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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
Study period:
1992
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Remarks:
GLP, OECD Guideline 473 study.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1992
Report Date:
1992

Materials and methods

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

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Specific details on test material used for the study:
Because borated glycol ethers hydrolyse very rapidly in water, this substance can be considered a mixture of the parent glycol ethers and boric acid for the purpose of in vivo studies. On this basis, this substance can be considered to be 70-90% tri and tetraethylene glycol methyl ether.

Method

Target gene:
not applicable
Species / strain
Species / strain / cell type:
Chinese hamster Ovary (CHO)
Details on mammalian cell type (if applicable):
CHO-K1 cells were obtained from BIBRA, Surrey. Passage number was between 31 and 41. Cultures were sampled to confirm absence of mycoplasma contamination.
Additional strain / cell type characteristics:
not specified
Metabolic activation:
with and without
Metabolic activation system:
S9
Test concentrations with justification for top dose:
In absence of S9: 0, 10, 100, 250, 500, 1000, 1875, 2000, 3000, 4000, and 5000 micrograms/mL
In presence of S9: 0, 100, 200, 400, 937.5, 1500, 1875, 2000, 3000, 4000, and 5000 micrograms/mL
Vehicle / solvent:
0.47% methanol in test medium
Controls
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
benzo(a)pyrene
Remarks:
Migrated to IUCLID6: methyl methanesulfonate was used in absence of S9
Details on test system and experimental conditions:
Cell cultures were grown in medium containing the test substance or controls for 3 hours in the presence of S9, or for 24 hours in the absence of S9 mix. Metaphase cells were prepared on glass slides 24 hours after the start of test material exposure for both + and - S9 cultures.
Evaluation criteria:
Statistical significance compared with concurrent untreated control cultures.
Statistics:
Fisher's Exact Test (p < 0.05)

Results and discussion

Test results
Species / strain:
Chinese hamster Ovary (CHO)
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity nor precipitates, but tested up to recommended limit concentrations
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Remarks on result:
other: strain/cell type: CHO-K1
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

Metaphase chromosome analysis of CHO cells – without metabolic activation – experiment 1

Concentration ug/ml

# cells examined for abberations

Percentage of polyploid cells

# cells with abberations

Untreated control

198

1

0

Solvent control

199

0.5

0

250

200

0

0

1000

198

1

0

1875

200

0

0

MMS

181

0.55

48

 

Metaphase chromosome analysis of CHO cells – without metabolic activation – experiment 2

Concentration ug/ml

# cells examined for abberations

Percentage of polyploid cells

# cells with abberations

Untreated control

200

0

0

Solvent control

197

1.5

3

1500

199

0.5

1

3000

198

1

2

5000

196

2

0

MMS

196

2

61

 

Metaphase chromosome analysis of CHO cells – with metabolic activation – experiment 1

Concentration ug/ml

# cells examined for abberations

Percentage of polyploid cells

# cells with abberations

Untreated control

200

0

1

Solvent control

200

0

1

250

200

0

0

1000

199

0.5

0

1875

200

0

0

BP

147

1.34

25

 

Metaphase chromosome analysis of CHO cells – with metabolic activation – experiment 2

Concentration ug/ml

# cells examined for abberations

Percentage of polyploid cells

# cells with abberations

Untreated control

200

0

0

Solvent control

199

0.5

2

1500

200

0

3

3000

200

0

1

5000

200

0

0

BP

200

0

38

Applicant's summary and conclusion

Conclusions:
Interpretation of results: negative

Brake fluid DOT 4 was negative in this in vitro chromosomal aberration study using CHO cells.
Executive summary:

Brake Fluid DOT 4, a mixture primarily of borated and unborated triethylene glycol methyl ether, was tested for potential to cause chromosomal aberrations (CA) in cultured Chinese hamster ovary cells (CHO), at concentrations up to 5000 micrograms/mL, in the presence or absence of S9 mix. No treatment-related increase in incidence of chromosomal aberrations was observed with the test substance. Positive controls benzo(a)pyrene, and methylmethanesulfonate showed significantly increased CA formation.