2,2,2-trifluoroethanol

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2003-09-16 to 2003-09-29

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2004

Report date:

2004

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Principles of method if other than guideline:

Not applicable

GLP compliance:

yes

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Reference substance name:

2,2,2-trifluoroethanol

EC Number:

200-913-6

EC Name:

2,2,2-trifluoroethanol

Cas Number:

75-89-8

Molecular formula:

C2H3F3O

IUPAC Name:

2,2,2-trifluoroethan-1-ol

Test material form:

liquid

Details on test material:

- Name of test material (as cited in study report): 2,2,2 trifluoroethanol (TFE)
- Physical state: colorless liquid
- Lot/batch No.: 02 092 01
- Expiration date of the lot/batch: no data
- Stability under test conditions: assumed to be stable during the test (sponsor responsibility)
- Storage condition of test material: at room temperature
- Other: the pH of the undiluted test item, measured at CIT, was approximately 4.

In vivo test system

Test animals

Species:

mouse

Strain:

other: CBA/J

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source : Janvier, Le GEnest-Saint-Isle, France
- Age at study initiation: 9 weeks old
- Weight at study initiation: 20 g (+/- 1.0 g)
- Housing: in individual crystal polystyrene cages (22 cm x 8.5 cm x 8 cm)
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22°C (+/- 2°C)
- Humidity (%): 30-70%
- Air changes (per hr): approximately 12 cycles per hour of filtered, non-recycled air
- Photoperiod (hrs dark / hrs light): 12h/12h

IN-LIFE DATES: From: To: no data

Study design: in vivo (LLNA)

Vehicle:

dimethylformamide

Remarks:

Batch No. 06743LA (Aldrich, Saint-Quantin-Fallavier, France)

Concentration:

For the preliminary test the concentrations were 10, 25, 50 and 100% of the test item.
For the main test the concentrations were 0, 5, 10, 25, 50 and 100% of the test item.

No. of animals per dose:

For the preliminary test: 2 females/dose (no controls): Right and left ear were treated with different concentrations.
For the main test: 4 females/dose, 4 females for the negative control and 4 females for the positive control
See details on table 7.4.1/1

Details on study design:

RANGE FINDING TESTS:
- Compound solubility: Due to the unsatisfactory solubility of the test item in the first recommended vehicle (acetone/olive oil), Dimethylformamide was chosen among the other proposed vehicles. A homogeneous dosage form preparation was obtained whatever the proportion.
- Irritation: Measurement of the ear thickness (using a micrometer) was performed each day before treatment and 24 hours after the last application. The test item was non-irritant in the preliminary test, whatever the concentration. The highest concentration retained for the main test was therefore the maximal practicable concentration (100%).
- Lymph node proliferation response: no data

MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: Lymph node cell proliferative responses were measured as described by Kimber and Dearman (1991).
- Criteria used to consider a positive response: The results were expressed as disintegration per minute (dpm) per group. Stimulation indices (SI) were calculated according to the following formula: SI = dpm of treated group / dpm of control group. The test item was considered as a skin sensitizer when the SI for a dose group is higher than or equal to 3. Other relevant criteria such as cellularity (amount of cells in treated group compared to the amount in control vehicle group), radioactivity levels and ear thickness were also taken into account for the interpretation of results.


TREATMENT PREPARATION AND ADMINISTRATION:
The test item was prepared in the vehicule at the chosen concentrations. All dosage form preparations were made freshly on the morning of the administration and any unused material was discarded that same day. On days 1, 2 and 3, a dose-volume of 25 μL of the control or dosage form preparations was applied to the dorsal surface of both ears, using an adjustable pipette fitted with a plastic tip. In order to avoid licking and to ensure an optimized application of the test materials, the animals were placed under light isoflurane anesthezia during the administration. No massage was performed but the tip was used to spread the preparation over the application sites. No rinsing was performed between each application.

Positive control substance(s):

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

Statistics:

no data

Results and discussion

Positive control results:

In the positive control group given HCA at the concentration of 25%, a moderate increase in cellularity and a stimulation index exceeding the threshold value of 3 (SI=4.77) were noted.
The study was therefore considered valid.

In vivo (LLNA)

Results

Results 1

Key result

Parameter:

SI

Value:

< 1

Variability:

Lymph nodes pooled

Test group / Remarks:

concentration 5 % - 4 females/group

Results 2

Key result

Parameter:

SI

Value:

< 1

Variability:

Lymph nodes pooled

Test group / Remarks:

Concentration 10 % - 4 females /group

Results 3

Key result

Parameter:

SI

Value:

< 1

Variability:

Lymph nodes pooled

Test group / Remarks:

Concentration 25 % - 4 females per group

Results 4

Key result

Parameter:

SI

Value:

< 1

Variability:

Lymph nodes pooled

Test group / Remarks:

Concentration 50 % - 4 females /group

Results 5

Key result

Parameter:

SI

Value:

< 1

Variability:

Lymph nodes pooled

Test group / Remarks:

Concentration 100 % - 4 females/group

Results 6

Key result

Parameter:

SI

Value:

ca. 4.77

Variability:

Lymph nodes pooled

Test group / Remarks:

Positive control (HCA) - concentration 25 % - 4 females /group

Any other information on results incl. tables

No clinical signs and no mortality were observed during the study. The body weight gain of the treated animals was similar to that of the control animals. No cutaneaous reactions and no increase in ear thickness were observed at any of the tested concentrations.

Table 7.4.1/3:Results of the main test for the dermal irritation level and the sensitisation

Treatment	Concentration (%)	Irritation level	Stimulation Index (SI)
TFE	5	Non-irritant	0.95
TFE	10	Non-irritant	0.95
TFE	25	Non-irritant	0.58
TFE	50	Non-irritant	0.47
TFE	100	Non-irritant	0.42
HCA	25	-	4.77

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Under the test conditions, the test item 2,2,2-trifluoroethanol does not induce delayed contact hypersensitivity in the murine Local Lymph Node Assay (stimulation index < 1).

Executive summary:

A dermal sensitization study was performed according to the OECD guideline No.429 and in compliance with the GLP. 2,2,2-trifluoroethanol (99.95%) diluted in Dimethylformamide at the doses of 0, 5, 10, 25, 50 and 100% was administered to CBA/J mice after a preliminary study to determine main test useful concentrations. The Lymph node proliferative responses were measured as described by Kimber and Dearman (1991).

The positive control used was HCA (α-hexylcinnamaldehyde) which presented a Stimulation index of 4.77. Therefore, the positive control gave acceptable positive results and the study was considered as valid.

No clinical sign and no mortality were observed during the study. Furthermore, no skin irritation was noted following the application of the TFE even at the highest tested concentration (100%). The LLNA gave negative results, as the SI is lower than 1 in the animals treated whatever the concentration of the test item.

Under the test conditions, the 2,2,2-trifluoroethanol is not classified as a dermal sensitizer in the murine Local Lymph Node Assay.

 

This study is considered as acceptable as it satisfies the criteria of the OECD guideline No.429.