Registration Dossier

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:
Aug 22 - Oct 01, 2012
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2014
Report Date:
2014

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)
Deviations:
no
Principles of method if other than guideline:
None
GLP compliance:
yes (incl. certificate)
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid

Method

Target gene:
HIS operon (S. thyphimurium)
TRY operon (E. coli)
Species / strainopen allclose all
Species / strain / cell type:
S. typhimurium TA 1535
Details on mammalian cell type (if applicable):
his G 46, uvrB, rfa
Additional strain / cell type characteristics:
other: mutations in the histidine operon
Species / strain / cell type:
S. typhimurium TA 1537
Details on mammalian cell type (if applicable):
his C 3076, uvrB, rfa
Additional strain / cell type characteristics:
other: mutations in the histidine operon
Species / strain / cell type:
S. typhimurium TA 98
Details on mammalian cell type (if applicable):
his D 3052, uvrB, rfa + R-factor
Additional strain / cell type characteristics:
other: mutations in the histidine operon
Species / strain / cell type:
S. typhimurium TA 100
Details on mammalian cell type (if applicable):
his G 46, uvrB, rfa + R-factor
Additional strain / cell type characteristics:
other: mutations in the histidine operon
Species / strain / cell type:
E. coli WP2
Details on mammalian cell type (if applicable):
his C 3076, uvrB, rfa
Additional strain / cell type characteristics:
other: mutations in the tryptophan operon
Metabolic activation:
with and without
Metabolic activation system:
rat liver homogenate (S9 mix) with standard co-factors with metabolic activation (Aroclor 1254)
Test concentrations with justification for top dose:
The test material concentrations were used selected according to the EC and OECD guidelines for this test system and the requirements of the Labor Ministry of Japan:
1. Series: 5, 15.8, 50, 158, 500, 1580, and 5000 µg/plate
2. Series: 1.58, 5.00, 15.8, 50.0, 88.9, 158, and 500 µg/plate
Vehicle / solvent:
Acetone
Controls
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
4-nitroquinoline-N-oxide
9-aminoacridine
sodium azide
benzo(a)pyrene
other: 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 in-crease 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 in-creases".
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.

In all further cases, a third test series with the bacterial strain in question should be performed.
If the criteria for a positive test result are not fulfilled in at least two out of the three series, the test material is defined as being non-mutagenic in this test system.
Evaluation criteria:
-----------------------------------------------------------------------------------------
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

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

Results and discussion

Test resultsopen allclose all
Key result
Species / strain:
S. typhimurium TA 1535
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
in the first series
Vehicle controls validity:
valid
Untreated negative controls validity:
not examined
True negative controls validity:
not examined
Positive controls validity:
valid
Key result
Species / strain:
S. typhimurium TA 98
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity, but tested up to precipitating concentrations
Vehicle controls validity:
valid
Untreated negative controls validity:
not examined
True negative controls validity:
not examined
Positive controls validity:
valid
Key result
Species / strain:
S. typhimurium TA 1537
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity, but tested up to precipitating concentrations
Vehicle controls validity:
valid
Untreated negative controls validity:
not examined
True negative controls validity:
not examined
Positive controls validity:
valid
Key result
Species / strain:
S. typhimurium TA 100
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
in the first series
Vehicle controls validity:
valid
Untreated negative controls validity:
not examined
True negative controls validity:
not examined
Positive controls validity:
valid
Key result
Species / strain:
E. coli WP2 uvr A
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity, but tested up to precipitating concentrations
Vehicle controls validity:
valid
Untreated negative controls validity:
not examined
True negative controls validity:
not examined
Positive controls validity:
valid

Applicant's summary and conclusion

Conclusions:
The test material was not mutagenic under the test conditions with and without metabolic activation from induced rat liver S9 mix.
Executive summary:

This study was performed according to GLP and the methods applied are fully compliant with OECD TG 471. The test material was not mutagenic under the test conditions with and without metabolic activation from induced rat liver S9 mix.