UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C. 20460

OFFICE OF

PREVENTION, PESTICIDES, AND

TOXIC SUBSTANCES

			PC Code:	 098301

			DP barcode: D331981

MEMORANDUM						

August 25th, 2006

Subject:	Aldicarb - Ecological risk results for alternative application
rate and incorporation efficiencies

To:	Bob McNally, Branch Chief

	Sherrie Kinard, Review Manager

Special Review Branch

Special Review and Reregistration Division

From:		Jonathan Angier

		Jeannette Martinez

		Donna Randall	

Environmental Risk Branch II 

Environmental Fate and Effects Division 

Through:	Dana Spatz, RAPL

Tom Bailey, Ph.D, Branch Chief, ERB II, 

Environmental Fate and Effects Division 

In response to your request, the following assessment includes
alternative application rates and granule incorporation efficiencies to
help characterize the aldicarb ecological risk assessment. Aquatic RQs
and mitigation option:

EFED has modeled maximum and EPA typical application rate scenarios at
99% incorporation efficiency for cotton, potato, citrus, soybeans, and
pecans which include incorporation methods such as banded/sidedress and
in-furrow. EPA believes that a 99% incorporation efficiency is
over-optimistic.  Although 99% efficiency may be achievable under ideal
circumstances with optimally calibrated equipment, under most field
conditions there is likely to be less efficiency due to non-ideal field
settings (e.g., soil too wet or too dry, uneven topography, natural
small-scale spatial variations in soil surface texture, crusting,
shallow hardpans, etc.), handling error, and other unforeseen
circumstances. Furthermore, 99% incorporation assumptions are
non-achievable for post-emergent, side-dress applications such as, for
example, for cotton and citrus. 

There are listed species Level of Concern (LOC) exceedances for almost
all modeled maximum application rate scenarios. However, modeled EPA
typical application rates lead to risk below the LOCs for all aquatic
animals except for listed estuarine/marine invertebrates (pecan,
cotton). If EPA typical application rates became the ‘new’ maximum
possible application rates on the newest TEMIK® label, then risk for
aquatic organisms would be greatly reduced. Present maximum and EPA
typical application rates, crops, and their respective RQs are listed in
the Tables 1a through 4.b. Below is a summary of Tables 1.a through 4.b.

1. Freshwater and estuarine/marine Fish:

a. Maximum application rates at 99% incorporation efficiency assumption
eliminate all acute LOC exceedances for non-listed organisms (LOC >0.5).


There are LOC exceedances for listed species (LOC >0.05); exceedances
are for cotton, pecans, and soybeans with RQs ranging from 0.05-0.1.

 

There are chronic LOC exceedances for cotton, soybeans, and pecans with
RQs ranging from 1.0-4.6.

b. EPA typical application rates at 99% incorporation efficiency
assumption eliminate all acute LOC exceedances for non-listed and listed
organisms (LOC >0.05).

2. Freshwater and estuarine/marine invertebrates:

a. Maximum application rates at 99% incorporation efficiency assumption
eliminate all acute LOC exceedances for non-listed organisms (LOC >0.5).

There are LOC exceedances for listed species (LOC >0.05); exceedances
are for all uses except for potato with RQs ranging from 0.05-0.3

There are chronic LOC exceedances for cotton and pecans with RQs ranging
from 1.6-3.0.

b. EPA typical application rates at 99% incorporation efficiency
assumption eliminate all acute LOC exceedances for non-listed organisms
(LOC >0.5). 

There are LOC exceedances for listed species (LOC >0.05); exceedances
are for cotton and pecans with RQs of 0.06 and 0.07, respectively.

