r/EPA
EPA/635/R-13/108
Preliminary Materials
www.epa.gov/iris
Preliminary Materials for the Integrated Risk Information System (IRIS)
Toxicological Review of Ethyl tert-Butyl Ether (ETBE)
[CASRN 637-92-3]
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
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Preliminary Materials for the IRIS Toxicological Review ofETBE
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.
This document is a draft for review purposes only and does not constitute Agency policy.
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Preliminary Materials for the IRIS Toxicological Review ofETBE
CONTENTS
1 PREFACE v
2 1. DRAFT LITERATURE SEARCH STRATEGY 1-1
3 1.1. Literature Search and Screening Strategy for ETBE 1-1
4 1.2. List of References Based on Search Strategy for ETBE 1-5
5 1.2.1. Primary Sources of Health Effects Data 1-5
6 1.2.2. Not Primary Source of Health Effects Data, but Kept as Additional Resources 1-9
7 1.2.3. Kept for Possible Further Review 1-12
8 2. PRELIMINARY EVIDENCE TABLES AND PRELIMINARY EXPOSURE-RESPONSE ARRAYS 2-1
9 2.1. Data Extraction: Preparation of Preliminary Evidence Tables and Preliminary Exposure-
10 Response Arrays 2-1
11 2.2. Kidney Effects 2-3
12 2.3. Liver Effects 2-12
13 2.4. Reproductive Effects 2-20
14 2.5. Body Weight Effects 2-23
15 2.6. Other Systemic Effects 2-28
16 2.7. Carcinogenic Effects 2-35
17 2.8. Genotoxic Effects 2-38
This document is a draft for review purposes only and does not constitute Agency policy.
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Preliminary Materials for the IRIS Toxicological Review ofETBE
TABLES
Table 1-1. Database search strategy for ETBE 1-3
Table 1-2. Summary of additional search strategies for ETBE 1-4
Table 2-1. Evidence pertaining to kidney effects in animals following oral exposure to ETBE 2-3
Table 2-2. Evidence pertaining to kidney effects in animals following inhalation exposure to
ETBE 2-7
Table 2-3. Evidence pertaining to liver effects in animals following oral exposure to ETBE 2-12
Table 2-4. Evidence pertaining to liver effects in animals following inhalation exposure to ETBE 2-15
Table 2-5. Evidence pertaining to reproductive effects in animals following oral exposure to
ETBE 2-20
Table 2-6. Evidence pertaining to body weight effects in animals following oral exposure to ETBE 2-23
Table 2-7. Evidence pertaining to body weight effects in animals following inhalation exposure
to ETBE 2-25
Table 2-8. Evidence pertaining to other systemic effects in animals following oral exposure to
ETBE 2-28
Table 2-9. Evidence pertaining to other systemic effects in animals following inhalation
exposure to ETBE 2-30
Table 2-10. Evidence pertaining to carcinogenic effects in animals exposed to ETBE 2-35
Table 2-11. Evidence pertaining to genotoxic effects in animals exposed to ETBE 2-38
Table 2-12. Summary of in vitro studies of ETBE genotoxicity 2-40
FIGURES
Figure 1-1. Literature search approach for ETBE 1-2
Figure 2-1. Exposure-response array of kidney effects following oral exposure to ETBE 2-10
Figure 2-2. Exposure-response array of kidney effects following inhalation exposure to ETBE 2-11
Figure 2-3. Exposure-response array of liver effects following oral exposure to ETBE 2-18
Figure 2-4. Exposure-response array of liver effects following inhalation exposure to ETBE 2-19
Figure 2-5. Exposure-response array of reproductive effects following oral exposure to ETBE 2-22
Figure 2-6. Exposure-response array of body weight effects following oral exposure to ETBE 2-26
Figure 2-7. Exposure-response array of body weight effects following inhalation exposure to
ETBE 2-27
Figure 2-8. Exposure-response array of other systemic effects following oral exposure to ETBE 2-33
Figure 2-9. Exposure-response array of other systemic effects following inhalation exposure to
ETBE 2-34
Figure 2-10. Exposure-response array of carcinogenic effects following oral exposure to ETBE 2-36
Figure 2-11. Exposure-response array of carcinogenic effects following inhalation exposure to
ETBE 2-37
This document is a draft for review purposes only and does not constitute Agency policy.
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Preliminary Materials for the IRIS Toxicological Review ofETBE
1
2 PREFACE
3 This document presents the draft literature search strategy, preliminary evidence tables,
4 and preliminary exposure-response arrays for ethyl tert-butyl ether (henceforth referred to as
5 ETBE) prepared under the auspices of EPA's Integrated Risk Information System (IRIS) Program.
6 This material is being released for public viewing and comment prior to a public meeting, providing
7 an opportunity for the IRIS Program to engage in early discussions with stakeholders and the public
8 on data that may be used to identify adverse health effects and characterize exposure-response
9 relationships.
10 The draft literature search strategy, preliminary evidence tables, and preliminary
11 exposure-response arrays are responsive to the National Research Council (NRC) 2011 report
12 Review of the Environmental Protection Agency's Draft IRIS Assessment of Formaldehyde. The
13 literature search strategy, which describes the processes for identifying scientific literature,
14 screening studies for consideration, and selecting studies for inclusion in evidence tables, is
15 responsive to NRC recommendations regarding systematic review of the scientific literature. In
16 addition, NRC recommendations for standardized presentation of key study data are addressed in
17 the preliminary evidence tables and preliminary exposure-response arrays.
18 EPA welcomes all comments on the draft literature search strategy, preliminary evidence
19 tables, and preliminary exposure-response arrays, such as remarks on the following:
20 the clarity and transparency of the materials;
21 the approach for identifying pertinent studies;
22 the selection of studies for data extraction to preliminary evidence tables and
23 exposure-response arrays;
24 any methodological considerations that could affect the interpretation of or confidence in
25 study results; and
26 any additional studies published or nearing publication that may provide data for the
27 evaluation of human health hazard or exposure-response relationships.
28 The preliminary evidence tables and exposure-response arrays should be regarded solely as
29 representing the data on each endpoint that have been identified as a result of the draft literature
30 search strategy. They do not reflect any conclusions as to hazard identification or dose-response
31 assessment After obtaining public input and conducting additional study evaluation and data
32 integration, EPA will revise these materials to support the hazard identification and dose-response
33 assessment in a draft Toxicological Review.
This document is a draft for review purposes only and does not constitute Agency policy.
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Preliminary Materials for the IRIS Toxicological Review ofETBE
1
2 1. DRAFT LITERATURE SEARCH STRATEGY
3 1.1. Literature Search and Screening Strategy for ETBE
4 The overall literature search approach is shown graphically in Figure 1-1. The initial
5 chemical-specific search was conducted in four online scientific databases in January, 2013, using
6 the keywords and limits described in Table 1-1. After electronically eliminating duplicates from the
7 citations retrieved through these databases, 658 unique citations were identified. An additional
8 112 citations were obtained using additional search strategies described in Table 1-2.
9 The resulting 758 citations were screened using the title, abstract, and/or full text for
10 pertinence to examining the health effects ofETBE exposure. A total of 671 references were
11 identified as not being pertinent and were excluded from further consideration (see Figure 1-1 for
12 the exclusion categories). A total of 52 references were identified as primary sources of health
13 effects data and were considered for data extraction to evidence tables and exposure-response
14 arrays (see Section 1.2.1). A total of 38 references were considered pertinent, but not as primary
15 sources of health effects data (e.g., ADME studies), and kept as additional resources for
16 development of the Toxicological Review (see Section 1.2.2). If a reference did not provide enough
17 material to evaluate pertinence (e.g., no abstract), it would be reserved for further possible review;
18 no such studies were identified for ETBE (see Section 1.2.3).
This document is a draft for review purposes only and does not constitute Agency policy.
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Preliminary Materials for the IRIS Toxicological Review ofETBE
Pubmed
n=188
Database Searches
(see Table 1 for keywords and limits)
Web of Science
n=490
Toxline
(incl.TSCATS)
n=110
TSCATS 2
n=l
(After duplicates removed electronically)
n=658
Additional Search Strategies
(see Table 2 for methods and results)
n =
Combined Dataset
(After duplicates removed electronically)
n=758
Manual Screening For Pertinence
{Title/Abstract/Full Text)
Excluded (not pertinent)
72 Biodegradation/environmental fate
350 Chemical analysis/fuel chemistry
161 Other chemical/non ETBE studies
30 Policy/Commentary
18 Society abstracts
3 Exposure studies
3 Analytical methods
1 Structure activity relationship study
33 Duplicates (identified by title, abstract,
or full text)
1
2
Kept for Possible Further Review
None identified (e.g., abstract only, foreign
language, case reports)
Not Primary Source of Health Effects
Data, but Kept As Additional
Resource
14 Reviews, editorials
2 Health effects assessments by others
18 Toxicokinetic studies (not including PBTK)
2 PBTK modeling studies
20dorthreshold
Primary Sources of Health Effects
Data
1 Human health effects studies
39 Animal toxicology studies
8 Genotoxicity studies
4 Other studies involving direct
administration of chemical, including
mechanistic studies
Figure 1-1. Literature search approach for ETBE.
This document is a draft for review purposes only and does not constitute Agency policy,
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Preliminary Materials for the IRIS Toxicological Review ofETBE
Table 1-1. Database search strategy for ETBE
Database
(Search Date)
Keywords
Limits
PubMed
(01/08/2013)
"ETBE" OR "Ethyl tert-butyl ether"
OR "2-ethoxy-2-methyl-propane"
OR "ethyl tertiary butyl ether" OR
"ethyl tert-butyl oxide" OR "tert-
butyl ethyl ether" OR "ethyl t-
butyl ether" OR "637-92-3"
None
Web of Science
(01/08/2013)
"ETBE" OR "ethyl tert-butyl ether"
OR "2-ethoxy-2-methyl-propane"
OR "ethyl tertiary butyl ether" OR
"ethyl tert-butyl oxide" OR "tert-
butyl ethyl ether" OR "ethyl t-
butyl ether" OR "637-92-3"
Lemmatization on
Toxline
(includes
TSCATS)
(01/08/2013)
"ETBE" OR "Ethyl tert-butyl ether"
OR "2-Ethoxy-2-methyl-propane"
OR "ethyl tertiary butyl ether" OR
"ethyl tert-butyl oxide" OR "tert-
butyl ethyl ether" OR "ethyl t-
butyl ether" OR "637-92-3"
Not PubMed
TSCATS2
(1/08/2013)
637-92-3
01/01/2004 to 01/01/2013
2
3
This document is a draft for review purposes only and does not constitute Agency policy,
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Preliminary Materials for the IRIS Toxicological Review ofETBE
Table 1-2. Summary of additional search strategies for ETBE
Approach used
Electronic
backward
search through
Web of Science
Personal
communication
Source(s)
Review article: McGregor (2007).
"Ethyl tertiary-butyl ether: a
toxicological review." Critical
Reviews in Toxicology 37(4):
287-312.
Review article: de Peyster (2010).
"Ethyl t-butyl ether: Review of
reproductive and developmental
toxicity." Birth Defects Research,
Part B: Developmental and
Reproductive Toxicology 89(3):
239-263.
Japanese Petroleum Energy
Center.
Date
performed
1/2013
1/2013
1/2013
Number of additional
citations identified
68 citations
26 citations
18 citations
This document is a draft for review purposes only and does not constitute Agency policy,
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Preliminary Materials for the IRIS Toxicological Review ofETBE
l 1.2. List of References Based on Search Strategy for ETBE
2 Citations for excluded references are not listed here, but can be found on the Health and
3 Environmental Research Online (HERO) Website (http://hero.epa.gov/ETBE).
4 1.2.1. Primary Sources of Health Effects Data
5 Data from citations in bold are displayed in Section 2. See Section 2.1 for a description of
6 the process of selecting these studies for evidence tables and exposure-response arrays.
7 Human health effects studies
8 1) Nihlen, A; Lof, A; Johanson, G. (1998b) Controlled ethyl tert-butyl ether (ETBE) exposure of
9 male volunteers II. Acute effects. Toxicol Sci46(l):143-150.
10 Animal toxicology studies
11 1) Asano, Y; Ishikura, T; Kudoh, K; et al. (2011) Prenatal developmental toxicity study of
12 ethyl tertiary-butyl ether in rabbits. Drug and Chem Toxicol 34(3): 311-317.
13 2) Banton, MI; Peachee, VL; White, KL; et al. (2011) Oral subchronic immunotoxicity
14 study of ethyl tertiary butyl ether in the rat. J of Immunotoxicol 8(4): 298-304.
15 3) Berger, T; Horner, CM. (2003) In vivo exposure of female rats to toxicants may affect
16 oocyte quality. Reprod Toxicol 17(3):273-281.
