Disodium sulphide

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:

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 for cross-reference:

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

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

Test material information

Constituent 1

Reference substance name:

Disodium sulphide

EC Number:

215-211-5

EC Name:

Disodium sulphide

Cas Number:

1313-82-2

Molecular formula:

Na2S

IUPAC Name:

disodium sulfide

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

Controls

Controls 1

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

Controls 2

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)

Controls 3

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

Controls 4

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.