study were not provided)

NTP (1995)

B6C3F1 mouse; 10/sex/treatment

Drinking water (0, 2.5, 5, 10, 20, 40 mg/mL)

 M: 0, 350, 640, 1,590, 3,940, 8,210a mg/kg-d 

 F: 0, 500, 820, 1,660, 6,430, 11,620a mg/kg-d 

13 weeks

No treatment-related effects observed (histopathology data for the 13-week 

study were not provided)
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

2-32 DRAFT—DO NOT CITE OR QUOTE

Table 2-9. Evidence pertaining to liver effects in animals following oral 

exposure to tert-butanol (continued)

Reference and study design Results

NTP (1995)

F344/N rat; 60/sex/treatment 

(10/sex/treatment evaluated at 15 months)

Drinking water (0, 1.25, 2.5, 5, 10 mg/mL)

 M: 0, 90, 200, or 420a mg/kg-d 

 F: 0, 180, 330, or 650a mg/kg-d 

2 years

No treatment-related effects observed.

NTP (1995)

B6C3F1 mouse; 60/sex/treatment

Drinking water (0, 5, 10, 20 mg/mL) 

 M: 0, 540, 1,040, or 2,070a mg/kg-d 

 F: 0, 510, 1,020, or 2,110 mg/kg-d 

2 years

Males Females

Dose

(mg/kg-d)

Incidence of fatty 

change

Dose

(mg/kg-d)

Incidence of fatty 

change

0 12/59 0 11/60

540 5/60 510 8/60

1,040 8/59 1,020 8/60

2,070 29/59* 2,110 6/60

a 1 The high-dose group had an increase in mortality.

2 

3 

4 

5 

* Statistically significant p ≤ 0.05 as determined by study authors. 

Conversions from drinking water concentrations to mg/kg-d performed by study authors.

Percentage change compared to control = (treated value – control value) ÷ control value × 100.
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

2-33 DRAFT—DO NOT CITE OR QUOTE

1 Table 2-10. Evidence pertaining to liver effects in animals following 

2 inhalation exposure to tert-butanol

Reference and study design Results

Liver Weight

NTP (1997)

F344/N rat; 10/sex/treatment

Analytical concentration: 0, 135, 270, 540, 

1,080, or 2,101 ppm (0, 406, 824, 1,643, 3,273 

or 6,368 mg/m3) 6 hr/d, 5 d/wk 

13 weeks 

Percent change compared to control:

Males Females

Dose

(mg/m3)

Absolute

weight

Relative

weight

Absolute

weight

Relative

weight

0 0 0 0 0

406 −8 −8 0 +3

824 −2 −1 0 0

1,643 +1 −1 +3 +2

3,273 +10 +7 +9 +9*

6,368 +5 +5 +4 +8*

NTP (1997)

B6C3F1 mouse; 10/sex/treatment

Analytical concentration: 0, 134, 272, 542, 

1,080, or 2,101 ppm (0, 406, 824, 1,643, 3,273 

or 6,368 mg/m3) 6 hr/d, 5 d/wk 

13 weeks 

Percent change compared to control:

Males Females

Dose

(mg/m3)

Absolute

weight

Relative

weight

Absolute

weight

Relative

weight

0 0 0 0 0

406 −1 0 +1 −4

824 +4 +9 +1 +5

1,643 +7 +5 +5 +1

3,273 −8 -2 +2 +9*

6,368 +5 +7 +8 +21*

3 * Statistically significant p ≤ 0.05 as determined by the study authors. 

4 

5 

6 

7

8

Conversion from ppm to mg/m3 is 1 ppm = 3.031 mg/m3. 

Percentage change compared to control = (treated value – control value) ÷ control value × 100.
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

2-34 DRAFT—DO NOT CITE OR QUOTE

1 Table 2-11. Evidence pertaining to urinary bladder effects in animals 

2 following oral exposure to tert-butanol

Reference and study design Results

Histopathology

NTP (1995)

F344/N rat; 10/sex/treatment

Drinking water (0, 2.5, 5, 10, 20, 40 

mg/mL)

 M: 0, 230, 490, 840, 1,520, 3,610a

mg/kg-d 

 F: 0, 290, 590, 850, 1,560, 3,620a

mg/kg-d 

13 weeks

Incidence (severity):

Males Females

Dose (mg/kg-d)

