Registration Dossier

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