Potassium titanium oxide (K1.88-2.13Ti8O16.94-17.07)

Genetic toxicity: in vitro

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

Study period:

18th August 2004 - 31st August 2004

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

other: Body responsible for the test

Title:

Unnamed

Year:

2004

Report date:

2004

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.5100 - Bacterial Reverse Mutation Test (August 1998)

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Terracess TF

IUPAC Name:

Terracess TF

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

- Name of test material (as cited in study report): Terracess TF-L
- Appearance: white powder
- Purity: 99.6%
- Lot/batch No.: 26472 (laboratory identification number)

Method

Target gene:

histidine locus (salmonella)
tyryptophan locus (Ecoli)

Species / strain

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2

Details on mammalian cell type (if applicable):

Tester strain cultures were checked for the following genetic markers on the day of the preparation of master plates.

The histidine requirement was tested by comparing the growth of each Salmonella tester strain on a histidine/biotin-supplemented minimum glucose agar plate with their growth on a biotin-only minimum glucose agar plate.

The tryptophan requirement was tested by comparing the growth of WP2uvrA strain on a tryptophan-supplemented minimum glucose agar plate with their growth on a minimum glucose agar plate.

For the Salmonella tester strains the presence of the rfa wall mutation was confirmed by demonstration of the sensitivity of the cultures to crystal violet.

The presence of uvrA and uvrB mutation was demonstrated by their sensitivity to ultraviolet light of the tester strains.

The presence of the pKM101 plasmid was confirmed for cultures of tester strains TA98 and TA 100 by demonstration of resistance to ampicillin.

Metabolic activation:

with and without

Metabolic activation system:

Aroclor induced rat liver (S-9 mix).

Test concentrations with justification for top dose:

Initial toxicity mutation test: 33.3, 66.7, 100, 333, 667, 1000, 3333, and 5000 µg per plate.
Confirmatory mutagenicity test: 333, 667, 1000, 3333, and 5000 µg per plate.

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO (dimethyl sulfoxide)

- Justification for choice of solvent/vehicle: DMSO was chosen as the dosing vehicle based on the solubility of the test substance and compatibility with the target cells. Terracess TF-L was a homogeneous suspension in DMSO at the highest concentration, 50 mg/ml, tested in the study.

Controls

Untreated negative controls:

yes

Remarks:

DMSO

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

True negative controls:

no

Positive controls:

yes

Positive control substance:

benzo(a)pyrene

Remarks:

Others used: benzo[a]pyrene 2-nitrofluorene; 2-arninoanthracene; sodium azide and ICR-191

Details on test system and experimental conditions:

Concentration of the test substance resulting in precipitation: 667 µg/plate

Evaluation criteria:

Strains TA1535 and TA1537: Data will be judged positive if the increase in mean revertants at the highest numerical dose response is ? 3.0-fold the mean concurrent negative control value (vehicle control). This increase in the mean number of revertants per plate must be accompanied by a dose response
associated with increasing concentrations of the test substance.
2. Strains TA98, TAl00 and WP2uvrA: Data sets will be judged positive if the increase in mean revertants at the highest numerical dose
response is ? 2.0-fold the mean concurrent negative control value (vehicle control). This increase in the mean number of revertants per plate must be accompanied by a dose response to increasing concentrations of the test substance.

Statistics:

For each tester strain, the mean of the number of revertants and the standard deviation were calculated.

Results and discussion

Test results

Test results 1

Key result

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

(> 5000 µg/plate)

Vehicle controls validity:

valid

Positive controls validity:

valid

Test results 2

Key result

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Remarks:

(> 5000 µg/plate)

Vehicle controls validity:

valid

Positive controls validity:

valid

Test results 3

Key result

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Remarks:

(> 5000 µg/plate)

Vehicle controls validity:

valid

Positive controls validity:

valid

Test results 4

Key result

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Remarks:

(> 5000 µg/plate)

Vehicle controls validity:

valid

Positive controls validity:

valid

Test results 5

Key result

Species / strain:

E. coli WP2 uvr A

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Remarks:

(> 5000 µg/plate)

Vehicle controls validity:

valid

Positive controls validity:

valid

Additional information on results:

No appreciable toxicity was observed in any of the tester strains.
No positive mutagenic responses were observed in any of the tester strains at any dose level in either the presence or absence of the metabolic activation.

Any other information on results incl. tables

The S9 was thawed and the 10% S9 mix prepared immediately prior to its use. The S9 mix was held on ice at all times before use. The S9 mix contained the following components:

 

dd-H20	2.4 mL
0.825 M KCI/0.2 M MgCl2	0.4 mL
0.2 M phosphate buffer, pH 7.4	5.0 mL
10 mL	0.2 mL
0.04MNADP	l.0 mL
S9	l.0 mL
Total Volume	10 mL

 

 No contaminant colonies were observed on the sterility plates for the most concentrated test substance dilution (50 mg/mL) and the S9 and sham mixes (100 mM phosphate buffer at pH 7.4)

Applicant's summary and conclusion

Conclusions:

All criteria for a valid study were met. Under the conditions of this study, Terracess TF-L showed no evidence of mutagenicity in the Bacterial Reverse Mutation Test either in the presence or absence of Aroclor-induced rat liver S9. The test substance was concluded to be negative in this study.