Page 1 of 23 UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D. C. 20460 MEMORANDUM Date: February 28, 2006 Subject: TCMTB. Summary of Analytical Chemistry and Residue Data for the Reregistration Eligibility Decision ( RED) Document.

DP Barcode: D322617 PC Code: 035603 40 CFR § : 180.288 Chemical Class: Benzothiazole From: Samuel Ary, Chemist Reregistration Branch II Health Effects Division ( 7509C)

Through: P. Yvonne Barnes, Chemist Reregistration Branch II Health Effects Division ( 7509C)

William Hazel, Branch Chief Reregistration Branch II Health Effects Division ( 7509C)

To: Deborah Smegal, Risk Assessor Reregistration Branch I Health Effects Division ( 7509C)

Kathryn Avivah Jakob, Chemical Review Manager Regulatory Management Branch II Antimicrobial Division ( 7510C) OFFICE OF PREVENTION, PESTICIDES, AND TOXIC SUBSTANCES TCMTB Summary Analytical Chemistry and Residue Data  RED DP Barcode: 322617 Page 2 of 23 Executive Summary As an antimicrobial pesticide, TCMTB [( 2 benzothiazolylthio) methyl thiocyanate] is used largely as a wood preservative. It is also used as a microbiocide/ microbiostat and bacteriocide/ bacteriostat in industrial processes and water systems, as well as in industrial materials, as a preservative. As an agricultural pesticide, TCMTB is a fungicide used as a seed treatment on barley, corn, cotton, oat, rice, safflower, sorghum, sugar beet, and wheat.

The reregistration of TCMTB is being supported by Bayer CropScience ( Bayer) and Wilbur Ellis Company ( Wilbur Ellis). TCMTB food/ feed end use products are marketed in the United States under the trade names Busan ® , Cotguard ® , Nusan ® , and Nu Flow ® . The Bayer and Wilbur Ellis TCMTB formulations registered for food/ feed uses include emulsifiable concentrate ( EC) and soluble concentrate ( SC). For food/ feed uses, Bayer is supporting TCMTB use on cotton only, while Wilbur Ellis is supporting uses on barley, cotton, oat, rice, wheat, safflower, and sugar beet. The technical registrant of TCMTB, Buckman Laboratories, Inc. ( Buckman) has requested cancellation of all food/ feed uses. Therefore, use on corn and sorghum is no longer being supported. Bayer and Wilbur Ellis will be responsible for providing the Agency with the appropriate data needed to maintain the supported uses on their product labels.

Tolerances are established for residues of the fungicide 2( thiocyanomethylthio) benzothiazole in/ on barley ( grain and straw), sugar beets ( roots and tops), corn ( forage, grain, and stover), cotton ( forage and undelinted seed), oats ( forage, grain, hay, and straw), rice ( grain and straw), safflower ( seed), sorghum ( forage, grain, and stover), and wheat ( forage, grain, hay, and straw) at 40 CFR § 180.288. The permanent tolerances for residues in plant commodities are established at the limit of quantitation ( LOQ) of 0.1 ppm ( N). The " N" designation, denoting " negligible" residues must be deleted from 40 CFR § 180.288.

The reregistration requirements for plant metabolism have not been fulfilled. Data have been submitted depicting the uptake of TCMTB in corn, cotton, safflower, and wheat and were found to be inadequate due to lack of identification and/ or characterization of parent and/ or metabolites. Additional metabolism studies conducted with tomatoes and melons have been submitted and briefly reviewed; however, translation to the currently registered crops is not adequate for reregistration purposes. Confirmatory metabolism data should be submitted depicting the nature of residues in wheat, cotton, and sugar beets. Adequate identification and/ or characterization of parent and/ or metabolites should be conducted as required by OPPTS 860 Series Guidelines. The Risk Assessment Review Committee ( RARC) met and determined that the interim residue of concern for tolerance expression and risk assessment is TCMTB in/ on plants ( P. Deschamp, Report of the RARC, 1/ 11/ 2006). This is a preliminary decision and the additional confirmatory plant metabolism data should be submitted in a timely manner.

No livestock metabolism studies have been submitted for review. Livestock metabolism studies may be required if the requested plant metabolism studies show uptake of residues. If livestock metabolism studies are required, the registrant must provide poultry and ruminant metabolism studies following OPPTS 860 Series Guidelines.

A tolerance enforcement method is available for determining thiobenzothiazole containing residues in barley, corn, cotton, oat, rice, safflower, sugar beet, and wheat. This method was originally submitted with Pesticide Petition ( PP) 0F0954 by Buckman. Residues are converted to 2 chlorobenzothiazole, which is determined by a gas liquid chromatography ( GLC) method TCMTB Summary Analytical Chemistry and Residue Data  RED DP Barcode: 322617 Page 3 of 23 using an electron capture detector ( ECD). The quantitation limit of the method has been determined at 0.10 ppm. This method is listed as Method B in PAM Vol. II. The method is outdated and uses toxic reagents; therefore, if an additional method that is adequate for tolerance enforcement is available, it should be submitted immediately for review.

Two data collection methods are available for determining thiocyanate containing residues. The first method was originally submitted with PP 0F0954 by Buckman for the determination of residues in barley, corn, cottonseed, oat, rice, and wheat. The method is listed as Method I in PAM Vol. II. The second method was originally submitted with PP 5F1613 by Buckman for the determination of residues in safflower seed, sorghum grain and foliage, and sugar beet and foliage. The method is listed as Method A in PAM Vol. II. Residues are converted from thiocyanate to cyanogen bromide; then the cyanogen bromide is treated with pyridine benzidine reagent to form an intensely colored dye. The absorbance of the dye solution is determined at 532 nm. In a method tryout ( Method I), the Agency obtained recoveries of 90% and 110% ( duplicate samples) at the 0.10 ppm fortification level and 105% and 115% ( duplicate samples) at the 0.20 ppm fortification level. The quantitation limit of both methods has been determined at 0.10 ppm.

If the requested metabolism studies show additional residues are of concern and the current enforcement method does not capture these additional residues, development of a method capable of doing so will be required.

The requirement of a tolerance enforcement method for livestock is put on reserve pending the results from the requested plant metabolism studies, and, if required, the livestock metabolism studies.

The FDA PESTDATA database dated 11/ 2001 ( PAM Volume I, Appendix I) indicates that TCMTB per se is completely recovered (> 80%) using Multiresidue Methods Section 302 ( Luke Method), but is only partially recovered ( 50 80%) using 303 ( Mills, Onley, Gaither Method) and 304 ( Mills fatty food Method). If additional residues of concern are determined from the requested metabolism studies, all additional residues of concern for tolerance expression will need to be tested through Multiresidue Methods.

Storage stability data for TCMTB in/ on barley, cotton, oat, rice, wheat, safflower, and sugar beet have not been submitted by the registrant. No data were provided on how long samples from the submitted field trials were stored prior to analysis; therefore, storage stability data for the previously submitted field trials are required and should be submitted immediately. Additionally, if field trials are required or additional uses are requested, concurrent storage stability data will be required under this guideline topic.

TCMTB is not intended for application to livestock and no livestock feeding studies have been submitted. The grain crops, their byproducts and forages, are livestock feed items. It is therefore necessary to consider if TCMTB residues are transferred to meat, milk, poultry, and eggs of livestock through ingestion of the residue bearing commodities. It has been indicated in the foregoing considerations that the nature of residue in plants has not been adequately described. In the absence of such data, the residue level is unclear. If the requested residue data show finite residues in the feed items, livestock feeding studies would be essential to an evaluation of the transfer of residues to milk, meat, poultry, and eggs. Therefore, no valid conclusions relative to 40 CFR § 180.6 ( the necessity of tolerances in livestock commodities) can be made in the TCMTB Summary Analytical Chemistry and Residue Data  RED DP Barcode: 322617 Page 4 of 23 absence of livestock feeding studies.

The available field trial data are not adequate according to current OPPTS 860 Series Guidelines. The correct number of field trials, number of samples collected, and locations of trials are all insufficient. Additionally, no storage stability data was submitted with the field trial studies and the application rates are unknown for the barley, corn, oat, rice, and wheat studies. The method used for determining residues in barley, corn, oat, rice, and wheat is the data collection method which only determines the thiocyanate ion ( Method I or A in PAM Vol. II). The method used for determining residues in cotton is the tolerance enforcement method which determines thiobenzothiazole containing residues ( Method B in PAM Vol. II). If the requested metabolism studies show additional metabolites of concern are expected, new field trials should be conducted using a method which is capable of determining all residues of concern as determined by the tolerance expression. Additionally, tolerances should be proposed in/ on barley hay and cotton gin byproducts as these are now considered significant livestock feed items according to Table 1 of OPPTS 860.1000. Field trial data are not available for sugar beets; therefore, magnitude of residue data in sugar beets should be submitted following all OPPTS 860 Series Guidelines.

No processing studies have been submitted. Once the requested metabolism studies have been submitted, reviewed, and the metabolites of concern are determined, data should be submitted which show whether residues concentrate in the byproducts of the registered raw agricultural commodities.

No confined accumulation data in rotational crops are available; however, soil persistence studies are available. The registrant should provide confirmatory method data along with storage stability data in order for the data to be considered scientifically adequate. Contingent upon the adequacy of the storage stability and method data, soil persistence is not likely to be a concern with respect to follow up crops. However, the method used is unknown and the exact compounds that make up the residues found is unknown; therefore, this data requirement is put on reserve awaiting submission of the requested data and pending the results from the plant metabolism studies.

Residue Chemistry Deficiencies and Regulatory Guidelines 1. Confirmatory metabolism data should be submitted depicting the nature of residues in wheat, cotton, and sugar beets.

2. The available enforcement method ( Method B in PAM Vol. II.) is outdated and uses toxic reagents; therefore, if an additional method that is adequate for tolerance enforcement is available, it should be submitted immediately for review.

3. Storage stability data were not included with the original field trial data submissions; therefore, storage stability data for the previously submitted field trials are required and should be submitted immediately.

4. Storage stability and method data were not provided with the original soil persistence studies summarized under OPPTS 860.1850 in this document. Storage stability and method data are required and should be submitted immediately.

5. Application rates in lbs a. i./ 100 lbs seed for all the submitted field trial studies should be TCMTB Summary Analytical Chemistry and Residue Data  RED DP Barcode: 322617 Page 5 of 23 provided.

6. Tolerances for barley hay and cotton gin byproducts should be proposed once the requested metabolism data are submitted and reviewed.

7. Data should be submitted which show whether residues concentrate in the byproducts of the registered raw agricultural commodities.

8. Magnitude of residue data in sugar beets following all OPPTS 860 Series Guidelines should be submitted.

9. Additionally, numerous OPPTS 860 Series Guidelines have been placed on reserve pending the requested plant metabolism data ( see Table 4).

Background The TCMTB Phase 4 Review dated 3/ 11/ 1991 summarized the status of available residue chemistry data for the reregistration of TCMTB. The Phase 4 Review requested plant metabolism data on corn or wheat, cotton, and sugar beet. Data requirements for livestock metabolism, residue analytical methods, storage stability, and magnitude of the residue in plants were put on reserve status pending the results from the plant metabolism studies. This document presents an overall and up to date Residue Chemistry Science Assessment with respect to the reregistration of TCMTB. The PC Code and nomenclature of TCMTB are listed below in Table 1 and the physicochemical properties are listed in Table 2. The structure of TCMTB and metabolites/ degradates of concern are presented in Table 3.

