0 **OFFICE OF CHEMCICAL SAFETY AND**  **POLLUTION PREVENTION UNITED STA** 

**TES ENVIRONMENTA L PROTECTION A** **GENCY WA** **SHINGTON , D.C. 20460** 

**PC Code: 119302**  **DP Barcode :**  **D368070 Date:**  **February 6, 2013 MEMORANDUM**  **SUBJECT** : Propamocarb hydrochloride (Propamocarb
- HCl) : Refined Drinking Water

Estimated Environmental Concentrations for use in the Human Health Risk Assessment in support of the proposed new use on Lima beans . **TO:** Laura Nollen, Risk Manager Reviewer

Barbara Madden, Risk Manager RIMUERB Registration Division (7505P) **AND:** Kelly

Lowe, Environmental Scientist Charles Smith, Acting Branch Chief RAB 1 Health Effects Division (7509P) **FROM:** Mohammed A. Ruhman , Senior Scientist

Environmental Risk Branch 5 Environmental Fate and Effects Division (7507P **) APPROVED**  **BY:** Mah Shamim, Branch Chief

Environmental Risk Branch 5 Environmental Fate and Effects Division (7507P **) EXECUTIVE SUMMARY**  This memo summarizes the revised /refined Tier IEstimated Drinking Water Concentrations (EDWCs) f

or propamocarb hydrochloride (propamocarb
- HCl) in support of the proposed new use on Lima beans
. P ropamocarb
- HCl (CAS 25606
- 41
- 1 ), a fungicide, is an active ingredient in several registered pesticide products , including Banol 432
- 942 (Bayer); Proplant 552 60
- 9 (Agriphar); Advan 83070
- 8 (Advan); VPP 59639
- 143 (Valent) ; and Previcure Flex 264
- 6781

(Bayer) **1** Based on the current labels for propamocarb
- HCl, **EDWCs** for surface waters are **8,762 ppb** of propamocarb
- HCl for **acute exposure, 1,067ppb**  of propamocarb
- HCl for **non -**  **cancer chronic exposure**  and **494 ppb** of propamocarb
- HCl for **cancer chronic exposure**
. **Acute/chronic EDWCs**  for ground waters is **15.6 ppb .**  **(1) BACKGROUND**  A drinking water assessment was executed for propamocarb
- HCl in 2003 (**Attachment 1**  **- 1**  , Drinking water memo of November 10, 2003; DP Barcode 267925). This 2003 assessment was evaluated along with this same proposed new use on Lima beans in 2009 (**Attachment 1**  **- 2:**  Drinking water memo of August 7 , 200 9 ; DP Barcode 359105). H owever, a potential higher rate to container
grown ornamental s was identified, modeled and gave the highest acute/chronic EDWCs. These EDWCs was reported, in the 2009 Memo (**Attachment 1**  **- 2**  ), to represent the Tier I EDWCs for use in the Human Health Risk Assessment. Iti s noted that the potential high rates for ornamentals were used in the assessment conservatively because labels didn’t indicate the maximum number of applications, nor did it limit the maximum amount applied/year. In January, 2012, the Agency requested the Registrants to mitig ate identified label issues in order to arrive at a more accurate estimation of application rates for ornamentals. The Registrants responded with new mitigated labels which are used as the basis for this current assessment. Additionally, in November, 2012 , a meeting was conducted between EFED, HED and RD and a refinement of the surface/ground water EDWCs from previous assessments was requested. This Memo contains the requested refinement. **(2) REFINED**  **EDWCs** In reference to the two previous EDWCs Memos, the fo llowing can be stated: (1) Acute and chronic EDWCs of propamocarb
- HCl for turf grass use were **972** and **77 pp**  b for surface water and **2.99 ppb**  for ground water. This was based on an application rate of 8.2 lbs ai/acre applied three times with a 7
- day retreatment interval (**Attachment 1 -**  **1)** ; (2) Acute and chronic EDWCs of propamocarb
- HCl for c ontainer
- grown ornamental use were **14,56 8**  **ppb** and **1,15 7**  ppb for surface water and **264** ppb for ground water
. This was based on 17 applications of 128 lbs a.i/A with a 21
- day reappli cation interval (**Attachment 1**  **- 1**  , Drinking water memo of August 7 , 200 9 ; DP Barcode 359105 ); and (3) Acute and chronic EDWCs of propamocarb
- HCl for Lima bean s use were **221** and **18 ppb** for surface water and **0.7 ppb**  for ground water. This was based on 4 applications of 1.5 lbs a.i/A with a 7 - day

reapplication interval (**Attachment 1**  **- 1:**  Drinking water memo of August 7 , 200 9 ; DP Barcode 359105 )
.

