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Endpoint:
in vitro cytogenicity / chromosome aberration study in mammalian cells
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP-guideline study
Qualifier:
according to
Guideline:
OECD Guideline 473 (In Vitro Mammalian Chromosome Aberration Test)
GLP compliance:
yes
Remarks:
RCC-Cytotest Cell Research GmbH
Type of assay:
in vitro mammalian chromosome aberration test
Species / strain / cell type:
Chinese hamster lung fibroblasts (V79)
Details on mammalian cell type (if applicable):
CELL CULTURE DETAILS:
- Type and identity of media: Minimal Essential Medium supplemented with 10% fetal calf serum.
- Properly maintained: yes
- Periodically checked for Mycoplasma contamination: yes
- Periodically checked for karyotype stability: yes
Metabolic activation:
with and without
Metabolic activation system:
Phenobarbital / ß-Naphthoflavone induced rat liver S9-mix
Test concentrations with justification for top dose:
19.5, 39.1, 78.1 & 156.3 µg active ingredient/mL
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
Remarks:
medium
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 300-400 µg/mL Ethylmethane sulfonate (-S9), 1.4-2.0 µg/mL Cyclophosphamide (+S9)
Details on test system and experimental conditions:
- Spindle inhibitor: 0.2 µg/ml Colcemid
- Stain: Giemsa
- No. of metaphases analyzed: 100
- Dosing: Cytotoxic concentrations were determined in a range-finder study with and without metabolic activation. 312.5 µg/ml was chosen as top concentration in the actual experiments.
- Number of replicates: 2
Evaluation criteria:
Breaks, fragments, deletions, exchanges, and chromosome disintegrations were recorded as structural chromosome aberrations. Gaps were recorded as well, but not included in the calculation of aberration rates. Only metaphases with characteristic chromosome numbers (22+-1) were included in the analysis. The mitotic index (% cells in mitosis) and the percentage of polyploid cells in 500 metaphase plates/culture were determined.
Species / strain:
Chinese hamster lung fibroblasts (V79)
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
156.3 - 312.5 µg active ingredient/mL
Vehicle controls validity:
not specified
Untreated negative controls validity:
not specified
Positive controls validity:
not specified

PRECIPITATION CONCENTRATION:

156.3 µg active ingredient/ml (except experiment II after 18h preparation interval without S9 mix where precipitation occurred at 78.1 µg/ml and above)

Endpoint:
in vitro gene mutation study in mammalian cells
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: according to OECD 476
Qualifier:
according to
Guideline:
OECD Guideline 476 (In Vitro Mammalian Cell Gene Mutation Test)
Guideline:
EU Method B.17 (Mutagenicity - In Vitro Mammalian Cell Gene Mutation Test)
Guideline:
EPA OPPTS 870.5300 - In vitro Mammalian Cell Gene Mutation Test
Guideline:
other: Japanese Guidelines: Kanpoan No. 287, Environment Protection Agency; Eisei No. 127, Ministry of Health and Welfare; Heisei 09/10/31 Kikyoku No. 2, Ministry of International Trade and Industry
Principles of method if other than guideline:
first experiment 4 hours treatment with and without metabolic activation
second experiment 24 hours treatment without metabolic activation and 4 hours treatment with metabolic activation
GLP compliance:
yes (incl. certificate)
Remarks:
Harlan Cytotest Cell Research GmbH
Type of assay:
mammalian cell gene mutation assay
Target gene:
HPRT
Species / strain / cell type:
Chinese hamster lung fibroblasts (V79)
Details on mammalian cell type (if applicable):
- Type and identity of media: MEM
- 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:
Rat liver S9
Test concentrations with justification for top dose:
Experiment I:
without S9 mix: 28.1; 56.3; 112.5; 225.0; 337.5; 450 µg/mL
with S9 mix: 56.3; 112.5; 225.0; 450.0; 675.0; 900.0 µg/mL
Experiment II:
without S9 mix: 28.1; 56.3; 112.5; 225.0; 450.0; 675.0 µg/mL
with S9 mix: 112.5; 225.0; 450.0; 900.0; 1350.0; 1800 µg/mL
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: water
- Justification for choice of solvent/vehicle: solubility properties
Negative solvent / vehicle controls:
yes
Remarks:
water
True negative controls:
no
Positive controls:
yes
Positive control substance:
ethylmethanesulphonate
Remarks:
Migrated to IUCLID6: 7,12-dimethylbenz(a)anthracene
Details on test system and experimental conditions:
METHOD OF APPLICATION: in medium


