2,2-Difluoroethyl Acetate

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 27 JUNE 2013 to 19 AUGUST 2013.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Report date:

2013

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Version / remarks:

2002

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

2,2-difluoroethyl acetate

EC Number:

801-773-4

Cas Number:

1550-44-3

Molecular formula:

C4H6F2O2

IUPAC Name:

2,2-difluoroethyl acetate

Test material form:

liquid

Remarks:

clear and colorless.

Test animals

Species:

rabbit

Strain:

other: New Zealand Albino.

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: animals were received from Robinson Services, Inc. Mocksville, NC, USA.
- Sex: female, nulliparous and non-pregnant.
- Age at study initiation: young adult.
- Weight at study initiation: the initial weight ranged from 2131 g to 2371 g, see Table 1 below in section "Any other information on results incl. tables".
- Housing: the animals were individually housed in suspended stainless steel caging with mesh floors which conform to the size recommendations in the most recent Guide for the Care and Use of Laboratory Animals (Natl. Res. Council, 2011). Enrichment (e.g. toy) was placed in each cage. Litter paper was placed beneath the cage and was changed at least three times per week.
- Diet: Harlan Teklad Global High Fiber Rabbit Diet® #2031. A designated amount of the diet was available to each rabbit (approximately 150 grams/day).
- Water: filtered tap water was supplied ad libitum.
- Acclimation period: 6 or 13 days.

ENVIRONMENTAL CONDITIONS
- Temperature: 18 - 22°C.
- Humidity: 64 - 77%. The humidity was above the targeted upper limit for four days during the study. A portable dehumidifier was used to lower the humidity levels during this time.
- Air changes (per hr): 12. Airflow measurements were evaluated regularly.
- Photoperiod: 12 hour light/dark cycle.

IN-LIFE DATES: From 2 July 2013 to 12 July 2013.

Test system

Type of coverage:

semiocclusive

Preparation of test site:

clipped

Remarks:

Approximately 24 hours prior to application, the animals were prepared by clipping the dorsal area and the trunk.

Vehicle:

unchanged (no vehicle)

Controls:

not required

Amount / concentration applied:

Five-tenths of a millilitre of the undiluted test material was applied.

Duration of treatment / exposure:

4 hours.

Observation period:

The observation period lasted up to 72 hours after patch removal.

Number of animals:

3 animals.
Initially, only one rabbit was placed on test. Since no dermal irritation was observed at the dose site on this animal, the test was completed with two additional rabbits.

Details on study design:

TEST SITE
- Area of exposure: the test substance was applied to one 6-cm2 intact dose site on each animal.
- Type of wrap: After application of the test substance, the dose site was covered with a 1-inch x 1-inch, 4-ply gauze pad. The pad and entire trunk of each animal were wrapped with semi-occlusive 3-inch Micropore tape to avoid dislocation of the pad. Elizabethan collars were placed on each rabbit.

REMOVAL OF TEST SUBSTANCE
- Washing and time after start of exposure: After 4 hours of exposure to the test substance, the pads and collars were removed and the test sites were gently cleansed of any residual test substance.

OBSERVATION TIME POINTS
Individual dose sites were scored immediately following patch removal (initial rabbit only) and at approximately 30-60 minutes, 24, 48, and 72 hours after patch removal.

SCORING SYSTEM:
- Method of calculation: Draize scoring system.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

edema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

0

Reversibility:

other: Not applicable since there was no effect.

Results 2

Irritation parameter:

erythema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

0

Reversibility:

other: Not applicable since there was no effect.

Results 3

Irritation parameter:

edema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

0

Reversibility:

other: Not applicable since there was no effect.

Results 4

Irritation parameter:

erythema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

0

Reversibility:

other: Not applicable since there was no effect.

Results 5

Irritation parameter:

edema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Max. score:

0

Reversibility:

other: Not applicable since there was no effect.

Results 6

Irritation parameter:

erythema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Max. score:

0

Reversibility:

other: Not applicable since there was no effect.

Irritant / corrosive response data:

There was no dermal irritation observed at any treated dose site during the study. See more details in "Any other information on results incl. tables" below.

Other effects:

- Body weight: All animals gained body weight during the study. See more details in Table 1 in the field "Any other information on results incl. tables".
- Clinical signs: All animals appeared active and healthy during the study. There were no clinical signs observed.

Any other information on results incl. tables

Table 1: Individual body weights

Animal No.	Sex	Body Weight (g)
		Initial	Terminal
3501	F	2219	2350
3502	F	2371	2599
3503	F	2131	2170

 

Table 2: Individual skin irritation scores: erythema / edema

Animal No.	Sex	Time After Patch Removal
		Immediately after patch removal	30-60 mins	24 hrs	48 hrs	72 hrs
3501	F	0/0	0/0	0/0	0/0	0/0
3502	F	N/A	0/0	0/0	0/0	0/0
3503	F	N/A	0/0	0/0	0/0	0/0

N/A – Not Applicable

 

Table 3: Summary of mean scores for dermal responses

Rabbit No.	Erythema^a	Edema^a
3501	0.0	0.0
3502	0.0	0.0
3503	0.0	0.0

^a Calculated from the 24, 48 and 72-hour dermal responses.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Under the conditions of this study, 2,2-Difluoroethyl acetate did not induce dermal irritation in rabbits.

Executive summary:

The skin corrosion/irritation potential of 2,2-Difluoroethyl acetate was investigated in a study performed according to OECD test guideline 404 under GLP compliance.

The study was carried out with three female New Zealand albino rabbits. Approximately 24 hours prior to application, the animals were prepared by clipping the dorsal area and the trunk. Initially, one rabbit was treated as follows: 0.5 mL of the test substance was applied to one 6-cm² intact dose site and covered with a 1-inch x 1-inch, 4-ply gauze pad. The pad and entire trunk were then wrapped with semi-occlusive 3-inch Micropore tape to avoid dislocation of the pad. Elizabethan collar was placed and the rabbit was returned to its cage. After an exposure period of 4 hours, the pad and collar were removed. Dose site was scored according to the Draize scoring system (Draize et al., 1944) immediately following patch removal and at approximately 30-60 minutes, 24, 48, and 72 h after patch removal. Since there was no dermal irritation noted at the dose site of this animal, the test was completed on two additional animals, as described above, except the dose sites were not evaluated immediately after patch removal.

No clinical signs of toxicity were observed in the study. None of the three rabbits tested showed dermal irritation at the treated dose site.

Under the conditions of this study, 2,2-Difluoroethyl acetate did not induce dermal irritation in rabbits.