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Administrative data

specific investigations: other studies
Adequacy of study:
other information

Data source

Reference Type:
other: Body responsible for the test

Materials and methods

Principles of method if other than guideline:
Test procedure:
Animals: mouse CBA strain (females)

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 epidermally exposed to test substance concentrations
of 5%, 25% or 50% on three consecutive days. Five vehicle
control animals were similarly treated, but with vehicle
alone (Dimethyl sulphoxide).

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 is calculated for each group.

Results and discussion

Details on results:
The irritation of the ears as shown by the animals, was
considered not to have a toxicologically significant effect
on the activity of the nodes.

All nodes of the experimental and control groups were
considered normal in size.

No macroscopic abnormalities of the surrounding area were

Mean DPM/animal values for the experimental groups treated
with test substance concentrations 5, 25 and 50% were 195,
164 and 126 respectively.

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

The SI values calculated for the substance concentrations 5,
25 and 50% were 0.7, 0.6 and 0.5 respectively.

There was no indication that the test substance could elicit
an SI >= 3.

The six monthly reliability check with Hexylcinnamic
aldehyde indicates that the Local Lymph Node Assay as
performed at NOTOX is an appropriate model for testing for
contact hypersensitivity.

Applicant's summary and conclusion