Reaction mass of butane and butene

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 from supporting substance (structural analogue or surrogate)

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 & Matsushima T

Year:

1994

Bibliographic source:

Mutation Research, 307, 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:

2-butene

EC Number:

203-452-9

EC Name:

2-butene

Cas Number:

107-01-7

IUPAC Name:

but-2-ene

Details on test material:

2-butene 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): none (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, buta,-1,3-diene was used as a positive substance & the data presented indicates that an air control was used

Details on test system and experimental conditions:

Mutagenicity testing was performed by the gas exposure method using a gas sampling bag with or without metabolic activation. The exposure condition was : bacterial plates 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 gas was 500 mL per plate. Tests were performed at toxic concentration levels or about 50% levels as the maximum concentration.

The conditions listed above were chosen based on 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, which corresponded to 14, 8, 4, 2 or 1 plates/bag), the amount of S9 (50, 100, 200 or 400 µL/plate), the exposure temperature (30 or 37°C), exposure period (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:

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

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:

not specified

Untreated negative controls validity:

not specified

Positive controls validity:

not specified

Test results 2

Species / strain:

E. coli WP2 uvr A

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:

not specified

Untreated negative controls validity:

not specified

Positive controls validity:

not specified

Additional information on results:

none

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 with metabolic activation
negative without metabolic activation

2 -Butene was not mutagenic, with and without metabolic activation, in S. Typhimurium strains: TA 1535, TA 1537, TA 98 and TA 100 and E. Coli WP2 uvr A.

Executive summary:

2-butene was not mutagenic to S Typhimurium TA98, TA100, TA1535, TA 1537 and E.coli WP2uvrA, with or without metabolic activation, using a gas sampling bag method. Concentrations were not specified but tests were carried out at increasing levels until toxicity was observed. Buta-1,3-diene was mutagenic under these conditions indicating that the method was robust.