Registration Dossier

Administrative data

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

Zeiger E. et al, 1987, test in Salmonella typhimurium species: no cytotoxicity, no genotoxicity

Hsie et. al., Multiple-endpoint mutagenesis with Chinese Hamster Ovary (CHO) cells: Evaluation with eight carcinogenic and non-carcinogenic compounds, Hemisphere Publishing Corporation) and (Ihidate, and Odashima, 1977) no cytotoxicity, no genotoxicity

Link to relevant study records

Referenceopen allclose all

Endpoint:
in vitro gene mutation study in bacteria
Remarks:
Type of genotoxicity: gene mutation
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: similar to guideline study; no data regarding GLP
Qualifier:
according to guideline
Guideline:
other: Haworth, S. et al.: Environ. Mutagen. 5, Suppl. 1, 3-142
Principles of method if other than guideline:
Use of S. typhymurium strain TA98, TA100, TA1535, TA1537 and/or TA97, but no E.coli strain.
not toxic chemicals tested up to a maximum dose of 10 mg/plate, poorly soluble chemicals were tested up to the dose defined by solubility, A maximum of 0.05 ml solvent was added to each plate, only 2-Aminoanthracene was used as the indicator of the efficacy of the S9-Mix, not every individual plate count is displayed, no justification that no confirmation of the negative result has been made
GLP compliance:
no
Type of assay:
bacterial reverse mutation assay
Target gene:
his-
Species / strain / cell type:
S. typhimurium, other: Salmonella Typhimurium TA98, TA100, TA1535, TA1537, TA97
Metabolic activation:
with and without
Metabolic activation system:
rat and hamster S9 (10% Aroclor 1254-induced)
Test concentrations with justification for top dose:
0.000, 33.000, 100.000, 333.000, 1000.000, 3333.000, 4500.000 µg/plate
Vehicle / solvent:
H2O
Untreated negative controls:
not specified
Negative solvent / vehicle controls:
yes
Remarks:
run with each trial
Positive controls:
yes
Remarks:
without S9: Sodium azide (TA1535, TA100), 9-aminoacridine (TA1537), 4-nitro-o-phenylenediamine (TA98) with S9: 2-aminoanthracene
Evaluation criteria:
An individual trial was judged mutagenic (+) if a dose-related increase over the corresponding solvent control was seen, and it was judged weakly mutagenic C+W) if a low-level dose response was seen. A trial was considered questionable (?) if a dose related
increase was judged insufficiently high to justify a call of " + W," if only a single dose was elevated over the control, or if a non-dose-related increase was seen.
The distinctions between a weak mutagenic response and a mutagenic response, or between a weak mutagenic response and a questionable mutagenic response are highly subjective.
A chemical was judged to be mutagenic (+), or weakly mutagenic (+W), if it produced a reproducible, dose-related increase in his+ revertants over the corresponding solvent controls in replicate trials. A chemical was considered to be questionable (?) if a reproducible increase of hist revertants did not meet the criteria for either a " + " or " + W," or if only single doses produced an increase in his+ revertants in repeat trials
Statistics:
no data
Species / strain:
S. typhimurium TA 98
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
other: > 1000 µg/plate
Vehicle controls validity:
valid
Untreated negative controls validity:
not specified
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 100
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
other: > 1000 µg/plate
Vehicle controls validity:
valid
Untreated negative controls validity:
not specified
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 1535
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
other: > 1000 µg/plate
Vehicle controls validity:
valid
Untreated negative controls validity:
not specified
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 1537
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
other: > 1000 µg/plate
Vehicle controls validity:
valid
Untreated negative controls validity:
not specified
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 97
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
other: > 1000 µg/plate
Vehicle controls validity:
valid
Untreated negative controls validity:
not specified
Positive controls validity:
valid

Table 82.1 DIMETHYLAMINE (LAB: EGG   SOLVENT: H2O)

DOSE

TA100

TA1535

TA1537

TA98

NA

10% HLI

10% RLI

NA

10% HLI

10% RLI

NA

10% HLI

10% RLI

NA

10% HLI

10% RLI

ug/PLATE

MEAN

SEM

MEAN

SEM

MEAN

SEM

MEAN

SEM

MEAN

SEM

MEAN

SEM

MEAN

SEM

MEAN

SEM

MEAN

SEM

MEAN

SEM

MEAN

SEM

MEAN

SEM

0.000

93

8.0

89

9.1

76

2.5

24

1.9

8

1.7

13

1.2

4

1.5

4

0.9

8

1.5

18

5.2

20

0.6

24

3.2

33.000

92

5.4

 

