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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)
GLP compliance:
yes (incl. QA statement)
Type of assay:
bacterial reverse mutation assay

Test material

Constituent 1
Chemical structure
Reference substance name:
Reaction products of acrylonitrile and 2-methylcyclohexane-1,3-diamine and 4-methylcyclohexane-1,3-diamine, hydrogenated
EC Number:
948-816-4
Molecular formula:
C13H30N4
IUPAC Name:
Reaction products of acrylonitrile and 2-methylcyclohexane-1,3-diamine and 4-methylcyclohexane-1,3-diamine, hydrogenated
Specific details on test material used for the study:
Test substance No.: 17/0592-1
Batch identification: Bähr63/Dest/F4-5
Homogeneity: The homogeneity of the test substance was ensured by mixing before preparation of the test substance solutions.
Physical state, appearance: liquid, colorless to yellowish, clear

Method

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
Test concentrations with justification for top dose:
33 - 5000 µg/plate
Vehicle / solvent:
water
Controls
Untreated negative controls:
yes
True negative controls:
yes
Positive controls:
yes
Details on test system and experimental conditions:
The test substance Reaction mass of N1,N3-bis(3-aminopropyl)-2-methyl-cyclohexane-1,3-diamine and N1,N3-bis(3-aminopropyl)-4-methyl-cyclohexane-1,3-diamine was tested for its mutagenic potential based on the ability to induce point mutations in selected loci of several bacterial strains, i.e. Salmonella typhimurium and Escherichia coli, in a reverse mutation assay.
Evaluation criteria:
Generally, the experiment was considered valid if the following criteria were met:
• The number of revertant colonies in the negative controls was within the range of the historical negative control data for each tester strain
• The sterility controls revealed no indication of bacterial contamination
• The positive control substances both with and without S9 mix induced a distinct increase in the number of revertant colonies within the range of the historical positive control data or above
• Fresh bacterial culture containing approximately 109 cells per mL were used.


The test substance was considered positive in this assay if the following criteria were met:
• A dose-related and reproducible increase in the number of revertant colonies, i.e. at least doubling (bacteria strains with high spontaneous mutation rate, like TA 98, TA 100 and E.coli WP2 uvrA) or tripling (bacteria strains with low spontaneous mutation rate, like TA 1535 and TA 1537) of the spontaneous mutation rate in at least one tester strain either without S9 mix or after adding a metabolizing system.

A test substance was generally considered non-mutagenic in this test if:
• The number of revertants for all tester strains were within the range of the historical negative control data under all experimental conditions in at least two experiments carried out independently of each other.

Results and discussion

Test resultsopen allclose all
Species / strain:
S. typhimurium TA 1535
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 1537
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 98
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 100
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Species / strain:
E. coli WP2 uvr A
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Additional information on results:
A bacteriotoxic effect (reduced his- or trp- background growth, slight decrease in the number of his+ revertants) was observed in the standard plate test depending on the strain and test conditions from about 5000 μg/plate.

Applicant's summary and conclusion

Conclusions:
A relevant increase in the number of his+ or trp+ revertants (factor ≥ 2: TA 100, TA 98 and E.coli WP2 uvrA or factor ≥ 3: TA 1535 and TA 1537) was not observed in the standard plate test or in the preincubation test without S9 mix or after the addition of a metabolizing system.
Executive summary:

Under the experimental conditions of this study, the test substance Reaction mass of N1,N3 -bis(3-aminopropyl)-2-methyl-cyclohexane-1,3-diamine and N1,N3-bis(3-aminopropyl)-4-methyl-cyclohexane-1,3-diamine is not mutagenic in the Salmonella typhimurium/Escherichia coli reverse mutation assay in the absence and the presence of metabolic activation.

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