Lithium [ethanedioato-O,O’]tetrafluorophosphate

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 2014-03-04 to 2014-04-15

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2014

Report date:

2014

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

2010

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Reference substance name:

Lithium [ethanedioato-O,O’]tetrafluorophosphate

EC Number:

826-676-4

Cas Number:

521065-36-1

Molecular formula:

LiPF4C2O4

IUPAC Name:

Lithium [ethanedioato-O,O’]tetrafluorophosphate

Specific details on test material used for the study:

Batch No.: 140116
Purity: 99.8 wt%

In vivo test system

Test animals

Species:

mouse

Strain:

CBA/Ca

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Charles River UK
- Females nulliparous and non-pregnant: not specified]
- Age at study initiation: approximately eight to ten weeks
- Weight at study initiation: 17.7 to 20.3 g
- Housing: housed two animals per cage, in solid bottomed polycarbonate cages with a stainless steel mesh lid. Each cage contained a quantity of autoclaved wood flake bedding, additionally Nestlets and a plastic shelter were included for environmental enrichment.
- Diet: standard rodent diet (Rat and Mouse No. 1 Maintenance Diet, ad libitum
- Water: Potable water, ad libitum
- Acclimation period: at least 6 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19 to 23°C
- Humidity (%): 40 to 70%
- Air changes: The animal room was kept at positive pressure with respect to the outside by its own supply of filtered fresh air, which was passed to atmosphere and not re-circulated.
- Photoperiod: 12 hrs dark / 12 hrs light

Study design: in vivo (LLNA)

Vehicle:

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

Concentration:

1, 2.5 and 5% w/v in AOO

No. of animals per dose:

4

Details on study design:

PRE-SCREEN TESTS:
- Compound solubility: A vehicle trial performed with LiPF4(OX) showed that it formed a fine off-white suspension, (nearly in solution) at 50% w/v in AOO and a pale yellow solution at 5% w/v and below in AOO.
- Irritation:
10% w/v: Slight erythema was observed on the ears of both mice on Day 3.
5% w/v: No erythema was observed on either mouse throughout the study.
- Systemic toxicity:
10% w/v: Both animals were terminated on Day 3 due to the severity of clinical signs seen these included, under activity, fasciculation’s (whole body), irregular breathing, unsteady gait, reduced body temperature, flat posture, shallow breathing, partially closed eyelids, cloudy discharge from eyes and gasping.
5% w/v: There were no deaths and no signs of ill health or toxicity were observed during this study. Greasy fur on the head was noted following each dosing occasion, this was related to unoccluded dermal administration of a liquid formulation/vehicle and not an effect of the test substance.
- Body weight:
- Ear thickness measurements: A marked loss in body weight was noted for both mice dosed at 10% w/v and a slight loss for both mice dosed at 5% w/v over the study period.
10% w/v: Due to signs of toxicity animals were terminated before the end of the study so no measurements were made on Day 6.
5% w/v: There was no evidence of an effect of treatment on ear thickness
- Erythema scores: 0for all animals tested at 5% w/v. 1 for all animals tested at 10% w/v at Day 3.

MAIN STUDY

ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: local lymph node assay (LLNA)
- Criteria used to consider a positive response: If the SI is 3 or more, the test substance is regarded as a skin sensitizer.

TREATMENT PREPARATION AND ADMINISTRATION:
- Test Formulation:
The test substance was prepared for administration as a series of graded concentrations in the vehicle, by direct dilution.
- Administration of test substance:
Groups of four mice were treated at one of three concentrations of the test substance. The mice were treated by daily application of 25 μL of the appropriate concentration of the test substance to the dorsal surface of each ear for three consecutive days (Days 1-3). The test substance was applied to the dorsal surface of each ear using a microlitre syringe and was spread over the entire dorsal surface of the ear using the tip of the syringe.
- Administration of 3H-methyl Thymidine:
Five days following the first topical application of test substance (Day 6) all mice were injected via the tail vein with 250 μL of phosphate buffered saline containing 3H-methyl Thymidinea (3HTdR: 80 μCi/mL) giving a nominal 20 μCi to each mouse. The injection into the tail vein was carried out using a plastic syringe and needle after the mouse had been heated in a warming chamber.

OBSERVATIONS
- Clinical signs: observed daily
- Body weight: recorded on arrival (data not reported), Day 1 (before dosing) and prior to termination (Day 6)

Positive control substance(s):

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

Results and discussion

Positive control results:

The SI for the positive control substance hexyl cinnamic aldehyde (HCA) was 9.3.

In vivo (LLNA)

Results

Results 1

Parameter:

SI

Value:

5.9

Test group / Remarks:

1% w/v

Results 2

Parameter:

SI

Value:

22.3

Test group / Remarks:

2.5 % w/v

Results 3

Parameter:

SI

Value:

21.8

Test group / Remarks:

5% w/v

Cellular proliferation data / Observations:

CELLULAR PROLIFERATION DATA

DETAILS ON STIMULATION INDEX CALCULATION
This was derived by dividing the mean dpm/mouse for each treated group and the positive control group by the mean dpm/mouse in the vehicle control group.

EC3 CALCULATION
EC3 value was extrapolated from the two lowest doses utilized according to the following formula:
EC3ex = 2^{log2(c) + (3 - d) / (b - d) x [log2(a) - log2(c)]}
Where a = concentration giving SI greater than 3
b = SI at concentration a
c = concentration giving SI less than 3
d = SI at concentration c.
The EC3 value is calculated to be 0.9% w/v.

CLINICAL OBSERVATIONS:
There were no deaths and no signs of ill health or toxicity were observed during this study. Wet/greasy fur on the head was noted following each dosing occasion, this was related to unoccluded dermal administration of a liquid formulation/vehicle and not an effect of the test substance.

BODY WEIGHTS
There was no indication of an effect of treatment on body weight gain.
A loss in body weight was noted for one mouse dosed at 2.5% w/v and one mouse dosed at 5% w/v over the study period, however, a small loss in body weight is not uncommon in young laboratory mice and is not considered to be an effect of treatment.

DERMAL REACTIONS
No signs of dermal irritation were seen on the ear during the study.

Applicant's summary and conclusion

Interpretation of results:

Category 1A (indication of significant skin sensitising potential) based on GHS criteria

Conclusions:

The test item is regarded as a potential skin sensitizer. The EC3 value was calculated to be 0.9% w/v.

Executive summary:

The skin sensitization potential of test item was assessed using the local lymph node assay (LLNA) according to OECD 429.

 

The study comprised three treated groups, each comprising four female mice receiving test item at concentrations of 1, 2.5 or 5% w/v. The mice were treated by daily application of 25 μL of the appropriate concentration or control (vehicle or positive), to the dorsal surface of both ears for three consecutive days.

The SI obtained for 1, 2.5 and 5% w/v were 5.9, 22.3 and 21.8 respectively which indicates that the test item showed the potential to induce skin sensitization.

The EC3 value was calculated to be 0.9% w/v.

The test item is regarded as a potential skin sensitizer. The EC3 value was calculated to be 0.9% w/v.