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Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

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Description of key information

growth rate
72 h NOEC: 4.65 mg/L
72 h LOEC: 10.9 mg/L
72 h EC50: 74.5 mg/L (95% c.l. could not be determined)
yield
72 h NOEC: 4.65 mg/L
72 h LOEC: 10.9 mg/L
72 h EC50: 11.5 mg/L (95% c.l. could not be determined)

Key value for chemical safety assessment

EC50 for freshwater algae:
11.5 mg/L
EC10 or NOEC for freshwater algae:
4.65 mg/L

Additional information

The toxicity of tributyl acetylcitrate towards algae was investigated in a study conducted according to EU Method C.3 (Algal Inhibition test; 2008) and OECD Guideline 201 (Alga, Growth Inhibition Test; 2006). Based on the results of a screening test, test substance concentrations of 10, 20, 40, 80, and 100 mg/L nominal were used. Due to the poor water solubility of the test substance water accommodated fractions were prepared and used in the tests. The stability of the test substance was checked by IR measurements. Based on the comparison of test substance concentrations/recoveries at time 0 and after 72h it can be concluded that the test substance was stable during the test duration (recovery 94.9 - 124.2 % of initial concentration). However, the measured concentrations deviated more than 20 % from the nominal values. Based on this, the reported effect concentrations refer to mean measured concentrations (arithmetic mean). For the evaluation of the effects the mean values of the cell numbers per treatment were used.

With respect to growth rate, the 72 h NOEC and LOEC values were determined to be 4.65 and 10.9 mg/L, respectively; the 72 h EC50 was determined to be 74.4 mg/L. In respect to yield, the 72 h NOEC and LOEC values were determined to be 4.5 and 10.9 mg/L, respectively; the 72 h EC50 was determined to be 11.5 mg/L. The 95% C.I. could not be determined due to mathematical reasons.