211(b) Toxicology Research Group 

Draft Final Baseline Gas + MTBE VC Chronic Carcinogenicity Study in Rats 

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Updated October 1, 2009 Final 

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EPA 

Scientists have reviewed the submission dated 

November 20, 2006 from the Section 211(b) 

Research Group of the American Petroleum 

Institute regarding the reports reviewers’ 

comments and the Research Group responses 

for the 211(b) Draft Baseline Gasoline Vapor 

Condensate Chronic Carcinogenicity Study 

and Draft Baseline Gasoline + MTBE Vapor 

Condensate Chronic Carcinogenicity Study. 

No response required. NA 

In general, the API extramural reviewers 

found that the study was appropriate 

conducted based on the current 

recommendations for a chronic 

carcinogenicity study. In addition, the 

reviewers identified several important points 

with regard to presentation and additional 

small data needs. In response to those reviews 

the Research Group has identified the 

appropriate actions. 

No response required. NA 

In addition, the NHEERL reviewers suggest 

that the following issues be considered by API 

in preparing a revised final report. 

See responses below. NA 

Comments on Study FY01-013 GMVC 

Page 3-4 [Abstract]. While there was not a 

great number of early deaths in this study, the 

summary tables use 50 as the denominator. 

This would underestimate the significance of a 

finding at the end of a study for low incidence 

events that occur late (say 600 days on study). 

For example renal tumors tend to be a late 

event and it would be more in line with the 

NTP if one were to use time to earliest tumor 

as the cutoff for the denominator for the 

exposure groups in table 3-12 and 3-14. 

A denominator of all 50 animals is considered 

appropriate since there was no treatment-related 

effect on survival and statistical analysis to 

account for time of death (logistic regression) 

was conducted. 

Additionally, the study was conducted under 

Section 211(b) Alternative Tier 2 requirements 

and EPA Health Effects Test Guidelines OPPTS 

8700-4200 “Carcinogenicity.” Testing guideline 

Section (e)(1)(i) states: 

(e) Data Reporting--(1) Treatment of Results.

(i) Data should be summarized in tabular form, 

No change 

 

1 Page numbers refer to pages in body of report and pathologist report in documents with suggested revisions. Once LRRI revises the 

report, these number will need to corrected to the final page numbers. Also note, page designation of text revision in response to 

comments was specifically requested by EPA. 
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showing for each test group the number of 

animals at the start of the test, the number of 

animals showing lesions, the types of lesions, 

and the percentage of animals displaying each 

type of lesion. 

Page 3-21, Table 3-16. Using mean severity 

score is the only way to compare as 

nephropathy would usually be a finding in 

100% of rats in any chronic study (table O-3). 

Average severity scores have been added to 

table 3-17 (formerly Table 3-16). 

3-29 

Page 0-11. Top of page – a2u-globulin could 

account for these results. 

Alpha-2u-globulin overload as a potential 

mechanism for induction of male kidney 

adenomas has been specified in this discussion, 

since this mechanism has previously been 

associated with light hydrocarbons and MTBE 

in induction of renal adenomas, renal 

carcinomas and increased severity of 

nephropathy in male rats. 

P-14- P15 

Page O-14. Last sentence of full paragraph in 

middle of page beginning ...However, - this is 

an incorrect interpretation. It is not possible 

to specifically differentiate chronic 

nephropathy from a2u from chronic 

nephropathy due to spontaneous CPN in a 2-

year old male rat. If the lesions of linear 

mineralization are present in the animal they 

are typically associated with a2u but absence 

of that change does not rule out a2u 

contributing to the nephropathy. The protein 

a2u-globulin is no longer produced by the rat 

liver as the rat ages, usually after 1 year of age 

and so would not be expected to be present in 

the kidney of 2-year old rats. Therefore, it is 

not unexpected [RG note: ‘unexpected’ should 

probably be ‘expected’] to find to hyaline 

droplets in an aged male rat with a2u-induced 

tumors. Nephropathy in the female rats, does 

not indicate anything about the contribution of 

a2u in the males. 

Text in both the pathology report (Appendix P) 

and the body of the report has been revised to 

indicate that (1) CPN can mask a2u-globulin 

overload induced male nephropathy in older 

male rats; (2) a2u-globulin overload in the first 

year of life can increase the severity (not 

incidence) of male CPN; (3) a2u-globulin 

production by the male rat liver typically stops 

at ~ one year of age; (4) a2u associated hyaline 

droplets would not be expected after production 

of a2u-globulin ceases; (5) a2u-globulin 

nephropathy is male rat specific and would not 

be involved in female CPN; and (6) due to the 

sex differences, female CPN effects cannot be 

used to substantiate any conclusions in males 

regarding the role of a2u overload in male CPN 

and renal tumor induction. 

P-14 to P-15; 3-

29 

The following references should aid in 

interpretation of these data: 

• Licata et al. Tox Sci 62:191-204, 

2001 

• Williams and Borghoff. Tox Sci 

The RG and investigators thank EPA for 

providing these references to aid in data 

interpretation. 

[Note - Refs focus on MTBE as an a2u-globulin 

Cruzan reference 

used. P-16. 
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57:146-155, 2000 

• Williams et al. Tox Sci 54:168-176, 

2000 

• Prescott-Mathews et al. TAAP 

157:60-67, 1999 

• Poet and Borghoff, TAAP 145:340-

348, 1997 

• Prescott-Mathews et al. TAAP 

143:301-314. 1997 

• Borghoff et al. Fundam App Tox 

30:264-275, 1996 

inducer; MTBE as an inducer of testosterone 

biotranformation, altered endocrine responses & 

Leydig cell tumors; and MTBE & TBA PBPK 

models in rats and MTBE PBPK model humans. 

A recent review of MTBE tumorigenicity modes 

of action may also be of interest to the 

investigators; Cruzan et al., Reg. Tox. Pharm.

47:156-165, 2007] 

 

Peer Reviewer – Schlesinger 

Overall, this was a clearly written concise 

report, except for the Conclusions. As an 

aside the variability of the three exposure 

atmospheres was almost identical, which is 

excellent for a study of this duration (Table 3-

2). There were no significant deviations from 

the accepted study protocol that would have 

affected the outcome. However, the 

conclusions and summary need to be modified 

so that the reader has a clear “picture” of 

changes induced by exposure and of the 

biological significance of these in relation to 

the goals of the study. As written, things 

seem to be somewhat “muddled” and this 

reviewer, after, reading the report, could not 

decide whether the exposures did or did not 

result in biologically significant effects of 

potential concern to human health. 