Table 1.a.  Aldicarb: Acute and chronic RQs for freshwater fish using
maximum application rates with 99% incorporation efficiency 

Site/Rate in lbs ai/Acre (no. of apps)	LC50

(ppb)	NOAEC

(ppb)	EEC Initial/Peak (ppb)	EEC 60 day average (ppb)	Acute RQ
(EEC/LC50)	Chronic RQ (EEC/ENEC)

Cotton

4.05 (1 apps)	52	0.46	4.047	1.6635	0.08**	3.6

Cotton

4.95 (2 apps)1	52	0.46	2.9227	1.1521	0.06**	2.5

Potato

3.0 (1 app)	52	0.46	0.23163	0.114533	0.004	0.25

Citrus

4.95 (1 app)1	52	0.46	0.64165	0.20684	0.01	0.4

Soybeans

3.0 (1 app)	52	0.46	1.3739	0.45791	0.009	1.0

Pecans

10.05 (1 app)	52

	0.46	2.5716	0.84294	0.05**	1.8



Bluegill sunfish LC50 = 52 ppb

Bluegill sunfish ENEC = 0.46 ppb

199% incorporation efficiency is non-achievable for post-emergent
applications and for trees

Table 1.b. Aldicarb: Acute and chronic RQs for freshwater fish using
typical application rates with 99% incorporation efficiency

Site/Rate in lbs ai/Acre (no. of apps)	LC50

(ppb)	NOAEC

(ppb)	EEC Initial/Peak (ppb)	EEC 60 day average (ppb)	Acute RQ
(EEC/LC50)	Chronic RQ (EEC/ENEC)

Cotton

0.6 (2 apps) 1	52	0.46	0.70432	0.27783	0.01	0.6

Potato

0.9 (1 app)	52	0.46	0.20824	0.102933	0.004	0.2

Citrus

3.7 (1 app) 1	52	0.46	0.48075	0.15498	0.009	0.3

Soybeans

0.7 (1 app)	52	0.46	0.31896	0.10627	0.006	0.2

Pecans

3.1 (1 app)	52	0.46	0.79222	0.25975	0.02	0.6



Bold RQs = acute and chronic LOC exceedances for non-listed species; * =
restricted use LOC exceedances; ** = listed LOC exceedances 

199% incorporation efficiency is non-achievable for post-emergent
applications and for trees

Table 2.a. Aldicarb: Acute and chronic RQs for freshwater inverts using
maximum application rates with 99% incorporation efficiency 

Site/Rate in lbs ai/Acre (no. of apps)	LC50

(ppb)	NOAEC

(ppb)	EEC Initial/Peak (ppb)	EEC 21 day average (ppb)	Acute RQ
(EEC/LC50)	Chronic RQ (EEC/NOAEC)

Cotton

4.05 (1 apps)	20	1	4.047	2.9952	0.2*	3.0

Cotton

4.95 (2 apps) 1	20	1	2.9227	2.0098	0.1*	2.0

Potato

3.0 (1 app)	20	1	0.23163	0.18288	0.006	0.2

Citrus

4.95 (1 app) 1	20	1	0.64165	0.40558	0.03	0.4

Soybeans

3.0 (1 app)	20	1	1.3739	0.89727	0.07**	0.9

Pecans

10.05 (1 app)	20	1	2.5716	1.664	0.1*	1.6

Chironomus tetanus LC50 = 20 ppb

Mysidopsis bahia NOAEC = 1.0 ppb

Table 2.b. Aldicarb: Acute and chronic RQs for freshwater inverts using
typical application rates with 99% incorporation efficiency 

Site/Rate in lbs ai/Acre (no. of apps)	LC50

(ppb)	NOAEC

(ppb)	EEC Initial/Peak (ppb)	EEC 21 day average (ppb)	Acute RQ
(EEC/LC50)	Chronic RQ 

(EEC/ NOAEC)

