Propanoic acid, 2-hydroxy-, C12-13-branched alkyl esters

Long-term toxicity to aquatic invertebrates

Description of key information

NOELR (21 d): 0.11 mg/L (measured; OECD 211)

Additional information

One study is available investigating the chronic toxicity of Propanoic acid, 2-hydroxy-, C12-13-branched-alkyl esters to aquatic invertebrates (Höger, 2013). The study was performed according to OECD 211 (GLP) using the water flea Daphnia magna. A test solution of nominal 100 mg/L was prepared and filtered using appropriate methods. The filtrate was further diluted and the five dilutions (1:2, 1:6.3, 1:10, 1:63 and 1:100) were tested in a semi-static exposure regime. Actual concentrations of the dilutions were determined analytically by GC/FID. The concentrations in the freshly prepared test media of the relevant concentrations (NOEC and LOEC) were 0.0611 - 0.141 mg/L (dilution 1:10) and 0.0891 - 0.231 mg/L (dilution 1:6.3), respectively. In the aged test media samples (with and without food), the measured concentrations decreased and were between <LOQ (limit of quantification, LOQ=0.03 mg/L) and 85% of initially measured values. Under the conditions of the test, the test item was not stable during the test medium renewal periods of two and three days. As it is unknown whether the parent molecules (propanoic acid, 2-hydroxy-, C12-13-branched-alkyl esters) or the degradation products are responsible for the toxic effects, all reported biological results were related to the mean of the initially measured concentrations of the test item. At the end of the study an effect on mobility of D. magna was observed with immobilization of 40% at a concentration of 0.18 mg/L. The reproduction was not inhibited. Thus, a NOELR (21 d) of 0.11 mg/L (measured, initial) was derived based on immobilisation.