2-(morpholinothio)benzothiazole

Genetic toxicity: in vivo

Administrative data

Endpoint:

in vivo mammalian germ cell study: cytogenicity / chromosome aberration

Remarks:

Type of genotoxicity: chromosome aberration

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: acceptable well-documented publication which meets basic scientific principles

Data source

Reference

Reference 1

Reference Type:

publication

Title:

Mutagenic evaluations of two rubber accelerators

Author:

Hinderer, R., K.; et al.

Year:

1982

Bibliographic source:

Toxicology and Applied Pharmacology, 62, 335-341

Reference 2

Reference Type:

publication

Title:

Dominant lethal assay with OBTS

Author:

Hinderer, R., K.; et al.

Year:

1981

Bibliographic source:

The Toxicologist, 1(1), 24

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 478 (Genetic Toxicology: Rodent Dominant Lethal Test)

GLP compliance:

not specified

Type of assay:

rodent dominant lethal assay

Test material

Test material information

Constituent 1

Reference substance name:

2-(morpholinothio)benzothiazole

EC Number:

203-052-4

EC Name:

2-(morpholinothio)benzothiazole

Cas Number:

102-77-2

Molecular formula:

C11H12N2OS2

IUPAC Name:

2-(morpholin-4-ylsulfanyl)-1,3-benzothiazole

Details on test material:

OBTS, purity: 90 to 95 %

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Administration / exposure

Route of administration:

oral: gavage

Duration of treatment / exposure:

56 d

Frequency of treatment:

daily

Post exposure period:

no

Doses / concentrations

Remarks:

Doses / Concentrations:
0, 125, 250, 500 mg/kg bw
Basis:

No. of animals per sex per dose:

10 males per dose; 20 females per dose

Control animals:

yes, concurrent vehicle

Results and discussion

Test results

Sex:

male/female

Genotoxicity:

negative

Toxicity:

no effects

Vehicle controls validity:

valid

Negative controls validity:

not specified

Positive controls validity:

valid

Any other information on results incl. tables

Males

Clinical observations: during the dosing phase there was a low incidence of discharge (dried blood) around the nose. Although sequalae were noted, no physical abnormalities were observed during the test period that could be ascribed to the administration of the test material.

Body weight and body weight gain: no effects

Organ weight/body weight ratio

Stomach 125 and 250 mg/kg: significant increased, 500 mg/kg no effects

all other tissue/organ body weight rations: no effects

Gross pathology: no effects

Pregnancy of rats:

pregnancy rates: treated females comparable to control females

range of pregnant rats for mating I: 80 to 100 % and 90 to 95% in the test groups and 90 and 75% in the controls; no evidence of any compound-related effect or trend was observed

Positive control group (TEM group): pregnancy rates comparable to vehicle control (mating I 95 %, mating II: 70 %)

Dominant lethal evaluations

Number of implantation sites

vehicle control mating I: 13.7, mating II: 11.5

positive control: significant decrease in the number of implantation sites (ca. 23 to 56%)

OBTS groups:

250 and 500 mg/kg groups: comparable to vehicle control

125 mg/kg bw group increased but was within vehicle control range for both mating periods

Preimplantation loss:

No significant changes was evident in any of the OBTS groups compared to vehicle controls; the mean number of early fetal deaths per pregnancy was not affected by OBTS

Positive control TEM: significant increased of early fetal deaths ( 6 to 38 fold)

Late fetal deaths:

No effects in any treatment groups compared to vehicle control

Postimplantation mutation index

No effects of pregnant female rats mated with OBTS treated males compared to vehicle control

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information): negative