### Page 2 of 38 1.0 Introduction

This document serves as the human health risk assessment for met hyl bromide which is based on the results of the recent emission studies completed under the MBIP research plan. These studies can be identified by the following information:

EPA MRID 480060-01: Monitoring of Methyl Bromide and Ch loropicrin Field Emissions From Shank Applications at Shallo w and Deep Injection Depths ; Authors: Ajwa, H. and Sullivan, D,; Sponsor: Methyl Bromide Industry Panel, LLC c/ o David McAllister Chemtura Corporation 1801 Highway 52, West Lafayette IN 93905

EPA MRID 481076-01: Monitoring of Methyl Bromide and Ch loropicrin Field Emissions From Shank Applications (Bedded and Broadcast) and a Methyl Bromide Hot-Gas Application Under Totally Impermeable Film ; Authors: Ajwa, H. and Sullivan, D, ; Sponsor: Methyl Bromide Industry Panel and Hendrix and Dail, Inc.

This document provides several types of information including:

• Section 2: Study Results – The design and results of the studi es are summarized as well as any data quality issues which have been identified are described in this section.

• Section 3: Flux Calculations - The flux calculations completed ba sed on the data are described. Values are also compared to previous em ission profiles used for methyl bromide.

• Section 4: 1 st 

### Principles Factors – The different conditions in the fields which may have an impact on the factors which regulate emissions are presented.

• Section 5: Risk Analysis - Modeling outputs are summarized a nd discussed in this section.

• Section 6: Conclusions - This section contains a summary of the overall conduct of the studies and analysis based on there results.

### Page 3 of 38 2.0 Study Results

The results of the MBIP monito ring studies are summarized in this section. The data from California are presented in Section 2. 1 while the results from the Florid a site are summarized in Section 2.2.

2.1 California Study Results (MRID 480060-01)

The design of this study featured the treatment of five 1 acre field plots located in Wasco California on the same day separated by a sufficient distance so th e emissions from each would not interfere with one another. The treatment conditions examined different t ypes of agricultural practi ces. All field sites were tarped with a “TIF” film except the control plot which was tarped with the current industry standard LDPE film. 3 4 

### In order to vary the effect of various cultural practices, different combinations of fumigation types (strip or broadcast), injection dept hs (shallow or deep), and the us e of reactive adjuvants (potassium thiosulfate at field 3) were utilized per the research plan. All applic ations were made on June 2, 2009 by a commercial applicator using a 50/ 50 methyl bromide/chloropicrin product (Tri-Con 50/50 EPA Reg 11220- 10). At fields 1 through 3 a “Noble Plow” shank was us ed and at sites 4 and 5 fo rward swept chisels were used. Tarp cutting was complete d on all fields on June 8, 2009 and removal 1 day later on June 9, 2009 (i.e., sample period 18 is tarp cutting). The specific scenarios exam ined are summarized in Table 1 below.

Table 1: Description of 5 Application Sc enarios At California Site (MRID 480060-01)

Scenario Application Method Injection Depth (inches) Nominal Application Rate (lb/treated acre) * Soil Sealing Method Product (Tri-Con 50/50) Methyl bromide Chloropicrin

1 Shallow, broadcast tarped 12 360 180 180 Polyethylene tarp

2 Shallow, broadcast tarped 12 360 180 180 EVOH Resin Barrier Tarp

3 Shallow, broadcast tarped 12 360 180 180 EVOH Resin Barrier Tarp &

potassium thiosulfate

4 Deep, strip, tarped (50% of field area treated) 18 360 180 180 EVOH Resin Barrier Tarp

5 Deep, broadcast, tarped 18 360 180 180 EVOH Resin Barrier Tarp *All application rates are based on the amount applied per treated area. In a broadcas t application where an entire contiguous field is treated the entire ar ea is accounted for in the calculation. In situations where beds or strip fumigation is completed only the parts of a treated field where the fumigant is actually applied are included. If desired this information, along with information on bed spacing can be used to calculate a broadcast equivalent rate.

3 The tarp was referenced in the study repor t as “10.5-foot wide, 1-mil thick, EVOH-re sin barrier tarp: VaporSafeTM by Raven Indu stries, Sioux Falls, SD.” A March 31, 2010 letter to J. Dawson indicating Kuraray has concerns over the description of the films used in the study. The letter indicated the copolymer “EVOH” can have a wide spectrum of properties based on the comonomer ratios and the specific manufacturing process of the material s. Kuraray would have preferred the report refer to the resin as “ EVALTM , more specifically EVAL SP292B or EVAL H171B ” as these specific grades we re utilized in all TIF testi ng conducted over the past three years. The selection of one grade over the other depends on the relationship between the manu facturing equipment capabilities and the desired film width, w ith EVAL SP292B providing a wider processing window than EVAL H171B.

4 Note that current methyl bromide use permit conditions do not allo w for use of high barrier films (e .g., VIF) in California com mercial agricultural production. This study used such a film for resear ch purposes but commercial implementation in California would d epend upon a modification of these conditions by the Ca lifornia Department of Pe sticide Regulation which is also reviewing these data.

### Page 4 of 38 An overview of the research plots is presented in Figures 1, 2, and 3. Figure 1 shows each plot with associated GPS coordinates. Figure 2 is similar but describes the scenario associated with each plot. Figure 3 illustrates the sampler locations around field plot 1. A similar approach was used for all plots in this study. All flux values were quantifie d in this study using the indirect method. Methyl bromide emission levels from each field were determined by measuring ai r concentrations in eight directions surrounding the field for six hour periods for the firs t two days, then every 12 hours for the remainder of the eleven days of monitoring, except for during the tarp splitting and removal phases in which the intervals were reverted to every 6 hours for this 24 hour period. Air was pumped th rough Anasorb 747® solid so rbent tubes to capture methyl bromide in the air at each sampler. Methyl bromide was extracted from the charcoal tubes with carbon disulfide and analyzed by gas chromatography using an electron capture detector. Appropriate weather data were collected and sonic anemometers were used at each plot.

Figure1: Satellite Image of California Pl ots with GPS Coordinates (MRID 480060-01)

Figure 2: Aerial Photograph of California Plots with Scenario Descriptors (MRID 480060-01)

### Page 5 of 38 Figure 3: California Field Plot 1 with Sampler Locations (MRID 480060-01)



### Background samples indicated that no cross-c ontamination occurred during the monitoring. Analytical recovery values were acceptable and no corre ctions to measured residue values were warranted. The average percent recovery was 106.12% with a sta ndard deviation of 13.8%. Results for blind positive control samples also exceeded 100 % r ecovery. [Note: Three samples of th is type were inadvertently left out of ice storage during shipment and were consider ed invalid by the investigators – this was verified during the review process so the resu lts for these samples were not includ ed herein.] Results for duplicate samples also were very close indicating that there were no significant sample collection issues. The results of emissions studies of this type are used as the basis for developing a flux profile that is associated with the application method and the conditions on/around a particular field afte r application. Th e calculation of these profiles for each field site in this study is described below in Section 3.

Like previous field research on methyl bromide the majority of the cumulative emissions occurred in the first few sampling periods after a pplication and no significant changes in emissions were seen as a result of tarp cutting. This is illustrated by total mass loss over time, as calculated by the investigators, for each plot (Figure 4). Total emissions from Plot #1 (shallow broadcast under polyethylene tarp) were 62.48%. 5 

### The total mass loss of methyl bromide from Plot #2 (shallow broadcast under VaporSafeTM) was 45.5%. When potassium thiosulfate was applied to the soil surface during the deploymen t of VaporSafeTM (Plot #3), the mass loss of methyl bromide was reduced to 22.13%. The total mass loss of methyl bromide from the deep strip application under VaporSafeTM was 41.77% (Plot #4). The total mass loss from the deep broadcast application under VaporSafeTM was 27.11% (Plot #5). [Note: Tarp cutting occurred in sample period 18 and in each case where VaporSafeTM (plots 2, 3, and 5) was used for broadcast applications there is an inflection which can be observed in Figure 4. Th is is likely due to methyl bromide being retained under the tarp and then being released by the cutti ng operation. In each case there appears to be a substantive portion of the total mass released occurring in this timeframe.]

5 For comparative purposes, the single day emi ssion ratio established by th e California Department of Pesticide Regulation permi t conditions for methyl bromide is 0.25 and these current data indicate about 45% dissipated on the 1 st day. This phenomenon would be expected given anticipated variability in emissions due to the number of possible factors which can influence emissions.

### Page 6 of 38 Figure 4: Total Mass Loss for Methyl Bromide At Calfornia Test Sites (MRID 480060-01)


### 2.2 Florida Study Results (MRID 481076-01)

The design of this study featured th e treatment of 3 field plots (0.4 to 0.6 acres) located just north of Fort Pierce Florida on the same day separated by a su fficient distance so the emissions from each would not interfere with one another. The tr eatment conditions examined different types of agricultural practices. All field sites were tarped with a “TIF” film. 6 

### No control plot using typical films was incorporated as in the California study described above. In order to vary the effect of va rious cultural practices, different fumigation types were considered (i.e ., tarped shank injection, broadcast and hot-gas). Other factors such as the use of reactive adjuvants (potassium thiosulfate) or different film types (i.e., metalized) were not evaluated in the field even though they were specified in the MBIP resear ch plan also as described above. The evaluation of emissions from a hot-gas treatment were also not specifically included in the MBIP research plan but have been previous ly discussed with the Ag ency by other stakeholders . It is not clear why no further attempts were made to evaluate emissions using broadcast applications after the reported tarp failure for that appl ication method at S ite 3 of this study. 7



### All applications were made on January 15, 2010 by a commercial applicator. Application using a 50/50 methyl bromide/chloropicrin mixture for the tarp ed raised bed field plot 1 was made using “extralong back swept gas knives” in conjunction with a “K ennco-style bedder.” Hole punching was not included

6 Report described the films used in this study as follows “Vapor SafeTM (manufactured by Raven In dustries, Sioux Falls, South Dak ota); also known as “TIF” or “Totally Imperm eable Film”; which is a 5-laye r EVAL-resin barrier film (EVAL is a specific product of EVOH re sin manufactured by Kuraray Amer icas, Houston, Texas).”

7 In the T. Heinzman letter (8/6 /10) it was indicated that the California data should be considered representative of other regi ons (i.e., Florida) and the argument is appropriate because field capacity was 70% in California and >100% in Florida in similar soils. It also in dicated Florida soils tend to have higher water content than in California. A comparison was also made using ch loropicrin emissions data. The Agency agrees that California emissions are probably the best general approximation for Florida situations if specific data are lacking but t hat many site specific issues have to be considered that were not when attempting to compare specific sites such as was done in this letter ( e.g., temperature, compaction level, application equipment specifics, etc.). It is also not appropriate to develop a rationale using chloropicrin data because of the significant physical/chemica l differences between the two fumigants (e.g., meth yl bromide is more stable and much more volatile ).

The letter also indicates that basically 30% of growers use me talized tarps for commercial produc tion in Florida. Metalized fi lms were to be evaluated in this study but no additional explanation was provided concerning why this aspect of the research plan was deleted. Finally, the letter also indicates that there are viable methods for gluing TIF/VIF tarps in commercial produc tion. No further explanation of these practices relative to the failure at the Florida site was discussed.

### Page 7 of 38 in this study because for high barr ier tarps it is typically done between 21 and 28 da ys after application according to the study report which the investigators noted was impractical from a field research perspective in this case. At field plot 2 a hot-gas application was completed. Th e field set-up was completed the night prior to the application event. Drip tape was installed at approximately 9 foot intervals across the field. The hot-gas kettles operated at a temperat ure of approximately 155 degrees F a nd fumigant was applied at a rate of about 3 lb/minute. Tarp cutting for the hot gas application site was completed on January 22, 2010 (i.e., sampling period 19). The specific scenarios examined in this study are summarized in Table 2 below.

Table 2: Description of 2 Application Scenarios At Florida Site (MRID 481076-01)

Scenario Application Method Injection Depth (inches) Nominal Application Rate (lb/treated acre)* Soil Sealing Method Product Methyl bromide Chloropicrin

1 Shank, bedded, Tarped (59% of field area treated) 8 470 (50/50 product) 235 235 EVOH Resin Barrier Tarp

2 Hot-gas, tarped 0 435 (98/2 product) 426 9 EVOH Resin Barrier Tarp *All application rates are based on the amount applied per treated area. In a broadcas t application where an entire contiguous field is treated the entire area is accounted for in the calculation. In situations where beds or strip fumigation is completed only the parts of a treated field where the fu migant is actually applied are included. If desired this information, along with information on bed spacing (59%) can be used to calculate a broadcast equivalent rate.



### An overview of the research plots is presented in Figures 5, 6, and 7. Figure 5 shows a satellite map of each plot. Associated GPS coordinates are also availa ble if needed. Figures 6 and 7 illustrate the sampler locations around each of the completed field plots. Flux values in this study were quantified using both the indirect (used for 1 st 

### sample collection period only for the tarped raised bed site while application still ongoing) and direct (Integrated Ho rizontal Flux approach used) sa mpling methods. Methyl bromide emission levels from each field were determined by m easuring air concentrations for six hour periods for the first two days, then every 12 hours for the rema ining monitoring periods (completed 10 days after application, 1/25/10). In-direct samp lers (N=8) were located approximately 12.2 meters from the corners and sides of each plot at a height of 1.5 meters. On-field samplers were located at 4 heights from the field including 0.3, 0.9, 1.8, and 3.0 meters. Air was pumped through Anasorb 747® solid sorbent tubes to capture methyl bromide in the air at each sampler. Me thyl bromide was extracted from the charcoal tubes with carbon disulfide and analyzed by gas chromatogr aphy using an electron captu re detector. Appropriate weather data were collected and sonic anemometers were used at each plot.

### Page 8 of 38 Figure 5: Satellite Image of Florida Plots (MRID 481076-01)

Figure 6: Florida Tarped Raised Bed Field Pl ot 1 with Sampler Locations (MRID 481076-01)

### Page 9 of 38 Figure 7: Florida Hot-Gas Field Plot 2 with Sampler Locations (MRID 481076-01)


### Background samples indicated that no cross-c ontamination occurred during the monitoring. Analytical recovery values were acceptable and no corre ctions to measured residue values were made by the investigators (i.e., laborat ory recovery = 87.5 ± 6.4% and field recove ry = 86.1 ± 8.0%). However, because the average field recovery values were less than 90 pe rcent residue values were corrected by the Agency for use in the calculation of flux estimates using the average field recovery value. Results for duplicate samples also were very close indicating that there were no significant sample collection issues. The results of emissions studies of this type are used as the basis fo r developing a flux profile that is associated with the application method and the conditions on/around a particular field afte r application. Th e calculation of these profiles for each field site in this study is described below in Sectio n 3. Like previous field research on methyl bromide the majority of emissions occurred in the first few sampling periods after application in the bedded scenario with a di urnal pattern the first few days. In th e hot gas treatment a diurnal pattern was noted following application for a day or so and a signifi cant emissions peak was observed as a result of tarp cutting.

The investigators calculated total mass loss for each plot (Figure 8). Tota l emissions from Plot 1 (tarped raised bed) were 15.26 percen t. The total mass loss of methyl bromide from Plot 2 (hot-gas) was 33.4 percent. [Note: Tarp cutting occurred in sample period 19 and at th e hot gas site and, as described for the California plots, there is an infl ection which can be observed in Figure 8. This is likely due to methyl bromide being retained under the tarp and then being released by the cutting operatio n. There appears to be a substantive portion of the total mass released occurring in this timeframe.]

### Page 10 of 38 0 5 10 15 20 25 30 35

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Sampling IntervalsCumulative Mass Loss of Methyl Bromide Relativeto Amount Applied (%) Hot Gas (Plot 2) Tarped Raised Bed (Plot 1)

Figure 8: Total Mass Loss for Methyl Brom ide At Florida Test Sites (MRID 481076-01)

### Page 11 of 38 3.0 Flux Calculations

The flux estimates calculated based on the MBIP m onitoring studies are summari zed in this section. The flux estimates for the data from California are pr esented in Section 2.1 while the flux estimates from the Florida site are summarized in Section 2.2.

3.1 California Study Flux Estimates (MRID 480060-01)

The Agency calculated flux using the indirect method and compared them against the values calculated by the investigators. Th e flux profiles were calculated based on the field conditions including the application rates used to make the applications in the study. For the purposes of completing the PERFUM analyses, these flux profiles were subsequently adjusted to an application rate for methyl bromide of 430 lb methyl bromide per acre treated which was the highest rate evaluated in the previous risk assessment for comparison purposes (Table 3). [Note: All PERFUM analyses contained an array of results based on a variety of application rates including the field application rate for each te st plot.] Appendix A contains the flux rates calculated for all sampling periods at all sites. All of the values presented in Appendix A are based on the application rate for the particular study site and have not be en adjusted to the 430 lb methyl bromide per treated acre rate.

Table 3: California Site Emission Profiles Adjusted To Maximum Application Rate - Basis For PERFUM Model Analyses (MRID 480060 -01)
Application rate (lb MB/treated acre) 189.1 180.3 177.9 202.6 181.1

Application start time 8:26 AM 8:28 AM 10:35 AM 1:18 PM (real time 18:30) 1:13 PM

Plot Application method 1 HDPE Shallow Broad cast 2 EVOH Shallow Broadcast 3 EVOH/KTS Shallow Broadcast 4 EVOH Deep Strip (50% area treated) 5 EVOH Deep

Broadcast

Hour Day 1 Day 2 Day 1 Day 2 Day 1 Day 2 Day 1 Day 2 Day 1 Day 2 Flux (μg/m 2 -s) Flux (μg/m 2 -s) Flux (μg/m 2 -s) Flux (μg/m 2 -s) Flux (μg/m 2 -s)
1 86.09 53.44 8.87 2.03 2.23 1.77 22.68 19.47 31.75 5.81 2 132.68 26.02 11.50 1.04 5.44 0.94 47.45 6.34 9.01 1.01
3 132.68 26.02 11.50 1.04 5.44 0.94 47.45 6.34 9.01 1.01
4 132.68 26.02 11.50 1.04 5.44 0.94 47.45 6.34 9.01 1.01
5 132.68 26.02 11.50 1.04 5.44 0.94 47.45 6.34 9.01 1.01
6 132.68 26.02 11.50 1.04 5.44 0.94 47.45 6.34 9.01 1.01
7 132.68 26.02 11.50 1.04 5.44 0.94 47.45 6.34 9.01 1.01 8 63.41 32.64 5.32 36.90 5.12 17.32 10.11 11.17 2.79 8.49 9 63.41 32.64 5.32 36.90 5.12 17.32 10.11 11.17 2.79 8.49 10 506.97 63.41 167.53 5.32 65.47 5.12 44.37 10.11 45.79 2.79 11 506.97 63.41 167.53 5.32 65.47 5.12 44.37 10.11 45.79 2.79 12 506.97 63.41 167.53 5.32 65.47 5.12 44.37 10.11 45.79 2.79 13 506.97 63.41 167.53 5.32 65.47 5.12 44.37 10.11 45.79 2.79 14 479.64 64.05 234.24 135.43 86.14 66.43 44.37 69.18 45.79 32.02 15 479.64 64.05 234.24 135.43 86.14 66.43 44.37 69.18 45.79 32.02 16 479.64 64.05 234.24 135.43 86.14 66.43 44.37 69.18 45.79 32.02 17 479.64 64.05 234.24 135.43 86.14 66.43 44.37 69.18 45.79 32.02 18 479.64 64.05 234.24 135.43 86.14 66.43 44.37 69.18 45.79 32.02 19 479.64 64.05 234.24 135.43 86.14 66.43 44.37 69.18 45.79 32.02

### Page 12 of 38 Table 3: California Site Emission Profiles Adjusted To Maximum Application Rate - Basis For PERFUM Model Analyses (MRID 480060 -01)
Application rate (lb MB/treated acre) 189.1 180.3 177.9 202.6 181.1

Application start time 8:26 AM 8:28 AM 10:35 AM 1:18 PM (real time 18:30) 1:13 PM

Plot Application method 1 HDPE Shallow Broad cast 2 EVOH Shallow Broadcast 3 EVOH/KTS Shallow Broadcast 4 EVOH Deep Strip (50% area treated) 5 EVOH Deep

Broadcast

Hour Day 1 Day 2 Day 1 Day 2 Day 1 Day 2 Day 1 Day 2 Day 1 Day 2 Flux (μg/m 2 -s) Flux (μg/m 2 -s) Flux (μg/m 2 -s) Flux (μg/m 2 -s) Flux (μg/m 2 -s)
20 86.09 53.44 8.87 2.03 2.23 1.77 22.68 19.47 31.75 5.81 21 86.09 53.44 8.87 2.03 2.23 1.77 22.68 19.47 31.75 5.81 22 86.09 53.44 8.87 2.03 2.23 1.77 22.68 19.47 31.75 5.81 23 86.09 53.44 8.87 2.03 2.23 1.77 22.68 19.47 31.75 5.81
24 86.09 53.44 8.87 2.03 2.23 1.77 22.68 19.47 31.75 5.81


### An example of the specific analyses used to dete rmine the flux values for each site is presented in Table 4 for plot 1 in this study. All analyses were completed using the indirect method. Graphs which illustrate the differences between the flux estimates cal culated by the investigators and those calculated by the Agency have also been developed and an example is presented in Figure 9. In general there is good agreement between the values calculated by the inve stigators and those calculated by the Agency. The Agency flux profiles have been used to estimate risk s using the PERFUM model. [Note: More detailed information can be provided if needed concer ning the details of the flux calculations.]

