UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, 

### D.C. 20460

OFFICE OF CHEMICAL SAFETY AND POLLUTION PREVENTION

MEMORANDUM

Date: 15-SEP-2015

SUBJECT: Profenofos: Review of "Worker Reentry Exposure to Profenofos in Cotton Treated with Curacron ® 8E "

PC Code: 111401 Decision Number: 482022 Petition Number: NA Risk Assessment Type: NA TXR Number: NA MRID Numbers: 42851302 DP Barcode: 0429108 Registration Number: N I A Regulatory Action: N I A Case Number: 2540 CAS Number: 41198-08-7 40CFR: §180.404

FROM: Kelly Lowe, Environmental

## Scientist**~~** Risk Assessment Branch I (RAB 1)

THROUGH:

TO: Health Effects Division (HED)

, 7509P

Thurston Morton

, Acting Branch Chief RABI I HED

, 7509P

Christina Scheltema Patricia Parrott Pesticide Re-Evaluation Division (PRD) (7508P)

ACTION REQUESTED: 

# , /



# -

The Registration Division (RD) requested that the Health Effects Division (HED) conduct a review of the submitted worker reentr y exposure study (with concurrent dislodgeable foliar residue data) for profenofos.

SUMMARY OF STUDY RESULTS: The study was conducted during the 1992 growing season at three test sites located in NAFTA Region 2. Test sites 1

, 2

, and 3 were located in Cheraw

, SC

, McFarlan

, NC

, and Chesterfield, SC

, respectivel y. The sites were appro x imately 2 to 8 miles from each other. Geographical and climatic conditions were relevant to the use pattern proposed. The trial sites consisted of one control plot and one treatment plot

, with the treatment plot receiving six foliar broadcast applications of profenofos

, formulated as an emulsifiable concentrate (EC) containing 73% of the acti v e ingredient (ai) profenofos

. Applications were made to cotton via tractor-mountedPage 2 of 56 

### groundboom sprayers at a target rate of 1 lb ai/A/application. The applications were made at 5-8 day re-treatment intervals using a spray volum e of 15-17 gallons of water per acre (GPA).

DFR: Duplicate control plot and tr eated plot DFR samples were collected using a Birkestrand leaf punch sampler prior to and after the first a pplication, after the sec ond application, prior to and after the third application, afte r the fourth and fifth applicatio ns, prior to and after the sixth (last) application, and at the following intervals after th e last application: 1, 2, 3, 7, 14, 21, 28 and 35 days.

EPA calculated DFRs in μg/cm 2 

### (based on a 250 cm 2 

### leaf surface area) with correction for the average low and high field fortificat ion recoveries of each site separa tely. In general, DFRs at all sites declined rapidly within the first week afte r the last application, and then remained at low levels through the end of the sampling pe riod. Residues did not decline to <LOQ (0.003 μ g/cm 2 

### ) by 35DAT6. The average DFR (and percent of app lication rate) at Site 1 (Cheraw, SC) was the highest at the 0DAT5 interval (2.83 μ g/cm 2 

### ; 26.5%). After the last a pplication, the average DFR was a maximum of 1.74 μ g/cm 2 

### (16.3%) at 0DAT6, declined to 0.40 μ g/cm 2 

### (3.8%) at 1DAT6, and continued to decline to 0.0047 μ g/cm 2 

### (0.04%) at 35DAT6. The average DFR (and percent of application rate) at Site 2 (McFarlan, NC ) was the highest at th e 0DAT2 interval (3.99
μ g/cm 2 

### ; 29.7%). After the last application, the average DFR was a maximum of 1.82 μ g/cm 2 

### (17.1%) at 0DAT6, declined to 0.251 μ g/cm 2 

### (2.4%) at 1DAT6, and continued to decline to 0.0046 μ g/cm 2 

### (0.04%) at 35DAT6. The average DFR (and pe rcent of applicati on rate) at Site 3 (Chesterfield, SC) was the highest at the 0DAT5 interval (5.19 μ g/cm 2 

### ; 44.5%). After the last application, the average DFR was a maximum of 2.48 μ g/cm 2 

### (23.3%) at 0DAT6, declined to 1.54 μ g/cm 2 

### (14.4%) at 1DAT6, and continued to decline to 0.0056 μ g/cm 2 

### (0.05%) at 35DAT6. Actual DFRs on 0DAT6 were 7 to 12 times higher than the predicted DFRs on 0DAT6.

The Registrant assumed first-order dissipation kinetics to generate dissipation curves for profenofos, using the natural log of average DF R values. Using the 0DAT6 to 35DAT6 data, the Registrant calculated half-lives of 5 days (r = -0 .85) for Site 1 (Cheraw, SC), 4.9 days (r = -0.77) for Site 2 (McFarlan, NC), and 4.6 days (r = -0.79) for Site 3 (Chesterfield, SC). The Registrant also performed regressions using the 0DAT 6 through 7DAT6 data only, which assumes a biphasic curve. The Registrant calculated half- lives of 1.2 days (r = -0.91) for Site 1 (Cheraw, SC), 1.1 days (r = -0.80) for Site 2 (McFarla n, NC), and 0.86 days (r = -0.95) for Site 3 (Chesterfield, SC).

EPA first assumed first-order dissi pation kinetics and conducted li near regression analysis using the natural logarithm of the av erage DFR values from 0DAT6 to 35DAT6. EPA's estimated halflife values were 5.1 days (R 2 

### = 0.7132) for Site 1, 5.7 days (R 2 

### = 0.6351) for Site 2, and 4.7 days (R 2 

### = 0.6271) for Site 3. However, the regression anal ysis did not appear visually to be a good fit for the data, and the actual DFRs on 0DAT6 were 7 to 12 times higher than the predicted DFRs on 0DAT6. Therefore, EPA did additional analys is and conducted a biphasic (“hockey stick”) regression analysis using Excel’s Solver, and the corrected average DFRs from immediately after the last application through the last sampling inte rval. This regression an alysis appears (visually) to be a better fit of the data, and prov ides predicted Day 0 values of 2.3 μg/cm 2 

### , 3.0 μg/cm 2 

### , and 2.7 μg/cm 2 

### , for Site 1 (Cheraw, SC), Site 2 (Chest erfield, SC), and Site 3 (McFarlan, NC), respectively.Page 3 of 56 

### Worker Reentry Exposure (Dermal and Inhalation) : At each of the three sites, five re-entry workers were monitored during post-application activities on the day of the last application (0DAT6) and the day after the last application (1DAT6). Three of the workers were scouters and two of workers were hoers. The work pe riod was approximately 4 hours in duration.

Dermal exposures were monitored using whole-body inner dosimeters, whole-body outer dosimeters, hand washes, and face/neck wipes. Inhalation exposures were monitored using air sorbent tubes and pre-loaded filter cassettes attached to air sampling pumps at an air flow rate of 1 L/min . All workers wore 100% cotton, long underwear (inner dosimeter) over their choice of undergarments. Additionally, all workers were ou ter long sleeve and long pant garments (outer dosimeter) over the inner dosimeters. All work ers also wore a baseba ll cap, and scouters only wore a pouch around the waist to collect cott on bolls. No additional personal protective equipment (PPE) was worn during monitoring activities (i.e., gloves, goggles, face masks, or respirators).

Field fortification samples were prepared for each matrix at each sampling interval at one or two fortification levels. Average field fortificati on recoveries were gene rally acceptable (i.e., 70- 120%) with a few exceptions. Most notably, av erage recoveries were 37-65% for the inner whole body dosimeter at the low fortification level.

Dermal exposures: EPA calculated both total dermal e xposure and potential dermal exposure and presented the results in terms of transfer coefficients (μg/cm 2 

### ). The average DFRs used for 0DAT6 and 1DAT6 intervals were 1.74 and 0.403 μ g/cm 2 

### at Site 1 (Cheraw, SC), 1.82 and 0.251
μ g/cm 2 

### at Site 2 (McFarlan, NC), and 2.48 and 1.54 μ g/cm 2 

### at Site 3 (Chesterfield, SC). For scouters, average transfer coefficients fo r total dermal exposure were 176, 123, and 237 cm 2 

### /hr on 0DAT6 for Sites 1, 2, and 3, respectively, and 330, 318, and 293 cm 2 

### /hr on 1DAT6 for Sites 1, 2, and 3, respectively. For hoers, average transfer coefficients for total dermal exposure were 86.9, 96.9, and 200 cm 2 

### /hr on 0DAT6 for Sites 1, 2, and 3, respectively, and 192, 198, and 122

cm 2 

### /hr on 1DAT6 for Sites 1, 2, and 3, respectively.

Based on average values of transfer coefficien ts for total dermal exposure, body parts with significant residues (i.e., >10%) were the arm, leg and hand. For scouters and hoers on 0DAT6, the average distribution was a pproximately 30% each to the legs, arms, and hands. A similar distribution was observed for hoers on 1DAT6 (leg s, arms and hands each receiving an average of 24-33%). For scouter on 1DAT6, the majority of the distribution was on the legs (average of 59%), with 23% on the arms, and only 8.1% on the hands. Average penetra tion from the outer to inner dosimeters was highest for the arms (29 to 40%). Average penetration for the other regions ranged from 3.8 to 9.3%.

Inhalation exposures: For scouters, average inhalati on exposure was 5.48, 4.26, and 5.82 μg/hr on 0DAT6 for Sites 1, 2, and 3, respectively, and 2.05, 1.52, and 0.95 μg/hr on 1DAT6 for Sites 1, 2, and 3, respectively. For hoers, average inhalation exposure was 7.47, 6.24, and 7.83 μg/hr on 0DAT6 for Sites 1, 2, and 3, respectively, and 2.86, 2.21, and 2.28 μg/hr on 1DAT6 for Sites 1, 2, and 3, respectively.Page 4 of 56 

### Cotton Boll residues: Duplicate cotton boll sa mples were collected at two sampling intervals at each site. Cotton bolls with carpels were co llected at 35DAT6 to 38DAT6 and cotton bolls without carpels were collected on 44DAT6 to 70DAT6. Residues were <LOQ in all cotton boll only samples collected at 44-70DAT6. In the bo ll+carpel samples collec ted at 35-38DAT6, the average profenofos values were 0.0015 to 0.0025 μ g/cm 2



### .

CONCLUSIONS: No major issues were identifie d during review of this study an d the results ar e considered acceptable for risk assessment purposes. The DFR da ta can be used to estimate post-application worker exposure from the use of profenofos on agricultural crops. The worker reentry exposure data are not recommended to be used independently as chemical-specific data for risk assessment purposes. These data have already been incorporated into EPA’s Scie nce Advisory Council for Exposure (ExpoSAC) Policy 3 ( http://www.epa.gov/pesticides /science/exposac-policy-3- march2013.pdf ). The recommended transfer coefficients from this policy are recommended for use in the profenofos risk assessment in conj unction with the available chemical-specific DFR data.

There were some concerns noted with respec t to the DFR study. However, these are not anticipated to impact the validity of the data or its use in risk assessment. These concerns included: (1) only duplicate DFR samples were collected at each inte rval; the guidelines recommend the collection of triplicate DFR samples; (2) two field fortifica tion levels were used (200 μg and 20,000 μg), as recommended in the EP A guidelines; however, the high fortification level was significantly higher than the treated sa mples; and (3) the EPA guidelines recommend a sample surface are of 400 cm 2 

### ; however, in this study, the to tal leaf surface was only 250 cm 2 

### , as reported in the main text of the study. It shoul d also be noted that th e study actually used a surface area of 227 cm 2 

### to calculate DFRs, based on a punch diameter of 1.7 cm. The Rabbit Tool website (the manufacturer of Birk estrand punches) states that the 2.5 cm 2 

### punch has a diameter of 1.784 cm 2 

### , thus it appears that the surface area of 227 cm 2 

### is incorrect.

Summary of DFR Values and Regression Analysis Re sults for Treated Cotton with Profenofos (MRID# 42851302).
Site Cheraw, SC Chesterfield, SC McFarland, NC Study Target Rate (lb ai/A) 1 lb ai/acre Spray Volume (GPA) 15-17
Measured Average Day 0 Residue (μg/cm 2 ) 0DAT6: 1.74 0DAT6: 2.48 0DAT6: 1.82
Linear Regression Predicted Day 0 Residue (μg/cm 2 ) 0DAT6: 0.234 0DAT6: 0.296 0DAT6: 0.146 Slope -0.135 -0.149 -0.121 Half-life (days) 5.1 4.7 5.7

R 2 0.7132 0.6271 0.6351
Biphasic Regression Predicted Day 0 Residue (ug/cm 2 ) 0DAT6: 2.3 0DAT6: 3.0 0DAT6: 2.7
Slope -1.587, -1.587 -0.912, -1.588 -2.345, -1.588Page 5 of 56 0.000 0.500 1.000 1.500 2.000 2.500

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30DFR (ug/cm2)

DAT 42851302 - Cheraw, SC_profenofos

Residue (ug/cm 2 ) vs. Time (days) Raw DFR Data
Log-linear 1st Order

Non-linear 1st Order

Hockey Stick

0.000 0.500 1.000 1.500 2.000 2.500 3.000 3.500

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30DFR (ug/cm2)

DAT 42851302_profenofos_Chesterfield, SC Residue (ug/cm 2 ) vs. Time (days) Raw DFR Data

Log-linear 1st Order

Non-linear 1st Order

Hockey StickPage 6 of 56 0.000 0.500 1.000 1.500 2.000 2.500 3.000

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30DFR (ug/cm2)

DAT 42851302_profenofos_McFarlan, NC

Residue (ug/cm2) vs. Time (days) Raw DFR Data

Log-linear 1st Order

Non-linear 1st Order

Hockey StickPage 7 of 56 

### DATA EVALUATION RECORD

STUDY TYPE: Determination of Dislodgeable Foli ar Residue in Cotton Treated with Profenofos; 875.2100 and Agricultural Post-application Exposure Study (Dermal and Inhalation); 875.2400, and 875.2500

PC CODE: 111401

TEST MATERIAL Curacron® 8E, an emulsifiable concen trate (EC) formulation containing a nominal 73% of active ingredient (ai) profenofos (8 lb ai/gal)

SYNONYMS: Common name: Profenofos Formulation Trade name: Curacron® 8E Chemical name: 0-(4-bromo-2-chlorphenyl) 0-ethyl S-propyl phosphorothioate CAS No.: 41198-08-7

CITATIONS: Study Authors: Richard C. Honeycutt Stephen Mabon Title: Worker Reentry Exposure to Profenofos in Cotton Treated with Curacron® 8E Report Date: May 21, 1993 Field Laboratory: H.E.R.A.C., Inc. 3704-B Boren Drive Greensboro, NC 27407 Analytical Laboratory: EN -CAS Analytical Laboratories, Inc. 2359 Farrington Point Dr. Winston-Salem, NC 27107 Identifying Codes: H.E.R.A. C. Study No. 92-205HE; H.E.R.A.C. Report No. 93-302; EN-CAS Study No. 92- 0064

SPONSOR: CIBA-GEIGY Corporation (cur rently Syngenta Crop Protection) Greensboro, NC 27419

EXECUTIVE SUMMARY:

Concurrent dislodgeable foliar re sidue (DFR) and agri cultural post-applica tion exposure studies were conducted with the purpose of:

1) Determining the dissipation of DFR of the activ e ingredient profenofos applied to cotton; 2) Estimating potential dermal and inhalation exposure to agricultural workers performing scouting and hoeing activities after application of prof enofos to cotton; and 3) Calculating transfer coefficients (cm 2 

### /hr) for scouting and hoeing cotton using the DFR and dermal exposure data.Page 8 of 56 

### The study was conducted during the 1992 growing seas on at three test site s located in NAFTA Region 2. Test sites 1, 2, and 3 were located in Cheraw, SC, McFarlan, NC, and Chesterfield, SC, respectively. The sites were approximately 2 to 8 miles from each other. Geographical and climatic conditions were relevant to the use pa ttern proposed. The trial sites consisted of one control plot and one treatment plot, with the treatment plot receiving six foliar broadcast applications of profenofos, formulated as an emulsifiable concentrate (EC) containing 73% of the active ingredient (ai) profe nofos. Applications were made to cotton via tractor-mounted groundboom sprayers at a target rate of 1 lb ai/A/application. The applications were made at 5-8 day re-treatment intervals using a spray volum e of 15-17 gallons of water per acre (GPA).

DFR: Duplicate control plot and tr eated plot DFR samples were collected using a Birkestrand leaf punch sampler prior to and after the first a pplication, after the sec ond application, prior to and after the third application, afte r the fourth and fifth applicatio ns, prior to and after the sixth (last) application, and at the following intervals after th e last application: 1, 2, 3, 7, 14, 21, 28 and 35 days.

Residues were dislodged from the leaf punch sa mples immediately afte r collection using 0.004% dioctyl sodium sulfosuccinate (DSS) (Aerosol OT brand) solution. The samples were stored frozen prior to extraction for analysis by gas chromatography with flame photometric detection (GC-FPD). Concurrent recoveries were w ithin the acceptable range of 70 to 120%. The reported limit of quantitation (LOQ) was 0.005 μg/mL (0.003 μg/cm 2 

### ); the limit of detection (LOD) was not reported. Field fortification samples were prepared in duplicate at two fortification levels at three sampling intervals. Average field fortific ation recoveries were acceptable (i.e., within 70-120%).

The Registrant provided DFRs in μg/sample with correction for laboratory recovery (uncorrected results were not provi ded) and in μg/cm 2 

### (based on a 227 cm 2 

### leaf surface area) with and without an additional correction for the overall average field fortificat ion recovery from all sites combined. EPA calculated DFRs in μg/cm 2 

### (based on a 250 cm 2 

### leaf surface area) with correction for the average low and high field fortif ication recoveries of each site separately.

In general, DFRs at all sites d eclined rapidly within the first w eek after the last application, and then remained at low levels through the end of the sampling period. Residues did not decline to <LOQ (0.003 μ g/cm 2 

### ) by 35DAT6.

The average DFR (and percent of application rate) at Site 1 (Cheraw, SC) was the highest at the 0DAT5 interval (2.83 μ g/cm 2 

### ; 26.5%). After the last appl ication, the average DFR was a maximum of 1.74 μ g/cm 2 

### (16.3%) at 0DAT6, declined to 0.40 μ g/cm 2 

### (3.8%) at 1DAT6, and continued to decline to 0.0047 μ g/cm 2 

### (0.04%) at 35DAT6.

The average DFR (and percent of application rate ) at Site 2 (McFarlan, NC) was the highest at the 0DAT2 interval (3.99 μ g/cm 2 

### ; 29.7%). After the last application, the average DFR was a maximum of 1.82 μ g/cm 2 

### (17.1%) at 0DAT6, declined to 0.251 μ g/cm 2 

### (2.4%) at 1DAT6, and continued to decline to 0.0046 μ g/cm 2 

### (0.04%) at 35DAT6.Page 9 of 56 

### The average DFR (and percent of application rate) at Site 3 (Chesterfield, SC) was the highest at the 0DAT5 interval (5.19 μ g/cm 2 

### ; 44.5%). After the last application, the average DFR was a maximum of 2.48 μ g/cm 2 

### (23.3%) at 0DAT6, declined to 1.54 μ g/cm 2 

### (14.4%) at 1DAT6, and continued to decline to 0.0056 μ g/cm 2 

### (0.05%) at 35DAT6. Actual DFRs on 0DAT6 were 7 to 12 times higher than the predicted DFRs on 0DAT6.

The Registrant assumed first-order dissipation kinetics to generate dissipation curves for profenofos, using the natural log of average DF R values. Using the 0DAT6 to 35DAT6 data, the Registrant calculated half-lives of 5 days (r = -0 .85) for Site 1 (Cheraw, SC), 4.9 days (r = -0.77) for Site 2 (McFarlan, NC), and 4.6 days (r = -0.79) for Site 3 (Chesterfield, SC). The Registrant also performed regressions using the 0DAT 6 through 7DAT6 data only, which assumes a biphasic curve. The Registrant calculated half- lives of 1.2 days (r = -0.91) for Site 1 (Cheraw, SC), 1.1 days (r = -0.80) for Site 2 (McFarla n, NC), and 0.86 days (r = -0.95) for Site 3 (Chesterfield, SC).

EPA first assumed first-order dissi pation kinetics and conducted li near regression analysis using the natural logarithm of the av erage DFR values from 0DAT6 to 35DAT6. EPA's estimated halflife values were 5.1 days (R 2 

### = 0.7132) for Site 1, 5.7 days (R 2 

### = 0.6351) for Site 2, and 4.7 days (R 2 

### = 0.6271) for Site 3. However, the regression anal ysis did not appear visually to be a good fit for the data, and the actual DFRs on 0DAT6 were 7 to 12 times higher than the predicted DFRs on 0DAT6. Therefore, EPA did additional analys is and conducted a biphasic (“hockey stick”) regression analysis using Excel’s Solver, and the corrected average DFRs from immediately after the last application through the last sampling inte rval. This regression an alysis appears (visually) to be a better fit of the data, and prov ides predicted Day 0 values of 2.3 μg/cm 2 

### , 3.0 μg/cm 2 

### , and 2.7 μg/cm 2 

### , for Site 1 (Cheraw, SC), Site 2 (Chest erfield, SC), and Site 3 (McFarlan, NC), respectively.

Worker Reentry Exposure (Dermal and Inhalation) : At each of the three sites, five re-entry workers were monitored during post-application activities on the day of the last application (0DAT6) and the day after the last application (1DAT6). Three of the workers were scouters and two of workers were hoers. The work pe riod was approximately 4 hours in duration.

Dermal exposures were monitored using whole-body inner dosimeters, whole-body outer dosimeters, hand washes, and face/neck wipes. Inhalation exposures were monitored using air sorbent tubes and pre-loaded filter cassettes attached to air sampling pumps at an air flow rate of 1 L/min . All workers wore 100% cotton, long underwear (inner dosimeter) over their choice of undergarments. Additionally, all workers were ou ter long sleeve and long pant garments (outer dosimeter) over the inner dosimeters. All work ers also wore a baseba ll cap, and scouters only wore a pouch around the waist to collect cott on bolls. No additional personal protective equipment (PPE) was worn during monitoring activities (i.e., gloves, goggles, face masks, or respirators). The samples were stored frozen prior to extraction for analysis by GC-FPD. Concurrent recoveries were generally within the acceptable range of 70 to 120%. The reported LOQ was 1 μg/sample for inner and outer dosimeters, 0.00015 μg/m L for handwashes, 0.05 μg/sample for face/neck wipes, and 0.1 μg/sampl e for air sorbent tubes and pre-loaded filter cassesstes; the LOD was not reported.Page 10 of 56 

### Field fortification samples were prepared for each matrix at each sampling interval at one or two fortification levels. Average field fortificati on recoveries were gene rally acceptable (i.e., 70- 120%) with a few exceptions. Most notably, av erage recoveries were 37-65% for the inner whole body dosimeter at the low fortification level.

Dermal exposures: Profenofos values for dermal matrix samples were presented in the study in units of μ g/sample, with correction for concurrent la boratory recovery (if <100%) and for the overall average field fortification recove ry for each matrix. Using the reported μ g/sample values (already corrected for concurrent laboratory recovery), EPA calculated dermal exposures for each matrix in μ g/sample and μ g/hour, with correction for site sp ecific average field fortification values from each recovery level. For all repl icates, EPA used the nominal work duration of 4 hours. For values <LOQ, EPA used a value of 1⁄2 LOQ in calculations. EPA also made adjustments, as necessary, to account for met hod extraction inefficien cies of handwash and face/neck wipes, and also extrapolated the face/n eck wipe residue to the rest of the head which was not sampled. It should be noted that one scouter on 1DAT6 dropped out early because of heat exhaustion and was replaced with a new worker. EPA did not include the replicate which dropped out in summary calculations.

EPA calculated both total dermal exposure and potential dermal expos ure and presented the results in terms of transfer coefficients (μg/cm 2 

### ). Total dermal exposure is the sum of the inner dosimeter, total head, and hand exposures, and re presents a worker wear ing a single layer of clothing (long pants and long shirt) and no PPE (i.e . gloves, goggles, face masks, or respirators). Potential dermal exposure is the sum of the i nner dosimeter, outer dosimeter, total head, and hand exposures and represents a worker wearing no clothing or PPE. Tran sfer coefficients are dermal exposure (μg/hr) di vided by the average DFR ( μ g/cm 2 

### ) on the reentry day. The average DFRs used for 0DAT6 and 1DAT6 intervals were 1.74 and 0.403 μ g/cm 2 

### at Site 1 (Cheraw, SC), 1.82 and 0.251 μ g/cm 2 

### at Site 2 (McFarlan, NC), and 2.48 and 1.54 μ g/cm 2 

### at Site 3 (Chesterfield, SC).

For scouters, average transfer coefficients for total dermal exposure were 176, 123, and 237

cm 2 

### /hr on 0DAT6 for Sites 1, 2, and 3, respectively, and 330, 318, and 293 cm 2 

### /hr on 1DAT6 for Sites 1, 2, and 3, respectively. For hoers, average transfer coefficients for total dermal exposure were 86.9, 96.9, and 200 cm 2 

### /hr on 0DAT6 for Sites 1, 2, and 3, respectively, and 192, 198, and 122 cm 2 

### /hr on 1DAT6 for Sites 1, 2, and 3, respectively.

Based on average values of transfer coefficien ts for total dermal exposure, body parts with significant residues (i.e., >10%) were the arm, leg and hand. For scouters and hoers on 0DAT6, the average distribution was a pproximately 30% each to the legs, arms, and hands. A similar distribution was observed for hoers on 1DAT6 (legs, arms and hands each receiving an average of 24-33%). For scouter on 1DAT6, the majority of the distribution was on the legs (average of 59%), with 23% on the arms, and only 8.1% on the hands.

Average penetration from the outer to inner dosimeters was highest for the arms (29 to 40%). Average penetration for the other regions ranged from 3.8 to 9.3%.