DURATION
- Exposure duration: 4 hours with and without metabolic activation in experiment 1, 24 hours without metaoblic activation in experiment 2
- Expression time (cells in growth medium): 72 hours
- Selection time (if incubation with a selection agent): 10 days

SELECTION AGENT (mutation assays): Thioguanine

NUMBER OF REPLICATIONS: 2

NUMBER OF CELLS EVALUATED: >1,5x10exp.6

DETERMINATION OF CYTOTOXICITY
- Method: cloning efficiency


Evaluation criteria:
A test item is classified as positive if it induces either a concentration-related increase of the mutant frequency or a reproducible and positive response at one of the test points.
A test item producing neither a concentration- related increase of the mutant frequency nor a reproducible positive response at any of the test points is considered non-mutagenic in this system.
A positive response is described as follows:
A test item is classified as mutagenic if it reproducibly induces a mutation frequency that is three times above the spontaneous mutation fre¬quency at least at one of the concentrations in the experiment.
The test item is classified as mutagenic if there is a reproducible concentration-related increase of the mutation frequency. Such evaluation may be considered also in the case that a threefold increase of the mutant frequency is not observed.

However, in a case by case evaluation this decision depends on the level of the corre-sponding negative control data. If there is by chance a low spontaneous mutation rate in the range normally found (0.5 – 31.8 mutants per 10exp.6 cells) a concentration-related in-crease of the mutations within this range has to be discussed. The variability of the mutation rates of negative and solvent controls within all experiments of this study was also taken into consideration.

Statistics:
Linear regression analysis (least squares) .
Species / strain:
Chinese hamster lung fibroblasts (V79)
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
Positive controls validity:
valid
Summary Table

 

 

relative

relative

mutant

 

relative

relative

mutant

 

 

conc. µg

S9

cloning

cloning

colonies/

induction

cloning

cloning

colonies/

induction

 

per mL

mix

efficiency I

efficiency II

106 cells

factor

efficiency I

efficiency II

106 cells

factor

 

 

%

%

 

%

%

 

