MEMORANDUM

SU BJ ECT :

TO:

FROM:

THR U: UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHIN G TON D. C., 2 0 46 0

Offi ce o f C h e mic a l Safety

a nd Pollution Pr eve nti o n

Date : 06 / 0 9/ 15

DP Bar co d e: 425662

P C Co de 129081

Addendum to th e E nvironmental Fate and E colo g ical Ri s k

As sess ment for Su lf entrazone Re g i s tr a tion Re v i ew

Kelly S h e rm a n
, Ac tin g Branch C hief

C h r i s tin a Sc h e lt e m a, C h e mic a l R eview Ma na ge r
Ri s k Management and Impl e m e nt a ti o n Br anc h 3

P est icide Re- eva lu at ion Division (75 0 5 P)

Office of Pe s ticid e Progr a m s

Kathr y n V. Mont ag u e, PM 23

, H er bicid e Bran c h

And

B a rbara Ma dd e n
, Minor Use Team Lead e r Ri s k Inte g ration Minor Use, and E m e r ge nc y Re s pon se Br a nch

R eg i s tration Divi s ion (7505C)

Geoffrey S inclair

, Biologist

Michael Barrett

, C hemi s t

E n v ironment a l Ri s k Branch 5

E n v ironmental Fate a nd Effe ct s Di v i s ion (7 507P)

M ah S hamim

, Bran c h C hief 

# /J/YJ_p .,J**11 ,._~AA'--**  E n v ironm e ntal Ri s k Branch 5 //**ffY~..=.:.::.::. --­**  E n v ironment a l Fate a nd E ffect s Di v i s i o n (7507P)

The purpose of this mem o i s t o correct an e rr o r in the Re g i s trati o n Revie w Pr e liminary

Eco l og i ca l Ri s k Assessmen t for Sulfentra zo n c (June 4

, 2014 DP Barcode D409753; abbrev i ated

as PRA e l sewhe r e in thi s document) and provide r efi n e m e nt s based on thi s correction and ad d

refinements from belter understanding of app li cat i o n rat es a nd methodologies. A d esc ripti o n of

the error in the terrestrial pla nt vegetative vigo r s tud y e ndp oint

, as well as the cha n ges
,

unc e rt a inti es, and poten ti a l r e fin e m e nt s to ri sk t o t e rr estr ial plants an d effec t s distances from th e

s it e of app li ca tion ne eded in o rd e r to be b e l ow the Level o f Co n ce rn (LOC) a r e provided

. Ri sk quoti e nt s t o avian s pe c i es a r e a l s o calcul a t e d ba se d on the ran ge of usage rat es provided b y th e Bi o l ogica l and Eco n om i c A n a l ys i s Di v i s i o n ( BEAD ) in th e April 6, 2015 m e m o e ntitled

· Sulfentra z one U sage Information'. Pr e limin a r y ri sk assessment citations in thi s Adde ndum

document r efer to the 6 / 4 / 2014 document.

12 

### Modification of the Vegetative Vigor Study IC25 Endpoint for Cucumber

The Environmental Fate and Effects Division (EFED) has reanalyzed the Tier 2 Vegetative Vigor Study conducted with sulfentrazone (MRID 43345412). As part of the registration review process, the registrant argued that the endpoint for the most sensitive dicot species, cucumber, which was used to calculate risk quotients and determine effects distances was not correctly calculated. In response to the registrant concerns, the cucumber endpoint was reanalyzed with updated statistical models using CETIS version 1. 8.7.12 with backend settings approved for use by EFED on 5/29/13. This analysis determined the IC 25 

### for cucumber was 0.001617 lbs ai/A based on dry weight . The IC 25 

### for cucumber will therefore be changed from the previous endpoint of 0.00052 lbs ai/A to 0.001617 lbs ai/A. The NOAEC of 0.00044 lbs a.i./A also based on dry weight was confirmed as a result of this analysis so the RQs for endangered ( listed ) species do not change. The CETIS reports that are associated with the modified DER are presented in Appendix A of this Addendum

.

