## AGENDA

**Meeting of the Federal Insecticide, Fungicide, and Rodenticide Act Scientific Advisory Panel (FIFRA SAP) to Consider and Review Scientific Issues Associated**  **with Weight** **- of** 

**- Evidence:**  **Evaluating Results of EDSP Tier 1 Screening Ju**  **ly 30 -**  **August 2 , 2013**  **Docket Number: EPA -**  **HQ -**  **OPP -**  **2013 -**  **0230 OPP Docket Tel: 703**  **- 305**  **- 5805** 

**Please note that all times are approximate ( s**  **ee note at the end of the a**  **genda) Tuesday,**  **Ju ly 30**  **, 2013 8:30**  **A.M. Opening of Meeting and Administrative Procedures** 

– Joseph Bailey , Designated Federal

Official, Office of Science Coordination and Policy, EPA **8:35 A.M.**  **Introduction and Identification of Panel Members**

– Daniel Schlenk , Ph.D., Chair, FIFRA

Scientific Advi sory Panel **8:45 A.M.**  **Opening Remarks**

– David Dix, Ph.D., Acting Director, Office of Science Coordination and

Policy (OSCP) ; Steven Bradbury, Ph.D., Director, Office of Pesticide Programs (OPP), EPA **9: 00**  **A.M. Overview**  **of the**  **E ndocrine**  **D isruptor**  **S creening**  **P rogram**  **(EDSP) -**  Mary Manibus an,

Director, Exposure Assessment Coordination and Policy Division (EACPD) , OSCP, EPA **9:30 A.M. EDSP Weight**  **- of**  **- Evidence**  **(WoE) Process**  **-** T h omas M. Steeger, Ph.D., Environmental Fate and Effects Division (EFED) , OPP, EPA **10:00 A.M. Case Study Chemical**  **s: Chemical A**  **-** Greg ory Akerman, Ph.D., Health Effects Division

(HED) , OPP, EPA **10: 30**  **A.M. Break**  **10: 45**  **A.M. Case Study Chemical**  **s: Chemical S**  **-** John Liccion e , Ph.D., HED, OPP, EPA **11:15 A.M. Case Study Chemical**  **s: Chemical**  **J -**  Amy Blankinship, M.S. , EFED, OPP, EPA **11:45 A.M. Case Study Chemical**  **s: Chemical N**  **-** Catherine Aubee, M. P .A ., EFED , OPP, EPA **12: 15**  **P .M.**  **Lunch 1:**  **15 P**  **.M. Case Study Chemical**  **s: Chemical X**  **-** Patience Brown e , Ph.D., E ACPD , OSCP, EPA **1:45 P.M. Concluding Remarks**  **-** T h omas M. Steeger, Ph.D., EFED , OPP, EPA **2: 15**  **P.M. Break**  **2: 30**  **P.M. Public Comments**  **5: 00**  **P.M. Adjournment** 

## AGENDA

2 **Wednesday, Ju**  **ly 31 , 2013**  **8:30 A.M.**  **Opening of Meeting and Administrative Procedures**

– Joseph Bailey , Designated Federal

Official, Office of Science Coordination and Policy, EPA **8:35 A.M.**  **Introduction and Identification of Panel Members**

– Daniel Schlenk , Ph.D., Chair, FIFRA

Scientific Advisory Panel **8 :**  **45 A.M.**  **Follow -**  **up f**  **rom Previous Day’s Meeting 9:**  **0 0 A.M.**  **Panel Discussion of Charge**  **Charge 1.1. Please comment on whether the agency has transparently described the conduct and results of the**  **individual Tier 1 studies and the OSRI for each of the case studies (Sections 6 -**  **9 of the white paper), and specifically whethe**  **r the level of detail is sufficient to ensure that a study is reliable for determining the potential to interact with E, A, or T signaling pathways and the rationale for the preliminary study conclusion.**  **10:15 A.M. Break**  **10:30 A.M.**  **P anel Discussion of C**  **harge Charge 1.2.**  **For each of the case studies, please comment on whether the perform ance criteria are clearly stated for**  **the Tier 1 assays and, when results were not within the boundaries of the perform ance criteria, whether EPA has**  **clearly expressed why the data are still considered reliable.**  **11:30 A**  **.M. P**  **anel Discussion of Charge**  **Charge 1.3.** The test guidelines for Tier 1 assays recommend that the organism is challenged by attaining sufficiently high treatment doses/concentrations. Difficult to test substances may be encountered in Tier 1 screening. Chemical S is an illustration of this situ ation. In the case of Chemical S, consistent exposure was not achieved in the Amphibian Metamorphosis assay (AMA) due to the physical

- chemical characteristics of the test substance. The compound has low solubility and is highly lipophilic (high Kow) and p rone to sorbing to surfaces (high Koc). Due largely to these properties, the contributing laboratory performing the AMA with Chemical S did not achieve a concentration level high enough to produce a response indicative of a maximum tolerated dose. Nonethe less, the agency concluded that the data were still useful in the WoE analysis. This determination was based on the agency’s understanding that while measured exposure concentrations were lower than the targeted nominal concentrations, exposure was reasonably quantified and that it is not likely that the chemical would be any less problematic to test if the study were repeated. Further, while higher exposure concentrations could have been achieved in the AMA, the FSTRA indicates that these higher concentrations likely would have resulted in overt toxicity. **Please comment on the agency’s conclusion regarding the utility of the AMA data for Chemical S to still reliably evaluate its potential endocrine interaction in a WoE analysis.**  **12:15 P.M. Lunch**  **1:15 P.M.**  **Panel Discussion of Charge Charge 2.1.a.**  Chemical A can result in cholinergic toxicity given that its pesticidal mode of action is cholinesterase inhibition. In particular, overt toxicity was observed at high concentrations in the FSTRA. Although a number of endocrine responses were observed (e.g., decrease in female VTG, fecundity/fertility, GSI, male tubercles) at the highest concentration in the FSTRA, there was also pronounced overt toxicity that included abnormal behavior and significant body we ight reductions consistent with cholinergic intoxication. Given the directionality of the FSTRA responses (i.e., decreases in th e measured endpoints), EPA concluded that the effects found at the high concentration in the FSTRA may not necessarily be re flective of an endocrine

- mediated response, but rather a reflection of a compromised organism with limited ability to maintain reproductive function and homeostasis. Although in male fish, overt toxicity was not observed at the intermediate

## AGENDA

3

concentration, possible endocrine responses were limited to two effects that lacked diagnostic specificity (i.e., altered GSI and histology). **Please comment on how the agency has applied its decision logic to integrate an understanding of overt toxicity in the context**  **of observed Tier 1 in vivo responses , and in particular, the agency’s determ ination not to place weight on the**  **FSTRA high concentration responses coincident with overt toxicity. 2**  **:15 P.M. P**  **anel Discussion of Charge Charge 2.1.b.**  The pesticidal mode of action of Chemical S involves the uncoupling of mitochondrial oxidative phosphorylation and resulting in the depletion of ATP. Another plausible mode of toxic action is related to its irritation properties including irritation that com promises the integrity of the gastro

- intestinal tract in mammals leading to restricted caloric intake due to reduced food consumption. Reflective of these toxic modes of action, observations in the Tier 1 studie s and OSRI included body weight reducti ons, behavioral effects, and decreased survival. The majority of potential androgen and estrogen