column

1

2

3

4

5

6

7

8

9

10

Experiment I / 4 h treatment

culture I

culture II

Solvent control with water

-

100.0

100.0

 18.4

1.0

100.0

100.0

 17.1

1.0

Positive control with

150.0

-

 76.2

 94.8

137.7

7.5

 84.7

 86.2

132.3

7.7

Test item

28.1

-

 98.4

114.2

 15.4

0.8

 92.7

104.2

 13.0

0.8

Test item

56.3

-

100.0

110.3

 12.0

0.7

 97.1

 98.0

 16.8

1.0

Test item

112.5

-

102.8

101.8

 16.7

0.9

 88.2

 96.3

 15.5

0.9

Test item

225.0

-

 87.2

102.0

 21.5

1.2

 76.9

 95.5

 19.9

1.2

Test item

337.5

-

  0.2

 98.4

 14.6

0.8

  8.8

 89.2

 20.5

1.2

Test item

450.0

-

  0.0

culture was not continued#

  0.0

culture was not continued#

Solvent control with water

+

100.0

100.0

 24.6

1.0

100.0

100.0

 17.9

1.0

Positive control with DMBA

 1.1

+

 43.9

 89.0

636.4

25.9

 36.6

 99.5

620.9

34.7

Test item

56.3

+

 94.4

culture was not continued##

 97.3

culture was not continued##

Test item

112.5

+

 89.5

 94.1

 16.9

0.7

 95.7

105.9

 22.3

1.2

Test item

225.0

+

 94.1

 89.8

 17.6

0.7

 94.2

 85.8

 20.6

1.2

Test item

450.0

+

 84.7

 90.5

 16.3

0.7

 94.5

 81.5

 20.9

1.2

Test item

675.0

+

 88.5

114.3

 13.2

0.5

 93.6

 92.6

 17.9

1.0

Test item

900.0

+

 85.0

 85.7

 27.8

1.1

 92.9

 96.4

 15.5

0.9

Experiment II / 24 h treatment

culture I

culture II

Solvent control with water

-

100.0

100.0

 13.7

1.0

100.0

100.0

 14.1

1.0

Positive control with

75.0

-

 92.5

 97.7

132.5

9.7

102.2

 93.2

105.6

7.5

Test item

28.1

-

104.7

culture was not continued##

101.8

culture was not continued##

Test item

56.3

-

102.5

 95.7

 16.9

1.2

102.2

 69.3

 18.8

1.3

Test item

112.5

-

 88.0

 94.5

 17.4

1.3

102.7

 97.8

  9.0

0.6

Test item

225.0

-

 95.1

 88.7

 23.2

1.7

102.0

 71.3

 17.4

1.2

Test item

450.0

-

 94.1

 84.2

 23.6

1.7

101.4

 65.3

 17.7

1.3

Test item

675.0

-

 43.3

 90.9

 16.2

1.2

102.9

 63.5

 28.4

2.0

Experiment II / 4 h treatment

culture I

culture II

Solvent control with water

+

100.0

100.0

 13.7

1.0

100.0

100.0

 16.1

1.0

Positive control with DMBA

 1.1

+

 55.9

 73.5

809.9

59.1

 51.2

 78.8

595.5

36.9

Test item

112.5

+

114.6

 78.2

 20.1

1.5

 95.6

 90.4

 22.6

1.4

Test item

225.0

+

 91.3

101.5

 24.6

1.8

107.2

 98.0

 14.5

0.9

Test item

450.0

+

 95.5

109.1

 22.9

1.7

 99.1

 83.9

 20.5

1.3

Test item

900.0

+

111.7

 99.4

 26.1

1.9

112.6

 80.5

 20.8

1.3

Test item

1350.0

+

 10.6

100.7

 11.4

0.8

  7.4

102.9

  8.8

0.5

Test item

1800.0

+

  0.0

culture was not continued#

  0.0

culture was not continued#

#     culture not continued due to exceedingly strong toxic effects

##    culture was not continued since a minimum of only four analysable concentrations is required

Conclusions:
In conclusion it can be stated that under the experimental conditions reported the test item did not induce gene mutations at the HPRT locus in V79 cells.
Therefore, C-SAT 080094 is considered to be non-mutagenic in this HPRT assay.
Executive summary:

The study was performed to investigate the potential of C-SAT 080094 to induce gene mutations at the HPRT locus in V79 cells of the Chinese hamster.

The assay was performed in three independent experiments, using two parallel cultures each. The first main experiment was performed with and without liver microsomal activation and a treatment period of 4 hours. The experimental part without metabolic activation was terminated prematurely due to exceedingly severe cytotoxic effects even al low concentrations. This part of the first experiment was repeated in experiment IA using a lower concentration range. The data of the repeat experiment IA are included in the first experiment.

The second experiment was performed in the absence of metabolic activation with a treatment period of 24 hours and in the presence of metabolic activation with a treatment period of 4 hours.

The highest applied concentration in the pre-test on toxicity (7300 µg/mL) was based on the purity of the test item (36 % active ingredient). The dose range of the main experiments was limited by toxicity of the test item.

No substantial and reproducible dose dependent increase of the mutation frequency was observed in both main experiments.

Appropriate reference mutagens, used as positive controls, induced a distinct increase in mutant colonies and thus, showed the sensitivity of the test item and the activity of the metabolic activation system.

