1 U. S. ENVIRONMENTAL PROTECTION AGENCY

Washington, D.C. 20460

OFFICE OF PREVENTION, PESTICIDES AND TOXIC SUBSTANCES PC Code: 099050 DP BARCODE: 364248 MEMORANDUM June 10 , 2009 S UBJECT : Tier I Drinking Water Assessment for Acetamiprid Proposed Uses on Red Clover

(Grown for Seed Onl y), Grape and Tomato (Greenhouse). TO : Laura Nollen, Risk Manager Reviewer

Barbara Madden, Team Leader (RM Team 5) RIMUERB/RD (7505P) FROM : David Lieu, Chemist Trainee

ERB4/EFED (7507P) THRU : Greg Orrick, Environmental Scientist

Elizabeth Behl, Chief ERB4/EFED (7507P) This memo includes a drinking water exposure assessment for proposed uses of acetamiprid on red clover (grown for seed only) , grapes and tomatoes in greenhouses. These proposed uses do not exceed those previously assessed in June 21, 2005 (DP BARCODE 303582) , which were based on acetamiprid maximum use patterns for citrus fruit (surface water) and tree nut s (groundwater)
. The use pattern for citrus fruit included the highest single application rate ( i.e. , 0.25 lb a.i./A, applied twice per season at 7
- day intervals). The use pattern for tree nut s included the highest application rate per season ( i.e. , 0.18 lb a.i./A, applied four times p er season at 14 day intervals )
. The proposed use on c lover in ID, OR, and WA only has a maximum application rate of 0.075 lb a.i./A applied once a season. The proposed use on grapes and other climbing small fruits (except fuzzy kiwifruit)(within crop sub
- group 13
- 07F) has a maximum application rate of 0.1 lb a.i./A, applied twice at 14 day intervals. The proposed use on greenhouse grown tomatoes has a maximum application rate of 0.075 lb a.i./A applied twice per crop. All use pattern s are summarized in Tabl e 1. Because previous exposure estimates (Table 2) were based on maximum application rate s that w ere greater than the proposed maximum application rate s for these uses, we recommend that these tier I estimates of exposure be used in support of human health risk assessment
.2

Table 1. Summary of a cetamiprid use patterns for different crops proposed Product Name EPA

Reg. No. Single

App. Rate (lbs. a.i./A) Number

of Apps. Seasonal

App. Rate (lbs. a.i./A) Interval

Between Apps. (days) App. Method Clover (f or use in ID, OR, and WA only) Assail 70 WP 8033
- 23 0.075 1 0.075 None Aerial spray Assail 30 SG 8033
- 36 0.075 1 0.075 None Aerial spray Grapes and other Climbing Vine Small Fruits (except Fuzzy Kiwifruit) (within Crop Sub - Group 13 - 07F) Assail 70 WP 803 3
- 23 0.1 2 0.2 14 Aerial spray
Assail 30 SG 8033
- 36 0.1 2 0.2 14 Aerial spray Greenhouse - grown Tomatoes (mature plants) TriStar 30 SG 8033
- 94 0.075 2 0.15 N/A Chemigation/soil drenching Citrus fruits (used in previous assessments) Assail 70 WP 8033
- 23 0.25 2 0.55* 7 Aerial spray Assail 30 SG 8033
- 36 0.25 2 0.55* 7 Aerial spray Tree Nuts (within Crop Group 14) (including Pistachio) Assail 70 WP 8033
- 23 0.18 4 0.72 14 Aerial spray

Assail 30 SG 8033
- 36 0.18 4 0.72 14 Aerial spray * The seasonal appli cation rate for citrus fruits is 0.55 lb a.i./A ; however the modeled application rate was only 0.50 lb a.i./A due to limitations imposed by the indivisibility of 0.55 by 0.25. Table 2. Tier I 1 - in - 10 -year EDWCs in surface water and ground water for acet amiprid. Drinking Water Source Maximum Use Pattern Exposure EDWC Surface water Citrus fruit Peak 20.1 ppb Annual average 4.9 ppb Ground water Tree nut Peak & annual average 1.6 ppt It is also recommended that the label for TriStar 3 0SG specify the maximum application rate (in lb s a.i./A) for a single application use on greenhouse
- grown tomatoes . The proposed label only implies such a rate
. A clearl y stated value on the label would prevent confusion and promote consistency
.