 

 

 

21

1.5

 

 

 

 

8

1.0

 

 

 

 

20

2.7

 

 

 

 

100.000

91

8.7

90

3.1

77

2.0

19

2.5

7

1.5

11

0.9

8

0.6

6

0.9

8

2.6

15

2.8

24

2.2

17

1.0

333.000

92

6.4

80

4.5

91

0.6

20

4.0

10

0.6

10

2.7

5

1.3

6

2.3

6

2.2

17

4.8

20

2.0

17

2.7

1000.000

88

6.3

92

7.0

88

5.2

16

2.3

7

1.2

8

1.7

5

1.5

8

0.3

5

1.7

17

1.2

20

3.9

24

3.0

3333.000

t

 

88

5.2

89

11.0

11s

1.5

8

1.2

9

1.3

6s

0.7

7

1.5

10

0.3

t

 

19

5.0

22

1.5

4500.000

 

 

82

6.7

86

2.5

 

 

9s

1.8

8

2.4

 

 

6

1.3

6

3.3

 

 

19

1.2

20

1.5

POS

2003

16.5

887

78.0

580

31.2

1176

36.1

80

1.9

51

2.7

573

199.4

94

4.2

58

8.7

840

81.5

1011

82.4

639

64.7

 

Table 82.2 DIMETHYLAMINE (LAB: EGG   SOLVENT: H2O)

DOSE

TA100

TA1535

TA1537

TA98

NA

10% HLI

10% RLI

NA

10% HLI

10% RLI

NA

10% HLI

10% RLI

NA

10% HLI

10% RLI

ug/PLATE

MEAN

SEM

MEAN

SEM

MEAN

SEM

MEAN

SEM

MEAN

SEM

MEAN

SEM

MEAN

SEM

MEAN

SEM

MEAN

SEM

MEAN

SEM

MEAN

SEM

MEAN

SEM

0.000

117

10.1

107

6.2

132

16.2

21

3.5

13

1.5

10

0.7

7

2.0

8

0.9

8

0.6

22

4.4

34

2.9

28

3.2

100.000

126

4.8

124

3.2

106

7.0

14

1.2

10

1.2

15

4.2

8

1.9

8

0.3

9

1.5

25

2.7

25

2.9

28

1.5

333.000

112

9.5

116

5.0

120

0.9

15

3.9

15

1.8

10

0.0

8

1.3

7

1.2

10

2.2

21

1.7

28

1.7

26

1.2

1000.000

126

4.4

136

4.4

127

4.3

18

3.2

10

2.0

10

1.7

5

0.3

5

0.9

9

0.6

22

0.7

29

6.2

31

1.9

2000.000

108

7.6

115

5.1

113

16.4

15s

3.0

12s

1.9

14

1.5

9s

2.8

9

0.3

11

1.7

24s

1.8

26

1.2

27

1.2

3333.000

97s

11.5

129s

4.7

117

14.7

t

 

11s

1.2

11

1.2

t

 

7

0.6

8

0.6

20s

1.5

29

2.4

27

1.8

4000.000

 

 

 

 

 

 

 

 

16s

2.3

 

 

 

 

 

 

 

 

 

 

 

 

 

 

POS

2012

55.2

1503

72.7

1255

49.0

1205

65.2

116

7.2

60

1.7

535

18.1

184

21.0

133

2.1

2002

38.4

1270

40.2

1022

55.2

 

Conclusions:
Interpretation of results: negative

Dimethylamine was considered not mutagenic in the tests performed.
Executive summary:

This test was performed according to Haworth, S. et al.: Environ. Mutagen. 5, Suppl. 1, 3-142 with Salmonella typhimurium TA1535, TA1537, TA98, TA100, and TA 97. The concentrations of the test substance ranged from 0.000, 33.000, 100.000, 333.000, 1000.000, 3333.000 and 4000.000 or 4500.000 µg/plate using the pre-incubation method in either the presence or absence of 10% rat or hamster liver metabolic activation. The highest in some strains nontoxic dose tested was 1000.000 mg/plate and the test result was negative according to all strains, with and without metabolic activation. (Zeiger et al., 1987).

