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Toxicological information

Genetic toxicity: in vivo

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Administrative data

Endpoint:
in vivo mammalian somatic cell study: cytogenicity / bone marrow 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: GLP guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1988
Report date:
1988

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 475 (Mammalian Bone Marrow Chromosome Aberration Test)
Principles of method if other than guideline:
m-dichlorobenzene was administered orally in a single dose of 1000 mg/kg bw to Chinese hamsters. Animals from each group were killed 12, 24 and 48 hours after treatment. The bone marrow obtained from femura was prepared and 50 metaphases per animals were evaluated.
GLP compliance:
yes
Type of assay:
chromosome aberration assay

Test material

Constituent 1
Chemical structure
Reference substance name:
1,3-dichlorobenzene
EC Number:
208-792-1
EC Name:
1,3-dichlorobenzene
Cas Number:
541-73-1
Molecular formula:
C6H4Cl2
IUPAC Name:
1,3-dichlorobenzene
Test material form:
other: liquid
Details on test material:
purity: techn. 96% - dest. > 99%

Test animals

Species:
hamster, Chinese
Strain:
other: Han: Chin
Sex:
male/female

Administration / exposure

Route of administration:
oral: gavage
Duration of treatment / exposure:
12, 24 or 48 hours
Frequency of treatment:
single treatment
Post exposure period:
none
Doses / concentrations
Remarks:
Doses / Concentrations:
1000 mg/kg bw
Basis:
actual ingested
No. of animals per sex per dose:
5 male and 5 femal animals/killing time (12, 24 or 48 hrs)
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:
valid
Positive controls validity:
valid

Any other information on results incl. tables

Under the conditions of the present study, m-dichlorobenzene caused no significant increase in the aberration rate in the bone marrow cells of the treated animals as compared with the control group. Endoxan however produced a marked increase in the aberration rate in the test animals. The results indicate that, under the conditions of the present study, m-dichlorobenzene is not mutagenic in the in vivo chromosome aberration test in bone marrow cells of the Chinese hamster.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information): negative
Executive summary:

m-dichlorobenzene was administered once orally by gavage in a single dose of 1000 mg/kg bodyweight to male and female Chinese hamsters. This dose had been shown in a preliminary study tobe the maximum tolerated dose.

A positive control group, induced exactly 24 hours later to run parallel with the negative control and the dose group, received Endoxan in an oral dose of 50 mg/kg bodyweight.

Animals from each group were killed 12, 24 and 48 hours after treatment by carbon dioxide asphyxiation. 5 males and 5 females from each group were killed at each of these times.

The bone marrow obtained from femora of the animals was prepared, placed on microskopic slides and stained, after which 50 metaphases per animal were evaluated. The completeness in the number of chromosomes and the various chromatic and chromosomal aberrations were assessed.

Under the conditions of the present study, m-dichlorobenzene caused no significant increase in the aberration rate in the bone marrow cells of the treated animals as compared with the control group.

Endoxan however produced a marked i ncrease in the aberration rate in the test animals.

The results indicate that, under the conditions of the present study, m-dichlorobenzene is not mutagenic in the in vivo chromosome aberration test in bone marrow cells of the Chinese hamster.

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