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Toxicological information

Acute Toxicity: oral

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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

Constituent 1
Chemical structure
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.