Registration Dossier

Data platform availability banner - registered substances factsheets

Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

Description of key information

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not sensitising)
Additional information:

The skin sensitisation potential of Leuco Sulfur Black 1 was investigated in the LLNA according to OECD test guideline No. 429 and GLP. Three groups each of four female mice were treated daily with the test item at concentrations of 5, 10 and 25% (w/w) in dimethylformamide by topical application to the dorsum of each ear lobe (left and right) for three consecutive days. A control group of four mice was treated with the vehicle (dimethylformamide) only. Five days after the first topical application the mice were injected 3H-methyl thymidine. Approximately five hours later, the mice were sacrificed, the draining auricular lymph nodes excised and pooled per group. Single cell suspensions of lymph node cells were prepared from pooled lymph nodes and the proliferative capacity of pooled lymph node cells was determined by the incorporation of 3H-methyl thymidine measured in a scintillation counter.

All treated animals survived the scheduled study period and no signs of toxicity were observed.

A test item is regarded as a sensitizer in the LLNA if the exposure to one or more test concentration resulted in 3-fold or greater increase in incorporation of3HTdR compared with concurrent controls, as indicated by the Stimulation Index (S.I.). The estimated concentration of test item required to produce a S.I. of 3 is referred to as the EC3 value.

In this study Stimulation Indices of 1.42, 1.12 and 1.61 were determined with the test item at concentrations of 5, 10 and 25% in dimethylformamide.

The EC3 value could not be calculated, since none of the tested concentrations induced a S.I. greater than 3. Thus, the test item was not a skin sensitizer.

Migrated from Short description of key information:
Leuco Sulfur Black 1 did not cause skin sensitisation in the LLNA in mice.

Respiratory sensitisation

Endpoint conclusion
Additional information:

At present there is no accepted experimental test system available to evaluate this endpoint. Based on the substance properties (mean MW >8000 Da and very poor solubility in water), the fact that no toxicity was seen in any of the available studies and that there are no human data available indicative of a respiratory sensitisation potential, it is concluded that Leuco Sulfur Black 1 does not raise any concern regarding respiratory sensitisation.

Justification for classification or non-classification

Based on the available data Leuco Sulfur Black 1 is not subject to classification and labelling according to Directive 67/548/EECand Regulation 1272/2008/EC.