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rates will result in soil residues of approximately 1 ppm trifluralin, a level that had no adverse effects on earthworms [140]. It is nontoxic to bees [1]. Environmental Fate: • Breakdown in soil and groundwater: Trifluralin is of moderate to high persistence in the soil environment, depending on conditions. Trifluralin is subject to degradation by soil microorganisms. Trifluralin remaining on the soil surface after application may be decomposed by UV light or may volatilize. Reported half-lives.of trifluralin in the soil vary from 45 to 60 days [11] to 6 to 8 months [1]. After 6 months to 1 year, 80 to 90% of its activity will be gone [8]. It is strongly adsorbed on soils and nearly insoluble in water [11]. Because adsorption is highest in soils high in organic matter or clay content and adsorbed herbicide is inactive, higher application rates may be required for effective weed control on such soils [58,8]. Trifluralin has been detected in nearly 1% of the 5590 wells tested. However, it has been detected at very low concentrations, typically ranging from 0.002 ug/L to 15 ug/L [8]. • Breakdown in water: Trifluralin is nearly insoluble in water [1]. It will probably be found adsorbed to soil sediments and particulates in the water column_ • Breakdown in vegetation: Trifluralin inhibits the growth of roots and shoots when it is absorbed by newly germinated weed seedlings [58]. Trifluralin residues in crop plants will occur only in root tissues which are in direct contact with contaminated soil. Trifluralin is not translocated into the leaves, seeds, or fruit of most plants. On most crops, trifluralin applied to the leaves has no effect, but on certain crops, such as tobacco and summer squash, leaf distortion may occur [58]. Physical Properties: • Appearance: Trifluralin is an odorless, yellow-orange crystalline solid [1]. • Chemical Name: a,a,a-trifluoro-2,6-dinitro-NN-dipropyl-p-toluidine [1] • CAS Number: 1582-09-8 • Molecular Weight: 335.50 • Water Solubility: <1 mg/L @ 27 C [1] • Solubility in Other Solvents: s. in organic solvents such as acetone and xylene [1] • Melting Point: 48.5-49 C [1] • Vapor Pressure: 13.7 mPa @ 25'C [1] • Partition Coefficient: 5.0719 @ pH 7 and 25 C [1] • Adsorption Coefficient: 8000 [11] Exposure Guidelines: • ADI: Not Available • MCL:Not Available • RID: 0.0075 mg/kg/day [13] • PEL: Not Available • HA: 0.005 mg/L (lifetime) [139] • TLV:Not Available Basic Manufacturer: DowElanco 9330 Zionsville Road J