17 4) Bond, JA; Medinsky, MA; Wolf, DC; et al. (1996a) Ethyl tertiary butyl ether (ETBE):
18 ninety-day vapor inhalation toxicity study in CD-I mice. Chemical Industry Institute
19 of Toxicology under contract to ARCO Chemical Company, Research Triangle Park,
20 NC; Laboratory Project ID 95030,1-69. Unpublished report.
21 5) Bond, JA; Medinsky, MA; Wolf, DC; et al. (1996b) Ethyl tertiary butyl ether (ETBE):
22 ninety-day vapor inhalation toxicity study with neurotoxicity evaluations in Fischer
23 344 rats. Chemical Industry Institute of Toxicology under contract to ARCO Chemical
24 Company, Research Triangle Park, NC; Laboratory Project ID 95029,1-90.
25 Unpublished report.
26 6) Cohen, SM; Hard, GC; Regan, KS; et al. (2011) Pathology working group review of
27 selected histopathologic changes in the kidneys of rats assigned to toxicology and
28 carcinogenicity studies of ethyl tertiary butyl ether (ETBE). Research Pathology
29 Associates under contract to Lyondell Chemical Company, Research Triangle Park,
30 NC; 1-30. Unpublished report.
31 7) dePeyster, A; Stanard, B; Westover, C. (2009) Effect of ETBE on reproductive steroids
32 in male rats and rat Leydig cell cultures. Toxicol Lett 190:74-80.
33 8) Dorman, DC; Struve, MF; Wong, BA; etal. (1997) Neurotoxicological evaluation of ethyl
34 tertiary-butyl ether following subchronic (90-day) inhalation in the Fischer 344 rat. J Appl
35 Toxicol 17(4):235-242.
This document is a draft for review purposes only and does not constitute Agency policy.
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Preliminary Materials for the IRIS Toxicological Review ofETBE
1 9) Fujii, S; Yabe, K; Furukawa, M; et al. (2010) A one-generation reproductive toxicity
2 study of ethyl tertiary butyl ether in rats. Reproduct Toxicol 30(3): 414-421.
3 10) Gaoua, W. [2003] Ethyl tertiary butyl ether (ETBE), CAS No. 637-92-3:
4 Reproductive/developmental toxicity dose-range finding/probe study by the oral route
5 (gavage) in two strains of rat CIT under contract for TOTAL France S.A., Evreux, France.
6 Study No. 24168 RSR. Unpublished report.
7 11)Gaoua, W. (2004a) Ethyl tertiary butyl ether (ETBE): prenatal developmental toxicity
8 study by the oral route (gavage) in rats. CIT under contract to TOTAL France S.A.,
9 Evreux, France; Study No. 24860 RSR. Unpublished report.
10 12)Gaoua, W. (2004b) Ethyl tertiary butyl ether (ETBE): two-generation study
11 (reproduction and fertility effects) by oral route (gavage) in rats. CIT under contract
12 to TOTAL France S.A., Evreux, France; Study No. 24859 RSR. Unpublished report.
13 13)Hagiwara, A; Doi, Y; Imai, N; et al. (2011) Medium-term multi-organ carcinogenesis
14 bioassay of ethyl tertiary-butyl ether in rats. Toxicol 289(2-3): 160-166.
15 14) IIT Research Institute (Illinois Institute of Technology Research Institute). [1989a] Acute
16 dermal toxicity study of ethyl-tert-butyl ether (ETBE) in rabbits. IIT Research Institute, Life
17 Sciences Research under contract to Amoco Corporation, Chicago, IL; Study No. 1495.
18 Unpublished report
19 15) IIT Research Institute (Illinois Institute of Technology Research Institute). fl989bl Acute
20 inhalation toxicity study of ethyl-t-butyl ether (ETBE) in rats. IIT Research Institute, Life
21 Sciences Research under contract to Amoco Corporation, Chicago, IL; Study No. 1496.
22 Unpublished report
23 16) IIT Research Institute (Illinois Institute of Technology Research Institute). (1991)
24 Four-week inhalation toxicity study of ethyl tert-butyl ether (ETBE) in rats. IIT Research
25 Institute, Life Sciences Research under contract to Amoco Corporation, Chicago, IL; Study
26 No. 1544. Unpublished report.
27 17) Japan Petroleum Energy Center (JPEC).(2008a) 28-day ETBE repeated dose full-body
28 inhalation toxicity test in rats (preliminary test). Mitsubishi Chemical Safety Institute Ltd.
29 Study No. B061828. Unpublished report
30 18)Japan Petroleum Energy Center (JPEC). (2008b) A 90-day repeat dose toxicity study
31 of ETBE by whole-body inhalation exposure in rats. Mitsubishi Chemical Safety
32 Institute Ltd. Study No. B061829. Unpublished report.
33 19)Japan Petroleum Energy Center (JPEC). (2008c) A 180-day repeat dose oral toxicity
34 study of ETBE in rats. Hita Laboratory, Chemicals Evaluation and Research Institute
35 (CERI), Japan. Study No. D19-0002. Unpublished report.
36 20)Japan Petroleum Energy Center (JPEC).(2008d) Medium-term multi-organ
37 carcinogenesis bioassay of 2-ethoxy-2-methylpropane in rat. Unpublished report.
This document is a draft for review purposes only and does not constitute Agency policy.
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Preliminary Materials for the IRIS Toxicological Review ofETBE
1 21)Japan Petroleum Energy Center (JPEC). (2008e) A one-generation reproduction study
2 of ETBE in rats. Safety Research Institute for Chemical Compounds. Study No.
3 SR07060. Unpublished report.
4 22) Japan Petroleum Energy Center (JPEC). (2008h) A prenatal developmental toxicity
5 study of ETBE in rats. Hita Laboratory, Chemicals Evaluation and Research Institute
6 (CERI), Japan. Study No. E09-0006. Unpublished report.
7 23) Japan Petroleum Energy Center (JPEC). [20081) Serum levels of triiodothyronine (T3),
8 thyroxine (T4), and thyroid-stimulating hormone (TSH) in rats following 4-weeks
9 administration of 2-ethoxy-2-methylpropane. DIMS Institute of Medical Science, Inc.,
10 Ichinomiya, Japan. Study No. 0760. Unpublished report.
11 24)Japan Petroleum Energy Center (JPEC). (2008)) Study for effects on embryo-fetal
12 development in rabbits treated orally with ETBE. Kannami Laboratory, Bozo
13 Research Center Inc., 1308-125 Kuwahara-Sambonmatsu,Kannami-cho, Tagata-gun,
14 Shizuoka 419-0101, Japan. Study No. R-965. Unpublished report.
15 25) Japan Petroleum Energy Center (JPEC). (2010a) Carcinogenicity test of 2-ethoxy-2-
16 methylpropane in rats (drinking water study). Japan Industrial Safety and Health
17 Association, Japan Bioassay Research Center. Study No. 0691. Unpublished report.
18 26) Japan Petroleum Energy Center (JPEC). (2010b) Carcinogenicity test of 2-ethoxy-2-
19 methylpropane in rats (inhalation study). Japan Industrial Safety and Health
20 Association, Japan Bioassay Research Center. Study No. 0686. Unpublished report.
21 27)Li, Q; Kobayashi, M; Inagaki, H; etal. (2011) Effects of subchronic inhalation exposure
22 to ethyl tertiary butyl ether on splenocytes in mice. Int J Immunopathol Pharmacol
23 24(4): 837-847.
24 28)Maltoni, C; Belpoggi, F; Soffritti, M; et al. (1999) Comprehensive long-term
25 experimental project of Carcinogenicity bioassays on gasoline oxygenated additives:
26 plan and first report of results from study of ethyl-tertiary-butyl-ether (ETBE). Eur J
27 Oncol 4:493-508.
28 29) Millennium Bioresearch Research Laboratories (MB Research Laboratories, Inc.). (1988a)
29 Acute dermal toxicity in rabbits/LD50 in rabbits. MB Research Laboratories, Inc. under
30 contract to ARCO Chemical Company, Spinnerstown, PA; Laboratory Project ID MB 88-9107
31 B. Unpublished report
32 30) Millennium Bioresearch Research Laboratories (MB Research Laboratories, Inc.). (1988b)
33 Eye irritation in rabbits. MB Research Laboratories, Inc. under contract to ARCO Chemical
34 Company, Spinnerstown, PA; Laboratory Project ID MB 88-9107 D. Unpublished report
35 31) Millennium Bioresearch Research Laboratories (MB Research Laboratories, Inc.). (1988c)
36 Primary dermal irritation in rabbits. MB Research Laboratories, Inc. under contract to
37 ARCO Chemical Company, Spinnerstown, PA; Laboratory Project ID MB 88-9107 C.
38 Unpublished report
39 32) Millennium Bioresearch Research Laboratories (MB Research Laboratories, Inc.). (1988d)
40 Single dose oral toxicity in rats/LD50 in rats. MB Research Laboratories, Inc. under contract
This document is a draft for review purposes only and does not constitute Agency policy.
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Preliminary Materials for the IRIS Toxicological Review ofETBE
1 to ARCO Chemical Company, Spinnerstown, PA; Laboratory Project ID MB 88-9137 A.
2 Unpublished report
3 33) Medinsky, MA; Wolf, DC; Cattley, RC; et al. (1999) Effects of a thirteen-week inhalation
4 exposure to ethyl tertiary butyl ether on Fischer-344 rats and CD-I mice. Toxicol Sci
5 51(1):108-118.
6 34)Suzuki, M; Yamazaki, K; Kano, K; et al. (2012) No carcinogenicity of ethyl tertiary-
7 butyl ether by 2-year oral administration in rats. J Toxicol Sci 37(6): 1239-1246.
8 35) Utah Biomedical Testing Laboratory (UBTL Inc.). [1994) Twenty-eight (28) day dermal
9 toxicity study in rats administered test article F-266. UBTL, Inc. under contract to ARCO
10 Chemical Company, Salt Lake City, UT; UBTL Study No. 66894; Protocol No. ATX-92-0114,
11 1-174. Unpublished report.
12 36) Weng, ZQ; Suda, M; Ohtani, K; et al. (2011) Aldh2 knockout mice were more sensitive
13 to DNA damage in leukocytes due to ethyl tertiary butyl ether exposure. Ind Health
14 49(3): 396-399.
15 37) Weng, Z; Suda, M; Ohtani, K; et al. (2012) Differential genotoxic effects of subchronic
16 exposure to ethyl tertiary butyl ether in the livers of Aldh2 knockout and wild-type
17 mice. Arch Toxicol 86(4): 675-682.
18 38) White, KL. [2002) Immunological evaluation of gasoline ETBE vapor condensate in female
19 Sprague-Dawley rats using the plaque forming cell assay. ImmunoTox, Inc. under contract
20 to Huntingdon Life Sciences, Richmond, VA; Project No. ITI 901. Unpublished report
21 39) White, RD; Daughtrey, WC; Wells, MS. [1995) Health effects of inhaled tertiary amyl methyl
22 ether and ethyl tertiary butyl ether. Toxicol Lett 82-83:719-724.
23 Genotoxicity studies
24 1) Japan Petroleum Energy Center (JPEC). (2007a) Micronucleus test of 2-ethoxy-2-
25 methylpropane (ETBE) using bone marrow of rats administered ETBE by gavage.
26 Japan Industrial Safety and Health Association. Japan Bioassay Research Center.
27 Study No. 7049. Unpublished report.
28 2) Japan Petroleum Energy Center (JPEC). (2007b) Micronucleus test of 2-ethoxy-2-
29 methylpropane (ETBE) using bone marrow of rats administered ETBE
30 intraperitoneally. Japan Industrial Safety and Health Association. Japan Bioassay
31 Research Center. Study No. 7048. Unpublished report.
32 3) Japan Petroleum Energy Center (JPEC). (2007c) Micronucleus test of ETBE using bone
33 marrow of rats of the "13-week toxicity study of 2-ethoxy-2-methylpropane in F344
34 rats (drinking water study) [preliminary carcinogenicity study]." Japan Industrial
35 Safety and Health Association. Japan Bioassay Research Center. Study No. 7046.
36 Unpublished report.
37 4) Japan Petroleum Energy Center (JPEC). (2007d) Micronucleus test of ETBE using bone
38 marrow of rats of the "13-week toxicity study of 2-ethoxy-2-methylpropane in F344
39 rats (inhalation study) [preliminary carcinogenicity study]." Japan Industrial Safety
This document is a draft for review purposes only and does not constitute Agency policy.
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Preliminary Materials for the IRIS Toxicological Review ofETBE
1 and Health Association. Japan Bioassay Research Center. Study No. 7047.
2 Unpublished report.
3 5) Vergnes, JS. (1995) Ethyl tertiary butyl ether: in vitro chromosome aberrations assay
4 in Chinese hamster ovary cells. Bushy Run Research Center, Union Carbide
5 Corporation under contract to ARCO Chemical Company, Export, PA; Laboratory
6 Project ID 94N1425. Unpublished report.
7 6) Vergnes, JS; Kubena, MF. (1995a) Ethyl tertiary butyl ether: bone marrow
8 micronucleus test in mice. Bushy Run Research Center, Union Carbide Corporation
9 under contract to ARCO Chemical Company, Export, PA; Laboratory Project ID
10 94N1426. Unpublished report.
11 7) Vergnes, JS; Kubena, MF. (1995b) Ethyl tertiary butyl ether: mutagenic potential in
12 the CHO/HGPRT forward mutation assay. Bushy Run Research Center, Union Carbide
13 Corporation under contract to ARCO Chemical Company, Export, PA; Laboratory
14 Project ID 94N1424. Unpublished report.
15 8) Zeiger, E; Anderson, B; Haworth, S; et al. (1992) Salmonella mutagenicity tests: V.
