Registration Dossier

Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

No toxic effects occur at the range of solubility.

Key value for chemical safety assessment

Additional information

Assessment of the parent compound Benzenepropanoic acid, 3,5-bis(1,1-dimethylethyl)-4-hydroxy-,C7-9-branched alkyl esters (CAS: 125643 -61 -0)

Acute algae test with vehicle (OECD 201):

In a limit test, according to OECD guideline 201, no effects of Benzenepropanoic acid, 3,5-bis(1,1-dimethylethyl)-4-hydroxy-,C7-9-branched alkyl esters at the highest test concentration of 3.0 mg/L on the growth of Scenedesmus subspicatus was observed (Safepharm 1995). Instead of 100 mg/l (OECD and EEC requirement) the highest test concentration used was 3.0 mg/l. This was the highest attainable test concentration that could be prepared due to the limited solubility of the test material in water and auxiliary solvent and having due regard to the amount of auxiliary solvent permitted in the test under the OECD Guidelines. At concentrations in excess of 3.0 mg/l, there was a marked precipitation of the test material on addition of the solvent stock solution to culture medium. Therefore, Benzenepropanoic acid, 3,5-bis(1,1-dimethylethyl)-4-hydroxy-,C7-9-branched alkyl esters are unlikely to cause acute or chronic effects towards algae.

Supporting assessment of the impurity Metilox (CAS 6386-38-5)

In a 72 h acute toxicity study to Scenedesmus subspicatus the NOEbC and EbC50 values based on cell number were 2.3 and 0.5 mg/L, respectively. 

Supporting assessment of the major degradation product Metilox acid (CAS: 20170-32-5)

In a 72 h algal growth inhibition test the EC50 value was determined to be 106 mg/L.