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Ecotoxicological information

Endpoint summary

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Fully reliable information on the long-term toxicity of cloquintocet-mexyl is available that can be used to derive PNEC soil.

Terrestrial toxicity studies are available concerning the effects of cloquintocet-mexyl on earthworms, soil microorganisms, plants and birds.

The substance is of low toxicity to earthworms, with a 14-day LC50 of >1000 mg/kg (dry weight) soil being reported in an OECD TG 207 study (Rufli, 1989).

A Nitrogen Transformation Test (OECD TG 216) and a Carbon Transformation Test (OECD TG 217) have been conducted under GLP (Schulze, 2013). The results are considered reliable and adequate for risk assessment. The 28-day NOEC in both tests was 1000 mg/kg soil dw, and this can be considered as a long-term result for microbial populations.

A reliable GLP and guideline compliant short-term terrestrial plant toxicity study (OECD TG 208) is available (Bramby-Gunary, 2013). Ten plant species have been tested, and the study results thus can be used to characterise long-term effects on terrestrial plants. The most sensitive species was tomato (Lycopersicon esculentum) with an EC50 of 275 mg/kg soil dw.

Cloquintocet-mexyl is of low toxicity to birds, as indicated by the long-term NOEC = 500 mg/kg obtained in two long-term toxicity studies.

Additional information