1. Buffer Zones and Credits
John Leahy, EPA Pesticide Re-evaluation Division

2. Buffer Zones Area around the application block or greenhouse
Bystanders must be excluded during buffer zone period except when in transit
“Buffer zone period” starts when fumigant is first delivered to soil and is in effect for 48 hours after application ends
Product labels will display distances in look-up tables based on rate, method and field size
Credits for certain site conditions or application practices that reduce emissions
A buffer zone provides distance between the application and bystanders, allowing airborne residues to disperse before reaching the bystanders.
A buffer will reduce the chances that air concentrations where bystanders are located will cause acute adverse health effects.
EPA’s goal when selecting distances was to be protective of all adverse health effects.
In the case of methyl bromide, a severe non-reversible endpoint (developmental) is the effect we are regulating on.
For the other fumigants, buffer zone distances selected that often result in concentrations outside buffers that will result in minor reversible effects if people are present, but the distances selected will usually be protective of the more severe and irreversible effects that occur at higher concentrations.
EPA goal was also to select buffer distances that will protect bystanders from acute exposures, but not so big to eliminate benefits of soil fumigant use.
Throughout the re-registration process growers and other stakeholders have commented that the air concentrations even within 25 feet of the treated area do not present a risk for bystanders.
This slide shows some of the general requirements including the prohibition of non-handlers from entering the buffer zone except when engaged in transit which I will cover in a few minutes
The buffer zone period starts when the application begins and last for 48 hours after the application has ended.
The 48 hour duration is based on EPA's analysis of the available flux data across the fumigants.

3. Buffer Zone Updates 2011 Will Consider New Flux Studies Including:
Temperature studies
Application method studies
Multi-chemical studies
Currently received over 20 new studies, more expected
EPA tarp testing
May result in performance based standards
We are in the process of reviewing some additional flux studies that we received after we completed the Amended REDs.
Over 20 new studies have been submitted, with a few more expected soon.
Also, our lab in Ft. Mead, MD has recently begun a tarp permeability testing study
The data from this testing may result in credits for additional tarps and may be the potential basis for development of a performance based credit versus listing specific tarp names on labels.
FYI
Studies Received:
Metam sodium shank and center pivot in WA (WSU)
Telone and chloropicrin shank in PNW (Dow)
Chloropicrin, 1,3-D, and metam potassium shank in FL (USDA Area-Wide)
Chloropicrin, metam sodium and DMDS shank in GA (USDA Area-Wide)
Flux Evaluation of a Metam Potassium Application Applied by the Drench Method (AMVAC)
Metam sodium shank in MI (MI Growers)
Metam sodium and chloropicrin shank in WI (WI Growers)
Metam Sodium for Shank Injection/ Compaction on a Daytime and Nighttime Basis (Metam Alliance)
Chloropicrin Bedded Shank in FL (CMTF)
Methyl bromide and chloropicrin in San Joaquin Valley, CA (MBIP)
Broadcast shallow tarped under standard HDPE
Broadcast shallow tarped under VIF
Broadcast shallow tarped under VIF with potassium thiosulfate soil spray
Broadcast shallow tarped under VIF with other emissions reduction treatment
Deep, tarped strip under VIF
Expected:
Methyl Bromide in Plant City, FL (MBIP)
Bedded tarp shank injection with VIF
Bedded tarp shank injection with VIF traditional emissions reduction treatment
Bedded tarp shank injection with metalized film
Broadcast shallow tarp under VIF
1,3-D and chloropicrin broadcast shank in a Florida sod production farm (USDA Area-wide)

4. Transit Through Buffer Zones
Vehicular and bicycle traffic on public and private roadways through the buffer zone is permitted.
Bus stops or other locations where persons wait for public transit are not permitted within the buffer zone.
Pedestrians are not permitted within the buffer zone.
The labels permit vehicles and bikes to travel along roadways in the buffer zones.
EPA believes that these activities will not result risks of concern.
However bus stops are prohibited from being in the buffer zone.
Pedestrians are not allowed in the buffer zone during the buffer zone period. 4 4

