### Comments **on ETBE and**  **te rt**  **- But**  **anol (TBA)**  **Pr eliminary**  **Ma te**  **rials fo**  **r IRIS T**  **ox icological R** **eview** General and Non - Cancer Endpoin ts

**On Behalf**  **of Ly** **ondell Chemical Compan**  **y Susan Bor** **ghoff**

**, PhD , D** **AB T**  **Senior Managing**  **Scientis t** 

**December 12, 2013**

## Gener**al Commen**  **ts**

**ETBE/TB A Pr** **eliminary Materials** 

**2** • Draft literature strategy; processes for identifying and screening scientific literature and literature results
• Preliminary evidence tables, and
• Preliminary exposure - response arrays Both summarizing key characteristics and findings from studies that EP A proposes to consider in identifying hazards and characterizing exposure response relationships. **The stated purpose of these materials is to document EP A’**  **s systematic review**  **of the scientific literature, demonstrate a standardized approach to presenting key study data, and foster early public involvement and transparency**  **.**

## Gener**al Commen**  **ts**

**ETBE/TB A Pr** **eliminary Materials**  Ly ondell has r eviewed the pr eliminary materials and offer s for consider ation our comments on:  t he clarity and tr anspar ency of the materials;  t he appr oach for iden tifying pertinen t s tudies;  t he selection of s tudies for data ex tr action to pr eliminary evidence t ables and e xposur e - re sponse arr ay s;  methodological consider ations that could affect the in te rpr etation of

, or confidence in, s tudy r esults; and  additional s tudies published or nearing publication that ma y pr ovide data for the ev aluation of human health haz ar d or ex posur e - re sponse r ela tionships. **3**

## Dr**aft Lit**  **er atur** **e Sear** **ch Str** **ategy (ETBE/TB** **A)**

• We ll documen te d database sear ch and st rate gy; > 600 citations fo r ETBE, > 2900 for TBA identified; Eur opean Chemical Ag ency (ECHAs) database for r egis te re d substances: http :// echa.eur opa.eu/web/guest/information - on - chemicals/r egistered substances • Fo r complete clarity and tr anspar ency , further te xt is r ec ommended to support the outline (Figur e 1.1) of the liter atur e sear ch appr oach. • Specific crit eria fo r selection of primary vs. not primary sour ces of data; **Request EP** 

**A provide their worksheet**  **that details**  **the basis for selecting and**  **/o r**  **exc luding**  **cit ations.**  • Cit ations identified as “Not Primary Sour ce of Health E ffects Data”
• Wha t is the decision pr ocess for including specific citations? • Will they be r eviewed for quality prior to incorpor at ion? • Will ther e be an opportunity fo r public comment prior to finalizing? **4**

## Pr**eliminary Ev**  **idence Ta**  **bles (ETBE/TB** **A)**

• Decision pr ocess for data ex tr action; **unclear wh**  **y certain endpoints**  **are considered individually**  **and others grouped**  **in evidence tables and ex**  **posure response arrays.**  • Re commendation that study quality be consider ed prior to including data; **consider similar approach**  **used by OE CD (**  **Klimisch et al.,**  **1997).** • Re ques t clarity on data normaliz ation str ate gy used; **although helps to mak** 

**e studies comparable,**  **it is not the same as e**  **xtracting the**  **specific data.**  • Clarify wh y some r epr oductiv e endpoints wer e pr esen te d as incidence and endpoin ts as per cen ta ge change.
• St atistical analysis of data; **Not clear what data**  **was statistical analyz** **ed.**
**5**

## Pr**eliminary Ev**  **idence Ta**  **bles (ETBE/TB** **A) Selection of Studies**  **and Endpoin ts f** **or Da**  **ta Extr** **action** • Borghoff et al., (2001) was only consider ed for mechanism data and not other endpoin ts of to xicity because it was a 10 - da y s tudy. • Inconsistency between r eviews for select ed endpoints e xtr act ed 

### ; **Serum enzymes for ETBE but not for TBA** 

### . • Cert ain st udies wer e select ed fo r body weight changes and other st udies not used (section 2.6 of TBA r eview).
• The appr oach used does not allow for consider ation of how changes in one endpoin t influences a chang e in another; data selected in isolation.  Org an weight chang es without hist ology  Body w eigh t chang es without food and water co nsumption  Ta rget org an effects without s ystemic tox icity measures **Overall clarity in the decision process for selecting endpoin**  **ts would**  **provide transparency .**  **6**

