Registration Dossier

Administrative data

Endpoint:
skin sensitisation: in vivo (LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
October 17-29, 2007
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Study has been performed according to OECD and EC guidelines and according to GLP principles.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2008
Report Date:
2008

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method B.42 (Skin Sensitisation: Local Lymph Node Assay)
Deviations:
no
Qualifier:
according to
Guideline:
EPA OPPTS 870.2600 (Skin Sensitisation)
Deviations:
no
GLP compliance:
yes (incl. certificate)
Type of study:
mouse local lymph node assay (LLNA)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Corsair Clear #12
- Substance type: Soft waxy beige solid
- Physical state: Solid
- Stability under test conditions: stable
- Storage condition of test material: At room temperature in the dark

In vivo test system

Test animals

Species:
mouse
Strain:
CBA
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River France, L’Arbresle Cedex, France
- Age at study initiation: approx. 12 weeks old
- Weight at study initiation: 22-26 g
- Housing: Individual housing in labeled Macrolon cages containing sterilized sawdust as bedding material
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21.1 – 23.5°C
- Humidity (%): 40 - 60%
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12

Study design: in vivo (LLNA)

Vehicle:
acetone/olive oil (4:1 v/v)
Concentration:
0 - 25 - 50 - 100%
No. of animals per dose:
5
Details on study design:
RANGE FINDING TESTS:
- Compound solubility:
- Irritation: slight erythema in 1 of 2 animals

MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: local lymph node assay
- Criteria used to consider a positive response: DPM values are presented for each animal and for each dose group. A Stimulation Index (SI) is calculated for each group. The SI is the ratio of the DPM/group compared to DPM/vehicle control group. If the results indicate a SI >= 3, the test substance may be regarded as a skin sensitiser, based on the test guideline and recommendations done by ICCVAM

TREATMENT PREPARATION AND ADMINISTRATION:
Three groups of five experimental animals were treated with test substance concentrations of 25%, 50% or 100% on three consecutive days, by open application on the ears (25 µl/ear). 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.
Positive control substance(s):
hexyl cinnamic aldehyde (CAS No 101-86-0)

Results and discussion

Positive control results:
The SI values calculated for the substance concentrations 5, 10 and 25% were 1.0, 2.0 and 5.7 respectively. An EC3 value of 14.1% was calculated using linear interpolation. The calculated EC3 value was found to be in the acceptable range of 2 and 20%. The results of the 6 monthly HCA reliability checks of the recent years were 10.3, 9.5, 13.1 and 15.6%. Based on the results, it was concluded that the Local Lymph Node Assay as performed at NOTOX is an appropriate model for testing for contact hypersensitivity.

In vivo (LLNA)

Resultsopen allclose all
Parameter:
SI
Remarks on result:
other: 0%: 1.0 +/- 0.2 25%: 1.2 +/- 0.2 50%: 1.7 +/- 0.3 100%: 2.1 +/- 0.3
Parameter:
other: disintegrations per minute (DPM)
Remarks on result:
other: 0%: 351 +/- 46 25%: 429 +/- 30 50%: 596 +/- 93 100%: 738 +/- 73

Applicant's summary and conclusion

Interpretation of results:
not sensitising
Remarks:
Migrated information
Conclusions:
The SI values calculated for the substance concentrations 25, 50 and 100% were 1.2, 1.7 and 2.1 respectively.
There was no indication that the test substance could elicit an SI >= 3 when tested up to 100%. Therefore the test substance does not have to be classified and has no obligatory labeling requirement for sensitization by skin contact.