The conclusions and summary have been 

modified to present a clearer picture of changes 

induced by exposure and of their biological 

significance. 

iii, S-3, 3-22 

p. 2.3 Diet and Drinking Water. How did the 

investigators conclude that any contaminants 

in the diet or water would not interfere with 

the study results? Were there any 

contaminants present and, if so, what were 

they? 

The methods section has been revised to indicate 

that the diet was analyzed by the manufacturers 

for various contaminants and that established 

maximum allowable concentrations were not 

exceeded. It will also indicate that water 

analyses for heavy metals, pesticides, PCBs, 

nitrates and microbes are conducted routinely by 

an independent laboratory and that all analytes 

are sufficiently low as to not interfere with the 

outcome of the study. 

2-4 

p. 2-11. Statistics. Body and Organ Weights. 

It is noted that if data were homogeneous, that 

significance was assessed using a modified 

The methods section has been revised to indicate 

that ANOVA is run as part of the statistics 

package. The Path Tox statistical package 

2-12 
211(b) Toxicology Research Group 

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Dunnett’s test. This is a post hoc test to assess 

differences between groups after a primary 

statistical test, such as ANOVA, is performed. 

What primary test was used in this regard by 

the investigators? Furthermore, how was the 

Dunnett and t-test modified and, for the latter, 

was any correction used for multiple testing? 

discussion of test modifications was limited; 

information available will be provided. 

p. 3-2. Confirmation of Absence of Aerosols. 

I would change the section title to Aerosol 

Concentration Analysis. In any case, were the 

particle measurements taken throughout the 

actual the exposure period or only in the preexposure calibration period? 

The Workgroup prefers the existing section title 

since the title “Aerosol Concentration Analysis” 

implies that aerosols are expected and are being 

characterized. These measurements were taken 

during the chamber trials. 

No particle measurements were taken during the 

actual exposures since animal dander could 

contribute to particles in the exposure 

atmosphere. 

Details on the TSI instrument use for particle 

analysis are now provided in Appendix E, page 

E-54. Actual data are provide on pages E-20 to 

E-31. No limit of detection has been located. 

No change to pg 

3-2. Appendix E, 

pages E-20 

through E31 and 

pg E-54 

p. 3-3. Gas Chromatographic Profiles of 

GMVC Exposure Atmospheres. It is noted 

that profiles remained “acceptably” constant 

through-out the study. What was the standard 

of acceptability? 

There was no rigorous standard of acceptability 

with respect to individual hydrocarbons. The 

Research Group is satisfied that the profiles 

generated and reviewed regularly demonstrated 

reproducible exposure atmospheres. 

No change 

p. 3.3. Mortality. The difference among the 

groups for the females is very close to the 

accepted level of significance at p=0.07. 

Should the results thus be carefully assessed 

for actual biological significance or was the 

exposure data statistical analysis made 

artificially close to statistical significance 

because the control values seem to be low 

after 600d. Some further discussion is needed 

about results that are close to statistical 

significance. 

In comparing the mean survival of control 

females in this study (666±11.5) with BGVC 

female control survival (687±11.4) and a 

previously conducted chronic inhalation study at 

this facility (682±10), GMVC control female 

survival was low. This would explain the low p 

value. The RG feels there is no biological 

significance for the higher mean survivals of the 

treated groups. 

No change 

p. 3-9. Clinical Signs of Toxicity. Some 

summary table would be useful here. 

Since there were no treatment-related effects on 

clinical observations, a summary table is not 

necessary. 

No change 

 
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p. 3-12. Table 3-9. The value for lungs for 

Male Exposure Group 2 shows a mean larger 

than in groups 3 and 4, yet is apparently not 

statistically significantly different from 

control due to the larger SD. Some 

explanation is needed, since this appears to 

indicate a real change in organ to body weight 

at all levels of exposure. 

There were no significant increases in absolute 

lung weights in any treatment group (Table 8). 

The significant increases in the lung-to-body 

weights in Table 9 are consistent with the 

treatment-related decreases in body weight for 

the mid- and high treatment groups, and are 

considered to be caused by the treatment effects 

on body weight rather than treatment-related 

effects on lung weight. The text has been 

revised. 

Table 8, pg 3-11; 

Table 9, pg 3-13 

and text on pg 3-

12 

p. 3-10. Percent Organ to Body Weight at 

Final Sacrifice. It is noted that the “effects 

were exposure concentration dependent.” 

However, this should be stated as an “eyeball” 

observation, since there was not trend analysis 

or no testing of exposure groups vs. each 

other, as opposed to exposure vs. control. 

No statistical test was performed to evaluate 

concentration dependence. The text has been 

modified state that there is an ‘. . . apparent

trend’ for exposure concentration dependence. 

3-12 

p. 3-15. Table 3-11. Was cell analysis 

performed at the lower exposure levels. 

Cell analysis was not performed at the low- and 

mid-exposure levels. 

No change 

p. 3-14 Proliferative Lesions. Data for 

testicular cell adenomas noted here does not 

seem to be included in Table 3-12. 

The data for testicular cell adenomas is included 

in Table 3-12. 

3-18 

p. 3-16. Table 3-12. The investigators should 

address the finding that the value for 

mononuclear leukemia for spleen at the high 

exposure level is not significantly different 

from control while the same mean values at 

the other exposure levels are different from 

control. 

Is it a function of the differences in sample 

size at the low and mid concentration and, if 

so, what conclusions of biological significance 

should be made for this endpoint? 

The high incidence of leukemia in low- and middose groups is likely a function of the low “n” 

since only spleens that appeared abnormal at 

gross observations were subjected to further 

analysis. It is likely the incidence in the mid and 

low dose groups would decrease if all spleens 

were analyzed. The Research Group appreciates 

the reviewer’s point about statistical significance 

and biological significance; however 

mononuclear cell leukemia is a common and 

expected phenomenon in aging rats. 

