Tetraoctyltin

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:

11 October 2002 to 1 November 2002

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP study conducted according to OCED guidelines

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2002

Report date:

2002

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:

equivalent or similar to guideline

Guideline:

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

Test guideline 3

Qualifier:

equivalent or similar to guideline

Guideline:

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

Principles of method if other than guideline:

No deviations from guidelines.

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Tetraoctyltin

EC Number:

222-733-7

EC Name:

Tetraoctyltin

Cas Number:

3590-84-9

Molecular formula:

C32H68Sn

IUPAC Name:

tetraoctylstannane

Details on test material:

- Name of test material (as cited in study report): tetraoctyltin
- Molecular formula (if other than submission substance): Not stated
- Molecular weight (if other than submission substance): 571.6
- Smiles notation (if other than submission substance): Not stated
- InChl (if other than submission substance): Not stated
- Structural formula attached as image file (if other than submission substance): Not stated
- Substance type: Monoconstituent
- Physical state: Slightly yellow turbid liquid, density = 0.96 g/cm3
- Analytical purity: 89.5% (reported); 90.79% (measured)
- Impurities (identity and concentrations):
Trioctyltin chloride = 8.44%
Dioctyltin dichloride = 0.74%
Monooctyltin trichloride = 0.03%
- Composition of test material, percentage of components: See above
- Isomers composition: N/A
- Purity test date: Not stated in this report ( 11-31 December 2002 given in 7.5.1, repeated dose toxicity report, for same compound lot)
- Lot/batch No.: 346272
- Expiration date of the lot/batch: 31 July 2004
- Radiochemical purity (if radiolabelling): N/A
- Specific activity (if radiolabelling): N/A
- Locations of the label (if radiolabelling): N/A
- Expiration date of radiochemical substance (if radiolabelling): N/A
- Stability under test conditions: Not stated
- Storage condition of test material: At less than -18C in the absence of light
- Other:

Method

Target gene:

Salmonella typhimurium: four strains with the following mutation (one per strain)- His D3052, His G46 (+R), His G46 (-R), His C3076
Escherichia coli: Trp

Species / strain

Species / strain 1

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98 and TA 100

Details on mammalian cell type (if applicable):

- Type and identity of media: Molten top agar (0.6% agar + 0.05mM L-histidine.HCl/0.05 biotin) and minimal glucose agar plates (1.5% agar in Vogel and Bonner medium E with 2% glucose)
- Properly maintained: yes
- Periodically checked for Mycoplasma contamination: no
- Periodically checked for karyotype stability: no
- Periodically "cleansed" against high spontaneous background: no

Additional strain / cell type characteristics:

not specified

Species / strain 2

Species / strain / cell type:

E. coli WP2 uvr A

Details on mammalian cell type (if applicable):

- Type and identity of media: Molten top agar (0.6% agar + 0.05mM L-histidine.HCl/0.05 biotin supplemented with 0.05 mM tryptophane) and minimal glucose agar plates (1.5% agar in Vogel and Bonner medium E with 2% glucose)
- Properly maintained: yes
- Periodically checked for Mycoplasma contamination: no
- Periodically checked for karyotype stability: no
- Periodically "cleansed" against high spontaneous background: no

Additional strain / cell type characteristics:

not specified

Metabolic activation:

with and without

Metabolic activation system:

S9 liver homogenate

Test concentrations with justification for top dose:

0, 62, 185, 556, 1667, 5000 µg tetraoctyltin/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO
- Justification for choice of solvent/vehicle: No justification given

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

not specified

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

other: See table 2

Details on test system and experimental conditions:

METHOD OF APPLICATION: in medium; in agar (plate incorporation)

ORIGIN OF STRAINS:
S. typhimurium strains - Dr. B.N. Ames (University of California, Berkeley, USA)
E. coli strain- Dr. C. Voogd National Institute of Public Health, Bilthoven, the Netherlands)

DURATION
- Preincubation period: Not stated
- Exposure duration: 48 to 72 hours
- Expression time (cells in growth medium): Not stated
- Selection time (if incubation with a selection agent): Not stated
- Fixation time (start of exposure up to fixation or harvest of cells): Not stated

SELECTION AGENT (mutation assays): L-histidine for S. typhimurium assays; tryptophan for E. coli assay

SPINDLE INHIBITOR (cytogenetic assays): N/A

STAIN (for cytogenetic assays): N/A

NUMBER OF REPLICATIONS: Three plates per treatment level in both dose-range finding test and main study

NUMBER OF CELLS EVALUATED: Not stated

DETERMINATION OF MUTAGENICITY
- Method: A test substance is considered to be positive in the bacterial gene mutation test if the mean number of revertant colonies on the test plates is concentration-related increased or if a reproducible two-fold or more increase is observed compared to that on the negative control plates. A test substance is considered to be negative in the bacterial gene mutation test if it produces niether a dose-related increase in the mean number of revertant colonies nor a reproducible positive at any of the test points.

