# UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON D.C., 20460

OFFICE OF

CHEMICAL SAFETY AND

POLLUTION PREVENTION



# 2 Nov 2010

MEMORANDUM

SUBJECT: Correction to Parameters “Task Durati on” and “Surface Area”, and Verification

of “AaiH” for EPA’s 4 October 2010 Science Review of the AEATF II Mop

Human Exposure Monitoring Study. MRIDs 48210201, 48231201, and

48231901

FROM: Tim Leighton, Environmental Scientist

Antimicrobials Division

TO: Nader Elkassabany, PhD, Chief

Risk Assessment and Science Support Branch

Antimicrobials Division

REF: Selim, S., and Taylor, M. (2010) A Study for Measurement of Potential Dermal

and Inhalation Exposure During Applicati on of a Liquid Antimicrobial Pesticide

Product Using Bucket and Mop Equipm ent for Cleaning Indoor Surfaces.

Unpublished study prepared by Golden P acific Laboratories, LLC, under Project

No. AEA03, Report No. 070265. 2116 p. (MRIDs 48210201, 48231201, and

48231901)

Leighton, T. (2010) Science Review of the AE ATF II Mop Human Exposure

Monitoring Study. MRIDs 48210201, 48231201, and 48231901. Memorandum

dated 4 October 2010 to Nader Elkassabany. 25 p.

This memorandum corrects and verifies three st udy parameters reported in the cited EPA

Science Review of the human exposure mop study submitted by the Antimicrobial Exposure

Assessment Task Force II (AEATF II). The attach ed tables report the corrected values for the

task duration and surface area. My science review of 4 Oct ober 2010 used the correct AaiH; no

changes have been made in the AaiH. Therefor e, the dermal and inhalation exposure data as

presented in the original EPA sc ience review were not affected by these changes. Appendix A of

my science review for the alternative proportiona lity analysis used the incorrect sampling time,

and will need to be re-run. However, this analysis was an alternative review and not presented in

the science review itself or at the HSRB meeting.

Page 1 of 6

# Data Errors Identified

Dr. William Popendorf, a member of the Human St udies Review Board, noticed that there were

inconsistencies between values of sampling duration and the amount of active ingredient handled

(AaiH) reported in the study report (MRID 48210201, Appendix K) and in Table 2 of EPA’s 4

October 2010 science review. These exceptions we re called to EPA’s attention via e-mail from

Dr. Popendorf on November 1, 2010.

EPA has reviewed the values in question, has consulted with the Study Director and the QA

Analyst at Golden Pacific Laboratories, and has determined that the AEATF’s study report

correctly reports sampling duration and AaiH fo r each subject in Tables 12, 13, and 14 (MRID

48210201 pp. 109-111). Table 84 of the same report (MRID 48210201 p. 181), however,

attributed sampling times to the wrong subjects , as a result of confusing the subject number

identification and the monitoring event assignment. That the error occurred in the transcription

of data from Tables 12, 13, and 14 to Table 84 was confirmed by the study’s QA Analyst.

In preparing Tables 2, 3, and 4 attached to EPA’s 4 October 2010 science review, EPA matched

the (incorrect) sampling times from Table 84 to the surface area mopped as reported in Tables

12, 13, 14 of the study report. This resulted in EPA incorrectly matching the surface area

mopped to the MEs. The AEATF study report co rrectly reported the surface areas. EPA’s

summary statistics, however, were based on Tables 12, 13, and 14, and are correct.

Finally, the Study Director has reported to EP A that Appendix K included erroneous summary

values of AaiH for subjects M8, M7, and M24. Ag ain the values for these 3 subjects reported in

study Tables 12, 13, 14 are correct. No AaiH errors were brought forward into EPA’s analysis of

the data.

Impact of the Identified Errors

The following consequences of the identified errors have been identified:

(1) Tables 2, 3, and 4 of the EPA Science Review memo must be corrected. Corrected tables

are attached below, with revi sions highlighted in yellow.

(2) Surface area of floor mopped was not used in the statistical analysis, and EPA presented

only summary statistics for th e surface area mopped to the HSRB. Since the actual

surface area mopped values were correct, and the error was in the incorrect attribution of

these correct values to particular subjects, the summary statistics were unaffected, the

summary information presented to the HSRB wa s correct, and no corrections are needed.

(3) Task duration was used only in an alternative analysis of proportiona lity between dermal

exposure and time. These results were summar ized only in the sta tistical Appendix A to

the EPA Science Review. EPA will re-run th e alternative analysis and update Appendix

A. EPA presented only summary statistics for the sampling time to the HSRB. Again

since the actual values were correct, their inco rrect attribution to s ubjects did not affect

Page 2 of 6

# Page 3 of 6 

# the summary statistics. In this case, t oo, the information presented to the HSRB was

correct.

(4) The AaiH for 3 subjects was reported incorrect ly in the study report’s Appendix K. The

AaiH values were correct for these same subjects in study Tables 13 and 14. EPA used

the correct values in its st atistical analysis reported in the EPA Science Review and

presented to the HSRB.

(5) Dr. Popendorf suggested at the HSRB meeting further investigation of the air sampling

results taking sampling time into account. If Dr. Popendorf is considering further

analysis himself, he will need the attached tables with corrected information for mopping

time by subject. He should also note that air sampling pumps were turned on before

mopping began and left on during breaks, so the pump time reported in Appendix K

differs from the mopping time reported in the attached tables.

