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Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

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Description of key information

The 72 h ErC50 for amides, C12-18 (even numbered) and C18-unsatd., N,N-bis(hydroxyethyl) on growth inhibition of freshwater algae range from 3.9 to 18.6 mg/L and the corresponding EC10 or NOEC from 0.3 to 2 mg/L. 

Key value for chemical safety assessment

EC50 for freshwater algae:
3.9 mg/L
EC10 or NOEC for freshwater algae:
0.3 mg/L

Additional information

A study was performed to evaluate the toxicity of amides, C12-18 (even numbered) and C18-unsatd., N,N-bis(hydroxyethyl) to Selenastrum subspicatus under static conditions. The study was conducted according to OECD guideline 201. Selenastrum subspicatus was exposed at 0.01 to 1,000 mg product/L (nominal) for 72 hours under static conditions. Growth inhibition was measured at 24, 48 and 72 hours. Both parameters i.e. e. algae biomass growth (EbC50) and algal growth rate (ErC50) were used to calculate the (inhibition) effect-concentrations (EC50) by probit method. The 72 h EbC50and ErC50were estimated to be 2.1 and 3.9 mg/L, respectively. The 72 h NOEC was 0.3 mg/L (Gode, 2001b).

A study was performed to evaluate the toxicity of amides, C12-18 (even numbered) and C18-unsatd., N, N-bis(hydroxyethyl) to Selenastrum subspicatus under static conditions according to OECD guideline 201. Selenastrum subspicatus was exposed at concentrations ranging from 0.32 to 32 mg/L (nominal) for 72 hours under static conditions. The growth inhibition concentration in terms of algae biomass growth (EbC50) and algal growth rate (ErC50) was measured at 24, 48 and 72 hours. Calculations were performed by the probit method. Under the test conditions, the EbC50and ErC50were estimated to be 2.2 and 7.4 mg/L, respectively. The 72 h NOEC and LOEC were 0.32 and 1.0 mg/L, respectively (Memmert U, 1995c).

A study was conducted to determine the toxicity of structurally similar amides, C8-18 and C18-unsatd., N,N-bis(hydroxyethyl) to the green algae Scenedesmus subspicatus according to EU Method C.3. Algae were exposed to the test substance for 72 hours at 0, 0.5, 1.0, 2.0, 4.0, 8.0, 16.0 and 32.0 mg/L in a static system. Biomass and growth rate were determined. Under the conditions of this study, the 72 h ErC50of the test substance for Scenedesmus subspicatus, based on nominal concentrations, was 18.6 mg/L. The 24-72 h EbC50was 23.4 mg/L and the NOEC 2.0 mg/L (Scholz, 1991).