Table 4: Flux Calculat ion Details For California Field Plot 1 (MRID 480060-01)

Period Duration Agency Registrant

Estimated flux

μg/m 2 -sec Source Estimated flux μg/m 2 -sec Source

1 06/02/2009 09:00 - 13:00 222.95 Slope -LR 224.06 DPR Regression Slope 2 06/02/2009 13:00 - 19:00 210.93 Slope -LR 172.81 DPR Regression Slope 3 06/02/2009 19:00 - 01:00 37.86 Slope-L SR 64.21 Meas./Modl. Slope Fail 4 06/03/2009 01:00 - 07:00 58.35 Slope -LSR 15.61 DPR Regression Slope 5 06/03/2009 07:00 - 13:00 27.89 Slope-L SR 24.74 Meas./Modl. Slope Fail 6 06/03/2009 13:00 - 19:00 28.17 Slope -LR 22.08 Meas./Modl. Slope Fail 7 06/03/2009 19:00 - 01:00 23.50 Slope -LSR 21.43 Least Squares Slope 8 06/04/2009 01:00 - 07:00 11.44 Slope -LSR 11.79 Least Squares Slope 9 06/04/2009 07:00 - 19:00 14.36 Slope -LR 10.66 Meas./Modl. Slope Fail 10 06/05/2009 19:00 - 07:00 7.24 Slope -LSR 6.62 DPR Regression Slope 11 06/05/2009 07:00 - 19:00 5.08 Slope -LR 4.35 DPR Regression Slope 12 06/06/2009 19:00 - 07:00 3.06 Slope -LR 2.73 DPR Regression Slope 13 06/06/2009 07:00 - 19:00 3.68 Slope -LSR 2.89 DPR Regression Slope 14 06/07/2009 19:00 - 07:00 1.74 Slope -LR 2.08 Least Squares Slope 15 06/07/2009 07:00 - 19:00 3.45 Slope -LR 3.31 DPR Regression Slope 16 06/08/2009 19:00 - 07:00 1.80 Slope -LR 2.31 Least Squares Slope 17 06/08/2009 07:00 - 13:00 8.63 Slope -LR 6.10 Meas./Modl. Slope Fail 18 06/08/2009 13:00 - 19:00 8.55 Slope -LSR 7.01 DPR Regression Slope 19 06/08/2009 19:00 - 01:00 6.26 Slope -LSR 4.27 Least Squares Slope 20 06/09/2009 01:00 - 07:00 2.62 Slope -LR 2.16 DPR Regression Slope

### Page 13 of 38 Table 4: Flux Calculat ion Details For California Field Plot 1 (MRID 480060-01)

Period Duration Agency Registrant

Estimated flux

μg/m 2 -sec Source Estimated flux μg/m 2 -sec Source

21 06/09/2009 07:00 - 19:00 0.79 Slope -LR 0.63 DPR Regression Slope 22 06/10/2009 19:00 - 07:00 1.25 Slope -LR 1.20 DPR Regression Slope 23 06/10/2009 07:00 - 19:00 0.99 Slope-L SR 1.59 Meas./Modl. Slope Fail 24 06/11/2009 19:00 - 07:00 1.05 Slope -LR 1.05 DPR Regression Slope 25 06/11/2009 07:00 - 19:00 0.65 Slope-L SR 1.30 Below Detection Limit 26 06/12/2009 19:00 - 07:00 0.88 Slope -LR 1.01 Least Squares Slope 27 06/12/2009 07:00 - 19:00 0.62 Slope-L SR 1.22 Below Detection Limit 28 06/13/2009 19:00 - 07:00 0.87 Slope -LR 0.91 DPR Regression Slope 29 06/13/2009 07:00 - 19:00 0.52 Slope-L SR 1.30 Below Detection Limit 30 06/14/2009 19:00 - 07:00 0.58 Slope -LR 0.56 DPR Regression Slope 31 06/14/2009 07:00 - 19:00 0.02 Slope -LR 1.25 Below Detection Limit 32 06/15/2009 19:00 - 07:00 0.34 Slope -LR 0.82 Least Squares Slope

0.0 50.0 100.0 150.0 200.0 250.0 300.0

0 5 10 15 20 25 30 35 Time (Sampling Interval)Flux (μg/m2-sec) Agency
Registrant

Figure 9: Methyl Bromide Flux Estimates From California Field 1 (MRID 480060-01) Comparison of EPA and Registrant Calculated Values


### This study was designed to elucid ate the impacts of various cont rol measures on methyl bromide emissions. The measures which were incorporated into this study included the use of barrier films, the use of a reactive adjuvant, and various types of shanks. Additionally, ca re was exerted to ensure that applications occurred that are as compliant as possible with the good agri cultural practices that have been under development by the Agency for fumigant applica tions. The results indicate that the measures attempted in this research reduced peak emission ra tes compared to current typical practices and also impacted cumulative emissions (Figures 10 and 4, resp ectively). Figure 10 presents the emissions profiles used in the previous 2007 risk assess ment to evaluate current practices (i.e., tarped, bedded tarped, and deep untarped) and compares them to the emissions qua ntified in this study for the first 24 hours after application. The emission profiles ha ve all been adjusted to an a pplication rate of 100 lb methyl

### Page 14 of 38 bromide/treated acre to ensure a valid comparison. The profiles with the line s and dots represent the emission reduction options evaluated in this study. The results indicat e that regardless of the other conditions, the barrier tarp seems to reduce emissions as does the use of the thio sulfate adjuvant. Deep instead of shallow injection also seems to reduce emissions. The single day cumulative emission rate exceeded the value currently used fo r this application method in the California permit conditions for methyl bromide (i.e., about 45% compared to 25% for sha llow broadcast tarped – Pe rmit Condition 3B1). This phenomenon would be expected given anticipated natura l variability in emissions within similar practices due to the number of possible factor s which can influence emissions (e.g., moisture levels, field preparation, tarp characteristics, etc.). This trend was also observed for th e hourly flux estimates illustrated in Figure 10 where the normalized rates for Site 1 exceed those used as the basis for the current Agency risk assessment because of the same issues (D337288).

Finally, the ability of hi gh barrier tarps to subs tantively retain methyl bromide over time is illustrated by the information presented in Appendix A. Once tarp cutting occurred after the broadcast applications it is clear that retained methyl bromide is released at higher levels co mpared to the periods just prior to that operation and in some cases flux is simila r to values immediately af ter application. Thus, the risks associated with such a phenomena appear to be similar to or less than predicted for periods immediately after application. Howe ver, there are potential impacts on the duration of a buffer zone or the restricted entry interval for workers.



# Methyl Bromide Flux - Normalized To 100 lb/acre

0.00 25.00 50.00 75.00 100.00 125.00 150.00 175.00 200.00



### HoursFlux (ug/m2-s) 1 HDPE Shallow Broad cast 2 EVOH Shallow Broadcast 3 EVOH/KTS Shallow Broadcast 4 EVOH Deep Strip

5 EVOH Deep Broadcast Shallow, untarped

Tarped

Bedded, Tarped

Deep, untarped

Figure 10: Comparison of MBIP Flux From California Research Plots (MRID 480060-01) and Existing Flux Estimates For Similar Application Methods (Nor malized to 100 lb ai/acre) For 1 st 24 Hours After Application

### Page 15 of 38 3.2 Florida Study Flux Estimates (MRID 481076-01)

The Agency calculated flux using the integrated horizontal flux method sinc e on-field sampling was completed in this study and compared them against th e values calculated by the investigators (except for Period 1 which is based on the indirect method). The flux profiles were calculated based on the field conditions including the application ra tes used to make the applications in the st udy. For the purposes of completing the PERFUM analyses, these flux profiles were subsequently adjusted to the application rate for methyl bromide of 430 lb methyl bromide per acre trea ted and for the average field recovery value for this site (Table 5). [Note: All PERFUM analyses cont ained an array of applica tion rates including the field application rate for each test plot.] Appendix A contains the flux rates ca lculated for all sampling periods at all sites. All of the values presented in Appendix A are based on the application ra te for the particular study site and have not been adjusted to the 430 lb methyl bromide per treated acre rate.

Table 5: Florida Site Emission Profiles Adjusted To Maximum Applica tion Rate and For Average Field Recovery – Basis For PERFUM Model Analyses (MRID 481076-01) Application rate (lb MB/treated acre) 235 426

Application start time 09:45 AM 09:50 AM

Plot Application method EVOH Raised Bed EVOH Hot Gas

Hour Day 1 Day 2 Day 1 Day 2 Flux (μg/m 2 -s) Flux (μg/m 2 -s)

1 0.1 16.1 106.0 5.5
2 0.1 16.1 106.0 5.5 3 0.1 16.1 106.0 5.5
4 0.1 16.1 106.0 5.5 5 36.2 29.8 106.0 7.1
6 36.2 29.8 15.5 7.1
7 36.2 29.8 15.5 7.1 8 36.2 29.8 15.5 7.1
9 36.2 29.8 15.5 7.1 10 36.2 29.8 15.5 7.1
11 19.0 11.5 151.7 1.5
12 19.0 11.5 151.7 1.5 13 19.0 11.5 151.7 1.5
14 19.0 11.5 151.7 1.5 15 19.0 11.5 151.7 1.5 16 19.0 11.5 151.7 1.5 17 11.9 28.7 20.0 12.7 18 11.9 28.7 20.0 12.7 19 11.9 28.7 20.0 12.7 20 11.9 28.7 20.0 12.7
21 11.9 28.7 20.0 12.7
22 11.9 28.7 20.0 12.7 23 16.1 3.5 5.5 1.5
24 16.1 3.5 5.5 1.5

### Page 16 of 38 An example of the specific analyses used to determ ine the flux values for each site is presented in Table 6 for plot 1 in this study. Anal yses were completed using either th e indirect method or the integrated horizontal flux method as appropriate. Graphs which i llustrate the differences between the flux estimates calculated by the investigators a nd those calculated by the Agency ha ve also been developed and an example is presented in Figure 11. In general there is good agreement between the values calculated by the investigators and those calculated by the Agency. The Agency flux profil es have been used to estimate risks using the PERFUM model because the Agency corr ected measured air concentr ations for average field recovery.
More detailed information can be provided if need ed concerning the details of the flux calculations. It should be mentioned that the flux calculations in this study were complex because there was poor correlation in the regression analys is required by the Integrated Ho rizontal Flux (IHF) method. The investigators tackled this problem by using interpolated concentration valu es for all those periods that had constant concentration across the di fferent heights. Since, the regr ession for the IHF method requires a minimum of 3 points, the Agency used the outlier rem oval method which removes at least one of the four concentration values to improve th e overall regression. This approach significantly improved the regression for several periods. For all the pe riods that could not be modified using the outlier removal method, the LOQ value for the air concentration for that period was used to calculate flux by multiplying the LOQ value by fetch for that period. In the critical earlier time pe riods where more intense exposures are more likely the outlier removal method was appropriate.

