Acetic acid, esters with turpentine-oil myrcene fraction terpene alcs.

Endpoint summary

Description of key information

KeratinoSens and DPRA are both positive for skin sensitisation. However, the LLNA was used for classification purposes as this is the most sensitive endpoint.

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:

weight of evidence

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)

Qualifier:

according to guideline

Guideline:

EU Method B.42 (Skin Sensitisation: Local Lymph Node Assay)

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.2600 (Skin Sensitisation)

GLP compliance:

yes (incl. QA statement)

Type of study:

mouse local lymph node assay (LLNA)

Specific details on test material used for the study:

Identification: Neobergamate Forte
Appearance: Pale yellow liquid
Batch: SC00015234
Purity/Composition: See Certificate of Analysis
Test item storage: At room temperature protected from light
Stable under storage conditions until: 07 November 2016 (expiry date)

Species:

mouse

Strain:

CBA:J

Sex:

female

Details on test animals and environmental conditions:

Species: Mouse, CBA/J strain, inbred, SPF-Quality.
Recognized by the international guidelines as the recommended test system (e.g. OECD, EC, EPA).
Source: Janvier, Le Genest-Saint-Isle, France
Number of animals 20 females (nulliparous and non-pregnant), five females per group (main study only).
Age and body weight Young adult animals (approx. 10 weeks old) were selected. Body weight variation was within +/- 20% of the sex mean.
Identification Tail mark with a marker pen.
Health inspection At least prior to dosing. It was ensured that the animals were healthy and that the ears were intact and free from any abnormality.
Reliability check The results of a reliability test with three concentrations of Hexylcinnamaldehyde (CAS No. 101-86-0) in Acetone/Olive oil (4:1 v/v), performed not more than 6 months previously and using the same materials, animal supplier, animal strain and essential procedures are summarized in APPENDIX 2 of this report. For both scientific and animal welfare reasons, no concurrent positive control group was included in the study.
An extensive data base is available with reliability checks performed at half year intervals during at least the past 9 years showing reproducible and consistent positive results.

Vehicle:

acetone/olive oil (4:1 v/v)

Concentration:

Test item concentrations: 10, 25 or 50% w/w

No. of animals per dose:

Five animals per dose

Details on study design:

Test item concentrations selected for the main study were based on the results of a pre-screen test.
In the main study, three experimental groups of five female CBA/J mice were treated with test item concentrations of 10, 25 or 50% w/w on three consecutive days, by open application on the ears. Five vehicle control animals were similarly treated, but with the vehicle alone (Acetone/Olive oil (4:1 v/v)). Three days after the last exposure, all animals were injected with 3H-methyl thymidine and after five hours the draining (auricular) lymph nodes were excised and pooled for each animal. After precipitating the DNA of the lymph node cells, radioactivity measurements were performed. The activity was expressed as the number of disintegrations per minute (DPM) and a stimulation index (SI) was subsequently calculated for each group.

Positive control substance(s):

hexyl cinnamic aldehyde (CAS No 101-86-0)

Parameter:

SI

Value:

> 3

Parameter:

EC3

Value:

16.1

The very slight erythema was noted for some animals treated at 25% and 50% between Days 3 and 5 was considered not to have a toxicologically significant effect on the activity of the nodes. The majority of auricular lymph nodes were considered normal in size, except for the nodes of all animals treated at 50% and three animals treated at 25%, which were considered slightly enlarged. Mean DPM/animal values for the experimental groups treated with test item concentrations 10, 25 and 50% were 544, 1122 and 2029 DPM, respectively. The mean DPM/animal value for the vehicle control group was 261 DPM. The SI values calculated for the test item concentrations 10, 25 and 50% were 2.1, 4.3 and 7.8, respectively.

Interpretation of results:

Category 1 (skin sensitising) based on GHS criteria

Conclusions:

These results indicate that Neobergamate Forte could elicit a SI ≥ 3. The data showed a dose-response and an EC3 value (the estimated test item concentration that will give a SI =3) of 16.1% was calculated.
The six-month reliability check with Alpha-hexylcinnamaldehyde indicates that the Local Lymph Node Assay as performed at Charles River Den Bosch is an appropriate model for testing for contact hypersensitivity.
Based on these results and according to the recommendations made in the test guidelines (including all amendments), Neobergamate Forte would be regarded as skin sensitizer.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (sensitising)