Registration Dossier

Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

Currently viewing:

Administrative data

Link to relevant study record(s)

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 C8-18AS Mg & TEA (CAS 85586-38-5), in accordance to Regulation (EC) 1907/2006 Annex XI, 1.5, a read-across to another structurally related category members was conducted. Read-across data from the following substances were used: with, C8-isoAS Na (CAS 126-92-1), C12AS Na (CAS 151-21-3), C12-14AS TEA (CAS 90583-18-9), C12-14AS Na (CAS 85586-07-8), C12-18AS Na (CAS 68955-19-1) and C16-18AS Na (CAS 68955-20-4). Toxicity of alkyl sulfates is dependent on the carbon chain length and the influence of the counter ion can be neglected.

One study investigating toxic effects of C8-isoAS Na (CAS 126-92-1) to freshwater algae Desmodesmus subspicatus is available (Scholz 1995). The test was performed according to EU Method C.3 and is GLP compliant. Growth inhibition caused by the test substance was determined after 24, 48 and 72 h of exposure to five test concentrations up to 511 mg a.i./L (measured concentration equal to 900 mg a.i./L of nominal concentration). The results show that the 72-hour EC50 value for growth rate was above the highest test concentration of 511 mg a.i./L (measured concentration). The 72-hour EC10 value for growth rate was determined to be 199 mg a.i./L (measured concentration).

Moreover, a GLP compliant study was performed with C12AS Na (CAS 151-2-3) according to DIN 38412, part 9 guideline (Rieche 1994). Aquatic algae (Desmodesmus subspicatus) 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). The NOEC value for growth rate was 12 mg/L (nominal concentration).

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 (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 a.i./L (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).

Additionally, a supporting GLP-compliant study with Desmodesmus subspicatus is available for C12-14AS Na (CAS 85586-07-8, Scholz 1995). This test was performed according to EU Method C.3. 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).

Two GLP compliant studies are available for C12-18AS Na (CAS 68955-19-1). The first study was performed with C12-18AS Na (CAS 68955-19-1) according to the EU method C.3 (Scholz 1997). Freshwater algae (Desmodesmus subspicatus) were exposed for 72 hours to seven test concentrations up to 96 mg/L (nominal concentrations in agreement with the measured ones). The results showed that the 72-hour EC50 value for growth rate was 20 mg a.i./L and the EC10 value for growth rate was 7.6 mg/L. The second study with C12-18AS Na (CAS 68955-19-1) was conducted according to the German standard method DIN 38412, part 9 (Mühlberg 1992).

Desmodesmus subspicatus algae were exposed to for 96 hours to the nominal concentrations up to 100 mg/L, no analytical measurements are available. The reported EC50 value was 38 mg/L based on cell number. The EC10 value reached 7.4 mg/L.

Moreover, one study investigating toxic effects of C16-18AS Na (CAS 68955-20-4) to freshwater algae is available. The non-GLP study was performed with Desmodesmus subspicatus according to EU Method C.3 (Richterich 2001). Growth inhibition caused by the test substance was determined after 24, 48 and 72 hours of exposure to eleven test concentrations up to 3000 mg/L substance of 55.5% purity (equal to 1650 mg a.i./L). No analytical monitoring is available. The results show that the 72-hour EC50 value for growth rate was 34 mg a.i./L and for biomass 30 mg a.i./L (nominal concentrations). The EC10 for biomass was 19 mg a.i./L (nominal concentrations).

Due to structural and property similarities with the tested category member these results apply also to C8-18AS Mg & TEA (CAS 85586-38-5). The composition of C8-18AS Mg & TEA (CAS 85586-38-5) is C8: 15.8%, C10: 15.8%, C12: 44.7%, C14: 15.8%, C16: 5.3% and C18: 2.6%. The EC50 and NOEC values of 11 mg/L and 3 mg/L respectively (both for growth rate) obtained in the aquatic algae test with C12-14AS TEA (CAS 90583-18-9) are the most conservative values and they considered to be a reliable also for C8-18AS Mg & TEA (CAS 85586-38-5).