- related responses (decreases in testosterone, decreases in male and female gonadal weights, delays in VO and PPS, decreases in male fertility, an increase in male GSI and VTG) were coincident with this overt toxicity. At concentrations where no apparent overt toxicity occurred, there were no endocrine related responses in the FSTRA, and responses in female rats were limited to a 2 day delay in VO, and for male rats, a decrease in the weights of two androgen

dependent tissues. The majority of Tier 1 responses were decreases in the measured endpoints, which were largely expressed in the presence of overt toxicity, are consistent with a depletion of ATP and restricted caloric intake. Although male VTG wa s increased in fish this is likely an artifact of a single elevated response. **Please comment on how the agency has applied its decision logic to integrate an understanding of overt toxicity in the context of ob**  **served Tier 1 in vivo responses, and in particular, on the agency’s determination to place less weight on the Tier 1 in vivo responses in the presence of overt toxicity.**  **3:15 P.M. Break**  **3 :**  **30 P.M.**  **Panel Discussion of Charge Charge 2.1.c.**  Chemical N is a cyclic unsaturated ketone whose acute mode of toxic action is nonpolar narcosis (toxicologically induced and reversible stages of neural disruption, i.e. general anesthesia). Unlike the other case study chemicals, there is no pesticidal mode of toxic action for N given that it is an inert ingredient. Testing required reaching limit doses/concentrations in order to sufficiently challenge the animal. Potential androgen responses only occurred in the FSTRA (decrease female VTG, decrease fecundity/fertility, altered histology) and in the male pubertal assay (decreases in testosterone, decreases in androgen sensitive tissue weights, delays in PPS) near limit doses/concentrations (as described in the white paper and test guidelines). However, a significant decre ase in female VTG was observed at the intermediate dose. Observations of overt toxicity (decreased body weights and feeding) were reported in the highest treatment group (i.e., near limit concentrations) in the FSTRA, but no overt toxicity wa s reported i n the male pubertal assay. Unlike Chemicals A and S, the overt toxicity is not as pronounced for Chemical N. The responses in fish and rats at the high dose could be due to a compromised metabolic ability and inability to reduce chemical load. **Please comment on the agency’s analysis in characterizing Tier 1 responses that are expressed at or near limit doses where som**  **e degree of overt toxicity occurs, and the extent to which such responses are considered in the WoE analysis.**  **4:15 P.M. Panel D**  **iscussion of Charge Charge 2.1.d.**  The case study analyses described above all involve situations in which overt toxicity was observed coincident with Tier 1 responses. **Please comment on the agency’s overall approach to characterizing Tier 1 responses coincident with overt toxicity and determining the weight to be given to such responses.**  **5: 0**  **0 P.M. Adjourn**  **ment**

## AGENDA

4 **Thursday, August 1**  **, 2013 8:30**  **A.M. Opening of Meeting**  **and Administrative Procedures**

– Joseph Bailey , Designated Federal

Official, Office of Science Coordination and Policy, EPA **8:35 A.M.**  **Introduction and Identification of Panel Members**

– Daniel Schlenk , Ph.D., Chair, FIFRA

Scientific Advisory Panel **8:45 A.M.**  **Follow -**  **up from Previous Day’s Meeting 9:00 A.M.**  **P anel Discussion of Charge**  **Charge 2.2.** In certain case studies, there was a lack of anticipated complementary and redundant responses (within an in vivo assay or across assays) at different levels of b iological organization (molecular, cellular, tissue/organ, and organism) indicative of a chemical interaction with an endocrine signaling pathway. The estrogen signaling pathway will be used as an illustration. In the case of Chemical N, the mammalian assays were negative and responses within the FSTRA did not progress to higher level responses (e.g., an effect on VTG did not translate to an effect on gonadal

- tissue or on fecundity). In the case of Chemical A, the rat uterotrophic and female pubertal assays (i.e., an organism with an intact hypothalamic

pituitary

- gonadal axis) were negative for estrogen

- related responses, and although there were some responses in the FSTRA in the absence of overt toxicity, they lacked diagnostic specificity (e.g., effects on ma le gonadal tissue or GSI). Given the lack of complementarity and redundancy in responses within and across assays, the agency considered these situations as insufficient to support a robust conclusion of an interaction with endocrine signaling pathways
. **Please comment on the decision logic the agency has used to characterize these types of situations where there is a lack of robustness in terms of complementarity and redundancy, and the transparency and reasonableness of the**  **approach. 10:**  **00 A.M.**  **Bre ak**  **1 0**  **: 15**  **A.M. P**  **ane l Discussion of Charge**  **Charge 2.3.** In contrast to the situation described in question 2.2., Chemical J appears to interact with the estrogen signaling pathway in terms of complementarity and redundancy across multiple levels of biological organization as evidenced through altered steroido genesis, resulting in decreased VTG in female fish which in turn translates to a higher