Table 6: Flux Calculat ion Details For Florida Field Plot 1 (MRID 481076)

Period Duration Estimated flux μg/m 2 -sec Agency Registrant
1 1/15/2010 9:45 - 13:00 0.06 5.10 2 1/15/2010 13:00 - 19:00 19.79 21.52 3 1/15/2010 19:00 - 01:00 10.42 12.28 4 1/16/2010 01:00 - 07:00 6.47 6.55 5 1/16/2010 07:00 - 13:00 8.82 9.30 6 1/16/2010 13:00 - 19:00 16.34 15.57 7 1/16/2010 19:00 - 01:00 6.34 7.10 8 1/17/2010 01:00 - 07:00 15.68 16.92 9 1/17/2010 07:00 - 19:00 1.88 0.10 10 1/17/2010 19:00 - 07:00 0.11 0.20 11 1/18/2010 07:00 - 19:00 1.18 1.34 12 1/18/2010 19:00 - 07:00 0.26 0.33 13 1/19/2010 07:00 - 19:00 0.80 0.97 14 1/19/2010 19:00 - 07:00 0.65 0.67 15 1/20/2010 07:00 - 19:00 0.99 1.17 16 1/20/2010 19:00 - 07:00 0.24 0.23 17 1/21/2010 07:00 - 19:00 0.46 1.16 18 1/21/2010 19:00 - 07:00 0.94 0.07 19 1/22/2010 07:00 - 19:00 1.00 0.08 20 1/22/2010 19:00 - 07:00 1.02 0.02 21 1/23/2010 07:00 - 19:00 0.94 0.07 22 1/23/2010 19:00 - 07:00 1.04 0.07 23 1/24/2010 07:00 - 20:00 0.36 0.11 24 1/24/2010 20:00 - 07:45 0.95 0.12

### Page 17 of 38 Table 6: Flux Calculat ion Details For Florida Field Plot 1 (MRID 481076)

Period Duration Estimated flux μg/m 2 -sec Agency Registrant
25 1/15/2010 9:45 - 13:00 0.06 5.10 26 1/15/2010 13:00 - 19:00 19.79 21.52 27 1/15/2010 19:00 - 01:00 10.42 12.28 28 1/16/2010 01:00 - 07:00 6.47 6.55 29 1/16/2010 07:00 - 13:00 8.82 9.30 30 1/16/2010 13:00 - 19:00 16.34 15.57 31 1/16/2010 19:00 - 01:00 6.34 7.10 32 1/17/2010 01:00 - 07:00 15.68 16.92

MeBr Flux from Field1

0.0 5.0 10.0 15.0 20.0 25.0

1/14/2010 1/16/2010 1/18/2010 1/20/2010 1/22/2010 1/24/2010 1/26/2010

TimeFlux (μg/m2-sec) Versar Registrant

Figure 11: Methyl Bromide Flux Estimates From Florida Field 1 (MRID 481076-01) Comparison of EPA and Registrant Calculated Values


### This study was designed to elucid ate the impacts of various cont rol measures on methyl bromide emissions. The measure evaluated in this study was the use of a barrier film. Additionally, care was exerted to ensure that applications occurred that are as compliant as possible with the good agricultural practices that have been under development for fumiga nt applications. The re sults indicate that the measures attempted in this research reduced peak em ission rates compared to cu rrent typical practices and also impacted cumulative emissions (Figures 12 and 8, respectively). Figure 12 presents the emissions profiles used in the previous assessment for current pr actices (i.e., bedded tarped, and hot gas) and compares them to the emissions quantified in this study for th e first 24 hours after applica tion. The emission profiles have all been adjusted to an appl ication rate of 100 lb methyl brom ide/treated acre to ensure a valid comparison. The profiles with the line s and dots represent the data from th is study. The results indicate the barrier tarp reduces emissions compared to the previously used profiles.

Finally, the ability of hi gh barrier tarps to subs tantively retain methyl bromide over time is illustrated by the information presented in Appendix A. Once tarp cutting occurred after the hot gas applications it is clear that retained methyl bromide is released at higher levels co mpared to the periods just prior to that operation and in some cases flux is simila r to values immediately af ter application. Thus, the risks associated with such a phenomena appear to be similar to or less than predicted for periods immediately after application. Howe ver, there are potential impacts on the duration of a buffer zone or the restricted entry interval for workers.

### Page 18 of 38 

## Methyl Bromide Flux - Normalized To 100 lb/acre

0.00 50.00 100.00 150.00 200.00 250.00 300.00 350.00 400.00

HoursFlux (ug/m2-s) Bedded, Tarped

Hot Gas

1 EVOH Tarped Raised Bed

2 EVOH Hot Gas

Figure 12: Comparison of MBIP Flux From Florida Research Plots (MRID 481076-01) and Existing Flux Estimates For Similar Application Method s (Normalized to 10 0 lb ai/acre) For 1 st 24 Hours After Application

### Page 19 of 38 4.0 1 st 

### Principles Factors

The 1 st 

### principles factors that impact emissions include subsurface soil conditions, application methods/parameters, film types, and many others. 8 

### The Agency has attempted to characterize conditions that tend to reduce emission rates whic h are consistent with the proper cult ivation of a crop of interest such as strawberries or tomatoes. The practices are referred to as Good Agricultural Practices or GAPs . GAPS include guidelines on proper field pr eparation, considerations for film selection, and discussions of the importance of maintaining proper soil moisture. This sec tion presents the data which were included in the MBIP study reports. The data from California are presented in Section 4.1 while the data from Florida are presented in Section 4.2. 9



### 4.1 California Study Results (MRID 480060-01)

At the California site soil samples were collected prior to application on June 2, 2009 and following the end of air monitoring on June 13, 2009. Core samples were collected at five depths at a minimum of three locations across each field. For each field, samp les from the same depth were combined. The cores were collected from the following depths: 0-3, 3-6, 6-9, 9-12, 12-18, and 18-24 inch es. Each soil sample consisted of approximately 1 pound of soil. The soil samp les were sealed in soil sampling plastic bags. The soil samples from each field were analyzed for texture, organic matter and soil moisture. PVC cores were used to sample the soil for bulk density determinati on. Fields 1 and 2 were rela tively dry the day before fumigation. Therefore, these two fields were irrigate d on June 1, 2010 (the day before fumigation) with a water truck and disked befo re fumigant application.

Soil Conditions:

Table 7 summarizes the conditions during the conduc t of the study for each field plot at varied depths down to 24 inches below the surface. It app ears that the study was conducted in compliance with the current recommendations for good agricultural practices. The field conditions also reflect what could be considered typical for fumigant applications in that area of California in that use season.

Table 7: Soil Condition Summary For Wasco California Field Plots Sample Depth (inches) Moisture Soil Characterization Approximate Soil Temperatures (deg F) (% by wgt) (% Field Capacity) (% Organic Matter) Soil Type Minimum Maximum

Field Plot 1 – HDPE Shallow Broadcast 0-3 5.2 48 0.74 Loamy sand 68 113 3-6 7.6 69 0.80 73 105 6-9 8.2 80 0.63 78 97 9-12 9.3 93 0.51 80 93 12-18 9.1 92 0.43 Not reported 18-24 8.7 87 0.34 Field Plot 2 – EVOH Shallow Broadcast 0-3 5.5 50 0.85 Loamy sand 68 109 3-6 7.3 68 0.92 72 102 6-9 7.8 77 0.86 74 95

8 Factors Which Impact Soil Fumigant Emissi ons - Evaluation For Use In Soil Fumigan t Buffer Zone Credit Factor Approach (D306857), Authors: Dawson and Smith, 6/9/08

9 A separate memo will be complete d which addresses the issue of 1 st principles factors and th eir relative impacts. This document will address information from all of the studies submitted to the Agency recen tly as a result of the RED documents for several fumigants.

### Page 20 of 38 Table 7: Soil Condition Summary For Wasco California Field Plots Sample Depth (inches) Moisture Soil Characterization Approximate Soil Temperatures (deg F) (% by wgt) (% Field Capacity) (% Organic Matter) Soil Type Minimum Maximum

9-12 9.1 90 0.66 75 95 12-18 8.3 83 0.27 Not reported 18-24 9.2 92 0.34 Field Plot 3 – EVOH & KTS Shallow Broadcast 0-3 5.3 48 0.72 Loamy sand 70 105 3-6 7.9 70 0.57 75 96 6-9 7.7 77 0.35 78 91 9-12 8.3 82 0.38 79 87 12-18 7.8 79 0.30 Not reported 18-24 7.1 72 0.26 Field Plot 4 – EVOH Deep Strip 0-3 5.8 53 0.51 Loamy sand 73 110 3-6 7.2 66 0.44 77 102 6-9 7.7 77 0.28 80 96 9-12 8.4 82 0.31 81 92 12-18 7.4 72 0.26 Not reported 18-24 7.9 77 0.21 Field Plot 5 – EVOH Deep Broadcast 0-3 6.4 59 0.58 Loamy sand 71 110 3-6 6.9 64 0.57 77 102 6-9 7.7 77 0.42 78 98 9-12 8.0 82 0.34 79 92 12-18 9.3 91 0.23 Not reported 18-24 8.7 87 0.18


### Application Methods:

Applications in field plots 1 through 3 were comple ted using a Noble plow (F igure 13) at a depth of 12 inches. The Noble Plow is a plow that consists of horizontal v-shaped blades mounted by a vertical arm of the tool bar that injects fumigants laterally to a depth of 12 inches beneat h the soil surface. The Noble Plow has two 32-inch wide plows on spacing not ex ceeding 48 inches. As described above, the key differences between plots 1 through 3 were the use of a barrier film (plots 2 and 3) and the reactive adjuvant, KTS, in plot 3.

Figure 13: Noble Plow Co nfiguration Used In Wasc o California Field Plots

### Page 21 of 38 Applications in field plots 4 and 5 were complete d using a forward swept chisel (Figure 14) at a depth of 18 inches. The fumigant release point was on th e rear of each shank near the bottom of the shank. As described above, the key differen ce between plots 4 and 5 was that si te 4 was a strip fumigation while a broadcast application was completed at site 5.

Figure 14: Forward Swept Chisel Configurat ion Used In Wasco California Field Plots



### Tarp Information:

Fresh (unused) tarp samples were collected from each roll used in this study. Also, five tarp samples were collected from each field after tarp splitting. Ta rp permeability was estimated by determining the mass transfer coefficient (cm/hr) using static permeability cells. The average results for the mass transfer coefficient and tarp thickness for the five fields ar e summarized below in Table 8. The permeability of the tarps was evaluated at 1000 ppm for each of methyl bromide. The physical stress of deploying the films using commercial equipment and cultural practices onto the test fields during ap plication had only nominal effects on the mass transfer coefficients determined for the polyethylene and VaporSafe TM 

### film samples. [Please refer back to footnote 2 (pg 3) that describe s issues raised by the tarp manufacturer indicating a more appropriate description of the barrier tarps used in this study as EVALTM rather than VaporSafe.]

