RTI-908; Project 0209189.000 Final Report 

Table of Contents 

Page

QUALITY ASSURANCE STATEMENT ........................................................................... iii 

GLP Compliance Statement ............................................................................................ v 

SUMMARY....................................................................................................................... 1 

INTRODUCTION ............................................................................................................. 1 

MATERIALS AND METHODS ......................................................................................... 2 

 Designation of Responsibilities.................................................................................. 2 

 Test Material............................................................................................................... 3

 Animals and Husbandry ............................................................................................. 4 

 Table A. Study Schedule........................................................................................... 4 

 Study Design .............................................................................................................. 7 

 Table B. Number of Animals Assigned to Study Groups........................................... 7 

 Statistics..................................................................................................................... 10 

 Storage of Records .................................................................................................... 10 

 Personnel ................................................................................................................... 11 

RESULTS ........................................................................................................................ 11 

Test Chamber Analyses ............................................................................................. 11 

Maternal Findings....................................................................................................... 12 

Uterine and Embryofetal Findings .............................................................................. 13 

DISCUSSION................................................................................................................... 14 

CONCLUSION ................................................................................................................. 16 

REFERENCES ................................................................................................................ 17 

List of Protocol Deviations ............................................................................................... 19 

Appendices

Appendix I: Inhalation Report 

Appendix II: Individual Animal Data Tables 

Appendix III: Protocol and 2 Amendments 

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RTI-908; Project 0209189.000 Final Report 

List of Tables 

Page

Table 1 Chamber Monitoring Results.......................................................................... 20 

Table 2 Summary and Statistical Analysis of the Maternal Body Weights, Weight 

 Changes, Organ Weights and Relative Organ Weights................................. 21 

Table 3 Summary and Statistical Analysis of the Maternal Feed Consumption.......... 25 

Table 4 Summary of the Maternal Clinical Observations ............................................ 28 

Table 5 Summary and Statistical Analysis of Ovarian Corpora Lutea, Uterine 

 Contents, Live Fetal Sex, and Live Fetal Body Weight .................................. 29 

Table 6 Summary and Statistical Analysis of Malformations and Variations............... 32 

Table 7 Summary of Morphological Abnormalities in CD-1 Mouse Fetuses: 

 Listing by Defect Type.................................................................................... 33 

Table 8 External Malformations in Control CD-1® Mouse Litters From Studies 

 Performed for Governmental Clients at RTI From 1997 to 2002.................... 34 

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RT1-908; Project 0209189.000 Final Report 

GLP COMPLIANCE STATEMENT 

This study was conducted in accordance with CFR Title 40, Vol. 16, Chapter 1, Subpart 

F, Paragraph 79.60 (U.S. EPA, 1994), and performed according to the protocol (and two 

amendments) and following the SOPs of HLS and RTI. This study complied with all appropriate 

parts of the USDA Animal Welfare Act regulations: 9 CFR Parts 1 and 2 Final Rules, Federal 

Register, Vol. 54, No. 168, August 31,1989, pp. 36112-36163, effective October 30,1989, and 9 

CFR Part 3 Animal Welfare Standards; Final Rule, Federal Register, Volume 55, No. 32, 

February 15,1991, pp. 6426-6505, effective March 18, 1991, and U.S. EPA TSCA GLPs (U.S. 

EPA, 1989). 

It was the Sponsor's responsibility to maintain the method of synthesis, fabrication, or 

derivation of the test fuel, and this was not completed at the time of the study conduct but has 

been completed since and is on file with the Sponsor. 

Roclfelle W. Tyl, Ph.D., DABt/ Date Study Director 

iomasM. Gray,^ / pate 

'Sponsor's Repr 
RTI-908; Project 0209189.000 Final Report 

SUMMARY 

 The purpose of this range-finding study was to determine a tolerable exposure level of 

Gasoline MTBE Vapor Condensate (G/MTBE) in pregnant CD-1 mice in order to identify an 

appropriate high exposure level for a subsequent developmental toxicity study. A previous 

developmental toxicity study conducted at another laboratory demonstrated that pregnant mice 

tolerated exposures of G/MTBE vapor condensate up to 20,000 mg/m3

 on gestation days (gd) 5 

through 16; this study provided suggestive evidence of an increase (not exposure-related) in 

midline defects among the offspring (EMBSI, 2009). In the present range-finding study, groups 

of pregnant CD-1 female mice were exposed to 0 or 30,000 mg/m3 of G/MTBE vapor condensate 

for 6 hours per day on gd 5 through 10. This 6-day exposure regimen was selected since 

exposing the dams to a higher concentration during the critical period of susceptibility for 

midline effects would maximize the opportunity to confirm whether G/MTBE causes an increase 

in midline defects. 

In this range-finding study, there were no deaths or moribund animals in either group of 

pregnant mice. The only clinical sign observed among the dams exposed to 30,000 mg/m3 of 

G/MTBE was lethargy. Embryofetal survival, growth, and development were not significantly 

affected by exposure to 30,000 mg/m3 of G/MTBE. Based on the results of this range-finding 

study, the pregnant CD-1 females and their offspring could tolerate inhalation exposure to 

30,000 mg/m3

 on gd 5 through 10. It was therefore recommended that the definitive 

developmental toxicity study of G/MTBE should proceed with 25 plug-positive females/group at 

0, 2,000, 10,000, and 20,000 mg/m3

 target concentration, with exposures on gd 5 through 16, and 

40 plug-positive females at 30,000 mg/m3 target concentration, with exposures on gd 5 through 

10. 

INTRODUCTION 

G/MTBE is a fraction of the most volatile components of a gasoline containing methyl 

tertiary butyl ether (MTBE) that was specially formulated to meet the specifications of the U.S. 

Alternative Tier 2 testing requirements (U.S. EPA, 1998a). To mimic real world human 

exposures, G/MTBE was produced by a method designed to produce a test substance reasonably 

similar in composition to the vapor produced in a vehicle fuel tank head space near the maximum 

in use temperature of 130°F (Daughtrey et al., 2004). 

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RTI-908; Project 0209189.000 Final Report 

Developmental toxicity evaluations of G/MTBE by inhalation exposure to rats and one 

other species were mandated by a final notification letter issued under the Alternative Tier 2 

testing provision of the fuels and fuel additives health effects testing regulation (U.S. EPA, 

1998b). The conduct and design of the studies were further proscribed by special and general 

EPA guidelines (U.S. EPA, 1994 and 1998c). 

One of the developmental studies conducted involved whole-body inhalation exposure of 

timed-pregnant CD-1® mice for at least 6 hours/day to baseline gasoline vapor condensate, 

containing approximately 25.5% MTBE, at target concentrations of 0, 2000, 10,000, and 20,000 

mg/m3 of G/MTBE (the last is 50% of the lower explosive limit) on gd 5 through 16 (EMBSI, 

2009). This study was conducted to confirm and extend the findings observed in that earlier 

study, in which suggestive evidence of an increase (not exposure-related) in midline defects was 

observed among the offspring. 

 The purpose of this range-finding study was to determine a tolerable exposure level of 

G/MTBE in pregnant CD-1 mice in order to identify an appropriate high exposure level for a 

subsequent developmental toxicity study. In the present range-finding study, groups of 

pregnant CD-1 female mice were exposed to 0 or 30,000 mg/m3 of G/MTBE for 6 hours per 

day on gd 5 through 10. This 6-day exposure regimen was selected since exposing the dams to 

a higher concentration during the critical period of susceptibility for midline effects would 

maximize the opportunity to confirm whether G/MTBE causes an increase in midline defects. 

Fetal malformations of specific interest in this study, ventral wall closure defects, are formed 

early in the embryonic period of gestation, gd 7-9 in the mouse (e.g., Rugh, 1968). 

MATERIALS AND METHODS 

Designation of Responsibilities

RTI International was responsible for study design, protocol generation, setting up mating 

and assignment of plug-positive study females, necropsy of the maternal and fetal animals on gd 

17, generation of summary and individual data tables, and study draft and final reports (with RTI 

QA oversight). RTI’s Quality Assurance Unit performed a prestudy on-site inspection, reviewed 

the protocol and any amendments, and monitored all phases of the study in which RTI personnel 

participated. Huntingdon Life Sciences was responsible for receipt of the test material, prestudy 

and study generation and analyses of the test vapors, receipt, quarantine, and housing of the test 

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RTI-908; Project 0209189.000 Final Report 

females and breeder males, setting up the mating and assignment of the study females, in-life 

observations, loading and unloading study females into and out of chambers, and submission of 

interim and final inhalation reports. The Quality Assurance Unit of HLS reviewed the protocol 

and monitored the facilities, equipment, personnel, methods, practices, records, raw data, draft 

and final inhalation reports, and controls used in this study to assure that they were in 

conformance with company standard operating procedures and the referenced Good Laboratory 

Practice (GLP) regulations. 

Test Material

 The test material, G/MTBE (MRD-00-713; “API 211BG with MTBE Vapor 

Condensate”), was a colorless liquid and identified by the supplier (Chevron Global Technology 

Services Company (CRTC, Richmond, CA) as Lot/Batch Number API 00-02. Methods of 

synthesis, fabrication, or derivation were documented by the Sponsor and located at API. 

Information on identity, strength, purity, and composition of G/MTBE was provided by the 

Sponsor and documented in the raw data and in this final report (Appendix III, protocol 

attachment). 

Two separate types of chemical analysis were performed on the test material. CRTC 

conducted proprietary characterization of all 120 components. ExxonMobil Biomedical Sciences, 

Inc. (EMBSI) conducted a GLP-compliant characterization of 18 representative hydrocarbons and 

MTBE. In the CRTC method, the weight percent of each of the components was measured, whereas 

in the EMBSI method, the relative amount of each of the representative components was measured 

on area-percent basis. 

EMBSI developed their method for API to share with CRTC and the laboratories performing 

toxicological studies on 211(b) testing program test substances. The objective of the method was to 

monitor and document the chemical and compositional stability of G/MTBE from manufacture 

through transportation, storage, and animal exposure using a standard method that all users could 

perform. 

The test material was stable and stored under ambient conditions in an outside solvent shed 

except when in use in the inhalation laboratory. The test substance was handled as a flammable 

liquid. Detailed information on chemical handling is provided in the MSDS attached to the 

protocol (Appendix III). 

