Sodium O-isobutyl dithiocarbonate

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

There are conclusive but not suffcient data for the classification of substance SIBX with regard to mutagenicity/genetic toxicity. It is concluded that the substance SIBX does not meet the criteria to be classified for human health hazards for Mutagenicity-Genetic Toxicity

Link to relevant study records

Reference

Reference 1

Endpoint:

in vitro cytogenicity / chromosome aberration study in mammalian cells

Remarks:

Type of genotoxicity: chromosome aberration

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for type of information:

2-methylpropan-1-ol /Isobutyl alcohol/ is both reagents used in the manufacture of sodium O-isobutyl dithiocarbonate . Therefore, 2-methylpropan-1-ol /Isobutyl alcohol/ need to be considered in the assessment of sodium O-isobutyl dithiocarbonate.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 473 (In Vitro Mammalian Chromosome Aberration Test)

Principles of method if other than guideline:

Clastogenic effects were studied by the micronucleus test using the Chinese hamster V79 cell line as a target.

GLP compliance:

not specified

Type of assay:

in vitro mammalian cell micronucleus test

Species / strain / cell type:

Chinese hamster lung fibroblasts (V79)

Details on mammalian cell type (if applicable):

- Type and identity of media: MEM Eagle medium (V79 cells) supplemented with 10% heat-inactivated fetal calf serum (FCS), 2 mM L-glutamine,
100 IU/ml penicillin and streptomycin.
- Properly maintained: yes
- Periodically checked for Mycoplasma contamination: no data
- Periodically checked for karyotype stability: no data
- Periodically "cleansed" against high spontaneous background: no data

Metabolic activation:

without

Test concentrations with justification for top dose:

11 and 53 mM

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: [no data]

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

methylmethanesulfonate

Details on test system and experimental conditions:

METHOD OF APPLICATION: in medium


DURATION
- Exposure duration: 4 hours at 37 °C
- Expression time (cells in growth medium): additional 24 hours


NUMBER OF CELLS EVALUATED: 1000 cells/culture


DETERMINATION OF CYTOTOXICITY
- Method: relative total growth

Evaluation criteria:

The test compound was classified as a clastogen when it was able to enhance the spontaneous MN frequency at least three-fold or higher over that of the control for at least one dose tested.

Statistics:

no data

Species / strain:

Chinese hamster lung fibroblasts (V79)

Metabolic activation:

without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

No mutagenic activity of Isobutyl Alcohol detected.Isobutyl Alcohol is both reagents used in the manufacture, as well as decomposition products of Sodium isobutyl xanthate. Therefore, the health effects of Isobutyl Alcohol need to be considered in the assessment of sodium isobutyl xanthate. In addition, xanthates decompose on aging to form a number of byproducts, depending on the pH, temperature, etc. Risks associated with xanthate are, therefore, a function of the breakdown of the product or un-reacted raw materials remaining in the product.

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Conclusions:

Interpretation of results:negative

No mutagenic activity of Isobutyl Alcohol detected. 2-methylpropan-1-ol /Isobutyl alcohol/ is both reagents used in the manufacture of sodium O-isobutyl dithiocarbonate. Therefore, 2-methylpropan-1-ol /Isobutyl alcohol/ need to be considered in the assessment of sodium O-isobutyl dithiocarbonate

Reference 2

Endpoint:

in vitro gene mutation study in bacteria

Remarks:

Type of genotoxicity: gene mutation

Type of information:

other: published data

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for type of information:

Carbon disulphide is both a reagent in the manufacture, as well as a decomposition product of xanthates. SIBX readily decomposes to carbon disulphide, especially in the presence of moisture/water. Therefore, the health effects of carbon disulphide (CS2) need to be considered in the assessment of SIBX. In addition, xanthates decompose on aging to form a number of byproducts, depending on the pH, temperature, etc. Risks associated with xanthate are, therefore, a function of the breakdown of the product or un-reacted raw materials remaining in the product.

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OTS 798.5265 (The Salmonella typhimurium Bacterial Reverse Mutation Test)

Deviations:

no

GLP compliance:

not specified

Type of assay:

bacterial reverse mutation assay

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and TA 102

Additional strain / cell type characteristics:

not specified

Metabolic activation:

with and without

Metabolic activation system:

S9 mix- rat liver, Aroclor 1254 administered

Test concentrations with justification for top dose:

0.005%, 0.01%, 0.025%, 0.05%, 0.1% v/v

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: none

Untreated negative controls:

yes

Negative solvent / vehicle controls:

no

Remarks:

no solvent/vehicle used

Positive controls:

yes

Positive control substance:

other: in the abscence and presence of metabolic activation: 2-aminoanthracene (TA1535), benzo[alpha]pyrene (TA1537, TA100, TA98); in the abscence of metabolic activation: sodium azide (TA1535, TA100), 9-aminoacridine (TA1537), 2-nitrofluorene (TA98);

Remarks:

dicloromethane in a vapour phase (7.5% v/v) was included in each test without metabolic activation

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation)

NUMBER OF REPLICATIONS:3/ treatment

DETERMINATION OF CYTOTOXICITY

- Method: abscence or thinning of the background lawn of non-revertant colonies

EXPOSURE TO CS2:
Sets of solidified plates were placed, with lids removed, in stainless steel racks, designed to keep the plates separate and permit atmospheric circulation, inside stainless steel vessels. These vessels were then sealed and partially evacuated. Calculated volumes of carbon disulphide liquid were injected into the vessels via a septum and allowed to vaporize, producing atmospheres containing carbon disulphide at the nominal concentrations
mentioned above.Sterile air was admitted to the vessels in order to equilibrate the contents to atmospheric pressure, and the vessels with their contents were incubated at 37°C for 48 hours. After removal from the vessels, the plates were incubated for a further day in order to permit revertant
colonies to grow to a size large enough to be scored.