16 Results from the testing of 311 chemicals. Environ Mol Mutagen 19(Suppl 21):2-141.
17 Other studies involving direct administration ofETBE, including mechanistic studies
18 1] Tapan Petroleum Energy Center (JPEG). [2012] Investigation of the Mechanisms of Ethyl
19 tertiary-butyl ether (ETBE) carcinogenicity in the liver of F344 rats- Transmission Electron
20 Microscopic Examination. Japan Industrial Safety and Health Association, Japan Bioassay
21 Research Center. Study No. 12138. Unpublished report
22 2) Martin, TV: Bilgin, NM: Iba, MM. [2002] Influence of oxygenated fuel additives and their
23 metabolites on the binding of a convulsant ligand of the gamma-aminobutyric acid(A]
24 [GABA(A] receptor in rat brain membrane preparations. Toxicol Lett 129(3]:219-226.
25 3] Martin, JV; Iyer, SV; Mcllroy, PJ; etal. [2004] Influence of oxygenated fuel additives and
26 their metabolites on gamma-aminobutyric acidA [GABAA] receptor function in rat brain
27 synaptoneurosomes. Toxicol Lett 147(3]:209-217.
28 4] Yamaki. K: Yoshino. S. [2009] Inhibition of IgE-induced mast cell activation by ethyl
29 tertiary-butyl ether, a bioethanol-derived fuel oxygenate. J Pharm Pharmacol
30 61:1243-1248.
31 1.2.2. Not Primary Source of Health Effects Data, but Kept as Additional Resources
32 Reviews, editorials
33 1] Ahmed, FE. [2001] Toxicology and human health effects following exposure to oxygenated
34 or reformulated gasoline. Toxicol Lett 123(2-3]: 89-113.
35 2] BIBRA Working Group. [2000] Ethyl tert-butyl ether. Bibra toxicology advice & consulting.
36 Surrey, United Kingdom.
This document is a draft for review purposes only and does not constitute Agency policy.
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Preliminary Materials for the IRIS Toxicological Review ofETBE
1 3) Burbacher, TM. [1993] Neurotoxic effects of gasoline and gasoline constituents. Environ
2 Health Perspect 101: 133-141.
3 4) Caprino, L and Togna, G. [1998] Potential health effects of gasoline and its constituents: A
4 review of current literature [1990-1997] on toxicological data. Environ Health Perspect
5 106(3]: 115-125.
6 5] de Peyster, A. [2010] Ethyl t-butyl ether: Review of reproductive and developmental
7 toxicity. Birth Defects Res B Dev Reprod Toxicol 89(3]: 239-263.
8 6] Dekant, W; Bernauer, U; Rosner, E; et al. [2001b] Toxicokinetics of ethers used as fuel
9 oxygenates. Toxicol Lett 124(1-3]: 37-45.
10 7] Hard. GC: RH Bruner: SM Cohen: etal. [2011] Renal histopathology in toxicity and
11 carcinogenicity studies with tert-butyl alcohol administered in drinking water to F344 rats:
12 A pathology working group review and re-evaluation. Regul Toxicol Pharmacol 59(3]:
13 430-436.
14 8] Hard, GC: Johnson, KT: Cohen, SM: etal. [2009] A comparison of rat chronic progressive
15 nephropathy with human renal disease-implications for human risk assessment. Grit Rev
16 Toxicol 39(4]: 332-346.
17 9] Hard, GC and Khan, KN. [2004] A contemporary overview of chronic progressive
18 nephropathy in the laboratory rat, and its significance for human risk assessment Toxicol
19 Pathology 32(2]: 171-180.
20 10] Johanson, G; Loef, A; Nihlen, A; et al. [1997] Toxicokinetics of ethers in humansA
21 comparison of MTBE, ETBE, and TAME. Toxicologist36 [1]: 339.
22 11] McGregor, D. [2007] Ethyl tertiary-butyl ether: a toxicological review. Grit Rev Toxicol
23 37(4]: 287-312.
24 12] McGregor, D. [2010] Tertiary-Butanol: A toxicological review. Grit Rev Toxicol 40(8]:
25 697-727.
26 13] U.S. EPA. [1995a] Letter Summarizing Review of Methyl-tert Butyl Ether and Ethyl Tert-
27 butyl Ether for Possible Relationship Based on Structure to Rodent Carcinogenicity, W/cvr
28 LtrDtd 02/13/95. Washington, DC. Office of Toxic Substances.
29 14] U.S. EPA. [1995b] Toxicity and health hazard summary of tert-butyl ethyl ether with cover
30 letter dated 01/10/95. Washington, DC.
31 Health effects assessments by others
32 1] American Conference of Governmental Industrial Hygienists [ACGIH]. [2001]
33 Documentation of the threshold limit values and biological exposure indices for ethyl tert-
34 butyl ether Vol:7th Ed (pp. 5]. Cincinnati, OH: American Conference of Governmental
35 Industrial Hygienists.
36 2] Duncan. B. [2008] Attention: TSCA 8(e] Coordinator. RE: Ethyl tertiary butyl ether (CASRN:
37 637-92-3]: Results from a Single Generation Reproduction in Rodents [Oral-Rat] and a Soil
This document is a draft for review purposes only and does not constitute Agency policy.
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Preliminary Materials for the IRIS Toxicological Review ofETBE
1 Bio degradation Study as part of The ETBE Utilization Study Working Group Testing
2 Program and Risk Assessment
3 Toxicokinetic studies (excluding physiologically-based toxicokinetic [PBTK] modeling studies)
4 1] Amberg, A; Rosner, E; and Dekant, W. [2000] Biotransformation and kinetics of excretion of
5 ethyl tert-butyl ether in rats and humans. Toxicol Sci 53:194-201.
6 2) Bernauer, U: Amberg, A: Scheutzow, D: etal. [1998] Biotransformation of 12C- and 2-13C-
7 labeled methyl tert-butyl ether, ethyl tert-butyl ether, and tert-butyl alcohol in rats:
8 identification of metabolites in urine by 13C nuclear magnetic resonance and gas
9 chromatography/mass spectrometry. Chem Res Toxicol ll(6]:651-658.
10 3] Borghoff, SJ. [1996] Ethyl tertiary butyl ether (ETBE] a pilot/methods development
11 pharmacokinetic study in male F344 rats and male CD-I mice after a single nose-only
12 inhalation exposure. Chemical Industry Institute of Toxicology under contract to ARCO
13 Chemical Company, Research Triangle Park, NC; Laboratory Protocol Number CIIT-95025.
14 Unpublished report
15 4] Dekant, W; Bernauer, U; Rosner, E; et al. [2001a] Biotransformation of MTBE, ETBE, and
16 TAME after inhalation or ingestion in rats and humans. Health Effects Inst Res Rep
17 102:29-71.
18 5] Hong, JY; Wang, YY; Bondoc, FY; et al. [1997] Rat olfactory mucosa displays a high activity
19 in metabolizing methyl tert-butyl ether and other gasoline ethers. Fundam Appl Toxicol
20 40(2]:205-210.
21 6] Hong, JY; Wang, YY; Bondoc, FY; et al. [1999a] Metabolism of methyl tert-butyl ether and
22 other gasoline ethers by human liver microsomes and heterologously expressed human
23 cytochromes P450: identification of CYP2A6 as a major catalyst Toxicol Appl Pharmacol
24 160(l]:43-48.
25 7] Hong, JY; Wang, YY; Bondoc, FY; et al. [1999b] Metabolism of methyl tert-butyl ether and
26 other gasoline ethers in mouse liver microsomes lacking cytochrome P450 2E1. Toxicol
27 Lettl05(l]:83-88.
28 8] Hong, JY; Wang, YY; Mohr, SN; et al. [2001] Human cytochrome P450 isozymes in
29 metabolism and health effects of gasoline ethers. Res Rep Health Effects Inst (102]:7-27.
30 9] Japan Petroleum Energy Center [TPEC]. [2008f] Pharmacokinetic study in rats treated with
31 [14C] ETBE repeatedly for 14 days. Kumamoto Laboratory, Mitsubishi Chemical Safety,
32 Institute Ltd., 1285 Kurisaki-machi, Uto-shi, Kumamoto 869-0425, Japan. Study No.
33 P070497. Unpublished report.
34 10] Japan Petroleum Energy Center [JPEC]. [2008g] Pharmacokinetic study in rats treated with
35 single dose of [14C] ETBE. Kumamoto Laboratory, Mitsubishi Chemical Safety, Institute
36 Ltd., 1285 Kurisaki-machi, Uto-shi, Kumamoto 869-0425, Japan. Study No. P070496.
37 Unpublished report
38 11] Kaneko, T; Wang, PY; Sato, A. [2000] Partition coefficients for gasoline additives and their
39 metabolites. J Occup Health 42(2]:86-87.
This document is a draft for review purposes only and does not constitute Agency policy.
1-11 DRAFT-DO NOT CITE OR QUOTE
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Preliminary Materials for the IRIS Toxicological Review ofETBE
1 12) Le Gal, A; Dreano, Y; Gervasi, PG; et al. [2001] Human cytochrome P450 2A6 is the major
2 enzyme involved in the metabolism of three alkoxyethers used as oxyfuels. Toxicol Lett
3 124(l-3):47-58.
4 13) Nihlen, A; Lof, A; Johanson, G. [1995] Liquid/air partition coefficients of methyl and ethyl t-
5 butyl ethers, t-amyl methyl ether, and t-butyl alcohol. J Expo Anal Environ Epidemiol
6 5(4):573-582.
7 14) Nihlen, A; Lof, A; Johanson, G. [1998a] Controlled ethyl tert-butyl ether (ETBE) exposure of
8 male volunteers I. Toxicokinetics. Toxicol Sci46(l):l-10.
9 15) Sun, JD and Beskitt, JL. [1995a] Ethyl tertiary butyl ether (ETBE): pharmacokinetics after
10 single and repeated inhalation exposures in mice. Bush Run Research Center, Union
11 Carbide Corporation under contract to ARCO Chemical Company, Export, PA; Laboratory
12 Project ID 94N1455. Unpublished report.
13 16) Sun, JD and Beskitt, JL. f!995bl Ethyl tertiary butyl ether (ETBE): pharmacokinetics after
14 single and repeated inhalation exposures in rats. Bush Run Research Center, Union Carbide
15 Corporation under contract to ARCO Chemical Company, Export, PA; Laboratory Project ID
16 94N1454. Unpublished report
17 17) Turini, A; Amato, G; Longo, V; et al. [1998] Oxidation of methyl- and ethyl- tertiary-butyl
18 ethers in ratliver microsomes: role of the cytochrome P450 isoforms. Arch Toxicol
19 72(4):207-214.
20 18) Zhang, YP; Macina, OT; Rosenkranz, HS; et al. f!9971 Prediction of the metabolism and
21 toxicological profiles of gasoline oxygenates. Inhal Toxicol 9(3):237-254.
22 PBTK modeling studies
23 1) Nihlen, A and Johanson, G. [1999]. Physiologically based toxicokinetic modeling of inhaled
24 ethyl tertiary-butyl ether in humans. Toxicol Sci 51(2):184-194.
25 2) Pierce, C.H. [2004]. Toxicokinetics of ethyl tertiary-butyl ether (ETBE) and methyl tertiary-
26 butyl ether (MTBE) in men and women. NIOSH report
27 Odor threshold
28 1) van Wezel, A; Puijker, L; et al. [2009]. Odour and flavour thresholds of gasoline additives
29 (MTBE, ETBE and TAME) and their occurrence in Dutch drinking water collection areas.
30 Chemosphere 76(5): 672-676.
31 2) Vetrano, KM. [1993]. Final report to ARCO Chemical Company on the odor and taste
32 threshold studies performed with methyl tertiary-butyl ether (MTBE) and ethyl tertiary-
33 butyl ether (ETBE). TRC Environmental Corporation under contract to ARCO Chemical
34 Company, Windsor, CT; Project no. 13442-M31. Unpublished report
35 1.2.3. Kept for Possible Further Review
36 None identified.
This document is a draft for review purposes only and does not constitute Agency policy.
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Preliminary Materials for the IRIS Toxicological Review ofETBE
This document is a draft for review purposes only and does not constitute Agency policy.
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Preliminary Materials for the IRIS Toxicological Review ofETBE
1
2 2. PRELIMINARY EVIDENCE TABLES AND
3 PRELIMINARY EXPOSURE-RESPONSE ARRAYS
4 2.1. Data Extraction: Preparation of Preliminary Evidence Tables and
5 Preliminary Exposure-Response Arrays
6 The 52 references identified as primary sources of health effects data were considered for
7 data extraction to evidence tables and exposure-response arrays. References were first collated
8 with respect to exposure route, exposure duration, and type of endpoint to identify those most
9 pertinent for evaluating the human health effects from chronic oral or inhalation exposure to ETBE.
