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Toxicological information

Skin sensitisation

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Administrative data

Endpoint:
skin sensitisation: in vivo (LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
October 15-29, 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 #34
- Substance type: Clear white lumpy 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: 22-27 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 - 62%
- 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 - 10 - 25 - 50%
No. of animals per dose:
5
Details on study design:
RANGE FINDING TESTS:
- Compound solubility:
- Irritation: No irritation was observed in any of the 2 animals examined.

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 10%, 25% or 50% 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 +/- 0.1 10%: 0.6 +/- 0.2 25%: 1.9 +/- 0.6 50%: 8.3 +/- 1.8
Parameter:
other: disintegrations per minute (DPM)
Remarks on result:
other: 0%: 257 +/- 27 10%: 163 +/- 51 25%: 485 +/- 146 50%: 2125 +/- 399

Any other information on results incl. tables

Slight erythema was observed in one or both ears of two animals at 50%. No oedema was observed in any of the animals examined.

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.

The scoring of the skin reactions was not hampered by sticky remnants of the test substance, which were present on the ears of experimental animals at the time of scoring.

The majority of nodes were considered normal in size, except for the enlarged nodes observed in all animals at 50%.

No macroscopic abnormalities of the surrounding area were noted.

Body weights and body weight gain of experimental animals remained in the same range as controls over the study period.

Applicant's summary and conclusion

Interpretation of results:
sensitising
Remarks:
Migrated information EC3 of 28.7%
Conclusions:
The SI values calculated for the substance concentrations 10, 25 and 50% were 0.6, 1.9 and 8.3 respectively. These results indicate that the test substance could elicit an SI >= 3. An EC3 value of 28.7% was calculated.
Based on these results, Corsair Clear #34 would be regarded as skin sensitizer.