Registration Dossier

Diss Factsheets

Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

Four studies were available assessing potential toxicity to algae and cyanobacteria. The key study, selected as it was carried out on the test substance and also provided the most conservative assessment of the toxicity, determined an EL50 (growth rate) of 0.29 mg/l, based on nominal loading rate WAF concentrations. The NOEC was calculated to be 0.10 mg/l.

Key value for chemical safety assessment

EC50 for freshwater algae:
0.29 mg/L
EC10 or NOEC for freshwater algae:
0.1 mg/L

Additional information

A reliable (Klimisch 1) was carried out on the test substance, 9-Octadecenoic acid (Z)-, reaction products with diethylenetriamine, di-Me sulfate-quaternized, to assess the toxicity to Pseudokirchneriella subcapitata, using a range of test concentrations under static conditions. The test solutions were prepared as Water Accommodated Fractions (WAF). Due to the nature of the test substance (various constituents) the dissolved test item may have been one or several constituents of the test item and toxicity could not be attributed to a single component or mix of components. The results, therefore, are based on nominal loading rates. Under the conditions of the test, the EL50 (growth rate) was determined to be 0.29 mg/l based on nominal loading rate WAF concentrations. The NOEC was calculated to be 0.10 mg/l.

Three supporting studies are also presented.

One supporting study (reliable, Klimisch 2) was carried out on the read across substance fatty acids, C16-18 (even numbered) and C18 unsatd., reaction products with diethylene triamine, di-. Growth of Pseudokirchneriella subcapitata was significantly inhibited at all test item treatments after 72 hours. For growth the 72hr EC50 was 4.8 mg/l (56 μg/l measured) and the NOEC 0.32 mg/l (7.6 μg/l measured). For yield, the 72hr EC50 was 1.5 mg/l (27 μg/l measured) and the NOEC 0.032 mg /l (0.52 μg/l measured).

Another supporting study (reliable, Klimisch 2) was carried out on the read across substance Fatty acids, C16-18 (even numbered) and C18 unsatd., reaction products with diethylene triamine, di-... / 937-237-2; Imidazolium compounds, 2-(C15-17(odd numbered), C17-unsatd. alkyl)-1-[2-(C16-18(even numbered), C18-...; partially unsaturated IQAC, DMS quaternised (3 separate constituents). The growth of Scenedesmus subspicatus was assessed over 72 hours at between 0.001 and 1000 mg/l. The EC50 was estimated at between 1.8 - 4.5 mg a.i./l. Very limited information is included in the report.

A third supporting study (reliable Klimisch 2) was carried out on the read across substance Imidazolium compounds, 2-C17-unsatd.-alkyl-1-(2-C18-unsatd. amidoethyl)-4,5-dihydro-N-methyl, Me sul... / 931-745-8; oleic-acid based IQAC, DMS quaternised (2 constituents). The growth rate and yield of Pseudokirchneriella subcapitata was assessed over 72hours. EC50 values for growth rate and yield were calculated to be > 400 µg a.i../l (highest test concentration). The 72h EC10 values were calculated to be 277 and 181 µg a.i./L for growth rate and yield, respectively. The NOEC values for growth rate and yield were estimated to be 178 and 79 µg a.i./l. All values were presented as nominal concentrations.

Categories Display