1 of 68 Dow AgroSciences LLC dowagro.com 9330 Zionsville Road, Indianapolis, IN 46268

- 1054

308/2E January 22, 2013

Dr. Neil Hoffman Science Advisor USDA/APHIS/BRS 4700 River Road, Unit 98 Riverdale, MD 20737

Diane Sinkowski Senior Environmental Protection Specialist USDA/APHIS/BRS 4700 River Road, Unit 147 Riverdale, MD 20737

DAS

- 68416

- 4 Soybean and DAS

- 40278

- 9 Corn Dow AgroSciences Petition Numbers 09

- 349

- 01p and 09

- 233

- 01p SUPPLEMENTARY DOCUMENTATION IN SUPPORT OF ENVIRONMENTAL ASSESSMENTS

Dear Dr. Hoffman and Ms. Sinkowski: This letter and attached information is in response to your email of Dec.10, 2012 which includ ed a request for information from Dow AgroSciences (DAS) to support your efforts in developing the final Environmental Assessment and Response to Comments for DAS

- 402780

- 9 corn and DAS

- 68416

- 4 soybean.
The attached information addresses Questions 8,9, 1 0 and 11 from Section C. Herbicide Drift Issues. Herewith, Dow AgroSciences (DAS) is submitting our response to these questions on the enclosed CD. If you should have any questions or require further information, please contact me at 317

- 337

- 3692.

Since rely,

Gregory L. Orr, Ph.D. Global Regulatory Leader 317

- 337

- 3692 317

- 337

- 4649 (fax) glorr@dow.com2 of 68 DISTRIBUTION PAGE

DED Code: D 1 C / B 1 C

bcc: Laura Tagliani, 308/2E Greg Orr, 308/2E Heidi Reistad, 308/2E Federal Action Files, 308/2E unstapled3 of 68 

### Table of Contents

Section C. Herbicide drift issues. Question 8. Where in the US is 2, 4

- D use restricted? .................................... 4 Question 9. Describe the incidents/history/political process that led to the restrictions in 2, 4

- D use.

.............................................................................. .............7

Question 10. How many offsite incidents from pesticide use are reported each year in the US? Question 11. What is the bre akdown with regards to where (what state or region) the incidents occurred, the active ingredient alleged to have caused the damage, the total number of applications of that active ingredient, types of crop affected, amount of damages sustained, amount of compensation paid? ........................................12 2,4

- D Off

- Target Exposure and Sensitive Crops .............................................594 of 68 

## DOW AGROSCIENCES RES PONSE TO USDA
- APHIS QUESTIONS RECEIVED D ECEMBER 10, 2012 REG ARDING DAS
- 40278
- 9 CORN AND DAS
- 68416
- 4 SOY.

C. Herbicide drift issues.

8. Where in the US is 2, 4

- D use restricted? 

### US Restrictions on the use of 2,4

- D Summary The USEPA's registration for 2,4

- D under section 3 of FIFRA includes certain restrictions on use that appear on the product's label, but USEPA has not class ified 2,4

- D as a “restricted use pesticide” (RUP). 2,4

- D, first registered in 1946, is one of the most widely used herbicides in the world and over 60 years later, it still is a viable product for weed control in multiple uses. The most frequently means b y which EPA addresses potential adverse effects is through warnings, prohibitions, restrictions and directions for use on the product label (40 CFR Part 156). When registering a product, the US EPA also has the ability to classify a pesticide as a RUP shou ld it deem that the product needs additional restrictions to decrease the risk of adverse affects (40 CFR Subpart I, 152.160). RUPs can only be applied by or under the direct supervision of an applicator certified by the state or EPA. After a pesticide is registered by US EPA, states can register pesticides under specific state pesticide registration laws. State lead agencies have primary authority for pesticides used within the state. In some cases, states may enact additional restrictions for use of a p roduct to meet the uses and needs of their state. Currently, there are 18 states with some type of restriction on the use of 2,4

- D. Types of use restrictions on registered products include general RUP regulations, formulation

- specific restrictions, time

- specific restrictions and/or location

specific restrictions.5 of 68 

### US State 2,4

- D Restrictions* TYPE OF RESTRICTION STATE State RUP designation, but with no spray/use restrictions ( e.g. licensed applicators, permitting, record keeping, etc .) MA, NJ, NM, VT
State RUP designation and spray/use restrictions CA, LA, TX, WA No state RUP designation but spray/use restrictions AR, FL, ID, IA, MI, MS, NY, OH, OK, OR
Total number of states 18

* State regulations subject to change. It is the applicator’s responsibility to be aware of and comply with all current state regulations. Types of state restrictions Four states have designated 2,4

- D products as a RUP

– Massachusetts, New Jersey, New Mexico and Vermont. The RUP designation means that applicators must be certified to use the RUP product or have a licensed applicator within the vicinity of the person making the application. The applicator must also keep spray records. Four state have designated 2,4

- D products as a RUP along with spray use restri ctions

– California, Louisiana, Texas and Washington. The types of additional spray use restrictions vary by state. In these states, applications are restricted or prohibited during certain times of the year (e.g. April through September) in designated c ounties. For the remaining counties in the states of Louisiana and Texas, buffers from sensitive or susceptible crops are established. Ten states have no RUP designation for 2,4

- D but do have specific spray use restrictions

– Arkansas, Idaho, Iowa, Flo rida, Michigan, Mississippi, New York, Ohio, Oklahoma and Oregon. The restrictions range from buffers to aerial versus ground applications to the type of 2,4

- D formulations. For example, New York has spray use restrictions in only three counties. No 2,4

- D can be applied within 100 feet of any grape vineyard and there is a 2 mile buffer for all ester formulations. In Mississippi, 2,4

- D is limited to ground applications only from April 1 to September 30. In Iowa, ester formulations only are prohibited in five counties.

