Phenolates from Hydrocarbon Resin production

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro cytogenicity / micronucleus study

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Remarks:

Final OECD Guideline 487 not yet available.

Data source

Reference

Reference Type:

publication

Title:

Evaluation of the micronucleus test in vitro using Chinese hamster cells: Results of four chemicals weakly positive in the In vivo micronucleus test

Author:

Miller, B.M.; Pujadas, E.; Gocke, E.

Year:

1995

Bibliographic source:

Environ. Mol. Mutagen., 26, 240-247

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 487 (In vitro Mammalian Cell Micronucleus Test)

Deviations:

no

GLP compliance:

not specified

Type of assay:

in vitro mammalian cell micronucleus test

Test material

Test material information

Constituent 1

Reference substance name:

Phenol

EC Number:

203-632-7

EC Name:

Phenol

Cas Number:

108-95-2

Molecular formula:

C6H6O

IUPAC Name:

phenol

Specific details on test material used for the study:

- Source: Sigma Chemical Co. (St. Louis, MO, USA).
- Analytical purity: ca. 99%
- Impurities (identity and concentrations): no data
- Lot/batch No.: Lot 71663
- Stability under test conditions: stable in aqueous solution

Method

Target gene:

Chromosomes

Species / strain

Species / strain / cell type:

Chinese hamster Ovary (CHO)

Metabolic activation:

with and without

Metabolic activation system:

S9 liver fraction of phenobarbital\beta-naphthoflavone-induced rats

Vehicle / solvent:

water / medium

Controls

Negative solvent / vehicle controls:

yes

Positive controls:

yes

Positive control substance:

other: bleomycin (-S9) / cyclophosphamide (+S9)

Details on test system and experimental conditions:

METHOD OF APPLICATION:
in medium
DURATION
- Preincubation period: 24 h
- Exposure duration: in fresh medium plus test substance for 48 h (without S9) or plus test substance plus S9 system for 3 h, aftrer washing with PBS the latter incubated for further 45 h in fresh medium.
- Fixation: with methanol containing I% acetic acid
NUMBER OF REPLICATIONS: minimal, two parallel cultures, two independent trials each
NUMBER OF CELLS EVALUATED for MN: 1000 per culture
DETERMINATION OF CYTOTOXICITY: phenol tested up to concentrations with signs of toxicity
DETERMINATION of micronuclei: Slides with cells air-dried, then treated with RNAse, after washing and air-drying, stained with 5% Giemsa.
Mononucleated cells with well-preserved cytoplasm containing five or fewer MN were scored (without apoptosis or nuclear fragmentation).

Evaluation criteria:

positive result: a dose-related effect at an increase in MN frequency at least 3 times above the control.

Statistics:

no data

Results and discussion

Test results

Key result

Species / strain:

Chinese hamster Ovary (CHO)

Metabolic activation:

with and without

Genotoxicity:

positive

Remarks:

at cytotoxic levels

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Applicant's summary and conclusion

Conclusions:

weakly positive at cytotoxic exposure concentrations.