UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON D.C., 20460 

August 7, 2009 

MEMORANDUM 

OFFICE OF 

PREVENTION, PESTICIDES AND TOXIC 

SUBSTANCES 

SUBJECT: Supplemental Ethics Review of Chlorpyrifos Human Toxicity St 

eta/. 

FROM: John M. Carley 

Human Research Ethics Review Officer 

Office of Pesticide Programs 

TO: Anna Lowit, Ph.D. 

Health Effects Division 

RE: Kisicki, J.; Seip, C.; Combs, M. (1999) A Rising Dose Toxicological Study to 

Determine the No-Observable-Effect-Levels (NOEL) For Erythrocyte 

Acetylcholinesterase (AChE) Inhibition and Cholinergic Signs and Symptoms of 

Chlorpyrifos at Three Dose Levels. Unpublished study prepared by MDS Harris 

Laboratories under Project No. 21438 and Dow AgroSciences Study No. DR K0044 793-284. 578 p. (MRID 44811 002) 

Juberg, D.; Mattsson, J. (2008) Updated Dow AgroSciences Response to EPA 

Query Regarding Two Toxicology Reports. Unpublished document prepared by 

Dow AgroSciences LLC under Study ID DRJ05282008. 27 p. (MRID 47436401) 

Carley, J. (2009) Ethics Review ofChlorpyrifos Human Toxicity Study. 

Memorandum dated May 29, 2009 to Anna Low it. 11 p. 

Kisicki, J. (2009) "Re: Ethics Review ofChlorpyrifos Human Toxicity Study". 

Unpublished letter dated June, 23, 2009 to K. Racke of Dow AgroSciences, 

responding to EPA Ethics Review ofMRID 44811002 dated May 29,2009. 7 p. 

Anon. (1998) Attachment to June 23, 2009 J. Kisicki letter to K. Racke with 

subjects de-identified. Unpublished Screening Logs dated September 21, 1998 

and October 6, 1998, used by MDS-Harris Laboratories in the execution of the 

study reported in MRID 44811002. Submitted to EPA July 1, 2009. 18 p. 

Page 1 of6 
The last two documents cited above came to EPA after I had completed my May 29, 

2009 ethics review of this study. I have reviewed them carefully to assess whether they provide 

evidence that would lead me to change my earlier conclusion that EPA is forbidden by 40 CFR 

§26.1704 to rely on the Kisicki et al. study, MRID 44811002, in actions taken under FIFRA or 

§408 of FFDCA. 

I have not yet seen the final recommendations of the HSRB concerning this study. At 

their meeting on June 24, and at least in part on the basis of assurances in the June 23, 2009 letter 

from Dr. Kisicki, they indicated disagreement with my conclusion. Nonetheless, my analysis of 

the new evidence does not persuade me to change that conclusion. 

Supplemental Ethics Review 

During the HSRB meeting on June 24, 2009, at which the Kisicki et al. study of 

chlorpyrifos RBC cholinesterase inhibition was discussed, Dow AgroSciences (DAS) submitted 

to EPA a letter dated June 23, 2009, from Dr. James C. Kisicki ofMSD Pharma Services to 

Kenneth D. Racke of DAS. Dr. Kisicki was the Study Director for this study, archived under 

MRIDs 4481 1002, 45144101 , 47429401, and 47436401. 

The description of the candidate screening procedure in the Kisicki letter was read to the 

HSRB during their meeting, and it materially affected their deliberations. The letter as 

submitted, however, did not include the subject sign-in logs cited as an attachment, which are 

critical to support the assertions in the letter. At EPA's request, DAS provided the logs to EPA 

later, after de-identification of subjects. 

The central concern of my May 29, 2009 ethics review was whether all participants had 

provided legally effective informed consent before becoming involved as subjects in th~ 

research, as is required by the regulations (21 CFR 50) which governed the conduct ofthis 

research. I concluded on the basis of information in the study report and the two earlier 

supplements submitted by DAS that they had not, and therefore that the conduct ofthis study 

was significantly deficient relative to standards prevailing when it was conducted. Dr. Kisicki's 

letter addressed this concern in two passages. 