Table 1. TCMTB Nomenclature.

Chemical structure N S S S N Common name TCMTB or TCMB Molecular formula C9H6N2S3 IUPAC name 2( thiocyanomethylthio) benzothiazole CAS name ( 2 benzothiazolylthio) methyl thiocyanate CAS number 21564 17 0 PC Code 035603 Supported food/ feed site uses barley, cotton, oat, rice, safflower, sugar beet, and wheat Table 2. Physicochemical Properties of TCMTB Parameter Value Reference Molecular weight 238.35 g/ mol Merck Index 12th Edition Melting point/ range Not applicable ( NA) for liquids NA Boiling point/ range Decomposed at 191 E C at 741.9 mm Hg C. Jiang, D322899, 11/ 17/ 05 pH 5.99 ( 1: 100 dilution in water) C. Jiang, D322899, 11/ 17/ 05 Density 1.3761 g/ cm3 C. Jiang, D322899, 11/ 17/ 05 TCMTB Summary Analytical Chemistry and Residue Data  RED DP Barcode: 322617 Page 6 of 23 Table 2. Physicochemical Properties of TCMTB Parameter Value Reference Water solubility 45 mg/ L C. Jiang, D322899, 11/ 17/ 05 Vapor pressure 1.45 x 10 4 mm Hg at 20 E C 1.72 x 10 4 mm Hg at 25 E C C. Jiang, D322899, 11/ 17/ 05 Vapor pressure1 2.44 x 10 10 mm Hg at 20 E C 4.04 x 10 10 mm Hg at 25 E C C. Jiang, D322899, 11/ 17/ 05 Dissociation constant, pKa NA NA Octanol/ water partition coefficient log Kow of 3.23 at 20 E C C. Jiang, D322899, 11/ 17/ 05 Viscosity 352.4 cSt C. Jiang, D322899, 11/ 17/ 05 1. Tests done with pure active ingredient ( PAI).

Table 3. Chemical Names, Metabolism Data, and Structures of TCMTB and Its Metabolites/ Degradates.

Percent TRR1 Chemical Name Commodity Major Residue (> 10% TRR) Minor Residue (< 10% TRR) Structure Melon fruit ND2 Melon plant 0.9%

Tomato fruit ND Tomato plant ND TCMTB [ 2 benzothiazolylthio) methyl thiocyanate] CAS number: 21564 17 0 Aerobic soil ( 58 DPT3) 0.6% N S S S N Melon fruit 31.9%

Melon plant 14.0%

Tomato fruit 61.7%

Tomato plant 32.6% 2 BTSA [ 2 benzothiazolesulfonic acid]

Aerobic soil ( 58 DPT) 70.8% N S SO 3 H Melon fruit 8.4%

Melon plant 2.6%

Tomato fruit 8.5% OH 2 BTSA4,5 [ 2( hydroxybenzothiazolyl) sulfonic acid]

Tomato plant 21.2% N S SO 3 H O H Melon fruit 1.3%

Melon plant 2.5%

Tomato fruit ND Tomato plant ND 2 OH BT [ 2 hydroxybenzothiazole] or BTOL [ 2 benzothiazolol] CAS number: 934 34 9 Aerobic soil ( 21 DPT) 7.0% N S OH Melon fruit 0.7%

Melon plant 0.1%

Tomato fruit ND Tomato plant ND Cotton forage ND Aerobic soil ( 1.5 DPT) 30.3% 2 MBT or 2 SH BT [ 2 mercaptobenzothiazole] CAS number: 149 30 4 Aerobic soil ( 14 21 DPT) 0.3 0.4% N S SH TCMTB Summary Analytical Chemistry and Residue Data  RED DP Barcode: 322617 Page 7 of 23 Table 3. Chemical Names, Metabolism Data, and Structures of TCMTB and Its Metabolites/ Degradates.

Percent TRR1 Chemical Name Commodity Major Residue (> 10% TRR) Minor Residue (< 10% TRR) Structure 2,2' DTBB or DBB [ 2,2' dithiobis( benzothiazole) CAS number: 120 78 5 Aerobic soil ( maximum at 1 DPT) 6.7%

N S S S N S 1. TRR = Total radioactive residue. 2. ND = Not detected. 3. DPT = Days post treatment. 4. Two isomers make up 2( hydroxybenzothiazolyl) sulfonic acid. The exact position of the hydroxyl group was not determined. The numbers presented in the table are the summation of the two isomers. The following is the breakdown of TRR for each isomer ( in parenthesis) following each individual commodity: melon fruit: 8.4% ( 1.1% and 7.3%); melon plant: 2.6% ( 1.4% and 1.2%); tomato fruit: 8.5% ( 6.9% and 1.6%); and tomato plant: 21.2% ( 6.7% and 14.5%).

Summary of Science Findings A tabular summary of the residue chemistry science assessments for reregistration of TCMTB is presented below in Table 4. The conclusions listed in Table 4 regarding the reregistration eligibility of TCMTB food/ feed uses are based on the use patterns being supported by Bayer and Wilbur Ellis. When end use product data call ins ( DCIs) are developed ( e. g., at issuance of the RED), the Registration Division ( RD) should require that all end use product labels ( e. g., MAI labels, special local needs ( SLNs), and products subject to the generic data exemption) be amended such that they are consistent with labels registered to Bayer and Wilbur Ellis.

Table 4. Residue Chemistry Science Assessment for the Reregistration of TCMTB.

GLN Data Requirements Current Tolerances, ppm [ 40 CFR] Must Additional Data Be Submitted? References 860.1200 Directions for Use Not applicable ( NA) No None 860.1300 Plant Metabolism NA Yes4 423768011, 204314712, 446541013, 446541023 860.1300 Livestock Metabolism NA Reserved None 860.1340 Residue Analytical Methods Plant commodities NA Yes6 PP 5F1613, PP 0F0954, FDA PAM Vol. II Livestock commodities NA Reserved7 None 860.1360 Multiresidue Methods NA Reserved8 None 860.1380 Storage Stability Data Plant commodities NA Yes5 None Processed commodities NA Reserved None TCMTB Summary Analytical Chemistry and Residue Data  RED DP Barcode: 322617 Page 8 of 23 Table 4. Residue Chemistry Science Assessment for the Reregistration of TCMTB.

GLN Data Requirements Current Tolerances, ppm [ 40 CFR] Must Additional Data Be Submitted? References Livestock commodities NA Reserved None 860.1400 Water, Fish, and Irrigated Crops NA No None 860.1460 Food Handling NA No None 860.1480 Meat, Milk, Poultry, and Eggs NA Reserved7 None 860.1500 Crop Field Trials Root and Tuber Vegetables Group Beet, sugar, roots 0.1( N) [ § 180.288( a)] Reserved9 None Leaves of Root and Tuber Vegetables Group Beet, sugar, tops 0.1( N) [ § 180.288( a)] Reserved9 None Cereal Grains Group Barley, grain 0.1( N) [ § 180.288( a)] Reserved9 0011787412 Corn, field, grain and aspirated grain fractions 0.1( N), grain [ § 180.288( a)] No11 0011787412 Corn, pop, grain None established No11 None Corn, sweet, K+ CWHR None Established No11 None Oat, grain 0.1( N) [ § 180.288( a)] Reserved9 0011787412 Rice, grain 0.1( N) [ § 180.288( a)] Reserved9 0011787412 Sorghum, grain, grain and aspirated grain fractions 0.1( N), grain [ § 180.288( a)] No11 None Wheat, grain and aspirated grain fractions 0.1( N), grain [ § 180.288( a)] Reserved9 0011787412 Fodder, Forage, Hay, and Straw of Cereal Grains Group Barley, hay and straw 0.1( N), straw [ § 180.288( a)] Reserved9 0011787412 Corn, field, forage and stover 0.1( N) [ § 180.288( a)] No11 0011787412 Corn, pop, stover None established No11 None Corn, sweet, forage and stover None established No11 None Oat, forage, hay, and straw 0.1( N) [ § 180.288( a)] Reserved9 0011787412 Rice, straw 0.1( N) [ § 180.288( a)] Reserved9 0011787412 TCMTB Summary Analytical Chemistry and Residue Data  RED DP Barcode: 322617 Page 9 of 23 Table 4. Residue Chemistry Science Assessment for the Reregistration of TCMTB.

GLN Data Requirements Current Tolerances, ppm [ 40 CFR] Must Additional Data Be Submitted? References Sorghum, grain, forage and stover 0.1( N) [ § 180.288( a)] No11 None Wheat, forage, hay, and straw 0.1( N) [ § 180.288( a)] Reserved9 0011787412 Miscellaneous Commodities Cotton, undelinted seed and gin byproducts 0.1( N), undelinted seed [ § 180.288( a)] Reserved9 0000423913 Safflower, seed 0.1( N) [ § 180.288( a)] Reserved9 None 860.1520 Processed Food/ Feed Barley None established Yes None Beet, sugar None established Yes None Corn, field None established No11 None Cotton None established Yes None Oat None established Yes None Rice None established Yes None Safflower None established Yes None Sorghum None established No11 None Wheat None established Yes None 860.1650 Submittal of Analytical Reference Standards NA Yes10 None 860.1850 Confined Rotational Crops NA Reserved9 None 860.1900 Field Rotational Crops None established Reserved9 None 1. F. Fort, D187529, MRID 42376801, 00/ 00/ 0000. 2. M. Perry, D221887, MRID 20431471, 5/ 11/ 1998. 3. Both studies ( MRID 44654101 and 44654102) are summarized in this chemistry summary document. Full review of both studies is currently underway. 4. Confirmatory metabolism data should be submitted depicting the nature of residues in wheat, cotton, and sugar beets. 5. Storage stability data was not included with the original field trial data submissions, therefore, it is required. 6. The available enforcement method ( Method B in PAM Vol. II.) is outdated and uses toxic reagents; therefore, if an additional method that is adequate for tolerance enforcement is available, it should be submitted immediately for review. Additionally, if the requested metabolism studies show additional residues are of concern and the current enforcement method does not capture these additional residues, development of a method capable of doing so will be required. 7. This requirement is put on reserve pending the results from the requested plant metabolism studies, and if required, the livestock metabolism studies. 8. If additional residues of concern are determined from the requested metabolism studies, all additional residues of concern for tolerance expression will need to be tested through Multiresidue Methods. 9. This requirement is put on reserve pending the results from the requested metabolism studies. TCMTB Summary Analytical Chemistry and Residue Data  RED DP Barcode: 322617 Page 10 of 23 10. Analytical standards must be replenished as requested by the Repository. If additional residues are included in the tolerance expression based on the requested metabolism data, analytical reference standards should be submitted and replenished as requested by the Repository. 11. The registrants are not supporting use of TCMTB on corn and sorghum; therefore, all tolerances associated with those uses should be revoked. 12. MRID 00117874 was reviewed in PP 2F1264. 13. MRID 00004239 was reviewed in PP 0F0954.

860.1200 Directions for Use Product List There are two Bayer and two Wilbur Ellis end use products containing the active ingredient TCMTB, which are registered for use on domestically grown food/ feed crops as indicated in Table 5.

Table 5. TCMTB End use Products ( EPs) Registered by Bayer and Wilbur Ellis.

