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

Endpoint summary

Description of key information

Short-term toxicity

Fish: LC50 (96 h) > 100 mg/l

Aquatic invertebrates: EC50 (48h) > 100 mg/l

Algae: ErC50 (72h) > 123 mg/l (nominal); NOEC (72h, growth rate) = 30.8 mg/l (nominal)

Long-term toxicity

Fish: NOEC (fry length) < 0.625 mg/l (nominal)

Aquatc invertebrates: NOEC (21d, overall threshold effects and reproduction) = 3.22 mg/l (twa)

Additional information

The aquatic toxicity of the substance was evaluated by considering data on the substance and on similar substances 2 -A and 3a-A(Na). Justification for Read Across is given in Section 13 of IUCLID.

At least one reliable study for each of the three acute trophic levels was reported with an EC50 greater than 100 mg/l and showing no general toxicity at high doses.

Regarding long term studies, a Daphnia magna reproductive study is available on the similar substance 3a-A(Na). A reproduction test on Daphnia magna (semi-static, 21 days) was carried out to assess the effect of the test item 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 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 NOEC for orverall threshold effects and for effects on reproduction was found as 3.22 mg/l.

For the evaluation of the long-term toxicity to fish, three studies on similar substances are available. All studies were performed according to the OECD Guideline 210.

2 -A caused significant effects on Zebrafish in an early life stage test, 30 days post hatch. For the parameter hatch, the NOEC was 10.0 mg/l. For the parameters post hatch survival and overall survival, the NOECs were 1.25 and 2.50 mg/l, respectively. For the parameter fry growth (expressed as length and fresh weight) the NOECs were < 0.625 mg/l (length) and 0.625 mg/l (weight).

3a-A(Na) partly caused significant effects on Zebrafish in an early life stage test, 30 days post hatch when tested with time-weighted arithmetic mean measured concentrations of 1.09 and 11.2 mg/l. For the parameters hatch, post-hatch survival, overall survival and fry growth (expressed as length) the NOEC was 11.2 mg/l. For the parameter fry growth (expressed as fresh weight) the NOEC was < 1.09 mg/l.

5 -A partly caused significant effects on Zebrafish in an early life stage test, 30 days post hatch when tested with nominal concentrations of 1.25 and 12.5 mg/l. For the parameters hatch, post-hatch survival and overall survival the NOEC was 12.5 mg/l. Therefore, the respective LOECs were determined to be > 12.5 mg/l. For the parameters fry growth (expressed as fresh weight and length) the NOEC was < 1.25 mg/l. Therefore, the LOEC for these parameters was determined to be 1.25 mg/l. All effect values are given based on the nominal concentrations of the test item.

Considering the available data on the three trophic levels, fish is considered to be the most sensitive species as the effect level during the fish early-life stage toxicity study on 2 -A was the lowest obtained.

Therefore, SELECTED NOEC for aquatic toxicity: 0.625 mg/l from the fish early-life stage toxicity on the similar substance 2 -A.

The study conducted on the similar substance 2 -A is used for the chemical safety assessment, following a conservative approach. More information on the results of the substances of the category are found on the document attached under "Ecotoxicological information".