Cotton

0.6 (2 apps) 1	20	1	0.70432	0.48454	0.04	0.5

Potato

0.9 (1 app)	20	1	0.20824	0.16432	0.01	0.2

Citrus

3.7 (1 app) 1	20	1	0.48075	0.30386	0.02	0.3

Soybeans

0.7 (1 app)	20	1	0.31896	0.2083	0.02	0.2

Pecans

3.1 (1 app)	20	1	0.79222	0.51287	0.04	0.4



Bold RQs = acute and chronic LOC exceedances for non-listed species; * =
restricted use LOC exceedances; ** = listed LOC exceedances

199% incorporation efficiency is non-achievable for post-emergent
applications and for trees

Table 3. a. Aldicarb: Acute and chronic RQs for estuarine/marine fish
using maximum application rates with 99% incorporation efficiency 

Site/Rate in lbs ai/Acre (no. of apps)	LC50

(ppb)	NOAEC

(ppb)	EEC Initial/Peak (ppb)	EEC 60 day average (ppb)	Acute RQ
(EEC/LC50)	Chronic RQ (EEC/ENEC)

Cotton

4.05 (1 apps)	41	0.36	4.047	1.6635	0.1*	4.6

Cotton

4.95 (2 apps) 1	41	0.36	2.9227	1.1521	0.07**	3.2

Potato

3.0 (1 app)	41	0.36	0.23163	0.114533	0.006	0.3

Citrus

4.95 (1 app) 1	41	0.36	0.64165	0.20684	0.02	0.6

Soybeans

3.0 (1 app)	41	0.36	1.3739	0.45791	0.03	1.3

Pecans

10.05 (1 app)	41	0.36	2.5716	0.84294	0.06**	2.3

Sheepshead minnow LC50 = 41 ppb

Sheepshead minnow ENEC = 0.36 ppb

199% incorporation efficiency is non-achievable for post-emergent
applications and for trees

Table 3.b. Aldicarb: Acute and chronic RQs for estuarine/marine fish
using typical application rates with 99% incorporation efficiency 

Site/Rate in lbs ai/Acre (no. of apps)	LC50

(ppb)	NOAEC

(ppb)	EEC Initial/Peak (ppb)	EEC 60 day average (ppb)	Acute RQ
(EEC/LC50)	Chronic RQ (EEC/ENEC)

Cotton

0.6 (2 apps) 1	41	0.36	0.70432	0.27783	0.02	0.8

Potato

0.9 (1 app)	41	0.36	0.20824	0.102933	0.005	0.3

Citrus

3.7 (1 app) 1	41	0.36	0.48075	0.15498	0.01	0.4

Soybeans

0.7 (1 app)	41	0.36	0.31896	0.10627	0.008	0.3

Pecans

3.1 (1 app)	41	0.36	0.79222	0.25975	0.02	0.7



Bold RQs = acute and chronic LOC exceedances for non-listed species; * =
restricted use LOC exceedances; ** = listed LOC exceedances 

199% incorporation efficiency is non-achievable for post-emergent
applications and for trees

Table 4.a. Aldicarb: Acute and chronic RQs for estuarine/marine inverts
using maximum application rates with 99% incorporation efficiency 

Site/Rate in lbs ai/Acre (no. of apps)	LC50

(ppb)	NOAEC

(ppb)	EEC Initial/Peak (ppb)	EEC 21 day average (ppb)	Acute RQ
(EEC/LC50)	Chronic RQ (EEC/NOAEC)

Cotton

4.05 (1 apps)	12	1	4.047	2.9952	0.3*	3.0

Cotton

4.95 (2 apps) 1	12	1	2.9227	2.0098	0.2*	2.0

Potato

3.0 (1 app)	12	1	0.23163	0.18288	0.02	0.2

Citrus

4.95 (1 app) 1	12	1	0.64165	0.40558	0.05**	0.4

Soybeans

3.0 (1 app)	12	1	1.3739	0.89727	0.1*	0.9

Pecans

10.05 (1 app)	12	1	2.5716	1.664	0.2*	1.6

Pink shrimp LC50 = 12 ppb

Mysidopsis bahia NOAEC = 1 ppb

199% incorporation efficiency is non-achievable for post-emergent
applications and for trees