Endpoint:
in vitro gene mutation study in bacteria
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
GLP - Guideline study, tested with the source substance disodium metasilicate nonahydrate. According to the ECHA guidance document “Practical guide 6: How to report read-across and categories (March 2010)”, the reliability was changed from RL1 to RL2 to reflect the fact that this study was conducted on a read-across substance.
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
no
GLP compliance:
yes
Type of assay:
bacterial reverse mutation assay
Target gene:
his operon (for S. tyhphimurium strains)
trp operon (for E. coli 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:
Aroclor-induced rat liver S-9 mix and uninduced hamster liver S-9 mix
Test concentrations with justification for top dose:
standard plate test: 33, 100, 333, 1000, 2500, 5000 µg/plate with and without metabolic activation
preincubation test: 10, 33, 100, 333, 1000, 2500 µg/plate with and without metabolic activation
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: water
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: with rat S-9: 2-aminoanthracene: TA tester strains, 2.5 µg; E.coli WP2uvrA, 60 µg
Remarks:
with S9 mix
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: N-methyl-N'-nitro-N-nitrosoguanidine (TA1535, TA100: 5 µg/plate), 4-nitro-o-phenylendiamine (TA98: 10 µg/plate), 9-aminoacridine (TA1537, 100 µg/plate), 4-nitroquinoline-N-oxide (E. coli WP2 uvrA, 5 µg/plate)
Remarks:
without S9 mix
Details on test system and experimental conditions:
METHOD OF APPLICATION: standard plate test and preincubation test

DETERMINATION OF CYTOTOXICITY
- Method: reduced background growth
Species / strain:
S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
Positive controls validity:
valid

Table 1: Results of tester strains TA1537 and TA98 with and without metabolic activation

(*reduced background growth)

 

 

TA 1537

TA 98

Dose [µg/plate]

S-9 mix

Standard Test

Preincubation Test

Standard Test

Preincubation Test

0

+

9

7

6

8

5

7

28

25

21

21

24

22

10

+

 -

6

8

6

 -

28

21

19

33

+

8

6

9

6

7

8

28

19

27

28

17

26

100

+

8

8

7

9

4

7

25

23

18

24

21

20

333

+

10

5

8

5

8

7

22

25

26

20

15

21

1000

+

8

5

7

4

5

4

21

23

24

17

10

11

2500

+

7

7

5

2*

2*

3*

18

14

17

4*

4*

5*

5000

+

2*

5*

5*

10*

8*

6*

 -

2-aminoanthracene

+

155

129

111

164

119

138

668

634

529

665

578

634

0

-

8

6

6

5

7

7

21

17

19

21

15

18

10

-

 -

 -

 -

7

5

6

 -

17

19

16

33

-

8

5

9

8

5

4

18

23

14

20

18

14

100

-

7

6

5

5

7

4

15

22

21

16

19

21

333

-

8

6

6

6

5

6

17

18

20

21

15

14

1000

-

7

8

5

2*

1*

2*

20

14

18

9*

5*

5*

2500

-

3

5

5

0*

0*

0*

12

13

17

0*

0*

0*

5000

-

2*

4*

1*

8*

5*

5*

 -

 -

AAC(TA1537)/NOPD(TA98)

-

336

378

329

335

412

368

558

534

611

551

539

571

 

Table 2: Results of tester strains TA1535 and TA100 with and without metabolic activation

(*reduced background growth)

 

 

TA 1535

TA 100

Dose [µg/plate]

S-9 mix

Standard Test

Preincubation Test

Standard Test

Preincubation Test

0

+

16

13

14

12

13

10

92

96

100

85

77

86

10

+

11

14

11

 -

89

86

80

33

+

16

13

15

10

12

12

103

102

81

80

74

95

100

+

15

14

12

13

14

13

109

90

113

81

93

83

333

+

20

11

11

14

10

11

100

91

103

71

83

81

1000

+

12

11

15

8

9

9

92

111

90

55

78

65

2500

+

10

10

8

2*

5*

5*

89

80

73

40*

51*

46*

5000

+

8*

5*

8*

46*

48*

40*

 -

 -

2-aminoanthracene

+

126

193

164

178

136

154

882

739

812

 -

0

-

10

13

9

12

10

10

100

85

97

71

69

80

10

-

 -

11

10

12

76

75

88

33

-

13

11

10

13

9

10

88

100

90

68

71

82

100

-

10

13

10

11

10

14

86

93

88

87

79

73

333

-

12

12

9

7

13

13

105

85

87

72

80

71

1000

-

9

10

12

2*

1*

1*

76

79

76

16*

11*

14*

2500

-

11

8

8

0*

0*

0*

70

57

66

0*

0*

0*

5000

-

7*

3*

6*

 -

33*

30*

24*

 -

 -

MNNG(TA1535 +TA100)