No change 

p. 3-16. Proliferative Lesions. It is noted that 

diagnoses were made on animals where gross 

lesions in the spleen were present and 

therefore there was some sampling bias. If so, 

how would this have affected the conclusions 

and why was the study conducted in a manner 

This study was conducted in compliance with 

EPA OPPTS 870.4200 as specified in the Clean 

Air Act Section 211(b) regulation. Toxicology 

studies very commonly use protocols in which 

all tissues at the highest level of exposure are 

examined for abnormalities, and at the lower 

No change 
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that included such bias? levels of exposure, only target tissues and tissues 

with gross findings are examined further. While 

this might introduce what the report and 

reviewer refers to as “sampling bias” and 

spurious incidences of statistical significance at 

the lower exposure levels, the Research Group 

believes the high incidence of mononuclear 

leukemia in spleen is more likely related to the 

low “n” based on evaluation of only spleens that 

appeared abnormal at necropsy at the terminal 

sacrifice. Had a significant number of findings 

been present in the high exposure group, all 

tissues in the lower dose groups would have 

been examined, as instructed in the protocol. 

This explanation for protocol-driven bias in the 

mid-dose groups is included in the report text. 

p. 3-18. Conclusions. In the third paragraph, 

it is noted that “...effects seen at 12 

months...were more likely due to difficulties 

in blood sampling than to GMVC inhalation.” 

What is the scientific basis for this 

conclusion? 

The difficulties in blood sampling at 12 months 

are explained on pg 3-15. 

No change 

p. 3-21. Conclusions. A better summary 

paragraph is needed at the end of this section. 

The term “few differentiators” is too vague 

and nonconclusive. 

This section of the conclusions has been revised 

to better describe the comparisons between the 

health effects BGVC and GMVC. 

3-22 thru 3-30 

p. O-8. Appendix O. Pathologist Report. As 

noted above, why was there a “protocol driven 

sampling bias” and how would such a bias 

affect conclusions of health significance of the 

test material? 

The explanation of protocol driven sampling 

bias is presented on pg P-11 and P-12. The 

biological significance of low- and mid-level 

sampling bias is that statistical increases in 

lesions found only at these two doses and not the 

high dose are spurious and not treatment related. 

No change, P-11, 

P-12. 

 

Peer Reviewer – Goldsworthy 

I have reviewed the API sponsored draft final 

report “211(b) Chronic Carcinogenicity 

Gasoline MTBE Vapor Condensate 

(GMVC)”. The purpose of the study was to 

evaluate the chronic toxicity, potential 

carcinogenicity and exposure-concentration 

response relationships associated with 

inhalation of GMVC. Groups of 50 male and 

No response required. 
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50 female F344 rats were exposed in H2000 

whole-body inhalation chambers at GMVC 

vapor concentrations of 2g/m3 (low level), and 

20g/m3

 (high level) for 6 hours/day, 5 days a 

week for 104 weeks. 

The study was appropriately designed and 

adequately conducted to assess the chronic 

toxicity and carcinogenicity of GMVC. 

Protocol deviations noted did not adversely 

affect the outcome of the study. 

Mean GMVC exposure concentrations were 

within a few percent of target through the 

study and were demonstrated to be 

reproducible from day to day. Relative 

percentages of major hydrocarbon 

components of condensate were constant 

throughout the exposure period. Homogeneity 

of vapors was distributed evenly within each 

chamber. Data on the daily percent normal 

usage demonstrated good agreement between 

anticipated and actual GMVC usage. 

Collectively, the GMVC whole body exposure 

procedures were properly conducted and 

allowed for the GMVC-induced toxicity and 

carcinogenicity assessments. 

GMVC did not affect survival and no clinical 

observations of toxicity were attributed to 

GMVC exposure. Serological analyses on 

sentinels were negative throughout the study. 

(Note: data, in C-2/C-3, is for only 5 animals 

that were tested on 5-30-01 even though text 

states that 10 animals (5 male/5 female) are to 

be tested). 

Due to the staggered start of the two studies, 

sera was collected and analyzed for the 5 males 

(5/22/01) and 5 females (5/20/01) separately. 

No change 

Text, p. 2-3, state that no contaminants were 

known to be in the diet or water in quantities 

that would be expected to interfere with study 

outcome; whereas it is stated that actual 

testing of water and diet were done annually, 

data is not presented. 

Diet and Water - the methods section has been 

revised to indicate that the diet was analyzed by 

the manufacturers for various contaminants and 

that established maximum allowable 

concentrations were not exceeded. It will also 

indicate that water analyses were conducted 

routinely by an independent laboratory and that 

all analytes are sufficiently low as to not 

interfere with the outcome of the study. These 

data are now in Appendix D-1. 

2-4; Appendix D1 
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Body weight of high-level GMVC males and 

high and mid-level GMVC females were 

lower than control animals during the study, 

and at final sacrifice in high level GMVC 

males and females. Text should note the 

percentage decrease in body weight at final 

sacrifice. Due to study start delay, the body 

weights of high-level males and mid and highlevel females at Day 1 were significantly 

below controls. Thus it would be appropriate 

for text/tables to present body weight gain 

data (this is routinely done) and may shed 

further light on the GMVC induced weight 

losses. 

The percent decrease in body weights at final 

sacrifice have been added to abstract, summary 

and results text. The body weights and percent 

of treated:control body weights presented in 

Tables 3-5 and 3-6 are considered to adequately 

demonstrate the treatment effects on body 

weight, without addition of a table on body 

weight gains.

i, S-1, 3-6, 3-7 

Statistical differences in high level exposed 

males were noted in hematological parameters 

at 12 months. Differences were not found in 

females, nor were they present at the 18 

month and terminal sacrifice. Report 

correctly notes that these changes should be 

“interpreted with caution”. Report also notes 

that results in 12 month males possibly were 

affected “by the tail sampling techniques, 

which improved by 18 months” (p. 344). 

However, in the pathologist report (p. 0-5), it 

was noted that these results may result “from 

initial blood sampling difficulties”. Were 

there difficulties? If so, these should be 

described in the results section to allow for 

full interpretation of these noted results. 

Additionally, it would be worthwhile to see 

and compare to similar data in the BGVC 

study; emphasis on the significance of these 

data would depend on the absence or presence 

of these findings within both studies. 

The difficulties in blood sampling at 12 months 

are explained on pg 3-15. A comparison of 

results between studies is difficult to interpret 

since there was difficulty in blood sampling in 

both studies at 12 mos, and there was no 

consistency in results between the two studies at 

the 12 month time point. Difficulties in drawing 

blood at 12 months (first time point) is 

considered to be a suitable explanation for the 

observed changes. 

No change 

Brain weights, adrenal weights and 

epididymides weights were less than 

corresponding controls among various dose 

groups. Absolute kidney and percent kidneyto-brain of all GMVC-exposed groups were 

significantly increased compared to controls. 

Kidney-to-body weights was significantly 

increased among males exposed to mid and 

high levels of GMVC. 