EPA Reg. No. Formulation1 Registrant Product Name Supported Seed Treatment Use Sites 264 965 30% EC Bayer CropScience Busan ® 30A cotton 264 9832 5% EC Bayer CropScience Cotguard ® cotton 2935 389 30% EC Wilbur Ellis Co. Nusan ® 30 EC barley, cotton, oat, rice, safflower, sugar beet, and wheat 2935 4133 9% SC Wilbur Ellis Co. Nu Flow ® ND cotton on farm 1. EC = Emulsifiable Concentrate and SC = Soluble Concentrate. 2. Formulation also contains Carboxin ( PC Code 090201) at 14.35% and Metalaxyl ( PC Code 113501) at 2.4%. 3. Formulation also contains Chloroneb ( PC Code 027301) at 23.5%.

Use Patterns As an agricultural pesticide, TCMTB is a fungicide used as a seed treatment on barley, corn, cotton, oat, rice, safflower, sorghum, sugar beet, and wheat. It is used in commercial and onfarm settings. For food/ feed uses, Bayer is supporting TCMTB use as a seed treatment on cotton only, while Wilbur Ellis is supporting uses on barley, cotton, oat, rice, wheat, safflower, and sugar beet ( K. Jakob, TCMTB Use Closure Memo, 1/ 30/ 2006). Use on corn and sorghum are not being supported. The technical registrant of TCMTB, Buckman, has requested cancellation of all food/ feed uses ( K. Jakob, TCMTB Use Closure Memo, 1/ 30/ 2006). An analysis of the current labeling and available use information was completed by HED. A summary of directions for the use of TCMTB is presented below in Table 6.

Table 6. Summary of Maximum Application Rates for Registered TCMTB Food/ Feed Seed Treatment Uses. EPA Reg. No. Product Name Formulation Crop Application Equipment Max. App. Rate ( fl oz/ 100 lbs of seed) Max. App. Rate ( lbs ai/ 100 lbs of seed) 264 965 Busan ®

30A 30% EC cotton commercial treater 4.5 fl oz/ 100 lbs of seed 0.093 lbs a. i./ 100 lbs of seed 264 983 Cotguard ® 5% EC cotton commercial treater 9.0 fl oz/ 100 lbs of seed 0.032 lbs a. i./ 100 lbs of seed cotton commercial treater 5.0 fl oz/ 100 lbs of seed 0.10 lbs a. i./ 100 lbs of seed barley, oat, rice, wheat commercial treater 1.25 fl oz/ 100 lbs of seed 0.026 lbs a. i./ 100 lbs of seed 2935 389 Nusan ®

30 EC 30% EC safflower, sugar beet commercial treater 2.0 fl oz/ 100 lbs of seed 0.041 lbs a. i./ 100 lbs of seed TCMTB Summary Analytical Chemistry and Residue Data  RED DP Barcode: 322617 Page 11 of 23 Table 6. Summary of Maximum Application Rates for Registered TCMTB Food/ Feed Seed Treatment Uses. EPA Reg. No. Product Name Formulation Crop Application Equipment Max. App. Rate ( fl oz/ 100 lbs of seed) Max. App. Rate ( lbs ai/ 100 lbs of seed) commercial treater 19.7 fl oz/ 100 lbs of seed 0.13 lbs a. i./ 100 lbs of seed 2935 413 Nu Flow ®

ND 9% SC cotton on farm treater 8.0 fl oz/ 100 lbs of seed 0.051 lbs a. i./ 100 lbs of seed 860.1300 Nature of the Residue  Plants The reregistration requirements for plant metabolism have not been fulfilled. In the Phase 4 review ( 3/ 11/ 1991) the registrant, Buckman, was instructed to provide three new plant metabolism studies, one each on corn or wheat, cotton and sugar beets, to determine if any uptake occurred in the aerial portion and/ or edible root portion of the growing crop. Based on this information, a determination would be made as to whether TCMTB uses are food or nonfood. Data have been submitted depicting the uptake of TCMTB in corn, cotton, safflower, and wheat and were found to be inadequate due to lack of identification and/ or characterization of parent and/ or metabolites. Additional metabolism studies conducted with tomatoes and melons have been submitted; however, translation to the currently registered crops is not adequate for reregistration purposes. Confirmatory metabolism data should be submitted depicting the nature of residues in wheat, cotton, and sugar beets. Adequate identification and/ or characterization of parent and/ or metabolites should be conducted as required by OPPTS 860 Series Guidelines.

The Risk Assessment Review Committee ( RARC) met and determined that the interim residue of concern for tolerance expression and risk assessment is TCMTB in/ on plants ( P. Deschamp, Report of the RARC, 1/ 11/ 2006). This is a preliminary decision dependent on the results from the requested metabolism data. For drinking water, the RARC decided that the residues of concern for risk assessment are TCMTB and 2 MBT. Summary of the preliminary decisions concerning the residues of concern in plants and drinking water are presented below in Table 7.

Table 7. Summary of TCMTB Residues to be Included in the Risk Assessment and Tolerance Expression.

Matrix Residues Included in Risk Assessment Residues Included in Tolerance Expression Primary crop  barley, cotton, oat, rice, safflower, sugar beet, and wheat TCMTB TCMTB Plants Rotational crop NA = not applicable NA Ruminant NA NA Livestock Poultry NA NA Drinking water TCMTB and 2 MBT NA All submitted studies are summarized below. No data have been submitted depicting the uptake of TCMTB in sugar beets.

Corn, Cotton, Safflower, and Wheat ( MRID 42376801 and 43147201)

Buckman submitted a study ( MRID 42376801) entitled " Uptake and Translocation of 14C Busan TCMTB Summary Analytical Chemistry and Residue Data  RED DP Barcode: 322617 Page 12 of 23 30A Used in Seed Treatment Combustion Analysis Phase".

Uniformly labelled 14C TCMTB in the benzene ring was applied ( as a solution of unknown concentration in an unspecified solvent) to four seed types, corn, cotton, safflower, and wheat at the maximum application rate at the time. No data were submitted depicting residues in/ on sugarbeets. The specific activity and radiopurity of the test substance were determined to be 45,600 dpm/ ug ( 5.26 mCi/ mmol) and 100%, respectively. Seeds were added to amber bottles that contained the radioactive material and placed on a roller for an hour to insure uniform coating. Acetonitrile washes of ten seeds were analyzed by liquid scintillation counting ( LSC) and the washed seeds were combusted to determine the rate of application. The remaining seeds were planted. Samples were taken from the aerial portion of the plant at various growth stages. Corn silage, haylage, grain and stover; wheat forage, hay, grain and straw; safflower forage, seed, thinnings, and stalk; and cotton forage samples were obtained. Control samples showed some uptake of radioactivity which increased with time. The registrant concluded that this was a result of housing the control samples in the same greenhouse with the treated plants. The Health Effects Division ( HED) previously concurred with this assumption; however, some of the control samples contained higher radioactive residues than its treated counterpart. The treated samples were stored frozen before processing and were analyzed by high performance liquid chromatography ( HPLC) using an ultraviolet detector ( UV).

Radioactive residues were found in all plant parts with the least amount of residue in corn commodities ( 0.0011 0.0021 ppm). The highest residues were found in cotton forage samples ( 2.7856 ppm). Cotton forage samples were analyzed for the presence of 2 MBT. No 2 MBT residues were found in the aqueous or organic cotton forage extracts. During the HPLC analysis of both the aqueous and organic extracts, a peak was noted to elute with a retention time similar to that of TCMTB. The identity of this peak was not confirmed by alternative means. Additionally, the registrant stated that subsequent analyses for the presence of 2 MBT in other plant extracts were being performed; however, no additional data have been submitted to the Agency for review.

Buckman submitted an addendum ( MRID 43147201) to the previous study report ( MRID 42376801) evaluating the uptake and translocation of C14 TCMTB in seed treatment of corn, wheat, safflower and cotton. This addendum includes the results of combustion analysis of radioactive residues in cotton seed, lint, and stalk. These results were not included in the previous study report because the treated cotton plants were not mature when the report was prepared. Table 8 below presents the results of the initial study and the addendum report.

Table 8. Radioactivity in Corn, Cotton, Safflower, and Wheat.

Crop Harvest Point Days Harvested After Planting Total DPM/ G1 Corrected ppm2 Corn Haylage Silage Grain Stover 62 days 114 days 139 days 139 days 68.4 95.83 54.7 50.2 0.0015 0.0021 0.0012 0.0011 Cotton Forage Seed Lint Stalk 52 days 211 days 211 days 211 days 127000 192 264 502 2.7856 0.0041 0.0058 0.0110 TCMTB Summary Analytical Chemistry and Residue Data  RED DP Barcode: 322617 Page 13 of 23 Table 8. Radioactivity in Corn, Cotton, Safflower, and Wheat.

Crop Harvest Point Days Harvested After Planting Total DPM/ G1 Corrected ppm2 Safflower Forage Seed Stalk 49 days 147 days 147 days 948.5 478.8 1860 0.0208 0.0105 0.0408 Wheat Forage Hay Grain Straw 22 days 63 days 141 days 141 days 18660 1158 538.1 3083 0.4092 0.0254 0.0118 0.0676 1. Total dpm/ g = corrected ppm X specific activity. 2. Corrected for machine recovery and matrix recovery. 3. Sample was combusted twice. Number represents average of both combustions.

Residues of 0.0011 ppm to 2.7856 ppm total radioactivity ( TCMTB equivalents) were found demonstrating uptake of TCMTB residues in crop parts. Identification and/ or characterization of parent and/ or metabolites were not performed. The solvent and TCMTB concentration in the treatment solution was not provided as well as the seed treatment rate. Both of these should be comparable with the commercial/ agricultural practices. Residues were found above 0.005 ppm, which is the trigger value for food use classification. Additional metabolism studies should be conducted with corn or wheat, cotton, and sugar beets where identification and/ or characterization of parent and/ or metabolites are completed.

Melon ( MRID 44654101)

Transplanted melon plants were grown in two confined plots. The treated plot received two soildrench applications of 14C TCMTB containing 20.0 mCi and supplementary unlabelled TCMTB in blank formulation of Busan 30 WB, so that the applications were equivalent to approximately 5.0 lb a. i./ A. The applications were made at the time of transplanting and again 14 days later. Immature melons ( 0.78 kg) were sampled at a preliminary sampling, at 29 days after last application. At the sampling at maturity, approximately 5.4 kg of melons was sampled and 0.59 kg of mature plant material was also taken. At all sampling events, the plant material was promptly frozen. It was stored frozen and shipped frozen to the analytical laboratory. The melons were stored and shipped under refrigeration to facilitate handling and chopping at the analytical laboratory.

On receipt at Xenobiotic Laboratories, the fruit and plant material were frozen and homogenized and samples were taken for determination of the total radioactive residue ( TRR) of each matrix. No radioactivity was detected in any of the untreated samples (< 0.001 ppm). The immature treated melons contained 0.304 ppm and the immature plant material contained 0.532 ppm and the mature plant material contained 8.00 ppm of radioactivity as TCMTB equivalents.

The parent compound, TCMTB, was found only in the plant material and at very low concentration, 0.073 ppm. One principle metabolite, 2 BTSA, was found in both the fruit and plant material. It was present in the fruit at 0.170 ppm and in the plant material at 1.12 ppm. 2 OH BT and 2 MBT were also detected, but at < 0.01 ppm in fruit and at 0.203 ppm and 0.010 ppm in the plant, respectively. Two positional isomers of OH 2 BTSA were also detected, but primarily in the plant at 0.113 ppm and 0.097 ppm. In addition, 14C incorporation was also detected in sucrose, fructose, and glucose at more than 27% of TRR. Table 9 presents the results TCMTB Summary Analytical Chemistry and Residue Data  RED DP Barcode: 322617 Page 14 of 23 of the melon metabolism study.

