° Exposures were estimated for handlers using 1,200 and 350 acres per day for aerial equipment. The use of 1,200 acres treated in one day by either the mixer/ loader or the applicator is considered a reasonable high end estimate, because these crops are high acreage field crops. This maximum acres treated aerially per day is based on published scientific literature, surveys, knowledge of agricultural practices, and calculated acreage estimates. 39 ° 350 acres for aerial applications to all agricultural crops, except for cotton, and alfalfa;

° 350 acres for flaggers supporting aerial applications;

° For groundboom equipment use on high acreage crops such as cotton, small grains ( wheat, barley, and oats), alfalfa and corn, a range of 200 acres per day to 80 acres per day was used. For all other crops, 80 acres was used;

° 1000 gallons for high pressure hand wands and rights of way sprayers;

° 350 acres for chemigation;

° 40 gallons for low pressure hand wands and backpack sprayers;

° 80 acres for tractor drawn spreader;

° 5 acres for a push type spreader and backpack spreaders, 1 acre for a belly grinder and 100 square feet for granular hand and spoon application; and ° 50 gallons for airless sprayer and 5 gallons for paintbrush.

° If scenario specific data are lacking, the Agency will calculate unit exposure values using generic protection factors that are applied to represent the use of personal protective equipment ( PPE) and engineering controls. This assessment used an 80 percent protection factor applied to baseline inhalation unit exposure values to represent use of a dust/ mist respirator ( currently required on some labels).

° The duration of exposure for handlers of diuron is assumed to be mostly shortterm ( one day to one month). Intermediate term exposure ( one month to several months) for handlers is possible for large field crops, including corn, wheat, oats and cotton, because of their long planting seasons. Since only aerial and chemigation equipment, and groundboom sprayers are used to treat these crops, only the scenarios with this equipment and the supporting flagger scenario were assessed for the intermediate term. Only for the highest application rate for the four crops, cotton at 2.2 lbs ai/ acre, was assessed for the intermediate term.

° Rights of way sprayer scenarios for utility and industrial areas are assumed to be intermediate term duration, because utility workers could possibly treat rights ofway areas ( roadsides, railroads, etc) all summer long.

c. Agricultural Handler Non Cancer Risk The duration of exposure is expected to be short, and intermediate term for occupational handlers. The exposure duration for short term assessments is 1 to 30 days, while intermediate 40 term durations are 1 to 6 months. Non cancer risk estimates are expressed in terms of the Margin of Exposure ( MOE). For occupationally exposed workers, MOEs greater than or equal to 100 and are not of concern. A summary of Occupational Handler Non Cancer Risks are shown in Table 15. 41 Table 15. Diuron: Summary of Occupational Handler Non Cancer Risks Exposure Scenario Crop Type or Target Acres Treated or Gallons per Application Application Rate ( lbs a. i./ A) Inhalation MOEs Necessary Level of PPE or Engineering Controls Short Term < 7 days Intermediate Term < 30 days Occupational Mixer/ Loader Estimates for MOE 100 or Highest Achievable MOE ( 1a) Mixing/ Loading Liquids for Aerial Application Sugarcane 350 acres/ day 6 lb ai/ acre 280  Baseline Alfalfa 1200 acres/ day 3.2 lb ai/ acre 150  Baseline Cotton 350 acres/ day 2.2 lb ai/ acre  380 Minimum Cotton 1200 acres/ day 2.2 lb ai/ acre  110 Minimum ( 1b) Mixing/ Loading Liquids for Chemigation Application Sugarcane 350 acres/ day 6 lb ai/ acre 280  Baseline Cotton 350 acres/ day 2.2 lb ai/ acre  380 Minimum ( 1c) Mixing/ Loading Liquids for Groundboom Application Grapes 80 acres/ day 9.6 lb ai/ acre 760  Baseline Alfalfa 200 acres/ day 3.2 lb ai/ acre 910  Baseline Cotton 80 acres/ day 2.2 lb ai/ acre  330 Baseline Cotton 200 acres/ day 2.2 lb ai/ acre  130 Baseline ( 1d) Mixing/ Loading Liquids for Rights of Way Application Grapes 1000 gallons/ day 0.19 lb ai/ gallon 3000  Baseline Utility/ industrial areas 1000 gallons/ day 0.9 lb ai/ gallon 650  Baseline Utility/ industrial areas 1000 gallons/ day 0.9 lb ai/ gallon  320 Minimum ( 1e) Mixing/ Loading Liquids for High Pressure Handwand Application Grapes 1000 gallons/ day 0.19 lb ai/ gallon 3000 Not Applicable Baseline Utility/ industrial areas 1000 gallons/ day 0.9 lb ai/ gallon 650 Not Applicable Baseline Exposure Scenario Crop Type or Target Acres Treated or Gallons per Application Application Rate ( lbs a. i./ A) Inhalation MOEs Necessary Level of PPE or Engineering Controls Short Term < 7 days Intermediate Term < 30 days 42 ( 2a) Mixing/ Loading Dry Flowables for Aerial Application Sugarcane 350 acres/ day 6.4 lb ai/ acre 410  Baseline Alfalfa 1200 acres/ day 3.2 lb ai/ acre 240  Baseline Cotton 350 acres/ day 2.2 lb ai/ acre  120 Baseline 1200 acres/ day  180 Minimum ( 2b) Mixing/ Loading Dry Flowables for Chemigation Application Sugarcane 350 acres/ day 6.4 lb ai/ acre 410  Baseline Cotton 350 acres/ day 2.2 lb ai/ acre  120 Baseline ( 2c) Mixing/ Loading Dry Flowables for Groundboom Application Grapes 80 acres/ day 9.6 lb ai/ acre 1200  Baseline Alfalfa 1200 acres/ day 3.2 lb ai/ acre 1400  Baseline Cotton 80 acres/ day 2.2 lb ai/ acre  520 Baseline 1200 acres/ day  210 Baseline ( 2d) Mixing/ Loading Dry Flowables for Rights of Way Sprayer Application Grapes 1000 gallons/ day 0.19 lb ai/ gallon 4700  Baseline Utility/ Industrial Areas 1000 gallons/ day 0.96 lb ai/ gallon 950  Baseline  490 Minimum ( 2e) Mixing/ Loading Dry Flowables for High Pressure Handwand Application Grapes 1000 gallons/ day 0.19 lb ai/ gallon 4700  Baseline Utility/ Industrial Areas 1000 gallons/ day 0.96 lb ai/ gallon 950  Baseline Exposure Scenario Crop Type or Target Acres Treated or Gallons per Application Application Rate ( lbs a. i./ A) Inhalation MOEs Necessary Level of PPE or Engineering Controls Short Term < 7 days Intermediate Term < 30 days 43 ( 3a) Mixing/ Loading Wettable Powders for Aerial Application Sugarcane 350 acres/ day 6.4 lb ai/ acre 1300  Engineering Controls Alfalfa 1200 acres/ day 3.2 lb ai/ acre 760  Engineering Controls Cotton 350 acres/ day 2.2 lb ai/ acre  380 Engineering Controls Cotton 1200 acres/ day 2.2 lb ai/ acre  110 Engineering Controls ( 3b) Mixing/ Loading Wettable Powders for Chemigation Application Sugarcane 350 acres/ day 6.4 lb ai/ acre 1300  Engineering Controls Cotton 350 acres/ day 2.2 lb ai/ acre  380 Engineering Controls ( 3c) Mixing/ Loading Wettable Powders for Groundboom Application Grapes 80 acres/ day 9.6 lb ai/ acre 110  Minimum Alfalfa 200 acres/ day 3.2 lb ai/ acre 130  Minimum Cotton 80 acres/ day 2.2 lb ai/ acre  1700 Engineering Controls 200 acres/ day 2.2 lb ai/ acre  660 Engineering Controls ( 3d) Mixing/ Loading Wettable Powders for Rights of Way Sprayer Application Utility/ Industrial Areas 1000 gallons/ day 0.96 lb ai/ gallon 170  Maximum Grapes 1000 gallons/ day 0.19 lb ai/ gallon 420  Minimum Utility/ Industrial Areas 1000 gallons/ day 0.96 lb ai/ gallon 300 Engineering Controls Exposure Scenario Crop Type or Target Acres Treated or Gallons per Application Application Rate ( lbs a. i./ A) Inhalation MOEs Necessary Level of PPE or Engineering Controls Short Term < 7 days Intermediate Term < 30 days 44 ( 3e) Mixing/ Loading Wettable Powders for High

Pressure Handwand Applications Grapes 1000 gallons/ day 0.19 lb ai/ gallon 420  Minimum Utility/ Industrial Areas 0.96 lb ai/ gallon 170  Maximum ( 4) Loading Granulars for Tractor Drawn Spreaders Application Utility/ Industrial Areas 80 acres/ day 87.1 lb ai/ acre 300 Not Applicable Minimum Applicator ( 5) Applying Sprays for Aerial Application Sugarcane 350 acres/ day 6.4 lb ai/ acre 4600  Engineering Controls Alfalfa 1200 acres/ day 3.2 lb ai/ acre 2700  Engineering Controls Cotton 350 acres/ day 2.2 lb ai/ acre  1300 Engineering Controls 1200 acres/ day 2.2 lb ai/ acre  390 Engineering Controls ( 6) Applying Sprays for Groundboom Application Grapes 80 acres/ day 9.6 lb ai/ acre 1200  Baseline Alfalfa 200 acres/ day 3.2 lb ai/ acre 1500  Baseline Cotton 80 acres/ day 2.2 lb ai/ acre  540 Baseline 200 acres/ day 2.2 lb ai/ acre  210 Baseline Exposure Scenario Crop Type or Target Acres Treated or Gallons per Application Application Rate ( lbs a. i./ A) Inhalation MOEs Necessary Level of PPE or Engineering Controls Short Term < 7 days Intermediate Term < 30 days 45 ( 7) Applying Sprays for Rights Of Way Grapes 1000 gallons/ day 0.19 lb ai/ gallon 930  Baseline Utility/ Industrial Areas 1000 gallons/ day 0.96 lb ai/ gallon 190  Baseline Utility/ Industrial Areas 1000 gallons/ day 0.96 lb ai/ gallon  190 Maximum ( 8) Applying Sprays for High Pressure Handwand Application Grapes 1000 gallons/ day 0.19 lb ai/ acre 230 Not Applicable Minimum Utility/ Industrial Areas 1000 gallons/ day 0.96 lb ai/ acre 92 Not Applicable Maximum ( 9) Applying Granulars for Tractor Drawn Spreaders Application Utility/ Industrial Areas 80 acres/ day 87.1 lb ai/ acre 420 Not Applicable Minimum ( 10) Applying Granulars with a Spoon Industrial Areas 100 sq. feet/ day 87.1 lb ai/ acre 78000 Not Applicable Baseline ( 11) Applying Granulars for Hand Application Industrial Areas 100 sq. feet/ day 87.1 lb ai/ acre 740 Not Applicable Baseline Flagger ( 12) Flagging for Sprays Application Sugarcane 350 acres/ day 6.4 lb ai/ acre 890  Baseline Cotton 350 acres/ day 2.2 lb ai/ acre  260 Baseline Mixer/ Loader/ Applicator ( 13) Mixing/ Loading/ Applying Liquids for Low Pressure Handwand Application Industrial Areas 40 gallons/ day 0.9 lb ai/ gallon 650 Not Applicable Baseline ( 14) Mixing/ Loading/ Applying Liquids for Backpack Sprayer Application Industrial Areas 40 gallons/ day 0.9 lb ai/ gallon 650 Not Applicable Baseline ( 15) Mixing/ Loading/ Applying Wettable Powders For Low Pressure Handwand Application Industrial Areas 40 gallons/ day 0.96 lb ai/ gallon 170 Not Applicable Maximum Exposure Scenario Crop Type or Target Acres Treated or Gallons per Application Application Rate ( lbs a. i./ A) Inhalation MOEs Necessary Level of PPE or Engineering Controls Short Term < 7 days Intermediate Term < 30 days 46 ( 16) Loading/ Applying Granulars with a Pump Feed Granular Spreader Industrial Areas 5 acres/ day 87.1 lb ai/ acre 380 Not Applicable Baseline ( 17) Loading/ Applying Granulars with Gravity Feed Backpack Spreader Industrial Areas 5 acres/ day 87.1 lb ai/ acre 180 Not Applicable Minimum ( 18) Loading/ Applying Granulars for Belly Grinder Application Industrial Areas 1 acres/ day 87.1 lb ai/ acre 130 Not Applicable Baseline ( 19) Loading/ Applying Granulars for Push type Spreader Application Industrial Areas 5 acres/ day 87.1 lb ai/ acre 210 Not Applicable Baseline a Crops named are index crops which are chosen to represent all other crops at or near that application rate for that use.

See the application rates listing in the use summary section of this document for further information on application rates used in this assessment.

b Application rates are based on the maximum application rates listed on the marketed diuron labels c Amount handled per day from Science Advisory Council on Exposure's Policy # 9.1 d Short term MOE = Short term NOAEL ( mg/ kg/ day) / Daily Inhalation Dose ( mg/ kg/ day)

e Baseline: long pants, long sleeved shirt shoes and socks ( no respirator)

f Minimum PPE: baseline plus dust mist respirator g Maximum PPE: baseline plus organic vapor respirator h Engineering controls: closed mixing/ loading, enclosed cab, truck, or cockpit.

See the appendix, Tables A, B, C, and D for the inputs and dermal and inhalation does calculations.

 Scenario's calculated MOE exceeds the target MOE at the previous level of mitigation.

( MOE > 100), NF = Not feasible for this scenario ( no available engineering controls). 47 d. Agricultural Handler Cancer Risk Cancer risk estimates are presented as a probability of developing cancer. The cancer handler exposure scenarios are identical to those assessed in the noncancer handler assessment. However, it should be noted that the cancer assessment assumes 4 percent dermal absorption since exposures may be of duration longer than six months. A 28 day dermal toxicity study showed no adverse effects from diuron up to the limit dose of 1200 mg/ kg/ day. To assess cancer risk, a total daily dose, a lifetime daily dose and a total cancer risk are calculated. The total daily dose is calculated to include both dermal and inhalation exposure ( dermal dose includes dermal absorption since an oral cancer endpoint was used) and used a Q 1*= 1.91 x 10 2 ( mg/ kg/ day) 1 in human equivalents. For occupational risks between 1x10 6 and 1x10 4, the Agency will pursue risk mitigation where feasible and cost effective to reduce the risks to 1x10 6 or less.

The assessment assumed that the average lifetime is 70 years, exposure duration is 35 years, and that the exposures per year are: 10 days per year for the private grower and 30 days per year for a commercial applicator. Maximum application rates were used in the private grower assessment. Typical application rates were used in both the private grower and commercial applicator assessments. It was assumed that as the frequency of exposure increased, the probability of being exposed to a maximum application rate would decrease. Therefore, maximum application rates were not assessed for the commercial applicator. Tables 16 and 17 summarize the cancer risks associated with the handling of diuron for the baseline, maximum PPE and engineering control level of mitigation for commercial and private farmers, respectively. In general, the Agency is concerned when occupational cancer risk estimates exceed 1 x 10 4. The Agency will seek ways to mitigate the risks, to the extent that it is practical and economically feasible, to lower the risks to 1 x 10 6 or less.

Five of the assessed scenarios have cancer risks greater than 1 x 10 4 at the highest feasible level of mitigation ( private farmer/ commercial applicator, typical/ max rate) and are of concern. Twenty six of the scenarios have cancer risks between 1 x 10 4 and 1 x 10 6 at the highest feasible level of mitigation ( private farmer/ commercial applicator, typical/ max rate).

