Benzenesulfonic acid, mono-C11-13-branched alkyl derivs.

Short-term toxicity to aquatic invertebrates

Description of key information

The 48-Hour EC50 to Daphnia magna for the BAB Acid is based on study conducted with BAB Na Salt, based on mean measured test concentrations was 0.83 mg/L a.i.; 95% confidence limits 0.76-0.94 mg/L a.i.  The No Observed Effect Concentration was 0.55 mg/L a.i.  Correspondingly the Lowest Observed Effect Concentration was considered to be 1.1 mg/L a.i.  

 

Two studies are available, one on LAS and the other comparing LAS and BAS. Results of the toxicity tests show that LAS is three times more toxic than BAS. Since the EC50 for LAS is 2.9 mg/L, the BAS EC50 is therefore three times this amount or 8.7 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

0.83 mg/L

Additional information

A study was performed to assess the acute toxicity of the BAB Na Salt toDaphnia magna. The method followed was designed to be compatible with the OECD Guidelines for Testing of Chemicals (April 2004) No 202, "Daphnia sp., Acute Immobilisation Test" referenced as Method C.2 of Commission Regulation (EC) No. 440/2008. Given these results it was considered appropriate to calculate the results based on the mean measured test concentrations. The 48-Hour EC₅₀for the BAB Na Salt toDaphnia magnabased on mean measured test concentrations was 0.83 mg/L a.i.; 95% confidence limits 0.76 -0.94 mg/L a.i. The No Observed Effect Concentration was 0.55 mg/L a.i. Correspondingly the Lowest Observed Effect Concentration was considered to be 1.1 mg/L a.i. 

In addition, two short-term toxicity studies are available using aquatic invertebrates for Linear Alkylbenzene. In a 48 hour acute toxicity study, Daphnia magna were exposed to Linear alkyl benzene sulfonate (LAS ex Petresa) based on a sample that was 12.1% active ingredient, and results were adjusted to the active ingredient basis. The resultant 48 hour EC50 value for LAS based on mobility was 2.9 mg a.i./L with 95% CL of 2.5 to 3.5 mg/L.

In the second study, eight samples of sewage water were collected, and the bacteria that made up the inoculum was determined. Two test substances, LAS and BAS were then added, and the biodegradation of the substances followed for 168 hrs. At the times 0, 16, 24, 40, 48, 72, and 168 hrs, samples from the biodegradation tests were taken, and these samples were used in 24 hr Daphnia magna acute toxicity experiments.

Based on the data comparing linear and branched alkylbenzene sulfonates, linear structures are more toxic than branched structures. Therefore, data on linear materials, e.g., the chronic aquatic studies using LAS, are considered to be a worst-case scenario.

The 48-Hour EC50 for BAB Acid to Daphnia magna based on mean measured test concentrations was 0.83 mg/L a.i.; as worst case.