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RTI-908; Project 0209189.000 Final Report 

Animals and Husbandry

 The test animals were Caesarean-originated Virus Antibody Free (VAF) Crl:CD-1®

(ICR) BR outbred albino mice supplied by Charles River Laboratories, Inc., Raleigh, NC. The 

use of live animals was requested by the Sponsor and required by U.S. EPA OPPTS Testing 

Guidelines (U.S. EPA, 1998c). Alternative test systems are not available for the assessment of 

chemical effects on prenatal mammalian development. The Charles River CD-1® mouse has 

been the subject of choice on developmental toxicology contracts at RTI since 1976. Large 

historical databases for reproductive performance and prevalence of spontaneous malformations 

in control mice are available from studies conducted at RTI (currently based on over 288 control 

litters and over 3600 fetuses [Table 8]). Thus, although the in-life study husbandry, exposures 

and observations occurred at HLS and could vary from that at RTI, the fetal evaluation criteria 

should be consistent. 

 The actual dates of all major phases of the study are presented in Table A. 

Table A. Study Schedule 

Event Dates 

 Animals arrive at HLS: August 31, 2004 

 Quarantine (14 days): August 31 – September 14, 2004 

 Animals paired: September 16-18, 2004 

 Dates of gd 0: September 17-19, 2004 

 TSCA experimental start date: September 22, 2004 

 Exposure dates (gd 5 through 10): September 22-29, 2004 

 Scheduled termination (gd 17) October 4-6, 2004 

 TSCA experimental termination date: October 6, 2004 

 Submission of draft data on test 

 atmospheres to Sponsor: October 6, 2004 (within 1 week after the last 

exposure date, September 29, 2004 

 Fifty (50) nulliparous female mice were ordered for this range-finding study. One extra 

female was received with the shipment. One hundred (100) male mice, 9-11 weeks old, and of 

the same strain and from the same supplier, were also ordered. The males from Charles River 

Laboratories were not from the same litters as the females. One female that would have been 

over the designated weight range on gd 0 (35 g) was excluded prior to mating. Fifty (50) male 

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RTI-908; Project 0209189.000 Final Report 

mice were used to generate timed-mated animals for this study, and all 100 of the males were 

used to generate timed-mated animals for the subsequent definitive developmental toxicity study 

which will require the mating of 170 female mice to generate 140 plug-positive females. 

Acclimating all 100 male mice assured that they were the same age for this range-finding study 

and subsequent definitive study, and were exposed to the same environmental conditions, etc. 

Female mice were 7-9 weeks old at arrival and were 9-11 weeks of age and 20-35 g in weight on 

gd 0. Fifty females were required to generate 20 plug-positive females in 2 to 3 consecutive 

days; 20 plug-positive females (10 per group and 2 groups) were required to supply the 

minimum number (based on EPA’s guidance; e.g., OPPTS 870.3600; U.S. EPA, 1996; for 

inhalation, range-finding, developmental toxicity studies) of pregnant animals to assess the 

maternal and embryofetal tolerance of the highest concentration, possibly to be used in the 

subsequent developmental toxicity study. 

 During an approximately 14-day quarantine and acclimation period at the HLS testing 

facility, animals were checked for viability twice daily. Prior to study assignment, all animals 

were examined to ascertain suitability for study. The HLS veterinarian formally released these 

animals for use by signature and date. Males and females were individually housed in stainless 

steel suspended cages with wire mesh floors and fronts, except for the mating period when 1 

male and 1 female were housed together. During cohabitation, male and female mice were 

housed in polycarbonate “shoebox” cages with stainless steel lids and Alpha-Dri® bedding 

(Shepherd Specialty Papers, Watertown, TN). Each cage was fitted to secure a glass feeder jar 

with a stainless steel lid. Clean feed jars and fresh feed were provided at least weekly for periods 

when feed consumption was not being recorded and at each interval when feed consumption was 

recorded. After cessation of exposures began on gd 11, a stainless steel, perforated insert was 

placed on the wire-mesh floor of the stainless steel suspended cage of each female and 1 

Nestlet® (Ancare, Bellmore, NY) added to each cage until scheduled sacrifice on gd 17. Feed 

(PMI 5002 Certified Meal) was available ad libitum, except during the daily 6-hour inhalation 

periods. Analytical certification of batches of feed provided by the manufacturer is maintained 

on file at the HLS testing facility, and there were no known contaminants found in the feed. 

Facility water (supplied by Elizabethtown Water Company, Westfield, NJ) was available ad 

libitum via the automatic watering system or water bottles (during mating), except during the 

daily 6-hour inhalation periods. Water analyses were conducted by Elizabethtown Water 

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RTI-908; Project 0209189.000 Final Report 

Company to assure that water met standards specified under the EPA Federal Safe Drinking 

Water Act Regulations (40 CFR Part 141). Water analyses provided by the supplier are 

maintained on file at the HLS testing facility. There were no known contaminants that interfered 

with the objectives of this study. At all times, animals were housed, handled, and used according 

to the National Research Council Guide (NRC, 1996). 

A 12-hour light/dark cycle was provided via automatic timer. Temperature and relative 

humidity were monitored in accordance with Testing Facility SOPs to ensure that the desired 

range of 18 to 26°C for temperature and 30 to 70% relative humidity was maintained to the 

maximum extent possible (NRC, 1996). The actual ranges were 21oC - 22oC and 43% - 52%, 

respectively. 

 Each animal was assigned a temporary identification number (designated on each cage) 

upon receipt. During the second week of the quarantine/acclimation period, the 51 females 

received were tail tattooed with consecutive numbers, 1 through 51. The 100 males were also 

tail tattooed with consecutive numbers, 1 through 100. After selection for use on the study, 

mating, indication of copulation, and assignment to either of the 2 groups, each female was ear 

tagged with a number assigned by the HLS testing facility. This number, plus the study number, 

comprised the unique animal identification for each animal. Each cage was provided with a cage 

card that was color coded for exposure level identification and contained the study and animal 

numbers. 

 It was anticipated that the concentration employed would not result in irritation or 

corrosion to the respiratory tract of the test animals (since previous studies at close to 30,000 

mg/m3

 did not report irritation or corrosion to the maternal respiratory tracts (e.g., Bevan et al., 

1997; EMBSI, 2009). Animals were not subjected to undue pain or distress. All procedures 

used in this study were designed to avoid discomfort, distress, and pain to the animals. The HLS 

IACUC Protocol Review Subcommittee and the RTI IACUC reviewed the protocol and found it 

to be in compliance with appropriate animal welfare regulations (9 CFR Parts 1 and 2 Final 

Rules, Federal Register, Vol. 54, No. 168, August 31, 1989, pp. 36112-36163, effective October 

30, 1989, and 9 CFR Part 3 Animal Welfare Standards; Final Rule, Federal Register, Volume 

55, No. 32, February 15, 1991, pp. 6426-6505, effective March 18, 1991). 

 Immediately prior to pairing, each female was weighed and subjected to a clinical 

examination. For breeding, 1 male with 1 female pairing was employed since other pairing 

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RTI-908; Project 0209189.000 Final Report 

patterns (e.g., 1 male with 2 females) may have resulted in an unacceptable number of plugpositive, nonpregnant females and/or sire effects. Individual females were placed in 

polycarbonate “shoebox” cages with stainless steel lids with singly-housed males. On the 

following morning and each morning thereafter, the females were examined for the presence of a 

vaginal or dropped copulation plug (Hafez, 1970). The day on which copulation plugs were 

found was designated as gd 0. Plug-positive females (dams) were individually housed until 

scheduled sacrifice on gd 17. Plug-negative females were retained in the same male's cage and 

checked for plugs on successive mornings until insemination occurred or the treatment groups 

were filled, whichever came first. RTI staff were present during the initial day of mating 

(September 17, 2004) to confirm expertise of HLS staff to detect vaginal copulation plugs and 

then set up the exposure schedule, based on the gd 0 dates. HLS staff continued to evaluate 

females for vaginal copulation plugs until both groups were filled and then completed the 

exposure schedule. When all treatment groups were filled, the remaining plug-negative and 

plug-positive females were sacrificed by asphyxiation with CO2. The males were retained for 

the definitive developmental toxicity study. The fate of all animals was fully documented in the 

study records. 

Study Design

 This preliminary study was conducted with 1 treatment group and 1 vehicle control 

group, each comprised of 10 plug-positive (presumed pregnant) female mice (Table B). 

Table B. Number of Animals Assigned to Study Groups 

Group No. No. Animals 

Exposed 

No. Days 

Exposed 

Exposure Period 

(gd) 

Target Exposure Concentration 

(mg/m3

) 

1 10 6 5 through 10 0 

2 10 6 5 through 10 30,000 

The 30,000 mg/m3 concentration was chosen to determine the tolerance of the dams and 

conceptuses to the highest exposure concentration to be possibly selected for the definitive 

toxicity study. 

 The test substance was administered as a vapor in the breathing air of the animals. The test 

atmosphere was generated by an appropriate procedure determined during prestudy trials and 

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RTI-908; Project 0209189.000 Final Report 

described in the Inhalation Report (Appendix I). The prestudy trials were performed (at least two 

6-hour periods) to evaluate the optimal set of conditions and equipment to generate a stable 

atmosphere at the target exposure levels and maintain uniform conditions throughout the exposure 

chambers. The whole-body exposure chambers each had a volume of approximately 1000 liters. 

The chambers were operated at a minimum flow rate of 200 liters per minute. The final airflow was 

set to provide at least 1 air change in 5 minutes (12 air changes/hour) and a T99 equilibrium time of 

at most 23 minutes. This chamber size and airflow rate was considered adequate to maintain the 

oxygen level at least 19% and the animal loading factor below 5%. At the end of each daily 6-hour 

exposure, all animals remained in the chamber for a minimum of the T99 equilibrium time. During 

this time, the chamber was operated at approximately the same flow rate using clean air only. 

 A nominal exposure concentration was calculated. The flow of air through the chamber was 

monitored using appropriate calibrated equipment. The test substance consumed during the 

exposure was divided by the total volume of air passing through the chamber (volumetric flow rate 

times total exposure time) to give the nominal concentration. 

 During each 6-hour exposure, measurements of airborne concentrations were performed in 

the animals’ breathing zone at least 4 times using an appropriate sampling procedure and IR 

analytical procedure. Airborne test material concentrations were within +/- 10% of the target 

concentration. One sample per chamber during the trials period and the treatment period was 

analyzed by gas chromatography to characterize at least 10 major components (comprising at least 

80% by weight of the test substance) to show test substance stability and comparison between the 

neat liquid test substance and the vaporized test atmospheres. During the treatment period, particle 

size determinations were performed once per chamber using a TSI Aerodynamic Particle Sizer to 

confirm the absence of particulate test substance condensate in the exposure atmosphere. 