Table 16. Diuron: Summary of Occupational Handler Cancer Risks for Commercial Applicators Diuron: Occupational Handler Cancer Risk Estimates Commercial Applicator/ 30 Exposures Per Year/ Typical Application Rate Exposure Scenario Cancer Risk Baseline ( single layer) Cancer Risk ( double layer + gloves + half face respirator w/ P 95 filter) Cancer Risk Engineering Controls Mixer/ Loader ( 1a) Mixing/ Loading Liquids for Aerial Application 1.8 E 3  3.9 E 3 1.3 E 5  2.7 E 5 6.7 E 6  1.4 E 5 ( 1b) Mixing/ Loading Liquids for Chemigation Application 1.8 E 3 1.3 E 5 6.7 E 6 Diuron: Occupational Handler Cancer Risk Estimates Commercial Applicator/ 30 Exposures Per Year/ Typical Application Rate Exposure Scenario Cancer Risk Baseline ( single layer) Cancer Risk ( double layer + gloves + half face respirator w/ P 95 filter) Cancer Risk Engineering Controls 48 ( 1c) Mixing/ Loading Liquids for Groundboom Application 4.2 E 4  6.6 E 4 2.9 E 6  4.5 E 6 1.5 E 6  2.4 E 6 ( 1d) Mixing/ Loading Liquids for Rights of Way Application 8.4 E 5  1.2 E 3 5.7 E 7  8.1 E 6 3.1 E 7  4.3 E 6 ( 1e) Mixing/ Loading Liquids for High Pressure Handwand Application 8.4 E 5  1.2 E 3 5.7 E 7  8.1 E 6 3.1 E 7  4.3 E 6 ( 2a) Mixing/ Loading Dry Flowable for Aerial Application 5.4 E 5  1.2 E 4 3.1 E 5  6.6 E 5 1.1 E 6  2.3 E 6 ( 2b) Mixing/ Loading Dry Flowable for Chemigation Application 5.4 E 5 3.1 E 5 1.1 E 6 ( 2c) Mixing/ Loading Dry Flowable for Groundboom Application 1.2 E 5  1.9 E 5 7.0 E 6  1.1 E 5 2.4 E 7  3.8 E 7 ( 2d) Mixing/ Loading Dry Flowable for Rights of Way Sprayer Application 2.5 E 6  3.7 E 5 1.4 E 6  2.1 E 5 4.8 E 8  7.2 E 7 ( 2e) Mixing/ Loading Dry Flowable for High Pressure Handwand Application 2.5 E 6  3.7 E 5 1.4 E 6  2.1 E 5 4.8 E 8  7.2 E 7 ( 3a) Mixing/ Loading Wettable Powders for Aerial Application 3.0 E 3  6.4 E 3 1.5 E 4  3.2 E 4 9.9 E 6  2.1 E 5 ( 3b) Mixing / Loading of Wettable Powders for Chemigation Application 3.0 E 3 1.5 E 4 9.9 E 6 ( 3c) Mixing/ Loading of Wettable Powders for Groundboom Application 6.9 E 4  1.1 E 3 3.4 E 5  5.3 E 5 2.3 E 6  3.5 E 6 ( 3d) Mixing/ Loading Wettable Powders for Rights of Way Sprayer Application 1.4 E 4  2.1 E 3 6.8 E 6  1.0 E 4 4.5 E 7  6.8 E 6 ( 3e) Mixing/ Loading Wettable Powders for High Pressure Handwand Application 1.4 E 4  2.1 E 3 6.8 E 6  1.0 E 4 4.5 E 7  6.8 E 6 ( 4) Loading Granular Formulation For Tractor Drawn Spreader Application 1.6 E 4 2.4 E 5 3.2 E 6 Applicator ( 5) Applying Sprays Aerially See Engineering Controls See Engineering Controls 4.2 E 6  9.0 E 6 ( 6) Applying Sprays with Groundboom 4.7 E 6  7.3 E 6 1.8 E 6  2.9 E 6 8.7 E 7  1.4 E 6 ( 7) Applying with a Rights of Way Sprayer 4.0 E 5  6.0 E 4 8.6 E 6  1.3 E 4 NF ( 8) Applying with a High Pressure Handwand 1.1 E 4  1.6 E 3 1.6 E 5  2.4 E 4 NF ( 9) Applying Granular Formulations with a Tractor Drawn Spreader 1.3 E 4 2.3 E 5 2.4 E 5 ( 10) Applying Granulars with a Spoon 2.8 E 7 2.0 E 7 NF ( 11) Applying Granulars by Hand 7.4 E 5 3.7 E 5 NF Flagger Diuron: Occupational Handler Cancer Risk Estimates Commercial Applicator/ 30 Exposures Per Year/ Typical Application Rate Exposure Scenario Cancer Risk Baseline ( single layer) Cancer Risk ( double layer + gloves + half face respirator w/ P 95 filter) Cancer Risk Engineering Controls 49 ( 12) Flagging for Spray Application 1.2 E 5 6.8 E 6 2.5 E 7 Mixer/ Loader/ Applicator ( 13) Mixing/ Loading/ Applying Liquids using Low Pressure Handwand 1.6 E 3 7.2 E 6 NF ( 14) Mixing/ Loading/ Applying Liquids using Backpack Sprayer 5.3 E 5 2.7 E 5 NF ( 15) Mixing/ Loading/ Applying Wettable Powder Formulations using Low Pressure Handwand 6.2 E 4 1.5 E 4 NF ( 16) Loading/ Applying Granulars using a Pump Feed Backpack Spreader 4.0 E 5 2.4 E 5 NF ( 17) Loading/ Applying Granulars using a Gravity Feed Backpack Spreader 3.3 E 4 1.6 E 4 NF ( 18) Loading/ Applying Granulars with a Belly Grinder 4.5 E 4 3.1 E 4 NF ( 19) Loading/ Applying Granules using a Push type Spreader 1.1 E 4 1.7 E 5 NF NF = Not feasible 50 Table 17. Diuron: Summary of Occupational Handler Cancer Risks for Private Farmer Diuron: Handler Risk Estimates for Cancer Private Farmer/ 10 Exposures Per Year Exposure Scenario Typical Application Rate Maximum Application Rate Cancer Risk Baseline ( i. e.,

single layer) Cancer Risk ( double layer +

gloves + respirator) Cancer Risk Engineering Controls Cancer Risk Baseline ( i. e.,

single layer) Cancer Risk ( double layer +

gloves + respirator) Cancer Risk Engineering Controls Mixer / Loader ( 1a) Mixing/ Loading Liquids for Aerial Application 6.1 E 4  1.3 E 3 4.2 E 6  9.0 E 6 2.2 E 6  4.8 E 6 9.2 E 4  1.7 E 3 6.3 E 6  1.2 E 5 6.1 E 6  3.4 E 6 ( 1b) Mixing/ Loading Liquids for Chemigation Application 6.1 E 4 4.2 E 6 2.2 E 6 9.2 E 4 6.3 E 6 3.4 E 6 ( 1c) Mixing/ Loading Liquids for Groundboom Application 1.4 E 4  2.2 E 4 9.6 E 7  1.5 E 6 5.1 E 7  8.0 E 7 2.8 E 4  3.4 E 4 1.9 E 6  2.3 E 6 1.0 E 6  1.2 E 6 ( 1d) Mixing/ Loading Liquids for Rights of Way Application 2.8 E 5  3.9 E 4 1.9 E 7  2.7 E 6 1.0 E 7  1.4 E 6 8.4 E 5  3.9 E 4 5.7 E 7  2.7 E 6 3.1 E 7  1.4 E 6 ( 1e) Mixing/ Loading Liquids for High Pressure Handwand Application 2.8 E 5  3.9 E 4 1.9 E 7  2.7 E 6 1.0 E 7  1.4 E 6 8.4 E 5  3.9 E 4 5.7 E 7  2.7 E 6 3.1 E 7  1.4 E 6 ( 2a) Mixing/ Loading Dry Flowable for Aerial Application 1.8 E 5  3.8 E 5 1.0 E 5  2.2 E 5 3.5 E 7  7.5 E 7 2.9 E 5  4.9 E 5 1.6 E 5  2.8 E 5 5.6 E 7  9.6 E 7 ( 2b) Mixing/ Loading Dry Flowable for Chemigation Application 1.8 E 5 1.0 E 5 3.5 E 7 2.9 E 5 1.6 E 5 5.6 E 7 ( 2c) Mixing/ Loading Dry Flowable for Groundboom Application 4.1 E 6  6.4 E 6 2.3 E 6  3.7 E 6 8.0 E 8  1.3 E 7 8.2 E 6  9.8 E 6 4.7 E 6  5.6 E 6 1.3 E 7  1.9 E 7 ( 2d) Mixing/ Loading Dry Flowable for Rights of

Way Sprayer Application 8.2 E 7  1.2 E 5 4.7 E 7  7.0 E 6 1.6 E 8  2.4 E 7 2.5 E 6  1.2 E 5 1.4 E 6  7.0 E 6 4.8 E 8  2.4 E 7 ( 2e) Mixing/ Loading Dry Flowable for High

Pressure Handwand Application 8.2 E 7  1.2 E 5 4.7 E 7  7.0 E 6 1.6 E 8  2.4 E 7 2.5 E 6  1.2 E 5 1.4 E 6  7.0 E 6 4.8 E 8  2.4 E 7 Diuron: Handler Risk Estimates for Cancer Private Farmer/ 10 Exposures Per Year Exposure Scenario Typical Application Rate Maximum Application Rate Cancer Risk Baseline ( i. e.,

single layer) Cancer Risk ( double layer +

gloves + respirator) Cancer Risk Engineering Controls Cancer Risk Baseline ( i. e.,

single layer) Cancer Risk ( double layer +

gloves + respirator) Cancer Risk Engineering Controls 51 ( 3a) Mixing/ Loading Wettable Powders for Aerial Application 10.0 E 4  2.1 E 3 5.0 E 5  1.1 E 4 3.3 E 6  7.1 E 6 1.6 E 3  2.7 E 3 8.0 E 5  1.4 E 4 5.3 E 6  9.1 E 6 ( 3b) Mixing / Loading of Wettable Powders for Chemigation Application 1.0 E 3 5.0 E 5 3.3 E 6 1.6 E 3 8.0 E 5 5.3 E 6 ( 3c) Mixing/ Loading of Wettable Powders for Groundboom Application 2.3 E 4  3.6 E 4 1.1 E 5  1.8 E 5 7.6 E 7  1.2 E 6 4.6 E 4  5.5 E 4 2.3 E 5  2.7 E 5 1.5 E 6  1.8 E 6 ( 3d) Mixing/ Loading Wettable Powders for Rights of Way Sprayer Application 4.6 E 5  6.9 E 4 2.3 E 6  3.4 E 5 1.5 E 7  2.3 E 6 1.4 E 4  6.9 E 4 6.8 E 6  3.4 E 5 4.5 E 7  2.3 E 6 ( 3e) Mixing/ Loading Wettable Powders for High

Pressure Handwand Application 4.6 E 5  6.9 E 4 2.3 E 6  3.4 E 5 1.5 E 7  2.3 E 6 1.4 E 4  6.9 E 4 6.8 E 6  3.4 E 5 4.5 E 7  2.3 E 6 ( 4) Loading Granular Formulation For Tractor

Drawn Spreader Application 5.3 E 5 8.0 E 6 1.1 E 6 5.3 E 5 8.0 E 6 1.1 E 6 Applicator ( 5) Applying Sprays Aerially See Engineering Controls See Engineering Controls 1.4 E 6  3.0 E 6 See Engineering Controls See Engineering Controls 2.2 E 6  3.9 E 6 ( 6) Applying Sprays with Groundboom 1.6 E 6  2.4 E 6 6.2 E 7  9.6 E 7 2.9 E 7  4.5 E 7 3.1 E 6  3.7 E 6 1.2 E 6  1.5 E 6 5.8 E 7  7.0 E 7 ( 7) Applying with a Rights of Way Sprayer 1.3 E 5  2.0 E 4 2.9 E 6  4.3 E 5 NF 4.0 E 5  2.0 E 4 8.6 E 6  4.3 E 5 NF ( 8) Applying with a High Pressure Handwand 3.6 E 5  5.4 E 4 5.3 E 6  8.0 E 5 NF 1.1 E 4  5.2 E 4 1.6 E 5  8.0 E 5 NF ( 9) Applying Granular Formulations with a Tractor Drawn Spreader 4.2 E 5 7.5 E 6 7.9 E 6 4.2 E 5 7.5 E 6 7.9 E 6 ( 10) Applying Granulars with a Spoon 9.3 E 8 2.0 E 7 NF 9.3 E 8 2.0 E 7 NF ( 11) Applying Granulars by Hand 2.5 E 5 1.2 E 5 NF 2.5 E 5 1.2 E 5 NF Diuron: Handler Risk Estimates for Cancer Private Farmer/ 10 Exposures Per Year Exposure Scenario Typical Application Rate Maximum Application Rate Cancer Risk Baseline ( i. e.,

single layer) Cancer Risk ( double layer +

gloves + respirator) Cancer Risk Engineering Controls Cancer Risk Baseline ( i. e.,

single layer) Cancer Risk ( double layer +

gloves + respirator) Cancer Risk Engineering Controls 52 Flagger ( 12) Flagging for Spray Application 4.1 E 6 2.3 E 6 8.3 E 8 6.6 E 6 3.6 E 6 1.3 E 7 Mixer/ Loader/ Applicator ( 13) Mixing/ Loading/ Applying Liquids using Low Pressure Handwand 5.4 E 4 2.4 E 6 NF 5.4 E 4 2.4 E 6 NF ( 14) Mixing/ Loading/ Applying Liquids using Backpack Sprayer 1.8 E 5 9.0 E 6 NF 1.8 E 5 9.0 E 6 NF ( 15) Mixing/ Loading/ Applying Wettable Powder Formulations using Low Pressure Handwand 2.1 E 4 5.1 E 5 NF 2.1 E 4 5.1 E 5 NF ( 16) Loading/ Applying Granulars using a Pump Feed Backpack Spreader 1.3 E 5 7.8 E 6 NF 1.3 E 5 7.8 E 6 NF ( 17) Loading/ Applying Granulars using a Gravity Feed Backpack Spreader 1.1 E 4 5.4 E 5 NF 1.1 E 4 5.4 E 5 NF ( 18) Loading/ Applying Granulars with a Belly Grinder 1.5 E 4 7.6 E 5 NF 1.5 E 4 7.6 E 5 NF ( 19) Loading/ Applying Granules using a Push type Spreader 3.5 E 5 5.5 E 6 NF 3.5 E 5 5.5 E 6 NF NF = Not feasible 53 e. Handler Exposure from Antimicrobial Use: Mildewcide in Paints, Stains, Solvents, Adhesives, and Coatings Diuron is used as a mildewcide in paints, solvents, adhesives, stains, polymer latices, plaster, stuccos, sealants, caulking, fillers, and coatings. These products are formulated as a flowable concentrate, a tablet, an emulsifiable concentrate, and a paste form. These pesticide products are incorporated into paint at 0.20 to 2.5 percent during the initial phase of the manufacturing process.

For the antimicrobial use of diuron, EPA considers both " primary" and " secondary" handler exposure. The primary handlers are defined as those individuals exposed to the formulated product ( i. e., adding the diuron product into vats of paint during its manufacturing). The secondary handlers are defined as those individuals exposed to the active ingredient as a direct result of its incorporation into an end use product ( i. e., individuals using the caulk or paint that in itself is not a registered product). The Agency has identified and assessed the primary handlers as those individuals who mix and load diuron formulation at the manufacturing facility for use as a mildewcide in adhesives, caulks, sealants, and paints. The secondary handlers are commercial applicators who apply adhesives, caulks, sealants, and paints.

