Hexasodium 2,2'-[vinylenebis[(3-sulphonato-4,1-phenylene)imino[6-[bis(2-hydroxyethyl)amino]-1,3,5-triazine-4,2-diyl]imino]]bis(benzene-1,4-disulphonate)

Endpoint summary

Description of key information

Rat oral LD50 > 5000 mg/kg bw

Rat inhalation LC50 > 1895 mg/m3

Rat dermal LD50 > 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:

5 000 mg/kg bw

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LC50

Value:

1 895 mg/m³

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Additional information

No specific tests on the substance under registration was performed, nevertheless the substance belongs to the Stilbene Fluorescent Whitening Agents category, group 3, in which all members share the common organic functional group dihydroxyethylamino derivative, with different sulphonation degrees: acid form (OB 3a-A(free acid), disulphonated sodium salt (OB 3a-A(Na), disulphonated sodium/potassium form (OB 3a-A(NaK) tetrasulphonated (OB 3a-MSA) and hexasulphonated (OB 3a-DSA).

For three representative substances valid tests were performed, which resulted in no effect up to the highest tested dose (2000-5000 mg/kg bw). The result for OB 3a-DSA can be well interpolated between results for the other substances: the less soluble OB 3a-A(Na) /OB 3a-A(NaK) and the more soluble OB 3a-MSA.

Within the whole category ten over fourteen registered substances were tested and none of the existing tests arisen any concern for acute oral toxicity.

Skin absorption was evaluated and calculated for all members of the category (see Category Justification Report, attached to the Section 13 of the technical dossier).

As it can be noted, the influence of the variability in functional group is very low, more related to the variability in the polarity of the substance than on potential reactivity that can arise a concern. From a metabolic point of view, estimation with OECD Toolbox of the dermal metabolism was performed in order to verify if breakdown products may be formed. Results are negative for all members.

 

A valid GLP study for acute dermal toxicity was reported (RCC, Research & Consulting Company AG., 1991), performed just at 2000 mg/kg bw with no effect. The tested substance is the analogous OB 3a-MSA the dihydoxyethyl derivative tetrasulphonated.

 

Because of the physical state and the trade forms, inhalation is not an appropriate route of exposure. Acute toxicity results for the other two exposure routes indicate no concern therefore no testing was performed. One test is available on an analogous substance, performed at the maximum allowed concentration of 1890 mg/m3: no effects were observed. The analogous substance, part of the Stilbene Fluorescent Whitening Agents, group 3, is the acid form of the disulphonated derivative dihydroxyethyl derivative, therefore contains the same organic functional groups, but due to the sulphonation/salification degree is less soluble. This property makes the Read Across substance 3a-A(free acid) a conservative representative because of the potential higher bioavailability.

 

As a conclusion, it can be stated that the substance is not acutely toxic for all the three exposure ways.

Justification for classification or non-classification

According to the CLP Regulation (EC 1272/2008), 3.1 Acute toxicity section, substances can be allocated to one of four toxicity categories based on acute toxicity by the oral, dermal or inhalation route according to the numeric criteria. Acute toxicity values are expressed as (approximate) LD50 (oral, dermal) or LC50 (inhalation) values or as acute toxicity estimates (ATE).

 

The oral LD50 value was established to be greater than 5000 mg/kg body weight, therefore the test substance is out of any classification limit for acute oral toxicity (oral acute toxicity category 4: 300 < ATE ≤ 2000 mg/kg bw).

 

The dermal LD50 value was established to exceed 2000 mg/kg body weight, which exceeded the highest CLP classification limit (dermal acute toxicity category 4: 1000 < ATE ≤ 2000 mg/kg bw).

 

The inhalation LC50 value was established to be greater than 1895 mg/m3. For powder the limit for classification is ATE > 5 mg/l i. e. 5000 mg/m3.

Since no effect was observed at the tested concentration and this was the maximum reachable concentration in the test condition, it is assumed that the substance is not classified for inhalation acute toxicity.

 

In conclusion, the available experimental data are adequate for classification and labelling and the test substance is non classified for oral and dermal acute toxicity, according to the CLP Regulation (EC 1272/2008).