1-[difluoro(trifluoromethoxy)methoxy]-1,2,2-trifluoroethylene

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

18 May 2016 - 15 June 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2016

Report date:

2016

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

July 2010

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

May 2008, including most recent amendments

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.2600 (Skin Sensitisation)

Version / remarks:

March 2003

Deviations:

no

GLP compliance:

yes

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Reference substance name:

{difluoro[(1,2,2-trifluoroethenyl)oxy]methoxy}trifluoromethane

EC Number:

615-064-0

Cas Number:

700874-87-9

Molecular formula:

C4F8O2

IUPAC Name:

{difluoro[(1,2,2-trifluoroethenyl)oxy]methoxy}trifluoromethane

Test material form:

liquid: volatile

Specific details on test material used for the study:

Name of test material (as cited in study report): MOVE3
Appearance: Clear colourless liquid
Storage conditions: In refrigerator (2-8°C)
Storage conditions for pressurised cylinders: 15-25°C, protected from light

In order to avoid volatilization of the test item, the test item and positive control item preparations (w/w) were prepared within 1 hour prior to each dosing and were put on ice immediately after preparations, the containers were closed and the headspace of the containers was as low as possible.

In vivo test system

Test animals

Species:

mouse

Strain:

other: CBA/J

Sex:

female

Details on test animals and environmental conditions:

- Source: Janvier, Le Genest-Saint-Isle, France.
- Age at study initiation: Young adult animals (approx. 10 weeks old)
- Weight at study initiation: 19.0 - 22.9 g
- Housing: Animals were group housed in labeled Makrolon cages. Paper and shelters were supplied as cage-enrichment. On Day 6, the animals were group housed in Makrolon cage with a sheet of paper instead of sawdus and cage enrichment.
- Diet: Free access to pelleted rodent diet (SM R/M-Z from SSNIFF® Spezialdiäten GmbH, Soest, Germany).
- Water: Free access to tap water.
- Acclimation period: At least 5 days

ENVIRONMENTAL CONDITIONS (set conditions)
- Temperature (°C): 18 – 24
- Humidity (%): 40 - 70
- Air changes (per hr): approx 10
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 18 May 2016 to 15 June 2016

Study design: in vivo (LLNA)

Vehicle:

methyl ethyl ketone

Concentration:

0, 25, 50, 100% w/w test item

No. of animals per dose:

5

Details on study design:

RANGE FINDING TESTS:
Two test item concentrations were tested; a 50% and 100% concentration. The highest concentration was the maximum concentration that could technically be applied. The test system, procedures and techniques were identical to those used in the main study except that the assessment of lymph node proliferation and necropsy were not performed. Two young adult animals per concentration were selected. Each animal was treated with one concentration on three consecutive days. Ear thickness measurements were conducted using a digital thickness gauge prior to dosing on Days 1 and 3, and on Day 6.
Animals were sacrificed after the final observation.

MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: Local Lymph Node Assay
- Criteria used to consider a positive response: A Stimulation Index (SI) is calculated for each group using the individual SI values. The individual SI is the ratio of the DPM/animal compared to the DPM/vehicle control group mean. If the results indicate a SI ≥ 3, the test substance may be regarded as a skin sensitizer, based on the test guideline and recommendations done by ICCVAM.

ANIMAL ASSIGNMENT
Three groups of five animals were treated with one test substance concentration per group. One group of five animals was treated with vehicle and another group of five animals was treated with the positive control substance.

TREATMENT PREPARATION AND ADMINISTRATION:
Test substance preparation: No adjustment was made for specific gravity of the vehicle. Homogeneity was assessed by visual inspection of the solutions.
Rationale for vehicle: The vehicle was selected on the basis of maximizing the solubility using the test item data provided by the Sponsor and trial preparation results performed at Charles River Den Bosch. The vehicle was chosen from the vehicles specified in the test guideline.


Induction - Days 1, 2 and 3; Excision of nodes - Day 6; Tissue processing for radioacitivity - Day 6; Radioactivity measurements - Day 7; Performed according to test guidelines.

Observations:
Mortality/Viability: Twice daily.
Body weights: On Day 1 (pre-dose) and Day 6 (prior to necropsy).
Clinical signs: Once daily on Days 1-6 (on Days 1-3 between 3 and 4 hours after dosing).
Irritation: Once daily on Days 1-6 (on Days 1 - 3 immediately after dosing) according to a numerical scoring system. Furthermore, a description of all other (local) effects was recorded according to guidelines.

Necropsy: No necropsy for gross macroscopic examination was performed according to study plan.

Positive control substance(s):

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

Statistics:

Not performed.

Results and discussion

Positive control results:

The positive control group added to the study showed that the positive control substance is suitable for eliciting a SI>3 in this batch of animals and with the procedures used for this study.
The six-month reliability check with Alpha-hexylcinnamicaldehyde indicates that the Local Lymph Node Assay as performed at WIl Research Europe is an appropriate model for testing for contact hypersensitivity.

In vivo (LLNA)

Results

Results 1

Key result

Parameter:

SI

Value:

<= 1.1

Remarks on result:

other: The SI values calculated for the test item concentrations 25, 50 and 100% were 1.1, 1.0 and 1.1, respectively and 4.1 for the positive control item.

Results 2

Key result

Parameter:

SI

Value:

1.1

Test group / Remarks:

25% Concentration

Results 3

Key result

Parameter:

SI

Value:

1

Test group / Remarks:

50% concentration

Results 4

Key result

Parameter:

SI

Value:

1.1

Test group / Remarks:

100% concentration

Cellular proliferation data / Observations:

RADIOACTIVITY MEASUREMENTS
Mean DPM/animal values for the experimental groups treated with test item concentrations 25, 50 and 100% were 891, 857 and 897 DPM, respectively. The mean DPM/animal value for the vehicle control group was 835 DPM and a mean DPM/animal value of 3401 DPM was obtained from the positive control group.

Any other information on results incl. tables

Results Pre-screen test:

No irritation and no signs of systemic toxicity were observed in any of the pre-screen animals. Scaliness noted for all animals on Days 2 and 3 was considered not to have a toxicologically significant effect on the activity of the nodes. Variations in ear thickness during the observation period were less than 25% from Day 1 pre-dose values. White test item remnants were present on the dorsal surface of the ears but did not hamper scoring of the skin reactions. Based on these results, the highest test item concentration selected for the main study was a 100% concentration.

Other results - main study:

No irritation was observed in any of the animals. Scaliness noted for some animals throughout the dose groups and vehicle control groups was considered not to have a toxicologically significant effect on the activity of the nodes. Very slight erythema, scaliness and/or scabs noted for the positive control animals between Days 2 and 6 was considered not to have a toxicologically significant effect on the activity of the nodes.

 

No mortality occurred and no clinical signs of systemic toxicity were observed in the vehicle control animals or animals treated with test item and body weights and body weight gain of experimental animals remained in the same range as controls over the study period. The animals treated with the positive control item showed piloerection and/or hunched posture between Days 1 and 3. This was considered not to have a toxicologically significant effect on the activity of the nodes.

 

All auricular lymph nodes of the animals of the experimental and vehicle control group were considered normal in size. The nodes of 4/5 positive control animals were considered enlarged. No macroscopic abnormalities of the surrounding area were noted for any of the animals.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

In an LLNA skin sensitisation study, performed according to OECD/EC test guidelines, MOVE3 was considered not to be a skin sensitiser, as the SI appeared not to be ≥ 3 when tested up to and including 100% w/w.

Executive summary:

An LLNA skin sensitisation study was performed with MOVE3 according to OECD/EC test guidelines and in compliance with GLP principles. Based on the results of a pre-screen test, the test concentrations were selected at 25%, 50% and 100% w/w. Since the test item has a low boiling point and it evaporates quickly at room temperature, test item preparations were placed in containers with reduced headspace and kept on ice until dosing. No irritation was observed in any of the animals. Scaliness noted for some animals throughout the dose groups was considered not to have a toxicologically significant effect on the activity of the nodes. All auricular lymph nodes of the animals of the experimental and control groups were considered normal in size. The nodes of 4/5 positive control animals were considered enlarged. No macroscopic abnormalities of the surrounding area were noted for any of the animals. No mortality occurred and no clinical signs of systemic toxicity were observed in the vehicle control animals or animals treated with test item. The animals treated with the positive control item showed piloerection and/or hunched posture between Days 1 and 3. Body weights and body weight gain of experimental animals remained in the same range as controls over the study period. Mean DPM/animal values for the experimental groups treated with test item concentrations 25, 50 and 100% were 891, 857 and 897 DPM, respectively. The mean DPM/animal value for the vehicle control group was 835 DPM and a mean DPM/animal value of 3401 DPM was obtained from the positive control group. The SI values calculated for the test item concentrations 25, 50 and 100% were 1.1, 1.0 and 1.1, respectively and 4.1 for the positive control item. Adequate positive and negative controls were included. Since there was no indication that the test item elicited a SI ≥ 3 when tested up to 100%, MOVE3 was not considered to be a skin sensitizer.

Based on these results, MOVE3 would not be regarded as a skin sensitizer according to the recommendations made in the test guidelines. The test item does not have to be classified and has no obligatory labelling requirement for sensitization by skin contact according to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) of the United Nations (2015) (including all amendments) and the Regulation (EC) No 1272/2008 on classification, labelling and packaging of items and mixtures (including all amendments).