Castor oil, hydrogenated, propoxylated

Endpoint summary

Description of key information

Daphnids were exposed during 48 h (static test) to control and nominal concentrations of 6.25, 12.5, 25, 50 and 100 mg/L (mean measured 0.35, 0.58, 3.9, 6.8 and 11 mg/L). At study start solutions (WAF) at and above 12.5 mg/L showed haziness/cloudiness that could be related to the increasing concentrations.

The EC50 is 6.8 mg/L. Based on immobility compared to the control (p <0.05) the 48 hour NOEC was determined to be 0.58 mg/L and the Lowest Observed Effect Concentration (LOEC) was 3.9 mg/L. There was no immobility observed in the dilution water control.

At 24 and 48 hours, all mobile D. magna in the 50 and 100 mg/L nominal loading concentrations were slow moving and at the bottom of the test vessels when compared to the controls. At 24 and 48 hours the solutions appeared similar to 0 hours test solution observations with addition of a residue on the surface in a dose-dependent quantity. The residue appears to be very fine particulate and/or droplets spread over the surface in patches that connect together.

Data on the analogue substance

In a limit test at 1.0 mg/L rainbow trouts were exposed for 96 hours in a static test according to OECD 203. Based on absence of mortality and signs of toxicity compared to the control, the 96 hour NOEC was determined to be 1.0 mg/L and the LC50 was >1.0 mg/L. No confirmatory analysis of the test solutions was performed due to lack of an analytical method.

Daphnids were exposed during 48 h (static test) to control, solvent control and nominal concentrations of 0.0625, 0.125, 0.25, 0.5 and 1.0 mg/L. No confirmatory analysis of the test solutions was performed due to lack of an analytical method. The EC50 is >1.0 mg/L. Based on immobility compared to the control (p <0.05) the 48h NOEC was determined to be 1.0 mg/L. Immobility in the 0.5 mg/L test concentration was significantly different (p <0.05) from the control. However, as immobility in the 1.0 mg/L test concentration was not significantly different (p <0.05) from the control, the NOEC was not affected.

In a study according to OECD 201, algae were exposed to 0, 0.0625, 0.125, 0.25, 0.5 and 1.0 mg/L (vehicle THF) of the substance during 72 hours. The highest concentration was based on the limited solubility of the substance. Effects on growth rate were seen at 1.0 mg/L, while effects on yield were observed at 0.5 mg/L. EC50 values for both growth rate and yield were > 1.0 mg/L.

Additional information

The study on daphnia with the substance was performed as a WAF and it is expected that undissolved particles influenced the result at the two highest concentrations. The EC50 of 6.8 mg/L is therefore considered to represent a worst case.

For the studies on the analogue substance, a 1 mg/L test concentration was selected as the highest concentration based on a non-GLP range finding study in daphnia. The test substance was dosed to the media via a solvent carrier (tetrahydrofuran (THF)) to assist in dosing the test compound. The concentration of solvent used in all exposure solutions and the vehicle control was 100 µL/L (with the exception of the negative control).