10 As a result, data from 19 studies with one or more of the following characteristics were not
11 extracted into evidence tables or exposure-response arrays:
12 The study involved dermal exposure;
13 The study only involved acute or short-term exposures (less than 90 days/13 weeks), and it
14 was not conducted in the context of immunotoxicity, neurotoxicity, developmental, or
15 reproductive toxicity;
16 The data in the study only included endpoints related to possible mechanisms of toxicity;
17 and
18 The study's endpoints did not exhibit responses in any of the 52 available references.
19 Data from the 33 remaining references were prepared in preliminary evidence tables. No
20 studies were excluded based on study quality considerations, so as to allow for public input on
21 methodological considerations that could affect the interpretation of or confidence in each study's
22 results. With regard to noncancer effects, health effect endpoints that were consistently affected in
23 chronic or subchronic studies were included in the evidence tables. All data demonstrating
24 carcinogenic effects were included. Supporting data that provide mechanistic information for each
25 selected endpoint were also included. For each included endpoint, all studies reporting data on that
26 endpoint are included regardless of the reported level or statistical significance of the response.
27 Several references are grouped together as "related" references because they represent pilot (e.g.,
28 range-finding), unpublished (e.g., technical report), and/or published (e.g., journal article) versions
29 of the same study. The tables for non-carcinogenic effects appear first and are arranged in the
30 order from the health effect with the most data to health effect with the least data. The evidence
31 tables for carcinogenic and genotoxic effects follow. For each endpoint, the studies are presented
32 beginning with chronic studies followed by subchronic exposures. The information in the
This document is a draft for review purposes only and does not constitute Agency policy.
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Preliminary Materials for the IRIS Toxicological Review ofETBE
1 preliminary evidence tables is displayed graphically in preliminary exposure-response arrays. In
2 these preliminary arrays, the doses are labeled based only on statistical significance as determined
3 by the study's authors, without consideration of biological significance.
4
This document is a draft for review purposes only and does not constitute Agency policy.
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Preliminary Materials for the IRIS Toxicological Review ofETBE
l 2.2. Kidney Effects
2
3
Table 2-1. Evidence pertaining to kidney effects in animals following oral
exposure to ETBE
Reference and study design
Results
Kidney Weight
Suzuki et al. (2012)
Rat, F344, male and female,
50 /sex/group
0, 625, 2,500, 10,000 ppm
(0, 28, 121, 542 mg/kg-day in males;
0, 46, 171, 560 mg/kg-day in
females)3
Drinking water
104 weeks
Related reference: JPEC (2010a)
(unpublished study)
JPEC(2008c)
Rats, Sprague-Dawley
Male and female, 50/sex/group
0, 5, 25, 100, 400 mg/kg-day
Gavage
26 weeks (180 consecutive days)
Hagiwara et al. (2011)
Rats, F344, male, 12/group
0, 1,000 mg/kg-day
Gavage
23 weeks
Related reference: JPEC (2008d)
(unpublished study)
Gaoua (2004b)
Rats, Sprague-Dawley,
Male and female
0, 250, 500, 1,000 mg/kg-day
Gavage
(FO generation)
18 weeks (10 weeks before mating,
during a 2-week mating period,
3-week gestation and until after
weaning Fl)
Absolute kidney weight (percent change compared to control)
M
F
0 28 121 542
-4% 5% 18%*
0 46 171 560
3% 10%* 14%*
Relative kidney weight (percent change compared to control)
M
F
0 28 121 542
0.1% 13%* 32%*
0 46 171 560
14%* 23%* 37%*
Absolute kidney weight (percent change compared to control)
M
F
0 5 25 100 400
0.6% 6% 5% 25%*
0 5 25 100 400
0.5% 0% 7% 10%*
Relative kidney weight (percent change compared to control)
M
F
0 5 25 100 400
8% 6% 12%* 21%*
0 5 25 100 400
7% 4% 11%* 15%*
Absolute kidney weight (percent change compared to control)
19%*
Relative kidney weight (percent change compared to control)
25%*
Absolute kidney weight (percent change compared to control)
M
F
0 250 500 1,000
11%* 15%* 21%*
0 250 500 1,000
-0.9% 2% 5%
Relative kidney weight (percent change compared to control)
M
F
0 250 500 1,000
11%* 18%* 28%*
0 250 500 1,000
9% 5% 3%
4
5
This document is a draft for review purposes only and does not constitute Agency policy,
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Preliminary Materials for the IRIS Toxicological Review ofETBE
Table 2-1. Evidence pertaining to kidney effects in animals following oral
exposure to ETBE (continued)
Reference and study design
Fuiiietal. (2010)
Rats, Sprague-Dawley,
male and female, 24/sex/group
0, 100, 300, 1,000 mg/kg-day
Gavage
16 weeks (males),
17 weeks (females)
Related reference: JPEC (2008e)
(unpublished study)
Results
Absolute kidney weight (percent change compared to control)
M 0 100 300
5% 8%
F 0 100 300
-2% 0.0
Relative kidney weight (percent change compared to
M 0 100 300
8%* 12%*
F 0 100 300
-3% -0.9%
1,000
18%*
1,000
7%*
control)
1,000
26%*
1,000
2%
Histopathology
Suzuki etal. (2012)
Rat, F344, male and female,
50 /sex/group
0, 625, 2,500, 10,000 ppm
(0, 28, 121, 542 mg/kg-d in males;
0, 46, 171, 560 mg/kg-d in females)3
Drinking water
104 weeks
Related reference: JPEC (2010a)
(unpublished study)
Incidence of chronic nephropathy
MO 28 121
49/50 43/50 45/50
F 0 46 171
41/50 37/50 37/50
542
48/50
560
39/50
Average severity of chronic nephropathyb
MO 28 121
2.1 1.7 1.8
F 0 46 171
1.0 0.9 1.1
542
2.3
560
1.2
Incidence of hyaline droplets
MO 28 121
Not examined
F 0 46 171
Not examined
542
560
Incidence of atypical tubule hyperplasia
MO 28 121
0/50 0/50 0/50
F 0 46 171
0/50 0/50 0/50
542
1/50
560
2/50
Incidence of papillary necrosis
MO 28 121
0/50 1/50 0/50
F 0 46 171
0/50 1/50 1/50
542
2/50
560
2/50
Incidence of papillary mineralization
MO 28 121
0/50 0/50 16/50*
F 0 46 171
0/50 0/50 1/50
542
42/50*
560
3/50
This document is a draft for review purposes only and does not constitute Agency policy,
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Preliminary Materials for the IRIS Toxicological Review ofETBE
Table 2-1. Evidence pertaining to kidney effects in animals following oral
exposure to ETBE (continued)
Reference and study design
Cohen et al. (2011)
Reanalysis of the renal sections
from Suzuki etal. (2012)
JPEC(2008c)
Rats, Sprague-Dawley
Male and female, 50/sex/group
0, 5, 25, 100, 400 mg/kg-day
Gavage
26 weeks (180 consecutive days)
Results
Incidence of chronic nephropathy
MO 28 121
49/50 Not examined Not examined
F 0 46 171
45/50 41/50 46/50
542
50/50
560
46/50
Average severity of chronic nephropathy
MO 28 121
2.1 Not examined Not examined
F 0 46 171
1.1 1.0 1.2
542
2.7
560
1.4
Incidence of hyaline droplets
MO 5 25 100
0/15 0/15 0/15 4/15*
F 0 5 25 100
0/15 Not examined
400
10/15*
400
0/15
Incidence of hyaline droplets positive for a2u-globulin
MO 5 25 100
Not reported Not examined 2/2
F 0 5 25 100
Not examined
400
1/1
400
Incidence of papillary mineralization
MO 5 25 100
0/15 0/15 0/15 1/15
F 0 5 25 100
0/15 Not examined
400
0/15
400
0/15
Urina lysis
Suzuki et al. (2012)
Rat, F344, male and female,
50/sex/group
0, 625, 2,500, 10,000 ppm
(0, 28, 121, 542 mg/kg-d in males;
0, 46, 171, 560 mg/kg-d in females)3
Drinking water
104 weeks
Related reference: JPEC (2010a)
(unpublished study)
Incidence of proteinuria
MO 28 121
39/39 37/37 34/34
F 0 46 171
37/37 37/37 38/38
542
35/35
560
38/38
Average severity of proteinuriab
MO 28 121
3.0 3.1 3.1
F 0 46 171
2.8 3.0 3.0
542
3.1
560
3.1
This document is a draft for review purposes only and does not constitute Agency policy,
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Preliminary Materials for the IRIS Toxicological Review ofETBE
Table 2-1. Evidence pertaining to kidney effects in animals following oral
exposure to ETBE (continued)
Reference and study design
JPEC(2008c)
Rats, Sprague-Dawley
Male and female, 50/sex/group
0, 5, 25, 100, 400 mg/kg-day
Gavage
26 weeks (180 consecutive days)
Results
Incidence of
M
F
0
10/10
0
8/10
proteinuria
5
10/10
5
9/10
25
10/10
25
7/10
100
10/10
100
9/10
400
10/10
400
7/10
Average severity of proteinuriab
M
F
0
1.5
0
1.2
Incidence of
M
F
0
0/10
0
0/10
5
1.6
5
1.3
urinary casts
5
Not examined
5
Not examined
25
1.6
25
1.0
25
0/10
25
0/10
100
1.3
100
1.3
100
100
400
1.5
400
1.0
400
400
1
2
3
4
5
6
Conversion performed by study authors.
Calculated by EPA Z(grade x #of affected animals)/total # of animals exposed.
'statistically significant (p < 0.05) based on analysis of data conducted by study authors.
Percentage change compared to control = (treated value - control value) -f control value x 100.
This document is a draft for review purposes only and does not constitute Agency policy,
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Preliminary Materials for the IRIS Toxicological Review ofETBE
1
2
Table 2-2. Evidence pertaining to kidney effects in animals following
inhalation exposure to ETBE
Reference and study design
Results
Kidney Weight
JPEC(2010b)
Rat, F344, male and female,
50 /sex/group
0, 500, 1,500, 5,000 ppm
(0, 2,090, 6,270, 20,900 mg/m3)a
Whole body inhalation
6 hours/day, 5 days/week
104 weeks
JPEC(2008b)
Rats, Sprague-Dawley
Male and female, 10-16/sex/group
0, 150, 500, 1,500, 5,000 ppm
(0, 627, 2,090, 6,270, 20,900
mg/m3)a
Whole body inhalation
6 hours/day, 5 days/week
13 weeks
{} = subset with 28 day recovery
after 13 week exposure
Medinskv et al. (1999)
Rats, F344, male and female
10/sex/group
0, 500, 1,750, 5,000 ppm
(0, 2,090, 7,320, 20,900 mg/m3)a
Whole body inhalation
6 hours/day, 5 days/week
13 weeks
Related reference: Bond et al.
(1996b) (unpublished study)
Medinskv et al. (1999)
Mice, CD-I, male and female
10/sex/group,
0, 500, 1,750, 5,000 ppm
(0, 2,090, 7,320, 20,900 mg/m3)a
Whole body inhalation
6 hours/day, 5 days/week
13 weeks
Related reference: Bond et al.
(1996a) (unpublished study)
Absolute kidney weight (percent change compared
M
F
0
0
2,090 6,270
8%* 17%*
2,090 6,270
5% 6%*
to control)
20,900
23%*
20,900
18%*
Relative kidney weight (percent change compared to control)
M
F
0
0
2,090 6,270
19%* 26%*
2,090 6,270
11%* 16%*
Absolute kidney weight (percent change compared
M
F
0 627
10%
0 627
0.2%
2,090 6,270
11% 18%*
2,090 6,270
-0.9% 4%
20,900
66%*
20,900
51%*
to control)
20,900
15%* {19%}
20,900
7% {8%}
Relative kidney weight (percent change compared to control)
M
F
0 627
10%
0 627
8%
2,090 6,270
9% 20%*
2,090 6,270
7% 13%*
20,900
24%* {15%*}
20,900
20%* {5%}
Absolute kidney weight (percent change compared
M
F
0
0
2,090 7,320
7% 10%*
2,090 7,320
5% 12%*
to control)
20,900
19%*
20,900
21%*
Absolute kidney weight (percent change compared
M
F
0
0
2,090 7,320
9% 10%
2,090 7,320
-0.2% 6%
to control)
20,900
5%
20,900
4%
This document is a draft for review purposes only and does not constitute Agency policy,
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Preliminary Materials for the IRIS Toxicological Review ofETBE
Table 2-2. Evidence pertaining to kidney effects in animals following
inhalation exposure to ETBE (continued)
Reference and study design
Results
Histopathology
JPEC(2010b)
Rat, F344, male and female,
50 /sex/group
0, 500, 1,500, 5,000 ppm
(0, 2,090, 6,270, 20,900 mg/m3)a
Whole body inhalation
6 hours/day, 5 days/week
104 weeks
JPEC (2008b)
Rats, Sprague Dawley
Male and female, 10-16/sex/group
0, 150, 500, 1,500, 5,000 ppm
(0, 627, 2,090, 6,270, 20,900
mg/m3)a
Whole body inhalation
6 hours/day, 5 days/week
13 weeks
Incidence of chronic nephropathy
M 0 2,090 6,270
49/50 50/50 49/50
F 0 2,090 6,270
32/50 38/50 41/50
20,900
50/50
20,900
40/50
Average severity of nephropathy
M 0 2,090 6,270
2.4 2.6 2.7
F 0 2,090 6,270
0.9 1.3 1.3
20,900
3.1*
20,900
1.6*
Incidence of hyaline droplets
M 0 2,090 6,270
Not examined
F 0 2,090 6,270
Not examined
20,900
20,900
Incidence of papilla mineralization
M 0 2,090 6,270
0/50 0/50 1/50
F 0 2,090 6,270
Not examined
20,900
6/50*
20,900
Incidence of atypical tubule hyperplasia
M 0 2,090 6,270
Not examined
F 0 2,090 6,270
Not examined
20,900
20,900
Incidence of hyaline droplets, proximal tubule
M 0 627 2,090 6,270
0/10 3/10 8/10* 8/10*
F 0 627 2,090 6,270
Not observed
20,900
8/10*
20,900
Incidence of hyaline droplets positive for a2u-globulin
M 0 627 2,090 6,270 20,900
Unspecified representative samples reported positive for a2u-globulin
F 0 627 2,090 6,270
Not examined
20,900
Incidence of urinary casts
M 0 627 2,090 6,270
0/6 0/6 0/6 0/6
F 0 627 2,090 6,270
0/6 0/6 0/6 0/6
20,900
0/6
20,900
0/6
This document is a draft for review purposes only and does not constitute Agency policy,
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Preliminary Materials for the IRIS Toxicological Review ofETBE
Table 2-2. Evidence pertaining to kidney effects in animals following
inhalation exposure to ETBE (continued)
Reference and study design
Medinskv et al. (1999)
Rats, F344, male and female
10/sex/group
0, 500, 1,750, 5,000 ppm
(2,090, 7,320, 20,900 mg/m3)a
Whole body inhalation
6 hours/day, 5 days/week
13 weeks
Related reference: Bond et al.
