UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D. C. 20460 OFFICE OF PREVENTION, PESTICIDES AND TOXIC SUBSTANCES MEMORANDUM 11/ 26/ 2001 Subject: Linuron Tolerance Reassessment Eligibility Decision Residue Chemistry Considerations.

Reregistration Case No.: 0047 PC Code: 035506 DP Barcode No.: 272368 FROM: John S. Punzi, Ph. D., Chemist Reregistration Branch II Health Effects Division [7509C]

THROUGH: Alan Nielsen, Branch Senior Scientist Reregistration Branch II Health Effects Division [7509C]

TO: Tom Myers, Chemical Review Manager Special Review and Reregistration Division [7508C]

Attached is a review of the Linuron Tolerance Reassessment Eligibility Decision Residue Chemistry Considerations. The Residue Chemistry Chapter for the Linuron Reregistration Eligibility Document (RED) was published 2/ 18/ 94. An Addendum to the Linuron Residue Chemistry RED Chapter was issued on 2/ 21/ 95. This updated review (post FQPA) of the available residue chemistry database was completed by the Dynamac Corporation under supervision of HED and has undergone secondary review/ modification in Reregistration Branch 2 for consistency with current EPA policies.

Conclusions/ Recommendations The residue chemistry database is incomplete. 1. A review of the product labels and the supporting residue data indicate that the following label amendments are required:

° The product labels include directions for use for a number of tank mixes. In many cases, the tank mix products are no longer registered for use on the subject crop. Inappropriate tank mix recommendations are noted in Table 2.

° A number of grazing/ feeding restriction are considered to be impractical by HED and must be removed from the appropriate product labels.

° Several crops/ use directions require preharvest intervals (PHIs) to be specified.

° Product labels which contain use directions for asparagus must be modified to make it clear that the maximum combined application rate is 4.0 lb ai/ A/ season when more than one type of application (preemergence, postemergence, or application at the fern stage) is made.

° The product label for EPA Reg. No. 1812 245 includes two tables of application rates at the end of the soybean use directions which are titled "Soybeans: Broadcast Application  Linex 4L and Sencor DF and Lasso" and "Soybeans: Broadcast Application  Linex 4L and Sencor DF and Duel 8E." The label should be modified to clarify application timing for these tables; it is not clear to which application type (preemergence or postemergence) these application rates pertain..

2. The reregistration requirements for residue analytical methods are not fulfilled. The registrants must propose the current data collection method, a GC/ ECD method, as an enforcement method for plant and animal commodities to replace the current colorimetric enforcement method, which is outdated.

3. The reregistration requirements for storage stability are not fulfilled. The final reports for ongoing storage stability studies on cotton gin byproducts, cotton processed commodities, and sweet corn commodities must be submitted. In addition, information pertaining to sample storage intervals and conditions for samples of parsnips and for the animal feeding studies are required (MRIDs 00018209, 00018210, 00018375, 00018383, 00018450, and 00018775).

4. The reregistration requirements for magnitude of the residue in plants are not fulfilled for: celery; corn, field, aspirated grain fractions; corn, sweet (K+ CWHR); corn, sweet, forage; corn, sweet, stover; cotton gin byproducts; sorghum forage and stover; wheat forage, hay, and straw. Additional crop field trial data and/ or information is required for these commodities.

5. Tolerances for linuron residues of concern in milk must be proposed.

cc: JSPunzi (RRB2), Linuron Reg. Std. File, Linuron SF, RF, LAN. RD/ I: RRB2 Chem Review Team (01/ 26/ 2001), Alan Nielsen (11/ 30/ 2001). 7509C: RRB2: John S. Punzi: CM2: Rm 804E: 703 305 7727: 11/ 26/ 2001. LINURON PC Code 035506; Case 0047 Tolerance Reassessment Eligibility Decision Residue Chemistry Considerations September 26, 2001 Contract No. 68 W 99 053 Submitted to: U. S. Environmental Protection Agency Arlington, VA Submitted by: Dynamac Corporation 20440 Century Boulevard, Suite 100 Germantown, MD 20874 LINURON TOLERANCE REASSESSMENT ELIGIBILITY DECISION RESIDUE CHEMISTRY CONSIDERATIONS PC Code 035506; Case 0047 TABLE OF CONTENTS page A. INTRODUCTION ........................................................ 1 B. USE PATTERN SUMMARY ............................................... 1 1. Product List ......................................................... 1 2. Use Pattern Table .................................................... 2 C. SUMMARY OF RESIDUE CHEMISTRY DATA REQUIREMENTS ............... 24 D. RESIDUE CHARACTERIZATION .......................................... 32 General Discussion on Residue Chemistry of Linuron .............................. 32 1. Nature of the Residue in Plants .......................................... 32 2. Nature of the Residue in Livestock ....................................... 34 3. Residue Analytical Methods ............................................ 35 4. Multiresidue Method Testing ........................................... 36 5. Storage Stability Data ................................................ 36 6. Magnitude of the Residue in Crop Plants .................................. 38 Root and Tuber Vegetables Group ....................................... 38 Leafy Vegetables Group .............................................. 39 Legume Vegetables Group ............................................. 41 Foliage of Legume Vegetables Group ..................................... 41 Cereal Grain Group .................................................. 41 Forage, Fodder, and Straw of Cereal Grains Group .......................... 44 Miscellaneous Commodities ............................................ 46 7. Magnitude of the Residue in Processed Food/ Feed ........................... 47 Corn, field ......................................................... 47 Cotton ............................................................ 48 Potato ............................................................ 48 Sorghum, grain ...................................................... 49 Soybean .......................................................... 49 Wheat ............................................................ 49 8. Magnitude of the Residue in Meat, Milk, Poultry, and Eggs ..................... 49 9. Reduction of Residues ................................................ 52 3 10. Confined and Field Accumulation in Rotational Crops ......................... 52 E. TOLERANCE REASSESSMENT SUMMARY ................................ 53 1. Tolerance Reassessments for Linuron ..................................... 53 Tolerances Listed Under 40 CFR §180.184( a) ............................. 53 Tolerances To Be Proposed Under 40 CFR §180.184( a) ..................... 54 Tolerances Listed Under 40 CFR §180.184( c) ............................. 54 Tolerances To Be Proposed Under 40 CFR §180.184( c) ..................... 54 Pending Tolerance Petitions ............................................ 54 2. Tolerance Reassessment Table .......................................... 56 3. Codex/ International Harmonization ....................................... 59 F. BIBLIOGRAPHY ....................................................... 60 1. Study Citations ..................................................... 60 2. Agency Memoranda Citations .......................................... 67 LINURON TOLERANCE REASSESSMENT ELIGIBILITY DECISION RESIDUE CHEMISTRY CONSIDERATIONS PC Code 035506; Case 0047 A. INTRODUCTION Linuron [3( 3,4 dichlorophenyl) 1 methoxy 1 methylurea] is a selective herbicide that is classified as a nonquantifiable Group C carcinogen. Linuron, which is formulated as dry flowable (DF) or flowable concentrate (FlC) formulations, is currently registered by Griffin Corporation, Drexel Chemical Company, and Micro Flo Company for pre or postemergence use on asparagus, carrot, celery, field corn, sweet corn, cotton, parsley, parsnip, potato, sorghum, soybean, and winter wheat.

The nature of the residue in plants and animals is adequately understood based on plant metabolism studies on corn, soybeans, and potatoes and animal metabolism studies on goats and poultry. Currently tolerances for plant and animal commodities are expressed in terms of linuron per se. The HED Metabolism Committee has determined that the residues of concern are linuron and its metabolites convertible to 3,4 dichloroaniline, expressed as linuron (D. McNeilly, 11/ 17/ 93); residues of 3,4 dichloroaniline per se need not be regulated separately.

The Residue Chemistry Chapter for the Linuron Reregistration Eligibility Document (RED) was published 2/ 18/ 94. An Addendum to the Linuron Residue Chemistry RED Chapter was issued on 2/ 21/ 95. The Residue Chemistry Chapter of the Linuron Reregistration Standard was issued 6/ 30/ 82, and the Residue Chemistry Chapter of the Linuron Reregistration Standard Update was issued 6/ 20/ 90.

B. USE PATTERN SUMMARY 1. Product List A search of the Agency's Reference Files System (REFS) on 6/ 14/ 01 indicates that there are five linuron end use products (EPs) registered to Griffin Corporation, Drexel Chemical Company, and Micro Flo Company that have uses on food and/ or feed crops (Table 1). At the time of the 02/ 94 RED, there were 15 linuron EPs with food/ feed uses; these were registered to E. I. du Pont de Nemours and Company, Griffin Corporation, Drexel Chemical Company, Platte Chemical Company, and Micro Flo Company. Since the 2/ 94 RED, all the Dupont EPs have been canceled except for one EP (EPA Reg. No. 352 394) which was transferred to Griffin Corporation (EPA Reg. No. 1812 417) and then subsequently canceled. In addition, one Drexel EP (EPA Reg. No. 19713 79) and one Platte EP (EPA Reg. No. 34704 703) have been canceled. There are 13 SLN registrations with food/ feed uses associated with linuron. 2 Table 1. Linuron EPs with Uses on Feed/ Food Crops Registered to Griffin Corporation, Drexel Chemical Company, and Micro Flo Company.

EPA Reg. No. Label Acceptance Date Formulation Class Product Name Griffin Corporation 1812 245 a 3/ 27/ 98 4 lb/ gal FlC Linex® 4L Herbicide 1812 320 b 4/ 15/ 99 50% DF Lorox® DF Drexel Chemical Company 19713 97 5/ 17/ 94 4 lb/ gal FlC c Linuron 4L Weed Killer 19713 251 4/ 1/ 94 50% DF Linuron DF Herbicide Micro Flo Company 51036 78 12/ 22/ 93 4 lb/ gal FlC Linuron 4L Weed Killer a Including SLN Nos. AL000002, AR000007, LA000013, MS000003, TN000005, and TX000012. b Including SLN Nos. AR000008, CO970001, ID970004, LA000015, MS000011, TN000006, and WA000036. c Product formulation is listed as emulsifiable concentrate (EC) in REFs; however, upon examination of the product label, the formulation should be classified as a flowable concentrate (FlC).

2. Use Pattern Table A comprehensive summary of the registered use patterns of linuron, based on the product labels registered to Griffin Corporation, Drexel Chemical Company, and Micro Flo Company, is presented in Table 2. A tabular summary of the residue chemistry science assessments for reregistration of linuron is presented in Table 3. The conclusions listed in Table 3 regarding the tolerance reassessment eligibility are based on the use patterns registered by the basic producers, Griffin Corporation and Drexel Chemical Company. When end use product DCIs are developed, RD should require that all end use product labels (e. g., MAI labels, SLNs, and products subject to the generic data exemption) be amended such that they are consistent with the basic producers' labels.

A review of the above EP labels and the supporting residue data indicate that the following label amendments are required:

° The product labels include directions for use for a number of tank mixes. In many cases, the tank mix products are no longer registered for use on the subject crop. The following tank mix recommendations must be removed from all relevant product labels: chloramben on any crop (no currently registered chloramben products); dinoseb on any crop (no currently registered dinoseb products); oryzalin on soybeans; and propachlor on soybeans. Also, the product labels for the 50% DF formulations (1812 320 and 19713 251) include tank mix recommendations for 3 Bronco®, a product which was cancelled 3/ 9/ 00. Inappropriate tank mix recommendations are highlighted in Table 2.

° The following grazing/ feeding restriction are considered to be impractical by HED and must be removed from the appropriate product labels: restrictions against the grazing or feeding of treated sorghum forage or silage to dairy animals (EPA Reg. Nos. 1812 320, 19713 97, 19713 251, and 51036 78); restrictions against the feeding of cotton gin trash to livestock (EPA Reg. Nos. 1812 245, 19713 251, and 51036 78 as well as SLN Nos. AL000002, AR0000007, AR000008, LA000013, LA000015, MS000001, MS000011, TN000005, TN000006, and TX000012); and restrictions against the grazing/ feeding of immature wheat plants to livestock (EPA Reg. Nos. 1812 245, 19713 97, and 51036 78).

° The following crops/ use directions require preharvest intervals (PHIs) to be specified: postemergence uses on sorghum (EPA Reg. Nos. 1812 245, 1812 320, 19713 97, 19713 251, and 51036 78); application to newly planted or direct seeded asparagus (EPA Reg. Nos. 1812 245, 1812 320, 19713 97, 19713 251 and SLN No. ID970004); postemergence application to carrots grown in NY (EPA Reg. Nos. 1812 245 and 1812 320); postemergence application to field corn (EPA Reg. Nos. 1812 245, 19713 97, 19713 251, and 51036 78); posttransplant application to celery (EPA Reg. No. 1812 245, 1812 320, 19713 97, 19713 251, and 51036 78); and postemergence application to cotton (EPA Reg. Nos. 1812 245, 19713 251, and 51036 78 as well as SLN Nos. AL000002, AR0000007, AR000008, LA000013, LA000015, MS000001, MS000011, TN000005, TN000006, and TX000012).

° Product labels which contain use directions for asparagus must be modified to make it clear that the maximum combined application rate is 4.0 lb ai/ A/ season when more than one type of application (preemergence, postemergence, or application at the fern stage) is made. In addition, the available crop field trial data for asparagus are sufficient to support application of linuron to asparagus in all areas of the U. S. Therefore, the registrants may wish to modify product labels to remove the restrictions limiting use on asparagus to certain states.

° The product label for EPA Reg. No. 1812 245 includes two tables of application rates at the end of the soybean use directions which are titled "Soybeans: Broadcast Application  Linex 4L and Sencor DF and Lasso" and "Soybeans: Broadcast Application  Linex 4L and Sencor DF and Duel 8E." The label should be modified to clarify application timing for these tables; it is not clear to which application type (preemergence or postemergence) these application rates pertain. 4 (continued; footnotes follow) Table 2. Food/ Feed Use Patterns Subject To Reregistration for Linuron (PC Code 035506).

Site Application Type Application Timing Application Equipment Formulation [EPA Reg. No.] Single Application Rate, lb ai/ A Maximum Number of Applications Maximum Seasonal Application Rate, ai Preharvest Interval, days Use Limitations 1 Asparagus Soil broadcast or band Direct seeded or newly planted crowns Preemergence (after planting) Ground 4 lb/ gal FlC [1812 245] 1.0 2.0 1 2.0 Not specified (NS) Use limited to CA, MI, MN, NC, OR, and WA for a single preemergence application and up to two postemergence applications (when ferns are 6 18 inches) to direct seeded or newly planted crowns. Direct seeded or newly planted crowns Postemergence Ground 0.5 1.0 2 NS Soil broadcast or band Direct seeded or newly planted crowns Preemergence (after planting) Ground 50% DF [1812 320] [ID970004] 1.0 2.0 1 2.0 NS Use limited to CA, HI, ID, MI, MN, NC, ND, NJ (preemergence only), OR, WA, and WI for a single preemergence application and up to two postemergence applications (when ferns are 6 18 inches) to direct seeded or newly planted crowns. Direct seeded or newly planted crowns Postemergence Ground 0.5 1.0 2 NS Soil broadcast or band Direct seeded or newly planted crowns Preemergence (after planting) Ground 4 lb/ gal FlC [19713 97]

50% DF [19713 251] 1.0 2.0 1 2.0 NS Use limited to CA for a single preemergence application and up to two postemergence applications (when ferns are 6 18 inches) to direct seeded or newly planted crowns. Direct seeded or newly planted crowns Postemergence 0.5 1.0 2 NS Table 2 (continued).