## Pr**eliminary Ev**  **idence Ta**  **bles (ETBE/TB** **A) Selection of Studies and Endpoin**  **ts f or Data**  **Extr action**  Re ques t further e xplanation for not e xtr acting data from the fo llowing s tudies; • Dermal e xposur e st udies, • Acut e or short - te rm e xposur es (less than 90 da ys ); e xc ept in the contex t of immunoto xicity , neur oto xicity

, dev elopmen ta l or r epr oductiv e t ox icity , and • Endpoin ts r ela te d to possible mechanisms of to xicity

**7**

## Pr**eliminary Exposur** **e Arr** **ay s**  **(ETBE/TB A)** 

• The pr esen tation of r esults in the e xposur e r esponse arr ay s is ques tionable; **St atis**  **tical findings**  **alone may not be meaningful and**  **often severity of**  **changes should**  **be considered .**  • Re commend consistent presentation of lesions; **Ea sier to compare**  **across studies.**  • In the ETBE r eview; hepatocellular adenomas (benign neoplasms) ha ve been combined with hepatocellular car cinomas (malignan t neoplasms). **Recommendation: presen**  **tation of malignant**  **neoplasms should be separated**  **from benign**  **neoplasms with**  **pre -**  **neoplastic lesions**  **having a separate**  **category .**  • Ther e w er e man y r ela te d endpoin ts not men tioned in the ta bles/figur es for the ve ry c ompr ehensiv e D ART st udies. **Recommendation: Clarify**  **criteria for endpoint**  **selection for**  **inclusion in**  **summary tables and arrays.**  **A narrative for each**  **subsection would be**  **useful. 8** 

## ETBE: Non **- Cancer Endpoin**  **ts Preliminary E**  **vidence T**

**ables and Exposur e**  **- Re**  **sponse Arr ay**  **s** Kidney E ffects – Ta bles and Figur es 2.1 and 2.2 Liv er E ffects - Ta bles and Figur es 2.3 and 2.4 Re pr oductiv e E ffects – Ta bles and Figur es 2.5 Body W eigh t E ffects – Ta bles and Figur es 2.6 and 2.7 Other Systemic Ef

fe cts - Ta bles and Figur es 2.8 and 2.9

**9**

## ETBE: Kidne**y E ff** 

**ects (T ables**  **2.1 and 2.2)**

**10** • Consis te ncy in citing primary r efer ences (Suzuki et al., 2012 vs. JPEC, 2010a) ; **A typical**  **hy**

**perplasia, papillary**  **necrosis, average severity**  **of CPN, and relative kidney**  **weights were ex** **tracted from JPE**  **C report**  **and not Suzuki publication**  . • Re commend re moving category for kidney weights fr om 2 - ye ar study ; **Q uestionable**  **endpoint to evaluate**  **tox icity**  **at the end of a chronic study**  **.** • Re commend re moving category for incidence of h yaline droplets fr om 2 - ye ar study; **Suggests a**  **lack of understanding of the biology**  **underlying α2u**  **** **globulin nephropath**  **y**

**.** • Fully utiliz e the depth /a mount of information in Cohen et al., 2011 st udy; **C urren**  **tly restricted**  **to data on nephropath**  **y (CPN).**  • EP A state s that both quan tit ative and qualitative data is to be consider ed; **Recommend Including granular**  **casts, a lesion characteristic**  **of**  **2u**   ** globulin** **(α2u -**  **g) nephropath**  **y.**

## ETBE: Kidne**y E ff** 

**ects (T ables**  **2.1 and 2.2)**

**11** • Re commend re moving category of urinalysis endpoin ts ( JPEC, 2008c; JPEC, 2010a; Suzuki el al., 2012 ); **Casts in the urine and granular**  **casts at the junction**  **of the outer and inner stripes**  **of outer medulla of kidney**  **are totally**  **diff**

**eren t entities with**  **diff**

**eren t biological**  **implications** • Corr ections in Ta ble based on r eview of study r eport ( JPE C, 2010b)  EP A s tates tha t miner aliz at ion in the papilla w as not e xa mined in female rat s, it should be changed to not observed; **mineraliz ation**  **in the papilla was observed in male rats**  **only ,**  **implies females were e** 