Inhalation exposures: Profenofos values for inhalation sa mples were presented in the study inPage 11 of 56 

### units of μ g/sample, with correction for concurrent la boratory recovery (if <100%) and for an overall average field fortification recovery of a ll sites combined. Air sorbent tube samples did not require correction because all resi dues were <LOQ. Using the reported μ g/sample values (already corrected for concurrent laboratory r ecovery), EPA calculated air concentrations in
μ g/m 3 

### and inhalation exposures in μ g/hr, with correction for s ite specific average field fortification values from each recovery level. For values <LOQ, EPA used a value of 1⁄2 LOQ in calculations. EPA summed the pre-loaded-filter casse tte and air sorbent tube residues to provide total profenofos residues. The airborne concentration of profenofos was then calculated by dividing the corrected total residue value by th e total volume of air drawn by the personal sampler over the sampling duration. The air concen trations were then ad justed for the NAFTA recommended inhalation rate of 1.0 m 3 

### /hr (light activity) for scouters and 1.6 m 3 

### /hr (moderate activity) for hoers to calculate th e inhalation exposure values.

For scouters, average inhalation exposure was 5.48, 4.26, and 5.82 μg/hr on 0DAT6 for Sites 1, 2, and 3, respectively, and 2.05, 1.52, and 0.95 μg/hr on 1DAT6 for Sites 1, 2, and 3, respectively. For hoers, average inhalati on exposure was 7.47, 6.24, and 7.83 μg/hr on 0DAT6 for Sites 1, 2, and 3, respectively, and 2.86, 2.21, and 2.28 μg/hr on 1DAT6 for Sites 1, 2, and 3, respectively.

Cotton Boll residues: Duplicate cotton boll sa mples were collected at two sampling intervals at each site. Cotton bolls with carpels were co llected at 35DAT6 to 38DAT6 and cotton bolls without carpels were collected on 44DAT6 to 70DAT6. The sample s were dislodged with using 0.004% Aerosol OT solution. The samples were stor ed frozen prior to ex traction for analysis by GC-FPD. Concurrent recoveries were within the acceptable range of 70 to 120%. The reported LOQ was 0.005 μg/mL (0.003 μg/cm 2 

### ); the LOD was not reported. Field fortification samples were prepared in duplicate at two fortification levels at three sampling intervals. Average field fortification recoveries were gene rally acceptable (i.e., within 70-120%).

Profenofos values for cotton bol l samples (with and without carpe l) were presented in the study in units of μ g/sample and in μ g/cm 2 

### with correction for concurrent laboratory recovery (if <100%). No field fortification recovery correction was applied. Using the reported μ g/sample values (already corrected for concurrent labo ratory recovery), EPA calculated values in μ g/cm 2 

### with correction for site specific average field for tification values from each recovery level.

Residues were <LOQ in all cotton boll only sample s collected at 44-70DAT6. In the boll+carpel samples collected at 35-38DAT6, the averag e profenofos values were 0.0015 to 0.0025 μ g/cm 2



### . The following concerns are noted with respec t to the worker expos ure study (Series 875.2400 and 875.2500 Guidelines):

 Fifteen workers were monitored at each in terval; however, these were divided between all three sites and both worker types. On a per site basis, only three scouters and two hoers were monitored at each interval.

 The exact monitoring time for each worker re plicate was not provided. It was assumed for all calculations that each worker was monitored for the nominal 4 hour work duration.

 The following issues with fi eld fortification are noted:

o Single field fortification leve ls were used for handwash, face/neck wipe, air filter,Page 12 of 56 

### and air sorbent tube samples.

o The average low level field fortificati on recoveries for the inner whole body dosimeters were 37.0-64.9%. No explanati on for the extremely low recoveries was provided.

o The fortification levels were not within range or did not bracket the field residues for the following matrices:

 For face/neck wipes, the fortification level (200 μg) was at least an order of magnitude higher than the residue levels detected in the post-exposure treated samples (0.446 to 25.8 μg).

 For inner dosimeters, the low fortific ation level (200 μg) was within the range of the treated samples (1.53 to 1,439 μg), but the high fortification level (20,000 μg) was an order of ma gnitude higher than the residue levels.

 For air filters, the fortification leve l (25 μg) was higher than the residue levels detected in the treated samples (0.083 to 1.61 μg).

 Profenofos residues were detected in handw ash and face/neck wipe sample collected prior to the exposure event. No explanat ion was provided for the presence of these residues. The study subtracted these resi dues out from the post-exposure samples.

 Profenofos residues were detected in dermal and inhalation field blank residues (up to 34xLOQ). The study states that residues were pr obably detected due to the proximity of the sample preparation area to the field being sprayed.

 For the face/neck wipe samples at Site 1 (C heraw, SC) and 2 on 1DAT6, it appears that the study did not assign the correct worker activity to some of the samples. EPA used the worker activity assigned to the replicate for the other matrices.

The following concerns were noted with resp ect to the DFR study (Series 875.2100 Guidelines):

 Only duplicate DFR samples were collected at each interval. The guidelines recommend the collection of triplicate DFR samples.

 Two field fortification levels were used (200 μg and 20,000 μg), as recommended in the EPA guidelines. The low fortification level wa s within range of the treated samples (0.80 to 1,434 μg), but the high fortification leve l was significantly highe r than the treated samples.

 The EPA guidelines recommend a sample surface are of 400 cm 2 

### . In this study the total leaf surface was only 250 cm 2 

### , as reported in the main text of the study. It should also be noted that the study actually used a surface area of 227 cm 2 

### to calculate DFRs, based on a punch diameter of 1.7 cm. The Rabbit Tool we bsite (the manufacturer of Birkestrand punches) states that the 2.5 cm 2 

### punch has a diameter of 1.784 cm 2 

### , thus it appears that the surface area of 227 cm 2 

### is incorrect.Page 13 of 56 

### COMPLIANCE:

Signed and dated GLP, Quality Assurance, and Da ta Confidentiality statements were provided. The study sponsor waived claims of confidentiality within the scope of FIFRA Section 10(d) (1) (A), (B), or (C). The Study Report indicat ed that the study was conducted under EPA Good Laboratory Practice Standa rds (40 CFR Part 160).

ETHICS REVIEW :

Each worker signed a consent form stating that they were informed of adverse effects and expected exposure levels of profenofos. No information on an ethics review was provided.

GUIDELINE OR PROTOCOL FOLLOWED: Series 875, Occupational and Residential Exposure Test Guidelines, Part B, Postappl ication Exposure Monitoring Test Guidelines: 875.2100 (dislodgeable foliar residue dissipation), 875.2400 (dermal exposure), and 875.2500 (inhalation exposure).

I. MATERIALS AND METHODS

A. MATERIALS:

1. Test Material:

Formulation: Curacron® 8E, an EC formulation Lot/Batch # formulation: FL -921451/MC 206046 (formulated product) Formulation guarantee: 73% ai (8 lb ai/gal ) nominal, 73.4% purity analysis (assay date 7/10/92) Purity: 98.1% in technical (Lot 50429-1) CAS #: 41198-08-7 Other Relevant Information: None

2. Relevance of Test Material to Proposed Formulation(s):

The test product used in this study, Curacron® 8E, appears to be the same product identified on the label for Curacron® 8E Insecticide-Mitic ide (EPA Reg. No. 100-669, dated 7/11/14) based on the product name, amount ai (73% ai ), and crop use site (cotton).

B. STUDY DESIGN:

The study protocol (CIBA GEIGY Corporation Protocol No. 127-92 and H.E.RA.C Protocol No. 92-205HE) was signed on July 10, 1992 by the Study Director. There were 33 amendments and 40 deviations to the protocol. The amendments and deviations are described in detail in Appendix 1 of the Study Report.

1. Site Description:Page 14 of 56 

### Test locations: The field phase of the study was conducted at three test sites located in NAFTA Region 2. Test sites 1, 2, and 3 were located in Cheraw, SC, McFarlan, NC, and Chesterfield, SC, respectively. The sites were approximately 2 to 8 miles from each other. The cotton fields were typical for application of the test substa nce. A control plot and a treatment plot was established at each site; however, the distance be tween the control and tr eatment plot was not provided.

Areas sprayed, re-entered, and sampled: The treate d plot at each site was approximately 25 acres and was divided into 10 subplots of approximately 2.5 acres each.

Meteorological Data: On the days of app lication and re-entry testing, wind speed, wind direction, air temperature, and relative humidities were generally gathered. If weather data were not available at the site, then nearby reporting stations were used to gather the data. A 10 year NOAA weather summary was also provided for the area around Cheraw, SC (9-13 miles from all sites).

During July-October (first application through la st sampling), average monthly temperatures were 79-61.2°F and were -0.8 to -1.4 °F from normal. Monthly precipitation ranged from 2.41 to 9.04 inches and was -3.8 to 3.18 inches from normal.

2. Crop Characteristics:

Crop, variety: Cotton, D & PL90

Row width, plant spacing: Not reported.

Stage of growth: Not reported.

Other products used on crop: Not reported.

3. Application Rates and Regimes :

Application rate(s): The target application rate for each of the six applications was 1 lb ai/A/application, for a to tal seasonal rate of 6 lb ai/A/season. Actual application rates ranged from 0.95 to 1.23 lb ai/A/applicati on, as shown in Table 1. The current label reports a maximum application rate of 0.5 lb ai/A/a pplication, with a maximum seasona l rate of 5 lb ai/A/season.

Table 1. Actual Application Rates (lb ai/A/application) at Each Test Site Application No. Site 1 (Cheraw, SC) Site 2 (McFarlan, NC) Site 3 (Chesterfield, SC) 1 1.20 1.09 1.12 2 1.23 1.20 1.12 3 1.18 1.18 1.2 4 0.99 0.99 1.18 5 0.95 0.99 1.04 6 0.95 0.95 0.95 Total 6.5 6.4 6.6



### Application Regime: Six applications were made to cotton fields at a 5 to 8 day retreatmentPage 15 of 56 

### interval. Applications were made between 8/11/92 and 9/11/92 at Site 1 (Cheraw, SC), 8/6/92 and 9/8/92 at Site 2 (McFarlan, NC ), and 7/29/92 to 9/2/92 at S ite 3 (Chesterfield, SC). The label reports a minimum retreatment interval of 5 days.

Application Equipment: All applications were made usi ng a John-Deere Hi-Boy ground boom sprayer fitted with 25 flat fan nozzles on a 40-ft wide boom. Each nozzle was fitted with a #50 mesh screen. The pressure of th e sprayer was approximately 60 psi.

Spray Volume: The spray volume was 15 to 17 gall ons of water per acre. The current label reports a minimum spray volume of 3 to 5 GP A for spray solutions diluted with water.

Equipment Calibration Procedures: The sprayer wa s calibrated prior to each treatment using either a one-gallon plastic jug or directly using a Spraymate Calibrator. When using the plastic jug, the gallon per minute was calculated by running the sprayer for a preset period of time (usually 30 seconds). The speed of the spraye r was also calibrated prior to each treatment by determining the time to spray 10.1 acres.

Spray Verification: Spray verification was performed by placing 15 cm diameter filter paper (in petri dishes) in random spots on the plot prior to applications 1, 3, and 6. The filter paper was collected immediately after the application and stored frozen until analysis. The overall average deposition (corrected for an average field fo rtification recovery of 80%) was 1,980 μg/sample (n=80) over the course of the study, whic h was 93.5% of the theoretical amount.

4. Number and type of workers: Consent forms were provided for 13 volunteers. The volunteers were male or female and at least 21 years of age. The volunteers had been instru cted on work activities. Several scouters were experienced scouters.

5. Protective clothing: The workers wore the following clothing:

 Outer coveralls (long denim pants a nd long sleeve chambray shirt)

 Inner dosimeter (one-p iece cotton union suit)

 New white socks

 New tennis shoes

 Clean baseball-style cap

 Cotton pouches, tied around the waist, fo r collecting cotton bolls during scouting (scouters only)

The workers did not wear gloves, goggles, f ace masks, or respirators during monitoring activities. The outer and inner dosimeters were washed with detergent water once, rinsed, washed twice with water with no detergent, rinse d, dried, and placed into zip-lock bags prior to

use.

6. Time Interval(s) for Reentry: Two reentry intervals were monitored for each wo rker type (scouting and hoeing). The reentryPage 16 of 56 

### intervals were 1-2 hours after the last application (0DAT6; after spray had dried) and 24 hours after the last application (1DAT6).

7. Replicates: At each test site, five workers (three scouters and two hoers) were monitored at each of the two reentry intervals (0DAT6 and 1DAT6). At all s ites combined, there were 9 scouter replicates and 6 hoer replicates on each reentry day. Howeve r, on 1DAT6 at Site 3 (Chesterfield, SC), one scouter (replicate 4) dropped out of the study due to heat e xhaustion approximately halfway through the monitoring period, and an additiona l worker (replicate 4A) was monitored.

During each re-entry period one volunteer entere d one of the five assigned subplots, and was monitored for approximately 4 hours while pe rforming their assigned activity. The beginning time of each worker was staggered so that all wo rkers did not end simultaneously. In general the workers did not move out of th eir assigned subplots unless the wo rker had to be removed from the study, took a break from the fiel d activities, emptied apron containing cotton bolls (scouters only), or ate lunch. An optional 0.5 hour lunch break was not included in the 4 hour test period.

The protocol states the North Carolina agricultu ral extension agent indicated that cotton scouts typically spend 2 to 4 hours scout ing cotton during a normal day.

Scouting Activities: The scouters performed the routine below, three times, while zig-zagging through the field (going through cott on rows). In most cases the scouts performed all duties and recorded the data, but in a few instances the scout s failed to record all data as requested. The scouter routine was as follows:

1. Walk along a row while spreading plants, c ounting bolls, and obser ving insect damage. 2. Pick 50 terminals each hour and observe t op and bottom leaves for bollworm eggs and live worms. 3. Pull 100 squares from all lo cations on the plant. 4. Record the number of eggs found under the fruiting form. 5. Record the number of live bollworms under squares’. 6. Pull 100 young bolls (1/2 to 3/4 mature) from all locations on the plants. 7. Record the number of live bollworms. 8. Slice bolls with a sharp knife. 9. Record damage to the bolls.

Hoer Activities: The hoers cultivated the weeds in the plot by going systematically through the plot with a hoe.

8. Exposure monitoring methodology:

Dermal: Dermal exposure was monitored using inner dosimeters, outer dosimeters, face/neck wipes, and hand washes. Designated personnel suited up the workers and removed samples as needed. The field technicians and workers were provided with latex gloves to wear while removing each item of clothing to minimize cros s contamination. All samples were labelled, wrapped, taped, and stored on dry ice immediately after sampling.Page 17 of 56 

### Outer Dosimeters - The outer dosimeters cons isted of a long-sleeved chambray shirt and denim long-sleeve pants. These outer dosim eters were worn directly over the inner dosimeters. At the end of each monitoring pe riod, the outer dosimeters were carefully removed and place in aluminium foil. The dosimet ers were then cut into the following four sections: (1) left/right arms combined; (2) left /right legs combined; (3) front torso; and (4) back torso. Each section was wrapped in alum inium foil and placed into a labelled zip-lock bag.

Inner Dosimeters - The inner dosimeters cons isted of a one-piece long-underwear suit constructed of 100% cotton. They were worn di rectly under the outer clothing/dosimeters. At the end of each monitoring period, the outer dosimeters were carefully removed and place in aluminium foil. The dosimeters were then cut into the followi ng four sections: (1) left/right arms combined; (2) left/right legs combined; (3) front torso; and (4) back torso. Each section was wrapped in aluminium foil and placed into a labelled zip-lock bag.

Hand Washes – Hand exposure wa s assessed by rubbing the work ers hands together for 30 seconds in 250 mL of 0.004% DSS solution. This solution was poured into a prelabeled jar, and the procedure was repeated. The two ha ndwashes were pooled as one sample, capped, labeled, and prepared for storage and shipment to the laboratory. Samples were collected from each worker prior to the beginning of wo rk and at the end of the monitoring period.

A few deviations were made w ith respect to handwash sample collection: (1) The handwash for volunteer 3 was conducted as a 150 mL wash with 0.004% DSS solution and a 100 mL with a 0.04% DSS solution (date not provided, devi ation #10), and (2) on 9/3/92 for replicate 4A, the two 250 mL washes were not pooled, but were collected and analyzed separately.

Face and Neck Wipes - Face/neck exposure was assessed by wi ping the exposed area with cotton handkerchiefs which were folded to ma ke a 4.5 inch x 4.5 inch square and saturated with 0.004% DSS. Samples were collected by wiping the face area for about 15 seconds and the neck area for about 15 seconds. The face/n eck wipe was then placed in a labeled jar, capped, and prepared for storage and shipment to the laboratory. Samples were collected from each worker prior to the beginning of wo rk and at the end of the monitoring period.

A few deviations were made with respect to face/neck wipe collection: (1) Face/neck wipe samples from volunteer 3 were done with 0.04% DSS instead of 0.004% DSS (date not provided, deviation #10); (2) on 9/13/12 and on 9/12/12, an additional face/neck wipe with distilled water was collected from volunteer 3 after the normal face/neck wipe with DSS; and (3) on 9/3/12 volunteer 4 dropped out and an additional face/neck wipe was conducted on this volunteer with distilled water pr ior to a normal facewipe with DSS.

Inhalation: Airborne concentr ations of profenofos in the worker’s breathing zone were monitored utilizing a preloaded fi lter cassette (mixed cellulose-est er filter material) to capture particulate matter and chromosorb sorbent tube to capture vapor. The sampling train was attached to a Flow-Lite air pump with tygon tubi ng, and calibrated to 1 L/min. The pumps were turned on just prior to entering the treated cotton field and ge nerally left on throughout the testPage 18 of 56 

### period. On one occasion (Site 3 (Chesterfield, SC), 0DAT6), the air pumps were turned off during a lunch break, and turned back on when the workers returned to the field. The air flow rates were measured and recorded prior to and af ter the monitoring period. At the end of the monitoring period the air sorbent tubes were capped and both th e air sorbent tubes and preloaded filter cassettes were wrapped, labeled, and stored on dry ice.

9. Dislodgeable Foliar Residue Sampling Procedures :

Method and Equipment: DFR samples consisted of 50 leaf disks which were collected with a Birkestrand leaf puncher. The punch size was reported as 2.5 cm 2 

### in the main body of the text. The punch samples were collected directly into pre-labelled glass jars.

Sampling Procedure: At each sampling interval, tw o replicate samples were collected from the treated plot. The 50 leaf discs pe r sample were taken from random ar eas of the designated plots. Usually, two leaf discs per plant were taken from the most mature part of the cotton plant, resulting in using 25 plants per sample. The pun ches were taken using an alternating quadrant system. Plants on the end of the rows were avoided.

Surface area sampled (two sides): The double sided surface area per leaf punch was approximately 5 cm 2



### . Total Surface Area per Replicate: The main study text reports the total surface area per replicate as 250 cm 2 

### ; however, in all calculations the study used a surface area of 227 cm 2 

### based on a punch diameter of 1.7 cm. Based on the Rabbit T ool website (the manufacturer of Birkestrand punches), the 2.5 cm 2 

### punch has a diameter of 1.784 cm 2 

### , thus it appears that the surface area of 227 cm 2 

### is incorrect. EPA used a total surface area of 250 cm 2 

### in all calculations.

Replicates per activity: – Replicates per sampling time: At each samp ling interval, duplicate DFR samples were collected from the treated plots.

– Number of sampling times: There were a tota l of 17 sampling events, including nine after the last application.

Times of sampling: Samples were collected prio r to and after the first application, after the second application, prior to and af ter the third app lication, after the fourth and fifth applications, prior to and after the sixth (l ast) application, and at the fo llowing intervals after the last application: 1, 2, 3, 7, 14, 21, 28 and 35 days.

Part(s) of foliage sampled: Usually, two leaf di scs per plant were taken from the most mature part of the cotton plant.

DFR Dislodging solution: Profenofos residu es were dislodged with 0.004% DSS solution.

DFR Dislodging procedure: Each sample wa s dislodged twice usi ng 100 mL of the 0.004% DSS solution. Dislodging was conducted by shaking the sample on a reciprocating shaker for 10Page 19 of 56 

### minutes. The two washes were pooled, resul ting in a 200 mL sample. On two occasions (7/28/92 and 7/29/29), 125 mL of 0.004% DSS solution was used to dislodge samples, resulting in a final volume of 250 mL.

DFR Time interval (sample collection to dislo dging): The time between sample collection and dislodging was not reported. A ccording to the study protocol, l eaf punch samples were to be transported on wet ice for 30 to 40 minutes to a site where dislodging occurred.

10. Dislodgeable Cotton Boll Residue Sampling Procedures :

Method and Equipment: Mature cotton bolls were picked by hand.

Sampling Procedure: Two samples (five bolls per sample) were collected per area. Cotton bolls were collected with or without husks attached.

Cotton boll weight: The study report noted that the mean weight of 20 cotton bolls (without husks) was measured and was reported to be 5.75 g. Based on a sample containing 5 cotton bolls, the mean weight per samp le was calculated to be 1.44 g.

Surface area sampled: The surface area of the co tton portion of the cotton bolls was calculated by assuming that the boll was sphe re shaped. The diameter of 15 bolls collected from one site were measured on three separate occasions by in serting a measuring rod. For a 5 boll sample, the total surface area was 503 cm 2 

### . The surface area of the leaf portion of the cotton bolls was calculated by assuming that the carpel was an elli pse. One carpel per boll was removed and the width was measured along the wi dest portion of the leaf. The total surface area for each carpel was calculated to be 4.15 cm 2 

### . It was determined than the percentage of bolls with 3, 4, or 5 leaves was <1, 68, and 30%, respectively. Based on a cotton boll containing 4 carpels, and a sample containing 5 bolls per sample, the total surface for the carpels per sample was 83 cm 2



### . Times of sampling: Two sampling intervals were used at each site. At the first interval mature cotton bolls with husks a ttached were collected. At the s econd interval mature cotton bolls without husks attached were collected. Sample s were collected at th e following intervals:

Site 1 (Cheraw, SC): 35DAT6 (with husks) and 61DAT6 (without husks) Site 2 (McFarlan, NC): 38DAT6 (with husks) and 44DAT6 (without husks) Site 3 (Chesterfield, SC): 36DAT6 (w ith husks) and 70DAT6 (without husks)

Dislodging solution: Profenofos residues were dislodged with 0.004% DSS solution.

Dislodging procedure: Five cotton bolls were pressed into a ja r, 125 mL of 0.004% DSS solution was added, and the bolls were tamped down below th e liquid level. The sample was then shaken for approximately 10 minutes, and the wash was pour ed into a separate ja r. The procedure was repeated twice, and the first and second washes were combined, resulting in a 250 mL sample.

Dislodging Time interval (sample collection to dislodging): The time between sample collection and dislodging was not reported.Page 20 of 56 

### 11. Sample Handling:

All dermal, inhalation, DFR, and cotton boll samp les were labelled, wrap ped, taped and stored on dry ice immediately after sampli ng was complete. Samples were stored in coolers on dry ice for 1-2 days and were then shipped directly to the analytical laborat ory (EN-CAS Analytical Laboratories, Winston-Salem, NC) or to a temp orary freezer in Monroe , NC prior to final shipment to the analytical laboratory. At the laboratory, all samples remained in freezer storage (-23° to -27°C) until thawed for subsampling. The length of frozen storage between sample collection and analysis was 113- 160 days for the treated field samples. Field fortification samples were stored for a similar, but longer, length of time.

12. Analytical Methodology:

The analytical method used for all matrices was EN-CAS Analytical Method No. ENC-5/91.

Extraction method: Outer & Inner Dosimeters – Profenofos was ex tracted from the dosimeter sections with dichloromethane (DCM) by shaking on a mechani cal shaker. An ali quot was collected and evaporated to dryness using rotary evaporation. The evaporated sample was reconstituted in toluene and analyzed by GC/FPD-P . For the outer dosimeters only, a “high” and “low” approach was then used. If the residue was >100 μg then analysis was complete (h igh method). If residue was <100 μg then a new aliquot of the sample was taken, evaporated to dryness, and was taken through the low method. The low method involved adding hexane (saturat ed with acetonitrile) to the sample, vacuum filtering, and evaporati ng to dryness using rotary evaporation. The sample was reconstituted in hexane and loaded onto a silica gel Mega Bond-Elut cartridge, and profenofos was eluted with DC M/hexane (75/25). The eluate was evaporated to dryness, reconstituted in toluene, a nd analyzed by GC/FPD-P.

Face/Neck Wipes and Hand Washes - Profenofos wa s extracted from the face/neck wipe samples with hexane/DCM (80/20) usi ng a reciprocating shaker. Th e sample was decanted into a separatory funnel, and the hexane/DCM phase was poured through a sodium sulphate pad and concentrated to dryness. The sample was rec onstituted in toluene and analyzed by GC/FPD-P. Air sorbent tubes - The front por tion of the air sorbent tube was extracted with toluene by shaking on a mechanical shaker. The extracti on solvent was evaporated to dryness and the sample was reconstituted in to luene and analyzed by GC/FPD-P.

Pre-loaded Filter Cassettes - Profenofos was extr acted from the pre-loaded filter cassettes with DCM using a reciprocating shaker. The extrac tion solvent was evaporated to dryness and the sample was reconstituted in to luene and analyzed by GC/FPD-P.

DFR and Cotton Boll - Profe nofos was extracted from the DFR and cotton boll dislodging solutions by adding sodium chloride and partitio ning the sample three times with hexanes/DCM (80/20). The organic phase wa s concentrated to dryness usin g rotary evaporation, then reconstituted in toluene and analyzed by GC/FPD-P.Page 21 of 56 

### Detection methods: All samples were analyz ed by GC/ FPD-P. A summary of the GC conditions are shown in Table 2 for whole body dosimeters, handw ashes and air sorbent tubes, and Table 3 for face/neck wipes, preloaded filter cassettes, and cotton leaf and cotton boll dislodging solutions.

Table 2. Summary of Typical GC/FPD-P Condition s for Whole Body Dosimet ers, Handwashes and Air sorbent tubes Instrument (GC): Hewlett-Packard 5890

Column: Fused silica megabore capillary 30-m x 0.32-mm D-17 column, 0.25-

μ m film thickness
Temperature: Injector: 240 °C Detector: 250 °C

Program: Oven Temp = 205°C Hold Time = 4 min Ramp = 10°C /min Final Oven Temp. = 250°C Final Hold Time = 12 min
Injection: 2 -4 μL, splitless

Gas: Carrier: Helium = 4.4 mL/min Detector: Hydrogen = 62 mL/min, Air = 104 mL/min
Approximate Retention Time: 6.1 minutes

Mode: Phosphorus

Table 3. Summary of Typical GC/FPD-P Conditions for Face/Neck Wipes, Preloaded Filter Cassettes, Cotton Leaf and Cotton Boll Dislodging Solutions
Instrument (GC): Hewlett-Packard 5890

Column: Fused silica megabore capillary 15-m x 0.542-mm DB-5 column, 1.5-

μ m film thickness
Temperature: Injector: 240°C Detector: 250°C

Program: Oven Temp = 200°C Hold Time = 10 min
Injection: 5 μL, splitless

Gas: Carrier: Helium = 16 mL/min Detector: Hydrogen = 90 mL/min, Air = 100 mL/min

Total Run Time: 12 minutes (20 min for CA DFR samples)
Approximate Retention Time: 4.7 minutes

Mode: PhosphorusPage 22 of 56 

### Method validation: The analytical method used to quantify residues of prof enofos in each matrix was validated on control samples prior to the determination of the residue in the treated samples for this study.

