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Toxicological information

Genetic toxicity: in vivo

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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

Referenceopen allclose all

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 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:
OECD Guideline 478 (Genetic Toxicology: Rodent Dominant Lethal Test)
GLP compliance:
not specified
Type of assay:
rodent dominant lethal assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
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 valid:
yes
Negative controls valid:
not specified
Positive controls valid:
yes

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