Zinc di(benzothiazol-2-yl) disulphide

Endpoint summary

Description of key information

The acute dermal and oral toxicity of the test substance ZMBT is very low, indicated by LD50 values greater than 5000 mg/kg. The acute oral LD50 value in rats is 7500 mg/kg bw mg/kg (Monsanto Co. 1975) and the dermal LD50 value in rabbits is greater than 7940 mg/kg bw (Monsanto Co. 1975).

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: limited but acceptable documented study report which meets basic scientific principles

Principles of method if other than guideline:

Method: other acute oral toxicity study

GLP compliance:

no

Test type:

other: acute oral toxicity study

Limit test:

no

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Route of administration:

oral: gavage

Vehicle:

corn oil

Doses:

5000, 6310, 7940, 10000 mg/kg

No. of animals per sex per dose:

5 combined males and females

Control animals:

no

Sex:

male/female

Dose descriptor:

LD50

Effect level:

7 500 mg/kg bw

Based on:

test mat.

95% CL:

6 820 - 8 250

Remarks on result:

other: clinical signs and death

Mortality

5000 mg/kg: male (0/3), female (0/2), combinded (0/5)

6310 mg/kg: male (1/2), female (0/3), combinded (1/5)

7940 mg/kg: male (1/3), female (2/2), combinded (3/5)

10000 mg/kg: male (2/2), female (3/3), combinded (5/5)

Time of mortality: One to two days after test substance application

Clinical signs:

Reduced appetite and activity (one to three days in survivors), increasing weakness, collapse, and death

Gross autopsy

Decedents: hemorrhagic areas of the lungs, liver hyperemia, and gastrointestinal inflammation

Survivors (14 day): viscera appeared normal

Endpoint conclusion

Dose descriptor:

LD50

Value:

7 500 mg/kg bw

Acute toxicity: via dermal route

Link to relevant study records

Reference

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: limited but acceptable documented study report which meets basic scientific principles

Principles of method if other than guideline:

Method: other acute dermal toxicity study

GLP compliance:

no

Test type:

other: acute dermal toxicity study

Species:

rabbit

Strain:

New Zealand White

Sex:

male/female

Type of coverage:

semiocclusive

Vehicle:

corn oil

Duration of exposure:

24 h

Doses:

7940

No. of animals per sex per dose:

2

Control animals:

no

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 7 940 mg/kg bw

Based on:

test mat.

Remarks on result:

other: clinical signs like reduced appetite and activity

Mortality: no death occured during the study (0/2)

Clinical signs observed: reduced appetite and activity (two to four days)

Gross autopsy (survivors): viscera appeared normal

Endpoint conclusion

Dose descriptor:

LD50

Value:

7 940 mg/kg bw

Additional information

Acute toxicity: oral

The acute oral toxicity of ZMBT was evaluated in acute oral toxicity studies in rats. Although the study designs do not fully comply with current guidelines the results are reliable.

In an acceptable documented study with Sprague-Dawley Albino rats a 20% solution-suspension of the test substance in corn oil was administered by gavage to male and female rats at doses of 5000, 6310, 7940 and 10000 mg/kg bw. A 14-day observation period followed administration. The oral LD50 calculated was 7500 mg/kg bw. Mortality occurred (one to two days after application) in the mid and higher dose groups evaluated (0/5, 1/5, 3/5, 5/5 at 5000, 6310, 7940 10000 mg/kg bw, respectively). Clinical signs were observed and included reduced appetite and activity (one to three days in survivors), increasing weakness, collapse and death. Autopsy of decedent showed hemorrhagic areas of the lungs, liver hyperemia, and gastrointestinal inflammation; viscera of surviving animals appeared normal at sacrifice (Monsanto Co. 1975).

In a limited acute toxicity study with rats, a LD50 value greater 10000 mg/kg bw is suggested (TNO 1975). Male and female rats (10 per sex) were administered once by gavage with the test substance, which was suspended in propylene glycol (33 % w/v). After the treatment the rats were observed for signs of intoxication for 14 days. Autopsy was carried out at study termination. Two males and two females died 2 to 15 hours after treatment. Clinical signs occurred within a few minutes after treatment. All treated animals showed sluggishness followed by loss of consciousness (dosing volume 30ml/kg). After 24 hours the survivors recovered and looked quite healthy at study termination.

Acute toxicity: dermal

The acute dermal toxicity of ZMBT was evaluated in a limited but acceptable documented acute dermal toxicity study with New Zealand Albino rabbits (Monsanto Co. 1975). One male and one female rabbit were treated with 7940 mg/kg ZMBT (40% test substance solution-suspension in corn oil) for 24 hours. No mortality occurred during the study. Clinical signs observed included reduced appetite and activity (two to four days). Gross autopsy at study termination revealed no abnormalities in viscera in the treated animals. A dermal LD50 value greater than 7940 mg/kg bw is suggested.

Justification for classification or non-classification

No classification is required according to the classification criteria 67/548/EWG and regulation no. 1272/2008 (GHS).