(1996b)
Results
Average severity of
M
F
0
1.8
0
hyaline droplets
2,090
3.0
7,320
3.2
2,090 7,320
Not observed
20,900
3.8
20,900
Average proximal tubule proliferation
M
F
0
0.91
0
0.59
2,090
2.16*
2,090
1.02
7,320
3.4*
7,320
0.97
20,900
2.47*
20,900
0.87
Urinalysis
JPEC(2010b)
Rat, F344, male and female,
50 /sex/group
0, 500, 1,500, 5,000 ppm
(0, 2,090, 6,270, 20,900 mg/m3)a
Whole body inhalation
6 hours/day, 5 days/week
104 weeks
JPEC (2008b)
Rats, Sprague-Dawley
Male and female, 10-16/sex/group
0, 150, 500, 1,500, 5,000 ppm
(0, 627, 2,090, 6,270, 20,900
mg/m3)a
Whole body inhalation
6 hours/day, 5 days/week
13 weeks
Incidence of proteinuria
M
F
0
44/44
0
35/38
Average severity of
M
F
0
3.7
0
2.8
2,090
38/38
2,090
39/39
proteinuria
2,090
3.5
2,090
3.1
6,270
40/40
6,270
30/30
6,270
3.6
6,270
3.3
20,900
31/31
20,900
30/30
20,900
3.6
20,900
3.4*
Incidence of proteinuria
M
F
0
3/6
0
1/6
Average severity of
M
F
0
0.5
0
0.2
627 2,090
5/6 5/6
627 2,090
1/6 1/6
proteinuria
627 2,090
1.2 1.2
627 2,090
0.3 0.2
6,270
6/6
6,270
2/6
6,270
1.3
6,270
0.5
20,900
4/6
20,900
2/6
20,900
1.0
20,900
0.3
1
2
3
4
5
6
a4.18mg/m = 1 ppm.
'statistically significant (p<0.05) based on analysis of data conducted by study authors.
Percentage change compared to control = (treated value - control value) -f control value x 100.
This document is a draft for review purposes only and does not constitute Agency policy,
2-9 DRAFT-DO NOT CITE OR QUOTE
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Preliminary Materials for the IRIS Toxicological Review ofETBE
1000
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T3
M
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^ LU ^ LU
M n N n
3 , 3 ,
on on
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104 weeks
Chronic
Progressive
Nephropathy
2
3
Figure 2-1. Exposure-response array of kidney effects following oral exposure
to ETBE.
This document is a draft for review purposes only and does not constitute Agency policy,
2-10 DRAFT-DO NOT CITE OR QUOTE
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Preliminary Materials for the IRIS Toxicological Review ofETBE
100,000
10,000
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13 weeks
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Severity
2
o
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5
Figure 2-2. Exposure-response array of kidney effects following inhalation
exposure to ETBE.
This document is a draft for review purposes only and does not constitute Agency policy,
2-11 DRAFT-DO NOT CITE OR QUOTE
-------
Preliminary Materials for the IRIS Toxicological Review ofETBE
l 2.3. Liver Effects
2
3
Table 2-3. Evidence pertaining to liver effects in animals following oral
exposure to ETBE
Reference and study design
Results
Liver Weight
Suzuki etal. (2012)
Rats, F344, male and female,
50/sex/group
0, 625, 2,500, 10,000 ppm
(0, 28, 121, 542 mg/kg-d in males;
0, 46, 171, 560 mg/kg-d in females)3
Drinking water
104 weeks
Related reference: JPEC (2010a)
(unpublished study)
JPEC(2008c)
Rats, Sprague-Dawley
Male and female, 15/sex/group
0, 5, 25, 100, 400 mg/kg-day
Gavage
26 weeks (180 consecutive days)
Hagiwara et al. (2011)
Rats, F333, male, 12/group
Gavage 0, 1,000 mg/kg-day
23 weeks
Related reference: JPEC (2008d)
(unpublished study)
Gaoua (2004b)
Rats, Sprague-Dawley,
Male and female, 25/sex/group
0, 250, 500, 1,000 mg/kg-day
Gavage
(FO generation)
18 weeks (10 weeks before mating,
during a 2-week mating period,
3-week gestation and until after
weaning Fl)
Absolute liver weight (percent change compared to control)
M
F
0 28 121 542
-11%* -4% 2%
0 46 171 560
-6% -2% -10%
Relative liver weight (percent change compared to control)
M
F
0 28 121 542
-8% 3%* 12%*
0 46 171 560
4% 9% 8%
Absolute liver weight (percent change compared to control)
M
F
0 5 25 100 400
-2% 7% 4% 19%
0 5 25 100 400
-4% -1% 2% 9%
Relative liver weight (percent change compared to control)
M
F
0 5 25 100 400
5% 7% 9% 17%*
0 5 25 100 400
1% 1% 4% 12%*
Absolute liver weight (percent change compared to control)
21%*
Relative liver weight (percent change compared to control)
27%*
Absolute liver weight (percent change compared to control)
M
F
0 250 500 1,000
2% 2% 17%*
0 250 500 1,000
-1% 4% 6%
Relative liver weight (percent change compared to control)
M
F
0 250 500 1,000
3% 6% 24%*
0 250 500 1,000
10% 8% 4%
4
5
This document is a draft for review purposes only and does not constitute Agency policy,
2-12 DRAFT-DO NOT CITE OR QUOTE
-------
Preliminary Materials for the IRIS Toxicological Review ofETBE
Table 2-3. Evidence pertaining to liver effects in animals following oral
exposure to ETBE (continued)
Reference and study design
Fuiiietal. (2010)
Rats, Sprague-Dawley,
Male and female, 24/sex/group
0, 100, 300, 1,000 mg/kg-day
Gavage
16 weeks (males),
17 weeks (females)
Related reference: JPEC (2008e)
(unpublished study)
Results
Absolute liver weight (percent change compared to control)
M 0 100
-3%
F 0 100
-1%
300
1%
300
4%
1,000
13%*
1,000
14%*
Relative liver weight (percent change compared to control)
M 0 100
1%
F 0 100
-2%
300
3%
300
2%
1,000
21%*
1,000
8%*
Serum Liver Enzymes
Suzuki et al. (2012)
Rats, F344, male and female,
50 /sex/group
0, 625, 2,500, 10,000 ppm
(0, 28, 121, 542 mg/kg-d in males;
0, 46, 171, 560 mg/kg-d in females)3
Drinking Water
104 weeks
Related reference: JPEC (2010a)
AST, ALT, and ALP Enzymes in
M
AST
ALT
ALP
F
AST
ALT
ALP
0 28
-21%
-17%
-5%
0 46
-19%
-10%
-16%
Liver (% change compared
121
-3%
2%
3%
171
-17%
-15%
2%
to control]
542
-1%
-4%
0.3%
560
-46%*
-26%
-15
(unpublished study)
JPEC(2008c)
Rats, Sprague-Dawley
Male and female, 15/sex/group
0, 5, 25, 100, 400 mg/kg-day
Gavage
26 weeks (180 consecutive days)
AST, ALT, and ALP Enzymes in
M
AST
ALT
ALP
F
AST
ALT
ALP
0 5
16%
10%
2%
0 5
10%
11%
6%
Liver (% change compared
25 100
19% 20%
48% 13%
12% -8%
25 100
13% 20%
21% 46%
-21% -18%
to control]
400
23%
36%
27%
400
4%
21%
-19%
Centrilobular Hypertrophy
Suzuki etal. (2012)
Rats, F344, male and female,
50 /sex/group
0, 625, 2,500, 10,000 ppm
(0, 28, 121, 542 mg/kg-d in males;
0, 46, 171, 560 mg/kg-d in females)3
Drinking Water
104 weeks
Related reference: JPEC (2010a)
(unpublished study)
Centrilobular hypertrophy
Not observed
This document is a draft for review purposes only and does not constitute Agency policy,
2-13 DRAFT-DO NOT CITE OR QUOTE
-------
Preliminary Materials for the IRIS Toxicological Review ofETBE
Table 2-3. Evidence pertaining to liver effects in animals following oral
exposure to ETBE (continued)
Reference and study design
JPEC(2008c)
Rats, Sprague-Dawley
Male and female, 15/sex/group
0, 5, 25, 100, 400 mg/kg-day
Gavage
26 weeks (180 consecutive days)
Gaoua (2004b)
Rats, Sprague-Dawley,
Male and female, 25/sex/group
Gavage, (FO generation)
0, 250, 500, 1,000 mg/kg-day
18 weeks (10 weeks before mating,
during a 2-week mating period, 3-
week gestation and until after
weaning Fl)
Results
Incidence of centrilobular hypertrophy
M 0
0/15
F 0
0/15
5 25
0/15 0/15
5 25
0/15 0/15
100 400
0/15 6/15*
100 400
0/15 6/15*
Incidence of centrilobular hypertrophy
M 0
0/25
F 0
0/25
250
0/25
250
0/25
500 1,000
0/25 3/25
500 1,000
0/25 0/25
1
2
3
4
5
Conversion performed by study authors.
*Statistically significant (p < 0.05) based on analysis of data conducted by study authors.
Percentage change compared to control = (treated value - control value) 4- control value x 100.
This document is a draft for review purposes only and does not constitute Agency policy,
2-14 DRAFT-DO NOT CITE OR QUOTE
-------
Preliminary Materials for the IRIS Toxicological Review ofETBE
1
2
Table 2-4. Evidence pertaining to liver effects in animals following inhalation
exposure to ETBE
Reference and study design
Results
Liver Weight
JPEC(2010b)
Rats, F344, male and female,
50 /sex/group
0, 500, 1,500, 5,000 ppm
(0, 2,090, 6,270, 20,900 mg/m3)a
Whole body inhalation
6 hours/day, 5 days/week
104 weeks
JPEC(2008b)
Rats, Sprague-Dawley
Male and female,
10-16/sex/group
0, 150, 500, 1,500, 5,000 ppm
(0, 627, 2,090, 6,270, 20,900
mg/m3)a
Whole body inhalation
6 hours/day, 5 days/week
13 weeks
{} = subset with 28 day recovery
after 13 week exposure
Medinskv et al. (1999)
Rats, F344, male and female
10/sex/group
0, 500, 1,750, 5,000 ppm
(2,090, 7,320, 20,900 mg/m3)a
Whole body inhalation
6 hours/day, 5 days/week
13 weeks
Related reference: Bond et al.
(1996b) (unpublished study)
Medinskv et al. (1999)
Mice, CD-I, male and female
10/sex/group
0, 500, 1,750, 5,000 ppm
(2,090, 7,320, 20,900 mg/m3)a
Whole body inhalation
6 hours/day, 5 days/week
13 weeks
Related reference: Bond et al.