Table 9. Major TCMTB Metabolites Found in Melons. Residue Melon Fruit Melon Plant Compound ppm % ppm % TCMTB < 0.001 0 0.073 0.9 2 BTSA 0.170 31.9 1.12 14.0 2 OH BT 0.007 1.3 0.203 2.5 2 MBT 0.004 0.7 0.010 0.1 OH 2 BTSA1 0.006 1.1 0.113 1.4 OH 2 BTSA1 0.039 7.3 0.097 1.2 Sugars2 0.144 27.1 0.032 0.4 Totals 0.370 69.4 1.65 20.5 Post Extraction Solids 0.109 20.5 5.80 72.5 Grand Totals 0.479 89.9 7.45 93.0 1. Two positional isomers of hydroxy 2 benzothiazolesulfonic acid were detected. The exact position of the hydroxyl group could not be determined. 2. Sucrose + glucose + fructose with 14C incorporation.

Tomato ( MRID 44654102)

Transplanted tomato plants were grown in two confined plots. The treated plot received two soil drench applications of 14C TCMTB containing 20.0 mCi and supplementary unlabelled TCMTB in blank formulation of Busan 30 WB, so that the applications were equivalent to approximately 5.0 lb a. i./ A. The applications were made at the time of transplanting and again 14 days later. Immature tomatoes ( 0.24 kg) were sampled at a preliminary sampling, at 29 days after last application. Tomatoes were sampled twice at maturity, approximately 1.0 kg of ripe tomatoes was sampled at 56 days after last application and 1.5 kg of ripe tomatoes as well as 1.2 kg of green tomatoes were sampled two weeks later. In addition, approximately 1.0 kg of mature plant material was also taken. Samples were taken from the untreated control plants on the same schedule. At all sampling events, the plant material was promptly frozen. It was stored frozen and shipped frozen to the analytical laboratory. The tomatoes were stored and shipped under refrigeration to facilitate handling and chopping at the analytical laboratory.

On receipt at Xenobiotic Laboratories, the fruit and plant material were frozen and homogenized and samples were taken for determination of the total radioactive residue ( TRR) of each matrix. No radioactivity was detected in any of the untreated samples (< 0.001 ppm). The immature ( 29 day sampling) treated tomatoes contained 0.298 ppm and the immature plant material contained 6.41 ppm of radioactivity as TCMTB equivalents. The mature ( 56 day sampling) treated tomatoes contained 0.221 ppm and the mature plant material contained 4.08 ppm of radioactivity as TCMTB equivalents.

The parent compound, TCMTB, was not found in the tomato fruit of in the plant material, < 0.001 ppm. One principle metabolite, 2 BTSA, was found in both the fruit and plant material. It was present in the fruit at 0.136 ppm and in the plant material at 1.33 ppm. Two positional isomers of OH 2 BTSA were also detected, but only in significant quantities in the plant material ( 0.272 ppm and 0.590 ppm). In addition, 14C incorporation was also detected in sucrose, fructose, and glucose at more than 18% of TRR. Table 10 presents the results of the tomato metabolism study. TCMTB Summary Analytical Chemistry and Residue Data  RED DP Barcode: 322617 Page 15 of 23 Table 10. Major TCMTB Metabolites Found in Tomatoes. Residue Tomato Fruit Tomato Plant Compound ppm % ppm % TCMTB < 0.001 0 < 0.001 0 2 BTSA 0.136 61.7 1.33 32.6 OH 2 BTSA1 0.015 6.9 0.272 6.7 OH 2 BTSA1 0.004 1.6 0.590 14.5 Sugars2 0.031 14.1 0.193 4.7 Unidentified 0.008 3.6 0.494 12.1 Totals 0.194 87.9 2.88 70.6 Post Extraction Solids 0.017 7.8 0.927 22.7 Grand Totals 0.211 95.7 3.81 93.3 1. Two positional isomers of hydroxy 2 benzothiazolesulfonic acid were detected. The exact position of the hydroxyl group could not be determined. 2. Sucrose + glucose + fructose with 14C incorporation.

The reregistration requirements for plant metabolism have not been fulfilled. Data have been submitted depicting the uptake of TCMTB in corn, cotton, safflower, and wheat and were found to be inadequate due to lack of identification and/ or characterization of parent and/ or metabolites. Additional metabolism studies conducted with tomatoes and melons have been submitted; however, translation to the currently registered crops is not adequate for reregistration purposes. Confirmatory metabolism data should be submitted depicting the nature of residues in wheat, cotton, and sugar beets. Adequate identification and/ or characterization of parent and/ or metabolites should be conducted as required by OPPTS 860 Series Guidelines. The Risk Assessment Review Committee ( RARC) met and determined that the interim residue of concern for tolerance expression and risk assessment is TCMTB in/ on plants ( P. Deschamp, Report of the RARC, 1/ 11/ 2006). This is a preliminary decision and additional confirmatory data should be submitted in a timely manner. For drinking water, the RARC decided that the residues of concern for risk assessment are TCMTB and 2 MBT.

The determination of the residues of concern in plant commodities is based on the tomato and melon metabolism studies and the available toxicity data. 2 BTSA was found at significant levels ( 62% in tomato fruit); however, it should be excluded as a residue of concern because it is expected to be less toxic than the parent TCMTB. 2 BTSA is likely to not contribute significantly to the chronic toxicity of the parent based on the following considerations:

1. 2 BTSA has a very polar structure lacking the structural features of the parent ( TCMTB) that might lead to toxicologically significant species. Although the mode of toxic action of the parent is not known, its thiocyanomethylthio group is likely to be metabolized to toxic species. This group is not present in 2 BTSA. Thus, 2 BTSA cannot contribute to toxicity via this group.

2. If the benzimidazole ring of TCMTB is involved in its toxic effects by biotransformation to electrophilic species, 2 BTSA is not likely to undergo this type of biotransformation. 2 BTSA, being a sulfonic acid, is expected to undergo little or no metabolism. Smallmolecule sulfonic acids generally undergo little or no biotransformation. For example, methanesulfonic, benzenesulfonic, and naphthylaminesulfonic acids are excreted untransformed in laboratory animals ( Biological Basis of Detoxication, Caldwell J. & Jakoby W. B. [ eds], 1984, p. 162). TCMTB Summary Analytical Chemistry and Residue Data  RED DP Barcode: 322617 Page 16 of 23 3. In a chemical with a mercapto group ( SH), oxidation of the mercapto group to the corresponding sulfonic acid is known to produce a marked decrease in toxicity. For example, phenyl mercaptan ( i. e. benzenethiol) is a fairly toxic chemical producing neurotoxicity, liver toxicity, and other effects and has a rat acute oral LD50 of 46 mg/ kg ( McCord & Witheridge, 1949, cited in NIOSH website). In contrast, the oxidized form, benzenesulfonic acid is reported as having a rat acute oral LD50 of 890 mg/ kg ( Benzenesulfonic acid MSDS). This marked decrease of toxicity can be attributed to polarity resulting from the replacement of the  SH group with a sulfonic acid group.

4. 2 BTSA is the oxidized ( sulfonic acid) form of 2 MBT; thus, it is expected to be equally or less systemically toxic than 2 MBT by analogy with the benzenethiol/ benzenesulfonic acid pair of compounds. Barring high dose effects such as gastrointestinal effects, the chronic RfD for 2 MBT of 0.6 mg/ kg/ day set by the HED RfD/ Peer Review suggests that the chronic toxicity of 2 BTSA is much smaller than that of the parent TCMTB with a chronic RfD of 0.013 mg/ kg/ day. Although there are concerns for the carcinogenic potential of 2 MBT ( Group C), there are no such concerns for 2 BTSA due to its very high polarity and probable absence of metabolism.

Additionally, 2 MBT and other TCMTB metabolites were not found at significant levels to be considered residues of concern. Therefore, only TCMTB should be considered a residue of concern in plant commodities.

For drinking water, the residues of concern should include TCMTB and 2 MBT and is based on the available aerobic soil metabolism study ( MRID 43532201). 2 BTSA was found at 71% TRR; however, it should be excluded as a residue of concern for reasons noted in the above section. 2 MBT was found at 30% TRR after 1.5 days post treatment and should be considered a residue of concern. 2 MBT is distinctly less toxic than the parent; however, it can not be ruled out as a residue of concern and should be included in the dietary risk assessment. All other metabolites were not found at significant levels; therefore, they should not be considered residues of concern.

860.1300 Nature of the Residue   Livestock Livestock metabolism studies may be required if the requested plant metabolism studies show uptake of residues. If livestock metabolism studies are required, the registrant must provide poultry and ruminant metabolism studies following OPPTS 860 Series Guidelines.

860.1340 Residue Analytical Methods   Plants A tolerance enforcement method is available for determining thiobenzothiazole containing residues in barley, corn, cotton, oat, rice, safflower, sugar beet, and wheat. This method was originally submitted with Pesticide Petition ( PP) 0F0954 by Buckman. Residues are extracted by blending with water and the extract is refluxed with NaOH. After partition with CH2Cl2, glacial acetic acid and sulfuryl chloride are added to convert the residues to 2 chlorobenzothiazole, which is determined by a gas liquid chromatography ( GLC) method using an electron capture detector ( ECD). The quantitation limit of the method has been determined at 0.10 ppm. This method is listed as Method B in PAM Vol. II. The method is outdated and uses toxic reagents; therefore, if an additional method that is adequate for tolerance enforcement is available, it TCMTB Summary Analytical Chemistry and Residue Data  RED DP Barcode: 322617 Page 17 of 23 should be submitted immediately for review.

Two data collection methods are available for determining thiocyanate containing residues. The first method was originally submitted with PP 0F0954 by Buckman for the determination of residues in barley, corn, cottonseed, oat, rice, and wheat. Residues are extracted with benzene and the extract is cleaned up with liquid liquid extractions ( isooctane to H2SO4 water and then H2SO4 water to CH2Cl2). The TCMTB residue is heated with sodium polysulfide solution to liberate thiocyanate ion. Bromine is added to convert the thiocyanate to cyanogens bromide; then the cyanogen bromide is treated with pyridine benzidine reagent to form an intensely colored dye. The absorbance of the dye solution is determined at 532 nm. In a method tryout, the Agency obtained recoveries of 90% and 110% ( duplicate samples) at the 0.10 ppm fortification level and 105% and 115% ( duplicate samples) at the 0.20 ppm fortification level. The quantitation limit of the method has been determined at 0.10 ppm. The method is listed as Method I in PAM Vol. II.

The second method was originally submitted with PP 5F1613 by Buckman for the determination of residues in safflower seed, sorghum grain and foliage, and sugar beet and foliage. TCMTB is extracted from samples by blending with acetone. The extract is filtered and cleaned up on a Florisil column, and TCMTB is eluted with benzene. After liquid liquid partitioning, the same procedure described above for Method I is followed. Samples of safflower seed, sorghum grain and foliage, and sugar beet and foliage were fortified with 0.10 ppm to 0.30 ppm TCMTB and recoveries ranged from 70% to 93%. The quantitation limit of the method has been determined at 0.10 ppm. The method is listed as Method A in PAM Vol. II.

If the requested metabolism studies show additional residues are of concern and the current enforcement method does not capture these additional residues, development of a method capable of doing so will be required.

860.1340 Residue Analytical Methods  Livestock This requirement is put on reserve pending the results from the requested plant metabolism studies, and if required, the livestock metabolism studies.

