1,1,1,3,3,3-hexafluoropropan-2-ol

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

26 Apr-01 Jun 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 guideline

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

Adopted 22 July 2010

Deviations:

no

GLP compliance:

yes

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Reference substance name:

1,1,1,3,3,3-hexafluoropropan-2-ol

EC Number:

213-059-4

EC Name:

1,1,1,3,3,3-hexafluoropropan-2-ol

Cas Number:

920-66-1

Molecular formula:

C3H2F6O

IUPAC Name:

1,1,1,3,3,3-hexafluoropropan-2-ol

Test material form:

liquid

In vivo test system

Test animals

Species:

mouse

Strain:

CBA:J

Remarks:

SPF

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Charles River Japan, Inc.
- Females nulliparous and non-pregnant: yes
- Microbiological status of animals: SPF
- Age at study initiation: 7 weeks
- Weight at study initiation: 19.62 - 23.79 g
- Housing: 4 animals per cage in polycarbonate cages with spruce wood chips
- Diet: MF pelleted diet, Oriental Yeast Co Ltd., ad libitum
- Water: chlorinated water from Sugito machi via water bottles, ad libitum
- Acclimation period: at least 13 days
- Indication of any skin lesions: not specified

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 23 ± 1.65
- Humidity (%): 50 - 64
- Air changes (per hr): 50
- Photoperiod (hrs dark / hrs light): 12 / 12
- IN-LIFE DATES: From: 26 Apr 2017 To: 09 May 2017

Study design: in vivo (LLNA)

Vehicle:

dimethylformamide

Concentration:

10, 25 and 50% (w/v)

No. of animals per dose:

4

Details on study design:

PRE-SCREEN TESTS:
- Compound solubility: N,N-dimethylformamide was used as the vehicle to produce test material dosing concentrations of 0.5, 1.0, 2.5, 5.0, 10.0, 25.0, 50.0 and 100%
- Irritation: none noted
- Systemic toxicity: 3 h after the first application on the first day, mice treated with 100% test material showed prone posture, gasping respiration, red coloured urine, reduced touch response and reduced startle response, and were therefore all euthanised on Day 1. No other animals showed any abnormalities during the prescreen period.
- Ear thickness measurements: no difference between dose groups, and overall mean ear thickness change (%): <25
- Erythema scores: none noted

MAIN STUDY

ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: ³H-methyl thymidine incorporation determined by β-scintillation
- Criteria used to consider a positive response: the test system will be regarded as a sensitizer if at least one concentration of the test material results in a threefold increase or greater increase in ³H-methyl thymidine incorporation, compared to control values.

TREATMENT PREPARATION AND ADMINISTRATION: 25 µL of test material in DMF was applied to the entire dorsal surface of each ear of each mouse, 4 mice per concentration. The application was repeated on Days 2 and 3; local irritation reactions were assessed. On Day 6, an injection of 250 µL phosphate buffered saline (PBS) containing 20 µCi of ³H-methyl thymidine (³H-TdR) was made into the tail vein of each mouse. Five hours later, the draining auricular lymph nodes from the four mice in each dose group were excised, per experimental group. A single cell suspension of lymph node cells was prepared by gentle mechanical disaggregation through a 200-mesh stainless steel mesh. The lymph node cells were rinsed through the mesh with PBS, transferred to a centrifuge tube, pelleted by centrifugation, re-suspended in PBS, and then re-pelleted by centrifuging. The pellet was re-suspended in 5% trichloroacetic acid. Macromolecules were precipitated with the TCA at 4°C for eighteen hours.

Positive control substance(s):

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

Statistics:

SI of the vehicle treated controls and test material treated dose groups, BWs, and lymph node weights were calculated as means and standard errors. Percent change(s) in ear thickness were calculated for the prescreen test animals.

Results and discussion

Positive control results:

The positive control substance (α-Hexylcinnamaldehyde 25% w/v in N,N-dimethylformamide) induced positive reactions in 4/4 animals (100%), thus meeting the reliability criteria of the LLNA test. The SI-value for the positive control group averaged 13.9.

In vivo (LLNA)

Results

Results 1

Key result

Parameter:

SI

Value:

ca. 1

Variability:

0.8 to 1.3

Test group / Remarks:

Vehicle treated control (DMF)

Results 2

Key result

Parameter:

SI

Value:

ca. 13.9

Variability:

12.4 to 16.9

Test group / Remarks:

Positive control (HCA 25% w/v in DMF)

Results 3

Key result

Parameter:

SI

Value:

ca. 0.7

Variability:

0.5 to 1.0

Test group / Remarks:

10% (w/v) in DMF

Results 4

Key result

Parameter:

SI

Value:

ca. 0.8

Variability:

0.4 to 1.2

Test group / Remarks:

25% (w/v) in DMF

Results 5

Key result

Parameter:

SI

Value:

ca. 0.7

Variability:

0.6 to 0.8

Test group / Remarks:

50% (w/v) in DMF

Cellular proliferation data / Observations:

DETAILS ON STIMULATION INDEX CALCULATION: The mean incorporation of ³H-methyl thymidine (dpm/mouse) was calculated for the vehicle control group. Then each value of incorporation of ³H-methyl thymidine in all mice was divided by the mean dpm of the vehicle treated control group to calculate the stimulation index (SI). SI of the vehicle treated control and test material treated groups were expressed as means and standard errors. The decision process regards as positive when SI of any test material treated group ≥3.

EC3 CALCULATION: the EC3 value was not able to be calculated because the SI of any test material treated dose groups did not exceed 3.

CLINICAL OBSERVATIONS: none

BODY WEIGHTS: no abnormalities were noted

Any other information on results incl. tables

Concentration (% w/v) in DMF	dpm	Stimulation Index^a	Result
Vehicle control	533	1.3	Negative
	334	0.8	Negative
	490	1.1	Negative
	348	0.8	Negative
10	388	0.9	Negative
	417	1.0	Negative
	222	0.5	Negative
	206	0.5	Negative
25	399	0.9	Negative
	230	0.5	Negative
	182	0.4	Negative
	505	1.2	Negative
50	237	0.6	Negative
	266	0.6	Negative
	312	0.7	Negative
	336	0.8	Negative
Positive control^b	5300	12.4	Positive
	5444	12.8	Positive
	7189	16.9	Positive
	5671	13.3	Positive

dpm = disintegrations per minute

DMF = N,N-dimethylformamide

^a= Stimulation Index of 3.0 or greater indicates a positive result

^b= α-Hexylcinnamaldehyde (25% w/v) in DMF

NA = not applicable

Applicant's summary and conclusion

Interpretation of results:

other: CLP/EU GHS criteria are not met, no classification required according to Regulation (EC) No 1272/2008

Conclusions:

The Stimulation Indices (SI) of all dose groups of HFIP-treated mice did not exceed 3, this test material was considered as negative in the LLNA Skin sensitisation assay.