(1996a) (unpublished study)
Absolute liver weight (percent change compared
M
F
0 2,090
0.9%
0 2,090
-4%
6,270
11%*
6,270
-8%
to control)2
20,900
10%
20,900
0.5%
Relative liver weight (percent change compared to control)
M
F
0 2,090
9%*
0 2,090
3%
6,270
19%*
6,270
1%*
Absolute liver weight (percent change compared
M
F
0 627 2,090
5% 6%
0 627 2,090
-3% -8%
6,270
4%
6,270
-2%
20,900
49%*
20,900
30%*
to control)
20,900
2% {13%}
20,900
5% {11%}
Relative liver weight (percent change compared to control)
M
F
0 627 2,090
5% 5%
0 627 2,090
4% -1%
6,270
6%
6,270
6%
20,900
10% {9%*}
20,900
18%* {7%}
Absolute liver weight (percent change compared
M
F
0 2,090
6%
0 2,090
2%
7,320
14%*
7,320
9%
to control)
20,900
32%*
20,900
26%*
Absolute liver weight (percent change compared
M
F
0 2,090
4%
0 2,090
2%
7,320
13%*
7,320
19%*
to control)
20,900
18%*
20,900
33%*
This document is a draft for review purposes only and does not constitute Agency policy,
2-15 DRAFT-DO NOT CITE OR QUOTE
-------
Preliminary Materials for the IRIS Toxicological Review ofETBE
Table 2-4. Evidence pertaining to liver effects in animals following inhalation
exposure to ETBE (continued)
Reference and study design
Serum Liver Enzymes
JPEC(2010b)
Rats, F344, male and female,
50/sex/group
0, 500, 1,500, 5,000 ppm
(0, 2,090, 6,270, 20,900 mg/m3)a
Whole body inhalation
6 hours/day, 5 days/week
104 weeks
Centrilobular Hypertrophy
JPEC(2010b)
Rats, F344, male and female,
50/sex/group
0, 500, 1,500, 5,000 ppm
(0, 2,090, 6,270, 20,900 mg/m3)a
Whole body inhalation
6 hours/day, 5 days/week
104 weeks
JPEC(2008b)
Rats, Sprague-Dawley
Male and female,
10-16/sex/group
0, 150, 500, 1,500, 5,000 ppm
(0, 627, 2,090, 6,270,
20,900 mg/m3)a
Whole body inhalation
6 hours/day, 5 days/week
13 weeks
{} = subset with 28 day recovery
after 13 week exposure
Medinskv et al. (1999)
Rats, F344, male and female
10/sex/group
0, 500, 1,750, 5,000 ppm
(0, 2,090, 7,320, 20,900 mg/m3)a
Whole body inhalation
6 hours/day, 5 days/week
13 weeks
Related reference: Bond et al.
(1996b) (unpublished study)
Results
AST, ALT, and ALP Enzymes in Liver (percent change compared to
control)
M 0 2,090 6,270 20,900
AST - 29% -16% -2%*
ALT - 53% -3% 24%
ALP - 0% -21%* -5%
F 0 2,090 6,270 20,900
AST - 22% 10% 18%*
ALT - 2% -5% 4%*
ALP - 12% -4% 4%
Centrilobular hypertrophy
Not observed
Incidence of Centrilobular hypertrophy
M 0 627 2,090 6,270 20,900
0/10 0/10 0/10 0/10 4/10* {0/6}
F 0 627 2,090 6,270 20,900
0/10 0/10 0/10 0/10 6/10* {0/6}
Centrilobular hypertrophy
Not observed
This document is a draft for review purposes only and does not constitute Agency policy,
2-16 DRAFT-DO NOT CITE OR QUOTE
-------
Preliminary Materials for the IRIS Toxicological Review ofETBE
Table 2-4. Evidence pertaining to liver effects in animals following inhalation
exposure to ETBE (continued)
Reference and study design
Medinskv et al. (1999)
Mice, CD-I, male and female
10/sex/group
0, 500, 1,750, 5,000 ppm
(0, 2,090, 7,320, 20,900 mg/m3)a
Whole body inhalation
6 hours/day, 5 days/week
13 weeks
Related reference: Bond et al.
(1996b) (unpublished study)
Weng et al. (2012)
Mice, C57BL/6, male and female
5/sex /group
0, 500, 1,750, 5,000 ppm
(0, 2,090, 7,320, 20,900 mg/m3)a
Whole body inhalation
6 hours/day, 5 days/week
13 weeks
Results
Incidence of centrilobular hypertrophy
M 0
0/15
F 0
0/13
2,090
0/15
2,090
2/15
7,320
2/15
7,320
1/15
20,900
8/10*
20,900
9/14*
Incidence of centrilobular hypertrophy
M 0
1/5
F 0
0/5
2,090
0/5
2,090
0/5
7,320
0/5
7,320
1/5
20,900
5/5*
20,900
5/5*
2 a4.18mg/m3 = lppm.
3 *Statistically significant (p < 0.05) based on analysis of data conducted by study authors.
4 Percentage change compared to control = (treated value - control value) -f control value x 100.
This document is a draft for review purposes only and does not constitute Agency policy,
2-17 DRAFT-DO NOT CITE OR QUOTE
-------
Preliminary Materials for the IRIS Toxicological Review ofETBE
1000
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a
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jiiet al., 2010;
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104 weeks
Serum Live
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M
26w
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3 o -n Gaoua 2004b; rate
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< ^ Suzuki etal., 2012;
3 ~" JPEC 2010a; rats
TO
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eeks
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* statistically significant decrease in absolute liver weight
** statistically significant decrease in AST, no statistically significantly change in ALTor ALP
Figure 2-3. Exposure-response array of liver effects following oral exposure to
ETBE.
This document is a draft for review purposes only and does not constitute Agency policy,
2-18 DRAFT-DO NOT CITE OR QUOTE
-------
Preliminary Materials for the IRIS Toxicological Review ofETBE
1000
nj
a
BO
O
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100
10
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] L
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jiiet al., 2010;
EC 2008e; rats
A f
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:
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kietal., 2012;
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1 ^ 1 ^
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104 weeks
Serum Live
(AST, A
3EC 2008c; rate
M
26w
r Enzyn
.T, ALP
3EC 2008c; rats
F
eeks
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-Ei Eh-
r
a a
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n M
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< ^ Suzuki etal., 2012;
? ~" JPEC 2010a; rats
TO
LT
00
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26w
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TO
LT
00
o
o
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a
Q.
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eeks
* statistically significant decrease in absolute liver weight
** statistically significant decrease in AST, no statistically significantly change in ALTor ALP
4
Figure 2-4. Exposure-response array of liver effects following inhalation
exposure to ETBE.
This document is a draft for review purposes only and does not constitute Agency policy,
2-19 DRAFT-DO NOT CITE OR QUOTE
-------
Preliminary Materials for the IRIS Toxicological Review ofETBE
l 2.4. Reproductive Effects
2
3
Table 2-5. Evidence pertaining to reproductive effects in animals following
oral exposure to ETBE
Reference and study design
Results
Reproductive effects
Gaoua (2004b)
Rat, Sprague-Dawley, male and
female, 25/sex/group
0, 250, 500, 1,000 mg/kg-d
Gavage
Approximately 18 wks in FO (10 wks
before mating, 2-wk
mating period, 3-wk gestation,
until weaning Fl); Fl
generation gavaged from weaning
until weaning of F2 offspring
Fuiiietal. (2010)
Rat, Sprague-Dawley, male and
female, 24/sex/group
0, 100, 300, 1,000 mg/kg-d
Gavage
16-17 week exposure to FO rats
Related reference: JPEC (2008e)
(unpublished study)
JPEC(2008h)
Rat, Sprague-Dawley, female
21-22litters/ group
0, 100, 300, 1,000 mg/kg-d
Gavage
Gestational days 5-19
FO reproductive effects (percent change compared to control)
F
Viability index PND4
Lactation index
Body weight gain (GDO-20)
Fertility index
M
Spermatazoa
0 250 500 1,000
-5% -16% 0.1%
-3% 2% 5%
2% 3% 3%
-9% -4% 9%
0 250 500 1,000
2% 1% -0.5%
FO reproductive effects (incidence)
F
Post implantation loss(%)a
Total litter loss PND 4
0 250 500 1,000
4% 6% 5% 7%
0/23 1/21 3/22 0/25
Fl reproductive effects (percent change compared to control)
F
Viability index PND 4
Lactation index
Body weight gain (GDO-20)
0 250 500 1,000
-3% -1% -5%
1% 2% 2%
-1% -3% -6%
Fl reproductive effects (incidence)
F
Post implantation loss(%)b
Total litter loss PND 4
0 250 500 1,000
4% 5% 3% 7%
0/21 1/21 0/22 1/20
FO reproductive effects (percent change compared to control)
M
Fertility index
F
Viability index PND 4
Lactation index0
Body weight gain (GDO-20)
Fertility index
0 100 300 1,000
14% 9% 5%
0 100 300 1,000
-1% 2% -10%
-1% -1% -5%
-4% 8% 12%*
14% 9% 5%
FO reproductive effects (incidence)
F
Post implantation loss(%)a
Total litter loss PND 4
0 100 300 1,000
7% 14% 11% 10%
0/21 0/22 0/23 3/22
Reproductive effects (percent change compared to control)
F
Body weight gain (GDO-20)
0 100 300 1,000
-7% -4% -7%
Reproductive effects (incidence)
F
Pre-implantation loss (%)b
Post-implantation loss(%)a
0 100 300 1,000
7% 9% 8% 12%
6% 7% 4% 5%
This document is a draft for review purposes only and does not constitute Agency policy,
2-20 DRAFT-DO NOT CITE OR QUOTE
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Preliminary Materials for the IRIS Toxicological Review ofETBE
Table 2-5. Evidence pertaining to reproductive effects in animals following
oral exposure to ETBE (continued)
Reference and study design
Gaoua (2004a)
Rats, Sprague-Dawley, female
19-22 litters/ group
0, 250, 500, 1,000 mg/kg-d
Gavage
Gestational days 5-19
Asano et al. (2011)
Rabbits, New Zealand white, female
22-24/ sex/ group
0, 100, 300, 1,000 mg/kg-d
Gavage
Gestational days 6-27
Related reference: JPEC (2008i)
(unpublished study)
de Pevster et al. (2009)
Rats, F344, male
12/sex/group
0, 600, 1,200, 1,800 mg/kg-d
Gavage
14 days
Bergerand Horner (2003)
Rats, Simonson, female
3-4/sex/group
0.3% (estimated 1,887 mg/kg-day)
Drinking water
2 weeks
Gaoua (2004b)
Rats, Sprague Dawley, male and
female,25/sex/group
0, 250, 500, 1,000 mg/kg-d
Gavage
(FO generation)
18 weeks (10 weeks before mating,
during a 2-week mating period,
3-week gestation and until after
weaning Fl)
Results
Reproductive effects (percent change compared to control)
F
Body weight gain (GD5-20)
0 250 500 1,000
-4% -3% -17%*
Reproductive effects (incidence)
F
Pre-implantation loss (%)b
Post-implantation loss(%)a
0 250 500 1,000
15% 13% 13% 14%
5% 7% 7% 8%
Reproductive effects (percent change compared to control)
F
Body weight gain (GDO-28)
Uterine weight
0 100 300 1,000
-13% 0% -38%*
4% 5% -16%
Reproductive effects (incidence)
F
Pre-implantation loss (%)b
Post-implantation loss (%)a
0 100 300 1,000
20% 15% 11% 23%
11% 11% 7% 9%
Plasma hormone levels (percent change compared to control)
M 0
Testosterone
Estradiol
600 1,200 1,800
50% 26% -34%
29% 106%* 105%*
Oocyte effects
F
Oocytes/female
Oocyte fertilized
0 1,887
30 29
84% 82%
Number of spermatozoa in
M 0
FO (Percent change compared to control)
250 500 1,000
2% 1% -0.5%
2 aPost-implantation loss = (Resorptions + dead fetus/ total implantations) x 100, calculated per litter.
3 bPre-implantation loss = (corpora lutea-implantations/corpora lutea) x 100, calculated per litter.
4 °Lactation index = (pups alive at day 21/pups at day 4) x 100; LI is the same as viability index on day 21.
5 'statistically significant (p < 0.05) based on analysis of data conducted by study authors.
6 Percentage change compared to control = (treated value - control value) -f control value x 100.
This document is a draft for review purposes only and does not constitute Agency policy,
2-21 DRAFT-DO NOT CITE OR QUOTE
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Preliminary Materials for the IRIS Toxicological Review ofETBE
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-------
Preliminary Materials for the IRIS Toxicological Review ofETBE
l 2.5. Body Weight Effects
2
3
Table 2-6. Evidence pertaining to body weight effects in animals following
oral exposure to ETBE
Reference and study design
Body Weight
Suzuki et al. (2012)
Rats, F344, male and female,
50/sex/group
0, 625, 2,500, 10,000 ppm
(0, 28, 121, 542 mg/kg-d in males;
0, 46, 171, 560 mg/kg-d in females)3
Drinking water
104 weeks
Related reference: JPEC (2010a)
(unpublished study)
JPEC(2008c)
Rats, Sprague-Dawley
Male and female, 15/sex/group
0, 5, 25, 100, 400 mg/kg-day
Gavage
26 weeks (180 consecutive days)
Hagiwara et al. (2011)
Rats, F344, male, 12/group
Gavage 0, 1,000 mg/kg-day
23 weeks
Related reference: JPEC (2008d)
(unpublished study)
Gaoua (2004b)
Rats, Sprague-Dawley,
Male and female, 25/sex/group
0, 250, 500, 1,000 mg/kg-day
Gavage
(FO generation)
18 weeks (10 weeks before mating,
during a 2-week mating period,
3-week gestation and until after
weaning Fl)
Results
Body weight (percent change compared to control)
MO 28 121
-5% -7%*
F 0 46 171
-10*% -11*%
Body weight (percent change compared to control)
MO 5 25 100
-6% 0% -6%
F 0 5 25 100
-5% -2% -2%
Body weight (percent change compared to control)
-5%*
Body weight (percent change compared to control)
M 0 250 500
-1% -3%
F 0 250 500
-7% -2%
542
-10*%
560
-17*%
400
2%
400
-3%
1,000
-5%*
1,000
0%
This document is a draft for review purposes only and does not constitute Agency policy,
2-23 DRAFT-DO NOT CITE OR QUOTE
-------
Preliminary Materials for the IRIS Toxicological Review ofETBE
Table 2-6. Evidence pertaining to body weight effects in animals following
oral exposure to ETBE (continued)
Reference and study design
Fuiiietal. (2010)
Rats, Sprague-Dawley,
Male and female, 24/sex/group
0, 100, 300, 1,000 mg/kg-day
Gavage
16 weeks (males),
17 weeks (females)
Related reference: JPEC (2008e)
(unpublished study)
Results
FO generation body weight (percent change compared to control)
M
F
0 100
-4%
0 100
1%
300 1,000
-4% -7%
300 1,000
1% 5%
Fl generation body weight (percent change compared to control)
M
F
0 100
2%
0 100
-1%
300 1,000
0% 1%
300 1,000
-3% -2%
1
2
3
4
5
Conversion performed by study authors.
