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Toxicological information

Acute Toxicity: dermal

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Administrative data

Endpoint:
acute toxicity: dermal
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 restriction; comparable to guideline study with acceptable restrictions
Cross-reference
Reason / purpose for cross-reference:
reference to same study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1978

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 402 (Acute Dermal Toxicity)
GLP compliance:
no
Test type:
standard acute method
Limit test:
no

Test material

Constituent 1
Chemical structure
Reference substance name:
Thiourea
EC Number:
200-543-5
EC Name:
Thiourea
Cas Number:
62-56-6
Molecular formula:
CH4N2S
IUPAC Name:
thiourea
Test material form:
solid: particulate/powder
Remarks:
migrated information: powder
Details on test material:
- Name of test material (as cited in study report): Thioharnstoff
- Substance type: Cream coloured solid
- Physical state: Solid

Test animals

Species:
rabbit
Strain:
New Zealand White
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: No data
- Age at study initiation: Young adults
- Weight at study initiation: 2.5 to 3.08 kg
- Fasting period before study: No
- Housing: Individually
- Diet: Ad libitum
- Water: Ad libitum
- Acclimation period: No data

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18 °C

Administration / exposure

Type of coverage:
occlusive
Vehicle:
water
Details on dermal exposure:
TEST SITE
- Area of exposure: 10 % of total body area
- % coverage: 10 %
- Type of wrap if used: Thin layer of cellulose sheet wrapped in polyethylene foil

REMOVAL OF TEST SUBSTANCE
- Washing (if done): The test substance was removed from the skin with water
- Time after start of exposure: 24 h

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 9 ml/kg body weight
- Constant volume or concentration used: Yes (constant volume: 9 ml/kg body weight)

VEHICLE
- Amount(s) applied (volume or weight with unit): The test substance was applied as solution in water (9 ml/kg)
Duration of exposure:
24 h
Doses:
0, 1.0, 2.0 and 2.8 g/kg body weight
No. of animals per sex per dose:
2 animals per sex and dose (altogether 8 males and 8 females)
Control animals:
yes, concurrent vehicle
Details on study design:
- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: At day 0, and at the end of week 1 and 2
- Necropsy of survivors performed: Yes
- Other examinations performed: Clinical signs, microscopic pathology (treated skin, liver, heart, kidneys), food consumption, water intake, body weights, haematological data, autopsy, histological examination of fixed organs (heart, liver, kidney, spleen).
Statistics:
none

Results and discussion

Effect levels
Sex:
male/female
Dose descriptor:
LD50
Effect level:
> 2 800 mg/kg bw
Based on:
test mat.
Mortality:
No mortality
Clinical signs:
Slight erythema of the skin of rabbits treated with 2000 or 2800 mg/kg
Body weight:
Comparable to control group
Gross pathology:
No gross changes that could be related to the treating
Other findings:
None

Any other information on results incl. tables

Table 1: Individual body weights of male and female rabbits after a single dermal application of thiourea

Animal number and sex

Dose g/kg

Condition of skin

Body weights (in kg)

At day 0

At the end of week 1

At the end of week 2

6336 M

0

Abraded

3.08

3.00

3.24

6338 M

0

Intact

2.80

2.83

2.93

6348 F

0

Abraded

2.83

2.82

3.00

6352 F

0

Intact

2.50

2.57

2.84

6337 M

1

Abraded

3.07

2.96

3.24

6343 M

1

Intact

2.84

2.85

2.97

6346 F

1

Abraded

2.6

2.35

2.50

6353 F

1

Intact

2.78

2.55

2.90

6340 M

2

Abraded

2.81

2.73

2.88

6341 M

2

Intact

3.05

3.04

3.12

6349 F

2

Abraded

2.66

2.68

2.94

6351 F

2

Intact

2.75

2.35

2.78

6334 M

2.8

Abraded

2.93

2.94

3.04

6339 M

2.8

Intact

2.88

2.86

3.00

6345 F

2.8

Abraded

2.70

2.60

2.91

6350 F

2.8

Intact

2.70

2.43

2.70

Applicant's summary and conclusion

Interpretation of results:
practically nontoxic
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
Thiourea is practically non-toxic in rabbits, when applied dermally at a single dose of up to 2.800 mg/kg.
Executive summary:

In an acute dermal toxicity study, groups of young adult New Zealand White albino rabbits (8/sex) were dermally exposed to thiourea in water for 24 hours, covering 10 % of body surface area at doses of 0, 1000, 2000 and 2800 mg/kg bw. Animals were subsequently observed for 14 days. No mortality occured at the highest dose of 2800 mg/kg bw.

Thiourea is practically non-toxic when applied in a single dose to the skin of rabbits.