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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Endpoint conclusion
Endpoint conclusion:
adverse effect observed (corrosive)

Eye irritation

Endpoint conclusion
Endpoint conclusion:
adverse effect observed (irritating)

Respiratory irritation

Endpoint conclusion
Endpoint conclusion:
no study available

Additional information

Data on skin and eye irritation studies show that indigo itself is not irritating to rabbit skin and eyes. Studies with a positive outcome regarding skin or eye irritation contained at least 3% NaOH/KOH.

Based on animal data it can be concluded that a KOH solution of 8% can be considered corrosive for skin. Based on human data concentrations of 0.5–4% were irritating. In 2 different studies a concentration of 0.5% was irritating for only 55 and 61% of the volunteers, respectively and therefore it is assumed that a concentration, which is slightly lower than 0.5%, is the non-irritating concentration.

The available animal data on eye irritation of KOH revealed small differences in eye irritation levels. The non-irritant level was 0.2-1.0%, while the corrosive concentration was 1.2% or higher than 2%.


Effects on skin irritation/corrosion: corrosive

Effects on eye irritation: corrosive

Justification for classification or non-classification