**xa mined but the**  **lesion was absent.**   EP A states tha t a typical tubule h yperplasia w as not exa mined; **should be**  **stated as not observed.**   Hyperplasia of the papilla observ ed in this st udy wa s not included; **Papillary hy** 

**perplasia is a lesion that**  **results from, and**  **accompanies advanced**  **CPN, clarifying that**  **CPN is unique**  **from chronic nephropath**  **y.**

## ETBE: Kidne**y E ff** 

**ects (T ables**  **2.1 and 2.2)**

**12 Re**  **commend reviewing the f** **ollowing publication f** **or inclusion:** Har d G. C., Ban ton M.I., Br etzlaff R.S., Dek an t W. , Fow les J.R ., Mallet t A.K., McGr egor D .B , R oberts K.M., Sielk en Jr . R .L., Valdez Flor es C ., and Cohen S.M. (2013). Consider ation of Rat Chr onic Pr ogr essiv e Nephr opath y (CPN) in R egulatory Eva luations for Car cinog enicity. To

xicological Sciences . 132(2):268 - 275. **Although there**  **is no quan tit** **ative dat a**  **in this paper**  **, it describes**  **the link between CPN and induction of**  **renal tubule tumors.** 

## ETBE: Liv**er Ef** 

**fe cts (T**  **ables and Figur** **es 2.3 and**  **2.4)**

**13** • Re commend including s tudies of shorter dur ation (< 90 - da ys); **Ea rly**  **changes can be used t o in**  **te rpret longer t** **erm responses (i.e. liver enzyme induction and**  **his to** **pathology ).**  • Re move categories ev aluated at the end of 2 - ye ar studies; **L iver**  **weight changes**

**, clinical chemistry**

**, and centrilobular**  **hy**

**pertroph y.**   Seller s et. al., 2007 , “ In these long - term studies, normal ph ysiological aging changes and inter - curr ent disease ma y contribute to inter - animal va riability , which will confound orga n weight interpretation (Long et al.,1998a; 1998b ).  The Society of To xicologic Pa thology r ecommends orga n - to - body weight rat ios in t ox icology st udies ra nging fr om 7 da ys to 1 year .  Liv er enlargement in response to hepatic enzyme induction is typically associated with centrilobular hy pertr oph y ( Mar onpot et al., 2010 ), not typically observ ed fo llowing 104 weeks (Seller s et al., 2007).

## ETBE: Liv**er Ef** 

**fe cts (T**  **ables and Figur** **es 2.3 and**  **2.4)**

**14** • Pr ovide r ationale fo r inclusion and e xc lusion of specific liv er to xicity endpoin ts; **Clinical chemistry:**  **AL T**  **vs. cholesterol** . • Consis te ncy in citing primary refer ences; **Unclear as to**  **where study data**  **is e xtracted**  **(study reports**  **vs. published papers).**  • Clarify fo r how data was ex tr act ed, tr ans fo rmed, and s tatistically analyz ed for evidence tables. • Re commend that quality contr ol checks ar e conducted on data pr esen te d in evidence tables prior to r eview; **Specific errors**  **are iden**  **tified in L** **yondell’**

**s written comments.**  • Re commend that a distinction is made between adaptiv e vs. adv er se effects ; **Liver weight increases**  **accompanied by hepatocellular**  **hy pertroph**  **y are common events in to**  **xicity studies**  **in rodents .** 

## ETBE: Liv**er Ef** 

**fe cts (T**  **ables and Figur** **es 2.3 and**  **2.4)**

**15** • Clarify wh y liv er w eigh ts ar e only e xtr act ed fr om F0 gener ation; **Gaoua ,**  **2004b; Fujii**  **et al., 2010; JPE**  **C, 2008e .**  • Insur e that data ex tr act ed is not misr epr esen te d ; **Cen trilobular**  **hy pertroph**  **y was not evaluated**  **in all the animals (** **Gaoua ,**  **2004b).** • The e xposur e - re sponse arr ay s of liv er effects w as duplicated; **Figure 2.4,**  **Exposure to ETBE via inhalation**  **is a copy of Figure 2.3,**  **ETBE oral administration.**  • Re commend inclusion of additional endpoints ; **livers of**  **mice ex**  **hibited time**  **- and**  **concentration -**  **dependent increases**  **in hepatocyte labeling**  **inde**

**x, quantitative data**  **for response**  **array and**  **mode -**  **of -**  **action (**  **Medinsky et al** **., 1999; Bond**  **et al., 1996a).** 