Table 4.b. Aldicarb: Acute and chronic RQs for estuarine/marine inverts
using typical application rates with 99% incorporation efficiency 

Site/Rate in lbs ai/Acre (no. of apps)	LC50

(ppb)	NOAEC

(ppb)	EEC Initial/Peak (ppb)	EEC 21 day average (ppb)	Acute RQ
(EEC/LC50)	Chronic RQ 

(EEC/ NOAEC)

Cotton

0.6 (2 apps) 1	12	1	0.70432	0.48454	0.06**	0.5

Potato

0.9 (1 app)	12	1	0.20824	0.16432	0.02	0.2

Citrus

3.7 (1 app) 1	12	1	0.48075	0.30386	0.04	0.3

Soybeans

0.7 (1 app)	12	1	0.31896	0.2083	0.03	0.2

Pecans

3.1 (1 app)	12	1	0.79222	0.51287	0.07**	0.4



Bold RQs = acute and chronic LOC exceedances for non-listed species; * =
restricted use LOC exceedances; ** = listed LOC exceedances 

199% incorporation efficiency is non-achievable for post-emergent
applications and for trees

Terrestrial RQs and mitigation options:

Current 85% (banded/sidedress) and 99% (in-furrow) incorporation
efficiency assumptions (Bayer Crop Science and EPA) do not reduce the
level of risk to avian and mammalian species below the Level Of Concern
(LOC). EFED modeled 99% (for banded/sidedress), 99.5% (banded/sidedress
and in-furrow) and 99.9% (banded/sidedress and in-furrow) incorporation
efficiency at EPA typical application rates to investigate whether such
assumptions, albeit unrealistic, would reduce the risk to below LOC for
terrestrial wildlife. None of the modeling scenarios decreased the avian
or the mammalian risk beyond Agency level of concern for any of the
crops. Table 5 and 6 list the crops, application rates, application
methods and RQs for avian and mammalian species.



Table 5. Aldicarb: Recalculated acute avian RQs for different
incorporation efficiencies at typical application rates with different
incorporation efficiencies

Crop Scenario	Bird Type	Typical Application





Rate

(lbs ai/A)	RQ

(85% incorporated)	RQ

(99% incorporated)	RQ

(99.5% incorporated)	RQ

(99.9% incorporated)