No response required.
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Histopathology revealed significant increases 

in proliferative lesions 

(adenomas/carcinomas) and nonproliferative 

lesions. Chronic nephropathy was observed at 

a high incidence in controls and exposed male 

and female study animals. Of particular 

relevance to the observed renal proliferation 

lesions, the severity of nephropathy was 

significantly increased in mid- and high-level 

males and high-level females. This finding 

may be a contributor to the induction of 

adenomas. Since severity, not incidence, may 

be a more relevant observation, conclusion 

section should emphasize this point more so 

than what is currently represented, including 

providing severity score in Table 3-16. Other 

non-proliferative lesions in GMVC-exposed 

rats were hyaline degeneration of olfactory 

epithelium (males) and respiratory epithelium 

(females) of the nose, an expected finding. 

Discussion of the severity of nephropathy has 

been added. Comparisons of effects seen with 

BGVC are also now provided. 

3-21, 3-21, 3-23, 

Table 3-13. For 

comparisons see 

Table 3-17, and 

pages 3-28, 3-29. 

The most significant responses observed in 

this study were the statistical increases in 

renal tumors and testicular interstitial 

adenomas. Testicular adenoma incidence was 

quite high in control males and was 

significantly greater in mid-dosed males. A 

number of comments pertain to the renal 

tumor findings: 

Text should more comprehensively note the 

renal tumor response and not just note the 

single statistical change in the mid-level male 

rats. For example, 10 tumors were observed 

in the study and all were found in exposed 

animals, and two carcinomas were observed in 

exposed animals (carcinomas are very rare in 

untreated rats). 

Renal tumor response have discussed in more 

detail for clarity and completeness. 

3-17 

Hyperplasias and atypical hyperplasias should 

be evaluated and noted in tables and text 

where proliferative renal lesions are 

discussed; these lesions are considered 

relevant to the end-stage adenoma/ carcinoma 

response. 

Hyperplasias and atypical hyperplasias were not 

observed in the kidneys of these animals.

No change 

It is surprising that (1) a statistical trend was Statistics have been performed on the combined Table 3-12, Pages 
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not observed in the induction of renal lesions, 

and (2) that, in mid-level exposed rats, the 

renal tubule adenoma and carcinoma, 

combined, is not significantly statistical even 

though values are the same as adenoma alone. 

renal adenomas and carcinomas incidence data 

and added/discussed in the revised report. 

3-17 and 3-18, 

Appendix O. 

Text (p. S-1) states incorrectly that the 

incidence of renal tubule adenomas was 

statistically increased in high-level males – it 

should be mid-level exposed rats. Also, text 

(p. 3-19; Table 3-14) has an error in reporting 

BGVC control results; the renal tubule 

adenoma, renal tubule carcinoma, combined 

must be “1(2%)” if the adenoma renal tubule 

result is correct. Are BGVC statistical 

differences noted? 

The text has been corrected to indicate that the 

mid-level exposed rats had statistically increased 

renal tubule adenomas. The error in the 

combined incidences of control renal adenomas 

plus carcinomas in Table 3-14 has been 

corrected. Statistics were not initially performed 

on the combined results; that has been corrected 

in the revised report. 

I, ii, S-1, S-2, 

Table 3-15, 

Appendix P, 

Table P-2. 

I recommend that a kidney step section review 

is undertaken to further understand the 

unusual dose-response observed in renal 

tumors and to better assess the renal findings 

in the two studies (BGVC and MGVC) being 

compared. Following evaluation of chronic 

carcinogenicity studies (NTP and others), an 

increased incidence of proliferative renal 

tubular lesions (hyperplasia, adenoma and 

carcinoma) may be observed in treated groups 

compared to controls. Often, full 

understanding requires further investigations 

of the kidney tissues to confirm the overall 

incidence of renal lesions. Kidney step 

section reviews are conducted on additional 

sections per kidney. Results are summarized 

by treatment group which show the incidences 

seen in the original kidney section, the kidney 

section review, and a combined incident table 

of lesions seen in both the original kidney 

sections and in the step sections. Given the 

importance of the renal lesions following 

hydrocarbon exposure and the difficulties in 

evaluation, I also would recommend a Peer 

Working Group (PWG) on the kidney 

histopathology analyses for the MGVC and 

BGVC studies. 

The Research Group questions the necessity of 

reconfirming the current study results and 

previously reported associations between 

gasoline and neat MTBE treatment and 

induction of renal adenomas and carcinomas 

with a male kidney step section and/or 

Pathology Working Group review. 

Additionally, this type of analysis would not 

have the benefit of cell proliferation assessments 

and immunohistochemical staining for α2-u 

globulin. 

Not applicable 

Discussion should comment if earlier deaths 

and/or body weight losses noted in the highlevel GMVC exposed rats would affect the 

The results section has been revised to comment 

on the influence of mortality on renal 

adenoma/carcinoma response. 

3-17 
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renal adenoma/carcinoma response noted. 

In previous studies in rodents, unleaded 

gasoline and MTBE have been postulated to 

interfere with the hormonal milieu and 

potentially impact lesion development, 

including liver tumors and uterine atrophy in 

female mice, and the testicular and mammary 

gland findings in rats. In this light, it was 

interesting to note that data demonstrated 

increased mammary gland hyperplasia and 

increased fibroadenoma in female rats. This 

data should be noted in Results and discussed 

comprehensively. 

Testicular and mammary gland findings along 

with the pathologists conclusions have been 

brought into the main body of the report and 

pathologist’s report and discussed appropriately. 

A brief discussion on the mechanistic hypothesis 

of hormonal disruption has been added in the 

Results section. For mammary gland hyperplasia 

in males, there was a trend toward an increase in 

incidence, but because there was no hyperplasia 

in the mid dose group, there was no real doseresponse relationship. Further, if the hyperplasia 

were a result of GMVC exposure, tumors would 

have been expected, but were not seen in a 

concentration-dependent manner. With 

fibroadenomas in females, although the 

incidence of adenomas was statistically 

increased in the low dose (15%) and high dose 

(11%) groups, the control group incidence was 

extremely low (0%) compared to expected 

values reported in the literature by Boorman et 

al and Haseman et al. These ranges were 27-

40%. The references were cited by the 

pathologist in his report. 

3-17 Table 3-12, 

P-12, P-13, Table 

P-2. 