## ETBE: R**epr oductiv** **e and**  **Developmental E ff**  **ects**

**16** CA OEHHA DA RT (Nov. 21, 2013 ) Committe e vo te d unanimously that ETBE has **not** been clearly shown t o c ause developmen ta l tox icity , male r epr oductive tox icity , or female r epr oductive t ox icity. **Therefore ETBE will be removed from the Proposition 65 lis t** **. 17**  • Pr ovide clarity on data ex tr act ed and tr ans fo rmed; **I nclude**  **information on sample**  **siz e based on**  **litter and**  **unit of analysis**  **(litter vs.**  **individual pup).**  • Confirm that sample siz e r eflects lit te rs assigned to e xposur e gr oups and not number of impr egnated dams; **Litter of origin**  **is the appropriate**  **ex**

**perimen tal**  **unit of analysis.**  • Re commend quality control checks on evidence t ables prior to re view ; **Specific errors**  **are identified in L** **yondell’ s**  **written comments.**  • Consis te ncy in citing primary r efer ences; **Unclear as to where study**  **data was e** 

**xtracted, F1**  **post implantation and total**  **litter losses,**  **( Fuji et**  **al.,2010 or JPE** 

**C, 2008e ).**  

## ETBE: R**epr oductiv** **e Ef** 

**fe cts**  **(T ables**  **and Figur** **es 2.5** **18** • Pr ovide criteria fo r endpoin t selection; **Suggest inclusion**  **of more ex**  **planatory te** 

**xt for selecting specific**  **endpoints (i.e. Berger and Horner**  **, 2003).**  • Caution with e xtr acting data from reports tr anslated to English; **R ecommend a complete understanding**  **of how data is collected (**  **Fujii et al.,**  **2010 ; JPE** 

**C, 2008e).**  • Clarification of pos t - implan tation loss; **Reported diff**  **eren tly**  **in the original**  **publications vs.**  **in the e vidence table**  **( Fujii**  **et al., 2010 ; JPE** 

**C, 2008e) .**  • All data ex tr act ed in to E vidence T ables should be check ed fo r consistency and accur acy; **( Gaoua**  **, 2008;**  **Asano et al., 2011; JPE**  **C, 2008j).**  

## ETBE: R**epr oductiv** **e Ef** 

**fe cts**  **- Ta**  **bles and**  **Figur es**  **2.5**

## ETBE: Body W**eigh t**  **- Ta**  **ble and Figur** **es 2.6 and**  **2.7**

**19** • Consis te ncy in citing primary refer ences; **Unclear from what report**  **the body weight data**  **was e xtracted**  **(Hagiwara et al., 2011**  **vs. JPE C,**  **2008d)** • Re ques t clarity as to wh y EP A only ev aluated body we igh ts fo r F0, and not the F1 g ener ation; **( Gaoua**  **, 2004b).**  • Re commend that body we igh t assessmen ts consider (female) re pr oductiv e s ta ge s (i.e., mating , pr egnancy , lactation) as well as life s ta ge s (pups, adults ); **a single body weight value**  **does not represent** **ative all possible changes in this s tudy (**  **Fu jii**  **et al., 2010).**  • Re commend that body weight changes incorpor ate changes in fe ed consumption and water intak e to pr ovide mor e meaningful data.

## ETBE: Other **Syste mic**  **Ef fe**  **cts Ta**  **bles and**  **Figur es**  **2.8 and 2.9**

**20** • Re ques t explanation as to wh y r esponses w er e combined on one ex posur e arr ay ; **antibody response,**  **immunological eff**  **ects, adrenal weight,**  **and mortality** 

**.** • Consis te ncy in citing primary refer ences; **spleen and adrenal weights**  **(Suzuki et al., 2012 vs. JPE**  **C, 2010a).** • Insur e data fr om r eports is r epr esen te d corr ectly; **Ev idence table**  **notes a statistically**  **significant change in relative**  **adrenal weights for male**  **rats whereas**  **the report**  **does not (JPE C, 2010a).**  • Include r ela tiv e adr enal and spleen w eigh ts in evidence tables; **provided in publication**  **the following reports/publications,**  **Medinsky et al.,**  **1999; Bond et al., 1996.**  • Spleen and adr enal w eigh ts only pr esen te d for F0 and not F1 ge ner ation; **( Gaoua** 