Attachments:

Table 2. Summary (Empirical) of Dermal a nd Inhalation Results for Mop—Long Pants, Longsleeved Shirt, Shoes/socks, and No Gloves. (Corrected)

Table 3. Summary (Empirical) of Dermal Results for Mop—Long Pants, Short-sleeved shirt,

Shoes/socks, and No Gloves. (Corrected)

Table 4. Summary (Empirical) of Dermal Results for Mop—Short Pants, Short-sleeved shirt,

Shoes/socks, and No Gloves. (Corrected)Table 2. Summary (Empirical) of Dermal and Inhalation Results for Mop—Long Pants, Long-sleeved Shirt, Shoes/Socks, and No GlovesUnit ExposuresClusterSubjectOrderSubjectNumber IDTaskDuration(minutes)SurfaceArea(sq ft)NumberBucketsPounds aiHandledDermalExposure(μg)InhalationExposure(μg/m3)Dermal(mg/lb ai)Inhalation(μg/m3/lbai)MW-01M1353188430.0030840.70.41313.2133.9MW-02M685515560.0066942.80.3346.449.9MW-03M1245499730.00584136.30.33323.357.0MW-04M2859505040.00538289.40.20953.738.8MW-05M1567418950.00556191.80.43734.578.5MW-06M2731332420.0041975.70.29218.169.7Mean57410040.005131290.33624.971.31Std19129110.00129980.08317.033.7MW-07M890668860.0055622666.90.12312.022.1MW-08M24791419150.01833364154.30.1078.45.8MW-09M269495250.0040609166.90.10816.526.6MW-10M463829540.0061509162.70.24226.539.3MW-11M1051439040.00546085112.30.21620.639.6MW-12M2138588430.00482371134.30.12827.826.5Mean65740050.007401160.15418.626.72Std19359910.00540420.05927.812.5MW-13M789616160.00838418288.30.27334.432.6MW-14M1879536260.00703495116.50.39116.655.6MW-15M2669433950.00740312365.20.43149.358.2MW-16M1459542540.0069908670.30.25710.136.8MW-17M2049498940.0052844879.20.24915.047.1MW-18M138400830.0039286495.90.19524.449.6Mean64504750.006501690.29925.046.63Std1978310.001611250.09114.710.2Mean62551640.006341380.26322.848.2Std18255310.00328920.11013.327.6Median61502340.005561140.25319.343.3Geo Mean59509440.005851140.23919.540.9Overall95th%tile89917960.009883010.43250.086.8Page 4 of 6Table 3. Summary (Empirical) of Dermal Results for Mop—Long Pants, Short-sleeved shirt, Shoes/socks, and No GlovesClusterSubjectOrderSubjectNumber IDTask Duration(minutes)Surface Area(sq ft)Number ofBucketsPounds ai HandledUnit ExposuresDermal(mg/lb ai)MW-01M1353188430.0030820.3MW-02M685515560.0066912.3MW-03M1245499730.0058425.2MW-04M2859505040.0053862.4MW-05M1567418950.0055640.3MW-06M2731332420.0041918.4Mean57410040.0051329.81Std19129110.0012918.5MW-07M890668860.0055612.6MW-08M24791419150.018338.50MW-09M269495250.0040617.5MW-10M463829540.0061527.5MW-11M1051439040.0054624.9MW-12M2138588430.0048234.9Mean65740050.0074021.02Std19359910.005409.87MW-13M789616160.0083835.3MW-14M1879536260.0070318.6MW-15M2669433950.0074055.2MW-16M1459542540.0069914.1MW-17M2049498940.0052815.8MW-18M138400830.0039326.9Mean64504750.0065027.63Std1978310.0016115.6Mean62551640.0063426.1Std18255310.0032814.7Median61502340.0055622.6Geo Mean59509440.0058522.8Overall95th%tile89917960.0098856.3Page 5 of 6Page 6 of 6Table 4. Summary (Empirical) of Dermal Results for Mop—Short Pants, Short-sleeved shirt, Shoes/socks, and No GlovesClusterSubjectOrderSubjectNumberIDTaskDuration(minutes)SurfaceArea(sq ft)NumberBucketsPounds ai HandledDermalExposure(μg)Unit ExposuresDermal(mg/lb ai)MW-01M1353188430.003088226.4MW-02M685515560.006693690551.2MW-03M1245499730.0058456997.5MW-04M2859505040.00538565104.9MW-05M1567418950.0055625345.4MW-06M2731332420.0041910324.7Mean57410040.00513877141.71Std19129110.001291395203.6MW-07M890668860.00556698125.5MW-08M24791419150.0183349326.9MW-09M269495250.0040622756.0MW-10M463829540.0061523237.8MW-11M1051439040.0054640073.2MW-12M2138588430.0048219841.1Mean65740050.0074037560.12Std19359910.0054019635.9MW-13M789616160.0083878994.1MW-14M1879536260.0070344062.5MW-15M2669433950.0074050568.2MW-16M1459542540.0069924535.0MW-17M2049498940.0052815228.8MW-18M138400830.00393403102.5Mean64504750.0065042265.23Std1978310.0016122229.9Mean62551640.0063455889.0Std18255310.00328807120Median61502340.0055640159.2GeoMean59509440.0058535861.3Overall95th%tile89917960.009881224189