Zinc bis[12-hydroxyoctadecanoate]

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:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

supporting study

Study period:

Not reported

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for data waiving:

other:

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

reference to same study

Cross-reference 2

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

1978

Report date:

1977

Materials and methods

Principles of method if other than guideline:

Animals were exposed to test material by inhalation and sacrificed after treatment. Chromosome preparations were made from the bone marrow cells and stained. Cells were analysed for chromosome aberrations.

GLP compliance:

not specified

Type of assay:

chromosome aberration assay

Test material

Test material information

Constituent 1

Reference substance name:

Zinc oxide

EC Number:

215-222-5

EC Name:

Zinc oxide

Cas Number:

1314-13-2

Molecular formula:

OZn

IUPAC Name:

oxozinc

Details on test material:

- Name of test material (as cited in study report): Zinc oxide

Test animals

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

Not reported

Administration / exposure

Route of administration:

inhalation

Vehicle:

Not applicable

Details on exposure:

The exposure chambers were equipped with dosing devices, to ensure a constant concentration throughout the exposure period, with a fluctuation not exceeding +/- 10% of the set values of 0.1 and 0.5 mg/m3.

Duration of treatment / exposure:

5 months

Frequency of treatment:

Animals were exposed to the test material aerosol continuously

Post exposure period:

Not reported

Doses / concentrations

Remarks:

Doses / Concentrations:
0.5 and 0.1 mg/m3
Basis:
nominal conc.

No. of animals per sex per dose:

Not reported

Control animals:

yes

Positive control(s):

Not reported

Examinations

Tissues and cell types examined:

Bone marrow cells examined for all types of chromosome and chromatid-type aberrations and hyperdiploid cells.

Details of tissue and slide preparation:

Specimens were prepared according to Tjio and Whang (1962) method.

Evaluation criteria:

Not reported

Statistics:

Frequencies of chromosome damages, the Student criterion and the confidence intervals were calculated using the Fisher transformation. The level of significance was 0.05.

Results and discussion

Test results

Sex:

female

Genotoxicity:

positive

Toxicity:

not specified

Vehicle controls validity:

not specified

Negative controls validity:

not applicable

Positive controls validity:

not applicable

Additional information on results:

RESULTS OF DEFINITIVE STUDY

- Statistical evaluation: Both the total number of cells with chromosomal damage and frequency of hyperdiploid cells were increased significantly (p<0.05) at 0.1 and 0.5 mg/m3.

Any other information on results incl. tables

Frequency of cells with chromosome damages (%) in the bone marrow:

Type of chromosome damages	Control	ZnO (mg/m^3)
		0.1	0.5
Structural aberrations	0	1.0	0.5
Hyperdiploid cells	1.0	3.5*	6.0*
Total cells damaged	1.0	4.5*	6.5*
Metaphases studied	200	200	200

*significant at p<0.05

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information): other: weakly positive
The test material caused a statistically significant increase in the frequency of damaged cells, primarily hyperdiploid under the conditions of this test.

Executive summary:

A study was conducted to determine the potential genotoxicity of the test material using chromosomal aberration assay. 

Non-inbred female white rats were exposed to the test material aerosols at a concentration of 0.5 and 0.1 mg/m³ continuously for 5 months. The samples for chromosomal analysis were prepared according to Tjio and Whang (1962) method.

Statistically significant increase in the frequency of damaged cells, primarily hyperdiploid cells were observed at both tested concentration.

The test material caused a statistically significant increase in the frequency damaged cells, primarily hyperdiploid under the conditions of this test.