First, in his response # ll, Dr. Kisicki states: 

In 1998, when this study was conducted, our internal standard operating procedure (SOP) for 

screening was as follows: 

When potential subjects arrived at the research facility, they were given a packet of information 

about the study. The packet contained a copy of the IRB-approved Informed Consent Form. 

Prior to any screening procedures, the subjects were required to sit and listen to an audio tape of 

the Informed Consent Form and follow along with the written document. An associate was 

available to answer any questions. Documentation is available of the subject signing a log 

indicating that they had listened to the audio tape of the Informed Consent Form, they 

understood it, and that they had no further questions. (See attachment documenting subject 

Page 2 of6 
listened to the audio recording of the Informed Consent Form and the packet given to the study 

subjects) 

Then in discussing compliance with 21 CFR standards, Dr. Kisicki states: 

At the time the research was conducted, it was our standard operating procedure to have the 

subject listen to an audio recording of the Informed Consent From and follow along with the 

written document. However, subjects were not required to sign at that time. Documentation is 

provided noting subjects listened to the audio recording, they understood it, and they bad no 

further questions. The subjects were allowed to take the Informed Consent Form with them 

after they complete the screening process. The Informed Consent was signed when the subject 

arrived at the research facility the evening before dosing. 

The submitted screening logs, however, were not signed by all the participants in the 

research. Only 18 of the 47 primary and alternate subjects enrolled in Phase 1 ofthe study, and 

only 31 of the 35 primary and alternate subjects enrolled in Phase 2 of the study signed one or 

the other of the logs provided to EPA. Thus my concern has not been laid to rest. 

.Analysis of the Screening Log 

Two logs were included in the DAS submission of July 1. First is a ten-page list entitled 

"Screening List- Full: Screen Date: 21-SEP-1998: Study Number 21438 Group ID: 1." This list 

includes 107 entries, each consisting of a Harris Subject ID in the range from 3 through 335 with 

or without an associated (redacted) signature. It appears to be complete- i.e., each page but the 

last includes 11 entries, but the last page includes only 8, the last of them hand-written. The 

second log is a similar seven-page list entitled "Screening List- Full: Screen Date: 06-0CT1998: Study Number 21438 Group 10: 2." This list includes 98 entries, each consisting of a 

Harris Subject ID in the range from 133 through 579, each one again with or without a (redacted) 

signature. This list also appears to be complete; the final page contains only 1 0 entries. In no 

case does the same Subje~t ID appear on both the Group 1 and Group 2 lists. 

DAS reports that these logs originally included the full name, address, and SSN of each 

candidate. These identifiers have been masked completely, and the signatures have been blacked 

out. It is, however, still possible to tell which candidates, identified by Subject ID, signed the 

log. At the bottom of each page the log bears this language: 

Volunteers are to sign beside their name after listening to the Informed Consent Form, 

if they understand it and have no further questions. 

Table 1 below summarizes the numbers of unique Subject IDs appearing either on the 

screening logs (lines 1-4) or, in line 5, not appearing on the logs provided but included as 

enrolled primary or alternate subjects in the accounting by SID provided in Appendices II and III 

to the DAS supplemental submission of May 28,2008 (MRID 47436401.) 

Page 3 of6 
1 

2 

3 

4 

5 

Table 1: 

Summary Analysis of Screening Logs vs. Enrollment Status 

On Log Signed Log Enrolled Phase 1 Phase 2 Total 

y N N 55 41 96 

y y y 18 31 49 

y y N i' 31 22 IJ 53 

y N y 3 4 7 

N n/a y 26 0 26 

133 98 231 

Neither the study report nor Dr. Kisicki's letter explains how the screening logs were 

compiled; I assume they incorporated the results of initial recruiting. A high percentage of these 

candidates (51% for Phase 1 and 42% for Phase 2) were apparently "no-shows"- they did not 

sign the log and were not enrolled as either primary or alternate subjects. 17% of the screened 