5. Roads and Rights-of-Ways
Buffers may NOT include roads and rights-of-way UNLESS,
The area is not occupied during the buffer zone period
Entry by non-handlers is prohibited
Applicators comply with all local laws and regulations
To include a road or right of way there are also certain conditions that must be met.
The area can not be occupied during the buffer zone period and entry by non-handlers is prohibited
applicators will need to comply with all local laws and regulations
Comments that we received indicate that the buffer zone’s proximity to roads is one of the biggest challenges of the RED requirements to comply with. 5 5

6. Other Publicly Owned and/or Operated Areas
Buffers may NOT include areas such as parks, sidewalks, permanent walking paths, playgrounds, and athletic fields UNLESS,
The area is not be occupied during buffer zone period
Entry by non-handlers is prohibited
Applicators comply with all local laws and regulations AND
Written permission to include the public area in the buffer zone is granted by the state/local authorities responsible for management and operation of the area
For all other publicly owned and/or operated areas such as parks, sidewalks, permanent walking paths, playgrounds, and athletic fields that are in the buffer zone, the same restrictions that I just mentioned for roads apply plus:
Written permission to include the public area in the buffer zone by the appropriate state and/or local authorities responsible for management and operation of the area is required
In situations where a road does not have a sidewalk (picture on previous slide) and it is in the buffer zone, the label doe not require written permission. 6 6

7. Buffer Zone Distances
Product labels will display distances in look-up tables based on
application rate
field size
application equipment and methods
Buffer zone credits may be applied for certain site conditions or application practices that reduce emissions (e.g., certain tarps)
To assist in figuring out buffer zone sizes:
EPA is requiring that labels contain look-up tables that applicators will use to determine the buffer zone distances for a particular application scenario.
Buffer zone credits may be applied based on certain site conditions or use of high barrier tarps.
These credits are based on available data, modeling, and other information.
The Buffer zone distance and the credits applied must be recorded in the FMP.
If measurements are needed to utilize a credit those results must also be recorded in the FMP. 7 7

8. Chloropicrin Drip Tarped Buffer Zone Distances
This is a sample buffer zone table from the 2009 RED for chloropicrin.
It shows the buffer zone distances in feet for various application block sizes for a drip application of the chloropicrin when the drip tape is at the soil surface under a standard tarp
Using the label maximum 300 lb ai per acre rate for drip with a 10 acre application block would require a buffer zone of 75 feet without any credits.
The distances increase as the rate and block size increase but the scale is NOT linear. For the example of a 300 lb ai rate with a 10 acre block and a 75 foot buffer,
- if you cut the rate by 50% the buffer is 30 feet NOT 37.5 feet
Also if you double the block size to 20 acres the buffer distance is 130 feet NOT 150 feet.

9. Buffer Zone Credits
This slide summarizes what conditions qualify for credits which include:
specific high barrier tarps listed by name on labels
soil conditions,
application equipment, and
application of water with and without potassium thiosulfate over tarps
For similar conditions like organic matter and soil temp, only one credit can applied.
Later this year the Agency plans on updating the emission factors document that was the basis for these credits based on new data that was recently submitted or that is expected. 9 9

10. Buffer Zone Calculator
Being developed by EPA to assist users determine buffer zone distances required by label
Optional to use
Internet accessible
Ability to save, retrieve, edit, and print records
No information will be collected by EPA
Potential to integrate into EPA’s FMP web-based FMP program
To further assist users determine the buffer zone distance required by the label and to EPA is in developing a web-based buffer zone calculator that will be available on our EPA website
It will be optional to use; applicators can use the tables on the labels and get the same results.
Users will be able to save, retrieve, and edit inputs and results on their own computer but no information will be collected or stored by EPA
There is a potential to integrate this tool into a web-based fumigant management plan program that EPA is also developing (this will be presented later) 10 10

