1,4-Cyclohexanedicarboxylic acid, 1,4-diisononyl ester

Endpoint summary

Description of key information

In the available aquatic toxicity studies, no negative effects of the test substance on aquatic organisms in a saturated solution with a nominal loading of 1 mL/L have been observed. Therefore effect levels are above the limit of water solubility.

Additional information

Acute toxicity of the test substance on aquatic organisms has been examined and data is available for the three trophic species algae, invertebrates and fish. Due to the low water solubility of the test substance, a slow stirring procedure has been chosen according to OECD Guidance document No.23 (2000) to test a saturated solution of the test substance with a nominal loading rate of 1.00 mL/L in all aquatic toxicity studies. The measured concentrations were below the limit of quantification (6 µg/L) in the studies on algae and daphnia. Therefore, effect levels were based on the nominal loading of the saturated solution. In the fish study and the chronic study with daphnia test substance could be detected at very low levels. The test substance concentration declined through the study, thus, the effect levels were based on the geometric mean concentrations.

The toxicity of the test substance on the freshwater green algae P. subcapitata has been tested in a GLP-conform study according to OECD TG 201. After 72 h exposure, no effects on algae or inhibition of growth has been observed in the saturated solution with a nominal loading rate of 1.00 mL/L. The EL50 (72 h) for growth rate (ErL50) and yield (EyL50 is above 1.00 mL/L and the NOEL is 1.00 mL/L based on yield and growth rate.

Daphnia magna has been tested in an acute toxicity test according OECD TG 202. No effects on Daphnia magna were observed in the saturated solution. The EC50 and the LOEL after 48 hours are >1.00 mL/L. The NOEL is >=1.00 mL/L based on the nominal loading rate of the test substance.

Acute toxicity of the test substance to the zebrafish (Danio rerio) was determined according to OECD guideline 203 under semi-static conditions with daily renewal of the test substance. The fish did not show any symptoms of toxicity and no mortality has been observed during the study. The saturated solution with a nominal loading of 1.00 ml/L of the test substance has been found to have no effect on the vitality of zebrafish. Therefore, the LC0 corresponds to >= 0.0136 mg/L. The LC50 and the LC100 are > 0.0136 mg/L, which represents the geometric mean of the test substance concentration during the study.

Additionally, a long-term study on daphnia has been conducted. The study has been performed in accordance to OECD TG 211 and a saturated solution with a nominal loading of 1 mL/L has been used with a daily renewal. The test substance in a saturated solution with a nominal loading rate of 1 mL/L showed neither no effects on the mortality of the parental daphnia and no reduction of the reproduction rate of daphnia in 21 days. The NOEC (21 d) on reproduction has been determined to be >= 6.6 µg/L and the LOEC is >6.6 µg/L after 21 days of exposure.