The pathology report is presented in Appendix 

O. Page O-6 states that it is “unlikely that the 

(renal) carcinoma(s) was related to GMVC 

inhalation”; given the rate of occurrence of 

this lesion in untreated rats, the preponderance 

of literature findings and the other renal 

lesions (adenomas) seen in the present study, I 

disagree with this comment. 

The Research Group agrees that the renal 

carcinomas were treatment-related for the same 

reasons given by the reviewer. Although the 

incidence of these lesions may not be 

statistically different in treated vs. control 

groups, the background incidence of renal 

carcinoma is low in male F344 rats, thus the 

observed increases in treated groups are 

biologically significant. Additionally, the lesions 

observed in this study confirm previously 

reported associations between gasoline and neat 

MTBE treatment and induction of renal 

carcinoma in male F344 rats. The discussion of 

these effects has been expanded and modified to 

conclude that the renal findings are treatmentrelated. 

i, iii, S-1, S-3, 3-

17, 3-23, P-6, P14, P-19 

The Pathology report notes the likelihood of 

“gross lesions sampling bias” (p O-8). Where 

findings are significant or possibly considered 

significant, or also seen in the BGVC study, 

then I would consider evaluating all animals 

This study was conducted in compliance with 

EPA OPPTS 870.4200 as specified in the Clean 

Air Act Section 211(b) regulation. Toxicology 

studies very commonly use protocols in which 

all tissues at the highest level of exposure are 

3-20, Table 3-12 
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in these dose groups to avoid the potential bias 

and difficulties in interpretations. As stated 

above, mammary gland hyperplasia and 

fibroadenomas of the mammary gland have a 

mechanistic underpinning to BGVC/MGVC 

exposure. Thus, I would like to know what 

information was used by the Pathologist to 

lead him to choose to list both of these 

findings as “not attributable to GMVC 

exposure” (Table O-5 and O-6). 

examined for abnormalities, and at the lower 

levels of exposure, only target tissues and tissues 

with gross findings are examined further. While 

this might introduce what the report and the 

reviewer refer to as “sampling bias” and 

spurious incidences of statistical significance at 

the lower exposure levels, the Research Group 

believes the higher lesion incidences in the lowand/or mid-dose groups are more likely related 

to the low “n” based on evaluation of only 

spleens that appeared abnormal at necropsy at 

the terminal sacrifice. Had a significant number 

of findings been present in the high exposure 

group, all tissues in the lower dose groups would 

have been examined, as instructed in the 

protocol. This explanation for protocol-driven 

bias in the mid-dose groups is included in the 

report. The rationale for not attributing the 

mammary findings to treatment has been 

included, as described in the response to the 

similar comment above. 

 

211 (b) Research Group Comments2 

The following EPA comment made on BGVC 

report is also relevant to GMVC: 

“Page O-6. 2/27 thyroid follicular cell 

carcinomas would be of concern for a tumor 

that is very rare in control rats, especially 

when associated with thyroid follicular 

hyperplasia. Likewise nasal squamous cell 

carcinoma is very rare in rats so should not 

have been so easily dismissed.”

The RG feels the incidence data should be 

reviewed for both studies along with LRRI (and 

other?) historical control data to aid in 

interpretation of these findings. A table 

summarizing the incidence data from both 

studies and NTP historical controls is attached 

for LRRI’s convenience. 

Squamous cell carcinoma was reviewed by the 

pathologist. The lesion was determined to be of 

oral, not nasal origin. This, along with historical 

data are now provided in the text and in the 

Pathologists report. 

Without access to LRRI historical controls, the 

RG cannot form an opinion on the relationship 

between treatment and thyroid follicular cell 

carcinoma incidence. Incidence from BGVC 

study is consistent with GMVC study. Thyroid 

tumors reviewed by the pathologist and found 

not to be statistically significant. 

Comparisons of results in the BGVC and 

ii, S-2, 3-19, 3-

29, Table 3-12; P7, P-15. Table P2 

Comparisons 

found on pages 3-

23 to 3-30. 

 

2 API minor editorial comments that were already addressed in the 9/2/04 draft or were duplicative of EPA/independent peer reviewer 

comments are not included.
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GMVC report are now provided. 

Relationship of GMVC treatment to testicular 

interstitial cell adenomas: 

After review of data from both reports, and 

previous literature to include a recent review 

on mechanisms of MTBE induced cancer in 

rodents (Cruzan et al., 2007 added to refs in 

report), rather than a definite association, an 

‘equivocal’ association between treatment and 

tumor may be more appropriate. The high 

background incidence of this tumor (43/50 for 

GMVC and 48/50 for GBVC) tends to 

confound interpretation. 

Suggested revisions throughout the report. ii, S-2, Table 3-

12, 3-17, 3-22, P7, P-15. 

Page 2-1. 1st para, indicate that the 

concentration of the MTBE in the gasoline 

from which the vapor condensates were 

prepared was 15%. 

We are continuing to use 20% as that was the 

concentration in the vapor exposure atmosphere. 

I, S-1, page 3-24 

and Table 3-14. 

Page 3-3. Middle of page, change 

“Mortality” to “Survival Analysis” to be 

consistent with BGVC report. 

Revised to “survival analysis” 3-3 

Page 3-18. 1st sentence – indicate that the 

severity of the hyaline degeneration is very 

low (0.2-0.3 out of possible score of 4). 

Text has been revised to indicate range of 

severity scores. 

3-22 

Page O-5, O-7, O-13. Pathology report has 

what appear to be reporting errors for 

• 12 mos male hematology changes 

• “Increased incidence” of male rat 

nephropathy in the mid-dose group. See 

stat report, pg N-22: no differences in 

nephropathy incidence for any group 

were reported. Is the stat report in error? 

It does look as though there could be a 

statistical difference between the control 

incidence of 44/50 (88%) and mid-dose 

incidence of 50/50 (100%) 

Text has been corrected to agree with 

hematology results table in body of the study 

(Table 3-11) and nephropathy incidence results 

in statistical report. 

P-5, P-9, P-17 

Table P-3 

 

Inclusion of comparisons between BGVC and 

GMVC results in the conclusion section is 

Text has been revised to break out 

GMVC/BGVC comparison into a separate 

3-23 to 3-30 
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very useful. It is suggested that this 

comparison be broken out into a separate 

section so as not to cause confusion with the 

conclusions from the GMVC study itself. 

section after GMVC study conclusions 

Summary of the organ weight changes 

contradicts the summary tables in the results 

section. 

Text corrected in abstract and summary. i, S-1 

Pg 3-1: Chamber Trials – the data for the 

chamber trials should be added to the report as 

an appendix, there is no appendix data to 

verify results summary provided in the text. 

