Benzene, C20-24 (even numbered) sec-alkyl derivs.

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in mammalian cells

Remarks:

Type of genotoxicity: gene mutation

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: GLP study reported in peer-reviewed journal article.

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

1992

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 476 (In Vitro Mammalian Cell Gene Mutation Test)

Version / remarks:

HGPRT point mutation

GLP compliance:

yes

Type of assay:

mammalian cell gene mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Alkylate 225

IUPAC Name:

Alkylate 225

Constituent 2

Reference substance name:

Benzene, C10 -16 alkyl derivs.

IUPAC Name:

Benzene, C10 -16 alkyl derivs.

Details on test material:

- Composition of test material, percentage of components: <1% C9, 11% C10, 27% C11, 51% C12, 11% C13, 1% C14; average C11.84
- Analytical purity: 98.5%

Method

Species / strain

Species / strain / cell type:

Chinese hamster Ovary (CHO)

Metabolic activation:

with and without

Metabolic activation system:

S9 from aroclor 1254 induced rat liver

Test concentrations with justification for top dose:

100-2000 microliter/mL

Vehicle / solvent:

ethanol

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Positive controls:

yes

Positive control substance:

other: ethylmethanesulfonate, benzo(a)pyrene, dimethylnitrosamine

Evaluation criteria:

A response was considered positive if one of the three highest concentrations with survival of at least 10% had a mean mutation frequency significantly greater than that of controls, and if there was a dose-response relationship.

Statistics:

Student's t-test was used to compare mutation frequency. Dose-response was analyzed using one-way analysis of variance.

Results and discussion

Test results

Species / strain:

Chinese hamster Ovary (CHO)

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

0.5 mg/mL both with and without activation

Additional information on results:

No significant increase in mutation frequency was seen in the treatment groups.

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

Mutagenicity

Concentration	Mutagenicity (mutation frequency x 10^-6)
Without S9
100	2.2
150	-
250	-
500	2.3
750	-
1000	3.0
1100	13.2
1250	1.1
1500	1.6
1750	-
2000	-
Solvent control	3.5
Ethyl methanesulfonate	237.9
5% S9
100	0.4
500	0.8
1000	8.1
1250	3.7
1500	0.8
1750	-
2000	-
Solvent control	4.3
DMN	202.8

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative

Negative for mutagenicity in CHO/HGPRT assay.

Executive summary:

This study examined the potential of the test substance to cause mutations in mammalian cells. Chinese hamster ovary cells were exposed to concentrations of 100-2000 microliter/mL of test substance both in the presence and absence of metabolic activation. Ethanol was used as a vehicle. Ethylmethanesulfonate, benzo(a)pyrene, and dimethylnitrosamine were used as positive controls. Cytotoxicity was seen at concentrations of 0.5 mg/mL and above both with and without metabolic activation. No significant increase in mutation frequencies was seen in treatment groups. The test substance is not mutagenic to mammalian cells.