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Toxicological information

Genetic toxicity: in vitro

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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
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: The study was conducted according to a protocol that is similar to the appropriate OECD test guideline, and in compliance with GLP.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1993
Report Date:
1993

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
no
GLP compliance:
yes
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent

Method

Species / strainopen allclose all
Species / strain / cell type:
other: TA-98,TA-100,TA-1535,TA-1537,TA-1538, TA-102
Species / strain / cell type:
E. coli WP2 uvr A
Metabolic activation:
with and without
Metabolic activation system:
0.5 ml Aroclor 1254 induced rat liver S9
Test concentrations with justification for top dose:
100, 333, 1000, 3333 and 5000 µg/plate
Vehicle / solvent:
- Vehicle: DMSO at 50 µl
Controlsopen allclose all
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 2-aminoanthracene
Remarks:
with activation, all strains except TA 102
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other:  sterigmatocystin
Remarks:
TA 102 with activation
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
2-nitrofluorene
Remarks:
TA 98 and TA 1537 without activation
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
sodium azide
Remarks:
TA 100 and TA 1535 without activation
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
cumene hydroperoxide
Remarks:
TA 102 without activation
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
methylmethanesulfonate
Remarks:
E coli without activation
Details on test system and experimental conditions:
METHOD OF APPLICATION: in agar (plate incorporation)

DURATION
- Exposure duration: 48-72 hours
- Expression time (cells in growth medium): 48-72 hours
- Fixation time (start of exposure up to fixation or harvest of cells): 48-72 hours

NUMBER OF REPLICATIONS: triplicate plates

DETERMINATION OF CYTOTOXICITY
- Method: other: condition of background lawn
Evaluation criteria:
All cultures must demonstrate the characteristic mean number of spontaneous revertants in the vehicle control as shown below:  

TA98          10 - 50
TA100         80 - 240
TA1535         5 - 45
TA1537         3 - 21
TA1538         5 - 35
TA102        200- 380
WP2uvrA     10 - 60

For the test article to be evaluated positive, it must cause a dose-related increase in the mean revertants per plate of at least one tester strain with a minimum of two increasing concentrations of test article. Data sets for strains TA1535, TA1537 and TA1538 will be judged positive if the increase in mean revertants at the peak of the dose response is equal to greater than three times the mean vehicle control value. Data sets for strains TA98, TA100, and WP2uvrA will be judged positive if the increase in mean revertants at the peak of the dose-response is equal to or greater than two times the mean vehicle control value.
Statistics:
None

Results and discussion

Test resultsopen allclose all
Species / strain:
S. typhimurium TA 98
Metabolic activation:
without
Genotoxicity:
positive
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Remarks:
none
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
Positive controls validity:
valid
Species / strain:
other: TA-100 and TA-1535
Metabolic activation:
with and without
Genotoxicity:
positive
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
Positive controls validity:
valid
Species / strain:
other: Salmonella typhimurium/TA-1537,TA-1538, TA-102; Escherichia coli/WP2uvrA
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
Positive controls validity:
valid
Additional information on results:
No precipitate or bacterial toxicity was observed in this assay. 
A positive response was observed with bacterial tester strain  TA-98 in the absence of metabolic activation and tester strains TA-100 and TA-1535 with and without metabolic activation. The authors concluded that under these experimental conditions, the test material caused mutagenicity in three bacterial tester strains.
Cytotoxic concentration: 
*   With metabolic activation:  No toxicity observed at the  maximum dose of 5000 ug/plate
*   Without metabolic activation: No toxicity observed at the  maximum dose of 5000 ug/plate
Genotoxic effects (e.g. positive, negative, unconfirmed, dose-response, equivocal): 
*   With metabolic activation: Positive in TA-100 and TA-1535
*   Without metabolic activation: Positive in TA-98, TA-100 and TA-1535
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

Table 1: Dose range-finding study

 

TA 100

E.coli WP2 uvrA

Conc.
(
µl/ml)

- MA

+ MA

Cytotoxic
(yes/no)

- MA

+ MA

Cytotoxic
(yes/no)

0

122

129

no

13

15

no

6.7

140

163

no

16

23

no

10

121

140

no

11

15

no

33

142

129

no

17

14

no

67

143

118

no

26

18

no

100

144

119

no

20

21

no

333

151

129

no

20

23

no

667

148

158

no

26

10

no

1000

209

196

no

25

18

no

3333

298

275

no

22

20

no

5000

308

446

no

23

27

no

*solvent control with DMSO

 

Table 2: - Plate incorporation:Number of revertants per plate (mean of 3 plates)

 

TA 98

TA 100

TA 1535

Conc.
(
µl/ml)

- MA

+ MA

Cytotoxic
(yes/no)

- MA

+ MA

Cytotoxic
(yes/no)

- MA

+ MA

Cytotoxic
(yes/no)

0*

19

NT

no

115

169

no

9

12

no

100

12

NT

no

137

168

no

18

13

no

333

24

NT

no

148

166

no

21

16

no

1000

30

NT

no

136

206

no

61

41

no

3333

34

NT

no

232

271

no

138

165

no

5000

43

NT

no

246

356

no

190

248

no

Positive control

262

NT

no

494

1023

no

428

176

no

*solvent control with DMSO

NT: not tested

 

Table 3: -Plate incorporation:Number of revertants per plate (mean of 3 plates)

TA 1537

TA 1538

TA 102

E.coli WP2 uvrA

Conc.
(
µl/ml)

- MA

+ MA

Cytotoxic
(yes/no)

- MA

+ MA

Cytotoxic
(yes/no)

- MA

+ MA

Cytotoxic
(yes/no)

- MA

+ MA

Cytotoxic
(yes/no)

0*

7

7

no

6

23

no

263

359

no

17

21

no

100

6

7

no

4

16

no

30

348

no

18

12

no

333

6

12

no

6

18

no

309

358

no

14

22

no

1000

9

9

no

6

20

no

295

414

no

20

22

no

3333

6

9

no

9

22

no

314

409

no

25

27

no

5000

9

8

no

11

18

no

329

404

no

23

25

no

Positive control

1052

129

no

321

944

no

1300

2312

no

132

570

no

*solvent control withDMSO

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
positive with and without activation in strains TA 100 and TA 1535
positive without metabolic activation strain TA 98
negative with metabolic activation strain TA 98
negative with and without activation in all other strains

The substance has been tested in a valid study under GLP using a method equivalent to OECD TG 471. An dose-dependent increase in the number of revertants was observed in Salmonella strains TA-100 and TA-1535 with and without metabolic activation, and in strain TA-98 in the absence of metabolic activation. It is concluded that 3-chloropropltrimethoxysilane is positive for mutagenicity to bacteria under the conditions of this test.