 Chamber temperature, humidity, airflow rate, and static pressure were monitored 

continuously and recorded every 30 minutes during exposure. Chamber temperature and relative 

humidity were maintained, to the maximum extent possible, between 20 to 24°C and 40 to 60%, 

respectively. Chamber oxygen levels (maintained at least 19%) were measured pretest and at the 

beginning, middle, and end of the exposure period of the study. Air samples were taken in the 

vapor generation area pretest and at the beginning, middle, and end of the exposure period of the 

study. Light (maintained approximately 30 foot-candles at 1.0 meter above the floor) and noise 

levels (maintained below 85 decibels) in the exposure room were measured pretest and at the 

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RTI-908; Project 0209189.000 Final Report 

beginning, middle, and end of the exposure period of the study. The minimum frequency of 

chamber activity during the treatment period is summarized below: 

Activity Frequency/Chamber 

Measured test substance concentration 4X/day 

Measured test substance characterization 1X 

Particle size 1X 

Temperature 13X/day 

Relative humidity 13X/day 

Airflow rate 13X/day 

Static pressure 13X/day 

Nominal test substance concentration (excluding the air control chamber) 1X/day 

Rotation pattern of exposure cages 1X/day 

Loading/unloading verification 1X/day 

 Plug-positive female mice (dams) were assigned to treatment groups by a stratified 

randomization method designed to provide uniform mean body weights between the 2 exposure 

groups on gd 0. Females were exposed to G/MTBE or air 6 hours per day from gd 5 through 10. 

For each daily exposure, females were transferred to inhalation cages, and the cages were moved 

into the appropriate chambers for exposure. Following each daily exposure, females were 

transferred back to home caging for feed consumption measurements overnight. Dams at 0 

mg/m3

 were also exposed to air in the chambers for 6 hours per day on gd 5 through 10. 

 Clinical observations of all animals were made once daily on gd 0 through 4 (prior to the 

exposure period), on gd 11 through 17 (after the exposure period, prior to necropsy), and twice 

daily, prior to and immediately after each daily exposure, throughout the exposure period (gd 5 

through 10). In addition, during each daily exposure period, animals were observed at least once 

during each exposure. This was routinely performed near the middle of each exposure. 

 Dams were weighed in the mornings (prior to exposures for those days that exposures 

occurred) on gd 0, 5, 6, 7, 8, 9, 10, 12, 14, 16, and 17. Maternal weight gains were calculated for 

gd 0-5 (pre-exposure period), gd 5-6, 6-7, 7-8, 8-9, 9-10, 10-12, 12-14, 14-16, 16-17, gd 5-10 

(exposure period), gd 10-17 (postexposure period), and gd 0-17 (gestational period). 

 Maternal feed consumption was evaluated in the mornings from gd 0-5 (pre-exposure 

period), gd 5-6, 6-7, 7-8, 8-9, 9-10, 10-12, 12-14, 14-16, 16-17, 5-10 (exposure period), gd 10-17 

(postexposure period), and gd 0-17 (gestation period). 

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 On gd 17, approximately 1 to 11⁄2 days before expected parturition, all maternal animals 

were killed by CO2 asphyxiation by RTI staff. The thoracic and abdominal cavities and organs 

were examined, and pregnancy status was confirmed by uterine examination. Uteri that 

presented no visible implantation sites were stained with ammonium sulfide (10%) in order to 

visualize any implantation sites that may have undergone very early resorption (Salewski, 1964). 

At sacrifice, the body, liver, uterus, paired adrenal glands, and paired kidneys of each plugpositive female were weighed. Ovarian corpora lutea were counted and uterine contents (i.e., 

number of implantation sites, early and late resorptions, dead fetuses, live fetuses) recorded. 

 Live fetuses were counted, weighed, sexed externally, and examined externally for gross 

malformations (including cleft palate) and variations by RTI staff. Each fetus was killed by 

intraperitoneal injection of sodium pentobarbital, dissected longitudinally, and the thoracic and 

abdominal viscera removed intact and retained individually in labeled vials in buffered neutral 

10% formalin for possible subsequent visceral examination. The fetal carcasses were blanched, 

skinned, and retained in individually labeled scintillation vials in 70% ethanol for possible 

subsequent double staining (alizarin Red S and alcian blue) and skeletal evaluation. All maternal 

organs and carcasses were destroyed by incineration. 

Statistics

 The unit of comparison was the dam or the litter, as appropriate. The single 

treatment group was compared by RTI staff to the concurrent control group using the 

Student’s t-Test (SAS® Releases 8.0 and 8.2; SAS® Institute 1999a,b,c,d,e; 2000; 2001). 

Litter derived percentage data were arcsine transformed and then analyzed using 

ANOVA (Analysis of Variance) (SAS® Institute 1999a,b,c,d,e; 2000; 2001) weighted 

according to litter size. For frequency data, such as percent litters with resorptions, the 

Chi-square test was used. 

Storage of Records

 All data documenting experimental details and study procedures and observations were 

recorded and maintained as raw data. At the completion of the study, all reports, raw data, 

preserved specimens, and retained samples will be maintained in RTI’s secure archives for a 

period of 1 year after submission of the signed final report. The Sponsor will be contacted in 

order to determine the final disposition of these materials. 

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RTI-908; Project 0209189.000 Final Report 

Personnel

 This study was conducted at HLS (Mr. G.M. Hoffman, Principal Investigator; Animal 

Research Facility Veterinarian, Dr. Teresa S. Kusznir; Animal Research Facility Director, Mr. I. 

Vanterpool; Necropsy Laboratory Supervisor, Ms. G.E. Baxter; Inhalation Laboratory 

Supervisor, Mr. S. Cracknell; Associate Director of Formulation Chemistry Services, Ms. K. 

Saladdin; Quality Assurance, Ms. N.S. Iacono) under contract to Research Triangle Institute. 

Dr. R.W. Tyl of RTI served as Study Director. RTI Reproductive and Developmental 

Toxicology personnel included Ms. M.C. Marr (Laboratory Supervisor), Ms. C.B. Myers 

(Reproductive Toxicity Study Supervisor and Data Analyst), and Mr. W.P. Ross 

(Neurotoxicology Supervisor). RTI Quality Assurance personnel were Ms. D.A. Drissel 

(Manager), Ms. C.A. Ingalls, Ms. S.C. Wade, and Ms. M.M. Oh. 

 Dr. Tyl and Ms. Marr went to HLS for the first day of pairing and the first gd 0 to train 

HLS staff on detection of vaginal plugs/sperm and on distributing the plug/sperm positive 

females into the two groups by stratified randomization. Ms. Marr, Mr. Ross, and Ms. Wade 

went to HLS to perform the term necropsy and fetal evaluations. Ms. Wade (the RTI QA study 

auditor) accompanied the staff to HLS for the necropsies. 

 The final report was prepared by Dr. R.W. Tyl and Ms. M.C. Marr, with assistance from 

Ms. C.B. Myers for statistical analyses and generation of tables, and by Mr. T.W. Wiley for data 

entry. Ms. M.C. Marr was responsible for all transfer of custody procedures for fetal viscera, 

fetal carcasses, data generated at HLS by HLS staff from HLS to RTI, and for archiving the 

study records. 

RESULTS 

Test Chamber Analyses

Table 1, Appendix I 

Prestudy chamber distribution analyses showed that the test substance was evenly 

distributed within the chamber. Prestudy and on-study chamber monitoring showed that the 

chamber oxygen levels were 20%. 

The analytically measured exposure levels of the airborne test substance were reasonably 

close to the targeted exposure level. The measured and nominal concentrations varied somewhat 

(less than 10%), but reasonably, from the expected 1:1 ratio for this type of vapor exposure. 

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RTI-908; Project 0209189.000 Final Report 

Chamber environmental conditions averaged 21.5oC temperature and 46.6% relative humidity. 

Mean particle size distribution measurements for the exposures indicated that the atmospheres 

were essentially vapor only, as expected, since there was no substantial difference between the 

test substance chamber and the air control chamber for particle size distribution. 

Analysis of the major components in the neat test substance and the test atmospheres 

showed a reasonably close concordance between the neat test substance and the vaporized test 

substance. These data demonstrated that the test animals were exposed, as expected, to all of the 

major components of the test substance in their proper proportions. The data were consistent 

between the prestudy and on-study analyses, indicating stability of the test substance and the 

atmosphere generation techniques. 

Maternal Findings

Tables 2, 3, 4, Appendix II 

 The test substance had no effect on maternal survival, body weights, body weight gains, 

or food consumption. No maternal animals died, delivered early, were euthanized moribund, or 

were removed during the course of the study. Maternal body weights were statistically 

equivalent between the 2 groups throughout gestation; on gd 0, 5-10, 12, 14, 16, and 17 for inlife, and on gd 17 at sacrifice. Maternal body weight change was similarly unaffected between 

the 2 groups throughout gestation, including intervals gd 0-5 (pre-exposure period); 5-6, 6-7, 7-8, 

8-9, 9-10, 10-12, 12-14, 14-16, 16-17, and 5-10 (exposure period); gd 10-17 (postexposure 

period); gd 0-17 (gestation); and corrected gestational body weight change (gd 0-17 minus 

gravid interim weight) (Table 2). Maternal feed consumption in g/day and g/kg body weight/day 

was equivalent across both groups for all intervals during gestation, although the mean 

consumption values at 30,000 mg/m3

 in g/day and g/kg/day were slightly (but not statistically 

significantly) lower for gd 5 through gd 9 during the exposure period (Table 3). 

Some maternal toxicity (e.g., “lethargy (narcosis)”) was noted in females in the 30,000 

ppm chamber, particularly on the first days of exposure, as described below. There were no 

maternal clinical signs before or after the daily, 6-hour exposure periods (gd 5 through 10; Table 

4). Observations taken during each daily exposure period indicated “most” (defined by HLS as 

51-99% of the animals exhibiting a given observation) of the females at 30,000 mg/m3

 exhibited 

“lethargy (narcosis)” on the first chamber exposure day (all animals at gd 5), with the 

12
RTI-908; Project 0209189.000 Final Report 

approximate incidence dropping to “some” on chamber exposure days 2 through 4 and 6 (defined 

by HLS as 21-50% of the animals exhibiting a given observation), and then “few” observed on 

chamber exposure days 7 and 8 (defined by HLS as <20% of the animals exhibiting a given 

observation), and no animals on gd 9 or 10, as the exposure period progressed. These 

observations suggest that the initial responsiveness attenuated over time. 

The test substance had no effect on the absolute or relative weights of the gravid uterus 

and maternal liver, paired adrenal glands, and paired kidneys. They were equivalent between the 

2 groups (Table 2). 

In this small study, the test substance had no apparent effect on pregnancy or 

postimplantation loss. Of the 10 plug-positive females in each of the 2 groups (0 and 30,000 

mg/m3

), 1 female in each group was nonpregnant, so the pregnancy rate was 90% in both groups. 

Two litters at 0 mg/m3

 and 1 litter at 30,000 mg/m3 were fully resorbed, so the numbers (and 

percentage) of live litters were 7 of 9 (77.8%) at 0 mg/m3 and 8 of 9 (88.9%) at 30,000 mg/m3. 