Endpoint:
in vitro gene mutation study in mammalian cells
Remarks:
and further multiple-endpoint mutagenesis tests
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: well-described experimental result, no guideline followed
Principles of method if other than guideline:
CHO cells were treated with DMA in the presence of metabolic activation (Aroclor-1254 induced rat liver microsomes) and analyzed for cytotoxicity and specific gene mutation, and collected for chromosome aberration and SCE assays.
GLP compliance:
no
Type of assay:
other: Chinese Hamster Ovary (CHO) cells
Target gene:
hprt locus
Species / strain / cell type:
Chinese hamster Ovary (CHO)
Additional strain / cell type characteristics:
other: subclone CHO-KrBH4 of the CHO-K-, cell line, referred to as CHO cells
Metabolic activation:
not specified
Metabolic activation system:
no data
Test concentrations with justification for top dose:
0.5% (5 µL in 5 mL medium)
Vehicle / solvent:
details see below
Remarks:
details see below
Details on test system and experimental conditions:
details see below
Evaluation criteria:
details see below
Statistics:
details see below
Species / strain:
Chinese hamster Ovary (CHO)
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
other: no but tested up to a concentraton of 22 mM
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Additional information on results:
all details are given below

The Mutagenicity and Toxicity of DMN and DMA

DMA did not exhibit cytotoxic and mutagenic effects up to 22 mM even with S9, and a marginal effect on SCE and chromosome aberration were seen in the presence of S9. The significance of this marginal cytogenetic activity needs to be further assesed. These results suggest that nitrosation is required for the genetic toxicity of DMN since its nonnitrosated analogue DMA is relatively inert. In addition, it shows that the carcinogenic chemical DMN causes cytotoxicity, gene mutation, chromosome aberration and SCE, while DMA, the noncarcinogenic analogue of DMN, is almost totally inert. A close examination of the SCE data indicated that DMA might exhibit a marginally weak response using the 2-fold criteria. Since DMA requires 5 times higher concentration than DMN to achieve a marginal response, it is not unreasonable to consider DMA as negative or nonpositive in the SCE assay.

Conclusions:
Interpretation of results: negative

DMA exhibits no cytotoxic and mutagenic effects.
Executive summary:

Hsie et al. reported in 1987 an multiple-endpoint mutagenesis test was performed. Chinese Hamster Ovary (CHO) cells were used with and without metabolic activation system. The test concentration of dimethylamine was up to 22 mM. Before performing this experimental study it was known that DMA is a noncarcinogen. It was used as analogue to the cancerogen DMN (dimehylnitrosamine).

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (negative)

Genetic toxicity in vivo

Description of key information

Isakova et al., 1971. In vivo Mammalian Chromosome Aberration Assay; no genotoxicity

Link to relevant study records
Reference
Endpoint:
in vivo mammalian germ cell study: cytogenicity / chromosome aberration
Remarks:
Type of genotoxicity: chromosome aberration
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1971
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Acceptable, well-documented publication which meets basic scientific principles.
Qualifier:
no guideline followed
Principles of method if other than guideline:
DMA was investigated on male Wistar rats weighing 150-200 g. These were subjected to long-term poisning by inhalation in 100-liter chambers, predetermined vapor concentrations being maintained around the clock for 3 month.
GLP compliance:
no
Remarks:
The study was conducted prior to the adoption of the OECD guidelines
Type of assay:
chromosome aberration assay
Species:
rat
Strain:
Wistar
Sex:
male
Route of administration:
inhalation
Vehicle:
not applicable
Details on exposure:
Rats were exposed by inhalation in 100-L chambers
Duration of treatment / exposure:
15 and 90 days
Frequency of treatment:
daily
Post exposure period:
no
Dose / conc.:
0 mg/m³ air (nominal)
Dose / conc.:
0.5 mg/m³ air (nominal)
Dose / conc.:
1 mg/m³ air (nominal)
No. of animals per sex per dose:
no data
Control animals:
yes, sham-exposed
Tissues and cell types examined:
bone marrow cells
Details of tissue and slide preparation:
The preparation for cytological investigation were prepared by the method of Ford and Woolam (Ford C.E. and Woolam D.H. Stain technology, Vol.38, p.271, 1963).
Evaluation criteria:
The incidence of structural chromosome breakages and aneuploidy, recorded in metaphases of marrow cells, was used as the criterion of a mutagenic effect. The control was provided by the incidence of similar breakages in the marrow of intact rats of the same age and sex, maintained under identical conditions.
Statistics:
Student's test.
Sex:
male
Genotoxicity:
negative
Toxicity:
not specified
Vehicle controls validity:
not applicable
Negative controls validity:
valid
Positive controls validity:
not examined
Additional information on results:
The incidence of cells with structural chromosome breakages was similar to that in the control preparations (0-2%), and was independent of the duration of poisoning or the concentration of DMA. Analysis of the chromosome count in the same cells revealed that the incidence of aneuploid cells in the experimental animals was somewhat higher than in the controls, for both DMA concentrations and at various times after the beginning of exposure. Statistically significant differences from the controls (p < 0.01) were detected only after 3 month' poisoning, for both DMA concentartions. The incidence of aneuploid cells in the marrow after 90 days poisoning was nearly double that after 15 days poisoning. The significant increase in the incidence of aneuploidy with both DMA concentrations and after different poisoning periods was due to both hypoploid and hyperploid cells.
Conclusions:
Interpretation of results: negative
DMA did not produce cytologically detectable chromosome breakages.
Executive summary:

Male Wistar rats were exposed to 0.5 and 1 mg/cm³ dimethylamine via continuous inhalation for 15 and 90 days. 50 to 100 bone marrow cells were scored per animal. The incidence of cells with chromosomal breakage was did not exceed controls (0 -2%) in any experimantal variant but the incidence of aneuploid cells was significantly higher at both concentrations after 90 days. No decrease in mitotic activity was observed.

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (negative)

Additional information

In vitro

Gene mutation properties of dimethylamine were investigated in a bacterial reverse mutation assay (Ames test). This test was performed according to Haworth, S. et al.: Environ. Mutagen. 5, Suppl. 1, 3-142 with Salmonella typhimurium TA1535, TA1537, TA98, TA100, and TA 97. The concentrations of the test substance ranged from 0.000, 33.000, 100.000, 333.000, 1000.000, 3333.000 and 4000.000 or 4500.000 µg/plate using the pre-incubation method in either the presence or absence of 10 % rat or hamster liver metabolic activation. The highest in some strains nontoxic dose tested was 1000.000 mg/plate and the test result was negative according to all strains, with and without metabolic activation. (Zeiger et al., 1987).

Hsie et al. reported in 1987 an multiple-endpoint mutagenesis test was performed (Hsie et al., 1987). Chinese Hamster Ovary (CHO) cells were used with and without metabolic activation system. The test concentration of dimethylamine was up to 22 mM. Before performing this experimental study it was known that DMA is a noncarcinogen. It was used as analogue to the cancerogen DMN (dimehylnitrosamine).

Additionally, an in vitro mammalian chromosome aberration test with CHO cells testing among various other chemicals DMA-HCl showed no chromosomal aberrations and no mutations, therefore is stated that DMA is not genotoxic nor cytotoxic in concentrations um to 0.12 mg/mL (Ishidate et al., 1977).

In vivo

In an in Vivo Mammalian Chromosome Aberration Assay (Isakova et al., 1971), Wistar rats were exposed to vapours of DMA by inhalation at concentrations of 0.05 mg/m³ and 1 mg/m³ during 15 and 90 days. The incidence of structural chromosome breakages and aneuploidy, recorded in metaphases of marrow cells, was used as the criterion of a mutagenic effect. The control was provided by the incidence of similar breakages in the marrow of intact rats of the same age and sex, maintained under identical conditions. 50 to 100 metaphases were analyzed for each experimental and control animal.

The incidence of cells with structural chromosome breakages was similar to that in the control preparations (0 - 2 %), and was independent of the duration of poisoning or the concentration of DMA. Analysis of the chromosome count in the same cells revealed that the incidence of aneuploid cells in the experimental animals was somewhat higher than in the controls, for both DMA concentrations and at various times after the beginning of exposure. Statistically significant differences from the controls (p < 0.001) were detected only after 3 month' poisoning, for both DMA concentrations. The incidence of aneuploid cells in the marrow after 90 days poisoning was nearly double that after 15 days poisoning. The significant increase in the incidence of aneuploidy with both DMA concentrations and after different poisoning periods was due to both hypoploid and hyperploid cells.

Since only 50 to 100 metaphases from the bone marrow of each animal were evaluated, the increased aneuploidy and hyperploidy can not be evaluated.

Overall, it can be concluded that DMA is not genotoxic.

Justification for classification or non-classification

Classification is not warranted according to the criteria of EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008.