860.1360 Multiresidue Methods There is no information in the review documents regarding submittal of data for FDA Multiresidue Methods by the petitioner. However, the FDA PESTDATA database dated 11/ 2001 ( PAM Volume I, Appendix I) indicates that TCMTB per se is completely recovered (> 80%) using Multiresidue Methods Section 302 ( Luke Method), but is only partially recovered ( 50 80%) using 303 ( Mills, Onley, Gaither Method) and 304 ( Mills fatty food Method).

If additional residues of concern are determined from the requested metabolism studies, all additional residues of concern for tolerance expression will need to be tested through Multiresidue Methods.

860.1380 Storage Stability Storage stability data for TCMTB in/ on barley, cotton, oat, rice, wheat, safflower, and sugar beet have not been submitted by the registrant. No data were provided on how long samples from the TCMTB Summary Analytical Chemistry and Residue Data  RED DP Barcode: 322617 Page 18 of 23 submitted field trials were stored prior to analysis; therefore, storage stability data for the previously submitted field trials are required and should be submitted immediately. Additionally, if field trials are required or additional uses are requested, storage stability data will be required under this guideline topic.

860.1400 Water, Fish, and Irrigated Crops TCMTB is not intended for direct use on water and aquatic food and feed crops; therefore, no residue chemistry data are required under this guideline topic.

860.1460 Food Handling TCMTB is not intended for use in food handling establishments; therefore, no residue chemistry data are required under this guideline topic.

860.1480 Meat, Milk, Poultry, and Eggs TCMTB is not intended for application to livestock. The grain crops, byproducts, and forages are livestock feed items. It is therefore necessary to consider if TCMTB residues are transferred to meat, milk, poultry, and eggs of livestock through ingestion of the residue bearing commodities.

It has been indicated in the foregoing considerations that the nature of residue in plants has not been adequately described. In the absence of such data, the residue level is unclear.

No livestock feeding studies have been submitted. If the requested residue data show finite residues in the feed items, livestock feeding studies would be essential to an evaluation of the transfer of residues to milk, meat, poultry, and eggs. Therefore, no valid conclusions relative to 40 CFR § 180.6 ( the necessity of tolerances in livestock commodities) can be made in the absence of livestock feeding studies.

860.1500 Crop Field Trials The available field trial data are not adequate according to current OPPTS 860 Series Guidelines. The correct number of field trials, number samples collected, and locations of trials are all insufficient. Additionally, no storage stability data were submitted with the field trial studies and the application rates are unknown for the barley, corn, oat, rice, and wheat studies. The method used for determining residues in barley, corn, oat, rice, and wheat is the data collection method which only determines the thiocyanate ion ( Method I or A in PAM Vol. II). The method used for determining residues in cotton is the tolerance enforcement method which determines thiobenzothiazole containing residues ( Method B in PAM Vol. II). If the requested metabolism studies show that additional metabolites of concern are expected, new field trials should be conducted in which the method samples for all residues of concern as determined by the tolerance expression. Field trial data are not available for sugar beets; therefore, magnitude of residue data in sugar beets should be submitted following all OPPTS 860 Series Guidelines.

Cotton ( MRID 00004239)

Cotton: Four studies reflecting seed treatments of 2 3 oz of Busan 72/ 100 lbs seed are reported. TCMTB Summary Analytical Chemistry and Residue Data  RED DP Barcode: 322617 Page 19 of 23 The exact application rate in lbs a. i./ 100 lbs of seed is unknown. Control values ranged from 0.01 ppm to 0.04 ppm, with values from treated samples ranging from 0.01 ppm to 0.09 ppm. These data are inadequate to determine whether of not real residues are present. Additionally, no data on cotton gin byproducts have been provided and are currently required.

Barley, Corn, Oat, Rice, and Wheat ( MRID 00117874)

Barley: Grain and foliage samples were obtained from crops in Wisconsin, Tennessee, and North Dakota which had received seed treatments of 0.7x to 5.6x the original application rate. Apparent residues in grain or foliage were 0.01 0.04 ppm. Untreated grain or foliage samples had residues of 0.01 0.04 ppm.

Corn: Grain and foliage samples were obtained from crops in Indiana, Illinois, Kansas, Missouri, and Wisconsin which had received seed treatments of 1x to 1.5x the original application rate. Apparent residues in grain or foliage were 0.01 0.04 ppm. Untreated grain and foliage samples had residues of 0.01 0.05 ppm.

Oat: Grain and foliage samples were obtained from crops in Arkansas and Wisconsin which had received seed treatments of 0.6x to 1.4x the original application rate. Apparent residues in grain and foliage were 0.02 0.04 ppm. Residues in untreated grain and foliage samples were 0.02 0.04 ppm.

Rice: Grain and foliage samples were collected from crops in Arkansas and Louisiana which had received seed treatments of 1x to 2.4x the original application rate. Apparent residues in grain and foliage were 0.02 0.04 ppm. Residues in untreated grain or foliage were 0.02 0.04 ppm.

Wheat: Samples of grain and foliage were taken from crops in Arkansas and North Dakota which had received seed treatments of 1.2x to 5.6x the original application rate. Apparent residues in grain and foliage were 0.02 0.04 ppm. Residue in untreated grain and foliage samples were 0.02 0.04 ppm.

A comparison of the data for the field studies of all the crops indicates that there is no significant difference between residue levels for the treated and untreated crops ( grain or foliage). It may be concluded that no residues of the parent compound, TCMTB, are likely to occur in the grain or foliage of barley, cotton, corn, oats, rice, and wheat from the current use pattern. Thus, the tolerance level of 0.1 ppm represents the analytical method's sensitivity rather than determinable residues.

The above conclusions apply only to the residues of the parent compound. No data have been submitted indicating if plant residues contain components other than the parent compound. If additional metabolism data show the presence in the residue of components other than the parent compound in significant quantities, then residue data on the subject crops may be necessary.

860.1520 Processed Food and Feed No processing studies have been submitted. Once the requested metabolism studies have been submitted, reviewed, and the metabolites of concern are determined, data should be submitted which show whether residues concentrate in the byproducts of the registered raw agricultural commodities. If concentration occurs, and the concentrated residue levels exceed the proposed TCMTB Summary Analytical Chemistry and Residue Data  RED DP Barcode: 322617 Page 20 of 23 tolerance, then food additive tolerances to cover such residues will be necessary.

860.1650 Submittal of Analytical Reference Standards An analytical reference standard for TCMTB was submitted by Buckman in February of 2002 and expires February of 2012. The standard is available at the EPA National Pesticide Standards Repository. If additional residues are included in the tolerance expression based on the requested metabolism data, analytical reference standards should be submitted and replenished as requested by the Repository.

860.1850 Confined Accumulation in Rotational Crops and 860.1900 Field Accumulation in Rotational Crops TCMTB treated seeds were planted in silt loam and yellow clay loam soils. The seeds were treated at 0.75 4.5 fl oz/ 100 lbs seed. Less than 0.10 ppm of TCMTB residues were noted in the soils at intervals of 30 days and beyond.

Loess and clay loam soils were treated in furrow or broadcast at 1.2 1.6 lbs a. i./ 100 lbs seed ( 9x the current maximum seed treatment rate). Residues were 1.1 1.7 ppm at 30 days, 0.6 1.0 ppm at 100 days, less than 0.10 1.0 ppm at 189 days, and less than 0.10 ppm at 215 days.

Sandy loam and silt loam soils were treated at 0.72 4.32 lb a. i./ 100lbs seed. Residues were less than 0.10 1.0 ppm at 30 days and less than 0.10 ppm at 60 days.

It is unclear which method was used to determine residue levels in the above soil persistence studies. The registrant should provide method data along with storage stability data in order for the data to be considered scientifically adequate. However, with the exception of storage stability and method data, soil persistence is not likely to be a concern with respect to follow up crops. However, the method used is unknown and the exact compounds that make up the residues found is unknown; therefore, this data requirement is put on reserve awaiting submission of the requested data and pending the results from the plant metabolism studies.

Tolerance Reassessment Summary Tolerances for residues in/ on plant livestock commodities have been established under 40 CFR § 180.288. The tolerances for residues of TCMTB in/ on plant commodities is expressed in terms of residues of TCMTB per se [( 2 benzothiazolylthio) methyl thiocyanate].

Tolerances Established Under 40 CFR § 180.288 Confirmatory metabolism data conducted with wheat, cotton, and sugar beet are requested to determine the nature of residues in plants. Depending on the results from the requested confirmatory metabolism studies, additional guideline requirements may be requested for: livestock metabolism; enforcement and data collection methods; multiresidue methods; storage stability; and livestock, crop, processed commodity, and rotational crop magnitude of residue studies. A summary of the TCMTB tolerance reassessment is presented below in Table 11. TCMTB Summary Analytical Chemistry and Residue Data  RED DP Barcode: 322617 Page 21 of 23 Tolerances To Be Proposed Under 40 CFR § 180.288 Because of changes to Table 1 ( OPPTS 860.1000), tolerances for barley hay and cotton gin byproducts must be proposed.

Table 11. Tolerance Reassessment Summary for TCMTB.

Commodity Current Tolerance Tolerance Reassessment Comment/[ Correct CommodityDefinition] Tolerances Established Under 40 CFR § 180.288: Barley, grain 0.1 ( N1) TBD2 Barley, straw 0.1 ( N) TBD Beet, sugar, roots 0.1 ( N) TBD Beet, sugar, tops 0.1 ( N) TBD Corn, grain 0.1 ( N) Revoke The registrants do not intend to support use of TCMTB on corn.

Corn, forage 0.1 ( N) Revoke The registrants do not intend to support use of TCMTB on corn.

Corn, stover 0.1 ( N) Revoke The registrants do not intend to support use of TCMTB on corn.

Cotton, forage 0.1 ( N) Revoke No longer considered a significant livestock feed item. Cotton, undelinted seed 0.1 ( N) TBD Oat, forage 0.1 ( N) TBD Oat, grain 0.1 ( N) TBD Oat, hay 0.1 ( N) TBD Oat, straw 0.1 ( N) TBD Safflower, seed 0.1 ( N) TBD Sorghum, grain, forage 0.1 ( N) Revoke The registrants do not intend to support use of TCMTB on sorghum.

Sorghum, grain, grain 0.1 ( N) Revoke The registrants do not intend to support use of TCMTB on sorghum.

Sorghum, grain, stover 0.1 ( N) Revoke The registrants do not intend to support use of TCMTB on sorghum. Wheat, forage 0.1 ( N) TBD Wheat, grain 0.1 ( N) TBD Wheat, hay 0.1 ( N) TBD Wheat, straw 0.1 ( N) TBD Tolerances To Be Proposed Under 40 CFR § 180.288: Barley, hay None established TBD Cotton, gin byproducts None established TBD 1. N = Negligible. The " N" designation must be removed from all tolerances. 2. TBD = To be determined. Tolerances cannot be determined at this time because additional data are required.

Codex Harmonization There are no Codex maximum residue limits ( MRLs) for TCMTB; therefore, no questions of compatibility with U. S. tolerances exist. TCMTB Summary Analytical Chemistry and Residue Data  RED DP Barcode: 322617 Page 22 of 23 Bibliography Agency Memoranda Citations Table 12. Agency Memoranda Citations.

