Registration Dossier

Diss Factsheets

Toxicological information

Genetic toxicity: in vitro

Currently viewing:

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:
Not stated
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP-guideline study.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1998
Report date:
1998

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Version / remarks:
Salmonella typhimurium
Qualifier:
according to guideline
Guideline:
OECD Guideline 472 (Genetic Toxicology: Escherichia coli, Reverse Mutation Assay)
Version / remarks:
Escherichia coli
Principles of method if other than guideline:
Not relevant
GLP compliance:
yes
Type of assay:
bacterial reverse mutation assay

Test material

Constituent 1
Chemical structure
Reference substance name:
Cyclohexyldimethylamine
EC Number:
202-715-5
EC Name:
Cyclohexyldimethylamine
Cas Number:
98-94-2
Molecular formula:
C8H17N
IUPAC Name:
N,N-dimethylcyclohexanamine
Constituent 2
Reference substance name:
DMCHA
IUPAC Name:
DMCHA
Constituent 3
Reference substance name:
N,N-dimethylcyclohexylamine
IUPAC Name:
N,N-dimethylcyclohexylamine
Details on test material:
- Name of test material (as cited in study report): N,N-dimethylcyclohexylamine
- Test substance no. 96/327
- Physical state: Colourless liquid
- Analytical purity: 99.4 %
- Lot/batch No.: Behalter 508 0619
- Storage condition of test material: Room temperature

Method

Target gene:
Histidine
Species / strainopen allclose all
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Details on mammalian cell type (if applicable):
All strains have a defective excision repair system (uvrB), which prevents the repair of lesions which are induced in the DNA, and this deficiency results in greatly enhanced sensitivity of some mutagens. Furthermore, all strains show a considerably reduced hydrophilic polysaccharide layer (rfa), which leads to an increase in permeability to lipophilic substances.
Additional strain / cell type characteristics:
other: The strains TA 1535 and TA 100 are derived from histidine-prototrophic Salmonella strains by the substitution mutation his G 46 and are used to detect base pair substitutions. TA 1537 and TA 98 are strains for the detection of frameshift mutagens.
Species / strain / cell type:
E. coli WP2 uvr A
Details on mammalian cell type (if applicable):
Escherichia coli WP2 uvrA is a derivative of E . coli WP2 with a deficient excision repair and is used to detect substances which induce base pair
substitutions. The rate of induced back mutations from tryptophan auxotrophy to tryptophan independence is determined.
Additional strain / cell type characteristics:
not specified
Metabolic activation:
with and without
Metabolic activation system:
Arochlor induced rat liver S-9 mix
Test concentrations with justification for top dose:
For the Standard plate test (SPT) the doses were 20, 100, 500, 2500 and 5000 µg/plate, and for the preincubation test (PIT) the doses were 4, 20, 100, 500 and 2500 µg/plate.
Vehicle / solvent:
DMSO for both strains
Controlsopen allclose all
Untreated negative controls:
yes
Remarks:
with and without S-9 mix
Negative solvent / vehicle controls:
yes
Remarks:
DMSO free
Positive controls:
yes
Positive control substance:
other: with S-9 mix: 2.5 µg 2-aminoanthracene
Remarks:
for the strains TA 100, TA 98, TA 1537 and TA 1535
Untreated negative controls:
yes
Remarks:
with and without S-9 mix
Negative solvent / vehicle controls:
yes
Remarks:
DMSO free
Positive controls:
yes
Positive control substance:
other: with S-9 mix: 60 µg 2-aminoanthracene
Remarks:
for the strain E . coli WP2 uvrA
Untreated negative controls:
yes
Remarks:
with and without S-9 mix
Negative solvent / vehicle controls:
yes
Remarks:
DMSO free
Positive controls:
yes
Positive control substance:
other: without S-9 mix: 5 µg N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)
Remarks:
for the strains TA 100 and TA 1535
Untreated negative controls:
yes
Remarks:
with and without S-9 mix
Negative solvent / vehicle controls:
yes
Remarks:
DMSO free
Positive controls:
yes
Positive control substance:
other: without S-9 mix: 10 µg 4-nitro-o-phenylendiamine (NOPD)
Remarks:
for the strain TA 98
Untreated negative controls:
yes
Remarks:
with and without S-9 mix
Negative solvent / vehicle controls:
yes
Remarks:
DMSO free
Positive controls:
yes
Positive control substance:
9-aminoacridine
Remarks:
for the strain TA 1537 Migrated to IUCLID6: without S-9 mix: 100 µg
Untreated negative controls:
yes
Remarks:
with and without S-9 mix
Negative solvent / vehicle controls:
yes
Remarks:
DMSO free
Positive controls:
yes
Positive control substance:
N-ethyl-N-nitro-N-nitrosoguanidine
Remarks:
for the strain E . coli WP2 uvrA Migrated to IUCLID6: without S-9 mix: 10 µg
Details on test system and experimental conditions:
Three test plates were used per dose or per control. 
Evaluation criteria:
In general, a substance to be characterized as positive in the bacterial tests has to fulfill the following requirements :
- doubling of the spontaneous mutation rate (control)
- dose-response relationship
- reproducibility of the results .
Statistics:
Not relevant