-

819

802

915

668

712

731

773 

813

761

 -

 

Table 3: Results of E.coli WP2 uvrA with and without metabolic activation (*reduced background growth)

 

 

E. coli WP2 uvrA

Dose [µg/plate]

S-9 mix

Standard Test

Preincubation Test

0

+

44

45

39

40

37

37

10

+

 -

38

38

37

33

+

41

38

51

37

36

34

100

+

45

42

40

38

41

35

333

+

40

41

36

40

39

31

1000

+

47

36

45

17

14

21

2500

+

33

29

32

12*

15*

14*

5000

+

17*

14*

14*

 -

 -

2-aminoanthracene

+

265

228

255

247

258

264

0

-

32

38

41

40

33

35

10

-

 -

40

30

37

33

-

45

39

33

31

44

32

100

-

36

41

42

36

35

37

333

-

41

36

29

31

32

34

1000

-

38

41

45

26

25

20

2500

-

32

28

18

7*

8*

8*

5000

-

12*

14*

14*

4-NQO

-

559

688

634

731

712

644

 

MNNG: N-methyl-N'-nitro-N-nitrosoguanidine

NOPD: 4-nitro-o-phenylendiamine

AAC: 9-aminoacridine

4NQO: 4-nitroquinoline-N-oxide

Conclusions:
Interpretation of results:
negative
Endpoint:
in vitro gene mutation study in bacteria
Type of information:
experimental study
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Well-documented study, but not according to established guidelines.
Principles of method if other than guideline:
E. coli reverse mutation assay according to Demerec (1951), Bertani (1951).
GLP compliance:
no
Type of assay:
bacterial gene mutation assay
Species / strain / cell type:
E. coli, other: B/Sd-4/1,3,4,5 and B/Sd-4/3,4
Additional strain / cell type characteristics:
other: streptomycin-dependant strains
Metabolic activation:
without
Test concentrations with justification for top dose:
0.025 - 0.30%
Untreated negative controls:
not specified
Negative solvent / vehicle controls:
not specified
True negative controls:
not specified
Positive controls:
no
Details on test system and experimental conditions:
- Number of replicates: 3 hrs exposure, 5-10 replicates/dose
Species / strain:
E. coli, other: B/Sd-4/1,3,4,5 and B/Sd-4/3,4
Metabolic activation:
without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Vehicle controls validity:
not specified
Untreated negative controls validity:
not specified
Positive controls validity:
not examined

mutant frequency (mutants per 10E6 bacteria): 
conc. (%) mut.freq.(treated) mut.freq.(control) survival (%)
0.025
      5.9                 6.3                 66
0.100
      2.4                 5.3                 33
0.050
      8.7                 6.3                 27
0.100
      6.6                 6.1                  16
0.100
      11.4                6.2                 4.6
0.150
      2.0                 6.2                 3
0.300
      0.0                 7.0                 0.11