Transitional 

epithelial 

hyperplasia Dose (mg/kg-d)

Transitional 

epithelial 

hyperplasia

0 0/10 0 0/10

230 not evaluated 290 not evaluated

490 not evaluated 590 not evaluated

840 0/10 850 not evaluated

1,520 1/10 (3.0) 1,560 0/10

3,610 7/10* (2.9) 3,620 3/10 (2.0)

Severity: 1 = minimal, 2 = mild, 3 = moderate, 4 = marked

NTP (1995)

B6C3F1 mouse; 10/sex/treatment

Drinking water (0, 2.5, 5, 10, 20, 40 

mg/mL)

 M: 0, 350, 640, 1,590, 3,940, 

8,210a mg/kg-d 

 F: 0, 500, 820, 1,660, 6,430, 

11,620a mg/kg-d 

13 weeks

Incidence (severity):

Males Females

Dose

(mg/kg-d)

Transitional 

epithelial 

hyperplasia

InflammationDose

(mg/kg-d)

Transitional 

epithelial 

hyperplasia

Inflammation

0 0/10 0/10 0 0/10 0/10

350 not evaluated 500 0/1 0/1

640 not evaluated 820 not evaluated

1,590 0/10 0/10 1,660 not evaluated

3,940 6/10* (1.3) 6/10* (1.3) 6,430 0/10 0/10

8,210 10/10* (2.0) 10/10* (2.3) 11,620 3/9 (2.0) 6/9* (1.2)

Severity: 1 = minimal, 2 = mild, 3 = moderate, 4 = marked

NTP (1995)

F344/N rat; 60/sex/treatment 

(10/sex/treatment evaluated at 15 

months)

Drinking water (0, 1.25, 2.5, 5, or 10 

mg/mL)

 M: 0, 90, 200, 420a mg/kg-d 

 F: 0, 180, 330, 650a mg/kg-d 

2 years

No treatment-related effects observed

3 
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

2-35 DRAFT—DO NOT CITE OR QUOTE

Table 2-11. Evidence pertaining to urinary bladder effects in animals 

following oral exposure to tert-butanol (continued)

Reference and study design Results

NTP (1995)

B6C3F1 mouse; 60/sex/treatment

Drinking water (0, 5, 10, or 20 mg/mL) 

 M: 0, 540, 1,040, 2,070a mg/kg-d 

 F: 0, 510, 1,020, 2,110 mg/kg-d 

2 years

Incidence (severity):

Males Females

Dose

(mg/kg-d)

Transitional 

epithelial 

hyperplasia

InflammationDose

(mg/kg-d)

Transitional 

epithelial 

hyperplasia

Inflammation

0 1/59 (2.0) 0/59 0 0/59 0/59

540 3/59 (1.7) 3/59 (1.7) 510 0/60 0/60

1,040 1/58 (1.0) 1/58 (1.0) 1,020 0/59 0/59

2,070 17/59* (1.8) 37/59* (2.0) 2,110 3/57 (1.0) 4/57* (2.0)

Severity: 1 = minimal, 2 = mild, 3 = moderate, 4 = marked

a 1 The high-dose group had an increase in mortality.

2 

3 

4 

* Statistically significant p ≤ 0.05 as determined by study authors. 

Conversions from drinking water concentrations to mg/kg-d performed by study authors.
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

2-36 DRAFT—DO NOT CITE OR QUOTE

1 

2 

3 

4 

5 

6 

10

100

1,000

10,000

100,000

Dose (mg/kg-day)

M rat (D)M rat (A)

F rat (D)

M mouse (D)

F mouse (D)

M rat (C)

F rat (C)

Transitional epithelium hyperplasia; M rat (D)

Transitional epithelium hyperplasia; F rat (D)

Transitional epithelium hyperplasia; M mouse (D)

Inflammation; M mouse (D)

Inflammation; F mouse (D)

Transitional epithelium hyperplasia; F mouse (D)

Transitional epithelium hyperplasia; M mouse (D)

Inflammation; M mouse (D)

Inflammation; F mouse (D)

Transitional epithelium hyperplasia; F mouse (D)

Increased glycogen; M rat (B)

Relative weight; M rat (B)

Relative weight; M rat (D)

Absolute weight; F rat (D)

Relative weight; F rat (D)

Absolute weight; M rat (D)

Relative weight; M mouse (D)

Relative weight; F mouse (D)