11. Buffer Zone Calculator (sample screens)
This slide shows some sample screens (this are only theoretical examples and not the actual program)
(Top Left) Each user will have a user ID and password
(Top Right) Users can start a new calculation or open an existing calculation
(Bottom Left) There will be entry screen that allows users to enter a specific product according to its EPA Reg Number.
- The program will have drop down menus that list those numbers
- For this example an EPE REG #for a Methyl Bromide Product is shown
(Bottom Right) After the product is entered the user will see Product Name and other information and be able to go back if its not correct 11 11

12. Buffer Zone Calculator (sample screens)
(Top Left) Based on the EPA Reg No that is entered the applicable application methods that are allowed by the labels are displayed
- For this example the method is tarped bedded (shank)
(Top Right) The application rate is entered expressed as the broadcast or broadcast equivalent rate
For this example the user is using broadcast equivalent rate of 240 lbs product per acre which would be 120 lbs of MeBr per acre (a typical rate used for several crops in the SE) and a block size of 20 acres
There will be an option to enter the rate expressed as the treated area rate with the % of the block untreated to get the broadcast equivalent rate
The buffer zone distances on the 2011 labels will based on the broadcast or broadcast equivalent rate.
(Bottom Left) Next a list of tarps that qualify for credits would appear. This screen would not display if the application method selected in the previous was “untarped” . For this example a Pliant Blockade tarp that qualifies for a 60% reduction of the buffer zone distance is selected.
(Bottom Right) potential credits for organic content, clay content, and the application of potassium thiosulfate are displayed. For this example these credits do not apply 12 12

13. Buffer Zone Calculator (sample screen)
Results:
Date and time of calculation: 3/23/ :53 AM
Product Name: Pic-Brom Preplant Soil Fumigant
EPA Reg No:
Active ingredients in the product that will be applied:
MeBr (50%) and Chloropicrin (50%)
Application Method: Tarped bedded
Application rate: 240 lbs product/acre
Application Block Size: 20 acres
Buffer Zone Credits Applied: Pliant Blockade Tarp (60% reduction)
Total % of reduction with credits: 60% reduction
Minimum buffer zone distance without credits: 323 feet
Minimum buffer zone distance with credits: 130 feet
This is a sample results screen for the calculator.
It shows all of the inputs and the buffer zone distance with and without credits.
For this example the minimum distance would be 130 feet
Users can save the results to their computer or print the results that can attached to their FMP
We are looking to the possibility of giving users the option of dumping the results into web-based FMP program that is being developed.
Once we get this working for single products we are considering including the ability to calculate co-applied fumigant products
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14. Questions and discussion
Buffer Zones
Questions and discussion 14 14

15. Buffer Zones
Extra Slides
Background and additional details

16. Recently Submitted Flux Studies
Metam sodium shank and center pivot in WA (WSU)
Telone and chloropicrin shank in PNW (Dow)
Chloropicrin, 1,3-D, and metam potassium shank in FL (USDA Area-Wide)
Chloropicrin, metam sodium and DMDS shank in GA (USDA Area-Wide)
Flux Evaluation of a Metam Potassium Application Applied by the Drench Method (AMVAC)
The next 3 slides slide identify flux studies that have been recently submitted to EPA
The studies are being reviewed by our Health Effects Division and the results of that review may warrant additional changes to buffer zone distances and possibly to the buffer zone credits.
We believe that since the RED process began, and growers and applicators have also said, that users have been transitioning to lower emission application methods and the new data seem to confirm this. 16 16

17. Recently Submitted Flux Studies (cont)
Metam sodium shank in MI (MI Growers)
Metam sodium and chloropicrin shank in WI (WI Growers)
Metam Sodium for Shank Injection/ Compaction on a Daytime and Nighttime Basis (Metam Alliance)
Chloropicrin Bedded Shank in FL (CMTF)
Here are additional flux studies. 17 17

18. Recently Submitted Flux Studies (cont)
Methyl bromide and chloropicrin in San Joaquin Valley, CA (MBIP)
Broadcast shallow tarped under standard HDPE
Broadcast shallow tarped under VIF
Broadcast shallow tarped under VIF with potassium thiosulfate soil spray
Broadcast shallow tarped under VIF with other emissions reduction treatment
Deep, tarped strip under VIF
And more. 18 18

