Disodium 1,3,4-thiadiazole-2,5-dithiolate

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Remarks:

In vivo study performed prior (1980) to REACH implementation.

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1980-09-19 - 1980-10-03 (experimental phase)

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

Given information allows the conclusion the study was well performed according to adopted guidelines, given data allows also conclusions on classification according to Regulation 1272/2008.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1980

Report date:

1980

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: CFR Section 1500.41

Version / remarks:

The method employed in the testing, evaluation and the scoring of the results was similar to that described in Section 1500.41 ― Federal Hazardous Substances Act Regulations ― 16 CFR - P. 124,

Deviations:

not specified

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Disodium 1,3,4-thiadiazole-2,5-dithiolate

EC Number:

259-886-4

EC Name:

Disodium 1,3,4-thiadiazole-2,5-dithiolate

Cas Number:

55906-42-8

Molecular formula:

C2H2N2S3.2Na

IUPAC Name:

disodium 1,3,4-thiadiazole-2,5-dithiolate

Constituent 2

Reference substance name:

Water

EC Number:

231-791-2

EC Name:

Water

Cas Number:

7732-18-5

Molecular formula:

H2O

IUPAC Name:

Water

Test material form:

liquid - solid: mixture of

Remarks:

water, Disodium 2,5-dimercapto-1,3,4-thiadiazole

Test animals

Species:

rabbit

Strain:

other: Albino

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Housing: The animals were housed and maintained in compliance with the Animal Welfare Act (Pub. L-94-279) 9 CFR Part 3.

Test system

Type of coverage:

occlusive

Preparation of test site:

other: abraded and intact (clipped only)

Vehicle:

unchanged (no vehicle)

Controls:

not required

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 ml

Duration of treatment / exposure:

24h occlusive under Wrap. no wash-off

Observation period:

72h

Number of animals:

6

Details on study design:

TEST SITE
- Area of exposure: A 0.5 ml portion of material was applied to an abraded and an intact skin site on the same rabbit.
- Type of wrap if used: Gauze patches were then placed over the treated areas and an impervious material was wrapped snugly around the trunks of the animals to hold the patches in place.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): none washing stated

OBSERVATION TIME POINTS
after 24 and 72 hours

SCORING SYSTEM:
- Method of calculation: The Draize method of scoring was employed. Scoring of the results was similar to that described in Section 1500.41 ― Federal Hazardous Substances Act Regulations ― 16 CFR - P. 124.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

mean

Time point:

other: 24&72h

Score:

0

Max. score:

0

Reversibility:

other: not applicable

Remarks on result:

no indication of irritation

Results 2

Irritation parameter:

edema score

Basis:

mean

Time point:

other: 24&72h

Score:

0

Max. score:

0

Reversibility:

other: not applicable

Remarks on result:

no indication of irritation

Results 3

Irritation parameter:

overall irritation score

Basis:

mean

Time point:

other: 24&72h

Score:

0

Max. score:

0

Reversibility:

other: not applicable

Remarks on result:

no indication of irritation

Results 4

Irritation parameter:

erythema score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

0

Reversibility:

other: not applicable

Remarks on result:

no indication of irritation

Remarks:

Information on the 48h timepoint not given, but as after 24h and 72h the score in each animal is zero, it can be concluded that this is the case also after 48h.

Results 5

Irritation parameter:

edema score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

0

Reversibility:

other: not applicable

Remarks on result:

no indication of irritation

Remarks:

Information on the 48h timepoint not given, but as after 24h and 72h the score in each animal is zero, it can be concluded that this is the case also after 48h.

Irritant / corrosive response data:

not irritant

Other effects:

- Other adverse local effects: none stated
- Other adverse systemic effects: none stated

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Study was performed scientifically reasonable similar to that described in Section 1500.41 ― Federal Hazardous Substances Act Regulations ― 16 CFR - P. 124 on a 30% aqueous solution of disodium 1,3,4-thiadiazole-2,5-dithiolate, and is sufficiently documented. Hence, the results can be considered as reliable to assess the irritating potential of disodium 1,3,4-thiadiazole-2,5-dithiolate on intact and abraded rabbit skin. The primary irritation score was 0.00, none of the 6 rabbits showed any sign of irritation. Hence, the substance does not need to be classified as skin irritant acc. Regulation 1272/2008.

Executive summary:

In a primary dermal irritation study (16 CFR Section 1500.41), six Albino rabbits were dermally exposed to each 0.5 ml of a 30% aqueous solution of disodium 1,3,4-thiadiazole-2,5-dithiolate for 24 hours to intact and abraded skin, no washing.  Animals then were observed for 3 days.  Irritation was scored by the method of Draize.

The primary irritation score was 0.00, none of the 6 rabbits showed any sign of irritation. The substance does not need to be classified as skin irritant acc. Regulation 1272/2008