Site Application Type Application Timing Application Equipment Formulation [EPA Reg. No.] Single Application Rate, lb ai/ A Maximum Number of Applications Maximum Seasonal Application Rate, ai Preharvest Interval, days Use Limitations 1 5 (continued; footnotes follow) Asparagus (continued)

Established beds Preemergence (after planting) Ground 4 lb/ gal FlC [1812 245] 1.0 2.0 1 4.0 NS Use limited to CA, MI, MN, NC, OR, and WA for a single preemergence application and up to four postemergence applications (before cutting season or immediately after cutting) to established beds. A one year PBI has been established for any other crop if more than 2.0 lb ai/ A/ season is applied. Established beds Postemergence Ground 0.5 1.0 4 1 Established beds Preemergence (after planting) Ground 4 lb/ gal FlC [19713 97]

50% DF [19713 251] 1.0 2.0 1 4.0 NS Use limited to CA for a single preemergence application and up to four postemergence applications (before cutting season or immediately after cutting) to established beds. Established beds Postemergence Ground 0.5 1.0 4 1 Established beds Preemergence (after planting) Ground 50% DF [1812 320] 1.0 2.0 1 2.0 NS Use limited to CA, HI, ID, MI, MN, NC, ND, NJ preemergence only), OR, WA, and WI for a single preemergence application and up to three postemergence applications (before cutting season or immediately after cutting) to established beds. Established beds Postemergence Ground 0.5 1.0 3 1 Established beds Preemergence (after planting) Ground 50% DF [ID970004] 1.0 2.0 1 4.0 NS Use limited to ID for a single preemergence application and up to four postemergence applications (before cutting season or immediately after cutting) to established beds. A one year PBI has been established for any other crop if more than 2.0 lb ai/ A/ season is applied. Established beds Postemergence Ground 0.5 1.0 4 1 Table 2 (continued).

Site Application Type Application Timing Application Equipment Formulation [EPA Reg. No.] Single Application Rate, lb ai/ A Maximum Number of Applications Maximum Seasonal Application Rate, ai Preharvest Interval, days Use Limitations 1 6 (continued; footnotes follow) Asparagus (continued)

Directed spray Postharvest Ground 4 lb/ gal FlC [1812 245] 2.0 4.0 1 4.0 NS Use limited to CA, MI, MN, NC, OR, and WA for a single postemergence directed spray application to the base of plant in the fern stage. A one year PBI has been established for any other crop if more than 2.0 lb ai/ A/ season is applied.

50% DF [1812 320] 2.0 1 2.0 NS Use limited to CA, HI, ID, MI, MN, NC, ND, NJ (preemergence only), OR, WA, and WI for a single postemergence directed spray application to the base of plant in the fern stage.

4 lb/ gal FlC [19713 97]

50% DF [19713 251] 2.0 4.0 1 4.0 NS Use limited to CA for a single postemergence directed spray application to the base of plant in the fern stage. A one year PBI has been established for any other crop if more than 2.0 lb ai/ A/ season is applied.

50% DF [ID970004] 2.0 4.0 1 4.0 NS Use limited to ID for a single postemergence directed spray application to the base of plant in the fern stage. A one year PBI has been established for any other crop if more than 2.0 lb ai/ A/ season is applied. Table 2 (continued).

Site Application Type Application Timing Application Equipment Formulation [EPA Reg. No.] Single Application Rate, lb ai/ A Maximum Number of Applications Maximum Seasonal Application Rate, ai Preharvest Interval, days Use Limitations 1 7 (continued; footnotes follow) Carrot Preemergence (after planting) Ground 4 lb/ gal FlC [1812 245] 0.5 1.5 1 1.5 NS Use limited to FL, MI, NJ, OH, and WI.

4 lb/ gal FlC [19713 97] 0.5 1.0 for FL 0.5 1.5 for MI, OH, and WI 1 1.0 (FL)

1.5 (MI, OH, and WI) 14 Use limited to FL, MI, OH, and WI.

50% DF [19713 251] 0.5 1.0 for FL 0.5 1.5 for MI and WI 1 1.0 (FL)

1.5 (MI and WI) 14 Use limited to FL, MI, and WI.

50% DF [1812 320] 0.5 1.0 for CA, FL, MN, ND, OR, and WA 0.5 1.5 for MI, OH, and WI 1 1.0 (CA, FL, MN, ND, OR, and WA)

1.5 (MI, OH, and WI) 14 Use limited to CA, FL, MI, MN, ND, OH, OR, WA, and WI.

4 lb/ gal FlC [51036 78] 0.5 1.5 1 1.5 14 Use limited to MI and WI. Table 2 (continued).

Site Application Type Application Timing Application Equipment Formulation [EPA Reg. No.] Single Application Rate, lb ai/ A Maximum Number of Applications Maximum Seasonal Application Rate, ai Preharvest Interval, days Use Limitations 1 8 (continued; footnotes follow) Carrots (continued)

Postemergence Ground 4 lb/ gal FlC [1812 245] [19713 97]

50% DF [1812 320] [19713 251 0.75 1.5 NS 2.0 1.5 (west of Rocky Mountains) 14 Multiple foliar applications for use in the entire U. S. Postemergence applications are to be made after carrots reach 3 inches in height. Maximum seasonal rate includes preemergence applications, if made.

4 lb/ gal FlC [51036 78] 0.75 1.5 NS 2.0 14 4 lb/ gal FlC [1812 245]

50% DF [1812 320] 0.125 0.25 NS NS NS Use limited to NY for multiple broadcast applications made postemergence. Applications may be made at lower rate when carrots have at least one fully developed true leaf or at the higher rate to carrots having three or more leaves.

Preemergence (after planting) Ground 50% DF [CO970001] 0.125 0.25 1 2.0 14 Use limited to CO. Additional postemergence applications may be made as long as the total application rate does not exceed 2.0 lb ai/ A/ season.

Celery Foliar Posttransplant Ground 4 lb/ gal FlC [1812 245]

50% DF [1812 320] 0.75 1.5 1 1.5 NS Use allowed in all states except CA. Application is to be made before celery reaches 8 inches in height.

0.75 1.0 1 1.0 NS Use limited to CA. Application is to be made before celery reaches 8 inches in height.

50% DF [19713 251]

4 lb/ gal FlC [19713 97] [51036 78] 0.75 1.5 1 1.5 NS Use limited to east of the Rocky Mountains. Application is to be made before celery reaches 8 inches in height. Table 2 (continued).

Site Application Type Application Timing Application Equipment Formulation [EPA Reg. No.] Single Application Rate, lb ai/ A Maximum Number of Applications Maximum Seasonal Application Rate, ai Preharvest Interval, days Use Limitations 1 9 (continued; footnotes follow) Corn, field Preemergence (after planting) Ground 4 lb/ gal FlC [1812 245] Sandy loam soils: 0.3 1.0 1 1.0 NS Use limited to east of the Rocky Mountains. A single preemergence application may be made as a tank mix with alachlor (Lasso®), propachlor (EPA Nos. 19713 97 and 51036 78 only), or atrazine. Silt loam soils: 0.5 1.25 1 1.25 Clay loam soils: 0.6 1.5 1 1.5 Preemergence (after planting) Ground 50% DF [1812 320] Sandy loam soils: 0.33 0.75 1 0.75 NS Use limited to east of the Rocky Mountains. A single preemergence application may be made as a tank mix with alachlor (Lasso®), propachlor (Ramrod®), or atrazine. Loam, silt loam, silt, sandy clay, sandy clay loam soils: 0.5 0.75 Silty clay, silty clay loam, clay, clay loam soils: 0.6 0.75 50% DF [19713 251] Sandy loam soils: 0.3 1.0 1 1.0 NS Use limited to east of the Rocky Mountains. A single preemergence application may be made as a tank mix with alachlor, propachlor, or atrazine. Loam, silt loam, silt, sandy clay, sandy clay loam soils: 0.5 1.5 1.5 Silty clay, silty clay loam, clay, clay loam soil: 0.625 1.5 1.5 Table 2 (continued).

Site Application Type Application Timing Application Equipment Formulation [EPA Reg. No.] Single Application Rate, lb ai/ A Maximum Number of Applications Maximum Seasonal Application Rate, ai Preharvest Interval, days Use Limitations 1 10 (continued; footnotes follow) Corn, field (continued)

Directed spray Postemergence Ground 4 lb/ gal FlC [1812 245] [19713 97] [51036 78] 0.625 1.5 1 1.5 NS A single postemergence directed (to weeds) spray application to field corn at least 15 inches in height.

50% DF [19713 251] 0.625 1 0.625 NS Corn, sweet Directed spray Postemergence Ground 4 lb/ gal FlC [19713 97] [51036 78] 0.625 1.5 1 1.5 NS A single postemergence directed (to weeds) spray application to sweet corn at least 15 inches in height. 50% DF [19713 251] 0.625 1 0.625 NS Cotton Directed spray Postemergence Ground 4 lb/ gal FlC [1812 245] [51036 78] [MS000003]

50% DF [19713 251] 0.5 0.75 2 1.5 (implied) NS Use limited to east of the Rocky Mountains for one or two postemergence directed (to weeds) spray applications made after cotton is at least 15 inches tall. Feeding forage or gin trash from treated areas to livestock and grazing treated fields are prohibited.

Directed spray After last cultivation (layby) Ground 1.0 1.5 1 1.5 NS Use limited to east of the Rocky Mountains for a single postemergence directed (to weeds) spray application made after the last cultivation (layby) when cotton is at least 20 inches tall. Feeding forage or gin trash from treated areas to livestock and grazing treated fields are prohibited. Table 2 (continued).

Site Application Type Application Timing Application Equipment Formulation [EPA Reg. No.] Single Application Rate, lb ai/ A Maximum Number of Applications Maximum Seasonal Application Rate, ai Preharvest Interval, days Use Limitations 1 11 (continued; footnotes follow) Cotton (continued)

Directed spray Postemergence Ground 4 lb/ gal FlC [AL010001] [AR000007] [LA000013] [TN000005] [TX000012]

50% DF [AR000008] [LA000015] [MS000011] [TN000006] 0.5 0.75 2 1.5 (implied) NS Use limited to AL, AR, LA, MS, TN, and TX for one or two postemergence directed spray applications made after cotton is at least 8 inches tall. Feeding forage or gin trash from treated areas to livestock and grazing treated fields are prohibited.

Directed spray After last cultivation (layby) Ground 1.0 1.5 1 1.5 NS Use limited to AL, AR, LA, MS, TN, and TX for a single postemergence directed spray application made after the last cultivation (layby) when cotton is at least 20 inches tall. Feeding forage or gin trash from treated areas to livestock and grazing treated fields are prohibited.

Parsley Preemergence (after planting) Ground 50% DF [1812 320] Mineral and muck soils: 0.5 1.5 1 1.5 30 Use limited to east of the Mississippi River and Texas.

Postemergence Ground Muck soils only: 0.5 1 30 Use limited to east of the Mississippi River and Texas. Application should be made after parsley has a minimum of three true leaves.

Parsnip Preemergence (after planting) Ground 4 lb/ gal FlC [1812 245] [19713 97] [51036 78]

50% DF [1812 320] [19713 251] 0.75 1.5 1 1.5 NS Table 2 (continued).

Site Application Type Application Timing Application Equipment Formulation [EPA Reg. No.] Single Application Rate, lb ai/ A Maximum Number of Applications Maximum Seasonal Application Rate, ai Preharvest Interval, days Use Limitations 1 12 (continued; footnotes follow) Potato Preemergence (after planting) Ground or aerial 4 lb/ gal FlC [1812 245] Lighter soils (sandy loams, silty loams): 0.75 1.25 1 1.25 NS Use limited to east of the Rocky Mountains for a single preemergence application. Application must be made in a minimum of 3 gal/ A when using aerial equipment. Heavier soils (silts, clay loams): 1.25 2.0 1 2.0 NS Sand soil: 0.5 1 0.5 NS Use limited to WI (central sands area) for a single preemergence application. Loamy sand soil: 1.0 1 1.0 NS Coarse soils (sandy loam): 0.5 1.0 1 1.0 NS Use limited to the Northeast. A single preemergence application may be made as a tank mix with metolachlor (Dual 8E). Medium soils (loam, silt loam, silt, sandy clay, sandy clay loam): 0.75 1.25 1 1.25 NS Table 2 (continued).

Site Application Type Application Timing Application Equipment Formulation [EPA Reg. No.] Single Application Rate, lb ai/ A Maximum Number of Applications Maximum Seasonal Application Rate, ai Preharvest Interval, days Use Limitations 1 13 (continued; footnotes follow) Potato (continued)

Preemergence (after planting) Ground 4 lb/ gal FlC [19713 97] [51036 78] Coarser soils (sandy loam, silt loam): 0.75 1.25 1 1.25 NS Use limited to east of the Rocky Mountains for a single preemergence application. Finer soils (silts, clay loams): 1.25 2.0 1 2.0 NS Sand soil: 0.5 1 0.5 NS Use limited to WI (central sands area) for a single preemergence application. Loamy sand soil: 1.0 1 1.0 NS 50% DF [19713 251] Coarser soils (sandy loam, silt loam): 0.75 1.25 1 1.25 NS Use limited to east of the Rocky Mountains for a single preemergence application. Finer soils (silts, clay loams): 1.25 2.0 1 2.0 NS Sand soil: 0.5 1 0.5 NS Use limited to WI (central sands area) for a single preemergence application. Loamy sand soil: 1.0 1 1.0 NS Coarse soils (sandy loam): 0.5 1.0 1 1.0 NS Use limited to Northeast. A single preemergence application may be made as a tank mix with metolachlor. Medium soils (loam, silt loam, silt, sandy clay, sandy clay loam): 0.75 1.25 1 1.25 NS Table 2 (continued).

Site Application Type Application Timing Application Equipment Formulation [EPA Reg. No.] Single Application Rate, lb ai/ A Maximum Number of Applications Maximum Seasonal Application Rate, ai Preharvest Interval, days Use Limitations 1 14 (continued; footnotes follow) Potato (continued)

Preemergence (after planting) Ground 50% DF [1812 320] Coarse soils (sandy loam, silt loam): 0.75 1.25 1 1.25 NS Use limited to east of the Rocky Mountains for a single preemergence application. Fine soils (silts, clay loams): 1.25 1.5 1 1.5 NS Coarse soils (sandy loam): 0.5 1.0 1 1.0 NS Use limited to Northeast. A single preemergence application may be made as a tank mix with metolachlor (Dual 8E). Medium soils (loam, silt loam, silt, sandy clay, sandy clay loam):

0.75 1.25 1 1.25 NS Sorghum Preemergence (after planting) Ground 4 lb/ gal FlC [1812 245] Sandy loam soils: 0.3 0.75 1 0.75 90 PGI 2 Rotating to fall crops, sugar beets, tobacco, potatoes or other vegetables following treated sorghum crop is prohibited. Loam, silt loam, silt, sandy clay or sandy clay loam: 0.5 1.0 1 1.0 Directed spray Postemergence Ground 0.5 1.0 1 1.0 90 PGI A single postemergence directed (to weeds) spray application to sorghum. Application may be made at lower rate when sorghum is at least 12 inches in height or at the higher rate when sorghum is at least 15 inches tall. Rotating to fall crops, sugar beets, tobacco, potatoes or other vegetables following treated sorghum crop is prohibited. Table 2 (continued).

