Registration Dossier

Administrative data

Description of key information

Rat oral LD50: 7562 mg/kg bw
Rat inhalation LD50 > 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:
7 562 mg/kg bw
Quality of whole database:
The quality of the database is high, since a number of studies are available of good quality and consistent results.

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

Several acute toxicity studies are available: all were performed on rats and they were conducted following test procedures similar to those outlined into the OECD guideline 401. The lots tested were different, with different concentration percentages of the substance. Nevertheless, all the test clearly indicated that the substance is not harmful and thus the lowest LD50 identified has been chosen for the Risk Assessment: 7562 mg/kg bw (Ciba-Geigy Ltd., 1975).

A good GLP Klimish 1 study for acute dermal toxicity is reported (Ciba-Geigy Ltd., 1990). It was performed just at 2000 mg/Kg bw and no systemic signs were observed in the animals during the entire observation period (RCC, Research & Consulting Company AG., 1990).

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 Withening Agents, group 3, is the acid form of the disulphonated derivative dihydroxyethyl derivative (Justification for Read Across is reported in the Category Justification Report attached to the Section 13 of the dossier).

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


Justification for selection of acute toxicity – oral endpoint
Several acute toxicity studies performed on rats are available and all the test clearly indicated that the substance is not harmful; thus the lowest LD50 identified has been chosen for the Risk Assessment. The study was conducted according to internationally accepted testing guidelines.

Justification for selection of acute toxicity – dermal endpoint
Study conducted according to internationally accepted testing guidelines, in GLP. Furthermore the active ingredient tested was 83 %.

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 ca 7562 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).