**, 2004b).** 

## ETBE: Other **Syste mic**  **Ef fe**  **cts Ta**  **bles and**  **Figur es**  **2.8 and 2.9**

**21** • Ra tionale for inclusion and e xc lusion of data; **Wild -**  **type and**  **knock -**  **out mice evaluated,**  **data presen**  **ted for only**  **knock -**  **out mice only**  **( We**  **ng et al.,**  **2011).** • Re commend describing how numerical data is e xtr act ed fr om publication figur es; **Numerical percent**  **change reported**  **in E vidence**  **Ta ble**  **( We**  **ng et al.,**  **2011).** • Re commend ev aluating s tudy quality prior to inclusion of data ; **Study quality**  **concerns including**  **design and methods (**  **We ng**  **et al., 2011).** 

• Ra tionale fo r inclusion and e xc lusion of specific data; ( Li et al., 2011)  Only data on one of tw o s tr ains w as included  Not all hematological and immunological mark er s wer e included  Extr action numerical da ta fr om publica tion figur es**22** • JPEC, 2008h/

Aso et al., 2013; Prenatal Dev elopmental to xicity s tudy in rat s. • Ka ke hasi et al., 2013; Mode of action of eth yl t ertiary - buty ether hepa totumoigenicity in the r at : E vidence for a r ole of o xidative ste ss via activ at ion of CAR, P XR and PP AR signaling pathw ays. To xicol . Applied Pharmacol . 273 (2013) 390 - 400.
• Gaoua , 2003, Male r at pilot s tudy
• Malark ey

, 2011 Summary Re port sponsor ed by the NTP and EP A of Pa thology Materials fr om Selected Ramazzini Ins titute R odent Cancer Bioassa ys, November 29, 2011. 

## Additional **Studies/R eports**  **- ETBE** 

## TB**A: Non -**  **Cancer Endpoin**  **ts**

**Preliminary E vidence T** 

**ables and Exposur**  **e -**  **Re sponse Arr** **ay s** 

• Kidney • Th yr oid • Re pr oductiv e • Dev elopmen t • Neur odevelopmental • CNS • Body we igh t • Liv er • Urinary Bladder

**23**

## TB**A: Kidne** **y E ff**  **ects**

**24** • Insur e s tudy r esults ar e clearly re pr esen te d; **It is stated “**  **There were no changes**  **in kidney histopathology**  **observed” implies that the**  **kidneys were evaluated.**  **Kidneys were**  **fix ed,**  **but not microscopically**  **exa mined.**  **Ly ondell**  **Chemical Compan** **y, 2004**  **- should**  **be cited as**  **HLS, 2004.** • Study quality ev aluated; **Histopathologic observations**  **not diagnosed with accepted**  **terminology** ( **Acharya et al** **.,1995 ,**  **1997).** • Qualification of lesions; **It should be noted**  **that mineraliz** **ation was**  **mainly at the “** 

**corticomedullary ”**  **junction** . **This lesion represents**  **an imbalance**  **of the Ca** 

**/PO4 ratio**  **and is affected by dietary factors,**  **and not necessarily**  **an indication of nephroto**  **xicity .**  **It is**  **distinct from linear**  **mineraliz ation**  **seen in the papilla in the 2**  **- year**  **study ,**  **which is a “mark**

**er ”**  **of a preceding α2u**  **- globulin**  **nephropath y**  **event the (NTP ,**  **1995; Cirvello**  **et al., 1995)**  **.**

## TB**A: Kidne** **y E ff**  **ects**

**25** • Re commend inclusion of k ey endpoin t; **Hyaline droplet**  **accumulation is**  **an important pathologic**  **en tity**  **that increases**  **in all TBA**  **ex posed male rats.**  • Clarify conflicting te xt within the pr eliminary ma te rials; **It was**  **stated that “no**  **renal histopathological**  **changes reported**  **in mice at 13**  **- weeks” and also stated**  **that “**  **histopathologic data for the 13**  **- week study**  **were not provided.**  **”** • Re commend clarifying his tological lesion with a footnote; **On re**   ** exa** **mination of kidney slides**  **from the 15 -**  **month time point**  **(NTP , 1995),**  **it was determined**  **that the mineraliz** **ation in**  **male rats was linear**  **mineraliz ation**  **in the papilla,**  **c onfirming**  **a chronic**  **end -** **point associated**  **with α2u -**  **g nephropath**  **y occurs**  **at an earlier time point (**  **Hard, 2005) .** 

