N,N-dimethyldecan-1-amide

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

OECD Guideline 471 (Bacterial Reverse Mutation Assay); GLP compliant: negative (BASF 1999)

OECD Guideline 473 (In Vitro Mammalian Chromosome Aberration Test); GLP compliant; test substance = N,N-Dimethyldecan-1-amide, mixture with N,N-Dimethyloctanc-1-amide: negative (Bayer 1995)

OECD Guideline 476 (In Vitro Mammalian Cell Gene Mutation Test); GLP compliant; test substance = N,N-Dimethyldecan-1-amide, mixture with N,N-Dimethyloctanc-1-amide: negative (Bayer 1994)

Link to relevant study records

Reference

Reference 1

Endpoint:

in vitro cytogenicity / chromosome aberration study in mammalian cells

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Sep 1992 - Jan 1993

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 473 (In Vitro Mammalian Chromosome Aberration Test)

Version / remarks:

May 26, 1983

Deviations:

yes

Remarks:

deviation from current version: only 200 metaphases scored (instead of at least 300)

GLP compliance:

yes

Type of assay:

in vitro mammalian chromosome aberration test

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and Lot/batch No.of test material: Bayer AG; batch-no.002949
- Expiration date of the lot/batch: July 21, 1992
- Purity test date: July 21, 1992

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: room temperature
- Stability under test conditions: The batch used was analytically examined prior to study initiation and was approved for use for the test period.
- Solubility and stability of the test substance in the solvent/vehicle: A stability test in the solvent did not reveal significant degradation of the active ingredient.

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: dilution in ethanol

Species / strain / cell type:

Chinese hamster Ovary (CHO)

Details on mammalian cell type (if applicable):

CELLS USED
- Source of cells: Dr. Sheldon Wolff, Laboratory of Radiobiology and Environmental Health, University of California, San Francisco
- Suitability of cells: chromosome number verified on August 31, 1992
- Number of passages if applicable: not specified
- Methods for maintenance in cell culture if applicable: Cells were normally grown in 20 ml of medium in 75 cm² flasks. Incubation of the cells was always performed at 37°C in a CO2-incubator (air to CO2 ratio 95:5).
- Modal number of chromosomes: 21
- Normal (negative control) cell cycle time: 14 h

MEDIA USED
- Type and identity of media: Ham´s F 12 medium supplemented with 5 or 10% fetal calf serum, 1mM L-glutamine, Penicillin-Streptomycin-Solution (50 I.U./ml; 50 µg/ml)
- Properly maintained: yes
- Periodically checked for Mycoplasma contamination: yes
- Periodically checked for karyotype stability: chromosome number verified on August 31, 1992

Cytokinesis block (if used):

Colcemid (40 µg/ml water)

Metabolic activation:

with and without

Metabolic activation system:

S9 Mix from Aroclor 1254 treated wistar rats

Test concentrations with justification for top dose:

10, 40, 160 µg/ml (without S9)
7.2, 36, 180 µg/ml (with S9)
with harvest time 24h;
highest concentrations testet again with harvest times 8h and 30 h

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: ethanol (stock solution containing 500 mg/ml in ethanol was diluted in culture medium (with 10% FCS) up to a concentration of 1mg/ml)
- Justification for choice of solvent/vehicle: solubility (tested in a pre-test)

Untreated negative controls:

yes

Remarks:

untreated control

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

cyclophosphamide

mitomycin C

Details on test system and experimental conditions:

METHOD OF APPLICATION: in medium
- Cell density at seeding: approx. 1x10^6 cells were seeded in 20 ml of medium per 75 cm² flasks

DURATION
- Exposure duration: 4h at 37°C
- Fixation time (start of exposure up to fixation or harvest of cells): 8, 24h (main study), 30h

SPINDLE INHIBITOR (cytogenetic assays): Colcemid (40 µg/ml water)

STAIN (for cytogenetic assays): 5% Giemsa solution

NUMBER OF REPLICATIONS: duplicate cultures

NUMBER OF CELLS EVALUATED: The mitotic index was determined by counting 1000 cells per culture. Chromosomes of approx. 200 metaphases per concentration, 100 metaphases from each of two parallel cultures, were examined for structural changes.

