Distillates (petroleum), steam-cracked, C8-12 fraction

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

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: Non-GLP, non-guideline study, published in peer reviewed literature, minor restrictions in design and/or reporting but otherwise adequate for assessment

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

reference to same study

Cross-reference 2

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

publication

Title:

Improved method for mutagenicity testing of gaseous compounds by using a gas sampling bag.

Author:

Araki A, Noguchi T, Kato F and Matsushima T

Year:

1994

Bibliographic source:

Mutation Research, Vol 307, pp 335-344

Materials and methods

Test guideline

Qualifier:

no guideline followed

Deviations:

not applicable

Principles of method if other than guideline:

Mutagenicity test on S. Typhimurium TA98, TA100, TA1535 and TA1537 and E. Coli WP2 uvrA using the developed gas exposure method (using a gas sampling bag as an exposure vessel and a preparation vessel of diluted gas).

GLP compliance:

not specified

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

1,3-butadiene

IUPAC Name:

1,3-butadiene

Details on test material:

1,3-Butadiene was obtained from Tokyo Kasei Co. Ltd, Tokyo, Japan.

Method

Target gene:

Not applicable

Species / strain

Species / strain 1

Species / strain / cell type:

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

Additional strain / cell type characteristics:

not specified

Species / strain 2

Species / strain / cell type:

E. coli WP2 uvr A

Additional strain / cell type characteristics:

not specified

Metabolic activation:

with and without

Metabolic activation system:

S9 from Phenobarbitol and 5,6-benzoflavone induced rat liver

Test concentrations with justification for top dose:

Toxic concentration levels or about 50% of the maximum exposure concentration.

Vehicle / solvent:

- Vehicle(s)/solvent(s):diluted by HEPA-filtered air

Controls

Untreated negative controls:

not specified

Negative solvent / vehicle controls:

not specified

True negative controls:

not specified

Positive controls:

not specified

Positive control substance:

not specified

Remarks:

The objective was to develop an improved method for testing gases. Use of standard positive and negative control substances was not stated, but the data presented indicates that that an air control was used.

Details on test system and experimental conditions:

1,3-butadiene was used as a positive control for mutagenicity testing by the gas exposure method using a gas sampling bag with or without metabolic activation. Bacterial plates were made by the agar overlay method with 2mL top agar per plate, 100 µl of S9 per plate, exposure temperature of 37°C, exposure period of 48 h and exposure volume of 500 mL gas per plate. Tests were performed at toxic concentration levels or about 50% levels as the maximum exposure concentration

The above conditions were selected on the basis of the results of a preliminary study with 1,3-butadiene in which the effect of the volume of gas per plate (357, 625, 1250, 2500 or 5000 ml/plate, corresponding to 14, 8, 4, 2 or 1 plates/bag), the amount of S9 (50, 100, 200 or 400 microlitres/plate), the exposure temperature (30 or 37 degrees C), exposure time (2, 4, 14, 24 or 48 hours), the amount of top agar (0, 1, or 2 mL/plate) were examined.

Evaluation criteria:

After incubation, the number of revertant colonies was counted.

Statistics:

None

Results and discussion

Test results

Test results 1

Species / strain:

other: S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2 uvr A

Metabolic activation:

without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity nor precipitates, but tested up to recommended limit concentrations

Vehicle controls validity:

not specified

Untreated negative controls validity:

not specified

Positive controls validity:

not specified

Test results 2

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with

Genotoxicity:

positive

Cytotoxicity / choice of top concentrations:

no cytotoxicity nor precipitates, but tested up to recommended limit concentrations

Vehicle controls validity:

not specified

Untreated negative controls validity:

not specified

Positive controls validity:

not specified

Test results 3

Species / strain:

other: S. typhimurium TA 1537, TA 98, TA 100 and E. coli WP2 uvr A

Metabolic activation:

with

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity nor precipitates, but tested up to recommended limit concentrations

Vehicle controls validity:

not specified

Untreated negative controls validity:

not specified

Positive controls validity:

not specified

Additional information on results:

1,3-butadiene caused a dose-related marginal increase in revertants in TA 100 in the presence of S9 but this was classified as a negative result.

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

none

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative without metabolic activation
positive with metabolic activation

1,3-butadiene was mutagenic in S. typhimurium strain TA1535 in the presence of metabolic activation.

Executive summary:

1,3 -butadiene was tested for mutagenicity, with and without metabolic activation, in S. typhimirium strains: TA 1535, TA 1537, TA 98 and TA 100 andE. Coli WP2 uvr A, using gas sampling bags as both exposure and preparation vessels.

It was not mutagenic to S. typhimurium TA98, TA100, TA1535, TA 1537 and E.coli WP2uvrA without metabolic activiation or to S. typhimurium TA98, TA 1537 and E.coli WP2uvrA with metabolic activation.

1,3 -butadiene was mutagenic to S. typhimurium TA1535 with metabolic activation.

There was a dose-related marginal increase in revertant colonies in S. typhimurium TA100 under the same conditions which was classified as a negative result by the authors of the report.