Dihydrogen (ethyl)[4-[4-[ethyl(3-sulphonatobenzyl)]amino]-2'-sulphonatobenzhydrylidene]cyclohexa-2,5-dien-1-ylidene](3-sulphonatobenzyl)ammonium, disodium salt

Endpoint summary

Description of key information

No acute oral toxicity was observed in rats after a single gavage dose of 1900 mg/kg bw.  Poorly documented data on intraperitoneal injection also shows that the substance is of low toxicity.

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

discriminating dose

Value:

1 900

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Additional information

The substance has long been used as a colorant, and the oldest studies date back to the 1960ies. Accordingly, a number of non-standard studies with limited documentation are available. The overall data shows that the substance is of low acute toxicity.

A high quality study for acute oral toxicity in rats is available with an aqueous formulation containing 38% of the colorant (BASF 1982).

The formulation was applied by gavage. The study was not performed under GLP, but is reported in sufficient detail to be acceptable. The procedures provided in OECD testing guideline 423 were followed. The doses of the formulation were up to 5000 mg/kg bw, so high that for the substance itself, the highest dose was calculated to be 1900 mg/kg bw. This is slightly lower than the limit dose of 2000 mg/kg bw as defined in the OECD testing guideline. This is however considered acceptable because there were no adverse effects and no incidences of mortality. The only effect observed was the turquoise coloration of the urine which indicates that the blue colorant is at least partly taken up by the body and eliminated via the kidneys. It is highly unlikely that an LD50 would be lower than 2000 mg/kg bw. In addition, older literature publications with limited details indicate that the LD50 in rats after gavage or intraperitoneal dosing is greater than 2000 mg/kg bw (Gross 1961, Lu 1964). Also absence of acute oral toxicity observed in a range-finding study for a comet assay in mice is supportive of overall low acute toxicity (Sasaki 2002). The latter study has the major limitation that the postobservation period was probably only 24hours and certainly not two weeks.

Assessment of acute dermal toxicity:

Toxikokinetic data for the oral route showed that only ca 2% of the substance is absorbed. A very low absorption can also be assumed for the dermal route because the log Pow is less than -4 and the molecular weight of 792 g/mol is greater than 500 g/mol. The substance is not affected by the acidic pH of the stomach. In accordance with ECHA guidance, the dermal route does not need to be tested for substances causing no toxicity at the oral route at the limit dose.

No experimental data is available for the inhalation route.

Justification for classification or non-classification

Dangerous Substance Directive (67/548/EEC)

The available studies are considered reliable and suitable for classification purposes under 67/548/EEC. As a result the substance is not considered to be classified for acute oral or dermal toxicity under Directive 67/548/EEC, as amended for the 31st time in Directive 2009/2/EG.

Classification, Labelling, and Packaging Regulation (EC) No. 1272/2008

The available experimental test data are reliable and suitable for classification purposes under Regulation 1272/2008. No mortality was observed in rats at a dose of 1900 mg/kg bw. Therefore, the LD50 is not expected to be less than 2000 mg/kg bw. As a result the substance is not considered to be classified for acute oral or dermal toxicity under Regulation (EC) No. 1272/2008, as amended for the seventh time in Regulation (EC) No 2015/1221.