Recalculation of the Risk Quotients for Dicotyledon Species

As a result of the change in the cucumber endpoint, the risk quotients ( RQs ) for non

- listed species for the ‘Spray Drift Only’ category changed. This change is bolded in Table 1. No other RQs from the TerrPlant output changed as a result of this endpoint change. The resulting RQs

for non

- listed species exposed to spray drift on ly, as calculated by the EFED model TerrPlant, ranged from 0.19 to 2.32

. For all crops except turf (with the lowest maximum application rate the Agency’s level of concern (LOC) was exceeded (i.e. the RQs were 1.0 or greater

. Maximum label application rat es used to calculate the RQs largely bracket the state average application

rates from 2008

- 2012 presented in the BEAD Usage memo that range from 0. 06 for corn and

winter wheat to 0 .22 lbs. a.i./A for cabbage and strawberries with maximum single applicatio n rates ranging from 0.19 to 0.38 (Table 2

, Chism, Alsadek, Hill, BEAD Usage memo April 6,

2015 ). ). The average application rates range from 0.061 to 0.221 lb ai/A while application rates falling between the 80 th 

### and 100 th 

### percentile range from 0.06 to 0.31 lb ai/A.3 

### Table 1. Revised dicot RQ values for different application rates of sulfentrazone.

Crop Single Max. Application

Rate (lbs ai/A) Dicot RQ Values 2



### Spray Drift Only Runoff and Runoff and
Spray Drift Spray Drift

(Dry Areas) (Semi

- Aquatic Areas)

Nonlisted Species* Listed Species Nonlisted Species Listed Species 1 

### Nonlisted Species Listed Species 1



### Apple, Rhubarb, Turnip roots and tops, Sunflower Crop Subgroup 20B,Spring Wheat,Succulent cowpea,Succulent lima beans,Tree nut Crop Group 14 including,

Citrus Crop,Small berry and fruit Crop Group 13

- 07,Non

- grass animal feed Crop Group 18,Head/Stem Brassica Subgroup

5A,Leafy Greens Subgroup 5B,Melon Subgroup 9A, Fruiting Vegetable Group

8,Okra,Succulent Pea, Strawberry and Tuberous /Corm Vegetable Subgroup 1C, Sugarcane, Cabbage, Potato, Mint,

Horseradish 0.375 2.32 8.52 2.05 3.75 17.39 31.88

Peanuts 0.3 1.86 6.82 1.64 3 13.91 25.5

Sunflower/field corn/dry bean/dry pea, Peanuts incorporated up to 2

- 4", Asparagus 0.25 1.55 5.68 1.36 2.5 11.59 21.25

Brassica 0.22 1.36 5 1.2 2.2 10.2 18.7

Lima bean 0.18 1.11 4.09 0.98 1.8 8.35 15.3

Turf grass 0.03 0.19 0.68 0.16 0.3 1.39 2.55
*Bolded values indicate RQs that have changed from the previous assessment.4 

### Recalculation of Effects Distances Based on Revised Endpoint

The spray drift model AgDrift was rerun, using the new endpoint, different droplet sizes (per the American Society of Agricultural and Biological Engineers or ASABE) , and varying boom heights, to estimate effects distance. The boom heights used were 1.27 (high) and 0.5 (low)

meters a bove the ground. Droplet size categories used were the default AgDrift value s of Dv 0.5 

### = 175 microns (very fine to fine) and Dv 0.5 

### = 341 microns (fine to medium/coarse) for ground applications. T he Dv 0.5 

### is the size at which half of the spray volume is s maller and the other half is larger than this size. For this assessment, effects distance is defined as the distance from the site of application needed in order to be below the LOC . Buffer distances were calculated for both ground and aerial application.

Sulfentrazone is a soil

- applied, pre

- emergent herbicide which can be applied either preplant incorporated or preemergence to the weeds. Because sulfentrazone inhibits seed and propagule germination it needs to be applied as close to the soil surface as possible with the lowest possible amount of pesticide remaining on any leaf surfaces and the minimum amount of exposure to evaporation or the wind. For example

, the Sulfentr azone XP herbicideTM label says to “apply large droplets (>150

- 200 microns) ... setting the boom at the lowest height which provides uniform coverage and reduces the exposure of droplets to evaporation and wind.”

Table 32 in the previous assessment (DP B arcode D409753) presents effects distances for the very fine to fine droplet size category ( Dv 0.5 

### droplet size = 1 75 microns). Table 33 in the preliminary ecological risk assessment (DP Barcode D409753) presents effects distances for both monocots and dicots using fine to medium/coarse particle sizes ( Dv 0.5 

### droplet size = 341 microns) . Since the label was ambiguous and allowed a boom height that “provides uniform coverage and reduces the exposure of droplets to evaporat ion and wind’ the AgDrift model is run with both high boom height (1.27 meters) and low boom height (0.5 meters) . Th is previous assessment only used the highest label app lication rate of 0.375 lbs a.i./ A

, the most conservative assumption

.

