Page 1 of 40 UNITED STATES ENVIRONMEN TAL PROTECTION AGENCY WASHINGTON, DC 20460

OFFICE OF CHEMICAL SAFETY AND POLLUTION PREVENTION

MEMORANDUM

DATE: March 17, 2011

SUBJECT: Science Review of the AEATF II Wi pe Human Exposure Monitoring Study (Trigger Spray & Wipe and Rea dy-to-Use Wipes Scenarios).

PC Code(s): Not Applicable (NA) DP Barcode(s)/No(s): NA

Decision No.: NA Registration No(s).: NA

Petition No(s).: NA Regulator y Action: Human Health Risk Assess Type: Surrogate Handler Exposure Data Case No(s).: NA

TXR No.: NA CAS No(s): NA

MRID No(s).: 483756-01 40 CFR: None

FROM: Tim Leighton, Environmental Scientist

Risk Assessment and Scien ce Support Branch (RASSB) OPP/Antimicrobials Division (7510P)

TO: Nader Elkassabany, PhD, Branch Chief

Risk Assessment and Scien ce Support Branch (RASSB) OPP/Antimicrobials Division (7510P)

This memorandum presents the EPA/OPP Antimi crobials Division (AD) science review of the human exposure wipe study submitted by the Antimicrobial Exposure Assessment Task Force II (AEATF II). One wipe study was subm itted that contains two exposure scenarios: Ready-to-Use (RTU) Wipes and Trigger Spray & Wipe. The dermal and inhalation exposure data as represented in this review are acceptabl e and, subject to the c onsiderations described below, are recommended for use for pe sticide handler exposure assessments.Page 2 of 40 EXECUTIVE SUMMARY

This document represents the USEPA, Offi ce of Pesticides Program, Antimicrobials Division (AD) review of the Antimicrobial Exposure Assessment Task Force II (AEATF II) wipe study. The wipe study investigators monito red inhalation and dermal exposures to 18 workers wiping surfaces using ready-to-use (RTU ) wipes and 18 workers using trigger sprayers & wipes. EPA confirms that the data meet the study design objective outlined in the AEATF II Governing Document and are considered the mo st reliable data for assessing exposures from wiping surfaces. The reader is referred to S ection 3.0 for a discussion on the data limitations and use of the data as surrogate.

EPA intends to use these AEATF II wipe datase ts instead of the Chemical Manufacturers Association (CMA) datase t to assess exposure for persons usi ng an antimicrobial product while wiping surfaces. The exposure data in the AE ATF II wipe scenarios represent RTU wipes and the application of a trigger spray and subseque nt wipe only. The scenarios do not cover the pouring of the concentrate to prepare the RTU wi pes (hence the wipes are defined as “ready-touse”) or pouring the concentrate to prepare a dilu ted solution to add to the trigger pump sprayer; open pouring of the concentrate will be measured in a future study. If pesticide products are used with open pouring of concentrates (rather than as ready-to-use wi pes or with automatic dispensers to fill spray bottles), estimates of dermal and inhalation exposures from the future pour study will be combined with wipe exposures from this study when assessing exposures and risks from pesticide products applied by wiping.

Select summary statistics for the “unit expos ures” normalized to pounds active ingredient handled are presented in Table 1 for inhalation exposure as well as for 3 clothing configurations.

Each worker wore both inner and outer whole body dosimeters (WBD) that were sectioned and analyzed separately for each body part (e.g., lowe r leg, upper leg, lower arm, upper arm, etc). Therefore, the analyses of residues on the dosim eters worn by each individual worker allow for the estimation of exposure for the fo llowing 3 clothing configurations:

(1) long pants, long-sleeved shirt, and no gloves; (2) long pants, short-sleeved shirt, and no gloves; and (3) short pants, short-slee ved shirt, and no gloves.

For comparison, results from the earlier CMA study for wiping are also presented. The summary statistics reported in Table 1 for the AEATF II data are estimated using the lognormal

mixed model while the CMA resu lts are empirical estimates.Page 3 of 40 Table 1. Unit Exposures: Wiping Scenarios
Exposure

Route Clothing CMA a AEATF II b, c (n=18)

Arithmetic Mean Arithmetic Mean d 95 th Percentile e Ready-to-use (RTU) Wipes

Dermal (mg/lb ai) Long pants/long-sleeves, shoes/socks, no gloves

Not Available 2380 (1150, 5160) 5990 (2280, 16200) Long pants/short-sleeves,

shoes/socks, no gloves 2580 (1400, 4920) 6190 (2780, 14100) Short pants/short-sleeves,

shoes/socks, no gloves 2740 (1580, 4870) 6500 (3170, 13500)

Inhalation Breathing Zone (mg/m 3 /lb ai) 0.31 (0.13, 0.81) 1.13 (0.41, 3.09) Breathing Zone

(mg/lb ai) f 0.48 (0.24, 1.06) 1.67 (0.70, 3.97) Trigger Spray & Wipe

Dermal (mg/lb ai) Long pants/long-sleeves, shoes/socks, no gloves 2870 ± 4220 (n=6)(some workers shortsleeves and some longsleeves)

Not available 1050 (749, 1490) 2420 (1500.5, 3892.5)

Long pants/short-sleeves,

shoes/socks, no gloves 1530 (1160, 2050) 3220 (2148.2, 4835.4)

Short pants/short-sleeves,

shoes/socks, no gloves Not Available 1740 (1220, 2500) 3640 (2270, 5840)

Inhalation Breathing Zone (mg/m 3 /lb ai) 12.2 ± 22.4 (n=8) (7 non-detects) 11.6 (4.8, 29.9) 37.5 (13.0, 110)

Breathing Zone

(mg/lb ai) f 67.3 ± 71.6 (n=6) 18.5 (8.53, 42.3) 53.8 (20.5, 144)

a CMA data: Mean ± std. Inhalation LOQ varied among samples. Task of using trigger pump spray and wiping

restroom and dental fixtures.

b AEATF II dermal unit exposures reflect method removal e fficiencies of 90.3% for ha nds and 58.8% for face/neck measurements. The percent of average dermal exposure representing the hands for the long pants, long sleeved scenario for the RTU and Trigger Spray & Wipe are 98% and 92%, respectively.

c Lower and upper 95% confidence intervals reported in “( )”; statistics are estimated using a variance component model accounting for correlation between measurements conduc ted within the same field study (i.e., measurements collected during the same time and at the same location). Additional model estimates (e.g., empirical and simple random sample assumptions) are described in Appendices A and B.

d Arithmetic Mean (AM) = GM * exp{0.5*(lnGSD) 2 }

e 95 th percentile = GM * GSD 1.645

f Inhalation (mg/lb ai) = (air conc (mg/m 3 ) / lb ai) * breathing rate (1 m 3 /hour) * wipe duration (hours/day)

The following important points with respect to these data are noted:

• The AEATF II data and associated unit exposures are considered supe rior to the existing wipe dataset (i.e., CMA data). AEATF II e fforts represented a well-designed, concerted process to collect reliable exposure data in a way that takes advantage of and incorporates

a more robust statistical de sign, better analytical methods, and improved data handling techniques.Page 4 of 40 • The AEATF II study report containing derm al and inhalation exposure results are considered scientifically complete. No additional monitoring data are required at this

time.

• The data are applicable for assessment of e xposure to non-volatile pesticides. The cutoff for volatility is reviewed on a case-by-case basis (rule of thumb is that <E-4 mmHg @ 20° C is considered non-volatile).

• Ready to use wipes. Although the statistical analysis does not provide evidence of direct proportionality (1:1) between dermal expos ure and pounds of active ingredient (ai) handled (i.e., slope ≠ 1 in Table 10 below), the analysis does show that dermal exposure tends to increase with pounds of ai handled (AaiH) as described in Section 2.4 below. Inhalation exposure, however, is not propor tional to AaiH (slope is negative).

• Trigger spray and wipe . Although the statistical analysis does not provide evidence of direct proportionality (1:1) between dermal exposure and AaiH (i.e., slope ≠ 1 in Table 11 below), the analysis does show that dermal exposure tends to increase with AaiH as

described in Section 2.4 below. Inhalation exposure also sligh tly tends to increase with AaiH (i.e., slope = 0.25).

To assess the risks resulting from wiping exposures, EPA will combine appropriate unit exposure (UE) values with chemical-specific inpu ts (maximum labeled app lication rates, dermal absorption rates, and toxicologi cal endpoints of concern) and default inputs (high end area treated or volume applied) in the standard pesticide handler exposure algorithm: Potential exposure = UE (mg/lb ai or mg/m 3 /lb ai) x absorption (%) if applic able x maximum label rate (lb ai/gallon) x volume (gallons)Page 5 of 40 1.0 Background

The AEATF II is developing a database repres enting inhalation and de rmal exposure during

a number of antimicrobial handler scenarios. A sc enario is defined as a pesticide handling task based on activity (e.g., application) and equipment type (e.g., ready-to-use wipes, mop & bucket, pressure treatment of wood facilities, painti ng). The AEATF II is m onitoring both inner and

outer dosimeters which will allow the EPA to estimate exposures to various clothing configurations (e.g., long pants, long-sleeved sh irt or long pants, short-sleeved shirt or short pants, short-sleeved shirts, plus shoes, socks, and no gloves).

1.1 Wipe Scenarios Defined

Ready-to-Use (RTU) Wipes. The RTU wipe scenario in th is study is defined as wiping

various horizontal and vert ical surfaces such as tile walls, counter tops, sinks, faucets, elevator doors, railings, shelves, etc. Wiping motions included up & down, side-t o-side, and circular motions as the workers worked as they would normally do. The RTU wipes are pre-treated (pretreatment of wipes not monitored for exposure) . Subjects wore whol e body dosimeters (WBD) underneath long-sleeved shirts, long pants, and no gloves. The conditions under which the study participants handle the pesticide as they are monito red are referred to as the scenario. Both inner and outer dosimeters were worn by the monitore d study participants, and both inner and outer dosimeters were analyzed for residues.

Trigger Spray and Rag Wipe. The trigger spray and wipe scenario in this study is defined as using a 32 ounce trigger spray bottle to spray surfaces and subsequently wipe them.

Workers cleaned various horizontal and vertical su rfaces such as walls, toilets & stall walls, hand railings, shelves including underneath shelves, counter tops, etc using up & down, side-to-side,

and circular motions as the workers worked as they would normally do. Subjects wore WBD underneath long-sleeved shirts, long pants, and no gloves. The conditions under which the study participants handle the pesticide as they are monito red are referred to as the scenario. Both inner and outer dosimeters were worn by the monitore d study participants, and both inner and outer dosimeters were analyzed for residues. This scenario is defined to exclude pouring the antimicrobial product into the spray bottles. Antimicrobial products may be added to spray bottles in various ways, including open pouri ng from no-glug containers, open pouring from typical glug containers, packaged as ready-to-use, or automate d dispensers. Open pouring a pesticide concentrate will be mon itored in a future AEATF II study.

1.2 Study Objective

The AEATF II’s study objective is to monitor in halation and dermal exposures to be used as inputs in exposure algorithms to predict fu ture exposures to pers ons wiping surfaces with either RTU wipes or trigger sp ray & wipe/rag. Dermal and i nhalation exposure monitoring was conducted while study participants wiped various surfaces (walls, bathrooms, etc) for use in exposure assessments, as “unit exposures”.

“Unit exposure” (UE) is defined as the expect ed external chemical exposure an individual may receive (i.e., "to-the-skin" or “in the breath ing zone”) per weight-unit of chemical handledPage 6 of 40 and is the default data format used in pestic ide handler exposure assessm ents. Mathematically, unit exposures are expressed as "handler" exposure normalized by the amount active ingredient handled by participants in scenar io-specific exposure studies (e.g., mg exposure/lb ai handled). EPA uses these UEs generically to estimate e xposure for other chemicals having the same or different application rates.

Criteria for determining when a scenario is considered complete and operative have been developed (Christian 2007). Outlined in the AE ATF II Governing Document, the criteria can be briefly summarized as follows:

• The AEATF II’s objective for this study design is to be 95% confident that key statistics of normalized dermal exposure are accurate within 3-fold. Spec ifically, the upper and

lower 95% confidence limits should be no more than 3-fold (K=3) higher or lower than the estimates for each the geometric mean, arithmetic mean, and 95 th percentile dermal unit exposures. To meet this objective AEATF II proposed an experimental design with a 3 cluster by 6 monitoring events (MEs).

• EPA also plans to use the data to evaluate the presumption of proportionality between exposure and amount of active i ngredient handled. EPA used a log-log regression test to distinguish complete proportiona lity (slope = 1) from comple te independence (slope = 0),

with 80% statistical power, achieved when the width of the 95 th confidence interval of the regression slope is 1.4 or less.

1.3 Protocol Modifications, Amendments, and Deviations

1.3.1 Protocol Modifications Subse quent to EPA/HSRB Review

EPA required two science-based modifications to the protocol (EPA 2008). The EPA review of the protocol noted that the type of wipe to be used in the Trigger Spray & Wipe scenario was not specified. The protocol was modi fied to identify the wipe as cotton rags. EPA also required a residue removal efficiency study to address the efficiency of the hand wash and face/neck wipes. The AEATF II responded by purch asing an existing study conducted to assess the removal efficiency (Boatwright 2007, MRID 47214801).

The HSRB provided written discussion on a number of concerns including:

• Sampling size and replication of ME – The HSRB questioned whether or not the sampling size of 3 clusters by 6 MEs per clus ter would provide an accuracy goal of k=3. Based on EPA’s statistical review provided in Section 2.4 below, the sampling size as designed is sufficient to meet the accuracy goa l. The HSRB also discussed the need for repeat measurements or in lieu of repeat measurements the need for a discussion on the limitations of the study design. EPA acknowledg es that ideally, the sample design would benefit from a large sample size that includes multiple replicates from each worker. However, EPA also recognizes that the repe at measures is as a trade-off for overall sample size (resource issue). Sampling the sa me worker twice (or 3X, 4X....) would have provided information on the within-worker vari ability (e.g., do some workers consistentlyPage 7 of 40 experience high or low exposures day-after-day while others are highly variable?). Such information would be useful, especially beca use worker assessments generally represent longitudinal (multi-day) exposures. But any gain in characterizat ion of within-worker variability information would result in a lo ss in characterization of between-worker variability and, given a fixed sample size, in accuracy (the fold relative accuracy or "K" factor as discussed in the AEATF II Governing Document). With respect to the K-factor, because of the inherent correlation, sampling workers multiple times reduces "effective" sample size - which, due to the relationship between samp le size, variability, and accuracy -- would have made the K-factor un acceptably larger. Thus, if EPA wanted both within-worker variability informati on and a K=3, the AEATF II would need to

increase the total number of workers monitored not only in this study but for the other planned scenarios as well. Thus, the trade-o ff becomes the number of pesticide exposure

scenarios that could be m onitored by the AEATF II.

Alternatively, EPA could have accepted a larger K-factor if within-worker variability was more desirable. Instead, because assumptions can be made for with in-worker variability in order to model longitudinal exposures from the collected 1-day exposures, EPA elects

to continue to utilize the 3-fold K factor as its accuracy benchmar k In summary, given the fixed sample size, EPA has chosen the larg er "effective" sample size/smaller K-factor

and between-worker vari ability, while sacrificing more concrete information on withinworker variability.

• ME duration – The HSRB noted that the durations of the MEs should be longer. The AEATF II responded by increasing the proposed 30 to 120 minute range of monitoring to 30 to 210 minutes of wiping activities. The ju stification of the wipe sampling time is cited in the AEATF II’s Supplement 2 repor t submitted previously for the mop study (MRID 482102-01). MRID 482102-01 provides wi ping durations from time and motionbased estimates for wiping on a per room basi s from the International Sanitary Supply Association (ISSA) as 8.51 mi nutes/room. The theoretical maximum of 25 rooms/day cleaned was also provided in MRID 482102-01 and cited below: : “... information from the following sources: 1) the American Hospital Association ( http://www.aha.org/aha_app/index.jsp ), the American Society for Health Care Environmental Services ( http://www.ashes.org/ashes_app/index.jsp ), and the U.S. EPA’s Environmental Best Practices for Health Care Facilities ( JCAHO Environment of Care
Standards 1.3,2.3,4.0, November 2005) indicates that a single individual at a hospital would typically clean from 15 to 20 hospital patient rooms per day during a standard 6.5 hour shift. ....JohnsonDiversey Inc. feels that the lower typical r ange could be less than 15 rooms per day. Consequently, depending on the degree of conservatism desired, 20- 25 rooms/day would appear to be a reasonable upper bound for these professional applicators.” The maximum wiping durati on was thus increased to 210 minutes (i.e.,

8.51 minutes/room x 25 rooms = 212.75 minutes, rounded to 210 mi nutes). This change to the protocol was discussed and accept ed by the Joint Regulatory Committee (JRC).

• Amount active ingredient handled (AaiH) – The HSRB noted that the AaiH instead of exposure duration should be used to differe ntiate among MEs. Other protocols (e.g., aerosol can spray) have been modified to use the amount handled instead of exposure duration to differentiate among MEs. Howe ver, for the wipe study, the informationPage 8 of 40 above on wiping duration was determined by the JRC to be the best information available on the task of wiping. Individual workers we re given the ability to choose to use the appropriate amount of RTU wipes or diluted treatment solution in the Trigger Spray & Wipe as they would normally do. This approa ch was judged by EPA to lead to the most relevant information on how much active ingr edient would be used by workers working as they normally would do.

• Proportionality between exposure and AaiH – The HSRB indicated in their written protocol review comments that they want ed to see a discussion of proportionality and regressions with the completed data. EPA revi ewed the data and presents the analysis of proportionality in Section 2.4 below and Appendi ces A and B. In brief, the statistical analysis compared pounds of active ingredie nt to wiping duration and other relevant variables as the possible nor malization variables.

o RTU Wipes: Although the statistical an alysis does not provid e evidence of direct proportionality (1:1) between dermal e xposure and pounds of active ingredient (ai) handled (i.e., slope ≠ 1 in Table 10 below), the analysis does show that dermal exposure tends to increase with pounds of ai handled (AaiH) as described in Section 2.4 below. Inhalation exposu re, however, is not proportional to AaiH (estimated slope is negative). The statistical analysis al so suggests that the dermal exposure is proportional to the wiping duration (see Appendix A). The statistical analysis does not distinguish whether i nhalation exposure is proportional to or independent of the wiping duration.

o Trigger spray and wipe . Although the statistical an alysis does not provide evidence of direct proportio nality (1:1) between dermal exposure and AaiH (i.e., slope ≠ 1 in Table 11 below), the analysis does show that dermal exposure tends

to increase with AaiH as described in Sec tion 2.4 below. Inhalation exposure also slightly tends to increase with AaiH (i.e ., estimated slope = 0.25). The statistical analysis shows even less support for propor tionality between dermal or inhalation exposure and the wiping duration (see Appendix B).

The basis for the exposure extrapolation by AaiH is explained by the following:

Exposure = K(AiaH)^slope

If slope = 0 then exposure is independent of the AaiH. If slope = 1 then exposure is directly proportional (1:1) to AaiH. If slope is positive, not zero and not 1 then the exposure tends to increase with the AiaH but not proportionally, so that, for example, doubling the AiaH will not tend to double the expo sure. If the slope confidence interval

excludes both 1 and 0 then the statistical evidence rejects both proportionality and independence and shows that the exposure te nds to increase with the AiaH but not proportionally (see Tables 10 and 11 for results of proportionality test). This implies that using the normalized exposure results to estimate exposures for different pesticides or different concentrations is an approximation that tends to overesti mate exposure at the high end of AaiH. Section 2.4 below also pr ovides the threshold of AaiH where exposurePage 9 of 40 based on estimated AaiH lower than the th reshold results in an under-estimate of exposure and estimated AaiH higher than the threshold results in an over-estimate of exposure (i.e., protectiv e of human health).

• Monitoring equipment – The HSRB indicated that they wa nted to see better descriptions of the equipment used to measure light leve ls, air temperature, and relative humidity. Better descriptions of these monitoring devi ces within the protocol are not apparent. However, the environmental conditions (e.g., temperature & humidity) do not appear to have been a factor that would have hampered the workers in their performance of their wiping activities. This wipe study was c onducted during the same time period as the previously reviewed AEATF II mop study (but not on the same days). Therefore, the “lessons learned” (e.g., impact of the room size, ventilation, etc on air concentrations) from the previous HSRB review of the mop study could not be incorporated into this study as the wipe study was completed prio r to the HSRB comments on the mop study.