No handler exposure data have been submitted to determine the extent of these exposures. The Agency assessed the risks to the primary handlers using the dermal and inhalation exposure data for loading liquids and tablet formulations from the proprietary Chemical Manufacturers Association ( CMA) antimicrobial exposure study. No unit exposure data exists to assess the mixing and loading of the paste formulation into paint. It is assumed that this exposure would be similar to mixing and loading liquids into paint products. Two primary handler exposure scenarios have been identified and include:

( 1) Mixing/ Loading liquids ( 2) Mixing/ loading tablets In addition to the primary handlers, secondary handlers are assessed using an airless sprayer and a paint brush. Unit exposure data used to assess the exposure resulting from applying paint containing diuron with an airless sprayer and a paintbrush were taken from a previous chlorothalonil risk assessment. These data were merged with data contained in PHED to increase the number of replicates and the quality of the unit exposure data. The surrogate data are assumed to be representative of the exposure from the use of diuron using the same equipment, since the two chemicals are formulated together in three out of the four currently registered diuron paint products. The clothing and PPE scenarios for each type of exposure reflect the clothing and PPE worn in the study from which the unit exposure values were derived. Although there is potential exposure during the application of the other treated materials ( e. g., caulks and sealants), they are not included because no data are available to assess the uses. Although it is reasonable to assume that the exposure from these uses would be no greater than the exposure from use of diuron treated paints. There is also potential for exposure from applying paint with a 54 roller. The Agency believes that the airless sprayer and paintbrush scenarios represent the high end exposures for diuron antimicrobial secondary uses. Two secondary handler exposure scenarios have been identified and include:

( 3) Applying paints with an airless sprayer, and ( 4) Applying paints with a paint brush.

Assumptions for the Antimicrobial Assessment:

The following additional assumptions were used in this assessment:

° Application rates  The concentration of diuron is in the paint, caulking, and other products is 0.2 to 2.5 percent. The maximum amount of diuron per gallon of paint is 0.0532 lbs ai/ gallon paint.

° Amount handled  The amount of general preservatives treated per day is 100 to 1000 gallons for treated paint. The amount of paint used in the secondary exposure scenarios is 50 gallons for commercial airless sprayers and five gallons of paint for commercial painters using paint brushes/ rollers.

° CMA exposure data  The CMA data for liquid products are based on transferring liquids from large containers to smaller containers for measuring and pouring. These products were applied from five to 78 minutes per application during metal cutting operations. Gloves were worn for all eight of the replicates. The CMA data for solid place ( tablets, water soluble packets) had only one replicate for tablets. Again, the data used the metal fluid from a metal cutting operation. The tableted solid place data is considered low quality since there is only one replicate. No other data on adding tablets to paint or during other anti microbial uses exists.

° In addition to diuron's mildewcide use in paints and stains, it is also used in plaster, stuccos, sealants, caulking, and fillers. Unit exposure data only exist for the use of paints/ stains with airless sprayer and paintbrush. These exposure scenarios are assumed to have a higher exposure than use of diuron in plaster, stucco, sealants, caulking and fillers, since less material would be applied in a day. Therefore, the paint/ stain assessment will also be considered an estimate of the exposure resulting from the use of diuron in plaster, stucco, sealants, caulking, and fillers.

° Exposure frequency  The industrial and commercial painter exposure scenarios are believed to have a short ( one to 30 days) and intermediate term ( one month to 180 days) exposure duration. It is assumed that diuron would only be mixed into paint every other week, five days a week. This type of intermittent exposure frequency is not considered a chronic exposure scenario ( greater then 180 days) because diuron is not believed to be used continuously for at least 180 days and urinary and fecal excretion of diuron is nearly 55 complete within 24 hours at low dose groups( 10 mg/ kg/ day) and within 48 hours within high dose groups ( 400 mg/ kg/ day) in the rat metabolism study.

° For the cancer risk assessment, workers handling diuron in the industrial setting ( mixing diuron into paints) are assumed to be exposed to diuron in paints 125 days per year ( 50 weeks worked/ year x 0.5 " every other week" x 5 days/ week) and commercial painters applying diuron treated paint are assumed to be exposed 50 days per year ( only in paints needing mildewcide and less than one percent of all paint is treated with diuron).

f. Handler Risk from Antimicrobial Use: Mildewcide in Paints, Stains, Solvents, Adhesives, and Coatings The following scenarios have cancer risks between 1 x 10 4 and 1 x 10 6 at the assessed level of mitigation:

° Mixing/ loading of liquids into paint products;

° Loading of tablets into paint products;

° Applying paints with an airless sprayer; and ° Applying paints with a paint brush.

Usage information gathered subsequent to the risk assessment indicates that less than 1% of all paint contains diuron. All scenarios were assessed at the maximum rate of application. Because conservative assumptions were used to develop this assessment and it is unlikely that paint containing diuron would be applied for 35 years. Because the Agency believes a 35 year exposure to diuron treated paint is unlikely and believes the risks to workers applying paints with an airless sprayer is not of concern. Tables 18 and 19 summarize the non cancer and cancer risks, respectively from the antimicrobial use of diuron. 56 Table 18. Non Cancer Risks from Short and Intermediate term Antimicrobial Uses of Diuron Exposure Scenario ( Scenario #) Clothing Attire Inhalation Unit Exposure (

g/ lb ai) a Max Application Rateb ( lb ai/ gal) Amount Treatedc Short term Inhalation MOEd, e Intermediate. term Inhalation MOEd, e Primary Handlers ( 1) Mixing/ loadin g of Liquids into Paint Products Open pour, long pants, long sleeved shirt, chemical resistant gloves, and a 5 fold PF dust/ mist type respirator 1.7 0.0532 100 gal 77000 7700 1,000 gal 7700 770 ( 2) Loading of Tablets into Paint Products 11.8 0.0532 100 gallons 11000 1100 1,000 gal 1100 110 Secondary Handlers ( 3) Applying Paints with an Airless Sprayer Indoor Long pants, long sleeved shirt, and a 5 fold PF dust/ mist type respirator 470 0.0532 50 gallons 560 56 Long pants, long sleeved shirt, gloves, and a 5 fold PF dust/ mist type respirator 470 560 56 Outdoor Long pants, long sleeved shirt, and a 5 fold PF dust/ mist type respirator 86.6 0.0532 50 gallons 3000 300 Long pants, long sleeved shirt, gloves, and a 5 fold PF dust/ mist type respirator 86.6 3000 300 ( 4) Applying Paints with a Paint Brush Long pants, long sleeved shirt, and a 5 fold PF dust/ mist type respirator 101 0.0532 5 gallons 26000 2600 Footnotes: a Inhalation unit exposures are from CMA and Chlorothalonil studies. b Application rates are based on diuron paint labels c Amount treated is based on assumptions from EPA's Antimicrobial Division and HED Expo SAC Policy # 9.1.9 d Inhalation dose ( mg/ kg/ day) = [ unit exposure (

g/ lb ai) * 0.001 mg/

g unit conversion * max appl rate ( lb ai/ gal) * gallons handled] / Body weight ( 70 kg). e MOE = NOAEL ( mg/ kg/ day) / Daily Dose [ Short term inhalation NOAEL= 10 mg/ kg/ day, Intermediate term inhalation NOAEL = 1.0 mg/ kg/ day]. Target MOE is 100 for occupational/ commercial. 57 Table 19. Diuron Cancer Assessment for Antimicrobial Uses Exposure Scenario Clothing Maximum Application Ratea ( lb ai/ gal) Amount Treatedb Total Absorbed Dose ( mg/ kg/ day) c LADD ( mg/ kg/ day) d Riske Primary Handlers ( 125 day/ year)

( 1) Mixing/ loading of Liquids into Paint Products Open pour, long pants, long sleeved shirt, chemical resistant gloves, and a 5 fold PF dust/ mist type respirator 0.0532 100 gal 6.9 E 4 1.2 E 4 2.3 E 6 1,000 gal 6.9 E 3 1.2 E 3 2.3 E 5 ( 2) Loading of Tablets into Paint Products 0.0532 100 gallons 2.1 E 3 3.7 E 4 7.0 E 6 1,000 gallons 2.1 E 2 3.7 E 3 7.0 E 5 Secondary Handlers ( 50 day/ year)

( 3) Applying Paints with an Airless Sprayer Indoor Long pants, long sleeved shirt, and a 5 fold PF dust/ mist type respirator 0.0532 50 gallons 7.3 E 2 5.0 E 3 9.5 E 5 Long pants, long sleeved shirt, gloves, and a 5 fold PF dust/ mist type respirator 3.6 E 2 2.5 E 3 4.7 E 5 Outdoor Long pants, long sleeved shirt, and a 5 fold PF dust/ mist type respirator 0.0532 50 gallons 5.4 E 2 3.7 E 3 7.1 E 5 Long pants, long sleeved shirt, gloves, and a 5 fold PF dust/ mist type respirator 1.7 E 2 1.1 E 3 2.2 E 5 Exposure Scenario Clothing Maximum Application Ratea ( lb ai/ gal) Amount Treatedb Total Absorbed Dose ( mg/ kg/ day) c LADD ( mg/ kg/ day) d Riske 58 ( 4) Applying Paints with a Paint Brush Long pants, long sleeved shirt, and a 5 fold PF dust/ mist type respirator 0.0532 5 gallons 4.4 E 2 3.0 E 3 5.8 E 5 a Application rates are based on diuron paint labels b Amount treated is based on assumptions from EPA's Antimicrobial Division and HED Expo SAC Policy # 9.1.9 c Total daily absorbed dose ( mg/ kg/ day) = [( dermal dose ( mg/ lb ai) * dermal absorption ( 4%)+ inhalation dose ( mg/ lb ai)]. See Table 6 for the corresponding dermal dose and inhalation dose. d LADD ( Lifetime average daily dose) mg/ kg/ day = Total daily absorbed dose ( mg/ kg/ day) * ( days worked per year/ 365 days per year) * ( 35 years worked/ 70 year lifetime). Days worked per year are estimates. e Risk = LADD ( mg/ kg/ day) * Q 1 * = 1.91e 2 ( mg/ kg/ day g. Handler Exposures: Algaecide Use for Use in Commercial Fish Ponds Occupational risk assessments were conducted for the use of diuron as an algaecide in commercial fish ponds. Four short term occupational handler scenarios were identified for the use of diuron in commercial fish production and the inhalation MOEs from all four of the commercial fish production scenarios were greater than 100 at the baseline level of mitigation and are not of concern.

Diuron is used as an algaecide in the commercial production of ornamental fish, bait fish, and catfish. For these uses, there are two state labels ( FL99000200 and AR99000800), a section 18, and several other Griffin labels pending approval.

Based on the use patterns of diuron as an algaecide, four occupational exposure scenarios were identified:

( 1a) Mixing/ loading dry flowables for catfish production; ( 1b) Mixing/ loading dry flowables for ornamental fish production; ( 2a) Mixing/ loading wettable powders for catfish production; and ( 2b) Mixing/ loading wettable powders for ornamental fish production.

The assumptions used for catfish production in this assessment are assumed to be applicable to ornamental fish production as well, since no other data exist at this time. They are:

° Use instructions:

Weigh the correct amount of Diuron 80W into a five gallon bucket and fill the bucket half full with pond water. Stir the contents of the bucket. Pour the contents of the stirred 59 bucket into the outflow side of the aerator and rinse the bucket in the pond water. Operate the aerator for one hour after the addition of the Diuron 80W to the pond.

° The Agency assumed an average pond size of 15 acres, 4 feet deep, with 20 ponds per farm ( no more than 25% would be expected to be treated per day). The assumptions on pond size and numbers of ponds per farm are based on telephone conversations between EPA staff ( Pilot Interdisciplinary Risk Assessment Team) and contacts at Auburn and Mississippi State Universities in 1996.

° For commercial fish ponds treated with wettable powders, the application rates were calculated as follows. Diuron 80W, for use in catfish ponds, may be applied at a rate of 0.5 oz/ acre ft ( 0.025 lb ai/ acre ft) every seven days for a total of 9 applications. Therefore, it was estimated that handlers would mix up to 7.5 lb ai/ day ( 15 acres/ pond x 4 ft x 5 ponds/ day x 0.025 lb ai/ acre foot = 7.5 lb ai/ day). The label AR99000800, for use in ornamental fish ponds, states an application rate of 1.0 oz/ acre ft ( 0.05 lbs ai/ acre ft). Therefore it was estimated that handlers would mix up to 15.0 lbs ai/ day ( 15 acres/ pond x 4 ft x 5 ponds/ day x 0.050 lb ai/ acre foot = 15.0 lb ai/ day).

° For commercial fish ponds treated with dry flowables, the application rates were calculated as follows. The Nautillus Aquatic Herbicide label, for use in catfish ponds, states that it may be applied at a rate of 0.5 oz/ acre ft ( 0.025 lb ai/ acre ft) every seven days for a total of 9 applications. Therefore, it was estimated that handlers would mix up to 7.5 lb ai/ day ( 15 acres/ pond x 4 ft x 5 ponds/ day x 0.025 lb ai/ acre foot = 7.5 lb ai/ day). The label FL99000200, for use in ornamental fish ponds, states an application rate of 0.0038 grams ai/ gallon ( 2.73 lbs ai/ acre ft), applied up to three times a year. Therefore, it was estimated that handlers would mix up to 819 lbs ai/ day ( 15 acres/ pond x 4 ft x 5 ponds/ day x 2.73 lb ai/ acre foot = 819 lb ai/ day).

° Unit exposure data from PHED were used to assess the mixing and loading of wettable powders and dry flowables into commercial fish ponds. 60 h. Handler Risks: Algaecide Use for Use in Commercial Fish Ponds With maximum PPE, ( long pants, long sleeved shirt, socks, shoes, coveralls, gloves, and respirator) all four scenarios have estimated cancer risks of that range from 1.8 x 10 6 to 4.94 x 10 8 and are not of concern. Occupational postapplication exposure to diuron in treated fish production ponds is not likely to result in a risk of concern based on the extremely high dilution rate.

i. Postapplication Occupational Risk Occupational Non Cancer Postapplication Exposure and Risk Estimates It should be noted that a non cancer postapplication assessment was not conducted since no systemic toxicity by the dermal route is expected for the short or intermediate term durations and no post application inhalation exposure is expected.

Occupational Cancer Postapplication Agricultural Exposure Only crops that can receive direct foliar treatments were assessed for postapplication risks. These crops are not damaged by foliar treatments of diuron. Many of the applications of diuron are soil directed or pre plant, since the application of diuron to most of the registered crops would result in plant damage. The crops assessed are oats; forage; oats, grain; oats, hay; oats, straw; wheat, forage; wheat, grain; wheat, hay; wheat straw; birdsfoot trefoil, forage; birdsfoot trefoil, hay; grass, forage, except Bermuda grass; grass, hay, except Bermuda grass; alfalfa, forage; alfalfa, hay; asparagus; clover, forage; clover, hay; pineapple; and sugarcane.

EPA has determined that there are potential postapplication exposures to individuals entering treated fields. In the Worker Protection Standard, a restricted entry interval ( REI) is defined as the duration of time which must elapse before residues decline to a level so entry into a previously treated area and engaging in any task or activity would not result in exposures which are of concern. Typically, the activity with the highest risk will drive the selection of the appropriate REI for the crop. The current diuron labels have a REI requirement of 12 hours with the following early entry PPE required: coveralls over long sleeved shirt and long pants, waterproof gloves, chemical resistant footwear plus socks, protective eye wear and chemical resistant headgear for overhead exposures.

Significant exposure to diuron may result from contact with treated soil when planting seedlings, moving irrigation lines, or other soil related activities since diuron is applied directly to the soil. At this time, no transfer coefficients exist for activities resulting in contact with treated soil. There are also no data on the soil residue dissipation of diuron. A worker exposure study and a diuron soil residue dissipation study would be needed to assess this risk. Transfer coefficients do not exist for the mechanical harvesting of alfalfa and asparagus and these activities 61 are considered of special concern according to the Agriculture Transfer Coefficient Exposure SAC policy 3.1. Significant worker exposure is possible from mechanical harvesting these crops.

