N-tert-butylbenzothiazole-2-sulphenamide

Endpoint summary

Description of key information

The acute dermal and oral toxicity of the test substance TBBS is very low, indicated by LD50 values greater than 5000 mg/kg. The acute oral LD50 value in rats is greater than 6310 mg/kg (Monsanto Co. 1973) and the dermal LD50 value in rabbits is greater than 7940 mg/kg bw (Monsanto Co. 1973).

No acute inhalation study with TBBS is available.

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:

A 25% suspension of Santocure NS vulcanization accelerator (N-tert-butylbenzothiazole-2-sulphenamide) in corn oil was administrated by gavage to 4 groups of 5 (mixed males and females) Sprague-Dawley albino rats at doses of 6310 or 7940 mg/kg bw. A 10-day observation period followed administration.

GLP compliance:

no

Test type:

standard acute method

Limit test:

no

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Route of administration:

oral: gavage

Vehicle:

corn oil

Doses:

6310, 7940 mg/kg bw

No. of animals per sex per dose:

5 per dose (mixed males and females)

Control animals:

no

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 6 310 mg/kg bw

Based on:

test mat.

Remarks on result:

other: Clinical signs: reduced appetite and activity (three to five days in survivors), increased weakness, collapse, and death (in decedents).

Mortality:

6310 mg/kg bw: 0/3 males, 0/2 females, combined: 0/5
7940 mg/kg bw: 1/2 males, 2/3 females, combined: 3/5
time of mortality: 4 to 9 days

Clinical signs:

other: Reduced appetite and activity (three to five days in survivors), increased weakness, collapse, and death.

Gross pathology:

Decedents: Lung congestion, liver discoloration, acute gastrointestinal inflammation.
Surviors (10 days): Viscera appeared normal.

Mortality:

6310 mg/kg bw: 0/3 males, 0/2 females, combined: 0/5

7940 mg/kg bw: 1/2 males, 2/3 females, combined: 3/5

Time of mortality: 4 to 9 days

 

Clinical signs: reduced appetite and activity (three to five days in survivors), increased weakness, collapse, and death

Gross autopsy decedents: Lung congestion, liver discoloration, acute gastrointestinal inflammation

Surviors (10 days) viscera appeared normal

Interpretation of results:

GHS criteria not met

Conclusions:

LD50 > 6310 mg/kg bw (rats).

Executive summary:

A 25% suspension of Santocure NS vulcanization accelerator (N-tert-butylbenzothiazole-2-sulphenamide) in corn oil was administrated by gavage to 4 groups of 5 (mixed males and females) Sprague-Dawley albino rats at doses of 6310 or 7940 mg/kg bw. A 10-day observation period followed administration. A LD50 > 6310 mg/kg bw (rats) was determined.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

6 310 mg/kg bw

Quality of whole database:

Limited but acceptable documented study report which meets basic scientific principles.

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

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:

A 40 % suspension of Santocure NS vulcanization accelerator (N-tert-butylbenzothiazole-2-sulphenamide) in corn oil was applied for 24 hours directly to the clipped, intact skin of 2 (1 male/1 female) New Zealand albino rabbits at a dose of 7940 mg/kg bw using semi-occlusive dressings.

GLP compliance:

no

Test type:

standard acute method

Limit test:

yes

Species:

rabbit

Strain:

New Zealand White

Sex:

male/female

Type of coverage:

semiocclusive

Vehicle:

corn oil

Duration of exposure:

24 h

Doses:

7940 mg/kg bw

No. of animals per sex per dose:

2 animals per dose

Control animals:

no

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 7 940 mg/kg bw

Based on:

test mat.

Remarks on result:

other: Signs of intoxication: none

Mortality:

No mortalities occured.

Clinical signs:

other: None.

Gross pathology:

Viscera of animals appeared normal at sacrifice.

Mortality: 0/1 male, 0/1 female, combined 0/2

Signs of intoxication: none

Survivors: 14 day, viscera appeared normal.

No mortalities occured. The dermal LD50 for Santocure NS vulcanization accelerator was greater than 7940 mg/kg bw. No obvious clinical signs were observed. Viscera of animals appeared normal at sacrifice.

Interpretation of results:

GHS criteria not met

Conclusions:

LD50 > 7940 mg/kg bw (rabbit).

Executive summary:

A 40 % suspension of Santocure NS vulcanization accelerator (N-tert-butylbenzothiazole-2-sulphenamide) in corn oil was applied for 24 hours directly to the clipped, intact skin of 2 (1 male/1 female) New Zealand albino rabbits at a dose of 7940 mg/kg bw using semi-occlusive dressings.

No mortalities occured. No obvious clinical signs were observed. Viscera of animals appeared normal at sacrifice. The dermal LD50 for Santocure NS vulcanization accelerator was greater than 7940 mg/kg bw.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

discriminating dose

Value:

7 940 mg/kg bw

Quality of whole database:

Limited but acceptable documented study report which meets basic scientific principles.

Additional information

Acute toxicity: oral

The acute oral toxicity of TBBS was evaluated in an acute oral gavage study with Sprague-Dawley albino rats (Monsanto Co. 1973). A 25% suspension of the test substance in corn oil was administered by gavage to male and female rats at doses of 6310 or 7940 mg/kg bw. A 10-day observation period followed administration. The oral LD50 was greater than 6310 mg/kg bw. For the doses 6310 and 7940 mg/kg bw, the number of deaths were 0, and 3, respectively, out of 5 animals per group. Clinical signs were observed and included reduced appetite and activity (lasting 3 to 5 days in survivors), increasing weakness, collapse and death. Autopsy of decedents showed lung congestion, liver discoloration and acute gastrointestinal inflammation. Viscera of surviving animals appeared normal at sacrifice.

Acute toxicity: dermal

The acute dermal toxicity of the test substance TBBS was evaluated in acute dermal toxicity study with New Zealand albino rabbits (Monsanto Co. 1973). A 40 % suspension of the test substance in corn oil was applied for 24 hours directly to the clipped, intact skin of 2 (1 male and 1 female) New Zealand albino rabbits at a dose of 7940 mg/kg bw using semi-occlusive dressings. No mortality occurred. The dermal LD50 for the test substance TBBS was greater than 7940 mg/kg bw. No obvious clinical signs were observed. Viscera of animals appeared normal at sacrifice.

Justification for selection of acute toxicity – oral endpoint
The most reliable study is used

Justification for selection of acute toxicity – dermal endpoint
The most reliable study is used

Justification for classification or non-classification

The acute oral LD50 value in rats is greater than 6310 mg/kg (Monsanto Co. 1973) and the dermal LD50 value in rabbits is greater than 7940 mg/kg bw (Monsanto Co. 1973). No acute inhalation study is available.

According to CLP classification criteria (Regulation (EC) No 1272/2008) a classification is not justified.