• October 2010 HSRB statistical suggestions – The HSRB raised several issues concerning the statistical analysis of the completed AEATF II mop study that are also relevant to this wipe study. During th e October 2010 HSRB review of the AEATF II’s mop study, one or more of the Board members suggested additional st atistical analysis including reviewing the quadr atic model, degrees of fr eedom, and non-parametric bootstrap methods. Section 2.4 below and A ppendices A and B explore these suggested

alternatives.

1.3.2 Protocol Amendments

The study report (page 116) lists 7 protocol amendments. The amendments range from changing the building selection criteria to improv ing clarity in definitions/statements to adding additional steps to insure enough st udy participants for the study to improved efficiency of the conduct of the study. Additionally, amendments were made to address study personnel changes.

1.3.3 Protocol Deviations

A total of 23 minor deviations were note d in the study (study re port pages 117-118). The deviations included, but not limited to, washing hands and face prior to the monitoring period

with 50:50 IPA:water instead of onl y Ivory soap; light levels not monitored; break times did not follow protocol exactly; slight und er-dilution of the trigger bottle sp ray solution in clusters 2 and 3 (1/65 th DDAC/water instead of the target 1/64 th dilution); etc. For a de tailed description of the protocol deviations the reader is referred to the study report. Th ese deviations did not adversely affect the outcome of the study.

1.4 Material & Methods

The following is a summary of the field aspects of the study:

• Study Location: The wipe study was conducted in Fresno County, CA. Pictures and floor plans for both scenarios are provided in Appendices H (page 324) through J (pagePage 10 of 40 330) of the study report. Each cluster is a di fferent building. The buildings are an office building, a Rite Aid, and a re tired teacher’s memorial bui lding. These are the same buildings used in the previously conducted AEATF II mop study; separated by time and different test subjects.

• Pesticide Tested: The test substance monitored was didecyl dimethyl ammonium chloride (DDAC), CAS number 7173-51-5. DDAC was formulated in a product known as Buckeye Sanicare Lemon Quat (EPA Reg No. 47371-131-559). This product also contained another Quat, ADBAC . DDAC and ADBAC are in Lemon Quat at 2.54% and 1.69%, respectively (total of 2.54% + 1.69% = 4 .23%). There is a discrepancy on page 32 of the study report, lis ting the total DDAC and ADBAC concentration at 4.51% ai. Golden Pacific Laboratories (GPL) noted in a subsequent discussion that the certificate of analysis listed the total ai as 4.51% ai. GPL also noted th at DDAC was determined to be at 2.58%, 2.5%, and 2.44% in clusters 1, 2, 3, respectively. The imp act of the certificate of analysis listing the to tal ADBAC and DDAC as 4.51% is considered minor because the percent DDAC was determined for each cluster.

• Test System:

o RTU Wipes: The RTU wipes were prepared (s olution preparation discussed in the bullets below) at least 1 week in a dvance of the monitoring and stored in 8.5 x 5 inch plastic cylinders. Each wipe was 8 x 7 inches with the wipes connected to each other. A photo of RTU wipes and cont ainer are presented below in Figure 1.

o Trigger Spray & Wipe: The trigger bottle was a 32 ounce GRIP AND GO! (Buckeye International, product #41076000) and the rags used for wiping were cotton (Bag-o-Rags). Photos of trigger spray bottle and wipe/rag are presented below in Figure 1a.Page 11 of 40 Figure 1. RTU Wipes and Wipe Container.

Figure 1a. Trigger Spray Bottle and Wipe/Rag.

• Sequence of Events: A table listing the chronological order of key events for the study (e.g., test site selection, IIRB approval, subject recruitmen t, start of each monitoring events, etc) is reported on pages 121-122 of the study report.

• Sample Size: The study consisted of 3 clusters and 6 MEs per cluster (n=18) for each of the two wipe scenarios for a total of 36 MEs in the study.Page 12 of 40 • Treatment Solutions:

o RTU Wipes: The diluted treatment solution of Lemon Quat was prepared by the researchers for the RTU wipes in the la boratory (i.e., GPL). The Lemon Quat product was diluted with water 1:64 ( 0.0397% DDAC). Rolls of dry wipes (75 wipes per roll) were treated with 500 mL of the water dilu ted product. The treated wipes were then shaken on a shaker for 30 minutes. The nominal concentration of each wipe was 2.61 mg DDAC/wipe. The measured concentrations for the wipes were 2.3 4, 2.90, and 2.55 mg DDAC/wipe in clusters 1, 2, 3, respectively. The preparation of the treatment solution and RTU wipes were not part of the monitoring events.

o Trigger Sprayers: The diluted treatment solutio n of Lemon Quat was prepared by the researchers in a 50 gallon tank. The preparati on of the treatment solution was not part of the monitoring events. The 2.54% DDAC in concentrated solution was diluted 1:64 (0.0397% DDA C) in cluster 1 and 1:63 (0.0403% DDAC) in clusters 2 and 3.

• Duration & AaiH: For each of the 3 clusters (in each of the two scenarios), the MEs were randomly assigned to 1 of the 6 purpos ively selected wiping times. The predetermined wiping times were:

o 30 to <60 minutes

o 60 to <90 minutes

o 90 to <120 minutes

o 120 to <150 minutes

o 150 to <180 minutes

o 180 to 210 minutes

Actual wiping durations followed the predeter mined sampling times closely. Individual wiping times for each of the MEs are reported in Table 2 below. The amount of DDAC handled by the 18 MEs in each scenario ranged from 0.00014 to 0.00160 lbs ai with a

mean ± one standard deviation of 0.00074 ± 0.00044 lb ai for the RTU Wipes scenario and ranged from 0.00038 to 0.00474 lbs ai with a mean of 0.0014 ± 0.0010 lb ai for the trigger spray scenario. The 18 MEs in the RT U Wipes scenario used varying numbers of wipes ranging from 27 to 250 wipes per ME. The amount ai per ME for the Trigger Spray and Wipe scenario is the amount actually sprayed onto surfaces, determined by weighing the spray container before and afte r wiping. These data are also reported in

Table 2 below. The correlation coefficients between AaiH and wiping duration were 0.8 for RTU and 0.7 for spray and wi pe. Some workers used more wipes or spray solution than others. For example, in the ready-to-u se wipe study, in clus ter 1 subject number W16 wiped for 165 minutes and used 156 wipe s (0.0008 lb ai) while subject number W17 wiped for 162 minutes yet onl y used 88 wipes (0.00045 lb ai).Page 13 of 40 • Wiping Procedures : Appendix K on pages 333 to 351 of the study report records the observation notes taken during each ME for the RTU scenario and Appendix L pages 352 to 371 for the trigger spray scenario. Th e workers were instructed to wipe “ as they would normally do ”. Typical wiping procedures/observa tions were that the workers cleaned

various horizontal and vertical surfaces such as walls, coun ter tops, etc using up & down, side-to-side, and circular motions.

• Environmental Conditions : Environmental conditions ( humidity and temperature) are reported for the MEs on pages 136 to 141 of the study report (note: humidity and/or temperature readings not available for 8 of the MEs). The humidity averaged in the 40% range. Temperatures averaged in the lo w 70o F range. The h eating ventilation air conditioning (HVAC) system descriptions fo r clusters 1 and 3 ar e reported on page 142 of study report (not available for cluster 2 for both scenarios). Cluster 1 reports the only air changes per hour (ACH), which is 8.1 ACH. It is unclear how the ACH was measured and if it represented ACH of outside make-up air or re-circulating air. Lighting

levels were not measured. The HSRB noted at the October 2011 review of the AEATF II mop study that more attention should be given by the researchers to record the environmental conditions. However, this wi pe study was conducted roughly at the same time period as the mop study. Therefore, limite d information is available in this study

too.

2.0 Results

2.1 QA/QC Recovery Results

Controls: The non-fortified field and laboratory cont rol samples were all less than the limit of quantification (LOQ) which indicates no backgro und contamination. The LOQs for the various matrices are air sampling tubes 10 ng/sample, neck/face wipe 50 ng/sample, WBD sections 3 μg/sample, and hand wash 1 μg/sample.

Laboratory Recoveries: Concurrent laboratory recoveries serve both scenarios (RTU & trigger spray). Most of the individua l laboratory fortified recovery values range within 70 to 120 percent. Exceptions include a few outside of the 120 percent upper bound, none below 70 percent. A summary of the overall concurrent laboratory recovery samp les for each monitoring matrix by cluster is reported in the study report starting on page 76 (individual recovery values can be viewed starting on page 144). The mean recoveries in cluster 1 for all matrices range from 103 ± 15 to 113 ± 17; cluster 2 ranged from 99 ± 5 to 113 ± 6; and cluster 3 ranged from 95

± 4 to 108 ± 6.

Field Recoveries: Field recoveries serve both scenarios (RTU & trig ger spray). Most of the

individual field fortified recove ry values range within 70 to 12 0 percent. Exceptions include a few outside of the 120 percent upper bound, none be low 70 percent. A summary of the overall field fortified recovery samples for each monitori ng matrix by cluster is reported on page 78 of the study report (individual recove ry values can be viewed starting on page 150). The mean

recoveries in cluster 1 for all matrices range from 83 ± 11 to 107 ± 21; cluster 2 ranged from 93Page 14 of 40 ± 10 to 109 ± 12; and cluster 3 ranged from 92 ± 9 to 103 ± 5. All exposure/field matrices were corrected for the field fortified recovery results.

2.2 Calculating Unit Exposures

Dermal Unit Exposure: Dermal exposure is measured using 100% cotton inner and outer “whole body dosimeters” (WBD). The inne r WBDs were worn underneath normal work clothing (i.e., long-sleeved shirt and long pants). The normal work clothing worn over the inner WBDs were also analyzed and reported as “out er” dosimeters. In addition, dermal exposures also included hand washes (colle cted at the end of the day an d during breaks), and face/neck wipes (also collected during the ME to wipe off sweat; see study report page 48). The inner and outer WBDs are sectioned and analyzed by body part (i.e., upper and lower arms, front and rear torso, and upper and lower legs). The inne r WBD sections were only analyzed if the corresponding outer dosimeter sec tion tested above the LOQ. On e-half the LOQ was substituted for all non detected (ND) samples. If the outer dosimeter was ND then the inner dosimeter for the same body section was also considered to be ND and 1⁄2 LOQ was substituted for those WBD sections as well. The study report for total de rmal exposure substituted a single 1⁄2 LOQ value for multiple ND samples. EPA has recalculated the total dermal exposure substituting 1⁄2 LOQ for each of the ND WBD sections (r esulting in a minimal impact on the results). All samples are adjusted as appropriate accord ing to recovery results from field fortification samples.

Dermal exposures to the hands and face/neck are also corrected for sampling efficiency (see study report pages 67 and 69 for equations). A removal efficiency study for hand washes and wipes was performed using the test substa nce, DDAC, in a previous study (Boatwright 2007, MRID 47214801). The hand wash removal efficiency for DDAC is 90.3%. The same study also performed wipes. The wipe removal efficiency is calculated as 58.8% and is used to correct the face/neck samples.

Total dermal exposure is calculated by su mming exposure across all body parts for each individual monitored. The following WBD s ections are summed to calculate the clothing configuration of long pants, long-sleeved sh irts (plus face/neck wash and hand wash):

• inner lower and inner upper arms,

• inner front and inner rear torso, and

• inner lower and inner upper legs.

The following WBD sections are summed to cal culate the clothing configuration of long pants, short-sleeved shirts (plus face/neck wash and hand wash):

• outer and inner lower arm,

• inner upper arm,

• inner front and inner rear torso, and

• inner lower and inner upper leg.

The following WBD sections are summed to calcu late the clothing configuration of short pants, short-sleeved shirts (plus face/neck wash and hand wash):Page 15 of 40 • outer and inner lower arm,

• inner upper arm,

• inner front and inner rear torso,

• inner upper leg, and

• inner and outer lower leg.

Dermal unit exposures (i.e., mg/lb ai handled) are calculated by dividing the summed total exposure by the amount of active ingredient handled. The AEATF II’s study report normalized the dermal exposures by milligrams (mg) of ac tive ingredient applied. EPA recalculated the exposures and expressed the re sults as mg/lb ai applied. EPA prefers the normalization by pounds to coincide with the English units re ported on pesticide labels (e.g., pounds, ounces).

Inhalation Exposure: Inhalation exposure is measured using a personal air sampling pump and an OSHA Versatile Sampler (OVS) tubes. Th e tube is attached to the worker’s collar to continuously sample air from the breathing zone . The sampling pumps were run continuously, even during breaks. Collected residue, per standa rd practice, is adjusted for recovery from field fortification samples.

Inhalation unit exposures (i.e., mg/m 3 /lb ai handled) are calculated by dividing the air concentrations by the amount of ai handled. When the need arises for the unit inhalation exposures to be in units of mg/lb ai (e.g., when assessing in halation risks using an oral toxicological endpoint) the inhalation unit exposur e is calculated as the (air conc (mg/m 3 ) / lb ai) * breathing rate (1 m 3 /hour) * wipe duration (hours/day).

2.3 Dermal and Inhalation Exposure Results

Results -- A summary of the results of the 18 MEs for each scenario are presented in Tables 2 and 5 (long pants, long sleeved-shirts), Ta bles 3 and 6 (long pants, short-sleeved shirts), and Tables 4 and 6 (short pants, short-sleeved shir ts). These tables report the results for each individual worker along with empirical statis tical summaries of each cluster and overall exposures. The inhalation UEs are the same for each of the clothing configurations (i.e., the three clothing scenarios are from the same worke r). Therefore, the inhalation exposures are only reported once (in Tables 2 and 5).

Appendices A and B provides alternative stat istical models to estimate the exposure summary statistics, including:

• Empirical simple random sampling mode l (see Appendices A and B Table 1);

• Lognormal simple random sampling model (see Appendices A and B Tables 3 through 6); and

• Lognormal mixed model (see Appendices A and B Table 2 for a summary, and Appendices A and B Tables 3 th rough 6 for detailed results).

The results of the lognormal mixed model have been selected to best represent the summary statistics for the unit exposures (as reported in Table 1 above). For a detailed discussion of thePage 16 of 40 lognormal mixed model calculations and results (along with a di scussion of the HSRB-suggested quadratic models) the reader is referred to Appendices A and B.

Observations -- This wipe study includes the recordi ng of individual part icipant activities by observers. The study report indicates... “ There were always three to four study personnel following the subject during a given monitoring event”, with one being the “observer”. Observations recorded during each ME are repo rted starting on page 333 of the study report and record the “real world” events during wiping as a worker would normally do. A review of these observations and resulting exposures did not indicate any obvious outliers in the data.

Impact of Non-detects -- Minimal exposure inside of the clothing was expected for many of the body parts sampled for the wipe pesticide ap plication technique. Even with sensitive analytical methods for the surrogate compound, DDAC, many samples were non-detect (ND). Samples with results less than the limit of quantif ication (LOQ) are included in the calculation of total exposure as 1⁄2 LOQ. For the ready-to-use wipes study, all of the hand wash and face/neck samples and 12 of the 18 air samples were greater than the LOQ. Also for the ready-to-use wipes study, 81 of the 108 inner WBD sectioned body pa rts and 20 of the 108 outer WBD sectioned body parts were less than the LOQ or not meas ured (because they were inner sections corresponding to an outer section that was below the LOQ). For th e trigger spray and wipe study, all of the hand wash, face/neck samples and air sa mples were greater than the LOQ. Also for the trigger spray and wipe study, 38 of the 108 i nner WBD sectioned body parts and 2 of the 108 outer WBD sectioned body parts were less than the LOQ or not measured.

The impact of the ND samples for the short pant s, short-sleeved shirt, and no glove clothing configuration for the dermal UE is minimal. The following data presentation (empirical estimates) illustrate the change in the dermal UE values when NDs were substituted with 0, 1⁄2 LOQ, and the full LOQ.

Comparison of Dermal UE (mg/lb ai) for Non-detects Equal to 0, 1⁄2 LOQ, Full LOQ Study Statistic NDs = 0 NDs = 1⁄2 LOQ NDs = Full LOQ RTU Wipes Mean 2600 2620 2640 RTU Wipes 95 t h % tile 5620 5640 5650 Trigger Spray & Wipe Mean 1730 1740 1740 Trigger Spray & Wipe 95 t h % tile 3310 3310 3320

A similar analysis was not performed for the long pants, long-sleeved shirt or the long pants, short-sleeved shirt clot hing configurations but the impa ct of the non-detects on these clothing configurations is expected to be mini mal too. This expectati on is based on the higher contribution of the hand exposure to total dermal exposure for the long pants, long-sleeved shirt clothing configuration. For the ready-to-use wipes, for the long pants, long-sleeved shirt configuration, 98 percent of the total dermal exposure is attr ibuted to the hand exposure and only 82 percent of the total dermal exposure for the short pants, short-sleev ed shirt scenario is attributed to the hands. For the trigger spray and wipe study, for the l ong pants, long-sleeved shirt configuration, 92 percent of the total dermal exposure is attr ibuted to the hand exposure and only 51 percent of the total dermal exposure for the short pants, s hort-sleeved shirt scenario is

attributed to the hands.Page 17 of 40Table 2. RTU Wipes: Summary (Empirical) of Dermal and Inhalation Results -- Long Pants, Long-sleeved Shirt and No Glove Scenario.ClusterSubjectOrderSubjectNumberIDTaskDuration(minutes)SurfaceArea(sq ft)NumberWipesPounds aiHandledDermalExposure(mg)InhalationExposure(mg/m3)Unit ExposuresDermal(mg/lb ai)Inhalation(mg/m3/lb ai)1WS-02 W45 37 1614.5 40 0.000206 0.6656 0.000048 3225.62 0.2336WS-08 W13 73 1509.8 27 0.000139 0.7067 0.000289 5071.69 2.0742WS-10 W42 104 3504.0 103 0.000531 1.3874 0.000070 2611.34 0.1308WS-11 W32 131 2750.8 216 0.001113 1.6163 0.000143 1451.74 0.1284WS-05 W17 162 1790.1 88 0.000454 2.2305 0.000224 4911.30 0.4932WS-01 W16 165 5029.6 156 0.000805 2.8259 0.000058 3511.84 0.0716Mean 112 2699.8 105 0.000542 1.5721 0.000139 3463.92 0.5220Std 51 1378.3 71 0.000368 0.8500 0.000099 1379.47 0.77512WS-13 W37 61 557.0 37 0.000236 0.4229 0.000180 1792.87 0.7631WS-20 W26 90 1752.0 165 0.001056 0.9662 0.000073 914.90 0.0687WS-24 W29 120 2786.0 138 0.000882 1.2203 0.000146 1383.81 0.1656WS-21 W5 149 2663.0 131 0.000838 0.6179 0.000043 737.54 0.0516WS-17 W14 180 703.0 222 0.001420 1.6167 0.000200 1138.70 0.1409WS-14 W41 182 1603.0 250 0.001598 0.8203 0.000011 513.23 0.0068Mean 130 1677.3 157 0.001005 0.9440 0.000109 1080.18 0.1994Std 49 939.8 75 0.000482 0.4295 0.000077 462.54 0.28233WS-32 W49 59 876.0 37 0.000208 0.4432 0.000035 2131.87 0.1693WS-28 W2 89 1110.0 71 0.000399 1.3682 0.000070 3428.86 0.1752WS-30 W34 119 1160.0 123 0.000692 1.0243 0.000058 1479.71 0.0842WS-27 W39 133 1800.0 84 0.000472 1.2331 0.000015 2613.73 0.0309WS-31 W52 179 1899.0 177 0.000994 0.9362 0.000029 941.58 0.0290WS-34 W8 201 4907.0 213 0.001197 2.5280 0.000430 2111.74 0.3592Mean 130 1958.7 118 0.000660 1.2555 0.000106 2117.91 0.1413Std 53 1500.1 67 0.000377 0.6997 0.000160 866.69 0.1245OverallMean 124 2111.9 127 0.000736 1.2572 0.0001182220.670.2876Std 49 1295.1 71 0.000437 0.6931 0.0001111360.840.4841Median 126 1771.1 127 0.000748 1.1223 0.0000701952.300.1358GeoMean 113 1781.4 104 0.000594 1.0926 0.0000771840.680.129095th%tile 185 4925.4 226 0.001447 2.5727 0.0003104935.360.9597Page 18 of 40Table 3. RTU Wipes: Summary (Empirical) of Dermal Results -- Long Pants, Short-sleeved Shirt and No Glove Scenario.ClusterSubjectOrderSubjectNumberIDTaskDuration(minutes)SurfaceArea(sq ft)NumberWipesPounds aiHandledDermalExposure (mg)Unit ExposuresDermal(mg/lb ai)1WS-02 W45 37 1614.5 40 0.000206 0.6896 3341.92WS-08 W13 73 1509.8 27 0.000139 0.7701 5526.72WS-10 W42 104 3504.0 103 0.000531 1.4518 2732.55WS-11 W32 131 2750.8 216 0.001113 1.7303 1554.13WS-05 W17 162 1790.1 88 0.000454 2.4105 5307.65WS-01 W16 165 5029.6 156 0.000805 2.8987 3602.31Mean 112 2699.8 105 0.000542 1.6585 3677.55Std 51 1378.3 71 0.000368 0.8809 1522.952WS-13 W37 61 557.0 37 0.000236 0.7139 3026.47WS-20 W26 90 1752.0 165 0.001056 1.0222 967.93WS-24 W29 120 2786.0 138 0.000882 1.4383 1631.02WS-21 W5 149 2663.0 131 0.000838 0.9229 1101.61WS-17 W14 180 703.0 222 0.001420 1.7807 1254.21WS-14 W41 182 1603.0 250 0.001598 0.9203 575.79Mean 130 1677.3 157 0.001005 1.1330 1426.17Std 49 939.8 75 0.000482 0.3975 856.853WS-32 W49 59 876.0 37 0.000208 0.4496 2162.41WS-28 W2 89 1110.0 71 0.000399 1.3884 3479.48WS-30 W34 119 1160.0 123 0.000692 1.0969 1584.58WS-27 W39 133 1800.0 84 0.000472 1.2461 2641.29WS-31 W52 179 1899.0 177 0.000994 1.0462 1052.21WS-34 W8 201 4907.0 213 0.001197 3.0470 2545.28Mean 130 1958.7 118 0.000660 1.3790 2244.21Std 53 1500.1 67 0.000377 0.8780 852.86OverallMean 124 2111.9 127 0.000736 1.3902 2449.31Std 49 1295.1 71 0.000437 0.7417 1424.35Median 126 1771.1 127 0.000748 1.1715 2353.85GeoMean 113 1781.4 104 0.000594 1.2279 2068.5395th%tile 185 4925.4 226 0.001447 2.9210 5340.51Page 19 of 40Table 4. RTU Wipes: Summary (Empirical) of Dermal Results-- Short Pants, Short-sleeved Shirt and No Glove Scenario.ClusterSubjectOrderSubjectNumberIDTaskDuration(minutes)SurfaceArea(sq ft)NumberWipesPounds aiHandledDermalExposure (mg)Unit ExposuresDermal(mg/lb ai)1WS-02 W45 37 1614.5 40 0.000206 0.6911 3349.19WS-08 W13 73 1509.8 27 0.000139 0.9411 6754.00WS-10 W42 104 3504.0 103 0.000531 1.4750 2776.21WS-11 W32 131 2750.8 216 0.001113 1.7399 1562.80WS-05 W17 162 1790.1 88 0.000454 2.4698 5438.22WS-01 W16 165 5029.6 156 0.000805 2.9026 3607.08Mean 112 2699.8 105 0.000542 1.7032 3914.58Std 51 1378.3 71 0.000368 0.8585 1877.492WS-13 W37 61 557.0 37 0.000236 0.7154 3032.83WS-20 W26 90 1752.0 165 0.001056 1.0425 987.16WS-24 W29 120 2786.0 138 0.000882 2.1983 2492.84WS-21 W5 149 2663.0 131 0.000838 1.1079 1322.44WS-17 W14 180 703.0 222 0.001420 2.0777 1463.40WS-14 W41 182 1603.0 250 0.001598 0.9319 583.05Mean 130 1677.3 157 0.001005 1.3456 1646.95Std 49 939.8 75 0.000482 0.6292 931.923WS-32 W49 59 876.0 37 0.000208 0.4540 2183.58WS-28 W2 89 1110.0 71 0.000399 1.3928 3490.43WS-30 W34 119 1160.0 123 0.000692 1.1675 1686.57WS-27 W39 133 1800.0 84 0.000472 1.2525 2654.85WS-31 W52 179 1899.0 177 0.000994 1.0657 1071.82WS-34 W8 201 4907.0 213 0.001197 3.2280 2696.48Mean 130 1958.7 118 0.000660 1.4268 2297.29Std 53 1500.1 67 0.000377 0.9402 848.35OverallMean 124 2111.9 127 0.000736 1.4919 2619.61Std 49 1295.1 71 0.000437 0.7861 1570.45Median 126 1771.1 127 0.000748 1.2100 2573.85GeoMean 113 1781.4 104 0.000594 1.3126 2211.3695th%tile 185 4925.4 226 0.001447 2.9514 5635.59Page 20 of 40Table 5. Trigger Spray & Wipe: Summary (Empirical) of Dermaland Inhalation Results -- Long Pants, Long-sleeved Shirt and No Glove Scenario.ClusterSubjectOrderSubjectNumberIDTaskDuration(minutes)SurfaceArea(sq ft)Pounds aiHandledDermalExposure(mg)InhalationExposure(mg/m3)Unit ExposuresDermal(mg/lb ai)Inhalation(mg/m3/lb ai)1WS-04 W50 51 1077.4 0.000419 1.4571 0.019400 3478.65 46.3142WS-06 W24 70 640.0 0.000375 0.4272 0.009930 1139.85 26.4951WS-07 W27 93 1406.5 0.000928 2.5802 0.004130 2779.98 4.4497WS-09 W10 142 3243.7 0.001153 0.6361 0.011700 551.64 10.1473WS-12 W19 174 3628.7 0.001764 0.8415 0.023000 477.12 13.0408WS-03 W7 187 3186.3 0.002055 0.7894 0.017800 384.19 8.6630Mean 120 2197.1 0.001116 1.1219 0.014327 1468.57 18.1850Std 56 1298.2 0.000689 0.7933 0.006975 1331.76 15.68892WS-16 W6 60 1269.0 0.000672 0.4342 0.008640 645.68 12.8493WS-23 W25 89 1444.0 0.000822 0.5088 0.003470 618.78 4.2197WS-18 W18 121 1130.0 0.001435 0.7107 0.005490 495.18 3.8252WS-22 W44 150 2501.0 0.002013 2.3867 0.015000 1185.74 7.4522WS-19 W12 180 3076.0 0.004742 2.1591 0.014100 455.30 2.9733WS-15 W56 209 3617.0 0.001973 1.0917 0.000859 553.28 0.4353Mean 135 2172.8 0.001943 1.2152 0.007927 658.99 5.2925Std 56 1043.5 0.001481 0.8535 0.005734 267.87 4.33693WS-36 W55 59 387.0 0.000399 0.8074 0.003300 2023.28 8.2699WS-25 W35 60 1256.0 0.000747 0.7648 0.005560 1023.26 7.4395WS-35 W4 104 1072.0 0.001177 1.2772 0.005350 1084.87 4.5444WS-33 W1 137 2740.0 0.001307 1.0788 0.018900 825.16 14.4568WS-29 W40 153 421.0 0.001276 0.8842 0.004100 692.70 3.2120WS-26 W28 185 2047.0 0.001268 0.9754 0.005360 769.41 4.2283Mean 116 1320.5 0.001029 0.9646 0.007095 1069.78 7.0251Std 51 926.2 0.000373 0.1908 0.005850 490.67 4.1344OverallMean 124 1896.8 0.001363 1.1006 0.0097831065.7810.1676Std 52 1115.4 0.001003 0.6491 0.006716853.9510.8404Median 129 1425.3 0.001222 0.8629 0.007100731.067.4458GeoMean 112 1547.1 0.001112 0.9554 0.007420859.166.672695th%tile 190 3618.8 0.002458 2.4157 0.0199402884.7829.4680Page 21 of 40Table 6. Trigger Spray & Wipe: Summary (Empirical) of Dermal Results -- Long Pants, Short-sleeved Shirt and No Glove Scenario.ClusterSubjectOrderSubjectNumberIDTaskDuration(minutes)Surface Area(sq ft)Pounds ai HandledDermalExposure (mg)Unit Exposures Dermal(mg/lb ai)1WS-04 W50 51 1077.4 0.000419 2.0281 4841.81WS-06 W24 70 640.0 0.000375 0.7222 1926.97WS-07 W27 93 1406.5 0.000928 2.7192 2929.74WS-09 W10 142 3243.7 0.001153 0.9741 844.78WS-12 W19 174 3628.7 0.001764 1.1855 672.17WS-03 W7 187 3186.3 0.002055 2.6234 1276.77Mean 120 2197.1 0.001116 1.7088 2082.04Std 56 1298.2 0.000689 0.8656 1582.782WS-16 W6 60 1269.0 0.000672 0.7702 1145.37WS-23 W25 89 1444.0 0.000822 0.6868 835.24WS-18 W18 121 1130.0 0.001435 1.0797 752.28WS-22 W44 150 2501.0 0.002013 4.1687 2071.06WS-19 W12 180 3076.0 0.004742 5.9021 1244.61WS-15 W56 209 3617.0 0.001973 1.3197 668.83Mean 135 2172.8 0.001943 2.3212 1119.57Std 56 1043.5 0.001481 2.1844 517.793WS-36 W55 59 387.0 0.000399 0.8411 2107.73WS-25 W35 60 1256.0 0.000747 1.2978 1736.43WS-35 W4 104 1072.0 0.001177 2.0282 1722.78WS-33 W1 137 2740.0 0.001307 1.3478 1030.92WS-29 W40 153 421.0 0.001276 1.3502 1057.77WS-26 W28 185 2047.0 0.001268 1.1904 939.02Mean 116 1320.5 0.001029 1.3426 1432.44Std 51 926.2 0.000373 0.3865 485.34OverallMean 124 1896.8 0.001363 1.7908 1544.68Std 52 1115.4 0.001003 1.3566 1027.18Median 129 1425.3 0.001222 1.3087 1194.99GeoMean 112 1547.1 0.001112 1.4736 1325.1495th%tile 190 3618.8 0.002458 4.4287 3216.55Page 22 of 40Table 7. Trigger Spray & Wipe: Summary (Empirical) of Dermal Results -- Short Pants, Short-sleeved Shirt and No Glove Scenario.ClusterSubjectOrderSubjectNumber IDTask Duration(minutes)Surface Area(sq ft)Pounds aiHandledDermalExposure (mg)Unit Exposures Dermal(mg/lb ai)1WS-04 W50 51 1077.4 0.000419 2.1591 5154.55WS-06 W24 70 640.0 0.000375 0.9432 2516.64WS-07 W27 93 1406.5 0.000928 2.7738 2988.57WS-09 W10 142 3243.7 0.001153 1.2061 1045.99WS-12 W19 174 3628.7 0.001764 1.7475 990.82WS-03 W7 187 3186.3 0.002055 2.9414 1431.54Mean 120 2197.1 0.001116 1.9619 2354.69Std 56 1298.2 0.000689 0.8140 1593.252WS-16 W6 60 1269.0 0.000672 0.8237 1224.94WS-23 W25 89 1444.0 0.000822 0.7361 895.19WS-18 W18 121 1130.0 0.001435 1.1271 785.31WS-22 W44 150 2501.0 0.002013 4.5297 2250.41WS-19 W12 180 3076.0 0.004742 6.1951 1306.39WS-15 W56 209 3617.0 0.001973 1.3512 684.79Mean 135 2172.8 0.001943 2.4605 1191.17Std 56 1043.5 0.001481 2.3191 573.613WS-36 W55 59 387.0 0.000399 0.8660 2170.13WS-25 W35 60 1256.0 0.000747 1.8248 2441.57WS-35 W4 104 1072.0 0.001177 2.0637 1752.94WS-33 W1 137 2740.0 0.001307 1.6288 1245.86WS-29 W40 153 421.0 0.001276 1.4952 1171.37WS-26 W28 185 2047.0 0.001268 1.5134 1193.82Mean 116 1320.5 0.001029 1.5653 1662.61Std 51 926.2 0.000373 0.4041 549.05OverallMean 124 1896.8 0.001363 1.9959 1736.16Std 52 1115.4 0.001003 1.4024 1083.42Median 129 1425.3 0.001222 1.5711 1276.12Geo Mean 112 1547.1 0.001112 1.6762 1507.3495th%tile 190 3618.8 0.002458 4.7795 3313.47Page 23 of 40 2.4 Evaluation of Scenario Benchmark Objective

Benchmark Objective -- The data from the two wipe studies have been analyzed to see if the two wipe scenarios meet the AEATF II objectiv e of a relative 3-fold accuracy (i.e., K=3). Using the SAS code originally developed by th e Agricultural Handler Exposure Task Force (AHETF) and independently confirmed by th e Health Effects Division (HED) (and now modified by AD), EPA has determined and presents the analysis that the wipe study results meet the 3-fold relative accuracy objective. Appe ndices A and B provide the detail benchmark analysis which is summarized as follows:

Benchmark Objective: fo ld Relative Accuracy (fRA)

The benchmark objective for AEATF II scenarios is for select statistics – the geometric mean (GM), the arithmetic mean (AM), and the 95 th percentile (P95) – to be accurate within 3- fold with 95% confidence (i.e ., “fold relative accuracy”). EPA has analyzed the data using various statistical techniques to evaluate this benc hmark. First, to characterize the unit exposures (also referred to as “normalized exposure”), log normal probability plots of dermal and inhalation UEs (adjusted for residue method collection effici encies) are provided in Figures 2 to 5 (RTU Wipes) and Figures 6 to 9 (Trigger Spray & Wipe ) for the 3 clothing configurations as well as inhalation exposure. These plots support the assumed lognormal di stributions for the normalized exposure. Note: The figure titles are provide d both above and below the graphs because they were cut and pasted as file images.



### Quantile plot normalized long dermal exposure data with a lognormal distribution Normalized by Pounds Active Ingredient Handled

-2 -1 0 1 2 6.0 6.5 7.0 7.5 8.0 8.5 9.0log (Normalized Long Dermal Exposure)

Normal Quantiles

Figure 2. RTU Wipes: Quantile plot of norm alized long dermal exposure data with a lognormal distribution normalized by pounds of Active Ingredient handled.Page 24 of 40 Quantile plot normalized short dermal exposure data with a lognormal distribution Normalized by Pounds Active Ingredient Handled

-2 -1 0 1 2 6.0 6.5 7.0 7.5 8.0 8.5 9.0log (Normalized Short Dermal Exposure)

Normal Quantiles

Figure 3. RTU Wipes: Quantile plot of norm alized short dermal exposure data with a lognormal distribution normalized by pounds of Active Ingredient handled.

Quantile plot normalized long short dermal exposure data with a lognormal distribution Normalized by Pounds Active Ingredient Handled

-2 -1 0 1 2 6.0 6.5 7.0 7.5 8.0 8.5 9.0lnnrmdermls

Normal Quantiles

Figure 4. RTU Wipes: Quantile plot of normaliz ed long short dermal exposure data with a lognormal distribution normalized by pounds of Active Ingredient handled.Page 25 of 40 

### Quantile plot normalized inhalation exposure data with a lognormal distribution Normalized by Pounds Active Ingredient Handled

-2 -1 0 1 2 -5 -4 -3 -2 -1 0 1log (Normalized Inhalation Exposure)

Normal Quantiles

Figure 5. RTU Wipes: Quantile plot of norm alized inhalation exposure data with a lognormal distribution normalized by pounds of Active Ingredient handled.



### Quantile plot normalized long dermal exposure data with a lognormal distribution Normalized by Pounds Active Ingredient Handled

-2 -1 0 1 2 5.5 6.0 6.5 7.0 7.5 8.0 8.5log (Normalized Long Dermal Exposure)

Normal Quantiles

Figure 6. Trigger Spray & Wipe: Quantile plot of normalized long dermal exposure data with a lognormal distribution normalized by pounds of Active Ingredient handled.Page 26 of 40 Quantile plot normalized short dermal exposure data with a lognormal distribution Normalized by Pounds Active Ingredient Handled

-2 -1 0 1 2 6.5 7.0 7.5 8.0 8.5 9.0log (Normalized Short Dermal Exposure)

Normal Quantiles

Figure 7. Trigger Spray & Wipe: Quantile plot of normalized short dermal exposure data with a lognormal distribution normalized by pounds of Active Ingredient handled.

Quantile plot normalized long short dermal exposure data with a lognormal distribution Normalized by Pounds Active Ingredient Handled

-2 -1 0 1 2 6.5 7.0 7.5 8.0 8.5lnnrmdermls

Normal Quantiles

Figure 8. Trigger Spray & Wipe: Quantile plot of normalized long short dermal exposure data with a lognormal distribution normalized by pounds of Active Ingredient handled.Page 27 of 40 

### Quantile plot normalized inhalation exposure data with a lognormal distribution Normalized by Pounds Active Ingredient Handled

-2 -1 0 1 2 -1 0 1 2 3 4log (Normalized Inhalation Exposure)

Normal Quantiles

Figure 9. Trigger Spray & Wipe: Quantile plot of normalized inhalation exposure data with a lognormal distribution normalized by pounds of Active Ingredient handled.

Next, EPA calculated estimates of the GM, AM and P95 based on three different

calculation methods:

• Empirical estimates;

• Assuming a lognormal distribution and a simple random sample (SRS); and,

• Hierarchical variance component modeling to account for potential ME correlations.

The 95% confidence limits for each of th ese estimates were obtained by generating 10,000 parametric bootstrap samples. Then, the fRA for each was determined as the maximum of the two ratios of the statistical point esti mates with their respective upper and lower 95% confidence limits. Table 8 below presents the resu lts for the ready-to-use wipes scenario, for the long pants, short-sleeved shirt and the inhalation exposures. Tabl e 9 below presents the results for the trigger spray and wipe scenario, for the long pants, short-sleeved shirt and the inhalation exposures. The results of the benchmark analys is for the other clothi ng configurations are reported in Appendices A and B, Table 3 (long pants, long-sleeved shirt) and Appendices A and B, Table 4 (short pants, short-sleeved shirt).Page 28 of 40 Table 8. RTU Wipes: Results of Primary Benchmark Analysis for Long Pants, Short-sleeved Shirt and

Inhalation. Dermal Exposure Inhalation Exposure

Statistic Unit Exposure Estimate (mg/lb ai) 95% CI fRA Unit Exposure Estimate (mg/m 3 /lb ai) 95% CI fRA

GM S 2068.5 1170.4 –

3630.9 1.8 0.13 0.07 – 0.26 2.0

GSD S 1.9 1.5 – 2.6 1.4 3.70 2.41 – 5.69 1.5

GM M 2068.5 1170.4 –

3630.9 1.8 0.13 0.07 – 0.26 2.0

GSD M 1.9 1.5 – 2.9 1.5 3.73 2.43 – 5.92 1.6

ICC 0.5 0.0 – 0.8 0.05 0.0 – 0.47

GM S = geometric mean assuming SRS = “exp(average of 18 ln(UE)) values”

GSD S = geometric standard deviation assuming SRS = “exp(standard deviation of 18 ln(UE)) values”

GM M = variance component model-based geometric mean

GSD M = variance component model-based geometric standard deviation

ICC = intra-cluster correlation

AM S 2449.3 1356.7 –

4526.5 1.8 0.29 0.12 – 0.71 2.5

AM U 2505.4 1375.5 –

4613.8 1.8 0.30 0.13 – 0.77 2.5

AM M 2583.6 1397.7 –

4916.1 1.9 0.31 0.13 – 0.81 2.6

AM S = average of 18 unit exposures

AM U = arithmetic mean based on GM S = GM S *exp{0.5*(ln(GSD S ) 2 }

AM M = variance component model-based arithmetic mean = GM M * exp{0.5*(ln(GSD M ) 2 }

P95 S 5526.7 2753.6 –

14895.8 2.7 2.07 0.40 – 6.70 5.2

P95 U 5726.4 2726.2 –

11872.3 2.1 1.11 0.40 – 2.94 2.8

P95 M 6194.8 2783.4 –

14093.2 2.3 1.13 0.41 – 3.09 2.8

P95 S = 95 th percentile (i.e., estimated as the maximum unit exposure from the 18 unit exposures)

P95 U = 95 th percentile based on GM S = GM S * GSD S 1.645

P95 M = variance component model-based 95 th percentile = GM M * GSD M 1.645Page 29 of 40 Tables 3, 4, 5 and 6 of Appendices A and B al so present confidence intervals computed using a non-parametric bootstrap approach inst ead of the bootstrap para metric approach, as suggested by HSRB reviewers of the mop study. Th e parametric bootstrap approach assumes that the exposure data were generated from the f itted lognormal mixed model. The non-parametric bootstrap approach assumes that the data were generated using a simple random sample from each cluster. For the RTU wipe scenario, th e parametric and non-parametric bootstrap confidence intervals were generally similar fo r inhalation exposure, but the non-parametric bootstrap intervals tended to be narrower than the parametric bootstrap intervals for dermal exposure. For the Trigger Spray & Wipe scenar io, the parametric and non-parametric bootstrap confidence intervals were generally similar fo r dermal exposure, but the non-parametric bootstrap intervals tended to be narrower than the parametric bootstrap intervals for inhalation

exposure.

The benchmark of 3-fold accuracy for dermal and inhalation unit exposures has been met for the wipe scenarios for all 3 clothing scenario s and inhalation exposures for all 3 statistical models, except (as highlighted in yell ow in the tables) for the empirical 95 th percentile for the inhalation exposure where the fold relative accur acy is 5.2 for the RTU Wipes scenario (Table 8 above) and is 3.6 for the Trigger Spray & Wipe scenario (Table 9 above). Table 9. Trigger Spray & Wipe: Results of Primary Be nchmark Analysis for Long Pants, Short-sleeved Shirt

and Inhalation. Dermal Exposure Inhalation Exposure

Statistic Unit Exposure Estimate (mg/lb ai) 95% CI fRA Unit Exposure Estimate (mg/m 3 /lb ai) 95% CI fRA

GM S 1325.1 1016.8 –

1735.7 1.3 6.7 3.1 – 14.4 2.2

GSD S 1.7 1.4 – 2.1 1.2 2.7 1.9 – 4.1 1.5

GM M 1325.1 1016.8 –

1735.7 1.3 6.7 3.1 – 14.4 2.2

GSD M 1.7 1.4 – 2.1 1.2 2.9 1.9 – 4.7 1.6

ICC 0.0 0.0 – 0.4 0.3 0.0 – 0.7

GM S = geometric mean assuming SRS = “exp(average of 18 ln(UE)) values”

GSD S = geometric standard deviation assuming SRS = “exp(standard deviation of 18 ln(UE)) values”

GM M = variance component model-based geometric mean

GSD M = variance component model-based geometric standard deviation

ICC = intra-cluster correlation

AM S 1544.7 1150.0 –

2021.2 1.3 10.2 4.5 – 25.2 2.5

AM U 1531.9 1160.2 –

2038.8 1.3 11.0 4.7 – 26.6 2.4

AM M 1533.3 1162.6 –

2050.8 1.3 11.6 4.8 – 29.9 2.6

AM S = average of 18 unit exposures

AM U = arithmetic mean based on GM S = GM S *exp{0.5*(ln(GSD S ) 2 }

AM M = variance component model-based arithmetic mean = GM M * exp{0.5*(ln(GSD M ) 2 }

P95 S 4841.8 2138.5 –

6653.3 2.3 46.3 12.8 – 153.4 3.6

P95 U 3213.0 2138.3 –

4753.6 1.5 34.8 12.6 – 92.8 2.8

P95 M 3222.2 2148.2 –

4835.4 1.5 37.5 13.0 – 109.6 2.9

P95 S = 95 th percentile (i.e., estimated as the maximum unit exposure from the 18 unit exposures)

P95 U = 95 th percentile based on GM S = GM S * GSD S 1.645

P95 M = variance component model-based 95 th percentile = GM M * GSD M 1.645Page 30 of 40 Presumption of Proportionality -- EPA evaluated the presumption of proportionality between exposure and amount of active ingredient handled (AaiH). EPA tested proportionality using a statistical benchmark to be able to di stinguish, with 80% sta tistical power, complete proportionality from complete independence betw een exposure and amount of active ingredient

handled.

To evaluate the relationship for this scen ario EPA performed regression analysis of ln(exposure) and ln(AaiH) to de termine if the slope is not si gnificantly different than 1 – providing support for a proportional re lationship – or if the slope is not significantly different than 0 – providing support for an independent rela tionship. If slope is positive, not zero and not 1 then the exposure tends to increase with the Ai aH but not proportionally, so that, for example, doubling the AiaH will not tend to double the ex posure. If the slope confidence interval

excludes both 1 and 0 then the statistical eviden ce rejects both proportionality and independence and shows that the exposure tend s to increase with the AiaH but not proportionally. Note: the slope measures the change in log mg dermal exposure for each unit ch ange in log lb ai.

A simple linear regression, a mixed-effect regression, and a more complex “repeated measures” model (see Appendix A page 36 or Appe ndix B page 34 for more details) were used to analyze the data to take into account the cluste red nature of the data and were used to evaluate the relationship between exposure and AaiH. Appendices A and B al so provide an analysis of the proportionality for each of the three clothi ng configurations for each scenario. For the RTU Wipes scenario, all three clothi ng configurations did not show proportionality and did not show independence. However, for this same scenari o, the alternative approach in the Appendix to Appendix A shows proportionality to the wiping duration, For the Trigger Spray and Wipe scenario, the results of the proportionality anal ysis for the three clothing configurations are inconsistent; either all or none of the clothing configurations should show proportionality to AaiH. To investigate the proportionality issues further, an alternat ive model (“repeated measures”) was developed to fit the data from a ll of the clothing configur ations. The reader is referred to the SAS code for specific details on this repeated measures model.

The resulting regression slope and confidence intervals for the two wipe scenarios are summarized in Tables 10 and 11 and in Figures 10 to 13 (for the long pants, short-sleeved shirt dermal exposure and for inhalation exposure) belo w. To calculate the confidence intervals, the Kenwood-Rogers method was used to estimate th e denominator degrees of freedom for the repeated measures models and for the mixed-e ffect regression with a non-zero estimated ICC. However, following comments from HSRB reviewer s of the mop study analyses, we used the

containment method to estimate the denominator degrees of freedom for the mixed-effect regression with a zero estimated ICC, since in those cases the Kenwood-Rogers method ignores the uncertainty of the estimated ICC and produces a confidence interval that is too narrow.

Note that a confidence interval width of 1.4 (or less) indicat es at least 80% statistical power, which was achieved for dermal exposures and almost achieved (width = 1.47 for RTU Wipes) for inhalation exposures. Although the slopes are positive, the results for the dermal models indicate that exposure is not directly proportional (1:1) to AaiH (i.e., the confidence interval does not include 1) and al so indicate that exposure is not independent of AiaH (i.e., the confidence interval does not contain 0, except for the trigger spray and wipe scenario long pants and long-sleeves dermal exposure). The results fo r the inhalation models indicate that exposure is not directly proportional (1:1) to AaiH (i.e ., the confidence interval does not include 1) and suggest that exposure is independe nt of AiaH (i.e., confidence in terval contains 0). For morePage 31 of 40 details including results for othe r normalizing variables, the read er is referred to Appendices A and B, Tables 8, 8b, 8c, 8d, and 8e.

Table 10. RTU Wipes: Results of Analysis of Proportionality for Dermal and Inhalation Exposure.

Exposure

Route Clothing Model Slope Confidence

Interval Confidence

Interval

Width
Dermal (mg) Long pants and long

sleeves Mixed 0.56 0.28 – 0.85 0.57

Short pants

and short

sleeves Mixed 0.48 0.15 – 0.81 0.66

Long pants

and short

sleeves Mixed 0.50 0.21 – 0.80 0.59

Any Repeated

Measures 0.54 0.12 – 0.87 0.66

Inhalation

(mg/m 3 ) Mixed -0.15 -0.89 – 0.58 1.47

Table 11. Trigger Spray & Wipe: Results of Analysis of Proportionality for Dermal and Inhalation Exposure.

Exposure

Route Clothing Model Slope Confidence

Interval Confidence

Interval

Width
Dermal (mg) Long pants and long

sleeves Mixed 0.37 -0.02 – 0.76 0.78

Short pants

and short

sleeves Mixed 0.57 0.21 – 0.93 0.73

Long pants

and short

sleeves Mixed 0.58 0.20 – 0.97 0.77

Any Repeated

Measures 0.49 0.03 – 0.96 0.93

Inhalation

(mg/m 3 ) Mixed 0.25 -0.46 – 0.96 1.42Page 32 of 40 Figure 10. RTU Wipes: Mixed and simple linea r regression plots for long short dermal

exposurePage 33 of 40 Figure 11. RTU Wipes: Mixed and simple linear regression plots for inhalation exposure.Page 34 of 40 Figure 12. Trigger Spray & Wipe: Mixed and simp le linear regression pl ots for long short dermal exposure.Page 35 of 40 Figure 13. Trigger Spray & Wipe: Mixed and simp le linear regression pl ots for inhalation

exposure.

Threshold of AaiH for Over- or Under-Predicting Exposure -- Although the confidence intervals for the regression slope s are below one, it is shown in Appendices A and B that if the

mixed model formulation is correct and the estima ted regression slope is le ss than one, then the exposure will be over-predicted if the proportionality model is extrap olated to high levels of the amount of active ingredient and the exposure will be under-predicted at low levels of the amount of active ingredient. Tables 12 and 13 give the minimum amount of active ingredient handled for which the proportionality model will over-estimate the expected exposure.Page 36 of 40 Table 12. RTU Wipes: Minimum Pounds of Active Ingredient for Which Norm alized Exposure Model OverPredicts Dermal and Inhalation Exposure. Exposure

Route Clothing Model Slope Threshold Level (lb AiaH)
Dermal (mg) Long pants and long

sleeves Mixed 0.56 0.00033

Short pants

and short

sleeves Mixed 0.48 0.00039

Long pants

and short

sleeves Mixed 0.50 0.00038

Inhalation

(mg/m 3 ) Mixed -0.15 0.00028

Table 13. Trigger Spray & Wipe: Mi nimum Pounds of Active Ingredie nt for Which Norm alized Exposure

Model Over-Predicts Dermal and Inhalation Exposure. Exposure

Route Clothing Model Slope Threshold Level (lb AiaH)
Dermal (mg) Long pants and long

sleeves Mixed 0.37 0.00081

Short pants

and short

sleeves Mixed 0.57 0.00080

Long pants

and short

sleeves Mixed 0.58 0.00078

Inhalation

(mg/m 3 ) Mixed 0.25 0.00053

In response to suggestions from HSRB revi ewers of the mop study analyses, we also considered quadratic models for the relations hip between the logarith m of exposure and the logarithm of the amount of active ingredient. Appendices A and B present the equations for the quadratic models and discuss thei r applicability for pr edicting exposures attr ibutable to use of antimicrobial pesticides. For both scenarios, and in all cases, the quadra tic coefficient was not statistically significantly different from zero, so we concluded that the quadratic models are not supported and that the simple linear m odels discussed here are preferred.

3.0 Discussion of Data Gen eralizations and Limitations

The regulatory need for a generic data base of pesticide handlers for antimicrobial pesticide products has been discussed previously (Chris tian 2007). This wipe study represents two exposure scenarios in the overall design of an AEATF II generic ha ndler data base. This wipe study was designed to represent the high end of potential exposure for RTU wipes and triggerPage 37 of 40 spray and wipe activities. The study design also incorporated random di versity selection where feasible. Such a study design requ ires a discussion of how the da ta can be generalized and the limitations of the results. The following items ar e provided to characterize the results of this sampling effort:

(1) The study purposively selected Fresno, CA, as the study location. This selection criterion,

rather than a random selection of sites acro ss the country, limits to some degree the statistical generalizati ons of the data. Thus we cannot determine whether these results provide unbiased estimates of exposure distri butions from wiping activities in locations other than Fresno, CA, and it is not possible to us e these data to estimate the potential bias or the geographic variability. To generalize these results to the whole country requires an assumption that the exposure distribution fo r these scenarios is independent of the geographic location. The statistical limitations of the purposive site selection are deemed acceptable by the JRC. It is reasonable to a ssume that the mechanics of wiping surfaces inside buildings in Fresno are not substantially different than wiping surfaces inside other buildings throughout the country. Given a limite d set of resources for the overall AEATF II monitoring program, the assumption that indoor wiping of surfaces does not vary geographically was sufficiently reasonable to forgo the random site se lection in favor of spending the limited resources to monitor additi onal distinctly different scenarios (e.g., wiping, aerosol cans, painting, metal working fluids, pressure trea tment of wood, etc). (2) The data generated in this study are acceptabl e to use as surrogate for assessing other chemicals considered to have low volatility (i.e., vapor pressures less than ~1E-4 mmHg @ 20C). This “rule-of–thumb” for the vapor pres sure threshold is reviewed by EPA on a caseby-case basis, particularly for those antimicrobi al pesticides with vapor pressures that are near to this threshold. For example, for t hose chemicals with vapor pressures of ~1E-4 mmHg, EPA reviews the pestic ide application method for the potential for aerosol generation and the available inha lation toxicity data to see if the toxicity studies were performed as a gas or with an aerosol. (3) The data generated in this study are acceptable to use as surrogate to assess pesticide labeled uses of wiping surfaces. This includes the pesticide products that are packaged as RTU wipes or the products that indicate th ey can be applied by spray and wipe. (4) The dermal wipe exposure data generated in this study are acceptable to use for clothing configurations of long pants, long-sleeved shirts, and no glov es; long pants, short-sleeved shirts, and no gloves; as we ll as short pants, short sleeved-shirts, and no gloves. (5) The small sample size by itself does not cause statistical limitations other than the high level of uncertainty shown by wide confidence interv als for some of the summary statistics. More important is the fact that the original se ts of subject participants, locations, and dates from which the subjects, clusters, and sampli ng dates were chosen were limited and hence might not be representative of all Fresno wipers (e.g., wipers th at did not volunteer), buildings (e.g. only empty buildings were eligib le for this study), a nd time periods (e.g., winter versus summer, night versus day, etc. ). In other words, the most significant

limitation is that these data were not derived from a stratified random sample of MEs even though the statistical analyses made that a ssumption. At a minimum this increases the uncertainty of the estimates (so the calculated confidence intervals are too narrow) and there may also be some bias (e.g., study participants not in the volunteer pool might be more or less prone to exposure th an the selected group). (6) The wipe study report noted: “ There were always three to four study personnel following the subject during a given monitoring event”, with one being the “observer”. The HSRB review of the protocol disc ussed the Hawthorne Effect a nd cautioned the researchers on observing the workers as they work ed. The Hawthorne Effect isPage 38 of 40 ( http://psychology.about.com/ od/hindex/g/def_hawthorn.htm ) ... “ A term referring to the tendency of some people to work harder and pe rform better when they are participants in an experiment. Individuals may change their behav ior due to the atten tion they are receiving from researchers rather than b ecause of any manipulation of independent variables. This effect was first discovered and named by re searchers at Harvard University who were studying the relationship between productiv ity and work environment. Researchers conducted these experiments at the Hawthorne Works plant of Wester n Electric. The study was originally commissioned to determine if in creasing or decreasing the amount of light

workers received increased or decreased wo rker productivity. The researchers found that productivity increased due to attention from the research team and not because of changes to the experimental variable. Later research into the Hawthorne eff ect has suggested that the original results may have been overstate d. In 2009, researchers at the University of Chicago reanalyzed the original data and found t hat other factors also played a role in productivity and that the e ffect originally described was weak at best. ” It is unknown what, if any, effect the observers had on the workers’ s potential exposure. The AEATF II is again

cautioned for future research on the need fo r less obtrusive observations during the monitoring event balanced with the need to collect information on the event itself. (7) EPA will continue using exposures normalized by AaiH as a default condition. The results of the two wipe study scenarios show that derm al exposure tends to increase with AaiH but that the proportionality is not a one-to-one ratio. The choice of nor malizing variable of AaiH is based upon considerations of suita bility for product labeling and consistency

between scenarios. The lack of a direct proportionality of exposure to AaiH when extrapolating to the high end of AaiH – the EPA regulates on the hi gh end of AaiH – tends to overestimate the exposure, re sulting in conservative risk assessments and human health protective regulatory decisions. Tables 12 and 13 above provide for the minimum amount of AaiH for the normalized exposures to be over-predicting exposures (i.e., protective of human health). Data will continue to be collected by the AEATF II to add to the knowledge base of normalized exposures.

4.0 Conclusions

EPA has reviewed the AEATF II wipe study an d concludes that the AEATF II made the appropriate changes to the pr otocol proposed by the EPA a nd HSRB and has executed the study successfully. The protocol deviations that o ccurred and were reported on have not adversely impacted the reliability of these data. The EP A recommends that the inhalation and dermal UE generated in this wipe study be used provided the data are used within the boundaries set forth in

this review.

The following is a summary of our conclusions.

• The AEATF II data for inhalation and dermal exposures represent reliable data for assessing wiping of surfaces using either RTU wipes or a trigger sprayer and subsequent wipe with a rag using antimicrobial products . Alternative data sources or special circumstances will be considered on a case by case basis.

• Estimates of the GM, AM, and P95 were show n to be accurate within 3-fold with 95% confidence for all of the analys es, except for the empirical 95 th percentile for the inhalation exposure where the fold relative accuracy is 5.2 for the RTU Wipes scenario and is 3.6 for the Trigger Spray & Wipe scenario (see Tables 8 and 9).

• The data provided 80% statistical power to distinguish complete proportionality or independence between exposure and AaiH fo r both dermal and inhalation routes ofPage 39 of 40 exposure. A direct proportiona lity (1:1 relationship) between inhalation or dermal exposure and AaiH was not established but th e trend of dermal exposure increases as AaiH increases. Additionally, Tables 12 a nd 13 provide thresholds that are minimum AaiH values where exposure will be over-e stimated when extrapolating the normalized exposure (mg/lb ai) to other chemical asse ssments (i.e., using these unit exposures as surrogates to assess other chemicals that handle more than the threshold).

5.0 References

Boatwright, M. (2007) Determination of Remova l Efficiency of Didecyl Dimethyl Ammonium Chloride (DDAC) from Hand Surfaces Us ing Isopropyl Alcohol/Water Wash. Unpublished study prepared by Golden Pacific Laborat ories under Study No. 050211. 341 p. MRID

47214801.

EPA, 2008. Science and Ethics Review of AEAT F Wipe Scenario Design and Protocol for Exposure Monitoring. Memorandum dated March 10, 2008 from John Carley, Timothy Leighton, and Cassi Walls, PhD. To Norm Cook.

Hackathorn, D.R. and D.C. Eberhart. 1985. Data Ba se Proposal for Use in Predicting Mixer-loaderapplicator Exposure. American Chemical Society Symposium Series 273, pp. 341-355.

MRID 48375601. Selim, S., and Taylor, M. (201 1) A Study for Measurement of Potential Dermal and Inhalation Exposure During Applicati on of a Liquid Antimicrobial Pesticide Product Using Trigger Spray and Wipe or Ready-to-U se Wipes for Cleaning Indoor Surfaces. Unpublished study prepared by Golden Pacific Laboratories, LLC, under Project No. AEA02, Report No. 070264. 2000 p. (MRID 48375601)

MRID 48210201. Selim, S., and Taylor, M. (201 0) A Study for Measurement of Potential Dermal and Inhalation Exposure During Applicati on of a Liquid Antimicrobial Pesticide Product Using Bucket and Mop Equipment for Cleani ng Indoor Surfaces: Supplement 2 to MRID 48210201. Unpublished study prepared by Golden P acific Laboratories, LLC, under Project No. AEA03, Report No. 070265. 35 p. (MRID 48231901)

Christian, M. 2007. Memorandum: Transmittal of Meeting Minutes of the FIFRA Scientific Advisory Panel Meeting Held January 9 – 12, 2007 on the Review of Worker Exposure Assessment Methods. U.S. Environmental Protection Agency.

Popendorf W, Selim M, and Kross, B. 1990. Chemical Manufacturers Association Antimicrobial Exposure Assessment Study. MRID No. 41412201.Page 40 of 40 Appendix A

Statistical Review of th e AEATF II Wipe Study for Ready-to-use Wipes

(Attached in a separate electronic .pdf file)

Appendix B

Statistical Review of th e AEATF II Wipe Study for Trigger Spray & Wipe

(Attached in a separate electronic .pdf file)