Hydrocarbons, C7-C9, n-alkanes, isoalkanes, cyclics

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 based on grouping of substances (category approach)

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Acceptable, well documented publication which meets basic scientific principles

Data source

Reference

Reference Type:

publication

Title:

Assessment of the genotoxic potential of unleaded gasoline and 2,2,4-trimethylpentane in human lymphoblasts in vitro.

Author:

Richardson, K. et al.

Year:

1986

Bibliographic source:

Toxicol Appl Pharmacol 82: 316-322

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Deviations:

yes

Remarks:

- using microtiter plates

GLP compliance:

not specified

Type of assay:

mammalian cell gene mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

2,2,4-trimethylpentane

EC Number:

208-759-1

EC Name:

2,2,4-trimethylpentane

Cas Number:

540-84-1

IUPAC Name:

2,2,4-trimethylpentane

Details on test material:

- Name of test material (as cited in study report): 2,2,4-trimethylpentane (TMP; isooctane)
- Analytical purity: no data

Method

Target gene:

thymidine kinase

Species / strain

Species / strain / cell type:

human lymphoblastoid cells (TK6)

Details on mammalian cell type (if applicable):

- Type and identity of media: RPMI 1640 medium supplemented with 15% heat-inactivated horse serum

Additional strain / cell type characteristics:

not specified

Metabolic activation:

with and without

Metabolic activation system:

with Aroclor induced-rat liver homogenate

Test concentrations with justification for top dose:

5 % v/v TMP in DMEM medium, administered undiluted or as 50 % (1:1 saturated to normal medium)

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMEM medium

Controls

Controls 1

Untreated negative controls:

yes

Remarks:

with and without S9

Negative solvent / vehicle controls:

yes

Remarks:

DMEM medium

Positive controls:

yes

Remarks:

for S9 activated cultures

Positive control substance:

benzo(a)pyrene

Remarks:

Migrated to IUCLID6: 15 µM

Controls 2

Untreated negative controls:

yes

Remarks:

with and without S9

Negative solvent / vehicle controls:

yes

Remarks:

DMEM medium

Positive controls:

yes

Remarks:

for non-activated cultures

Positive control substance:

ethylmethanesulphonate

Remarks:

Migrated to IUCLID6: 0.2 mM

Details on test system and experimental conditions:

see "any other information on materials and methods"

Results and discussion

Test results

Species / strain:

human lymphoblastoid cells (TK6)

Metabolic activation:

with and without

Genotoxicity:

negative

Remarks:

TMP did not induce significant increases in the mutation frequency at the thymidine kinase locus.

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

Cell survival in TMP-saturated medium with and without metabolic activation was greater than 50-60 %.

Vehicle controls validity:

not specified

Untreated negative controls validity:

not specified

Positive controls validity:

valid

Additional information on results:

The elevated mutation frequencies of positive control compounds were as expected.

ADDITIONAL INFORMATION ON CYTOTOXICITY:
Cell survival in positive control treated cultures was 40 or 30% for benzo(a)pyrene and EMS, respectively

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

Based on the study design there is no incidence of increased genetic toxicity caused by the test substance.

Executive summary:

Based on the study design there is no incidence of increased genetic toxicity caused by the test substance.