4-(1,1-dimethylethyl)cyclohexyl acrylate

Short-term toxicity to aquatic invertebrates

Description of key information

In an acute immobilisation test with Daphnia magna (STRAUS) according to OECD guideline 202 an EC50 of 1.03 mg/L based on the geometric mean measured test substance concentration was determined (BASF, 50E0580/09X175, 2015).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

1.03 mg/L

Additional information

An acute immobilisation test with Daphnia magna (STRAUS) was performed according to OECD guideline 202 (BASF, 50E0580/09X175, 2015). The results of preliminary tests including a solubility test carried out as part of a toxicity test with algae demonstrated, that the analysed concentration of the test item in saturated solutions in concentrations clearly above the limit of solubility in water increased with the loading of test item per litre water. Thus the test item cannot be treated like a monomolecular substance with a specific water solubility and aquatic tests have to be conducted with differential loadings. The loadings were considered for the evaluation of the test results.

The main test was conducted in a closed system (sealed glass flasks) under semi-static conditions and the daphnids were exposed to the test substance loading levels of 0 (control), 1, 3.2, 10, 32 and 100 mg/L over a period of 48 hours. The test concentrations were analytically verified. Since the measured test item concentration did not remain within ±20% of the nominal loadings or the initially measured concentrations, the geometric mean measured concentrations of the test item were determined: 0.270, 0.768, 2.52, 2.83 and 4.35 mg/L. After an exposure period of 48 hours an EC50 of 1.03 mg/L (CI: 0.803 - 1.32, nominal EC50: 4.25 mg/L (CI: 3.34 - 5.37)) based on geometric mean measured test item concentrations was determined.