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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:
June 2009
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2009
Report Date:
2009

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
GLP compliance:
yes (incl. certificate)
Type of study:
mouse local lymph node assay (LLNA)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: crystalline
Details on test material:
- Colour: colourless
- Odour: odourless
- CAS-Number: 89-32-7
- Molecular formula: C10 H2 O6
- Molecular weight: 218.12
Specific details on test material used for the study:
- Sponsor's identification: LZ6119
- Description: white powder
- Batch number: CSA 0901038
- Purity: >= 99.5% w/w
- Date received: 01 May 2009
- Storage conditions: room temperature in the dark

In vivo test system

Test animals

Species:
mouse
Strain:
CBA/Ca
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Harlan Laboratories UK, Limited, Bicester, Oxon, UK.
- Females (if applicable) nulliparous and non-pregnant: yes
- Age at study initiation: 12 weeks
- Weight at study initiation: 15-23 g
- Housing: individual housing
- Diet (e.g. ad libitum): 2014 Teklad Global Rodent diet supplied by Harlan Teklad, Blackthorn, Bicester, Oxon, UK
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 5 days
- Indication of any skin lesions: no

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19-25°C
- Humidity (%): 30-70%
- Air changes (per hr): 15 changes/hr
- Photoperiod (hrs dark / hrs light): 12 hrs continuous light (06.00 to 18.00) and twelve hrs darkness

Study design: in vivo (LLNA)

Vehicle:
dimethylformamide
Concentration:
Groups of four mice were treated with the test material at concentrations of 25%, 10% or 5% w/w in dimethyl formamide. The preliminary screening test suggested that the test material would not produce systemic toxicity or excessive local irritation at the highest suitable concentration. A further group of four mice received the vehicle alone in the same manner.
No. of animals per dose:
Groups of four mice were treated with the test material at concentrations of 25%, 10% or 5% w/w. A further group of four mice received the vehicle alone in the same manner.
Details on study design:
The mice were treated by daily application of 25 ul of the appropriate concentration of the test material to the dorsal surface of each ear for three consecutive days (Days 1, 2, 3). The test material formulation was administered using an automatic micropipette and spread over the dorsal surface of the ear using the tip of the pipette.
Positive control substance(s):
hexyl cinnamic aldehyde (CAS No 101-86-0)
Statistics:
None

Results and discussion

Positive control results:
Methods:
A group of five animals was treated with 50 ul (25 ul per ear) of alpha-Hexylcinnamaldehyde as a solution in dimethylformamide at a concentration of 15% v/v. A further control group of five animals was treated with dimethyl formamide alone.

Results:
The Stimulation Index expressed as the mean radioactive incorporation for each treatment group divided by the mean radioactive incorporation of the vehicle control group are as follows:
- Concentration (% v/v) in DMF: 15%
- Stimulation Index: 4.24
- Result: 4.24

Conclusion:
alpha-Hexylcinnamaldehyde was considered to be a sensitiser under the conditions of the test

In vivo (LLNA)

Resultsopen allclose all
Key result
Parameter:
SI
Value:
9.12
Test group / Remarks:
Test item concentration 5%
Key result
Parameter:
SI
Value:
8.62
Test group / Remarks:
Test item concentration 10%
Key result
Parameter:
SI
Value:
9
Test group / Remarks:
Test item concentration 25%
Cellular proliferation data / Observations:
CLINICAL OBSERVATIONS:
There were no deaths. No signs of systemic toxicity were noted in the test or control animals during the test. White residual test material on the ears was noted post dose on Days 1 to 3 in animals treated with the test material at a concentration of 25% w/w in dimethyl formamide.

BODY WEIGHTS:
Body weight changes of the test animals between Day 1 and Day 6 were comparable to those observed in the corresponding control group animals over the same period.

Applicant's summary and conclusion

Interpretation of results:
Category 1 (skin sensitising) based on GHS criteria
Conclusions:
The test material was considered to be a sensitiser under the conditions of this LLNA-study.
Executive summary:

A study was performed to assess the skin sensitisation potential of the test material in the CBA/Ca strain mouse following topical application to the dorsal surface of the ear. The method was performed in accordance with OECD-guideline no. 429 and EU-test method B.42. Following a preliminary screening test in which no clinical signs of toxicity were noted at a concentration of 25% w/w, this concentration was selected as the highest dose investigated in the main test of the Local Lymph Node Assay. Three groups, each of four animals, were treated with the test materialcas a solution in dimethylformamide (DMF) at concentrations of 25%, 10% or 5% w/w. A further group of four animals was treated with DMF alone. The Stimulation Index ranged from 8.62 to 9.12 for the three dose groups. In conclusion, the test material was considered to be a sensitiser under the conditions of the test.