Site Application Type Application Timing Application Equipment Formulation [EPA Reg. No.] Single Application Rate, lb ai/ A Maximum Number of Applications Maximum Seasonal Application Rate, ai Preharvest Interval, days Use Limitations 1 15 (continued; footnotes follow) Sorghum (continued)

Preemergence (after planting) Ground 50% DF [1812 320] Sandy loam soils: 0.25 0.75 1 0.75 NS For use as a tank mix with registered herbicides. Grazing or feeding sorghum forage or silage from treated fields to dairy animals is prohibited. Rotating to fall crops, sugar beets, tobacco, potatoes or other vegetables following treated sorghum crop is prohibited. 3 Loam, silt loam, silt, sandy clay, or sandy clay loam soils: 0.5 1.0 1 1.0 NS Directed spray Postemergence Ground 0.5 1.0 1 1.0 NS A single postemergence directed (to weeds) spray application to sorghum. Application may be made at lower rate when sorghum is at least 12 inches in height or at the higher rate when sorghum is at least 15 inches tall. Grazing or feeding sorghum forage or silage from treated fields to dairy animals is prohibited. Rotating to fall crops, sugar beets, tobacco, potatoes or other vegetables following treated sorghum crop is prohibited. 3 Table 2 (continued).

Site Application Type Application Timing Application Equipment Formulation [EPA Reg. No.] Single Application Rate, lb ai/ A Maximum Number of Applications Maximum Seasonal Application Rate, ai Preharvest Interval, days Use Limitations 1 16 (continued; footnotes follow) Sorghum (continued)

Preemergence (after planting) Ground 4 lb/ gal FlC [19713 97] [51036 78] Sandy loam soils: 0.3 0.75 1 0.75 NS Use limited to the Southwest. A single preemergence application may be made as a tank mix with propazine. The rotation of treated sorghum with any fall crop or with sugar beets, tobacco, potatoes, or vegetables is prohibited. Silt loam, clay loam soils: 0.5 1.0 1 1.0 Sandy loam soils: 0.3 1.0 1 1.0 NS Use limited to the Great Plains. A single preemergence application may be made as a tank mix with propachlor. The grazing or feeding of sorghum forage or silage from treated fields to dairy animals is prohibited. Silt loam soils: 0.5 1.25 1 1.25 NS Clay loam soils: 0.6 1.5 1 1.5 NS Directed spray Postemergence Ground 0.5 1.0 1 1.0 90 PGI A single postemergence directed (to weeds) spray application to sorghum. Application may be made at the lower rate when sorghum is at least 12 inches in height or at the higher rate when sorghum is at least 15 inches tall. Table 2 (continued).

Site Application Type Application Timing Application Equipment Formulation [EPA Reg. No.] Single Application Rate, lb ai/ A Maximum Number of Applications Maximum Seasonal Application Rate, ai Preharvest Interval, days Use Limitations 1 17 (continued; footnotes follow) Sorghum (continued)

Preemergence (after planting) Ground 50% DF [19713 251] Sandy loam soils: 0.3 1.0 1 1.0 NS Use limited to the Great Plains. A single preemergence application may be made as a tank mix with propachlor. The grazing or feeding of sorghum forage or silage from treated fields to dairy animals is prohibited. Loam, silt loam, silt, sandy clay, sandy clay loam soils: 0.5 1.25 1 1.25 NS Silty clay, silty clay loam, clay, clay loam soils: 0.6 1.5 1 1.5 NS Directed spray Postemergence Ground 0.5 1.0 1 1.0 90 PGI A single postemergence directed (to weeds) spray application to sorghum. Application may be made at lower rate when sorghum is at least 12 inches in height or at the higher rate when sorghum is at least 15 inches tall.

Soybean Conventional tillage systems Preemergence (after planting) Ground or aerial 4 lb/ gal FlC [1812 245] Sandy loam soils: 0.1 1.5 1 1.5 NS Application may be made alone or as a tank mix with alachlor (Lasso®; use limited east of the Rocky Mountains), metolachlor (Dual 8E), pendimethalin (Prowl®), or metribuzin (Lexone® DF). Application must be made in a minimum of 3 gal/ A when using aerial equipment. Feeding of treated forage to livestock is prohibited following tank mix use with Dual 8E. Loam, silt loam, silt, sandy clay, sandy clay loam soils: 0.25 2.0 1 2.0 NS Silty clay, silty clay loam, clay, clay loam soils: 0.4 3.0 1 3.0 NS Table 2 (continued).

Site Application Type Application Timing Application Equipment Formulation [EPA Reg. No.] Single Application Rate, lb ai/ A Maximum Number of Applications Maximum Seasonal Application Rate, ai Preharvest Interval, days Use Limitations 1 18 (continued; footnotes follow) Soybean (continued)

Conventional tillage systems Preemergence (after planting) Ground 4 lb/ gal FlC [19713 97] Sandy loam soils: 0.3 1.5 1 1.5 NS Application may be made alone or as a tank mix with alachlor, chloramben, metolachlor, oryzalin (Surflan®), pendimethalin (Prowl®), or propachlor (seed crop only). Feeding of treated forage to livestock is prohibited following tank mix use with metolachlor, oryzalin, or propachlor. Silt loam soils: 0.5 2.0 1 2.0 NS Clay loam soils: 0.6 3.0 1 3.0 NS 50% DF [19713 251] Sandy loam soils: 0.3 1.5 1 1.5 NS Application may be made alone or as a tank mix with alachlor, metolachlor, or metribuzin. Feeding of treated forage to livestock is prohibited following tank mix use with metolachlor. A 40 day PGI has been established for tank mix use with alachlor. Loam, silt loam, silt, sandy clay, sandy clay loam soils: 0.5 2.0 1 2.0 NS Silty clay, silty clay loam, clay, clay loam soils: 0.6 3.0 1 3.0 NS 50% DF [1812 320] Coarse soils (sandy loam): 0.2 1.0 1 1.0 NS Application may be made alone or as a tank mix with alachlor (Lasso®), metolachlor (Dual 8E), or metribuzin (Lexone® DF). Grazing or feeding forage from treated areas to livestock is prohibited. Medium soils (loam, silt loam, silt, sandy clay, sandy clay loam): 0.25 1.0 1 1.0 NS Fine soils (silty clay, silty clay loam, clay, clay loam): 0.4 1.0 1 1.0 NS Table 2 (continued).

Site Application Type Application Timing Application Equipment Formulation [EPA Reg. No.] Single Application Rate, lb ai/ A Maximum Number of Applications Maximum Seasonal Application Rate, ai Preharvest Interval, days Use Limitations 1 19 (continued; footnotes follow) Soybean (continued)

Conventional tillage systems Preemergence (after planting) Ground 4 lb/ gal FlC [51036 78] Sandy loam soils: 0.3 1.5 1 1.5 NS Application may be made alone or as a tank mix with alachlor (Lasso®), chloramben, and propachlor (Ramrod®; seed crop only). Grazing or feeding of treated forage to livestock is prohibited following tank mix use with propachlor. Silt loam soils: 0.5 2.0 1 2.0 NS Clay loam soils: 0.6 3.0 1 3.0 NS Minimum or no tillage systems Preemergence (before, during, or after planting) Ground or aerial 4 lb/ gal FlC [1812 245] Sandy loam soils: 0.3 1.0 1 1.0 NS Tank mix use with paraquat or glyphosate. To improve control of grasses and volunteer small grains, tank mix may be combined with alachlor (Lasso®) or metolachlor (Dual 8E). Application must be made in a minimum of 3 gal/ A when using aerial equipment. The grazing or feeding of treated forage to livestock is prohibited. Silt loam soils: 0.5 1.25 1 1.25 NS Clay loam soils: 0.6 1.5 1 1.5 NS Minimum or no tillage systems Preemergence (before, during, or after planting) Ground 4 lb/ gal FlC [19713 97] Sandy loam soils: 0.3 1.0 1 1.0 NS Tank mix use with paraquat or glyphosate. To improve control of grasses and volunteer small grains, tank mix may be combined with alachlor, metolachlor, or oryzalin (Surflan®). Feeding of treated forage to livestock is prohibited following tank mix use with metolachlor or oryzalin. Silt loam soils: 0.5 1.25 1 1.25 NS Clay loam soils: 0.6 1.5 1 1.5 NS 50% DF [19713 251] Sandy loam soils: 0.3 1.5 1 1.5 NS Application may be made alone or as a tank mix with paraquat or glyphosate. To improve control of grasses and volunteer small grains, tank mix may be combined with alachlor, metolachlor, or oryzalin. Feeding of treated forage to livestock is prohibited following tank mix use with metolachlor or oryzalin. Loam, silt loam, silt sandy clay, sandy clay loam soils: 0.5 2.0 1 2.0 NS Table 2 (continued).

Site Application Type Application Timing Application Equipment Formulation [EPA Reg. No.] Single Application Rate, lb ai/ A Maximum Number of Applications Maximum Seasonal Application Rate, ai Preharvest Interval, days Use Limitations 1 20 (continued; footnotes follow) Silty clay, silty clay loam, clay, clay loam soils: 0.6 3.0 1 3.0 NS Table 2 (continued).

Site Application Type Application Timing Application Equipment Formulation [EPA Reg. No.] Single Application Rate, lb ai/ A Maximum Number of Applications Maximum Seasonal Application Rate, ai Preharvest Interval, days Use Limitations 1 21 (continued; footnotes follow) Soybean (continued)

Minimum or no tillage systems Directed spray Postemergence Ground 4 lb/ gal FlC [1812 245] 0.5 1.0 2 1.0 60 Use limited to Midsouth and Southeast. Application is to be directed to weeds. For single application, application may be made at lower rate when soybean is at least 8 inches in height (Midsouth) or at the higher rate when soybean is at least 12 inches tall (Southeast). For split applications, the first application may be made when soybean is 12 inches tall with a 7 day retreatment interval. Feeding of treated forage or hay to livestock is prohibited.

0.5 2 1.0 (implied) 60 Tank mix use with 2,4 DB. Application may be made when soybean is at least 8 inches in height.

4 lb/ gal FlC [19713 97] 0.5 1.0 1 1.0 60 For single application, application may be made at lower rate when soybean is at least 8 inches in height or at the higher rate when soybean is at least 12 inches tall. For split applications, the first application may be made when soybean is 12 inches tall with a 7 day retreatment interval. Feeding of treated forage or hay to livestock is prohibited. 0.5 2 1.0 0.5 2 1.0 NS Tank mix use with 2,4 DB or dinoseb.

Conventional, minimum, or no tillage systems Directed spray Postemergence Ground 50% DF [19713 251] 0.5 1.0 1 1.0 60 For single application, application may be made at lower rate when soybean is at least 8 inches in height or at the higher rate when soybean is at least 12 inches tall. For split applications, the first application may be made when soybean is 12 inches tall with a 7 day retreatment interval. Feeding of treated forage or hay to livestock is prohibited. 0.5 2 1.0 (implied)

0.5 2 1.0 (implied) 60 Tank mix use with 2,4 DB. Feeding of treated forage or hay to livestock is prohibited. Table 2 (continued).

Site Application Type Application Timing Application Equipment Formulation [EPA Reg. No.] Single Application Rate, lb ai/ A Maximum Number of Applications Maximum Seasonal Application Rate, ai Preharvest Interval, days Use Limitations 1 22 (continued; footnotes follow) Soybean (continued)

Conventional tillage systems Directed spray Postemergence Ground 4 lb/ gal FlC [51036 78] 0.25 1.0 2 2.0 (implied) 60 Use limited to Midsouth and Southeast. Application is to be directed to weeds. In Midsouth, a single application may be made at 0.25 0.5 lb ai/ A when soybean is at least 8 inches in height. In Midsouth and Southeast, a single application may be made at 0.5 1.0 lb ai/ A when soybean is at least 12 inches in height. A second application may be made. Feeding of treated forage or hay to livestock is prohibited. Application may be made alone or as a tank mix with 2,4 DB.

Minimum or no tillage systems Preemergence (before, during, or after planting) Ground 50% DF [1812 320] Coarse soils (sandy loam): 0.4 1.0 1 1.0 NS Application may be made alone or as a tank mix with alachlor (Lasso®), metolachlor (Dual 8E), oryzalin (Surflan), paraquat, glyphosate (Roundup®), and/ or alachlor plus glyphosate (Bronco®). Medium soils (loam, silt loam, sandy clay, sandy clay loam): 0.6 1.0 1 1.0 NS Fine soils (silty clay, silty clay loam, clay, clay loam): 0.7 1.0 1 1.0 NS Table 2 (continued).

Site Application Type Application Timing Application Equipment Formulation [EPA Reg. No.] Single Application Rate, lb ai/ A Maximum Number of Applications Maximum Seasonal Application Rate, ai Preharvest Interval, days Use Limitations 1 23 1. Inappropriate tank mix recommendations are highlighted. The restricted entry interval (REI) for the 4 lb/ gal FlC (EPA Reg. Nos. 1812 245 and 19713 97) and 50% DF (EPA Reg. Nos. 1812 320 and 19713 251) formulations is 24 hours. The REI for the 4 lb/ gal FlC (EPA Reg. No. 51036 78) formulation is 12 hours.

The labels for the 4 lb/ gal FlC (EPA Reg. Nos. 1812 245, 19713 97, and 51036 78) and the 50% DF (EPA Reg. Nos. 1812 320 and 19713 251) formulations include the following restrictions: application should not be made on sand, loamy sand, gravelly soils or exposed subsoils nor on soils containing less than 1% organic matter.

For EPA Reg. Nos. 1812 245, 1812 320, and 19713 251, the following general rotational crop restrictions have been established: unless otherwise stated, any crop may be planted after 4 months except cereals where only barley, oats, rye, and wheat may be planted; West of the Rocky Mountains, carrots or celery may be planted after 4 months and no other crop may be planted within one year. Additional crop specific restrictions are noted in the table. EPA Reg. No. 1812 320 includes the following additional restriction: in the state of WA, when applications are made during the months of October, November, and December then crops can be planted 6 months after application. In addition, SLN No. WA000036 adds the following rotational crop restriction to EPA Reg. No. 18121 320: asparagus, barley, carrots, celery, corn (field and sweet), oats, potatoes, rye, soybeans, and wheat may be planted after 4 months except when applications are made during the months of October, November and December, for which crops may be planted 6 months after application; all other crops may be planted 12 months following application.

For EPA Reg. No. 19713 97, the following rotational crop restrictions have been established: if initial seeding fails to produce a stand, the same crop may be replanted in soil treated preemergence with the 4 lb/ gal FlC [EPA Reg. No. 19713 97] formulation (or with recommended tank mixtures). Thoroughly rework soil application as injury to the crop may result. West of the Rocky Mountains, carrots or celery may be planted 4 months after last application; unless otherwise directed, no other crop may be planted within one year after the last application.

For EPA Reg. No. 51036 78, the following rotational crop restrictions have been established: do not rotate crops used for food or feed which Wheat, winter (drill planted)

Preemergence, early postemergence, or semi dormant Ground 4 lb/ gal FlC [1812 245] [19713 97] [51036 78] 0.25 1.75 1 1.75 (west of the Cascade Range)

0.75 (east of the Cascade range) NS Use limited to ID, OR, and WA for a single preemergence, early postemergence, or semidormant application made in the fall or winter. Application may be made alone or as a tank mix with bromoxynil. Grazing or feeding immature plants to livestock is prohibited. A 6 month PBI for any rotational crop has been established. Table 2 (continued).

24 are not registered for use with linuron onto areas previously treated with this chemical.

2. PGI = pregrazing interval.

3. Label also states that sorghum and field corn may be planted within 4 months and that any crop may be planted after 4 months. 25 (continued) C. SUMMARY OF RESIDUE CHEMISTRY DATA REQUIREMENTS Table 3. Summary of Residue Chemistry Data Requirements for Linuron (PC Code 035506).

OPPTS Guideline No. Guideline Description / Commodity §180.184 Tolerances (ppm) 1 Must Additional Data Be Submitted? MRID Nos. 2 Comments 860.1200 Directions for Use NA Yes – Several label amendments are required. 3 860.1300 Nature of the Residue  Plants NA No 00018173 00018176 00027624 00164195 00164196 40084801 4 41716101 5 41716102 5 41938101 6 42542101 7 42548401 8 Metabolism studies on corn, soybeans, and potatoes are adequate.

860.1300 Nature of the Residue  Animals NA No 00029932 42635401 9 43245101 10 Ruminant and poultry metabolism studies are adequate.

860.1340 Residue Analytical Method Plant commodities NA Yes 00018087 00018089 00018127 00018176 The registrants must propose the current GC/ ECD data collection method as an enforcement method.

Animal commodities NA Yes 00018176 The registrants must propose the current GC/ ECD data collection method as an enforcement method.

860.1360 Multi Residue Method NA No See PAM, Vol. I, Appendix II No comment 860.1380 Storage Stability Data Plant commodities NA Yes 00159802 11 41716103 5 42836701 12 42836702 12 42913301 13 42974401 13 43040001 13 43104401 14 43215901 15 43215902 15 43288301 16 43288302 16 43356202 15 43356203 15 43681401 17 The final reports for ongoing storage stability studies on cotton gin byproducts and cotton processed commodities (up to 3 months) and sweet corn commodities (up to 6 months) must be submitted. In addition, information pertaining to sample storage intervals and conditions for samples used for tolerance reassessment must be submitted for parsnips. Table 3 (continued).

OPPTS Guideline No. Guideline Description / Commodity §180.184 Tolerances (ppm) 1 Must Additional Data Be Submitted? MRID Nos. 2 Comments 26 (continued) Animal commodities NA Yes none Storage conditions and intervals for samples from the animal feeding studies must be submitted. Supporting storage stability data may be needed if samples were stored longer than one month prior to analysis.

860.1400 Magnitude of the Residue  Water, Fish, and Irrigated Crops NA NA NA No comment 860.1460 Magnitude of the Residue  Food Handling NA NA NA No comment 860.1480 Magnitude of the Residue  Meat, Milk, Poultry, Eggs  Milk, fat, meat, and meat byproducts of cattle, goat, hog, horse, and sheep 1, fat, meat, and meat byproducts No 00018209 00018210 00018375 00018450 00018775 00029932 Adequate feeding study data are available for tolerance reassessment, pending submission of storage stability information.

 Eggs, fat, meat, and meat byproducts of poultry None No 00018383 Tolerances for poultry commodities are not required.

860.1500 Crop Field Trials Root and Tuber Vegetables Group  Carrot 1 No 00018172 00027635 00163267 18 40210901 19 40537601 41503401 20 Adequate field trial data are available.

 Parsnip 0.5 No 00018171 Adequate field trial data are available.

 Potato 1 No 00027635 00163267 18 40210901 19 41452701 20 Adequate field trial data are available. Table 3 (continued).

OPPTS Guideline No. Guideline Description / Commodity §180.184 Tolerances (ppm) 1 Must Additional Data Be Submitted? MRID Nos. 2 Comments 27 (continued) Leafy Vegetables Group  Celery 0.5 Yes 00018443 40537601 41501501 20 43681401 17 Griffin Corporation submitted IR 4 residue data in support of a request for amended use of the 4 lb/ gal FlC and 50% DF formulations on celery grown west of the Rocky Mountains. HED concluded that two additional field trials in Region 10 are required to fulfill the residue data requirements.

 Parsley 0.25 [180.184( c)] No 41189801 21 Adequate field trial data are available.

Legume Vegetables Group  Soybean seed and aspirated grain fractions 1, seed No 00018076 00018206 00027635 00163267 18 40210901 19 43039101 22 Adequate field trial data are available for soybean seed. Residue data for soybean aspirated grain fractions are not required.

Foliage of Legume Vegetables Group  Soybean forage and hay 1, forage 1, hay No 00018076 00018206 00027635 Provided that pertinent labels are modified to prohibit the feeding of soybean forage and hay to livestock, no data are required.

Cereal Grains Group  Corn, field, grain and aspirated grain fractions 0.25, grain No 00018171 00018206 00018375 00018382 00018450 00163267 18 40210901 19 40537601 42948501 23 43044101 24 Adequate data are available for field corn grain.

 Corn, pop, grain 0.25 No NA There are currently no registered uses on popcorn. Table 3 (continued).

OPPTS Guideline No. Guideline Description / Commodity §180.184 Tolerances (ppm) 1 Must Additional Data Be Submitted? MRID Nos. 2 Comments 28 (continued)  Corn, sweet (K+ CWHR) 0.25 Yes 00018171 00018206 00018375 00018382 00018450 45444101 25 Crop field trial data from three additional trial sites must be submitted to fulfill geographic representation requirements. Because the data submitter (Griffin) has deleted uses on sweet corn from product labels, a use on sweet corn must be proposed prior to acceptance of the field trial data.

 Sorghum, grain and aspirated grain fractions 0.25, grain No 00018171 00018148 40537601 41377601 Adequate field trial data are available for sorghum grain. Residue data for sorghum aspirated grain fractions are not required.

 Wheat, grain and aspirated grain fractions 0.25, grain No 00018171 00018175 40537601 42605901 26 Adequate field trial data are available for wheat grain. Residue data for wheat aspirated grain fractions are not required.

Forage, Fodder, and Straw of Cereal Grains Group  Corn, field, forage and stover 1, forage 1, fodder No 00018171 00018206 00018375 00018382 00018450 00163267 18 40210901 19 40537601 42948501 23 43044101 24 Adequate field trial data are available.

 Corn, pop, stover 1, fodder No None There are currently no registered uses on popcorn.

 Corn, sweet, forage and stover 1, forage 1, fodder Yes 00018171 00018206 00018375 00018382 00018450 45444101 25 Crop field trial data from three additional trial sites must be submitted to fulfill geographic representation requirements. Because the data submitter (Griffin) had deleted uses on sweet corn from product labels, a use on sweet corn must be proposed prior to acceptance of the field trial data. Table 3 (continued).

OPPTS Guideline No. Guideline Description / Commodity §180.184 Tolerances (ppm) 1 Must Additional Data Be Submitted? MRID Nos. 2 Comments 29 (continued)  Sorghum, forage and stover 1, forage 1, fodder Yes 00018171 00018148 40537601 No data have been submitted in response to the Update. Data pertaining to residues in/ on sorghum forage and fodder following a single postemergence application of a 50% DF or 4 lb/ gal FlC formulation at the maximum registered rate remain outstanding.

 Wheat, forage, hay, and straw 0.5, forage 0.5, hay 0.5, straw Yes 00018171 40537601 42605901 26 Adequate field trial data are available for wheat straw, which indicate that the established tolerance is too low; however these data reflect application at >1x. Field residue data remain outstanding for wheat forage and wheat hay; the registrants may also wish to generate field trial data for wheat straw.

Miscellaneous Commodities  Asparagus 7.0 No 00018087 00018089 00163267 18 40210901 19 41452601 20 Adequate field trial data are available.

 Cotton, seed and gin byproducts 0.25, seed Yes 00018067 41569901 20 45302201 27 Additional data and/ or information is required to fulfill geographic representation requirements.

860.1520 Processed Food/ Feed  Corn, field None No 42560001 28 Adequate processing data are available.

 Cotton, seed None No 45302201 27 Adequate processing data are available.

 Potato None Yes 40049201 29 42397201 30 Additional information pertaining to sample storage, the processing protocol, and LOQ determination, as well as an explanation for low method recoveries from potato chips, are required to upgrade the submitted potato processing study.

 Sorghum, grain None No 42542102 7 Adequate processing data are available. Table 3 (continued).

OPPTS Guideline No. Guideline Description / Commodity §180.184 Tolerances (ppm) 1 Must Additional Data Be Submitted? MRID Nos. 2 Comments 30 1. All tolerances are established under §180.184( a) unless otherwise specified.

2. Bolded references were reviewed in the 6/ 90 Update. Unbolded references were reviewed in the 6/ 82 Registration Standard. Otherwise, MRIDs were reviewed as noted.

3. A review of the above EP labels and the supporting residue data indicate that the following label amendments are required:

° The product labels include directions for use for a number of tank mixes. In many cases, the tank mix products are no longer registered for use on the subject crop. The following tank mix recommendations must be removed from all relevant product labels: chloramben  Soybean None No 00018206 41241202 31 42462901 32 Adequate processing data are available.

 Wheat None No The requirement for a wheat processing study has been waived.

860.1560 Reduction of Residues NA Yes 41241201 31 42397201 30 42379901 33 Additional information on sample storage, the cooking protocol, and the determination of LOQs is required to upgrade the potato cooking study. Additional information on the determination of limits of quantitation and an adequate description of the cooking procedure are required to upgrade the carrot cooking study.

860.1850 Confined Accumulation in Rotational Crops NA No 40104101 40730101 An adequate confined rotational crop study is available.

860.1900 Field Accumulation in Rotational Crops None Yes None The requirements for field rotational crop studies have been waived based on the results of the confined rotational crop study. The registrants must modify all rotational crop restrictions such that specific plantback intervals are defined (e. g., "do not plant any crop within 4 months of application to treated sorghum"). In addition, the registrants must provide justification for any plantback intervals on the product labels. Table 3 (continued).

31 on any crop (no currently registered chloramben products); dinoseb on any crop (no currently registered dinoseb products); oryzalin on soybeans; and propachlor on soybeans. Also, the product labels for the 50% DF formulations (1812 320 and 19713 251) include tank mix recommendations for Bronco®, a product which was cancelled 3/ 9/ 00. Inappropriate tank mix recommendations are highlighted in Table 2.

° The following grazing/ feeding restriction are considered to be impractical by HED and must be removed from the appropriate product labels: restrictions against the grazing or feeding of treated sorghum forage or silage to dairy animals (EPA Reg. Nos. 1812 320, 19713 97, 19713 251, and 51036 78); restrictions against the feeding of cotton gin trash to livestock (EPA Reg. Nos. 1812 245, 19713 251, and 51036 78 as well as SLN Nos. AL000002, AR0000007, AR000008, LA000013, LA000015, MS000001, MS000011, TN000005, TN000006, and TX000012); and restrictions against the grazing/ feeding of immature wheat plants to livestock (EPA Reg. Nos. 1812 245, 19713 97, and 51036 78).

° The following crops/ use directions require preharvest intervals (PHIs) to be specified: postemergence uses on sorghum (EPA Reg. Nos. 1812 245, 1812 320, 19713 97, 19713 251, and 51036 78); application to newly planted or direct seeded asparagus (EPA Reg. Nos. 1812 245, 1812 320, 19713 97, 19713 251 and SLN No. ID970004); postemergence application to carrots grown in NY (EPA Reg. Nos. 1812 245 and 1812 320); postemergence application to field corn (EPA Reg. Nos. 1812 245, 19713 97, 19713 251, and 51036 78); posttransplant application to celery (EPA Reg. No. 1812 245, 1812 320, 19713 97, 19713 251, and 51036 78); and postemergence application to cotton (EPA Reg. Nos. 1812 245, 19713 251, and 51036 78 as well as SLN Nos. AL000002, AR0000007, AR000008, LA000013, LA000015, MS000001, MS000011, TN000005, TN000006, and TX000012).

° Products labels which contain use directions for asparagus must be modified to make it clear that the maximum combined application rate is 4.0 lb ai/ A/ season when more than one type of application (preemergence, postemergence, or application at the fern stage) is made. In addition, the available crop field trial data for asparagus are sufficient to support application of linuron to asparagus in all areas of the U. S. Therefore, the registrants may wish to modify product labels to remove the restrictions limiting use on asparagus to certain states.

° The product label for EPA Reg. No. 1812 245 includes two tables of application rates at the end of the soybean use directions which are titled "Soybeans: Broadcast Application  Linex 4L and Sencor DF and Lasso" and "Soybeans: Broadcast Application  Linex 4L and Sencor DF and Duel 8E." The label should be modified to clarify application timing for these tables; it is not clear to which application type (preemergence or postemergence) these application rates pertain.

4. CBRS No. 2838, 12/ 24/ 87, L. Propst.

5. DP Barcode D160079, 4/ 25/ 91, R. Perfetti.

6. DP Barcode D167107, 5/ 21/ 92, P. Deschamp.

7. DP Barcode D187993, 11/ 18/ 93, D. McNeilly.

8. DP Barcode D187998, 11/ 18/ 93, D. McNeilly. Table 3 (continued).

32 9. DP Barcode D188002, 11/ 18/ 93, D. McNeilly.

10. DP Barcode D204807, 7/ 27/ 94, D. Miller.

11. CBRS No. 1244, 8/ 12/ 85, J. Garbus.

12. DP Barcode D195090, 10/ 5/ 93, D. McNeilly.

13. DP Barcode D198861, 3/ 29/ 94, D. McNeilly.

14. DP Barcode D199375, 3/ 16/ 94, D. McNeilly.

15. DP Barcodes D203624 and D207488, 1/ 11/ 95, S. Hummel.

16. DP Barcode D206666, 9/ 23/ 94, D. Miller.

17. DP Barcodes D216614 and D216621, 10/ 13/ 95, W. Cutchin.

18. CB No. 1317, 10/ 29/ 86, J. Garbus.

19. CB No. 2333, 6/ 2/ 87, J. Garbus.

20. CB Nos. 6663 and 6994, 3/ 26/ 91, R. Perfetti.

21. CB No. 5658, 10/ 5/ 89, F. Griffith.

22. DP Barcode D198859, 3/ 16/ 94, D. McNeilly.

23. DP Barcode D196857, 12/ 15/ 93, D. McNeilly.

24. DP Barcode D198851, 3/ 31/ 94, D. McNeilly.

25. DP Barcode D276294, 9/ 21/ 01, J. Punzi.

26. DP Barcode D188028, 5/ 10/ 93, D. McNeilly.

27. DP Barcode D271950, 9/ 24/ 01, J. Punzi.

28. DP Barcode D188001, 7/ 13/ 93, D. McNeilly.

29. CBRS No. 2279, 6/ 2/ 87, J. Garbus.

30. DP Barcode D181454, 9/ 2/ 92, S. Knizner.

31. CBRS No. 5858, 10/ 31/ 89, C. Olinger.

32. DP Barcode D182595, 3/ 18/ 93, D. McNeilly.

33. DP Barcode D181455, 9/ 8/ 92, S. Knizner. 33 D. RESIDUE CHARACTERIZATION General Discussion on Residue Chemistry of Linuron 1. Nature of the Residue in Plants The qualitative nature of the residue in plants is adequately understood (D. McNeilly, 11/ 17/ 93). Metabolism studies with corn, soybeans, and potatoes indicate that linuron is absorbed from the soil and translocated (i. e., systemic). The metabolic pathway involves demethylation to 3( 3,4 dichlorophenyl) 1 methoxyurea (desmethyl linuron) which is further metabolized to 3,4 dichloroaniline (3,4 DCA); metabolism may also occur through demethoxylation of linuron.

The residues of concern in plants are linuron and its metabolites convertible to 3,4 DCA; the chemical structures of linuron and its metabolites identified in plant and animal metabolism studies are presented in Figure 1.

Corn (MRID 40084801): Corn samples (forage, fodder, silage, and dry ear corn) were harvested 0 116 days following a single over the top application of uniformly ring labeled [phenyl 14 C] linuron at 1.4 lb ai/ A (-1x the maximum registered postemergence application rate) when corn plants were 15 18 inches tall. The TRR, expressed as [ 14 C] linuron equivalents, were: (i) 66.10 ppm in corn forage harvested 0 days posttreatment and 2.05 ppm in corn forage harvested 31 days posttreatment; (ii) 0.34 0.37 ppm in silage harvested 89 days posttreatment; and (iii) 0.01 0.014 ppm in corn grain, 0.844 1.09 ppm in corn fodder, and 0.049 0.31 ppm in cobs & husks harvested 98 116 days posttreatment. The parent linuron was found at 7.5 91.7% of TRR (0.15 60.6 ppm) in forage, 4.8% of TRR (0.016 ppm) in silage, 4.7% of TRR (0.051 ppm) in fodder, and 5.2% of TRR (0.002 ppm) in cobs & husks. Other residues identified in corn matrices were desmethyl linuron at 0.5 10.9% of TRR (0.001 0.80 ppm), desmethoxy linuron at <1 3.5% TRR (< 0.001 0.76 ppm), DCPU at 0.5 6.9% of TRR (0.002 0.30 ppm), and 3,4 DCA at <0.05< 1% of TRR (< 0.001< 0.04 ppm). Polar unknowns accounting for 0.8 40.0% of TRR (0.089 1.82 ppm) in forage, silage, fodder, and cobs & husks were observed. Additional studies were conducted in order to generate more samples for isolation of larger amounts of polar metabolites for characterization. Based on the analysis of samples using the enforcement analytical method, it was concluded that unidentified polar components in plants are hydrolyzed to 3,4 DCA.

Potato (MRID 42542101): Immature potato plant samples were harvested 24, 31, 51, 72, and 111 days, and mature potato plants were harvested 115 days following a single preemergence (after planting) application of uniformly ring labeled [phenyl 14 C] linuron at 2.0 lb ai/ A (1x the maximum registered seasonal application rate). Plants harvested <72 days after treatment were analyzed as whole plants, and plants harvested at 72, 77, 111, and 115 days after treatment were separated into foliage and tubers for analysis. The TRR, expressed as [ 14 C] linuron equivalents, were: (i) 0.24 0.34 ppm in whole plants harvested 24 51 days posttreatment; (ii) 0.22 0.26 ppm in foliage and 0.01 0.02 ppm in tubers harvested 72 111 days posttreatment; (iii) 0.67 ppm in foliage, 0.03 ppm in unpeeled 34 tubers, 0.02 ppm in peeled tubers, and 0.09 ppm in peelings harvested (at maturity) 115 days posttreatment. The parent linuron was found at 30.7 56.7% of TRR (0.14 0.21 ppm) in potato foliage at 24 115 days postreatment. Other residues identified in potato foliage were desmethyl linuron at 1.7 4.7% of TRR (< 0.01 0.02 ppm; 24 and 31 day posttreatment samples only), desmethoxy linuron at 5.8 13.1% (0.02 0.09 ppm), and norlinuron (DCPU) at 1.9 8.1% TRR (< 0.01 0.05 ppm). Polar unknowns accounting for 2.4 33.2% of TRR (< 0.01 0.11 ppm) in potato foliage were observed. Even though the specific identity of the polar metabolites was unknown, enforcement method analyses indicated that they were all converted to 3,4 DCA under the alkaline conditions of the enforcement method.

Soybean (MRID 42548401: Mature soybean plants were harvested 87 days following a single postemergence directed spray application (to the lower three inches of the soybean stem) of uniformly ring labeled [phenyl 14 C] linuron at 1.0 lb ai/ A (1x the maximum registered postemergence application rate). The TRR, expressed as [ 14 C] linuron equivalents, were 75.2% of TRR (3.76 ppm) in foliage, 16.2% of TRR (0.81 ppm) in pods, and 8.6% of TRR (0.43 ppm) in soybeans harvested (at maturity) 87 days posttreatment. The parent linuron was found at 3.4% of TRR (0.2 ppm) in soybean foliage, 1.0% of TRR (< 0.01 ppm) in soybean pods, and was nondetectable in soybeans. Other residues identified were: (i) desmethyl linuron at 0.3% of TRR (0.02 ppm), desmethoxy linuron at 6.1% of TRR( 0.26 ppm), and norlinuron at 12.6% of TRR (0.54 ppm) in soybean foliage; (ii) desmethoxy linuron at 5.7% of TRR (0.05 ppm) and norlinuron at 11.1% of TRR (0.10 ppm) in soybean pods; and (iii) desmethoxy linuron at 31.3% of TRR (0.1 ppm) and norlinuron at 8.4% of TRR (0.04 ppm) in soybeans. Polar unknowns accounting for 57.2% of TRR (2.48 ppm) in soybean foliage, 52.6% of TRR (0.47 ppm) in soybean pods, and 49.2% of TRR (0.22 ppm) in soybeans were also observed. Even though the specific identity of the polar metabolites was unknown, the metabolites appeared to be quantitatively converted to 3,4 DCA under the alkaline conditions of the enforcement method. 35 N H Cl Cl O N O CH 3 CH 3 N H N H O Cl Cl CH 3 N H NH 2 O Cl Cl N H Cl Cl O N H O CH 3 N H Cl Cl O NH 2 OH NH 2 Cl Cl Figure 1. Chemical names and structures of linuron and its metabolites identified in plant and animal commodities.

Linuron: 3( 3,4 dichlorophenyl) 1 methoxy 1 methylurea DCPMU; IN 15654; Desmethoxy linuron: 3( 3,4 dichlorophenyl) 1 methylurea DCPU; Norlinuron; IN R915: 3,4 dichlorophenylurea Desmethyl linuron: 3( 3,4 dichlorophenyl) 1 methoxyurea Hydroxy norlinuron: (4,5 dichloro 2 hydroxyphenyl) urea 3,4 DCA: 3,4 dichloroaniline 2. Nature of the Residue in Livestock The qualitative nature of the residue in ruminants and poultry is adequately understood (D. McNeilly, 11/ 17/ 93). An acceptable metabolism study with goats indicates that linuron is rapidly metabolized by demethylation, demethoxylation, and hydroxylation and is primarily eliminated by excretion. The metabolism of linuron in poultry has been found to be consistent with metabolism in goats. The terminal residues of concern are the parent and its metabolites which are convertible to 3,4 DCA.

Ruminants (MRID 00029932): Lactating goats were dosed with uniformly ring labeled 14 C] linuron at 1 and 5 ppm (0.14x and 0.7x, respectively, the maximum dietary burden of 7.22 ppm for dairy cattle) for 5 consecutive days. During the feeding period, ~85 86% of the radioactivity was rapidly eliminated from the body. The TRR in milk, expressed as linuron equivalents, were 0.004 0.005 ppm for the 1 ppm dose group and 0.014 0.027 ppm from the 5 ppm dose group. For the 1 ppm dose group, TRR were 0.070 ppm in liver, 0.029 ppm, in kidney, and 0.001 ppm in muscle and fat. For the 5 ppm dose group, TRR were 0.358 ppm in liver, 0.150 ppm in kidney, 0.015 ppm in fat, and 0.014 ppm in muscle. No intact linuron (< 0.001 ppm) was detected in the milk, tissues, or urine of the test animals. About 95% of the radioactivity in milk was identified as polar metabolites based on polar solvents used in TLC procedure. No attempts were made to identify these polar metabolites in the study.

Poultry (MRIDs 42635401 and 43245101): Laying hens were dosed with uniformly ring labeled [phenyl 14 C] linuron at 10 ppm (~ 45x the maximum dietary burden of 0.22 ppm) for 5 consecutive 36 days. At sacrifice, the highest levels of radioactivity in poultry tissues and eggs were observed in liver (0.57 1.13 ppm; mean of 0.78 ppm) and kidney (0.44 0.75 ppm; mean of 0.60 ppm). Residues were 0.1 0.17 ppm (mean of 0.13 ppm) in fat and 0.05 0.12 ppm in muscle (mean of 0.09 ppm for thigh muscle and 0.07 ppm for breast muscle), while residues in whole eggs ranged from 0.02 ppm (Day 1) to 0.12 ppm (Day 5). Linuron was observed only in egg yolk and fat as a minor component of the residue profile (< 1.3 2.8% TRR, <0.01 0.01 ppm). Norlinuron was the primary metabolite found in poultry tissues and eggs which comprised 65 68.5% of TRR (0.05 ppm) in muscle, 40.8% of TRR (0.04 ppm) in fat, 65.2% of TRR (0.38 ppm) in liver, 41.6% of TRR (0.17 ppm) in kidney, 51.9 64.7% of TRR (0.01 0.19 ppm) in egg yolk and 12.0 15.5% of TRR (< 0.01 ppm) in egg white. Desmethyl linuron, DCPMU, and hydroxy norlinuron were also detected at low levels (#0.05 ppm). 3,4 DCA was detected at very low levels in poultry tissues; <0.01 ppm for kidney, muscle, fat, egg white, and egg yolk and 0.01 ppm in liver.

The HED Metabolism Committee concluded (D. McNeilly, 11/ 17/ 93) that linuron can be regulated using the enforcement method. Residues of concern are linuron and metabolites convertible to 3,4 DCA, expressed as linuron. 3,4 DCA, per se, need not be regulated separately.

3. Residue Analytical Methods The reregistration requirements for residue analytical methods are not fulfilled. The registrants must propose the current data collection method, a GC/ ECD method, as an enforcement method for plant and animal commodities to replace the current colorimetric enforcement method, which is outdated.

The Pesticide Analytical Manual (PAM) Vol. II lists a colorimetric method (Method I, Bleidner et al.) and a paper chromatographic method (Method II) for the enforcement of tolerances for linuron residues. Residues of diuron may interfere in Method I. A modified version of Method I (H. L. Pease, Journal of Agric. and Food Chem., 1962, Vol. 10, p. 279), which includes a cellulose column step to separate linuron from diuron, has been used for tolerance enforcement purposes. Both these methods determine linuron and all metabolites hydrolyzable to 3,4 DCA and have limits of detection of 0.05 ppm. A GLC/ ECD method for linuron residues in/ on asparagus from the CA Department of Food and Agriculture has been validated by the Agency and sent to FDA to be published in PAM Vol. II as Method III. This method determines residues of linuron per se and the limit of detection is 0.05 ppm. We note however that this method is inadequate for tolerance enforcement since it does not determine all the residues of concern. In addition, this method uses benzene as the extraction solvent.

Residue data for linuron for plant and animal commodities were collected using Method I (or modifications thereof) or a GC/ ECD method similar to Method I.

The GC/ ECD data collection method involves conversion of residues to 3,4 DCA and therefore will detect residues of linuron and its metabolites, or any compound that can be hydrolyzed to 3,4 DCA (such as diuron). The method involves hydrolysis of samples by alkaline reflux to convert residues to 3,4 DCA, distillation into concentrated acid, neutralization, and clean up by silica gel column 37 chromatography. The eluates are then analyzed by GC/ ECD. The LOQ is 0.01 ppm. We note that this method is the same method used for data collection purposes for residues of diuron in/ on plant and animal commodities.

As discussed above, samples from the plant and animal metabolism studies were analyzed using the extraction procedures of the enforcement methods, which demonstrated that the identified metabolites plus a large portion of the unidentified polar metabolites were converted to 3,4 DCA and would therefore be determined using the enforcement method.

4. Multiresidue Method Testing The FDA PESTDATA database dated 10/ 99 (PAM Vol. I, Appendix II) contains data concerning the applicability of multiresidue methods D and E (fatty and nonfatty foods) for recovery of linuron and its metabolites desmethyl linuron, DCPMU, DCPU, and 3,4 DCA. Linuron recovery using Multiresidue Methods Sections 302 (Luke Method; Protocol D), 303 (Mills, Onley, and Gaither; Protocol E, nonfatty), and 304 (Mills, fatty food) is variable (but $40%). There is a small recovery (< 50%) of 3,4 DCA using Section 303, and variable recovery using Section 302; no data are available for Section 304. Linuron metabolites desmethyl linuron, DCPMU, and DCPU are not recovered using Sections 303 and 304. Linuron metabolite desmethyl linuron is recovered using Section 302, but no quantitative information is available. No recovery data are available for Section 302 for linuron metabolites DCPMU and DCPU.

5. Storage Stability Data The reregistration requirements for storage stability are not fulfilled. The final reports for ongoing storage stability studies on cotton gin byproducts, cotton processed commodities (up to 3 months), and sweet corn commodities (up to 6 months) must be submitted. In addition, information pertaining to sample storage intervals and conditions for samples used for tolerance reassessment must be submitted. This information is needed for parsnips (field trial data in MRID 00018171) and for the animal feeding studies (MRIDs 00018209, 00018210, 00018375, 00018383, 00018450, and 00018775).

The available storage stability data indicate that linuron residues of concern are stable during frozen storage at 20 C in asparagus (fresh and cooked) for at least 24 months, carrots (fresh and cooked) for at least 21 months, potatoes for at least 18 months, celery for at least 18 months, corn grain for at least 12 months, sorghum grain for at least 12 months, corn oil for at least 12 months, sorghum starch for at least 12 months, potato wet peel for at least 18 months, potato dry peel for at least 18 months, mashed potatoes for at least 18 months, potato chips for at least 20 months, dehydrated potato granules for at least 20 months, soybean oil for at least 18 months, and soybean tofu for at least 18 months. 38 The available storage stability data will support field trial data on leafy vegetables, oilseeds/ nuts, and root crops stored for 2 years at 18 C and on grain crops stored for 1 year at 18 C. Available storage stability data on processed commodities will support processing studies on grains, oilseeds, and root crops where samples were stored at 18 C up to 12 months and 18 months for soybean oil and tofu studies, and 18 20 months for potato processed commodities.

HED concludes that additional storage stability data (beyond those already promised to HED) will not be necessary provided that storage intervals do not exceed one year for non oily grains and two years for oilseeds/ nuts, leafy vegetables, and root crops: the registrant has provided sufficient data to indicate that significant linuron residue declines are not expected to occur in oilseeds/ nuts, leafy vegetables, root vegetables, and non oily grains over short to intermediate storage intervals. Since residues have been shown to be stable in several matrices of several different crop groupings, no additional storage data other than studies currently in progress discussed above will be required, provided that linuron is not registered for use on fruits, fruiting vegetables, or citrus.

Storage stability data for soybean seeds and sugar beet tops were submitted previously (MRID 00159802). Additional raw data were required to support these data before HED could conclude that the data were adequate (CB No. 1244, 8/ 12/ 85, J. Garbus); these data have not been submitted. Although not supported by raw data, the study indicated that residues of linuron were stable during up to two years of frozen storage in/ on soybeans and sugar beet tops.

