Dipotassium heptafluorotantalate

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:

11th April 2000 to 25th April 2000

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Study conducted in compliance with agreed protocols, with no deviations from standard test guidelines and no methodological deficiencies, which do not affect the quality of the relevant results. The study report was conclusive, done to a valid guideline and the study was conducted under GLP conditions.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2001

Report date:

2001

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

Test guideline 3

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Test guideline 4

Qualifier:

according to guideline

Guideline:

JAPAN: Guidelines for Screening Mutagenicity Testing Of Chemicals

Deviations:

no

GLP compliance:

yes

Type of assay:

bacterial gene mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Dipotassium heptafluorotantalate

EC Number:

240-986-1

EC Name:

Dipotassium heptafluorotantalate

Cas Number:

16924-00-8

Molecular formula:

F7Ta.2K

IUPAC Name:

Tantalate(2-), heptafluoro-, potassium (1:2)

Test material form:

solid: crystalline

Details on test material:

- Name of test material (as cited in study report): Potassium fluorotantalate
- Substance type: White crystals
- Storage condition of test material: Room temperature

Method

Target gene:

S. typhimurium: Histidine locus
E. coli: Tryptophan locus

Species / strain

Species / strain 1

Species / strain / cell type:

E. coli WP2 uvr A pKM 101

Details on mammalian cell type (if applicable):

- Type and identity of media: Strains were kept in nutrient broth cultures and stored at -80ºC. Dimethyl sulphoxide was added to the cultures at 8% v/v as a cryopreservative.
- Properly maintained: yes
- Each batch was tested for cell membrane permeability, sensitivity to UV light and the pKM101 plasmid. Responses to a series of diagnostic mutagens were also tested.

Species / strain 2

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: Strains were kept in nutrient broth cultures and stored at -80ºC. Dimethyl sulphoxide was added to the cultures at 8% v/v as a cryopreservative.
- Properly maintained: yes
- Each batch was tested for cell membrane permeability, sensitivity to UV light and the pKM101 plasmid. Responses to a series of diagnostic mutagens were also tested.

Metabolic activation:

with and without

Metabolic activation system:

S9 mix

Test concentrations with justification for top dose:

5000, 1500, 500, 150, 50, 15 and 5 µg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: 1% methyl cellulose
- Justification for choice of solvent/vehicle: Test material is insoluble in; water, dimethyl sulphoxide, ethanol, acetone and hexane. After grinding the test material with methyl cellulose an dosable suspension was formed.

Controls

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

Remarks:

1% methyl cellulose

True negative controls:

no

Positive controls:

yes

Positive control substance:

9-aminoacridine

2-nitrofluorene

sodium azide

benzo(a)pyrene

other: 2-(2-furyl)-3-(5-nitro-2-furyl) acrylamide (AF-2) and 2-aminoanthracene

Details on test system and experimental conditions:

METHOD OF APPLICATION: First test: in agar (plate incorporation). Second test: preincubation

First test
- 0.1 mL of a 10 hour bacterial culture and 0.5 mL S-9 mix or 0.5 mL 0.1 M sodium phosphate buffer (pH 7.4) were placed in glass bottles. 100 µL of the test solution was added, followed immediately by 2 mL of molten agar containing 0.05 mM histidine/biotin/tryptophan. The mixture was thoroughly shaken and overlaid onto previously prepared petri dishes containing 25 mL minimal agar. All plates were incubated at 37 ºC for approximately 72 hours. After this period, the appearance of the background bacterial lawn was examined and revertant colonies counted.

Second Test
- A second test was performed due to the negative response of the first test with a variation in procedure. A pre-incubation assay was used in which the bottles contained mixtures of bacteria, buffer or S9 mix and test solution were incubated at 37 ºC for 30 minutes with shaking before the addition of the agar overlay. Only 5 concentrations of the test material were used: 5000, 1500, 500, 150 and 50 µg/plate.

NUMBER OF REPLICATIONS: Each concentration was performed on 3 plates

EXAMINATIONS: After the total incubation period the plates were examined and colony numbers quantified for comparison.

Evaluation criteria:

- If the plates treated with the test material produce an increase in colony numbers of at least twice the concurrent vehicle controls, with evidence of a positive dose-relationship, in two separate experiments, with any bacterial strain either in the presence or absence of S9 mix, it is considered to show evidence of mutagenic activity in the test material.
- If exposure to the test material does not produce reproducible increase of at least 1.5 times the concurrent vehicle controls, in either mutation test, it is considered to show no mutagenic activity in the test material.
- If there is no clear positive response then the results will be subjected to statistical analysis.

Statistics:

The statistical analysis will be performed as described in Mahon et al (1989) and will normally be analysis of variance followed by a Dunnett's test.

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:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Test results 2

Species / strain:

E. coli WP2 uvr A pKM 101

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 precipitation or thinning of background lawn was observed in either Test 1 or Test 2 at any test substance concentration in either the absence or presence of S9.
There were no significant increases in the number of revertant colonies compared to the vehicle control in either Test 1 or Test 2 at any test substance concentration in either the absence or presence of S9.

Full details of results for the test material (table 2) and positive controls (table 3) can be seen in the field "Any other information on results incl. tables".