IDs in Phase 1 and 32% in Phase 2 signed the log and were enrolled. These candidates are 

highlighted in light green in Tables 1-4. A still-significant percentage of the IDs on the log (29% 

for Phase 1 and 22% for Phase 2) signed the log but were not enrolled; these are highlighted in 

yellow in the tables, and may correspond to the group reported in Appendix 4.24 to the study 

report (MRID 44811002, pp. 506-508) as "Subjects not Enrolled on the Study." Candidates who 

were enrolled as subjects but who did not sign one of the screening logs provided are highlighted 

in red in the tables. Detailed listings of both the Group 1 and Group 2 logs are appended to this 

review as Tables 2 and 4. 

Line 5 in Table 1 reports 26 subjects whose Subject IDs were not included on the 

September 21 screening log but who were subsequently enrolled in Phase 1. A detailed listing of 

these 26 enrolled subjects appears in appended Table 3. I note, however, that in Appendices 

4.6.1 and 4.6.2 to the study report (MRlD 44811002, pp. 253-264) all but one of the 20 among 

these 26 candidates who actually participated in Phase I testing 1 (as subjects 17-30 and 32-36) 

are reported to have been screened on 30 September, whereas the candidates who participated as 

subjects 1-16 and 31 were all reported to have been screened on September 23. Thus it appears 

likely that a second Group 1 screening log was generated and used for screening on September 

30-a log which has not yet been submitted to EPA. 

The anomaly is Subject 31, reported in Appendices 4.6.1 and 4.6.2 to have been screened 

on September 23. SID 343 is linked to Subject 31 in Appendix II to the second DAS 

supplemental report (MRID 47436401, p. 23), but SID 343 does not appear on the September 21 

screening log used on that date, and is outside the range of SIDs that are on the log. The highest 

SID n~mber on the September 21 log, however, is handwritten; perhaps SID 343 should have 

1 The accounting is necessarily less than complete, since the screening date is reported in Appendices 4.6.1 and 

4.6.2 only for the 60 subjects who were ultimately treated, and not for those enrolled as primary subjects but 

subsequently replaced or for those enrolled as alternate subjects and not used. 

Page 4 of6 
been added to the log by hand as well. Most of these 26 subjects, however-excepting SID 

343/Subject 31, and perhaps others-can probably be accounted for on the screening log used on 

September 30. · 

Additional documentation cannot, however, overcome the evidence in hand that three 

candidates who were screened on September 23 but who did not sign the screening log were 

subsequently enrolled in Phase I: SID 234 was enrolled and treated as Subject 5, SID 313 was 

enrolled as Subject 3 but replaced before treatment, and SID 322 was enrolled and treated as 

Subject 25. Furthermore, four more candidates who were screened on October 13 but who did 

not sign the screening log were subsequently enrolled in Phase 2: SID 487 was enrolled as 

Alternate 3 but not treated; SID 495 was enrolled and treated as Subject 46; SID 498 was 

enrolled as Alternate 1 but not treated; SID 557 was enrolled and treated as Subject 44. 

It is clear from this evidence that the SOP described in Dr. Kisicki's June 23 letter was 

not consistently followed in the conduct of this study. The ethical significance of this lapse is 

less clear. 

In my May 29 ethics review I noted that "by the time of check-in ... subjects had given 

blood and urine samples, provided medical and surgical history, and been subjected to a physical 

examination at screening, had visited the clinic 48 h before check-in to obtain urine collection 

containers, and had been collecting their urine for two days." ·J concluded " in my judgment the 

subjects should all have provided written informed consent at or before the time of screening." 

They did not, however, sign consent forms until check-in on the evening before treatment. 

Dr. Kisicki' s letter asserts that at the time of screening all candidates received a packet 

containing the approved consent form, that they were required to follow along as they listened to 

an audio recording of it, and that they all signed the screening log to acknowledge receipt and 

understanding of the consent form and to indicate that they had no questions about it, all before 

the first collection of data and samples. On the strength of this assurance the HSRB concluded 

that the delay in signing the consent form until after initiation of data collection was a technical 

lapse only, without substantive ethical significance. The HSRB indicated at the meeting that 

their summary judgment would be that the conduct of this research was not "significantly 

deficient relative to standards prevailing when it was conducted," and thus that the study is 

ethically acceptable under the standard of 40 CFR §26.1704. 