STATE RUP RESTRICTIONS

Arkansas No All 2,4

- D are in Class F with use restrictions. Apr. 15

- Sept. 15: no use in Clay, Greene, Craighead, Poinsett, Cross, Crittenden, St. Francis, Lee, Phillips, and Mississippi Counties. Permits may be obtained to allow exemption with key requirements recording application details. Buffer zone/wind speed requirements. Buffer zones set: e.g. 4 mile aerial; 1 mile ground. AR Regulations on Pesticide Classification

- Final Rule (Rev. 06/07):6 of 68 California Yes RUP for products 1 gal or greater containing over 15% active ingredient. Areas: Central Valley...specifically defined areas of: Sacramento, Madera, Fresno, Kings, Tulare, Kern, San Joaquin Counties. Authorized permits needed. Restrictions based on dates, formulation type, wind speed, set

- back from commercial vineyard or cotton planting. 2,4

- D use restrictions to protect CRLF (buffer zones in 33 counties); 2,4

- D salts and esters designated as toxic air contaminants. Title 3, CCR 3, Sec. 6400

Florida No (1)(2)Sale and use of highly volatile 1 forms of organo

- auxin herbicides...is prohibited except for those products labeled as PGR on citrus. (3) Minimum set

- back distances from susceptible crops are specified based on wind speed. Max wind speed = 10 mph. (6) Applicator record keeping requirement. (7) Aerial applica tion by fixed

- wing aircraft prohibited Jan 1 until May 1 in Hendry, Palm Beach, Glades, Martin counties. Florida Administrative Code Chapter 5E

- 2.033 (Effective 7

- 29

- 04)

Idaho No 2,4

- D ester restrictions for counties: Latah, Nez Perce, Clearwater Counties. Restrictions based on aerial or ground, formulation type, set

- back from susceptible crop, wind speed. Buffers from hazard areas for 2,4

- D amines and acids 2 , MCPA, MCPB, and dicamba. IDAPA 02.03.03 Sec. 550

Iowa No The use of high volatile esters formulations of 2,4

- D and 2,4,5

- T, the alcohol fraction of which contains five or fewer carbons, shall be prohibited in the counties of Harrison, Mills, Lee, Muscatine and that part of Pottawattamie county west of Range 41 W est of the 5th P.M. to become effective upon filing. 21

— 45.27(206)

Louisiana Yes RUP for ag uses of 2,4

- D. Restrictions for commercial and private applicators based on timing, location, wind speed. Complex 2008 waiver process specifically for 2,4

- D in place impacting aerial and ground applications based on timing and location. 32 parishes with restrictions. LA Title 7, Part XXIII, § 1103

Massachusetts Yes If product contains >20% 2,4

- D it is State RUP

-- application made by certified applicators and reporting requirements. 333 CMR 1.00

Michigan No No use of volatile ester forms of 2,4

- D and MCPA within specified regions from May 1 to Oct. 1 in parts of Berrien, Cass, Kalamazoo and Van Buren counties. Sprayer specifications for amine forms. MDA Reg 285.637

Mississippi No Hormone

- type herbicide 3 restrictions for aerial application. By date, fixed

- wing or helicopter, No ester formulations, 1/2 mile set

- back from cotton and susceptible crops. Wind speed < 5 mph. Recording of application data. Applicator requirements and licensing. Miss. Code Ann. § 69

- 21

- 109 (Part 3

- Ch 10

- Sub 01) New Jersey Yes 2,4

- D (concentrations >20%) purchased and used only by certified applicators N.J.A.C. 7:30

- 2.10

New Mexico Yes All 2,4

- D Ag

- use products are state

- restricted use. Spray restrictions in Curry, Roosevelt counties based on timing, application method, < 10 mph. Certified applicators. Need permits for applications of low volatile. No permits issued for esters in these 2 cou nties. No aerial application in these 2 counties Apr.15 to Oct. 1. 21.17.56 NMAC7 of 68 New York No 2,4

- D, 2,4

- 5T, MCP spray restrictions and set

- backs of 100 ft from grape vineyards in portions of Chautauqua, Erie, Niagara counties. NY ECL Art. 33 § 321

- 324
Ohio No Restriction from use of ester formulation in Madison township of Lake County. ORC Title IX, Ch. 921

Oklahoma No Spray restrictions in 5 counties: (a) Applications of products containing 2,4

- D esters or dicamba to agricultural lands shall not be made in Greer, Harmon, and Kiowa counties May 1

- October 15; (b) Applications of products containing 2,4

- D, dicamba, picloram, triclopyr, or clopyralid shall not be made in Jackson and Tillman counties May 1

- October. No tification and reporting procedures defined to allow applications. 2 O.S. § 3

- 84 (35:30

- 17

- 24.1)
Oregon No Restrictions on high volatile esters of 2,4

- D in areas of Morrow and Umatilla counties: no use Apr 1

- Sept 1 except by permit. OAR 603

- 057

- 0301 to 0320

Texas Yes Regulated: 2,4

- D, MCPA, dicamba, quinclorac . 53 "Pesticide Regulated Herbicide Counties". General restrictions: highly volatile prohibited within 4 miles of susceptible crop. No applications in wind >10 mph. Additional provisions set county

- by

- county for 53 counties. Processes for spray permi ts when required. Process for counties to become regulated. TAC 4

- 1

- 7

- E §7.50, 53

Vermont Yes Class A restricted use. Application and reporting requirements like Federal RUP. 6 V.S.A. Ch 87

Washington Yes All phenoxy hormone

- type herbicides restrictioned throughout eastern Washington with additional restrictions in 14 counties: Adams, Benton, Columbia, Douglas/Chelan, Franklin, Garfield, Grant, Kittitas, Klickitat, Lincoln, Okanogan, Spokane, Walla Walla, Whitman, Yakima. Specific restricti ons set in specific rules by county: boundaries defined; formulation type, application parameters, dates, aerial or ground, set

- backs. Applications by permit process. 16 WAC 16

- 228,232

1 Note: High volatility esters of 2,4

- D are those that have five or fewer carbons on the alcohol side chain. Currently there are no high volatility esters registered for use in the United States.

2 Note: the 2,4

- D choline in Enlist Duo is a quaternary ammonium salt. Not an amine or an est er.

3 Hormone

- type herbicides include 2,4

- D, 2,4

- DB, aminopyralid, clopyralid, dicamba, dichlorprop, fluroxypyr, MCPA, MCPB, mecoprop, picloram, quinclorac and triclopyr.8 of 68 

## DOW AGROSCIENCES RES PONSE TO USDA
- APHIS QUESTIONS RECEIVED D ECEMBER 10, 2012 REG AR DING DAS
- 40278
- 9 CORN AND DAS
- 68416
- 4 SOY.

