Methyl cyclopentylideneacetate

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

The study was performed to GLP and the method followed OECD 429 to assess the skin sensitisation potential of the test material in the CBA/J strain mouse following topical application to the dorsal surface of the ear. In a preliminary screening test mice were treated by daily application of 25 μl of the undiluted and 50% v/v in acetone/olive oil 4:1 diluted test item to the dorsal surface of each ear for three consecutive days (Days 1, 2, 3). The mice were observed twice daily and local skin irritation was scored daily. Any clinical signs of toxicity, if present, were also recorded. The bodyweight was recorded on Day 1 (prior to dosing) and on Day 6. Ear thickness measurements were conducted using a digital thickness gauge prior to dosing on Days 1 and 3, and on Day 6. A mean ear thickness increase of equal to or greater than 25% and/or well-defined irritation at the most (maximum grade 2) was considered to indicate excessive irritation and limited biological relevance to the endpoint of sensitisation. No irritation or signs of systemic toxicity were observed in the animals examined except for the very slight erythema seen in one animal in the 100% group, on both ears, post dosing on Day 3 (right ear only; very slight erythema and 2% increase in ear thickness measurement observed). Variations in ear thickness during the observation period were less than 25% from Day 1 pre-dose values. Based on the preliminary test, the concentrations selected for the main test were 0%, 25%, 50% and 100% v/v. In the main test, three groups of five female CBA/J mice were treated with test substance concentrations of 25, 50 or 100% w/w on three consecutive days, by open application on the ears. Five vehicle control animals were similarly treated, but with vehicle alone (Acetone/Olive oil (4:1 v/v)). No irritation of the ears was observed in any of the animals examined. Body weights were within the range seen for controls over the study period. The auricular lymph nodes of the vehicle control group and 25% group were considered normal in size. The nodes of the 50% and 100% groups were considered enlarged. The largest nodes were found in the highest dose group. All auricular lymph nodes of the animals of the experimental and control groups were considered normal in size. No macroscopic abnormalities of the surrounding area were noted for any of the animals. Mean DPM/animal values for the experimental groups treated with test substance concentrations 25, 50 and 100% were 861, 1313 and 1326 DPM, respectively. The mean DPM/animal value for the vehicle control group was 667 DPM. The SI values calculated for the substance concentrations 25, 50 and 100% were 1.3, 2.0 and 2.0, respectively. Under the conditions of this study, there was no indication that the test substance elicited an SI ≥ 3 when tested up to 100%, the test substance would not be considered a skin sensitizer.

Migrated from Short description of key information:
Skin sensitisation: not sensitising, OECD 429, Wil Research B.V. 2014

Justification for selection of skin sensitisation endpoint:
one GLP compliant Klimisch 1 LLNA study

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

The substance does not meet classification criteria under EU Directive 67/548/EEC for skin sensitisation.

The substance does not meet classification criteria under Regulation (EC) No 1272/2008 for skin sensitisation.