Since diuron can be applied as a defoliant soon before harvest, exposure to cotton harvesters is of special concern for this chemical. According to data recently submitted to the Agency, there is exposure during the mechanical harvesting of cotton. Exposure can result from the following occupational job functions: picker operator, module builder, tramper, and raker. A picker operator is the individual that drives the harvesting machine, usually with an enclosed cab. A module builder operator is the individual that operates the controls of the module builder that the picker dumps the cotton into. The module builder is used to receive the cotton and then compact it into modules or bales. A tramper is the individual who stands on top of the module builder and helps direct the cotton out of the picker and into the module builder. The tramper than jumps into the module builder and redistributes the cotton around inside. A raker is the individual who rakes up the spilled cotton and puts it back into the module builder. The models presently used to assess occupational postapplication exposure cannot be used since the foliage has dropped off of the cotton plants by the time of harvest. There are no standard default transfer coefficients for these activities at this time.

Chemical specific postapplication exposure and/ or environmental fate data have not yet been submitted by the registrant in support of reregistration of diuron. In lieu of these data, a surrogate postapplication assessment was conducted to determine potential risks. The surrogate assessment is based on both the typical and maximum application rates that a private farmer/ grower may reasonably be expected to be exposed to for a short term duration ( 10 days), and on the typical application rates that a commercial applicator may be reasonably expected to be exposed to for a longer term duration ( 30 days). The maximum application rates are not included in the postapplication assessment for the commercial applicator, as it is unlikely that a commercial applicator would be exposed at the maximum application rate for 30 days a year.

Occupational Data Sources and Assumptions ( 1) Data Sources ° Typical application rates were supplied by the primary registrant, Griffin. The sources of the data were quoted as Doane, the National Center for Food and Agricultural Policy ( NCFAP), the U. S. Department of Agriculture, and Griffin. A range of the typical application rates was given. The highest value of the typical range of application rates was used in this assessment. BEAD has evaluated the typical application rates and determined that they are typical to high end. No data on the typical application rates of paints, ponds, and non crop/ industrial areas were supplied. Therefore, only the maximum application rates were used in the cancer assessments for these uses.

° No chemical specific DFR data exists for diuron. Therefore, the DFR values are derived from using an estimated 20 percent of the rate applied as initial dislodgeable residues for cotton and an estimated 10 percent dissipation rate per day. 62 ° The transfer coefficients used in this assessment are from the Agricultural Re entry Task Force ( ARTF) database. An interim transfer coefficient policy was developed by HED's Science Advisory Council for Exposure using the ARTF database ( policy # 3.1). It is the intention of HED's Science Advisory Council for Exposure that this policy will be periodically updated to incorporate additional information about agricultural practices in crops and new data on transfer coefficients. Much of this information will originate from exposure studies currently being conducted by the ARTF, from the further analysis of studies already submitted to the Agency, and from the studies in the published scientific literature.

( 2) Assumptions The following assumptions were used in the occupational postapplication assessment.

° The maximum transfer coefficients for each crop were used to determine the highest possible postapplication exposure. Other activities, such as scouting and irrigation, were also assessed to determine possible exemptions to the restricted entry intervals calculated for the highest postapplication exposures.

° Exposure time is assumed to be 8 hours per day. This represents a typical work day.

° The average body weight of 70 kg is used.

° Exposures per year: Ten days of exposure per year was assumed for the private grower and 30 days of exposure per year was assumed for a commercial applicator.

° Maximum application rates were used in the private grower assessment. Typical application rates were used in both the private grower and commercial applicator assessments. It is assumed that as the frequency of exposure increases, the probability of being exposed to a maximum residue resulting from the maximum application rate decreases. Therefore, maximum application rates were only assessed for the professional grower.

Occupational Postapplication Cancer Risk Summary When evaluating cancer risks for the occupational population, EPA closely examines risks in the 1x10 4 to 1x10 6 range and seeks cost effective ways to reduce occupational cancer risks to the greatest extent feasible, preferably 1x10 6 or less. This diuron postapplication cancer assessment assumes that a worker would contact residues on the day of application for ten or thirty days a year, every year for 35 years. Since it is unlikely that a postapplication worker would contact the highest possible residue value for that length of time, this assessment is considered very conservative. 63 Private Growers ( 10 Days Exposure Per Year)

Postapplication cancer risks for private growers were calculated at both the typical application rate and the maximum application rate for each crop grouping. As mentioned previously, the occupational cancer risk assessment is a conservative assessment; therefore, all cancer risks to private growers were less than 1 x 10 4 on the day of treatment and are not of concern.

Commercial Farm Workers ( 30 Days Exposure Per Year)

Postapplication cancer risks for commercial farm workers were calculated at the typical application rate only for each crop grouping. All cancer risks to commercial farm workers were less than 1 x 10 4 on the day of treatment and are not of concern.

Historically, setting REIs on cancer endpoints has been difficult because of the need for lifetime use assumptions. To estimate the LADD ( Life time Average Daily Dose) the typical application rate, the number of days worked per year, and the number of years one would be exposed during a working lifetime are needed. Each one of these variables is dependent upon many factors. For example, the number of days worked per year must correspond to the days worked when the pesticide of concern has been applied. Additionally, the residue dissipation over the work interval should be estimated. Without an estimate for residue dissipation one needs to assume ( conservatively) that the worker travels from one treated field to another so that the highest residue value is always contacted. In the case of diuron, a screening estimate was developed because lifetime use data are not available.

Occupational Postapplication Exposures to Paint Containing Diuron Postapplication exposures may occur in industrial settings around open vats used in paint processing. Inhalation and dermal exposures may also occur while maintaining industrial equipment. No postapplication exposure data have been submitted to determine the extent of postapplication exposures in the industrial settings. However, usage information gathered subsequent to the risk assessment indicates that less than 1 % of all paint contains diuron. Inhalation exposures are expected to be minimal because of the low vapor pressure of diuron ( 2 x 10 7 mmHg at 30

C) and aerosol formation is not expected to be registered. Dermal postapplication exposures are expected to be lower than when handling/ loading the formulated product. Therefore, postapplication exposures in the industrial settings are expected to be minimal and not of concern.

Occupational Postapplication Exposures to Commercial Fish Ponds Diuron is applied to ponds/ aquariums in the form of a liquid or an effervescent tablet. Due to the high dilution rate of the liquid in pond and aquarium water ( 0.0000074 lb ai per gallon of water), and the effervescent nature of the tablet ( expected to dissolve in less than five minutes), postapplication exposure to diuron in pond and aquarium water is expected to be minimal. 64 Furthermore, postapplication activities in and around ponds/ aquariums treated with diuron are assumed to be infrequent.

j. Human Incident Data The Agency searched several databases for reports of incidents resulting from exposures to diuron. The databases searched were the Incident Data System ( IDS), American Association of Poison Control Centers ( AAPCC), California Pesticide Illness Surveillance Program, and National Pesticide Telecommunication Network ( NPTN). There were incidents reported involving both adults and children. Most were treated on an outpatient basis but a few required hospitalization and one death occurred. A direct connection between exposure to diuron as the cause and the reported death has not been made. Some incident reports described symptoms such as eye irritation, rash, dizziness, respiratory irritation and headaches for both agricultural and nonagricultural exposures. Specific details may be found in, " Review of Diuron Poisoning Incident Data. Chemical: # 035505," dated October 11, 2001.

The incident data show that the number of poisoning incidents for diuron alone is relatively small in any one surveillance system. Also, the incidents are scattered in time and location, and many of the incidents involve diuron use in mixtures. Therefore, few conclusions can be drawn. However, a 1995 Louisiana elementary school incident in which diuron was associated with the illnesses of 23 children and 9 adults, remains unexplained. There are no known recreational or school building registered uses of diuron.

B. Environmental Risk Assessment A summary of the Agency's environmental risk assessment is presented below. For detailed discussions of all aspects of the environmental risk assessment, see the " Environmental Risk Assessment for the Reregistration of Diuron", dated August 27, 2001, the " Drinking Water Reassessment for Diuron and its Degradates", dated March 11, 2002, and the memorandum entitled, " Surface Water Monitoring Data for Diuron" dated August 5, 2003. These documents are also available in the OPP public docket and on the Agency's website at: http:// cfpub. epa. gov/ oppref/ rereg/ status. cfm? show= rereg.

1. Environmental Fate and Transport The environmental fate database for diuron is essentially complete. Diuron is mobile and has the potential to leach to ground and to contaminate surface waters. An upgradable adsorption/ desorption/ leaching study ( MRID 44490501) showed that diuron has low to medium K oc values ( 468 1666) and Freundlich K ads values ( 7.9 28). In addition, diuron has relatively low water solubility ( 42 ppm) and low volatility ( 2 x 10 7 mm Hg at 30 ° C).

Diuron is persistent in terrestrial environments. The major routes of dissipation for diuron in the environment is microbial degradation in water. Diuron also degrades through photolysis in both water and soil, but at a slower rate. 65 Diuron is stable to hydrolysis at pH 5, 7, and 9. The minor degradate 3,4 dichloroaniline ( 3,4 DCA) was identified in all hydrolysis test solutions ( 0.5% of applied). In aqueous and soil photolysis studies with diuron, calculated half lives were 43 and 173 days, respectively. In water, photolysis degradates were carbon dioxide ( CO 2) and at least 13 minor ( each < 9% of applied) polar products. In soil, the major photolysis degradate was N'( 3,4 dichlorophenyl) N methylurea ( DCPMU), and the minor degradates were demethylated DCPMU ( DCPU), dichloroaniline ( DCA), and 3,3', 4,4' tetrachlorobenzene ( TCAB). The calculated half lives in aerobic and anaerobic soil metabolism studies were 372 ( aerobic) and 1000 ( anaerobic) days. Under aerobic conditions, the major degradate was DCPMU ( 20.9 22.5 % of the amount applied at 365 days), and minor degradates were DCPU and CO 2. Under anaerobic conditions, the only degradate identified was DCPMU, which accounted for a maximum of 10.3% of applied ( at 45 days).

In contrast to its persistence in laboratory studies of hydrolysis, aqueous and soil photolysis, and aerobic and anaerobic soil metabolism, diuron degraded relatively quickly in aquatic metabolism laboratory studies, with a half life of 33 days under aerobic conditions and of 5 days under anaerobic conditions. The major metabolism degradate under aerobic conditions was N'( 3 chlorophenyl) N, N dimethylurea ( MCPDMU) which reached 25 % of the applied dose by the end of the study and was evenly distributed between the soil and aqueous phase. The minor degradates identified were DCPMU and CPMU and were primarily associated with the soil phase. The major degradate under anaerobic conditions was MCPDMU, which was mainly associated with the aqueous phase. The two minor degradates were PDMU and MCPMU.

In terrestrial field dissipation studies in FL, MS, and CA with sand, silt loam, and silty clay loam soils, diuron dissipated in bare ground plots with half lives of 73, 139, and 133 days, respectively. The major degradate DCPMU dissipated in the same plots with half lives of 217, 1733, and 630 days. In aquatic field dissipation studies, half lives were 115 177 days and the major degradate was DCPMU.

The major degradate formed in laboratory studies of soil photolysis, aerobic soil metabolism, and anaerobic soil metabolism, and in all field dissipation studies was DCPMU. The major degradate formed in laboratory studies of aerobic and anaerobic aquatic metabolism studies was MCPDMU. The major and minor degradates of diuron are shown in Table 20. The environmental degradates of toxicological concern to humans and other non target species are shown in italics.

The degradate 3,4 DCA is of toxicological concern for human health and is a common degradate for diuron, linuron, and propanil. Based on limited environmental fate data ( three hydrolysis studies), 3,4 DCA is formed at < 1% of applied diuron. Although the environmental risk assessment for diuron noted the lack of fate and transport data on 3,4 DCA, additional data will not be required for diuron since this degradate is formed at such a low percent of applied parent.

Tetrachloroazobenzene ( TCAB), also a degradate of concern for human health, was identified as one of the minor degradates of diuron in a soil photolysis study with a maximum concentration of 0.038 ppm. 66 Table 20. Major and Minor Degradates of Diuron in Environmental Fate Studies Environmental Fate Study Major degradate Minor degradates Hydrolysis ( MRID 41418804) None 3,4 DCA Photodegradation in Water ( MRID 41418805) CO2 13 polar products Photodegradation in Soil ( MRID 41719302) DCPMU DCPU, 3,4 DCA, TCAB Aerobic Soil Metabolism ( MRID 4179303) DCPMU DCPU, CO2 Anaerobic Soil Metabolism ( MRID 41418806) DCPMU None Aerobic Aquatic Metabolism ( MRID 44221002) MCPDMU DCPMU, CPMU Anaerobic Aquatic Metabolism ( MRID 44221001) MCPDMU PDMU, MCPMU Terrestrial Field Dissipation ( MRIDs 44654001, 44865001) DCPMU Not Measured Aquatic Field Dissipation ( MRIDs 43762901, 43978901) DCPMU Not Measured 2. Toxicity ( Hazard) Assessment a. Toxicity to Terrestrial Organisms Diuron is sightly toxic to bobwhite quail and practically nontoxic to mallard duck on an acute oral basis. It is practically nontoxic to bobwhite quail and slightly toxic to mallard duck on a subacute dietary basis. Diuron is relative nontoxic to both honey bees and laboratory rats ( acute basis). In a 2 generation rat reproduction study, diuron caused pup body weight loss. No avian reproduction study was submitted by the registrant and one is required because diuron is persistent in the environment and has the potential to cause chronic effects. In Table 21, the toxicity endpoints used in calculating risk are shaded. 67 Table 21. Summary of Acute and Chronic Toxicity Values for Terrestrial Organisms Species Acute Toxicity Chronic Toxicity Acute LD50 ( mg/ kg) Acute Oral Toxicity ( MRID) Subacute LC50 ( ppm) Subacute Dietary Toxicity ( MRID) NOEC/ LOEC ( ppm) ( MRID) Affected endpoint Northern bobwhite quail Colinus virgianus 940 Slightly toxic ( 50150170) > 5000 Practically nontoxic ( 00022923)

Mallard duck Anas platyrhynchous > 2000 Practically nontoxic ( 00160000) 1730 Slightly toxic ( 00022923)

Honey bee Apis meliferus 1451 Practically nontoxic ( 00036935)

Laboratory rat Rattus norvegicus Male: 5,000 Female: 10,000 Class. III ( 00146145)     NOEC = 250 LOEC = 1750 ( 00146145) Pup body weight b. Toxicity to Aquatic Organisms Diuron is moderately toxic to the majority of aquatic animals tested, including rainbow trout, bluegill sunfish, water flea, striped mullet, sheepshead minnow, Eastern oyster, and brown shrimp. However, it is highly toxic to cutthroat trout and scuds. Diuron is only slightly acutely toxic to fathead minnows. In chronic studies, diuron reduced the number of surviving fathead minnows, the growth and survival of sheepshead minnows, and the growth and reproduction of mysid shrimp. Chronic studies on water fleas and sheepshead minnows will need to be repeated because they failed to provide a LOEC ( water flea, no observed effect at all doses tested) or a NOEC ( sheepshead minnow, reduced growth and survival at all doses tested). In Table 22, the toxicity endpoints used in calculating risk are shaded. 68 Table 22. Summary of Acute and Chronic Toxicity Values for Aquatic Organisms Species Acute Toxicity Chronic Toxicity 48 h EC50 ( ppm) 96 hr LC50 ( ppm) Acute Toxicity ( MRID) NOEC/ LOEC ( ppm) Affected Endpoint ( MRID)

Cutthroat trout Oncerynchus clarki ( freshwater fish)   0.71 Highly toxic ( 40098001)

Fathead minnows Pimephales promelas ( freshwater fish)   14 Slightly toxic ( 00141636) NOEC = 0. 026 LOEC = 0.062 No. of survivors ( 00141636)

Scud Gammmarus fasciatus ( freshwater invertebrate) 0.16   Highly toxic ( 40094602)

Water flea Daphnia magna ( freshwater invertebrate) 1.4   Moderately toxic ( 40094602) NOEC = 0. 2 No LOEC No effect ( STODIV05)

Striped mullet Mugil cephalus ( marine/ estuarine fish)   6.3 Moderately toxic ( 40228401)

Sheepshead minnow Cypprinoden varieggatus ( marine/ estuarine fish)   6.7 Moderately toxic ( 41418805) No NOEC LOEC = 0.44 Reduced growth, survival ( 42312901)

Brown shrimp Penaeus aztecus ( marine/ estuarine invertebrate) 1   Moderately toxic ( 40228401)     Mysid shrimp Americamysis bahia ( marine/ estuarine invertebrate)       NOEC = 0.27 LOEC = 0.56 Growth Reproduction c. Toxicity to Non target Plants Tier II terrestrial plant seedling emergence and vegetative vigor toxicity studies were conducted with four species of monocotyledonous plants ( corn, onion, sorghum, and wheat) and six species of dicotyledonous plants ( soybean, pea, rape, cucumber, sugar beet, and tomato). Onion and tomato were most sensitive species for seedling emergence; and wheat and tomato were most sensitive species for plant vegetative vigor. Tier II aquatic plant toxicity testing was conducted on fifteen species of nonvascular plants including aquatic algae and diatoms. However, only one study on green algae ( Selenastrum capricornutum) was acceptable because the other 69 submitted studies tested inappropriate species. No vascular aquatic plant studies were submitted for diuron; an aquatic plant study on four species including the vascular plant Lemna gibba ( duckweed) is required. Tables 23 and 24 show a summary of acute toxicity values for non target terrestrial plants and non target aquatic plants, respectively.

