Alcohols, C18-22, reaction products with maleic anhydride and sodium bisulfite

Toxicity to aquatic algae and cyanobacteria

Description of key information

EC50 = 93 mg/L
EC10 = 4.7 mg/L

Key value for chemical safety assessment

EC50 for freshwater algae:

93 mg/L

EC10 or NOEC for freshwater algae:

4.7 mg/L

Additional information

Algae toxicity has been tested on two similar substance, both monoesters sulphosuccinate, with long alkyl chain, higher than C18.

The influence of the test item Sulfosuccinate of Lanolin Alcohol on the growth of the green algal species Pseudokirchneriella subcapitata, formerly known as Selenastrum capricornutum, was investigated in a 72-hour test according to the OECD Guideline No. 201, 2006.

In the test item solutions the algal growth rate (r) after 72 hours of exposure was inhibited by a minimum value of 1.1 % for the nominal active ingredient concentration of 1.0 mg/L ( 3.2 mg/L as test item) to a maximum value of 11.2 % for the highest active ingredient concentration of 100.0 mg/L (333.3 mg/L as test item), compared to the negative control.

In the test item solutions the algal yield (Y) after 72 hours of exposure was inhibited by a minimum value of 6.0 % for the nominal active ingredient concentration of 1.0 mg/L ( 3.2 mg/L as test item) to a maximum value of 45.9 % for the highest active ingredient concentration of 100.0 mg/L (333.3 mg/L as test item), compared to the negative control.

In the study from Kimmel (2013) the toxicity of Butanedioic acid, sulfo-, 4-[2-[(2-hydroxyethyl)amino]ethyl] ester, N-C18-unsatd. acyl derivs., disodium salts to Desmodesmus subspicatus was determined in a static 72-Hour Algal Growth Inhibition Test. The test was performed according to OECD 201 and EU Method C.3. The nominal concentrations of 1.0, 3.2, 10, 32 and 100 mg test item/L. were tested in parallel with a control. Dose verification analysis was performed except for the nomoinal 1.0 mg/L test groups since this concentration was below the NOEC. The measured concentrations of the test item in the test media of the test concentrations of 3.2 to 100 mg test item/L were between 109 to 113% of the nominal values at the start of the test and between 78 to 90% at the end of the test. Thus, the correct dosing of the test item was confirmed. During the test period of 72 hours, a decrease of test item concentration in the test media occurred. The biological results were related to the mean measured test item concentrations (calculated as the geometric means of the concentrations measured at the start and end of the test), i.e., mean measured 3.2, 9.6, 30 and 93 mg/L for nominal concentrations of 3.2, 10, 32 and 100 mg test item/L, respectively. In order to determine the growth of the cultures, the cultures were measured with the coulter counter. The cell density was determined at 0, 24, 48 and 72 hours. The growth of the control cultures fulfilled the validity criteria from OECD 201 (2006). The 72 -hour ErC10 and ErC50 are 4.7 and > 93 mg/L based on the mean measured concentrations.

As a conclusion, no algae toxicity is evident from the two studies and applicable to the registered substance as well. The most conservative values have been taken for risk assessment