Cobalt di(acetate)

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Remarks:

Type of genotoxicity: gene mutation

Type of information:

migrated information: read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP, OECD guideline study (BASF) with acceptable restrictions (no E. coli or T102 tested, test substance not characterized)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1992

Report date:

1992

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

yes

Remarks:

(no characterisation of the test substance, no E. coli or TA 102)

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Cobalt dinitrate

EC Number:

233-402-1

EC Name:

Cobalt dinitrate

Cas Number:

10141-05-6

IUPAC Name:

cobalt(2+) dinitrate

Details on test material:

- Name of test material (as cited in study report): Co-Nitrat
- Physical state: fluid
- Analytical purity: not reported
- Lot/batch No.: 91/7671
- Stability under test conditions: not analyzed
- Storage condition of test material: room temperature

Method

Target gene:

His operon

Species / strain

Species / strain / cell type:

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

Details on mammalian cell type (if applicable):

- Properly maintained: yes

Additional strain / cell type characteristics:

other: Defective excision repair system, reduced hydrophilic polysaccharide layer

Metabolic activation:

with and without

Metabolic activation system:

Aroclor 1254 induced rat liver S9 mix

Test concentrations with justification for top dose:

test substance: 20, 100, 500, 2500, 5000 µg/plate

positive controls
- 2-aminoanthracene: 2.5µg/plate
- 5-methyl-N'-nitro-N-nitrosoguanidine: 5 µg/plate
- 4-nitro-o-phenylendiamine: 10 µg/plate
- 9-aminoacridine chloride monohydrate: 100 µg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: water (test substance); DMSO (positive controls)
- Justification for choice of solvent/vehicle: complete solubility

Controls

Untreated negative controls:

yes

Remarks:

Sterility controls

Negative solvent / vehicle controls:

yes

Remarks:

Solvent controls

Positive controls:

yes

Positive control substance:

other: +S9: 2-aminoanthracene (TA 1535, 1537, 98, 100); -S9: 5-methyl-N'-nitro-N-nitrosoguanidine (TA 100, 1535), 4-nitro-o-phenylendiamine (TA 98), 9-aminoacridine chloride monohydrate (TA 1537)

Details on test system and experimental conditions:

METHOD OF APPLICATION: preincubation test
- Preincubation period: 20 minutes
- Exposure duration: 48 hours

METHOD OF APPLICATION: standard plate test
- Exposure duration: 48 hours

SELECTION AGENT (mutation assays): histidine


NUMBER OF REPLICATIONS: 2 experiments, á 3 culture/experiment

DETERMINATION OF CYTOTOXICITY
- Method: relative total growth

Evaluation criteria:

In general, a substance to be characterized as positive in the Ames test has to fulfil the following requirements:
- doubling of the spontaneous mutation rate (control)
- dose-response relationship
- reproducibility of the results

Results and discussion

Test results

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:

cytotoxicity

Remarks:

>= 2500 µg/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Additional information on results:

ADDITIONAL INFORMATION ON CYTOTOXICITY: occasionally observed >=2500 µg/plate depending on strain and test conditions

Any other information on results incl. tables

Maximum number of revertants (means ±SD):

In brackets: concentration of test substance

Standard Plate Test:

Strain	negative control		test substance
	-S9	+S9	-S9	+S9
TA 1535	18±1	24±3	16±2 (20 µg/plate)	22±2 (20 µg/plate)
TA 100	105±4	123±7	121±12 (2500 µg/plate)	136±8 (100 µg/plate)
TA 1537	9±2	10±2	8±1 (2500 µg/plate)	10±3 (100 µg/plate)
TA 98	25±3	46±2	25±3 (2500 µg/plate)	48±5 (20 µg/plate)

There was no increase in the number of his+ revertants in the standard plate test, neither in presence nor in absence of a metabolizing system.

Preincubation Test:

Strain	negative control		test substance
	-S9	+S9	-S9	+S9
TA1535	13±2	14±1	14±2 (20 µg/plate)	13±1 (20 µg/plate)
TA 100	103±3	102±7	103±7 (20 µg/plate)	110±4 (500 µg/plate)
TA 1537	7±2	8±2	6±2 (20 µg/plate)	6±1 (100 µg/plate)
TA 98	22±4	32±2	18±3 (500 µg/plate)	32±2 (20 µg/plate)

There was no increase in his+ revertants in the preincubation test, neither in presence nor in absence of a metabolizing system.

A slight decrease in the number of his+ revertants was occasionally observed depending on the strain and test conditions from about 2500 µg/plate onward.

The test substance was completely soluble in distilled water.

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative with metabolic activation
negative without metabolic activation