Table 23. Summary of Acute Toxicity Values for Non Target Terrestrial Plants ( Endpoint = Shoot Dry Weight).

Classification Toxicity test Crop ( MRID) EC25/ EC05 ( lbs. ai/ A)

Monocot Seedling emergence Onion ( MRID 44114301) 0.099/ 0.089 Vegetative vigor Wheat ( MRID 44113401) 0.021/ 0.002 Dicot Seedling emergence Tomato ( MRID 44113401) 0.08 / 0.047 Vegetative vigor Tomato ( MRID 42398501) 0.002/ 0.001 Table 24. Summary of Acute Toxicity Values for Non Target Aquatic Plants Classification Species ( MRID) EC50 ( ppb)

Non vascular Green algae Selenastrum capricornutum ( MRID 42218401) 2.4 Vascular Duckweed Lemna Gibba ( No study available) None available 3. Exposure and Risk Assessment a. Risk Calculation Levels of Concern To evaluate the potential ecological risk to non target organisms from the use of diuron products, risk quotients ( RQs) are calculated from the ratio of estimated environmental concentrations ( EEC) to ecotoxicity values. The Agency calculates risk quotients ( RQs) by dividing exposure estimates by acute and chronic ecotoxicity values:

RQ = EXPOSURE/ TOXICITY RQs are then compared to OPP's levels of concern ( LOCs). These LOCs are criteria used by OPP to indicate potential risk to nontarget organisms and the need to consider regulatory action. The criteria indicate that a pesticide used as directed has the potential to cause adverse effects on non 70 target organisms. Risk presumptions, along with the corresponding LOCs, are given in Table 25.

Table 25. Risk Presumptions for Terrestrial and Aquatic Animals Risk Presumption LOC terrestrial animals LOC aquatic animals LOC terrestrial plants LOC aquatic plants Acute High Risk there is potential for acute risk; regulatory action may be warranted in addition to restricted use classification, 0.5 0.5 1 1 Acute Restricted Use  there is potential for acute risk, but may be mitigated through restricted use classification, 0.2 0.1 1 1 Acute Endangered Species  endangered species may be adversely affected; regulatory action may be warranted, 0.1 0.05 1 1 Chronic Risk  there is potential for chronic risk; regulatory action may be warranted. 1 1 NA NA When available, field studies and incident data are used to further characterize the risk to non target organisms. Risk characterization integrates the results of all available data to evaluate the likelihood of adverse ecological effects.

b. Exposure and Risk to Non target Terrestrial Organisms ( 1) Avian Risk In order to assess risk to birds, estimated environmental concentrations ( EECs) on food items following product application are compared to LC 50 values to assess risk by the Risk Quotient ( RQ) method. Estimates of maximum and average residue levels ( EECs) of diuron on avian food items were based on the nomograph of Hoerger and Kenega ( 1972), as modified by Fletcher et al. ( 1994). The upper limit values from the nomograph represent the 95th percentile of residues from actual field measurements ( Hoerger, 1972). The Fletcher et al. ( 1994) modification to the Kenaga nomograph are based on measured field residues from 249 published research papers, including 118 various species of plants, 121 pesticides, and 17 chemical classes. These modifications represent the 95th percentile of the expanded data set. 71 Avian risk quotients are calculated using the most sensitive LC 50 ( acute risk) and NOEC ( chronic risk) for birds. In this instance, the mallard duck 5 day LC 50 of 1730 ppm was used to calculate acute risk. Short grass represents the food items with the highest residue concentration and therefore, the highest RQ, conversely, seeds represent the foodstuffs with the lowest RQs. Other food items fall within this range. Chronic risk to birds could not be calculated because no chronic avian toxicity data were available for diuron; an avian reproduction study is required.

The highest calculated avian acute RQ is 1.7 and is based on a single application of diuron at 12 lbs a. i./ A to rights of way. The highest RQ associated with an agricultural use is 1.3, based on a single ground application of 9.6 lbs a. i./ A to grapes, or two applications of 4.8 lbs a. i./ A to citrus. Acute ( LOC = 0.5), acute high risk ( LOC = 0.2), and acute endangered species ( LOC = 0.1) levels of concern are exceeded for birds feeding on short grass, tall grass ( not shown) and broadleaf plants and insects ( not shown). However, LOCs are not exceeded if RQs are calculated using mean EECs ( not shown) based on mean residues from Hoerger and Kenega 1972 as modified by Fletcher et al. 1994. Table 26 shows the range of acute avian RQs based on maximum EECs and maximum labeled application rates for birds feeding on short grass and seeds, only.

Table 26: Avian Acute Risk Quotients for Single and Multiple Applications Based on Maximum Residues ( LC50 = 1730 ppm).

Use site/ application methods ( number of applications) Rate ( lbs ai/ A) Food Items Single Application Multiple Applications Acute only Acute only Rights of way/ aerial ( 1) 12 Short grass 1.7

Seeds 0.1   Grapes/ ground ( 1) 9.6 Short grass 1.3

Seeds 0.08   Citrus/ ground ( 2) 6.4 ( 4.8 for 2 applications) Short grass 0.9 1.3 Seeds 0.06 0.08 Fruits/ ground ( 1) 4.0 Short grass 0.6

Seeds 0.03

Sugarcane/ aerial ( 3) 3.2 Short grass 0.4 0.8 Seeds 0.03 0.05 Cotton/ aerial ( 2) 1.6 ( 1.2 for 2 applications) Short grass 0.2 0.3 Seeds 0.01 0.02 72 ( 2) Mammalian Risk In order to assess risk to small mammals, estimated environmental concentrations ( EECs) of diuron on food items are compared to LC 50 values from laboratory studies on small mammals ( rats, mice) to calculate risk quotients ( RQs). Wild mammal toxicity studies are required on a case by case basis, depending on the results of laboratory mammalian studies, intended chemical use patterns and pertinent environmental fate characteristics. For most chemicals, including diuron, rat or mouse toxicity values obtained from the Agency's Health Effects Division substitute for wild mammal testing.

To calculate acute risk and maximum chronic risk values, estimates of maximum residue levels ( EECs) of diuron on mammalian food items were based on the model of Hoerger and Kenega ( 1972), as modified by Fletcher et al. ( 1994). In addition, a second estimate of maximum chronic risk values and an estimate of average chronic risk values were calculated using the LFATE model.

The concentration of diuron in the diet that is expected to be acutely lethal to 50% of the test population ( LC 50) is determined by dividing the LD 50 value ( in this case, the male rat 5 day LD 50 of 5,000 mg/ kg) by the % ( decimal of) body weight consumed ( 95% for grass, forage, and insects, and 21% for seeds). An acute risk quotient is then determined by dividing the EEC by the derived LC 50 value. Chronic risk quotients are calculated in a similar manner using the most sensitive chronic endpoint, in this case, a NOEC of 250 ppm from a 2 generation rat reproduction study ( chronic effect = pup body weight loss). Risk quotients are calculated for three separate weight classes of mammals ( 15, 35, and 1000 g), each presumed to consume four different kinds of food ( grass, forage, insects, and seeds).

The acute level of concern ( LOC = 0.5) for mammals is only exceeded for 15 g mammals feeding on short grass following a 12 lb a. i./ A application of diuron to rights of way, a use which results in the highest calculated RQ for mammals, 0.6. The highest calculated RQ associated with an agricultural use is 0.4, for a single ground application to grapes of 9.6 lbs a. i./ A, two ground applications of 4.8 lbs a. i./ A to citrus, or three applications of 3.2 lbs a. i./ A to sugarcane. Acute high risk ( LOC = 0.2) and acute endangered species ( LOC = 0.1) levels of concern are exceeded for small ( 15 g) and medium sized ( 35 g) mammals for some use sites and application rates.

The chronic level of concern ( LOC = 1) for mammals is exceeded for small ( 15 g) mammals feeding on short grass, tall grass, and broadleaf plants and insects, for all crops with multiple diuron applications ( citrus, sugarcane, and cotton). The highest calculated chronic RQ value is 9.2, based on 2 ground applications ( 4.8 lbs a. i./ A per application) to citrus and 3 aerial applications ( 3.2 lbs a. i./ A per application) to sugarcane.

Table 27 shows the acute and chronic risk quotients for the smallest mammals ( 15 g, most sensitive, highest risk) feeding on seeds ( lower residues and risk) and short grass ( highest residues and risk) calculated using maximum Kenaga nomogram residues, only. These values represent the 73 most conservative estimate of risk ( highest RQs).

Table 27: Mammalian ( 15 g mammal) Acute and Chronic Risk Quotients for Single and Multiple Applications Based on Maximum Residues ( LD50 = 5,000 mg/ kg, NOEC = 250 ppm).

Use site/ application methods ( number of applications) Rate ( lbs ai/ A) Food Items Single Application Multiple Applications Acute Chronic Acute Chronic Rights of way/ aerial ( 1) 12 Short grass 0.6

Seeds 0.01

Grapes/ ground ( 1) 9.6 Short grass 0.4

Seeds < 0.01

Citrus/ ground ( 2) 6.4 ( 4.8 for 2 applications Short grass 0.3  0.4 9.2 ( 3.1) 1 Seeds < 0.01  < 0.01 0.6 ( 0.3) 1 Fruits/ ground ( 1) 4.0 Short grass 0.2

Seeds < 0.01

Sugarcane/ aerial ( 3) 3.2 Short grass 0.2  0.4 9.2 ( 2.1) 1 Seeds < 0.01  < 0.01 0.6 ( 0.2) 1 Cotton/ aerial ( 2) 1.6 ( 1.2 for 2 applications) Short grass 0.07  0.1 2.1 ( 0.8) 1 Seeds < 0.01  < 0.01 0.1 ( 0.06) 1 1Value in parentheses is the average chronic RQ, calculated using average residue values from the FATE model.

( 3) Risk to Non target Insects Diuron is practically non toxic to honeybees and risk to non target insects is expected to be minimal.

c. Exposure and Risk to Non target Aquatic Organisms 74 ( 1) Surface Water Resources Assessment Diuron aquatic estimated environmental concentrations ( EECs) were generated using the Tier I surface water model GENEEC II, a screening level model generating upper bound EECs. Diuron EEC values were calculated based on applications to various crops using aerial or ground equipment. In addition, the Tier II surface water model PRZM/ EXAMS was used to generate less conservative EEC values for the grape ( CA), citrus ( FL) and apple ( NY) diuron use scenarios. These scenarios were chosen to reflect a wide range of diuron application rates and regional weather conditions.

( 2) Risk to Fish and Aquatic Invertebrates Risk to freshwater fish and invertebrates To calculate acute RQs for freshwater aquatic organisms, peak EEC values were divided by the most sensitive acute toxicity endpoints: the cutthroat trout LC 50 ( 0.71 ppm) for fish, and the scud LC 50 ( 0.16 ppm) for invertebrates. Chronic RQ values were calculated by dividing 21 day average EECs ( for invertebrates) and 60 day average EECs ( for fish) by the most sensitive chronic toxicity endpoints: the fathead minnow NOEC ( 0.0264 ppm) for fish, and the water flea NOEC ( 0.2 ppm) for invertebrates.

The acute level of concern for aquatic organisms ( LOC = 0.5) is not exceeded for freshwater fish except for the 12 lbs a. i./ A right of way use, which results in the highest calculated RQ for freshwater fish, 0.6 ( Table 28). However, the acute restricted use level of concern ( LOC = 0.1) is exceeded for freshwater fish for all uses except sugarcane ( multiple applications) and cotton ( single and multiple applications). The acute endangered species level of concern ( LOC = 0.05) is exceeded for freshwater fish for all uses except multiple applications to cotton.

The highest acute RQ for freshwater invertebrates is 2.6 and is associated with the use of diuron on rights of way. The acute LOC ( 0.5) is exceeded for freshwater invertebrates for all uses except sugarcane ( multiple applications) and cotton ( single and multiple applications). The acute restricted use ( 0.2) and acute endangered species ( 0.05) levels of concern are exceeded for all uses.

The highest calculated chronic RQs for freshwater fish are 9.0 ( rights of way) and 7.2 ( grapes), and the highest calculated RQs for freshwater invertebrates are 1.8 ( rights of way) and 1.3 ( grapes). The chronic level of concern for aquatic organisms ( LOC = 1) is exceeded for freshwater fish for all uses except multiple applications to cotton. For invertebrates, the chronic LOC ( 1) is exceeded for single applications to rights of way and grapes, and for multiple applications to citrus.

Table 28. Freshwater Fish and Invertebrate Acute and Chronic Risk Quotients 75 Use site/ application methods ( number of applications) Rate ( lbs ai/ A) Acute Risk Quotients Chronic Risk Quotients Freshwater Fish Freshwater Invertebrates Freshwater Fish Freshwater Invertebrates Rights of way/ aerial ( 1) 12 0. 6 2. 6 9.0 1.8 Grapes/ ground ( 1) 9.6 0.5 ( 0.05) 1 2. 1 ( 0.2) 1 7. 2 ( 1.4) 1 1.3 ( 0.2) 1 Citrus/ ground ( 1) 6.4 0.3 ( 0.2) 1 1.4 ( 0.9) 1 4.8 ( 4.9) 1 0.9 ( 0.7) 1 Citrus/ ground ( 2) 4.8 0.1 0.6 2.0 1.2 Fruits/ ground ( 1) 4.0 0.2 ( 0.07) 1 0.9 ( 0.3) 1 3.0 ( 1.9) 1 0.5 ( 0.3) 1 Alfalfa, sugarcane, grass seeds/ aerial ( 1) 3.2 0.2 0.7 2.5 0.6 Sugarcane/ aerial ( 3) 3.2 0.09 0.4 1.4 0.8 Cotton/ aerial ( 1) 1.6 0.08 0.4 1.3 0.2 Cotton/ aerial ( 2) 1.2 0.03 0.1 0.5 0.3 1 RQ values in parentheses were calculated using Tier II PRZM/ EXAMS modeling.

