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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
Study period:
no data
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Well documented guideline study. Purity of the test substance is not stated. Only four test strains were used instead of five (E.coli WP2 strains or S. typhimurium TA102 should be used in addition acc. to OECD guideline).
Cross-reference
Reason / purpose:
reference to same study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1989
Report Date:
1989

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
yes
Remarks:
Only minor deviations from the test guideline: 4 bacteria strains were tested instead of 5 strains.
GLP compliance:
not specified
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): Natriumsulfid
- Substance type: technical product
- Physical state: solid
- Storage condition of test material: room temperature
No further details are given.

Method

Species / strain
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Additional strain / cell type characteristics:
other: histidine auxothrophe, uvrB (defective excision repair system); rfa (reduced hydrophilic polysaccharide layer
Metabolic activation:
with and without
Metabolic activation system:
S-9 mix
Test concentrations with justification for top dose:
0, 20, 100, 500, 2500 and 5000 µg/plate (standard plate test) and 0, 4, 20, 100, 500 and 2500 µg/plate (preincubation test)
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: DMSO
Controlsopen allclose all
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 10µg of 2-aminoanthracene (dissolved in DMSO)
Remarks:
for with metabolic activation; strains TA100, TA98, TA1537 and TA1535
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
N-ethyl-N-nitro-N-nitrosoguanidine
Remarks:
without metabolic activation; strains TA100 and TA1535

Migrated to IUCLID6: 5 µg (dissolved in DMSO)
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 10µg of 4-nitro-o-phenylendiamine (dissolved in DMSO)
Remarks:
without metabolic activation; strain TA98
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 100µg of 9-aminoacridine chloride monohydrate (dissolved in DMSO)
Remarks:
without metabolic activation; strain TA1537
Details on test system and experimental conditions:
METHOD OF APPLICATION: in agar (plate incorporation) and preincubation

DURATION
- Preincubation period: 20 minutes
- Exposure duration: 48 hours at 37°C in the dark

SELECTION AGENT (mutation assays): minimal glucose agar

NUMBER OF REPLICATIONS: triplicate

DETERMINATION OF CYTOTOXICITY
- Method: relative total growth

Evaluation criteria:
In general, a substance to be characterised 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.
Statistics:
Not required for the Ames test.

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:
other: Reduced his- background growth was observed at doses >=2500µg/plate using TA1535, TA1537 and TA98. With TA100 there was only a slight decrease in the number of his+ revertants in the preincubation test at 2500µg/plate.
Vehicle controls validity:
valid
Untreated negative controls validity:
not examined
Positive controls validity:
valid
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative According to the results of the study, the test substance sodium sulfide is not mutagenic in the Ames test under the experimental conditions chosen here.

According to the results of the study, the test substance sodium sulfide is not mutagenic in the Ames test under the experimental conditions chosen here.