Outer Dosimeters -- Control oute r whole body dosimeter arm sections (chambray) were fortified at three levels: 1.0, 10 and 100 μg/sample. The overall mean recovery was 103 ± 7.5% (n=3) for fortifications with analytical standard and 91 ± 9.1% (n=9) for fortifications with the test formulation. Control outer whole body dosimeter leg sections (denim) we re fortified at four levels: 1.0, 10, 100, and 1,000 μg/sample. The overall mean recovery was 114 ± 12% (n=3) for fortifications with analytical standard and 84 ± 12% (n=15) for fortifications with the test formulation. The validated LOQ was 1 μg/sam ple for the “low” method and 100 μg/sample for the “high” method; the LOD was not reported.

Inner Dosimeters -- Control inner whole body dosimet er sections were for tified at one level: 1.0 μg/sample. The overall mean recovery was 76 ± 18% (n=3) for fortifications with analytical standard and 87 ± 12% (n=9) for fortifications wi th the test formulati on. The validated LOQ was 1.0 μg/sample; the LOD was not reported.

Handwashes -- 0.004% DSS solution was for tified at three le vels: 0.00015, 0.0015, and 0.015 μg/mL. The overall mean recovery was 97 ± 3.8% (n=3) for fortifications with analytical standard and 88 ± 11% (n=9) for fortifications wi th the test formulati on. The validated LOQ was 0.00015 μg/mL; the LOD was not reported.

Face/neck Wipes -- Control face/neck wipe sample s were fortified at four levels: 0.05, 0.5, 5 and 250 μg/sample. The overall mean recovery was 117 ± 2.1% (n=3) for fortifications with analytical standard and 91 ± 16% (n=12) for fo rtifications with the test formulation. The validated LOQ was 0.05 μg/sample; the LOD was not reported.

Air sorbent tubes -- Air sampling tubes were for tified at three levels: 0.1, 1.0, and 25 μg/section. The overall mean recovery was 80 ± 19% (n=3) for fortifications with analytical standard and 86 ± 16% (n=12) for fortifications with the test formulation. The validated LOQ was 0.1 μg/sample; the LOD was not reported. Profenofos breakth rough was investigated by fortifying the front sections of the air sorbent tubes with profe nofos at 0.1 and 1.0 μg/sample, and drawing air through the sample for 6 hours at a rate of 1 L/mi n. Tests were done at a humidity of 30% and 90%. Profenofos was not found in the back secti ons of any air sorbent tubes. At 30% humidity, recoveries ranged from 33-82% at the low level and 128 to 142% at the high level. At 90% humidity, recoveries ranged from 73-101% at the low level and 134 to 138% at the high level. It was noted that under the 30% humidity conditions it was difficult to remove the chromosorb material from the glass tube. An apparent electrostatic charge cau sed sticking to the inside glass walls, which may have caused the lower than normal recovery at the 0.1 μg/sample level.

Preloaded Filter Cassettes -- Preloaded filter casse ttes were fortified at three levels: 0.1, 1.0, and 25 μg/section. The overall mean recovery was 98 ± 26% (n=3) for fortifications with analytical standard and 103 ± 14% (n=12) for fortifications with the test formulation. The validated LOQ was 0.1 μg/sample; the LOD was not reported.Page 23 of 56 

### Dislodgeable Foliar Residues -- Cotton leaf 0.004% DSS solution was fortif ied at three levels: 0.1, 1.0, and 25 μg/section. The overall mean recove ry was 120% (n=2) for fortifications with analytical standard and 105 ± 19% (n=12) for fo rtifications with the test formulation. The validated LOQ was 0.003 μg/cm2; the LOD was not reported. Since both cotton bolls and leaves were extracted with 0.004% DSS solution, the co tton leaf validation was considered acceptable for cotton bolls. The LOQ for cotton bolls was 0.003 μg/mL (0.0015 μg/cm2).

Instrument performance: A series of calibration st andards were injected with each set to quantify residues in the samples. The standards are inject ed after every 2 to 3 samples throughout the GC run. Typical calibration curves were provided for handwash and cotton leaf dislodgeable solution. The curves showed calibration standa rd concentrations ranging from 0.02 to 5 ng and r2 values of 0.998 to 0.999.

Quantification: Residue levels were calculated from linear regression standard curves.

13. Quality Control:

Lab Recovery: A typical analysis set included at least two labora tory fortified samples and one control blank. A summary of the laboratory recoveries is presen ted in Table 4 below. Overall average recoveries ranged from 78 to 93% per matr ix. All procedural reco veries were corrected for contribution from the control. Profenofos residues in the control were <LOQ for outer and inner WBD, air sorbent tubes, preloaded filter cassettes, and cotton leaf DFR. Profenofos residues in the control were <LOQ to 0.059 μg for face/neck wipes, <LOQ to 0.00051 μg for handwashes, and <LOQ to 0.006 μg/mL for cotton bolls.

Table 4. Summary of La boratory Fortification Matrix Fortification Levels n Overall Recovery ± Standard Deviation (%) 1 Outer WBD 1 – 20,000 μg 26 83 ± 17 Inner WBD 0.1 – 20,000 μg 31 89 ± 19 Face/Neck Wipes 0.05 – 5 μg 20 78 ± 10 Handwashes 0.00015- 10 μg/mL 24 87 ± 13 Air Sorbent tubes 0.1 – 30 μg 9 90 ± 13 Preloaded Filter Cassettes 0.1 – 1 μg 12 89 ± 12 Cotton Leaf DFR 0.003 – 300 μg/mL 34 90 ± 12 Cotton Bolls 0.03 – 0.03 μg/mL 8 93 ± 27 1. Recoveries were corrected for c ontribution from the control.



### Field blanks: For each site, duplicate field bl ank samples were prepared for each dermal and inhalation matrix at each reentr y interval. For DFR samples, single field blank samples were prepared on each application day as well as the day before application 1 and 3. The samples were exposed to the environment in the same manner as the field fortification samples (see below). Residues of profenofos were not detected in a ny control air sorbent tube samples, but were detected in some samples for all other matrices (up to 34xLOQ), as shown in Table 5. The study states that residues were probably detected due to the proximity of the sample preparation area to the field being sprayed. Field resi dues were not corrected for resi dues detected in the field blank samples.Page 24 of 56 Table 5. Profenofos Residues 1 in Field Blank Samples Matrix Site 1 (Cheraw, SC) Site 2 (McFarlan, NC) Site 3 (Chesterfield, SC) Outer WBD 1.2 - 3.64 μg <LOQ 8.3 - 48.2 μg Inner WBD <LOQ - 1.88 μg <LOQ 1.71 – 23.9 μg Face/Neck Wipes <LOQ – 0.167 μg/mL <L OQ - 0.074 μg/mL <LOQ - 0.119 μg/mL Handwashes <LOQ-0.0002 μg/mL 0.00019-0.00127 μg/mL 0.00057-0.00533 μg/mL Air Sorbent tubes <LOQ <LOQ <LOQ Preloaded Filter Cassettes <LOQ <LOQ <LOQ – 0.518

Cotton Leaf DFR <LOQ <LOQ <LOQ Cotton Bolls <LOQ <LOQ - 0.034 μg/mL <LOQ 1. Residues shown are not corrected for field fortification recovery.



### Field recovery: Field fortific ation samples for all dermal, i nhalation, and cotton boll matrices were prepared at one fortification level (handwas h, face/neck wipes, air f ilters, and air sorbent tubes) or at two fortification levels (inner and outer dosimeters, DFRs and cotton bolls). Field fortification samples for DFRs were prepared in triplicate on -1DAT6, 7DAT6, and 35DAT6. For other matrices, field fortification samples were prepared on each sample collection day. Profenofos spiking solutions were prepared at the analytical laboratory and brought to the field sites. After spiking control samples, the samples were exposed to the environment for approximately the same duration as the field samp les. However, for inner and outer dosimeter sections and air samples, the duration of exposur e was 4-7 hours, which was longer than the field samples to accommodate supervision of undressi ng volunteers. Handwash and face/neck wipe samples were exposed for 5 to 8 minutes and 5 to 10 minutes, respectively. Air was drawn through the air samples at a rate of 1 L/min.

A summary of the field fortific ation recoveries are provided in Tables 6 through 13 for each matrix. The recoveries were not corrected for an y apparent residues detected in the field control samples. Recoveries were corrected for conc urrent laboratory rec overy, if <100%. Average recoveries were generally between 70 and 120%, with standard deviations <20%, with a few exceptions as follows:

For outer whole body dosimeters, standard devia tions were 25.1-55.9% for two sets at the low fortification level (0DAT6 at Si te 1 (Cheraw, SC) and 1DAT6 at Site 2 (McFarlan, NC)). For inner whole body dosimeters, averag e recoveries were 37.0-64.9% fo r all low fortification sets and standard deviations were 23.0-29.0% for 3 of the 4 sets atSite 2 (McFarlan, NC). No explanation was provided for the extremely low r ecoveries. For face/neck wipes, the standard deviation was 29.8% for the high fortification le vel at Site 2 (McFarlan, NC) on 1DAT6. For DFRs, the standard deviations were 21.2 - 27.2% for three sets (high fortific ation level for Site 1 (Cheraw, SC), both levels for Site 2 (McFarlan, NC)). For cotton bolls, average recoveries were 65.8-68.9% for the high level sets at Site 3 (Chesterfield, SC) and standard deviations were 40.1- 42.4% for both low and high sets at the 36DAT6 interval for S ite 3 (Chesterfield, SC).

The fortification levels were not within range or did not bracket the field residues for the following matrices:

 For face/neck wipes, the fortification level (200 μg) was at least an order of magnitude higher than the residue levels detected in the post-exposur e treated samples (0.446 to 25.8 μg).Page 25 of 56 

###  For inner dosimeters, the low fortification level (200 μg) was within the range of the treated samples (1.53 to 1,439 μg), but the hi gh fortification level (20,000 μg) was an order of magnitude higher th an the residue levels.

 For DFRs, the low fortification level (200 μg ) was within range of the treated samples (0.80 to 1,434 μg), but the high fortification level (20,000 μg) was an order of magnitude higher than the residue levels.

 For air filters, the fortification level (25 μg) wa s higher than the residu e levels detected in the treated samples (0.083 to 1.61 μg).

The average recovery results were used as multip liers to adjust, or correct, all measured field samples. If multiple fortification levels were used, the average recovery from the fortification level closest to the measured field sample was us ed to adjust the field samples. The midpoint between each fortification le vel (i.e. 10,100 μg for whole body dosimeters and cotton boll samples and 40.4 μg/cm 2 

### for DFR samples) was used as th e threshold for determining which average recovery to use.

Table 6. Field Fortification Recoveri es for Outer Whole Body Dosimeters 1
Sample Interval Fortification Level (μg/sample) Count Recoveries 2 (%)
Range Average ± Standard Deviation
Site 1 (Cheraw, SC)

0DAT6 200 5 42.0 - 160 92.5 ± 55.9 20,000 5 86.9 - 102 93.6 ± 6.4

1DAT6 200 7 58.5 - 88 74.7 ± 10.8 20,000 9 100 - 137 120 ± 10.2 Site 2 (McFarlan, NC)

0DAT6 200 5 94.0 - 136 108 ± 16.2 20,000 5 95.5 - 107 103 ± 4.5

1DAT6 200 5 65.5 - 127 85.1 ± 25.1 20,000 5 107- 127 115 ± 7.6 Site 3 (Chesterfield, SC)
0DAT6 200 5 94.0 - 110 104 ± 6.6

1DAT6 200 5 87.0 - 130 98.2 ± 17.7 20,000 5 98.7 - 118 108 ± 7.0
1. Leg, arm, front torso, and back torso sections were fo rtified. Recoveries from all sections were combined for summary statistics. 2. Recoveries were calculated by reviewer using the reported residues found. The reported residues were corrected for concurrent laboratory recovery, if <100%.

Table 7. Field Fortification Recoveri es for Inner Whole Body Dosimeters 1
Sample Interval Fortification Level (μg/sample) Count Recoveries 2 (%)
Range Average ± Standard Deviation
Site 1 (Cheraw, SC)

0DAT6 200 5 44.2 - 89.0 55.9 ± 18.8 20,000 2 97.6 - 98.6 98.1 ± 0.7Page 26 of 56 Table 7. Field Fortification Recoveri es for Inner Whole Body Dosimeters 1
Sample Interval Fortification Level (μg/sample) Count Recoveries 2 (%)
Range Average ± Standard Deviation

1DAT6 200 5 44.6 - 65.0 58.8 ± 8.4 20,000 9 56.1 - 118 93.7 ± 17.3 Site 2 (McFarlan, NC)

0DAT6 200 5 30.4 - 43.0 37.0 ± 4.9 20,000 5 65.0 - 124 86.9 ± 23.0

1DAT6 200 5 48.0 - 117 64.9 ± 29.0 20,000 4 60.4 - 131 96.2 ± 28.8 Site 3 (Chesterfield, SC)

0DAT6 200 5 33.7 - 40.1 38.1 ± 2.7 20,000 5 54.8 - 88.1 73.5 ± 15.0

1DAT6 200 5 34.9 - 40.8 38.0 ± 2.8 20,000 5 56.5 - 99.1 79.2 ± 16.1
1. Leg, arm, front torso, and back torso sections were fo rtified. Recoveries from all sections were combined for summary statistics. 2. Recoveries were calculated by reviewer using the reported residues found. The reported residues were corrected for concurrent laboratory recovery, if <100%.

Table 8. Field Fortificatio n Recoveries for Handwashes
Sample Interval Fortification Level (μg/mL) Count Recoveries 1 (%)
Range Average ± Standard Deviation
Site 1 (Cheraw, SC)
0DAT6 0.4 5 75.4 - 99.4 89.7 ± 9.5
1DAT6 0.4 5 89.3 - 116 99.5 ± 10.0 Site 2 (McFarlan, NC)
0DAT6 0.4 5 73.3 - 96.6 83.7 ± 10.7
1DAT6 0.4 5 70.7 - 93.3 78.8 ± 8.6 Site 3 (Chesterfield, SC)
0DAT6 0.4 5 76.5 - 94.4 86.1 ± 6.9
1DAT6 0.4 5 92.0 - 107 98.5 ± 5.5
1. Recoveries were calculated by reviewer using the reported residues found. The reported residues were corrected for concurrent laboratory recovery, if <100%.

Table 9. Field Fortification R ecoveries for Face/Neck Wipes Sample Interval Fortification Level (μg) Count Recoveries 1 (%) Range Average ± Standard Deviation Site 1 (Cheraw, SC)
0DAT6 200 5 68.5 - 97.0 84.9 ± 10.9

1DAT6 200 5 62.0 - 111 88.5 ± 19.3
Site 2 (McFarlan, NC)Page 27 of 56 0DAT6 200 5 67.5 - 86.5 75.5 ± 8.2
1DAT6 200 5 42.5 - 112 95.7 ± 29.8 Site 3 (Chesterfield, SC)
0DAT6 200 5 52.0 - 96.0 77.1 ± 16.8
1DAT6 200 5 62.5 - 98.0 83.0 ± 14.0
1. Recoveries were calculated by reviewer using the reported residues found. The reported residues were corrected for concurrent laboratory recovery, if <100%.

Table 10. Field Fortification Re coveries for Air Sorbent Tubes Sample Interval Fortification Level (μg) Count Recoveries 1 (%) Range Average Site 1 (Cheraw, SC)
0DAT6 25 2 79.6 - 99.6 89.6
1DAT6 25 2 91.2 - 105 98.2 Site 2 (McFarlan, NC)
0DAT6 25 2 86.4 - 86.8 86.6
1DAT6 25 2 88.4 - 94.4 91.4 Site 3 (Chesterfield, SC)
0DAT6 25 2 75.6 - 81.6 78.6 1DAT6 25 1 (37) 2 - 75.2 75.2 1. Recoveries were calculated by reviewer using the reported residues found. The reported residues were corrected for concurrent laboratory recovery, if <100%. 2. One replicate was identified as an outlier and was not used in the summary calculations.

Table 11. Field Fortification Recov eries for Preloaded Filter Cassettes Sample Interval Fortification Level (μg) Count Recoveries 1 (%) Range Average Site 1 (Cheraw, SC)
0DAT6 25 2 92.0 - 99.6 95.8
1DAT6 25 2 65.2 - 75.6 70.4 Site 2 (McFarlan, NC)
0DAT6 25 2 95.6 - 98.8 97.2
1DAT6 25 2 86.0 - 89.2 87.6 Site 3 (Chesterfield, SC)
0DAT6 25 2 74.0 - 88.0 81.0
1DAT6 25 2 95.6 - 107 101
1. Recoveries were calculated by reviewer using the reported residues found. The reported residues were corrected for concurrent laboratory recovery, if <100%.

Table 12. Field Fortification Recoveries for DFR

Sample Interval Fortification Level (μg) Count Recoveries 1 (%)
Range Average ± Standard Deviation
Site 1 (Cheraw, SC)Page 28 of 56 Table 12. Field Fortification Recoveries for DFR

Sample Interval Fortification Level (μg) Count Recoveries 1 (%)
Range Average ± Standard Deviation
-1DAT6, 7DAT6, 35DAT6 200 6 69.5 - 118 103 ± 17.1
-1DAT6, 7DAT6, 35DAT6 20,000 6 82.4 - 151 107 ± 27.2 Site 2 (McFarlan, NC) -1DAT6, 7DAT6, 35DAT6 200 6 91.0 - 152 112 ± 23.2
-1DAT6, 7DAT6, 35DAT6 20,000 6 81.7 - 131 105 ± 21.2 Site 3 (Chesterfield, SC) -1DAT6, 7DAT6, 35DAT6 200 8 61.5 - 115 86.3 ± 19.1
-1DAT6, 7DAT6, 35DAT6 20,000 8 77.5 - 137 95.2 ± 19.6
1. Recoveries were calculated by reviewer using the reported residues found. The reported residues were corrected for concurrent laboratory recovery, if <100%.

Table 13. Field Fortification Recoveries for Cotton Bolls

Sample Interval Fortification Level (μg) Count Recoveries 1 (%)

Range Average ± Standard Deviation
Site 1 (Cheraw, SC)

35DAT6 (Boll + Carpel) 200 2 105 - 119 112 ± 9.5 20,000 2 86.1 - 112 99.1 ± 18.3

61DAT6 (Carpel) 200 2 92.0 - 103 97.3 ± 7.4
20,000 2 79.5 - 87.25 83.4 ± 5.5
Site 2 (McFarlan, NC)

38DAT6 (Boll + Carpel) 200 2 113 - 123 118 ± 7.1

20,000 2 103 - 106 104 ± 2.2

44DAT6 (Carpel) 200 2 94.5 - 96.5 95.5 ± 1.4

20,000 2 94.0 - 96 95.0 ± 1.4 Site 3 (Chesterfield, SC)

36DAT6 (Boll + Carpel) 200 2 60.5 - 121 90.5 ± 42.4
20,000 2 40.5 - 97.3 68.9 ± 40.1

70DAT6 (Carpel) 200 2 99.0 - 101 99.8 ± 1.1

20000 2 58.1 - 73.5 65.8 ± 10.9
1. Recoveries were calculated by reviewer using the reported residues found. The reported residues were corrected for concurrent laboratory recovery, if <100%.



### Formulation: Curacron® 8E is an emulsifiab le concentrate formulation containing a nominal 73% of ai (8 lb ai/gal). Duplicate samples of fo rmulation used at each si te were analyzed. The mean concentration of profenofos was 1.07 ± 0.092 g/mL, which is 89.6% of theoretical.

Tank mix: Tank mix samples were collected for each application at each site in duplicate priorPage 29 of 56 

### to each application. The mean concentrati on of profenofos was 7,157 ± 656 μg/mL (n=18), which is 85 ± 30% of theoretical.

Travel Recovery: Travel recovery samples were not prepared.

Storage Stability: According to the analytical method protocol, stor age stability tests were to be conducted for all matrices; however, the result s were not reported. As reported in MRID 42851304, a freezer storage stability study was c onducted in which Aerosol OT dislodging solution was fortified with profenofos at 0.05 μg /mL and analyzed after 0, 1 and 3 months of frozen storage. After correction for concurrent recovery, storage stability recoveries were 106, 88 and 88%, respectively. The field fo rtification samples demonstrated the stability of profenofos during storage. All field fortification samples were stored for a greater length of time than the treated samples prior to analysis.

II. RESULTS AND CALCULATIONS



### DFR: Profenofos values for DFR samples were presented in the study in units of μ g/sample with correction for concurrent laborato ry recovery (if <100%), and in μ g/cm 2 

### with an additional correction for the overall average field fortificati on recovery. The Registrant used a leaf surface area of 227 cm 2 

### /sample for calculations. Using the reported μ g/sample values (already corrected for concurrent laboratory rec overy), EPA calculated DFRs in μ g/cm 2 

### with correction for site specific average field fortification values from eac h recovery level (refer to Table 12). EPA used a leaf surface area of 250 cm 2 

### /sample for calculations.

Tables 14-16 provide a summary of the profenofos DFR values for the cotton foliage at Sites 1, 2, and 3, respectively. In general, DFRs declined rapidly within the first week after the last application, and then remained at low levels through the end of the sampling period. Residues did not decline to <LOQ (0.003 μ g/cm 2 

### ) by 35DAT6.

The average DFR (and percent of application rate) at Site 1 (Cheraw, SC) was the highest at the 0DAT5 interval (2.83 μ g/cm 2 

### ; 26.5%). After the last appl ication, the average DFR was a maximum of 1.74 μ g/cm 2 

### (16.3%) at 0DAT6, declined to 0.40 μ g/cm 2 

### (3.8%) at 1DAT6, and continued to decline to 0.0047 μ g/cm 2 

### (0.04%) at 35DAT6.

The average DFR (and percent of application rate ) at Site 2 (McFarlan, NC) was the highest at the 0DAT2 interval (3.99 μ g/cm 2 

### ; 29.7%). After the last application, the average DFR was a maximum of 1.82 μ g/cm 2 

### (17.1%) at 0DAT6, declined to 0.251 μ g/cm 2 

### (2.4%) at 1DAT6, and continued to decline to 0.0046 μ g/cm 2 

### (0.04%) at 35DAT6.

The average DFR (and percent of application rate) at Site 3 (Chesterfield, SC) was the highest at the 0DAT5 interval (5.19 μ g/cm 2 

### ; 44.5%). After the last application, the average DFR was a maximum of 2.48 μ g/cm 2 

### (23.3%) at 0DAT6, declined to 1.54 μ g/cm 2 

### (14.4%) at 1DAT6, and continued to decline to 0.0056 μ g/cm 2 

### (0.05%) at 35DAT6. Actual DFRs on 0DAT6 were 7 to 12 times higher than the predicted DFRs on 0DAT6.

The Registrant assumed first-order dissipation kinetics to generate dissipation curves for profenofos, using the natural log of average DF R values. Using the 0DAT6 to 35DAT6 data, thePage 30 of 56 

### Registrant calculated half-lives of 5 days (r = -0 .85) for Site 1 (Cheraw, SC), 4.9 days (r = -0.77) for Site 2 (McFarlan, NC), and 4.6 days (r = -0.79) for Site 3 (Chesterfield, SC). The Registrant also performed regressions using the 0DAT 6 through 7DAT6 data only, which assumes a biphasic curve. The Registrant calculated half- lives of 1.2 days (r = -0.91) for Site 1 (Cheraw, SC), 1.1 days (r = -0.80) for Site 2 (McFarla n, NC), and 0.86 days (r = -0.95) for Site 3 (Chesterfield, SC).

EPA first assumed first-order dissi pation kinetics and conducted li near regression analysis using the natural logarithm of the av erage DFR values from 0DAT6 to 35DAT6. EPA's estimated halflife values were 5.1 days (R 2 

### = 0.7132) for Site 1, 5.7 days (R 2 

### = 0.6351) for Site 2, and 4.7 days (R 2 

### = 0.6271) for Site 3. However, the regression anal ysis did not appear visually to be a good fit for the data, and the actual DFRs on 0DAT6 were 7 to 12 times higher than the predicted DFRs on 0DAT6. Therefore, EPA did additional analys is and conducted a biphasic (“hockey stick”) regression analysis using Excel’s Solver, and the corrected average DFRs from immediately after the last application through the last sampling inte rval. This regression an alysis appears (visually) to be a better fit of the data, and prov ides predicted Day 0 values of 2.3 μg/cm 2 

### , 3.0 μg/cm 2 

### , and 2.7 μg/cm 2 

### , for Site 1 (Cheraw, SC), Site 2 (Chest erfield, SC), and Site 3 (McFarlan, NC), respectively.

Dermal: Profenofos values for dermal matrix samples were presented in the study in units of
μ g/sample, with correction for concurrent labora tory recovery (if <100%) and for the overall average field fortification recovery for each specific matrix. Using the reported μ g/sample values (already corrected for concurrent laborato ry recovery), EPA calculated dermal exposures for each matrix in μ g/sample and μ g/hour with correction for s ite specific average field fortification values from each rec overy level (refer to Tables 6-11) . For all replicates, EPA used the nominal work duration of 4 hours. For values <LOQ, EPA used a value of 1⁄2 LOQ in calculations. It should be noted that one scouter on 1DAT6 droppe d out early because of heat exhaustion and was replaced with a new worker . EPA did not include the replicate which dropped out in summary calculations.

For scouts and hoers at all sites combined, the Registrant provided mean exposure ( μ g/sample) for each matrix, and summed the average exposures for the inner dosimeter, handwash, and face/neck wipes to obtain averag e total dermal exposure values for scouts and hoers on each reentry day. The Registrant did not calculate total dermal exposures per replicate.

