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Administrative data

Description of key information

The potential of the substance to induce delayed contact hypersensitivity was investigated using the Local lymph Node Assay (OECD 429, GLP). The result of the Local lymph Node Assay was negative, the substance was not a skin sensitizer.

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records
Reference
Endpoint:
skin sensitisation: in vivo (LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2010-07-27 to 2010-08-17
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)
Deviations:
no
GLP compliance:
yes (incl. certificate)
Type of study:
mouse local lymph node assay (LLNA)
Species:
mouse
Strain:
other: CBA/J
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source : Janvier, Le Genest-Saint-Isle, France
- Age at study initiation: 10 weeks old
- Weight at study initiation: 23.3 (+/- 0.9 g)
- Housing: in individual crystal polystyrene cages (22 cm x 8.5 cm x 8 cm)
- Diet (e.g. ad libitum): ad libitum (SSNIFF R/M-H pelleted maintenance diet )
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22°C (+/- 2°C)
- Humidity (%): 50 ± 20%,
- Air changes (per hr): approximately 12 cycles per hour of filtered, non-recycled air
- Photoperiod (hrs dark / hrs light): 12h/12h

IN-LIFE DATES: From: To: no data
Vehicle:
acetone/olive oil (4:1 v/v)
Concentration:
For the preliminary test the concentrations were 2.5, 5, 10 and 25%, of the test item.
For the main test the concentrations were 0, 0.5, 1, 2.5, 5 and 10% of the test item.
No. of animals per dose:
For the preliminary test: 2 females/dose (no controls)
For the main test: 4 females/dose, 4 females for the negative control and 4 females for the positive control
See details on table 7.4.1/1
Details on study design:
RANGE FINDING TESTS:
- Compound solubility: The test item was not soluble in any of the proposed vehicles at concentrations of 50%. As a homogeneous suspension was obtained at the concentration of 25% in acetone/olive oil (4/1; v/v), it was chosen as vehicle.
- Irritation: Measurement of the ear thickness (using a micrometer) was performed each day before treatment and 24 hours after the last application. The test item was non-irritant in the preliminary test, whatever the concentration. The highest concentration retained for the main test was therefore the maximal practicable concentration (100%).
- Lymph node proliferation response: no data

MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: Lymph node cell proliferative responses were measured as described by Kimber and Dearman (1991).
- Criteria used to consider a positive response: The results were expressed as disintegration per minute (dpm) per group. Stimulation indices (SI) were calculated according to the following formula: SI = dpm of treated group / dpm of control group. The test item was considered as a skin sensitizer when the SI for a dose group is higher than or equal to 3. Other relevant criteria such as cellularity (amount of cells in treated group compared to the amount in control vehicle group), radioactivity levels and ear thickness were also taken into account for the interpretation of results.


TREATMENT PREPARATION AND ADMINISTRATION:
The test item was prepared in the vehicule at the chosen concentrations. All dosage form preparations were made freshly on the morning of the administration and any unused material was discarded that same day. On days 1, 2 and 3, a dose-volume of 25 µL of the control or dosage form preparations was applied to the dorsal surface of both ears, using an adjustable pipette fitted with a plastic tip. In order to avoid licking and to ensure an optimized application of the test materials, the animals were placed under light isoflurane anesthezia during the administration. No massage was performed but the tip was used to spread the preparation over the application sites. No rinsing was performed between each application.
Positive control substance(s):
hexyl cinnamic aldehyde (CAS No 101-86-0)
Statistics:
not applicable
Positive control results:
In the positive control group given HCA at the concentration of 25%, a significant lymphoproliferation and a stimulation index of 12.57 were noted.
The study was therefore considered valid.
Parameter:
SI
Value:
0.59
Test group / Remarks:
0.5%
Parameter:
SI
Value:
0.87
Test group / Remarks:
1%
Parameter:
SI
Value:
0.91
Test group / Remarks:
2.5%
Parameter:
SI
Value:
1.19
Test group / Remarks:
5%
Parameter:
SI
Value:
1.01
Test group / Remarks:
10%
Parameter:
SI
Value:
12.57
Test group / Remarks:
Positive control
Interpretation of results:
GHS criteria not met
Conclusions:
The test substance does not induce delayed contact hypersensitivity in the murine Local Lymph Node Assay ( maximum stimulation index = 1.19)
Executive summary:

A dermal sensitization study was performed according to the OECD guideline No.429 and in compliance with the GLP. The test substance diluted in acetone/olive oil (4/1; v/v) at the doses of 0, 0.5, 1, 2.5, 5 and 10% was administered to CBA/J female mice after a preliminary study to determine main test useful concentrations. The Lymph node proliferative responses were measured as described by Kimber and Dearman (1991).

The positive control used was HCA (a-hexylcinnamaldehyde) which presented a Stimulation index of 12.57. Therefore, the positive control gave acceptable positive results and the study was considered as valid.

No clinical sign and no mortality were observed during the study. Furthermore, no skin irritation was noted following the application of the test substance even at the highest tested concentration (10%). The LLNA gave negative results, as the maximum SI was not higher than 1.19 at the highest test substance concentration.

 

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not sensitising)
Additional information:

A study was performed according to OECD guideline 429 and in compliance with good Laboratory Practices. The test substance was administered to mice and the Lymph node proliferative responses were measured as described by Kimber and Dearman (1991). No clinical signs and no mortality were observed during the study.

Furthermore, no increase in ear thickness was observed following the application of the test item up to the highest tested concentration (10%). The LLNA gave negative results, as the Stimulation Index (SI) was not higher than 1.19 whatever the tested concentrations. The test substance was not considered as a dermal sensitizer in the murine Local Lymph Node Assay.


Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no study available

Justification for classification or non-classification

The maximum Stimulation Index (SI) found in the study was 1.19. According to Regulation (EC) No. 1272/2008 and its subsequent amendments on classification, labeling and packaging (CLP) of substances and mixtures, the substance is not classified as a skin sensitiser as the SI is lower than 3%.