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Toxicological information

Genetic toxicity: in vitro

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Administrative data

Endpoint:
in vitro cytogenicity / chromosome aberration study in mammalian cells
Remarks:
Type of genotoxicity: chromosome aberration
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
GLP - Guideline study, tested with the source substance CAS 112-85-6. In accordance to the ECHA guidance document "Practical guide 6: How to report read-across and categories (March 2010)", the reliability was changed from RL1 to RL2 to reflect the fact that this study was conducted on a read-across substance.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2002

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 473 (In Vitro Mammalian Chromosome Aberration Test)
Deviations:
no
GLP compliance:
yes
Type of assay:
in vitro mammalian chromosome aberration test

Test material

Constituent 1
Reference substance name:
Docosanoic acid
EC Number:
204-010-8
EC Name:
Docosanoic acid
Cas Number:
112-85-6
IUPAC Name:
docosanoic acid
Details on test material:
- Name of test material (as cited in study report): Docosanoic acid
- Physical state: white solid
- Analytical purity: 85.9 %
- Lot/batch No.: 60805X
- Storage condition of test material: at room temperature

Method

Target gene:
not applicable
Species / strain
Species / strain / cell type:
mammalian cell line, other: Chinese hamster lung (CHL) cells
Details on mammalian cell type (if applicable):
- Type and identity of media: MEM (Eagle)
Metabolic activation:
with and without
Metabolic activation system:
post-mitochondrial fraction (S9 mix), prepared from the livers of rats treated with phenobarbital and 5,6-benzoflavone
Test concentrations with justification for top dose:
6 h: 875, 1750 and 3500 µg/mL, with and without metabolic activation
24 h: 350, 700, 1400 and 2800 µg/mL, without metabolic activation
48 h: 288, 575, 1150 and 2300 µg/mL, without metabolic activation
Vehicle / solvent:
Carboxymethylcellulose sodium (1.0% )
Controls
Untreated negative controls:
not specified
Negative solvent / vehicle controls:
yes
True negative controls:
not specified
Positive controls:
yes
Positive control substance:
other: long term exposure: mitomycin C (0.05 µg/mL (24 h exp) or 0.025 µg/mL (48 h exp)); short term exposure: cyclophosphamide 12.5 µg/mL (6 h exp)
Details on test system and experimental conditions:
METHOD OF APPLICATION: in medium

DURATION
- Preincubation period: 3 days
- Exposure duration: 6, 24 and 48 h

STAIN (for cytogenetic assays): Giemsa

NUMBER OF CELLS EVALUATED: 200

DETERMINATION OF CYTOTOXICITY
- Method: relative total growth
Evaluation criteria:
The frequency of polyploid cells or cells with abnormal structure of each test group were determined according to the criteria of Ishidate.
Statistics:
Probit test

Results and discussion

Test results
Species / strain:
mammalian cell line, other: Chinese hamster lung (CHL) cells
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
not specified
Positive controls validity:
valid
Additional information on results:
TEST-SPECIFIC CONFOUNDING FACTORS
- Water solubility: the test material was insoluble in water and soluble in alcohol, ether, chloroform and acetone.
- Precipitation: in the high dose group on the slide of continuous exposure precipitation was observed.

RANGE-FINDING/SCREENING STUDIES:
No cytotoxicity was observed in a preliminary test at concentrations of 4.05, 13.5, 45.0, 150 and 500 μg/mL. Therefore, cytotoxicity was tested at: (6 h exposure): 272, 453, 756, 1260, 2100, 3500 μg/mL with and without metabolic activation, (24 and 48 h exposure): 272, 453, 756, 1260, 3500 µg/mL without metabolic activation.
Result of cytotoxicity test 50 % cytotoxicity concentration:
24 h exposure: 2703 μg/mL
48 h exposure: 2248 μg/mL
6 h exposure: not observed
Based on this cytotoxicity test, test concentration of the main test were determined.

Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative