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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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






















In a skin sensitisation assay (Bühler test: 95-0258-DGT), 20 female Guinea pigs received three dermal doses (day 0, 7 and 14) of 0.5 g 4-Hydroxy-TEMPO as a paste in petrolatum at a 50 % (w/w) concentration onto their left caudal flank, while nine female negative control animals received the vehicle alone. The maximum concentration feasible was determined in a pre-test. The animals were challenged on day 28, using the same vehicle and test item concentration, applied onto the right flank. No signs of skin sensitisation where detected. The latest positive control using 2-Mercaptobenzothiazol was positive. The study was performed according to GLP and it satisfies the requirements of OECD test guideline 406. The study is considered acceptable (key study).


























Short description of key information:
The test substance 4-Hydroxy TEMPO did not induce delayed contact hypersensitivity in the Bühler test and is thus not regarded as a skin sensitiser.

Justification for selection of skin sensitisation endpoint:
Adequate assay to address endpoint

Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no study available
Additional information:

The test item has no structural alert indicative for respiratory sensitisation. In addition, no human data on respiratory sensitisation have been reported. The test item is considered not to induce respiratory sensitisation.



Short description of key information:
Considered not to induce respiratory sensitisation.

Justification for classification or non-classification

Skin sensitisation

Based on the results of an in vivo skin sensitisation test, the test item should not be classified with regard to skin sensitisation according to Directive 67/548/EEC and Regulation (EC) No 1272/2008 (GHS, CLP).

Respiratory sensitisation

Considered not to induce respiratory sensitisation.