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Ecotoxicological information

Short-term toxicity to aquatic invertebrates

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Description of key information

The following results were determined for the test item reaction mass of 2,2'-oxybisbutane (DSBE), DIPE, SBA and 2-methylpropan-2-ol (TBA) (species: Daphnia magna): 24h-NOEC = 31 mg/L; 48h-NOEC = 31 mg/L; 24h-EC50i = 47 mg/L; 48h-EC50i = 46 mg/L

Key value for chemical safety assessment

EC50/LC50 for freshwater invertebrates:
46 mg/L

Additional information

The EC50 value and the NOEC for the immobilisation of Daphnia magna of reaction mass of 2,2'-oxybisbutane (DSBE), DIPE, SBA and 2-methylpropan-2-ol (TBA) was measured according to OECD 202, respectively EU C.2 guideline under GLP. Following results were obtained: 24h-NOEC = 31 mg/L; 48h-NOEC = 31 mg/L; 24h-EC50i = 47 mg/L; 48h-EC50i = 46 mg/L

The analytical determinations of the test item showed poor correlation between nominal and measured concentrations and acceptable recovery rates. This is probably caused by the high volatility of the test item. Therefore, the determination of the results of the test item reaction mass of 2,2'-oxybisbutane (DSBE), DIPE, SBA and 2-methylpropan-2-ol (TBA) was based on the geometric mean of the measured concentrations.

Based on these data in combination with the fact that the substance is not readily biodegradable, a classification into aquatic chronic category 3 (H412) according to the CLP regulation (corresponding to R52/53) is necessary (EC50 10-100 mg/l).

Based on the lowest EC50 value of the three species daphnia, algae and fish (available studies), an aquatic PNEC value was calculated for the risk assessment.