1,1-dimethylheptanethiol

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2011-10-28 to 2011-11-08

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: This study is considered reliable without restriction. The study was followed GLP and adhered to the recommendations of OECD Guideline 404.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2012

Report date:

2012

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

1,1-dimethylheptanethiol

EC Number:

246-896-9

EC Name:

1,1-dimethylheptanethiol

Cas Number:

25360-10-5

Molecular formula:

C9H20S

IUPAC Name:

3,5-dimethylheptane-3-thiol

Test material form:

other: Clear Liquid

Details on test material:

- Name of test material (as cited in study report): 1,1 dimethylheptanethiol
- Substance type: Aliphatic thiol
- Physical state: Liquid
- Analytical purity: 97.87%
- Lot/batch No.: 11BPTNM02
- Storage condition of test material: At room temperature and in the dark

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Huntingdon Life Sciences Limited
- Age at study initiation: Approximately 39 weeks
- Weight at study initiation: 4.09 to 4.40 kg
- Housing: individually in plastic cages with perforated floors
- Diet (e.g. ad libitum): 125 g of a standard laboratory rabbit diet per day
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 20 weeks

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 16 to 20°C
- Humidity (%): 40 to 70%
- Air changes (per hr): Not reported
- Photoperiod (hrs dark / hrs light): 12 hrs dark/12 hrs light

IN-LIFE DATES: Not available

Test system

Type of coverage:

semiocclusive

Preparation of test site:

clipped

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent no treatment

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 mL

Duration of treatment / exposure:

4 hours

Observation period:

Four days

Number of animals:

3

Details on study design:

TEST SITE
- Area of exposure: dorso-lumbar region
- % coverage: appropriate area
- Type of wrap if used: 2-ply 25 mm x 25 mm porous gauze pad secured with ‘blenderm’ surgical tape covered with cotton wool and "Tubigrip" elasticated bandage dressing

REMOVAL OF TEST SUBSTANCE
- Washing (if done): Yes, lukewarm water (30-40°C)
- Time after start of exposure: 4 hours

SCORING SYSTEM: See 'Any other information on materials and methods incl. tables'

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

mean

Time point:

other: 24, 48, and 72 hours

Score:

0

Max. score:

4

Results 2

Irritation parameter:

edema score

Basis:

mean

Time point:

other: 24, 48, and 72 hours

Score:

0

Max. score:

4

Irritant / corrosive response data:

Very slight erythema and oedema were apparent at the test site of one animal one hour after bandage removal; the erythema persisted to the 24 hour examination. All test sites were overtly normal 48 hours after bandage removal.

Other effects:

There was no sign of toxicity or ill health in any rabbit during the observation period.

Any other information on results incl. tables

Table 2. Erythema and Oedema Scores

Test Animal	24-, 48-, and 72-hour mean scores
	Erythema	Oedema
1	0.0	0.0
2	0.0	0.0
3	0.0	0.0

Applicant's summary and conclusion

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Based on the lack of irritation (erythema and oedema) observed in rabbits, 1,1-dimethylheptanethiol is not considered to be irritating to the skin.

Executive summary:

In a dermal irritation study, three New Zealand White rabbits were dermally administered 0.5 mL of 1,1-dimethylheptanethiol. The test material was applied undiluted to the clipped dorso-lumbar region of each animal and covered with semi-occlusive wrap for a period of 4 hours. An additional site was similarly treated with the exception of test substance and acted as a control. All animals were subsequently observed for a period of four days.

 

Very-slight erythema and oedema were apparent at the test site of one animal one hour after bandage removal. The erythema persisted to the 24 hour examination but all test sites were normal 48 hours after bandage removal. The mean 24-, 48-, and 72-hour erythema and oedema scores were 0. No other signs of test-material related clinical toxicity were observed during the study.

 

Based on the lack of effects observed in this study, 1,1-dimethylheptanethiol is not considered to be irritating to the rabbit skin.