Disulphur dichloride

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:

1987

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline study with restrictions (Only 4 strains were tested. The hydrolised product of disulphur dichloride were tested).

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1988

Report date:

1988

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

yes

Remarks:

Only 4 strains were tested. The hydrolised product of disulphur dichloride were tested

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Disulphur dichloride

EC Number:

233-036-2

EC Name:

Disulphur dichloride

Cas Number:

10025-67-9

Molecular formula:

Cl2S2

IUPAC Name:

dichlorodisulfane

Details on test material:

- Name of test material (as cited in study report): sulphur chloride (hydrolysed)
- Physical state: liquid
- Analytical purity: 99.9%
- Lot/batch No.: 5442, production dated 11 June 1987
- Storage condition of test material: the test substance was stored in refrigerator.
- Other: disulphur dichloride was tested in the form of its hydrolysis products in aqueous solution. 1 L solution of hydrolysis products contains 97 g disulphur dichloride.
The batch of disulphur dichloride used to produce the hydrolysis products and the solution of hydrolysis products were analytically examined and released for at least the test period. The hydrolysis products were stored under prevention from air using N2. Before use or dilution the aqueous solution of hydrolysis products was centrifuged and filtered to separate from precipitates. Afterwards the solution was filter-sterilized and prevented from air by N2.
Deionized water for dilutions was blown free of air by treatment with N2 for at least 30 minutes. The dilution of the aqueous solution of hydrolysis products using the deionized water was stable.

Method

Target gene:

his operone

Species / strain

Species / strain / cell type:

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

Additional strain / cell type characteristics:

other: strains are partly deficient in lipopolysaccharide side chain

Metabolic activation:

with and without

Metabolic activation system:

S9 mix

Test concentrations with justification for top dose:

first test: 0, 1.3, 6.2, 31.2, 156.0, 780 µg per plate
1st repeated test: 0, 12.8, 64.0, 320.0, 1600, 8000 µg per plate
2nd repeated test: 0, 500, 1000, 2000, 4000, 8000 µg per plate

Vehicle / solvent:

the solvent used for sulfur chloride (hydrolysed) was deionized water, and for the positive controls DMSO

Controls

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

Remarks:

deionized water

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: sodium azide (only TA 1535; -S9), nitrofurantoin (only TA 100; -S9), 4-nitro-1,2-phenylenediamine (TA 1537 + TA 98; -S9), 2-aminoanthracene (all strains; +S9 mix).

Details on test system and experimental conditions:

Ames test
METHOD OF APPLICATION: in agar (plate incorporation)

DETERMINATION OF CYTOTOXICITY
- Method: The toxicity of the substance was assessed in 3 ways. First, the background growth on the plates for the mutant determination was grossly appraised. Secondly, a toxic effect of the substance was assumed when the mutant count per plate was clearly lower than the negative control count in dose correlation. Thirdly, the titer was determined. If this is indicated in the tables under the heading "Titer", the total bacteria count was taken on two plates per concentration with S9 mix. However, if evaluation was performed only without S-9 mix, the bacterial count was taken on two plates per concentration without S9 mix.

Evaluation criteria:

A reproducible and dose-related increase (ie. > twice the negative control count) in mutant counts for at least one strain is considered positive. Otherwise, the result is evaluated as negative

Statistics:

no data

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:

Up to 156 µg, 64 µg, 500 µg (respectively in the 1st, 2nd, and 3rd experiment) per plate no bacteriotoxic effect was observed. At high doses, the substance had a weak-strain-specific bacteriotoxic effect (not used for evaluation purposes)

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Additional information on results:

no further data

Remarks on result:

other: strain/cell type: S. typhimurium TA 1535, TA 1537, TA 98 and TA 100

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

Maximum number of revertants(means ± SD):

Trial 1 (1.3 - 780.0 µg/plate)
	Control		Test Substance (µg/plate)
Strain	-S9	+S9	-S9	+S9
TA1535	12	11	11 (6.2; 780.0)	16 (780.0)
TA100	87	131	99 (6.2)	147 (156.0)
TA1537	20	19	26 (31.2)	21 (780.0)
TA98	17	37	24 (780.0)	43 (156.0)
Trial 2 (12.8 - 8000.0 µg/plate)
TA1535	12	15	14 (64.0; 320.0; 8000.0)	20 (320.0)
TA100	98	139	108 (320.0)	148 (64.0)
TA1537	11	20	16 (1600.0)	19 (1600.0)
TA98	93	90	125 (8000.0)	116 (1600.0)
Trial 3 (500 - 8000.0 µg/plate)
TA1535	16	15	18 (500.0)	18 (1000; 4000)
TA100	97	160	115 (2000)	151 (4000)
TA1537	14	12	13 (500)	14 (500; 2000; 4000)
TA98	18	25	19 (500.0; 1000.0; 2000.0; 8000.0)	37 (4000)

 

Conclusion:

The test substance was not genotoxic in bacteria up to a concentration of 8000 µg/plate with and without metabolic activation.

Applicant's summary and conclusion

Conclusions:

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

Executive summary:

Herbold BA (1988)

The mutagenic potential of disulphur dichloride (hydrolysed) was investigated in a Salmonella/microsome test in doses up to 8000 µg per plate on four Salmonella typhimurium LT2 mutants according to the OECD guideline 471 with restrictions ( Only 4 strains were tested. The hydrolised product of disulphur dichloride were tested).

For the test were used the histidine-auxotrophic strains TA 1535, TA 100, TA 1537 and TA 98.

Doses up to and including 156 µg per plate did not cause any batteriotoxic effects. The total bacteria counts remained unchanged. No inhibition of growth was observed.

At higher doses, the substance had a weak strain-specific bacteriotoxic effect, so that this range could nevertheless be used for evaluation purposes.

Evidence of mutagenic activity of disulphur dichloride (hydrolysed) was not found with and without metabolic activation.

Neither a dose- related doubling, nor a biologically relevant increase in the mutant count, in comparison with the negative controls, was observed.

The positive controls sodium azide (Na-azid) , nitrofurantoin (NF), 4-nitro-1,2-phenylene-diamine (4 -NPDA),  and 2-aminoanthracene (2 -AA), had a marked mutagenic effect, as was seen by  a biologically relevant increase in mutant colonies compared to the corresponding negative controls.