Overall, the combined pregnancy rate was 90.0% (18/20), and the combined percentage of 

pregnant females with live litters was 83.3% (15/18). The higher incidence of resorptions in the 

control group is obviously not an indication of test substance effects. 

Uterine and Embryofetal Findings

Tables 5, 6, 7, Appendix II 

 Of the 9 dams pregnant in each group, there were no differences between groups for the 

number of ovarian corpora lutea per dam (a measure of eggs ovulated), uterine implantation sites 

per litter (a measure of zygotes implanted), or percent preimplantation loss/litter (the difference 

between ovarian corpora lutea and uterine implant sites). 

In this small study, the test substance had no effect on the number or percentage of 

resorptions/litter, late fetal deaths per litter, nonlive implants (resorptions plus late fetal deaths) 

per litter, or litters with adversely affected (nonlive plus malformed) implants. The number of 

resorptions/litter were nonsignificantly lower at 30,000 mg/m3

, due to 2 females at 0 mg/m3 and 

1 female at 30,000 mg/m3 with full litter resorption. RTI’s historical control range, based on 288 

CD-1 mouse litters, for full litter resorption, is 0.0-20.0% per study, with the overall mean of 

2.8%. In this study, the percentage of litters with resorptions was significantly lower at 30,000 

mg/m3

 than at 0 mg/m3; all 9 litters at 0 mg/m3 had 1 or more resorptions, whereas only 4 of 9 

13
RTI-908; Project 0209189.000 Final Report 

litters at 30,000 mg/m3 had 1 or more resorptions. The number and percentage of late fetal 

deaths per litter and litters with late fetal deaths were statistically equivalent between the 2 

groups. The number and percentage of nonlive implants per litter were statistically equivalent 

but clearly lower at 30,000 mg/m3

 due to the lower number of resorptions and fully resorbed 

litters at 30,000 mg/m3. The number (nonsignificant) and percentage (significant) of litters with 

1 or more nonlive implants were lower at 30,000 mg/m3

, respectively, due to fewer resorptions 

and fully resorbed litters. The number and percentage of adversely affected (nonlive plus 

malformed) implants and litters with 1 or more adversely affected implants were nonsignificantly 

lower at 30,000 mg/m3

. In this study, with small numbers of litters/group and only 2 groups, 

there is no apparent risk to embryofetal survival at 30,000 mg/m3. A larger study would be 

required to definitively confirm this finding (Table 5). 

 In this study, the test substance had no effect on the number of live fetuses per litter, the 

percentage of male fetuses per litter, the number of male and female fetuses per litter, or fetal 

body weight/litter, with sexes combined or separately. For the 7 live litters at 0 mg/m3 and the 8 

live litters at 30,000 mg/m3

, the data were all equivalent between the 2 groups (Table 5). 

 Also in this study, the test substance had no impact on external malformations or 

variations. There were clearly no differences in fetal findings between the 2 groups. There were 

71 live fetuses examined in the 7 litters at 0 mg/m3 and 94 fetuses in the 8 litters at 30,000 

mg/m3. There was 1 fetus (in 1 litter) in each group with an external malformation (cleft palate), 

with no fetuses in either group with an external variation (Tables 6 and 7). 

DISCUSSION 

The objective of this study was to determine whether mouse dams and conceptuses could 

tolerate 30,000 mg/m3

 of G/MTBE on gd 6 through 10. The results of this study indicate both 

dams and conceptuses tolerated such exposures, and that 30,000 mg/m3

 can be used in a 

guideline study to maximize the likelihood of causing and detecting ventral wall closure deficits 

should they occur. Among the dams, there were no deaths or moribund animals, no clinical 

signs before or after exposures and only “lethargy (narcosis)” during the 30,000 mg/m3

exposures, with an incidence high initially and dropping slowly over time. This lethargy was 

anticipated since narcosis was observed in CD-1® female mice exposed to pure MTBE at 8000 

ppm during the exposure periods (Bevan et al., 1997). “Lethargy” and “narcosis” are considered 

14
RTI-908; Project 0209189.000 Final Report 

interchangeable terms. Dorland’s Illustrated Medical Dictionary (27th Edition, 1988, W.B. 

Saunders Co., Philadelphia) defines lethargy as “abnormal drowsiness or stupor” and narcosis as 

“nonspecific and reversible depression of the function of the central nervous system marked by 

stupor.” Among the conceptuses, embryofetal survival, growth, and development were not 

adversely affected. 

The only fetal external malformation observed in this study was cleft palate, observed in 

1 fetus each at 0 and 30,000 mg/m3. Final palatal shelf fusion is completed on gd 14-15 in the 

mouse (Rugh, 1968), but methanol-induced cleft palate has an earlier peak sensitivity of gd 7-8 

(Rogers and Mole, 1997). However in this study, cleft palate is likely a spontaneous 

malformation since it was observed with equal frequency in the 0 and 30,000 mg/m3

 groups (1 

fetus in each), and it is one of the most common malformations observed in RTI’s historical 

control database for CD-1® mouse developmental toxicity studies. Whether (or not) continued 

exposure to G/MTBE vapor through gd 16 would result in higher incidences of cleft palate 

(versus the control group) was clearly not assessed in this study, but the presence of maternal 

toxicity at this concentration provides some support for the supposition (also supported in the 

literature that maternal stress results in increased adrenal corticosteroid production, which in turn 

causes fetal cleft palate; Carmichael et al., 2007; Senda et al., 2005; Pradat et al., 2003). RTI 

historical control data on 3641 control CD-1 mouse fetuses from 288 dams, from 16 

governmental studies from 1997-2002, indicated cleft palate was present in 18 control fetuses 

from 11 control litters from 8 (50%) of the studies, with an overall litter incidence of 3.8% and 

fetal incidence of 0.50 (range 0.0-2.51%) (Table 8). 

 The last finding (or lack thereof) in this small study is the absence of any other fetal 

external malformations (for discussion on cleft palate, see above). There was no evidence of any 

effect on ventral midline closure. Although this was a small study, there were 71 fetuses 

examined at 0 mg/m3

 and 94 fetuses examined at 30,000 mg/m3 G/MTBE (a concentration 

higher than any of those employed in the 2009 EMBSI study). The results of this range-finding 

study, although not definitive, lend credence to a tentative interpretation that the fetal findings 

observed in the EMBSI study may not be related to test substance from exposure. The 

differences between the EMBSI (2009) study and this study are the source of the CD-1® mice 

(Charles River, Portage, MI, at EMBSI and Charles River, Raleigh, NC, for the present study), 

duration of exposure (EMBSI employed gd 5 through 17 with necropsy on gd 18, the present 

15
RTI-908; Project 0209189.000 Final Report 

study employed gd 5 through 10 with necropsy on gd 17), the number of dams/group (25 in the 

EMBSI study and 10 in the present study), and the exposure concentrations (EBMSI employed 4 

groups [0, 2000, 10,000, and 20,000 mg/m3

] and the present study had 2 groups [0 and 30,000 

mg/m3

]). Both studies employed 6-hour daily exposures. Since the fetal malformations of 

concern are both failures of ventral midline body wall fusion, which takes place on gd 7-9 in the 

mouse (Rugh, 1968), the different durations are not germane since both studies employed 

exposure periods that encompassed the period of time when ventral midline body wall fusion 

occurs in the mouse. 

CONCLUSION

The results of this range-finding tolerance study indicate that pregnant CD-1 mice (and 

their conceptuses) tolerated inhalation exposure of G/MTBE to 30,000 mg/m3

 for 6 hours/day on 

gd 5 through 10. Therefore, the results of this study support a design for the subsequent robust 

study with 25 plug-positive females/group at 0, 2000, 10,000, and 20,000 mg/m3

, with exposures 

on gd 5 through 16, and 40 plug-positive females at 30,000 mg/m3, with exposures on gd 5 

through 10 (with scheduled necropsy of all groups on gd 17). 

16
RTI-908; Project 0209189.000 Final Report 

REFERENCES

Bevan, C., R.W. Tyl, T.L. Neeper-Bradley, L.C. Fisher, R.D. Panson, J.F. Douglas, and L.S. 

Andrews (1997). Developmental toxicity evaluation of methyl tertiary-butyl either (MTBE) by 

inhalation in mice and rabbits. J. Appl. Toxicol. 17(1), 521-529. 

Carmichael, S.L., G.M. Shaw, C. Ma, M.M. Werler, S.A. Rasmussen and E.J. Cammer (2007). 

Maternal corticosteroid use and orofacial clefts. Am. J. Obstet. Gynecol. 197(6), 585, e1-7. 

Daughtrey, W.C., D.M. Burnett, P. Podhasky, M. Henley, and R.D. White (2004). Inhalation 

Toxicity of Gasoline & Fuel Oxygenates: Test Sample Preparation. The Toxicologist (Abstract 

711). 

ExxonMobil Biomedical Sciences, Inc. (EMBSI) (2009). Whole-Body Inhalation 

Developmental Toxicity Study in Mice With Gasoline With MTBE Vapor Condensate (MRD00-713). Study Director, Mr. G.W. Trimmer, EMBSI. Performed for the American Petroleum 

Institute, Washington, DC. DRAFT final report, Project No. 171334M, by EMBSI, Annandale, 

NJ. 

Hafez, E.S.E. (Ed.) (1970). Reproduction and Breeding Techniques for Laboratory Animals. 

Lea and Febiger, Philadelphia, PA. 

NRC (1996). Guide for the Care and Use of Laboratory Animals. Institute of Laboratory 

Animal Resources, Commission on Life Sciences, National Research Council. National 

Academy Press, National Institutes of Health. Revised 1996. 

Pradat, P., E. Robert-Gransia, G.L. DiTanna, A. Rosario, A. Lisi, and P. Mastroiacovo (2003). 

First trimester exposure to corticosteroids and orofacial clefts. Birth Defects Res. A. Clin. Mol. 

Teratol. 67(12), 968-970. 

Rogers, J.M., and M.L. Mole (1997). Critical periods of sensitivity to the developmental 

toxicity of inhaled methanol in the CD-1 mouse. Teratology 55(6), 364-372. 

Rugh, R. (1968). The Mouse: Its Reproduction and Development. Chapter 3, Normal 

Development of the Mouse, Chapter 4, Chronology of Development, and Chapter 5, Organogeny. 

Burgess Publishing Company, Minneapolis, MN. 

Salewski, E. (1964). Färbemethode zum makroskopischen Nachweis von Implantationsstellen 

am Uterus der Ratte. Naunyn-Schmiedebergs Arch. Exp. Pathol. Pharmakol. 247, 367. 

SAS Institute Inc. (1999a). SAS® Language Reference: Concepts, Version 8, Cary, NC: SAS 

Institute Inc. 554 pp. 

