2-Butenoic acid, 1-ethyl-2-methylpropyl ester, (2E)-

Toxicity to aquatic algae and cyanobacteria

Description of key information

The toxicity to aquatic algae by the test substance, TM 12-209, was assessed according to OECD Test Guideline 201. The test organisms, Pseudokirchneriella subcapitata cells were exposed to a series of nominal test concentrations of 1.0, 3.2, 10, 32 and 100% v/v saturated solution for a period of 72 hours under static conditions. The test was conducted in 250 mL glass conical flasks each completely filled with test preparation and sealed with a ground glass stopper to reduce evaporation and minimize losses due to the test items potentially volatile nature. Six replicates each concentration. The control group was maintained under identical conditions but not exposed to the test item. Analysis of the 1.0, 3.2, 10, 32 and 100% v/v saturated solution test preparations at 0 hours showed measured test concentrations as 0.6, 2.13, 6.9, 23.4 and 64.4 mg/L, respectively. There was no significant change in the measured concentrations at 72 hours and so the results are based on 0-Hour measured test concentrations only. Chemical analysis also confirmed that no losses occurred due to the need to open the test vessels on a daily basis to remove an aliquot for cell density determination. The growth rate EC50 was 20 mg/L with 95 % confidence limits of 14 – 28 mg/L. The NOEC was 2.1 mg/L and the LOEC was 6.9 mg/L. 

Key value for chemical safety assessment

EC50 for freshwater algae:

20 mg/L

EC10 or NOEC for freshwater algae:

2.1 mg/L