C. Herbicide drift issues.
9. Describe the incidents/history/political process that led to the restrictions in 2, 4

- D
use. History of 2,4

- D regulations in Arkansas
From Arkansas State Plant Board Annual Report (2011

- 2012) i
All pesticides registered for sale in Arkansas are assigned to a Class. Each Class carries with it one or more restrictions that must be complied with by the user, applicator, or dealer. The classification system ranges from Class A which pre sumably all pesticides are registered as initially, until a problem develops. The only use

- restrictions assigned to Class A products are those on the product label. If problems develop with a product, the Plant Board, after a public hearing, can move a pro duct from the Class A designation to another designation (B, C, D, E or F) which has more restrictions. Each classification carries with it all the restriction(s) that are specified for that class plus all that came before it. That is, if a product is cla ssified as Class D it will be bound to the restriction(s) specified for Class D and those specified for Classes A, B and C. This allows the Plant Board to a have a systematic approach to placing use

- restrictions on products when needed as opposed to crea ting a unique set of restrictions for each product as needed. This has also cut down on the confusion that existed as to what regulations apply to what products.
2,4

- D containing products are assigned to Class F. This designation was enacted by the Arkan sas State Plant Board (ASPB) in 2007 after an unusual number of off

- target incidences were reported in the 2006 crop season. More than 100 complaints about 2,4

- D drift were made to the ASPB Pesticide Division. It is the Board’s responsibility to investig ate each complaint they receive. With the record number of complaints received that year, not all requests could be attributed to a definitive cause. However, the ASPB Pesticide Division Director said that based on the information from university extensi on and ASPB field inspectors the widespread occurrences of off

- target movement of 2,4

- D occurred “probably not due to a specific application as much as it is volatilization...It’s almost assuredly something that was applied in a temperature inversion.” ii The 2006 crop season in northeast Arkansas iii had a very wet spring which resulted in many applications being conducted aerially and done in a short period of time. A similar spike in incidences occurred in 2003 when the crop season was unusually wet iv . [ NOTE: The proposed label for Enlist Duo prohibits aerial application and also provides specific instructions on avoiding applications during temperature inversions. ]9 of 68 The ASPB created a 2,4

- D task force and a glyphosate task force in 2006 charged with the mission of developing proposed regulations for the board to consider. v The task forces, led by the director of ASPB Pesticide Division, included representatives from University of Arkansas Extension and researchers, and crop consultant Ford Baldwin. vi A fter conducting public meetings and taking testimony from representatives from various agriculture sectors, the task forces submitted recommendations to the ASPB at the end of 2006. The final rule, adopted in February 2007 vii , called for ban on most aerial and ground applications of 2,4

- D in ten northeastern counties (area known as Crowley’s Ridge) between April 15 and September 15 and buffers of 2,4

- D applications from susceptible crops in the remaining counties. Applications of glyphosate were limited to wind speeds no higher than 10 mph or 15 mph if using a commercially available hooded sprayer. University of Arkansas Cooperative Extension also held over 340 applicator education classes, well above their target 90. viii
In the ASPB Annual report for 2011

- 20 12, the Pesticide Division reported 195 requests for investigations made in 2011. Of these 195 investigations, only 5 were attributed to 2,4

- D. ix (See appendix A). On average over the past four years, the ASPB conducted about 170 investigations each year

.

i Arkansas State Plant Board annual report (2011

- 2012), page 43. http://plantboard.arkansas.gov/Pages/default.aspx i i Bennett, David. “ 2,4

- D damages Arkansas cotton”, Delta Farm Press; A ug. 15, 2006. i ii National Weather Service, Little Rock, AR Yearly Climate Summary (2006). http://www.srh.noaa.gov/lzk/?n=2006.htm i v National Weather Service, Little Rock, AR “Severe Storms Flash Flooding (May 2003), http://www.srh.noaa.gov/lzk/?n=events2003.htm

v Bennett, David. “ Proposed regulations target Arkansas 2,4

- D and glyphos ate drift ”, Delta Farm Press; Jan. 25, 2007.

v i Bennett, David. “ In Arkansas: Task force tackles drift problems”, Delta Farm Press; Aug. 11, 2006.

v ii Arkansas Regulations on Pesticide Classification , Agency # 209.02, (Rev. 06/07). V iii University of Arkansas Combined Research and Extension Annual Report (2007), pg. 152. i x Arkansas State Plant Board annual report (2011

- 2012), page 41

- 42.10 of 68 APPENDIX A Arkansas State Plant Board Annual Report (2011

- 2012)11 of 68 2005 281 2004 249 2003 256 2002 21512 of 68 

## DOW AGROSCIENCES RES PONSE TO USDA
- APHIS QUESTIONS RECEIVED D ECEMBER 10, 2012 REG ARDING DAS
- 40278
- 9 CORN AND DAS
- 68416
- 4 SOY.

C. Herbicide drift issues.

10. How many offsite incident s from pesticide use are reported each year in the US? 11. What is the breakdown with regards to where (what state or region) the incidents occurred, the active ingredient alleged to have caused the damage, the total number of applications of that active ingredient, types of crop affected, amount of damages sustai ned, amount of compensation paid?

Dow AgroSciences is not aware of a comprehensive, national database of offsite incidents from pesticide use 1 . Incidents involving alleged pesticide spray drift may be reported by various sources to the grower, applicato r, retailer, state or federal agency and/or the product manufacturer. Information associated with the alleged incidents and investigations is managed by each respective party or entity. Pesticide product registrants are required under FIFRA Section 6(a)( 2) to submit certain types of factual information to the U.S. Environmental Protection Agency (EPA) regarding adverse effects on human health or the environment from the use of their registered products. EPA maintains this information in its Aggregate Inc ident Reports database. Registrants are only required to submit information that has been provided to them or that they otherwise have knowledge of, and no investigation or follow

- up is required. Out of an abundance of caution, registrants routinely submi t reports on alleged incidents that have not been independently verified. Thus, due to the nature of incidents and how they are typically reported through the FIFRA 6(a)(2) process, the authenticity, validity, and/or accuracy of information contained in t he reports cannot be guaranteed by the registrants and may not accurately reflect actual incidents and products involved. In many cases there is not enough information to determine if the alleged adverse effects noted were in fact the result of pesticide spray drift and not another contributing factor. Thus, spray drift allegations may be reported as plant damage which may, in fact, have been caused by diseases, insects, nutrient deficiencies, herbicide residue (carryover) and growing conditions.

