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Ecotoxicological information

Toxicity to soil macroorganisms except arthropods

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Description of key information

NOEC chronic earthworm >= 104 mg/kg dw

Key value for chemical safety assessment

Long-term EC10, LC10 or NOEC for soil macroorganisms:
104 mg/kg soil dw

Additional information

The Guidance on information requirements and chemical safety assessment, Chapter R.7C: Endpoint specific guidance (November 2014), section R. 7.11.6.3, Table R.7.11-2, page 145, specifies the information needed to waive the terrestrial studies based on soil hazard categories.

The log Pow of the registered substance is <3. Therefore, accumulation and persistence of the registered substance in soil and organisms is very unlikely. A PNEC soil was calculated using the aquatic PNEC and the equilibrium partitioning method. Based on these characteristics, the registered substance is not expected to cause adverse effects on terrestrial organisms and consequently terrestrial toxicity tests are not needed.

Nevertheless, in the Klimisch 2 (Klimisch 2 since read across, otherwise Klimisch 1) GLP study from Straube (2016) the chronic toxicity of Butanedioic acid, sulfo-, 1,4-diisodecyl ester, sodium salt on earthworms (Eisenia fetida) reproduction and growth in artificial soil was determined in an 56 day test according to OECD 222. The test was performed with Control, 1.3, 13, 26, 52 and 104 mg a.i./kg soil dry weight. The biological results are based on nominal concentrations since the analysis of the stock solution confirmed correct preparation of this solution and the preparation and application of the application solutions was checked and documented by weighing.

Eight replicates with 10 worms each were set up for the control and 4 replicates for each test group. After 28 days 0, 0, 0, 0, 0, 0 and 0% mortality was observed in the control and at nominal test concentrations of 1.3, 13, 26, 52 and 104 mg a.i./kg soil dry weight, respectively.

The reproduction per pre replicate container with 10 adult worms was 190, 165, 171, 150, 170, and 170 living offspring per container (10 worms) control and at nominal test concentrations of 1.3, 13, 26, 52 and 104 mg a.i./kg soil dry weight, respectively.

 

The overall NOEC for reproduction, mortality, growth and food consumption was equal or greater than the highest test concentration, i.e. >= 104 mg/ kg dw.

Read across is justified since there is a general trend of decresing ecotoxicity with decreasing C-chain length and the source substance has a longer C-chain. Furthermore, the acute ecotoxicity of the target substance was lower than the ecotoxicity of the source substance. Further information is provided in the read across argumentation.

 

The result is considered relevant and reliable for the risk assessment.