DETERMINATION OF CYTOTOXICITY
- Method: determination of mitotic index (also determined in the main study) and cell survival in the presence and abscence of S9 mix (assessed in pre-tests)

Rationale for test conditions:

For the dose selection for the main study pre-tests using the following concentrations were performed: first pre-test: 1000, 750, 500, 250, 100, 50, 10 µg/ml (with and without S9 mix; 4 h exposure time; preparation time: 24 h after the beginning of the treatment, solvent DMSO); second pre-test: 250, 220, 190, 160, 130, 100 µg/ml. As indicators of cytotoxic effects, mitotic indices and numbers of surviving cells (survival index) were determined.
Based on these results, the highest doses for the main study were selected in order to be in a dose-range that induces a redcution of the mitotic index by about 50%.

Evaluation criteria:

A test was considered to be positive if a dose-dependent and statistically significant increase of aberration frequencies was observed which was outside the range of the historical solvent controls.

A test was considered to be negative if there was no evidence of increased aberration frequencies for any of the concentrations tested.

A test was considered equivocal if there was an increase which was statistically significant but not concentration-dependent, or if a concentration-dependent increase occurred which was not statistically significant.

Assay Acceptance Criteria:
An assay was acceptable if there was a biologically relevant increase in chromosome aberrations induced by the positive controls and if the numbers of aberrations for the negative controls were in the expected range based on results from the testing laboratory and from published studies.

Statistics:

The statistical analysis of the results was performed by pair-wise comparison of the numbers of metaphases with aberrations (including and excluding gaps) and of metaphases with exchanges among 200 cells for treatment and solvent control groups.
Fisher exact test was used for the statistical evaluation.

Species / strain:

Chinese hamster Ovary (CHO)

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

at the highest test concentrations 160µg/ml, 180µg/ml

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Table 1: Surviving cells after treatment in the second pre-test

Concentration (µg/ml)	S9 Mix	Length of Treatment*	Harvest Time*	Survival Index1
250 220 190 160 130 100	without	4 4 4 4 4 4	24 24 24 24 24 24	0.3 3.0 22.8 58.5 99.4 94.2
250 220 190 160 130 100	with	4 4 4 4 4 4	24 24 24 24 24 24	0.2 10.7 52.0 76.4 95.3 88.2

*: in hours

1: relative to solvent control cells [in%]

Table 2: Mitotic indices in the second pre-test

Concentration (µg/ml)	S9 Mix	Length of Treatment*	Harvest Time*	Mitotic Index1
250 220 190 160 130 100	without	4 4 4 4 4 4	24 24 24 24 24 24	0 0 5.1 59.5 75.9 75.9
250 220 190 160 130 100	with	4 4 4 4 4 4	24 24 24 24 24 24	0 0 53.5 97.2 109.9 70.4

*: in hours

1:relative to solvent control cells [in%]

Conclusions:

The test substance is not considered to be clastogenic for mammalian cells with and without metabolic activation in vitro.

Executive summary:

The clastogenic potential of the test substance was evaluated in a chromosome aberration test in vitro. Chinese hamster ovary (CHO) cells were exposed for 4 hours to concentrations of 10, 40 and 160 µg/ml medium without S9 mix and to the concentrations of 7.2, 36 and 180 µg/ml with S9 mix. Cells were harvested 8, 24 and 30 hours after the beginning of the treatment.

The test substance induced cytotoxic effects in cells exposed to the highest doses with and without metabolic activation at the early harvest time of 8 hours after the beginning of the treatment. The mitotic indices were markedly reduced to 66.7 and 43.2% relative to solvent controls.

With one exception, no statistically significant or biologically relevant increases of numbers of metaphases with aberrations were detected 8, 24 or 30 hours after the beginning of the four hour treatment with the test substance with and without S9 mix. A statistically significant increase of the numbers of cells with aberrations was calculated for cells exposed to the dose of 180 µg/ml with metabolic activation and the harvest time of 8 hours. However, the absolute number of cells with aberrations (3.5%)was within the normal range as compared to the values for other solvent controls within this study and for other studies performed in this laboratory. This statistically significant increase is therefore considered to be caused by the unusually low number of cells with aberrations in the corresponding solvent control group. This statistically significant result is therefore considered not to be biologically relevant.

