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

LD50 (Oral, rat) > 2000 mg/kg bw

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

ACUTE TOXICITY - ORAL ROUTE

The acute oral toxicity of the substance was investigated using a specific QSAR model, developed to predict the acute oral toxicity for dyes. The existing QSAR models have strong limitations to predict ionic complex structures as the organic dyes are, and consequently they provide unreliable results. The QSAR modelling used was developed in accordance with the OECD principles (Acute Oral Toxicity - QSAR Model Report N. 11).

Based on the estimation, the substance is expected to have no concern for acute oral toxicity. The estimation resulted to be in the applicability domain of the model.

 

In order to confirm the results obtained by the QSAR prediction, the investigations performed on two analogue substances (Similar Substance 01 and Similar Substance 02) are used as support of the prediction. Justification for Read Across is given in Section 13 of IUCLID.

 

The acute toxicity of the substance was investigated following a single oral administration to the Sprague Dawley rat followed by a 14-day observation period, according to OECD 423, in GLP. A first group of 3 female animals was initially dosed at 2000 mg/kg (Step 1). A second group of 3 female animals was then dosed at the same dose level (Step 2). No mortality occurred and no clinical signs were noted. The only finding observed was yellow staining on tail in all animals on Day 2 of the study. Body weight changes recorded during the study were within the expected range for this strain and age of animals. No abnormalities were observed at necropsy examination performed at the end of the observation period on animals of both groups, with the exception of animal no. 19 (Group 4), that showed red staining on the dorsum.

These results indicate that the test item did not induce toxic effects in the rat following oral administration of a single dose at a level of 2000 mg/kg. The lack of mortality demonstrates the acute toxicity expected (ATE) to be greater than 2000 mg/kg body weight.

The substance was tested for acute toxicity to rat by oral route. No relevant signs were observed after administered dose of 5000 mg/kg; therefore the LD50 was established to be more than 5000 mg/kg bw.

 

Justification for classification or non-classification

In the CLP Regulation (EC 1272/2008) acute toxicity is defined as “those adverse effects occurring following oral or dermal administration of a single dose of a substance or a mixture, or multiple doses given within 24 hours, or an inhalation exposure of 4 hours”. A substance can be allocated to one of four toxicity categories based on acute toxicity by the oral, dermal or inhalation route. The numeric criteria based on the acute toxicity estimates (ATE) in mg/kg bodyweight are presented in Annex I, Part 3, Table 3.1.1. For acute oral toxicity: "Category 4: 300 < ATE ≤ 2 000".

Based on the results of acute oral toxicity, no classification for acute oral toxicity is warranted under the CLP Regulation (EC 1272/2008).