Amides, C18 (unsaturated)

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

There is no test data from sensitisation studies available for oleamide. Therefore, read-across data from a Local Lymph Node Assay (LLNA), performed with the structurally related substance erucamide (CAS 112-84-5) according to OECD Guideline 429, was considered for regulatory purposes (Schmitt, 2010).

Erucamide is the fatty acid amide resulting from the amidation of erucic acid. Erucic acid is a mono-unsaturated fatty acid with a carbon chain consisting of 22 carbon atoms with a double bond at position 13 (omega-9) of the carbon chain (cis-docos-13-enoic acid). Comparable to stearamide it is not classified in Annex I of Directive 67/548/EEC, and does not have to be self-classified according to the available experimental data. Erucic acid is also present in various oils and fats which are part of our diets (20-40% in oils from mustard seeds and up to 60% in original high erucic rapeseed oil, <2% in low erucic acid rapeseed oil; Beare-Rogers, 2001) and will also be broken down into shorter-chain fatty acids in the process of beta-oxidation. One of the most famoust uses is in Lorenzo's oil, a 4:1 mixture of the triglyceride forms of oleic and erucic acid, i.e. an investigational drug used for the treatment of adrenoleukodystrophy, for which an U.S. Patent was established.

In this study the ears of 5 mice per group were topically treated with concentrations of 5, 10 and 25% of erucamide in tetrahydrofuran for 3 consecutive days. Five days after the first treatment the mice received an intravenous injection of tritiated thymidine. Five hours after treatment the mice were euthanised, the cells of the draining auricular lymph nodes were dissected, and the incorporated radioactivity was determined as number of disintegrations per minute (DPM) by means of a β-scintillation counter. Stimulation Indices were calculated as ratio of respective DPM of the individual animals from the treated groups versus the mean DPM of the control group. Subsequently, group mean Stimulation Indices of 0.81, 0.84 and 0.70 were determined for the 5%, 10% and 25% group, respectively. According to the criteria of OECD Guideline 429 the structurally related substance erucamide does not have to be regarded as skin sensitising.

Considering the similarity of physical chemical properties and of other toxicological parameters to erucamide, oleamide does not have to be considered as skin sensitising, either.

Migrated from Short description of key information:
RA-S CAS 112-84-5, OECD 429 (LLNA): not sensitising

Justification for classification or non-classification

According to the criteria of the DSD and the criteria of the CLP regulation the substance does not have to be classified as skin sensitising.