SAS Institute Inc. (1999b). SAS/STAT® Users’ Guide, Version 8, Cary, NC: SAS Institute Inc. 

3884 pp. 

SAS Institute Inc. (1999c). SAS® Language Reference: Dictionary, Version 8, Cary, NC: SAS 

Institute Inc. 1244 pp. 

17
RTI-908; Project 0209189.000 Final Report 

SAS Institute Inc. (1999d). SAS® Procedures Guide, Version 8, Cary, NC: SAS Institute Inc. 

1643 pp. 

SAS Institute Inc. (1999e). SAS® Companion for the Microsoft Windows Environment, Version 

8, Cary, NC: SAS Institute Inc. 562 pp. 

SAS Institute Inc. (2000). SAS/STAT® Software: Changes and Enhancements, Release 8.1, 

Cary, NC: SAS Institute Inc. 554 pp. 

SAS Institute Inc. (2001). SAS/STAT® Software: Changes and Enhancements, Release 8.2, 

Cary, NC: SAS Institute Inc. 343 pp. 

Senda, T., N. Natsume, J. Kuno, T. Toyoda, and K. Shimozato (2005). Rate of occurrence of 

dexamethasone-induced cleft palate affected by uterine environment in the mouse. Plast. 

Reconstr. Surg. 115(4), 1208-1210. 

U.S. EPA (1989). U.S. Environmental Protection Agency; Toxic Substances Control Act 

(TSCA), Good Laboratory Practice Standards; Final Rule. Federal Register 54, 34034-34050, 

August 17, 1989 (40-CFR-792). 

U.S. EPA (1994). U.S. Environmental Protection Agency. Good laboratory practices (GLP) 

standards for inhalation exposure health effects testing. -Federal Register 59 (122), 33119-

33124, June 27, 1994 (40 CFR, part 79, subpart F, §79.60). 

U.S. EPA (1996). U.S. Environmental Protection Agency; Prevention, Pesticides and Toxic 

Substances (OPPTS), Health Effects Test Guideline OPPTS 870.3600, Inhalation 

Developmental Toxicity Study (Public Draft, June 1996). 

U.S. EPA (1998a). U.S. Environmental Protection Agency. Final Notification of Health Effects 

Testing Requirements for Baseline Gasoline and Oxygenated Nonbaseline Gasolines and 

Approval of Alternative Emissions Generator. Federal Register 63 (236), 67877-67877, 

December 9, 1998 (40 CFR, part 79, subpart F). 

U.S. EPA (1998b). U.S. Environmental Protection Agency. Letter from M.T. Oge, Director, 

Office of Mobil Sources, to C. J. Henry, Ph.D., Director, Health and Environmental Sciences 

Department, American Petroleum Institute, November 2, 1998. 

U.S. EPA (1998c). U.S. Environmental Protection Agency; Prevention, Pesticides and Toxic 

Substances (OPPTS), Health Effects Test Guidelines, OPPTS 870.3700, Prenatal Developmental 

Toxicity Study (August, 1998). 

18
RTI-908; Project 0209189.000 Final Report 

LIST OF PROTOCOL DEVIATIONS

Study: Mi04-HLS1 Master Protocol No.: RTI-908 HLS Study Code: 04-4262 

HLS

1. Due to technician error, the gestational day 1 and 2 clinical observations were not recorded 

for Animal Nos. 1511-1513 or 2511-2513 on September 18, 2004. Animal Nos. 1511-1517 

and 2511-2517 did not have clinical observations recorded on September 19, 2004. 

2. On Exposure Day 2 (September 23, 2004), Sample No. 2008 (in Group 2) was more than 

10% (35,000 mg/m3) above the target (30,000 mg/m3). 

3. All pretest animals in Groups 1 and 2 were tattooed during the third week of quarantine/ 

acclimation instead of the second week. 

4. The study protocol, Section 4.0 Statistics (p. 12), inadvertently did not indicate how 

frequency data would be analyzed. The following text was added to the “Statistics” section 

of this final report and in a Memorandum to the Study Record: “For frequency data, such as 

percent litters with resorptions, the Chi-square test was used.” 

In the Study Director’s professional opinion, these protocol deviations did not affect the study 

design, performance, or interpretation and are presented for completeness. 

19
RTI-908; Project 0209189.000 Final Report 

Table 1. Chamber Monitoring Results (page 1 of 1) 

Target Chamber Concentrations: 0 mg/m3 30,000 mg/m3

Mean analytical chamber concentrations of G/MTBE 

(mg/m3

)

a

0d 30,688 ± 1,595 

Percent of target concentration NA 102.29% 

Particle Size Determinations:b

MMAD (μm) 1.317 3.667 

GSD 2.303 2.315 

TMC (mg/m3

) 4.41 x 10-3 1.02 x 10-2

Temperature (°C)c 21.0 ± 0.0 22.0 ± 0.0 

Relative humidity (%)c 46.6 ± 1.1 46.6 ± 0.7 

a

 Mean of 4 assays measured by infrared spectroscopy 

b

 Measured once 

c

 Measured 13 times 

d

 LOQ = 433 mg/m3

MMAD = mass median aerodynamic diameter 

GSD = geometric standard deviation 

TMC = total mass concentration (measure of aerosol concentration) 

NA = not applicable 

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RTI-908; Project 0209189.000 Final Report 

Table 2. Summary and Statistical Analysis of the Maternal Body Weights, Weight Changes, Organ 

Weights and Relative Organ Weights (page 1 of 4) 

G/MTBE (mg/m3, inhaled) 

0 30,000 

SUBJECTS (No. Dams): 

No. on Study 10 10 

No. Removed 0 0 

No. Dead or Euthanized 0 0 

No. Nonpregnant 1 1 

No. (%) Pregnant at Scheduled Sacrifice 9 (90.0) 9 (90.0) 

No. (%) with 100% Resorptions 2 (22.2) 1 (11.1) 

Maternal Body Weight (gd 0) (g)a 26.6 26.9 

+ 0.5 + 0.4 

N=9 N=9 

Maternal Body Weight (gd 5) (g)a 27.8 27.9 

+ 0.7 + 0.3 

N=9 N=9 

Maternal Body Weight (gd 6) (g)a 28.3 28.1 

+ 0.8 + 0.4 

N=9 N=9 

Maternal Body Weight (gd 7) (g)a 28.8 28.5 

+ 0.7 + 0.4 

N=9 N=9 

Maternal Body Weight (gd 8) (g)a 29.4 29.0 

+ 0.8 + 0.4 

N=9 N=9 

Maternal Body Weight (gd 9) (g)a 29.7 29.3 

+ 0.9 + 0.5 

N=9 N=9 

Maternal Body Weight (gd 10) (g)a 30.4 30.1 

+ 1.1 + 0.5 

N=9 N=9 

Maternal Body Weight (gd 12) (g)a 33.0 33.2 

+ 1.5 + 0.9 

N=9 N=9 

Maternal Body Weight (gd 14) (g)a 36.2 37.5 

+ 2.1 + 1.3 

N=9 N=9 

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RTI-908; Project 0209189.000 Final Report 

Table 2. Summary and Statistical Analysis of the Maternal Body Weights, Weight Changes, Organ 

Weights and Relative Organ Weights (page 2 of 4) 

G/MTBE (mg/m3, inhaled) 

0 30000 

Maternal Body Weight (gd 16) (g)a 40.9 43.4 

+ 2.9 + 2.1 

N=9 N=9 

Maternal Body Weight (gd 17) (g)a 43.0 46.1 

+ 3.3 + 2.4 

N=9 N=9 

Maternal Body Weight (gd 17 at sacrifice) (g)a 42.11 45.42 

+ 3.21 + 2.40 

N=9 N=9 

Maternal Body Weight Change (gd 0 to 5) (g)a 1.2 1.0 

+ 0.5 + 0.2 

N=9 N=9 

Maternal Body Weight Change (gd 5 to 6) (g)a 0.5 0.1 

+ 0.1 + 0.2 

N=9 N=9 

Maternal Body Weight Change (gd 6 to 7) (g)a 0.5 0.4 

+ 0.1 + 0.1 

N=9 N=9 

Maternal Body Weight Change (gd 7 to 8) (g)a 0.5 0.5 

+ 0.2 + 0.2 

N=9 N=9 

Maternal Body Weight Change (gd 8 to 9) (g)a 0.4 0.3 

+ 0.2 + 0.1 

N=9 N=9 

Maternal Body Weight Change (gd 9 to 10) (g)a 0.7 0.8 

+ 0.2 + 0.2 

N=9 N=9 

Maternal Body Weight Change (gd 10 to 12) (g)a 2.5 3.2 

+ 0.5 + 0.5 

N=9 N=9 

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RTI-908; Project 0209189.000 Final Report 

Table 2. Summary and Statistical Analysis of the Maternal Body Weights, Weight Changes, Organ 

Weights and Relative Organ Weights (page 3 of 4) 

G/MTBE (mg/m3, inhaled) 

0 30000 

Maternal Body Weight Change (gd 12 to 14) (g)a 3.2 4.3 

+ 0.7 + 0.5 

N=9 N=9 

Maternal Body Weight Change (gd 14 to 16) (g)a 4.7 5.9 

+ 0.8 + 0.8 

N=9 N=9 

Maternal Body Weight Change (gd 16 to 17) (g)a 2.0 2.7 

+ 0.4 + 0.4 

N=9 N=9 

Maternal Body Weight Change (gd 5 to 10) (g)a 2.7 2.2 

+ 0.5 + 0.4 

N=9 N=9 

Maternal Body Weight Change (gd 10 to 17) (g)a 12.5 16.0 

+ 2.3 + 2.0 

N=9 N=9 

Maternal Body Weight Change (gestation) (g)a 15.5 18.5 

+ 3.0 + 2.2 

N=9 N=9 

Maternal Body Weight Change (corrected) (g)a,b 3.58 2.95 

+ 0.91 + 0.42 

N=9 N=9 

Gravid Uterine Weight (g)a 11.9289 15.5566 

+ 2.3183 + 2.0903 

N=9 N=9 

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RTI-908; Project 0209189.000 Final Report 

Table 2. Summary and Statistical Analysis of the Maternal Body Weights, Weight Changes, Organ 

Weights and Relative Organ Weights (page 4 of 4) 

G/MTBE (mg/m3, inhaled) 

0 30000 

Maternal Liver Weight (g)a 2.2892 2.3848 

+0.1507 +0.0963 

N=9 N=9 

Maternal Paired Adrenal Gland Weight (g)a 0.0116 0.0103 

+0.0008 +0.0011 

N=9 N=9 

Maternal Paired Kidney Weight (g)a 0.4221 0.4303 

+0.0194 +0.0130 

N=9 N=9 

Relative Maternal Liver Weight (% sacrifice weight)a 5.4895 5.2984 

+ 0.1371 + 0.1390 

N=9 N=9 

Relative Maternal Paired Adrenal Gland Weight (% sacrifice weight)a

0.0283 0.0234 

+ 0.0017 + 0.0028 

N=9 N=9 

Relative Maternal Paired Kidney Weight (% sacrifice weight)a

1.0364 0.9770 

+ 0.0630 + 0.0786 

N=9 N=9 

aIncludes all pregnant dams until terminal sacrifice on gd 17. Reported as the mean + S.E.M.; 

gd=gestational day. 

bWeight change during gestation (gd 17 sacrifice weight minus gd 0 weight) minus gravid uterine weight. 

