Hydrocarbons, C10, aromatics, <1% naphthalene

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Remarks:

Type of genotoxicity: gene mutation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1998/11/05-1999/01/25

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: According to OECD 471 guidelines. GLP.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1999

Report date:

1999

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

no

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Hydrocarbons, C10, aromatics, <1% naphthalene

EC Number:

918-811-1

Cas Number:

64742-94-5

Molecular formula:

None available - not a single isomer - see remarks

IUPAC Name:

Hydrocarbons, C10, aromatics, <1% naphthalene

Method

Species / strain

Species / strain 1

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98 and TA 100

Species / strain 2

Species / strain / cell type:

S. typhimurium TA 102

Metabolic activation:

with and without

Metabolic activation system:

S9 liver fractions from Aroclor exposed rats

Test concentrations with justification for top dose:

Tests (done in triplicate) with and without Metabolic Activation: 0, 6.25, 12.5, 25, 50, 100, 200 ug/plate
Positive controls:
TA 1535 (S9-: sodium azide 1.0 ug/plate) (S9+: 2-aminoanthracene: 2.0 ug/plate)
TA 1537 (S9-: 9-aminoacridine 80 ug/plate) (S9+: benzo(a)pyrene: 4.0 ug/plate)
TA 98 (S9-: 2-nitrofluorene 2.0 ug/plate) (S9+: 2-aminoanthracene: 2.0 ug/plate)
TA 100 (S9-: sodium azide 1.0 ug/plate) (S9+: 2-aminoanthracene: 2.0 ug/plate)
TA102 (S9-: glutaraldehyde 25 ug/plate)

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

yes

Remarks:

non treated

Positive controls:

yes

Positive control substance:

other: See Test Concentrations

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar
DURATION
- Exposure duration: 48 hours


NUMBER OF REPLICATIONS:
- triplicate

DETERMINATION OF CYTOTOXICITY
- Method: reduction in the number of revertants and/or clearing of the background lawn of bacterial growth

Evaluation criteria:

The mutagenicity study is considered valid if the mean colony counts of the control values of the strains are within acceptable ranges, if the positive controls meet the criteria for a positive response and if no more than 5% of the plates are lost through contamination or other unforeseen events.

A test substance is considered to be positive in the bacterial gene mutation test if the mean number of revertant colonies on the test plates increases in a concentration-related manner and/or if a reproducible, two-fold or more increase is observed compared to that on the negative control plates.

A test substance is considered negative in the bacterial gene mutation test if it produces neither a dose-related increase in the mean number of revertant colonies nor a reproducible positive response at any of the test points.

Positive results from the bacterial reverse mutation test indicate that a substance induces point mutations by base substitution for frameshifts in the genome of Salmonella typhimurium. Negative results indicate that under the test conditions, the test substance in not mutagenic.

Statistics:

The mean plate count and standard deviation for each dose point were determined. Any test value that was equal to or greater than two times the mean value of the concurrent vehicle control was considered to be a positive dose.

Results and discussion

Test results

Key result

Species / strain:

S. typhimurium TA 1535, TA 1537, TA 98 and TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

Toxicity was observed at doses above 200 ug/plate with and without S9.

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Applicant's summary and conclusion

Conclusions:

Interpretation of results: negative

In all cases, Shellsol AB did not induce any significant changes in the number of revertant colonies. It is concluded in this study that Shellsol AB is not a mutagenic agent.

Executive summary:

Shellsol AB was examined for mutagenic activity in the bacterial reverse mutation test using histidine-requiring Salmonella typhimurium strains TA 1535, 1537, 98, 102,and 100 in the absence and presence of a liver S9 fraction for metabolic activation. Concentrations above 200 ug/plate were found to be cytotoxic and so the test was performed in triplicate using doses of 0, 6.25, 12.5, 25, 50, 100, 200 ug/plate. In all cases, Shellsol AB did not induce any significant changes in the number of revertant colonies.  It is concluded in this study that Shellsol AB is not a mutagenic agent.