The positive controls mitomycin C and cyclophosphamide induced clear clastogenic effects and demonstrated the sensitivity of the testsystem.

Based on this test, the test substance is not considered to be clastogenic for mammalian cells with and without metabolic activation in vitro.

 

Reference 2

Endpoint:

in vitro gene mutation study in mammalian cells

Type of information:

experimental study

Adequacy of study:

key study

Study period:

March - May 1993

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 476 (In Vitro Mammalian Cell Gene Mutation Test)

Version / remarks:

4 April, 1984

Deviations:

no

GLP compliance:

yes

Type of assay:

mammalian cell gene mutation assay

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Krahn Chemie GmbH, Hamburg, Germany; batch-no. 002949
- Expiration date of the lot/batch: July 8, 1993
- Contents: 98.08% - 98.26%
- Purity test dates: Jan 24, Jul 21, 1992 and Jan 08, 1993

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: room temperature
- Stability under test conditions: The batch used was analysed prior to study initiation and approved for use during the test period.
- Solubility and stability of the test substance in the solvent/vehicle: A stability test in the solvent did not detect a relevant change in the percent active ingredient.

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: dissolved in ethanol

Target gene:

HGPRT locus

Species / strain / cell type:

Chinese hamster lung fibroblasts (V79)

Details on mammalian cell type (if applicable):

CELLS USED
- Source of cells: gift from Prof. G. Speit, University of Ulm, Germany
- Suitability of cells: prooven
- Doubling time: 10 - 14 h
- Methods for maintenance in cell culture if applicable: Cells were maintained in plastic tissue culture vessels at 37°C in a humidified atmosphere containing approx. 5% CO2. The cells were subcultured at least twice a week to maintain exponential growth.
- Modal number of chromosomes: 22

MEDIA USED
- Type and identity of media: hypoxanthine-free Eagle´s Minimal Essential Medium (MEM) supplemented with nonessential aminoacids, L-glutamine (2 mM), MEM-vitamins, NaHCO3, penicillin (50 units/ml), streptomycin (50 µg/ml) and heat-inactivated fetal calf serum (10%). During treatment with the test substance the serum level was reduced to 2%.
- Properly maintained: yes
- Periodically checked for Mycoplasma contamination: yes
- Periodically checked for karyotype stability: yes
- Periodically 'cleansed' against high spontaneous background: yes

Metabolic activation:

with and without

Metabolic activation system:

S9 Mix Aroclor 1254 induced from Wistar rats

Test concentrations with justification for top dose:

Cytotoxicity test: 7.9, 15.7, 31.3, 62.5, 125.0, 250.0, 500.0, 750.0, 1000.0 µg/ml
Main test: 25.0, 50.0, 100.0, 125.0, 150.0, 200.0, 250.0 µg/ml

Following the determination of the cytotoxicty of the test substance in pre-tests the concentration range for the main study was chosen ranging from approx. 0% - 90% reduction in colony forming ability.

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: ethanol
- Justification for choice of solvent/vehicle: solubility

Untreated negative controls:

yes

Remarks:

untreated cells

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

ethylmethanesulphonate

other: dimethylbenzanthracene (DMBA) (20 µg/ml; with S9 mix)

Details on test system and experimental conditions:

METHOD OF APPLICATION: in medium (containing 2% FCS)
- Cell density at seeding: 4x10°6 cells per dose group in a 250 ml flask

DURATION
- Preincubation period: 16 - 24h
- Exposure duration: 5 h
- Expression period: 6 days
- Selection time (if incubation with a selection agent): 6 days

SELECTION AGENT (mutation assays): 6-Thioguanine (10 µg/ml)

STAIN (for cytogenetic assays): Giemsa

NUMBER OF REPLICATIONS: triplicates for cytotoxicity, 2 independent experiments;
Main test (repeated completely two times ): 8 dishes (from 1 flask) were examined, for each dosage 2 flask were used.