Table 8: Thickness & Mass Transfer Coefficients Of Tarps Used In Wasco California Field Plots For Methyl Bromide

Field Plot Film Type Film Thickness (mil) Mass Transfer Coefficients (cm/hr) Directly Off Roll After Field Use 1 Polyethylene 0.9 3.95 3.97 2 Vapor Safe (EVOH) 1.0 0.0035 0.0039 3 Vapor Safe (EVOH) 1.0 0.0037 0.0044 4 Vapor Safe (EVOH) 1.0 0.0029 0.0039 5 Vapor Safe (EVOH) 1.0 0.0022 0.0030

### Page 22 of 38 4.2 Florida Study Results (MRID 481076-01)

At the Florida site soil samples were collect ed prior to application on January 15, 2010 and following the end of air m onitoring on January 25, 2010. Core samples were collected at four depths at two locations across each field. For each field, samples from the same depth were combined. The cores were collected from the following depths : 0-3, 3-6, 6-9, and 9-12 inches. Each soil sample consisted of approximately 1 pound of soil. The soil samples were se aled in soil sampling plastic sample jars. The soil samples from each field were analyzed for texture, bulk density, organic matter and soil moisture.

Soil Conditions:

Table 9 summarizes the conditions during the conduc t of the study for each field plot at varied depths down to 12 inches below the surface. It app ears that the study was conducted in compliance with the current recommendations for good agricultural practices. The field conditions also reflect what could be considered typical for fumigant applications in that area of Florid a in that use season.

Table 9: Soil Condition Summary For Fort Pierce Florida Field Plots Sample Depth (inches) Moisture Soil Characterization Approximate Soil Temperatures (deg F) (% by wgt) (% Field Capacity) (% Organic Matter) Soil Type Minimum Maximum

Field Plot 1 – Tarped Raised Bed 0-3 11.3 134.1 3.1 Sand 60 82 3-6 11.6 136.5 3.5 61 75 6-9 11.6 137.7 1.4 58 73 9-12 12.6 152.8 2.3 58 73 Field Plot 2 – Hot Gas 0-3 8.9 108.5 1.5 Sand 57 81 3-6 11.0 145.3 1.6 58 74 6-9 13.3 153.2 1.2 58 72 9-12 13.0 170.6 1.1 58 72 Under tarp for plot 1 (53-95 deg) and plot 2 (50-120 deg).


### Application Methods:

The application in field plot 1 was complete d using a John Deere 6430 tr actor equipped with a Kennco-style bedder (Figure 15). The application equipment consisted of a standard Kennco-style bedder equipped with 3 extra-long back swept gas knives with the orifices located just under the press area of the bedder. Attached to the rear of the bedder was a plasti c layer with room for 2 rolls of film as well as a spooler for drip irrigation tubing, if required. The gas knives were positio ned to place the fumigant at the bottom of the bed (10 inches deep) and were spaced 12 inches apart. Rows were spaced 5.5 feet apart on center and the beds were 10 inches tall with a 32 inch wide bed top. Beds were 40 inches wide at the base and 36 inches was used by the investigator s for application cali bration calculations.

### Page 23 of 38 Figure 15: Tarped Raised Bed A pplication Configuration Used In Fort Pierce Florida Field Plot


### The application in field plot 2 was completed using a hot-gas arrangement (Figure 16). The boundary of the treated area was trenched to a depth of 12 to 14 inches. Drip tapes were placed under the tarp (12” space between emitters) 9 feet apart from each other. Once the fumigant had heated to the gas phase in the kettles the delivery ball valves at each lin e off of the manifold were opened and the gas rapidly deployed through the tubing to the drip tubing in the field. Th e initial kettle temperature was ~155° F. Application flow rate was controlled by a ball valve on th e cylinder, the nitrogen pressure (the propellant) and the kettle temperature. Initial nitrogen pressure was 5 psi and it wa s slowly increased to 30 psi. The flow rate was estimated at 3lb/minute based on weight change on the sc ale of the cylinder.

Figure 16: Hot Gas Application Configuratio n Used In Fort Pierce Florida Field Plot

### Page 24 of 38 5.0 Risk Analysis

The risk estimates calculated based on the MBIP m onitoring studies are summari zed in this section. The risks associated with the data from California are presented in Section 5.1 while the risk estimates from Florida are summarized in Section 5. 2. All risk estimates were calcula ted using the same hazard inputs and PERFUM modeling approaches as described in th e previous risk assessment for methyl bromide. 10 

### A summary of the results for the Vent ura weather station for a 40 acre fi eld at varied rates from the 2007 assessment is presented in Table 10 below for comparis on purposes with the results for the new studies.

Table 10: Comparison Of Results For Methyl Bromide PERFUM Buffer Distributions Based On A 40 Acre Square Field, Ventura California Weather Data, And All Flux Profiles At A UF=30 (Source D337288, 2007)

Percentile

s 100% (430 lb/Acre) 75% (323 lb/Acre) 50% (215 lb/Acre) 25% (108 lb/Acre) Max Distance Whole Field Max Distance Whole Field Max Distance Whole Field Max Distance Whole Field Flux Profile = Tarped Application Method 50 110 0 40 0 5 0 0 0 75 230 5 130 5 25 0 0 0 90 350 70 220 25 90 5 5 0 95 430 150 280 80 125 5 5 0 99 555 330 390 215 200 90 5 5 99.9 725 510 500 355 265 190 20 5 99.99 760 680 555 485 305 265 60 45 Flux Profile = Deep Untarped Application Method 50 165 0 85 0 5 0 0 0 75 305 20 195 5 70 0 0 0 90 450 105 305 55 140 5 5 0 95 530 200 370 125 185 40 5 0 99 695 420 490 285 290 140 45 5 99.9 875 635 630 445 365 260 110 45 99.99 935 850 700 605 430 350 115 100 Flux Profile = Hot Gas Application Method 50 505 25 360 10 200 5 35 0 75 705 135 510 95 305 50 85 5 90 985 315 725 235 450 135 150 25 95 1185 450 880 340 565 210 210 60 99 1440 790 1250 605 795 395 355 150 99.9 1440 1285 1440 970 1205 655 500 315 99.99 1440 1440 1440 1275 1330 845 545 455 Flux Profile = Bedded Tarped Application Method 50 135 0 70 0 10 0 0 0 75 200 30 115 10 40 5 5 0 90 295 95 190 50 80 10 5 0 95 395 145 260 90 120 30 5 5 99 670 290 525 195 305 95 85 5 99.9 1225 590 925 440 555 285 210 85 99.99 1305 1005 955 730 565 480 230 205

10 Methyl Bromide : Phase 5 Health Effects Division (HED) Human Health Risk Assessment For Soil, Greenhouse, and Residential/Structural Uses. PC Code: 053201, DP Barcode: D337288 (4/10/07) Authors: Mendez & Dawson

### Page 25 of 38 5.1 California Study Results (MRID 480060-01)

The risk estimates calculated for the MBIP monito ring data from the California monitoring plots are summarized below in Tables 11 and 12 using a 40 acre field and the Ventura weather data. The PERFUM modelling results based on the Ventura weather dataset have been summari zed for a 40 acre field using the same application rates to allow for a more direct comparison with the results presented in the 2007 risk assessment because this scenario was also used for illustrative purposes in that assessment. Results have been calculated using a variety of field sizes (1 to 160 acres) and a to tal of 6 weather data sources (e.g., Bradenton FL is another location). These are available in the form of PERFUM output files. A limited number of outputs have been summar ized herein for summary/illustrati ve purposes. Table 11 presents the PERFUM buffer distributional outputs for all of the field plots in California for the 24 hour period immediately after application. Both maximum and whol e field buffer results are presented. There is one additional set of outputs which have been included which are based on the actual application rates in each field plot. The results for field pl ot 1 were intended to serve as a comparison to common current practices and essentially are directly compar able to those presented above for the existing 2007 assessment. The other research plots evaluated measur es to reduce emission levels. Results indicate a combination of barrier films and a reactive adjuvant (i.e., KTS) or injecti on depth clearly reduce emissions and the length of predicted buffer zones.

Table 11: Methyl Bromide PERFUM Buffer Distributions Based On A 40 Acre Square Field, Ventura California Weather Data, And All Flux Profiles From The Wa sco California MBIP Study Plots

Percentile of Exposure 100% (430 lb/Acre) 75% (323 lb/Acre) 50% (215 lb/Acre) Study Rate (178-203 lb/Acre) 25% (108 lb/Acre)

Max Distance Whole Field Max Distance Whole Field Max Distance Whole Field Max Distance Whole Field Max Distance Whole Field Field Plot 1 - HDPE Shallow Broadcast (Treated at 189.1 lb methyl bromide/treated acre)
50 125 5 65 0 5 0 5 0 0 0
75 185 40 105 15 30 5 15 0 5 0 90 275 95 175 50 70 5 90 5 5 0 95 345 140 230 80 95 20 80 10 5 5 99 600 265 430 175 235 80 190 60 60 5 99.9 920 505 655 380 365 230 300 195 140 65 99.99 1440 835 850 605 640 395 580 355 290 210 Field Plot 2- EVOH Shallow Broadcast ( 180.3 lb methyl bromide/treated acre)
50 5 0 0 0 0 0 0 0 0 0
75 5 0 5 0 0 0 0 0 0 0 90 5 0 5 0 0 0 0 0 0 0 95 30 5 5 5 5 0 0 0 0 0 99 140 25 65 5 5 0 5 0 0 0 99.9 270 140 175 85 75 20 50 5 5 0 99.99 555 330 400 255 220 160 170 125 5 5 Field Plot 3- EVOH & KTS Shallow Broadcast( 177.9 lb methyl bromide/treated acre)
50 0 0 0 0 0 0 0 0 0 0
75 0 0 0 0 0 0 0 0 0 0 90 0 0 0 0 0 0 0 0 0 0 95 0 0 0 0 0 0 0 0 0 0 99 5 0 0 0 0 0 0 0 0 0 99.9 15 5 5 0 0 0 0 0 0 0

### Page 26 of 38 Table 11: Methyl Bromide PERFUM Buffer Distributions Based On A 40 Acre Square Field, Ventura California Weather Data, And All Flux Profiles From The Wa sco California MBIP Study Plots

Percentile of Exposure 100% (430 lb/Acre) 75% (323 lb/Acre) 50% (215 lb/Acre) Study Rate (178-203 lb/Acre) 25% (108 lb/Acre)

Max Distance Whole Field Max Distance Whole Field Max Distance Whole Field Max Distance Whole Field Max Distance Whole Field 99.99 55 45 5 5 5 5 0 0 0 0 Field Plot 4- EVOH Deep Strip (202.6 lb methyl bromide/treated acre)
50 0 0 0 0 0 0 0 0 0 0 75 0 0 0 0 0 0 0 0 0 0 90 0 0 0 0 0 0 0 0 0 0 95 5 0 0 0 0 0 0 0 0 0 99 5 5 5 0 0 0 0 0 0 0 99.9 5 5 5 5 0 0 0 0 0 0 99.99 15 5 5 5 0 0 0 0 0 0 Field Plot 5- EVOH Deep Broadcast(181. 1 lb methyl bromide/treated acre)
50 0 0 0 0 0 0 0 0 0 0
75 0 0 0 0 0 0 0 0 0 0 90 0 0 0 0 0 0 0 0 0 0 95 0 0 0 0 0 0 0 0 0 0 99 5 0 0 0 0 0 0 0 0 0 99.9 5 5 5 0 0 0 0 0 0 0 99.99 5 5 5 5 0 0 0 0 0 0



### Table 12 below reinforces the conclusions drawn base d on the buffer outputs descri bed above. It is only when values at the highest percentile s of exposure are considered that ri sks appear to be of concern. (e.g., Plot 1, MOE = 5 at 10 meters at the 99.99 th 

### percentile). Table 12 presents the air concentrations at specific distances from the edge of the tr eated fields considered in PERFUM for the 24 hour period immediately after application. Again, for comp arative purposes results for a 40 acr e field based on the Ventura weather data are presented. Results for dist ances of 10 to 150 meters from the fi eld edge were selected but results for additional distances of interest (i.e., a total of 30 points) up to 1440 meters from the field are available. 11

Table 12: Wasco Califonria Risks Based On Ring Concentrations From PERFUM – 40 Acre Field and Ventura Weather Data [MeBr Air] (ug/m3) Margins of Exposure

Percentile of Exposure 10m 30m 50m 100m 150m 10m 30m 50m 100m 150m Plot 1 (HDPE Shallow Boradcast) - At Highest Evaluated Applica tion Rate (430 lb methyl bromide/treated/acre) 50 949.0 611.0 429.0 195.0 91.0 41 64 91 199 427 75 1859.0 1417.0 1131.0 741.0 507.0 21 27 34 52 77 90 2509.0 2041.0 1729.0 1261.0 975.0 15 19 22 31 40 95 2925.0 2457.0 2093.0 1547.0 1235.0 13 16 19 25 31 97 3263.0 2769.0 2405.0 1781.0 1417.0 12 14 16 22 27 99 4199.0 3601.0 3133.0 2353.0 1885.0 9 11 12 17 21

11 The current requirements for buffer zone dur ation is 48 hours and entry restricted inte rval is 5 days. Ba sed on the available flux information, it appears that the TIF retains methyl bromide and some increased emissions are noted associated with tarp cutting operations t hat occurred 6 days after application in this study. However, the level of em issions is lower than observed (about 1⁄2 on average of peak) or s imilar to (deep broadcast – field 5 only) that immediately after application durin g tarp cutting. This consider ation along with the risk estim ates reported in Table 11 and 12 should be considered related to refinement of the restricted entry interval.

### Page 27 of 38 Table 12: Wasco Califonria Risks Based On Ring Concentrations From PERFUM – 40 Acre Field and Ventura Weather Data [MeBr Air] (ug/m3) Margins of Exposure

Percentile of Exposure 10m 30m 50m 100m 150m 10m 30m 50m 100m 150m

99.9 7189.0 6409.0 5629.0 4251.0 3419.0 5 6 7 9 11 Plot 1 (HDPE Shallow Boradcast) - At Study Application Rate (189 lb methyl bromide/treated/acre) 50 417.3 268.7 188.7 85.8 40.0 93 145 206 453 970 75 817.5 623.2 497.4 325.9 223.0 47 62 78 119 174 90 1103.4 897.6 760.4 554.5 428.8 35 43 51 70 91 95 1286.3 1080.5 920.4 680.3 543.1 30 36 42 57 71 97 1435.0 1217.7 1057.6 783.2 623.2 27 32 37 50 62 99 1846.6 1583.6 1377.8 1034.8 829.0 21 25 28 38 47 99.9 3161.5 2818.5 2475.5 1869.5 1503.6 12 14 16 21 26 Plot 2 (EVOH Shallow Broadcast) - At Highest Evaluated Application Rate (430 lb me thyl bromide/treated/acre) 50 195.0 117.0 91.0 39.0 13.0 199 332 427 996 2987 75 637.0 455.0 351.0 195.0 117.0 61 85 111 199 332 90 897.0 715.0 585.0 403.0 299.0 43 54 66 96 130 95 1027.0 845.0 715.0 507.0 403.0 38 46 54 77 96 97 1157.0 949.0 793.0 585.0 455.0 34 41 49 66 85 99 1495.0 1261.0 1079.0 793.0 611.0 26 31 36 49 64 99.9 2639.0 2327.0 2041.0 1521.0 1235.0 15 17 19 26 31 Plot 2 (EVOH Shallow Broadcast) - At Study Application Ra te (180.3 lb methyl bromide/trea ted/acre) 50 81.8 49.1 38.2 16.4 5.5 475 792 1018 2375 7124 75 267.1 190.8 147.2 81.8 49.1 145 204 264 475 792 90 376.1 299.8 245.3 169.0 125.4 103 130 158 230 310 95 430.6 354.3 299.8 212.6 169.0 90 110 130 183 230 97 485.1 397.9 332.5 245.3 190.8 80 98 117 158 204 99 626.9 528.7 452.4 332.5 256.2 62 73 86 117 152 99.9 1106.5 975.7 855.8 637.8 517.8 35 40 45 61 75 Plot 3 (EVOH & KTS Shallow Broadcast) - At Highest Evaluate d Application Rate (430 lb me thyl bromide/treated/acre) 50 65.0 39.0 13.0 13.0 13.0 597 996 2987 2987 2987 75 221.0 169.0 117.0 65.0 39.0 176 230 332 597 996 90 325.0 247.0 221.0 143.0 117.0 119 157 176 272 332 95 377.0 299.0 247.0 195.0 143.0 103 130 157 199 272 97 429.0 351.0 299.0 221.0 169.0 91 111 130 176 230 99 559.0 455.0 403.0 273.0 221.0 69 85 96 142 176 99.9 871.0 793.0 689.0 533.0 403.0 45 49 56 73 96 Plot 3 (EVOH & KTS Shallow Broadcast) - At Study App lication Rate (177.9 lb meth yl bromide/treated/acre) 50 26.9 16.1 5.4 5.4 5.4 1444 2407 7220 7220 7220 75 91.4 69.9 48.4 26.9 16.1 425 555 802 1444 2407 90 134.5 102.2 91.4 59.2 48.4 289 380 425 656 802 95 156.0 123.7 102.2 80.7 59.2 249 314 380 481 656 97 177.5 145.2 123.7 91.4 69.9 219 267 314 425 555 99 231.3 188.2 166.7 112.9 91.4 168 206 233 344 425 99.9 360.4 328.1 285.1 220.5 166.7 108 118 136 176 233 Plot 4 (EVOH Deep Strip) - At Highest Evaluated App lication Rate (430 lb meth yl bromide/treated/acre) 50 143.0 91.0 65.0 13.0 13.0 272 427 597 2987 2987 75 273.0 195.0 169.0 91.0 65.0 142 199 230 427 597 90 429.0 351.0 299.0 221.0 169.0 91 111 130 176 230

### Page 28 of 38 Table 12: Wasco Califonria Risks Based On Ring Concentrations From PERFUM – 40 Acre Field and Ventura Weather Data [MeBr Air] (ug/m3) Margins of Exposure

Percentile of Exposure 10m 30m 50m 100m 150m 10m 30m 50m 100m 150m 95 533.0 481.0 429.0 325.0 273.0 73 81 91 119 142 97 611.0 559.0 507.0 403.0 325.0 64 69 77 96 119 99 767.0 715.0 637.0 507.0 429.0 51 54 61 77 91 99.9 1027.0 949.0 871.0 715.0 585.0 38 41 45 54 66 Plot 4 (EVOH Deep Strip) - At Study Application Rate (202.6 lb methyl brom ide/treate d/acre) 50 67.4 42.9 30.6 6.1 6.1 576 906 1268 6339 6339 75 128.6 91.9 79.6 42.9 30.6 302 423 488 906 1268 90 202.1 165.4 140.9 104.1 79.6 192 235 276 373 488 95 251.1 226.6 202.1 153.1 128.6 155 171 192 254 302 97 287.9 263.4 238.9 189.9 153.1 135 147 163 204 254 99 361.4 336.9 300.1 238.9 202.1 107 115 129 163 192 99.9 483.9 447.1 410.4 336.9 275.6 80 87 95 115 141 Plot 5 (EVOH Deep Broadcast) - At Hi ghest Evaluated Applicatio n Rate (430 lb methyl bromide/tr eated/acre) 50 91.0 65.0 39.0 13.0 13.0 427 597 996 2987 2987 75 195.0 169.0 117.0 65.0 39.0 199 230 332 597 996 90 299.0 247.0 221.0 143.0 117.0 130 157 176 272 332 95 377.0 325.0 273.0 221.0 169.0 103 119 142 176 230 97 429.0 377.0 325.0 247.0 195.0 91 103 119 157 199 99 533.0 481.0 429.0 325.0 273.0 73 81 91 119 142 99.9 767.0 689.0 611.0 481.0 403.0 51 56 64 81 96 Plot 5 (EVOH Deep Broadcast) - At Study Application Rate (181.1 lb methyl bromide/treated/acre) 50 38.3 27.4 16.4 5.5 5.5 1013 1418 2364 7092 7092 75 82.1 71.2 49.3 27.4 16.4 473 546 788 1418 2364 90 125.9 104.0 93.1 60.2 49.3 308 373 417 645 788 95 158.8 136.9 115.0 93.1 71.2 245 284 338 417 546 97 180.7 158.8 136.9 104.0 82.1 215 245 284 373 473 99 224.5 202.6 180.7 136.9 115.0 173 192 215 284 338 99.9 323.0 290.2 257.3 202.6 169.7 120 134 151 192 229


### 5.2 Florida Study Results (MRID 481076-01)

The risk estimates calculated for the MBIP mon itoring data from the Florida monitoring plots are summarized below in Tables 13 and 14 using a 40 acre field and the Ventura weather data. The PERFUM modelling results based on the Ventura weather dataset have been summari zed for a 40 acre field using the same application rates in this table to allow for a mo re direct comparison with the results presented in the 2007 risk assessment because this scenario was also us ed for illustrative purposes in that assessment. Results have been calculated using a variety of field sizes (1 to 160 acr es) and a total of 6 weather data sources (e.g., Bradenton FL is anothe r location). These are available in the form of PERFUM output files. A limited number of outputs have been summarized herein for summary/illustrative purposes. Table 13 presents the PERFUM buffer distributional outputs for al l of the field plots in Florida for the 24 hour period immediately after application. Both maximum and whol e field buffer results are presented. There is one additional set of outputs which have been included which are based on the actual application rates in each field plot. No plots at the Florida site compared di rectly with the scenarios considered in the previous

### Page 29 of 38 assessment as described above. Both scenarios used a TIF with no other apparent changes from current cultural practices outside of addressing complia nce with prescribed good agricultural practices.