In this recalculation, the AgDrift model was run with all maximum label application rates from

0.03 to 0.375

, which bracket the state average application rates from 2008

- 2012 presented in the BEAD Usage memo that range from 0. 01 to 0. 4 lbs. a.i./A (Sulfent razone Usage Information (DP #12908 4 1))

. T h e model using very fine to fine droplet sizes encompasses the droplet sizes specified on the Sulfentrazone XP herbicideTM label (>150

- 200 microns). The model using fine

to me dium/coarse droplet sizes demonstrates the magnitude of reduction in effects distances that might be achieved with larger droplet sizes

. This section recalculates the effects distances using the newly revised dicot (cucumber) endpoint using both very fine to fine droplet sizes (Tab le 2 )

and fine to medium/coarse droplet sizes ( Table 3 ) at both high and low boom heights. Since cucumber is the most sensitive endpoint of either dicot species or monocot species, this recalculation represents the most conservative estim ate of effects d istances . Th ese calculation s

may either overestimate or underestimate effects distances depending on actual boom height and particle size of the spray.

Revised Effects Distances from Ground Applications of Sulfentrazone5 

### The effects distances generated by the EFED model AgDrift using the revised cucumber IC 25 

### endpoint are presented in Table 2 and Table 3 . The change in the cucumber IC 25 

### only

influence s the effects distances for non

- listed species. The listed species effects distanc es are presented for completeness since they were not calculated for all application rates in the PRA

. From 2008 to 2012, the total treated area ranged from <50 to 3,084,800 acres with average application rates that range from 0.06 to 0.22 lb a.i./A (Table 2 ; Appendix B)

Applications using sprays with a Dv 0.5 

### droplet siz e of 175 microns (very fine to fine)

Effects distances to mitigate risk for non

- listed species from applications using very fine to fine droplet sizes ranged from 19 feet using a lo w boom at the lowest application rate to 656 feet using a high boom with the highest application rate (Table 2)

. Effects distances for listed species ranged from 62 feet (low boom, lowest application rate) to greater than 1000 feet (high boom, highest application rate). The Sulfentrazone XP herbicideTM label says to “apply large droplets (>150

- 200 microns)”. This is similar to the very fine to fine droplet size category used by AgDrift which is 175 microns. Table 32 in the previ ous assessment presents effects distances that result using the very fine to fine size range at the highest application rate of 0.375

lbs a.i./A.

Table 2. Revised effects distances at different application rates of sulfentrazone using a mean droplet si ze of 175 microns.

Ground Application Buffer Distances

Very Fine to Fine Droplet size (175 μm)

High boom (1.27 m) Low Boom (0.5m height)

Application

Rate Nonlisted listed Nonlisted listed

0.375 656.16 >1000 242.78 918.62

0.3 564.3 >1000 193.57 757.86

0.25 492.12 921.9 157.48 643.04

0.22 449.47 849.73 137.79 570.86

0.18 383.85 744.74 108.27 472.44

0.03 75.46 183.72 19.68 62.34

Applications using sprays with a Dv 0.5 

### droplet size of 341 microns (fine to medium/coarse)

In high

- boom scenarios with coarse droplet sizes, effects distances for non

- listed species ranged from 9.84 feet to 187.01 feet for the lowest and highest application rates respectively. In low

boom scenarios effects distances for non

- listed species range d from 6.56 ft to 104.99 ft for the lowest and highest rates respectively. Listed species the effects distances were considerably larger ranging from 45.93

- 761.15 ft for high boom scenarios and 22.97

- 574.14 ft for low boom

scenarios Table 3 . These esti mates may underestimate the effects distances needed to eliminate6 

### risk of actual applications if droplet sizes are small er than the modeled Dv 0.5 

### droplet size of 341

microns. Table 33 in the previous assessment presents effects distances that result usin g the fine

to medium/coarse range at the highest application rate of 0.375 lbs a.i./A.

Table 3 . Revised effects distances at different application rates of sulfentrazone using Dv 0.5 

### droplet size of 341 microns.

BUFFER DISTANCES for C oarse droplet sizes for ground application

Fine to Medium Coarse Droplet sized (341 um)

High boom (1.27 m) Low Boom (0.5m height)

Application

Rate Nonlisted listed Nonlisted listed

0.375 187.01 761.15 104.99 574.14

0.3 141.07 623.35 78.74 425.75

0.25 114.83 524.93 62.34 367.45

0.22 95.14 465.87 52.49 318.24

0.18 75.46 380.57 39.37 249.34

0.03 9.84 45.93 6.56 22.97



### BUFFER DISTANCES for C oarse droplet sizes for ground application 

### Fine to Medium Coarse Droplet sized (341 um)

High boom (1.27 m) Low Boom (0.5m height)

Application

Rate Nonlisted listed Nonlisted listed

0.375 187.01 761.15 104.99 574.14

0.3 141.07 623.35 78.74 425.75

0.25 114.83 524.93 62.34 367.45

0.22 95.14 465.87 52.49 318.24

0.18 75.46 380.57 39.37 249.34

0.03 9.84 45.93 6.56 22.97

Revised Effects Distances from Aerial Applications of Sulfentrazone

Sulfentrazone is applied aerially to soybeans in Arkansas, Illinois, Iowa, and Ohio, and to sunflowers in Kansas, North Dakota and South Dakota. From 2008 to 2012 , t he total treated

area range d from 3,700 to acres with average application rates that range from 0. 09 to 0.149 lb

a.i./A ( Table 4 ). Maximum application rates listed on labels o f these crops are 0. 25 and 0.375

lbs a.i./A

. The effects distances that result from both labeled rates as w ell as average rates for the two most conservative model scenarios using medium to coarse (340 μm) and coarse to very coarse (439 μm) drople t sizes are presented in Table 5

. Effects distances using the maximum7 

### application rates range from 433 ft to greater than 1000 ft depending on droplet size. Effects distances that result from average application rates and using coarse to very coarse droplet sizes ( ( Dv 0.5 

### droplet size = = 439 μm) ranged fr om 177 feet to 262 feet (Table 5 ). Use of droplet sizes smaller than this would result in larger effects distances to eliminate risk to non

- target plants.

Table 4

. Sulfentrazone Aerial Application, Total Area Treated (acres) and Application Rate (lb. a.i. /acre), Averages for 2009

- 2013.

Crop State Total Area

Treated Average Application Rate (lb. ai/acre) Soybeans Arkansas 3,700 0.090 Soybeans Illinois 57,400 0.136 Soybeans Iowa 3,900 0.120 Soybeans Ohio 28,100 0.131

Sunflowers Kansas 5,600 0.089

Sunflowers North Dakota 12,200 0.122

Sunflowers South Dakota 40,000 0.149

Footnote : Proprietary data 2009

- 2013. All numbers are rounded. All other applications are ground applied.8 

### Table 5

. Aerial application with label rates and average rates . The average rates were p rovided

in a memorandum from BEAD ( see Appendix B of this Addendum ) and are in bold text

. Aerial Application Effects Distances

Coarse to very Coarse (( Dv 0.5 

### droplet size = 439 um) Medium to Coarse (( Dv 0.5 

### droplet size = 340 um)

Application

Rate Nonlisted listed Nonlisted listed

Maximum Rates Assumed

Sunflower/field corn/dry

bean/dry pea, Peanuts incorporated up to 2

- 4", Asparagus 0.25 433 >1000 778 >1000

Apple, Rhubarb, Turnip roots

and tops, Sunflower Crop

Subgroup 20B,Spring Wheat,Succulent cowpea,Succulent lima beans,Tree nut Crop Group 14 including, Citrus Crop,Small berry and fruit Crop Group 13

- 07,Non

- grass animal feed Crop Group 18,Head/Stem Brassica

Subgroup 5A,Leafy Greens Subgroup 5B,Melon Subgroup 9A, Fruiting Vegetable Group 8,Okra,Succulent Pea, Strawberry and Tuberous /Corm Vegetable Subgroup 1C, Sugarcane, Cabbage, Potato, Mint, Horseradish 0.375 640 >1000 >1000 >1000

Average Rates Assumed

Sunflowers (Kansas), Soybeans (Arkansas) 0.09 177 564.3 262 >1000

Soybeans (Iowa), Sunflowers (North Dakota) 0.12 220 846.5 335 >10009 

### Aerial Application Effects Distances

Coarse to very Coarse (( Dv 0.5 

### droplet size = 439 um) Medium to Coarse (( Dv 0.5 

### droplet size = 340 um)

Application

Rate Nonlisted listed Nonlisted listed

Soybeans (Ohio, Illinois) 0.13 236 948.2 361 > 1000

Sunflowers (South Dakota) 0.15 262 >1000 410 >1000

Aerial Application Buffer Distances

Coarse to very Coarse

(droplet = 439 um) Medium to Coarse (droplet = 340 um)