Evaluation criteria:

number of revertants/plate

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

other: yes, only at the highest concentration

Vehicle controls validity:

not applicable

Untreated negative controls validity:

valid

Positive controls validity:

valid

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

other: yes, only at the highest concentration

Vehicle controls validity:

not applicable

Untreated negative controls validity:

valid

Positive controls validity:

valid

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

other: yes, only at the highest concentration

Vehicle controls validity:

not applicable

Untreated negative controls validity:

valid

Positive controls validity:

valid

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

other: yes, only at the highest concentration

Vehicle controls validity:

not applicable

Untreated negative controls validity:

valid

Positive controls validity:

valid

Species / strain:

S. typhimurium TA 102

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

other: yes, only at the highest concentration

Vehicle controls validity:

not applicable

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

Carbon disulphide was examined for its mutagenic activity in four histidine-dependent auxotrophs ofSalmonella typhimurium, strains TA98, TA100, TA1535, TA1537, TA102. Agar plates, seeded with the tester strains, were exposed to the test material in vapour phase, in the abscence and presence of metabolic activation, in the following nominal concentrations: 0.005%, 0.01%, 0.025%, 0.05% and 0.1% v/v (nominal). These concentrations were selected following preliminary toxicity tests in strain TA 98. Carbon disulphide did not exhibit any mutagenic activity under the conditions of this test. No increases in revertants were obtained in any of the four tester strains following exposure to carbon disulphide at the concentrations tested. Inhibition of bacterial growth, observed as thinning of the background lawn of non-revertant cells and reduction in revertant colony numbers, occurred in all strains with carbon disulphide at a nominal concentration of 0.1 % v/v. The positive and negative controls were valid.
The study was performed according to the OECD Guidelines for Testing of Chemicals No. 471 (1983) and US EPA (TSCA) Guideline § 798.5265 (1985, amended 1987).

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Conclusions:

Interpretation of results:negative

No mutagenic activity of CS2 detected.Carbon disulphide is both a reagent in the manufacture, as well as a decomposition product of xanthates. SIBXreadily decomposes to carbon disulphide, especially in the presence of moisture/water. Therefore, the health effects of carbon disulphide (CS2) need to be considered in the assessment of SIBX.
In addition, xanthates decompose on aging to form a number of byproducts, depending on the pH, temperature, etc. Risks associated with xanthate are, therefore, a function of the breakdown of the product or un-reacted raw materials remaining in the product.

Executive summary:

Carbon disulphide was examined for its mutagenic activity in four histidine-dependent auxotrophs of Salmonella typhimurium, strains TA98, TA100, TA1535, TA1537, TA 102. Agar plates, seeded with the tester strains, were exposed to the test material in vapour phase, in the abscence and presence of metabolic activation, in the following nominal concentrations: 0.005%, 0.01%, 0.025%, 0.05% and 0.1% v/v (nominal). These concentrations were selected following preliminary toxicity tests in strain TA 98. Carbon disulphide did not exhibit any mutagenic activity under the conditions of this test. No increases in revertants were obtained in any of the four tester strains following exposure to carbon disulphide at the concentrations tested. Inhibition of bacterial growth, observed as thinning of the background lawn of non-revertant cells and reduction in revertant colony numbers, occurred in all strains with carbon disulphide at a nominal concentration of 0.1 % v/v. The positive and negative controls were valid. The study was performed according to the OECD Guidelines for Testing of Chemicals No. 471 (1983) and US EPA (TSCA) Guideline § 798.5265 (1985, amended 1987).

Reference 3

Endpoint:

in vitro gene mutation study in bacteria

Remarks:

Type of genotoxicity: gene mutation

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for type of information:

2-methylpropan-1-ol /Isobutyl alcohol/ is both reagents used in the manufacture of sodium O-isobutyl dithiocarbonate . Therefore, 2-methylpropan-1-ol /Isobutyl alcohol/ need to be considered in the assessment of sodium O-isobutyl dithiocarbonate

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Principles of method if other than guideline:

The mutagenicity of the test chemical was examined in Salmonella typhimurium (TA98, TA100, TA1535, TA1537, and TA1538) and Escherichia coli (WP2uvrA) using the preincubation method with and without S9 mix.

GLP compliance:

not specified

Type of assay:

bacterial reverse mutation assay

Species / strain / cell type:

S. typhimurium, other: TA98, TA100, TA1535, TA1537, and TA1538

Species / strain / cell type:

E. coli WP2 uvr A

Metabolic activation:

with and without

Metabolic activation system:

S-9 mix

Test concentrations with justification for top dose:

5; 10; 50; 100; 500; 1000; 5000 µg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: [water]
- Justification for choice of solvent/vehicle: none given

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: TA98, TA100 and E.coli WP2 uvrA:2-(2-Furyl)-3-(5-nitro-2-furyl)acrylamide; TA1535: N-ethyl-N-nitro-N-nitrosoguanidine; TA1537: 9-aminoacridine; TA1538: 4-nitroquinoline-N-oxide

Remarks:

without S-9 mix

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: TA100, TA98, TA1537 and TA1538: benzo(a)pyrene; TA1535 and E.coli WP2 uvrA: 2-aminoanthracene

Remarks:

with S-9 mix

Details on test system and experimental conditions:

METHOD OF APPLICATION: preincubation

DURATION
- Preincubation period: 20 min at 37 °c
- Exposure duration: 2 days at 37 °C


DETERMINATION OF CYTOTOXICITY
- Method: relative total growth

Evaluation criteria:

no data

Statistics:

no data

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Species / strain:

S. typhimurium TA 1538

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Species / strain:

E. coli WP2 uvr A

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

not valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

No mutagenic activity of Isobutyl Alcohol detected.Isobutyl Alcohol is both reagents used in the manufacture, as well as decomposition products of Sodium isobutyl xanthate. Therefore, the health effects of Isobutyl Alcohol need to be considered in the assessment of sodium isobutyl xanthate. In addition, xanthates decompose on aging to form a number of byproducts, depending on the pH, temperature, etc. Risks associated with xanthate are, therefore, a function of the breakdown of the product or un-reacted raw materials remaining in the product.