DETERMINATION OF CYTOTOXICITY
- Method: determination of the relative cloning efficiency

Evaluation criteria:

- An assay was considered positive if a dose-dependent, significant and in parallel cultures reproducible increased in mutant frequency was observed. It is desirable to obtain this dose-relationship for at least 3 doses. To be significant, the mutagenic response to the substance should be at least two to three times that of the highest negative or vehicle control value observed in that trial. If this result could be reproduced in a second assay, the test article was considered to be mutagenic.

- A test article was judged as equivocal if there was no dose-dependency but one or more doses induced a reproducible, significant mutant frequency in all assays.

- An assay was considered negative if none of the doses tested (for a range of applied concentrations which extends to toxicity causing about 30% survival or less) induced a reproducible
mutant frequency which was considered significant.

- If a positive result in the mutagenicity assay was evident, subsequently the osmolality of the tested concentration range in culture medium was determined. Only, if no significant change in osmolality compared to the vehicle control could be observed, the test article was considered to be mutagenic. Otherwise, unphysiological culture conditions may be the reason for the positive results (Scott et al., 1991).

Statistics:

Weighted analysis of variance followed by pairwise comparisons using Dunnetts test.

Species / strain:

Chinese hamster lung fibroblasts (V79)

Metabolic activation:

with and without

Genotoxicity:

negative

Remarks:

up to cytotoxic concentration

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

at concentrations >= 200 µg/ml (without S9 mix) and 250 µg/ml (with S9 mix)

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Conclusions:

The test article is considered to be non-mutagenic in the V79-HGPRT Forward Mutation Assay both with and without metabolic activation.

Executive summary:

The test substance was evaluated for mutagenic effects at the HGPRT locus (forward mutation assay) in V79 cell cultures after in vitro treatment at concentrations up to 250 µg/ml, both with and without S-9 mix.

Under non activation as well as under activation conditions, the test substance induced cytotoxic effects as seen by decreases in relative survival to treatment and relative population growth but not in cloning efficiency. These results revealed a significant concentration-related cytotoxicity of the test substance.

 

There was no significant dose-related or reproducible increase in mutant frequency above that of the negative con­trols. In contrast, the positive controls ethylmethane­sulfonate (without S-9 mix) and dimethylbenzanthracene (with S-9 mix) produced a clearly mutagenic effect in the assay.

 

Based on these results, the test substance is considered to be non-mutagenic in the V79-HGPRT Forward Mutation Assay, both with and without metabolic activation.

Reference 3

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

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Qualifier:

according to guideline

Guideline:

EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Target gene:

his operon

Species / strain / cell type:

S. typhimurium TA 102

Additional strain / cell type characteristics:

not applicable

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98 and TA 100

Additional strain / cell type characteristics:

not applicable

Metabolic activation:

with and without

Metabolic activation system:

S9 (Phenobarbital, ß-Napthoflavone)

Test concentrations with justification for top dose:

Experiment I (TA 98, TA 100): 3; 10; 33; 100 and 1000 µg/plate
Experiment I (TA 1535, TA 1537, TA102): 33; 66; 100; 333; 666 and 1000 µg/plate
Experiment II (all strains): 33; 66; 100; 333; 666 and 1000 µg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO
- Justification for choice of solvent/vehicle: chosen because of the test item solubility

Untreated negative controls:

yes

Remarks:

untreated controls

Negative solvent / vehicle controls:

yes

Remarks:

solvent controls

Positive controls:

yes

Positive control substance:

other: sodium azide, 4-nitro-o-phenylene-diamine, methyl methane sulfonate, 2-aminoanthracene

Details on test system and experimental conditions:

METHOD OF APPLICATION: pre mixed suspension (test solution, S9mix or buffer, bacteria suspension, overlay agar) were poured onto agar plates

Evaluation criteria:

according to guideline

Statistics:

no

Species / strain:

S. typhimurium TA 102

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

in higher concentrations, tested up to cytotoxic concentration

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Species / strain:

S. typhimurium TA 1535, TA 1537, TA 98 and TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

in higher concentrations, tested up to cytotoxic concentration

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

ADDITIONAL INFORMATION ON CYTOTOXICITY:
Cytotoxicity was checked for higher concentration in pre-experiment. The backround growth was reduced at 2500 µg/plate with and without S9 mix

Conclusions:

The test item did not induce gene mutations under the experimental conditions with the tested strains.
Therefore, the test substance is considered to be non-mutagenic in the salmonella typhimurium reverse mutation assay.