'statistically significant (p < 0.05) based on analysis of data conducted by study authors.
Percentage change compared to control = (treated value - control value) -f control value x 100.
This document is a draft for review purposes only and does not constitute Agency policy,
2-24 DRAFT-DO NOT CITE OR QUOTE
-------
Preliminary Materials for the IRIS Toxicological Review ofETBE
1
2
Table 2-7. Evidence pertaining to body weight effects in animals following
inhalation exposure to ETBE
Reference and study design
Body Weight
JPEC(2010b)
Rat, F344, male and female,
50 /sex/group
0, 500, 1,500, 5,000 ppm
(0, 2,090, 6,270, 20,900 mg/m3)a
Whole body inhalation
6 hours/day, 5 days/week
104 weeks
JPEC(2008b)
Rats, Sprague-Dawley
Male and female, 10-16/sex/group
0, 150, 500, 1,500, 5,000 ppm
(0, 627, 2,090, 6,270, 20,900
mg/m3)a
Whole body inhalation
6 hours/day, 5 days/week
13 weeks
{} = subset with 28 day recovery
after 13 week exposure
Medinskv et al. (1999)
Rats, F344, male and female
10/sex/group
0, 500, 1,750, 5,000 ppm
(0, 2,090, 7,320, 20,900 mg/m3)a
Whole body inhalation
6 hours/day, 5 days/week
13 weeks
Related reference: Bond et al.
(1996b) (unpublished study)
Medinskv et al. (1999)
Mice, CD-I, male and female
10/sex/group
0, 500, 1,750, 5,000 ppm
(2,090, 7,320, 20,900 mg/m3)a
Whole body inhalation
6 hours/day, 5 days/week
13 weeks
Related reference: Bond et al.
(1996a) (unpublished study)
Results
Body weight (percent change compared to control)
M 0 2,090 6,270
-7%* -7%*
F 0 2,090 6,270
-6%* -10%*
Body weight (percent change compared to control)
M 0 627 2,090 6,270
0% 1% -1%
F 0 627 2,090 6,270
-2% -4% -3%
Body weight (percent change compared to control)
M 0 2,090 7,320
2% 5%
F 0 2,090 7,320
-3% 3%
Body weight (percent change compared to control)
M 0 2,090 7,320
-1% -1%
F 0 2,090 7,320
-3% -1%
20,900
-26%*
20,900
-23%*
20,900
-6% {3%}
20,900
-6% {3%}
20,900
2%
20,900
6%*
20,900
-3%
20,900
2%
3
4
5
6
7
a4.18 mg/m3 = 1 ppm.
Statistically significant (p < 0.05) based on analysis of data conducted by study authors.
Percentage change compared to control = (treated value - control value) 4- control value x 100.
This document is a draft for review purposes only and does not constitute Agency policy,
2-25 DRAFT-DO NOT CITE OR QUOTE
-------
Preliminary Materials for the IRIS Toxicological Review ofETBE
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Preliminary Materials for the IRIS Toxicological Review ofETBE
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Medinskyet al., 1999;
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'statistically significant increase in body weight
2
3
4
Figure 2-7. Exposure-response array of body weight effects following
inhalation exposure to ETBE.
This document is a draft for review purposes only and does not constitute Agency policy,
2-27 DRAFT-DO NOT CITE OR QUOTE
-------
Preliminary Materials for the IRIS Toxicological Review ofETBE
l 2.6. Other Systemic Effects
2
3
Table 2-8. Evidence pertaining to other systemic effects in animals following
oral exposure to ETBE
Reference and study design
Results
Immunological Studies
Banton et al. (2011)
Rats, Sprague-Dawley, female,
10/group
0, 250, 500, 1,000 mg/kg-day
Gavage
28 consecutive days
Antibody response (percent change compared to control)
0 250 500
IgM antibody - -21% 42%
forming cells
1,000
8%
Spleen Weight
Suzuki et al. (2012)
Rats, F344, male and female,
50/sex/group
0, 625, 2,500, 10,000 ppm
(0, 28, 121, 542 mg/kg-d in males;
0, 46, 171, 560 mg/kg-d in females)3
Drinking water
104 weeks
Related reference: JPEC (2010a)
(unpublished study)
Hagiwara et al. (2011)
Rats, F344, male, 12/group
Gavage 0, 1,000 mg/kg-day
23 weeks
Related reference: JPEC (2008d)
(unpublished study)
Gaoua (2004b)
Rats, Sprague-Dawley,
Male and female, 25/sex/group
0, 250, 500, 1,000 mg/kg-day
Gavage
(FO generation)
18 weeks (10 weeks before mating,
during a 2-week mating period,
3-week gestation and until after
weaning Fl)
Banton et al. (2011)
Rats, Sprague-Dawley, female,
10/group
0, 250, 500, 1,000 mg/kg-day
Gavage
28 consecutive days
Absolute spleen weight (percent change compared to control)
MO 28 121
-3% 19%
F 0 46 171
-35% -0.6%
Relative spleen weight (percent change compared to
MO 28 121
2% 28%
F 0 46 171
-35% 3%*
542
39%
560
-50%*
control)
542
55%*
560
-45%
Absolute spleen weight (percent change compared to control)
-5%
Relative spleen weight (percent change compared to
control)
0%
Absolute spleen weight (percent change compared to control)
M 0 250 500
2% 2%
F 0 250 500
-4% -2%
Relative spleen weight (percent change compared to
M 0 250 500
3% 6%
F 0 250 500
4% 1%
1,000
0%
1,000
-3%
control)
1,000
6%
1,000
-6%
Absolute spleen weight (percent change compared to control)
0 250 500
-3% -15%
1,000
-9%
This document is a draft for review purposes only and does not constitute Agency policy,
2-28 DRAFT-DO NOT CITE OR QUOTE
-------
Preliminary Materials for the IRIS Toxicological Review ofETBE
Table 2-8. Evidence pertaining to other systemic effects in animals following
oral exposure to ETBE (continued)
Reference and study design
Results
Adrenal Weight
Suzuki etal. (2012)
Rats, F344, male and female,
50/sex/group
0, 625, 2,500, 10,000 ppm
(0, 28, 121, 542 mg/kg-d in males;
0, 46, 171, 560 mg/kg-d in females)3
Drinking water
104 weeks
Related reference: JPEC (2010a)
(unpublished study)
Gaoua (2004b)
Rats, Sprague-Dawley,
Male and female, 25/sex/group
0, 250, 500, 1,000 mg/kg-day
Gavage
(FO generation)
18 weeks (10 weeks before mating,
during a 2-week mating period,
3-week gestation and until after
weaning Fl)
Absolute adrenal weight (percent change compared to control)
M
F
0 28 121
5% 5%
0 46 171
-7%* 6%
Relative adrenal weight (percent change compared to
M
F
0 28 121
9% 9%*
0 46 171
4% 19%*
542
79%
560
-8%*
control)
542
105%*
560
11%*
Absolute adrenal weight (percent change compared to control)
M
F
0 250 500
15%* 13%*
0 250 500
-3% 5%
Relative adrenal weight (percent change compared to
M
F
0 250 500
16%* 17%*
0 250 500
6% 6%
1,000
27%*
1,000
6%
control)
1,000
34%*
1,000
4%
Mortality
Suzuki et al. (2012)
Rats, F344, male and female,
50/sex/group
0, 625, 2,500, 10,000 ppm
(0, 28, 121, 542 mg/kg-d in males;
0, 46, 171, 560 mg/kg-d in females)3
Drinking water
104 weeks
Related reference: JPEC (2010a)
(unpublished study)
Survival (percent change compared to control)
M
F
0 28 121
-3% -11%
0 46 171
3% 6%
542
-11%
560
6%
1
2
3
4
5
Conversion performed by study authors.
'statistically significant (p < 0.05) based on analysis of data conducted by study authors.
Percentage change compared to control = (treated value - control value) -f control value x 100.
This document is a draft for review purposes only and does not constitute Agency policy,
2-29 DRAFT-DO NOT CITE OR QUOTE
-------
Preliminary Materials for the IRIS Toxicological Review ofETBE
1
2
Table 2-9. Evidence pertaining to other systemic effects in animals following
inhalation exposure to ETBE
Reference and study design
Results
Immunological Studies
Li et al. (2011)
Mice, C57BL/6 and 129/SV
male, 5-6/group
0, 500, 1,750, 5,000 ppm
(0, 2,090, 7,320, 20,900 mg/m3)a
Whole body inhalation
6 hours/day, 5 days/week
6 or 13 weeks
Weng et al. (2011)
Mice Aldh2-/- and wt C57BL/6
male and female, 5/group
0, 500, 1,750, 5,000 ppm
(0, 2,090, 7,320, 20,900 mg/m3)a
Number of CD3+, CD4+, and CD8+ splenic T cells in C57BL/6 (percent
change compared to control)
6 weeks 0 2,090 7,320 5,000
CD3+ - -14% -13% -24%*
CD4+ - -15% -11% -23%
CD8+ - -12% -13%* -23%*
13 weeks 0 2,090 7,320 5,000
CD3+ - -9% -17%* -24%*
CD4+ - 11% -28%* -37%*
CD8+ - -8% -12% 20%
Leukocyte DNA damage in Aldh2-/- (percent change compared to
control)
M
F
0 2,090 7,320 20,900
35%* 61%* 74%*
0 2,090 7,320 20,900
9% 34% 56%*
Whole body inhalation
6 hours/day, 5 days/week
13 weeks
Spleen Weight
JPEC(2010b)
Rat, F344, male and female,
50 /sex/group
0, 500, 1,500, 5,000 ppm
(0, 2,090, 6,270, 20,900 mg/m3)a
Whole body inhalation
6 hours/day, 5 days/week
104 weeks
JPEC(2008b)
Rats, Sprague-Dawley
Male and female, 10-16/sex/group
0, 150, 500, 1,500, 5,000 ppm
(0, 627, 2,090, 6,270, 20,900
mg/m3)a
Whole body inhalation
6 hours/day, 5 days/week
13 weeks
{} = subset with 28 day recovery
after 13 week exposure
Absolute spleen weight (percent change compared to control)
M
F
0 2,090 6,270 2,090
4% 32% 17%
0 2,090 6,270 2,090
5% -39% -43%*
Relative spleen weight (percent change compared to control)
M
F
0 2,090 6,270 2,090
15% 43%* 66%*
0 2,090 6,270 2,090
30% -31% -25%
Absolute spleen weight (percent change compared to control)
M
F
0 627 2,090 6,270 20,900
-0.4% 7% -1% -9% {10%}
0 627 2,090 6,270 20,900
-9% -2% -5% -1%{6%}
Relative spleen weight (percent change compared to control)
M
F
0 627 2,090 6,270 20,900
0% 5% 1% -2% {6%}
0 627 2,090 6,270 20,900
-3% 5% 1% 12% {0%}
This document is a draft for review purposes only and does not constitute Agency policy,
2-30 DRAFT-DO NOT CITE OR QUOTE
-------
Preliminary Materials for the IRIS Toxicological Review ofETBE
Table 2-9. Evidence pertaining to other systemic effects in animals following
inhalation exposure to ETBE(continued)
Reference and study design
Medinskv et al. (1999)
Rats, F344, male and female
10/sex/group
0, 500, 1,750, 5,000 ppm
(2,090, 7,320, 20,900 mg/m3)a
Whole body inhalation
6 hours/day, 5 days/week
13 weeks
Related reference: Bond et al.
(1996b) (unpublished study)
Medinskv et al. (1999)
Mice, CD-I, male and female
10/sex/group
0, 500, 1,750, 5,000 ppm
(2,090, 7,320, 20,900 mg/m3)a
Whole body inhalation
6 hours/day, 5 days/week
13 weeks
Related reference: Bond et al.
(1996a) (unpublished study)
Results
Absolute spleen weight (percent change compared to
M
F
0 2,090 7,320
6% 3%
0 2,090 7,320
-3% 3%
control)
20,900
5%
20,900
0%
Absolute spleen weight (percent change compared to
M
F
0 2,090 7,320
-5% 0%
0 2,090 7,320
-11% -2%
control)
20,900
-15%
20,900
-11%
Adrenal Weight
JPEC(2010b)
Rat, F344, male and female,
50 /sex/group
0, 500, 1,500, 5,000 ppm
(0, 2,090, 6,270, 20,900 mg/m3)a
Whole body inhalation
6 hours/day, 5 days/week
104 weeks
JPEC(2008b)
Rats, Sprague-Dawley
Male and female, 10-16/sex/group
0, 150, 500, 1,500, 5,000 ppm
(0, 627, 2,090, 6,270, 20,900
mg/m3)a
Whole body inhalation
6 hours/day, 5 days/week
13 weeks
Absolute adrenal weight (percent change compared to control)
M
F
0 2,090 6,270
-42% -55%
0 2,090 6,270
-7% -13%*
Relative adrenal weight (percent change compared to
M
F
0 2,090 6,270
-35% -52%
0 2,090 6,270
-3% -6%
20,900
-49%
20,900
-9%
control)
20,900
-33%*
20,900
16%*
Absolute adrenal weight (percent change compared to control)
M
F
0 627 2,090 6,270
11% 8% 5%
0 627 2,090 6,270
-0.4% -4% 2%
Relative adrenal weight (percent change compared to
M
F
0 627 2,090 6,270
11% 7% 7%
0 627 2,090 6,270
6% 2% 9%
20,900
10%
20,900
-4%
control)
20,900
18%*
20,900
7%
This document is a draft for review purposes only and does not constitute Agency policy,
2-31 DRAFT-DO NOT CITE OR QUOTE
-------
Preliminary Materials for the IRIS Toxicological Review ofETBE
Table 2-9. Evidence pertaining to other systemic effects in animals following
inhalation exposure to ETBE(continued)
Reference and study design
Medinskv et al. (1999)
Rats, F344, male and female
10/sex/group
0, 500, 1,750, 5,000 ppm
(2,090, 7,320, 20,900 mg/m3)a
Whole body inhalation
6 hours/day, 5 days/week
13 weeks
Related reference: Bond et al.
(1996b) (unpublished study)
Medinskv et al. (1999)
Mice, CD-I, male and female
10/sex/group
0, 500, 1,750, 5,000 ppm
(2,090, 7,320, 20,900 mg/m3)a
Whole body inhalation
6 hours/day, 5 days/week
13 weeks
Related reference: Bond et al.
(1996a) (unpublished study)
Mortality
JPEC(2010b)
Rat, F344, male and female,
50 /sex/group
0, 500, 1,500, 5,000 ppm
(0, 2,090, 6,270, 20,900 mg/m3)a
Whole body inhalation
6 hours/day, 5 days/week
104 weeks
Results
Absolute adrenal weight (percent change compared
M 0 2,090 7,320
11% 9%
F 0 2,090 7,320
7% 7%
Absolute adrenal weight (percent change compared
M 0 2,090 7,320
0% 50%
F 0 2,090 7,320
-8% 8%
Survival rate
M 0 2,090 6,270
88% 76% 80%
F 0 2,090 6,270
76% 78% 60%*
to control)
20,900
34%*
20,900
18%*
to control)
20,900
0%
20,900
-8%
20,900
60%*
20,900
60%*
1
2
3
4
5
a4.18 mg/m3 = 1 ppm.
Statistically significant (p < 0.05) based on analysis of data conducted by study authors.
Percentage change compared to control = (treated value - control value) 4- control value x 100.
This document is a draft for review purposes only and does not constitute Agency policy,
2-32 DRAFT-DO NOT CITE OR QUOTE
-------
Preliminary Materials for the IRIS Toxicological Review ofETBE
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3
Figure 2-8. Exposure-response array of other systemic effects following oral
exposure to ETBE.
This document is a draft for review purposes only and does not constitute Agency policy,
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Preliminary Materials for the IRIS Toxicological Review ofETBE
100,000 a
10,000 :
BO
.§ 1,000
c
o
«
100
10
13
weeks
CD3+
statistically significantly changed
D not statistically significantly changed
13 weeks
Leukocyte
DMA
damage
104 weeks
M&F M&F M&F
13 weeks
4- Absolute spleen weight
Immunological effects
M F
104 weeks
MEM
13 weeks
T" Absolute adrenal weight
a!
si
11
a
M F
13 weeks
M F
104 weeks
Mortal ty
4
Figure 2-9. Exposure-response array of other systemic effects following
inhalation exposure to ETBE.
This document is a draft for review purposes only and does not constitute Agency policy,
2-34 DRAFT-DO NOT CITE OR QUOTE
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Preliminary Materials for the IRIS Toxicological Review ofETBE
l 2.7. Carcinogenic Effects
2
3
Table 2-10. Evidence pertaining to carcinogenic effects in animals exposed to
ETBE
Reference and study design
Results
Neoplastic lesions
Suzuki et al. (2012)
Rats, F344, male and female,
50/sex/group
0, 625, 2,500, 10,000 ppm
(0, 28, 121, 542 mg/kg-d in males;
0, 46, 171, 560 mg/kg-d in females)3
Drinking water
104 weeks
Related reference: JPEC (2010a)
(unpublished study)
Maltoni et al. (1999)
Rats, Sprague-Dawley,
Male and female, 60/sex/group
0, 250, 1,000 mg/kg-d
Gavage
104 weeks
Hagiwara et al. (2011)
Rats, F344, male
30/sex/group
0, 300, 1,000 mg/kg-d
Gavage
23 weeks following a 4 week tumor
initiation with DMBDD
JPEC(2010b)
Rats, F344, male and female,
50/sex/group
0, 500, 1,500, 5,000 ppm
(0, 2,090, 6,270, 20,900 mg/m3)b
Whole body inhalation
6 hours/day, 5 days/week
104 weeks
Neoplasms
No treatment related effects
Incidence of uterine malignancies
F 0 250
2/60 10/60*
1,000
2/60
Incidence of mouth epithelium tumors
M 0 250
6/60 14/60
1,000
15/60*
Incidence of neoplastic lesions
M
Thyroid
Forestomach
Colon
Liver
Kidney
0 300
8/30 17/30*
0/30 4/30
25/30 21/30
1/30 1/30
11/30 6/30
1,000
20/30*
3/30
28/30*
6/30*
13/30
Incidence of hepatocellular adenomas and carcinomas
M 0
0/50
F 0
1/50
2,090 6,270
2/50 1/49
2,090 6,270
0/50 1/50
20,900
10/50*
20,900
1/50
Preneoplastic lesions
JPEC(2010b)
Rats, F344, male and female,
50/sex/group
0, 500, 1,500, 5,000 ppm
(0, 2,090, 6,270, 20,900 mg/m3)b
Whole body inhalation
6 hours/day, 5 days/week
104 weeks
Incidence of acidophilic and basophilic foci in liver
M
Acidophilic
Basophilic
F
Acidophilic
Basophilic
0 2,090 6,270
31/50 28/50 36/49
18/50 10/50 13/49
0 2,090 6,270
2/50 1/50 4/50
36/50 31/50 32/50
20,900
39/50*
33/50*
20,900
2/50
28/50
4 Conversion performed by study authors.
5 b4.18mg/m3 = lppm.
This document is a draft for review purposes only and does not constitute Agency policy,
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Preliminary Materials for the IRIS Toxicological Review ofETBE
Statistically significant (p < 0.05) based on analysis of data conducted by study authors.
1000
re
7
M
.a:
M
£
LU ^ LJJ
«b > '5b >
D ro
: x
1 M
er Kidney
on with DMBDD
4
5
Figure 2-10. Exposure-response array of carcinogenic effects following oral
exposure to ETBE.
This document is a draft for review purposes only and does not constitute Agency policy,
2-36 DRAFT-DO NOT CITE OR QUOTE
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Preliminary Materials for the IRIS Toxicological Review ofETBE
100,000
^
U)
o
-------
Preliminary Materials for the IRIS Toxicological Review ofETBE
l 2.8. Genotoxic Effects
2
3
Table 2-11. Evidence pertaining to genotoxic effects in animals exposed to
ETBE
Reference and study design
Results
Micronucleus assays
JPEC(2007c)
Rats, F344,
Male and female, 10/sex/group
0, 1,600, 4,000, 10,000 ppm
(0, 101, 259, 626 mg/kg-d in males;
0, 120, 267, 629 mg/kg-d in
females)3
Drinking water
13 weeks
JPEC(2007d)
Rats, F344
Male and female, 10/sex/group
0, 500, 1,500, 5,000 ppm
(0, 2,090, 6,270, 20,900 mg/m3)b
Whole body inhalation
6 hours/day, 5 days/week
13 weeks
JPEC(2007a)
Rats, F344
Male and female, 5/sex/group
0, 500, 1,000, 2,000 mg/kg-d
Gavage
2 doses, 24 hr apart
2 days
Frequency of micronucleated polychromatic erythrocytes
M
F
0 101
0.2 0.2
0 120
0.1 0.2
259 626
0.1 0.2
267 629
0.1 0.1
Ratio of polychromatic erythrocytes / erythrocytes
M
F
0 101
24 26
0 120
24 25
259 626
25 24
267 629
25 24
Frequency of micronucleated polychromatic erythrocytes
M
F
0 2,090
0.1 0.2
0 2,090
0.2 0.2
Ratio of polychromatic erythrocytes /
M
F
0 2,090
23 24
0 2,090
24 23
6,270 20,900
0.2 0.2
6,270 20,900
0.2 0.2
erythrocytes
6,270 20,900
24 24
6,270 20,900
25 25
Frequency of micronucleated polychromatic erythrocytes
M
F
0 500
0.1 0.1
0 500
0.1 0.1
1,000 2,000
0.2 0.1
1,000 2,000
0.1 0.1
Ratio of polychromatic erythrocytes / erythrocytes
M
F
0 500
22 22
0 500
21 21
1,000 2,000
23 23
1,000 2,000
20 26
This document is a draft for review purposes only and does not constitute Agency policy,
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Preliminary Materials for the IRIS Toxicological Review ofETBE
JPEC(2007b)
Rats, F344
Male and female, 5/sex/group
0, 250, 500, 1,000 mg/kg-d
Intraperitoneal injection
2 doses, 24 hr apart
2 days
Frequency of micronucleated polychromatic erythrocytes
M
F
0 250 500 1,000
0.1 0.1 0.1 0.2
0 250 500 1,000
0.1 0.2 0.1 0.1
Ratio of polychromatic erythrocytes / erythrocytes
M
F
0 250 500 1,000
26 27 28 25
0 250 500 1,000
23 26 27 30
Micronucleus assays
Vergnesand Kubena (1995b)
Mice, CD-I
Male and female, 5/sex/group
0, 400, 2,000, 5,000 ppm
(0, 1,670, 8,360, 20,900 mg/m3)b
Whole body inhalation
6 hours/day for 5 days
Frequency of micronucleated polychromatic erythrocytes
M
F
0 1,670 8,360 20,900
0.2 0.2 0.2 0.2
0 1,670 8,360 20,900
0.2 0.1 0.1 0.2
Mean polychromatic erythrocytes / 1,000 erythrocytes (% of control)
M
F
0 1,670 8,360 20,900
99% 95% 92%
0 1,670 8,360 20,900
100% 96% 97%
1
2
3
4
5
6
Conversion performed by study authors.
b4.18 mg/m3 = 1 ppm.
Statistically significant (p < 0.05) based on analysis of data conducted by study authors.
Percentage change compared to control = (treated value - control value) 4- control value x 100.
This document is a draft for review purposes only and does not constitute Agency policy,
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Preliminary Materials for the IRIS Toxicological Review ofETBE
Table 2-12. Summary of in vitro studies of ETBE genotoxicity
Endpoint
Test system
Dose/
concentration3
Resultsb
Without
activation
With
activation
Comments
Reference
Genotoxicity studies in prokaryotic organisms
Reverse
mutation
SOS repair
induction
Salmonella
typhimurium
(TA97, TA98,
TA100, TA1535)
ND
10,000
u.g/plate
Zeiger et al.
(1992)
Genotoxicity studies in nonmammalian eukaryotic organisms
Mutation
Recombination
induction
Chromosomal
aberration
Chromosomal
malsegregation
Mitotic arrest
ND
ND
ND
ND
ND
Genotoxicity studies in mammalian cells in vitro
Mutation
Chromosomal
aberrations
Sister chromatid
exchange (SCE)
DNA damage
DNAadducts
Chinese hamster
ovary (HGPRT)
Chinese hamster
ovary
ND
ND
ND
5 mg/mL
5 mg/mL
-
-
Vergnes and
Kubena
(1995a)
Vergnes
(1995)
Genotoxicity studies in subcellular systems
DNA binding
ND
2
3
4
5
aLowest effective dose for positive results, highest dose tested for negative results.
b+ = positive, ± = equivocal or weakly positive, - = negative, T = cytotoxicity, NA = not applicable, ND = no data.
This document is a draft for review purposes only and does not constitute Agency policy,
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