Application

Rate Nonlisted listed Nonlisted listed

Sunflower/field corn/dry

bean/dry pea, Peanuts incorporated up to 2

- 4", Asparagus 0.25 433 >1000 778 >1000

Apple, Rhubarb, Turnip roots

and tops, Sunflower Crop

Subgroup 20B,Spring

Wheat,Succulent cowpea,Succulent lima beans,Tree nut Crop Group 14 including, Citrus Crop,Small berry and fruit Crop Group 13

- 07,Non

- grass animal feed Crop Group 18,Head/Stem Brassica

Subgroup 5A,Leafy Greens Subgroup 5B,Melon Subgroup 9A, Fruiting Vegetable Group 8,Okra,Succulent Pea, Strawberry and Tuberous /Corm Vegetable Subgroup 1C,

Sugarcane, Cabbage, Potato, Mint, Horseradish 0.375 640 >1000 >1000 >1000

Sunflowers (Kansas), Soybeans (Arkansas) 0.09 177 564.3 262 >100010 Soybeans (Iowa), Sunflowers (North Dakota) 0.12 220 846.5 335 >1000

Soybeans (Ohio, Illinois) 0.13 236 948.2 361 >1000

Sunflowers (South Dakota) 0.15 262 >1000 410 >1000



### Refinement of Chronic Avian RQs to bracket average application rates presented Usage

Memo

The below RQs are meant to supplement the RQs presented in the assessment after discussions with BEAD about usage rates that may be lower than the labeled rates. Table 6 presents the RQs based upon both the upper bound and mean K enaga exposure values along with the approximate number of days residue s on feed items are expected to remain and exceed the Agency’s level of concern (LOC). As stated in the preliminary risk assessment, the mean Kenega exposure values are derived from the central tendency of the model with 50% of the predictions being highe r than the modeled value and 50% of the predictions being lower than the predicted value and it is not recommended for use in making risk calculations because it is not sufficiently conservative to protect species of concern. The RQs calculated using uppe r bound Kenaga values exceeded the chronic LOC (1.0) for short grass at all application rates. At an application rate of 0.1 a.i./A the LOC was exceeded for three dietary items. Only one dietary item at the two highest application

rates did not exceed th e LOC of 1.0. The approximate number of days residues exceed the LOC range from zero at the lowest application rates to 100 days at the highest application rates.

Table 6

. Ch r onic a vian RQs calculated assuming a verage application r ates

Application

Rate (lb

a.i./A) Upper bound Kenaga Mean Kenaga Approximate

Number of Days Residues

Exceed LOC

0.3 Short Grass 7.2 2.6 100.0

Tall Grass 3.3 1.1 60.0
Broadleaf plants 4.1 1.4 71.0
Fruits/pods/seeds 0.5 0.2 0.0
Arthropods 2.8 2.0 52.0

0.2 Short Grass 4.8 1.7 78.0

Tall Grass 2.2 0.7 38.0
Broadleaf plants 2.7 0.9 49.0
Fruits/pods/seeds 0.3 0.1 0.0
Arthropods 1.9 1.3 31.0

0.1 Short Grass 2.4 0.9 45.0

Tall Grass 1.1 0.4 6.0
Broadleaf plants 1.4 0.5 16.0
Fruits/pods/seeds 0.2 0.1 0.0
Arthropods 0.9 0.7 0.011 

### 0.05 Short Grass 1.2 0.4 11.0

Tall Grass 0.6 0.2 0.0
Broadleaf plants 0.7 0.2 0.0
Fruits/pods/seeds 0.1 0.0 0.0
Arthropods 0.5 0.3 0.0

Uncertainty involved in the use of the acute to chronic ratio (ACR)

.