Executive summary:

This study was performed to investigate the potential of of the tets substance (N,N-Dimethyldecan-1 -amide) to induce gene mutations according to the plate incorporation test (experiment I) and the pre-incubation test (experiment II) using the Salmonella typhimurium strains TA1535,TA1537,TA98,TA100 and TA102. The assay was performed with and without liver microsomal activation. Due to technical reasons the results of experiment II had to be dismissed and an additional experiment was performed under identical conditions. The results of this additional experiment are included in this report as experiment II. Each concentration, including the controls, was tested in triplicate. The test item was tested at the following concentrations:

Experiment I(TA98,TA100): 3; 10; 33; 100; 333; and 1000 ug/plate

Experiment I(TA1535,TA1537,TA102): 33; 66; 100; 333; 666; and 1000 ug/plate

Experiment II (all strains): 33; 66; 100; 333; 666; and 1000 ug/plate

Toxic effects, evident as a reduction in the number of revertants, occurred at the following concentrations:

Strain	Experiment I(µg/plate)		Experiment II (µg/plate)
	withoutS9mix	with S9 mix	withoutS9mix	withS9mix
TA1535	333 - 1000	666 - 1000	333 - 1000	666 - 1000
TA1537	333 - 1000	666 - 1000	666 - 1000	666 - 1000
TA98	333 - 1000	/	666- 1000	1000
TA100	333 - 1000	1000	666- 1000	666 - 1000
TA102	666 - 1000	/	666 - 1000	/

/ no relevant toxic effects observed

In experiment I, the background growth was reduced at the higher concentrations with and without S9 mix in all strains.

No substantial increase in revertant colony numbers of any of the five tester strains was observed following treatment with the test substance (N,N-Dimethyldecan-1 -amide) at any dose level, neither in the presence nor absence of metabolic activation (S9 mix). There was also no tendency of higher mutation rates with increasing concentrations in the range below the generally acknowledged border of biological relevance.

Appropriate reference mutagens were used as positive controls and showed a distinct increase of induced revertant colonies.

In conclusion, it can be stated that during the described mutagenicity test and under the experimental conditions reported, the test item did not induce gene mutations by base pair changes or frameshifts in the genome of the strains used.

Therefore, the test substance (N,N-Dimethyldecan-1 -amide) is considered to be non-mutagenic in this Salmonella typhimurium reverse mutation assay.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Genetic toxicity in vivo

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

There are partial valid in vitro studies to assess the genotoxicity for pure N,N-dimethyldecanamide and partial in vitro studies with a mixture of N,N-dimethyldecanamide and N,N-dimethyloctanamide.

Due to the fact that a high amount in the mixture was N,N-dimethyl-decanamide and the rest of the mixture are homologues with a lower and higher molecular weight which can be assumed to have a similar toxicological behaviour it is concluded that the mixture has an nearly similar toxicological behaviour like pure N,N-dimethyldecanamide, further details can be found in the attached RA justification in chapter 13.

In summary there are valid in vitro data to assess the genetic toxicity of N,N-Dimethyldecanamide available.

In vitro tests with pure N,N-Dimethyldecanamide:

The test substance N,N-Dimethyldecanamide was tested in a salmonella typhimurium reverse mutation assay (TA1535, TA1537, TA98, TA100 and TA102) according to OECD 471 guideline with and without metabolic activation. The test item was tested at the following concentrations: (TA98,TA100): 3; 10; 33; 100; 333; and 1000 µg/plate and (TA1535,TA1537,TA102): 33; 66; 100; 333; 666; and 1000 µg/plate. Toxic effects, evident as a reduction in the number of revertants, occurred between 333 and 1000µg/plate depending on strain and activation. No substantial increase in revertant colony numbers of any of the five tester strains was observed following treatment with N,N-Dimethyldecan-1 -amide at any dose level, neither in the presence nor absence of metabolic activation (S9 mix). In conclusion the test item did not induce gene mutations by base pair changes or frameshifts in the genome of the strains used.