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

Table 2. Revertant colony counts obtained per plate

Test	Strain	Concentration	S9 mix	Mean revertant colony counts	SD
		(µg/plate)
1	TA 1535	5000	-	11	4
		1500	-	13	6
		500	-	14	2
		150	-	15	5
		50	-	13	8
		15	-	13	2
		5	-	13	2
		Vehicle	-	18	1
		5000	+	11	3
		1500	+	12	2
		500	+	17	5
		150	+	15	4
		50	+	17	2
		15	+	13	2
		5	+	12	5
		Vehicle	+	16	4
	TA 1537	5000	-	6	4
		1500	-	6	2
		500	-	7	3
		150	-	11	3
		50	-	7	2
		15	-	6	2
		5	-	11	5
		Vehicle	-	10	2
		5000	+	8	1
		1500	+	11	4
		500	+	11	2
		150	+	12	4
		50	+	10	4
		15	+	12	3
		5	+	9	3
		Vehicle	+	14	4
	TA 98	5000	-	23	2
		1500	-	24	2
		500	-	20	2
		150	-	25	7
		50	-	19	2
		15	-	22	7
		5	-	25	1
		Vehicle	-	25	1
		5000	+	30	1
		1500	+	26	3
		500	+	25	1
		150	+	27	9
		50	+	26	4
		15	+	27	3
		5	+	24	5
		Vehicle	+	30	5
	TA 100	5000	-	92	9
		1500	-	112	15
		500	-	98	8
		150	-	98	3
		50	-	98	20
		15	-	119	17
		5	-	123	5
		Vehicle	-	113	7
		5000	+	76	2
		1500	+	108	4
		500	+	111	10
		150	+	117	15
		50	+	115	21
		15	+	118	16
		5	+	97	11
		Vehicle	+	114	6
	CM 891	5000	-	181	17
		1500	-	242	4
		500	-	194	19
		150	-	206	7
		50	-	220	19
		15	-	238	12
		5	-	213	3
		Vehicle	-	235	22
		5000	+	215	30
		1500	+	228	9
		500	+	189	19
		150	+	209	5
		50	+	203	4
		15	+	210	45
		5	+	210	5
		Vehicle	+	221	12
2	TA 1535	5000	-	15	2
		1500	-	18	2
		500	-	12	2
		150	-	15	4
		50	-	9	1
		Vehicle	-	14	1
		5000	+	14	0
		1500	+	14	5
		500	+	12	2
		150	+	14	1
		50	+	14	1
		Vehicle	+	14	3
	TA 1537	5000	-	11	2
		1500	-	10	4
		500	-	10	3
		150	-	8	1
		50	-	10	2
		Vehicle	-	10	1
		5000	+	11	3
		1500	+	11	4
		500	+	9	2
		150	+	13	2
		50	+	13	2
		Vehicle	+	12	2
	TA 98	5000	-	27	6
		1500	-	23	3
		500	-	23	4
		150	-	24	3
		50	-	20	10
		Vehicle	-	24	2
		5000	+	26	4
		1500	+	24	2
		500	+	27	2
		150	+	28	4
		50	+	27	2
		Vehicle	+	29	6
	TA 100	5000	-	113	6
		1500	-	115	16
		500	-	115	7
		150	-	111	13
		50	-	110	13
		Vehicle	-	107	7
		5000	+	111	4
		1500	+	124	14
		500	+	122	14
		150	+	115	9
		50	+	117	11
		Vehicle	+	109	9
	CM 891	5000	-	190	19
		1500	-	186	6
		500	-	199	5
		150	-	211	9
		50	-	195	9
		Vehicle	-	189	5
		5000	+	198	10
		1500	+	209	11
		500	+	224	8
		150	+	217	14
		50	+	200	6
		Vehicle	+	193	13

CM 891 - WP2uvrA/pKM101

-      absence 

+   presence

SD  Standard deviation

Table 3. Revertant colony counts per plate for positive controls

Test	Strain	Compound	Concentration	S9 mix	Mean revertant colony counts	SD
			(µg/plate)
1	TA 1535	NaAz	0.50	-	182	34
	TA 1537	9AC	30.00	-	71	6
	TA 98	NF	1.00	-	211	12
	TA 100	NaAz	0.50	-	402	17
	CM 891	AF-2	0.05	-	2006	22
	TA 1535	AA	2.00	+	122	6
	TA 1537	B[a]P	5.00	+	69	6
	TA 98	B[a]P	5.00	+	229	17
	TA 100	B[a]P	5.00	+	750	61
	CM 891	AA	10.00	+	1848	38
2	TA 1535	NaAz	0.50	-	296	25
	TA 1537	9AC	30.00	-	125	4
	TA 98	NF	1.00	-	180	21
	TA 100	NaAz	0.50	-	541	9
	CM 891	AF-2	0.05	-	2365	35
	TA 1535	AA	2.00	+	101	11
	TA 1537	B[a]P	5.00	+	108	11
	TA 98	B[a]P	5.00	+	337	19
	TA 100	B[a]P	5.00	+	856	28
	CM 891	AA	10.00	+	1836	16

CM 891 - WP2uvrA/pKM101

-       absence 

+   presence

SD  Standard deviation

NaAz: sodium azide

9AC: 9-aminoacridine

NF: 2-nitrofluorene

AF-2: 2-(2-furyl)-3-(5-nitro-2-furyl) acrylamide

AA: 2-aminoanthracene

B[a]P: benzo[a]pyrene

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative

Under the conditions of the test, the test material shows no evidence of mutagenic activity in the bacterial system and therefore is considered to be negative for genotoxicity.

Executive summary:

In a GLP bacterial reverse mutation assay conducted in accordance with standardised guidelines OECD 471, EU Method B.13/14 and EPA OPPTS 870.5100, the genotoxicity of the test substance was determined. Four strains of S. typhimurium and one strain of E. coli were treated in the absence and presence of metabolic activation. Under the conditions of the test, no evidence of mutagenic activity in the bacterial system was observed and the test material was determined to be negative for genotoxicity.