**1 Note:**  Banol C 432
- 961 was cancelled as per Bayer letter dated March 15, 2011.2

**(a) Refined**  **EDWCs from Surface Water Sources**  The requested refinement was executed for the EDWCs , for uses stated above , by executing Tier II PRZM/EXAMS modeling following steps stated hereunder: **Step 1:** labeled use patterns **Table 2**  represents a summary for the Lima beans, turf and ornamentals use patterns. The use rates stated in Table 2 represent the current mitigated labe ls f or turf and ornamentals. **Table 2**  Use rate Table for propamocarb
- HCLon selected crops (refer to abbreviations **1** ) **Label Use Pattern**  **MSR MNOA**  **MYR MAI**  **Notes**

Banol 432
- 942 ( Bayer) Turf 8.2 3 25 7 Seeding/Seedling 45.9 2 92 7 Transplant Cutting 64 2 128 7 One of the applications could be as high as 81.7 Woody Plants 64 2 128 7 One of the applications could be as high as 66.5 Potting: 4" 64 2 128 7 For > 4” pots (refer to note below) 2

Proplant 55260
- 9 (Agriphar) Turf 8.2 3 25 7 One of the applic ations could be as high as 81.7 Seeding/Seedling 46 2 82 7 Transplant Cutting 64 2 128 7 One of the applications could be as high as 81.7 Woody Plants 64 2 128 7 One of the applications could be as high as 66.5 Potting: 4" 64 2 128 7 For > 4” pots (refer to note below) 2

Advan 83070
- 8 (Advan) Turf 8.2 3 25 7 Seeding/Seedling 46 2 92 7 Transplant Cutting 64 2 128 7 One of the applications could be as high as 81.7 Woody Plants 64 2 128 7 One of the applications could be as high as 66.5 Potting: 4" 64 2 128 7 For > 4” pots (refer to note below) 2 VPP 59639
- 143 (Valent) Turf 2.1 2 4.2 14 Ornamental Use Omitted from L abel Previcure Flex 264
- 678 Lima beans 1.5 4 6.0 7 Draft label with submittal **1 Abbreviations:**  **MSR=** Maximum Single Rate (lbs a.i/A) ; **MNOA=** Maximum Number of Applications ; **MYR=**Maximum Yearly Rate (lbs a.i/A) assuming yearly rates= seasonal rates; **MAI=** Minimum Application Intervals (days) ; Numbers in Red are calculated
. **2 For**  **pot sizes >4”:**  It is assumed that the label yearly rate restricts the single rate per/pot and the number of pots that can be placed/treated per acre
.3

**Step 2 :**  Selection of use patterns, scenarios and other parameters needed for modeling: In formation and parameters needed for modeling Tier II PRZM/EXAMS are summarized in **Tables 3** and **4**
. **Table 3**  Selected use parameters scenarios and others used for refining EDWCs for p ropamocarb
- HCl at Tier II
**Crop Type of Application**  **Application Parameters: Maximum Application Rates/ Number**  **& Minimum Intervals (Days)**  **Scenarios, and (** **Windo w**  **for 1 st**  **Applicatio n)**  **1 Single**  **lb a.i./A (Kg/A** 

**) Number**  **Intervals** Lima Beans Ground/Air (Foliar) 1.5 (1.7) 4 7 MI beans ( June - July) Turf Ground (Foliar) 8.2 (9.2) 3 7 CA/FL/PA turf ( May- June ) Ornamentals Soil Drench 64.3 (72. 1) 2 7 CA/FL/MI/NJ/OR/TN n ursery (All year) 1 Crop profiles: http://www.ipmcenters.org/cropprofiles/CP_form.cfm **Table 4**  Summary of PRZM/EXAMS input parameters for modeling propamocarb
- HC l Input Parameter (Unit) Value References Molecular Weight g/mole **224.73 Product chem** **istry** Henry’s constant (atm
- m3 mo l - 1 @ 20 o C) **2.5 x 10**  **- 1**  **3 (for both)**  **Calculated from Vapor Pressure (MRID 433684**  **- 09)**  Solubility in Water(mg/L) **>700,000 Product chem** **ist ry**  Photolysis in Water (t1⁄2 in days @ pH 7) **Stable MRID**  **000712 -**  **96** Aerobic Soil Metabolism s) **20.6 Table 4 (Attachm**  **ent 1 -**  **2 )**  Hydrolysis (t1⁄2 in days) **Stable MRID 000712**  **- 97**  Aerobic Aquatic Metabolism (Whole system t1⁄2 in days) **61.8 3 x 20.6 (Aerobic Soil ha**  **lf -**  **life)= 61.8 days** Anaerobic Aquatic Metabolism (Whole system t1⁄2 in days) **276 One value 92 (MRID 445385**  **- 04) x 3= 184 days**  Kd (Average in L/Kg) **4.68 MRIDs: 412781**  **- 30 and 458943**  **- 21**  Chemical Application Method (CAM) **2 for foliar (turf)**  **1 for Drench Param** **e ter Guidance**  **2 . In referenced Guidance, no** 

