Fatty acids, safflower-oil, Et esters

Short-term toxicity to aquatic invertebrates

Description of key information

EC50 (48h) = 0.074 mg/L (measured, WAF) for Daphnia magna (OECD 202)

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.074 mg/L

Additional information

One study investigating the short-term toxicity of the test substance to aquatic invertebrates is available. The test was performed according to GLP and OECD guideline 202 using Daphnia magna as test organism. An EC50 test and and additional limit test were performed based on the result of a preceding range-finding test.Twenty daphnids per test group were exposed to a control and glass fiber filtered solutions prepared at loading rates of 2.2, 4.6, 10, 22, 46 and 100 mg/L in the EC50 test and to a control and a glass fiber filtered solution prepared at a loading rate of 100 mg/L in the additional limit test. Samples for confirmation of actual exposure concentrations were taken at the start and the end of the test period.

A floating layer was formed in all test solutions prepared at a loading rate of 4.6 mg/L and higher. In addition, daphnids were observed trapped at the surface in filtered solutions of 22 mg/L and higher. In order to distinguish between toxic and physical effects, an additional limit test was performed using a physical barrier in the form of a net in the test vessels.

Analysis of the samples taken from the glass fiber filtered solution at the start of the additional limit test showed a measured concentration of 2.0 mg/L.This concentration decreased to 0.62 mg/L at the end of the test. The corresponding average exposure concentration was calculated to be 1.1mg/L and was comparable to the average concentration calculated for the100 mg/L loading rate of the EC50 test. No floating layer was observed in the limit concentration and no daphnids were observed to be trapped at the surface during the test period. However, the number of daphnids immobilized was comparable to the EC50 test. Therefore, immobilisation could be related to toxicity of the test substance rather than a physical effect. The 48h-EC50 was estimated to be between the concentrations present in glass fiber filtered solutions prepared at loading rates of 10 and 22 mg/L. The corresponding average exposure concentration is 0.074 mg/L. Based on this result, the test substance is considered to be very toxic to aquatic invertebrates.