Endpoint:
in vitro gene mutation study in bacteria
Type of information:
experimental study
Adequacy of study:
weight of evidence
Reliability:
4 (not assignable)
Rationale for reliability incl. deficiencies:
other: Study seems to be performed according to established test procedures, but report too limited in detail.
Principles of method if other than guideline:
Bacterial reverse mutation assay (e.g. Ames test), plate count
GLP compliance:
no
Type of assay:
bacterial reverse mutation assay
Species / strain / cell type:
other: Salmonella typhimurium TA98, TA100, TA1535, TA1537
Metabolic activation:
with and without
Metabolic activation system:
S9 mix
Test concentrations with justification for top dose:
0.1, 1 and 10 mg/plate
Untreated negative controls:
yes
Remarks:
buffer solution
Negative solvent / vehicle controls:
not specified
True negative controls:
not specified
Positive controls:
yes
Positive control substance:
other: 0.01 µg/plate AF2 without metabolic activation was used as a positive control for TA100 and TA 98, 100 µg/plate 9-aminoacridine without metabolic activation was used as a positive control for TA 1537, and 2 µg/plate 2-aminoanthracene with metabolic activa
Details on test system and experimental conditions:
plate incorporation
Species / strain:
S. typhimurium, other: TA98, TA100, TA1535, TA1537
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
at 10 mg/plate
Vehicle controls validity:
not specified
Untreated negative controls validity:
not specified
Positive controls validity:
not specified
Endpoint:
in vitro DNA damage and/or repair study
Type of information:
experimental study
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Acceptable, well-documented publication report which meets basic scientific principles
Principles of method if other than guideline:
Rec assay described by Kada et al. (1972)
GLP compliance:
no
Type of assay:
Bacillus subtilis recombination assay
Species / strain / cell type:
other: Bacillus subtilis H17 and M45
Additional strain / cell type characteristics:
other: H17 is recombination-repair-proficient, trp-deficient and arg-deficient. M45 is recombinant-repair-deficient, trp-deficient and arg-deficient.
Metabolic activation:
without
Test concentrations with justification for top dose:
0.005-0.5 M
Untreated negative controls:
not specified
Negative solvent / vehicle controls:
not specified
True negative controls:
not specified
Positive controls:
not specified
Species / strain:
bacteria, other: Bacillus subtilis H17 and M45
Metabolic activation:
without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
not specified
Vehicle controls validity:
not specified
Untreated negative controls validity:
not specified
Positive controls validity:
not specified

Genetic toxicity in vivo

Link to relevant study records
Reference
Endpoint:
in vivo mammalian somatic cell study: cytogenicity / bone marrow chromosome aberration
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Study was performed similar to OECD TG 475, with the restriction that no positive controls were used.
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 475 (Mammalian Bone Marrow Chromosome Aberration Test)
Deviations:
not specified
GLP compliance:
no
Type of assay:
chromosome aberration assay
Species:
mouse
Strain:
other: BDF1
Sex:
male
Details on test animals and environmental conditions:
- Age: 9 weeks
Route of administration:
oral: feed
Duration of treatment / exposure:
24 hours
Frequency of treatment:
once, 4 mg/kg bw  colchicine was  administered intraperitoneally 2 hours before necropsy.
Post exposure period:
sampling time was 24 h after administration
Remarks:
Doses / Concentrations:
740-1340 mg/kg bw (7 graduated  levels)
Basis:
nominal conc.
No. of animals per sex per dose:
4 - 6
Control animals:
yes, concurrent vehicle
Tissues and cell types examined:
femur bone marrow cells
Evaluation criteria:
The chromosomes were examined blind by three persons. Slides from femur  bone marrow cells were prepared according to standard methods, and 100  metaphases per animal analyzed for chromosomal aberrations (including  gaps, breaks, deletions, and exchanges).
Sex:
male
Genotoxicity:
negative
Toxicity:
no effects
Vehicle controls validity:
not specified
Negative controls validity:
not specified
Positive controls validity:
not specified

MUTANT/ABERRATION/mPCE/ POLYPLOIDY FREQUENCY:

No significant increase of chromosomal aberrations compared to negative control even at dosage  levels exceeding the M.T.D. of 940 mg/kg bw.

Additional information

The in-vitro genetic toxicity of disodium metasilicate nonahydrate was investigated in the Ames test (BASF SE, 2012).The standard plate test and the preincubation test were conducted each with S. typhimurium strains TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2 uvrA in the presence and absence of a metabolic activation system. Concentrations up to 5000 µg/plate were used for the standard plate test and concentrations up to 2500 µg/plate for the preincubation test. The test substance did not induce reversions in any of the S. typhimurium strains or in E. coli WP2 uvrA with or without metabolic activation.

All other in vitro mutagenicity tests with bacteria were negative. Sodium silicate (MR = 3.3) also did not induce chromosomal aberrations and HPRT mutations in V79 mammalian cells in vitro, both in the presence and the absence of metabolic activation. In vivo, sodium metasilicate did not induce chromosome aberrations in the bone marrow of mice. From the available results it can be concluded that there is no evidence of a genotoxic potential for potassium silicate.


Short description of key information:
in vitro: negative
in vivo: negative

Endpoint Conclusion:

Justification for classification or non-classification

The available data is conclusive but not sufficient for classification.