**value was given to ornam ental drench application.**  **For ornam ental Drench: no drift is expected (value=**  **0%); and CAM= 1 because drench= soil applied to possible incorporation (pesticide is applied with**  Application Efficiency **99% for ground 95% for Air**  **100% for Drench**

2 Guidance for Selecting Input P arameters in Modeling the Environmental Fate and Transport of Pesticides. URL : http://www.epa.gov/oppefed1/models/water/input_parameter_guidance.htm#Przm4

Input Parameter (Unit) Value References Spray Drift Fraction **Ground =**  **0.063 Air= 0.16**  **Drench= 0.00 penetrating w**  **ater) assum ing to a depth of 4 cm**  Percent Crop Area (PCA) **100% Multiple crops including ornam** **entals PCA Guidance**  **3** A total of 260 PRZM/EXAMS runs were executed the three scenarios using the multiple run feature of the graphical interface PE
- 5. **Table 5**  contains a summary of the results. **Step 3 :**  Model specified scenarios using PE
- 5/Multi
- run graphical interface for PRZM/EXAMS **Ta ble 5**  contains a summary for various PRZM/EXAMS runs. Data suggest that the highest EDWCs for surface waters are **8,762 ppb** of propamocarb
- HCl for acute exposure, 1 **,067ppb** of propamocarb
- HCl for non - cancer chronic exposure and **494 ppb** of propamocarb
- HCl for cancer chronic exposure. Scenarios giving these exposure values are for the ornamentals use pattern of FL nursery

(acute value) and MI

nursery (both chronic values). **Table 5** A S ummar

y for PRZM/EXAMS runs (EDWCs in **μg/L)**

**Scenario Application**  **Type Application** 

**Windo w**  **(DD/MM) Run**  **Dat e**  **Intervals N** 

**o. of**  **Runs Per**  **Scenario Total** 

**N o of**  **Runs Peak (μg/L)**  **Yearly Average 30** **- YearAverage**  **Acute Non**  **- Cancer Chronic**  **Cancer Chronic**  **Min Max**  **Min Max**  **Min Max**  Lima Beans Aerial 0 1
- 06 to 31
- 08 Every week 14 14x2= 28 138 373 40 102 28 52 Ground Every week 14 14x2= 28 127 367 36 98 23 48 Turf Ground
- FL 01
- 05 to 28
- 08 Every week 18 18x 1= 18 73 494 27 207 19 76 Ornamentals: FL Soil Drench 01
- 01 to 02
- 12 Every

Two we eks 18 18x2= 36 114 **8 ,**  **762** 154 995 10 2 344 Ornamentals: Others Soil Drench 25 25x6= 150 0.9 4 , 104 0.2 **1 ,**  **067** 0.1 **494**

**(b) Refined EDWCs from**  **Ground Water Sources**  Tier ISCIGRO modeling for turf and Lima beans stays the same as stated in the previous EDWC Memo (**Attachment 1 -**  **2** ) because application rates did not change. These acute/chronic values are **2.99 ppb** of propamocarb
- HCl for turf and **0.7 ppb** of propamocarb
- HCl for Lima beans. Based on the maximum application rate for current ornamental labels ( 2 x 64.3 lbs ai/A) , the acute/chronic EDWCs f

or ground water is **15.6 ppb**  of propamocarb
- HCl noting that the same chemical parameters were used for running SCIGRO ( **Table 5, Attachment 1 -**  **2** ).

3 Deve lopment and Use of Percent Cropped Area and Percent Turf Area Adjustment Factors in Drinking Water Exposure Assessments: 2012 Update. URL: http://www.epa.gov/oppefed1/models/water/pca_adjustment_dwa.pdf