On a per replicate basis, EPA cal culated total dermal exposure as the sum of the inner dosimeter, total head, and hand exposures, and potential derm al exposure as the sum of the inner dosimeter, outer dosimeter, total hea d, and hand exposures. The results are presented in Tables 18-21 in terms of transfer coefficients (μg/cm 2 

### ), and are summarized for each work er activity at each site.

Transfer coefficients are dermal expos ure (μg/hr) divided by the average DFR ( μ g/cm 2 

### ) on the reentry day. The average DFRs used for 0DAT6 and 1DAT6 intervals were 1.74 and 0.403
μ g/cm 2 

### at Site 1 (Cheraw, SC), 1.82 and 0.251 μ g/cm 2 

### at Site 2 (McFarlan, NC), and 2.48 and 1.54 μ g/cm 2 

### at Site 3 (Chesterfield, SC).

In addition to the adjustments and assumptions al ready discussed above (i .e. field fortificationPage 31 of 56 

### correction and use of 1⁄2 LOQ for values reported as <LOQ), the following procedures were used to calculate exposure values and transfer coefficients:

Pre-exposure values: Handwash and face/neck wipe samples were collected prior to and after the exposure event. Prior to the exposure event, residues in the handwash samples were <LOQ in 10 of 30 replicates and ranged from to 0.12 to 6.31 μg/sample in 20 of 30 replicates (0.04 to 39% of the post-exposure residues). For face/ neck wipe samples, residues were <LOQ (<0.05 μg/sample) in 12 of 30 replicates and range d from to 0.025 to 1.35 μg/sample in 18 of 30 replicates (0.34 to 58% of the pos t-exposure residues). The Regi strant subtracted out the preexposure residues from the post-exposure residu es to obtain net hand exposure values. EPA used only the post-exposure values in the calculation of hand exposure values. No explanation was provided for the detection of prof enofos in the pre-exposure samples.

Non-face/non-neck head exposure: No samples were collected from the non-face/non-neck regions of the head. Therefore, exposure fo r this area was estimated by extrapolating the face/neck wipe residue, value based on relativ e surface areas of the face/neck area that was wiped with the rest of the head that was not wi ped. An adjustment factor of 0.61 was applied to the face/neck residue to determine the non-face/non- neck reside. The factor was calculated as a ratio of the percent of total body surface area of the non-face/non-neck area to the face/neck area (2.95%/4.84% for males and 3.05%/5.01% for females). Total head exposure was calculated as the sum of the face/neck residue and the non-face/non-neck residue.

Method extraction adjustment: In order to a ccount for potential residue collection method inefficiencies for handwash and face/neck wipe field study measurements, the average contribution of hand and total head exposures to total dermal exposure wa s calculated across all workers in each statistical summary set. The fo llowing four sets requir ed an upward adjustment of the hand and total head exposure by a factor of 2 because the combined contribution of hand and total head exposure to total dermal exposur e fell within the range of 20 to 60%: Site 1 (Cheraw, SC) Scouters on 0DAT6, Site 2 (McFarlan, NC) Scouters on 0DAT6, Site 1 (Cheraw, SC) Hoers on 0DAT6, and Site 2 (McFarlan, NC ) Hoers on 0DAT6. The average measured exposure contribution from hands and total head contributed less than 20% for the other statistical summary sets, therefore no action was required for these sets.

Other issues to note include:

 The study did not specifically state which volun teer was assigned to which replicate. EPA assumed that each volunteer was a ssigned a unique replicate which remained consistent for each matrix collected from the volunteer.

 For the face/neck wipe samples at Site 1 (C heraw, SC) and 2 on 1DAT6, it appears that the study did not assign the correct worker activity to some of the samples. EPA used the worker activity assigned to the replicate for the other matrices.

 As noted in deviation no. 38, samples at Site 1 (Cheraw, SC) were labelled as Site 3 (Chesterfield, SC) and samples at Site 3 (C hesterfield, SC) were labelled as Site 1 (Cheraw, SC) for all dermal and inhalation samples.

 Handwash samples for replicate 4A (scouter at Site 3 (Chesterfield, SC) on 1DAT6) were divided into two 250 mL jars and analyzed separately. It appears that the studyPage 32 of 56 

### incorrectly used a volume of 500 mL to calcu late the residues in μg/sample for these samples. EPA used a volume of 250 mL to calculate the residues in μg/sample for these samples.

 One worker at Site 1 (Cheraw, SC) and Site 3 (Chesterfield, SC) on 1 DAT6 received a face/neck wipe with DSS and with water. Both samples were analyzed, and the results were combined.

Transfer coefficients are summarized in Tables 18-21. For scouters, average transfer coefficients for total dermal exposure were 176, 123, and 237 cm 2 

### /hr on 0DAT6 for Sites 1, 2, and 3, respectively, and 330, 318, and 293 cm 2 

### /hr on 1DAT6 for Sites 1, 2, and 3, respectively. For hoers, average transfer coefficients for total dermal exposure were 86.9, 96.9, and 200 cm 2 

### /hr on 0DAT6 for Sites 1, 2, and 3, respectively, and 192, 198, and 122 cm 2 

### /hr on 1DAT6 for Sites 1, 2, and 3, respectively.

Table 22 summarizes the distribu tion of residue on body parts. Based on average values of transfer coefficients for total dermal exposure, body parts with significant residues (i.e., >10%) were the arm, leg and hand. For scouters a nd hoers on 0DAT6, the average distribution was approximately 30% to the legs, arms, and hands each. A similar distribution was observed for hoers on 1DAT6 (legs, arms and hands each receiving an average of 24-33%). For scouter on 1DAT6, the majority of the distribution was on the legs (average of 59%), with 23% on the arms, and only 8.1% on the hands.

Table 23 summarizes the percent penetration from the outer to inner dosimeters. Average penetration was highest for the arms (29 to 40% ). Average penetrati on for the other regions ranged from 3.8 to 9.3%.

Inhalation: Profenofos values for inhalation samples were pres ented in the study in units of
μ g/sample, with correction for concurrent labora tory recovery (if <100%) and for overall average field fortification recovery. Air sorbent tube samples did no t require correction because all residues were <LOQ. Using the reported μ g/sample values (already corrected for concurrent laboratory recovery), EPA calcu lated air concentrations in μ g/m 3 

### and inhalation exposures in
μ g/hr, with correction for site spec ific average field fortification values from each recovery level (refer to Table 10 for air sorbent tubes and Table 11 for pre-loaded filter cassettes). For values <LOQ, EPA used a value of 1⁄2 LOQ in calculations. EPA summed the preloaded filter cassette and air sorbent tube residues to provide total profenofos residues. The airborne concentration of profenofos was then calculated by dividing the corrected total residue value by the total volume of air drawn by the personal sampler over the sa mpling duration. The air concentrations were then adjusted for the NAFTA recommended inhalation rate of 1.0 m 3 

### /hr (light activity) for scouters and 1.6 m 3 

### /hr (moderate activity) for hoers.

The results are shown in Table 24-25. For sc outers, average inhalation exposure was 5.48, 4.26, and 5.82 μg/hr on 0DAT6 for Sites 1, 2, and 3, respectively, and 2.05, 1.52, and 0.95 μg/hr on 1DAT6 for Sites 1, 2, and 3, respectively. For hoers, average inhalation exposure was 7.47, 6.24, and 7.83 μg/hr on 0DAT6 for Sites 1, 2, and 3, respectively, and 2.86, 2.21, and 2.28 μg/hr on 1DAT6 for Sites 1, 2, and 3, respectively.Page 33 of 56 

### Cotton Boll: Profenofos values for cotton boll sa mples (with and without carpel) were presented in the study in units of μ g/sample and in μ g/cm 2 

### with correction for concurrent laboratory recovery (if <100%). No field fortification re covery correction was applied. Using the reported
μ g/sample values (already corrected for concurrent laboratory recovery), EPA calculated values in ug/g (for cotton bolls only) and μ g/cm 2 

### with correction for site specific average field fortification values from each recovery level.

Table 26 provides a summary of the profenofos va lues for all sites. Residues were <LOQ in all cotton boll only samples collected at 44-70DAT6. In the boll+carpel samples collected at 35- 38DAT6, the average profenofos values were 0.0015 to 0.0025 μ g/cm 2



### .

III DISCUSSION:

A. LIMITATIONS OF THE STUDY:



### The following concerns are noted with respec t to the worker expos ure study (Series 875.2400 and 875.2500 Guidelines):

 Fifteen workers were monitored at each in terval; however, these were divided between all three sites and both worker types. On a per site basis, only three scouters and two hoers were monitored at each interval.

 The exact monitoring time for each worker re plicate was not provided. It was assumed for all calculations that each worker was monitored for the nominal 4 hour work duration.

 The following issues with fi eld fortification are noted:

o Single field fortification leve ls were used for handwash, face/neck wipe, air filter, and air sorbent tube samples.

o The average low level field fortificati on recoveries for the inner whole body dosimeters were 37.0-64.9%. No explanati on for the extremely low recoveries was provided.

o The fortification levels were not within range or did not bracket the field residues for the following matrices:

 For face/neck wipes, the fortification level (200 μg) was at least an order of magnitude higher than the residue levels detected in the post-exposure treated samples (0.446 to 25.8 μg).

 For inner dosimeters, the low fortific ation level (200 μg) was within the range of the treated samples (1.53 to 1,439 μg), but the high fortification level (20,000 μg) was an order of ma gnitude higher than the residue levels.

 For air filters, the fortification leve l (25 μg) was higher than the residue levels detected in the treated samples (0.083 to 1.61 μg).

 Profenofos residues were detected in handw ash and face/neck wipe sample collected prior to the exposure event. No explanat ion was provided for the presence of these residues. The study subtracted these resi dues out from the post-exposure samples.

 Profenofos residues were detected in dermal and inhalation field blank residues (up to 34xLOQ). The study states that residues were pr obably detected due to the proximity of the sample preparation area to the field being sprayed.

 For the face/neck wipe samples at Site 1 (C heraw, SC) and 2 on 1DAT6, it appears thatPage 34 of 56 

### the study did not assign the correct worker activity to some of the samples. EPA used the worker activity assigned to the replicate for the other matrices.

The following concerns were noted with resp ect to the DFR study (Series 875.2100 Guidelines):

 Only duplicate DFR samples were collected at each interval. The guidelines recommend the collection of triplicate DFR samples.

 Two field fortification levels were used (200 μg and 20,000 μg), as recommended in the EPA guidelines. The low fortification level wa s within range of the treated samples (0.80 to 1,434 μg), but the high fortification leve l was significantly hi gher than the treated samples.

 The EPA guidelines recommend a sample surface are of 400 cm 2 

### . In this study the total leaf surface was only 250 cm 2 

### , as reported in the main text of the study. It should also be noted that the study actually used a surface area of 227 cm 2 

### to calculate DFRs, based on a punch diameter of 1.7 cm. The Rabbit Tool we bsite (the manufacturer of Birkestrand punches) states that the 2.5 cm 2 

### punch has a diameter of 1.784 cm 2 

### , thus it appears that the surface area of 227 cm 2 

### is incorrect.Page 35 of 56 Table 14. Profenofos DFR Residues from Cotton Foliage Treated with Curacron® 8E – Site 1 (Cheraw, SC) 1
Sampling Interval (days) Measured Residue

( μ g) DFR ( μ g/cm 2 ) Corrected Residue Level 3 ( μ g/cm 2 ) Arithmetic Mean ( μ g/cm 2 ) Standard Deviation ( μ g/cm 2 ) Coefficient of Variance (%) Natural Log of Mean ( μ g/cm 2 ) Percent of Application Rate Dislodgeable 4
Pre App 1 1 0.004 0.00 0.00 0.002 62.6 -5.92 -- <LOQ 2 <0.003 0.0015

0DAT1 242 0.97 0.90 0.85 0.079 9.3 -0.16 6.3 212 0.85 0.79

0DAT2 764 3.06 2.86 2.57 0.407 15.9 0.94 18.6 610 2.44 2.28
Pre App 3 5.0 0.020 0.019 0.018 0.002 12.30 -4.02 0.13 4.2 0.017 0.016

0DAT3 598 2.39 2.24 2.19 0.058 2.7 0.79 16.6 576 2.30 2.15

0DAT4 446 1.78 1.67 1.56 0.159 10.2 0.44 14.0 386 1.544 1.44

0DAT5 900 3.60 3.36 2.83 0.761 26.9 1.04 26.5 612 2.45 2.29
Pre App 6 5.0 0.020 0.019 0.029 0.013 45.9 -3.55 0.27 9.8 0.039 0.038

0DAT6 424 1.70 1.59 1.74 0.217 12.5 0.55 16.3 506 2.02 1.89

1DAT6 82.4 0.330 0.308 0.403 0.134 33.2 -0.91 3.8 133 0.532 0.497

2DAT6 47 0.188 0.176 0.212 0.051 24.2 -1.55 2.0 66.4 0.266 0.248

3DAT6 14.2 0.0568 0.0551 0.0559 0.001 2.0 -2.88 0.53 14.6 0.0584 0.0567

7DAT6 6.6 0.0264 0.026 0.026 0.001 2.1 -3.65 0.24 6.8 0.0272 0.026

14DAT6 2.6 0.0104 0.0101 0.0097 0.001 5.7 -4.63 0.09 2.4 0.0096 0.0093

21DAT6 2 0.0080 0.0078 0.0089 0.002 18.4 -4.72 0.08 2.6 0.0104 0.0101

28DAT6 2.2 0.0088 0.0085 0.0078 0.001 14.1 -4.86 0.07 1.8 0.0072 0.0070

35DAT6 1.4 0.0056 0.0054 0.0047 0.001 23.6 -5.37 0.04 1.0 0.0040 0.0039 1. Six applications were made at a target rate of 1 lb ai/A/application (11.21 μg/cm 2 ). The actual application rate at the sixth application was 0.95 lb ai/A (10.6 μg/cm 2 ). 2. LOQ = 0.003 μg/cm 2 . Residues <LOQ were assigned a value of 1⁄2 LOQ for calculation purposes. 3. Residues were corrected for average field for tification recoveries. Residues <40.4 μg/cm 2 were corrected for 103% recovery. Residues >40.4 μg/cm 2 were corrected for 107%. 4. Percent of Original Applicati on Rate Dislodgeable = DFR (μg/cm 2 ) / Actual Amount applied (μg/cm 2 ) x 100%.Page 36 of 56 Table 15. Profenofos DFR Residues from Cotton Foliage Treated with Curacron® 8E – Site 2 (McFarlan, NC) 1
Sampling Interval (days) Measured Residue ( μ g) DFR ( μ g/cm 2 ) Corrected Residue Level 3 ( μ g/cm 2 ) Arithmetic Mean ( μ g/cm 2 ) Standard Deviation ( μ g/cm 2 ) Coefficient of Variance (%) Natural Log of Mean ( μ g/cm 2 ) Percent of Application Rate Dislodgeable 4
Pre App 1 <LOQ 2 <0.003 0.0015 0.00150 0.000 0.000 -6.50 -- <LOQ <0.003 0.0015

0DAT1 506 2.02 1.93 1.84 0.124 6.7 0.61 15.1 460 1.84 1.75

0DAT2 660 2.64 2.51 3.99 2.08 52.3 1.38 29.7 1434 5.74 5.46
Pre App 3 4.6 0.018 0.016 0.014 0.004 30 -4.30 0.10 3.0 0.012 0.011

0DAT3 562 2.25 2.14 1.98 0.221 11.1 0.69 15.0 480 1.92 1.83

0DAT4 1050 4.20 4.00 3.95 0.065 1.6 1.37 35.6 1026 4.10 3.91

0DAT5 444 1.78 1.69 1.48 0.302 20.4 0.39 13.3 332 1.33 1.26
Pre App 6 7.2 0.029 0.026 0.026 0.001 1.9 -3.65 0.23 7.4 0.030 0.026

0DAT6 468 1.87 1.78 1.82 0.054 3.0 0.60 17.1 488 1.95 1.86

1DAT6 72.2 0.289 0.275 0.251 0.034 13.8 -1.38 2.4 59.4 0.238 0.226

2DAT6 16.6 0.0664 0.0593 0.0539 0.008 14.0 -2.92 0.51 13.6 0.0544 0.0486

3DAT6 10.4 0.042 0.037 0.038 0.002 4.0 -3.26 0.36 11 0.044 0.039

7DAT6 6.8 0.027 0.024 0.021 0.005 21.6 -3.86 0.20 5 0.020 0.018

14DAT6 2.2 0.0088 0.0079 0.0089 0.002 17.0 -4.72 0.08 2.8 0.011 0.0100

21DAT6 2.2 0.0088 0.0079 0.010 0.004 34.1 -4.57 0.10 3.6 0.014 0.0129

28DAT6 1.4 0.0056 0.0050 0.0050 0.000 0.0 -5.30 0.05 1.4 0.0056 0.0050

35DAT6 1.2 0.0048 0.0043 0.0046 0.001 10.9 -5.37 0.04 1.4 0.0056 0.0050 1. Six applications were made at a target rate of 1 lb ai/A/application (11.21 μg/cm 2 ). The actual application rate at the sixth application was 0.95 lb ai/A (10.6 μg/cm 2 ). 2. LOQ = 0.003 μg/cm 2 . Residues <LOQ were assigned a value of 1⁄2 LOQ for calculation purposes. 3. Residues were corrected for average field for tification recoveries. Residues <40.4 μg/cm 2 were corrected for 112% recovery. Residues >40.4 μg/cm 2 were corrected for 105%. 4. Percent of Original Applicati on Rate Dislodgeable = DFR (μg/cm 2 ) / Actual Amount applied (μg/cm 2 ) x 100%.Page 37 of 56 Table 16. Profenofos DFR Residues from Cotton Foliage Treated with Curacron® 8E – Site 3 (Chesterfield, SC) 1
Sampling Interval (days) Measured Residue ( μ g) DFR ( μ g/cm 2 ) Corrected Residue Level 3 ( μ g/cm 2 ) Arithmetic Mean ( μ g/cm 2 ) Standard Deviation ( μ g/cm 2 ) Coefficient of Variance (%) Natural Log of Mean ( μ g/cm 2 ) Percent of Application Rate Dislodgeable 4

Pre 1 <LOQ 2 <0.003 0.0015 0.00150 0.000 0.000 -6.50 -- <LOQ <0.003 0.0015

0DAT1 384 1.54 1.61 1.44 0.244 16.9 0.37 11.5 302 1.21 1.27

0DAT2 756 3.02 3.18 2.78 0.559 20.1 1.02 22.2 568 2.27 2.39

Pre 3 7.4 0.030 0.034 0.050 0.022 43.6 -3.00 0.40 14 0.056 0.065

0DAT3 816 3.26 3.43 3.06 0.517 16.9 1.12 22.8 642 2.57 2.70

0DAT4 1114 4.46 4.68 4.36 0.458 10.5 1.47 32.9 960 3.84 4.03

0DAT5 1156 4.62 4.86 5.19 0.475 9.2 1.65 44.5 1316 5.26 5.53
Pre App 6 13.2 0.053 0.061 0.068 0.009 13.6 -2.69 0.58 16 0.064 0.074

