Sodium (2-butoxyethoxy)acetate

Toxicity to aquatic algae and cyanobacteria

Description of key information

The 72 hour EC50 and ErC10 of the test item on Raphidocelis subcapitata is >100 mg/L. The 72 hours NOEC is 100 mg/L and the Lowest observed effect concentration (LOEC) is >100 mg/L.

Using ECOSAR v1.11 the acute EC50 value for algae was calculated to be 6475.286 mg/L. The chronic toxicity for algae was calculated to be 1250.872 mg/L. The substance is within the applicability domain of the model.

Key value for chemical safety assessment

EC10 or NOEC for freshwater algae:

100 mg/L

Additional information

The test item was assessed on Raphidocelis subcapitata for Growth Inhibition Test as per the OECD Guidelines for Testing of Chemicals Guideline No. 201.  A range finding study was conducted with six concentrations of 0.1, 1.0, 10.0 and 100.0 mg/L along with control. The algal growth (cell density) was assessed at 24, 48 and 72 hours of post-exposure during the test. During the range finding study, exponentially growing cells were exposed to range of selected concentrations. Based on the results of range finding study, a limit test was conducted at the concentration of 100 mg/L along with control (each 6 replicates). The algal growth (cell density) was assessed at 24, 48 and 72 hours post-exposure. Exponentially growing alga cells were exposed to the limit concentration. The present alga growth inhibition study fulfills the validity criteria of the test. The test samples were analyzed for test item concentration at the start (0 hours) and for stability at the end of the treatment (72 hours) both during range finding study and limit test, and were found to be within the acceptable range of ± 20% recovery to the nominal concentrations. Therefore, the results are based on the nominal concentrations. From the experiment conducted under standard experimental conditions, the 72 hour ErC50 and ErC10 (growth rate) and EyC50 and EyC10 (yield) of the test item on Raphidocelis subcapitata is >100 mg/L. The 72 hours No Observed Effect Concentration (NOEC) is 100 mg/L and the Lowest observed effect concentration (LOEC) is >100 mg/L.

The toxicity to aquatic algae of the test substance was calculated using ECOSAR v.1.11 as part of EPISuite v4.11 from US Environmental Protection Agency. Using ECOSAR v1.11 the acute EC50 value for algae was calculated to be 6475.286 mg/L. The chronic toxicity for algae was calculated to be 1250.872 mg/L. The substance is within the applicability domain of the model.