Benzaldehyde, 4-[(3-fluorophenyl)methoxy]-

Endpoint summary

Description of key information

Toxicity to aquatic algae and cyanobacteria: EC₁₀(72h) growth rate = 0.244 mg/L and EC₅₀(72h) growth rate = 0.553 mg/L for the freshwater green algae Desmodesmus subspicatus (static, OECD 201, GLP)

Additional information

The study was conducted under GLP according to the valid OECD Guideline for Testing of Chemicals 201 and the Council Regulation (EC) No. 761/2009 on the registered substance itself.

The objective of this study was to evaluate the influence of the test item on the growth and growth rate of the green algal species Desmodesmus subspicatus.

The study design included one control group with six replicates and five test item groups with three replicates, each containing 100 mL reconstituted water or test medium and 10000 cells/mL at the start of the experimental phase.

The study was performed under static conditions with nominal concentrations of 1.0, 3.2, 10.0, 31.6 and 100.0 mg/L in reconstituted water. The study was performed in open vessels.

The growth of the algae was calculated after 24, 48, and 72 hours exposure in the test item and control groups.

The concentrations of the test item were analytically determined by HPLC-UV. Due to the results of a stability determination before start of study, analytical controls of the test item preparations were performed at the start of the study and then daily.

The concentrations of the test item in test media without algae exceeded the values analyzed from the preparations with algae after 24, 48 and 72 hours, respectively. Therefore, based on the results of the stability determination and the analytical results it can be assumed that the decrease of the test item in the preparation during the study is a combination of instability and adsorption of the test item to the algae.

During the experimental phase of the study, the test item concentrations could not be maintained within ± 20% of the initial analytical concentration. Therefore, the EC values were calculated with the geometric mean exposure concentration. In cases where no test item could be detected, the limit of detection of the analytical method was used for calculation as recommended in OECD Guidance Document No. 23. In cases where the test item is detected but not quantified, the half of the limit of quantification was used for calculation as recommended in OECD Guidance Document No. 23.

Based on the obtained biological and analytical results the following EC-values were determined for the test item:

EC₁₀(72h) growth rate = 0.244 mg/L

EC₂₀(72h) growth rate = 0.323 mg/L

EC₅₀(72h) growth rate = 0.553 mg/L

EC₁₀(72h) yield = 0.149 mg/L

EC₂₀(72h) yield = 0.186 mg/L

EC₅₀(72h) yield = 0.285 mg/L

Based on the obtained results the test substance needs to be classified as acutely toxic to the environment according to Regulation (EC) No 1272/2008 and amendments. The 72h E_rC₅₀ of 0.553 mg/L is below the limit value for classification as Aquatic Acute Cat. 1 (≤ 1.0 mg/L, H400). Furthermore, the test substance needs to be classified as Aquatic Chronic Cat. 1 (H410) according to Regulation (EC) No 1272/2008 and amendments, due to the 72h E_rC₁₀ of 0.244 mg/L below the limit value for classification as Aquatic Chronic Cat. 1 (≤ 0.1 mg/L) and due to the fact that the test material was determined to be not readily biodegradable.