After a careful review the new evidence provided by DAS and MDS Pharma Services, I 

remain concerned that at least some of the participants in this study may have been involved as 

subjects- i.e., may have provided information and tissue samples for analysis-without first 

having been properly informed and providing their informed consent. 

It is conceivable that all candidates who came to one of the screening meetings did, in 

fact, receive and review the consent form, understand it, and have no unanswered questions, but 

that they simply failed to sign the screening log. If that's what happened, then it suggests at least 

carelessness on the part of the laboratory staff in carrying out their SOPs and in ensuring 

compliance with the unambiguous regulatory requirement that "no investigator may involve a 

Page 5 of6 
human being as a subject in research covered by these regulations unless the investigator has 

obtained the legally effective informed consent of the subject." (21 CFR §50.20) 

I will finalize my ethics review of this study once we have received the recommendations 

of the HSRB. But based on all the evidence I have seen and· the concerns I have raised in both 

this supplemental review and in my ethics review of May 29, I remain of the view that its 

conduct was significantly deficient relative to standards of ethical research conduct prevailing 

when it was conducted, and that EPA is forbidden by 40 CFR §26.1704 to rely on it. 

Attachment 

cc: Paul Lewis, OSA 

Tom Myers 

Kelly Sherman 

William Jordan 

Page 6 of6 
Appendix 

Table 2: Disposition of Subject IDs on Scr eening Log of 21 Sep 98 

HID/SID is taken from Screening Log. An 'x' in the column headed 'Is/' means a redacted 

signature appears in the Screening Log opposite the indicated HID/SID. Original and Final 

Enrolled Subject Numbers linked to SIDs are taken from Appendix II to the second DAS 

supplemental report (MRID 47436401, p. 23). Screen Date is taken from Appendices 4.6.1 and 

4.6.1 to the primary study report (MRID 44811002, pp. 253-264) 

Enrolled Subject Screen HID/SID Is/ Number 

Original Final 

Date 

3 

4 

8 X 

15 

17 X 7 7 23-Sep 

22 

25 

32 

34 X 21 21 23-Sep 

36 

45 X 6 6 23-Sep 

51 

54 

65 

66 

72 X 19 n/a NR 

74 

78 

81 

82 

83 

84 X 

86 

89 

93 

101 

104 

111 

112 X 2 2 23-Sep 

115 X 

116 

121 X A10 13 23-Sep 

125 X 11 11 23-Sep 

126 

173 X 13 nla NR 
A

ppendix 

Enrolled Subject Screen HID/SID /s/ Number 

Original Final Date 

206 

207 

225 X 23 23 23-Sep 

234 5 5 23-Sep 

236 

237 X 

240 

242 X 

246 X 

248 X 1 1 23-Sep 

249 

250 

251 X 27 n/a NR 

252 X 

253 

255 X 

257 

258 

259 

260 X 

261 X 

262 X 

264 

267 

268 X 

270 

272 

273 X 

274 

275 X 

276 

277 X 

278 X 

279 

282 

284 X 

285 

286 X 

287 

290 X 

291 X 

292 X 

293 X 

294 

295 
Appe

ndix 

Enrolled Subject Screen HID/SID lsi Number 

Original Final Date 

296 

300 X 30 30 23-Seo 

301 X 

302 X 9 9 23-Sep 

303 X 

304 X 

305 X 

306 

307 

308 X 26 26 23

-Seo 

309 

312 X 313 3 

n/a NR 

314 X 10 10 23-Seo 

315 

316 

317 

318 X 

319 

320 X . A11 n/a NR 322 25 25 23-Sep 

323 

324 X 24 24 23-Sep 

326 X 

329 X 16 16 23-Sep 

330 X 

335 X 
Table 3: Subjects Not Listed On Screening Log of21 Sept 98 

But Enrolled as Subjects in Phase I 

Appendix 

Original and Final Enrolled Subject Numbers linked to SIDs are taken from Appendix II to the 

second DAS supplemental report (MRID 47436401 , p. 23). Screen Date is taken from 