Risk to estuarine/ marine fish and invertebrates To calculate acute RQ values for estuarine/ marine aquatic organisms, peak EEC values were divided by the most sensitive acute toxicity endpoints: the striped mullet LC 50 ( 6.3 ppm) for fish, and the brown shrimp LC 50 (> 1 ppm) for invertebrates. Chronic RQ values were calculated by dividing 21 day average EECs ( for invertebrates) and 60 day average EECs ( for fish) by the most sensitive chronic toxicity endpoints: the sheepshead minnow NOEC ( 0.44 ppm) for fish, and the mysid shrimp NOEC ( 0.27 ppm) for invertebrates.

The acute ( LOC = 0.5) and acute restricted use ( LOC = 0.1) levels of concern for aquatic organisms are not exceeded for estuarine/ marine fish ( Table 29). The acute endangered species level of concern ( LOC = 0.05) is exceeded for estuarine/ marine fish only for the uses on rights ofway ( RQ = 0.07) and grapes ( RQ = 0.05). The acute LOC ( 0.5) is not exceeded for estuarine/ marine invertebrates. The calculated RQs associated with a single application of diuron to rights of way ( RQ = 0.4), grapes ( RQ = 0.3), and citrus ( RQ = 0.2) exceed the acute restricted use level of concern ( 0.2) for invertebrates. The acute endangered species ( 0.05) level of concern is exceeded for estuarine/ marine invertebrates, for all uses except multiple applications to cotton.

The highest calculated chronic RQ for estuarine/ marine fish is 0.5 ( rights of way use), which does not exceed the chronic level of concern ( 1). The highest calculated chronic RQs for estuarine/ marine invertebrates are 1.3 ( rights of way) and 1.0 ( grapes); these are the only uses with 76 RQs that exceed the chronic LOC of 1.

Table 29. Estuarine/ Marine Fish and Invertebrate Acute and Chronic Risk Quotients Use site/ application methods ( number of applications) Rate ( lbs ai/ A) Acute Risk Quotients Chronic Risk Quotients Estuarine/ Marine Fish Estuarine/ Marine Invertebrates Estuarine/ Marine Fish Estuarine/ Marine Invertebrates Rights of way/ aerial and ground ( 1) 12 0. 07 0.4 0.5 1.3 Grapes/ ground ( 1) 9.6 0.05 ( 0.006) 1 0.3 ( 0.04) 1 0.4 ( 0.08) 1 1.0 ( 0.1) 1 Citrus/ ground ( 1) 6.4 0.03 ( 0.02) 1 0.2 ( 0.1) 1 0.3 ( 0.3) 1 0.06 ( 0.5) 1 Citrus/ ground ( 2) 4.8 0.01 0.09 0.1 0.9 Fruits/ ground ( 1) 4.0 0.02 ( 0.008) 1 0.1 ( 0.05) 1 0.2 ( 0.1) 1 0.4 ( 0.2) 1 Alfalfa, sugarcane, grass seeds/ aerial and ground ( 1) 3.2 0.02 0.1 0.2 0.4 Sugarcane/ aerial ( 3) 3.2 0.01 0.06 0.08 0.6 Cotton/ aerial ( 1) 1.6 0.01 0.06 0.08 0.2 Cotton/ aerial ( 2) 1.2 0.01 0. 02 0.03 0.2 1 RQ values in parentheses were calculated using Tier II PRZM/ EXAMS modeling.

d. Exposure and Risk to Non target Terrestrial and Aquatic Plants Risk to non target terrestrial plants Terrestrial plants inhabiting dry and semi aquatic areas may be exposed to diuron from runoff, spray drift. Semi aquatic areas are those low lying wet areas that may be dry at certain times of the year. The run off scenario used for dry areas is characterized as " sheet run off"; the run off scenario for semi aquatic areas is characterized as " channelized run off". EECs are calculated for ground and aerial applications. Spray drift exposure from ground application is assumed to be 1% of the application rate, whereas spray drift from aerial applications is assumed to be 5% of the application rate. The total loading to dry areas adjacent to treatment sites is the sum of sheet run off and drift ( EEC dry). The total loading to semi aquatic areas is the sum of channelized run off and drift ( EEC semi aquatic).

In order to calculate the acute RQs for terrestrial plants in dry areas adjacent to diuron application sites, the EEC dry was divided by the EC 25 value of the most sensitive species in the seedling emergence study ( tomatoes, EC 25 = 0.08 lbs a. i./ A). The acute RQs for terrestrial plants 77 in semi aquatic areas were calculated by dividing the EEC semi aquatic by the EC 25 value of the most sensitive species in the seedling emergence study ( tomatoes, EC 25 = 0.08 lbs a. i./ A).

Acute RQs for endangered terrestrial plants are calculated in the same manner as for nonendangered plants, except that the EC 05 values for the most sensitive species in the seedling emergence ( tomato, EC 05 = 0.047 lbs a. i./ A) and vegetative vigor ( tomato, EC 05 = 0.001 lbs a. i./ A) studies are used instead of the EC 25 values.

The acute RQs calculated for terrestrial and endangered terrestrial plants are shown in Table 30 for plants in dry areas adjacent to the application site, and semi aquatic areas. The acute levels of concern for terrestrial ( LOC = 1) and endangered terrestrial ( LOC = 1) plants are exceeded for both dry and semi aquatic areas. The acute RQs range from 0.6 to 9.3 for terrestrial plants in dry areas and from 3.4 to 77 for terrestrial plants in semi aquatic areas. The acute RQs for endangered terrestrial plants range from 5.0 to 48 for endangered plants in dry areas and from 29 to 306 for endangered plants in semi aquatic areas, as shown in Table 30.

Table 30. Risk Quotients for Terrestrial and Endangered Terrestrial Plants in Dry and Semi Aquatic Areas.

Use site/ application method Rate ( lbs a. i./ A) Acute Risk Acute Endangered Species Risk Dry Areas Semiaquatic Areas Vegatative Vigor Dry Areas Semiaquatic Areas Vegatative Vigor Rights of way/ ground 12 4.5 31.5 60 7.7 53.6 120 Grapes/ ground 9.6 3.6 25.3 50 6.1 42.8 100 Citrus/ ground 6.4 2.4 16.8 30 41 28.6 60 Alfalfa, Sugarcane, Grass seeds/ ground 3.2 1.1 8.4 15 2.0 14.3 30 Cotton/ ground 1.6 0.6 4.3 10 1.0 7.1 20 Rights of way/ aerial 12 9.3 25.5 300 15.8 43.4 600 Alfalfa, Sugarcane/ aerial 3.2 2.5 6.8 80 4.2 11.6 160 Cotton/ aerial 1.6 1.3 3.4 40 2.1 5.8 80 Risk to non target aquatic plants Exposure to non target aquatic plants may occur through runoff or spray drift from 78 adjacent treated sites. Diuron aquatic estimated environmental concentrations ( EECs) were generated using the Tier I surface water model GENEEC II, a screening level model generating upper bound EECs. Diuron EEC values were calculated based on applications to various crops using aerial or ground equipment.

The acute RQs for aquatic vascular plants are usually calculated by dividing the aquatic EECs by the EC 50 for the duckweed Lemna gibba. In the case of diuron, no vascular plant toxicity study was available ( one is required). Acute RQs for aquatic non vascular plants were calculated by dividing the aquatic EECs by the acute EC 50 ( 0.0024 ppm) for the green alga Selenastrum capricornutum.

The acute RQs for endangered aquatic vascular plants are usually calculated by dividing the aquatic EECs by the EC 05 for the duckweed Lemna gibba. Since no vascular plant toxicity study was available for diuron, risk to endangered aquatic vascular plants could not be calculated. To date, there are no known non vascular plant species on the endangered species list.

Acute RQs for aquatic non vascular plants ranged from 9.6 ( based on two aerial application to cotton) to 172 ( based on one aerial application to rights of way) ( Table 31). The acute level of concern for aquatic non vascular plants ( LOC = 0.1) plants is exceeded for all uses of diuron. 79 Table 31. Risk Quotients for Non Vascular Aquatic Plants.

Use site/ application methods ( number of applications) Rate ( lbs ai/ A) Single Application Multiple Applications Acute only Acute only Rights of way/ aerial ( 1) 12 172

Grapes/ ground ( 1) 9.6 138

Citrus/ ground ( 2) 6.4 ( 4.8 for 2 applications) 92 38 Fruits/ ground ( 1) 4.0 57

Sugarcane/ aerial ( 3) 3.2 48 25 Cotton/ aerial ( 2) 1.6 ( 1.2 for 2 applications) 24 9.6 4. Ecological Incidents There are 29 ecological incident reports involving diuron and non target organisms; most of these reports are from the1990s. Of the 29 incidents, one involved birds, 16 involved fish, and 12 involved plants. One incident report included tissue analysis for both fish and plants.

Of 20 reported incidents where fish were killed, 16 resulted from direct application to ponds, which is not allowed as a legal use in the U. S. Two incidents were from use on unidentified agricultural crops where diuron subsequently ran off into adjacent waters. In one instance 12 bass and catfish were killed in Oklahoma, and in the other, 3000 unidentified fish were killed in Maryland. It is considered " probable" that diuron caused these kills, but it is unknown if the diuron was applied according to the label. Another incident resulted from spraying fence rows, with subsequent runoff into a pond, killing all of the algae within two days and 30 40 fish two days later. Diuron was applied by a pressure spray in combination with imazapyr and metsulfuronmethyl It is likely that the spray application was the causative event, but it seems very likely that the cause of the fish deaths was low dissolved oxygen which was found to be markedly reduced; fish were observed " groping for air." The fourth incident was associated with application of a bromacil diuron product to an electrical substation. It appears to be unlikely to have resulted from diuron because copper sulfate had been applied several days previously, and measured amounts of diuron and bromacil in the pond were very low, whereas copper concentrations were above median lethal levels for several fish species.

The absence of additional documented incidents does not necessarily mean that such incidents did not occur. Mortality incidents must be seen, reported, investigated, and submitted to the Agency in order to be recorded in the incident database. Incidents may not be noticed because the carcasses decayed, were removed by scavengers, or were in out of the way or hard to see locations. Due to the voluntary nature of incident reporting, an incident may not be reported to 80 appropriate authorities capable of investigating it.

5. Endangered Species Endangered species LOCs for diuron are exceeded for terrestrial plants, herbivorous mammals and herbivorous and insectivorous birds from all uses; freshwater fish and crustaceans from all uses but cotton; and mollusks and estuarine fish from the uses on grapes and nonagricultural sites. The Agency consulted with the US Fish and Wildlife Service ( FWS or the Service) on the agricultural uses of diuron in the " reinitiation" of the cluster assessments in 1988. The resulting 1989 opinion found jeopardy to the Wyoming toad ( extirpated in the wild except on FWS refuges). The Service proposed a Reasonable and Prudent Alternative ( RPA) ( no spray zone within 100 yards of occupied habitat for ground applications and 1/ 4 mile for aerial application) to avoid the likelihood of jeopardizing the continued existence of this species. In addition, the Service had Reasonable and Prudent Measures ( RPM) to reduce incidental take of 20 fish and two aquatic invertebrate species. The details of the RPM recommendations are provided in the FWS 1989 biological opinion.

Many additional species, especially aquatic species, have been federally listed as endangered/ threatened since the biological opinion of 1989 was written; determination of potential effect to most of these species has not yet been assessed for diuron. Species and site specific assessments have been done for the various uses of diuron with respect to listed Pacific salmon and steelhead, in accordance with a court order, and consultation has been requested of the National Marine Fisheries Service for those that exceed criteria of concern; these latter include nonagricultural uses and the highest rates of certain agricultural uses of diuron. These assessments should not be extrapolated to other species and other parts of the U. S. In addition, endangered plants, birds, and mammals were not considered in the 1989 Biological Opinion or the consultation request for salmon and steelhead. These need to be addressed along with newly listed aquatic species and the non crop uses of diuron for all species other than Pacific salmon and steelhead because the 1989 biological opinion dealt only with crop uses. Finally, not only are more refined methods to define ecological risks of pesticides being used, but also new data that did not exist in 1989, such as that for spray drift, are now available. The RPMs in the 1989 opinion may need to be re assessed and consultation reinitiated, as appropriate. For additional information, please see: http:// www. epa. gov/ oppfead1/ endanger/ effects/ diuron_ analysis_ final2. pdf 81 IV. Risk Management, Reregistration and Tolerance Reassessment Decisions A. Determination of Reregistration Eligibility Section 4( g)( 2)( A) of FIFRA calls for the Agency to determine, after submission of relevant data concerning an active ingredient, whether or not products containing the active ingredient are eligible for reregistration. The Agency has previously identified and required the submission of the generic ( i. e., active ingredient specific) data to support reregistration of products containing the active ingredient diuron.

The Agency has completed its assessment of the occupational, residential, and ecological risks associated with the use of pesticide products containing the active ingredient diuron, as well as a diuron specific dietary risk assessment. Based on a review of these data and on public comments on the Agency's assessments for the active ingredient diuron, EPA has sufficient information on the human health and ecological effects of diuron to make decisions as part of the tolerance reassessment process under FFDCA and reregistration process under FIFRA, as amended by FQPA. EPA's tolerance reassessment decision was completed in July 2002, and has been included in this document. The Agency has determined that diuron products are eligible for reregistration provided that: ( i) current data gaps and confirmatory data needs are addressed; ( ii) the risk reduction measures outlined in this document are adopted; and ( iii) label amendments are made to reflect these measures. Label changes are described in Section V. Appendix A summarizes the uses of diuron that are eligible for reregistration. Appendix B identifies the generic data requirements that the Agency reviewed as part of its determination of reregistration eligibility of diuron, and lists the submitted studies that the Agency found acceptable. Data gaps are identified as generic data requirements that have not been satisfied with acceptable data.

Based on its evaluation of diuron, the Agency has determined that diuron products, unless labeled and used as specified in this document, would present risks inconsistent with FIFRA. Accordingly, should a registrant fail to implement any of the risk mitigation measures identified in this document, the Agency may take regulatory action to address the risk concerns from use of diuron. If all changes outlined in this document are incorporated into the product labels, then all current risks for diuron will be adequately mitigated for the purposes of this determination.

B. Public Comments and Responses When making its reregistration decision, the Agency took into account all comments received after opening of the public docket. These comments in their entirety are available in the docket ( OPP 2002 0249). Comments on the risk assessment were submitted by the registrant, Griffin LLC. A formal Agency response to these comments can be found in the following document which is available in the public docket: " HED Response to Public Comments on the Diuron Preliminary Risk Assessment" dated July 9, 2003. No other comments were received on the preliminary risk assessments for diuron. 82 C. Regulatory Position 1. FQPA Assessment a. " Risk Cup" Determination As part of the FQPA tolerance reassessment process, EPA assessed the risks associated with this pesticide. EPA has determined that risk from dietary ( food sources only) exposure to diuron is within its own " risk cup." An aggregate assessment was conducted for exposures through food, drinking water, and residential uses. The Agency has determined that the human health risks from these combined exposures are within acceptable levels. In other words, EPA has concluded that the tolerances for diuron meet the FQPA safety standards. In reaching this determination, EPA has considered the available information on the special sensitivity of infants and children, as well as the chronic and acute food exposure. The Tolerance Reassessment Decision was completed in July 2002, and can be found on the EPA website: http:// www. epa. gov/ oppsrrd1/ REDs/ diuron_ tred. pdf.

