1,3-diethyl-2-thiourea

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2001

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2001

Report date:

2001

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

yes

Remarks:

minors deviations (see below)

Principles of method if other than guideline:

The minor deviations were :
-the relative humidity recorded in the animal room was sometimes outside of the target ranges specified in the protocol,
-on day 1, one animal had a body weight slightly lower than 2.2 kg,
-the animals were given 110 pelleted diet (instead of 112c pelleted diet).
These minor deviations were not considered to have compromised the validity or integrity of the study.

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

1,3-diethyl-2-thiourea

EC Number:

203-308-5

EC Name:

1,3-diethyl-2-thiourea

Cas Number:

105-55-5

Molecular formula:

C5H12N2S

IUPAC Name:

1,3-diethyl-2-thiourea

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: CEGAV, Saint Mars d'Egrenne, France.
-Sex: male
- Age at study initiation: no data
- Weight at study initiation: 2.3 ± 0.2 kg.
- Housing: individually in polystyrene cages (48.2 cm x 58 cm x 36.5 cm)
- Diet (e.g. ad libitum): free access to 110 pelleted diet (UAR, Villemoisson, Epinay-sur-Orge, France).
- Water (e.g. ad libitum): Drinking water filtered by a FG Millipore membrane (0.22 micron) was provided ad libitum
- Acclimation period: at least 5 days before the beginning of the study.

ENVIRONMENTAL CONDITIONS
. temperature: 18 ± 3°C
. relative humidity: 30 to 70%
. light/dark cycle: 12 h/12 h
. ventilation: approximately 12 cycles/hour of filtered, non-recycled air.

Test system

Type of coverage:

semiocclusive

Preparation of test site:

other: clipped

Vehicle:

unchanged (no vehicle)

Controls:

yes

Amount / concentration applied:

undiluted

Duration of treatment / exposure:

4 hour(s)

Observation period:

The skin was examined approximately 1 hour, 24, 48 and 72 hours after removal of the dressing.

Number of animals:

3

Details on study design:

The day before treatment, both flanks of each animal were clipped using electric clippers and the skin of each animal was examined. Only animals with healthy intact skin were used.

ADMINISTRATION:
- Area of exposure: left flank (3-minute exposure) and right flank (4-hour exposure)
- Total quantity applied: 500 mg
- Administration frequency: once
- Removal of test substance: residual is wiped with a dry gauze patch
The test substance and the gauze pad were held in contact with the skin by means of an adhesive hypoallergenic aerated semi-occlusive dressing and a restraining bandage. The untreated skin served as control.

EXAMINATIONS:
- Scoring system: Draize's score

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

animal: #1, 2 and 3

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Results 2

Irritation parameter:

edema score

Basis:

animal: #1, 2 and 3

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Irritant / corrosive response data:

Neither erythema nor oedema were observed in the three rabbits at any exposure duration (3 minutes and 4 hours).

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Under these experimental conditions, the test substance DETU (DIETHYL THIOUREE) is non-irritant to skin when applied topically to rabbits.

Executive summary:

The potential of the test substance DETU (DIETHYL THIOUREE) to induce skin irritation was evaluated in rabbits according to OECD (No. 404, 17th July 1992) guideline, and in compliance with the principles of Good Laboratory Practice Regulations.

In the first instance, the test substance was applied for periods of 3 minutes and 4 hours to a single male New Zealand White rabbit. Since the test substance was not 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 substance in its original form was applied to the closely­clipped skin of one flank. The test substance 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.

No cutaneous reactions were observed during the study.

Mean scores over 24, 48 and 72 hours for each animal were 0.0 for erythema and oedema.

Under these experimental conditions, the test substance DETU (DIETHYL THIOUREE) is non-irritant when applied topically to rabbits.