Registration Dossier

Administrative data

Description of key information

In vivo Skin Sensitization study: Local Lymph node assay: Not sensitizer.

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Referenceopen allclose all

Endpoint:
skin sensitisation: in vivo (LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
13/12/2011-10/01/2012
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Reference:
Composition 0
Qualifier:
according to
Guideline:
OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)
Qualifier:
according to
Guideline:
EU Method B.42 (Skin Sensitisation: Local Lymph Node Assay)
Qualifier:
according to
Guideline:
EPA OPPTS 870.2600 (Skin Sensitisation)
GLP compliance:
yes (incl. certificate)
Type of study:
mouse local lymphnode assay (LLNA)
Test material information:
Composition 1
Specific details on test material used for the study:
Lot number: 290110720
Species:
mouse
Strain:
CBA
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Harlan Laboratories UK Ltd., Oxon, UK
- Age at study initiation: 8-12 weeks
- Weight at study initiation: 15 -23 g
- Housing:in suspended sold-floor polypropylene cages furnished with softwood woodflakes
- Diet (e.g. ad libitum):ad libitum
- Water (e.g. ad libitum):ad libitum
- Acclimation period:5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C):19-25°C
- Humidity (%):30-70%
- Air changes (per hr):15
- Photoperiod (hrs dark / hrs light):12 hours light, 12hrs dark
Vehicle:
dimethylformamide
Concentration:
10, 25 and 50% in dimethylformamide
No. of animals per dose:
5
Details on study design:
RANGE FINDING TESTS:
- Compound solubility: /
- Irritation: the thickness of each ear was measured using an Oditest micrometer on day 1, 3 and 6, a thickness increase > 25% was considered to indicate excessive irritation
- Lymph node proliferation response:/

MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method:
- Criteria used to consider a positive response: The test item will be regarded as a sensitiser if at least one concentration of the test item results in a threefold or greater increase in 3HTdR incorporation compared to control values. Any test item failing to produce a threefold or greater increase in 3HTdR incorporation will be classified as a "non-sensitiser".

TREATMENT PREPARATION AND ADMINISTRATION:
Groups fo five mice were treated with the test item at concentrations of 50%, 25% and 10% w/w in dimethyl formamide. The preliminary screening test suggested that the test item would not produce systemic toxicity or excessive local irritation at the highest suitable concentration. The mice were treated by daily application of 25μl of the appropriate concentration of the test item to the dorsal surface of each ear for three consecutive days (days 1,2,3). The test item 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:
Data was processed to give group mean values for disintegrations per minute and standard deviations where appropriate. Individual and group mean disintegrations per minute values were assessed for dose relationships by analysis of homogeneity of variance followed by one way analysis of variance (ANOVA). In the event of a significant result from the ANOVA, pairwise comparisons were performed between control and treated groups. For homogenous datasets Dunnett's Multiple Comparison test was used and for non-homogenous datasets Dunnett's T3 Multiple Comparison Method was used.
Positive control results:
Stimulation index: 6.72 (positive)
Key result
Parameter:
SI
Remarks on result:
other: Vehicle: N/A 10%: 0.98 25%:1.13 50%:1.30 Positive control: 6.72
Key result
Parameter:
other: disintegrations per minute (DPM)
Remarks on result:
other: Vehicle: 1459.65 ± 347.68 10%: 1432.75 ± 764.01 25%: 1649.22 ± 647.59 50%: 1904.07 ± 373.59 Positive control: 9814.79 ± 2746.79
Interpretation of results:
not sensitising
Conclusions:
The test item was considered to be a non-sensitiser under the conditions of the test.
Executive summary:

INTRODUCTION

A study was performed to assess the skin sensitisation potential of the test item in the CBA/Ca strain mouse following topical application to the dorsal surface of the ear. The method was designed to be compatible with the following: OECD 429, B42, OPPTS 870.2600.

METHODS

Following a preliminary screening test in which no clinical signs of toxicity were noted at a concentration of 50% 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 five animals, were treated with 50µL (25 µL per ear) of the test item as a solution in dimethyl formamide at concentrations of 50%, 25% or 10% w/w. A further group of five animals was treated with dimethyl formamide alone. A concurrent positive control test, using a group of five animals, was also performed with the known sensitiser, alfa-hexylcinnamaldehyde tech., 85% at a concentration of 25% v/v in dimethyl formamide.

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:

 Treatment group Concentration  Stimulation Index  Results 
Test item  10% w/w in dimethylformamide   0.98  Negative
  25%  w/w in dimethylformamide   1.13 Negative 
  50%  w/w in dimethylformamide    1.30  Negative 
 Positive Control Item 25%   v/v in dimethylformamide   6.72  Positive

CONCLUSION

The test item was considered to be a non-sensitiser under the conditions of the test.

The test item did not meet the criteria for classification as a sensitiser according to EU labelling regulations Commision Directive 2001/59/EC or the globally harmonised system of classification and labelling of chemicals.

The positive control item, alfa-hexylcinnamaldehyde, tech. 85%, gave a SI of greater than 3 when tested at a concentration of 25% v/v in dimethyl formamide.

Endpoint:
skin sensitisation: in chemico
Data waiving:
study scientifically not necessary / other information available
Justification for data waiving:
other:
Endpoint:
skin sensitisation: in vitro
Data waiving:
study scientifically not necessary / other information available
Justification for data waiving:
other:
Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not sensitising)

Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no study available

Justification for classification or non-classification

The test item did not meet the criteria for classification as a sensitiser according to EU labelling regulations Commision Directive 2001/59/EC or the globally harmonised system of classification and labelling of chemicals.