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Conclusions:

Interpretation of results:
negative with metabolic activation
negative without metabolic activation

No mutagenic activity of Isobutyl Alcohol detected. 2-methylpropan-1-ol /Isobutyl alcohol/ is both reagents used in the manufacture of sodium O-isobutyl dithiocarbonate . Therefore, 2-methylpropan-1-ol /Isobutyl alcohol/ need to be considered in the assessment of sodium O-isobutyl dithiocarbonate

Reference 4

Endpoint:

in vitro gene mutation study in bacteria

Remarks:

Type of genotoxicity: gene mutation

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for type of information:

2-methylpropan-1-ol /Isobutyl alcohol/ is both reagents used in the manufacture of sodium O-isobutyl dithiocarbonate . Therefore, 2-methylpropan-1-ol /Isobutyl alcohol/ need to be considered in the assessment of sodium O-isobutyl dithiocarbonate

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Principles of method if other than guideline:

The test substance was tested for mutagenicity in Salmonella typhimurium, using a preincubation protocol. The test was performed in the absence of exogenous metabolic activation, and in the presence of liver S-9 from Aroclor-induced male Sprague-Dawley rats and Syrian hamsters.

GLP compliance:

not specified

Type of assay:

bacterial reverse mutation assay

Species / strain / cell type:

S. typhimurium, other: TA 1535, TA 1537, TA 98, TA97 and TA 100

Metabolic activation:

with and without

Metabolic activation system:

S-9 mix

Test concentrations with justification for top dose:

100 - 10000 µg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: [DMSO]
- Justification for choice of solvent/vehicle: none given

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: Without S9: sodium azide (TA1535 and TA100), 9-aminoacridine (TA97 and TA1537), 4-nitro-o-phenylenediamine (TA98). With S9: 2-aminoanthracene (all strains)

Details on test system and experimental conditions:

METHOD OF APPLICATION: preincubation

DURATION
- Preincubation period: 20 min at 37 °C
- Exposure duration: 2 days at 37 °C

DETERMINATION OF CYTOTOXICITY
- Method: relative total growth

Evaluation criteria:

Evaluations were made at both the individual trial and overall chemical levels. Individual trials were judged mutagenic: (+), weakly mutagenic (+W), questionable (?), or nonmutagenic (-), depending on the magnitude of the increase of his+ revertants, and the shape of the dose-response. A trial was considered questionable (?) if the dose-response was judged insufficiently high to support a call of "+ W", if only a single dose was elevated over the control, or if the increase seen was not dose related. The distinctions between a questionable mutagenic response and a nonmutagenic or weak mutagenic response and between a weak mutagenic response and mutagenic response are highly subjective. It was not necessary for a response to reach twofold over background for a chemical to be judged mutagenic.
A chemical was judged mutagenic (+) or weakly mutagenic (+W) if it produced a reproducible dose-related response over the solvent control in replicate trials. A chemical was judged questionable (?) if the results of individual trials were not reproducible, if increases in his+ revertants did not meet the criteria for a "+W" response, or if only single doses produced increases in his' revertants in repeat trials.
Chemicals were judged nonmutagenic (-) if they did not meet the criteria for a mutagenic or questionable response. The chemicals were decoded by the chemical repository only after a determination had been made regarding their mutagenicity or nonmutagenicity.

Statistics:

no data

Species / strain:

S. typhimurium, other: TA 1535, TA 1537, TA97, TA 98 and TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

reduction of the background lawn at the highest concentration tested in some strains without S-9 mix

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

reduction of the background lawn at the highest concentration tested in some strains without S-9 mix

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

reduction of the background lawn at the highest concentration tested in some strains without S-9 mix

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Species / strain:

S. typhimurium TA 97

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

reduction of the background lawn at the highest concentration tested in some strains without S-9 mix

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

reduction of the background lawn at the highest concentration tested in some strains without S-9 mix

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

reduction of the background lawn at the highest concentration tested in some strains without S-9 mix

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Species / strain:

S. typhimurium TA 102

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

reduction of the background lawn at the highest concentration tested in some strains without S-9 mix

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

ADDITIONAL INFORMATION ON CYTOTOXICITY:
Reduction of the background lawn at the highest concentration tested in TA100, TA1535, TA97 and TA98 without S-9 mix
Alcohol is both reagents used in the manufacture, as well as decomposition products of Sodium isobutyl xanthate. Therefore, the health effects of Isobutyl Alcohol need to be considered in the assessment of sodium isobutyl xanthate. In addition, xanthates decompose on aging to form a number of byproducts, depending on the pH, temperature, etc. Risks associated with xanthate are, therefore, a function of the breakdown of the product or un-reacted raw materials remaining in the product.

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Conclusions:

Interpretation of results:
negative with metabolic activation
negative without metabolic activation

No mutagenic activity of Isobutyl Alcohol detected. 2-methylpropan-1-ol /Isobutyl alcohol/ is both reagents used in the manufacture of sodium O-isobutyl dithiocarbonate . Therefore, 2-methylpropan-1-ol /Isobutyl alcohol/ need to be considered in the assessment of sodium O-isobutyl dithiocarbonate .

