Tetrasodium 4,4'-bis[[4-[bis(2-hydroxyethyl)amino]-6-(4-sulphonatoanilino)-1,3,5-triazin-2-yl]amino]stilbene-2,2'-disulphonate]

Long-term toxicity to aquatic invertebrates

Description of key information

NOEC (21d, overall threshold effects) = 1.10 mg/l

NOEC (21d, reproduction) = 2.53 mg/l

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

1.1 mg/L

Additional information

The long-term toxicity of the substance to aquatic invertebrates was evaluated by considering data on both the substance and on similar substances, in a weight of evidence approach. Justification for Read Across is given in Section 13 of IUCLID

A Daphnia magna reproductive study is available on 3a-MSA. The test substance's chronic toxicity was evaluated according to the OECD guideline 211; the nominal concentrations used were 10, 31.6, 100, 316 and 1000 mg/l. The NOEC was reported at 6.59 mg/l as geometric mean because the difference between nominal and measured values is often greater than ± 20 %.

A reproduction test on Daphnia magna (semi-static, 21 days) was carried out to assess the effect of the similar substance 3a-A(Na) on the reproductive output of Daphnia magna, according to the OECD Guideline 211. Ten daphnids, held individually, were used per concentration level and control. Nominal concentrations of the test item were selected based on the results of a preliminary range finding test (non-GLP) as follows: 1.0 - .2.0 - 4.0 - 8.0 - 16.0 mg/l. The effects on reproduction were evaluated based on the reproduction per introduced parent animal, since this parameter is the ecologically most relevant response variable and is required by the OECD test guideline 211 (2012), when a significant trend in mortality is detected. NOEC (21d, overall threshold effects) = 3.22 mg/l; NOEC (21d, reproduction) = 3.22 mg/l

A reproduction test on Daphnia magna (semi-static, 21 days) was carried out to assess the effect of the similar substance 3a-DSA on the reproductive output of Daphnia magna, according to the OECD Guideline 211. Ten daphnids, held individually, were used per concentration level and control. Nominal concentrations of the test item were selected based on the results of a preliminary range finding test (non-GLP) as follows: 0.480 - 1.20 - 3.00 - 7.50 - 18.8 mg/l (separation factor 2.5), corresponding to the time-weighted mean measured test item concentrations 0.540 – 1.29 – 3.22 – 7.78 – 19.3 mg/l. The following results were obtained: NOEC (21d, overall threshold effects) = 2.0 mg/l; NOEC (21d, reproduction) = 4.0 mg/l

A reproduction test on Daphnia magna (semi-static, 21 days) was carried out to assess the effect of the similar substance 1 -MSA on the reproductive output of Daphnia magna, according to the OECD Guideline 211. Ten daphnids, held individually, were used per concentration level and control. Nominal concentrations of the test item were selected based on the results of a preliminary range finding test (non-GLP) as follows: 0.478 - 1.10 - 2.53 - 5.82 - 13.4 mg/l. The effects on reproduction were evaluated based on the reproduction per introduced parent animal, since this parameter is the ecologically most relevant response variable and is required by the OECD test guideline 211 (2012), when a significant trend in mortality is detected. NOEC (21d, overall threshold effects) = 1.10 mg/l; NOEC (21d, reproduction) = 2.53 mg/l

The choice of the use of data from the two similar substances 3a-A(Na) and 3a-DSA is due to the fact that 3a-MSA is in between the two substances considering that 3a-A(Na) does not contain any sulfonate group, 3a-MSA contains one sulfonate group and 3a-DSA contains two sulfonate groups. The difference in the sulfonation degree is not reflected in the effect levels obtained in the relevant studies for the two similar substances 3a-A(Na) and 3a-DSA.

The use of the similar substance 1 -MSA is due to the fact that the effect levels obtained in the long-term toxicity study to aquatic invertebrates is the lowest among the ones available in the category. Moreover the degree of sulfonation and the structural similarity is taken into account. Following a conservative approach, the results obtained in the long-term toxicity study on acquatic invertebrates on the Similar Substance 1 -MSA will be used for the chemical safety assessment.

More details on the results of the other substances in the Category will be provided in the attached document under "Ecotoxicological Information".