1,3-dihydro-4(or 5)-methyl-2H-benzimidazole-2-thione, zinc salt

Acute Toxicity: oral

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

Test material information

Constituent 1

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 levels

Effect levels 1

Sex:

male

Dose descriptor:

LD50

Effect level:

3.2 mL/kg bw

Based on:

test mat.

95% CL:

2.5 - 4.3

Effect levels 2

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.