Reference 5

Endpoint:

in vitro gene mutation study in mammalian cells

Remarks:

Type of genotoxicity: gene mutation

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for type of information:

2-methylpropan-1-ol /Isobutyl alcohol/ is both reagents used in the manufacture of sodium O-isobutyl dithiocarbonate . Therefore, 2-methylpropan-1-ol /Isobutyl alcohol/ need to be considered in the assessment of sodium O-isobutyl dithiocarbonate

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 476 (In Vitro Mammalian Cell Gene Mutation Test)

Principles of method if other than guideline:

The test substance was evaluated for mutagenic effects by the hypoxanthine-guanine-phosphoribosyl transferase gene mutation test (HPRT test).

GLP compliance:

not specified

Type of assay:

mammalian cell gene mutation assay

Target gene:

hypoxanthine-guanine-phosphoribosyl transferase gene

Species / strain / cell type:

Chinese hamster lung fibroblasts (V79)

Details on mammalian cell type (if applicable):

- Type and identity of media: MEM Eagle medium (V79 cells) supplemented with 10% heat-inactivated fetal calf serum (FCS), 2 mM L-glutamine,
100 IU/ml penicillin and streptomycin.
- Properly maintained: yes
- Periodically checked for Mycoplasma contamination: no data
- Periodically checked for karyotype stability: no data
- Periodically "cleansed" against high spontaneous background: no data

Metabolic activation:

with and without

Metabolic activation system:

S-9 mix

Test concentrations with justification for top dose:

up to 107 mM

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: [no data]

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

methylmethanesulfonate

Details on test system and experimental conditions:

METHOD OF APPLICATION: in medium

DURATION
- Exposure duration: 2 hours
- Expression time (cells in growth medium): 7 days
- Selection time (if incubation with a selection agent): 7 days
- Fixation time (start of exposure up to fixation or harvest of cells): ca. 14 days


SELECTION AGENT (mutation assays): 6-thioguanine

DETERMINATION OF CYTOTOXICITY
- Method: cloning efficiency

Evaluation criteria:

The test compound was classified as a mutagen when it was able to enhance in a concentration-depended manner the spontaneous HPRT frequency by a factor of three or more.

Statistics:

no data

Species / strain:

Chinese hamster lung fibroblasts (V79)

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Remarks:

no cytotoxicity observed up to 107 mM

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

No mutagenic activity of Isobutyl Alcohol detected.2-methylpropan-1-ol /Isobutyl alcohol/ is both reagents used in the manufacture of sodium O-isobutyl dithiocarbonate . Therefore, 2-methylpropan-1-ol /Isobutyl alcohol/ need to be considered in the assessment of sodium O-isobutyl dithiocarbonate

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Conclusions:

Interpretation of results:negative

No mutagenic activity of Isobutyl Alcohol detected.2-methylpropan-1-ol /Isobutyl alcohol/ is both reagents used in the manufacture of sodium O-isobutyl dithiocarbonate . Therefore, 2-methylpropan-1-ol /Isobutyl alcohol/ need to be considered in the assessment of sodium O-isobutyl dithiocarbonate .

Reference 6

Endpoint:

in vitro gene mutation study in mammalian cells

Remarks:

Type of genotoxicity: gene mutation

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for type of information:

2-methylpropan-1-ol /Isobutyl alcohol/ is both reagents used in the manufacture of sodium O-isobutyl dithiocarbonate . Therefore, 2-methylpropan-1-ol /Isobutyl alcohol/ need to be considered in the assessment of sodium O-isobutyl dithiocarbonate.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 476 (In Vitro Mammalian Cell Gene Mutation Test)

Principles of method if other than guideline:

The test substance was evaluated for mutagenic effects in the L5178Y thymidine kinase mouse lymphoma cell assay.

GLP compliance:

not specified

Type of assay:

mammalian cell gene mutation assay

Target gene:

thymidine kinase gene

Species / strain / cell type:

mouse lymphoma L5178Y cells

Details on mammalian cell type (if applicable):

- Type and identity of media: The cells were maintained in Fischer's medium for leukemic cells of mice with 10% horse serum and sodium pyruvate.
Cloning medium consisted of Fischer's medium with 10 % horse serum, sodium pyruvate, and 0 .35% Noble agar. Selection medium was made from cloning medium by the addtion of 5 ml BrdU to 100 ml cloning medium.
- Properly maintained: yes
- Periodically checked for Mycoplasma contamination: no data
- Periodically checked for karyotype stability: no data
- Periodically "cleansed" against high spontaneous background: yes

Metabolic activation:

with and without

Metabolic activation system:

S-9 mix

Test concentrations with justification for top dose:

up to 12.5 µl/ml without activation (10 mg/ml); up to 6.25 µg/ml (5 mg/ml) with activation

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: [water]
- Justification for choice of solvent/vehicle: Isobutyl Alcohol, was partially soluble in sterile, deionized water at a concentration of 250 µl/ml and was then further diluted for testing.

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

ethylmethanesulphonate

Remarks:

without S-9 mix

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

no

Positive control substance:

other: Dimethylnitrosamine

Remarks:

with S-9 mix

Details on test system and experimental conditions:

METHOD OF APPLICATION: in medium


DURATION
- Exposure duration: 4 hours at 37 °C
- Expression time (cells in growth medium): 2-3 days
- Selection time (if incubation with a selection agent): 10 days
- Fixation time (start of exposure up to fixation or harvest of cells): ca. 12-13 days


SELECTION AGENT (mutation assays): bromodeoxyuridine (BrdU)

DETERMINATION OF CYTOTOXICITY
- Method: relative total growth

Evaluation criteria:

A compound is considered mutagenic in this assay if:
- A dose-response relationship is observed over 3 of the 5 dose levels employed.
- The minimum increase at the low level of the dose-response curve is at least 2.5 times greater than the solvent and/or negative control values.
- The solvent and negative control data are within the normal range of the spontaneous background for the TK locus.

