5,5'-dithiodi-1,3,4-thiadiazole-2(3H)-thione

Eye irritation

Administrative data

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

November 1982

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1983

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

other: 40 CFR, Section 163.81-1 (b) (4) (ii), Federal Register, August 22, 1978.

Deviations:

no

Test guideline 2

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Deviations:

no

GLP compliance:

no

Remarks:

Prior to GLP

Test material

Test material information

Constituent 1

Reference substance name:

5,5'-dithiodi-1,3,4-thiodiazole-2(3H)-thione

IUPAC Name:

5,5'-dithiodi-1,3,4-thiodiazole-2(3H)-thione

Constituent 2

Reference substance name:

5,5'-dithiodi-1,3,4-thiadiazole-2(3H)-thione

EC Number:

276-763-0

EC Name:

5,5'-dithiodi-1,3,4-thiadiazole-2(3H)-thione

Cas Number:

72676-55-2

Molecular formula:

C4-H2-N4-S6

IUPAC Name:

5,5'-dithiodi-1,3,4-thiadiazole-2(3H)-thione

Test material form:

solid: particulate/powder

Test animals / tissue source

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

A group of nine New Zealand white rabbits (albino) were employed in this study.
Animal weight: 2.0 - 3.0 kg
Animal age: 9-10 weeks of age.
Animals housed and maintained in compliance with the Animal Welfare Act (Pub. L-94-279) 9 CFR Part 3.
Acclimatisation was at least 5 days prior to the study taking place.
Animal husbandry conditions:
Temperature 70 ± 2ºC
Relative humidity 45% ±5%
Light - 12 hour light/dark cycle
Diet - Wayne 15% Rabbit ration and tap water were provided ad libitum.
Caging - Stainless steel with elevated wire mesh flooring 1 rabbit/cage.

Animals were uniquely identified by ear tag.

Test system

Vehicle:

unchanged (no vehicle)

Controls:

other: The left eye of each animal served as control.

Amount / concentration applied:

The sample was dosed as supplied. A 0.1 gm sample of material was instilled into the right eye of each test animal with the other eye remaining untreated and to serve as the controls.

Duration of treatment / exposure:

The first six rabbits did not have their eyes washed subsequent to instillation. The remaining three rabbits had the treated eyes washed after 30 seconds for 1 minute with gently flowing tepid tap water (1000 ml/ minute).

Observation period (in vivo):

The treated eyes were examined at 1, 2, 3, 4 & 7 days following instillation. The readings of the eyes were made in accordance with the Draize technique for scoring occular lesions.

Number of animals or in vitro replicates:

Total number of animals = 9.
The treated eyes of six animals remained unwashed and a mean score determined. The treated eyes of three animals were washed and a mean score determined.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

cornea opacity score

Basis:

mean

Remarks:

--unwashed eyes

Time point:

24/48/72 h

Score:

0

Max. score:

4

Results 2

Irritation parameter:

iris score

Basis:

mean

Remarks:

-- unwashed eyes

Time point:

24/48/72 h

Score:

0

Max. score:

2

Results 3

Irritation parameter:

conjunctivae score

Remarks:

Redness

Basis:

mean

Remarks:

--unwashed eyes

Time point:

24/48/72 h

Score:

0.4

Max. score:

2

Reversibility:

fully reversible within: 4 days

Results 4

Irritation parameter:

chemosis score

Basis:

mean

Remarks:

--unwashed eye

Time point:

24/48/72 h

Score:

0.3

Max. score:

3

Reversibility:

fully reversible within: 7 days

Irritant / corrosive response data:

Unwashed eye animals (1 through 6):
No corneal opacity or iritis was noted in animals 1 through 6 at 24 hours through post-exposure day 7. Conjunctival redness was noted in all animals at 24 hours post-exposure observation.
Animal 2 exhibited a positive response for conjunctival chemosis with a maximum score of 3, fully reversible within 7 days.
Washed eye animals (Animals 7 through 9):
No corneal opacity, iritis or conjunctival chemosis was noted in animals 7 through 9 at 24 hours through post-exposure day 7.
Conjunctival redness was noted in animals 7 and 9 at 24 hours post exposure, but was fully reversible within 48 hours.
Based on the data, the test substance does not appear to be an occular irritant in the unwashed eye. Washing does not appear to alter this conclusion. The minimal conjunctival irritation observed cleared up within 7 days.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Remarks:

Not eye irritating

Conclusions:

5,5'-dithiodi-1,3,4-thiadiazole-2(3H)-thione is not irritating to the eye.