We note that the available storage stability studies reflect fortification of samples with linuron per se; storage stability data for the metabolites were not submitted. Because the methods used for analysis were the methods which convert residues to 3,4 DCA and because any degradation product of linuron or its metabolites would likely be a compound hydrolyzable to 3,4 DCA, HED concludes that storage stability data for linuron metabolites will not be required.

There is no indication in HED files that storage stability data for livestock commodities have been submitted. As stated above, information pertaining to the storage conditions and intervals of samples used for tolerance reassessment must be submitted. If samples from the animal feeding studies were stored for longer than one month prior to analysis, supporting storage stability data will be required.

6. Magnitude of the Residue in Crop Plants The reregistration requirements for magnitude of the residue in plants are fulfilled for asparagus, carrots; field corn grain; field corn forage and fodder; cottonseed; parsley; parsnips; potatoes; sorghum grain; sorghum aspirated grain fractions; soybeans; soybean forage and hay; soybean aspirated grain fractions; and wheat grain. Adequate field trial data depicting linuron residues of concern following applications made according to the maximum registered use patterns have been submitted for these commodities. Geographical representation is adequate, and a sufficient number of trials reflecting representative formulation classes were conducted. 39 The reregistration requirements for magnitude of the residue in plants are not fulfilled for: celery; corn, field, aspirated grain fractions; corn, sweet (K+ CWHR); corn, sweet, forage; corn, sweet, stover; cotton gin byproducts; sorghum forage and stover; wheat forage, hay, and straw. Additional crop field trial data and/ or information is required for these commodities. Brief summaries of available linuron residue data, useful for tolerance reassessment only, along with the status of requirements for RACs eligible for reregistration, are presented below.

Root and Tuber Vegetables Group Carrot: The 2/ 94 RED concluded that Griffin and Drexel must submit additional residue data for carrots. However, the 2/ 95 RED Addendum concluded that, provided label amendments are made to reflect a 14 day PHI, no additional field trial data would be required for carrots. Data reported in MRID 41503401 indicate that the linuron residues of concern will not exceed the established tolerance of 1.0 ppm in/ on carrots harvested 14 days following a preemergence application at 0.5 lb ai/ A plus a postemergence application at 1 1.5 lb ai/ A using a 50% DF or 4 lb/ gal FlC formulation. Tests conducted in FL and NJ received a total of 1.5 lb ai/ A (0.75x the maximum seasonal rate), and tests conducted in CA and WI each received a total of 2.0 lb ai/ A (1x the maximum seasonal rate). Linuron residues of concern were 0.08 0.45 ppm in/ on six samples treated at 1x and 0.37 0.56 ppm in/ on four samples treated at 0.75x. Samples were stored frozen for 368 648 days prior to analysis, which is within the 2 year interval that linuron residues have been shown to be stable in root crops.

Data from additional carrot field trials (MRID 40537601) indicate that residues ranged from 0.28 0.50 ppm and 0.30 0.60 ppm in/ on samples of washed and unwashed carrots, respectively, harvested 14 days following either a single postemergence application of a 50% WP or 50% DF formulation at 2.0 lb ai/ A (1x the maximum seasonal application rate) or two applications for a total rate of 2.0 or 4.0 lb ai/ A (1x or 2x the maximum seasonal application rate). Samples were stored frozen for 125 127 days prior to analysis.

Currently, the Griffin labels (EPA Reg. Nos. 1812 245 and 1812 320) for the 4 lb/ gal FlC and 50% DF formulations do not specify a PHI for postemergence application to carrots in NY. The registrant must modify the product labels to reflect a 14 day PHI for carrots.

Parsnip: No additional residue data for parsnips are required. Previously, data had been required comparing the use of a DF formulation with that of an FlC formulation on parsnips. These requirements have been waived, based on residue data for field trials conducted on asparagus, carrots, celery, corn, cotton, potatoes, sorghum, soybeans, and wheat, which indicated similar residue patterns regardless of formulation.

Data reviewed in the 6/ 82 Reregistration Standard (MRID 00018171) indicate that the linuron residues of concern will not exceed the established tolerance of 0.5 ppm in/ on parsnips harvested 155, 169, and 182 days following a single application of the 50% WP at 1.0 or 2.0 lb ai/ A (0.7x or 1.3x the maximum seasonal rate). Linuron residues of concern were nondetectable (< 0.05 ppm). There is no 40 storage stability information available for these samples; these data are required (see Storage Stability Data).

Potato: The 2/ 94 RED and the 2/ 95 RED Addendum concluded that no additional field trial data are required for potato. Data reported in MRID 41452701 indicate that the linuron residues of concern will not exceed the established tolerance of 1.0 ppm in/ on potatoes harvested 42 110 days following a single preemergence application of the 4 lb/ gal FlC formulation at 2.0 lb ai/ A (1x the maximum seasonal rate). Linuron residues of concern were nondetectable (< 0.01 ppm) in/ on five samples of potato tubers. Samples were stored frozen for 279 593 days, which is within the 2 year interval that linuron residues have been shown to be stable in root crops.

Data from additional potato field trials (MRID 00163267) indicate that residues were nondetectable (< 0.05 ppm) in/ on all but one sample (0.07 ppm) of potato harvested 125 to 155 days after planting. A single preeemergence or postemergence application of the WP or DF formulation was made at 1.0 4.0 lb ai/ A (0.5 2x the maximum seasonal application rate) using ground equipment.

No additional field trial data are required for potatoes.

Leafy Vegetables Group Celery: The 2/ 94 RED and the 2/ 95 RED Addendum concluded that no additional field trial data are required for celery grown east of the Rocky Mountains. This conclusion was based on field residue data (MRID 41501501) indicating that linuron residues of concern were 0.04 0.42 ppm in/ on six celery samples harvested 68 102 days following a single posttransplant application of the 4 lb/ gal FlC or 50% DF formulation at 1.5 lb ai/ A (1x the maximum seasonal rate) in tests performed in FL, MI, and NY (east of the Rocky Mountains). Data from additional celery field trials (MRID 40537601) indicate that linuron residues of concern were nondetectable (< 0.05 ppm) to 0.32 ppm in/ on celery (washed/ unwashed and trimmed /untrimmed) harvested 44 82 days following postemergence application of either the 4 lb/ gal FlC, 50% WP, or 50% DF formulation at (i) 0.5 1.5 lb ai/ A (0.33 1x the maximum single application rate) and (ii) two or four applications at consecutive intervals of 22, 13, and 19 days for a total seasonal rate of 1.5 or 3.0 lb ai/ A (1 or 2x the maximum registered seasonal rate) in tests performed in CA, FL, and MI. Samples were stored frozen for 74 343 days prior to analysis, which is within the 2 year interval that linuron residues have been shown to be stable in leafy vegetable crops.

Currently, the Griffin labels for the 4 lb/ gal FlC and 50% DF (EPA Reg. Nos. 1812 245 and 1812 320) formulation permit use on celery in all states including CA. Griffin Corporation submitted Interregional Research Project No. 4 (IR 4) residue data (MRID 43681401) in support of a request for amended use of the 4 lb/ gal FlC and 50% DF formulations (EPA Reg. Nos. 1812 245 and 1812 320) on celery grown west of the Rocky Mountains. Linuron residues of concern were 0.04 0.12 ppm in/ on celery grown in CA or OR and harvested 66 or 77 days following posttransplant application at 1.5 lb ai/ A (1x the maximum seasonal rate for all states except CA; 1.5x the maximum seasonal rate 41 for CA). Samples were stored frozen for up to 390 days prior to analysis. HED concluded that the geographic representation of the submitted studies was not adequate to represent the celery growing regions requested by the amended use petition; two additional field trials in Region 10 are required to fulfill the residue data requirements for celery grown west of the Rocky Mountains. HED concluded that the data were not sufficient to support the request to add uses west of the Rockies, however it was concluded that a conditional registration would be recommended while the data were generated.

Parsley: The 2/ 94 RED and the 2/ 95 RED Addendum concluded that no additional field trial data are required for the regional registration for parsley grown in all states east of the Mississippi River. Data reported in MRID 41189801 indicate that the linuron residues of concern will not exceed the established tolerance of 0.25 ppm in/ on parsley grown in OH or NJ and harvested: (i) 52 90 days following a single preemergence application of the 4 lb/ gal FlC formulation at either 1.5 lb ai/ A (1x the maximum seasonal rate) or 3.0 lb ai/ A (2x the maximum seasonal rate) and (ii) 24 days following a preemergence application at 1.5 lb ai/ A plus a postemergence application at 0.5 lb ai/ A (1.3x the maximum seasonal application rate). Linuron residues of concern from the single preemergence application at 1x were <0.06 0.11 ppm in/ on 14 samples of parsley. Linuron residues of concern from the single preemergence application at 2x were 0.14 0.21 ppm in/ on four samples of parsley. Linuron residues of concern from the single preemergence plus postemergence application at 1.3x were 0.09 0.18 ppm in/ on parsley. Storage stability information for these studies was not discussed in the study review.

Legume Vegetables Group Soybean seed and aspirated grain fractions: The 2/ 94 RED concluded that Griffin and Drexel must submit additional residue data for soybean because Craven data were submitted to support reregistration of linuron on soybeans. Craven replacement data reflecting postemergence application of the 50% DF or 4 lb/ gal FlC formulation at the maximum registered rate were submitted and deemed acceptable (DP Barcode D198859, 3/ 16/ 94, D. McNeilly). The 2/ 95 RED Addendum concluded that no additional soybean data were required. Data reported in MRID 43039101 indicate that the linuron residues of concern will not exceed the established tolerance of 1 ppm in/ on soybeans harvested 56 77 days following either (i) a single preemergence application of the DF formulation at 2.5 lb ai/ A followed by a single directed postemergence application at 1.0 lb ai/ A for a total rate of 3.5 lb ai/ A (-1x the maximum seasonal rate) or (ii) a single preemergence application of the DF formulation at 2.5 lb ai/ A (0.8x the maximum seasonal rate). Linuron residues of concern from the single preemergence plus single directed postemergence application at -1x were <0.01 1.0 ppm in/ on 15 samples of soybeans. Linuron residues of concern from the single preemergence application at 0.8x were <0.01 0.18 ppm in/ on 17 samples of soybeans. Samples were stored frozen up to 8.5 months prior to analysis, which is within the 2 year interval that linuron residues have been shown to be stable in oilseeds. 42 There are no data available for soybean aspirated grain fractions. Because processing data for soybeans indicated no concentration of residues of concern in light impurities, data for soybean aspirated grain fractions will not be required.

Foliage of Legume Vegetables Group Soybean forage and hay: The 2/ 94 RED concluded that because restrictions against the feeding of treated soybean forage and hay existed on all pertinent product labels, no data would be required for soybean forage and hay, and that the established tolerances for soybean forage and hay should be revoked. However, the 2/ 95 RED Addendum concluded that these restrictions were no longer considered practical and required tolerances and supporting residue data. The Agency has since amended its policy on label restrictions on feeding of soybean forage and hay and now allows these label restrictions on soybean forage and hay. Residue data and tolerances for soybean forage and hay will not be required, provided all pertinent labels are amended to include the following feeding restriction on the product labels: "The feeding of treated forage or hay to livestock is prohibited."

Cereal Grain Group Barley, oats, and rye grain: There are no longer registered uses of linuron on barley, oats, and rye. Applicable tolerances have been revoked since the 2/ 95 RED Addendum.

Corn, field, grain and aspirated grain fractions: The 2/ 94 RED concluded that Griffin and Drexel must submit additional residue data for corn because Craven data were submitted to support reregistration of linuron on field corn. Craven replacement data (MRID 42948501) reflecting two different treatments, differing only in the timing of postemergence application were submitted and deemed acceptable (DP Barcode D198851, 3/ 28/ 94, D. McNeilly). The 2/ 95 RED Addendum concluded that no additional field corn grain data were required, but that field corn aspirated grain fractions data were required. Data indicate that the linuron residues of concern will not exceed the established tolerance of 0.25 ppm in/ on field corn grain harvested 57 65 days following a single preemergence application of the DF formulation at 1.5 lb ai/ A followed by a single postemergence application at 1.5 lb ai/ A for a total rate of 3.0 lb ai/ A (1x the maximum seasonal rate). Linuron residues of concern from the single preemergence plus single directed postemergence application were <0.01 0.018 ppm in/ on nine samples of field corn grain. Storage stability information for these samples was not discussed in the study review.

Data from an additional field corn grain field trial (MRID 40537601) indicate that linuron residues were nondetectable (< 0.05 ppm) to 0.06 ppm in/ on two samples of field corn grain harvested 98 and 116 days following a single postemergence application of the 4 lb/ gal FlC formulation at 1.5 lb ai/ A (1x the maximum postemergence application rate). Samples were stored frozen for up to 110 days prior to analysis, which is within the 1 year interval that linuron residues have been shown to be stable in grain crops. 43 Data from an additional field corn grain field trial (MRID 00163267) indicate that linuron residues were nondetectable (< 0.05 ppm) in/ on 31 samples of field corn grain harvested 128 150 days after planting following a single preemergence application of the DF formulation at 0.5 1.5 lb ai/ A (0.3 1x the maximum preemergence application rate). Storage stability information for these samples was submitted but was not discussed in the study review.

Corn field trial data (MRIDs 00018171, 00018206, 00018375, 00018382, and 00018450) reviewed in the 6/ 82 Reregistration Standard indicate that linuron residues were: (i) nondetectable (< 0.05 ppm) in/ on corn grain harvested 56 65 days following a single postemergence application of the WP formulation at 0.75 6.0 lb ai/ A; and (ii) nondetectable (< 0.05 ppm) in/ on corn grain harvested 116 125 days following a single preemergence application of the WP formulation at 1.5 lb ai/ A. Note: No distinction was made in the Science Chapter about the type of corn (field or sweet) that was treated. No storage stability information is available for these samples.

There are no data available for field corn aspirated grain fractions. This data requirement cannot be waived because the corn grain processing study indicated concentration of linuron residues of concern in light impurities. Aspirated grain fractions data remain outstanding.

Corn, pop, grain: There are no registered uses of linuron on popcorn. The applicable tolerance for popcorn should be revoked.

Corn, sweet (K+ CWHR): Additional data were required for sweet corn (K+ CWHR) in the 6/ 90 Update. The 2/ 94 RED and the 2/ 95 RED Addendum reiterated this data requirement. Crop field trial data for sweet corn were submitted by Griffin; these data are inadequate to fulfill reregistration requirements because of incomplete geographic representation. An additional three crop field trials must be conducted in Regions 1 (1 trial) and 5 (2 trials). In addition, because Griffin had deleted uses on sweet corn from product labels, a use on sweet corn must be proposed. Although inadequate, the field trial data indicate that linuron residues of concern were below the LOQ (< 0.01 ppm) to 0.048 ppm in/ on sweet corn K+ CWHR harvested at maturity following a single soil directed application of the 50% DF or 4 lb/ gal FlC formulation at 1.48 1.57 lb ai/ A made when sweet corn plants were at least 15 inches tall. Samples were stored frozen for up to 6 months prior to analysis; a supporting storage stability study is ongoing.

