Tin zinc oxide (SnZnO3)

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:

14 February 1989 - 3 March 1989

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Read across to similar substance. Study conducted to GLP in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not affect the quality of the relevant results.

Justification for type of information:

See read-across justification in Section 13.

Cross-reference

Reason / purpose for cross-reference:

other: Target substance

Reference

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study conducted on read across material

Justification for type of information:

See read-across justification in Section 13.

Reason / purpose for cross-reference:

read-across source

Species / strain:

S. typhimurium, other: TA 1535, TA100, TA 1537, TA 98

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

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Report date:

1989

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Automatically generated during migration to IUCLID 6, no data available

IUPAC Name:

Automatically generated during migration to IUCLID 6, no data available

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

Description: White powder

Method

Target gene:

S. typhimurium: Histidine locus

Species / strain

Species / strain / cell type:

S. typhimurium, other: TA1535, TA100, TA1537, TA1538 and TA98

Additional strain / cell type characteristics:

other: TA1535 and TA100 are sensitive to agents inducing base-pair substitutions. TA1537, TA1538 and TA98 are sensitive to agents inducing frame-shift mutations.

Metabolic activation:

with and without

Metabolic activation system:

S9. Prepared from the livers of male Sprague-Dawley rats that had each recieved a single i.p. injection of Aroclor 1254 at 500 mg/kg 5 days before S9 preparation.

Test concentrations with justification for top dose:

Experiment 1 ± S9: 0, 8, 40, 200, 1000, 5000 µg/plate
Experiment 2 ± S9: 0, 312.5, 625, 1250, 2500, 5000 µg/plate

Vehicle / solvent:

The test material was accurately weighed and dissolved in sterile distilled water and appropriate dilutions made.

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Remarks:

A solvent treatment group was used as the negative control

Positive controls:

yes

Positive control substance:

other: N-Methyl-N'-nitro-N-nitrosoguanidine (MNNG); 9-Aminoacridine (9AA); 4-Nitro-O-phenylenediamine (4NOPD) and 2-Aminoanthracene (2AA)

Details on test system and experimental conditions:

Test Procedure
a) Preliminary Toxicity Study
In order to select appropriate dose levels for use in the main study, a preliminary test was carried out to determine the toxicity of the test material to the tester organisms. 0.1 mL of bacterial suspension (TA100) and 0.L ml of test solution were added to 2 mL of molten, trace histidine supplemented media (histidine/biotin & top agar) and overlayed onto sterile plates of Vogel-Bonner agar (minimal agar - 25 mL/ plate). Five doses of the test compound and a solvent control (distilled water) were tested in duplicate. After 48 - 72 hours incubation the plates were scored for revertant colonies and examined for a thinning of the background lawn.
b) Mutation Study
EXPERIMENT 1
Five concentrations of the test material were assayed in triplicate against each tester strain, using the direct plate incorporation method in accordance with the standards for mutagenicity tests using microorganisms.
Test Material and Negative Controls
0.1 mL of the appropriately diluted test material or negative control solution was placed in sets of sterile test tubes containing 2.0 mL of molten, trace histidine supplemented, top agar at 45°C. These sets comprised of two test tubes for each bacterial tester strain. A 0.1 mL aliquot of one of the bacterial suspensions was also added to each of the two test tubes. Into one of the test tubes was placed 0.5 mL of the S9 liver microsome mix; in the other tube 0.5 mL of pH 7.4 buffer was added. This procedure was repeated, in triplicate, for each bacterial strain and for each concentration of test material.
Positive Controls
Without Activation
0.1 mL of one of the positive control solutions (MNNG, 9AA, or 4NOPD) was added to a test tube containing 2.0 mL of molten, trace histidine supplemented, top agar. 0.1 mL of the appropriate bacterial suspension and 0.5 mL of pH 7.4 buffer was also added to the test tube. This procedure was then repeated, in triplicate, for each of the positive controls.
With Activation
0.1 mL of 2AA solution was added to a test tube containing 2.0 mL of molten, trace histidine supplemented, top agar. 0.1 mL of one of the test bacterial suspensions and 0.5 mL of S9 mix were also added to the test tube. The procedure was then repeated, in triplicate, for each tester strain.

The contents of each test tube were equally distributed onto the surface of Vogel-Bonner agar plates (one tube per plate). These plates were incubated at 37°C for at least 48 hours and the number of revertant colonies counted.
EXPERIMENT 2
The complete experiment was repeated using fresh bacterial cultures, test material and control solutions.

Statistics:

For a substance to be considered positive in this test system, it should have induced a dose-related and statistically significant increase in mutation rate (of at least twice the spontaneous reversion rate) in one or more strains of bacteria in the presence and/or absence of the S9 microsomal enzymes in both experiments. To be considered negative the number of induced revertants compared to spontaneous revertants should be less than twofold at each dose level employed, the intervals of which should be between 2 and 5 fold and extend to the limits imposed by toxicity, solubility or up to the maximum recommended dose of 5000 µg/plate. In this case the limiting factor was the maximum recommended dose.