0DAT6 444 1.78 1.87 2.48 0.868 35.0 0.91 23.3 736 2.94 3.09

1DAT6 362 1.45 1.52 1.54 0.024 1.5 0.43 14.4 370 1.48 1.55

2DAT6 42.6 0.17 0.179 0.179 0.001 0.3 -1.72 1.7 42.4 0.17 0.178

3DAT6 15.2 0.0608 0.070 0.072 0.002 2.7 -2.63 0.67 15.8 0.0632 0.073

7DAT6 2.0 0.0080 0.0093 0.010 0.001 12.9 -4.59 0.10 2.4 0.0096 0.011

14DAT6 2.2 0.0088 0.0102 0.0125 0.003 26.2 -4.38 0.12 3.2 0.013 0.0148

21DAT6 1.2 0.0048 0.0056 0.0056 0.000 0.0 -5.19 0.05 1.2 0.0048 0.0056

28DAT6 1.2 0.0048 0.0056 0.0060 0.001 10.9 -5.11 0.06 1.4 0.0056 0.0065

35DAT6 1.6 0.0064 0.0074 0.0056 0.003 47.1 -5.19 0.05 0.8 0.0032 0.0037 1. Six applications were made at a target rate of 1 lb ai/A/application (11.21 μg/cm 2 ). The actual application rate at the sixth application was 0.95 lb ai/A (10.6 μg/cm 2 ). 2. LOQ = 0.003 μg/cm 2 . Residues <LOQ were assigned a value of 1⁄2 LOQ for calculation purposes. 3. Residues were corrected for average field for tification recoveries. Residues <40.4 μg/cm 2 were corrected for 86.3% recovery. Residues >40.4 μg/cm 2 were corrected for 95.2%. 4. Percent of Original Applicati on Rate Dislodgeable = DFR (μg/cm 2 ) / Actual Amount applied (μg/cm 2 ) x 100%.Table 18. Summary of Transfer Coefficient’s for Scouters on the Day of Last Treatment (0DAT6)1, 2SiteReplicateTransfer Coefficients3(cm2/hr)Outer DosimeterInner DosimeterTotalHead4, 5Hand5TotalDermal6PotentialDermal7ArmBackTorsoFrontTorsoLegTotal OuterDosimeterArmBackTorsoFrontTorsoLegTotal InnerDosimeter11 113 134 161 2,649 3,057 25.6 10.2 11.3 42.9 90.0 12.53 90.1 193 3,2492 133 218 136 1,688 2,175 28.0 10.213.3 48.3 100 5.89 51.7 157 2,3325 68 134 165 2,380 2,747 38.0 6.149.79 78.9 133 3.91 41.9 179 2,925Average 104 162 154 2,239 2,660 30.6 8.85 11.4 56.7 108 7.44 61.2 176 2,836SD 33.1 48.9 15.5 496 447 6.59 2.341.76 19.4 22.5 4.52 25.4 17.7 465GM 101 157 154 2,199 2,633 30.1 8.6211.4 54.7 106 6.61 58.0 176 2,80921 280 91 238 2,108 2,718 49.7 3.4 12.5 33.2 98.8 11.66 104.5 215 2,9332 64 6.63 69.1 1,020 1,160 15.1 1.283.48 14.8 34.7 3.47 32.9 71.1 1,2315 67 48.8 50.2 909 1,075 26.1 2.71 5.94 27.6 62.4 3.13 18.3 83.8 1,159Average 137 48.8 119 1,346 1,651 30.3 2.467.30 25.2 65.3 6.09 51.9 123 1,774SD 124 42.2 103 663 925 17.7 1.07 4.659.46 32.2 4.83 46.2 79.7 1,004GM 107 30.9 93.8 1,250 1,502 27.0 2.276.37 23.8 59.8 5.02 39.8 109 1,61131 200 147 219 1,657 2,223 188 13.0 11.2 70.6 282 5.43 39.3 327 2,5502 108 121 163 1,195 1,587 82.3 13.010.5 76.7 182 2.21 33.4 218 1,8055 88 98.4 76.7 713 976 57.4 5.58 6.54 69.1 139 1.42 26.1 166 1,142Average 132 122 153 1,188 1,595 109 10.59.43 72.1 201 3.02 32.9 237 1,832SD 59.4 24.1 71.8 472 623 69.1 4.28 2.53 4.05 73.8 2.13 6.6 82.3 704GM 124 121 140 1,122 1,510 96.1 9.809.17 72.1 193 2.57 32.4 228 1,7391.Six applications were made at a target rate of 1 lb ai/A/application.2. LOQ = 1 μg/sample for outer and inner dosimeters, 0.05 μg/sample for face/neck wipes, 0.00015 μg/mL (or 0.08 μg/sample for a500 mL sample) for handwash.3. Transfer Coefficient (cm2/hr) = (Corrected residue (μg) / Time worked (hr)) / Average DFR on day of reentry. Refer toassociated spreadsheet created byreviewer for corrected residue andexposure values for each matrix. Residues were corrected for the average field fortification valuesshown in Tables 6-9. If two fortification levels were used, the midpoint between the fortificationlevels was used as the threshold for determining which recoveryto use. The time worked for each replicate was 4 hours. The average DFR on the day of reentry (0DAT6) was 1.74 μg/cm2for Site1 (Cheraw, SC), 1.82 μg/cm2for Site 2 (McFarlan, NC), and 2.48 μg/cm2for Site 3 (Chesterfield, SC).4. Total head includes exposure to theface/neck areas and the non-face/non-neck areas of the head. Since exposure to the non-face/non-neck portions of the head was not measured, residues from theface/neck wipes were extrapolatedto the non-face/non-neck portions of the head by applying a factor of 0.61. This factor is the ratio of the % of total body surface area of thenon-face/non-neckportion to the face/neck portion of the head for males and females.5. For Site 1 (Cheraw, SC) and 2, thehead and hand exposure values were adjustedupward by a factor of 2 for method efficiency because measured exposure contribution from hands and head fell inthe range of 20 to 60% of total.This adjustment was not neededfor Site 3 (Chesterfield, SC)because measured exposures were<20%.6. Total Dermal is the sum of inner dosimeters, hands, and head. The scenario represents a worker wearing a single layer of clothing (long pants and long shirt) and no gloves, goggles, face masks, orrespirators.7. Potential Dermal is the sum of outerdosimeters, inner dosimeters, hands, and head. The scenario represents a worker wearing no clothing or personal protective equipment.Page 39 of 56Table 19. Summary of Transfer Coefficient’s for Scouters on 24 hours After Last Treatment (1DAT6)SiteReplicateTransfer Coefficients3(cm2/hr)Outer DosimeterInner DosimeterTotalHead4, 5Hand5TotalDermal6PotentialDermal7ArmBackTorsoFrontTorsoLegTotalOuterDosimeterArmBackTorsoFrontTorsoLegTotal InnerDosimeter11 113 134 161 2,649 3,057 25.6 10.2 11.3 42.9 90.0 17.04 93.0 476 6,5583 133 218 136 1,688 2,175 28.0 10.213.3 48.3 100 5.15 10.4 170 1,5134 120 166 217 1635 2,138 107 19.3 12.3 170 308 5.09 30.4 344 2,481Average 170 374 442 2,201 3,188 108 21.7 15.2 131 276 9.09 44.6 330 3,517SD 160 371 444 1,571 2,538 52.3 15.89.44 44.4 110 6.88 43.1 154 2,678GM 120 274 318 1,861 2,594 99.2 17.6 13.4 125 259 7.65 30.8 303 2,90923 132 181 204 6162 6,680 19.6 8.98 5.72 108 143 2.68 24.1 169 6,8494 166 335 542 12,169 13,212 57.6 12.511.3 526 608 6.95 57.0 672 13,8835 60.6 69.6 85.0 2125 2,341 20.4 5.115.05 72.6 103 0.75 9.50 113 2,454Average 120 195 277 6,819 7,411 32.5 8.887.37 236 285 3.46 30.20 318 7,729SD 53.9 133 237 5,054 5,472 21.7 3.723.45 252 281 3.18 24.35 308 5,765GM 110 162 211 5,422 5,911 28.5 8.326.89 160 208 2.41 23.54 235 6,15733 16.7 42 37 467 563 47.8 5.21 4.18 70.9 128 2.09 10.9 141 7044 (excluded)922.8 54.6 61.5 296 435 23.5 4.425.61 66.3 100 2.45 4.58 107 5424A 5.5 7.08 87.8 65.1 166 6.37 0.7600.654 10.4 18.2 0.17 0.47 18.8 1845 86.5 165 380 2907 3,539 46.1 16.0 36.5 615 713 1.77 5.19 720 4,260Average 36.2 71.5 168 1,146 1,423 33.57.33 13.8 232 287 1.34 5.52 293 1,716SD 43.9 83.2 185 1,538 1,844 23.5 7.85 19.8 333 374 1.03 5.22 375 2,218GM 20.0 36.6 107 445 691 24.1 3.994.64 76.8 118 0.86 2.98 124 8211.Six applications were made at a target rate of 1 lb ai/A/application.2. LOQ = 1 μg/sample for outer and inner dosimeters, 0.05 μg/sample for face/neck wipes, 0.00015 μg/mL (or 0.08 μg/sample for a500 mL sample) for handwash.3. Transfer Coefficient (cm2/hr) = (Corrected residue (μg) / Time worked (hr)) / Average DFR on day of reentry. Refer toassociated spreadsheet created byreviewer for corrected residue andexposure values for each matrix. Residues were corrected for the average field fortification valuesshown in Tables 6-9. If two fortification levels were used, the midpoint between the fortificationlevels was used as the threshold for determining which recoveryto use. The time worked for each replicate was 4 hours. The average DFR on the day of reentry (1DAT6) was 0.40 μg/cm2for Site1 (Cheraw, SC), 0.251 μg/cm2for Site 2 (McFarlan, NC), and 1.54 μg/cm2for Site 3 (Chesterfield, SC).4. Total head includes exposure to theface/neck areas and the non-face/non-neck areas of the head. Since exposure to the non-face/non-neck portions of the head was not measured, residues from theface/neck wipes were extrapolatedto the non-face/non-neck portions of the head by applying a factor of 0.61. This factor is the ratio of the % of total body surface area of thenon-face/non-neckportion to the face/neck portion of the head for males and females.5. Method efficiency adjustments were not needed because measured exposure contribution from hands and head were <20% of total for all sites.6. Total Dermal is the sum of inner dosimeters, hands, and head. The scenario represents a worker wearing a single layer of clothing (long pants and long shirt) and no gloves, goggles, face masks, orrespirators.7. Potential Dermal is the sum of outerdosimeters, inner dosimeters, hands, and head. The scenario represents a worker wearing no clothing or personal protective equipment.8.It appears that the study incorrectly assigned the worker activity for face/neck wipereplicates at Sites 1 and 2 on 1DAT6. The reviewer assumed that the samplenumbers for all matrices should beconsistent between matrices. Specifically, at Site 1 (Cheraw, SC) and Site 2 (McFarlan, NC), the study assigned replicates 3 and 4 as hoers, but the reviewer assumed these are actually scouterreplicates.9. Replicate 4 at Site 3 (Chesterfield,SC) dropped out due to heat exhaustion, and was replaces with replicate 4A. Replicate4 was not used in statistical summaries of the data.Page 40 of 56Table 20. Summary of Transfer Coefficient’s for Hoers on the Day of Last Treatment (0DAT6)SiteReplicateTransfer Coefficients3(cm2/hr)Outer DosimeterInner DosimeterTotalHead4, 5Hand5TotalDermal6PotentialDermal7ArmBackTorsoFrontTorsoLegTotalOuterDosimeterArmBackTorsoFrontTorsoLegTotal InnerDosimeter13 62.6 107 156 254 580 25.7 1.99 7.924.83 40.4 1.97 49.0 91.4 6714 46.6 108 160 956 1,271 13.5 6.53 6.4529.8 56.3 3.86 22.2 82.5 1,354Average 54.6 107 158 605 926 19.6 4.26 7.18 17.3 48.4 2.915 35.6 86.9 1,012GM 54.0 107 158 493 858 18.7 3.61 7.15 12.0 47.7 2.757 33.0 86.8 95323 86.2 48.2 245 843 1,223 46.0 2.21 5.72 12.7 66.7 0.750 27.2 94.6 1,3174 68.8 52.7 48.5 888 1,058 13.6 2.70 5.64 36.3 58.2 1.769 39.1 99.1 1,157Average 77.5 50.4 147 866 1,140 29.8 2.465.68 24.5 62.4 1.260 33.2 96.9 1,237GM 77.0 50.4 109 865 1,137 25.0 2.44 5.68 21.5 62.3 1.152 32.6 96.8 1,23533 98.3 95.8 118 1231 1,543 79.9 14.410.8 71.4 177 2.05 48.1 227 1,7704 81.8 87.1 89.1 958 1,216 37.0 7.966.91 102 154 3.58 16.1 173 1,389Average 90.0 91.5 103 1,095 1,379 58.511.2 8.86 86.7 165 2.82 32.1 200 1,580GM 89.7 91.4 102 1,086 1,370 54.4 10.7 8.64 85.3 165 2.71 27.8 198 1,5681. Six applications were made at a target rate of 1 lb ai/A/application.2. LOQ = 1 μg/sample for outer and inner dosimeters, 0.05 μg/sample for face/neck wipes, 0.00015 μg/mL (or 0.08 μg/sample for a500 mL sample) for handwash.3. Transfer Coefficient (cm2/hr) = (Corrected residue (μg) / Time worked (hr)) / Average DFR on day of reentry. Refer toassociated spreadsheet created byreviewer for corrected residue andexposure values for each matrix. Residues were corrected for the average field fortification valuesshown in Tables 6-9. If two fortification levels were used, the midpoint between the fortificationlevels was used as the threshold for determining which recoveryto use. The time worked for each replicate was 4 hours. The average DFR on the day of reentry (0DAT6) was 1.74 μg/cm2for Site1 (Cheraw, SC), 1.82 μg/cm2for Site 2 (McFarlan, NC), and 2.48 μg/cm2for Site 3 (Chesterfield, SC).4. Total head includes exposure to theface/neck areas and the non-face/non-neck areas of the head. Since exposure to the non-face/non-neck portions of the head was not measured, residues from theface/neck wipes were extrapolatedto the non-face/non-neck portions of the head by applying a factor of 0.61. This factor is the ratio of the % of total body surface area of thenon-face/non-neckportion to the face/neck portion of the head for males and females.5. For Site 1 (Cheraw, SC) and 2, thehead and hand exposure values were adjustedupward by a factor of 2 for method efficiency because measured exposure contribution from hands and head fell inthe range of 20 to 60% of total.This adjustment was not neededfor Site 3 (Chesterfield, SC)because measured exposures were<20%.6. Total Dermal is the sum of inner dosimeters, hands, and head. The scenario represents a worker wearing a single layer of clothing (long pants and long shirt) and no gloves, goggles, face masks, orrespirators.7. Potential Dermal is the sum of outerdosimeters, inner dosimeters, hands, and head. The scenario represents a worker wearing no clothing or personal protective equipment.Page 41 of 56Table 21. Summary of Transfer Coefficient’s for Hoers on 24 hours After Last Treatment (1DAT6)SiteReplicateTransfer Coefficients (cm2/hr)Outer DosimeterInner DosimeterTotal HeadHandTotalDermalPotentialDermalArmBackTorsoFrontTorsoLegTotalOuterDosimeterArmBackTorsoFrontTorsoLegTotal InnerDosimeter12 238 404 257 933 1,833 71.3 11.4 10.8 15.0 108 6.18 102.6 217 2,0505 81.6 140 263 772 1,257 45.4 15.7 17.1 39.0 117 3.81 45.2 166 1,424Average 160 272 260 853 1,545 58.3 13.613.9 27.0 113 5.00 73.9 192 1,737GM 139 238 260 849 1,518 56.9 13.4 13.6 24.2 113 4.86 68.1 190 1,70821 98.8 112 178 1379 1,767 33.8 10.5 14.4 162.7 221 4.09 32.1 258 2,0252 89.9 152 130 1118 1,490 20.9 3.53 10.82.58 37.8 6.03 93.7 137.5 1,627Average 94 132 154 1,248 1,629 27.3 7.01 12.6 82.6 130 5.06 62.9 198 1,826GM 94 130 152 1,241 1,623 26.5 6.0912.5 20.5 91.5 4.97 54.9 188 1,81531 77.0 55.2 39.2 341 513 61.9 3.694.91 48.7 119 0.731 4.76 125 6372 55.4 44.1 43.1 142 284 73.1 5.2110.6 12.0 101 1.96 16.2 119 403Average 66.2 49.7 41.2 241 398 67.5 4.45 7.73 30.3 110 1.35 10.5 122 520GM 65.3 49.4 41.1 220 382 67.3 4.387.20 24.1 110 1.20 8.78 122 5071. Six applications were made at atarget rate of 1 lb ai/A/application.2. LOQ = 1 μg/sample for outer and inner dosimeters, 0.05 μg/sample for face/neck wipes, 0.00015 μg/mL (or 0.08 μg/sample for a500 mL sample) for handwash.3. Transfer Coefficient (cm2/hr) = (Corrected residue (μg) / Time worked (hr)) / Average DFR on day of reentry. Refer toassociated spreadsheet created byreviewer for corrected residue andexposure values for each matrix. Residues were corrected for the average field fortification valuesshown in Tables 6-9. If two fortification levels were used, the midpoint between the fortificationlevels was used as the threshold for determining which recoveryto use. The time worked for each replicate was 4 hours. The average DFR on the day of reentry (1DAT6) was 0.40 μg/cm2for Site1 (Cheraw, SC), 0.251 μg/cm2for Site 2 (McFarlan, NC), and 1.54 μg/cm2for Site 3 (Chesterfield, SC).4. Total head includes exposure to theface/neck areas and the non-face/non-neck areas of the head. Since exposure to the non-face/non-neck portions of the head was not measured, residues from theface/neck wipes were extrapolatedto the non-face/non-neck portions of the head by applying a factor of 0.61. This factor is the ratio of the % of total body surface area of thenon-face/non-neckportion to the face/neck portion of the head for males and females.5. Method efficiency adjustments were not needed because measured exposure contribution from hands and head were <20% of total for all sites.6. Total Dermal is the sum of inner dosimeters, hands, and head. The scenario represents a worker wearing a single layer of clothing (long pants and long shirt) and no gloves, goggles, face masks, orrespirators.7. Potential Dermal is the sum of outerdosimeters, inner dosimeters, hands, and head. The scenario represents a worker wearing no clothing or personal protective equipment.8. It appears that the study incorrectlyassigned the worker activityfor face/neck wipe replicates at Sites 1 and 2 on 1DAT6. The reviewer assumed that the sample numbers for all matrices should beconsistent between matrices. Specifically, replicates 2 and 5 atSite 1 (Cheraw, SC) and replicates 1 and 2 at Site 2 (McFarlan, NC) were assigned as scouters, but the reviewer assumed these areactually hoer replicates.Page 42 of 56 Table 22. Distribution (Percent) of Total Exposure

Site Statistic Arm Back Torso Front Torso Leg Total Inner Dosimeter Face/Neck Hand

Scouters on 0DAT6 1 Average 17.5 5.1 6.6 32.4 61.5 4.14 34.4 2 Average 25.2 2.2 5.9 23.1 56.4 4.68 38.9 3 Average 43.2 4.4 4.1 32.8 84 1.18 14.3

All Sites Combined Average 28.6 3.9 5.5 29.4 67.5 3.33 29.2 Standard Deviation 13.4 1. 7 1.5 10.0 16.7 2.03 14.8 Scouters on 1DAT6 1 Average 32.8 6.0 4.5 42.5 86 2.70 11.5 2 Average 12.7 3.9 3.2 68.8 88.5 1.09 10.4 3 Average 24.0 3.5 4.2 63 95.0 1.24 3.8

All Sites Combined Average 23.3 4.4 4.0 58.7 90.3 1.63 8.1 Standard Deviation 11.4 1. 8 1.2 15.9 6.2 1.05 5.5 Hoers on 0DAT6 1 Average 22.3 5.0 8.2 20.7 56.3 3.42 40.3 2 Average 31.2 2.5 5.9 25.0 64.6 1.29 34.1 3 Average 28.3 5.5 4.4 45.1 83.3 1.48 15.2

All Sites Combined Average 27.3 4.4 6.2 30.3 68.1 2.06 29.9 Standard Deviation 13.1 2. 4 1.8 18.9 15.4 1.41 15.3 Hoers on 1DAT6 1 Average 30.1 7.4 7.6 15.2 60 2.57 37.2 2 Average 14.1 3.3 6.7 32.5 56.7 2.99 40.3 3 Average 55.5 3.7 6.4 25 90 1.12 8.7

All Sites Combined Average 33.2 4.8 6.9 24 69 2.22 28.7 Standard Deviation 19.1 2. 5 2.5 23.4 25.8 1.30 24.5

Table 23. Penetration (Percent) from Outer to Inner Dosimeter

Site Statistic Arm Back Torso Front Torso Leg Average

Scouters on 0DAT6 1 Average 23.9 5.3 7.0 2.5 9.7 2 Average 23.9 5.3 7.0 2.5 9.5 3 Average 42.6 7.6 6.6 6.9 15.9

All Sites Combined Average 29.1 7.1 6.8 3.8 11.7 Standard Deviation 12.0 3.9 1.9 2.5 3.7 Scouters on 1DAT6 1 Average 45.5 6.5 4.2 6.8 15.8 2 Average 45.5 6.5 4.2 6.8 8.2 3 Average 54.1 9.9 6.5 14.8 21.3

All Sites Combined Average 40.3 7.1 4.7 8.2 15.1 Standard Deviation 19.2 2.9 3.1 5.6 6.8 Hoers on 0DAT6 1 Average 25.8 3.8 4.3 2.4 9.1 2 Average 25.8 3.8 4.3 2.4 9.8 3 Average 38.0 10.7 7.8 7.5 16.0

All Sites Combined Average 29.8 6.4 6.2 4.2 11.7 Standard Deviation 9.8 3.9 3.1 3.0 3.7 Hoers on 1DAT6 1 Average 29.4 6.4 5.1 3.2 11.0 2 Average 29.4 6.4 5.1 3.2 10.1 3 Average 50.7 8.4 15.4 10.1 21.2

All Sites Combined Average 34.1 6.7 9.3 6.2 14.1 Standard Deviation 14.6 3.6 5.6 4.9 6.3Page 43 of 56Table 24. Inhalation Exposure (μg /hr) for Scouters Based on Residue Levels Found onPre-loaded Filter Cassettes and Air Sampling Tubes1, 2SiteReplicateFilter ResiduesAir Sorbent TubeResiduesTotalCorrected AirResidues4(μg)ActualSampleVolume5(L)Air Conc.6(μg/m3)Vent.Rate7(m3/min)Inhalation Exposure8(μg/hr)Measured(μg)Corrected3(μg)Measured(μg)Corrected3(μg)Per replicateAverageStandardDeviation0DAT611 1.61 1.68 <0.1 0.050 1.73 262.28 6.60 0.0167 6.605.48 0.982 1.12 1.17 <0.1 0.050 1.22 256.90 4.75 0.0167 4.755 1.12 1.17 <0.1 0.050 1.22 239.40 5.09 0.0167 5.0921 1.35 1.39 <0.1 0.050 1.44 248.30 5.79 0.0167 5.794.26 1.332 0.777 0.799 <0.1 0.050 0.849 244.40 3.48 0.0167 3.485 0.483 0.497 <0.1 0.050 0.547 155.70 3.51 0.0167 3.5131 1.32 1.63 <0.1 0.050 1.68 253.75 6.62 0.0167 6.625.82 1.782 1.26 1.56 <0.1 0.050 1.61 227.24 7.07 0.0167 7.075 0.731 0.902 <0.1 0.050 0.952 251.74 3.78 0.0167 3.781DAT611 0.408 0.580 <0.1 0.050 0.630 257.85 2.44 0.0167 2.442.05 0.363 0.328 0.466 <0.1 0.050 0.516 259.35 1.99 0.0167 1.994 0.270 0.384 <0.1 0.050 0.434 251.90 1.72 0.0167 1.7223 0.317 0.362 <0.1 0.050 0.412 274.40 1.50 0.0167 1.501.52 0.414 0.426 0.486 <0.1 0.050 0.536 277.20 1.93 0.0167 1.935 0.195 0.223 <0.1 0.050 0.273 245.00 1.11 0.0167 1.1133 0.359 0.355 <0.1 0.050 0.405 295.00 1.37 0.0167 1.370.95 0.41490.092 0.091 <0.1 0.050 0.141 100.50 1.40 0.0167 1.404A 0.083 0.082 <0.1 0.050 0.132 241.00 0.548 0.0167 0.555 0.262 0.259 <0.1 0.050 0.309 338.80 0.913 0.0167 0.911.Six applications were made at a target rate of 1 lb ai/A/application.2.LOQ = 0.1 μg. Residues <LOQ were assigneda value of 1⁄2 LOQ for calculation purposes.3.0DAT6: Site 1 (Cheraw, SC), 2, and 3 residues from the pre-loaded filter cassetteswere corrected for average field fortification recoveries of 95.8%, 97.2%, and 81.0%, respectively.1DAT6: Site 1 (Cheraw, SC), 2, and 3 residues from the pre-loaded filter cassetteswere corrected for average field fortification recoveries of 70.4%, 87.6%, and 101%, respectively. TotalCorrected Air Residues (μg) = correctedpre-loaded filter cassettes (μg) + corrected air sampling tube residues (μg)4.The actual air sample volume was reported, but actual air flow rates and durations were not reported. The nominal air flow rate was 1 L/min. The nominal duration was 4 hours.5.Concentration (μg/m3) = Residue (μg)/[Flow rate (L/min) x Duration (min)] x 1000 (L/m3)6.The NAFTA ventilation rate is for light activities.7.Inhalation Exposure (μg/hr) = Concentration (μg/m3) x Ventilation Rate (0.0167 m3/min) x 60 minutes/hr8.Replicate 4 at Site 3 (Chesterfield, SC) dropped out due to heatexhaustion, and was replaces with replicate 4A. Replicate 4was not used in statistical summaries of the data.Page 44 of 56Table 25. Inhalation Exposure (μg /hr) for Hoers Based on Residue Levels Found onPre-loaded Filter Cassettes and Air Sampling Tubes1, 2.SiteReplicateFilter ResiduesAir Sorbent Tube ResiduesTotalCorrected AirResidues4(μg)ActualSampleVolume5(L)Air Conc.6(μg/m3)Vent. Rate7(m3/min)Inhalation Exposure8(μg/hr)Measured(μg)Corrected3(μg)Measured(μg)Corrected3(μg)Per replicateAverage0DAT613 1.14 1.19 <0.1 0.050 1.24 240.56 5.15 0.0267 8.257.474 0.912 0.952 <0.1 0.050 1.00 239.32 4.19 0.0267 6.7023 0.901 0.927 <0.1 0.050 0.977 242.57 4.03 0.0267 6.446.244 0.879 0.904 <0.1 0.050 0.954 252.73 3.78 0.0267 6.0433 1.03 1.27 <0.1 0.050 1.32 242.59 5.45 0.0267 8.727.834 0.952 1.18 <0.1 0.050 1.23 282.15 4.34 0.0267 6.951DAT612 0.341 0.484 <0.1 0.050 0.534 260.72 2.05 0.0267 3.282.865 0.232 0.330 <0.1 0.050 0.380 248.43 1.53 0.0267 2.4421 0.268 0.306 <0.1 0.050 0.356 279.39 1.27 0.0267 2.042.212 0.309 0.353 <0.1 0.050 0.403 269.66 1.49 0.0267 2.3931 0.301 0.298 <0.1 0.050 0.348 267.00 1.30 0.0267 2.092.282 0.401 0.397 <0.1 0.050 0.447 289.08 1.55 0.0267 2.471. Six applications were made at a target rate of 1 lb ai/A/application.2. LOQ = 0.1 μg. Residues <LOQ were assigned a value of 1⁄2 LOQ for calculation purposes.3. 0DAT6: Site 1 (Cheraw, SC), 2, and 3 residues from the pre-loaded filter cassettes were corrected for average field fortification recoveries of 95.8%, 97.2%, and 81.0%, respectively. 1DAT6: Site1 (Cheraw, SC), 2, and 3 residues from the pre-loaded filter cassettes were corrected for average field fortification recoveries of 70.4%, 87.6%, and 101%, respectively.4. Total Corrected Air Residues (μg) = corrected pre-loaded filter cassettes (μg) +corrected air sampling tube residues (μg)5. The actual air sample volume was reported, but actual air flowrates and durations were not reported. The nominal air flowrate was 1 L/min. The nominal duration was 4 hours.6. Concentration (μg/m3) = Residue (μg)/Sample volume (L) * 1000 L/m37. The NAFTA ventilation rate is for light activities.8. Inhalation Exposure (μg/hr) = Concentration (μg/m3) x Ventilation Rate (0.0167 m3/min) x 60 minutes/hrPage 45 of 56 Table 26. Profenofos Residues from Co tton Bolls Treated with Curacron® 8E 1,2

Site Sampling Interval (days) Matrix Measured Residue

(μg) Dislodgeable Residue 3 Corrected Dislodgeable

Residue 4 Arithmetic Mean Percent of Application Rate Dislodgeable (ug/g) (μg/cm 2 ) (ug/g) (μg/cm 2 ) (ug/g) (μg/cm 2 )

1 35 Boll + carpel 1.25 NA 0.0021 NA 0.0019 NA 0.0021 0.019 1.5 0.0026 0.0023

61 Boll only <0.75 0.52 0.0015 0.26 0.00075 0.26 0.0007 0.007 <0.75 0.52 0.0015 0.26 0.00075

2 38 Boll + carpel 1.75 NA 0.0030 NA 0.0025 NA 0.0025 0.023 1.75 0.0030 0.0025

44 Boll only <0.75 0.52 0.0015 0.26 0.00075 0.26 0.0007 0.007 <0.75 0.52 0.0015 0.26 0.00075

3 36 Boll + carpel 1.25 NA 0.0021 NA 0.0024 NA 0.0015 0.013 <0.75 0.0013 0.00064

70 Boll only <0.75 0.52 0.0015 0.26 0.00075 0.26 0.0007 0.007 <0.75 0.52 0.0015 0.26 0.00075 1. Six applications were made at a target rate of 1 lb ai/A/application (11.21 μg/cm 2 ). 2. LOQ = 0.75 μg. Residues <LOQ were assigne d a value of 1⁄2 LOQ for calculation purposes. 3. Dislodgeable Residue (ug/g) = Measured residue (ug) / Mean cotton boll weight (g). The mean cotton boll weight was determi ned to be 1.44 g. Dislodgeable Residue (μg/cm 2 ) = Measured residue (μg) / Surface Area of Sample (cm 2 ). The surface areas were determined to be 586 cm 2 for boll + carpel and 503 cm 2 for boll only. 4. Residues were corrected for the low level average field for tification recovery for boll+carpe l or boll only, specifically. The Site 1 (Cheraw, SC), 2, and 3 boll +carpel residues were co rrected for recoveries of 112, 118, and 90. 5% recovery, respectively. No other samp les required correction because residues <LOQ were not corrected. 5. Percent of Original Application Ra te Dislodgeable = Dislodgeble residue (μg/cm 2 ) / Amount applied (μg/cm 2 ) x 100%.Page 46 of 56 

### Appendix A. First Order Kinetics Regression

Study Summary for Site 1

MRID 42851302 Crop Cotton

Region/State 2/ Cheraw, SC Application Rate (lb ai/acre) 0.95

Dislodgeable Foliar Residue (DFR) Analysis EPA/OPP/HED 1 st Order Kinetics Re-entry

Day (Day After Treatment) Measured DFR (ug/cm 2 )

Individual

Samples Average Standard Deviation DAT ln(DFR ) Modeled (ln DFR) Modeled DFR

0 1.585

1.7383 0.2168 0 0.553 -1.452 0.234
1.892 1 -0.910 -1.587 0.205

2 -1.551 -1.721 0.179

1 0.308

0.4026 0.1338 3 -2.884 -1.856 0.156
0.497 7 -3.649 -2.395 0.091

14 -4.635 -3.338 0.036

2 0.176

0.2120 0.0513 21 -4.718 -4.281 0.014
0.248 28 -4.858 -5.224 0.005

35 -5.369 -6.167 0.002

3 0.055

0.0559 0.0011 0.057

Residue Dissipation Decay constant (k) -0.135

7 0.026

0.0260 0.0005 Daily Dissipation (%) 13%
0.026 Half-life (days) 5.1

Initial Residue C 0 (ug/cm 2 ) 0.234

14 0.0101

0.0097 0.0005 % of application rate 2.20%
0.0093

21 0.0078

0.0089 0.0016 0.0101

28 0.0085

0.0078 0.0011 0.0070

35 0.0054

0.0047 0.0011 0.0039Page 47 of 56 y = -0.1347x - 1.4519 R2 = 0.7132

-7.000 -6.000 -5.000 -4.000 -3.000 -2.000 -1.000 0.000 1.000

0 5 10 15 20 25 30 35 40ln DFR (ug/cm2)

DAT Cheraw, SC Data ln DFR vs. DATPage 48 of 56 Study Summary for Site 2

MRID 42851302
Crop Cotton

Region/State 2/McFarlan, NC Application Rate (lb ai/acre) 0.95

Dislodgeable Foliar Residue (DFR) Analysis EPA/OPP/HED 1 st Order Kinetics Re-entry Day

(Day After Treatment) Measured DFR (ug/cm 2 )
Individual

Samples Average Standard Deviation DAT ln(DFR ) Modeled (ln DFR) Modeled DFR

0 1.783

1.8210 0.0539 0 0.599 -1.923 0.146
1.859 1 -1.384 -2.045 0.129

2 -2.920 -2.166 0.115

1 0.275

0.2507 0.0345 3 -3.265 -2.287 0.102
0.226 7 -3.860 -2.773 0.062

14 -4.718 -3.623 0.027

2 0.059

0.0539 0.0076 21 -4.570 -4.473 0.011
0.049 28 -5.298 -5.324 0.005

35 -5.372 -6.174 0.002

3 0.037

0.0382 0.0015 0.039

Residue Dissipation Decay constant (k) -0.121

7 0.024

0.0211 0.0045 Daily Dissipation (%) 11%
0.018 Half-life (days) 5.7

Initial Residue C 0 (ug/cm 2 ) 0.146

14 0.0079

0.0089 0.0015 % of application rate 1.37%
0.0100

21 0.0079

0.0104 0.0035 0.0129

28 0.0050

0.0050 0.0000 0.0050

35 0.0043

0.0046 0.0005 0.0050Page 49 of 56 y = -0.1214x - 1.9231 R2 = 0.6351

-7.000 -6.000 -5.000 -4.000 -3.000 -2.000 -1.000 0.000 1.000

0 5 10 15 20 25 30 35 40ln DFR (ug/cm2)

DAT McFarlan, NC Data

ln DFR vs. DATPage 50 of 56 Study Summary for Site 3

MRID 42851302
Crop Cotton

Region/State 2/Chesterfield, SC Application Rate (lb ai/acre) 0.95

Dislodgeable Foliar Residue (DFR) Analysis EPA/OPP/HED 1 st Order Kinetics Re-entry Day

(Day After Treatment) Measured DFR (ug/cm 2 )
Individual

Samples Average Standard Deviation DAT Ln (DFR) Modeled (ln DFR) Modeled DFR

0 1.8655

2.4790 0.8675 0 0.908 -1.219 0.296
3.0924 1 0.430 -1.368 0.255

2 -1.723 -1.516 0.219

1 1.5210

1.5378 0.0238 3 -2.633 -1.665 0.189
1.5546 7 -4.586 -2.260 0.104

14 -4.381 -3.301 0.037

2 0.1790

0.1786 0.0006 21 -5.192 -4.342 0.013
0.1782 28 -5.112 -5.383 0.005

35 -5.192 -6.425 0.002

3 0.0705

0.0718 0.0020 0.0732

Residue Dissipation Decay constant (k) -0.149

7 0.0093

0.0102 0.0013 Daily Dissipation (%) 14%
0.0111 Half-life (days) 4.7

Initial Residue C 0 (ug/cm 2 ) 0.296

14 0.0102

0.0125 0.0033 % of application rate 2.77%
0.0148

21 0.0056

0.0056 0.0000 0.0056

28 0.0056

0.0060 0.0007 0.0065

35 0.0074

0.0056 0.0026 0.0037Page 51 of 56 y = -0.1487x - 1.2189 R2 = 0.6271

-7.000 -6.000 -5.000 -4.000 -3.000 -2.000 -1.000 0.000 1.000 2.000

0 5 10 15 20 25 30 35 40ln DFR (ug/cm2)

DAT Chesterfield, SC Data ln DFR vs. DATPage 52 of 56 

### Appendix B. Biphasic (“Ho ckey Stick”) Regression

Site 1. Cheraw, SC "Hockey Stick" (untransformed residuals) Modeled DFR Squared Residuals 1.73 0.02 1.73 0.03 0.46 0.02 0.46 0.00 0.09 0.01 0.09 0.02 0.02 0.00 0.02 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Sum of Squared Errors (SSE) 0.11 C 0 (ug/cm 2 ) 2.3 C 0 : % of application rate 21% Decay constant 1 (k 1 ) -1.587 Decay constant 2 (k 2 ) -1.587 Inflection Point (day) 12Page 53 of 56 0.000 0.500 1.000 1.500 2.000 2.500

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30DFR (ug/cm2)

DAT 42851302 - Cheraw, SC_profenofos

Residue (ug/cm 2 ) vs. Time (days) Raw DFR Data
Log-linear 1st Order

Non-linear 1st Order
Hockey StickPage 54 of 56 Site 2. Chesterfield, SC "Hockey Stick" (untransformed residuals) Modeled DFR Squared Residuals 2.57 0.50 2.57 0.27 1.20 0.10 1.20 0.12 0.48 0.09 0.48 0.09 0.19 0.02 0.19 0.01 0.01 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Sum of Squared Errors (SSE) 1.21 C 0 (ug/cm 2 ) 3.0 C 0 : % of application rate 28% Decay constant 1 (k 1 ) -0.912 Decay constant 2 (k 2 ) -1.588 Inflection Point (day) 12

0.000 0.500 1.000 1.500 2.000 2.500 3.000 3.500

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30DFR (ug/cm2)

DAT 42851302_profenofos_Chesterfield, SC Residue (ug/cm 2 ) vs. Time (days) Raw DFR Data Log-linear 1st Order

Non-linear 1st Order Hockey StickPage 55 of 56Page 56 of 56 Site 3. McFarlan, NC "Hockey Stick" (untransformed residuals) Modeled DFR Squared Residuals 1.82 0.00 1.82 0.00 0.26 0.00 0.26 0.00 0.02 0.00 0.02 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Sum of Squared Errors (SSE) 0.01 C 0 (ug/cm 2 ) 2.7 C 0 : % of application rate 25% Decay constant 1 (k 1 ) -2.345 Decay constant 2 (k 2 ) -1.588 Inflection Point (day) 12

0.000 0.500 1.000 1.500 2.000 2.500 3.000

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30DFR (ug/cm2)

DAT 42851302_profenofos_McFarlan, NC

Residue (ug/cm 2 ) vs. Time (days) Raw DFR Data Log-linear 1st Order
Non-linear 1st Order Hockey StickUNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D.C. 20460

MEMORANDUM

DATE: 15-SEP-15 OFFICE OF CHEMICAL SAFETY AND POLLUTION PREVENTION

SUBJECT: Profenofos: Review of "Dissipation of Dislodgeable Foliar Residues of Profenofos (Curacron ® 8E) Applied to Cotton in California"

PC Code: 111401 Decision Number: 482022 Petition Number: NA Risk Assessment Type: NA TXR Number: NA MRID Numbers: 42851303 DP Barcode: 0429108 Registration Number: N I A Regulatory Action: N I A Case Number: 2540 CAS Number: 41198-08-7 40CFR: §180.404

FROM: Kelly Lowe, Environmental Scientist

# ~ Risk Assessment Branch I (RAB 1) Health Effects Division (HED)

, 7509P

THROUGH: Thurston Morton, Acting Branch Chief RABI I HED, 7509P

TO: Christina Scheltema Patricia Parrott Pesticide Re-Evaluation Division (PRD) (7508P)

ACTION REQUESTED: The Registration Division (RD) requested that the Health Effects Division (HED) conduct a review of the submitted dislodgeable foliar residue study for profenofos.

SUMMARY OF STUDY RESULTS: This study was designed to determine the dissipation of dislodgeable foliar residues (DFRs) of the active ingredient (ai) profenofos from treated cotton foliage. The test product was a 73% ai emulsifiable concentrate (EC) formulation

. One test site was examined in Madera

, CA (NAFT A Region 10) during the 1991 growing season. Geographical and climatic conditions were relevant
to the use pattern proposed. The trial site consisted of one control plot and one treatment plot, with the treatment plot receiving six foliar broadcast spray applications of the test substance via

Page I of 19Page 2 of 19 

### tractor-mounted groundboom sprayers at a nominal rate of 1.0 lb ai/A/application. Applications were made using a spray volume of approximately 30 gallons per acre, at re treatment intervals of 5-6 days.

Single control plot and triplicate treated plot DFR samples were collected using a Birkestrand leaf punch sampler prior to and after the first, third, and sixth (last) application, and at the following intervals after the la st application: 1, 2, 3, 7, 14, 21, 28, and 35 days. EPA calculated DFRs in μg/cm2, correcting for field fortification recoveries and a leaf su rface area of 400 cm2.

The highest average DFR was 1.66 μg/cm2, whic h occurred immediately after the first application (14.8% of application rate). The average DFR immediately prior to the last (sixth) application was 0.120 μg/cm2. The maximum average DFR after the last app lication occurred at the first sampling interval (after spray dried) wi th a value of 1.38 μg/cm2 (12.3% of application rate). DFRs declined rapidly in the first three days to 0.162 μg/cm2 (1.4% of application rate) at 3DAT6, and reached equilibrium at 21DAT6 with a value of 0.010 μg/cm2 (0.09% of application rate). DFRs on 28DAT6 and 35 DAT6 were 0.011 and 0.0081 μg/cm2, respectively.

The Registrant assumed first-order dissipation kinetics to generate dissipation curves for profenofos. The Registrant conducted linear regr ession analyses using the natural logarithm of average DFR values from the following samp ling intervals: 1) 0DAT6 through 35DAT6 (all sampling intervals after the last application) , 2) 0DAT6 though 21DAT6 (sampling intervals through the point of equilibrium), 3) 0DAT6 through 3DAT6 (first part of bi-phasic pattern), and 4) 3DAT6 through 35DAT6 (second part of bi-phasic pattern). The Registra nt’s calculated halflives for these intervals, re spectively, were 5.4 days (R 2 

### = 0.816), 3.4 days (R 2 

### = 0.881), 1.0 days (R 2 

### = 0.942), and 7.9 days (R 2 

### = 0.848). Additionally, the Registrant generated a decline curve fit using an equation representing the data specifically (y=a+bexp-x), as determined by Table Curve Fitting Software. The half-lif e calculated was 0.7 days (R 2 

### = 0.993).

EPA first assumed first-order di ssipation kinetics and conducted a linear regression analysis using the corrected average DFRs from immediat ely after the last application (0DAT6) through the last sampling interval (35DAT6), and determined a half-life of 5.4 days (R2 = 0.8212). However, the regression analysis did not appear visually to be a good fit for the data, and a comparison of the 0DAT6 actual and predicted DFRs show that the actual DFR (1.38 μg/cm 2 

### ) is ~4x higher than the linear regr ession predicted DFR (0.3357 μg/cm 2 

### ). Therefore, EPA did additional analysis and conducted a biphasic (“hockey stick”) regr ession analysis using Excel’s Solver, and the corrected average DFRs from im mediately after the last application through the last sampling interval. This regr ession analysis appears (visually) to be a better fit of the data, and provides a predicted Day 0 value of 1.74 μg/cm 2



### .

CONCLUSIONS: No major issues were identifie d during review of this study an d the results ar e considered acceptable for risk assessment purposes.

No major issues were identifie d during review of this study an d the results ar e considered acceptable for risk assessment purposes. There were some issues noted regarding the field fortification recovery samples: (1 ) only one field fortification level was used in the study, and thePage 3 of 19 

### EPA guideline recommends a minimu m of two field fortification le vels; (2) the level chosen was below most of the field samples (10 ug/sample fo r the field fortification samples vs a maximum of 648 ug/sample for the field samples); and (3) several recoveries were outside the guideline range of 70-120%. However, the study report did provide additional information with respect to laboratory recovery samples, which include d concentrations up to 1000 ug/sample, with recoveries ranging from 88 – 121%; therefore, it is unlikely that the field fortification issues would impact the utility of the study for risk assessment.

Summary of DFR Values and Regression Analysis Re sults for Treated Cotton with Profenofos (MRID# 42851303). Cotton; Site: Madera, CA Study Target Rate (lb ai/A) 1.00 lb ai/A Spray Volume (GPA) 30
Measured Average Day 0 Residue (μg/cm 2 ) 0DAT6: 1.38
Linear Regression Predicted Day 0 Residue (μg/cm 2 ) 0DAT6: 0.336
Slope -0.129
Half-life (days) 5.4

R 2 0.8212
Biphasic Regression Predicted Day 0 Residue (ug/cm 2 ) 0DAT6: 1.74 Slope -1.345, -0.251

0 0.5

1 1.5

2 2.5

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30DFR (ug/cm2)

DAT 

### 42851303_profenofos_CA Residue (ug/cm 2 

### ) vs. Time (days) Raw DFR Data
Log-linear 1st Order

Non-linear 1st Order
Hockey StickPage 4 of 19 

### DATA EVALUATION RECORD

STUDY TYPE: Determination of Dislodgeable Foli ar Residues on Cotton Treated with Profenofos; OCSPP 875.2100

PC CODE: 111401

TEST MATERIAL Curacron® 8E, an emulsifiable c oncentrate (EC) formulation containing 73% of active ingredient (ai) profenofos (8 lb ai/gal)

SYNONYMS: Common name: Profenofos Formulation Trade name: Curacron® 8E Chemical name: 0-(4-bromo-2-chlorphenyl) 0-ethyl S-propyl phosphorothioate CAS No.: 41198-08-7

CITATION: Author: Michael E. Miller Title: Dissipation of Disl odgeable Foliar Residues of Profenofos (Curacron ® 8E) Applied to Cotton in California Report Date: February 4, 1993 Field Research Laboratory: Pan-Ag ricultural Laboratories, Inc. 32380 Ave. 10 Madera, CA 93638 Analytical Laboratory: EN-CAS Analytical Laboratories, Inc. 2359 Farrington Point Dr. Winston-Salem, NC 27107 Identifying Codes: Pan-Agricult ural Laboratories, Inc. FR-91- 311; EN-CAS Analytical Laboratories 91- 0041B CGAG; MRID 42851303; Unpublished

SPONSOR: CIBA-GEIGY Corporation (cur rently Syngenta Crop Protection) Greensboro, NC 27419

EXECUTIVE SUMMARY:

This study was designed to determine the dissipati on of dislodgeable foliar residues (DFRs) of the active ingredient (ai) profenofos from treated cotton foliage. The test product was a 73% ai emulsifiable concentrate (EC) formulation. One test site was examined in Madera, CA (NAFTA Region 10) during the 1991 growing season. Geographical and clima tic conditions were relevant to the use pattern proposed. The trial site consisted of one cont rol plot and one treatment plot, with the treatment plot receiving six foliar broadcast spray applica tions of the test substance via tractor-mounted groundboom sprayers at a nominal rate of 1.0 lb ai/A/application. Applications were made using a spray volume of approximately 30 gallons per acre, at re treatment intervals of 5-6 days.Page 5 of 19 

### Single control plot and triplicate treated plot DFR samples were collected using a Birkestrand leaf punch sampler prior to and after the first, third, and sixth (last) application, and at the following intervals after the last appl ication: 1, 2, 3, 7, 14, 21, 28, and 35 days.

Residues were dislodged from the leaf punch sa mples immediately afte r collection using 0.004% Aerosol OT solution. The samples were stored frozen for up to 63 days prior to extraction for analysis by gas chromatography with flame photomet ric (GC/FPD). Concurre nt recoveries were within the acceptable range of 70 to 120%. Th e reported limit of quantitation (LOQ) was 0.005 μg/mL (0.003 μg/cm 2 

### ); the limit of detection (LOD) was not reported.

Field fortification samples were prepared in duplicate at nominal level of 0.050 μg/mL (10 μg/sample) for each DFR sampling interval. Th e samples were shipped and stored under the same conditions as the field samples, but were anal yzed in separate analytical sets than the field samples. The overall average field fortificati on recovery was 80.0 ± 15.9%, with correction for laboratory recovery (uncorrected re sults were not provided).

The Registrant provided DFRs in μg/sample with correction for laboratory recovery (uncorrected results were not provi ded) and in μg/cm 2 

### (based on a 393 cm 2 

### leaf surface area) with and without correction for the overall average field fortificati on recovery (80%). Versar calculated DFRs in μg/cm 2 

### using the same field fortification correcti on factor, but used a leaf surface area of 400

cm 2



### . The highest average DFR was 1.66 μg/cm 2 

### , which occurred immediately after the first application (14.8% of application rate). The average DFR immediately prior to the last (sixth) application was 0.120 μg/cm 2 

### . The maximum average DFR after th e last application occurred at the first sampling interval (after spra y dried) with a value of 1.38 μg/cm 2 

### (12.3% of application rate). DFRs declined rapidly in the first three days to 0.162 μg/cm 2 

### (1.4% of application rate) at 3DAT6, and reached equilibrium at 21DAT6 with a value of 0.010 μg/cm 2 

### (0.09% of application rate). DFRs on 28DAT6 and 35DAT6 were 0.011 and 0.0081 μg/cm 2 

### , respectively.

The Registrant assumed first-order dissipation kinetics to generate dissipation curves for profenofos. The Registrant conducted linear regr ession analyses using the natural logarithm of average DFR values from the following samp ling intervals: 1) 0DAT6 through 35DAT6 (all sampling intervals after the last application) , 2) 0DAT6 though 21DAT6 (sampling intervals through the point of equilibrium), 3) 0DAT6 through 3DAT6 (first part of bi-phasic pattern), and 4) 3DAT6 through 35DAT6 (second part of bi-phasic pattern). The Registra nt’s calculated halflives for these intervals, re spectively, were 5.4 days (R 2 

### = 0.816), 3.4 days (R 2 

### = 0.881), 1.0 days (R 2 

### = 0.942), and 7.9 days (R 2 

### = 0.848). Additionally, the Registrant generated a decline curve fit using an equation representing the data specifically (y=a+bexp-x), as determined by Table Curve Fitting Software. The half-life calcul ated postapplication 6 was 0.7 days (R 2 

### = 0.993).

EPA first assumed first-order di ssipation kinetics and conducted a linear regression analysis using the corrected average DFRs from immediat ely after the last application (0DAT6) through the last sampling interval (35DAT6), and determined a half-life of 5.4 days (R2 = 0.8212). However, the regression analysis did not appear visually to be a good fit for the data, and aPage 6 of 19 

### comparison of the 0DAT6 actual and predicted DFRs show that the actual DFR (1.38 μg/cm 2 

### ) is ~4x higher than the linear regr ession predicted DFR (0.3357 μg/cm 2 

### ). Therefore, EPA did additional analysis and conducted a biphasic (“hockey stick”) regr ession analysis using Excel’s Solver, and the corrected average DFRs from im mediately after the last application through the last sampling interval. This regr ession analysis appears (visually) to be a better fit of the data, and provides a predicted Day 0 value of 1.74 μg/cm 2



### . There were some issues noted regarding the fiel d fortification recovery samples: (1) only one field fortification level was used in the study, and the EPA guideline recommends a minimum of two field fortification levels; (2) the level c hosen was below most of the field samples (10 ug/sample for the field fortification samples vs a maximum of 648 ug/sample for the field samples); and (3) several recoveri es were outside the guideline ra nge of 70-120%. However, the study report did provide additional information with respect to laboratory recovery samples, which included concentrations up to 1000 ug/sa mple, with recoveries ranging from 88 – 121%; therefore, it is unlikely that the field fortification issues would im pact the utility of the study for risk assessment.

COMPLIANCE: Signed and dated GLP, Quality Assurance, and Data Confidentiality statements were provided. The study sponsor waiv ed claims of confidentia lity within the scope of FIFRA Section 10 (d) 1(A), (B), or (C). The Study Repor t indicated that the study was conducted under EPA Good Laboratory Practice Standards (40 CFR Part 160), with the following exceptions: Thirty-year averages for rainfall were based on data acquired from NOAA which were not collected in compliance with GLP; and ParsMadera on-site weather data were not collected under GLP.

CONCURRENT EXPOSURE STUDY: No

GUIDELINE OR PROTOCOL FOLLOWED : Series 875, Part B: Dislodgeable Foliar Residue Dissipation: Agricultural, Guideline 875.2100. A compliance checklist is provided in Appendix A.

I. MATERIALS AND METHODS

A. MATERIALS:

1. Test Material:

Formulation: Curacron® 8E, an EC formulation Lot/Batch # formulation: FL-910966 (formulated product) Formulation guarantee: 73% ai (8 lb ai/gal) nominal. Analysis of test substance on each application day yielded valu es 95 to 105% of nominal. Purity: 98.1% in technical CAS #: 41198-08-7 Other Relevant Information: None

2. Relevance of Test Material to Proposed Formulation(s): The test product used in thisPage 7 of 19 

### study, Curacron® 8E, appears to be the same pr oduct identified on the label for Curacron® 8E Insecticide-Miticide (EPA Re g. No. 100-669, dated 7/11/14) based on the product name, amount ai (73% ai), and crop use site (cotton). However, the EPA Re g No. provided in the study for the test product is 100-599, which was the registration number for the cancelled product Curacron 6E containing 59.7% ai.

B. STUDY DESIGN: The field phase study protocol (CIBA GEIGY Corpor ation Protocol No. 74-91), signed on June 27, 1991 by the Study Dir ector, was provided with the Study Report. There were three amendments and one deviatio n to the protocol. The amendments involved adding the collection of fortifie d shipping stability samples, ch anging the Birkestrand leaf punch size to 2.5 cm in diameter instead of 1.75 cm in diameter, removing the collection of fortified leaf discs, and correctin g the purity of the test substance. The deviation involved shipping the pre-treatment and post-treatment samples for appli cation 1 at 15 days afte r collection, instead of within 14 days of collection.

1. Site Description:

Test location: The field phase of the study was conducted at one location in Madera, CA (NAFTA Region 10). One control plot and one treated plot were establ ished at the test site. Both the treated and control plots were divided into three replicate subplots. The treated plot was located 1,300 feet from the control plot. According to the study, the test site selected was typical for the intended use of profenofos insecticide and miticide, and was representative of the cottonproducing regions of the te st state with respect to soil type and climate.

Areas sprayed and sampled: The treated and untr eated plots each measured 8 rows wide x 90 ft long. The exact width and area of each plot was not provided.

Meteorological Data: On-site weather data we re provided for the study duration (planting in May 1991 through last sampling interval in September 1991) for air temperature, soil temperature, wind speed, and precipitation. Additi onally, weather conditions during the first five applications were provided, in cluding air temperature, wind speed and direction, relative humidity, and percent cloud cover. Historical monthly average pr ecipitation and air temperature data were also provided fr om a nearby NOAA station.

Temperature and rainfall was sim ilar to historical averages. As shown in Table 1 below, monthly mean minimum temperatures were 49 to 63°F, and monthly mean maximum temperatures were 79 to 98°F. Precipitation was minimal, totalli ng 0 to 0.04 inches per month of the study. No rainfall occurred following the last application. In-furrow ir rigation, using well water, was applied as needed to maintain no rmal crop growth and development.

Table 1. Weather Conditions (Monthly) During Study Period

Month Temperature (°F) (mean min/max) Total Rainfall (inches) Irrigation (inches) May 1991 49/79 0.04 4.5 June 1991 54/89 0.00 4 July 1991 63/98 0.01 6 August 1991 59/92 0.00 5Page 8 of 19 September 1991 58/94 0.01 5



### 2. Crop Characteristics:

Crop, variety: Cott on, variety not reported

Row width, plant spacing: Not reported

Stage of growth: Growth stages were reported only for the time of application, as noted below.

1 st



### application: Early bloom 2 nd 

### application: Bloom 3 rd 

### application: Late bloom/early square set 4 th 

### application: Late bloom/ early square set 5 th 

### application: Late bloom/early square set 6 th 

### application: Boll set

Other products used on crop: No maintenance pesticides were app lied to the test plot during the trial, or during the previous two years.

3. Application Rates and Regimes :

Application rate(s): Six applica tions were made to cotton foliag e at a target rate of 1.00 lb ai/A/application. The label report s a maximum application rate of 0.5 lb ai/A/application, with a maximum seasonal rate of 5 lb ai/A/season.

Application Regime: Six folia r broadcast spray app lications were made using a 5 to 6 day retreatment interval (7/24/91, 7/29/91, 8/3/91, 8/8/91, 8/13/91, 8/19/91). The label reports a minimum retreatment interval of 5 days.

Application Equipment: Tractor-mounted Hahn Hi -boy commercial cotton sprayer fitted with 20 D-6 nozzles, allowing for 5 nozzles per bed. One nozzle was positioned above the bed and two nozzles were positioned on e ither side of the plants.

Spray Volume: 30 gallons per acre (GPA). The label reports a minimum spray volume of 3 to 5 GPA for spray solutions diluted with water.

Equipment Calibration Procedures: Sprayer cali brations were performed the day of each application (prior to application). The spray tank was partially filled with water, the pressure was adjusted to 50 psi, and the amount of time requi red to spray 5 gallons of water was checked and recorded three times. This information was used to calculate the flow rate in gallons per minute, and subsequently, the approximate tractor speed re quired to deliver the target application. The sprayer was timed over a distance of 90 feet. An example calculation was provided for the first application.Page 9 of 19 

### Spray Verification: Spray verification was performed by placing 15 cm diameter filter paper (in petri dishes) in five random spots on the plot prio r to each application. The samples were placed at varying heights to reflect the varying he ights of the cotton canopy. The filter paper was collected immediately after each application and stored frozen until analysis. The average recoveries, based on the nominal application rate of 1 lb ai/A , were 24.6 ± 15.3% for application 1, 33.6 ± 15.6% for application 2, 29.6± 5.8% for application 3, 34.5 ± 16.1% for application 4, 35.8 ± 3.6% for application 5, and 13.8 ± 7.0% for a pplication 6. The study report states that these recoveries reflect the fact that each petri dish would have only been exposed to 20-40% of the spray mix applied to each bed based on the positioning of the spray nozzles.

4. Dislodgeable Foliar Residue Sampling Procedures:

Method and Equipment: DFR samples consisted of 40 leaf disks which were collected with a ~2.5 cm diameter leaf punch sampler. The punc h samples were collecteddirectly into prelabelled glass jars.

Sampling Procedure: Leaf discs were collected from the entire row of each subplot, with the exception of the four plants on each end of the row. Discs were taken from alternating quadrants of the plant to decrease sample bias. The l eaf surface was dry at each sampling event. After each sample was collected, the jar containing the leaf punches was removed from the punch apparatus, capped, placed in a cooler with ice or ice substitute, and take n to the dislodging area.

Total Surface Area per Replicate: The total su rface area of each sample was reported as 393

cm 2 

### . For calculation purposes, HED assumed a leaf surface area of 400 cm 2



### . Replicates per activity:

 Replicates per sampling time: At each sampli ng interval, three treated replicate samples were collected from the treated plot. A si ngle control sample was collected at each sampling interval from the untreated plot.

 Number of sampling times: There were a total of 14 sampling events, including five sampling events before the last application.

Times of sampling: Leaf samples were collected immediately before applications 1, 3, and 6, as soon as foliage dried after appl ications 1, 3, and 6, and at 1, 2, 3, 7, 14, 21, 28, and 35 days after application 6.

Part(s) of foliage sampled: The leaf disks were collected from older but viable leaves along the middle towards the top of the leaf in an area representative of the es timated average leaf thickness.

5. Sample Handling: After each sample was collected, the jar containing the leaf punches was removed from the punch apparatus, capped, stored in a cooler with ice substitute, and taken to the dislodging area (laboratory room of the Field Department of Pan-Ag Labs). After dislodging, all samples were placed in freezers set to main tain temperatures at or below freezing (-23.9oC to -3.3oC). All samples were shippe d to EN-CAS Analytical Labo ratories via Federal Express within 15 days of sampling. Samples were received at the analytical facility from August 8, 1991Page 10 of 19 

### through September 25, 1991, and stored at a temp erature between -23o C to -27oC until the samples were thawed for subsampling

. The interval between sample collection and extraction for analysis was 24-63 days for field samples a nd 53-100 days for field fortification samples.

6. Analytical Methodology:

Dislodging Solution: Residues were dislodged with a 0.004% Ae rosol® OT solution, prepared by diluting 0.2 ml of 75% Aeroso l® OT with 100 mL water.

Dislodging Procedure: In the fi eld, the leaf disks were extrac ted twice with 100 mL of 0.004% Aerosol OT solution. Dislodging was conducted by shaking the sample for 10 minutes. The resulting solutions were combined (200 mL total) and the foliage was saved for possible analysis.

