Registration Dossier

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
Report Date:
2018

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
no
GLP compliance:
yes (incl. certificate)
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent

Method

Target gene:
HIS (for S.typhimurium) and TRYP (for 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:
S9 mix (microsome fraction prepared from Sprague Dawley rat liver homogenate)
Test concentrations with justification for top dose:
Assay 1: 50, 150, 500, 1500 and 5000 ug/plate
Assay 2: 50, 150, 500, 1500, 2500 and 5000 ug/plate
Vehicle / solvent:
Water
Controls
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True 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:
Preliminary cytotoxicity testing on strain S.typhimurium TA100
Mutagenic assay composed of one assay without metabolic activation and one assay with metabolic activation (If the first assay is positive, the second one is performed in the same manner. If the first assay, in presence of test item, is negative, the pre-incubation test is performed for the second assay).
Rationale for test conditions:
According to OECD guideline
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 resultsopen allclose all
Key result
Species / strain:
S. typhimurium TA 1535
Metabolic activation:
without
Genotoxicity:
positive
Remarks:
from 1500 to 5000 ug/plate
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Key result
Species / strain:
S. typhimurium TA 1537
Metabolic activation:
without
Genotoxicity:
positive
Remarks:
from 1500 to 5000 ug/plate
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Key result
Species / strain:
S. typhimurium TA 98
Metabolic activation:
without
Genotoxicity:
positive
Remarks:
from 1500 to 5000 ug/plate
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Key result
Species / strain:
S. typhimurium TA 100
Metabolic activation:
without
Genotoxicity:
positive
Remarks:
from 1500 to 2500 ug/plate
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Key result
Species / strain:
E. coli WP2 uvr A pKM 101
Metabolic activation:
without
Genotoxicity:
positive
Remarks:
from 1500 to 5000 ug/plate
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Key result
Species / strain:
S. typhimurium TA 1535
Metabolic activation:
with
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Key result
Species / strain:
S. typhimurium TA 1537
Metabolic activation:
with
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Key result
Species / strain:
S. typhimurium TA 98
Metabolic activation:
with
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Key result
Species / strain:
S. typhimurium TA 100
Metabolic activation:
with
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Key result
Species / strain:
E. coli WP2 uvr A pKM 101
Metabolic activation:
with
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid

Applicant's summary and conclusion

Conclusions:
Suspensions of the test item Gamma Chrome induce a mutagenic change in Salmonella typhimurium TA 1535, TA 1537, TA 98, TA 100 and in Escherichia coli WP2(uvrA¯) (pKM 101) without activation, according to the OECD Guidelines n° 471.