Sulfuric acid, mono-C12-14-alkyl esters, potassium salts

Toxicity to aquatic algae and cyanobacteria

Description of key information

72h EC50 (Desmodesmus subspicatus; growth rate) = 11 mg/L (nominal concentration, EU Method C.3)
72h NOEC (Desmodesmus subspicatus; growth rate) = 3 mg/L (nominal concentration, EU Method C.3)

Key value for chemical safety assessment

EC50 for freshwater algae:

11 mg/L

EC10 or NOEC for freshwater algae:

3 mg/L

Additional information

Since no reliable aquatic algae test is available for C12-14AS K (CAS 1268005-68-0), in accordance to Regulation (EC) 1907/2006 Annex XI, 1.5, a read-across to another structurally related category member was conducted. Read-across data from the following substances were used: C12AS Na (CAS 151-21-3) and also two similar C12-14 mixtures: C12-14AS TEA (CAS 90583-18-9) and C12-14AS Na (CAS 85586-07-8). Toxicity of alkyl sulfates is dependent on the carbon chain length and the influence of the counter ion can be neglected.

The key study investigating toxic effects of C12-14AS TEA (CAS 90583-18-9) to freshwater algae Desmodesmus subspicatus was performed according to EU Method C.3 and GLP principles (Scholz 1996). Growth inhibition caused by the test substance was determined after 24, 48 and 72 h of exposure under static conditions to seven test concentrations up to 300 mg/L as anionic active substance (nominal values in agreement with the measured values). The results show that the 72-hour EC50 value for growth rate was 11 mg a.i./L for growth rate and 9.3 mg a.i./L for biomass (nominal concentrations). The NOEC value for growth rate was determined to be 3 mg a.i./L (nominal concentration). Composition of carbon chains of the tested category member C12-14AS TEA (CAS 90583-18-9) is the same as of C12-14AS K (CAS 1268005-68-0). Due to structural and property similarity with the tested category member, the 72-hour EC50 value for of 11 mg/L and NOEC of 3 mg/L (both for growth rate) is considered as a reliable for C12-14AS K (CAS 1268005-68-0).

The toxicity of sulfuric acid, mono-C12-14 alkyl esters, sodium salts (CAS 85586-07-8) to aquatic algae was investigated in the GLP-compliant study with Desmodesmus subspicatus according to EU Method C.3 (Scholz 1995). Algae were exposed to six test concentrations up to 20 mg/L (nominal concentration corresponding to 17 mg/L of measured concentration). The study resulted in the 72-hour EC50 value for growth rate of above 20 mg a.i./L (nominal concentration). The EC10 (72 h) for growth rate was 5.4 mg a.i./L (nominal concentration).

One GLP compliant study was performed with C12AS Na (CAS 151-2-3) according to DIN 38412, part 9 guideline (Rieche 1994). Aquatic algae of Desmodesmus subspicatus species were exposed for 72 hours to four test concentrations up to 120 mg/L as nominal concentrations. Analytical check of test concentrations showed that the nominal concentrations were in agreement with the measured ones and therefore the nominal concentrations were used. The 72-h EC50 value for growth rate was above 120 mg/L (nominal concentration). The NOEC value for biomass was 30 mg/L (nominal concentration). These results are supported by a publication of Nyholm and Damgaard (1990). The non-GLP, test was performed with Pseudokirchnerella subcapitata exposed to six test concentrations. No special guideline was followed and analytical monitoring of test concentrations was not performed. Growth rate measurement after 96-h resulted in the ErC50 value of 117 mg/L (nominal concentration). NOEC for growth rate was 12 mg/L (nominal concentration).