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

	SUBJECT:		Tier I Drinking Water Assessment for Acetamiprid Proposed
Uses on Red Clover (Grown for Seed Only), 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 nuts (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
nuts included the highest application rate per season (i.e., 0.18 lb
a.i./A, applied four times per season at 14 day intervals). The proposed
use on clover 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 patterns are summarized in Table 1. Because previous
exposure estimates (Table 2) were based on maximum application rates
that were greater than the proposed maximum application rates for these
uses, we recommend that these tier I estimates of exposure be used in
support of human health risk assessment.

Table 1. Summary of acetamiprid 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 (for 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	8033-23	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 application 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 acetamiprid.

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 30SG specify the
maximum application rate (in lbs a.i./A) for a single application use on
greenhouse-grown tomatoes. The proposed label only implies such a rate.
A clearly stated value on the label would prevent confusion and promote
consistency.

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