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Under terrestial toxicity a study was performed to assess the acute toxicity of the test material to the earthworm (Eisenia foetida) in an artificial soil. The method followed that described in the OECD Guidelines for Testing of Chemicals (1984) No 207 "Earthworm, Acute Toxicity Tests" and EEC Commission Directive 87/302/EEC.

The test substance, Agrotain [reported purity 25% active ingredient; N-(n-butyl) thiophosphoric triamide (NBPT)] was supplied by the sponsor.

The test was performed with five concentrations of test substance and a control at 20 ± 2°C. The test media was artificial soil comprised of approximately 70% sand, 20% Kaolin clay, and 10% finely ground sphagnum peat moss. Test substance was mixed with deionized water then added to dry artificial soil in each test vessel. The final moisture content in each test vessel was approximately 25%. All nominal calculations are based on milligrams of active ingredient per kilogram of wet soil, unless otherwise noted.

Forty worms per concentration (10 worms per replicate, 4 replicates per concentration) were exposed to the following nominal concentrations of Agrotain (control), 130,220,360, 600, and 1,000 mg a.i./kg. Exposure ofwonns to Agrot~ resulted in a 7 day median lethal concentration (LC50) of 860 mg a.i./kg (equivalent to 1,100 mg a.i./kg, calculated dry weight), and a 14 day LC50 of 830 mg a.i./kg (equivalent to 1,100 mg a.i./kg, calculated dry weight).

The acute toxicity of the test material, to the earthworm Eisenia foetida, in an artificial soil test has been investigated. The 7 day LC50 for worms exposed to Agrotain is 860 mg a.i./kg (95% confidence interval = 600 to 1,000 mg a.i./kg), and the 14 day LC50 is 830 mg a.i./kg (95% confidence interval = 760 to 900 mg a.i./kg). The 7-day and 14-day LC50 values were equivalent to 1,100 mg a.i./kg when calculated on a dry weight basis. The NOEC is 600 mg a.i./kg (equivalent to 800 mg a.i./kg, calculated dry weight), based on survival, sublethal effects, time to burrow, and weight loss relative to the control.