AGENDA 

Federal Insecticide, Fungicide, and Rodenticide Act

Scientific Advisory Panel Open Meeting

May 21-23, 2013

FIFRA SAP WEB SITE http://www.epa.gov/scipoly/sap/

EPA Docket Number: EPA-HQ-OPP-2013-0075

Potomac Yard One South

2777 Crystal Drive

Arlington, VA 22202

Scientific Review of the Endocrine Disruptor Screening Program (EDSP); Tier I Assay and 

Battery Performance 

Please note that all times are approximate. (See note at the end of the Agenda).

Tuesday, May 21, 2013

9:00 A.M. Opening of Meeting and Administrative Procedures, Fred Jenkins, Ph.D., Designated 

Federal Official, Office of Science Coordination and Policy, EPA

9:05 A.M. Introduction and Identification of Panel Members, Daniel Schlenk, Ph.D., Chair 

FIFRA Scientific Advisory Panel 

9:15 A.M. Opening Remarks, David Dix, Ph.D., Acting Director, Office of Science Coordination 

and Policy, EPA: Steve Bradbury, Ph.D., Director, Office of Pesticide Programs, EPA

EDSP Program Overview, Mary Manibusan, Director, Exposure Assessment 

Coordination and Policy Division, Office of Science Coordination and Policy, EPA

10:00 A.M. Background: Current Validated EDSP Tier 1 Screening Assays and Battery, Leslie 

Touart, Ph.D., Exposure Assessment Coordination and Policy Division, Office of Science 

Coordination and Policy, EPA
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10:30 A.M. Break

Scientific Review of Tier 1 Assay and Battery Performance

10:45 A.M. In Vitro Assays, Gregory Akerman, Ph.D., Health Effects Division, Office of Pesticide 

Programs, EPA

11:30 A.M. In Vivo Mammalian Assays, John Liccione, Ph.D., Health Effects Division, Office of 

Pesticide Programs, EPA

12:00 P.M. Lunch

1:00 P.M. Fish Assay, Amy Blankinship, M.S., Environmental Fate and Effects Division, Office of 

Pesticide Programs, EPA

1:30 P.M. Frog Assay, Catherine Aubee, M.P.A., Environmental Fate and Effects Division, Office 

of Pesticide Programs, EPA

2:00 P.M. Battery Performance, Tom Steeger, Ph.D, Catherine Aubee, M.P.A, Amy Blankinship, 

M.S., Gregory Akerman, Ph.D., Office of Pesticide Programs, EPA

2:45 P.M. Break

3:00 P.M. Summary of Assay and Battery Review, Tom Steeger, Ph.D., Environmental Fate and 

Effects Division, Office of Pesticide Programs, EPA

3:15 P.M. Adjournment
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Wednesday, May 22, 2013

9:00 A.M. Opening of Meeting and Administrative Procedures, Fred Jenkins, Ph.D., Designated 

Federal Official, Office of Science Coordination and Policy, EPA

9:05 A.M. Follow-up from Previous Day’s Meeting, Daniel Schlenk, Ph.D., Chair, FIFRA 

Scientific Advisory Panel

9:20 A.M. Public Comments 

10:30 A.M. Break

10:45 A.M. Public Comments (Cont’d)

12:15 P.M. Lunch

1:15 P.M. Panel Discussion of Charge Questions

Charge Question 1. Based on the analysis of the data presented in Section III, please comment on the 

proficiency of the contributing laboratories to execute each assay in accordance with the test guidelines 

and achieve the performance criteria.

2:15 P.M. 

Charge Question 2. The performance criteria for each in vitro assay are clearly stated in the test 

guidelines for the ER binding (OCSPP 890.1250), AR binding (OCSPP 890.1150), ERα Transcriptional 

Activation (OCSPP 890.1300, OECD 455), H295R steroidogenesis (OCSPP 890.1550) and aromatase 

human recombinant (OCSPP 890.1200) assays. Although contributing laboratories did not always 

demonstrate that results were within the specified boundaries of the performance criteria, the majority of 

the deviations were still close to the performance criteria. In this regard, the EPA concluded that the 

data were still adequate for use. Please comment on the EPA’s conclusion. Please comment on when a 

deviation from the recommended performance criteria would render the study unreliable.

3:15 P.M. 

Charge Question 3. Unlike the Hershberger and Uterotrophic assays, a positive control is not required 

in the male (OCSPP 890.1500) and female (OCSPP 890.1450) pubertal assays. For these in vivo assays 

with rats, coefficient of variation (CV) limits are specified in the test guidelines for most endpoints. 

Submissions from different laboratories sometimes fell short of meeting all the test guidelinerecommended CV limits for the endpoints evaluated. However, in most cases these shortcomings were 

considered of minor importance to the overall results, and EPA concluded that the data are still adequate 

for endocrine screening. Please comment on the EPA’s conclusion. Please comment on when a 

deviation from the recommended CV limits would render the study unreliable.
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4:15 P.M.

Charge Question 4. The test guidelines for the six in vivo assays (Hershberger assay - OCSPP 

890.1400, OECD 441; Uterotrophic assay- OCSPP 890.1600, OECD 440; Male Pubertal assay- OCSPP 

890.1500; Female Pubertal assay - OCSPP 890.1450; FSTRA - OCSPP 890.1350, OECD 229 and AMA 

- OCSPP 890.1100) offer some guidance on setting the dose/concentration range when testing for 

specific effects on the E, A, or T signaling pathways. In some of the in vivo assays, overt toxicity was 

noted based on effects on growth, other sublethal effects, and even mortality at the highest 

dose/concentration tested. Positive Tier 1 findings indicating the potential for endocrine activity can be 

difficult to interpret in the presence of overt toxicity.

5:15 PM Adjourn 
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Thursday, May 23, 2013

9:00 A.M. Opening of Meeting and Administrative Procedures, Fred Jenkins, Ph.D., Designated 

Federal Official, Office of Science Coordination and Policy, EPA

9:05 A.M. Follow-up from Previous Day’s Meeting, Daniel Schlenk, Ph.D., Chair, FIFRA 

Scientific Advisory Panel 

9:20 A.M. Panel Discussion of Charge Questions (Cont’d)

Charge Question 5. Spinal curvature, usually manifesting as “bent tail” in X. laevis tadpoles, was 

reported in 15 of 18 AMA studies reviewed thus far. The anomaly appears to be first observed several 

days after study initiation, and prevalence increases with time. Overall, the prevalence of spinal 

curvature in these studies ranged from “a few per replicate” to 92% of a given treatment group by test 

termination. Experimental work by the EPA Office of Research and Development suggests that 

overfeeding can be a primary cause of spinal curvature in their Xenopus test populations; however, 

spinal curvature remained prevalent (range: 16-92%) in the five industry AMA studies in which feed 

was reduced by 50% compared to guideline recommendations.

Overall, the incidence of spinal curvature appears to be highly variable. From a qualitative review of the 

data, there appear to be no consistent differences in the incidence or variability of spinal curvature when 

studies using guideline versus reduced feeding regimes are compared. Please comment on whether the

presence or prevalence of spinal curvature in test specimens, including controls, compromises the utility

or validity of an AMA submission. If so, when does the prevalence of spinal curvature render the study

unreliable? What technical guidance may be useful for laboratories in reducing the occurrence of spinal 

curvature and determining if, or at what point within the study, a study may be compromised because of 

this phenomenon?

10:20 A.M. Break

10:30 A.M.

Charge Question 6. With the exception of thyroid gross pathology findings (thyroid gland atrophy and 

hypertrophy) in the AMA, severity grades are generally assigned based on comparison to “normal” X. 

laevis thyroid findings depicted in the guidance or based on the professional opinion of the pathologist 

conducting the assessment; they are not assigned in comparison to concurrent control findings from a 

given study. (Please refer to Section III.2.f in the document entitled “Interpreting Amphibian Thyroid 

Histopathology Diagnoses” and supporting documents, OECD Guidance Document on Amphibian 

Thyroid Histology No. 82, 2007 and Grim et al., 2009).
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a. In one study, the pathologist’s report identified a lower incidence and severity of follicular cell 

hypertrophy when compared to the incidence and severity of this trait in control specimens. 

Similar trends have been observed in other studies. In this case, the pathologist concluded that 

the finding was potentially consistent with treatment-related delay of metamorphosis because 

thyroid follicular cells normally increase in height during tadpole development. Please comment 

on the validity of this conclusion.

11:30 A.M.

b. What guidance may be given to better distinguish between histological changes in the thyroid 

associated with the normal progression of metamorphosis and treatment-related effects? Are 

there certain lesions or diagnoses which may, by their absence or lessened severity as compared 

to controls, be indicative of treatment-related HPT effects such as delayed metamorphosis?

12:30 P.M. Lunch

1:30 P.M.

Charge Question 7. In 2008, the SAP acknowledged that the in vivo assays included in the Tier 1 

battery provide both redundancy and complementarity for evaluating interactions with the E, A, or T 

signaling pathways. The panel also noted that all of the Tier 1 assays and the broad range of endpoints 

appeared to be necessary to “discriminate positive and negative results”.

a. Please comment on the battery performance with respect to the anticipated complementary

nature of the more complex, multi-parameter in vivo assays in the context of the observed 

responses with the case studies. Please comment separately on the E-, A-, and T-related assays 

and endpoints.

2:30 P.M. Break

2:45 P.M.

b. Please comment on the battery performance with respect to the anticipated redundancy across the 

11 assays in the context of the observed responses with the case studies. Please comment 

separately on the E-, A-, and T-related assays and endpoints.
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3:45 P.M.

c. The EPA concluded that the battery has performed as anticipated by the 2008 SAP. Please 

comment on this conclusion.

4:45 P.M.

Charge Question 8. The EPA is committed to minimizing animal usage in the screening battery while 

maintaining the effectiveness of the battery to answer the question of whether a chemical has the 

“potential” to interact with the endocrine system.

a. In 1998, the EDSTAC described the conceptual framework for Tier 1 assays and recommended 

the strategy to “require the minimal number of screens and tests necessary to make sound 

decisions, thereby reducing the time needed to make these decisions”, and that the screens 

should be conducted at a minimal cost necessary to make decisions. Based on the preliminary

battery performance evaluation, to what extent can the current Tier 1 battery of 11 assays be 

modified to reduce animal usage and/or lower cost while adequately ensuring the EPA’s ability

to answer the question of “whether a chemical has the potential to interact with the endocrine 

system?” More specifically, please comment on whether the Uterotrophic and Hershberger 

assays provide necessary redundancies in the Tier 1 battery based on this preliminary analysis. 

Please include in your comments what information may be lost and what uncertainties may be 

introduced by absence of either or both of these assays.

b. Please comment on the scientific criteria the Agency should consider in evaluating necessary

redundancies and eliminating assays from the current battery.

5:45 P.M. Closing Remarks, Daniel Schlenk, Ph.D., Chair FIFRA Scientific Advisory Panel; 

Fred Jenkins, Ph.D., Designated Federal Official, Office of Science Coordination and 

Policy, EPA

6:00 P.M. Adjournment

Note: 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, Dr. Fred Jenkins, via telephone: (202) 564-3327; 

fax: (202) 564-8382; or email: jenkins.fred@epa.gov.