Reaction mass of 5,5'-[sulphonylbis(3,1-phenyleneazo)]bis[6-amino-4-hydroxynaphthalene-2-sulphonic acid] and disodium 5,5'-[sulphonylbis(3,1-phenyleneazo)]bis[6-amino-4-hydroxynaphthalene-2-sulphonate]

Endpoint summary

Description of key information

EC50 (48h) invertebrate Daphnia magna: 54.9 mg/L

ErC50 (7d) aquatic plants Lemna minor: > 91.0 mg/L (frond number, dry weight)

Additional information

The following data were obtained for the Similar Substance 01. It is expected that the Target substance will present similar effect levels to daphnia and algae. Justification for Read Across is given in Section 13 of IUCLID.

 

The substance is very water soluble; it has a log Kow lower than 4 (indicating a low potential for bioaccumulation) and it is not readily biodegradable.

Invertebrate acute toxicity

The median effect concentration (EC50) and the no-effect concentration (NOEC) of the substance to Daphnia magna were investigated under static exposure conditions over a period of 48 h, following the guideline OECD 202 and EU C.2. The investigated nominal concentrations were 130, 59.1, 26.9, 12.2 and 5.55 mg/L test item, corresponding to 100, 45.5, 20.7, 9.39 and 4.27 mg/L of the active ingredient. The validity criteria were fulfilled.

The EC50 Daphnia magna at 48h was found to be 54.9 mg/L based on based on the nominal concentrations of the active ingredient. 

Aquatic Plants toxicity

The inhibitory effects of the substance to Lemna minor were investigated over a period of 7 days, based on the frond number and biomass (dry weight), following the guideline OECD 221 and the EU C.26. The analytical monitoring confirmed the right dosage of the test item, but showed that the concentrations of the test item decreased over the whole 7 day test period. The test solutions were prepared by respective dilutions of a stock solution in STEINBERG medium. The test was performed at the nominal test item concentrations of 130, 50.0, 19.2, 7.40 and 2.84 mg/L, corresponding to 100, 38.5, 14.8, 5.69 and 2.19 mg/L of the active ingredient. The validity criteria were fulfilled.

The NOEC frond number, on was found to be 4.27 mg/L of active ingredient. The 7 day ErC50 of on Lemna minor was found to be > 91.0 mg/L. This value is based on the geometric mean of the measured concentrations of the active ingredient.

 

Justification for classification or non-classification

According to the CLP Regulation (EC n. 1272/2008), Part 4: Environmental Hazards, the substances can be classified for hazardous to the aquatic environment when the following criteria are met:

A )Acute (short-term) aquatic hazard

Category Acute 1: 96 hr LC 50 (for fish) and/or 48 hr EC 50 (for crustacea) and/or 72 or 96 hr ErC 50 (for algae or other aquatic plants) ≤ 1 mg/l.

B) Long-term aquatic hazard

(iii) Substances for which adequate chronic toxicity data are not available and the substance is not rapidly degradable and/or the experimentally determined BCF ≥ 500 (or, if absent, the log K ow ≥ 4).

Category Chronic 1: 96 hr LC 50 (for fish) and/or 48 hr EC 50 (for crustacea) and/or 72 or 96 hr ErC 50 (for algae or other aquatic plants) ≤ 1 mg/l

Category Chronic2: 96 hr LC 50 (for fish) and/or 48 hr EC 50 (for crustacea) and/or 72 or 96 hr ErC 50 (for algae or other aquatic plants)> 1 to ≤10 mg/l

Category Chronic 3:96 hr LC 50 (for fish) and/or 48 hr EC 50 (for crustacea) and/or 72 or 96 hr ErC 50 (for algae or other aquatic plants) > 10 to ≤ 100 mg/l.

 

The substance is not rapidly degradable and the acute toxicity test to invertebrates fixed the effect levels within the range > 10 to ≤100 mg/L. Therefore, the classification as Category Chronic 3 is warranted, according to the CLP Regulation (EC 1272/2008).