Occasionally, a single point within a concentration range will show an increase 2.5 times greater than the spontaneous background. If the increase is at the high dose, is reproducible, and if an additional higher dose level is not feasible because of toxicity, the chemical can be considered mutagenic, if the increase is internal within the dose range and is not reproducible, the increase will normally be considered aberrant. If the internal increase is reproducible, several doses clustered around the positive concentration will be examined to either confirm or reject the reliability of the effect.

Statistics:

no data

Species / strain:

mouse lymphoma L5178Y cells

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

highly cytotoxic (survival at 3%) at 12.5 µl/ml without S-9 mix

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

ADDITIONAL INFORMATION ON CYTOTOXICITY:
The test substance was highly cytotoxic at 12.5 µl/ml when tested without S-9 mix. At all other concentration tested with and without S-9 mix, the relative growth was > 30%.

Isobutyl Alcohol is both reagents used in the manufacture, as well as decomposition products of Sodium isobutyl xanthate. Therefore, the health effects of Isobutyl Alcohol need to be considered in the assessment of sodium isobutyl xanthate. In addition, xanthates decompose on aging to form a number of byproducts, depending on the pH, temperature, etc. Risks associated with xanthate are, therefore, a function of the breakdown of the product or un-reacted raw materials remaining in the product.

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Conclusions:

Interpretation of results: negative

No mutagenic activity of Isobutyl Alcohol detected.2-methylpropan-1-ol /Isobutyl alcohol/ is both reagents used in the manufacture of sodium O-isobutyl dithiocarbonate. Therefore, 2-methylpropan-1-ol /Isobutyl alcohol/ need to be considered in the assessment of sodium O-isobutyl dithiocarbonate.

Reference 7

Endpoint:

in vitro cytogenicity / chromosome aberration study in mammalian cells

Remarks:

Type of genotoxicity: chromosome aberration

Type of information:

other: published data

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for type of information:

Dithiocarbamates are related compounds to xanthates. This is organosulfur compound is obtained by treating carbon disulfide with amine in the presence of sodium hydroxide: They arise from the reaction of the amine with CS2

Qualifier:

according to guideline

Guideline:

OECD Guideline 473 (In Vitro Mammalian Chromosome Aberration Test)

Deviations:

yes

Remarks:

At least duplicate cultures must be used for each experimental point. Only one harvest time was used.

Qualifier:

according to guideline

Guideline:

EPA OPP 84-2

GLP compliance:

yes

Type of assay:

in vitro mammalian chromosome aberration test

Species / strain / cell type:

other: Chinese hamster overy cells

Metabolic activation:

with and without

Metabolic activation system:

S9 mix

Test concentrations with justification for top dose:

3.1, 12.5, 25 ng/ml (without S-9 mix)
125, 500, 1000 ng/ml (with S-9 mix)

Vehicle / solvent:

DMSO

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: Mitomycin C, Cyclophosphamide

Species / strain:

other: Chinese hamster overy cells

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

 

Dose level [ng/mL]	No. of aberrant cells [%]		Dose level [ng/mL]	No. of aberrant cells [%]
	With MA			Without MA
	Exc. gaps	Inc. gaps		Exc. gaps	Inc. gaps
125	4.5	4.5	3.1	2.0	2.0
500	3.5	4.5	12.5	2.5	2.5
1000	3.5	3.5	25.0	4.0	4.0
Solvent	4.25	4.75	Solvent	2.25	2.25
Positive control	38.5	38.5	Positive control	29.0	29.0

 

Conclusions:

Interpretation of results :negative

No mutagenic activity of Ziram detected. Dithiocarbamates are related compounds to xanthates. This is organosulfur compound is obtained by treating carbon disulfide with amine in the presence of sodium hydroxide: They arise from the reaction of the amine with CS2

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Genetic toxicity in vivo

Link to relevant study records

Reference

Reference 1

Endpoint:

in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus

Remarks:

Type of genotoxicity: chromosome aberration

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for type of information:

2-methylpropan-1-ol /Isobutyl alcohol/ is both reagents used in the manufacture of sodium O-isobutyl dithiocarbonate . Therefore, 2-methylpropan-1-ol /Isobutyl alcohol/ need to be considered in the assessment of sodium O-isobutyl dithiocarbonate

Qualifier:

according to guideline

Guideline:

OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)

GLP compliance:

yes

Type of assay:

micronucleus assay

Species:

mouse

Strain:

NMRI

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Germany
- Age at study initiation: 5-8 weeks
- Weight at study initiation: mean: 26 g
- Assigned to test groups randomly: [yes, under following basis: Male and female animals were assigned to the test groups according to a randomization plan prepared with an appropriate computer program.]
- Housing: in groups of 5 during the acclimation period, individually later on
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: 3-5 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-24 °C
- Humidity (%): 30-70 %
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

oral: gavage

Vehicle:

- Vehicle(s)/solvent(s) used: [olive oil]
- Justification for choice of solvent/vehicle: Due to the insolubility of the test substance in water, olive oil was selected as the vehicle, which had been demonstrated to be suitable in the in vivo micronucleus test and for which historical data are available.
- Concentration of test material in vehicle: 5 g/100 ml; 10 g/100 ml and 20 g/100 ml
- Amount of vehicle (if gavage or dermal): 10 ml/kg

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:
The substance to be administered per kg body weight was dissolved in olive oil and prepared immediately before administration.
- The 500 mg/kg group was given 500 mg test substance/kg body weight or 10 ml/kg body weight of a solution with a concentration of 5 g/100 ml.
- The 1000 mg/kg group was given 1000 mg test substance/kg body weight or 10 ml/kg body weight of a solution with a concentration of 10 g/100 ml.
- The 2000 mg/kg groups were given 2000 mg test substance/kg body weight or 10 ml/kg body weight of a solution with a concentration of 20 g/100 ml.

Duration of treatment / exposure:

single application

Frequency of treatment:

single application

Post exposure period:

24 and 48 hours

Remarks:

Doses / Concentrations:
500, 1000, 2000 mg/kg bw
Basis:
nominal conc.