The data are now provided in revised Appendix 

E. Results of feed and water analyses have been 

inserted as new Appendix D 

E-2 through E-8. 

Pg 3-2: Homogeneity of Vapor Concentration 

– raw data should be added to report as an 

appendix to substantiate the summary 

conclusions. 

The data are now provided in revised Appendix 

E. Results of feed and water analyses have been 

inserted as new Appendix D.

E-9 through E-15. 

1. 3rd paragraph – last sentence stating that 

presence of atypical lymphocytes is 

consistent with age-related leukemia 

seemingly contradicts the finding in 

females of a significant decrease in 

atypical lymphocytes in high dose 

females, particularly since the splenic 

leukemia incidence was not significantly 

different from controls. It should be 

noted that significance of the female 

finding is unknown (or some other 

explanation, if there is one). 

Text has been revised to indicate that the 

significance of increased incidence (over time) 

is unknown. There is no significant difference 

between the incidence of high dose and control 

females at the 24 month time point. 

3-15 

Pg 4-1,2: Protocol Deviations – need 

investigator conclusion as to the impact of 

deviation in “Temporary Loss of 

Environmental Monitoring System Operation” 

on the study (no impact?) 

Text revised to state deviations had no impact on 

study integrity. 

4-6 

Gross Findings at Necropsy – this data is not 

presented in summary form or by individual 

animal in either the report or the appendixes. 

This data should be included in the report (it is 

an OPPTS 870-4200 guideline requirement). 

Gross necropsy findings are now included in the 

pathology appendices M and N. 

M-2 and N-2 
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211(b) Research Group QA/QC Reviewer 

General Comments: 

Date of Site Visit and Review: November 8-

10, 2004 

The draft final report for the Chronic 

Carcinogenicity Study was audited to assure 

compliance with the study protocol and GLP 

regulations (Part 79.60) and to verify that the 

report accurately reflects the data collected. 

One hundred percent of the text was verified 

with tables and appendices. At least 20 

percent of individual values were verified and 

20 percent of summary tables were verified 

with individual data. 

No response required. 

The following items require further 

consideration: 

1. Abstract, Page I, Fifth line: containing 

“approximately” 15%. 

Corrected to approximately 20% (sentence is 

describing the MTBE content of the vapor 

condensate, not the neat fuel used to make the 

condensate) 

I, S-1 

2. Abstract, Page I, last paragraph, first 

line: This incidence is referring to the 

mid-dose male rats and should indicate 

so. 

Correction already made in 2nd draft of report I, S-1 

3. Abstract, Page viii: A subcontractor is 

listed as the Statistician. This was not 

included in the protocol and should have 

been handled as an amendment, or now 

as a deviation. 

This protocol deviation has been added 4-1 

4. Abstract, Page viii: The Study 

Pathologist was changed from the 

original protocol and should have been 

amended. 

This protocol deviation has been added 4-1 

5. Abstract, Page x: The QA Statement 

should indicate more detail with respect 

to Phase inspections and data audits. 

What procedures or data were 

inspected/reviewed? 

More detail has been added.. xi- xv 
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6. Abstract, Page xi, and the Introduction, 

page1-1: The GLP Compliance 

Statement should indicate that the study 

was performed in accordance with the 

EPA regulations........ It seems that 

there are many procedures, not 

necessarily indicated in the protocol, that 

needed to be conducted in compliance 

with GLPs. 

EPA regulations and guidelines and exceptions 

have been added. 

xvi 

7. API will need to sign a compliance 

statement as well. It will need to include 

the fact that the method of fabrication 

was not available at the time the study 

initiated. It is, however, presently 

available. This statement can be 

separate from the Lovelace one, or a 

signature block can be added with the 

above statement to the one presented in 

this report. 

Fabrication statement & signature block for API 

added to existing compliance statement 

xvi 

8. Page 2-3, last sentence of first 

paragraph: Oxygen concentration was 

monitored but not recorded. It was 

recorded at some interval, wasn’t it? 

Please clarify. 

Oxygen concentration was monitored but not 

recorded. 

9. Page 2-4, Table 2-1, last line: All 

protocol-required tissues collected. 

Text revised. 2-5 

10. Page 2-11, Statistics: For Body and 

Organ Weights there were different 

statistical methods to be used. The ones 

listed here are for Organ Weights. 

Please indicate how Body Weights were 

evaluated. 

The text was revised to indicate that the 

statistical methods for body weights, organ 

weights, organ to body weight and organ to 

brain weight calculations all were done using the 

same statistical methods. 

2-12 

11. Page 2-12, Analysis of White Blood Cell 

Total and Differential Cell Counts: The 

protocol-prescribed statistical methods 

were not used, probably, because 

distributions were skewed. Since there 

were significant interactions between 

time and group, comparisons were done 

This protocol deviation has been added. 4-2, 4-3 
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to compare dose groups at each time 

point and to compare time points within 

each dose group. The protocol did not 

indicate that the three time points would 

be compared. Please comment. 

12. Page 2-13, Histopathology: The 

protocol indicates that statistical 

evaluation listed as number 2 (logistic 

regression) would be used, as well as the 

Hoel-Walburg test. The other tests (1, 

Cochran-Armitage and 3, Fisher’s exact) 

may be used as well, but the logistic 

regression and Hoel-Walburg test were 

protocol-required. Please comment. 

This protocol deviation has been added. 4-2, 4-3 

13. Page 3-1. Table 3-1: I could not verify 

exactly the values reported for the Day 2 

and 3 Achieved Concentrations. Could 

this be a rounding issue? Please verify 

these values. 

The data were verified against the date in 

Notebook 7401. The day 2 and Day 3 achieved 

concentration stability are correct. They are also 

correct in Appendix E (formerly Appendix D). 

No change 

14. Page 3-3, Chromatographic Profiles of 

GMVC: The reason for analyzing all 

large tanks of GMVC was to show that 

all tanks were similar in profile and to 

show that the test material was stable 

throughout the entire testing period. 

This should be indicated. 

This explanation was added to pg 2-1. 2-1 

15. Page 3-3, Animal Disposition: The 

second sentence should probably read, 

“The majority of animals not reaching 

termination underwent moribund 

sacrifices.” 

Revision made. 3-5 

16. Page 3-4, Figure 3-1: This is not the 

same figure as in the Stat. Report of the 

same information. Which one is correct? 