Date DP Barcode PP No. From To MRID Nos. Subject 12/ 16/ 1993 D187529 None F. Fort V. Dietrich and B. Sidwell 42376801 TCMB. Uptake of 14C from Seed Treatment. Case No. 2625. Chemical No. 035603. MRID No. 42376801. CBRS No. 11294. DP Barcode D187529.

5/ 11/ 1998 D221887 None M. Perry M. Swindell 20431471 TCMTB. Uptake of 14C from seed treatment. Case No. 2625. Chemical No. 035603. MRID No. 43147201. DP Barcode D221887.

7/ 31/ 1970 None 0F0954 A. Rathman None None PP # 0F0954: TCMTB on cotton, as amended. Evaluation of analytical method and residue data.

9/ 23/ 1972 None 2F1264 A. Smith None None PP # 2F1264. TCMTB in small grain crops.

Master Record Identification Numbers 00004239 Wilbur Ellis Company ( 1979) Residue Data Summary. Unpublished study including letter dated Oct 16, 1978 from J. H. Stoner to Dave T. Schulteis, received Feb 6, 1979 under 2935 413; pre pared in cooperation with Stoner Laboratories; CDL: 237334 A 00004241 Wilbur Ellis Company ( 1979) Results of Tests on the Amount of Resi due Remaining, Including a Description of the Analytical Method: Nu Flow ND. Unpublished study received Feb 6, 1979 under 2935 413; CDL: 237335 B.

00046073 Buckman Laboratories, Incorporated ( 1975) Analytical Procedures and Results of Residue Analyses: Busan 30. Undated method. Unpublished study received Nov 12, 1976 under 7F1885; CDL: 095601 D.

00078556 Buckman Laboratories, Incorporated ( 1972) Analytical Procedures and Results of Residue Analyses: Busan 30. Includes undated methods entitled: Analyses of 2 ( thiocyanomethylthio) benzothiazole in soil; Regulatory method of analysis. Unpublished study re ceived Mar 26, 1975 under 4F1613; CDL: 095525 F.

00112618 Buckman Laboratories, Inc. ( 1970) Results of Tests on the Amount of Residue Remaining, Including a Description of the Analytical Method: 2 ( Thiocyanomethylthio) benzothiazole. Compilation; unpublished study received on unknown date under 0F0954; CDL: 091624 K.

00117874 Buckman Laboratories, Inc. ( 1967) Study: TCMTB Residues in Selected Grains). ( Compilation; unpublished study received Sep 28, 1972 under 2F1264; CDL: 091795 A.

00124027 Buckman Laboratories, Inc. ( 19??) Analysis of Grains for Thioben zothiazole Containing Residues. Unpublished study received Oct 20, 1972 under 2F1264; CDL: 094858 A. TCMTB Summary Analytical Chemistry and Residue Data  RED DP Barcode: 322617 Page 23 of 23 00136342 Buckman Laboratories, Inc. ( 19??) Analysis of Grains for Thioben zothiazole Containing Residues. Unpublished study received on unknown date under 2F1264; CDL: 097967 A.

00138078 Buckman Laboratories, Inc. ( 1975) Residue Data: Busan 30: Sugar Cane. Unpublished study received Nov 12, 1976 under 7F1885; CDL: 097566 B.

42376801 Raub, M.; Valle, H. ( 1992) Uptake and Translocation of carbon 14| Busan 30A Used in Seed Treatment: Combustion Analysis Phase: Lab Project Number: 39601. Unpublished study prepared by ABC Labs, Inc. 34 p.

43147201 Raub, M. ( 1994) Uptake and Translocation of ( carbon 14) Busan 30A Used in Seed Treatment: Addendum Report: Lab Project Number: 39601A. Unpublished study prepared by ABC Labs., Inc. 13 p.

44501301 Singer, G. ( 1998) Nature of the Residue from ( carbon 14) TCMTB in/ on Tomatoes after Soil Drench Applications: Final Report: Lab Project Number: AA960317: XBL96101. Unpublished study prepared by American Agricultural Services, Inc. and XenoBiotic Labs. 26 p.

44501302 Singer, G. ( 1998) Nature of the Residue from ( carbon 14) TCMTB in/ on Melons after Soil Drench Applications: Final Report: Lab Project Number: AA960318: XBL96101. Unpublished study prepared by American Agricultural Services, Inc. and XenoBiotic Labs. 26 p.

44654101 Singer, G. ( 1998) Nature of the Residue from ( carbon 14) TCMTB in/ on Melons after Soil Drench Applications: Final Report: Lab Project Number: AA960318: XBL96101: AA960318. NC. Unpublished study prepared by American Agricultural Services, Inc. and XenoBiotic Laboratories. 268 p.

44654102 Singer, G. ( 1998) Nature of the Residue from ( carbon 14) TCMTB in/ on Tomatoes after Soil Drench Applications: Final Report: Lab Project Number: XBL96101: AA960317. Unpublished study prepared by American Agricultural Services, Inc. and XenoBiotic Laboratories. 257 p.


[Federal Register: August 6, 2008 (Volume 73, Number 152)]
[Rules and Regulations]
[Page 45620-45624]
[DOCID:fr06au08-13]

=======================================================================
-----------------------------------------------------------------------

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 174

[EPA-HQ-OPP-2007-0830; FRL-8374-2]

Bacillus thuringiensis Vip3Aa Proteins in Corn and Cotton;
Exemption from the Requirement of a Tolerance

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: This regulation establishes an exemption from the requirement
of a tolerance for residues of the Bacillus thuringiensis Vip3Aa
proteins in or on the food and feed commodities of corn; corn, field;
corn, sweet; corn, pop; and cotton; cotton, undelinted seed; cotton,
refined oil; cotton, meal; cotton, hay; cotton, hulls; cotton, forage;
and cotton, gin byproducts, when used as plant-incorporated protectants
in those food and feed commodities. Syngenta Seeds, Inc. submitted a
petition to EPA under the Federal Food, Drug, and Cosmetic Act (FFDCA),
as amended by the Food Quality Protection Act of 1996 (FQPA),
requesting an exemption from the requirement of a tolerance. This
regulation eliminates the need to establish a maximum permissible level
for residues of Bacillus thuringiensis Vip3Aa proteins in or on corn;
corn, field; corn, sweet; corn, pop; and cotton, undelinted seed;
cotton, refined oil; cotton, meal; cotton, hay; cotton, hulls; cotton,
forage; and cotton, gin byproducts, when applied or used as plant-
incorporated protectants.

DATES: This regulation is effective August 6, 2008. Objections and
requests for hearings must be received on or before October 6, 2008,
and must be filed in accordance with the instructions provided in 40
CFR part 178 (see also Unit I.C. of the SUPPLEMENTARY INFORMATION).

ADDRESSES: EPA has established a docket for this action under docket
identification (ID) number EPA-HQ-OPP-2007-0830. To access the
electronic docket, go to http://www.regulations.gov, select ``Advanced
Search,'' then ``Docket Search.'' Insert the docket ID number where
indicated and select the ``Submit'' button. Follow the instructions on
the regulations.gov website to view the docket index or access
available documents. All documents in the docket are listed in the
docket index available in regulations.gov. Although listed in the
index, some information is not publicly available, e.g., Confidential
Business Information (CBI) or other information whose disclosure is
restricted by statute. Certain other material, such as copyrighted
material, is not placed on the Internet and will be publicly available
only in hard copy form. Publicly available docket materials are
available in the electronic docket at http://www.regulations.gov, or,
if only available in hard copy, at the OPP Regulatory Public Docket in
Rm. S-4400, One Potomac Yard (South Bldg.), 2777 S. Crystal Dr.,
Arlington, VA. The Docket Facility is open from 8:30 a.m. to 4 p.m.,
Monday through Friday, excluding legal holidays. The Docket Facility
telephone number is<PHONE_NUMBER>.

FOR FURTHER INFORMATION CONTACT: Alan Reynolds, Biopesticides and
Pollution Prevention Division (7511P), Environmental Protection Agency,
1200 Pennsylvania Ave., NW., Washington, DC 20460-0001; telephone
number:<PHONE_NUMBER>; e-mail address<EMAIL_ADDRESS>
SUPPLEMENTARY INFORMATION:

I. General Information

A. Does this Action Apply to Me?

    You may be potentially affected by this action if you are an
agricultural producer, food manufacturer, or pesticide manufacturer.
Potentially affected entities may include, but are not limited to:
     Crop production (NAICS code 111).
     Animal production (NAICS code 112).
     Food manufacturing (NAICS code 311).
     Pesticide manufacturing (NAICS code 32532).
    This listing is not intended to be exhaustive, but rather provides
a guide for readers regarding entities likely to be affected by this
action. Other types of entities not listed in this unit could also be
affected. The North American Industrial Classification System (NAICS)
codes have been provided to assist you and others in determining
whether this action might apply to certain entities. If you have any
questions regarding the applicability of this action to a particular
entity, consult the person listed under FOR FURTHER INFORMATION
CONTACT.

B. How Can I Access Electronic Copies of this Document?

    In addition to accessing an electronic copy of this Federal
Register document through the electronic docket at http://
www.regulations.gov, you may access this ``Federal Register'' document
electronically through the EPA Internet under the ``Federal Register''
listings at http://www.epa.gov/fedrgstr. You may also access a
frequently updated electronic version of 40 CFR part 180 through the
Government Printing Office's pilot e-CFR site at http://
www.gpoaccess.gov/ecfr.

C. Can I File an Objection or Hearing Request?

    Under section 408(g) of FFDCA, as amended by FQPA, any person may
file an objection to any aspect of this regulation and may also request
a hearing on those objections. The EPA procedural regulations which
govern the submission of objections and requests for hearings appear in
40 CFR part 178. You must file your objection or request a hearing on
this regulation in accordance with the instructions provided in 40 CFR
part 178. To ensure proper receipt by EPA, you must identify docket ID
number EPA-HQ-OPP-2007-0830 in the subject line on the first page of
your submission. All requests must be in writing, and must be mailed or
delivered to the Hearing Clerk on or before October 6, 2008.
    In addition to filing an objection or hearing request with the
Hearing Clerk as described in 40 CFR part 178, please submit a copy of
the filing that does not contain any CBI for inclusion in the public
docket that is described in ADDRESSES. Information not marked
confidential pursuant to 40 CFR part 2 may be disclosed publicly by EPA
without prior notice. Submit your copies, identified by docket ID
number EPA-HQ-OPP-2007-0830, by one of the following methods.
     Federal eRulemaking Portal: http://www.regulations.gov.
Follow the on-line instructions for submitting comments.
     Mail: Office of Pesticide Programs (OPP) Regulatory Public
Docket (7502P), Environmental Protection Agency, 1200 Pennsylvania
Ave., NW., Washington, DC 20460-0001.
     Delivery: OPP Regulatory Public Docket (7502P),
Environmental Protection Agency, Rm. S-4400, One Potomac Yard (South
Bldg.), 2777 S. Crystal Dr., Arlington, VA. Deliveries are only
accepted during the Docket's

normal hours of operation (8:30 a.m. to 4 p.m., Monday through Friday,
excluding legal holidays). Special arrangements should be made for
deliveries of boxed information. The Docket Facility telephone number
is<PHONE_NUMBER>.

