Document ID: EPA-HQ-OPP-2008-0887-0008
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2013-06-05T04:00Z

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 (Bayer) 

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.

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 container-grown 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.

REFINED EDWCs

In reference to the two previous EDWCs Memos, the following can be
stated:

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);

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

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).

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.

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:   HYPERLINK
"http://www.ipmcenters.org/cropprofiles/CP_form.cfm" 
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-m3 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 (t½ in days @ pH 7)	Stable	MRID 000712-96

Aerobic Soil Metabolism s)	20.6	Table 4 (Attachment 1-2) 

Hydrolysis (t½ in days)	Stable	MRID 000712-97

Aerobic Aquatic Metabolism (Whole system t½ in days)	61.8	3 x 20.6
(Aerobic Soil half-life)= 61.8 days

Anaerobic Aquatic Metabolism (Whole system t½ 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 Guidance. 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 possible incorporation (pesticide is
applied with penetrating water) assuming to a depth of 4 cm 

Application Efficiency	99% for ground

95% for Air

100% for Drench

	Spray Drift Fraction	Ground= 0.063

Air= 0.16

Drench= 0.00

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

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

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).

 Note: Banol C 432-961 was cancelled as per Bayer letter dated March 15,
2011.

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

URL:  HYPERLINK
"http://www.epa.gov/oppefed1/models/water/input_parameter_guidance.htm"
\l "Przm"
http://www.epa.gov/oppefed1/models/water/input_parameter_guidance.htm#Pr
zm  

 Development and Use of Percent Cropped Area and Percent Turf Area
Adjustment Factors in

Drinking Water Exposure Assessments: 2012 Update. 

URL:  HYPERLINK
"http://www.epa.gov/oppefed1/models/water/pca_adjustment_dwa.pdf"
http://www.epa.gov/oppefed1/models/water/pca_adjustment_dwa.pdf   

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