In vitro tests with mixtures of N,N-Dimethylamides:

A mixture of N,N-dimethyldecanamide and N,N-Dimethyloctanamide (with traces of N,N-dimethyl-dodecanamide and ~5% N,N-dimethyl-hexanamide) was tested in an in vitro mammalian chromosome abberation test (CHO cells) and in an V79-HGPRT Forward Mutation Assay (V79 cells). It is concluded that, caused by a high amount of N,N-Dimethyl-decanamide in the mixture and the fact that the residual contains homologues with a lower and higher molecular weight (mainly N,N-Dimethyloctanamide) which can be assumed to have an similar toxicological behaviour as the mixture, the mixture has an similar behaviour in the different cell tests like pure N,N-Dimethyldecanamide. Therefore the following study results will be used for assessing the genetoxic behaviour of N,N-Dimethyldecanamide.

The genotoxic potential of a C8/C10 dimethylamide mixture was tested in an in vitro mammalian chromosome abberation test according to OECD 473 (Bayer 1995; R. Gahlmann). Therefore Chinese hamster ovary cells were treated with the substance at the concentrations of 10, 40 and 160 µg/ml medium without S9 mix and at the concentrations of 7.2, 36 and 180 µg/ml with S9 mix. The test substance induced cyto toxic effects in cells exposed to the highest doses with and without metabolic activation at the early harvest time of 8 hours after the beginning of the treatment. The mitotic indices were markedly reduced to 66.7 and 43.2 % relative to control cells. With one exception (which was considered as uncritical, see study summary), no statistically significant or biologically relevant increases of numbers of metaphases with aberrations were detected 8, 24 or 30 hours after the beginning of the four hour treatment with the test substance with and without S9 mix. Therefore the C8/C10 mixture not considered to be clastogenic for mammalian cells with and without metabolic activation

A further study was accomplished to observe the genotoxic potential of C8/C10 FADMA (Bayer, 1994, Brendler-Schwaab S.). Therefore the test material was assayed for mutagenic activity at the HGPRT locus in V79 cells from 25 to 250 µg/ml both, with and without metabolic activation according to OECD guideline 476. Under both treatment conditions, cyto toxic effects were induced. The vehicle control mutant frequencies were all in the normal range of background frequencies for the assay. In contrast, the positive controls and DMBA induced a distinct mutagenic effect in mutant frequency, which was significantly increased over the negative controls demonstrating the sensitivity of the test system and the ability to detect known mutagens. The test substance was considered to be non mutagenic in the V79-HGPRT Forward Mutation Assay both with and without metabolic activation.

Assessment of genetic toxicity:

In summary there were no hints for gene mutation or cytogenicity from the pure N,N-Dimethyldecanamide

or from the C8/C10 dimethylamide mixture in the different in vitro genotoxicity tests. Following the mutagenicity testing stragegy no in vivo experiment is proposed due to this result.

Key study assignment:

For each specific in vitro endpoint is only one reliability study with the substance identity identical to submission (highst priority) or read across substance (second priority) available.Therefore all studies were integrated as key studies.

Justification for classification or non-classification

In vitro genotoxicity test and in vitro mutagenicity test does not reveal a positive result.

Due to criteria of GHS (Regulation (EU) 1272/2008) for germ cell mutagens ("The classification in Category 2 is based on: positive evidence obtained from experiments in mammals and/or in some cases from in vitro experiments, obtained from: somatic cell mutagenicity tests in vivo, in mammals; or other in vivo somatic cell genotoxicity tests which are supported by positive results from in vitro mutagenicity assays....") the substance is not to classify as germ cell mutagen. Also according to EU-criteria DSD (67/548/EEC) the available information does not lead to a classification.

Labelling genotoxicity/mutagenicity:

GHS: no classification

DSD: no classification