## TB**A: Kidne** **y E ff**  **ects**

**26** • Re commend clarifying his tological lesions with a footnote ; **Fo r**  **both males and females, transitional**  **epithelium hy**  **perplasia and**  **suppurative inflammation**  **were iden tified**  **by NTP as being part of the**  **nephropath y**  **(CPN) comple x** **.** • Extr act ed data from these publications should be included in the His topathology subsection; **Ta ka**  **hashi et al.,**  **1993; Williams**  **and Borghoff**  **, 2001;**  **Hard et al., 2001. 27**  • Clarify that th yr oid weight changes wer e not ev aluated; **It would be useful to list**  **this endpoint and note that**  **weight changes were not**  **evaluated in the**  **13 -**  **week or at the**  **15 -**  **month in**  **terim necrops** **y.** • Clarify the r easoning for the e xc lusion of select ed th yr oid his tological changes; **Besides follicular cell h**  **yperplasia, other**  **histological changes**  **were noted but**  **not included**  **in the evidence table**  **( C** **** **cell hy**  **perplasia, follicle,**  **cys t,**  **ect ).**  • Clarify the timing of when follicular cell hy perplasia was obser ved in evidence t able ; **Observed following chronic e**  **xposure to TBA (2**  **- year s**  **tudy).** • Clarify the lack of dat a pr ovided in the evidence t ables at the high TBA ex posure c oncen tr ation ; **Lethality at this e**  **xposure concentration**  **should be noted.** 

## TB**A: Th**  **yr oid**  **Ef fe**  **cts 28**  • Clarify the r easoning for including single acute e xposur e st udy; **A single acute**  **ex posure of TBA in male mice**  **at dose levels( up**  **to 2,000 mg/** 

**kg with endpoints**  **measured several days later**  **( Billitti**  **, et al** **., 2005).** • Clarify crit eria fo r data inclusion and e xc lusion fr om the fo llowing r eports; • Ly ondell Chemical Compan y (2004) OECD 421 • NTP ( 1995 ) B6C3F1 mouse s tudy • NTP (1997) F344/N rat inhala tion rat s tudy • NTP ( 1997) B6C3F1 mouse inhalation s tudy 

### TBA: **Re pr** **oductiv e,**  **Developmen ta**  **l, and**  **Neur odev** **elopmen ta**  **l Ef** 

**fe cts** **29** • An MTBE r at inhalation study ( Bev an et al .,1997 ) is curr en tly included in the “Ex cluded (not pertinen t)” category of the Refer ence Lis t; **MTBE is metaboliz ed to TBA which is the primary**  **metabolite found in rats following**  **ex posure. Since**  **sy**

**stemic blood levels of a**  **chemical are required to cause reproductive**  **tox icity**  **, inclusion**  **of the MTBE two**  **- generation**  **study is well** **- justified**  **within the TBA IRIS process**  **.** • Re consider inclusion of the Gr an t and Samson, 1982 paper based on quality ; **poorly reported**  **and e xperimen**  **tally limited**  **study in which half**  **of the pups died due to e**  **xperimen tal procedures**  **that were very stressful**  **(e.g. cannulation**  **of pups raised away from their**  **dams in a cup).** 



## TB**A: Re**  **pr oductiv** **e E ff** 

**ects 30**  • Incomplete and/ or e xc lusion of endpoints without clear rat ionale; **the Ly** **ondell Chemical Compan** **y (2004)**  **OE CD 421**  • Ques tionable s tudy quality and/ or lacking details for inclusion.
• Daniel and E va ns (1982 ). • Fa ulkner

, et al., (1989) C57BL/6J mouse s tudy is incomplete . • Nelson et al., 1989 

## TB**A: Developmen**  **tal E** **ff**

**ects 31**  

### • Re commend a voiding using cat ch - all classification of " neur odevelopmental”; **general categories such as neurobehavioral**  **(c ognitive**  **, mot or),**  **neuropharmac ologic**  **, neuropathologic** 

**, or neuroph**  **ysiologic findings should be used to**  **avoid c onflicting results.**  

### • The selection pr ocess fo r including significant or non significant findings is not tr anspar en t; **Although cit ed as a source**  **of dat a,**  **none of the findings from Nelson et al. 1991 paper were included**  **in the e**

**xposure array**

**.** 

### • The fo llowing cit at ions should be r e - reviewed to determine quality of the publication and then r ecommend including complete data sets with complete dat a en try.

