9,9-bis-(methoxymethyl)fluorene

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro cytogenicity / chromosome aberration study in mammalian cells

Remarks:

Type of genotoxicity: chromosome aberration

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1995

Report date:

1995

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 473 (In Vitro Mammalian Chromosome Aberration Test)

GLP compliance:

yes (incl. QA statement)

Type of assay:

in vitro mammalian chromosome aberration test

Test material

Test material information

Constituent 1

Reference substance name:

Donor C20

IUPAC Name:

Donor C20

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Method

Species / strain

Species / strain / cell type:

Chinese hamster Ovary (CHO)

Metabolic activation:

with and without

Metabolic activation system:

S9

Test concentrations with justification for top dose:

0, 62.5, 125, and 250 ug/mL

Vehicle / solvent:

DMSO

Details on test system and experimental conditions:

METHOD OF APPLICATION: in medium

DURATION
- Preincubation period: 18 - 21 hours
- Exposure duration: 18 hours without S9, 3 hours in the presence of S9
- Expression time (cells in growth medium): 18 hours


SPINDLE INHIBITOR (cytogenetic assays): colcemid (0.1 ug/mL final concentration)
STAIN (for cytogenetic assays): 2% Giemsa

NUMBER OF REPLICATIONS: 2

NUMBER OF CELLS EVALUATED: 200 well spread metaphases (100 metaphases per culture)

DETERMINATION OF CYTOTOXICITY
- Method: visual - turbid cells or lack of growth

OTHER EXAMINATIONS:
- Determination of polyploidy: yes
- Determination of endoreplication: yes
- Other: structural chromosome and chromatid aberrations, interstitial deletions, and multiple aberrations

OTHER: The Verneir readings of all aberrant metaphases scored were recorded

Evaluation criteria:

A test is considered to be positive if the aberration yield at at least one concentration is significantly above the concurrent control frequencies.

A test is considered to be negative if there is no significant increase in aberration frequency at any dose level, above the concurrent control frequencies.

A chemical is designated as a clastogen (chromosome breaking agent) if a positive result is obtained in both of two sets.

A chemical is designated as not-clastogenic if a negative result is obtained in both of two tests, one of which utilises two sampling times.

Gaps are recorded separately and not included in the final assessment of clastogenic activity.

Both statistitcal significance and biological relevance are considered together in the evaluation of the results.

Statistics:

Fisher's exact probability test (two-sided)

Results and discussion

Test results

Test results 1

Species / strain:

Chinese hamster Ovary (CHO)

Metabolic activation:

with

Genotoxicity:

positive

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 2

Species / strain:

Chinese hamster Ovary (CHO)

Metabolic activation:

without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: all strains/cell types tested

Applicant's summary and conclusion

Conclusions:

From the aforementioned findings of the chromosome aberration assay it is concluded that 9,9 -bis(methoxymethyl)fluorene is clastogenic in the presence of S-9 mix under the conditions used in the study.