Table 13: Methyl Bromide PERFUM Buffer Distributions Based On A 40 Acre Square Field, Ventura California Weather Data, And All Flux Profiles From The Fort Pierce Florida MB IP Study Plots

Percentile of Exposure Max (430 lb/Acre) 75% (323 lb/Acre) Study Rate (235 lb/Acre) 50% (215 lb/Acre) 25% (108 lb/Acre)

Max Distance Whole Field Max Distance Whole Field Max Distance Whole Field Max Distance Whole Field Max Distance Whole Field Field Plot 1 – EVOH Tarped Raised Bed (235 lb methyl bromide/treated acre)
50 0 0 0 0 0 0 0 0 0 0
75 0 0 0 0 0 0 0 0 0 0
90 0 0 0 0 0 0 0 0 0 0
95 0 0 0 0 0 0 0 0 0 0
99 0 0 0 0 0 0 0 0 0 0
99.9 0 0 0 0 0 0 0 0 0 0
99.99 5 5 0 0 0 0 0 0 0 0 Field Plot 2- EVOH Hot Gas (426 lb methyl bromide/treated acre)
50 5 0 0 0

See 430 application rate block 0 0 0 0
75 35 0 5 0 0 0 0 0
90 105 5 30 0 5 0 0 0
95 150 20 65 5 5 0 0 0
99 240 110 130 40 5 5 0 0
99.9 310 220 195 120 55 10 5 0
99.99 335 290 200 175 55 55 5 5



### Table 14 below reinforces the conclusions drawn base d on the buffer outputs descri bed above. It is only when values at the highest percentile s of exposure are considered that ri sks appear to be of concern. (e.g., Plot 1, MOE = 5 at 10 meters at the 99.99 th 

### percentile). Table 14 presents the air concentrations at specific distances from the edge of the tr eated fields considered in PERFUM . Again, for comparative purposes results for a 40 acre field based on the Ventura weather data are presented. Results for distances of 10 to 150 meters from the field edge were se lected but results for additional distan ces of interest (i.e., a total of 30 points) up to 1440 meters from the field are available. 12 

### [Note: For site 1 (t arped raised bed) the air concentrations for the second day were slightly higher than day 1 so they have been used as the basis for this analysis.]

12 The current requirements for buffer zone dur ation is 48 hours and entry restricted inte rval is 5 days. Ba sed on the available flux information, it appears that the TIF retains methyl bromide and some increased emissions are noted associated with tarp cutting operations t hat occurred 7 days after application in this study for the hot gas treatment. The level of emissions is similar to that immediately after ap plication. This consideration along with the risk estimates reported in Table 13 a nd 14 should be considered related to refinement of the restr icted entry interval. Hole punching was not completed during the study at the for the raised bed field since it would not typically be done until 21 to 28 days after application just before planting.

### Page 30 of 38 Table 14: Wasco Califonria Risks Based On Ring Concentrations From PERFUM – 40 Acre Field and Ventura Weather Data [MeBr Air] (ug/m3) Margins of Exposure

Percentile of Exposure 10m 30m 50m 100m 150m 10m 30m 50m 100m 150m Plot 1 – EVOH Tarped Raised Bed At Highest Evaluated Application Rate (430 lb me thyl bromide/treated/acre) 50 65.0 39.0 13.0 13.0 13.0 597 996 2987 2987 2987 75 143.0 117.0 91.0 65.0 39.0 272 332 427 597 996 90 247.0 195.0 169.0 117.0 91.0 157 199 230 332 427 95 299.0 273.0 247.0 195.0 143.0 130 142 157 199 272 97 351.0 325.0 299.0 221.0 195.0 111 119 130 176 199 99 429.0 403.0 351.0 299.0 247.0 91 96 111 130 157 99.9 585.0 533.0 507.0 403.0 325.0 66 73 77 96 119 Plot 1 – EVOH Tarped Raised Bed At Study Application Rate (235 lb methyl bromide /treated/acre) 50 35.5 21.3 7.1 7.1 7.1 1093 1822 5465 5465 5465 75 78.2 63.9 49.7 35.5 21.3 497 607 781 1093 1822 90 135.0 106.6 92.4 63.9 49.7 288 364 420 607 781 95 163.4 149.2 135.0 106.6 78.2 238 260 288 364 497 97 191.8 177.6 163.4 120.8 106.6 202 219 238 321 364 99 234.5 220.2 191.8 163.4 135.0 166 176 202 238 288 99.9 319.7 291.3 277.1 220.2 177.6 121 133 140 176 219 Plot 2 - EVOH Hot Gas At Highest Ev aluated & Study Applicatio n Rate (430 lb methyl bromide/tr eated/acre) 50 169.0 117.0 65.0 13.0 13.0 230 332 597 2987 2987 75 559.0 429.0 351.0 195.0 117.0 69 91 111 199 332 90 1027.0 871.0 741.0 559.0 429.0 38 45 52 69 91 95 1365.0 1209.0 1079.0 845.0 663.0 28 32 36 46 59 97 1573.0 1443.0 1287.0 1027.0 845.0 25 27 30 38 46 99 1963.0 1833.0 1677.0 1339.0 1131.0 20 21 23 29 34 99.9 2561.0 2431.0 2249.0 1859.0 1573.0 15 16 17 21 25

### Page 31 of 38 6.0 Conclusions

The recent emissions data have been reviewed fr om a technical perspective and each have been found to be acceptable for use in the risk assessment pr ocess. These data reflect emissions based on the use of measures such as EVOH-containing high barrier film s, reactive adjuvants, and injection depths designed to reduce emissions. The studies were conducted in th e central valley of Californi a and on the eastern coast of Florida where a large percentage of actual methyl bromide use occurs. 13 

### The analytical aspects of the study were acceptable and no correction for recovery was re quired. The Agency also calculated flux values for each field plot and found that the results were comparable to those cal culated by the investigators. All flux estimates used in the risk a ssessment included in this document are based on the Agency-calculated flux estimates.

The results indicate that overall emissions were reduced when the control measures were used compared to current common agricultural practices. PERFUM predicted buffer zones were essentially zero meters or very short compared to those predicted in the 2007 risk assessment in all cases accept in selected circumstances at the highest percentil es of exposure or for very large fi elds. Air concentration data from PERFUM were also considered and the risks calculated based on this information were also not of concern in circumstances that are similar to those observed fo r the buffer outputs of PERFUM as would be expected. As expected, the impermeable nature of the TIFs used in this research retained methyl bromide to the point where emission levels were raised as a result of tarp cutting operations in some circumstances to levels similar to after application. This phenomenon should be considered, in ligh t of the associated risks, related to issues such as buffer zone duration and th e duration of the entry restricted interval.

[Note: The MBIP studies used as the basis for this assessment quantified chloropicrin emissions in addition to methyl bromide emissions since both fumigants were applied. The analysis of th e chloropicrin data have been completed in a separate memo that includes not only the results of these st udies but other pertinent chloropicrin emissions data.]

13 The research plan indicated that the Fl orida location was supposed to be Plant City but Fort Pierce was used instead, it is al so a substantial production area so it appears to be an acceptable modification of the research plan.

### Page 32 of 38 

# Appendix A

Summary of Unscaled Flux Values By Sampling Period

### Page 33 of 38 Appendix A - Summary of Unscaled California Flux Values By Sampling Period Period No. Sample Interval Times Duration (Hrs.) Est. Flux (ug/m2-s) Field 1 - Shallow Broadcast Tarped (polyethylene) 1 06/02/2009 09:00 - 13:00 4.0 222.95 2 06/02/2009 13:00 - 19:00 6.0 210.93 3 06/02/2009 19:00 - 01:00 6.0 37.86 4 06/03/2009 01:00 - 07:00 6.0 58.35 5 06/03/2009 07:00 - 13:00 6.0 27.89 6 06/03/2009 13:00 - 19:00 6.0 28.17 7 06/03/2009 19:00 - 01:00 6.0 23.50 8 06/04/2009 01:00 - 07:00 6.0 11.44 9 06/04/2009 07:00 - 19:00 12.0 14.36 10 06/05/2009 19:00 - 07:00 12.0 7.24 11 06/05/2009 07:00 - 19:00 12.0 5.08 12 06/06/2009 19:00 - 07:00 12.0 3.06 13 06/06/2009 07:00 - 19:00 12.0 3.68 14 06/07/2009 19:00 - 07:00 12.0 1.74 15 06/07/2009 07:00 - 19:00 12.0 3.45 16 06/08/2009 19:00 - 07:00 12.0 1.80 17 06/08/2009 07:00 - 13:00 6.0 8.63 18 06/08/2009 13:00 - 19:00 6.0 8.55 19 06/08/2009 19:00 - 01:00 6.0 6.26 20 06/09/2009 01:00 - 07:00 6.0 2.62 21 06/09/2009 07:00 - 19:00 12.0 0.79 22 06/10/2009 19:00 - 07:00 12.0 1.25 23 06/10/2009 07:00 - 19:00 12.0 0.99 24 06/11/2009 19:00 - 07:00 12.0 1.05 25 06/11/2009 07:00 - 19:00 12.0 0.65 26 06/12/2009 19:00 - 07:00 12.0 0.88 27 06/12/2009 07:00 - 19:00 12.0 0.62 28 06/13/2009 19:00 - 07:00 12.0 0.87 29 06/13/2009 07:00 - 19:00 12.0 0.52 30 06/14/2009 19:00 - 07:00 12.0 0.58 31 06/14/2009 07:00 - 19:00 12.0 0.02 32 06/15/2009 19:00 - 07:00 12.0 0.34 Field 2 - Shallow Broadcast Tarped (EVOH Resin Barrier Tarp) 1 06/02/2009 09:00 - 13:00 4.0 70.24 2 06/02/2009 13:00 - 19:00 6.0 98.22 3 06/02/2009 19:00 - 01:00 6.0 3.72 4 06/03/2009 01:00 - 07:00 6.0 4.82 5 06/03/2009 07:00 - 13:00 6.0 2.23 6 06/03/2009 13:00 - 19:00 6.0 56.79 7 06/03/2009 19:00 - 01:00 6.0 0.85 8 06/04/2009 01:00 - 07:00 6.0 0.44 9 06/04/2009 07:00 - 19:00 12.0 15.47 10 06/05/2009 19:00 - 07:00 12.0 0.83 11 06/05/2009 07:00 - 19:00 12.0 4.07 12 06/06/2009 19:00 - 07:00 12.0 0.55