Cotton1

Banded/Sidedress

4” band width

40” row spacing	Small Bird

Medium Bird

Large Bird	0.6

0.6

0.6	947.5

148.9

10.5	60.2

9.5

0.7	30.1

4.7

0.3*	6.0

1.1

0.7

Dry Beans

Banded

6” band width

48” row spacing	Small Bird

Medium Bird

Large Bird	1.0

1.0

1.0

	1247.6

196.0

13.4	80.2

12.6

0.9	40.1

6.3

0.5	8.0

1.3

0.09

Sorghum

Banded

2” band width

36” row spacing	Small Bird

Medium Bird

Large Bird	0.4

0.4

0.4	N/A

N/A

N/A	73.4

11.5

0.8	36.1

5.7

0.4*	7.2

1.1

0.08

Peanuts

Banded

6” band width

36” row spacing	Small Bird

Medium Bird

Large Bird	0.9

0.9

0.9	842.1

132.2

9.4	54.2

8.5

0.6	27.1

4.3

0.3*	5.4

0.9

0.06

Potatoes

Banded

6” band width

38” row spacing	Small Bird

Medium Bird

Large Bird	2.7

2.7

2.7	2666.7

419.0

29.7	171.5

26.9

1.9	85.7

13.5

1.0	17.2

2.7

0.2*

Soybeans

Banded

6” band width

30” row spacing	Small Bird

Medium Bird

Large Bird	0.7

0.7

0.7	545.8

85.8

6.1	35.1

5.5

0.4*	17.6

2.8

0.2*	3.5

0.6

0.04

Sugar Beets

Banded

6” band width

22” row spacing	Small Bird

Medium Bird

Large Bird	1.8

1.8

1.8	972.1

152.7

10.8	66.2

10.4

0.7	33.1

5.2

0.4*	6.6

1.1

0.07

Sweet Potatoes

Banded

12” band width

48” row spacing	Small Bird

Medium Bird

Large Bird	1.4

1.4

1.4	N/A

N/A

N/A	58.2

9.2

0.7	28.1

4.4

0.3*	5.6

0.9

0.1**



Mallard duck LD50 = 1 mg/kg- bw

Rat LD50 = 0.9 mg/kg-bw

199% incorporation efficiency is non-achievable for post-emergent
applications and for trees

Italicized numbers are RQs published in May 2006 RED; un-italicized
represent RQs from new modeling scenarios.

Bold RQs = acute and chronic LOC exceedances for non-listed species; * =
restricted use LOC exceedances; ** = listed LOC exceedances



Table 6. Aldicarb: Recalculated acute mammalian RQs for different
incorporation efficiencies at typical application rates with different
incorporation efficiencies

Crop Scenario	Mammal Type	Typical Application 





Rate

(lbs ai/A)	RQ

(85% incorporated)	RQ

(99% incorporated)	RQ

(99.5% incorporated)	RQ

(99.9% incorporated)

Cotton1

Banded/Sidedress

4” band width

40” row spacing	Small Bird

Medium Bird

Large Bird	0.6

0.6

0.6	320.1

169.6

13.7	21.1

11.2

0.9	10.5

5.6

0.5	2.1

1.1

0.09

Dry Beans

Banded

6” band width

48” row spacing	Small Bird

Medium Bird

Large Bird	1.0

1.0

1.0

	421.5

223.3

18.1	28.1

14.9

1.2	14.0

7.4

0.6	2.8

1.5

0.1**

Sorghum

Banded

2” band width

36” row spacing	Small Bird

Medium Bird

Large Bird	0.4

0.4

0.4	N/A

N/A

N/A	24.8

13.1

1.1	12.6

6.7

0.5	2.5

1.3

0.1**



Peanuts

Banded

6” band width

36” row spacing	Small Bird

Medium Bird

Large Bird	0.9

0.9

0.9	284.5

150.7

12.2	19.0

10.0

0.8	9.5

5.0

0.4*	1.9

1.0

0.08

Potatoes

Banded

6” band width

38” row spacing	Small Bird

Medium Bird

Large Bird	2.7

2.7

2.7	900.0

477.2

38.6	60.0

31.8

2.6	30.0

15.9

1.3	6.0

3.2

0.3*

Soybeans

Banded

6” band width

30” row spacing	Small Bird

Medium Bird

Large Bird	0.7

0.7

0.7	184.4

97.7

7.9	12.3

6.5

0.5	6.1

3.3

0.3*	1.2

0.7

0.05

Sugar Beets

Banded

6” band width

22” row spacing	Small Bird

Medium Bird

Large Bird	1.8

1.8

1.8	328.4

174.0

14.1	23.2

12.3

1.0	11.6

6.1

0.5	2.3

1.2

0.1**

Sweet Potatoes

Banded

12” band width

48” row spacing	Small Bird

Medium Bird

Large Bird	1.4

1.4

1.4	N/A

N/A

N/A	19.7

10.4

0.8	9.8

5.2

0.4*	2.0

1.0

0.08



Mallard duck LD50 = 1 mg/kg- bw

Rat LD50 = 0.9 mg/kg-bw

Italicized numbers are RQs published in May 2006 RED; un-italicized
represent RQs from new modeling scenarios.

Bold RQs = acute and chronic LOC exceedances for non-listed species; * =
restricted use LOC exceedances; ** = listed LOC exceedances

199% incorporation efficiency is non-achievable for post-emergent
applications and for trees

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