Registration Dossier

Administrative data

Endpoint:
skin sensitisation: in vivo (LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Skin sensitisation was determined according to OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay).

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2005
Report Date:
2005

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)
GLP compliance:
yes (incl. certificate)
Type of study:
mouse local lymph node assay (LLNA)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent

In vivo test system

Test animals

Species:
mouse
Strain:
CBA
Sex:
female
Details on test animals and environmental conditions:
Details on test animals:
- Source: Harlan, Indinapolis.
- Age at study initiation: 8-12 weeks old.
- Weight at study initiation: 17.5 to 22.8 grams.
- Housing: group housing (max 5 per cage).
- Diet: TEK 7012 Rodent diet, ad libitum.
- Water: tap water, ad libitum.

Environmental conditions:
- Temperature: 68°F
- Humidity: 30-70%
- Air changes: 10 to 15 per hr
- Photoperiod 12 hrs light/dark cycle, full spectrum fluorescent lights.

Study design: in vivo (LLNA)

Vehicle:
dimethyl sulphoxide
Concentration:
The test substance was evaluated at 3 different concentrations : 50, 5 and 0.5%.
No. of animals per dose:
Five animals per dose group with three concentrations of the test substance.
Details on study design:
Detail on study:
Day 1: 25µl of the tested substance or control substance were applied to the dorsum of both ears.
Days 2 & 3: same procedure performed on day 1.
Days 4 & 5: animals were not treated.
Day 6: 5 hours prior to sacrifice, all animals were injected intravenously with 250µl of Phosphate-Buffered Saline containing 20µlCi methyl-3H-thymidine.
The animals were sacrificied by carbon dioxide inhalation and the draining auricular lymph nodes were excised from each animal.
A single suspension of the lymph node cells from each mouse was prepared by gentle mechanical desegregation.
The cell suspension was centrifuged, resuspended in cold 5% TCA, and allowed precipitate at 4°C for 18 hours.
The cells were precipitated and resuspended in cold 5% TCA.

The proliferation response of lymph node cells is expressed as the number of radioactive disintegrations per minute per mouse (DPM/Mouse) and as the Stimulation Index (SI).
Positive control substance(s):
hexyl cinnamic aldehyde (CAS No 101-86-0)

Results and discussion

Positive control results:
The Simulation Index of the positive control animals was 6.95.
The positive control , 25% hexyl cinnamic aldehyde, did induce a Simulation Index greater than 3, thus validating the test system.

In vivo (LLNA)

Resultsopen allclose all
Parameter:
SI
Remarks on result:
other: Group Test 50% SI: 3.85 Group Test 5% SI: 1.25 Group Test 0.5% SI: 1.35 Negative control SI: NA Positive control SI: 6.95
Parameter:
other: disintegrations per minute (DPM)
Remarks on result:
other: Group Test 50% Net DPM Avg.: 277.63 Group Test 5% Net DPM Avg.: 90.42 Group Test 0.5% Net DPM Avg.: 97.71 Negative control Net DPM Avg.: 72.14 Positive control Net DPM Avg.: 501.46

Any other information on results incl. tables

The 5% and 0.5% solutions of the tested substance in DMSO did not induce a Stimulation Index greater than 3 when compared to the vehicle controls. The tested substance did induce a SI greater than 3 when tested at 50%, resulting a SI of 3.85 and a EC3 value of 35.3% (EC3 was calculated by using the concentration and SI values immediately above and below the threshold SI of 3 on the dos response curve).

Applicant's summary and conclusion

Interpretation of results:
Category 1 (skin sensitising) based on GHS criteria
Remarks:
Migrated information
Conclusions:
Based on the test protocol and evaluation criteria, the test substance is considered a weak dermal sensitizer.