No. of animals per sex per dose:

5

Control animals:

yes, concurrent vehicle

Positive control(s):

cyclophosphamide (CPP); vincristine sulphate (VCR)
- Justification for choice of positive control(s): Both positive control articles (CPP and VPR) are well-defined clastogens and aneugens respectively.
- Route of administration: orally or intraperitoneally
- Doses / concentrations: 20 mg/kg bw (CPP) / 0.15 mg/kg bw (VCR)

Tissues and cell types examined:

In general, 2000 polychromatic erythrocytes (PCE) from each of the male and female animals of every test group are evaluated and investigated for micronuclei (MN) . The normochromatic erythrocytes (NCE) which occur are also scored. The cells were prepared from the bone marrow of two femora from animals either sacrificed 24 or 48 hours after dosing.

Details of tissue and slide preparation:

CRITERIA FOR DOSE SELECTION:
In a pretest for the determination of the acute oral toxicity, all animals (male and female) survived treatment with 2000 mg/kg body weight recommended as the highest dose according to the OECD Guideline. As clinical signs only piloerection was observed.
Therefore, a dose of 2000 mg/kg body weight was selected as the highest dose in the present cytogenetic study. 1000 mg/kg and 500 mg/kg body weight were administered as further doses.

TREATMENT AND SAMPLING TIMES (in addition to information in specific fields):
The animals were treated once and samples of bone marrow were taken 24 hours and 48 hours after the treatment.

DETAILS OF SLIDE PREPARATION:
The bone marrow was prepared according to the method described by SCHMID, W.
- The two femora were prepared by dissection and removing all soft tissues.
-After cutting off the epiphyses, the bone marrow was flushed out of the diaphysis into a centrifuge tube using a cannula filled with fetal calf serum which was at 37°C (about 2 ml/femur).
-The suspension was mixed thoroughly with a pipette, centrifuged at 300 x g for 5 minutes, the supernatant was removed and the precipitate was resuspended in about 50 µl fresh FCS.
- 1 drop of this suspension was dropped onto clean microscopic slides, using a Pasteur pipette. Smears were prepared using slides with ground edges, the preparations were dried in the air and subsequently stained. The slides were stained in eosin and methylene blue solution for 5 minutes (May Grünwald solution modified = Wrights solution), rinsed in purified water and then placed in fresh purified water for 2 or 3 minutes. They were finally stained in 7.5% Giemsa solution for 15 minutes. After being rinsed twice in purified water and clarified in xylene, the preparations were mounted using Corbit-Balsam
METHOD OF ANALYSIS:
In general, 2000 polychromatic erythrocytes (PCE) from each of the male and female animals of every test group are evaluated and investigated for micronuclei (MN). The normochromatic erythrocytes (NCE) which occur are also scored. The following parameters are recorded:
- Number of polychromatic erythrocytes
- Number of polychromatic erythrocytes containing micronuclei
The increase in the number of micronuclei in polychromatic erythrocytes of treated animals as compared with the solvent control group provides an index of a chromosome-breaking (clastogenic) effect or of a spindle activity of the substance tested.
- Number of normochromatic erythrocytes
- Number of normochromatic erythrocytes containing micronuclei
The number of micronuclei in normochromatic erythrocytes at the early sacrifice intervals shows the situation before test substance administration and may serve as a control value. A substance-induced increase in the number of micronuclei in normocytes may be found with an increase in the duration of the sacrifice intervals.
- Ratio of polychromatic to normochromatic erythrocytes
An alteration of this ratio indicates that the test substance actually reached the target
Individual animals with pathological bone marrow depression may be identified and excluded from the evaluation.
- Number of small micronuclei (d < D/4) and of large micronuclei (d > D/4) (d = diameter of micronucleus, D = cell diameter)
The size of micronuclei may give an indication on the possible mode of action of the test substance, i.e. a clastogenic or a spindle poison effect.
Slides were coded before microscopic analysis.

Evaluation criteria:

The test chemical is to be considered positive in this assay if the following criteria are met:
- A dose-related and significant increase in the number of micronucleated polychromatic erythrocytes at any of the intervals.
- The proportion of cells containing micronuclei exceeded both the values of the concurrent negative control range and the negative historical control range.
A test substance is generally considered negative in this test system if:
- There was no significant increase in the number of micronucleated polychromatic erythrocytes at any dose above concurrent control frequencies and at any time.
- The frequencies of cells containing micronuclei were within the historical control range.

Statistics:

The statistical evaluation of the data was carried out using the program system MUKERN (BASF Aktiengesellschaft).
The number of micronuclei in polychromatic erythrocytes was analyzed.
A comparison of the dose group with the vehicle control was carried out using the Wilcoxon test for the hypothesis of equal medians. Here, the relative frequencies of cells with micronuclei of each animal were used . If the results of this test were significant, labels (* for p < 0.05, ** for p < 0 .01) wereprinted with the group means in the tables. This test was performed one-sided.

