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Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

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Description of key information

ErC50 (72h) > 120 mg/l (nominal)

NOEC (growth rate, 72h) = 120 mg/l (nominal)

Key value for chemical safety assessment

EC50 for freshwater algae:
100 mg/L
EC10 or NOEC for freshwater algae:
100 mg/L

Additional information

The evaluation of the toxicity to aquatic algae is performed based on data on the substance itself and on the similar substances 1 - MSA, 2 -DSA and 3a-DSA. Justification for Read Across is given in Section 13 of IUCLID.

The toxicity of the Similar Substance 1 -MSA to the unicellular freshwater green alga Pseudokirchneriella subcapitata was determined according to the principles of OECD 201 and Council Regulation (EC) No. 266/2016/Method C.3. The aim of the study was the determination of the effects on growth rate and yield over a period of 72 hours. The study was conducted under static conditions with an initial cell density of 5416 cells/ml. A stock solution with a nominal concentration of 120 mg test item/l was freshly prepared with dilution water. Five concentrations were tested in a geometrical series with a factor of √10: 1.20 - 3.79 - 12.0 - 37.9 - 120 mg/l. Three replicates were tested for each test item concentration and six replicates for the control. The environmental conditions were within the acceptable limits. The concentrations of the test item were determined at the start of the exposure (0 hours) and at the end of the exposure (72 hours) of all tested concentration levels and the control via HPLC-DAD. The measured concentrations of the test item were in the range of 96 to 101 % of the nominal values at the start of the exposure (0 hours) and 102 to 111 % of the nominal values at the end of the exposure (72 hours).

ErC50 (72h) > 120 mg/l (nominal)

NOEC (growth rate, 72h) = 120 mg/l (nominal)

Supporting data are considered from an aquatic toxicity on the substance.

Acute toxicity for algae (Pseudokirchnerella subcapitata) was evaluated in the 72 hours test, according to the OECD guideline 201. A single dose was administrated at 100 mg/l under static conditions. No analytical monitoring was performed. No effect was observed up to 100 mg/l

ECb50 (72 h) > 100 mg/l (nominal); ErC50 (72 h) > 100 mg/l (nominal)

Data from the analogue substances 2 -DSA and 3a-DSA has been representative as well, since they have the same sulfonation degree than 1 -DSA

No aquatic algae toxicity is expected for the substance under registration and an EC50 of 100 has been selected as a representative value.