The figures now match. 3-4 

17. Page 3-6, Table 3-5, the Mean Body 

Weight for Day 7 for Group 2 should be 

193.8, I believe. As well, why are some 

values carried out to a tenth of a gram, 

This has been corrected. 3-7, 3-7 
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while others are not? Please clarify. 

18. Page 3-9, second sentence: Body weights 

of high-level male and female rats 

remained statistically significantly 

below control values for the study. 

Text has been revised. 3-9, last 

paragraph. 

19. Page 3-9, Table 3-7, footnote b is not on 

the table. Should it be? 

There is no footnote b 3-7 

20. Page 3-10, third to last sentence: The 

epididymides weight was significantly 

decreased among mid-level males. As 

well, liver organ-to-body-weight ratios 

for high-dose males are statistically 

significantly increased. 

Text revised for epididymides. 

LRRI to verify if liver organ-to-body weight 

significantly increased. This is not indicated in 

table 3-9, nor do the values appear to be 

different by visual inspection. 

The liver statistics were verified on Jan 29, 2009 

by JB. The liver to body weight ratio for high 

level males at final sacrifice was not 

significantly increased. No text change 

necessary. 

3-10 

21. Page 3-11 to 3-13: these tables are only 

terminal sacrifice animal organ weights. 

This should be indicated clearly on the 

table. 

Table titles now indicate the weights are for 

terminal sacrifice animals. 

3-11, 3-13, 3-14. 

22. Page 3-10: It would probably be easier 

to refer to page numbers as Appendices 

J-2 through 6 are not clearly marked 

(only marked with page numbers J-#). 

References to the appendices are now included. 3-10, 3-12. 

23. Page 3-12: The significances noted for 

Brain, group 4 male, and Kidney, group 

4 male are significant at the P<0.01 

level, not 0.05 as indicated. 

No change. Significance levels were set at 

p<0.05. 

3-10, 3-12. 

24. If one compares the last clinical 

observation to the necropsy 

observations, it appears that the last 

observation of “skin growth” frequently 

was neither confirmed nor denied. One 

In life clinical observations recorded in Path Tox 

did not necessarily follow the same format as 

recording gross lesions at necropsy on IANR 

forms. In the former case, examples of Path/Tox 

notation of skin lesions include “Hair/skin/skin 

No page. 
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can only assume that the skin growths 

noted clinically were in fact preputial 

masses or enlargements. Please 

comment. 

growth (small), Hair/skin/sore (superficial 

wound/lesion)”, with no notation as to location. 

In the latter case, at necropsy more precise 

notation of anatomical location and more current 

notation of size occurred. Thus, correlating in 

life and necropsy observations may be difficult, 

requiring assumptions as to the location of the 

skin growths. These growths were likely 

subcutaneous masses, preputial or otherwise. 

25. Page 3-14, second paragraph, second 

sentence: In all cases, values for the 

high-level group males were greater. 

Corrected. 3-15 

26. Page 3-14, second paragraph, fourth 

sentence: The differences were not 

really present in males at the 18 or 24 

month intervals. It may also be helpful 

to indicate what the problem was with 

sampling the blood at the 12 month 

interval. 

Text was revised to indicate we had blood 

sampling problems. 

3-15 

27. Page 3-14, last paragraph, second 

sentence: testicular interstitial cell 

adenomas..... 

Text has been substantially revised in this 

section and the word interstitial has been 

included. 

3-17 

28. Page 3-16: When discussing the 

statistically significant incidence of 

Leukemia in the mid-doses, it is true that 

the percentage of those examined is 

misleading, but with the frequency of the 

lesion equal to that seen in the high-dose 

group, one can only assume that it would 

go up if all spleen tissue were examined. 

At what incidence would significance 

start? 

An additional header has been added before 

discussion of leukemia and mammary gland 

“Proliferative Lesions Not Attributable to 

GMVC Exposure”. Leukemia and mammary 

gland fibroadenoma are now discussed under the 

above header. 

3-20 

29. Page 4-1, Protocol Deviations, 

Environmental Conditions: These 

excursions from protocol-required 

ranges need to be further indicated. 

Some sense of how long and to what 

extent these excursions occurred need to 

be given. As well, the periods of data 

loss were sometimes days (May 24-28, 

This protocol deviation and several others have 

been added. 

4-5 
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02 and July 11-15/02 when the RH meter 

was not working). Give lengths of 

malfunctions and specific reasons why 

these excursions and losses did not affect 

the integrity of the data. 

30. Page 4-1, Protocol Deviations: There 

was also a day on which the airflow 

dropped affecting the next day’s 

exposures (11/28/01). Exposures were 

not run that day. This should be 

indicated as a deviation. 

This protocol deviation was added. 4-10 

31. Appendix B: Test Material 

Characterization for Tank A-27 (done on 

7-8-02) was not reported. Should it be? 

This data was added as pg B-21. B-21 

32. Appendix B, Tank 16: It is indicated that 

this tank was not analyzed. It was (in 

effect) analyzed as part of the weekly 

analysis of the atmosphere. This should 

be noted as a deviation and the analytical 

data applicable to this tank (weeks used 

for exposures) should be indicated. 

This protocol deviation was added. 4-3 

33. Appendix D, page 3, high dose value, 

7/6/01: Should this value be 20.53? 

Please clarify. 

The correct value is 20.53. The number in the 

table was corrected in Appendix E. 

E-33 

34. Appendix D, page 4: The standard 

deviation for the high dose group 

exposures for 9/17/01 now appears 0.11, 

but in all other audits the value was 0.54. 

How could this have changed? 

The value of 0.54 was an error not noted in 

previous audits. The value in the report (0.11) is 

correct and was verified to the 9/17/01 raw data 

sheet. 

E-34 

35. Appendix D, page 6: The Actual usage 

value for 4/1/02. Please verify that 5320 

is correct. I find 5515. 

The value 5320 is correct and verified to the raw 

data sheet for 4/1/02. 

E-36 

36. Appendix D, page 6: The Actual usage 

value for 4/1/02. Please verify that 5320 

is correct. I find 5515. 

Repeat comment, see number 35. NA 
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37. Appendix D, page 21: The heading of 

Table D-2 is unclear. These are not the 

components of GMVC, there is no 

MTBE. How are these values relative to 

BGVC? 

The correct table is now included. E-51 

38. Appendix D, page 23: The Table D-3, 

Day 2 and 3: Values could not be 

verified. Are these values of the reperformed stability tests? Please verify 

these values. 

