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Toxicological information

Skin irritation / corrosion

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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:
OECD Guideline 404 (Acute Dermal Irritation / Corrosion)
Deviations:
no
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder

Test animals

Species:
rabbit
Strain:
New Zealand White
Details on test animals 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

Resultsopen allclose all
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
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.

.