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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

No reliable key study on sensitising properties of selenous acid is available. Only one supportive human case report was cited in ATSDR (2003) and is summarised in section 7.10.4. However no clear conclusion on sensitising properties can be drawn from these case reports.


ATSDR (2003). Agency for toxic substances and disease registry. Toxicological profile for selenium. U.S. Department of Health and Human Services, Public Health Services, Atlanta, Georgia.

Justification for classification or non-classification

Since no clear conclusion on sensitising properties can be drawn from the available data on selenous acid, it is proposed to adopt the harmonised classification as laid down in Regulation (EC) No. 1272/2008 and subsequent regulations. Selenous acid (as part of the group entry "selenium compounds except cadmium sulphoselenide") is not classified for respiratory or skin sensitisation.