1-bromo-4-propylbenzene

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:

Sep 16-26, 2003

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2004

Report date:

2004

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

1-bromo-4-propylbenzene

EC Number:

454-790-0

EC Name:

1-bromo-4-propylbenzene

Cas Number:

588-93-2

Molecular formula:

Hill formula: C9H11Br CAS formula: C9H11Br

IUPAC Name:

1-bromo-4-propylbenzene

Test material form:

other: oily liquid

Method

Target gene:

HIS operon (S. thyphimurium)
TRY operon (E. coli)

Species / strain

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2

Metabolic activation:

with and without

Metabolic activation system:

Aroclor-induced rat liver S-9mix

Test concentrations with justification for top dose:

Concentration range in the main test (with metabolic activation): 5, 15.8, 50, 158, 1580, 5000 µg/plate
Concentration range in the main test (without metabolic activation): 50, 158, 500, 1580, 5000 µg/plate

Vehicle / solvent:

Solvent: acetone

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

9-aminoacridine

N-ethyl-N-nitro-N-nitrosoguanidine

benzo(a)pyrene

cumene hydroperoxide

other: Daunomycin, 2-Aminoanthracene

Details on test system and experimental conditions:

The assessment of test material-induced effects is dependent on the number of spontaneous revertants of each bacterial strain (solvent controls) and the increase in the number of revertants at the test material concentration which shows the highest number of colonies.
The following criteria, based upon the historical controls of the laboratory and statistical considerations,
are established:

-----------------------------------------------------------------------------------------
Mean Number of Colonies Maximal Mean Number of Colonies over the Actual
(Solvent Control) Solvent Control
(Test Material)
-----------------------------------------------------------------------------------------

<=10 <=9 >=30
<=30 <=19 >=40
<=80 <=29 >=80
<=200 <=49 >=120
<=500 <=79 >=200
Assessment No increase Clear increase

-----------------------------------------------------------------------------------------

All further results, ranging between "no" and "clear", are assessed as "weak increases".
Interpretations:
A test material is defined as non-mutagenic in this assay if "no" or "weak increases" occur in the first and second series of the main experiment.
("Weak increases" randomly occur due to experimental variation.)

A test material is defined as mutagenic in this assay if:

- a dose-related (over at least two test material concentrations) increase in the number of revertants is induced, the maximal effect is a "clear increase", and the effects are reproduced at similar concentration levels in the same test system;

- "clear increases" occur at least at one test material concentration, higher concentrations show strong precipitation or cytotoxicity, and the effects are reproduced at the same concentration level in the same test system.

Evaluation criteria:

see datails on test system

Results and discussion

Test results

Test results 1

Key result

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

True negative controls validity:

not examined

Positive controls validity:

valid

Test results 2

Key result

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

True negative controls validity:

not examined

Positive controls validity:

valid

Test results 3

Key result

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

True negative controls validity:

not examined

Positive controls validity:

valid

Test results 4

Key result

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

True negative controls validity:

not examined

Positive controls validity:

valid

Test results 5

Key result

Species / strain:

E. coli WP2

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

True negative controls validity:

not examined

Positive controls validity:

valid

Additional information on results:

Precipitation of the test material on the agar plates occurred at a concentration of 5000 µg/plate. Toxicity to the bacteria was not observed.

Any other information on results incl. tables

Two independent experimental series were performed. In the two series with S9 mix, 10 or 30 % S9 mix were used in the 1st and 2nd series, respectively.

Applicant's summary and conclusion

Conclusions:

With and without addition of S9 mix as the external metabolizing system, the test material was not mutagenic under the experimental conditions described.

Executive summary:

Study Design

The GLP compliant study was performed in accordance with OECD Guideline 471 (adopted 1997). The investigations for mutagenic potential were performed using Salmonella typhimurium tester strains TA 98, TA 100, TA 102, TA 1535 and TA 1537, and Escherichia coli WP2 uvrA. The plate incorporation test with and without addition of liver S9 mix from Aroclor 1254 -pretreated rats was used. Two independent experimental series were performed. In the two series with S9 mix, 10 % and 30 % S9 in the S9 mix were used in the 1^stand 2^ndseries, respectively.

Results

The test item  was dissolved in acetone and tested at concentrations ranging from 5 to 5000 µg/plate. Precipitation of the test material on the agar plates occurred at a concentration of 5000 µg/plate. Toxicity to the bacteria was not observed.

Daunomycin, N-ethyl-N`-nitro-N-nitrosoguanidine, 9-aminoacridine and cumene hydroperoxide served as strain specific positive control compounds in the absence of S9 mix. 2 -Aminoanthracene and benzo[a]pyrene were used for testing the bacteria and the activity of the S9 mix. Each treatment with the substances used as positive controls led to a clear increase in revertant colonies, thus, showing the expected reversion properties of all strains and good metabolic activity of the S9 mix used.
In both series of experiments, each performed with and without the addition of rat liver S9 mix as the external metabolizing system, the test material showed no increase in the number of revertants of any bacterial strain
Thus, the test item was not mutagenic under the described experimental conditions.

Conclusion

With and without addition of S9 mix as the external metabolizing system, the test material was not mutagenic under the experimental conditions described.