II. Background and Statutory Findings

    In the Federal Register of November 2, 2007 (72 FR 62237) (FRL-
8153-8), EPA issued a notice pursuant to section 408(d)(3) of FFDCA, 21
U.S.C. 346a(d)(3), announcing the filing of a pesticide tolerance
petition (PP 7F7254) by Syngenta Seeds, Inc., P.O. Box 12257, 3054 E.
Cornwallis Road, Research Triangle Park, NC 27709. The petition
requested that 40 CFR part 180 be amended by establishing an exemption
from the requirement of a tolerance for residues of Bacillus
thuringiensis Vip3Aa proteins in or on all food commodities when
applied or used as plant-incorporated protectants. This notice included
a summary of the petition prepared by the petitioner Syngenta Seeds,
Inc. One comment was received in response to the notice of filing. The
commenter objected to the petition and expressed concerns about EPA's
regulation of human exposure to toxic chemicals. The Agency understands
the commenter's concerns regarding toxic substances and the potential
effects to humans. Pursuant to its authority under the FFDCA, and as
discussed further in this Unit, EPA conducted a comprehensive
assessment of representative Vip3Aa proteins, including a review of
acute oral toxicity data on several Vip3Aa proteins, amino acid
sequence comparisons to known toxins and allergens, as well as data
demonstrating that the representative Vip3Aa proteins are rapidly
degraded by gastric fluid in vitro, are not glycosylated, and are
present in low levels in the tissues of the corn and cotton plants
containing these plant-incorporated protectants. Based on these data,
the Agency has concluded that there is a reasonable certainty that no
harm will result from dietary exposure to residues of these proteins in
or on the food and feed commodities corn; corn, field; corn, sweet;
corn, pop; and cotton, undelinted seed; cotton, refined oil; cotton,
meal; cotton, hay; cotton, hulls; cotton, forage; and cotton, gin
byproducts, when used as plant-incorporated protectants in those food
and feed commodities. Thus, under the standard in FFDCA section
408(b)(2), a tolerance exemption is appropriate.
    In taking this action, EPA, pursuant to its authority under section
408(d)(4)(A)(i) of the FFDCA, is issuing a final regulation that varies
from the regulation sought by petitioner Syngenta Seeds, Inc.
Specifically, instead of issuing a tolerance exemption that covers
residues of the subject plant-incorporated protectant in all food
commodities, EPA is issuing a tolerance exemption that covers such
residues in those commodities in which it will be used as a plant-
incorporated protectant - in this case, the food and feed commodities
of corn; corn, field; corn, sweet; corn, pop; and cotton, undelinted
seed; cotton, refined oil; cotton, meal; cotton, hay; cotton, hulls;
cotton, forage; and cotton, gin byproducts. In this way, the tolerance
exemption is coextensive with the registered uses for this particular
plant-incorporated protectant.
    Section 408(c)(2)(A)(i) of FFDCA allows EPA to establish an
exemption from the requirement for a tolerance (the legal limit for a
pesticide chemical residue in or on a food) only if EPA determines that
the exemption is ``safe.'' Section 408(c)(2)(A)(ii) of FFDCA defines
``safe'' to mean that ``there is a reasonable certainty that no harm
will result from aggregate exposure to the pesticide chemical residue,
including all anticipated dietary exposures and all other exposures for
which there is reliable information.'' This includes exposure through
drinking water and in residential settings, but does not include
occupational exposure. Pursuant to section 408(c)(2)(B) of FFDCA, in
establishing or maintaining in effect an exemption from the requirement
of a tolerance, EPA must take into account the factors set forth in
section 408(b)(2)(C) of FFDCA, which require EPA to give special
consideration to exposure of infants and children to the pesticide
chemical residue in establishing a tolerance and to ``ensure that there
is a reasonable certainty that no harm will result to infants and
children from aggregate exposure to the pesticide chemical
residue....'' Additionally, section 408(b)(2)(D) of FFDCA requires that
the Agency consider ``available information concerning the cumulative
effects of a particular pesticide's residues'' and ``other substances
that have a common mechanism of toxicity.''
    EPA performs a number of analyses to determine the risks from
aggregate exposure to pesticide residues. First, EPA determines the
toxicity of pesticides. Second, EPA examines exposure to the pesticide
through food, drinking water, and through other exposures that occur as
a result of pesticide use in residential settings.

III. Toxicological Profile

    Consistent with section 408(b)(2)(D) of FFDCA, EPA has reviewed the
available scientific data and other relevant information in support of
this action and considered its validity, completeness, and reliability
and the relationship of this information to human risk. EPA has also
considered available information concerning the variability of the
sensitivities of major identifiable subgroups of consumers, including
infants and children.
    Mammalian toxicity and allergenicity assessment. Syngenta Seeds,
Inc. has submitted acute oral toxicity data demonstrating the lack of
mammalian toxicity at high levels of exposure to the Vip3Aa19 and
Vip3Aa20 proteins. These data demonstrate the safety of these
particular Vip3Aa proteins at levels well above the maximum possible
exposure levels that are reasonably anticipated in cotton (Vip3Aa19)
and corn (Vip3Aa20). Basing this conclusion on acute oral toxicity data
without requiring further toxicity testing and residue data is similar
to the Agency position regarding toxicity testing and the requirement
of residue data for the microbial Bacillus thuringiensis products from
which these plant-incorporated protectants were derived (40 CFR
158.2140). For microbial products, further toxicity testing (Tiers II
and III) and residue data are triggered by significant adverse acute
effects in studies such as the mouse oral toxicity study, to verify the
observed adverse effects and clarify the source of these effects.
    Syngenta submitted four acute oral toxicity studies conducted on
mice. Three of the studies were conducted with microbially-produced
Vip3Aa proteins (Vip3Aa1, Vip3Aa19, and Vip3Aa20) with slight
variations in amino acid sequence (1-2 amino acid differences), and one
study was conducted with transgenic corn leaf tissue expressing
Vip3Aa19 as the test material. No treatment-related adverse effects
were observed in any of the studies. The results of these studies
showed that the oral LD50 for mice (males, females, and
combined) was greater than 3,675 milligrams/kilogram/body weight (mg/
kg/bwt) (the highest dose tested) for the tested Vip3Aa proteins.
    When proteins are toxic, they are known to act via acute mechanisms
and at very low dose levels (Sjoblad, Roy D., et al., ``Toxicological
Considerations for Protein Components of Biological Pesticide
Products,'' Regulatory Toxicology and Pharmacology 15, pages 3-9
(1992)). Therefore, since no acute effects were shown to be caused by
the Vip3Aa19 and Vip3Aa20 proteins, even at relatively high dose
levels, they are not considered toxic. (This is also true

of the Vip3Aa1 protein that was tested.) Further, amino acid sequence
comparisons showed no similarities between Vip3Aa19 and Vip3Aa20, on
the one hand, and known toxic proteins in protein databases, on the
other hand, that would raise a safety concern.
    Since Vip3Aa is a protein, allergenic potential was also
considered. Currently, no definitive tests for determining the
allergenic potential of novel proteins exist. Therefore, EPA uses a
weight-of-evidence approach, where the following factors are
considered: Source of the trait; amino acid sequence comparison with
known allergens; and biochemical properties of the protein, including
in vitro digestibility in simulated gastric fluid (SGF) and
glycosylation. This approach is consistent with the approach outlined
in the Annex to the Codex Alimentarius ``Guideline for the Conduct of
Food Safety Assessment of Foods Derived from Recombinant-DNA Plants.''
The allergenicity assessment for Vip3Aa follows:
     Source of the trait. Bacillus thuringiensis, the
microorganism from which Vip3Aa proteins are derived, is not considered
to be a source of allergenic proteins.
     Amino acid sequence. A comparison of the amino acid
sequence of Vip3Aa19 and Vip3Aa20 with known allergens showed no
significant sequence identity over 80 amino acids or identity at the
level of eight contiguous amino acid residues.
     Digestibility. Both Vip3Aa19 and Vip3Aa20 proteins are
digested rapidly in simulated gastric fluid containing pepsin.
     Glycosylation. Both Vip3Aa19 and Vip3Aa20 were shown not
to be glycosylated.
    Considering all of the available information on Vip3Aa19 and
Vip3Aa20, EPA concludes that the potential for these specific proteins
to be food allergens is minimal. Moreover, as further explained below
(and in section VI.a. of this final rule), EPA believes these data and
the other submitted data demonstrating a lack of mammalian toxicity at
high levels of exposure to Vip3Aa19 and Vip3Aa20 can be extrapolated to
cover Vip3Aa more generally.
    Vip3Aa is the designation assigned to a closely-related group of
similar insecticidal proteins isolated from Bacillus thuringiensis. The
specific variants referred to throughout this document (i.e., Vip3Aa19
and Vip3Aa20) are isolates of Vip3Aa protein. All Vip3Aa proteins
(there are 25 known Vip3Aa proteins and there are sequences available
for 19 of these) are highly related. Indeed, the amino acid sequence of
all the Vip3Aa proteins can only vary up to 5% to be considered a part
of the Vip3Aa group. With respect to the 19 Vip3Aa proteins for which
sequences are available, they vary by less than 28 amino acids out of
the 789 amino acids that make up the protein. This level of sequence
similarity makes that group of 19 Vip3Aa protein variants 96% identical
overall. The sequence identity between any two individual sequences is
even higher. For example, the sequences of the protein variants tested
by Syngenta (i.e., Vip3Aa19 and Vip3Aa20) are over 99.7% identical.
Finally, as to the few amino acid differences that do exist between the
Vip3Aa variants, these differences do not alter the surrounding
sequence, rarely occur as contiguous amino acids, and are often
substitutions with similar chemical side groups indicating similar
chemical functionality. Therefore, EPA finds that none of the Vip3Aa
variants would be expected to have significant amino acid sequence
identity -- which is defined as either 35% identity over an 80 amino
acid stretch and, for allergens, at the level of eight contiguous amino
acids -- with a toxin, an anti-nutrient or an allergen.
    This conclusion is further supported by EPA's overall safety
assessment that includes other considerations such as the source of the
trait, digestibility and glycosylation. As noted in this Unit, Bacillus
thuringiensis (from which the Vip3Aa proteins are derived) is not
considered to be a source of allergenic proteins. Furthermore, since
all the Vip3Aa proteins have extremely homogenous structural
similarities (as explained in this Unit), they are highly likely to
show similar biochemical characteristics in terms of digestibility and
glycosylation. So, as is the case for both Vip3Aa19 and Vip3Aa20, EPA
expects that all Vip3Aa proteins will be rapidly digested under
simulated gastric conditions and will not be glycosylated. Finally, it
is also highly relevant here that microbial pesticide products, which
are distinct from plant-incorporated protectant pesticide products,
containing Bacillus thuringiensis and its components (which could
include microbially-expressed Vip3Aa proteins) are already exempt from
the requirement for a tolerance under 40 CFR 180.1011.
    Accordingly, EPA believes that the foregoing supports EPA's
reasonable certainty of no harm finding not only for the Vip3Aa19 and
Vip3Aa20 protein variants, but also for all other closely-related
members of the Vip3Aa designation as described using the Crickmore
classification system (Crickmore, N., Zeigler, D.R., Schnepf, E., Van
Rie, J., Lereclus, D., Baum, J, Bravo, A. and Dean, D.H. ``Bacillus
thuringiensis toxin Nomenclature'' (2007) http://
www.lifesci.sussex.ac.uk/Home/Neil_Crickmore/Bt/).