Appendices 4.6.1 and 4.6.1 to the primary study report (MRID 4481 1002, pp. 253-264) 

Enrolled Subject Screen HID/SID Number 

Original Final 

Date 

14 A9 nla NR 

23 A4 27 3C>-Seo 

332 29 29 30-Seo 

343 31 31 23-Seo 

349 32 n/a NR 

384 A1 3 3C>-Seo 

385 8 n/a NR 

387 33 33 3C>-Seo 

390 12 12 30-Seo 

391 A2/A10 8 3C>-Seo 

395 4 4 30-Seo 

399 35 35 3C>-Seo 

407 14 14 30-Seo 

419 15 15 30-Seo 

421 A3 20 30-Seo 

428 A4 34 30-Seo 

432 A7 nla NR 

433 A6 32 30-Seo 

440 18 18 30-Sep 

442 28 28 30-Sep 

446 AS 19 30-Seo 

447 17 17 30-Seo 

462 22 22 3C>-Seo 

463 36 36 30-Seo 

470 A8 n/a NR 

472 20 n/a NR 
Appendix 

Table 4: Disposition of Subject IDs on Screening Log of 6 Oct 98 

HID/SID taken from Screening Log. An "x" in the column headed "Is/" indicates that a redacted 

signature appears in the Screening Log opposite the indicated HID/SID. Original and Final 

Subject Numbers associated with SIDs are taken from Appendix II to the second DAS 

supplemental report (MRID 47436401 , p. 23). Screen Date taken from Appendices 4.6.1 and 

4.6.1 to primary study report (MRID 4481 1002, pp. 253-264) 

Enrolled Subject Screen HID/SID /s/ Number Date Original Final 

133 

219 X 

222 X 54 54 13-0ct 

235 

281 X 52 52 13-0ct 

339 

350 X A4 58 13-0ct 

359 

363 X 

370 

406 X 

448 X 56 56 13-0ct 

449 X 

468 X A11 n/a NR 

469 X A9 n/a NR 

476 

477 X A5 n/a NR 

478 

479 

480 X 

481 

484 

485 X 45 45 13-0ct 

487 A3 n/a NR 

488 

489 X 51 51 13-0ct 

490 X A2 n/a NR 

491 

492 

493 X 40 40 13-0ct 

494 

495 46 46 13-0ct 

496 X 59 59 13-0ct 

497 

498 A1 n/a NR 

499 X 48 48 13-0ct 

501 
Ap

pendix 

Enrolled Subject Screen 

HID/SID 

/s/ Number 

Original Final Date 

502 

503 

504 

507 X 

509 X 43/A8' 47 13-0ct 

510 X 

511 X 

513 X 

514 

515 

516 X 

517 

518 X 55 55 13-0ct 

519 

521 X 

522 X 41 41 13-0ct 

523 X 

526 X A? 43 13-0ct 

528 

529 X 

530 X 

531 X 47 n/a NR 

532 

534 X 

535 X 58 n/a NR 

536 

537 X 37 n/a NR 

538 X 

539 X 38 38 13-0ct 540 

541 

542 

543 

544 X 

545 X 60 60 13-0ct 

546 

547 

548 X 

549 X 49 49 13-0ct 

550 X 

551 

552 

553 X 42 n/a NR 

554 

555 X A6 42 13-0ct 
Appendix 

Enrolled Subject Screen HID/SID /s/ Number Date 

Original Final 

556 

557 44 44 13-0ct 

558 X 39 39 13-0ct 

559 

560 X 53 53 13-0ct 

561 X 

562 

563 X 

565 

566 

568 X 57 57 13-0ct 

569 X 50 50 13-0ct 

571 X A8 n/a NR 

572 X 

578 

579 X A10 37 13-0ct