24
RTI-908; Project 0209189.000 Final Report 

Table 3. Summary and Statistical Analysis of the Maternal Feed Consumption (page 1 of 3) 

G/MTBE (mg/m3, inhaled) 

0 30000 

No. of Pregnant Dams 9 9 

Maternal Feed Consumption (gd 0 to 5) (g/day)a 5.4 5.4 

+ 0.3 + 0.3 

N=7b N=8b

Maternal Feed Consumption (gd 5 to 6) (g/day)a 6.6 5.2 

+ 1.1 + 0.2 

N=9 N=8b

Maternal Feed Consumption (gd 6 to 7) (g/day)a 6.1 5.5 

+ 0.3 + 0.2 

N=8b N=9 

Maternal Feed Consumption (gd 7 to 8) (g/day)a 6.2 5.5 

+ 0.6 + 0.2 

N=7b N=9 

Maternal Feed Consumption (gd 8 to 9) (g/day)a 6.5 5.7 

+ 0.6 + 0.1 

N=9 N=9 

Maternal Feed Consumption (gd 9 to 10) (g/day)a 5.7 5.6 

+ 0.3 + 0.2 

N=8b N=9 

Maternal Feed Consumption (gd 10 to 12) (g/day)a 5.9 5.9 

+ 0.4 + 0.2 

N=9 N=9 

Maternal Feed Consumption (gd 12 to 14) (g/day)a 6.6 6.9 

+ 0.6 + 0.3 

N=9 N=9 

Maternal Feed Consumption (gd 14 to 16) (g/day)a 7.2 7.3 

+ 0.7 + 0.3 

N=8c N=9 

Maternal Feed Consumption (gd 16 to 17) (g/day)a 7.1 7.3 

+ 0.5 + 0.4 

N=9 N=9 

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RTI-908; Project 0209189.000 Final Report 

Table 3. Summary and Statistical Analysis of the Maternal Feed Consumption (page 2 of 3) 

G/MTBE (mg/m3, inhaled) 

0 30000 

Maternal Feed Consumption (gd 5 to 10) (g/day)a 5.8 5.4 

+ 0.4 + 0.1 

N=7d N=8d

Maternal Feed Consumption (gd 10 to 17) (g/day)a 6.6 6.8 

+ 0.5 + 0.3 

N=8d N=9 

Maternal Feed Consumption (gd 0 to 17) (g/day)a 5.5 5.8 

+ 0.5 + 0.2 

N=5d N=7d

Relative Maternal Feed Consumption (gd 0 to 5) (g/kg/day)a

198.3 196.3 

+ 9.0 + 9.5 

N=7b N=8b

Relative Maternal Feed Consumption (gd 5 to 6) (g/kg/day)a

234.6 184.4 

+ 35.0 + 7.3 

N=9 N=8b

Relative Maternal Feed Consumption (gd 6 to 7) (g/kg/day)a

213.0 193.0 

+ 8.1 + 5.4 

N=8b N=9 

Relative Maternal Feed Consumption (gd 7 to 8) (g/kg/day)a

216.3 193.4 

+ 19.8 + 7.2 

N=7b N=9 

Relative Maternal Feed Consumption (gd 8 to 9) (g/kg/day)a

216.8 195.6 

+ 15.1 + 5.3 

N=9 N=9 

Relative Maternal Feed Consumption (gd 9 to 10) (g/kg/day)a

190.5 189.6 

+ 7.5 + 5.5 

N=8b N=9 

Relative Maternal Feed Consumption (gd 10 to 12) (g/kg/day)a

186.7 185.3 

+ 8.8 + 5.3 

N=9 N=9 

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RTI-908; Project 0209189.000 Final Report 

Table 3. Summary and Statistical Analysis of the Maternal Feed Consumption (page 3 of 3) 

G/MTBE (mg/m3, inhaled) 

0 30000 

Relative Maternal Feed Consumption (gd 12 to 14) (g/kg/day)a

189.2 193.6 

+ 13.1 + 5.6 

N=9 N=9 

Relative Maternal Feed Consumption (gd 14 to 16) (g/kg/day)a

189.5 180.2 

+ 10.5 + 4.8 

N=8c N=9 

Relative Maternal Feed Consumption (gd 16 to 17) (g/kg/day)a

171.5 164.0 

+ 6.8 + 5.4 

N=9 N=9 

Relative Maternal Feed Consumption (gd 5 to 10) (g/kg/day)a

202.6 189.8 

+ 10.3 + 3.6 

N=7d N=8d

Relative Maternal Feed Consumption (gd 10 to 17) (g/kg/day)a

183.7 177.9 

+ 8.6 + 4.1 

N=8d N=9 

Relative Maternal Feed Consumption (gd 0 to 17) (g/kg/day)a

179.4 180.1 

+ 4.9 + 4.7 

N=5d N=7d

aIncludes all pregnant dams until terminal sacrifice on gd 17. Reported as the mean + S.E.M.; gd = 

gestational day. 

bDecrease in N is due to one or more feeders spilling, and therefore an accurate feed weight could not be 

obtained. 

cDecrease in N is due to the feed being contaminated with feces and/or urine, and therefore the feed 

weight was excluded. 

dDecrease in N is due to interim feed consumption value(s) for one or more dams being missing, and 

therefore the overall feed consumption value could not be calculated. 

27
RTI-908; Project 0209189.000 Final Report 

Table 4. Summary of the Maternal Clinical Observations (page 1 of 1) 

G/MTBE (mg/m3, inhaled) 

Observation 0 30000 

Prior to Exposures:a

 Normal 10 10 

During Exposures: b

 Normal 10 0-8 e

 Lethargy (narcosis) 0 10-2 e

 Red vaginal discharge 

 (Female No. 1518 on gd 9 postexposure)c

1 0 

After Exposures:b

 Normal 10 10 

After Exposure Periodd

 Normal 10 10 

aThe daily clinical observations were recorded prior to the exposure period on gd 0-5 and on the days of 

treatment (gd 5 through 10) prior to the daily exposures. 

bThese clinical observations were recorded for gd 5 through 10 only. 

cFemale No. 1518 (at 0 mg/m3

) had all resorptions at scheduled necropsy on gd 17. 

dThese clinical observations were recorded for gd 11 through 17. 

e Numbers are presented as incidence on first exposure day (initial number) and incidence on last 

exposure day (end number).

28
RTI-908; Project 0209189.000 Final Report 

Table 5. Summary and Statistical Analysis of Ovarian Corpora Lutea, Uterine Contents, Live Fetal Sex, 

and Live Fetal Body Weight (page 1 of 3) 

G/MTBE (mg/m3, inhaled) 

0 30000 

ALL LITTERSa 9 9 

No. Corpora Lutea per Damb 11.56 12.56 

+ 1.76 + 1.37 

N=9 N=9 

No. Implantation Sites per Litterb 11.78 12.33 

+ 0.57 + 0.44 

N=9 N=9 

Percent Preimplantation Loss per Litterb 9.84 8.16 

+ 3.84 + 3.05 

N=9 N=9 

No. Resorptions per Litterb 3.67 1.67 

+ 1.41 + 1.30 

N=9 N=9 

Percent Resorptions per Litterb 32.72 13.84 

+12.92 +10.85 

N=9 N=9 

No. Litters with Resorptions 9 4 

% Litters with Resorptions 100.00 44.44££

No. Late Fetal Deaths per Litterb 0.22 0.22 

+ 0.22 + 0.15 

N=9 N=9 

Percent Late Fetal Deaths per Litterb 1.71 2.04 

+ 1.71 + 1.35 

N=9 N=9 

No. Litters with Late Fetal Deaths 1 2 

% Litters with Late Fetal Deaths 11.11 22.22 

29
RTI-908; Project 0209189.000 Final Report 

Table 5. Summary and Statistical Analysis of Ovarian Corpora Lutea, Uterine Contents, Live Fetal Sex, 

and Live Fetal Body Weight (page 2 of 3) 

G/MTBE (mg/m3, inhaled) 

0 30000 

No. Nonlive Implants per Litterb,c 3.89 1.89 

+ 1.38 + 1.29 

N=9 N=9 

Percent Nonlive Implants per Litterb,c 34.43 15.88 

+12.61 +10.70 

N=9 N=9 

No. Litters with Nonlive Implantsc 9 5 

% Litters with Nonlive Implantsc 100.00 55.56£

No. Litters with 100% Nonlive Implantsc 2 1 

% Litters with 100% Nonlive Implantsc 22.22 11.11 

No. Adversely Affected Implants per Litterb,d 4.00 2.00 

+ 1.35 + 1.27 

N=9 N=9 

Percent Adversely Affected Implants per Litterb,d 35.29 16.73 

+12.41 +10.57 

N=9 N=9 

No. Litters with Adversely Affected Implantsd

9 6 

% Litters with Adversely Affected Implantsd

100.00 66.67 

LIVE LITTERSe: 7 8 

No. Live Fetuses per Litterb

10.14 11.75 

+ 0.74 + 0.65 

N=7 N=8 

30
RTI-908; Project 0209189.000 Final Report 

Table 5. Summary and Statistical Analysis of Ovarian Corpora Lutea, Uterine Contents, Live Fetal Sex, 

and Live Fetal Body Weight (page 3 of 3) 

G/MTBE (mg/m3, inhaled) 

0 30000 

Percent Male Fetuses per Litterb 52.34 44.10 

+ 4.33 + 4.72 

N=7 N=8 

No. Male Fetuses per Litterb

5.29 5.13 

+ 0.52 + 0.55 

N=7 N=8 

No. Female Fetuses per Litterb

4.86 6.63 

+ 0.51 + 0.75 

N=7 N=8 

Average Fetal Body Weight (g) per Litterb 0.9697 0.9920 

+0.0380 +0.0440 

N=7 N=8 

Average Male Fetal Body Weight (g) per Litterb

0.9875 1.0177 

+0.0412 +0.0478 

N=7 N=8 

Average Female Fetal Body Weight (g) per Litterb

0.9424 0.9735 

+0.0304 +0.0392 

N=7 N=8 

aIncludes all dams pregnant at terminal sacrifice on gd 20; litter size = no. implantation sites per dam. 

bReported as the mean + S.E.M. 

cNonlive = late fetal deaths plus resorptions. 

dAdversely affected = nonlive plus malformed. 

eIncludes only dams with live fetuses; litter size = no. live fetuses per dam. 

