UNITED STATES ENVIRONMEN TAL PROTECTION AGENCY WASHINGTON, D.C. 20460

OFFICE OF CHEMICAL SAFETY AND
POLLUTION PREV ENTION

Chemical: Propiconazole
PC Code: 122101
DP barcode: 372880 July 6, 2010

MEMORANDUM

Subject: Drinking Water Assessment for Propicon azole Uses on Mint (IR-4 Action), Caneberry Subgroup 13-07A, Bushberry Subgroup 13-07B, Low Growing Berry Subgroup 13-07G, except Cranberry a nd Bulb Vegetable Crop, Group 3-07

To: Andrew Ertman
Barbara Madden Fungicide Branch Registration division (7505P)

From: James Lin, Environmental Engineer Brian Anderson, Acting Branch Chief
Environmental Risk Branch I
Environmental Fate and Effects Division (7507P)



### 1. Summary

The estimated surface water drinking water concentrations for propiconazole are:

55.78 ug /L for the 1 in 10 year annual peak concentration (acute)

21.61 ug /L for the 1 in 10 year annual mean concentration (non-cancer chronic) and

13.24 ug /L for the 30 year annual mean c oncentration (cance r chronic).

The SCI-GROW estimated ground water drinking water concentrations for propiconazole are not expected to exceed 0.64 μ g/L

.

These results are based on EDWCs for Turf (DP 325821, 328690, 07/07/2006). The proposed new uses do not result in higher EDWCs th an those estimated for turf uses.2 

### 2. Previous Drinking Water Assessment

EFED has issued four drinking wa ter assessments for propiconazole:

(1) Drinking Water Assessment of Propiconazole. (DP 312353, 06/29/2005) (2) Revised Drinking Water Assessment of Propiconazole. (DP 361358, 06/07/2006) The
first two assessments addressed the followi ng uses: wheat, seed crops (grasses), rice, pecans, peaches, sweet corn, dry beans, pea nuts, barley, celery, tu rf and ornamentals – lawn and turf, golf course, ground cover, and sod farm. (3) Drinking Water Assessment of Propiconazole for Uses of Cereals, Soybean, Berries and Cranberries, Carrot, Onions, Sorghum, Stra wberry, Sugar Beet, Mint, Tree Nuts, and Turf. (DP 325821, 328690, 07/07/2006) (4) Drinking Water Assessment for Propiconazole Uses on Garden Beet, Turnip, Leaves of Root and Tuber Vegetables, Herbs, and Pineapple – An IR-4 Action (DP 347906, 07/02/2008)

These drinking water assessments were for pa rent propiconazole only. The 1,2,4-triazole degradate is being characterized in a separate, cu mulative triazole assessment and is, therefore, not considered in these assessments (see DP322215, 02/07/2006). The resulting drinking water concentration estimations (EDWCs) are based on th e turf use due to its hi ghest total application rate of 6.285 lb ai/ac based on 8 applicati ons of 0.786 lb ai/ac at a 14-day interval.



### 3. Proposed Label Information

The proposed use rates are tabulated below based on the marked-up supplemental label for Tilt®.

Crop Use Rate (lb ai/ac) Number of Applications / Interval (day) Total Use Rate Per Season (lb ai/ac) Bulb Vegetables: Bulb Onions, Green
Onions 0.225 2 / 7 0.45

Caneberries,
Bushberries 0.16875 5 / 7 0.84

Mint 0.1125 3 / 14 0.338

Strawberries and Other Low Growing
Berries 0.1125 4 / 7 0.45

EDWCs were not estimated for the proposed new uses because the maximum single and annual application rates are approximately 3.5-fold and 7.5-fo ld lower, respectively, than the turf use. Therefore, EDWCs for the proposed new uses would not supersede EDWCs for turf.3 

### 4. Conclusion

The proposed use rates are much less than the total turf use rate of 6.285 lb ai/ac, which is based on 8 applications at a rate of 0.786 lb ai/ac with a 14-day interval. Theref ore, the turf drinking water assessment should be used to represen t estimated drinking wate r concentrations.