An acute to chronic ratio (ACR) was used in lieu of a mysid chronic toxicity endpoint which is accompanied by uncertainty in the endpoint for which the ACR is used

. In this assessment, (DP Barcode D409753), t his ratio compares the endpoints in the acute a nd chronic toxicity studies with the daphnid and relates them to the acute toxicity endpoint to the saltwater mysid to predict the chronic endpoint for the saltwater mysid

. The daphnia acute toxicity endpoint was determined to be 60.4 mg a.i/L classifying sulfentrazone as slightly toxic on an acute exposure basis (MRID 41911622). The chronic toxicity study with the daphnid determined the NOAEC to be 0.2 mg a.i./L (MRID 43588605)

, which suggests that sulfentrazone could potentially be 300 times more toxic to daphnids on a chronic basis than on an acute basis. The acute endpoint for the saltwater mysid ( Americamysis bahia ) was determined to be 1.0 mg a.i/L ( MRID 43588603), classifying sulfentrazone as highly toxic to the mysid and m aking mysid shrimp 60 times more sensitive than the daphnid on an acute basis. While it is common to have chronic endpoints much lower than acute endpoints and have significant differences in sensitivity between freshwater and marine/estuarine organisms, utilizing a factor of 300 introduces uncertainty for the chronic toxicity endpoint for the mysid

. The low endpoint for the chronic mysid that was derived from the ACR resulted in an RQ exceedance . If the ACR underestimated the chronic mysid endpoint

, it would overestimate the RQ which was estimated between 5 and 9 depending on water clarity.

Lack of registration in Florida.

The preliminary risk assessment presented a worse

- case scenario for sulfentrazone use in

Florida. EFED has confirmed that sulfentrazone is not registered or used in the entire state of

Florida. Therefore, table 3 from the preliminary risk assessment has been corrected.

Correction of Table 3. Application for registered use sites and the Apples proposed use of

sulfentrazone

.12 Crop or

Non

Agricultural Use Site[1] Single Min, lb

ai/A product;

All sites Rates vary by

soil

texture /

% Organic

Matter Max # Applic. Aerial appli

cation? Minim.

Interval

(days) PHI, days Maxim. single (1st) aplica.,

lb ai/A Maxim.

Annual Rate, lb

ai/A

Brassica leafy greens 0.07 Yes NS 2 NS 2 NS 2 NS 2 0.2 0.22

Corn (GMO

tolerant to

PPO herbicides) 0.094 Yes NS 2 NS 2 NS 2 NS 2 0.1875 0.375

Cowpeas,

succulent (TN) 0.07 Yes NS 2 NS 2 NS 2 NS 2 0.1875 0.1875

Dry beans & peas (ND

SD MT MN

WY CO NE

KS Wl Ml

OR ID WA OR) 0.07 Yes NS 2 NS 2 NS 2 NS 2 0.25 0.25

Fallow,

Postharv est

Burndown 0.094 Yes NS 2 NS 2 NS 2 NS 2 0.25 0.25

Horseradish ((MN ND

SD MT CO

NE WY ID

WA OR Wl Ml) 0.07 Yes NS 2 NS 2 NS 2 NS 2 0.25 0.25

Lima beans succul. (TN) 0.07 Yes NS 2 NS 2 NS 2 NS 2 0.1875 0.1875

Melons 0.09 No NS NS NS NS 0.25 0.25

Peanuts (AL, GA, MS, NC, SC, VA) 0.15 No NS NS NS NS 0.25 0.3

Potatoes 0.094 Yes NS Yes NS NS 0.25 0.25

Rhubarb 0.25 No 1 NS NA 46 0.25 0.25

Succulent

Peas 0.07 Yes NS No NS NS 0.1875 0.187513 Crop or

Non

Agricultural Use Site[1] Single Min, lb

ai/A product;

All sites Rates vary by

soil

texture /

% Organic

Matter Max # Applic. Aerial appli

cation? Minim.

Interval

(days) PHI, days Maxim. single (1st) aplica.,

lb ai/A Maxim.

Annual Rate, lb

ai/A

Sunflower subgroup

20B 0.094 Yes NS Yes NS NS 0.25 0.25

Turnips 0.25 No 1 NS NA 3 0.25 0.25

Wheat

- spring (ID, OR, WA) 0.188 No NS NS NS ca. 120 0.1875 0.1875

Apples ( new use) 0.125 No 2*[2] No 60 14 0.375 0.375

Asparagus 0.141 Yes NS NS NS 14 0.375 0.375

Berries 0.125 No 2 NS 60 3 0.375 0.375

Brassica

head & stem (Broccoli, Cabbage 0.07 Yes NS NS NS NS 0.375 0.375

Cabbage transplante d (MN ND

SD MT CO

NE WY ID

WA OR Wl or Ml) 0.07 Yes NS NS NS NS 0.375 0.375

Citrus 0.125 No 2 NS 60 3 0.375 0.375

Flax (ND

SD MT MN

WY CO NE KS) 0.07 Yes NS NS NS NS 0.375 0.375

Fruiting veg. & Okra (except cucurbits) 0.07 Yes NS NS NS NS 0.375 0.375

Grapes 0.125 No 2 NS 60 3 0.375 0.375

Mint 0.141 Yes NS NS NS NS 0.375 0.37514 Crop or

Non

Agricultural Use Site[1] Single Min, lb

ai/A product;