Sorghum, grain and aspirated grain fractions: The 2/ 94 RED and the 2/ 95 RED Addendum concluded that no additional field trial data are required for sorghum grain. Data reported in MRID 40537601 indicate that the linuron residues of concern were nondetectable (< 0.05 ppm) in/ on six samples of sorghum grain harvested 137 154 days following a single preplant application of the 50% DF at 0.5 0.63 lb ai/ A (0.3 0.4x the maximum preemergence application rate). Data reported in MRID 41377601 indicate that the linuron residues of concern were <0.01 0.16 ppm in/ on eight samples of sorghum grain harvested 69 98 days following a single preemergence application of the 4 lb/ gal FlC formulation at 1.5 lb ai/ A (1x the maximum preemergence application rate) followed by a single postemergence application of the 50% DF formulation at 1.0 lb ai/ A (1x the maximum postemergence 44 application rate). Samples were stored frozen up to 364 days prior to analysis, which is within the 1 year interval that linuron residues have been shown to be stable in grain crops.

Data reviewed in the 6/ 82 Reregistration Standard indicate that linuron residues of concern were <0.05 0.27 ppm in/ on sorghum grain harvested 72 111 days following a single postemergence application of a 50% WP formulation at 1.0 lb ai/ A (1x the maximum registered postemergence application rate); tolerance exceeding residues (0.27 ppm) were observed at the 72 and 74 day harvest intervals. No information pertaining to sample storage conditions and intervals is available for this study. The registrants are required to specify a preharvest interval for postemergence use on sorghum (see Directions for Use). If a PHI greater than 74 days is specified, then no increase in the sorghum grain tolerance will be required.

No data were submitted for sorghum aspirated grain fractions, however, the Agency recommended that a waiver be granted for residue data on sorghum aspirated grain fractions because residues did not concentrate in sorghum processed commodities flour or starch.

Wheat, grain and aspirated grain fractions: There are three linuron EPs (EPA Reg. Nos. 1812 245, 19713 97, and 51036 78) currently registered for use on winter wheat (drill planted) in ID, OR, and WA. The 2/ 94 RED and the 2/ 95 RED Addendum concluded that no additional field trial data are required for wheat grain. Data reported in MRID 42605901 indicate that the linuron residues of concern were nondetectable (< 0.03 ppm) in/ on two samples of wheat grain harvested 128 days following a single postemergence application of the DF formulation at 2.5 or 5.0 lb ai/ A (1.4x or 2.9x the maximum seasonal rate for areas west of the Cascade Range and 3.3x or 6.7x the maximum seasonal rate for areas east of the Cascade Range). No data are available for the current maximum rates of 1.75 lb ai/ A, for west of the Cascade Range, and 0.75 lb ai/ A, for east of the Cascade Range. Samples were stored frozen for up to 5 months prior to analysis, which is within the 1 year interval that linuron residues have been shown to be stable in grain crops.

There are no crop field trial data available for wheat aspirated grain fractions, however, no residue data for aspirated grain fractions of wheat are required because linuron is registered for use on wheat during the early vegetative stage (preemergence, early postemergence or semi dormant) and/ or before the reproduction stage begins and seed heads are formed. In addition, the requirements for a wheat processing study were waived because the magnitude of the residue study performed to obtain wheat grain for processing employed a 6.7x treatment rate and nondetectable residues (< 0.03 ppm) were observed (DP Barcode D185892, 1/ 15/ 93, R. Perfetti).

Prior to cancellation of their linuron products, Dupont proposed canceling the use on wheat in the U. S., but maintaining the tolerances for wheat commodities to support imported commodities, primarily from Canada. HED reviewed this request and concluded that additional data/ information pertaining to use patterns, export quantities, and the residue data used to support the import tolerances would be required before the Agency could recommend for any import tolerances (DP Barcode D227293, 1/ 7/ 97, C. Olinger). 45 Forage, Fodder, and Straw of Cereal Grains Group Barley, oats, and rye (forage, hay, and straw): There are no longer registered uses of linuron on barley, oats, and rye. Applicable tolerances have been revoked since the 2/ 95 RED Addendum.

Corn, field, forage and stover: The 2/ 94 RED concluded that additional residue data for field corn forage and fodder must be submitted because Craven data were submitted to support reregistration of linuron on field corn. Craven replacement data (MRIDs 42948501 and 43044101) reflecting two different treatments, differing only in the timing of postemergence application were submitted and deemed acceptable (D196857, 12/ 15/ 93, D. McNeilly and DP Barcode D198851, 3/ 28/ 94, D. McNeilly, respectively). The 2/ 95 RED Addendum concluded that no additional field trial data were required for field corn forage and fodder. Field corn forage data indicate that the linuron residues of concern will not exceed the established tolerance of 1.0 ppm in/ on field corn forage harvested 58 73 days following a single preemergence application of the DF formulation at 1.5 lb ai/ A followed by a single directed postemergence application at 1.5 lb ai/ A for a total rate of 3.0 lb ai/ A. Linuron residues of concern from the single preemergence plus single directed postemergence application were 0.023 0.54 ppm in/ on nine samples of field corn forage. Field corn fodder data indicate that the linuron residues of concern will exceed the established tolerance of 1.0 ppm in/ on field corn fodder (stover) harvested 57 65 days following a single preemergence application of the DF formulation at 1.5 lb ai/ A followed by a single directed postemergence application at 1.5 lb ai/ A for a total rate of 3.0 lb ai/ A. Linuron residues of concern from the single preemergence plus single directed postemergence application were 0.1 5.5 ppm in/ on nine samples of field corn fodder. The data for corn fodder (stover) showed five of nine samples had tolerance exceeding residues (> 1 ppm). Storage stability information for these samples was not discussed in the study review.

Data from additional field corn forage and fodder field trials (MRID 40537601) indicate that linuron residues will not exceed the established tolerance in/ on field corn forage and fodder. Linuron residues of concern were as follows: (i) 0.37 0.87 ppm in/ on three forage, silage, and whole plant samples harvested 98 116 days following a single postemergence application of the 4 lb/ gal FlC formulation at 1.5 lb ai/ A (1x the maximum postemergence application rate); (ii) 0.065 and 0.11 ppm in/ on two forage samples harvested 47 days following a single preemergence application of the 4 lb/ gal FlC formulation at 0.75 and 1.5 lb ai/ A (0.5x and 1x the maximum preemergence application rate) one day after planting; and (iii) <0.05 0.1 ppm in/ on six forage samples harvested 70 days following a single preemergence application of the 50% DF formulation at 0.5 1.65 lb ai/ A (0.4 1x the maximum preemergence application rate). Samples were stored frozen for 92 638 days prior to analysis, which is within the 2 year interval that linuron residues have been shown to be stable in leafy vegetable crops.

Data from an additional field corn grain field trial (MRID 00163267) indicate that linuron residues were nondetectable (< 0.05 ppm) in/ on 31 samples of field corn fodder harvested 128 150 days after planting following a single preemergence application of the DF formulation at 0.5 1.5 lb ai/ A (0.3 1x the maximum preemergence application rate). Storage stability information for these samples was not discussed in the study review. 46 Corn, pop, stover: There are no registered uses of linuron on popcorn.

Corn, sweet, forage and stover: The 2/ 94 RED and the 2/ 95 RED Addendum required additional data for sweet corn forage, but concluded that sweet corn fodder (stover) was no longer considered a significant livestock feed item. However, Table 1 has been updated, and HED now requires field trial data for sweet corn stover. Crop field trial data for sweet corn commodities were submitted by Griffin; these data are inadequate to fulfill reregistration requirements because of incomplete geographic representation. An additional three crop field trials must be conducted in Regions 1 (1 trial) and 5 (2 trials). In addition, because Griffin had deleted uses on sweet corn from product labels, a use on sweet corn must be proposed. Although inadequate, the field trial data indicate that linuron residues of concern were below the LOQ (< 0.01 ppm) to 2.44 ppm in/ on sweet corn forage and 0.0189 to 4.00 ppm in/ on sweet corn stover harvested at maturity following a single soil directed application of the 50% DF or 4 lb/ gal FlC formulation at 1.48 1.57 lb ai/ A made when sweet corn plants were at least 15 inches tall. Samples were stored frozen for up to 7 months prior to analysis; a supporting storage stability study is ongoing.

Sorghum, forage and stover: The 2/ 94 RED and the 2/ 95 RED Addendum concluded that no data for sorghum forage and fodder (stover) have been submitted in response to the Update. Data pertaining to residues in/ on sorghum forage and fodder (stover) following a single postemergence application of the 50% DF or 4 lb/ gal FlC formulation at the maximum registered rate remain outstanding.

Wheat, forage, hay, and straw: At the request of the Agency, Dupont previously submitted a petition (PP# 4F4293) to increase linuron tolerances on wheat straw (CBTS No. 13020, DP Barcode D197620, 3/ 9/ 94, D. McNeilly). No data were submitted or are available for wheat forage and hay. These data are required. Restrictions against the feeding of wheat forage are not considered practical, and the Agency now requires field trial data for wheat hay.

There are three linuron EPs (EPA Reg. Nos. 1812 245, 19713 97, and 51036 78) currently registered for use on winter wheat (drill planted) in ID, OR, and WA. The 2/ 95 RED Addendum concluded that no additional field trial data are required for wheat straw. Data reported in MRID 42605901 indicate that the linuron residues of concern exceeded the established tolerance of 0.5 ppm in/ on wheat straw, grown in OR, harvested 128 days following a single postemergence application of the DF formulation at 2.5 lb ai/ A (1.4x the maximum seasonal rate for areas west of the Cascade Range, and 3.3x the maximum seasonal rate for areas east of the Cascade Range). Linuron residues of concern from the single postemergence application were 0.64 and 2.0 ppm in/ on two samples of wheat straw following application at a slightly exaggerated rate (1.4x). No data are available for the current maximum rates of 1.75 lb ai/ A, for west of the Cascade Range, and 0.75 lb ai/ A, for east of the Cascade Range. Samples were stored frozen for up to 5 months prior to analysis. These data indicate that a higher tolerance is needed; a 2 ppm tolerance is recommended, as proposed in PP# 4F4293 (CB No. 16149, DP Barcode D218971, 10/ 3/ 95, S. Hummel). Alternatively to proposing a higher tolerance, the registrants may wish to conduct wheat straw field trials, in conjunction with the required 47 wheat forage and hay field trials, which reflect application to winter wheat at the current maximum registered rates.

Miscellaneous Commodities Asparagus: The 2/ 94 RED and the 2/ 95 RED Addendum concluded that additional data for asparagus reflecting application of the 4 lb/ gal FlC formulation at the maximum registered rate were required; these data were required to be submitted by linuron registrants other than Dupont. In addition, it was concluded that a higher tolerance for asparagus must be proposed.

Residue data (MRID 41452601) previously evaluated (CB Nos. 6663 and 6994, 3/ 26/ 91, R. Perfetti) were reevaluated in conjunction with the petition request (PP# 5E04464; DP Barcode D211335, 5/ 9/ 95, W. Cutchin) by IR 4 to increase the tolerance for asparagus from 3 ppm to 7 ppm. These data indicate that linuron residues of concern were 0.4 5.0 ppm in/ on asparagus harvested 1 or 2 days following four applications (one at preemergence, a second at early emergence, followed by two postemergence applications) at 1.0 lb ai/ A/ application for a total rate of 4.0 lb ai/ A (1x the maximum seasonal rate). If the maximum residue of 5.0 ppm is corrected for method recovery (74%) the maximum residue would be 6.8 ppm. Samples were stored frozen for 532 634 days prior to analysis, which is within the 2 year interval that linuron residues have been shown to be stable in leafy vegetable crops.. These data are adequate to satisfy data requirements for asparagus; the tolerance for asparagus has been increased to 7 ppm.

Cotton, seed and gin byproducts: The 2/ 94 RED and the 2/ 95 RED Addendum concluded that no additional data were required for cotton because a Federal Register Notice (3/ 4/ 92) was issued cancelling use of Dupont products on cotton. Subsequently, Griffin Corporation submitted cotton field trial data (MRID 45302201) in support of reregistration. The submitted cotton field trial data, in conjunction with field trial data reviewed previously in the 6/ 82 Reregistration Standard and Agency memorandum (CB Nos. 6663 and 6994, 3/ 26/ 91, R. Perfetti), are adequate to satisfy data requirements for cottonseed but are inadequate to satisfy data requirements for cotton gin byproducts. For the gin byproducts field trials, information describing the type of equipment used for harvesting in the machine harvest trials must be submitted. In addition, additional cotton gin byproducts field trials must be conducted, such that the requirements of GLN 860.1000 (Table 1) for gin byproducts field trials are fulfilled, or a justification for the substitution of data from field trials reflecting hand harvesting must be submitted.

Field trial data (MRID 41569901) indicate that linuron residues of concern were nondetectable (< 0.05 ppm) in/ on cottonseed harvested 76 107 days following a single postemergence broadcast application with the 4 lb/ gal FlC and 50% DF formulation to 20 inch tall cotton plants at 1.5 lb ai/ A (1x the 48 maximum registered rate). Samples were stored frozen for 524 551 days prior to analysis, which is within the 2 year interval that linuron residues have been shown to be stable in oilseeds.

Although inadequate, the submitted gin byproducts field trial data indicate that linuron residues of concern were nondetectable (< 0.01 ppm) to 8.14 ppm in/ on cotton gin products harvested 54 104 days following application of either the 50% DF or 4 lb/ gal FlC formulation as follows: (i) a single layby application at 1.48 1.58 lb ai/ A (-1x the maximum registered seasonal rate); or (ii) two split applications at 0.75 lb ai/ A/ application, for a total application rate of 1.50 1.53 lb ai/ A (-1x the maximum registered seasonal rate). Samples were stored frozen for 14 66 days prior to analysis; a supporting storage stability study is ongoing.

7. Magnitude of the Residue in Processed Food/ Feed The reregistration requirements for the magnitude of the residue in processed food/ feed are fulfilled for field corn, cotton, soybeans, and wheat. An acceptable cottonseed processing study has been submitted to satisfy the requirements identified in the the 2/ 94 RED and the 2/ 95 RED Addendum. The 2/ 94 RED and 2/ 95 RED Addendum also concluded that additional data were required to upgrade an existing potato processing study (S. Knizner, 9/ 2/ 92); these data remain outstanding.

Outstanding potato processing data are considered confirmatory; sufficient data are available to reassess tolerances and estimate dietary exposure for potato processed products.

A summary of the available data and reregistration status for each commodity is presented below.

Corn, field: The 2/ 94 RED and the 2/ 95 RED Addendum concluded that no additional data were required for the processed commodities of field corn. An acceptable field corn processing study has been submitted (MRID 42560001; DP Barcode D188001, 7/ 13/ 93, D. McNeilly). The data indicate that linuron residues of concern do not concentrate in starch, grits, meal, flour, or crude or refined oil (from both wet and dry milling) processed from field corn grain bearing trace residues following treatment at 5x. No tolerances are required for the processed commodities of field corn. Processing factors were not calculated because residues in/ on all commodities were greater than or equal to the LOD of 0.003 ppm (except starch which bore nondetectable residues) but below the LOQ (< 0.01 ppm). The processing data also indicated that linuron residues of concern in light impurities and large screenings were approximately 3x those in the RAC. Samples were stored frozen for up to 12 months prior to analysis, which is supported by 12 month storage stability data for corn grain, corn oil, and sorghum starch.