1 US EPA Office of Pesticide Programs’. (2007). Report on Incident Information: The Baseline

.

Retrieved from http://www.epa.gov/pesticides/ppdc/2007/oct2007/session10

- finalrpt.pdf

.13 of 68 For its p art, EPA does not require reporting of adverse effects to non

- target plants at the use site when the pesticide label provides adequate notice. As a result, some incidents may not be reported because EPA is already aware of the potential for those effects to occur under certain conditions. Adverse effects and incident data are not shared across registrants and duplicative reporting is possible. Therefore, to obtain adverse effects data for all products across registrants requires submitting a request to th e EPA pursuant to the Freedom of Information Act (FOIA). Dow AgroSciences is not aware of the extent to which EPA can search its Aggregate Incident Reports database for specific types of adverse effects information, such as damage to non

- target plants.

E PA’s Office of Pesticide Program's also maintains the Ecological Incident Information System database (EIIS), which includes information on ecological incidents reported to EPA prior to 1998 by pesticide registrants and all of the "major" incidents reporte d by pesticide registrants since 1998. EIIS also includes information on incident reports submitted through other sources, such as the States, regardless if they are "major" incidents or not. Incidents of adverse effects on lawns and other ornamentals caus ed by direct application of pesticide products are not entered into EIIS. When available, EIIS includes date and location of incident, type and magnitude of effects observed in various species, use(s) of pesticides known or suspected of contributing to the incident. However, the database contains a limited number of reported incidents and is not readily available to the public. While accurate, comprehensive, and reliable national data on offsite incidents from pesticide use is not readily available, EPA’s O ffice of Pesticide Programs may publish incident data as part its periodic review of all pesticides to ensure that their registrations continue to meet current scientific standards. Recently, EPA published a scoping document for 2,4

- D acid, salts, and est ers to support registration review that includes the results of a search of the EIIS and the Aggregate Incident Reports databases for ecological incidents involving 2,4

- D acid and its forms 2

. A summary of the incident data is provided in Section 3.3 of the scoping document. ( See Appendix 1). The EIIS database returned both residential and agricultural incidents involving 2,4

- D reported from 1949 to the present, as summarized in Table 9. A listing of each of the individual incidents from the search of the EIIS database is provided in Table C.1 Ecological Information from the EIIS Database ( See Appendix 2). Many of the plant incidents appeared to result from over

- application of 2,4

- D products to lawns or application of 2,4

- D products to types of grass t hat are sensitive to 2,4

- D. Other plant incidents were the result of spray drift in agricultural settings. As noted in the report, these incidents need to be carefully reviewed to determine the role that 2,4

- D products may have played as many incidents a lso involved the application of other pesticides. Table 10 of the EPA Report provides a summary of incidents reported in the Aggregate Incident Reports database from 1996 to the present for 2,4

- D acid and its forms. However,

2 US EPA Environmental Fate and Effects Division. (2012). EFED Registration Revie w Problem Formulation for 2,4

- D. Retrieved from http://www.regulations.gov/#!documentDetail;D=EPA

- HQ

OPP

- 2012

- 0330

- 000314 of 68 specific information was not available for these incidents (e.g., species involved, other chemicals, etc.). In many cases there is not enough information to determine if the alleged effects noted were in fact the result of pesticide spray drift and not another contributing factor. Thu s, spray drift allegations may be reported as plant damage which may, in fact, have been caused by diseases, insects, nutrient deficiencies, herbicide residue (carryover) and growing conditions. It is also important to note that the incident data summarized in the EPA report is for 2,4

- D acid, salts, and esters. The herbicide solution for DAS

- 40278

- 9 corn is centered on the innovative choline salt of 2,4

- D. This proprietary salt provides significant advantages over 2,4

- D amine salts and esters, inc luding exceptionally low volatility. Dow AgroSciences has developed innovative formulations for use with DAS

- 40278

- 9 corn that will combine the 2,4

- D choline salt with glyphosate in a premix. These new formulation technologies significantly reduce the pote ntial for off

- target movement via spray droplet drift. New premix formulations of 2,4

- D choline plus glyphosate also will provide greater spray tank stability and compatibility than current tank mixes of 2,4

- D plus glyphosate. The novel attributes and tech nologies offered in the premix of 2,4

- D choline plus glyphosate have been shown to significantly reduce the amount of driftable spray droplets (droplets below 150 μm) compared with tank mixtures of commercial glyphosate and 2,4

- D formulations. The premix f

ormulation will combine excellent efficacy and stability in the spray solution with low potential for off

- target movement via particle or vapor drift. In addition to the technology innovations, the herbicide product label and product use guide do not all ow applications into areas where temperature inversions are present, do not allow applications when winds exceed 15 mph, do not allow aerial applications, and require use of only spray nozzles that produce a coarse or coarser spray droplet size. Such stewa rdship and responsible use requirements will help to further minimize the potential for off

- target herbicide movement.
Use of the innovative choline salt of 2,4

- D, the new formulation technologies, and Dow AgroSciences’ Stewardship Program will help reduc e the potential for off

- target impacts on sensitive crops and non

- crop plants/organisms.15 of 68 **Appendix 1**

**– Report Excerpt Section 3.3 Ecological Incidents** 16 of 68 **Appendix 2**

**– Table C.1 Ecological Information from the EIIS Database** 

Incident Information from the EIIS Database17 of 6818 of 6819 of 6820 of 6821 of 6822 of 6823 of 6824 of 6825 of 6826 of 6827 of 6828 of 6829 of 6830 of 6831 of 6832 of 6833 of 6834 of 6835 of 6836 of 6837 of 6838 of 6839 of 6840 of 6841 of 6842 of 6843 of 6844 of 6845 of 6846 of 6847 of 6848 of 6849 of 6850 of 6851 of 6852 of 6853 of 6854 of 6855 of 6856 of 6857 of 6858 of 6859 of 68 

## 2,4
- D Off
- Target Exposure and Sensitive Crops

Federal and state regulation of off

- target pesticide movement EPA is the federal agency vested with the authority and responsibility for regulating the sale, distribution and use of pesticides, including herbicides such as 2,4

