thiourea; thiocarbamide

Eye irritation

Administrative data

Endpoint:

eye 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:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference Type:

publication

Title:

Überprüfung der Durchführbarkeit von Prüfungsvorschriften und der Aussagekraft der Grundprüfung des E.Chem.G. - Schleimhautverträglichkeit (OECD-Richtlinie)

Author:

Korte, F.; Greim, H.

Year:

1981

Bibliographic source:

Umweltbundesamt (UBA-FB 82-019) Forschungsbericht 107 04 006/01

Materials and methods

Test guideline

Test guideline 1

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: Entwurf der Prüfungsvorschrift der OECD "Short term toxicology group, Acute eye irritation/corrosivity" vom 31.12.1979

GLP compliance:

no

Test material

Test material information

Constituent 1

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

Test animals / tissue source

Species:

rabbit

Strain:

Himalayan

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source: own breed
- Age at study initiation: no data
- Weight at study initiation: 2.5 to 2.8 kg
- Housing: individually
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: no data

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20°C +/- 3°C
- Humidity (%): 60% +/- 5%
- Air changes (per hr): no data
- Photoperiod (hrs dark / hrs light): 12/12

Test system

Vehicle:

unchanged (no vehicle)

Controls:

other: the right eye of the animals served as control

Amount / concentration applied:

TEST MATERIAL
- Amount applied: 100 mg or 0.1 mL (1 g equates to 1.5 mL)
- Concentration: n.a.

VEHICLE
- Amount applied: no vehicle
- Concentration: n.a.
- Lot/batch no.: n.a.
- Purity: n.a.

Duration of treatment / exposure:

The substance is put into the left eye and kept close for 1 second. The substance was not washed out the eye. The exposure was throughout the observation period.

Observation period (in vivo):

An observation of the animals was done immediatetly after the application and 1, 24, and 72 hours after apllication of the test substance.

Number of animals or in vitro replicates:

6 male Himalayan rabbits

Details on study design:

REMOVAL OF TEST SUBSTANCE
- Time after start of exposure: n.a.

SCORING SYSTEM: The scoring was done after Draize et al. 1944

TOOL USED TO ASSESS SCORE: fluorescein

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

cornea opacity score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

0

Reversibility:

not specified

Remarks on result:

other: There were no individual animal data available.

Results 2

Irritation parameter:

iris score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

0

Reversibility:

not specified

Remarks on result:

other: There were no individual animal data available.

Results 3

Irritation parameter:

conjunctivae score

Basis:

mean

Time point:

24/48/72 h

Score:

1

Max. score:

2

Reversibility:

not specified

Remarks on result:

other: There were no individual animal data available.

Results 4

Irritation parameter:

chemosis score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

0

Reversibility:

not specified

Remarks on result:

not measured/tested

Other effects:

No other effects were reported.

Any other information on results incl. tables

No effects were reported after examination of the eyes following the fluorescein treatment.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

In this study Thiourea is not considered to be irritation to the eye.

Executive summary:

In a primary eye irritation study similar to the OECD guideline 405, 100 mg Thiourea were instilled undiluted without any vehicle into the conjunctival sac of the left eye of 6 male Himalayan rabbits. The eye lids were kept close for 1 second and the application lasted during the whole observation period for 72 hours as the eyes were not washed after application. Animals were observed immediately after application, and 1, 24 and 72 hours after the treatment. Irritation was scored according to Draize et al. (1944). Fluorescein was used to assess the score. The right eye in which 0.1 ml isotonic NaCl were instilled served as control.

A deficiency of the study is that there is no detailled documentation of individual animal data. Due to the fact that thiourea is not considered to be irritating in this eye irritation test and the detailled description of the procedure of the test this fact can be neglected.

The scores were reported as mean. Thiourea is reported to be not irritating to the eye. Nevertheless a with respect to the conjunctiva an irritation score of 1-2 has been reported for swelling and redness.