Butane, 2-ethoxy-2-methyl-

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP complant guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2009

Report date:

2009

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EU Method B.4 (Acute Toxicity: Dermal Irritation / Corrosion)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

UK Department of Health, 4 March 2009

Test material

Test material information

Constituent 1

Reference substance name:

2-ethoxy-2-methylbutane

EC Number:

618-804-0

Cas Number:

919-94-8

Molecular formula:

C7H16O

IUPAC Name:

2-ethoxy-2-methylbutane

Details on test material:

- Name of test material (as cited in study report): TAEE, tert-amyl ethyl ether, CAS No. 919-94-8
- Lot/batch No.: 00931302
- Description: colourless liquid
- Purity: 99.4%
- Date received: 26 September 2008

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan laboratories UK Ltd, Bicester, UK
- Age at study initiation: 12-20 wk
- Weight at study initiation: 2.55 - 2.72 kg
- Housing: individually housed
- Diet (e.g. ad libitum): yes
- Water (e.g. ad libitum): yes
- Acclimation period: 5 d minimum


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 17-23
- Humidity (%): 30-70
- Air changes (per hr): at least 15
- Photoperiod (hrs dark / hrs light): 12/12 (lights on 0600-1800 hr)


IN-LIFE DATES: From: 06 May 2009 To: 07 May 2009

Test system

Type of coverage:

semiocclusive

Preparation of test site:

other: clipped

Vehicle:

unchanged (no vehicle)

Controls:

not required

Amount / concentration applied:

0.5 ml (neat)

Duration of treatment / exposure:

4 hr

Observation period:

14 d

Number of animals:

2

Details on study design:

Skin on the dorsal/flank was clipped free of hair on the day before treatment. On the day of treatment 0.5 ml neat test substance applied to an area of clipped skin, covered with 2.5 cm x 2.5 cm piece of gauze secured with surgical tape and the trunk of animal wrapped with elasticated corset for the duration of the exposure. The wrappings were removed after 4 hr and test site wiped with cotton wool moistened with distilled water. The treatment site was examined for local reactions 24, 48 and 72 hr after patch removal and any dermal responses recorded using Draize criteria.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

mean

Time point:

other: 1 hr

Score:

0

Max. score:

0

Remarks on result:

other: No response present

Results 2

Irritation parameter:

erythema score

Basis:

mean

Time point:

other: 24 hr, 48 hr and 72 hr

Score:

2

Max. score:

2

Remarks on result:

other: Erythema present in both animals to 72 hr. Crust formation at 7 days; slight desquamation at 14 days

Results 3

Irritation parameter:

edema score

Basis:

mean

Time point:

other: 1 hr

Score:

0

Max. score:

0

Remarks on result:

other: No response present

Results 4

Irritation parameter:

edema score

Basis:

mean

Time point:

other: 24 hr

Score:

2

Max. score:

2

Remarks on result:

other: Oedema present in both animals.

Results 5

Irritation parameter:

edema score

Basis:

mean

Time point:

other: 48 hr and 72 hr

Score:

1

Max. score:

1

Remarks on result:

other: Oedema present in both animals to 72 hr, resolved by day 7

Any other information on results incl. tables

Only 2 animals used given irritant response obtained.

No evidence of skin corrosion.

Body weight gains appeared normal.

Applicant's summary and conclusion

Interpretation of results:

irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Irritating to skin

Executive summary:

Skin irritation potential was evaluated in a GLP-compliant guideline study (method B4 of directive 2004/73/EC) using 2 male New Zealand White rabbits. The test sample (0.5 ml) was applied undiluted to an area of clipped dorsal skin (approx. 2.5cm x 2.5 cm) and covered with a semi-occlusive dressing for 4 hr. The wrappings were then removed, the test skin wiped clean with cotton wool moistened with distilled water and skin reactions recorded (Draize criteria) at 1, 24, 48 and 72 hr after patch removal. Well defined erythema (grade 2) and slight or very slight oedema (initially grade 2, decreasing to grade 1) were present from 24 hr to 72 hr at the test site, followed by crust formation at day 7 and slight desquamation at day 14. No corrosive effects were noted. The test substance was irritating to rabbit skin under the conditions of the study.