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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:
01 March 2017 - 09 May 2017
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2017
Report Date:
2017

Materials and methods

Test guidelineopen allclose all
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)
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: particulate/powder
Specific details on test material used for the study:
SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: 112Z5
- Expiration date of the lot/batch: 30 June 2017

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Room temperature

In vivo test system

Test animals

Species:
mouse
Strain:
CBA/Ca
Remarks:
CBA/CaOlaHsd
Sex:
female
Details on test animals and environmental conditions:
Non-pregnant

Identification: The animals were distributed into the test groups at random. All animals belonging to the same experimental group were kept in one cage. In the main experiment, the animals were identified by tail tags. In the pre-experiment, animals were identified by cage number.

Acclimation: At least 5 days prior to the start of dosing under test conditions after health examination. Only animals without any visible signs of illness were used for the study.

Housing: group
Cage: Makrolon Type II (pre-test) / III (main study), with wire mesh top
Bedding: granulated soft wood bedding
Feed: 2018C Teklad Global 18% protein rodent diet (certified), ad libitum
Water: tap water, ad libitum
Environment: temperature 22 ± 2°C relative humidity approximately, 45-65% (except for deviations), artificial light 6.00 a.m. - 6.00 p.m.

Study design: in vivo (LLNA)

Vehicle:
acetone/olive oil (4:1 v/v)
Concentration:
0.25, 0.5 and 1 %
No. of animals per dose:
4
Positive control substance(s):
hexyl cinnamic aldehyde (CAS No 101-86-0)

Results and discussion

Positive control results:
The sensitivity and reliability of the experimental technique employed was assessed by use of α-hexyl cinnamaldehyde dissolved in acetone/olive oil (4+1 v/v) (compound listed in OECD 429 Guideline) which is known to have skin sensitisation properties in mice. The periodic positive control experiment was performed using CBA/CaOlaHsd mice in April 2017.
Test item concentration %: 0, 5, 10 and 15
S.I.: 1.00, 1.78, 3.43, 10.06 respectively

In vivo (LLNA)

Resultsopen allclose all
Key result
Parameter:
EC3
Remarks on result:
other: ould not be calculated, since all obtained SI´s were above the threshold value of 3
Key result
Parameter:
SI
Value:
12.73
Test group / Remarks:
0.25% (w/w)
Key result
Parameter:
SI
Value:
18.2
Test group / Remarks:
0.5% (w/w)
Key result
Parameter:
SI
Value:
30.66
Test group / Remarks:
1% (w/w)
Cellular proliferation data / Observations:
No signs of systemic toxicity were observed during the study period. From day 2 to 4, the animals treated with a test item concentration of 0.5 and 1% showed an erythema of the ear skin. Animals treated with 0.25% test item concentration did not show any signs of local skin irritation.

Any other information on results incl. tables

In this study Stimulation Indices of 12.73, 18.20, and 30.66 were determined with the test item at concentrations of 0.25, 0.5, and 1% in MEK. The EC3 value could not be calculated, since all obtained SI´s were above the threshold value of 3.

Applicant's summary and conclusion

Interpretation of results:
Category 1 (skin sensitising) based on GHS criteria
Conclusions:
The test item LA-63P was found to be a skin sensitiser under the test conditions of this study.
Executive summary:

In the study the test item LA-63P formulated in MEK (methyl ethyl ketone) was assessed for its possible skin sensitising potential.

For this purpose a local lymph node assay was performed using test item concentrations of 0.25, 0.5, and 1%. The highest concentration tested was the highest concentration that could be achieved whilst avoiding systemic toxicity and excessive local skin irritation as confirmed by three pre-experiments.

The animals did not show any signs of systemic toxicity during the course of the study and no cases of mortality were observed. From day 2 to 4, the animals treated with a test item concentration of 0.5 and 1% showed an erythema of the ear skin (Score 1, see Appendix 3 for details). Animals treated with 0.25% test item concentration did not show any signs of local skin irritation.

In this study Stimulation Indices (S.I.) of 12.73, 18.20, and 30.66 were determined with the test item at concentrations of 0.25, 0.5, and 1% in MEK, respectively.

The test item LA-63P was found to be a skin sensitiser. An EC3 value could not be derived, since all tested concentrations induced an S.I. value greater than the threshold value of 3.