Registration Dossier

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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

There is guinea pig data for a 50% leucoindigo preparation. Positive skin reactions were found in 5 animals ( 4 x score 1, 1 x score 2) at the 24-hour and in 4 animals (4 x score 1) at the 48-hour assessment. According to the evaluation system used in this study, the test item was classified as "mild sensitizer". According to the EU evaluation system the test item has no sensitizing properties

The leucoindigo rapidly oxidizes to indigo under testing conditions, which can be noticed by the blue staining of the animals' skin. Furthermore, human data from literature using Indigo dispersible powder as test substance confirmed the negative test result. In addition, there is several hundred years of experience with the usage of indigo, and no sensitizing effect during this usage is reported.


Migrated from Short description of key information:
No skin-sensitizing properties

Respiratory sensitisation

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

Based on the negative skin sensitization test, no respiratory sensitization is expected. In addition, the acute inhalation studies with Indigo in rats exposed to a saturated atmosphere for up to 8 hours did not lead to any adverse effects.


Migrated from Short description of key information:
No respiratory-sensitizing properties

Justification for classification or non-classification

No sensitizing effects observed in animal and human studies