1,3,4-thiadiazole-2,5-dithiol

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1980-09-24 - 1980-10-15 (experimental phase)

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Remarks:

No guideline stated, given information allows the conclusion the study was well performed similar to adopted guidelines.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1980

Report date:

1980

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Deviations:

not applicable

GLP compliance:

not specified

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

1,3,4-thiadiazole-2,5-dithiol

EC Number:

214-014-1

EC Name:

1,3,4-thiadiazole-2,5-dithiol

Cas Number:

1072-71-5

Molecular formula:

C2H2N2S3

IUPAC Name:

1,3,4-thiadiazole-2,5-dithiol

Test animals

Species:

rat

Strain:

other: Sherman-Wistar albino rats

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Weight at study initiation: 200-300g
- Fasting period before study: The rats were deprived of food but not water overnight prior to dosing.
- Housing: The animals were housed and maintained in compliance with the Animal Welfare Act (Pub. L-94-279) 9 CPR Part 3.
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 50% w/v suspension in corn oil

Doses:

0.25, 0.50, 1.0, 2.0, 4.0 g/kg

No. of animals per sex per dose:

5 males

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Mortality daily, weight at the beginning and after 14 days
- Necropsy of survivors performed: yes
- Other examinations performed: body weight

Statistics:

The LD50 was calculated employing the Thompson Moving Average Method as modified by Weil, (Biometrics, September, 1952, Vol. 8, No. 3, page 249-263).

Results and discussion

Effect levels

Key result

Sex:

male

Dose descriptor:

LD50

Effect level:

930 mg/kg bw

Based on:

test mat.

95% CL:

>= 660 - <= 1 310

Mortality:

Observed, 3/5 rats at 2 g/kg, 5/5 at 4 g/kg

Clinical signs:

other: 0.25 gm/kg: No untoward symptoms were observed. 0.50 gm/kg: No untoward symptoms were observed during the first 4-6 hours. After 24 hours the animals were slightly ruffled and dirty . They appeared normal within 48 hours. 1.0 gm/kg: After 4-6 hours the an

Gross pathology:

Gross pathologic examination of the 4 g/kg group revealed nothing remarkable.

Applicant's summary and conclusion

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

Study was performed scientifically reasonable similar to OECD TG 401 on 1,3,4-Thiadiazole-2,5-dithiole, and is sufficiently documented. Hence, the results can be considered as reliable to assess the acute oral toxicity of 1,3,4-Thiadiazole-2,5-dithiole towards rats. The LD50 was determined as 0.93 (0.66 - 1.31) g/kg, which is within the boundary values of 300 and 2000 mg/kg, which triggers according to Regulation 1272/2008 the classification as acute toxic Cat. 4.

Executive summary:

In an acute oral toxicity study similar to OECD 401, groups of fasted, male Sherman-Wistar rats (5/group) were given a single oral dose of 1,3,4-Thiadiazole-2,5-dithiole, 50% in corn oil at doses of 250, 500, 1000, 2000, 4000 mg/kg bw and observed for 14 days.

The LD50 was determined as 0.93 (0.66 - 1.31) g/kg in males .

1,3,4-Thiadiazole-2,5-dithiole is of slight Toxicity based on the LD50 in males and needs to be classified as acute toxic oral Cat. 4.