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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Data on skin sensitisation were reported by Park et al (1995) (EU RAR, 2007; section, page 70). Male volunteers were exposed on the back to sodium hydroxide concentrations of 0.063-1.0% (induction). After 7 days the volunteers were challenged to a concentration of 0.125%. The irritant response correlated well with the concentration of NaOH, but an increased response was not observed when the previously patch tested sites were re-challenged.

Furthermore, NaOH has been used widely and for a long time and no human cases of skin sensitisation have been reported and therefore NaOH is not considered to be a skin sensitiser (EU RAR 2007).

Migrated from Short description of key information:
Based on a study with male volunteers sodium hydroxide has no skin sensitisation potential (Park et al., 1995).

Justification for classification or non-classification

Existing data do not demonstrate that NaOH is a skin sensitizer.