Time Interval (sample collection to dislodgi ng): According to the Study Report, samples were dislodged right after collec tion (exact times not provided).

Detection methods: Sodium chlo ride was added to an aliq uot of the dislodging solution sample, and then the sample was partitioned thr ee times with hexanes:dichloromethane (80:20). The organic phases were filtered through a sodium sulphate pad and the phase was reduced to dryness, reconstituted, sonicated, and analyzed by gas chromatography with flame photometric detection (GC/FPD) in the phosphorous mode. A su mmary of the typical GS/FPD conditions are shown in Table 2.

Table 2. Typical GC/FPD Instrument Parameters

Instrument: Tracor Model 540 Gas chromatograph with a flame photometric detector (FPD) Column: Fused silica megabore capillary 15-M X 0.548 mm DB-5 column

Gases Carrier: Helium = 1.0 mL/min Detector: Hydrogen = 100 mL/min Air = 150 mL/min Injection Volume: 5.00 μ L, direct Temperatures: Injector: 230°C Detector: 230°C Oven Temp.: 200°C Approximate Retention Times: 4.5 minutes



### Method validation: Residues of profenofos in dislodging solution were determined using method ENC-5/91. The method was ve rified prior to sample analys is using cotton leaf control dislodging solution samples fortified with prof enofos at concentrations of 0.005, 0.05, and 0.5 μg/mL. Individual method validation recoveries ranged from 96% to 113% with an overall mean recovery of 106% ± 5.94% (n= 9). The LOQ was 0.005 μ g/mL (corresponding to 0.003 μg/cm 2 

### leaf disk surface area based on a dislodging soluti on sample volume of 200 mL and a leaf surface area of 400 cm 2 

### ). The LOD was not reported.Page 11 of 19 

### Instrument performance: For all runs, standard s of known concentration were injected at the beginning and end of the run, as well as inters persed throughout the run. These standards were used to construct linear re gression standard curves.

Quantification: Concentrations of profenofos we re interpolated from the standard calibration curve, which was generated using linear regression.

7. Quality Control:

Lab Recovery: Two 

### concurrent laboratory fortified samples were analyzed with each set of field samples. Control dislodging solution samples were fortified with profenofos at concentrations of 0.005, 0.05, 0.5 and 5.0 μg/mL (assuming 200 mL samples = range of 1 μg/sample to 1000 μg/sample). Individual concurrent laboratory recoveries ranged from 88% to 121%, with an overall mean recovery of 108% ± 10.7% (n=14). Residues of profenofos were not detected above the LOQ (0.003 μg/cm 2 

### ) in any laboratory control samples.

Field blanks: One control sample was collected at each sampling interval from the untreated plot. Residues of profenofos were not detected above the LOQ (0.003 μg/cm 2 

### ) in the control samples.

Field recovery: Field fortifica tion samples were prepared at th e end of each sampling interval. Samples were prepared in duplicate at one for tification level of 0.050 μg/mL (10 μg/sample) by adding 1 mL of a 10 μg/mL profenofos analytic al standard to 200 mL of 0.004% Aerosol OT solution which had been shaken with control cotton leaf discs. A control blank of non-fortified Aerosol OT solution was also prepared at each interval. The samples were shipped and stored with the field samples, but were analyzed in sepa rate analytical sets th an the field samples.

Table 3 provides a summary of the field fortif ication recoveries. The overall mean field fortification recovery was 80.0 ± 15.9%. The field fortification recoveries were corrected for concurrent laboratory recovery by the study author. Profenofos wa s not detected in any of the field fortification blank sa mples at any interval.

Table 3. Summary of Field Fortification Recoveries

Sampling Interval Fortification Level a (μg/sample) n Recoveries (%) b, c Average Recovery (%)

Pre-App 1

10 (0.05 μg/mL) 2 66, 104 85
Post-App 1 2 64, 94 79
Pre-App 3 2 74, 74 74
Pre-App 3 2 80, 86 83
Pre-App 6 2 76, 76 76
Post-App 6 2 76, 52 64

1DAT6 2 92, 84 88

2DAT6 2 90, 82 86Page 12 of 19 Table 3. Summary of Field Fortification Recoveries

Sampling Interval Fortification Level a (μg/sample) n Recoveries (%) b, c Average Recovery (%)

3DAT6 2 84, 90 87

7DAT6 2 86, 74 80

14DAT6 2 58, 80 69

21DAT6 2 130, 92 111

28DAT6 2 74, 74 74

35DAT 2 48, 80 64
Overall (n=28) 80.0±15.9

a. Fortification level is equivalent to ~0.050 μg/mL, or 0.025 μg/cm 2 based on a 400 cm 2 sample b. Reported residues were corrected fo r concurrent laboratory recovery.

c. Recoveries outside of 70-120% are in bold.



### Formulation: Curacron® 8E is an emulsifiab le concentrate formulation containing a nominal 73% of ai (8 lb ai/gal). Anal ysis of formulation samples taken at each application showed the amount of profenofos was 95 to 105% of nominal.

Tank mix: Tank mix samples were collected in triplicate prior to each application. Average recoveries ranged from 19 to 102%, with an ove rall recovery of 42.3 ± 52.0% (n=18). The study stated that no reason could be found for the low recoveries.

Travel Recovery: Travel recovery samples were not prepared.

Storage Stability: A freezer storage stabi lity study was conducted in which Aerosol OT dislodging solution was fortified with profenofos at 0.05 μg/mL and analyzed after 0, 1 and 3 months of frozen storage. After correction for co ncurrent recovery, storag e stability recoveries were 102, 95, and 105%, respectively. The storage st ability data, in conj unction with the field fortification data, are adequate to demonstrate that residues of prof enofos are stable in dislodging solution for the storage duration and conditions in the field study (24 to 63 days).

II. RESULTS AND CALCULATIONS

The Registrant provided DFRs in μg/sample with correction for laboratory recovery (uncorrected results were not provi ded) and in μg/cm 2 

### (based on a 393 cm 2 

### leaf surface area) with and without correction for the overall average field fortificat ion recovery (80.0%). EPA calculated DFRs in μg/cm 2 

### using the same field fortification correcti on factor, but used a l eaf surface area of 400

cm 2 

### . Table 4 provides a summary of the profen ofos DFR values and statistical summaries calculated by EPA.

The highest average DFR was 1.66 μg/cm 2 

### , which occurred immediately after the first application (14.8% of application rate). The average DFR immediately prior to the last (sixth) application was 0.120 μg/cm 2 

### . The maximum average DFR after th e last application occurred at the first sampling interval (after spra y dried) with a value of 1.38 μg/cm 2 

### (12.3% of applicationPage 13 of 19 

### rate). DFRs declined rapidly in the first three days to 0.162 μg/cm 2 

### (1.4% of application rate) at 3DAT6, and reached equilibrium at 21DAT6 with a value of 0.010 μg/cm 2 

### (0.09% of application rate). DFRs on 28DAT6 and 35DAT6 were 0.011 and 0.0081 μg/cm 2 

### , respectively.

The Registrant assumed first-order dissipation kinetics to generate dissipation curves for profenofos. The Registrant conducted linear regr ession analyses using the natural logarithm of average DFR values from the following samp ling intervals: 1) 0DAT6 through 35DAT6 (all sampling intervals after the last application) , 2) 0DAT6 though 21DAT6 (sampling intervals through the point of equilibrium), 3) 0DAT6 through 3DAT6 (first part of bi-phasic pattern), and 4) 3DAT6 through 35DAT6 (second part of bi-phasic pattern). The Registra nt’s calculated halflives for these intervals, re spectively, were 5.4 days (R 2 

### = 0.816), 3.4 days (R 2 

### = 0.881), 1.0 days (R 2 

### = 0.942), and 7.9 days (R 2 

### = 0.848). Additionally, the Registrant generated a decline curve fit using an equation representing the data specifically (y=a+bexp-x), as determined by Table Curve Fitting Software. The half-life calcul ated post-application 6 was 0.7 days (R 2 

### = 0.993).

EPA assumed first-order dissipati on kinetics and conducted a linear regression analysis using the corrected average DFRs from immediately after the last application (0DAT6) through the last sampling interval (35DAT6), and determined a half-life of 5.4 days (R 2 

### = 0.8212). A comparison of the 0DAT6 actual and predicted DFRs show that the actual DFR (1.38 μg/cm 2 

### ) is ~4x higher than the predicted DFR (0.3357 μg/cm 2 

### ). EPA’s dissipation cu rves and regression analysis results are presented in Ap pendix B and summarized in Table 5.

III DISCUSSION:

There were some issues noted regarding the fiel d fortification recovery samples: (1) only one field fortification level as us ed in the study, and the EPA guideline recommends a minimum of two field fortification levels; (2) the level c hosen was below many of the field samples (10 ug/sample for the field fortification samples vs a maximum of 648 ug/sample for the field samples); and (3) several recoveri es were outside the guideline ra nge of 70-120%. However, the study report did provide additional information with respect to laboratory recovery samples, which included concentrations up to 1000 ug/sa mple, with recoveries ranging from 88 – 121%.Page 14 of 19 Table 4. DFRs for Cotton Leaves Treated with Profenofos a

Sampling Interval Measured Residue

(μg) b DFR (μg/cm 2 ) c Corrected DFR ( μ g/cm 2 ) d Arithmetic Mean ( μ g/cm 2 ) Standard Deviation ( μ g/cm 2 ) Coefficient of Variance (%) Natural Log of Mean ( μ g/cm 2 ) Percent of Application Rate

Dislodgeable e

Pre-Treatment 1 (-1DAT1) <LOQ <0.0025 0.0013
0.0013 0.000 0.000 -6.68 -- <LOQ <0.0025 0.0013 <LOQ <0.0025 0.0013

Post-Treatment 1 (0DAT1) 642 1.61 2.01
1.66 0.317 19.0 0.51 14.8 514 1.29 1.61
442 1.11 1.38

Pre-Treatment 3 (5DAT2) 50.8 0.127 0.159
0.200 0.089 44.4 -1.61 1.8 44.6 0.112 0.139
96.6 0.242 0.302

Post-Treatment 3 (0DAT3) 592 1.48 1.85
1.92 0.093 4.86 0.65 17.1 648 1.62 2.03
602 1.51 1.88

Pre-Treatment 6 (6DAT5) 42.4 0.106 0.133
0.120 0.016 13.4 -2.12 1.1 40.2 0.101 0.126
32.6 0.082 0.102

0DAT6 628 1.57 1.96
1.38 0.519 37.7 0.32 12.3 382 0.955 1.19
312 0.780 0.975

1DAT6 189 0.473 0.591
0.449 0.135 30.1 -0.80 4.0 139 0.348 0.434
103 0.258 0.322

2DAT6 71.4 0.179 0.223
0.227 0.032 14.3 -1.48 2.0 63.0 0.158 0.197
83.6 0.209 0.261

3DAT6 59.6 0.149 0.186

0.162 0.056 34.4 -1.82 1.4 31.4 0.079 0.098

64.4 0.161 0.201

7DAT6 28.2 0.071 0.088

0.060 0.024 40.1 -2.81 0.54 13.8 0.035 0.043

16.0 0.040 0.050

14DAT6 9.2 0.023 0.029

0.026 0.006 21.7 -3.66 0.23 6.2 0.016 0.019

9.4 0.024 0.029

21DAT6 3.4 0.0085 0.011

0.010 0.002 20.5 -4.63 0.09 3.6 0.0090 0.011

2.4 0.0060 0.0075

28DAT6 3.6 0.0090 0.011
0.011 0.001 8.6 -4.51 0.10 3.8 0.0095 0.012
3.2 0.0080 0.010

35DAT6 2.0 0.0050 0.0063 0.0081 0.002 27.7 -4.81 0.008 2.4 0.0060 0.0075Page 15 of 19 Table 4. DFRs for Cotton Leaves Treated with Profenofos a

Sampling Interval Measured Residue

(μg) b DFR (μg/cm 2 ) c Corrected DFR ( μ g/cm 2 ) d Arithmetic Mean ( μ g/cm 2 ) Standard Deviation ( μ g/cm 2 ) Coefficient of Variance (%) Natural Log of Mean ( μ g/cm 2 ) Percent of Application Rate

Dislodgeable e

3.4 0.0085 0.0106

a. Six applications were made at a rate of 1.0 lb ai/A/application (approx. 11.2 μg/cm 2 ). b. LOQ = 0.003 μg/cm 2 ; LOD was not reported.

c. DFR = Measured residue (μg) / leaf surface area (400 cm 2 ) d. DFR values were corrected for the average field fortification recovery (80.0%). For statistical calculations, residues <LOQ we re assigned a value of 1⁄2 LOQ.

e. Percent of Original Applicati on Rate Dislodgeable = DFR (μg/cm 2 ) / Amount applied (μg/cm 2 ) x 100%.Page 16 of 19 

### Appendix A: First Order Kinetics Regression

Study Summary

MRID 42851303 Crop Cotton Region/State Region 10/California Application Rate (lb ai/acre) 1

Dislodgeable Foliar Residue (DFR) Analysis

Re-entry Day (Day After Treatment) Measured DFR (ug/cm 2 )
Individual Samples Average Standard Deviation

0.000 1.9625
1.38 0.5186 1.1938

0.9750

1.00 0.5906
0.449 0.1350 0.4344

0.3219

2 0.2231
0.227 0.0324 0.1969

0.2613

3 0.1863
0.162 0.0557 0.0981

0.2013

7 0.0881
0.0604 0.0242 0.0431

0.0500

14 0.0288 0.0258 0.0056 0.0194

0.0294

21 0.0106
0.0098 0.0020 0.0113

0.0075

28 0.0113
0.0110 0.0010 0.0119

0.0100

35 0.0063
0.0081 0.0023 0.0075

0.0106Page 17 of 19 EPA/OPP/HED 1 st Order Kinetics DAT ln(DFR) Modeled (ln DFR) Modeled DFR

0.00 0.320 -1.091 0.336

1.00 -0.801 -1.221 0.295

2 -1.482 -1.350 0.259

3 -1.821 -1.480 0.228

7 -2.806 -1.998 0.136

14 -3.656 -2.904 0.055

21 -4.626 -3.810 0.022

28 -4.506 -4.716 0.009

35 -4.813 -5.622 0.004

Residue Dissipation Decay constant (k) -0.129 Daily Dissipation (%) 12% Half-life (days) 5.4

Initial Residue C 0 (ug/cm 2 ) 0.3357 % of application rate 2.99%Page 18 of 19 

### y = -0.1294x - 1.0915 R2 = 0.8212

-6.000 -5.000 -4.000 -3.000 -2.000 -1.000 0.000 1.000

0.00 5.00 10.00 15.00 20.00 25.00 30.00 35.00 40.00ln DFR (ug/cm2)



### DAT ln DFR vs. DATPage 19 of 19 

### Appendix B: Biphasic (“Ho ckey Stick”) Regression

"Hockey Stick" (untransformed residuals) Modeled DFR Squared Residuals 1.38 0.34 1.38 0.03 1.38 0.16 0.45 0.02 0.45 0.00 0.45 0.02 0.22 0.00 0.22 0.00 0.22 0.00 0.17 0.00 0.17 0.01 0.17 0.00 0.06 0.00 0.06 0.00 0.06 0.00 0.01 0.00 0.01 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Sum of Squared Errors (SSE) 0.59 C 0 (ug/cm 2 ) 1.7 C 0 : % of application rate 15% Decay constant 1 (k 1 ) -1.345 Decay constant 2 (k 2 ) -0.251 Inflection Point (day) 1UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D.C. 20460



### MEMORANDUM

Date: 15-SEP-2015 OFFICE OF CHEMICAL SAFETY AND POLLUTION PREVENTION



### SUBJECT: Profenofos: Review of " Dissipation of Dislodgeable Foliar Residues of Profenofos (Curacron® 8E) Applied to Cotton in Texas"

PC Code: 111401 Decision Number: 482022 Petition Number: NA Risk Assessment Type: NA TXR Number: NA MRID Numbers: 42851304 DP Barcode: D429108 Registration Number: N I A Regulatory Action: N I A Case Number: 2540 CAS Number: 41198-08-7 40CFR: § 180.404



### FROM: Kelly Lowe, Environmental Scientist Risk Assessment Branch I (RAB I) Health Effects Division (HED), 7509P



### THROUGH:

TO: Thurston Morton, Acting Branch Chief RABI 

### I HED, 7509P

Christina Scheltema Patricia Parrott Pesticide Re-Evaluation Division (PRD) (7508P)



### ACTION REQUESTED: The Registration Division (RD) requested that the Health Effects Division (HED) conduct a review of the submitted dislodgeable foliar residue study for profenofos

.



### SUMMARY OF STUDY RESULTS: This study was designed to determine the dissipation of dislodgeable foliar residues (DFRs) of the active ingredient (ai) profenofos from treated cotton foliage. The test product was a 73% ai emulsifiable concentrate (EC) formulation. One test site was examined in Snook, Texas (NAFTA Region 6) during the 1991 growing season

. Geographical and climatic conditions were relevant to the use pattern proposed. The trial site consisted of one control plot and one treatment plot, with the treatment plot receiving six foliar broadcast spray applications of the test substance via tractor-mounted groundboom sprayers at a nominal rate of 1. 0 lb ai/ Napplication.

Page I o f 20Page 2 of 20 

### Applications were made using a spray volume between 19.4-21.5 gallons per acre, at retreatment intervals of 5-7 days.

Single control plot and triplicate treated plot DFR samples were collected using a Birkestrand leaf punch sampler prior to and after the first, third, and sixth (last) application, and at the following intervals after the la st application: 1, 2, 3, 7, 14, 21, 28, and 35 days. EPA calculated DFRs in μg/cm2 using the same field fortificatio n correction factor, and us ed a leaf surface area of 400 cm2.

The highest average DFR was 2.11 μg/cm2, whic h occurred immediately after the first application (20.4% of application rate). The average DFR immediately prior to the last (sixth) application was 0.054 μg/cm2. The maximum average DFR after the last app lication occurred at the first sampling interval (after spray dried) wi th a value of 1.74 μg/cm2 (16.0% of application rate). DFRs declined rapidly in the first three days to 0.076 μg/cm2 (0.7% of application rate) at 3DAT6, and reached equilibrium at 21DAT6 with a value of 0.0086 μg/cm2 (0.08% of application rate). DFRs on 28DAT6 and 35 DAT6 were 0.0066 and 0.0086 μg/cm2, respectively.

The Registrant assumed first-order dissipation kinetics to generate dissipation curves for profenofos. The Registrant conducted linear regr ession analyses using the natural logarithm of average DFR values from the following samp ling intervals: 1) 0DAT6 through 35DAT6 (all sampling intervals after the last application) , 2) 0DAT6 though 21DAT6 (sampling intervals through the point of equilibrium), 3) 0DAT6 through 3DAT6 (first part of bi-phasic pattern), and 4) 3DAT6 through 35DAT6 (second part of bi-phasic pattern). The Registra nt’s calculated halflives for these intervals, re spectively, were 5.7 days (R 2 

### = 0.659), 3.4 days (R 2 

### = 0.723), 16 hours (R 2 

### = 0.924), and 10.8 days (R 2 

### = 0.731).

EPA first assumed first-order di ssipation kinetics and conducted a linear regression analysis using the corrected average DFRs from immediat ely after the last application (0DAT6) through the last sampling interval (35DAT6), and determined a half-life of 5.7 days (R2 = 0.6694). However, the regression analysis did not appear visually to be a good fit for the data, and a comparison of the 0DAT6 actual and predicted DFRs show that the actual DFR (1.74 μg/cm 2 

### ) is ~4x higher than the linear regr ession predicted DFR (0.2005 μg/cm 2 

### ). Therefore, EPA did additional analysis and conducted a biphasic (“hockey stick”) regr ession analysis using Excel’s Solver, and the corrected average DFRs from im mediately after the last application through the last sampling interval. This regr ession analysis appears (visually) to be a better fit of the data, and provides a predicted Day 0 value of 2.4 μg/cm 2



### .

CONCLUSIONS: No major issues were identifie d during review of this study an d the results ar e considered acceptable for risk assessment purposes.

There were some issues noted regarding the fiel d fortification recovery samples: (1) only one field fortification level as us ed in the study, and the EPA guideline recommends a minimum of two field fortification levels; (2) the level c hosen was below most of the field samples (10 ug/sample for the field fortification samples vs a maximum of 648 ug/sample for the field samples); and (3) several recoveri es were outside the guideline ra nge of 70-120%. However, thePage 3 of 20 

### study report did provide additional information with respect to laboratory recovery samples, which included concentrations up to 1000 ug/sa mple, with recoveries ranging from 88 – 121%.

Summary of DFR Values and Regression Analysis Re sults for Treated Cotton with Profenofos (MRID# 42851303). Cotton; Site: Snook, TX Study Target Rate (lb ai/A) 1.00 lb ai/A Spray Volume (GPA) 19.4-21.5
Measured Average Day 0 Residue (μg/cm 2 ) 0DAT6: 1.74
Linear Regression Predicted Day 0 Residue (μg/cm 2 ) 0DAT6: 0.2005
Slope -0.121
Half-life (days) 5.7

R 2 0.6694 Biphasic Regression Predicted Day 0 Residue (ug/cm 2 ) 0DAT6: 2.4 Slope -2.015, -0.272

0 0.5

1 1.5

2 2.5

3

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30DFR (ug/cm2)

DAT 

### 42851303_profenofos_TX Residue (ug/cm2) vs. Time (days) Raw DFR Data

Log-linear 1st Order

Non-linear 1st Order

Hockey StickPage 4 of 20 

### DATA EVALUATION RECORD

STUDY TYPE: Determination of Dislodgeable Foli ar Residues on Cotton Treated with Profenofos; OCSPP 875.2100

PC CODE: 111401

TEST MATERIAL Curacron® 8E, an emulsifiable c oncentrate (EC) formulation containing 73% of active ingredient (ai) profenofos (8 lb ai/gal)

SYNONYMS: Common name: Profenofos Formulation Trade name: Curacron® 8E Chemical name: 0-(4-bromo-2-chlorphenyl) 0-ethyl S-propyl phosphorothioate CAS No.: 41198-08-7

CITATION: Author: R.C. Jordan Title: Dissipation of Dislogdgeable Foliar Residues of Profenofos (Curacron® 8E) Applied to Cotton in Texas Report Date: March 8, 1993 Field Research Laboratory: American Agricultural Services, Inc. P.O. Box 12193 Cary, NC 27512 Analytical Laboratory: EN -CAS Analytical Laboratories, Inc. 2359 Farrington Point Dr. Winston-Salem, NC 27107 Identifying Codes: CIBA-GEI GY Corporation 75-91; EN-CAS Analytical Laborat ories 91-0041A CGAG; MRID 42851304; Unpublished

SPONSOR: CIBA-GEIGY Corporation (cur rently Syngenta Crop Protection) Greensboro, NC 27419

EXECUTIVE SUMMARY:

This study was designed to determine the dissipati on of dislodgeable foliar residues (DFRs) of the active ingredient (ai) profenofos from treated cotton foliage. The test product was a 73% ai emulsifiable concentrate (EC) formulation. One test site was examined in Snook, Texas (NAFTA Region 6) during the 1991 growing season. Geographical and climatic conditions were relevant to the use pattern pr oposed. The trial site consiste d of one control plot and one treatment plot, with the treatment plot receiving six foliar broadcast spray applications of the test substance via tractor-mounted groundboom sprayers at a nominal rate of 1.0 lb ai/A/application. Applications were made using a spray volume between 19.4-21.5 gallons per acre, at retreatmentPage 5 of 20 

### intervals of 5-7 days.

Single control plot and triplicate treated plot DFR samples were collected using a Birkestrand leaf punch sampler prior to and after the first, third, and sixth (last) application, and at the following intervals after the last appl ication: 1, 2, 3, 7, 14, 21, 28, and 35 days.

Residues were dislodged from the leaf punch sa mples immediately afte r collection using 0.004% Aerosol OT solution. The samples were stored frozen for up to 73 days prior to extraction for analysis by gas chromatography with flame photomet ric (GC/FPD). Concurre nt recoveries were generally within the acceptable range of 70 to 120%. The repo rted limit of quantitation (LOQ) was 0.005 μg/mL (0.003 μg/cm 2 

### ); the limit of detection (LOD) was not reported.

Field fortification samples were prepared in duplicate at a nominal level of 0.050 μg/mL (11.3 μg/sample) for each DFR sampling interval. Th e samples were shipped and stored under the same conditions as the field samples, but were anal yzed in separate analytical sets than the field samples. The overall average field fortifica tion recovery was 113±16.5%, with correction for laboratory recovery (uncorrected re sults were not provided).

The Registrant provided DFRs in μg/sample with correction for laboratory recovery (uncorrected results were not provi ded) and in μg/cm 2 

### (based on a 404 cm 2 

### leaf surface area) with and without correction for the overall average field fortificat ion recovery (113%). EPA calculated DFRs in μg/cm 2 

### using the same field fortification correcti on factor, but used a leaf surface area of 400

cm 2



### . The highest average DFR was 2.11 μg/cm 2 

### , which occurred immediately after the first application (20.4% of application rate). The average DFR immediately prior to the last (sixth) application was 0.054 μg/cm 2 

### . The maximum average DFR after th e last application occurred at the first sampling interval (after spra y dried) with a value of 1.74 μg/cm 2 

### (16.0% of application rate). DFRs declined rapidly in the first three days to 0.076 μg/cm 2 

### (0.7% of application rate) at 3DAT6, and reached equilibrium at 21DAT6 with a value of 0.0086 μg/cm 2 

### (0.08% of application rate). DFRs on 28DAT 6 and 35DAT6 were 0.0066 and 0.0086 μg/cm 2 

### , respectively.

The Registrant assumed first-order dissipation kinetics to generate dissipation curves for profenofos. The Registrant conducted linear regr ession analyses using the natural logarithm of average DFR values from the following samp ling intervals: 1) 0DAT6 through 35DAT6 (all sampling intervals after the last application) , 2) 0DAT6 though 21DAT6 (sampling intervals through the point of equilibrium), 3) 0DAT6 through 3DAT6 (first part of bi-phasic pattern), and 4) 3DAT6 through 35DAT6 (second part of bi-phasic pattern). The Registra nt’s calculated halflives for these intervals, re spectively, were 5.7 days (R 2 

### = 0.659), 3.4 days (R 2 

### = 0.723), 16 hours (R 2 

### = 0.924), and 10.8 days (R 2 

### = 0.731).

EPA first assumed first-order di ssipation kinetics and conducted a linear regression analysis using the corrected average DFRs from immediat ely after the last application (0DAT6) through the last sampling interval (35DAT6), and determined a half-life of 5.7 days (R2 = 0.6694). However, the regression analysis did not appear visually to be a good fit for the data, and aPage 6 of 20 

### comparison of the 0DAT6 actual and predicted DFRs show that the actual DFR (1.74 μg/cm 2 

### ) is ~4x higher than the linear regr ession predicted DFR (0.2005 μg/cm 2 

### ). Therefore, EPA did additional analysis and conducted a biphasic (“hockey stick”) regr ession analysis using Excel’s Solver, and the corrected average DFRs from im mediately after the last application through the last sampling interval. This regr ession analysis appears (visually) to be a better fit of the data, and provides a predicted Day 0 value of 2.4 μg/cm 2



### .

There were two issues noted in the review of the study. One was with regard to the field fortification recoveries. It was noted that (1) only one field for tification level was used; the EPA guideline recommends a minimum of two field fo rtification levels; (2) the level chosen was below many of the field samples (11.3 ug/sample for the field fortification samples vs a maximum of 1,300 ug/sample for the field samples); and (3) several recoveries were outside the guideline range of 70-120%. However, the study report did provide additional information with respect to laboratory recovery samples, which included a rang e of concentrations from 1.125 ug/sample up to 1,125 ug/sample, with recoveries ranging from 92 – 134%; therefore, it is unlikely that the field fortification issues would impact the utility of the study for risk assessment. The other issue of note in the study is that profenofos residues were detected in the untreated control plot samples and in the bla nk field fortification samples at all sampling intervals except for the pre- and post- treatment 1 intervals. Th e profenofos levels were 1.58 to 16.0 μg for the untreated control plot samples a nd 1.58 to 4.28 μg for the field fortification blank samples.