IV. Aggregate Exposures

    In examining aggregate exposure, section 408 of FFDCA directs EPA
to consider available information concerning exposures from the
pesticide residue in food and all other non-occupational exposures,
including drinking water from ground water or surface water and
exposure through pesticide use in gardens, lawns, or buildings
(residential and other indoor uses).
    The Agency has considered available information on the aggregate
exposure levels of consumers (and major identifiable subgroups of
consumers) to the pesticide chemical residue (i.e., the Vip3Aa
proteins) and to other related substances. These considerations include
dietary exposure under the tolerance exemption and all other tolerances
or exemptions in effect for the plant-incorporated protectant's
chemical residue, and exposure from non-occupational sources. Exposure
via the skin or inhalation is not likely since the plant-incorporated
protectant is contained within plant cells, which essentially
eliminates these exposure routes or reduces these exposure routes to
negligible. In addition, even if exposure can occur through inhalation,
the potential for Vip3Aa to be an allergen is low, as discussed in this
Unit. Although the allergenicity assessment focuses on potential to be
a food allergen, the data also indicate a low potential for Vip3Aa to
be an inhalation allergen. Exposure via residential or lawn use to
infants and children is also not expected because the use sites for
Vip3Aa proteins are agricultural. Oral exposure, at very low levels,
may occur from ingestion of food commodities containing Vip3Aa protein
residues and, theoretically, drinking water. However oral toxicity
testing (as discussed above) showed no adverse effects.

V. Cumulative Effects

    Pursuant to FFDCA section 408(b)(2)(D)(v), EPA has considered
available information on the cumulative effects of residues of
representative Vip3Aa proteins and other substances that have a common
mechanism of toxicity. These considerations include the cumulative
effects on infants and children of such residues and other substances
with a common mechanism of toxicity. Because there is no

indication of mammalian toxicity resulting from exposure to Vip3Aa
proteins, we conclude that there are no cumulative effects for the
Vip3Aa proteins.

VI. Determination of Safety for U.S. Population, Infants and Children

    1. Toxicity and allergenicity conclusions. The data submitted and
cited regarding potential health effects for Vip3Aa proteins includes
the characterization of representative Vip3Aa proteins, as well as the
acute oral toxicity studies, amino acid sequence comparisons to known
allergens and toxins, and in vitro digestibility of the representative
Vip3Aa proteins. The results of these studies were used to evaluate
humansk, and the validity, completeness, and reliability of the
available data from the studies were also considered.
    Adequate information was submitted to show that the Vip3Aa test
materials derived from microbial cultures were biochemically and
functionally equivalent to the proteins produced by the plant-
incorporated protectant ingredient in the plants. Microbially produced
proteins were used in the studies so that sufficient material for
testing was available.
    The acute oral toxicity data submitted for the representative
Vip3Aa proteins support the prediction that Vip3Aa proteins will be
non-toxic to humans. As mentioned above, when proteins are toxic, they
are known to act via acute mechanisms and at very low dose levels
(Sjoblad, Roy D., et al., ``Toxicological Considerations for Protein
Components of Biological Pesticide Products,'' Regulatory Toxicology
and Pharmacology 15, pages 3-9 (1992)). Since no treatment-related
adverse effects were shown to be caused by the representative Vip3Aa
proteins, even at relatively high dose levels, Vip3Aa proteins are not
considered toxic. Basing this conclusion on acute oral toxicity data
without requiring further toxicity testing or residue data is similar
to the Agency position regarding toxicity and the requirement of
residue data for the microbial Bacillus thuringiensis products from
which this plant-incorporated protectant was derived (see 40 CFR
158.2140). For microbial products, further toxicity testing (Tiers II
and III) and residue data are triggered when significant adverse
effects are seen in studies such as the acute oral toxicity study.
Further studies verify the observed adverse effects and clarify the
source of these effects.
    Residue chemistry data were not required for a human health effects
assessment of the subject plant-incorporated protectant ingredients
because of the lack of mammalian toxicity. However, data submitted
demonstrated low levels of the representative Vip3Aa proteins in corn
and cotton tissues.
    Since Vip3Aa are proteins, potential allergenicity is also
considered as part of the toxicity assessment. Considering all of the
available information, including that:
     Vip3Aa originates from a non-allergenic source.
     Vip3Aa19 and Vip3Aa20 have no sequence similarities with
known allergens.
     Vip3Aa19 and Vip3Aa20 are not glycosylated.
     Vip3Aa19 and Vip3Aa20 are rapidly digested in simulated
gastric fluid.
     The data developed for Vip3Aa19 and Vip3Aa20 can be
extrapolated to all Vip3Aa proteins due to the extremely high level of
structural similarity that exists between and among Vip3Aa proteins,
EPA has concluded that the potential for Vip3Aa to be an allergen is
minimal.
    Neither available information concerning the dietary consumption
patterns of consumers (and major identifiable subgroups of consumers
including infants and children) nor safety factors that are generally
recognized as appropriate for the use of animal experimentation data
were evaluated. The lack of mammalian toxicity at high levels of
exposure to representative Vip3Aa proteins, as well as the minimal
potential to be a food allergen, demonstrate the safety of Vip3Aa at
levels well above possible maximum exposure levels anticipated.
    The genetic material necessary for the production of the plant-
incorporated protectant active ingredient include the deoxyribo nucleic
acids/ribonucleic acid (DNA/RNA) that encode these proteins and
regulatory regions. The genetic material DNA/RNA necessary for the
production of Vip3Aa proteins has been exempted from the requirement of
a tolerance under 40 CFR 174.507 (Nucleic acids that are part of a
plant-incorporated protectant; exemption from the requirement of a
tolerance).
    2. Infants and children risk conclusions. FFDCA section
408(b)(2)(C) provides that EPA shall assess the available information
about consumption patterns among infants and children, special
susceptibility of infants and children to pesticide chemical residues
and the cumulative effects on infants and children of the residues and
other substances with a common mechanism of toxicity. In addition,
FFDCA section 408(b)(2)(C) also provides that EPA shall apply an
additional tenfold margin of safety for infants and children in the
case of threshold effects to account for prenatal and postnatal
toxicity and the completeness of the database unless EPA determines
that a different margin of safety will be safe for infants and
children.
    In this instance, based on all the available information, the
Agency concludes that there is a finding of no toxicity for Vip3Aa
proteins. Thus, there are no threshold effects of concern and, as a
result, the provision requiring an additional tenfold margin of safety
does not apply. Further, the considerations of consumption patterns,
special susceptibility, and cumulative effects do not apply.
    3. Overall safety conclusion. There is a reasonable certainty that
no harm will result from aggregate exposure to the U.S. population,
including infants and children, to Vip3Aa proteins. This includes all
anticipated dietary exposures and all other exposures for which there
is reliable information. The Agency has arrived at this conclusion
because, as discussed above, no toxicity to mammals has been observed,
nor any indication of allergenicity potential for Vip3Aa proteins.

VII. Other Considerations

A. Endocrine Disruptors

    The pesticidal active ingredient is a protein, derived from a
source that is not known to exert an influence on the endocrine system.
Therefore, the Agency is not requiring information on the endocrine
effects of the plant-incorporated protectant at this time.

B. Analytical Method(s)

     A lateral flow enzyme-linked immunosorbent assay (ELISA) protocol
has been provided to the Agency for detecting Vip3Aa in cotton as well
as a qualitative ELISA method for detecting Vip3Aa in corn.

C. Codex Maximum Residue Level

    No Codex maximum residue level exists for the plant-incorporated
protectant Bacillus thuringiensis Vip3Aa proteins and the genetic
material necessary for their production in corn and cotton.

VIII. Statutory and Executive Order Reviews

    This final rule establishes a tolerance under section 408(d) of
FFDCA in response to a petition submitted to the Agency. The Office of
Management and Budget (OMB) has exempted these types of actions from
review under Executive

Order 12866, entitled Regulatory Planning and Review (58 FR 51735,
October 4, 1993). Because this final rule has been exempted from review
under Executive Order 12866, this final rule is not subject to
Executive Order 13211, Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution, or Use (66 FR 28355,
May 22, 2001) or Executive Order 13045, entitled Protection of Children
from Environmental Health Risks and Safety Risks (62 FR 19885, April
23, 1997). This final rule does not contain any information collections
subject to OMB approval under the Paperwork Reduction Act (PRA), 44
U.S.C. 3501 et seq., nor does it require any special considerations
under Executive Order 12898, entitled Federal Actions to Address
Environmental Justice in Minority Populations and Low-Income
Populations (59 FR 7629, February 16, 1994).
    Since tolerances and exemptions that are established on the basis
of a petition under section 408(d) of FFDCA, such as the tolerance in
this final rule, do not require the issuance of a proposed rule, the
requirements of the Regulatory Flexibility Act (RFA) (5 U.S.C. 601 et
seq.) do not apply.
    This final rule directly regulates growers, food processors, food
handlers, and food retailers, not States or tribes, nor does this
action alter the relationships or distribution of power and
responsibilities established by Congress in the preemption provisions
of section 408(n)(4) of FFDCA. As such, the Agency has determined that
this action will not have a substantial direct effect on States or
tribal governments, on the relationship between the national government
and the States or tribal governments, or on the distribution of power
and responsibilities among the various levels of government or between
the Federal Government and Indian tribes. Thus, the Agency has
determined that Executive Order 13132, entitled Federalism (64 FR
43255, August 10, 1999) and Executive Order 13175, entitled
Consultation and Coordination with Indian Tribal Governments (65 FR
67249, November 9, 2000) do not apply to this final rule. In addition,
this final rule does not impose any enforceable duty or contain any
unfunded mandate as described under Title II of the Unfunded Mandates
Reform Act of 1995 (UMRA) (Public Law 104-4).
    This action does not involve any technical standards that would
require Agency consideration of voluntary consensus standards pursuant
to section 12(d) of the National Technology Transfer and Advancement
Act of 1995 (NTTAA), Public Law 104-113, section 12(d) (15 U.S.C. 272
note).

IX. Congressional Review Act

    The Congressional Review Act, 5 U.S.C. 801 et seq., generally
provides that before a rule may take effect, the agency promulgating
the rule must submit a rule report to each House of the Congress and to
the Comptroller General of the United States. EPA will submit a report
containing this rule and other required information to the U.S. Senate,
the U.S. House of Representatives, and the Comptroller General of the
United States prior to publication of this final rule in the Federal
Register. This final rule is not a ``major rule'' as defined by 5
U.S.C. 804(2).

List of Subjects in 40 CFR Part 174

    Environmental protection, Administrative practice and procedure,
Agricultural commodities, Pesticides and pests, Reporting and
recordkeeping requirements.

    Dated: June 26, 2008.
Debra Edwards,
Director, Office of Pesticide Programs.

0
Therefore, 40 CFR chapter I is amended as follows:

PART 174--[AMENDED]

0
1. The authority citation for part 174 continues to read as follows:

    Authority: 21 U.S.C. 321(q), 346a and 371.

0
2. Section 174.501 in subpart D is revised to read as follows:

Sec.  174.501  Bacillus thuringiensis Vip3Aa protein in corn and
cotton; exemption from the requirement of a tolerance.

    Residues of Bacillus thuringiensis Vip3Aa proteins in or on corn or
cotton are exempt from the requirement of a tolerance when used as
plant-incorporated protectants in or on the food and feed commodities
of corn; corn, field; corn, sweet; corn, pop; and cotton; cotton,
undelinted seed; cotton, refined oil; cotton, meal; cotton, hay;
cotton, hulls; cotton, forage; and cotton, gin byproducts.

Sec.  174.528  [Removed]

0
3. Section 174.528 is removed from Subpart D.
[FR Doc. E8-17931 Filed 8-5-08; 8:45 am]

BILLING CODE 6560-50-S