£p<0.05; Chi-Square Test. 

££p<0.01; Chi-Square Test. 

31
RTI-908; Project 0209189.000 Final Report 

Table 6. Summary and Statistical Analysis of Malformations and Variations (page 1 of 1) 

G/MTBE (mg/m3, inhaled) 

0 30000 

No. Fetuses Examineda 71 94 

No. Litters Examinedb 7 8 

No. Fetuses with External Malformations per Litterc, d 0.14 0.13 

+ 0.14 + 0.13 

N=7 N=8 

Percent Fetuses with External Malformations per Litterc,d

1.19 0.96 

+ 1.19 + 0.96 

N=7 N=8 

No. Fetuses with External Malformationsd 1 1 

% Fetuses with External Malformationsd 1.40 1.06 

No. Litters with External Malformationse 1 1 

% Litters with External Malformationse 14.29 12.50 

No. Fetuses with External Variations per Litterc,d 0.00 0.00 

+ 0.00 + 0.00 

N=7 N=8 

Percent Fetuses with External Variations per Litterc,d 0.00 0.00 

+ 0.00 + 0.00 

N=7 N=8 

No. Fetuses with External Variationsd 0 0 

% Fetuses with External Variationsd 0.00 0.00 

No. Litters with External Variationse 0 0 

% Litters with External Variationse 0.00 0.00 

aOnly live fetuses were examined for malformations and variations. 

bIncludes only litters with live fetuses. 

cReported as the mean + S.E.M. 

dFetuses with one or more malformations or variations. 

eLitters with one or more fetuses with malformations or variations. 

32
RTI-908; Project 0209189.000 Final Report 

Table 7. Summary of Morphological Abnormalities in CD-1 Mouse Fetuses: Listing by Defect Typea 

(page 1 of 1) 

G/MTBE (mg/m3, inhaled) 

0 30000 

EXTERNAL MALFORMATIONS 

Total No. of Fetuses Examined for External Malformationsb 71 94 

No. of Fetuses with External Malformationsc 1 1 

% Fetuses with External Malformations 1.4% 1.1% 

Total No. of Litters Examined for External Malformationsd 7 8 

No. of Litters with External Malformationse 1 1 

% Litters with External Malformations 14.3% 12.5% 

Cleft Palate 1(1) 1(1) 

EXTERNAL VARIATIONS 

Total No. of Fetuses Examined for External Variationsb 71 94 

No. of Fetuses with External Variationsc 0 0 

% Fetuses with External Variations 0.0% 0.0% 

Total No. of Litters Examined for External Variationsd 7 8 

No. of Litters with External Variationse 0 0 

% Litters with External Variations 0.0% 0.0% 

aA single fetus may be represented more than once in listing individual defects. Data are presented as 

the number of fetuses (number of litters). 

bOnly live fetuses were examined. 

cFetuses with one or more malformations/variations. 

dIncludes only litters with live fetuses. 

eLitters with one or more malformed/variant fetuses. 

33
RTI-908; Project 0209189.000 Final Report 

34

Table 8. External Malformations in Control CD-1® Mouse Litters From Studies Performed for 

Governmental Clients at RTI From 1997 to 2002 (page 1 of 1) 

Control Group With Gastroschisisb

Study 

Code Year Study Typea No. 

Dams 

No. 

Fetuses 

No. 

Fetuses 

No. 

Litters 

Incidence of External 

Malformations 

No. Fetuses (No. Litters) 

A 2002 RF 10 138 0 0 1 (1) cleft palate 

B 2002 RF 9 123 0 0 1 (1) exencephaly 

C 1999 RF 15 184 0 0 0 

D 1999 RF 15 200 0 0 0 

E 2000 RF 14 172 0 0 0 

F 1999 RF 15 187 0 0 0 

G 2000 RF 12 165 0 0 0 

H 1999 D 24 302 0 0 0 

I 2000 D 24 326 0 0 2 (1) cleft palate 

J 1999 D 23 291 0 0 0 

K 1997 D 22 271 0 0 1 (1) cleft palate 

L 2000 D 23 283 0 0 1 (1) exencephaly 

M 2001 D 24 270 0 0 1 (1) cleft palate 

N 2002 D 20 254 0 0 6 (4) cleft palate 

O 2002 D 22 279 0 0 7 (3) cleft palate 

P 2000 D 16 196 0 0 0 

TOTAL 288 3641 0 0 18 (11) cleft palate 

2 (2) exencephaly 

a

 RF = range-finding study D = definitive study 

b

 There were no fetuses with ectopia cordis 
Appendix I: 

Inhalation Report 

Huntingdon Life Sciences, Inc. 

Study No. 04-4262 








































Appendix II: 

Individual Animal Data Tables 
Table of Contents 

A-1 Individual Maternal Body Weights and Organ Weights (g) 1 

A-2 Individual Maternal Feed Consumption (g/day) 2 

A-3 Individual Embryo/Fetal Data 3 
Appendix II 

1 

Table A-1. Individual Maternal Body Weights and Organ Weights (g) (page 1 of 1) 

Gestational Day 

Dosea Dam ID 0 5 6 7 8 9 10 12 14 16 17 17b

Gravid Uterus 

Weight 

Liver 

Weight

Paired 

Adrenal

Glands

Weight

Paired 

Kidney

Weight

0 1511 24.7 29.0 29.5 30.0 31.5 32.1 33.4 36.2 39.1 44.4 46.1 45.60 11.9625 2.6173 0.0150 0.4708

 1512 27.7 28.3 28.6 29.0 30.0 30.1 30.8 34.3 38.9 44.8 47.5 46.26 15.7460 2.4840 0.0146 0.3892 1513 27.7 29.2 30.2 30.4 30.4 30.8 32.1 35.2 39.2 45.6 47.9 46.89 15.9233 2.4676 0.0118 0.4999 1514 25.6 26.2 27.3 27.2 27.7 28.1 28.2 30.7 35.1 40.7 42.8 41.94 12.5632 2.5244 0.0123 0.4241 1515 26.6 26.6 27.3 27.9 27.5 27.3 27.0 26.9 27.5 28.5 28.2 27.41 0.1131 1.6844 0.0089 0.3874

 1516c

 1517 27.4 29.2 29.6 30.5 30.9 32.5 34.0 37.4 41.9 48.0 50.9 49.88 17.3224 2.4481 0.0126 0.4708

 1518 24.6 23.8 23.7 24.5 25.1 24.8 24.7 24.7 23.9 24.4 24.7 24.34 0.1135 1.3532 0.0085 0.3047

 1519 26.1 26.6 26.7 28.0 27.9 28.4 29.8 33.4 37.7 42.7 45.9 45.26 16.5531 2.3760 0.0101 0.4168 1520 29.0 31.0 31.6 31.9 33.2 33.4 33.8 37.8 42.4 49.3 52.6 51.39 17.0628 2.6478 0.0109 0.4350

30000 2511 25.3 26.8 26.0 26.2 26.9 27.4 28.7 33.0 38.3 45.1 48.5 48.10 18.8171 2.5123 0.0132 0.4865

 2512 26.8 28.3 27.5 27.9 29.3 29.5 29.8 32.2 37.7 43.3 46.3 45.56 14.9403 2.3680 0.0116 0.3781 2513c

 2514 26.2 26.7 27.1 27.1 28.2 28.5 29.3 31.7 35.5 42.0 44.9 44.03 13.8178 2.3036 0.0110 0.4367

 2515 26.5 27.3 27.7 28.4 28.5 28.9 29.3 32.7 36.8 43.2 46.1 45.58 17.4442 2.3534 0.0033 0.3982 2516 27.0 28.3 29.4 29.6 30.4 30.9 32.7 36.9 43.2 50.5 53.0 52.75 21.2817 2.5755 0.0116 0.4759 2517 29.5 29.3 29.9 30.1 30.3 31.2 31.7 35.5 39.7 48.4 51.3 50.28 19.8939 2.5127 0.0087 0.4627 2518 25.6 27.5 27.5 27.7 27.8 27.4 27.6 27.7 28.5 28.4 28.2 27.70 0.1236 1.6867 0.0099 0.4376

 2519 27.4 28.5 28.7 29.3 30.1 30.4 31.4 35.6 39.4 46.3 50.0 49.09 18.2453 2.4512 0.0093 0.3942 2520 27.9 28.6 28.8 29.8 29.5 29.6 30.3 33.9 38.8 43.4 46.9 45.70 15.4457 2.6996 0.0145 0.4027

aMg/m3 of gasoline MTBE vapor condensate. bBody weight at sacrifice. cFemale was not pregnant. 
Appendix II 

2 

Table A-2. Individual Maternal Feed Consumption (g/day) (page 1 of 1) 

Gestational Days 

Dosea Dam ID 0-5 5-6 6-7 7-8 8-9 9-10 10-12 12-14 14-16 16-17 5-10 10-17 0-17 

0 1511 6.0 7.5 7.2 .b 8.8 5.8 6.9 6.6 9.9 8.7 .c 7.9 .c

 1512 4.9 4.9 5.0 5.4 5.1 5.1 5.3 6.5 7.4 7.1 5.1 6.5 5.6  1513 .b 15.0 .b .b 7.9 .b 5.9 8.4 7.9 7.9 .c 7.4 .c

 1514 .b 6.0 5.8 8.4 7.6 6.3 7.3 9.1 8.7 8.1 6.8 8.3 .c

 1515 4.7 4.7 5.3 4.7 4.4 4.8 4.5 4.6 5.5 5.8 4.8 5.0 4.8  1516d 1517 5.8 5.4 6.3 8.1 6.7 6.9 6.1 6.3 .e 8.0 6.7 .c .c

 1518 5.5 4.3 5.1 4.6 4.2 4.3 4.4 3.7 3.9 4.0 4.5 4.0 4.6  1519 4.5 5.6 6.1 4.9 5.8 6.2 5.8 6.3 6.4 6.4 5.7 6.2 5.6  1520 6.3 6.4 7.6 7.5 7.6 6.2 7.3 8.0 8.1 8.2 7.1 7.8 7.2 

30000 2511 .b 4.5 4.8 5.9 6.1 6.1 6.1 8.4 8.0 8.3 5.5 7.6 .c

 2512 5.2 4.2 5.0 5.7 5.4 4.9 5.3 6.3 6.5 6.7 5.0 6.1 5.5  2513d

 2514 4.1 5.3 4.6 5.2 5.7 5.1 5.6 6.1 6.6 7.0 5.2 6.2 5.3 

 2515 5.1 4.8 5.7 5.2 5.5 5.2 5.1 6.7 6.9 6.6 5.3 6.2 5.6  2516 6.5 .b 6.6 6.5 5.3 6.5 6.7 7.5 8.1 8.4 .c 7.5 .c