Some tolerances will change because the data indicate either that a lower or higher tolerance is needed. Some will be revoked because they are no longer a regulated commodity or significant livestock feed items. Some will be deleted because a crop group tolerance will be established.

b. Determination of Safety for U. S. Population In its July 2002, TRED, EPA determined that the established uses for diuron, with amendments and changes as specified in that document, met the safety standard under the FQPA amendments to section 408( b)( 2)( D) of the FFDCA, that there is a reasonable certainty of no harm for the general population. In reaching this determination, EPA considered all available information on the toxicity, use practices, and scenarios, and the environmental behavior of diuron. As discussed in chapter 3, an acute dietary risk assessment was not performed because no adverse effects attributed to a single exposure were identified in any available study. For chronic ( noncancer risk from food alone, the risks from diuron are not of concern. The estimated cancer dietary risk associated with the use of diuron indicates a slight exceedance above 1 x 10 6 and shows a lifetime risk estimate of 1.68 x 10  6 for the general population. However, the Agency has determined that potential dietary cancer risk is not of concern because the residues used in the calculations are from field trials conducted at the highest application rates and some residue processing data are still outstanding. Therefore, the exposure calculation is a conservative estimate.

Acute risks from drinking water exposures are not of concern. For chronic drinking water risk, drinking water monitoring data from Florida, California, and the U. S. Geological Survey National Water Quality Assessment ( NAWQA) Program were used to determine the estimated environmental concentrations ( EECs) in surface water. These monitoring data confirm that actual concentrations of diuron are substantially less than previous model estimates. Although modeled 83 estimates showed only a marginal exceedance of the DWLOC, monitoring data show concentrations substantially below the chronic DWLOC. Short term residential exposures to diuron are not of concern. The Agency has concluded that the potential cancer risk from residential use is negligible because of the low volume of diuron used in paint and the sporadic, short term duration of homeowner exposures.

c. Determination of Safety for Infants and Children In its July 2002 TRED, EPA determined that the established tolerances for diuron, meet the safety standards under the FQPA amendments to section 408( b)( 2)( C) of the FFDCA, that there is a reasonable certainty of no harm for infants and children. The safety determination for infants and children considered the factors noted above for the general population, but also takes into account the possibility of increased dietary exposure due to the specific consumption patterns of infants and children, as well as the possibility of increased susceptibility to the toxic effects of diuron residues in this population subgroup.

In determining whether or not infants and children are particularly susceptible to toxic effects from diuron residues, EPA considered the completeness of the database for developmental and reproductive effects, the nature of the effects observed, and other information. The FQPA Safety Factor has been removed ( i. e., reduced to 1x) for diuron because: 1) there is no indication of quantitative or qualitative increased susceptibility of rats or rabbits to in utero or postnatal exposure; 2) a DNT study with diuron is not required; and 3) the dietary ( food and drinking water) and non dietary ( residential) exposure assessments will not underestimate the potential exposures for infants and children.

d. Endocrine Disruptor Effects EPA is required under the FFDCA, as amended by FQPA, to develop a screening program to determine whether certain substances ( including all pesticide active and other ingredients) " may have an effect in humans that is similar to an effect produced by a naturally occurring estrogen, or other endocrine effects as the Administrator may designate." Following recommendations of its Endocrine Disruptor Screening and Testing Advisory Committee ( EDSTAC), EPA determined that there was scientific basis for including, as part of the program, the androgen and thyroid hormone systems, in addition to the estrogen hormone system. EPA also adopted EDSTAC's recommendation that EPA include evaluations of potential effects in wildlife. For pesticides, EPA will use FIFRA and, to the extent that effects in wildlife may help determine whether a substance may have an effect in humans, FFDCA authority to require the wildlife evaluations. As the science develops and resources allow, screening of additional hormone systems may be added to the Endocrine Disruptor Screening Program ( EDSP).

When the appropriate screening and/ or testing protocols being considered under the EDSP have been developed, diuron may be subject to additional screening and/ or testing to better characterize effects related to endocrine disruption. 84 e. Cumulative Risks The Food Quality Protection Act ( FQPA) requires that, when considering whether to establish, modify, or revoke a tolerance, the Agency consider " available information" concerning the cumulative effects of a particular pesticide's residues and " other substances that have a common mechanism of toxicity." Diuron is a dimethylurea herbicide. The Agency does not currently have data available to determine with certainty whether diuron has a common mechanism of toxicity with any other substances. Therefore for purposes of this Reregistration Eligibility Decision, the Agency has assumed that diuron does not have a common mechanism of toxicity with any other pesticides.

f. Tolerance Summary A summary of EPA's July 2002 diuron tolerance reassessment is presented in Table 24. The tolerance reassessment information is presented in this RED document for the sake of completeness and for the convenience of the reader. A full description of the tolerance reassessment can be found in the Residue Chemistry Assessment for diuron dated July 9, 2003. Diuron tolerances are currently expressed as diuron per se. The Agency is recommending that the tolerance expression for diuron be revised to include metabolites hydrolyzable to 3,4 dichloroaniline ( 3,4 DCA). This determination is based on the results of the reviewed plant and animal metabolism studies. Tolerances for residues of diuron in/ on plant and animal commodities are established under 40 CFR § 180.106.

Table 24. Tolerance Reassessment Summary for Diuron Commodity Established Tolerance ( ppm) 1 Reassessed Tolerance ( ppm) 2 Comment Correct Commodity Definition Tolerances Listed Under 40 CFR § 180.106( a)

Alfalfa 2 2/( TBD3) [ Alfalfa, forage]

2.0 [ Alfalfa, hay]

Apples 1 0.10 The available data indicate that the tolerance should be reduced to 0.10 ppm. [ Apple]

Artichokes 1 1/( TBD3) [ Artichoke, globe]

Asparagus 7 7.0 Treatment of asparagus is restricted to early season, prior to the appearance of asparagus spears.

Bananas 0.1 0.05 This tolerance should be reclassified under 180.106( c), as use of diuron on banana will be restricted to HI. The available data indicate that the tolerance should be reduced to 0.05 ppm. [ Banana] Commodity Established Tolerance ( ppm) 1 Reassessed Tolerance ( ppm) 2 Comment Correct Commodity Definition 85 Barley, grain 1 Reassign; 0.20 These tolerances should be reclassified under 180.106( c), as use of diuron on barley is restricted to western OR and WA. The available data indicate that the tolerance should be reduced to 0.20 ppm for barley, grain; and to 1.5 ppm for barley, straw. Barley, hay 2 Reassign; 2 Barley, straw 2 1.5 Birdsfoot trefoil, forage 2 0.10 T hese tolerances should be reclassified under 180.106( c), as use of diuron on trefoil is restricted to western OR. The available data indicate that the tolerance should be reduced to 0.10 ppm for birdsfoot trefoil, forage and to 0.15 ppm for birdsfoot trefoil, hay. Birdsfoot trefoil, hay 2 0.15 Blackberries 1 Reassign; 0.10 The established tolerances for blackberries, blueberries, boysenberries, currants, dewberries, gooseberries, huckleberries, loganberries, and raspberries should be revoked concomitant with the establishment of a tolerance for: The available data indicate that these tolerances should be reduced to 0.10 ppm. [ Berry Group]. Blueberries 1 Boysenberries 1 Currants 1 Dewberries 1 Gooseberries 1 Huckleberries 1 Loganberries 1 Raspberries 1 Cattle, fat 1 15 Cattle, meat 1 15 Cattle, meat byproducts 1 15 Citrus fruits 1 1/( TBD3) [ Fruit, citrus, group]

Citrus pulp, dried 4 4/( TBD3) [ Citrus, dried pulp]

Clover, forage 2 0.10 These tolerances should be reclassified under 180.106( c), as use of diuron on clover is restricted to western OR. The available data indicate that the tolerance should be reduced to 0.10 ppm for clover, forage and to 1 ppm for clover, hay. Clover, hay 2 1 Corn in grain or ear form ( including sweet corn, field corn, popcorn) 1 0.10 Concomitant with the reassignment of this tolerance, a separate tolerance should be established for [ Corn, field, grain]. The available data indicate that the tolerance should be reduced to 0.10 ppm. Commodity Established Tolerance ( ppm) 1 Reassessed Tolerance ( ppm) 2 Comment Correct Commodity Definition 86 1 0.10 Concomitant with the reassignment of this tolerance, a separate tolerance should be established for [ Corn, pop, grain]. The available data indicate that the tolerance should be reduced to 0.10 ppm.

1 0.10 Concomitant with the reassignment of this tolerance, a separate tolerance should be established for [ Corn, sweet, grain]. The available data indicate that the tolerance should be reduced to 0.10 ppm.

1 0.10 Concomitant with the reassignment of this tolerance, a separate tolerance should be established for [ Corn, field, ear]. The available data indicate that the tolerance should be reduced to 0.10 ppm.

1 0.10 Concomitant with the reassignment of this tolerance, a separate tolerance should be established for [ Corn, pop ear]. The available data indicate that the tolerance should be reduced to 0.10 ppm.

1 0.10 Concomitant with the reassignment of this tolerance, a separate tolerance should be established for [ Corn, sweet ear]. The available data indicate that the tolerance should be reduced to 0.10 ppm.

Corn, sweet, fodder 2 Revoke There are no registered uses of diuron on sweet corn. Corn, sweet, forage 2 Corn, field fodder 2 2/( TBD3) This tolerance was inadvertently omitted from the 1/ 14/ 98 Final Rule technical amendment consolidating 40 CFR parts 185 186 to 40 CFR part 180. This action will reinstate this tolerance to 40 CFR part 180.106. [ Corn, field, stover]

Corn, pop, fodder 2 2/( TBD3) This tolerance was inadvertently omitted from the 1/ 14/ 98 Final Rule technical amendment consolidating 40 CFR parts 185 186 to 40 CFR part 180. This action will reinstate this tolerance to 40 CFR part 180.106. [ Corn, pop, stover]

Corn, field forage 2 2/( TBD3) This tolerance was inadvertently omitted from the 1/ 14/ 98 Final Rule technical amendment consolidating 40 CFR parts 185 186 to 40 CFR part 180. This action will reinstate this tolerance to 40 CFR part 180.106. [ Corn, field, forage] Commodity Established Tolerance ( ppm) 1 Reassessed Tolerance ( ppm) 2 Comment Correct Commodity Definition 87 Corn, pop, forage 2 2/( TBD3) This tolerance was inadvertently omitted from the 1/ 14/ 98 Final Rule technical amendment consolidating 40 CFR parts 185 186 to 40 CFR part 180. This action will reinstate this tolerance to 40 CFR part 180.106. [ Corn, pop, forage]

Cottonseed 1 0.20 The available data indicate that the tolerance should be reduced to 0.20 ppm. [ Cotton, undelinted seed]

Goats, fat 1 15 [ Goat, fat]

Goats, meat 1 15 [ Goat, meat]

Goats, meat byproducts 1 15 [ Goat, meat byproducts]

Grapes 1 0.05 The available data indicate that the tolerance should be reduced to 0.05 ppm. [ Grape]

Grass crops ( other than Bermuda grass) 2 2/( TBD 3 ) [ Grass, forage, except Bermuda grass]

Grass, hay ( other than Bermuda grass hay) 2 2/( TBD 3 ) [ Grass, hay, except Bermuda grass]

Hogs, fat 1 15 [ Hog, fat]

Hogs, meat 1 15 [ Hog, meat]

Hogs, meat byproducts 1 15 [ Hog, meat byproducts]

Horses, fat 1 15 [ Horse, fat]

Horses, meat 1 15 [ Horse, meat]

Horses, meat byproducts 1 15 [ Horse, meat byproducts]

Nuts 0.1 0.1/( TBD3) Concomitant with the reassignment of this tolerance, separate a separate tolerance should be established for [ Filbert ].

0.05 Concomitant with the reassignment of this tolerance, separate a separate tolerance should be established for [ Nut, macadamia]. The available data indicate that the tolerance should be reduced to 0.05 ppm.

0.05 Concomitant with the reassignment of this tolerance, separate a separate tolerance should be established for [ Pecan]. The available data indicate that the tolerance should be reduced to 0.05 ppm. Commodity Established Tolerance ( ppm) 1 Reassessed Tolerance ( ppm) 2 Comment Correct Commodity Definition 88 0.05 Concomitant with the reassignment of this tolerance, separate a separate tolerance should be established for [ Walnut]. The available data indicate that the tolerance should be reduced to 0.05 ppm.

Oats, forage 2 2/( TBD3) These tolerances should be reclassified under 180.106( c), as use of diuron on oats is restricted to ID, OR, and WA. The available data indicate that the tolerance should be reduced to 0.10 ppm for oats, grain; and to 1.5 ppm for oats, straw. Oats, grain 1 0.10 Oats, hay 2 2/( TBD3)

Oats, straw 2 1.5 Olives 1 1/( TBD3) [ Olive]

Papayas 0.5 0.50 [ Papayas]

Peaches 0.1 0.10 [ Peach]

Pears 1 1/( TBD3) [ Pear]

Peas 1 0.10 The available data indicate that the tolerance should be reduced to 0.10 ppm. [ Pea, field, seed]

Peas, forage 2 2/( TBD3) [ Pea, field, vines]

Peas, hay 2 2/( TBD3) [ Pea, field, hay]

Peppermint, hay 2 1.5 The available data indicate that the tolerance should be reduced to 1.5 ppm. [ Peppermint, tops]

Pineapple 1 0.10 The available data indicate that the tolerance should be reduced to 0.10 ppm.

Potatoes 1 Revoke There are no registered uses of diuron on potatoes.

Rye, forage 2 Revoke There are no registered uses of diuron on rye. Rye, grain 1 Rye, hay 2 Rye, straw 2 Sheep, fat 1 15 Sheep, meat 1 15 Sheep, meat byproducts 1 15 Sorghum, fodder 2 2/( TBD3) [ Sorghum, grain, stover]

Sorghum, forage 2 2/( TBD3) [ Sorghum, grain, forage]

Sorghum, grain 1 0.50 The available data indicate that the tolerance should be reduced to 0.50 ppm. [ Sorghum, grain, grain] Commodity Established Tolerance ( ppm) 1 Reassessed Tolerance ( ppm) 2 Comment Correct Commodity Definition 89 Sugarcane 1 0.20 The available data indicate that the tolerance should be reduced to 0.20 ppm.

Vetch, forage 2 0.10 These tolerances should be reclassified under 180.106( c), as use of diuron on vetch is restricted to ID, OR, and WA. The available data indicate that these tolerances should be reduced to 0.10 ppm for vetch, forage and to 1.5 ppm for vetch, hay. Vetch, hay 2 1.5 Vetch, seed 1 Revoke No longer considered a significant livestock feed item.

Wheat, forage 2 2/( TBD3)

Wheat, grain 1 0.50 The available data indicate that the tolerance should be reduced to 0.50 ppm.

Wheat, hay 2 2/( TBD3)

Wheat, straw 2 1.5 The available data indicate that the tolerance should be reduced to 1.5 ppm.

Tolerance Listed Under 40 CFR § 180.106( b)

Catfish fillets 2.03 2.0 Expiration date of 06/ 30/ 05 [ Catfish]

Tolerances To Be Proposed Under 40 CFR § 180.106( a)

Aspirated grain fractions N/ A 5.0 Barley, bran N/ A 0.7 Citrus, oil N/ A TBD3 Cotton, gin byproducts N/ A TBD3 Eggs N/ A TBD3 Grass, seed screenings N/ A TBD3 Grass, straw N/ A TBD3 Milk N/ A TBD3 Pineapple, process residue N/ A 0.40 Poultry, meat byproducts N/ A TBD3 Prickly pear N/ A 0.05 Commodity Established Tolerance ( ppm) 1 Reassessed Tolerance ( ppm) 2 Comment Correct Commodity Definition 90 Spearmint N/ A 1.5 Sugarcane, molasses N/ A 0.70 Wheat, bran N/ A 0.70 1. Expressed as diuron per se, unless otherwise stated. 2. To be expressed as the combined residues of diuron and its metabolites convertible to 3,4 DCA, expressed as diuron. The residues of 3,4 DCA are low but diuron residues are converted to 3,4 DCA for the tolerance expression based on the assumption that the metabolites would not be any more toxic than diuron and the consideration that the analytical methods used to collect the field trial data are not capable of measuring each metabolite individually. The reassessed tolerances are contingent upon the recommended label revisions outlined in Table B of the Residue Chemistry Chapter For The Diuron Reregistration Eligibility Decision ( RED) Document, dated 7/ 29/ 2001. 3. TBD = To be determined. These commodities were included in the dietary risk assessment using the Current Tolerance level. Additional confirmatory field trial residue data are required; therefore, the final tolerance may be revised. 4. Expressed as combined residues of diuron and its metabolites convertible to 3,4 DCA. 5. 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. Residue data are not available for several potential feed items. If the maximum dietary burden does not increase when recalculated from all potential feed items after acceptable field trial data are submitted then the established tolerances for residues in fat, meat, and meat byproducts of cattle, goats, hogs, horses, and sheep can be lowered.