- level response (e.g., reduced fecundity) in fish. However, this biological continuum was not observed in the Tier 1 rat female pubertal assays and the Part 158 mammali an data. **Please comment on the how the agency has characterized this endocrine interaction at different levels of biological organization across taxa, and the transparency and reasonableness of the conclusions drawn. Please include in your**  **response, c omments regarding the agency’s conclusion about differences in sensitivities between taxa (i.e., fish and**  **rats), regarding chem icals that appear to alter steroidogenesis.**  **1 1:**  **15 A**  **.M. P**  **ane l Discussion of Charge**  **Charge 2.4.** Chemical A illustrates a situation where a molecular event has been initiated along a pathway via binding to the androgen receptor and by altered steroidogenesis, with corroborative evidence from the Hershberger assay. However, at a higher level of biolog ical organization, an anti

- androgenic response is not expressed within the context of the mammalian intact hypothalamic

- pituitary

- gonadal axis (based on the Tier 1 mammalian assays and the mammalian in vivo OSRI). In the absence of overt toxicity, there were some possible endocrine

- related responses in the FSTRA, but they lacked diagnostic specificity (e.g., reduced GSI and altered histology). The agency concluded that although there is evidence of an endocrine interaction (i.e., the androgen signaling pathway) at lower levels of biological organization, clear endocrine

- driven responses are not expressed at higher levels of biological organization in organisms with an intact HPG

- axis, presumably due to compensatory processes.

## AGENDA

5

**Please comment on how the agency has integrated different sources of data along a biological continuum** **to characterize endocrine interactions of Chem** **ical A and the transparency and reasonableness of the decision logic. 12:00 P.M.**  **Lunch 1**  **: 00**  **P.M. P**  **anel Discussion of Charge Charge 2.5.**  In some chemical situations, the in vitro Tier 1 data are negative. Nonetheless, this does not necessarily detract from a conclusion of a potential endocrine interaction in vivo either because a different molecular initiating event (MIE) may b e occurring than what the in vitro assay evaluates or because an activated metabolite may be responsible for the in vivo effects. Chemicals N and S provide an illustration of this situation in that the MIE is uncertain due to the negative Tier 1 in vitro a ssays. But, there were Tier 1 in vivo responses that are consistent with potential interactions with the androgen or estrogen signaling pathways. For Chemical N, anti

- androgen related responses were observed in the male pubertal assay that were compleme ntary within the assay (i.e., decreased in testosterone levels that progressed to effects at the organ (tissue weight decreases in androge n sensitive tissues) and organism level (delay in PPS). In the FSTRA, more limited responses were observed in the abs ence of overt toxicity, i.e., a decrease in female VTG that did not manifest into higher level effects. In this case, there is in vivo evidence of an endocrine interaction but compared to other case studies (e.g., as Chemical J), the complementarity and r edundancy in responses are not as robust. In the case of Chemical S for the A pathway, in the Hershberger there was a decrease in androgen

- sensitive tissue weights. In the case of the male pubertal assay, there were complementary responses in that a cel lular response (i.e., decreases in testosterone levels) progressed to effects at the organ (tissue weight decreases in androgen sensitive tissues) and organism level (delay in PPS). In the FSTRA, there were altered male gonadal weights and reduced tubercl es. Although these effects in the fish lack specificity, they are supported by the mammalian responses. Tier 1 in vivo responses are not observed at the lower concentrations in organisms with an intact HPG