- D. EPA registers or approves a pesticide for one or more uses only after determi ning that the product will not cause unreasonable adverse effects on the environment

– the statutory test for registration under FIFRA. When EPA approves the registration of a pesticide, it approves a particular product for a particular use or uses under specified conditions (including composition, application methods, usage rates, and protective measures) and specifies the language that must appear on the label of the pesticide product that sets forth those conditions and limitations. If a pesticide prod uct is used in a manner that is inconsistent with its labeling, the user is subject to federal and state enforcement action. When making its registration decision, EPA specifies the data and information it needs to support that registration. Among the da ta EPA requires are those relating to off

- target pesticide movement including, e.g., spray drift and volatilization (40 C.F.R. Part 158, Subparts L and N). Federal law requires EPA to periodically review existing pesticide registrations to ensure that t hey meet the FIFRA standard for registration (the "no unreasonable adverse effects" criteria of FIFRA) under current scientific standards. EPA specifically addressed issues regarding off

- site pesticide movement of 2,4

- D in EPA’s 2005 Reregistration Eligib ility Decision (RED) for 2,4

- D, which incorporated major label revisions to products containing 2,4

- D. These revisions included:

• lower limits for spray droplet size;

• prohibitions on spraying at wind speeds greater than 15 mph, spraying with a wind direct ion that is not favorable to on

- target deposition, or spraying with sensitive non

target crops within 250 feet downwind;

• a prohibition on spraying at wind speeds of less than 3 mph if there are temperature inversion conditions, or stable atmospheric condi tions at or below nozzle height;

• a prohibition on spraying where sensitive crops might otherwise be susceptible to drift;

• restrictions on boom length and spray release height for aerial applications, and nozzle height for ground boom applications;

• lower limits on application rates and total applications per year for specific crops; and

• compliance with any state and local laws that are more stringent (e.g., California, areas of which have seasonal limitations on use of 2,4

- D) ( EPA, 2005a )

. EPA determined the use of the then

- existing formulations of 2,4

- D to be eligible for reregistration with those label restrictions. As mentioned above, states also regulate the use of pesticides, including herbicides. A number of states have passed laws to specifically address spray drift ( Feitshans, 1999 ) . These laws may include penalties and/or restrict application methods, require prior notification, impose buffer zones, etc., as each state has deemed appropriate.60 of 68 Additional EPA actions to address spray drift and volatility In addition to registering individual pesticides, EPA also regularly assesses the safety of pesticide use more broadly, and has repeatedly addressed issues associated with off

- target pesticide movement. Some of these efforts include:

• In 2009, EPA developed and issued for public comment a draft guidance document (PR Notice) on Pesticide Drif t Labeling to provide guidance to pesticide manufacturers on labeling statements concerning pesticide drift, and to inform the public of EPA’s policies with regard to pesticide drift. EPA continues to work with stakeholders to finalize this guidance.

• For m any years EPA has contributed funding to support education and training programs on drift management. EPA provides annual funds to states to support pesticide applicator training programs, many of which include educational material on drift management, and EPA has contributed to other educational programs, such as the National Coalition on Drift Minimization educational video and CD

- Rom, the National Pesticide Applicator Certification Core Manual, and the National Agricultural Aviation Association’s Profess ional Aerial Applicator Support System (PAASS) to support their training and education programs to reduce drift incidents.

• EPA encourages pesticide applicators to use all feasible means available to them to minimize off

- target drift. To support this goal, EPA has stated its intent to work with applicators, agricultural extension agents, registrants, environmental groups, and other interested stakeholders to collect and develop information on best management practices (BMPs) to reduce off

- target drift for sp ecific application methods and crop sector combinations. These guidance documents will be consolidated by EPA and made available online.

• OPP and the EPA’s Office of Research and Development are developing a new voluntary program, the Drift Reduction Techn ology (DRT) Program, which encourages the development, marketing, and use of application technologies, verified to significantly reduce spray drift.

• EPA has also taken action to address issues around pesticide volatility. In December 2009, EPA convened th e FIFRA Scientific Advisory Panel (SAP) to examine scientific issues associated with field volatilization of conventional pesticides, focusing on methodologies by which bystander inhalation could be measured. Additional information relating to EPA’s acti ons to address spray drift may be found at its website at http://www.epa.gov/pesticides/factsheets/spraydrift.htm

.61 of 68 Existing precautions against off

- target exposure Despite federal and state controls and the best efforts of applicators, off

- target pesticide movement occasionally damages neighboring crops. Crops may be exposed to pesticide volatility or drift from a variety of sources, including public right of way uses for road main tenance and utilities, and agricultural uses ( Moses, 2009 ) . Crops that have the potential for damage due to exposure to a particular pesticide are considered sensitive crops. Sensitive cr op growers use a number of approaches to protect their crops from off

- target exposure. Location of where the crop is grown is a key consideration; sensitive crop growers may choose to plant in fields that are sheltered or protected from potential exposure , and are not immediately adjacent to conventional crops 3 . Buffer zones and vegetative barriers are often used as a no spray zone between a sensitive area and a crop being sprayed. A buffer zone may be a vegetative barrier consisting of groves, hedge ro ws, wind breaks, pastures, or even the grower’s own conventional crops. Vegetation planted in strategic lines can reduce the extent of spray drift of agricultural chemicals by filtering out spray droplets in air passing through their foliage ( DPI, 2009 ) . In some cases, growers are able to select a sensitive crop variety that is less sensitive to pesticides that are commonly applied to neighboring areas. Modified cultural practices, including timing of operations, are another approach that can be used t o protect against off

- target exposure ( Maynard et al. , 2012 )

. Sensitive crop growers may avoid exposure in right of way areas by posting signs and making arrangements with government road crews or utility companies to do their own maintenance of easements and road ways near their sensitive crops. Similarly, neighboring farms can be notified of the presence of sensitive crops that require protection from herbicide spray drift and volatility. Since applications of herbicides ar e increasingly being made by custom applicators, signage placed near field entrances alerting operators to the presence of sensitive crops and that no sprays are allowed, are also used. Alternatively, sensitive crop growers may notify the local coops and applicators directly. There are also tools available on the internet for growers to register sensitive crop fields so that pesticide applicators can easily locate registered sites before they spray using a Google MapsTM interface ( Driftwatch, 2012 )