– Gr ant and Sampson, 1981

– Wo od and La ve rty

, 1979

– Snell and Harris, 1980

– Thurman et al., 1980

– McComb and Golds tein, 1979a and 1979b 

## TB**A: Neur** **ot ox**  **icity and**  **CNS E ff**  **ects 32**  • Ta bles r ec or ding absolute and re lative (body weight) liver weights; **Consider brain**  **weight as**  **the basis for relative liver weights. It has been**  **recogniz ed**  **that brain**  **weight is more stable than body**  **weight.** • Although e xposur e (t o females) occurr ed during pr e - ma ting, mating, ge stat ion, and lactation, the body weight data pr esen te d appear s to be only the lactation body we igh ts; **HRL ,**  **2004.** • Numer ous tr anscription err or s were identified in the tables; **NTP ,**  **1995.** • Body weight changes following inhalation e xposur e t o TBA should ha ve been included in the evidence ta ble; **NTP , 1997**  **.** 

## TB**A: Body W** **eigh t** **33** • Not all liv er effects r eport ed in this paper wer e included in the ta ble; **Acharya et al.,**  **1995.** • Clarify the inclusion and e xc lusion of select ed endpoints; **in general only**  **selected measurements of liver to xicity**  **where included.** • Figur e 2 - 6; Err or s identified in the e xposur e - re sponse arr ayof body we igh t, liv er effects, and urinary bladder ef fe cts following or al ex posur e t o TBA; **D ata reported**  **in this array needs to be corrected**  **or alternatively**  **this figure could be**  **deleted.** • Re commend re viewing Blanck et al., 2010 for inclusion; **Relevant endpoints**  **for mode of action**  **for hepatic enzyme inducer**  **.** • Re commend including r eviews by McGr egor et al., 2010; **Provides a**  **detailed evaluation**  **of all endpoints discussed**  **and should be considered**  **in the overall**  **evaluation.** 

## TB**A: Liv** **er Ef**  **fe cts** 

## Summary **Commen ts**  **Pe rt**  **aining to** 

**ETBE/TB A**  **Pr eliminary**  **Materials**

**34** • Pr eliminary ma te rials ar e in te nded to pr ovide opportunity for early discussion; **however , content presented does not adequately**  **support this**  **objective.** • Lack of consider ation of study quality; **A s ys**  **tematic approach**  **for evaluating**  **the quality of e**  **xperimen tal data should**  **be considered before**  **accepted for an**  **y further**  **evaluations (such**  **as evidence tables). Recommended approach**  **comparable to**  **Klimisch scores. (**  **Klimisch et al.,**  **1997)** • Time allot te d for public r eview was limited; **Encourage EP A to QC**  **on data e xtracted**  **and provide clear identification**  **of where in report/publication**  **the data was e**  **xtracted from, allowing**  **more transparency**  **in the review .** 

## Summary **Commen ts**  **Pe rt**  **aining to** 

**ETBE/TB A**  **Pr eliminary**  **Materials**

**35** • Pr eliminary mat erials do not adequat ely pr ovide the documen tation fo r a s ystematic review of the scien tific lit er ature. • Appr oach used for cr eating evidence t ables and e xposure - responses arr ays does not iden tify the findings that are meaningful and does not relate endpoints that need t o be ev aluated together (e. g. or ga n weight chang es and body weigh t chang es, t ox icity and c ancer endpoin ts). • Inc onsist en t crit eria for use of mechanistic dat a. EP A’ s applic ation of these c onflicting crit eria is also inc onsist en t with some mechanistic information included, whereas other dat a is e xc luded. Re co mmendation : Da ta on k ey health endpoin ts much be included as pertinen t t o assessmen t of these endpoin ts . **These and our other c omments identify significant deficiencies**  **in the preliminary**  **mat**

**erials that EP** 

**A is enc** **ouraged to** **address before proceeding with**  **preparation of the draft assessment.** 

# In Summary

**36** • The pr esen t pr eliminary materials, although a good start, at this point, do not satisfact orily achiev e their purpose. • Ther e ar e significant deficiencies in the pr eliminary materials that EP A is encour ag ed t o addr ess befor e pr oceeding with pr epar ation of the dr aft assessment. • Over all, ther e is concern as to whether ther e will be another opportunity for the public to r eview the final “pr eliminary ma te rials” once a completed and corr ect ed data set ar e finaliz ed and prior to the final IRIS assessmen t.