1,4-dibromonaphthalene

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

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:

1,4-dibromonaphthalene

EC Number:

201-484-8

EC Name:

1,4-dibromonaphthalene

Cas Number:

83-53-4

Molecular formula:

C10H6Br2

IUPAC Name:

1,4-dibromonaphthalene

Method

Target gene:

Histidine (for Salmonella typhimurium) and Tryptophane (for Escherichia 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:

S9 fraction, microsome fraction prepared from Sprague Dawley rat liver homogenate

Test concentrations with justification for top dose:

50, 150, 500, 1500 and 5000 ug/plate

Vehicle / solvent:

DMSO

Controls

Untreated negative controls:

yes

Positive controls:

yes

Positive control substance:

7,12-dimethylbenzanthracene

9-aminoacridine

2-nitrofluorene

sodium azide

other: 2-anthramine and cis-Platinum (II) Diammine Dichloride

Details on test system and experimental conditions:

The genotype of bacterial strains is checked:
-Histidine and tryptophane requirements with cultures in presence and in absence of L-histidine and L-triptophane for Salmonella typhimurium and Escherichia coli strains respectively.
-Loss of cell wall LPS (rfa mutation) measuring crystal violet inhibition for Salmonella typhimurium strains.
-Ampicillin resistance for the strains which have the pKM 101 plasmide.
-delta-uvr B mutation i.e. U.V.B sensitivity for Salmonella typhimurium and delta-uvr A mutation i.e. U.V.A sensitivity for Escherichia coli.
-Spontaneous revertant rate.
-Sensitivity to reference mutagens

Evaluation criteria:

Ensure that the criteria of validity of the study are well respected namely :
- the bacteriostatic activity of the highest concentration tested shall be equal to or less than 75 %,
- the spontaneous reversion rate of the absolute negative control shall comply with the historical values of the laboratory,
- the spontaneous reversion rate of the solvent shall not be statistically different from absolute negative control,
- the mean number of revertant colonies obtained for each strain and the corresponding positive control, with and/or without metabolic activation shall comply with the historical values of the laboratory.
- Negative and positive values should not show significant difference with the historical values of the laboratory (± 2 standard deviations).

Results and discussion

Test results

Test results 1

Key result

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 2

Key result

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 3

Key result

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 4

Key result

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 5

Key result

Species / strain:

E. coli WP2 uvr A pKM 101

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Untreated negative controls validity:

valid

Positive controls validity:

valid

Applicant's summary and conclusion

Conclusions:

Doses (5 000, 1 500, 500, 150 and 50 μg/plate) prepared from solutions of the test item 1,4-DIBROMONAPHTHALENE do not induce any mutagenic change in Salmonella typhimurium TA 1535, TA 1537, TA 98, TA 100 and in Escherichia coli WP2(uvrA¯) (pKM 101) without, or with metabolic activation, according to the OECD Guidelines n° 471.