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Description of key information

An LLNA study on the test substance was carried out based on the guidelines described in: OECD, Section 4, Health Effects, No.429 (2002),

EC, Council Directive 67/548/EEC, Annex V, B.42 (2004);

EPA, OPPTS 870.2600 (2003) "Skin Sensitisation".

Test substance concentrations selected for the main study were based on the results of a preliminary study.

In the main study, three groups of five experimental animals were treated with test substance concentrations of 10%, 25% or 50% 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)).

Three days after the last exposure, all animals were injected with 3H-methyl thymidine and after five hours the draining (auricular) lymph nodes were excised.

After precipitating the DNA of the lymph node cells, radioactivity measurements were performed. The activity was expressed as the number of Disintegrations Per Minute (DPM) and a stimulation index (SI) was subsequently calculated for each group.

No skin reactions were observed in any of the animals examined.

All nodes of the experimental and control groups were considered normal in size. No macroscopic abnormalities of the surrounding area were noted.

Mean DPM/animal values for the experimental groups treated with test substance concentrations 10, 25 and 50% were 710, 529 and 298 respectively.

The mean DPM/animal value for the vehicle control group was 399.

The Sl values calculated for the substance concentrations at 10%, 25% and 50% were 1.8, 1.3 and

0.7 respectively. Therefore, according to the guidelines, the test substance is considered non-sensitizing to skin.

Key value for chemical safety assessment

Justification for classification or non-classification