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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:
no data
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Valid with restrictions; meets generally accepted scientific standards, well documented and acceptable for assessment

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1983
Report Date:
1983

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 404 (Acute Dermal Irritation / Corrosion)
Deviations:
yes
Remarks:
: exposure 4h, no reading after 1 h and 48 h; animals are treated on intact and abraded skin
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
not specified
Details on test material:
- Name of test material (as cited in study report): Thioharnstoff

Test animals

Species:
rabbit
Strain:
New Zealand White

Test system

Type of coverage:
occlusive
Preparation of test site:
abraded
Vehicle:
unchanged (no vehicle)
Controls:
no
Amount / concentration applied:
TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 g undiluted test material
Duration of treatment / exposure:
24 hours
Observation period:
72 hours
Number of animals:
12
Details on study design:
TEST SITE
- Area of exposure: 1 inch²
- Type of wrap if used: surgical patch, adhesive tape, impervious material to wrap

SCORING SYSTEM: Draize and CIVO grading

Results and discussion

In vivo

Resultsopen allclose all
Irritation parameter:
other: edema and erythema score
Basis:
mean
Remarks:
of the animals with intact skin
Time point:
other: 24 h
Score:
1
Max. score:
2
Reversibility:
fully reversible within: 72 h
Irritation parameter:
other: edema and erythema
Basis:
mean
Remarks:
of the animals with intact skin
Time point:
other: 72 h
Score:
0
Max. score:
0
Irritation parameter:
other: edema and erythema score
Basis:
mean
Remarks:
of the animals with abraded skin
Time point:
other: 24 h
Score:
1.5
Max. score:
2
Reversibility:
fully reversible within: 72 h
Remarks on result:
other: only in one animal very slight scaliness was observed after 72 hours
Irritation parameter:
other: edema and erythema score
Basis:
mean
Time point:
other: 72 h
Score:
0.2
Max. score:
1
Reversibility:
fully reversible
Remarks on result:
other: one of six animals showed very slight scaliness after 72 hours
Other effects:
No other effects were observed

Any other information on results incl. tables

Table 1: Individual and average skin irritation scores of undiluted thiourea

Rabbit number

Intact skin

Rabbit number

Abraded skin

24 hours

72 hours

24 hours

72 hours

A

B

A

B

1

1

0

0

7

2

2

1

2

0

0

0

8

2

0

0

3

1

2

0

9

0

0

0

4

1

1

0

10

0

0

0

5

0

0

0

11

1

1

0

6

0

0

0

12

1

0

0

average

1.0

0

average

1.5

0.2

Applicant's summary and conclusion

Interpretation of results:
not irritating
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
On the basis of the results it is concluded that undiluted thiourea is a very slight to slight primary skin irritant but not relevant for classification.
Executive summary:

In a primary dermal irritation study 12 healthy, adult New Zealand White albino rabbits were dermally exposed to 0.5 g of undiluted thiourea on 1 inch² of the body surface area on the back of the animals. Test sites were covered with an occlusive dressing for 24 hours. Animals were then observed for 72 hours. Irritation was scored by the method of Draize (1944) and the CIVO grading system. After 24 hours dermal effects were observed in seven out of twelve rabbits. These effects consisted of very slight to well-defined erythema with or without very slight or slight oedema. After 72 hours one rabbit treated on the abraded skin showed slight scaliness. No other dermal effects were observed. In this study, thiourea is very slightly to slightly irritatin but not relevant for classification.