The stability tests were performed on three 

consecutive days. They were not re-performed. 

The values are correct and re-verified to 

Notebook 7401. 

E-53 

39. Appendix D, page 24, second 

distribution assay: The daily exposure 

sheet indicates that data are in Notebook 

7401. I could not find any data in 

Notebook 7401 that was recorded on 

6/6/01. 

The daily exposure sheet for 6/6/01 has a note 

that the information about the control chamber 

valves (not values) was to be found in Notebook 

7401. The protocol-required chamber 

distribution data for the chambers with animals 

present were entered on a “chamber 

homogeneity data sheet” located in the study 

file. The control chamber was tested on 6/6/01; 

the low level chamber on 6/8/01 and the highlevel chamber on 6/13/01. The data in Appendix 

D (now E) were re-verified and are correct. 

E-54 

40. Appendix E, Page 4: Analytical data for 

week of 7/23 and 9/10/01 are missing 

from the report. There is no mention of 

this in the text or in the deviations 

section of the report. There should be. 

Please include the reason for missing 

data as well as any affect it could have 

had on the study. Appendix E, Page 4: 

Analytical data for week of 7/23 and 

9/10/01 are missing from the report. 

There is no mention of this in the text or 

in the deviations section of the report. 

There should be. Please include the 

reason for missing data as well as any 

affect it could have had on the study. 

These deviations and statement of impact are 

included in the report. 

4-3 

41. Appendix E, Page 9: Analytical data is 

labeled as 5/17/01 in the middle of Dec. 

This is actually data collected for the 

week of 12/17/01. 

The date on the table and was corrected in the 

second draft of the report. (re-verified by JB 

2/1/09 

F-9 
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42. Appendix K, Page 16, Animal number 

470: The monocyte count should be 1 

and the eosinophil should be 4. 

The monocyte count of 1 and eosinophil count 

of 4 are correct. The values were corrected in 

the 2nd draft of the report. JB verified that they 

were corrected on 2/1/09. 

L-16 

43. Appendix K, Page 22, Animal number 

770: There is 1 NRBC present for this 

animal, not 0. 

The value was corrected to 1 NRBC in the 

second draft of the report. The change was 

verified by JB on 2/1/09. 

L-22 

44. Appendix L, Page 257, Animal number 

410: Gross necropsy observation does 

not indicate “pituitary enlarged” but the 

gross to micro report does. The gross 

necropsy observation indicates 

“discolored pituitary, but the gross to 

micro does not. Please clarify. 

The pituitary for animal 410 was discolored, not 

enlarged. The entry was edited in Path Tox N 

module during preparation of the 2nd draft of the 

report. 

M-274 

45. Appendix L, Page 256, Animal number 

406: The gross observation “tooth 

perforation, maxillary was not entered on 

gross to micro. This lesion was not 

trimmed, no section was made, and no 

correlating entry was made. 

The lesion related to tooth perforation was 

actually trimmed in as a portion of the nasal 

turbinate. The correlation was entered by the 

pathologist. 

M-273 

46. Appendix L, Pate 256, Animal number 

406: The gross observation “tooth 

perforation, maxillary was not entered on 

gross to micro. This lesion was not 

trimmed, no section was made, and no 

correlating entry was made. 

Repeat comment. See number 45. M-273 

47. Appendix M, Appendix L: At the end of 

each of these appendices, there is a 

Lesion incidence summary with K-S 

(Kolmogorov-Smirnov) comparison. It 

is somewhat misleading in that there 

Use of the Kolmogorov-Smirnov statistic in Path 

Tox to assess the statistical significance of the 

severity of nephropathy was described in the 

Statistics section of the 2nd draft of the text. A 

protocol deviation is also included. 

2-14, 4-2. 

48. Appendix O, page 3, Histology: Please 

give more identifying information about 

the Path-Tox database including version 

numbers, amendments, etc. 

The information has been added. P-4 to P-5. 

 
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49. Appendix O, page 5, next to last 

sentence: The increase in all groups in 

atypical lymphocytes...... 

Text now indicates high dose and control rats. 

Comparisons are made only between the two 

groups. 

P-5 

50. Appendix O, page 6, third paragraph, 

third sentence: One cannot confirm that 

most testicular adenomas were bilateral 

and multiple as they were not reported 

this way. 

This description has been removed. P-7 

51. Appendix O, page 6, third paragraph, 

last sentence: It appears that this 

sentence is not true. For example, 

Animal numbers 718, 650, and 644 have 

reported both interstitial cell hyperplasia 

as well as bilateral adenomas of the 

testes. Please clarify. 

The text has been modified to say that interstitial 

cell hyperplasia was recorded PRIMARILY in 

testes without tumors 

P-7, paragraph 2 

52. Appendix O, page 7, Table O-3: The 

kidney nephropathy incidence in the 

mid-dose is indicated in the text as 

statistically significant. Should this be 

indicated here? 

The incidence of chronic nephropathy is not 

statistically increased and is not noted as such in 

either the text table 3-13 or in Table P – 3. The 

severity score is increased at both the mid and 

high levels, and this is correctly noted in the 

tables and text. 

3-20, Table 3-13, 

P-9, Table P-3. 

53. Appendix O, page 8, Table O-4: The 

Nose/Turbinate 2 findings are also 

statistically significantly positive for 

trend according to the text. Please 

clarify. 

Table corrected. P-4 

54. Appendix O, page 10, Table 0-6, 

Pituitary Gland: There is a sampling 

bias in the statistical evaluation of the 

pituitary gland lesions because only 

gross lesions of the pituitary were 

examined, but since the incidence is 

already as high as in the high dose, 

further examination of tissue could only 

increase the incidence of the finding. It 

is not clear what one can draw from 

these results. 

LRRI agrees. There is a high incidence among 

controls, and no clear dose response with 

exposure. 

Table P-6 

55. There is no gross observation summary Gross observations have been included in the M-2, N-2. 
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table. pathology appendices. 

56. Gross to Microscopic correlation: 

Animal number 713, liver foci “1-4” 

foci. Should be 1-4 mm. 

The IANR form for animal 713 was rechecked. 

The form showed that the liver had 1 – 4 foci. 

The size was not measured. No revision is 

necessary. 

No change 

57. I do not have responses to QA audits for 

the following dates: Reports dated 

10/23-24/01, 1/28-29/02, 5/20-21/02, 

9/24-25/02. 

Responses have been incorporated into the 

revisions of the final report. The final report has 

been reviewed by Christine Sexsmith.