 2517 5.5 6.5 6.0 5.8 6.2 6.1 5.9 7.5 7.9 8.0 6.1 7.2 6.4  2518 5.9 5.3 5.0 5.8 5.8 5.3 5.8 5.3 5.9 4.7 5.4 5.5 5.6  2519 6.2 5.1 5.8 5.3 5.9 6.2 6.8 6.9 8.4 7.3 5.7 7.3 6.5  2520 5.0 5.5 5.7 4.5 5.3 5.3 5.7 7.2 7.4 9.0 5.3 7.1 5.9 

aMg/m3 of gasoline MTBE vapor condensate. bFeed spilled; therefore an accurate feed weight could not be obtained. cInterim feed consumption value(s) are missing and therefore the overall feed consumption value could not be calculated. 

dFemale was not pregnant. eFeed was contaminated; therefore the feed weight was excluded. 
Appendix II 

3 

Table A-3. Individual Embryo/Fetal Data (page 1 of 5) 

 Implant 

 Dam Posi- Fetus Defectf

Dosea ID# NCLb # Typec tiond # Sex Wt.e Exam Type Description 

0 1511 11 1 A L 1 M 1.2080 

 2 E L 

 3 A L 2 M 1.1416 

 4 A L 3 M 1.1652 

 5 E L 

 6 A L 4 F 1.1544 

 7 E L 

 8 A R 5 M 1.1947 

 9 A R 6 M 1.2229 

 10 A R 7 F 0.8638 

 1512 13 1 A L 1 F 1.0607 

 2 A L 2 F 0.8947 

 3 A L 3 F 0.9114 

 4 A L 4 M 0.6561 

 5 A L 5 M 0.9103 

 6 A L 6 M 0.8906 

 7 A L 7 F 0.9512 

 8 A R 8 M 0.9243 

 9 A R 9 M 1.0387 

 10 E R 

 11 A R 10 F 0.9565 

 12 A R 11 M 1.0578 

 1513 18 1 A L 1 F 0.8099 

 2 E L 

 3 A L 2 M 0.9897 

 4 A L 3 M 0.9108 

 5 A L 4 F 0.8661 

 6 A L 5 M 0.8298 

 7 A R 6 F 0.7425 

 8 F R 0.2490 

 9 A R 7 F 0.7755 

 10 A R 8 F 0.7934 

 11 A R 9 M 0.8145 

 12 A R 10 M 0.8377 

 13 A R 11 M 0.8503 

 14 A R 12 F 0.8192 

 1514 13 1 A L 1 F 0.8836 

 2 A L 2 M 0.9409 

 3 A L 3 F 0.7931 

 4 A L 4 M 0.8536 

 5 E L 

 6 A L 5 F 0.9164 

 7 A R 6 F 0.9430 

 8 A R 7 M 0.9992 

 9 A R 8 F 0.9298 

 1515 0 1 I L 

 2 I L 

 3 I L 

 4 I L 

 5 I R 

 6 I R 

 7 I R 

 8 I R 

 9 I R 

 10 I R 

 11 I R 

 12 I R 

 1516 .g 
Appendix II 

4 

Table A-3. Individual Embryo/Fetal Data (page 2 of 5) 

 Implant 

 Dam Posi- Fetus Defectf

Dosea ID# NCLb # Typec tiond # Sex Wt.e Exam Type Description 

0 1517 13 1 A L 1 F 1.0828 

 2 A L 2 F 1.0061 

 3 A L 3 M 1.1616 

 4 A L 4 F 1.0813 

 5 A R 5 F 0.9930 

 6 A R 6 M 1.0533 External Malformation Cleft Palate 

 7 A R 7 M 0.9497 

 8 A R 8 M 1.1190 

 9 E R 

 10 A R 9 M 0.9991 

 11 A R 10 M 1.0107 

 12 A R 11 F 1.0039 

 13 A R 12 M 1.0375 

 1518 7 1 I L 

 2 I L 

 3 I L 

 4 I L 

 5 I L 

 6 I L 

 7 I L 

 8 I R 

 9 I R 

 10 I R 

 1519 13 1 A L 1 F 0.8887 

 2 D L 0.7886 

 3 A L 2 F 0.8797 

 4 A L 3 F 0.8849 

 5 E L 

 6 A L 4 F 0.9113 

 7 A L 5 M 0.8804 

 8 D L 0.7497 

 9 A R 6 M 0.9570 

 10 A R 7 F 0.9628 

 11 A R 8 M 0.9181 

 12 A R 9 F 0.9405 

 13 A R 10 M 0.9491 

 1520 16 1 A L 1 M 0.9749 

 2 A L 2 M 1.1073 

 3 E L 

 4 A L 3 M 1.0296 

 5 A L 4 M 1.0548 

 6 A R 5 M 1.1481 

 7 A R 6 F 0.9627 

 8 A R 7 F 1.0874 

 9 E R 

 10 A R 8 M 0.9004 

 11 A R 9 F 1.0246 

 12 A R 10 F 0.8967 

 13 A R 11 F 0.9971 
Appendix II 

5 

Table A-3. Individual Embryo/Fetal Data (page 3 of 5) 

 Implant 

 Dam Posi- Fetus Defectf

Dosea ID# NCLb # Typec tiond # Sex Wt.e Exam Type Description 

30000 2511 16 1 A L 1 F 0.9097 

 2 A L 2 F 0.8902 

 3 A L 3 F 1.0038 

 4 A L 4 M 1.0807 

 5 A L 5 M 1.0045 

 6 A L 6 F 0.9964 

 7 A R 7 F 1.1017 

 8 A R 8 F 0.9516 

 9 A R 9 F 1.0171 

 10 A R 10 F 0.9881 

 11 A R 11 F 0.9327 

 12 A R 12 M 0.9888 

 13 A R 13 F 0.8993 

 2512 13 1 A L 1 M 0.8966 

 2 A L 2 F 0.9912 

 3 A R 3 F 0.9295 

 4 A R 4 M 0.9734 

 5 A R 5 F 0.9657 

 6 E R . 

 7 A R 6 M 0.9817 

 8 A R 7 F 0.9658 

 9 A R 8 M 0.8802 

 10 A R 9 M 1.0423 

 11 A R 10 F 0.9900 

 2513 .g 

 2514 11 1 A L 1 M 0.9541 

 2 A L 2 F 0.7654 

 3 A R 3 M 0.9092 

 4 D R . 0.5424 

 5 A R 4 F 0.8117 

 6 A R 5 F 0.8227 

 7 A R 6 F 0.9987 

 8 A R 7 F 0.9737 

 9 A R 8 M 0.9013 

 10 A R 9 F 0.8918 

 2515 17 1 A L 1 F 0.9424 

 2 A L 2 M 0.9124 

 3 A L 3 M 0.8148 External Malformation Cleft Palate 

 4 A L 4 F 0.8965 

 5 A L 5 F 0.8518 

 6 A L 6 F 0.8904 

 7 A L 7 F 0.9606 

 8 A R 8 F 0.9293 

 9 A R 9 M 0.9842 

 10 A R 10 M 0.9846 

 11 A R 11 M 0.9588 

 12 A R 12 F 0.9191 

 13 A R 13 F 0.9280 
Appendix II 

6 

Table A-3. Individual Embryo/Fetal Data (page 4 of 5) 

 Implant 

 Dam Posi- Fetus Defectf

Dosea ID# NCLb # Typec tiond # Sex Wt.e Exam Type Description 

30000 2516 14 1 A L 1 M 1.3223 

 2 L L 

 3 A L 2 M 1.2995 

 4 A L 3 F 1.1934 

 5 A L 4 M 1.4107 

 6 A L 5 M 1.3818 

 7 A R 6 M 1.3251 

 8 A R 7 F 1.2660 

 9 A R 8 F 1.2325 

 10 A R 9 M 1.2527 

 11 A R 10 F 1.2141 

 12 A R 11 F 1.2527 

 13 A R 12 F 1.2403 

 14 A R 13 M 1.3281 

 2517 15 1 A L 1 F 0.9643 

 2 A L 2 F 1.0539 

 3 A L 3 F 0.9751 

 4 A L 4 M 1.1039 

 5 A L 5 M 1.0307 

 6 A L 6 M 1.0258 

 7 A L 7 M 1.0202 

 8 A R 8 F 0.9284 

 9 A R 9 F 0.9127 

 10 A R 10 F 0.8877 

 11 A R 11 F 0.9235 

 12 A R 12 F 0.9446 

 13 A R 13 M 1.0347 

 14 A R 14 F 0.9547 

 2518 3 1 I L 

 2 I L 

 3 I L 

 4 I L 

 5 I L 

 6 I L 

 7 I L 

 8 I L 

 9 I R 

 10 I R 

 11 I R 

 12 I R 

 2519 12 1 A L 1 F 0.9621 

 2 A L 2 F 0.9309 

 3 A L 3 M 1.0104 

 4 A L 4 M 1.0717 

 5 A L 5 F 0.9861 

 6 A R 6 M 0.9635 

 7 A R 7 M 1.0321 

 8 A R 8 M 0.9550 

 9 A R 9 F 0.9994 

 10 A R 10 F 1.0005 

 11 A R 11 M 1.0335 

 12 A R 12 M 0.9762 
Appendix II 

7 

Table A-3. Individual Embryo/Fetal Data (page 5 of 5) 

 Implant 

 Dam Posi- Fetus Defectf

Dosea ID# NCLb # Typec tiond # Sex Wt.e Exam Type Description 

30000 2520 12 1 A L 1 F 0.8464 

 2 A L 2 M 0.8999 

 3 A L 3 F 0.9263 

 4 A L 4 M 0.9872 

 5 A L 5 F 1.0089 

 6 A R 6 M 0.9040 

 7 A R 7 M 0.8767 

 8 D R . 0.4609 

 9 A R 8 M 0.9586 

 10 A R 9 F 0.8164 

 11 M R . . 

 12 A R 10 M 0.9416 

aMg/m3 of gasoline MTBE vapor condensate. 

bNumber of corpora lutea. 

cImplant type codes are as follows: A - Live Fetus; D - Dead Fetus; F - Full Resorption; L - Late Resorption; M - 

Middle Resorption; E - Early Resorption and I - Implantation Site. 

dPosition refers to uterine horn (R - right, L - left). 

eWeight is in grams. 

f

Absence of entries under "Exam," "Type," and "Description" for "Defect" indicates no external malformation or 

variation observed for that fetus. 

gFemale was not pregnant.