### Page 34 of 38 Appendix A - Summary of Unscaled California Flux Values By Sampling Period Period No. Sample Interval Times Duration (Hrs.) Est. Flux (ug/m2-s) 13 06/06/2009 07:00 - 19:00 12.0 4.26 14 06/07/2009 19:00 - 07:00 12.0 0.47 15 06/07/2009 07:00 - 19:00 12.0 6.35 16 06/08/2009 19:00 - 07:00 12.0 0.50 17 06/08/2009 07:00 - 13:00 6.0 33.25 18 06/08/2009 13:00 - 19:00 6.0 43.88 19 06/08/2009 19:00 - 01:00 6.0 22.88 20 06/09/2009 01:00 - 07:00 6.0 11.10 21 06/09/2009 07:00 - 19:00 12.0 6.39 22 06/10/2009 19:00 - 07:00 12.0 3.31 23 06/10/2009 07:00 - 19:00 12.0 2.80 24 06/11/2009 19:00 - 07:00 12.0 2.49 25 06/11/2009 07:00 - 19:00 12.0 1.50 26 06/12/2009 19:00 - 07:00 12.0 2.76 27 06/12/2009 07:00 - 19:00 12.0 1.69 28 06/13/2009 19:00 - 07:00 12.0 4.81 29 06/13/2009 07:00 - 19:00 12.0 0.90 30 06/14/2009 19:00 - 07:00 12.0 1.72 31 06/14/2009 07:00 - 19:00 12.0 0.45 32 06/15/2009 19:00 - 07:00 12.0 1.60 Field 3 - Shallow Broadcast Tarped (EVOH Resin Barrier Tarp & KTS) 1 06/02/2009 09:00 - 13:00 4.0 27.09 2 06/02/2009 13:00 - 19:00 6.0 35.64 3 06/02/2009 19:00 - 01:00 6.0 0.92 4 06/03/2009 01:00 - 07:00 6.0 2.25 5 06/03/2009 07:00 - 13:00 6.0 2.12 6 06/03/2009 13:00 - 19:00 6.0 27.48 7 06/03/2009 19:00 - 01:00 6.0 0.73 8 06/04/2009 01:00 - 07:00 6.0 0.39 9 06/04/2009 07:00 - 19:00 12.0 7.17 10 06/05/2009 19:00 - 07:00 12.0 0.01 11 06/05/2009 07:00 - 19:00 12.0 1.17 12 06/06/2009 19:00 - 07:00 12.0 0.36 13 06/06/2009 07:00 - 19:00 12.0 1.40 14 06/07/2009 19:00 - 07:00 12.0 0.45 15 06/07/2009 07:00 - 19:00 12.0 1.35 16 06/08/2009 19:00 - 07:00 12.0 0.10 17 06/08/2009 07:00 - 13:00 6.0 32.29 18 06/08/2009 13:00 - 19:00 6.0 20.04 19 06/08/2009 19:00 - 01:00 6.0 17.34 20 06/09/2009 01:00 - 07:00 6.0 7.21 21 06/09/2009 07:00 - 19:00 12.0 2.70 22 06/10/2009 19:00 - 07:00 12.0 3.13 23 06/10/2009 07:00 - 19:00 12.0 1.29 24 06/11/2009 19:00 - 07:00 12.0 2.24 25 06/11/2009 07:00 - 19:00 12.0 0.32 26 06/12/2009 19:00 - 07:00 12.0 1.10

### Page 35 of 38 Appendix A - Summary of Unscaled California Flux Values By Sampling Period Period No. Sample Interval Times Duration (Hrs.) Est. Flux (ug/m2-s) 27 06/12/2009 07:00 - 19:00 12.0 0.01 28 06/13/2009 19:00 - 07:00 12.0 0.92 29 06/13/2009 07:00 - 19:00 12.0 0.02 30 06/14/2009 19:00 - 07:00 12.0 1.18 31 06/14/2009 07:00 - 19:00 12.0 0.47 32 06/15/2009 19:00 - 07:00 12.0 0.76 Field 4 - Deep Strip Tarped (EVOH Resin Barrier Tarp) 1 06/02/2009 09:00 - 13:00 4.0 20.91 2 06/02/2009 13:00 - 19:00 6.0 20.91 3 06/02/2009 19:00 - 01:00 6.0 10.68 4 06/03/2009 01:00 - 07:00 6.0 22.36 5 06/03/2009 07:00 - 13:00 6.0 4.76 6 06/03/2009 13:00 - 19:00 6.0 32.60 7 06/03/2009 19:00 - 01:00 6.0 9.18 8 06/04/2009 01:00 - 07:00 6.0 2.99 9 06/04/2009 07:00 - 19:00 12.0 5.26 10 06/05/2009 19:00 - 07:00 12.0 4.80 11 06/05/2009 07:00 - 19:00 12.0 4.03 12 06/06/2009 19:00 - 07:00 12.0 3.26 13 06/06/2009 07:00 - 19:00 12.0 2.76 14 06/07/2009 19:00 - 07:00 12.0 2.06 15 06/07/2009 07:00 - 19:00 12.0 2.57 16 06/08/2009 19:00 - 07:00 12.0 3.05 17 06/08/2009 07:00 - 13:00 6.0 8.27 18 06/08/2009 13:00 - 19:00 6.0 3.99 19 06/08/2009 19:00 - 01:00 6.0 8.28 20 06/09/2009 01:00 - 07:00 6.0 5.39 21 06/09/2009 07:00 - 19:00 12.0 1.88 22 06/10/2009 19:00 - 07:00 12.0 2.91 23 06/10/2009 07:00 - 19:00 12.0 1.35 24 06/11/2009 19:00 - 07:00 12.0 1.90 25 06/11/2009 07:00 - 19:00 12.0 0.64 26 06/12/2009 19:00 - 07:00 12.0 1.07 27 06/12/2009 07:00 - 19:00 12.0 0.42 28 06/13/2009 19:00 - 07:00 12.0 0.51 29 06/13/2009 07:00 - 19:00 12.0 0.69 30 06/14/2009 19:00 - 07:00 12.0 1.34 31 06/14/2009 07:00 - 19:00 12.0 0.57 32 06/15/2009 19:00 - 07:00 12.0 0.39 Field 5 - Deep Broadcast Tarped (EVOH Resin Barrier Tarp) 1 06/02/2009 09:00 - 13:00 4.0 19.29 2 06/02/2009 13:00 - 19:00 6.0 19.29 3 06/02/2009 19:00 - 01:00 6.0 13.37 4 06/03/2009 01:00 - 07:00 6.0 3.80 5 06/03/2009 07:00 - 13:00 6.0 1.17 6 06/03/2009 13:00 - 19:00 6.0 13.48 7 06/03/2009 19:00 - 01:00 6.0 2.45

### Page 36 of 38 Appendix A - Summary of Unscaled California Flux Values By Sampling Period Period No. Sample Interval Times Duration (Hrs.) Est. Flux (ug/m2-s) 8 06/04/2009 01:00 - 07:00 6.0 0.43 9 06/04/2009 07:00 - 19:00 12.0 3.58 10 06/05/2009 19:00 - 07:00 12.0 0.54 11 06/05/2009 07:00 - 19:00 12.0 1.52 12 06/06/2009 19:00 - 07:00 12.0 0.26 13 06/06/2009 07:00 - 19:00 12.0 1.82 14 06/07/2009 19:00 - 07:00 12.0 0.44 15 06/07/2009 07:00 - 19:00 12.0 2.47 16 06/08/2009 19:00 - 07:00 12.0 0.34 17 06/08/2009 07:00 - 13:00 6.0 42.72 18 06/08/2009 13:00 - 19:00 6.0 49.07 19 06/08/2009 19:00 - 01:00 6.0 28.44 20 06/09/2009 01:00 - 07:00 6.0 22.93 21 06/09/2009 07:00 - 19:00 12.0 4.31 22 06/10/2009 19:00 - 07:00 12.0 7.73 23 06/10/2009 07:00 - 19:00 12.0 2.84 24 06/11/2009 19:00 - 07:00 12.0 6.03 25 06/11/2009 07:00 - 19:00 12.0 2.08 26 06/12/2009 19:00 - 07:00 12.0 3.02 27 06/12/2009 07:00 - 19:00 12.0 2.30 28 06/13/2009 19:00 - 07:00 12.0 4.29 29 06/13/2009 07:00 - 19:00 12.0 1.10 30 06/14/2009 19:00 - 07:00 12.0 3.63 31 06/14/2009 07:00 - 19:00 12.0 0.60 32 06/15/2009 19:00 - 07:00 12.0 1.29

### Page 37 of 38 Appendix A - Summary of Unscaled Florida Flux Values By Sampling Period Period No. Sample Interval Times Duration (Hrs.) Est. Flux (ug/m2-s) Field 1 - Tarped Raised Bed 1 1/15/2010 9:45 - 13:00 3:15 0.06 2 1/15/2010 13:00 - 19:00 6:00 19.79 3 1/15/2010 19:00 - 01:00 6:00 10.42 4 1/16/2010 01:00 - 07:00 6:00 6.47 5 1/16/2010 07:00 - 13:00 6:00 8.82 6 1/16/2010 13:00 - 19:00 6:00 16.34 7 1/16/2010 19:00 - 01:00 6:00 6.34 8 1/17/2010 01:00 - 07:00 6:00 15.68 9 1/17/2010 07:00 - 19:00 12:00 1.88 10 1/17/2010 19:00 - 07:00 12:00 0.11 11 1/18/2010 07:00 - 19:00 12:00 1.18 12 1/18/2010 19:00 - 07:00 12:00 0.26 13 1/19/2010 07:00 - 19:00 12:00 0.80 14 1/19/2010 19:00 - 07:00 12:00 0.65 15 1/20/2010 07:00 - 19:00 12:00 0.99 16 1/20/2010 19:00 - 07:00 12:00 0.24 17 1/21/2010 07:00 - 19:00 12:00 0.46 18 1/21/2010 19:00 - 07:00 12:00 0.94 19 1/22/2010 07:00 - 19:00 12:00 1.00 20 1/22/2010 19:00 - 07:00 12:00 1.02 21 1/23/2010 07:00 - 19:00 12:00 0.94 22 1/23/2010 19:00 - 07:00 12:00 1.04 23 1/24/2010 07:00 - 20:00 13:00 0.36 24 1/24/2010 20:00 - 07:45 11:45 0.95 Field 2 - Hot Gas 1 1/15/2010 1000 – 1345 3:45 104.99 2 1/15/2010 1345 – 1845 5:00 15.38 3 1/15/2010 1845 – 0130 6:45 150.29 4 1/16/2010 0130 – 0700 5:30 19.79 5 1/16/2010 0700 – 1245 5:45 5.38 6 1/16/2010 1245 – 1845 6:00 0.62 7 1/16/2010 1845 – 0045 6:00 0.57 8 1/17/2010 0045 – 0645 6:00 12.56 9 1/17/2010 0645 – 1845 12:00 1.46 10 1/17/2010 1845 – 0700 12:15 0.56 11 1/18/2010 0700 – 1845 11:45 14.52 12 1/18/2010 1845 – 0700 12:15 0.54 13 1/19/2010 0700 – 1900 12:00 41.32 14 1/19/2010 1900 – 0700 12:00 0.10 15 1/20/2010 0700 – 1845 11:45 13.60 16 1/20/2010 1845 – 0700 12:15 0.11 17 1/21/2010 0700 -1845 11:45 1.84 18 1/21/2010 1845 – 0645 12:00 0.55 19 1/22/2010 0645 – 1245 6:00 190.11 20 1/22/2010 1245 – 1900 6:15 87.36

### Page 38 of 38 Appendix A - Summary of Unscaled Florida Flux Values By Sampling Period Period No. Sample Interval Times Duration (Hrs.) Est. Flux (ug/m2-s) 21 1/22/2010 1900 - 0030 5:30 26.06 22 1/23/2010 0030 - 0700 6:30 21.35 23 1/23/2010 0700 - 1900 12:00 6.78 24 1/23/2010 1900 - 0700 12:00 0.90 25 1/24/2010 0700 - 1845 11:45 0.44 26 1/24/2010 1845 - 0645 12:00 0.51