. If crop damage occurs, affected growers can seek compensation by a variety of mechanisms. The pesticide applica tor may have insurance to cover such losses. State pesticide enforcement bureaus are notified to view and document the damage. In some states, the applicator may be subject to fines or other penalties ( Feitshans, 1999 ) . The crop damage may also give rise to claims for legal damages in private lawsuits. Potential off

- target pesticide impacts on organic crops Growers of organic crops may also face economic damages from off

- target pestic ide movement, even if their crops are not damaged. If a certifying agent tests a crop grown under organic production and the test reveals the presence of residues from a pesticide not approved for use

3 U of IL Extension. Reducing Pesticide Drift . University of Illinois Extension and Illinois Department of Agriculture62 of 68 under the National Organic Program (NOP), the crop may not be sold as organic if the residue is present at a level greater than five percent of the EPA tolerance for the detected prohibited residue (7 CFR 205.671). A grower whose organic crops were subject to off

- target pesticide movement that resulted in re sidue levels greater than five percent of the EPA tolerance could then lose the organic premium he may otherwise have obtained for his crop. While some certifying agents have refused to allow organic production on fields that have been the objects of spra y drift, a recent court decision found this three year ban on organic production following spray drift to be inconsistent with the NOP ( Johnson v. Paynesville Farmers Union Cooperative Oil Co., 2012 WL 3101667 (Minn.) at 16). In finalizing the NOP, USDA de scribed the following in regards to grower’s responsibilities to protect against chemical drift (65 FR 80556): Drift has been a difficult issue for organic producers from the beginning. Organic operations have always had to worry about the potential for d rift from neighboring operations, particularly drift of synthetic chemical pesticides. As the number of organic farms increases, so does the potential for conflict between organic and nonorganic operations. It has always been the responsibility of organi c operations to manage potential contact of organic products with other substances not approved for use in organic production systems, whether from the nonorganic portion of a split operation or from neighboring farms. The organic system plan must outline steps that an organic operation will take to avoid this kind of unintentional contact. When we are considering drift issues, it is particularly important to remember that organic standards are process based. Certifying agents attest to the ability of organic operations to follow a set of production standards and practices that meet the requi rements of the Act and the regulations. All of the preventions discussed above are available to organic growers and many are required by the NOP as part of their organic production plan. Similarly, insurance and legal recourse may be available to organi c growers who lose premiums as a result of spray drift.
2,4

- D and off

- target movement
One of the herbicides that DAS

- 40278

- 9 corn and DAS 68416

- 4 soybean have been engineered to tolerate is commonly known as 2,4

- D. 2,4

- D is a synthetic plant growth regu lator (auxin) that has been registered for use in the US as a broadleaf weed herbicide since 1948. ( EPA, 2005b ) 2,4

- D is absorbed through the leaves and is translocated to the meristems of the plant. Uncontrolled, unsustainable growth ensues, causing stem curl

- over, leaf withering, and eventual plant death. Thus, an y inadvertent contact to an adjacent broadleaf crop plant, through drift or volatility, has the potential to produce very noticeable physiological symptomology. As of 2005, EPA had registered over 600 end

- use products containing 2,4

- D. ( EPA, 2005b ) Throughout the period 2001

- 2007, 2,4

- D remained the #1

- ranked herb icide for industrial, commercial, governmental, home and garden use, with a total annual usage for these applications in the range 24

- 33 million pounds. ( EPA, 2011 ) Although from 2001 to 2007 its ranking as a63 of 68 herbicide for agricultural use fell from #4 to #5, annual usage was in a similar range: 28

- 33 million pounds in 2001 and 25

- 29 million pounds in 2007. Since it was introduced in 1948, there have been reports of 2,4

- D adversely affecting non

- target broadleaf food and feed crops, such as cotton, grapes and tomatoes, growing in the vicinity of target crops. ( Schultz et al. , 1956 ) Such incidents have been linked to drift of spray droplets (especially through aerial spraying) or drift of vapors formed by volatilization of the 2,4

- D itself. ( Dexter, 1993 ) Drift is the physical movement of spray droplets moving off

- site as a chemic al application is made. Under certain conditions, the potential for physical drift from an application site to adjacent non

- target environments is possible for all types of pesticide spray applications. This is an application

- related phenomenon independent of the chemical pesticide, which may be influenced by the formulation ingredients and spray mix additives. Volatilization refers to the transformation of a liquid or solid pesticide into a gas. The extent of volatilization is dependent on properties of t he chemical and herbicide formulation, and environmental factors such as air temperature, wind speed, and relative humidity. Volatilized pesticides can be carried by air currents potentially leading to off

- target exposure.
Increased control of drift an d volatilization across pesticides has been achieved with proper equipment setup and attention paid to climatic conditions at the time of application. University extension agencies have been especially prominent in developing and disseminating “Good Applic ation Practices” to minimize drift. Additionally, pesticide label restrictions, state pesticide regulations, nozzle technology and manufacturer stewardship programs have helped to develop and establish application practices that minimize the potential for off

- target exposure.
2,4

- D is currently formulated as an ester or amine salt. Attributions of volatility to 2,4

- D have largely been associated with the esters, particularly short chain esters. Early forms of 2,4

- D included short chain esters that were f avored due to rapid herbicidal activity, but these were relatively volatile ( Nice et al. , 2004 ) . A desire to reduce risk of off

- target injury to sensitive crops, such as cotton, tomatoes or grapes, led to the development of longer chain esters that were notably less volatile, and to development of various amine salts that are considered much less volatile than ester formulations ( ( International Programme on Chemical Safety, 1989 ) ( NPIC ) )

. The volatility of the salt forms approac hes two orders of magnitude reduction compared to the short chain esters ( Dow AgroSciences, 2011 ) . In the last two decades, longer chain esters have replaced the shorter chain esters and as a result, volatility iss ues have largely abated. New technologies for controlling drift and volatility DAS conducted an extensive evaluation of various salts under conditions inducing high volatility to identify candidates that had significantly reduced volatility and thus lowered potential for injury to susceptible plants. The results led to the development of 2,4

- D choline salt. This novel form of 2,4

- D has been tested in the laboratory and subsequently in field studies. Quantification of volatilized 2,4