19. Expected Flux Studies Methyl Bromide in Plant City, FL (MBIP)
Bedded tarp shank injection with VIF
Bedded tarp shank injection with VIF traditional emissions reduction treatment
Bedded tarp shank injection with metalized film
Broadcast shallow tarp under VIF
1,3-D and chloropicrin broadcast shank in a Florida sod production farm (USDA Area-wide)
This slide shows flux studies that we expect to receive this year.
Again the results of these studies could impact the buffer zone distances and credits that appear on 2011 labels 19 19

20. EPA Tarp Permeability Testing
EPA is testing several tarps determine mass transfer coefficient (MTC) for 1,3-D,MeBr, MeI, MITC, chloropicrin, DMDS, sulfuryl fluoride, and PPO
MTC data may result in additional/revised buffer zone credits for 2011 labels
Potential basis for development performance based credits (in lieu credits for specific tarp names) with a standard tarp testing protocol
Our lab in Ft. Mead, MD has recently begun a tarp permeability testing study
The data from this testing may result in credits for additional tarps and may be the potential basis for development of a performance based credit versus listing specific tarp names on labels. 20 20

21. Tarps Received by EPA AEP, Sun Film High Barrier AEP-One
Berry Plastic, EVOH-High Barrier
Berry Plastic, EVOH-High Barrier/improved toughness
Berry Plastic, EVOH-Supreme Barrier
Cadillac VIF mil
Cadillac, HDPE
Canslit Metallic mil, Black
Canslit Metallic mil, White
Canslit, Embossed HDPE, 0.6 ml
Canslit, Embossed LDPE, 1.25 ml
Dow SARANEX A
Dow SARANEX B
FilmTec VIF mil
Ginegar, Ozgard mil
Ginegar VIF mil
Guardian Olefinas VIF - Black 1.2 mil, Embossed
Mid South VIF mil
Pliant, Embossed Polyethylene Film
Pliant, Blockade Black mil
Pliant, Blockade White on Black mil
Pliant, Metalized mil
Raven TIF “VaporSafeTM” 1 mil with EVOH core
Raven TIF “VaporSafeTM” 1.4 mil LDPE with EVOH core
Here is a list of tarps our lab has tested. These are the most commonly used agricultural tarps used in fumigation. 21 21

22. Expected Tarps Bromostop VIF - 1.30 mil
Bruno Rimini IPM Clear VIF 1.38
Klerk Hytibar VIF mil
We also expect to test these tarps which will be sent to the lab. 22 22

23. Buffers and Agricultural Areas
Buffer zones may include agricultural areas owned/operated by someone other than the owner/operator of the application block IF
The buffer zone will not overlap with a buffer zone from a nearby fumigation, and
The owner/operator provides written agreement that they, their employees, and others will stay out of the buffer zone.
Similar to residential areas, buffer zones may only include land owned by other growers if
growers can ensure that buffers on their properties will not overlap, and
If the adjacent grower and the grower’s employees agree to stay out of the buffer zone that crosses onto their land.
Buffer overlap will be covered next. 23 23

24. Buffers and Residential Areas
Buffer zones may include residential areas IF
The occupants provide written agreement to voluntarily vacate the buffer zone during the entire buffer zone period
For applications of methyl bromide products with less than 20 percent chloropicrin, air monitoring inside residential structures is required after the buffer zone period ends
Buffer zones may include residential areas ONLY if certain conditions are met:
- - The occupants provide written agreement to voluntarily vacate the buffer zone during the buffer zone period
For applications of methyl bromide products with less than 20 percent chloropicrin, air monitoring within residential structures with a direct read device is required after the buffer zone period ends.
This requirement will ensure that the methyl bromide air concentrations within structures are less than 1 ppm and safe for re-entry
May Note: Concern about voluntary agreement; potential coercion if the grower is also landlord or otherwise has leverage over the residents. 24 24