0

OFFICE OF

CHEMCICAL SAFETY AND

POLLUTION PREVENTION

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, 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 I Estimated Drinking Water Concentrations 

(EDWCs) for propamocarb hydrochloride (propamocarb-HCl) in support of the proposed new

use on Lima beans. Propamocarb-HCl (CAS 25606-41-1), a fungicide, is an active ingredient in 

several registered pesticide products, including Banol 432-942 (Bayer); Proplant 55260-9 

(Agriphar); Advan 83070-8 (Advan); VPP 59639-143 (Valent); and Previcure Flex 264-678
1

(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, 2009; DP Barcode 359105). However, a potential higher rate to containergrown ornamentals 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. It is 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 mitigate 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 following can be stated:

(1) Acute and chronic EDWCs of propamocarb-HCl for turf grass use were 972 and 77 ppb 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 container-grown ornamental use were 

14,568 ppb and 1,157 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 reapplication interval (Attachment 1-1, 

Drinking water memo of August 7, 2009; DP Barcode 359105); and

(3) Acute and chronic EDWCs of propamocarb-HCl for Lima beans 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, 

2009; 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 labels for turf and ornamentals.

Table 2 Use rate Table for propamocarb-HCL on selected crops (refer to abbreviations1)

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 applications 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 Label

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:

Information 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 

propamocarb-HCl at Tier II

Crop Type of Application

Application Parameters: Maximum 

Application Rates/ Number & 

Minimum Intervals (Days)

Scenarios, and

(Window for 1st Application)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 nursery (All 

year)

1 Crop profiles: http://www.ipmcenters.org/cropprofiles/CP_form.cfm

Table 4 Summary of PRZM/EXAMS input parameters for modeling propamocarb-HCl

Input Parameter (Unit) Value References

Molecular Weight g/mole 224.73 Product chemistry

Henry’s constant (atm-m

3 mol-1 @ 20 oC) 2.5 x 10-13

(for both) Calculated from Vapor Pressure (MRID 433684-09)

Solubility in Water(mg/L) >700,000 Product chemistry

Photolysis in Water (t1⁄2 in days @ pH 7) Stable MRID 000712-96

Aerobic Soil Metabolism s) 20.6 Table 4 (Attachment 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 half-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

Parameter Guidance2. In referenced Guidance, no 

value was given to ornamental drench application. 

For ornamental Drench: no drift is expected (value= 

0%); and CAM= 1 because drench= soil applied to 

Application Efficiency possible incorporation (pesticide is applied with 

99% for ground

95% for Air

100% for Drench

 

2 Guidance for Selecting Input Parameters in Modeling the Environmental Fate and Transport of Pesticides. 

URL: http://www.epa.gov/oppefed1/models/water/input_parameter_guidance.htm#Przm
4

Input Parameter (Unit) Value References

Spray Drift Fraction

Ground= 0.063

Air= 0.16

Drench= 0.00

penetrating water) assuming to a depth of 4 cm

Percent Crop Area (PCA) 100% Multiple crops including ornamentals PCA Guidance3

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

Table 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 Summary for PRZM/EXAMS runs (EDWCs in μg/L)

Scenario

Application 

Type

Application 

Window 

(DD/MM)

Run Date

Intervals

No. of

Runs

Per

Scenario

Total 

No of Runs

Peak (μg/L) Yearly Average

30-

YearAverage

Acute Non-Cancer Chronic

Cancer 

Chronic

Min Max Min Max Min Max

Lima Beans

Aerial 01-06 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

weeks

18 18x2= 36 114 8,762 154 995 102 344

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 I SCIGRO 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 for 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 Development 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