- axis, presumably due to compensatory processes. **P lease comment on the how the agency has integrated different sources of data along a biological continuum** **to characterize this endocrine interaction and the transparency and reasonableness of the conclusion drawn.**  **2 :**  **00 P.M.**  **Panel Discussion of Charge Cha**  **rge 2.6.** In each of the cases studies, there was a lack of anticipated complementary and redundant responses indicative of a chemical’s interaction with the thyroid signaling pathway. In the rat, there were T4 changes that were either marginal o r equivocal (Chemical A), or isolated organ weight changes (Chemicals J and S) or histopathological changes of the thyroid gland (Chemical J) that were not coincident with hormone changes. In the AMA, there were some isolated responses not necessarily indicative in terms of the endpoint specificity of a hypothalamic

- pituitary

- thyroid axis perturbation (Chemicals A and N). The agency considered the lack of complementarity and redundancy in responses to support a conclusion of no interaction with the HPT axis, and view ed these isolated responses insufficient to support a conclusion of an interaction with the thyroid signaling pathway. **Please comment on the how the agency has characterized this endocrine interaction at different levels of biological organization, and th**  **e transparency and reasonableness of the conclusion drawn. 3:00 P.M.**  **Break 3**  **: 15**  **P.M. Panel Discussion of Charge**  **Charge 2.7.** In the absence of Tier 1 data, OSRI was available for Chemical X that indicated effects on thyroid endpoints in the rat but the results were inconsistent within and among studies and there was no OSRI presented from amphibian studies. Because of studies that were not specifically validated to detect an interaction with the thyroid hormonal pathway, limited data, and ambiguous results, the potential for Chemical X to interact with the thyroid pathway cannot be excluded. **Please comment on the how the agenc y has characterized this endocrine interaction at different levels of biological**  **organization, and the transparency and reasonableness of the conclusion drawn.**

## AGENDA

6

**4:15 P.M. Panel Discussion of Charge**  **Charge 3. Based on all of the case study analyses, please provide overall comments on how the agency has em** **ployed its WoE guidance and characterized the evidence and conclusions and include in your response the following points:**  **a. How consistent and transparent the cases studies are in terms of documentation.**  **b. How adequately the agency has described the extent of complementarity and redundancy of responses and has integrated and interpreted diverse lines of evidence across different biological levels of o**  **rganization and taxa to reach preliminary conclusions regarding endocrine interactions.**  **c. How the agency has used OSRI data to further characterize the observations from EDSP Tier 1 assays in determining potential chemical interactions with the E, A,**  **and T signaling pathways. d. How the agency has considered the understanding of a chem** **ical’s mo**  **de of action and how that inform s the weight**  **that is placed on Tier 1 responses in the presence of uncertainties introduced by dose setting, overt toxicity, a nd portal**  **of entry issues. 5:**  **0 0 P.M.**  **Adjournment Friday,**  **August 2 , 2013**  **8:30 A.M.**  **Opening of Meeting and Administrative Procedures**

– Joseph Bailey , Designated Federal

Official, Office of Science Coordination and Policy, EPA **8:35 A.M.**  **Introduction and Identification of Panel Members**

– Daniel Schlenk , Ph.D., Chair, FIFRA

Scientific Advisory Panel **8:45 A.M. Follow**  **- up from Previous Day’s Meeting**  **9:00 A.M. P**  **ane l Discussion of Charge**  **10: 00**  **A.M. Break**  **10:15 A.M. Panel Discussion of Charge**  **11:00 A.M. P**  **anel Discussion of Charge 12:00 P.M.**  **Lunch 1:00 P.M.**  **P anel Discussion of Charge**  **3:00 P.M. Break**  **3:15 P.M. P**  **anel Discussion of Charge 5:00 P.M.**  **Adjournment** Please be advised that agenda times are approximate; when the discussion for one topic is completed, discussions for the next topic will begin. For further information, please contact the Designated Federal Official for this meeting : Joseph Bailey , t elephone: (202)

- 564
- 2045 , fax: (202) 564

- 8382, or email: bailey.joseph @epa.gov.