- D from soybean and bare soil fields demonstrated: 2,4

- D ethylhexylester was the most volatile, with calculated loss rates of the 2,4

- D ethylhexylester as much as two orders of magnitude greater than the 2,4

- D dimethylamine (DMA) form, which is considered to be much less vol atile than ester formulations ( ( NPIC ; International Programme on Chemical Safety,64 of 68 1989 ) ). As detailed in materials submitted to AP HIS by DAS ( Dow AgroSciences, 2011 ) , the choline form of 2,4

- D measured as much as 50X less volatility than the DMA form and had dramatically less injury to a variety of crops known to be sensitive to auxin herbicide s under confined conditions as compared to ester and amine forms of 2,4

- D. DAS’s new product containing 2,4

- D choline and glyphosate DMA (Enlist Duo herbicide) will make the herbicide spray droplets larger and more uniform in size compared to a standard 2,4

- D and glyphosate tank mix application. DAS has measured a 3X improvement (reduction) in driftable fines (<150 μ) for both 2,4

- D choline and glyphosate under field conditions using commercial application equipment. This validates observations made under controlled laboratory and wind tunnel conditions. Coupled with using the latest in drift reduction nozzles, as much as a 10X reduction in drift was achieved compared to a standard tank mix application of the same active ingredients using conventional nozz les. Pending registration by EPA, DAS intends to market Enlist Duo Herbicide with Colex

- D Technology, a pre

- mix of the new 2,4

- D choline salt and glyphosate dimethylamine with reduced drift and volatility characteristics, for use with DAS

- 40278

- 9 corn an d DAS

- 68416

- 4 soybeans. Via a Technology Use Agreement, DAS will require growers of DAS

- 40278

- 9 corn and DAS

68416

- 4 soybean who choose to use 2,4

- D in post

- plant applications to “use only EPA accepted and DAS authorized 2,4

- D formulations containing Cole x
- D Technology, such as EnlistTM Duo, for in

- crop application” to provide this added protection against off

- target exposure. A combination of EPA

- required label restrictions, contractual obligations and grower education and outreach will further minimize a ny off

- target effects to neighboring crops caused by application of Enlist Duo to DAS

- 40278

- 9 corn and DAS

- 68416

- 4 soybeans. Proposed herbicide label language for Enlist Duo DAS has submitted to EPA for approval a proposed label for its Enlist Duo Herbi cide with Colex

- D Technology, a pre

- mix of the new 2,4

- D choline salt and glyphosate DMA. The first submission to EPA is for use on Enlist corn, DAS

- 40278

- 9, and once approved then DAS will submit a label amendment for the use of Enlist Duo on DAS

- 68416

- 4 soybean. DAS’s proposed label contains the instructions for use directly addressing the potential for spray drift and volatility. The same label instructions will be submitted for use on Enlist soybean, DAS

- 68416

- 4. Of course, during its label approva l process, EPA may impose additional use restrictions or other protective measures for corn and/or soybean. DAS has submitted for EPA approval the following Enlist Duo label language specifically addressing spray drift management:65 of 68 Spray Drift Management Avoid drift. Use extreme care when applying this product to prevent injury to desirable plants and crops. Do not allow GF

- 2726 to mist, drip, drift or splash onto desirable vegetation since minute quantities of this product can ca use severe damage or destruction to the crop, plants or other areas on which treatment was not intended. The likelihood of injury occurring from the use of this product increases when winds are gusty, as wind velocity increases, when wind direction is cons tantly changing or when there are other meteorological conditions that favor spray drift. When spraying, avoid combinations of pressure and nozzle type that will result in fine particles (mist) which are likely to drift. Do not apply at excessive speed o r pressure

. Use of this product in any manner not consistent with this label may result in injury to persons, animals or crops, or other unintended consequences. Avoiding spray drift at the application site is the responsibility of the applicator. The interaction of many equipment

- and

- weather

- related factors determines the potential for spray drift. The applicator and the grower are responsible for considering all these factors when making decisions. Do not aerially apply this product.

Droplet Size Apply as a coarse or very coarse spray (ASABE S

- 572 Standard). Use drift reducing nozzle tips in accordance with manufacturer directions that produce a droplet cla ssification of coarse or very coarse to significantly reduce the potential for drift. Groundboom Application Use the minimum boom height based upon the nozzle manufacturer’s directions. Spray drift potential increases as boom height increases. Spray dri ft can be minimized if nozzle height is not greater than the maximum height specified by the nozzle manufacturer for the nozzle selected. Wind Drift potential is lowest at wind speeds of 10 mph or less. However, many factors, including droplet size and e quipment type, determine drift potential at any given speed. Do not apply at wind speeds greater than 15 mph. Note : Local terrain can influence wind patterns. The applicator should be familiar with local wind patterns and how they affect drift.
Temperatu re and Humidity When making applications in low relative humidity, set up equipment to produce larger droplets to compensate for evaporation. Droplet evaporation is most severe when conditions are both hot and dry.66 of 68 Temperature Inversions If applying a t wind speeds less than 3 mph, the applicator must determine if: a) conditions of temperature inversion exist, or b) stable atmospheric conditions exist at or below nozzle height. Do not make applications during a temperature inversion or stable atmospheri c conditions. Temperature inversions restrict vertical air mixing, which causes small suspended droplets to remain in a concentrated cloud. This cloud can move in unpredictable directions due to the light variable winds common during inversions. Temperatur e inversions are characterized by increasing temperatures with altitude and are common on nights with limited cloud cover and light to no wind. They begin to form as the sun sets and often continue into the morning. Their presence can be indicated by groun d fog; however, if fog is not present, the presence of an inversion can also be identified by the movement of smoke from a ground source. Smoke that layers and moves laterally in a connected cloud (under low wind conditions) indicates an inversion, while s moke that moves upwards and rapidly dissipates indicates good vertical air mixing.

