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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:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Guideline study (non-GLP), no confirmatory experiment

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1991
Report Date:
1991

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
yes
Remarks:
(no confirmatory experiment)
GLP compliance:
no
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid
Details on test material:
- Name of test substance (as cited in study report): Tinuvin 329
- Analytical purity: >99%
- Batch No.: EN 171744.92
- Physical state: solid
- Storage conditions: room temperature
- Validity: November 1993
Specific details on test material used for the study:
- Name of test substance (as cited in study report): Tinuvin 329
- Analytical purity: >99%
- Batch No.: EN 171744.92
- Stability: checkt via reanalysis

Method

Target gene:
his- and trp-operon
Species / strain
Species / strain / cell type:
other: Salmonella typhimurium: TA 98, TA 100, TA 1535, TA 1537; Escherichia coli: WP2uvrA
Metabolic activation:
with and without
Metabolic activation system:
S9-mix: Aroclor-induced rat liver S9 fraction (1 part) and co-factors: NADP, MgCl2, KCl, Glucose-6-phosphate in Na-phosphate buffer) (9 parts)
Test concentrations with justification for top dose:
Concentration range in the cytotoxicity/range finding test: 20.6 - 5,000 µg/plate
Concentration range in the mutagenicity test: 625 - 5,000 µg/plate (with and without metabolic activation)
Vehicle / solvent:
DMSO
Controls
Negative solvent / vehicle controls:
yes
Positive controls:
yes
Positive control substance:
other: (- S9-mix): sodium azide (TA 100 and TA 1535), 4-nitroquinoline-N-oxide (WP2uvrA), 2-nitrofluorene (TA 98), 9(5)-aminoacridine (TA1537); (+S9-mix): 2-aminoanthracene (TA 100, TA 98, TA 1537, WP2uvrA), cyclophosphamide (TA 1535)
Details on test system and experimental conditions:
METHOD OF APPLICATION: in medium; in agar (plate incorporation)

DURATION
- Exposure duration: 48 h at 37 °C

NUMBER OF REPLICATIONS: 2 plates/dose

DETERMINATION OF CYTOTOXICITY
- Method: number of colonies and determination of background lawn in comparison to the corresponding control values

OTHER: range finding test
- Strains: S. typhimurium TA 100 and E. coli WP2uvrA
- Concentrations: 20.6, 61.7, 185.2, 555.6, 1666.7 and 5000.0 µg/plate
- Number of replications: 1 plate/dose
- Exposure duration: 48 h
5000 µg/plate was chosen as highest dose for the mutagenicity assay.
Evaluation criteria:
Criteria for a positive response: The test substance is considered to be mutagenic in this test system if:
- A positive effect is observed in one strain and the effect can be reproduced in a confirmatory experiment.
- A positive effect is observed in two or more strains.
A positive effect is defined as an increase of the mean number of revertants per plate for any concentration above that of the negative control by at least a factor of 2.0 with strains TA 98, TA 1535, TA 1537 and WP2uvrA, or by a factor of at least 1.5 with strain TA 100. Generally a concentration-related effect should be demonstrable.

Acceptance critaria: A test is considered acceptable if the mean colony counts of the control values of all strains are within the acceptable ranges and if the results of the positve controls meet the criteria for a positive resoponse.

Results and discussion

Test results
Species / strain:
other: Salmonella typhimurium: TA 98, TA 100, TA 1535, TA 1537; Escherichia coli: WP2uvrA
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
(reduced number of revertants at 5000 µg/plate in TA 98 without metabolic activation: factor 0.39 compared to control)
Vehicle controls validity:
valid
Positive controls validity:
valid
Additional information on results:
- Precipitation: Precipitation occurred at concentrations >= 1666.7 µg/plate
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

Standard plate test:

 Dose (µg/plate)

 TA100

 TA1535   

 TA1537   

 TA98   

    E. coli WP2 uvrA

 

 -S9

 +S9

 -S9

 +S9

 -S9

 +S9

-S9

 +S9

-S9 

+S9 

 0

166.5

140.0

10.0

12.5

6.5

12.5

20.5

40.5

19.5

22.0

625 

161.5

141.5

8.5

13.0

8.0

12.0

15.5

31.5

13.0

23.5

1250

147.0

123.0

11.0

13.0

6.5

13.0

18.5

27.5

13.5

15.0

 2500

143.5

120.0

6.5

9.0

7.0

11.5

18.0

25.5

14.5

13.0

 5000

128.5

113.0

6.5

9.0

6.0

7.5

8.0

30.0

18.0

15.5

 Sodium azide

1778.0

-

1452.5

-

-

-

-

-

-

-

 4-NQO

-

-

-

-

-

-

-

-

847.0

-

 2-nitrofluorene

 -

-

-

-

-

-

1278.5

-

-

-

 AAC

-

 

-

-

1491.5

-

-

-

-

-

2-AA

-

1936.0

-

-

-

249.0

-

2239.5

-

1015.0

Cyclophosphamide

 -

-

-

377.0

-

-

-

-

-

-

Mean ± SD 

X: reduced background growth

4-NQO: 4-nitroquinoline-N-oxide

AAC: 9-aminoacridine chloride monohydrate

2-AA: 2-aminoanthracene

 

 

According to the results of the study, the test substance is not mutagenic in the Ames test and in the Escherichia coli - reverse mutation assay under the experimental conditions chosen here. The positive controls gave the expected values.

 

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative