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Toxicological information

Genetic toxicity: in vitro

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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:
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

Reference
Name:
Unnamed
Type:
Constituent
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