Drift Setbacks from Sensitive Areas Allow setbacks (buffer zones) upwind of sensitive area (e.g., residential areas, bodies of water, known habitat for threatened or endangered species, sensitive non

- target crops other than those listed above) according to the following table. If a coarse o r very coarse droplet classification cannot be maintained, an upwind setback of 250 feet from sensitive areas must be observed. Susceptible Plants Do not apply under circumstances where spray drift may occur to food, forage, or other plantings that migh t be damaged or crops thereof rendered unfit for sale, use or consumption. Avoid contact of herbicide with foliage, green stems, exposed
non

- woody roots of crops, desirable plants and trees because severe injury or destruction may result. Small amounts of spray drift that may not be visible may injure susceptible broadleaf plants. Before making an application, please refer to your state’s sensitive crop registry (if available) to identify any commercial specialty or certified organic crops that may be loca ted nearby. Commercially grown tomatoes and other fruiting vegetables (EPA crop group 8), cucurbits (EPA crop group 9), and grapes are particularly sensitive to drift from this product. Do not apply when wind direction favors off

- target movement onto t hese crops. State and Local Requirements Applicators must follow all state and local pesticide drift requirements regarding application of 2,4

- D herbicides. Where states have more stringent regulations, they must be observed.

The submitted Enlist Duo l abel language also requires additional measures to avoid off

target movement and crop injury, including detailed instructions for clean

- out of sprayer equipment, use of drift control additives, and boom and nozzle height instructions.67 of 68 Additional DAS meas ures to address spray drift and volatility As noted above, DAS will contractually require growers of DAS

- 40278

- 9 corn and DAS

- 68416

- 4 soy who wish to use 2,4

- D as an in

- crop herbicide to use only EPA accepted and DAS authorized 2,4

- D formulations (all of which will contain Colex

- D Technology), such as EnlistTM Duo, for in

- crop application. This new 2,4

- D technology will provide substantially lower volatility than any other form of 2,4

- D, as well as improved drift control, low odor, and improved handling ch aracteristics. Through its Technology Use Agreement, DAS will impose a legal and contractual obligation that will require all growers of DAS

- 40278

- 9 corn and DAS

- 68416

- 4 soybean to:

• Use only EPA accepted and DAS authorized 2,4

- D formulations containing Colex

- D Technology, such as Enlist Duo, for in

- crop applications to DAS

- 40278

- 9 corn and DAS

68416

- 4 soybean.

• Read and follow FIFRA Pesticide Product Label directions.

• Read and follow the Enlist Weed Control System Product Use Guide.

• Use properly mainta ined and calibrated ground application equipment for Enlist Duo with Colex

- D Technology with minimum boom heights.

• Use nozzles that reduce the potential for physical drift of Enlist Duo with Colex

- D Technology.

• Follow instructions for equipment clean

- out after product use. DAS will provide comprehensive training on its technology and portfolio of products to growers, dealers and distributors through a variety of formats. Education and training, reinforced through product profiles, technical bulletins, sales literature, direct mailing and websites will also be presented in multiple formats to enhance learning and mastery of core concepts related to stewardship to be employed around DAS

- 40278

- 9 corn and DAS

- 68416

- 4 soybean. A variety of educational format s will be used to promote concept learning. This training will include education on spray technology and herbicide application, including spray quality basics, as well as spray quality of Enlist Duo, as well as how to minimize the potential for off

- target movement of Enlist Duo.

References Dexter, A.G., 1993. Herbicide spray drift. North Dakota State University. Dow AgroSciences, 2011. Research demonstrating reduction in potential off

- target movement for 2,4

- d choline and colex

- dTM technology as part of the enlistTM weed control system. Dow AgroSciences LLC. Indianapolis IN. DPI, V., 2009. Using buffer zones and vegetative barriers to reduce spray drift. http://www.dpi.vic.gov.au/agriculture/farming

- management/chemical

- use/agricultural

chemical

- use/spraying

- spray

- d rift

- and

- off

- target

- damage/ag0860

- using

- buffer

- zones

and

- vegetative

- barriers

- to

- reduce

- spray

- drift

. Driftwatch, 2012. Driftwatch registry of pesticide sensitive crops.68 of 68 EPA, 2005a. Gis

- based risk assessment of pesticide drift case study: Fresno county, cal ifornia. . EPA/600/R

- 05/029. EPA, 2005b. Reregistration eligibility decision for 2,4

- d. EPA 738

- R

- 05

- 002. www.epa.gov/oppsrrd1/REDs/24d_red.pdf

. EPA, 2011. Pesticides industry sales and usage 2006 and 2007 market estimates. EPA 733

- R

- 11

- 001 U.S Environmental Protection Agency. Washington DC. Feitshans, T.A., 1999. An analysis of state pesticide drift laws,. San Joaquin Agriculture Law Review 37. International Programme on Chemical Safety, 1989. Env ironmental health criteria, 2,4

- d environmental aspects. http://www.inchem.org/documents/ehc/ehc/ehc84.htm Maynard, E., Overstreet, B., Riddle, J., 2012. Pesticide drift and organic productio n. https://mdc.itap.purdue.edu/item.asp?itemID=20611. Moses, 2009. Protecting your organic land from unwanted chemical sprays. http://www.mosesorganic.org/attachments/produ ctioninfo/fsnospray.html

. Nice, G.R.W., Johnson, B., Bauman, T.T., 2004. Amine or ester, which is better? Purdue Extension Weed Science. NPIC, State pesticide regulatory agencies. http://npic.orst.edu/state1.ht m

. Schultz, H.B., Akesson, N.B., Yates, W.E., Ingebretson, K.H., 1956. Drift of 2,4

- d applied by plane. California agriculture, . California Agriculture.

i Arkansas State Plant Board annual report (2011

- 2012), page 43. http://plantboard.arkansas.gov/Pages/default.aspx ii Bennett, David. “ 2,4

- D damages Arkansas cotton”, Delta Farm Press; Aug. 15, 2006. iii National Weather Service, Little Rock, AR Yearly Climate Summary (2006).
< http://www.srh.noaa.gov/lzk/?n=2006.htm > iv National Weather Service, Little Rock, AR “Severe Storms Flash Flooding (May 2003), http://www.srh.n oaa.gov/lzk/?n=events2003.htm

v Bennett, David. “ Proposed regulations target Arkansas 2,4

- D and glyphosate drift ”, Delta Farm Press; Jan. 25, 2007. vi Bennett, David. “ In Arkansas: Task force tackles drift problems”, Delta Farm Press; Aug. 11, 2006. vii A rkansas Regulations on Pesticide Classification , Agency # 209.02, (Rev. 06/07). viii University of Arkansas Combined Research and Extension Annual Report (2007), pg. 152. ix Arkansas State Plant Board annual report (2011

- 2012), page 41

- 42.