COMPLIANCE: Signed and dated GLP, Quality Assurance, and Da ta Confidentiality statements were provided. The study sponsor waived claims of confidentiality within the scope of FIFRA Section 10 (d) 1(A), (B), or (C). The Study Report indicat ed that the study was conducted under EPA Good Laboratory Practice Standa rds (40 CFR Part 160).

CONCURRENT EXPOSURE STUDY: No

GUIDELINE OR PROTOCOL FOLLOWED : Series 875, Part B: Dislodgeable Foliar Residue Dissipation: Agricultural, Guideline 875.2100. A compliance checklist is provided in Appendix A.

I. MATERIALS AND METHODS

A. MATERIALS:

1. Test Material:

Formulation: Curacron® 8E, an EC formulation Lot/Batch # formulation: FL-910966 (formulated product) Formulation guarantee: 73% ai (8 lb ai/gal ) nominal, 73.2% purity analysis (assay date 5/14/93) Purity: 98.1% in technicalPage 7 of 20 

### CAS #: 41198-08-7 Other Relevant Information: None

2. Relevance of Test Material to Proposed Formulation(s): The test product used in this study, Curacron® 8E, appears to be the same product identified on the label for Curacron® 8E Insecticide-Mitic ide (EPA Reg. No. 100-669, dated 7/11/14) based on the product name, amount ai (73% ai ), and crop use site (cotton).

B. STUDY DESIGN: The field phase study protocol (CIBA GEIGY Corporation Protoc ol No. 75-91), signed on July 2, 1991 by the Study Director, was provided with the Study Report. There were three amendments and one deviation to the protocol . The amendments involved altering the field project coordinator, adding information on soil ch aracterization, and clearl y defining test plots and correcting grammatical errors. The deviation involved field extracted and fortification leaf disks that were intended for analysis in the event of very low 0-day residu es or highly variable study residues. Neither event actually occurred.

1. Site Description:

Test location: The field phase of the study was conducted at one location in Snook, Texas (NAFTA Region 6). One control plot and one treated plot were esta blished at the test site. The treated plot was divided into th ree replicate subplots. The treate d plot was located at 217 feet from the control plot. Accordi ng to the study, the test site sele cted was typical for the intended use of profenofos insecticide and miticide, and was representative of the cotton-producing regions of the test state with resp ect to soil type and climate.

Areas sprayed and sampled:

 Treated Plot: 60 ft x 95 ft (5,700 ft 2 

### ); each sub plot was 20 ft x 95 ft (1,900 ft 2 

### )

 Control Plot: 60 ft x 80 ft (4,800 ft 2 

### )

Meteorological Data: Weather data were prov ided for the study duration (planting in May 1991 through last sampling interval in September 1991) for air temperatur e (daily minimum and maximum) and precipitation (daily ). Precipitation was monitored on-site and temperature was monitored from a nearby airport (~4 miles away). Additionall y, on-site weather data were collected on the time of each application for wind speed/direction, air and soil temperature, % cloud cover, and first rainfall af ter application. Historical mont hly average precipitation and air temperature data were also provided (measured ~2-4 miles away). Temperature was considered normal during the trial period. As shown in Table 1 below, monthly mean minimum temperatures were 66 to 73°F and monthly mean maximum temperatures were 89 to 96°F. The first rainfall after applic ation occurred 40 minutes ( 0.1 in.) for application 4, and 3 to 14 days for the remaining applications (0.1 to 0.25 in.). Precipita tion totalled 0 to 5.54 inches per month of the study, and was considered below normal in July during the application phase and above normal in August after the last application. The firs t rainfall after the last application occurred on 3DAT6 (0.25 in.). Rainfall after the last application also occurred on 12DAT6 (0.73 in.), 13DAT6 (0.1 in.), 19 DAT6 (0.05 in.), 28DAT6 (2.1 in.), and 32-35DAT6 (4.83 in.). ThePage 8 of 20 

### rainfall on 28DAT6 occurred prior to sample co llection, however, plants were allowed to dry prior to collection. In-furrow ir rigation, using river water, was applied once to maintain normal crop growth and development.

Table 1. Weather Conditions (Monthly) During Study Period

Month Temperature (°F) (mean min/max) Total Rainfall (inches) Irrigation (inches) May 1991 67/92 0.00 - June 1991 66/94 5.54 - July 1991 73/95 0.22 2.00 August 1991 73/96 3.22 0.00 September 1991 73/89 4.83 0.00



### 2. Crop Characteristics:

Crop, variety: Cotton, D&PL90

Row width, plant spacing: Not reported

Stage of growth: The first application was made approximately 1 week before full bloom and each subsequent application was made at 5-7 day intervals. The growth stage at each sampling interval was not provided.

Other products used on crop: Fe rtilizer and maintenance pestic ides were applied as needed during the trial period. Mainte nance chemicals applied incl uded Cotoran 4L, Karmex 4L, MSMA 6E, Orthene 90S, Vydate, Vydate CLU, Capture PBO8, and Azodrin. No orgnophosaphate pesticides were app lied within 2 weeks of the initia l test substance application.

3. Application Rates and Regimes :

Application rate(s): Six appli cations were made to cotton folia ge at a target rate of 1.00 lb ai/A/application for a total seasonal rate of 6 lb ai/application. The actua l application rates were 0.92 lb ai/A for the first applic ation, 1.02 lb ai/A for the second and third applications, 0.99 lb ai/A for the fourth application, and 0.97 lb ai/A for the fifth and sixth applications. The label reports a maximum application rate of 0.5 lb a i/A/application, with a ma ximum seasonal rate of 5 lb ai/A/season.

Application Regime: Six foliar broadcast sp ray applications were made using a 5-7 day retreatment interval (7/8/1991, 7/13/1991, 7/18/ 1991, 7/23/1991, 7/28/1991, and 8/2/1991). The label reports a minimum retreatment interval of 5 days.

Application Equipment: John Deere Hi-cycle sp rayer with a 20-ft boom (12 nozzle spaced at 20 inches).

Spray Volume: 19.4-21.5 gallons per acre (GPA). The label reports a minimum spray volumePage 9 of 20 

### of 3 to 5 GPA for spray solutions diluted with water.

Equipment Calibration Procedures: Sprayer cali brations were performed the day of each application (prior to applicati on) by measuring the output of th e 12 nozzles for 30 seconds. The tractor speed was calculated from three test runs prior to each application.

Spray Verification: Spray verification was performed by placing 15 cm diameter filter paper (in petri dishes) in each subplot prior to each appl ication. The samples were placed at crop canopy level. The filter paper was coll ected immediately afte r each application and stored frozen until analysis. Based on the nominal application rate of 1 lb ai/A, the aver age percent profenofos expected per application ranged from 14.5±2.2% (application 6) to 66.3± 4.0% (application 1), with a mean of 50.3±29.4%

4. Dislodgeable Foliar Residue Sampling Procedures:

Method and Equipment: DFR samples consisted of 40 leaf disks which were collected with a ~2.5 cm diameter leaf punch sampler. The punc h samples were collecteddirectly into prelabelled glass jars.

Sampling Procedure: Leaf disc s were collected by avoiding the outer rows and a 10 ft. border at each plot. The leaf surface was dry at each sa mpling event. After each sample was collected, the jar containing the leaf punches was removed from the punch apparatus, capped, placed in a cooler with ice or ice substitute, and taken to the dislodging area.

Total Surface Area per Replicate: The total surface area of each sample was reported as 404 cm 2



### . For calculation purposes, HED assumed a leaf surface area of 400 cm 2



### . Replicates per activity:

 Replicates per sampling time: At each sampli ng interval, three treated replicate samples were collected from the treated plot. A si ngle control sample was collected at each sampling interval from the untreated plot.

 Number of sampling times: There were a to tal of 14 sampling events, including five sampling events before the last application.

Times of sampling: Leaf samples were collected immediately before applications 1, 3, and 6, as soon as foliage dried after appl ications 1, 3, and 6, and at 1, 2, 3, 7, 14, 21, 28, and 35 days after application 6.

Part(s) of foliage sampled: The leaf disks we re cut from the center of a leaf excluding any primary veins.Page 10 of 20 

### 5. Sample Handling: After each sample was collected, the jar containing the leaf punches was removed from the punch apparatus, capped, stored in a cooler with ice substitute, and taken to the dislodging area (laboratory ro om of the Nemec Aqriservices, Inc.). The extraction was performed by Nemec Agriservies, Inc. personnel, but Nemec Agrise rvices did not participate in the collection of the leaf disks. After dislodging, all samples were placed in freezers set tomaintain temperatures at or below freezing (-18oC to -29oC). All samples were shipped to ENCAS Analytical Laboratories via ACDS freezer tr uck within 19 days of sampling. Samples were received at the analytical f acility from August 2, 1991 through September 24, 1991 and stored at a temperatures between -23oC to -27oC until the samples were thawed for subsampling

. The interval between sample collecti on and extraction for analysis was 40-73 days for field samples and 63-105 days for field fortification samples.

6. Analytical Methodology:

Dislodging Solution: Residues were dislodged with a 0.004% Ae rosol® OT solution, prepared by diluting 2 mL of 75% Aerosol® OT with 100 mL water.

Dislodging Procedure: In the fi eld, the leaf disks were extrac ted three times with 75 mL of 0.004% Aerosol OT solution by shaking the sample for 2 minutes per extraction. The resulting solutions were combined (225 mL total) and the foliage was saved for possible analysis.

Time Interval (sample collection to dislodging): According to the Study Report, samples were dislodged right after collection (exact times not provided).

Detection methods: Sodium chloride was added to an aliquot of the dislodging solution sample, and then the sample was partitioned three times with hexanes:dichloromethane (80:20). The organic phases were filtered th rough a sodium sulfate pad and the phase was reduced to dryness, reconstituted, sonicated, and analyzed by gas chromatography with flame photometric detection (GC/FPD) in the phosphorous mode. A summary of the typical GC/FPD conditions are shown in Table 2.

Table 2. Typical GC/FPD Instrument Parameters

Instrument: Tracor Model 540 Gas chromatograph with a flame photometric detector (FPD) Column: Fused silica megabore capillary 15-M X 0.548 mm DB-5 column

Gases Carrier: Helium = 1.0 mL/min Detector: Hydrogen = 100 mL/min Air = 150 mL/min Injection Volume: 5.00 μ L, direct Temperatures: Injector: 230°C Detector: 230°C Oven Temp.: 200°C Approximate Retention Times: 4.2 minutesPage 11 of 20 

### Method validation: Residues of profenofos in dislodging solution were de termined using method ENC-5/91. The method was verified prior to sa mple analysis using cotton leaf control dislodging solution samples fortified with prof enofos at concentrations of 0.005, 0.05, and 0.5 μg/mL. Individual method validation recoveries (with correction for residues in control) ranged from 90% to 102% with an overall m ean recovery of 97% ± 3.7% (n= 9). The LOQ was 0.005
μ g/mL (corresponding to 0.003 μg/cm 2 

### leaf disk surface area ba sed on a dislodging solution sample volume of 225 mL and a leaf surface area of 400 cm 2 

### ). The LOD was not reported.

Instrument performance: For all runs, standard s of known concentration were injected at the beginning and end of the run, as well as interspersed throughout the run.

Quantification: Concentrations of profenofos we re interpolated from the standard calibration curve, which was generated using linear regression.

7. Quality Control:

Lab Recovery: Two 

### concurrent laboratory fortif ied samples were analyzed with each set of field samples. Control dislodging solution samples were fortified with profenofos at concentrations of 0.005, 0.05, 0.5 and 5.0 μg/mL (assuming 225 mL samples = range of 1.125 μg/sample to 1,125 μg/sample). Individual concurre nt laboratory recoveries (correct ed for any contro l contribution) ranged from 92% to 134%, with an overall mean recovery of 112% ± 11.2% (n=14). Residues of profenofos were not detected a bove the LOQ (0.003) in the lab c ontrols, but were detected at 0.0002 μg/mL in one laboratory control sample.

Field blanks: One control sample was collected at each sampling interval from the untreated plot. Residues of profenofos were not detected above the LOQ at the pre- or post-treatment 1 intervals, but were detected at all other sampling intervals at levels ranging from 0.004 to 0.040 μg/cm 2



### . Field recovery: Field fortifica tion samples were prepared at th e end of each sampling interval. Samples were prepared in duplicate at one fortification level of 0.050 μg/mL (11.3 μg profenofos/225 mL of 0.004% Aerosol OT soluti on which had been shaken with control cotton leaf discs). A control blank of non-fortified Ae rosol OT solution was also prepared at each interval. The samples were shipped and stored wi th the field samples, but were analyzed in separate analytical sets than the field samples.Page 12 of 20 

### The profenofos residues found in th e field fortification samples were reported with correction for individual control contribution, which were <LOQ at the pre- a nd post-treatment 1 intervals and were detected at 0.007 to 0.019 μg/mL at all ot her sampling intervals. Additionally, the profenofos residues were corrected for concurre nt laboratory recover y. Table 3 provides a summary of the field fortificati on recoveries. The overall mean fi eld fortification recovery was 113±16.5%. The profenofos levels found in the DF R samples bracketed the fortification level.

Table. 3 Summary of Fiel d Fortification Recoveries

Sampling Interval Fortification Level a (μg/sample) n Recoveries (%) b,c Average Recovery (%)
Pre-App 1

11.3 (0.05 μg/mL) 2 84, 94 89
Post-App 1 2 100, 92 96
Pre-App 3 2 100, 97 99
Pre-App 3 2 110, 102 106
Pre-App 6 2 104, 92 98
Post-App 6 2 104, 100 102

1DAT6 2 134, 121 127

2DAT6 2 113, 119 116

3DAT6 2 112, 105 108

7DAT6 2 121, 129 125

14DAT6 2 142, 124 133

21DAT6 2 142 , 113 127

28DAT6 2 116, 126 121

35DAT6 2 129, 145 137
Overall (n=28) 113±16.5

a. Fortification level is equivalent to ~0.050 μg/mL, or 0.028 μg/cm 2 based on a 400 cm 2 sample. b. Reported residues were corrected for the control contribution and concurrent laboratory recovery.

c. Recoveries outside of 70-120% are in bold.



### Formulation: Curacron® 8E is an emulsifiab le concentrate formulation containing a nominal 73% of ai (8 lb ai/gal). Anal ysis of formulation samples taken at each application showed the amount of profenofos was 93 to 107% of nominal.

Tank mix: Tank mix samples were collected in duplicate prior to each application. Average recoveries ranged from 27.6 to 74.9%, with an overall recovery of 43.5 ± 17.2% (n=18). The study stated that no reason could be found for the low recoveries.

Travel Recovery: Travel recovery samples were not prepared.Page 13 of 20 

### Storage Stability: A storage st ability study was not conducted.

II. RESULTS AND CALCULATIONS

The Registrant provided DFRs in μg/sample with correction for laboratory recovery (uncorrected results were not provi ded) and in μg/cm 2 

### (based on a 404 cm 2 

### leaf surface area) with and without correction for the overall average field fortificat ion recovery (113.0%). EPA calculated DFRs in μg/cm 2 

### using the same field fortification correcti on factor, but used a l eaf surface area of 400

cm 2 

### . Table 4 provides a summary of the profen ofos DFR values and statistical summaries calculated by EPA.

The highest average DFR was 2.11 μg/cm 2 

### , which occurred immediately after the first application (20.4% of application rate). The average DFR immediately prior to the last (sixth) application was 0.054 μg/cm 2 

### . The maximum average DFR after th e last application occurred at the first sampling interval (after spra y dried) with a value of 1.74 μg/cm 2 

### (16.0% of application rate). DFRs declined rapidly in the first three days to 0.076 μg/cm 2 

### (0.7% of application rate) at 3DAT6, and reached equilibrium at 21DAT6 with a value of 0.0086 μg/cm 2 

### (0.08% of application rate). DFRs on 28DAT 6 and 35DAT6 were 0.0066 and 0.0086 μg/cm 2 

### , respectively.

The Registrant assumed first-order dissipation kinetics to generate dissipation curves for profenofos. The Registrant conducted linear regr ession analyses using the natural logarithm of average DFR values from the following samp ling intervals: 1) 0DAT6 through 35DAT6 (all sampling intervals after the last application) , 2) 0DAT6 though 21DAT6 (sampling intervals through the point of equilibrium), 3) 0DAT6 through 3DAT6 (first part of bi-phasic pattern), and 4) 3DAT6 through 35DAT6 (second part of bi-phasic pattern). The Registra nt’s calculated halflives for these intervals, re spectively, were 5.7 days (R 2 

### = 0.659), 3.4 days (R 2 

### = 0.723), 16 hours (R 2 

### = 0.924), and 10.8 days (R 2 

### = 0.731).

EPA first assumed first-order di ssipation kinetics and conducted a linear regression analysis using the corrected average DFRs from immediat ely after the last application (0DAT6) through the last sampling interval (35DAT6), and determined a half-life of 5.7 days (R2 = 0.6694). However, the regression analysis did not appear visually to be a good fit for the data, and a comparison of the 0DAT6 actual and predicted DFRs show that the actual DFR (1.74 μg/cm 2 

### ) is ~4x higher than the linear regr ession predicted DFR (0.2005 μg/cm 2 

### ). Therefore, EPA did additional analysis and conducted a biphasic (“hockey stick”) regr ession analysis using Excel’s Solver, and the corrected average DFRs from im mediately after the last application through the last sampling interval. This regr ession analysis appears (visually) to be a better fit of the data, and provides a predicted Day 0 value of 2.4 μg/cm 2



### .

III DISCUSSION:

There were two issues noted in the review of the study. One was with regard to the field fortification recoveries. It was noted that (1) only one field for tification level was used; the EPA guideline recommends a minimum of two field fo rtification levels; (2) the level chosen wasPage 14 of 20 

### below many of the field samples (11.3 ug/sample for the field fortification samples vs a maximum of 1,300 ug/sample for the field samples); and (3) several recoveries were outside the guideline range of 70-120%. However, the study report did provide additional information with respect to laboratory recovery samples, which included a rang e of concentrations from 1.125 ug/sample up to 1,125 ug/sample, with recoveries ranging from 92 – 134%; therefore, it is unlikely that the field fortification issues would impact the utility of the study for risk assessment. The other issue of note in the study is that profenofos residues were detected in the untreated control plot samples and in the bla nk field fortification samples at all sampling intervals except for the pre- and post- treatment 1 intervals. Th e profenofos levels were 1.58 to 16.0 μg for the untreated control plot samples a nd 1.58 to 4.28 μg for the field fortification blank samples.Page 15 of 20 Table 4. DFRs for Cotton Leaves Treated with Profenofos a

Sampling Interval (days) Measured Residue

(μg) b DFR (μg/cm 2 ) c Corrected DFR ( μ g/cm 2 ) d Arithmetic Mean ( μ g/cm 2 ) Standard Deviation ( μ g/cm 2 ) Coefficient of Variance (%) Natural Log of Mean ( μ g/cm 2 ) Percent of Application Rate Dislodgeable e

Pre 1 <LOQ <0.0025 0.0013 0.00125 0.000 0.000 -6.68 -- <LOQ <0.0025 0.0013 <LOQ <0.0025 0.0013

Post 1 (0DAT1) 1,300 3.25 2.88
2.11 0.678 32.2 0.75 20.4 722 1.81 1.60
835 2.09 1.85

Pre 3 (5DAT2) 6.08 0.015 0.013
0.012 0.002 17.5 -4.39 0.11 4.50 0.011 0.010
6.30 0.016 0.014

Post 3 (0DAT3) 833 2.08 1.84
1.73 0.426 24.67 0.55 15.1 567 1.42 1.25
941 2.35 2.08

Pre 6 (5DAT5) 26.8 0.067 0.059
0.054 0.012 22.7 -2.91 0.50 28.6 0.072 0.063
18.2 0.046 0.040

0DAT6 1000 2.50 2.21
1.74 0.411 23.5 0.56 16.0 655 1.638 1.45
709 1.773 1.569

1DAT 6 156 0.390 0.345
0.325 0.078 24.1 -1.12 3.0 108 0.270 0.239
177 0.443 0.392

2DAT6 67.1 0.168 0.148
0.109 0.035 32.5 -2.22 1.0 36.5 0.091 0.081
43.9 0.110 0.097

3DAT6 47.9 0.120 0.106
0.076 0.026 33.6 -2.57 0.70 26.8 0.067 0.059
29.0 0.073 0.064

7DAT6 13.1 0.033 0.029
0.026 0.003 12.9 -3.66 0.24 11.7 0.029 0.026
10.1 0.025 0.022

14DAT6 4.73 0.012 0.010
0.012 0.004 31.2 -4.39 0.11 4.50 0.011 0.010
7.65 0.019 0.017

21DAT6 4.73 0.0118 0.010
0.0086 0.003 31.7 -4.75 0.08 4.50 0.0113 0.010
2.48 0.0062 0.0055

28DAT6 3.38 0.0085 0.007
0.0066 0.001 11.5 -5.01 0.06 2.93 0.0073 0.006
2.70 0.0068 0.006
35DAT6 3.83 0.0096 0.0085 0.0086 0.001 8.9 -4.75 0.08Page 16 of 20 Table 4. DFRs for Cotton Leaves Treated with Profenofos a

Sampling Interval (days) Measured Residue

(μg) b DFR (μg/cm 2 ) c Corrected DFR ( μ g/cm 2 ) d Arithmetic Mean ( μ g/cm 2 ) Standard Deviation ( μ g/cm 2 ) Coefficient of Variance (%) Natural Log of Mean ( μ g/cm 2 ) Percent of Application Rate Dislodgeable e

4.28 0.0107 0.0095
3.60 0.0090 0.0080

a. Six applications were ma de at a rate of 0.92-1.02 lb ai/A /application (approx. 10.3 -11.4 μg/cm 2 ). b. LOQ = 0.003 μg/cm 2 ; LOD was not reported.

c. DFR = Measured residue (μg) / leaf surface area (400 cm 2 ) d. DFR values were corrected for the average field fortification recovery (113%). For statistical calculations, residues <LOQ were assigned a value of 1⁄2 LOQ.

e. Percent of Original Application Rate Dislodgeable = DFR (μg/cm 2 ) / Amount applied (μg/cm 2 ) x 100%.Page 17 of 20 

### Appendix A. First Order Kinetics Regression

Study Summary

MRID 42851304 Crop Cotton Region/State Region 6/Texas Application Rate (lb ai/acre) 1

Dislodgeable Foliar Residue (DFR) Analysis Re-entry Day (Day After Treatment) Measured DFR (ug/cm 2 ) Individual Samples Average Standard Deviation

0.000 2.2124 1.74 0.4106 1.4491 1.5686

1.00 0.3451 0.325 0.0783 0.2389 0.3916

2 0.1485 0.109 0.0353 0.0808 0.0971

3 0.1060 0.076 0.0257 0.0593 0.0642

7 0.0290 0.0257 0.0033 0.0259 0.0223

14 0.0105 0.0124 0.0039 0.0100 0.0169

21 0.0105 0.0086 0.0027 0.0100 0.0055

28 0.0075 0.0066 0.0008 0.0065 0.0060

35 0.0085 0.0086 0.0008 0.0095 0.0080

EPA/OPP/HED 1 st Order Kinetics DAT ln(DFR) Modeled (ln DFR) Modeled DFR

0.00 0.556 -1.607 0.200

1.00 -1.123 -1.728 0.178

2 -2.218 -1.850 0.157

3 -2.571 -1.971 0.139

7 -3.660 -2.456 0.086Page 18 of 20 14 -4.386 -3.304 0.037

21 -4.752 -4.153 0.016

28 -5.014 -5.001 0.007

35 -4.752 -5.850 0.003

Residue Dissipation Decay constant (k) -0.121 Daily Dissipation (%) 11% Half-life (days) 5.7

Initial Residue C 0 (ug/cm 2 ) 0.2005
% of application rate 1.79%Page 19 of 20 

### y = -0.1212x - 1.6072 R2 = 0.6694

-7.000 -6.000 -5.000 -4.000 -3.000 -2.000 -1.000 0.000 1.000

0.00 5.00 10.00 15.00 20.00 25.00 30.00 35.00 40.00ln DFR (ug/cm2)



### DAT ln DFR vs. DATPage 20 of 20 

### Appendix B. Biphasic (“Ho ckey Stick”) Regression

"Hockey Stick" (untransformed residuals) Modeled DFR Squared Residuals 1.74 0.22 1.74 0.09 1.74 0.03 0.33 0.00 0.33 0.01 0.33 0.00 0.11 0.00 0.11 0.00 0.11 0.00 0.08 0.00 0.08 0.00 0.08 0.00 0.03 0.00 0.03 0.00 0.03 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Sum of Squared Errors (SSE) 0.35 C 0 (ug/cm 2 ) 2.4 C 0 : % of application rate 23% Decay constant 1 (k 1 ) -2.015 Decay constant 2 (k 2 ) -0.272 Inflection Point (day) 1