Sex:

male/female

Genotoxicity:

negative

Toxicity:

yes

Remarks:

narcotic like state and piloerection

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

RESULTS OF RANGE-FINDING STUDY
- Dose range: 2000 mg/kg
- Clinical signs of toxicity in test animals: piloerection


RESULTS OF DEFINITIVE STUDY
The single oral administration of olive oil in a volume of 10 ml/kg body weight led to 1.5 ‰ polychromatic erythrocytes containing micronuclei after the 24-hour sacrifice interval or to 1.1 ‰ after the 48-hour sacrifice interval.
After the single administration of the highest dose of 2000 mg/kg body weight, 1.8 ‰ polychromatic erythrocytes containing micronuclei were found after 24 hours and 1.3‰ after 48 hours.
In the two lower dose groups, rates of micronuclei of about 1.6 ‰ (1000 mg/kg group) and 1.5 ‰ (500 mg/kg group) were detected after a sacrifice interval of 24 hours in each case.
With 17.9‰ the positive control substance cyclophosphamide for clastogenicity, led to the expected increase in the number of polychromatic erythrocytes containing exclusively small micronuclei at a dose level of 20 mg/kg body weight.
With 67.3 ‰ the positive control vincristine for spindle poison effects also led to a clearly enhanced number of polychromatic erythrocytes containing micronuclei with the expected amount of large micronuclei, i.e. 8.0 ‰.
The number of normochromatic erythrocytes containing micronuclei did not differ to any appreciable extent in the negative control or in the various dose groups at any of the sacrifice intervals.
Thus, the test substance Isobutanol did not lead to any increase in the rate of micronuclei. The number of normochromatic or polychromatic erythrocytes containing small micronuclei (d < D/4) or large micronuclei (d > D/4) did not deviate from the vehicle control value at any of the sacrifice intervals and was within the historical control range.
No inhibition of erythropoiesis induced by the treatment of mice with Isobutanol was detected the ratio of polychromatic to normochromatic erythrocytes was always in the same range as that of the control values in all dose groups.

Conclusions:

Interpretation of results: negative
Oral gavage dose of 500, 1,000 or 2,000 mg/kg of isobutanol did not have any chromosome-damaging (clastogenic) effect, and there were no
indications of any impairment of chromosome distribution in the course of mitosis.
2-methylpropan-1-ol /Isobutyl alcohol/ is both reagents used in the manufacture of sodium O-isobutyl dithiocarbonate . Therefore, 2-methylpropan-1-ol /Isobutyl alcohol/ need to be considered in the assessment of sodium O-isobutyl dithiocarbonate

Reference 2

Endpoint:

in vivo mammalian germ cell study: cytogenicity / chromosome aberration

Remarks:

Type of genotoxicity: chromosome aberration

Type of information:

other: published data

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for type of information:

Dithiocarbamates are related compounds to xanthates. This is organosulfur compound is obtained by treating carbon disulfide with amine in the presence of sodium hydroxide: They arise from the reaction of the amine with CS2

Qualifier:

according to guideline

Guideline:

OECD Guideline 483 (Mammalian Spermatogonial Chromosome Aberration Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.23 (Mammalian Spermatogonial Chromosome Aberration Test)

Qualifier:

according to guideline

Guideline:

EPA OPP 84-2

GLP compliance:

yes

Type of assay:

mammalian germ cell cytogenetic assay

Species:

mouse

Strain:

NMRI

Sex:

male

Details on test animals or test system and environmental conditions:

- Source: Charles River, Germany
- Age at study initiation: min. 10 weeks
- Weight at study initiation: ca. 30 g

Route of administration:

oral: gavage

Vehicle:

0.5% carboxymethylcellulose

Duration of treatment / exposure:

6, 24 and 48 h

Frequency of treatment:

Single application

Post exposure period:

n.a.

Remarks:

Doses / Concentrations:
20, 67 and 200 mg/kg b.w.
Basis:
nominal conc.

No. of animals per sex per dose:

5 males (positive control only 4)

Control animals:

yes, concurrent vehicle

Positive control(s):

Cyclophosphamide (CPA)
- Dose: 140 mg/kg b.w.

Tissues and cell types examined:

Spermatogonia

Details of tissue and slide preparation:

In the test article and the negative control groups 100 well spread metaphases per animal were scored for cytogenetic damage on coded slides. In the positive control group 50 metaphases per animal were scored. Only metaphases with the characteristic chromosome number of 40 were included in the analysis. To describe a cytotoxic effect the mitotic index (% cells in mitosis) was determined.
Five animals per test group were evaluated as described. The remaining animals of each test group were evaluated in case animals died in its test group.

Sex:

male

Genotoxicity:

negative

Toxicity:

yes

Remarks:

Tested in pre-experiments.

Vehicle controls validity:

valid

Negative controls validity:

not examined

Positive controls validity:

valid

Group	Dose [mg/kg]	Exposure [h]	No. of cells scored	Aberrant cells [%]		Mitotic index [%]
				Incl. gaps	Excl. gaps
Ziram	200	6	500	0.0	0.0	1.40
Vehicle control	0	24	500	0.4	0.2	2.80
Ziram	20	24	500	0.0	0.0	1.40
Ziram	67	24	500	0.2	0.0	2.34
Ziram	200	24	500	0.2	0.2	1.84
Positive control	140	24	200	8.0	7.5	0.34
Ziram	200	48	500	0.8	0.4	1.16

Conclusions:

Interpretation of results: negative
No mutagenic activity of Ziram detected. Dithiocarbamates are related compounds to xanthates. This is organosulfur compound is obtained by treating carbon disulfide with amine in the presence of sodium hydroxide: They arise from the reaction of the amine with CS2

Reference 3

Endpoint:

in vivo mammalian somatic cell study: cytogenicity / bone marrow chromosome aberration

Remarks:

Type of genotoxicity: chromosome aberration

Type of information:

other: published data

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for type of information:

Dithiocarbamates are related compounds to xanthates. This is organosulfur compound is obtained by treating carbon disulfide with amine in the presence of sodium hydroxide: They arise from the reaction of the amine with CS2

Qualifier:

according to guideline

Guideline:

OECD Guideline 475 (Mammalian Bone Marrow Chromosome Aberration Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.11 (Mutagenicity - In Vivo Mammalian Bone-Marrow Chromosome Aberration Test)

GLP compliance:

yes

Type of assay:

chromosome aberration assay

Species:

mouse

Strain:

NMRI

Sex:

male/female

Details on test animals or test system and environmental conditions:

- Source: BRL Tierfarm Füllinsdorf, Switzerland
- Age at study initiation: min. 10 weeks
- Weight at study initiation: ca. 30 g

Route of administration:

oral: gavage

Vehicle:

Carboxymethylcellulose

Duration of treatment / exposure:

6, 24 and 48 h

Frequency of treatment:

Single application

Post exposure period:

n.a.

