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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:
key study
Study period:
May 1977 - June 1977
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Study completed prior to GLP.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1977
Report date:
1977

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 401 (Acute Oral Toxicity)
GLP compliance:
no
Remarks:
Prior to GLP
Test type:
standard acute method

Test material

Constituent 1
Chemical structure
Reference substance name:
1,3-dihydro-4(or 5)-methyl-2H-benzimidazole-2-thione, zinc salt
EC Number:
262-872-0
EC Name:
1,3-dihydro-4(or 5)-methyl-2H-benzimidazole-2-thione, zinc salt
Cas Number:
61617-00-3
Molecular formula:
C8H8N2S.1/2Zn
IUPAC Name:
Zinc bis[4(or 5)-methyl-2-thioxo-2,3-dihydrobenzimidazol-1-ide]
Test material form:
solid: particulate/powder
Remarks:
migrated information: powder
Details on test material:
Substance name: Zinc Salt of 2-mercaptotolylimidazole
Sample received: May 3, 1977

Test animals

Species:
rat
Strain:
other: Sherman-Wistar
Sex:
male
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Weight at study initiation: 200 - 300 g

- Fasting period before study: The rates were deprived of food but not water for 24 hours prior to dosing.

- Diet: ad libitum

- Water: ad libitum

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
corn oil
Remarks:
25% w/v suspension
Doses:
The following dosage levels were administered:
0.5 mL/kg
1.0 mL/kg
2.0 mL/kg
4.0 mL/kg
8.0 mL/kg
No. of animals per sex per dose:
Five groups of five rats.
Control animals:
no
Details on study design:
- Duration of observation period following administration: 14 days

- Frequency of observations and weighing: Daily

Results and discussion

Effect levelsopen allclose all
Sex:
male
Dose descriptor:
LD50
Effect level:
3.2 mL/kg bw
Based on:
test mat.
95% CL:
2.5 - 4.3
Sex:
male
Dose descriptor:
LD50
Effect level:
800 mg/kg bw
Based on:
test mat.
95% CL:
630 - 1 080
Mortality:
Dose levels 0.5, 1.0, 2.0 ml/kg:
No mortalities observed.

Dose level 4.0 ml/kg:
2 mortalities observed on Day 1.
2 mortalities observed on Day 2.

Dose level 8.0 ml/kg:
5 mortalities observed on Day 1.
Clinical signs:
other: At the 4.0 ml/kg level the animals were severely depressed within 12 hours of dosing with the lone survivor not returning to normalcy throughout the study. At the 8.0 ml/kg level the animals were comatose within 8 hours and died within the first day.
Gross pathology:
Gross pathologic examination revealed nothing remarkable.

Applicant's summary and conclusion

Interpretation of results:
Toxicity Category IV
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
ZMB2, when studied in male albino rats has an acute oral LD50 of 3.2 ml/kg with 19/20 Confidence Limits of from 2.5 to 4.3 ml/kg or 800mg/kg with 19/20 Confidence Limits of from 630 to 1,080 mg/kg.