OTHER EXAMINATIONS:
- Determination of polyploidy: N/A
- Determination of endoreplication: N/A

Evaluation criteria:

The mutagenicity study is considered valid if the colony counts of the control values of the strains are within acceptable ranges, it the results of the positive controls meet the criteria for a positive response, and if no more than 5% of the plates are lost through contamination or other unforseen events.

Positive results from the bacterial reverse mutation test indicate that a substance induces point mutations by base substitutions or frameshifts in the genome of either S. typhimurium and/or E. coli. Negative results indicate that under test conditions, the test substance is not mutagenic in the tested strains.

Both numerical significance and biological relevance are considered together in the evaluation.

Statistics:

No statistical analysis was performed

Results and discussion

Test results

Test results 1

Species / strain:

S. typhimurium TA 1535, TA 1537, TA 98 and TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not determined

Vehicle controls validity:

not specified

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 2

Species / strain:

E. coli WP2 uvr A

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not determined

Vehicle controls validity:

not specified

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- Effects of pH: Not stated/measured
- Effects of osmolality: Not stated/measured
- Evaporation from medium: Not stated/measured
- Water solubility: Not stated/measured
- Precipitation: Not stated/measured
- Other confounding effects: Not stated/measured

RANGE-FINDING/SCREENING STUDIES: Yes. A dose range finding test to assess the toxicity of the test substance to the bacteria was performed with TA98 both in the absence and presence of S9-mix. DMSO was chosen as vehicle. Just before use, the test substance was dissolved in the vehicle at 50 mg/mL, assumed that the purity ws 89.5%. A colourless slightly viscous solution was obtained. Serial 3-fold dilutions in DMSO were prepared and in total ten dilutions were tested, ranging from 0.3 to 5000 µg/plate.

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

Table 1: Average number of revertants per plate- main study

	TA 1535		TA 1537		TA 98		TA 100		E. coli
	-S9	+S9	-S9	+S9	-S9	+S9	-S9	+S9	-S9	+S9
0µg/ plate	28	15	17	19	35	60	181	202	36	44
62µg/ plate	20	15	25	22	47	68	184	192	41	41
185µg/ plate	22	16	19	23	36	64	176	187	25	40
556µg/ plate	22	19	15	26	29	59	177	176	33	35
1667µg/ plate	20	17	19	21	43	54	177	174	42	49
5000µg/ plate	23	22	12	20	43	58	183	171	40	34
Positive control	659	544	2050	336	1818	1930	751	3169	160	1482

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative

It is concluded that the results obtained with the test substance in S. typhimurium strains TA 1535, TA 1537, TA98, and TA 100, and in the E. coli strain WP2 uvrA, in both the absence and presence of the S9-mix indicate that Tetraoctyltin was not mutagenic under the conditions employed in this study.

Executive summary:

1) The test substance Tetraoctyltin [CAS # 3590 -84 -9] was examined for mutgenic activity in the bacterial reverse mutation test using the histidine-requiring Salmonella typhimurium strains TA 1535, TA 1573, TA 98, and TA 100, the tryptophan-requiring Escherichia coli strain WP2 uvrA, and a liver fraction of Arochlor 1254 -induced rats for metabolic activation (S9 -mix).

2) The test substance was dissolved in DMSO. A dose range finding test was performed with TA 98 both in the absence and presence of S9 -mix with ten different concentrations of the test substance, ranging from 0.3 -5000 µg/plate. Tetraoctyltin was not toxic at any concentration.

3) In the main bacterial reverse mutation test, five different concentrations were tested ranging from 62 -5000 µg/plate. Negative controls (solvent) and positive controls were run simultaneously with the test substance.

4) Tetraoctyltin was not toxic to any strain at any concentration, as was evidenced by the absence of a decrease in the mean number of revertant colonies.

5) In both the absence and the presence of S9 -mix and in all strains, Tetraoctyltin did not cause a more than two-fold increase in the mean number of revertant colonies appearing in the test plates compared to the background spontaneous reversion rate observed with the negative control.

6) The mean number of his+ and trp+ revertant colonies of the negative controls were within the acceptable range, and the positive controls gave the expected increase in the mean number of revertant colonies.

7) It is concluded that Tetraoctyltin was not mutagenic under the conditions employed in this study.