1,3-dibutyl-2-thiourea

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 12 Oct 2004 to 19 oct 2004

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2005

Report date:

2005

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

1,3-dibutyl-2-thiourea

EC Number:

203-674-6

EC Name:

1,3-dibutyl-2-thiourea

Cas Number:

109-46-6

Molecular formula:

C9H20N2S

IUPAC Name:

1,3-dibutyl-2-thiourea

Test material form:

solid: particulate/powder

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

- Source: CEGAV, Saint Mars d'Egrenne, France
- Age at study initiation : 2 to 4 months
- Body weight at study initiation: 2.4 ± 0.2 kg
- Acclimation period: at least 5 days
- Housing: individually in polystyrene cages (48.2 cm x 58 cm x 36.5 cm).
- Diet: free access to 110 pelleted diet (SAFE, Villemoisson, Epinay-sur-Orge, France).
- water: Drinking water ad libidum
- Temperature: 18 ± 3°C
- Humidity: 30 to 70%
- Air changes: approximately 12 cycles/hour of filtered, non-recycled air.
- Photoperiod: 12 h/12 h

Test system

Type of coverage:

semiocclusive

Vehicle:

unchanged (no vehicle)

Controls:

no

Amount / concentration applied:

A single dose of 500 mg of the test item

Duration of treatment / exposure:

4 hour(s)

Observation period:

1 hour, 24, 48, 72 hours after removal of the dressing and then daily until reversibility of cutaneous reactions.

Number of animals:

3

Details on study design:

The test item was first applied for periods of 3 minutes and 4 hours to a single male New Zealand White rabbit. Since the test item was not severely irritant on this first animal, it was then applied for 4 hours to two other animals. A single dose of 500 mg of the test item in its original form was applied to the closely-clipped skin of one flank. The test item was held in contact with the skin by means of a semi-occlusive dressing.
The mean values of the scores for erythema and oedema were calculated for each animal.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

mean

Remarks:

3 rabbits

Time point:

other: 24-48-72 hours

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Results 2

Irritation parameter:

edema score

Basis:

mean

Remarks:

3 rabbits

Time point:

other: 24-48-72 hours

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Irritant / corrosive response data:

After a 3-minute exposure (one animal): a very slight erythema was observed from day 2 to day 5, followed by dryness of the skin on days 6 and 7.
After a 4-hour exposure (three animals) : No cutaneous reactions were observed in any animal. Mean scores over 24, 48 and 72 hours for each animal were 0.0, 0.0 and 0.0 for erythema and 0.0, 0.0 and 0.0 for oedema.

Other effects:

no

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The test item Dibutyl thiourea is non-irritant to skin when applied topically to rabbits .

Executive summary:

The potential of the test item Dibutyl thiourea to induce skin irritation was evaluated in rabbits according to OECD (No. 404, 17th July 1992) and EC (92/69/EEC, B.4, 31st July 1992) guidelines.

The study was conducted in compliance with the principles of Good Laboratory Practice Regulations.

The test item was first applied for periods of 3 minutes and 4 hours to a single male New Zealand White rabbit. Since the test item was not severely irritant on this first animal, it was then applied for 4 hours to two other animals.

A single dose of 500 mg of the test item in its original form was applied to the closely-clipped skin of one flank. The test item was held in contact with the skin by means of a semi-occlusive dressing.

Cutaneous reactions were observed approximately 1 hour, 24, 48 and 72 hours after removal of the dressing and then daily until reversibility of cutaneous reactions.

The mean values of the scores for erythema and oedema were calculated for each animal.

After a 3-minute exposure (one animal): a very slight erythema was observed from day 2 to day 5, followed by dryness of the skin on days 6 and 7.

After a 4-hour exposure (three animals) : No cutaneous reactions were observed in any animal. Mean scores over 24, 48 and 72 hours for each animal were 0.0, 0.0 and 0.0 for erythema and 0.0, 0.0 and 0.0 for oedema.

Based on these results, the test item Dibutyl thiourea is non-irritant to skin when applied topically to rabbits.

.