Sulfuric acid, C12-14 (even numbered)-alkyl esters, (2-hydroxylpropyl)ammonium salts

Toxicity to aquatic algae and cyanobacteria

Description of key information

EC50 (72 h, growth rate) = 11 mg a.i./L (Scenedesmus subspicatus, nominal, read-across, EU Method C.3)
NOEC (72 h, growth rate) = 3 mg a.i./L (Scenedesmus subspicatus, nominal, read-across, 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 toxicity tests with algae are available for C12-14AS MIPA (CAS 85681-66-9), read-across to other structurally related category members was conducted and corroborates the findings of the study mentioned above. Read-across data from the following similar C12-14 mixtures were used: 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 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 (Elementis 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). Due to structural and property similarity with the tested category member, the 72-hour EC50 value of 11 mg/L and NOEC of 3 mg/L (both for growth rate) is considered as reliable for C12-14 MIPA (CAS 85681-66-9) for freshwater algae.

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 (Elementis 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).

Additional information about the toxicity of C12-14AS Na to algae is available from a publication by Verge and Marino 1996. The authors performed a non-GLP-study with Pseudokirchnerella subcapitata, according to OECD guideline 201. In this study the EC50 (72 h) for growth rate was determined to be 27 mg/L.