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Ecotoxicological information

Toxicity to soil macroorganisms except arthropods

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Description of key information

The 14 d LC50 for earthworms in an artificial soil substrate was determined to be equivalent to 7.33 mg MON 13900/kg soil dw. The NOEC was < 2.57 mg MON 13900/kg soil dw.

Key value for chemical safety assessment

Short-term EC50 or LC50 for soil macroorganisms:
7.33 mg/kg soil dw
Long-term EC10, LC10 or NOEC for soil macroorganisms:
2.57 mg/kg soil dw

Additional information

A study was conducted to assess the acute toxicity of MON 69447 (containing acetochlor at 840 g/L and MON 13900 at 28 g/L) on Eisenia foetida according to OECD Guideline 207 in compliance with GLP. Adult earthworms (Eisenia foetida) with clitellum were exposed to the test substance mixed into artificial soil at nominal concentrations of 0 (control), 100.3, 180.0, 321.6, 560 and 1000 mg MON 69447/kg dry soil. Forty worms were allocated to each group, divided into 4 replicates/dose level. Test duration was 14 d. Worms were acclimated in artificial soil for four days before test initiation. There was no mortality at 100.3 mg/kg soil dry weight (dw). Signs of toxicity were seen as of 180 mg MON 69447/kg soil dw and included emaciation or lethargy. On Day 14, mean bodyweight change was significantly lower than controls (p = 0.05) at 100.3 mg MON 69447/kg soil dw and above. The pH of the soils and temperature ranged between 5.17 - 5.45 and 19.5 - 20.3°C, respectively. Soils showed little loss of moisture over the test period. Under the test condition, the 14 d LC50 for earthworms in an artificial soil substrate was determined to be 287 mg MON 69447/kg soil dw (95% confidence limits of 253 - 323 mg MON 69447/kg soil dw) using the moving average method. The NOEC was < 100.3 mg MON 69447/kg soil dw, based on effects on bodyweight at that dose. Given an MON 13900 content in the formulation of 28 g/L and a formulation density of 1.0945 g/mL, the LD50 and NOEC values correspond to 7.33 and < 2.57 mg MON 13900/kg soil dw.