Cotton: Acceptable residue data are available for cotton processed commodities (DP Barcode D271950, 9/ 24/ 01, J. Punzi). No concentration of linuron residues of concern was observed in cotton meal, hulls, and refined oil processed from cottonseed bearing detectable linuron residues of concern. No tolerances are required for the processed commodities of cotton. Samples were stored frozen for up to 2 months prior to analysis; a supporting storage stability study is ongoing. 49 Potato: The 2/ 94 RED and the 2/ 95 RED Addendum required additional information pertaining to sample storage, the processing protocol, and the LOQ determination, as well as an explanation for low method recovery from potato chips to upgrade the study (DP Barcode D181454, 9/ 2/ 92, S. Knizner). These data remain outstanding. Although inadequate, the processing data indicate that linuron residues of concern concentrate in wet peel waste (processing factor of 5.5x), chips (2.0x), dehydrated granules (3.4x), and oven baked potatoes (2.1x) but do not concentrate in peeled potato (0.82x) or mashed potato (0.61x). Samples were stored frozen for up to 20.5 months prior to analysis, which is supported by adequate storage stability data for potatoes and its processed commodities wet peel, dry peel, dehydrated granules, and mashed potatoes.

HED had previously concluded that no tolerances for potato processed commodities would be required (DP Barcode D218971, 10/ 3/ 95, S. Hummel). The highest average residue of linuron found in field trials at the maximum rate (HAFT) is 0.07 ppm. [In another study linuron residues of concern were below the limit of quantitation of 0.14 ppm when potatoes were treated at a 2x rate. A HAFT of 0.07 ppm will be used for calculation purposes.] Using the processing factor of 3.4x and the HAFT, expected residues in potato granules would be 0.07 ppm x 3.4 = 0.24 ppm. Because this amount does not significantly exceed the reassessed potato tolerance of 0.2 ppm, no food additive tolerance is needed for granules. Because the processing factor for chips is less than that for granules, expected residues in chips would be less than those in granules.

For processed potato waste, the same HAFT is used. Residues were found to concentrate in wet peel by 5.5x. In addition to wet peel, potato processing waste may contain cull potatoes and washing water. For the purposes of calculating expected residues, it was assumed that the dry matter content of wet peels is the same as the dry matter content of potatoes (20%). Potato processing waste has a dry matter content of 12%. The expected linuron residues of concern in potato processing waste will be no more than 0.07 ppm x 5.5x x 12%/ 20% = 0.23 ppm. The resulting residue does not significantly exceed the tolerance recommended for potatoes of 0.2 ppm. Thus, no tolerance is needed for linuron residues in processed potato waste.

Sorghum, grain: HED does not currently require data for the processed commodities of sorghum. However, sorghum processing data (DP Barcode D187993, 11/ 18/ 93, D. McNeilly) submitted by Dupont indicate that linuron residues of concern do not concentrate in sorghum flour (processing factor of <0.44x) or starch (< 0.44x).

Soybean: The available soybean processing data (CBRS No. 5858, 10/ 31/ 89, C. Olinger, and DP Barcode D182595, 3/ 18/ 93, D. McNeilly) indicate that linuron residues of concern do not concentrate significantly in hulls (processing factor of 0.5x), meal (1.2x), soapstock (0.7x), crude oil (0.2x), refined oil (0.2x), degummed oil (0.2x), tofu (0.3x), light impurities (0.9x), soybean milk (0.15x), or soybean kernels (0.9x). Residues were found to concentrate in soybean isolate (1.6x) and lecithin (2.3x). Samples were stored frozen for up to 19 months prior to analysis, which is supported by adequate storage stability data for soybean oil and tofu (18 month storage interval). The Agency does not 50 currently establish tolerances for soybean isolate or lecithin. Tolerances for soybean processed commodities are not required.

Wheat: HED granted a waiver for a wheat processing study for linuron (DP Barcode D185892, 1/ 15/ 93, R. Perfetti) based on the fact that linuron residues of concern were below the LOQ (< 0.03 ppm) in/ on wheat grain treated at an exaggerated rate of 6.7x. Note the "6.7x" rate is actually 6.7x the maximum rate for areas east of the Cascade Range but only 2.9x the maximum rate for areas west of the Cascade Range (and 2.9x the maximum rate currently registered).

8. Magnitude of the Residue in Meat, Milk, Poultry, and Eggs Reregistration requirements for magnitude of the residue in meat, milk, poultry, and eggs are fulfilled. Feeding study data are available depicting linuron residues of concern in animals. There are established tolerances for linuron residues of concern in the meat, fat, and meat byproducts of cattle, goat, hog, horses, and sheep. Tolerances for linuron residues of concern in milk and poultry commodities have not been established.

The 2/ 94 RED and the 2/ 95 RED Addendum reassessed the established tolerances for meat, fat, and meat byproducts of cattle, goats, hogs, horses, and sheep at lower levels and concluded that no tolerances are required for poultry and eggs. Since the issuance of the RED and RED Addendum, crop field trial data for sweet corn forage and fodder and cotton gin byproducts have been submitted. Although additional field trial data are required for these commodities, the available data indicate that the estimated cattle dietary burden used in the 2/ 95 RED Addendum (3.1 ppm based on a diet of 50% corn grain and 50% corn fodder) is too low.

The maximum theoretical dietary burdens of linuron to beef and dairy cattle, poultry, and swine are presented in the table below. We note that these dietary burdens are estimated because additional crop field trial data are required for several feed items (sweet corn forage and fodder, cotton gin byproducts, sorghum forage and fodder, and wheat forage, hay, and straw). 51 Calculation of maximum dietary burdens of linuron to livestock Feed Commodity % Dry Matter 1 % Diet 1 Estimated Residues Levels (ppm) 2 Dietary Contribution (ppm) 3 Beef Cattle Carrot, culls 12 25 1.00 2.08 Corn, sweet, forage 48 40 3.00 4 2.50 Cotton, gin byproducts 90 20 9.00 4 2.00 Cottonseed, meal 89 15 0.10 0.017 TOTAL BURDEN 100 6.60 Dairy Cattle Carrot, culls 12 25 1.00 2.08 Corn, sweet, forage 48 50 3.00 4 3.13 Cotton, gin byproducts 90 20 9.00 4 2.00 Cottonseed, meal 89 5 0.10 0.006 TOTAL BURDEN 100 7.22 Poultry Cottonseed, meal NA 20 0.10 0.02 Sorghum, grain NA 80 0.25 0.20 TOTAL BURDEN 100 0.22 Swine Carrot, culls NA 10 1.0 0.10 Sorghum, grain NA 90 0.25 0.225 TOTAL BURDEN 100 0.325 1 Table 1 (OPPTS Guideline 860.1000).

2 Reassessed tolerance based on data from field trials. 3 Contribution = [tolerance / % DM (if cattle)] X % diet). Poultry and swine diets are not corrected for % dry matter. 4 Estimated tolerance; additional crop field trial data are required.

A summary of the available livestock feeding studies follows:

Ruminant: Several dairy cattle feeding studies were discussed in the 6/ 82 Reregistration Standard. The results of these studies are summarized in the table below. Samples were analyzed for linuron residues of concern using Method I of PAM Vol. II. The LOQ was 0.05 ppm for each matrix. 52 Dosing Summary of residues from cow feeding studies Two cows at an average of 0.15 ppm (0.02x) for 37 days to obtain tissue samples; three cows at same level to obtain milk samples No detectable residues in milk or tissues. Milk was collected every three days during dosing (MRID 00018775).

Two cows fed at an average of 0.25 ppm (0.03x) for 37 days Kidney samples bore residues of 0.06 0.07 ppm. No residues were detected in any other tissue (MRID 00018375).

One cow at an average of 0.30 ppm (0.04x) for 30 days to obtain tissue samples; another cow at same level for milk samples Detectable residues observed in liver and kidney at 0.08 and 0.09 ppm, respectively. Residues in fat, muscle, and milk were not detectable. Milk was collected every other day during dosing (MRID 00018450).

Two cows at 1.0 ppm (0.14x) for 30 days Detectable residues observed in liver and kidney at 0.36 0.50 and 0.65 0.67 ppm, respectively. Residues in milk, lean muscle, and subcutaneous fat were not detectable. Milk was collected every other day during dosing (MRID 00018209).

Two cows at 50 ppm (6.9x) for 30 days Residues were 12.0 and 13.0 ppm in kidney, 11.0 and 13.0 in liver, 0.45 and 0.48 ppm in lean muscle, and 0.48 and 1.10 ppm in subcutaneous fat. Milk residues were 0.05 0.37 ppm, with the highest value observed on Day 27 of dosing; milk samples were collected every other day during dosing (MRID 00018210).

Using the results from the feeding study at 50 ppm, expected residues at a 1x feeding level would be 1.9 ppm in liver and kidney, 0.07 ppm in muscle, 0.16 ppm in fat, and 0.05 ppm in milk. These data indicate that increased tolerances for liver and kidney are necessary but that the established tolerances for meat and fat may be reduced. A tolerance for milk must be proposed.

The estimated dietary burden in swine is much less than that for beef and dairy cattle. If the results of the exaggerated rate cattle feeding study are used, expected levels of linuron residues of concern in swine commodities would be 0.08 ppm in liver and kidney, 0.007 ppm in fat, and 0.003 ppm in muscle. Therefore, the established tolerances for hog commodities may be reduced.

Poultry: Two poultry feeding studies were discussed in the 6/ 82 Reregistration Standard. Following feeding of poultry (broilers) at 0.35 ppm (1.6x) or 1 ppm (4.5x) for 28 days, no detectable residues were observed in liver, skin, muscle, or fat; and no detectable residue were observed in tissues or eggs from laying hens fed 0.7 ppm linuron (3.2x) for 21 days (MRID 00018383). Samples were analyzed using Method I of PAM, Vol. II with an LOQ of 0.05 ppm. In addition, analysis of samples from the poultry metabolism study, in which hens were fed at 10 ppm (45x) for 5 days, using the enforcement method resulted in residues of 0.23 ppm in egg yolk, <0.01 ppm in egg white, 0.46 ppm in liver, 0.03 ppm in breast and thigh muscle, and 0.04 ppm in fat. If these levels are adjusted to a 1x feeding level, expected residues would be below 0.05 ppm. Therefore, no linuron tolerances for poultry commodities are needed. 53 9. Reduction of Residues All data for reduction of residues have been evaluated and deemed adequate except that additional information is required to upgrade existing potato and carrot cooking studies.

The asparagus cooking study shows washing with water reduces residues by 40%. Boiling removes an additional 25% of the residues, while steaming had little or no effect on reducing residue levels in or on asparagus (D182590, 3/ 18/ 93, D. McNeilly).

A carrot cooking study indicated that linuron residues of concern concentrate in peels (3.3x) but reduce after boiling (0.3x) or steaming (0.4x). Additional information pertaining to how the carrots were cooked and how the LOQs were determined is required to upgrade this study (D181455, 9/ 8/ 92, S. Knizner).

The potato cooking study shows that linuron residues concentrate in oven baked potatoes (1.5x) and microwave baked potatoes (1.6x), but are reduced in boiled potatoes (0.48x). Additional information pertaining to the cooking procedures, LOQ determination, and sample handling/ storage is required to upgrade this study (D181454, 9/ 2/ 92, S. Knizner).

10. Confined and Field Accumulation in Rotational Crops All data for nature of the residue in confined rotational crops have been evaluated and deemed adequate. The requirement for field rotational crop studies has been waived.

The registrants have several varying plantback intervals established on product labels (see Table 2). Some plantback restrictions are too general; e. g., "Do not follow treated sorghum with any fall crop, nor with sugar beets, tobacco, vegetables or potatoes in rotation." In addition, some of the plantback intervals are conflicting. For example, EPA Reg. Nos. 1812 245 and 1812 320 include the following contradictory plantback restrictions under the use directions for sorghum: "Do not follow treated sorghum with any fall crop, nor with sugar beets, tobacco, vegetables or potatoes in rotation. Sorghum or field corn may be replanted within 4 months; after 4 months any crop may be planted."

The registrants must modify all rotational crop restrictions such that specific plantback intervals are defined (e. g., do not plant any crop within 4 months of application to treated sorghum). In addition, the registrants must provide justification for any plantback intervals on the product labels. 54 E. TOLERANCE REASSESSMENT SUMMARY 1. Tolerance Reassessments for Linuron Tolerances for residues of linuron are currently expressed in terms of linuron per se. Permanent tolerances are established for linuron residues in/ on several raw agricultural commodities and animal commodities under 40 CFR §180.184( a). A tolerance with regional restriction has been established for linuron residues in/ on parsley under 40 CFR §180.184( c). The tolerance expression under 40 CFR §180.184( a) and (c) should be revised as follows: "Tolerances are established for the combined residues of the herbicide linuron (3( 3,4 dichlorophenyl) 1 methoxy 1 methylurea) and its metabolites convertible to 3,4 dichloroaniline, calculated as linuron, in or on the following raw agricultural commodities: ".

The Agency has updated the list of raw agricultural and processed commodities and feedstuffs derived from crops (Table 1, OPPTS GLN 860.1000). As a result of changes to Table 1, diuron tolerances for certain RACs which have been removed from the livestock feeds table need to be revoked. Also, some commodity definitions must be corrected. A summary of linuron tolerance reassessments is presented in Table 5.

Tolerances Listed Under 40 CFR §180.184( a):

Pending label amendments for some crops, adequate residue data have been submitted to reassess the established tolerances for the following commodities, as defined: asparagus; carrots; corn, field, fodder; corn, field, forage; corn, grain; cottonseed; parsnips; potatoes; sorghum, grain; soybeans; wheat, grain; and wheat, straw. The available data indicate that the established tolerances for field corn fodder and wheat straw must be increased, that the established tolerances for asparagus, carrots, field corn forage, sorghum grain, and soybeans are reassessed at the same level, and that the tolerances for field corn grain, cottonseed, parsnips, potatoes, and wheat grain may be reduced.

The tolerances for soybean forage and hay should be revoked, provided that all registrants modify product labels to include restrictions against the feeding of soybean forage and hay from treated plants to livestock.

Adequate feeding study data have been submitted to reassess the established tolerances for the fat, meat, and meat byproducts of cattle, goats, hogs, horses, and sheep. The feeding study data indicate that separate tolerances are required for the liver and kidney of cattle, goats, horses, and sheep. The available data also indicate that the tolerances for the fat, meat, and meat byproducts of cattle, goat, horses, and sheep may be lowered, with the modification of the meat byproducts tolerances to state "meat byproducts, exc. liver and kidney". All tolerances for hog commodities may be lowered. 55 Inadequate residue data are available to reassess the established tolerances for: celery; corn, fresh; corn, sweet, fodder; corn, sweet, forage; sorghum, fodder; sorghum, forage; wheat, forage; and wheat, hay.

The established tolerances for the following commodities should be moved to §180.184( c) because use of linuron on these crops is restricted to certain geographical areas: cottonseed, potatoes, and all wheat commodities.

Tolerances To Be Proposed Under 40 CFR §180.184( a):

The available crop field trial and feeding study data indicate that tolerances for linuron residues must be proposed for: milk; liver of cattle, goats, horses, and sheep; and kidney of cattle, goats, horses, and sheep.

Tolerances Listed Under 40 CFR §180.184( c):

Adequate data are available to reassess the established tolerance for parsley.

Tolerances To Be Proposed Under 40 CFR §180.184( c):