All sites Rates vary by

soil

texture /

% Organic

Matter Max # Applic. Aerial appli

cation? Minim.

Interval

(days) PHI, days Maxim. single (1st) aplica.,

lb ai/A Maxim.

Annual Rate, lb

ai/A

Railroad, Highway, Roadside, Pipeline and Utility Rights

- of

Way,

Industrial Areas, Fence Rows,

and Other

listed Non

crop Sites 0.25 No 1 Yes* NA NS 0.375 0.375

Soybeans 0.141 Yes NS Yes NS NS 0.375 0.375

Strawberry 0.07 Yes NS NS NS NS 0.375 0.375

Sugarcane 0.141 Yes NS Yes NS 120 0.375 0.375

Tobacco 0.141 Yes NS NS NS NS 0.375 0.375

Tree nuts 0.125 No 2 NS 60 3 0.375 0.375

Turf: Sod Production, lawns, golf fairways and roughs 0.125 No NS NS NS 90 for sod 0.375 0.3750[3]

1 [1] Limitations to crop strains or certain geographical areas (states) are given in parenthesis.

2 NS: Not specified

1 [2] * = Implied, but not explicitly stated on product labels.

1 [3] Implied; some labels need to be clarified regarding the maximum annual rate. The maximum annual use rate is 0.375 lb ai/A for turf (sod production, lawns, golf fairways and roughs).15 

### Corrections of Table on Maximum Groundwater Concentrations from Prospective

Groundwater Studies in the P reliminary Risk Assessment

.

Some of the values for the Table 11 on page 39 of the preliminary risk assessment were for the 9

- foot depth lysimeter samples inste ad of the gro undwater samples. This table should be replaced with the updated Table 11 provided below

.

Table 11. Maximum observed concentrations of sulfentrazone and its acid degradate in shallow groundwater below or immediately downgradient of treated fields at four sites. Corrected values

are bolded.

Chemical NC1

Site IN1

Site IN2

Site IN3

Site

Concentration in ppb (days after initial application of obs.)

Sulfentrazone 37.4

(160d) 0.86

(577d) 0.11

(153d) 0.09

(1149d)

3

- Carboxylic Acid Sulfentrazone 11.4

(160d) 2.50

(455d) <0.1

(variable) 0.07

(753d)

SITE DESCRIPTIONS:

NC1 (>95 th site ) = The test site was located near the town of Tarboro in Edgecombe County, North Carolina, and was located in a setting classified as very high vulnerability to groundwater contamination. Soil series = Tarboro sand to loamy sand. Sulfentrazone application rat e = 0.50 lb ai/acre. (MRID 43345434 and 43926814 ). Average depth to groundwater = 9.2 feet.

IN1(95 th site) = The test site was located near the town of Leesburg in Kosciusko County, Indiana, and was located in a setting classified as 85 th percentile in t erms of vulnerability to groundwater contamination. Soil series = Tyner loamy sand to sandy loam. Sulfentrazone application rate = 0.17 lb ai/acre. Average depth to groundwater = 18.9 feet. (MRID 46816001 ).

N2 (85 th site = The test site was located near the town of Hanna in LaPorte County, Indiana, and was located in a setting classified as 95 th percentile in terms of vulnerability to groundwater contamination. Soil series = Shipshe loamy sand to sandy loam. Sulfentrazone application rate = 0.22 to 0.44 lb ai/acre. Average depth to groundwater = 30 feet. (MRID 47453601 ).

N3 (75 th site) = The test site was located near the town of La Porte in LaPorte County, Indiana, and was located in a setting classified as 75 th percentile in terms of vulnerability to g roundwater contamination. Soil series = Coupee silt loam. Sulfentrazone application rate = 0.22 lb ai/acre. Average depth to groundwater = 21 feet. (MRID 47453602 ).