Results and discussion

Test results

Species / strain:

S. typhimurium, other: TA1535, TA100, TA1537, TA1538 and TA98

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:

a) Preliminary Toxicity Study
The dose range of Substance 1658/5 used in the preliminary toxicity study was 0, 312.5, 625, 1250, 2500 and 5000 µg/plate. The test material was nontoxic in the strain of Salmonella used (TA100).
b) Mutation Study
Checks were done on viability and spontaneous reversion rate for each tester strain. The overnight culture of each strain was found to be in the required range of 10^7 – 10^9 bacteria per mL and the spontaneous reversion rate for each was found to be within the expected range.
No toxicity was exhibited to any of the strains of Salmonella used.
No significant increases in the numbers of revertant colonies of bacteria were recorded for any of the strains of Salmonella, at any dose level used, either with or without metabolic activation.
The positive control substances all produced marked increases in the number of revertant colonies and the activity of the S9 fraction was found to be satisfactory.

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

Experiment 1

 

Mutation Study Mean and Individual Plate Counts for Test Material and Negative Controls

Strain of Salmonella typhimurium	Concentration (µg/plate)	Metabolic Activation	Mean Number of Revertants
TA1535	5000 1000 200 40 8 0   5000 1000 200 40 8 0	- - - - - -   + + + + + +	14 18 13 15 20 15   11 12 13 15 10 13
TA1537	5000 1000 200 40 8 0   5000 1000 200 40 8 0	- - - - - -   + + + + + +	6 4 3 3 6 5   9 8 9 10 7 9
TA1538	5000 1000 200 40 8 0   5000 1000 200 40 8 0	- - - - - -   + + + + + +	8 13 11 9 8 11   16 18 14 19 20 18
TA98	5000 1000 200 40 8 0   5000 1000 200 40 8 0	- - - - - -   + + + + + +	17 23 15 17 19 20   25 29 20 26 21 28
TA100	5000 1000 200 40 8 0   5000 1000 200 40 8 0	- - - - - -   + + + + + +	85 84 95 89 93 98   94 93 102 104 102 85

 

Experiment 2

Mutation Study Mean and Individual Plate Counts for Test Material and Negative Controls

Strain of Salmonella typhimurium	Concentration (µg/plate)	Metabolic Activation	Mean Number of Revertants
TA1535	5000 2500 1250 625 312.5 0   5000 2500 1250 625 312.5 0	- - - - - -   + + + + + +	11 11 13 10 10 10   15 10 12 13 17 13
TA1537	5000 2500 1250 625 312.5 0   5000 2500 1250 625 312.5 0	- - - - - -   + + + + + +	7 8 8 7 5 8   9 11 8 8 9 11
TA1538	5000 2500 1250 625 312.5 0   5000 2500 1250 625 312.5 0	- - - - - -   + + + + + +	10 8 9 13 14 13   14 10 13 11 11 15
TA98	5000 2500 1250 625 312.5 0   5000 2500 1250 625 312.5 0	- - - - - -   + + + + + +	17 15 16 16 15 20   23 25 24 24 21 26
TA100	5000 2500 1250 625 312.5 0   5000 2500 1250 625 312.5 0	- - - - - -   + + + + + +	87 74 72 82 88 81   93 85 93 90 86 94

 

Positive Controls

Experiment 1

Mean and Individual Plate Counts for Concurrent Positive Controls

Strain of Salmonella typhimurium	Test Material	Concentration (µg/plate)	Metabolic Activation	Mean Number of Revertants
TA1535 TA1537 TA1538 TA98 TA100 TA1535 TA1537 TA1538 TA98 TA100	MNNG 9AA 4NOPD 4NOPD MNNG 2AA 2AA 2AA 2AA 2AA	2 50 10 10 2 3.3 3.3 3.3 3.3 3.3	- - - - - + + + + +	45 316 655 751 519 65 41 241 551 970

 

Experiment 2

Mean and Individual Plate Counts for Concurrent Positive Controls

Strain of Salmonella typhimurium	Test Material	Concentration (µg/plate)	Metabolic Activation	Mean Number of Revertants
TA1535 TA1537 TA1538 TA98 TA100 TA1535 TA1537 TA1538 TA98 TA100	MNNG 9AA 4NOPD 4NOPD MNNG 2AA 2AA 2AA 2AA 2AA	2 50 10 10 2 3.3 3.3 3.3 3.3 3.3	- - - - - + + + + +	103 401 509 678 394 124 219 335 375 558

 

REFERENCES

Ames, B.N., Durston, W.E., Yamasaki, E., and Lee, F.D. Proc. Nat. Acad. Sci. USA (1970), 70, 2285

Ames, B.N., McCann, J. and Yamasaki, E., Mutation Research (1975), 31, 347.

McCann, J., Coi, E., Yamasaki, E., and Ames, B.N. Proc. Nat. Acad. Sci. USA (1975) 75, 5135.

Garner, R.C., Miller, E.C., and Miller, J.A. Cancer Res. (1972), 33, 2058.

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative

The test material was found to be non-mutagenic under the conditions of this test.

Executive summary:

The test material, SUBSTANCE 1658/5, was found to be non-mutagenic under the conditions of this test, in both the presence and absence of metabolic activation. The method used conforms with the OECD Guidelines for the Testing of Chemicals, Protocol No. 471 and also with Method B14 in Annex V of EEC Commission Directive 84/449/EEC.