Results and discussion

Test resultsopen allclose all
Key result
Species / strain:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Metabolic activation:
with and without
Genotoxicity:
negative
Remarks:
An increase in the number of his+ or trp+ revertants was not observed in either the Standard plate test or in the Preincubation test.
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
Cytotoxicity was observed at doses >= 2500 µg/plate in the SPT and at doses >= 500 µg/plate in the PIT. 
Vehicle controls validity:
not specified
Untreated negative controls validity:
not specified
Positive controls validity:
not specified
Key result
Species / strain:
E. coli WP2 uvr A
Metabolic activation:
with and without
Genotoxicity:
negative
Remarks:
An increase in the number of his+ or trp+ revertants was not observed in either the Standard plate test or in the Preincubation test.
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
Cytotoxicity was observed at doses >= 2500 µg/plate in the SPT and at doses >= 500 µg/plate in the PIT. 
Vehicle controls validity:
not specified
Untreated negative controls validity:
not specified
Positive controls validity:
not specified
Additional information on results:
No further details
Remarks on result:
other: all strains/cell types tested

Any other information on results incl. tables

No additional information

Applicant's summary and conclusion

Conclusions:
According to the results of the present study, the test substance DMCHA is not mutagenic in the Ames test and in the Escherichia coli - reverse mutation assay under the experimental conditions outlined. Based on the results of the in vitro study provided, the test substance, does not require classification according to Regulation EC No. 1272/2008 or Directive 67/548/EEC.
Executive summary:

The substance cyclohexyldimethylamine (DMCHA0 was tested for its mutagenic potential based on the ability to induce back mutations in selected loci of several bacterial strains in the Ames test and in the Escherichia coli.- reverse mutation assay.

Strains : TA 1535, TA 100, TA 1537, TA 98 and E . coli WP2 uvrA

Dose range : 20 µg - 5,000 µg/plate (SPT), 4 µg - 2,500 µg/plate (PIT)

Test conditions : Standard plate test (SPT) and preincubation test (PIT) both with and without metabolic activation (Aroclor induced rat liver S-9 mix).

Solubility : No precipitation of the test substance was found.

Toxicity : A bacteriotoxic effect was observed depending on the strain and test conditions at doses 2,500 µg/plate (SPT) or at

doses 500 µg/plate (PIT).

Mutagenicity : No increase ín the number of his+ or trp+ revertants was observed both in the standard plate test and in the preincubation test either without S-9 mix or after the addition of a metabolizing system.

Conclusion :

According to the results of the present study, the test substance DMCHA is not mutagenic in the Ames test and in the Escherichia coli - reverse mutation assay under the experimental conditions chosen here.

Based on the results of the in vitro study provided, the test substance, does not require classification according to Regulation EC No. 1272/2008 or Directive 67/548/EEC.