Absolute weight; M mouse (D)

Absolute weight; F mouse (D)

Relative weight; M rat (D)

Relative weight; F rat (D)

Absolute weight; M rat (D)

Absolute weight; F rat (D)

Fatty tissue; M mouse (D)

Fatty tissue; F mouse (D)

Relative weight; M rat (C)

Absolute weight; M rat (C)

Absolute weight; F rat (C)

Relative weight; F rat (C)

BODY WEIGHT

Subchronic

URINARY BLADDER LIVER

Reproductive

Subchronic Chronic Subchronic Chronic Reproductive

 = exposures at which the endpoint was reported statistically significant by study authors

 = exposures at which the endpoint was reported not statistically significant by study authors

× = exposures at which all animals were dead and unable to be examined for the endpoint

Sources: (A) Acharya et al. (1995); (B) Acharya et al. (1997; 1995); (C) Lyondell (2004); (D) NTP (1995) 

Figure 2-6. Exposure-response array of body weight, liver effects, and urinary 

bladder effects following oral exposure to tert-butanol.
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

2-37 DRAFT—DO NOT CITE OR QUOTE

2.7. Genotoxic Effects

Table 2-12. Evidence pertaining to genotoxic effects of tert-butanol in vitro 

and in vivo studies

1 

2 

3 

Species/

cell line

Test system

(strain/species)

Exposure

(dose/

concentration)

Results

Metabolic activation

–S9 +S9 Reference

In vitro

Bacterial systems

Salmonella 

typhimurium

Reverse mutation 

(TA98, TA100, 

TA1535, TA1537, 

TA1538)

10 mg/plate – – Zeiger et al. (1987)

2.9–10,000 μg/plate – – ARCO (1994e)

Reverse mutation 

(TA102)

1–4 mg/plate ND + Williams-Hill et al. (1999)

Reverse mutation 

(TA98, TA100, TA102, 

TA1535, TA1537)

5–5,000 μg/plate – – McGregor et al. (2005)

E.coli Reverse mutation 

(WP2 uvrA/PKM101)

5–5,000 μg/plate – – McGregor et al. (2005)

Neurospora crassa Reverse mutation, ad3A locus (allele 38701)1.75mol/L – – Dickey et al. (1949)

Saccharomyces 

cerevisiae

Mitochondrial 

mutation (K5-5A, 

MMY1, D517-4B and 

DS8)

4.0% (vol/vol) +

a ND Jimenez et al. (1988)

Mammalian cells – rodent

Mouse lymphoma 

cells L5178Y TK+/–

Gene mutation 625–5,000 mg/mL – – McGregor et al. (1988)

2.4–32 μL/mL – – ARCO (1994a)

Chinese hamster 

ovary

Sister-chromatid 

exchange

1.25–5 mg/mL – – NTP (1995)

0.31–20 μL/mL

(-S9);

0. 625–20 μL/mL 

(+S9)

– b – ARCO (1994b)

Chromosomal 

aberrations

1.25–5 mg/mL – – NTP (1995)

Rat fibroblasts DNA damage (comet 

assay)

0.44 mmol/L (IC50) +

c ND Sgambato et al. (2009)
Preliminary Materials for the IRIS Toxicological Review of tert-Butanol

This document is a draft for review purposes only and does not constitute Agency policy.

2-38 DRAFT—DO NOT CITE OR QUOTE

Species/

cell line

Test system

(strain/species)

Exposure

(dose/

concentration)

Results

Metabolic activation

–S9 +S9 Reference

Mammalian cells – human

Human HL-60 

leukemia cells

DNA damage (comet 

assay)

1–30 mmol/L + ND Tang et al. (1997)

In vivo

Mammalian – rodent

Male Kunming 

mouse liver, kidney 

and lung cells

DNA adducts 0.1–1,000 μg/kg b.w. + NA Yuan et al. (2007)

B6C3F1 mouse 

peripheral blood 

cells

Micronucleus 

formation

2.5–40 mg/mL

drinking water

– NA NTP (1995)

1 ND = not determined; NA = not applicable

2 

3 

4 

5 

6 

7 

a

Effect is predicted to be due to mitochondrial membrane composition. b

Results were stated to be statistically increased in the 20 μg/mL with and without activation and the 10 μg/mL with activation, 

but results did not meet positive criteria for the assay.

c

DNA damage was completely reversed with increase in time of exposure.