( 1) Codex Harmonization The Codex Alimentarius Commission has not established or proposed Codex MRLs for residues of diuron; therefore, there are no issues pertaining to harmonization of U. S. tolerances with Codex MRLs.

Canadian tolerances ( from PMRA web site) include the following:

7 ppm in/ on asparagus 1 ppm in/ on citrus, corn, grapes, pineapple, potatoes, and wheat.

Mexican tolerances ( from 1992 Diuron Residue Chemistry Registration Standard Update) are established for diuron as follows:

7 ppm in/ on asparagus 4 ppm in/ on dry citrus pulp 2 ppm in/ on alfalfa, corn ( forage), sorghum ( forage), wheat ( straw, forage) 1 ppm in/ on artichoke, cottonseed, sugarcane, citrus fruit, apple, corn grain, peaches, potatoes, pears, pineapple, sorghum ( grain), wheat ( grain and straw), and grapes. 0.5 ppm in/ on papaya 0.1 ppm in/ on nuts 91 D. Risk Management and Rationale The following is a summary of the rationale for managing risks associated with the use of diuron. Where labeling revisions are warranted, specific language is set forth in the summary tables of Section V of this document. Application rates have been reduced and retreatment intervals have been increased for ten crops. The risk reduction by these actions have not been quantified but will reduce exposure to diuron. Table 25 lists all the crops that have revised application rates and retreatment intervals.

Table 25. Revised Crop Parameters Crop Current Maximum Application Rate Current Number of Applications/ Retreatment Interval Revised Application Rate ( Annual Rate) Number of Applications/ Other Revisions Non Crop Areas/ Rights of Way 12 lb ai/ A ( typically 18 lb ai/ A year) Not Specified ( Typically 2) 8 lb ai/ A except in areas of high rainfall or dense vegetation1 ( 12 lb ai/ A per year) 2 applications, with a 90 day retreatment interval Citrus ( other than Flatwood area) 3.2 lb ai/ A No Limit ( 1.6  3.2 lb/ A per application to max of 6.4 lb/ A per year) 3.2 lb ai/ A ( 6.4 lb ai/ A per year) 2 applications, with a 60 day retreatment interval ( Trees < 4 years)

2 applications, with a 80 day retreatment interval ( Trees > 4 years)

Citrus ( Flatwood area) 6.4 lb ai/ A ( 9.6 lb ai/ A per year) No Limit ( 1.6  6.4 lb/ A per application to max of 9.6 lb/ A per year) 6.4 lb ai/ A ( 6.4lb ai/ A per year) 2 applications, with a 60 day retreatment interval ( Trees < 4 years)

2 applications, with a 80 day retreatment interval ( Trees > 4 years)

Apple 3.2 lb ai/ A 1 2 ( 1.6  3.2 lb/ A to max of 3.2 lb/ A per year) 3.2 lb ai/ A per year 1 2 applications, ( 1.6  3.2 lb/ A to max of 3.2 lb ai/ A per year), with a 90 day retreatment interval Alfalfa 3.2 lb ai/ A 1 application/ year 2.4 lb ai/ A per year 1 application Crop Current Maximum Application Rate Current Number of Applications/ Retreatment Interval Revised Application Rate ( Annual Rate) Number of Applications/ Other Revisions 92 Cotton 2.2 lb ai/ A Not Specified Preplant/ Preemergence ( 0.8  1.6 lb ai/ A) 3 applications, with total ai per season limited to 0.8 lb ai/ A on coarse soils, 1.5 lb ai/ A on medium soils and 2.2 lb ai/ A on fine soils, with a 21 day retreatment interval Post emergence: ( 0.8  1.2 lb ai/ A, depending upon soil texture)

Grapes 9.6 lb ai/ A 2 4 lb ai/ A ( 8 lb ai/ A per year) 2 applications, with a 90 day retreatment interval Filberts 4 lb ai/ A Not Specified ( typically 2) 2.2 lb ai/ A/ year 1.6 lb ai/ A ( 3.2 lb ai/ A maximum) 2 applications, with a 150 day retreatment interval Walnuts 4 lb ai/ A Not Specified ( typically 2) 2.2 lb ai/ A/ year 1.6 lb ai/ A 3.0 lb ai/ A maximum in CA ( 3.2 lb ai/ A maximum) 2 applications with a 150 day retreatment interval Peaches 4 lb ai/ A Not Specified ( typically 2) 1.6  2.2 lb ai/ A 1.6  3.0 lb ai/ A in CA Do not apply within 3 months of harvest Do not apply within 8 months of harvest in the western U. S.

Grass Seed Crops 3.2 lb ai/ A 1 2.4 lb ai/ A 1 application, aerial applications are limited to the pacific northwestern U. S.

1 High rainfall is defined as > 40 inches per year; high density vegetation is defined as > 90% weed ground cover.

1. Human Health Risk Management a. Dietary ( Food) Risk Mitigation Diuron is not acutely toxic. No adverse effects attributed to a single exposure were identified in any available study. Therefore, no acute dietary risk assessment was conducted and no mitigation is needed. 93 The chronic non cancer dietary analysis indicates all risk estimates are below the Agency's level of concern for all population subgroups for diuron. The highest chronic dietary risk estimates are 7% of the chronic PAD, for diuron, with the highest exposed population subgroup being children ( 1 6 years). Therefore, the chronic dietary ( food) risk estimate is not of concern, and no risk reduction measures are necessary.

In accordance with the EPA Draft Guidelines for Carcinogen Risk Assessment, the Cancer Assessment Review Committee has classified diuron as " known/ likely to be carcinogenic to humans." The lifetime dietary cancer risk estimate is 1.68x10 6 for diuron, representing a borderline exceedance. Generally, the Agency is concerned when cancer risk estimates exceed the range of 1x10 6 or one in one million, although this negligible risk standard should not be viewed as a brightline standard. As discussed previously, the residues used in the calculations are from field trials conducted at the highest application rates and from tolerance level residues from certain commodities. In addition, some processing data are still outstanding, which would enable further refinement to the risk assessment. Therefore, the exposure calculation is a conservative estimate and the Agency is not concerned with the dietary cancer risk from diuron use.

b. Drinking Water Risk Mitigation In the preliminary risk assessment for diuron, surface and groundwater concentrations were modeled based on application to citrus in Florida; the crop with the highest application rate. An application rate of 6.4 lbs ai/ acre could be applied, with a second application of diuron applied at a rate of 3.2 lbs ai/ acre applied later for the seasonal maximum application of 9.6 lbs ai/ acre. Based on information gathered after the initial risk assessment was prepared, the Agency has analyzed surface water monitoring data from Florida and California that has enabled us to conduct a more refined drinking water assessment. In addition, the registrant has agreed to reduce the application rate and increase the retreatment interval for citrus. The application rate on Florida citrus ( Flatwood area) is reduced to 6.4 lbs ai/ acre per year, with a 60 day retreatment interval for trees less than 4 years old and an 80 day retreatment interval for trees older than 4 years. Application rate reductions in other crops ( Table 25) will also serve to reduce drinking water exposure to diuron in drinking water.

c. Residential Risk Mitigation Residential exposure to diuron can occur when homeowners apply diuron treated paints or stains or apply diuron to ornamental ponds or aquariums. For residential paint and stain uses, the short term inhalation risk from exposure to the liquid formulation of diuron indicates that inhalation MOEs are more than the target of 100 with baseline level of clothing. Therefore, the short term risks to homeowners from paint and stain use is not of concern. Diuron application to ponds and aquariums is not of concern and does not require further mitigation. In addition, the registrant has agreed to eliminate diuron application to home lawns. 94 ( 1) Residential Handler Mitigation The lifetime cancer risk estimates for applying diuron treated paint and stain products once per year for 50 years range from 9.5x10 7 to 1.1x10 6. However, the Agency believes these exposures are not of concern because it is unlikely that a homeowner would apply diuron treated paint or stain every year for 50 years. In addition, approximately one percent of all paint contains diuron and that paint contains a maximum of 0.0532 lbs. of diuron per gallon. Therefore, the Agency believes the risks to homeowners from applying diuron treated paints and stains are negligible and not of concern. No further risk mitigation is necessary.

( 2) Residential Postapplication Risk Mitigation Post application exposure to diuron treated paints, and stains is anticipated to be only by the inhalation route, as the treated materials will have dried and be relatively inert. The results of Multi Chamber Concentration and Exposure Model, as discussed previously, coupled with diuron's low vapor pressure ( 2 x 10 7 mm Hg at 30

C), show negligible postapplication inhalation exposure. Furthermore, diuron treated paint is only likely to be used in rooms where high humidity is expected, such as a bathroom, and would rarely be used in the entire house. It is unlikely that a homeowner would receive a significant amount of postapplication inhalation exposure from diurontreated paint, as the very nature of its use is as a mildewcide, and any substantial loss of the active ingredient from the paint would render the product ineffective. No risk mitigation is necessary for postapplication exposure to homeowners.

d. Aggregate Risk Mitigation ( 1) Acute Aggregate Risk There are no adverse effects expected from a single exposure to diuron; therefore, an acute aggregate risk assessment was not conducted.

( 2) Short term Aggregate Risk Short term aggregate exposure takes into account residential exposure plus chronic exposure to food and water. Short term aggregate risks from food, residential inhalation, and drinking water are not of concern; therefore, no mitigation is required.

( 3) Chronic ( Non Cancer) Aggregate Risk The chronic ( non cancer) aggregate risk assessment addresses exposure to diuron residues in food and water; there are no diuron uses that could result in chronic residential exposure. The estimated environmental concentration ( EEC) for surface water (< 1 ppb) does not exceed the drinking water level of comparison ( DWLOC) of 28 ppb for the most sensitive population subgroup ( children 1 6). Chronic dietary ( food + water) risks are below EPA's level of concern. Chronic aggregate risk is also below EPA's level of concern; therefore, no mitigation is required. 95 ( 4) Chronic ( Cancer) Aggregate Risk As mentioned previously, dietary risk from food is estimated to slightly exceed 1 x 10 6, based on field trial data and assuming maximum application rates. This estimate can be refined with additional residue data. Based on monitoring data, drinking water cancer risk is estimated in the 1 x 10 6 range. Lifetime exposure from residential uses is negligible. Although the combined risk slightly exceeds 1 x 10 6, EPA believes that, given the weight of evidence, diuron cancer risk is not of concern. The Agency does not apply the negligible risk standard for cancer ( 1 x 10 6 or one in a million) as a bright line test because of the lack of precision in the quantitative cancer risk assessment. There are protective assumptions in both the toxicological data used to derive the cancer potency of a substance and in the exposure calculations. In addition, other risk mitigation measures discussed in this document will result in lower aggregate risks.

e. Occupational Risk Mitigation The Agency met with the registrant to discuss occupational risk mitigation on August 6, 2003 and September 10, 2003. Stakeholders submitted information regarding use rates, acreage, and use practices to the Agency in order to further refine the cancer risk assessment. This information was confirmed and used by the Agency to further characterize the occupational risks.

( 1) Handler Risk Mitigation Handler exposure assessments are completed by EPA using a baseline exposure scenario and, if required, increasing levels of mitigation ( PPE and engineering controls) to achieve an adequate margin of exposure ( MOE). For diuron the target MOE for workers is 100. Analyses for handler/ applicator exposures were performed using PHED, ORETF, and available studies. The non cancer calculations indicate that the MOEs for many handler scenarios including all agricultural applicator scenarios are above 100 at the baseline level and are not of concern. Generally for diuron, the worker risk mitigation is driven by the cancer assessment.

For occupational cancer risks between 1x10 6 and 1x10 4, EPA carefully evaluates exposure scenarios to seek cost effective ways to reduce cancer risks to the greatest extent feasible, preferably to a risk of 1x10 6 or less. For the scenarios listed below, EPA has determined that the use of PPE or engineering controls would further reduce exposure to handlers but for some scenarios, such as mixing/ loading and applying with a backpack sprayer, and applying with a rightsof way sprayer, engineering controls are not available. For other scenarios, such as applying granular formulations with a tractor drawn spreader, some engineering controls may be available but they are not universally used for this type of application. The Agency encourages the use of engineering controls in all settings where practical and feasible, and allows for handlers to reduce PPE when engineering controls are used. However, EPA concludes that the risk reduction potential of requiring engineering controls for additional scenarios would not be commensurate with the costs and difficulties associated with implementing the requirement. 96 To address cancer risks to occupational handlers, the registrant has agreed to the following mitigation measures, which are necessary, reasonable, and cost effective:

° Eliminate aerial applications except for rights of way, alfalfa, cotton, winter barley, winter wheat, sugarcane, and grass seed crops ( in the pacific northwestern U. S. only).

° All wettable powder products will be voluntarily canceled.

° Use of the pump feed backpack spreader and the gravity feed backpack spreader will be prohibited.

° Cancel use of diuron on home lawns.

° Application of diuron using a spoon will be prohibited.

EPA has determined that worker risks from exposure to diuron in the scenario listed below would be adequately mitigated through the use of the following PPE: long pants, long sleeved shirt, socks, shoes, and gloves.

° Applying Granular Formulations by Hand; ° Loading/ Applying Granular Formulations with a Belly Grinder; and ° Loading/ Applying Granular Formulations with a Push Type Spreader.

EPA has determined that worker risks from exposure to diuron in the scenarios listed below would be adequately mitigated through the use of the following PPE: long pants, long sleeved shirt, dust mist respirator, socks, shoes, and gloves:

° Loading Granular Formulation for Tractor Drawn Spreader Application; ° Applying Granular Formulations with a Tractor Drawn Spreader; ° Applying Sprays Using a Rights of Way Sprayer ( no PPE required in closed cab); ° Applying Sprays Using a High Pressure Handwand; ° Mixing/ Loading/ Applying Liquids Using a Low Pressure Handwand; and ° Mixing/ Loading/ Applying Liquids Using a Backpack Sprayer.

EPA has determined that worker risks from exposure to diuron in the scenarios listed below would be adequately mitigated through the use of the following PPE: long pants, long sleeved shirt, dust mist respirator, socks, shoes, gloves, and apron:

° Mixing/ Loading Liquids for Aerial Application; ° Mixing/ Loading Liquids for Chemigation Application; ° Mixing/ Loading Liquids for Groundboom Application; ° Mixing/ Loading Liquids for Rights of Way Application; ° Mixing/ Loading Liquids for High Pressure Handwand Application; ° Mixing/ Loading Dry Flowable for Aerial Application; 97 ° Mixing/ Loading Dry Flowable for Chemigation Application ° Mixing/ Loading Dry Flowable for Groundboom Application; ° Mixing/ Loading Dry Flowable for Rights of Way Application; and ° Mixing/ Loading Dry Flowable for High Pressure Handwand Application.

EPA has determined that worker risks from exposure to diuron in the scenario listed below would be adequately mitigated through the use of an enclosed cockpit or enclosed cab.

° Applying Sprays Aerially; and ° Flagging for Spray Applications.