Cyclopentaneacetic acid, 3-oxo-2-pentyl-, methyl ester, (1R,2S)-rel-

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

No study was available on the substance itself, therefore a read-across approach was used. The supporting substance is considered adequate for read-across purpose as data relates to a mixture of cis- and trans-isomers whereas the registered substance is the pure cis-isomer (see Iuclid section 13 for additional justification).

Two skin sensitisation studies were identified on the supporting substance. Although these studies provided information to assess the skin sensitisation potential of the registered substance, none of them was considered as sufficient to be the key study on its own. Therefore, a weight-of-evidence approach was built:

- A Local Lymph Node Assay (LLNA, BRT, 2004, Rel.2)) was performed in compliance with GLP and similarly to the OECD test guideline No. 429 and in compliance with GLP. A significant lymphoproliferation was noted in the positive control group, therefore the study was considered valid. The test material (1%-40%) did not induce delayed contact hypersensitivity in this assay. None of the mice assigned to this study experienced visible irritation or other adverse toxic effects. In this study, the maximum concentration tested was not justified: a screening study was not performed and ear thickness measurements were not included.

- A Guinea-Pig Maximisation test (GMPT, Instituto di Recerche Biomediche, 1995, Rel.2) was performed according to the OECD test guideline No. 406 and in compliance with GLP. The test material, diluted in paraffin oil at 6.25% (v/v), was administered by injection for intradermal induction. Topical induction was performed with the test material as supplied, 7 days after intradermal injections. For the challenge, the test material was tested at 100% and 50% v/v in paraffin oil. There were no responses apparent in the treated and control groups. Under the test conditions, the test material is not classified as skin sensitizer. This study does not include positive control data, the sensitivity and the reliability of the method cannot be ascertained.

The registered substance is present at 25 -30% in the mixture, i.e. well above the concentration triggering classification of mixture as skin sensitizer as defined in the Annex VI of the Regulation (EC) No. 1272/2008, therefore it can be safely concluded that the pure cis-isomer does not need to be classified as skin sensitizer.

Migrated from Short description of key information:
- LLNA, Not sensitising (similar to OECD 429, GLP, read-across, WoE, Rel.2);
- GPMT, Not sensitising (OECD 406, GLP, read-across, WoE, Rel.2).

Justification for selection of skin sensitisation endpoint:
No study was available on the substance itself, therefore a read-across approach was used. The supporting substance is considered adequate for read-across purpose as data relates to a mixture of cis- and trans-isomers whereas the registered substance is the pure cis-isomer (see Iuclid section 13 for additional justification). No study was selected as Key since a weight-of-evidence approach using the LLNA and the GPMT assay on the supporting substance was considered more robust.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Harmonized classification:

The substance has no harmonized classification according to the Regulation (EC) No. 1272/2008 including ATP4.

Self-classification:

Based on the available data on the supporting substance, no additional self-classification is proposed according to the Annex VI of the Regulation (EC) No. 1272/2008 (CLP) and of the Directive 67/548/EC.

No data was available regarding respiratory sensitisation.