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Description of key information

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:
14 - 28 April 2008
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: The study has been performed according to OECD and EC guidelines and according to GLP principles.
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
Qualifier:
according to
Guideline:
EPA OPPTS 870.2600 (Skin Sensitisation)
Deviations:
no
GLP compliance:
yes (incl. certificate)
Type of study:
mouse local lymph node assay (LLNA)
Species:
mouse
Strain:
CBA
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River France, L’Arbresle Cedex, France
- Age at study initiation: approx. 10-12 weeks old
- Weight at study initiation: 20-25 g
- Housing: Individual housing in labeled Macrolon cages
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: at least 5 days, group housed in Macrolon cages.


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20.7 – 23.3
- Humidity (%): 41 - 63
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12

Vehicle:
methyl ethyl ketone
Concentration:
0, 2.5, 5 and 10%
No. of animals per dose:
5
Details on study design:
RANGE FINDING TESTS:
- Compound solubility: The vehicle was selected based on trial formulations performed at NOTOX and on test substance data supplied by the sponsor.
- Irritation: The animal at 50% showed hunched posture, ventro-lateral recumbency, laboured respiration, piloerection and hypothermia and was sacrificed in extremis on Day 1. Macroscopic post mortem examination of the animal at 50% revealed dark red discoloration of the glandular mucosa of the stomach. The animal at 25% showed hunched posture and ptosis on Day 1. After cleaning the ears of the animal at 25% with tap water on Day 3, corrosion of the cleaned skin was noted and the animal showed hunched posture, piloerection, and squeaking. Macroscopic post mortem examination of the animal at 25% revealed scabs at the right ear.
At 5 and 10% test substance concentration no signs of systemic toxicity, no severe irritation and no macroscopic abnormalities were observed.
Based on the results, the highest test substance concentration selected for the main study was a 10% concentration.


MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: LLNA
- Criteria used to consider a positive response: DPM values are presented for each animal and for each dose group. A Stimulation Index (SI) is calculated for each group. The SI is the ratio of the DPM/group compared to DPM/vehicle control group.
If the results indicate a SI >= 3, the test substance may be regarded as a skin sensitiser, based on the test guideline and recommendations done by ICCVAM.


TREATMENT PREPARATION AND ADMINISTRATION:
The test substance formulations (w/w) were prepared within 4 hours prior to each treatment. Homogeneity was obtained to visually acceptable levels.
The dorsal surface of both ears was epidermally treated (25 μL/ear) with the test substance concentration, at approximately the same time per day. The concentrations were mixed thoroughly using a vortex mixer immediately prior to dosing.
Positive control substance(s):
hexyl cinnamic aldehyde (CAS No 101-86-0)
Statistics:
Consideration was given to the EC3 value (the estimated test substance concentration that will give a SI =3) according to Basketter DA, Lea LJ, Dickens A, Briggs, D, Pate I, Dearman RJ and Kimber I. A comparison of statistical approaches to the derivation of EC3 values from local lymph node assay dose responses. J Appl Toxicol 1999;19:261-266.
Positive control results:
The SI values calculated for the substance concentrations 5, 10 and 25% were 1.7, 2.8 and 3.6 respectively. An EC3 value of 13.8 % was calculated using linear interpolation. The calculated EC3 value was found to be in the acceptable range of 2 and 20%.
Parameter:
SI
Remarks on result:
other: The SI values calculated for the substance concentrations 2.5, 5 and 10% were 0.9, 1.2 and 1.3 respectively.
Parameter:
other: disintegrations per minute (DPM)
Remarks on result:
other: Mean DPM/animal values for the experimental groups treated with test substance concentrations 2.5, 5 and 10% were 243, 341 and 370 respectively. The mean DPM/animal value for the vehicle control group was 285.

Slight erythema was noted in one or both ears of three animals at 5% and in both ears of all animals at 10%. No oedema was observed in any of the animals examined. The irritation of the ears as shown by the animals, was considered not to have a toxicologically significant effect on the activity of the nodes.

All nodes of the experimental and control groups were considered normal in size. No macroscopic abnormalities of the surrounding area were noted.

Body weights and body weight gain of experimental animals remained in the same range as controls over the study period.

No mortality occurred and no symptoms of systemic toxicity were observed in the animals of the main study.

Interpretation of results:
not sensitising
Remarks:
Migrated information
Conclusions:
Since there was no indication that the test substance could elicit an SI >= 3 when tested up to 10%, it was established that the EC3 value (if any) exceeds 10%.
Based on these results:
- according to the recommendations made in the test guidelines, LiPF6 would not be regarded as skin sensitizer.
- according to the Globally Harmonized System of Classification and Labeling of Chemicals (GHS) of the United Nations (2004), LiPF6 does not have to be classified for sensitization by skin contact.
- according to the EC criteria for classification and labeling requirements for dangerous substances and preparations (Council Directive 67/548/EEC), LiPF6 does not have to be classified and has no obligatory labeling requirement for sensitization by skin contact.
Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not sensitising)
Additional information:
Migrated from Short description of key information:
In a preliminary study, application of the test substance to mouse ears proved highly damaging when concentrations of 50% or 15% in methyl ethyl ketone (25 microl/ear) were employed:
- at 50%, the mouse was killed in extremis on the day of treatment
- at 25%, ear washing on day 3 revealed skin corrosion.

In the subsequent main study, application at 5 and 10% caused minor local irritation, but no evidence of sensitising activity was seen.

Justification for selection of skin sensitisation endpoint:
Reliable, key study of skin sensitisation.

Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no study available
Additional information:

No grounds for predicting sensitising action on the respiratory system have been identified.

Justification for classification or non-classification

No evidence of sensitising activity has been seen in a well conducted assay for delayed contact sensitisation. Hence no classification in respect of sensitising activity is warranted.