Remarks:

Doses / Concentrations:
0, 40, 120 and 400 mg/kg b.w.
Basis:
nominal conc.

No. of animals per sex per dose:

5

Control animals:

yes, concurrent vehicle

Positive control(s):

Cyclophosphamide (CPA)
- Dose: 20 mg/kg b.w.

Tissues and cell types examined:

Bone marrow cells

Details of tissue and slide preparation:

At least 50 well spread metaphases per animal were scored for cytogenetic damage on coded slides. Only metaphases with the characteristic chromosome number of 40 were included in the analysis. To describe a cytotoxic effect the mitotic index (% cells in mitosis; 1000 cells are scored) was determined.
Five animals per sex and group were evaluated as described. The remaining animal of each test group was evaluated in case an animal died in its test group spontaneously or due to gavage error.

Sex:

male/female

Genotoxicity:

negative

Toxicity:

yes

Remarks:

Tested in pre-experiments.

Vehicle controls validity:

valid

Negative controls validity:

not examined

Positive controls validity:

valid

Group	Dose [mg/kg]	Exposure [h]	No. of cells scored	Aberrant cells [%]		Mitotic index [%]
				Incl. gaps	Excl. gaps
Ziram	400	6	500	0.4	0.2	3.54
Vehicle control	0	24	500	0.4	0.0	4.91
Ziram	40	24	500	1.0	0.6	4.03
Ziram	120	24	500	0.6	0.0	5.50
Ziram	400	24	500	1.6	1.2	3.52
Positive control	20	24	500	28.4	27.8	5.00
Ziram	400	48	500	0.2	0.2	5.08

Conclusions:

Interpretation of results: negative
No mutagenic activity of Ziram detected. Dithiocarbamates are related compounds to xanthates. This is organosulfur compound is obtained by treating carbon disulfide with amine in the presence of sodium hydroxide: They arise from the reaction of the amine with CS2

Reference 4

Endpoint:

in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus

Remarks:

Type of genotoxicity: chromosome aberration

Type of information:

other: published data

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for type of information:

Dithiocarbamates are related compounds to xanthates. This is organosulfur compound is obtained by treating carbon disulfide with amine in the presence of sodium hydroxide: They arise from the reaction of the amine with CS2

Qualifier:

according to guideline

Guideline:

OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)

Deviations:

yes

Remarks:

No positive control.

Qualifier:

according to guideline

Guideline:

EU Method B.12 (Mutagenicity - In Vivo Mammalian Erythrocyte Micronucleus Test)

Qualifier:

according to guideline

Guideline:

EPA OPP 84-2

GLP compliance:

yes

Type of assay:

micronucleus assay

Species:

mouse

Strain:

CD-1

Sex:

male/female

Details on test animals or test system and environmental conditions:

- Source: Charles River, USA
- Age at study initiation: 5-6 weeks
- Weight at study initiation: no data

Route of administration:

oral: feed

Duration of treatment / exposure:

89 days

Frequency of treatment:

daily

Post exposure period:

none

Remarks:

Doses / Concentrations:
0, 25, 75, 225 and 675 ppm
Basis:
nominal in diet

No. of animals per sex per dose:

50

Control animals:

yes, plain diet

Tissues and cell types examined:

Peripheral blood

Details of tissue and slide preparation:

Peripheral blood smears were prepared from 5 male and 5 female animals in each group. The smears were stained using Giemsa then examined by light microscopy for the presence of micronuclei in normochromatic and polychromatic erythrocytes (1000 cells of each type were examined from each animal). The ratio of polychromatic to normochromatic erythrocytes was assessed by examination of at least 1000 erythrocytes from each animal.

Sex:

male/female

Genotoxicity:

negative

Toxicity:

no effects

Vehicle controls validity:

valid

Negative controls validity:

not examined

Positive controls validity:

not examined

Dose level [ppm]	Ration p/n (mean)	Incidence mnp (mean)	Incidence mnn (mean)
Control	0.108	0.9	1.1
25*	0.143	0.6	1.7
75**	0.124	1.2	2.0
225	0.095	0.8	0.7
675	0.135	0.5	1.2

p/n Ratio of polychromatic to normochromatic erythrocytes

mnp No. of micronucleated cells observed per 1000 polychromatic erythrocytes

mnn No. of micronucleated cells observed per 1000 normochromatic erythrocytes

* Prepared at 29 ppm initially to allow for loss during storage

** Prepared at 83 ppm initially to allow for loss during storage

 

Conclusions:

Interpretation of results: negative
No mutagenic activity of Ziram detected. Dithiocarbamates are related compounds to xanthates. This is organosulfur compound is obtained by treating carbon disulfide with amine in the presence of sodium hydroxide: They arise from the reaction of the amine with CS2

Reference 5

Endpoint:

in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus

Remarks:

Type of genotoxicity: chromosome aberration

Type of information:

other: published data

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for type of information:

Carbon disulphide is both a reagent in the manufacture, as well as a decomposition product of xanthates. SIBX readily decomposes to carbon disulphide, especially in the presence of moisture/water. Therefore, the health effects of carbon disulphide (CS2) need to be considered in the assessment of SIBX.

Qualifier:

according to guideline

Guideline:

OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)

GLP compliance:

not specified

Type of assay:

micronucleus assay

Species:

mouse

Strain:

CD-1

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Breeding Laboratories (UK)
- Age at study initiation: 4-5 weeks
- Weight at study initiation: 16.1-26 g
- Assigned to test groups randomly: yes
- Housing: high density polypropylene cages with stainless steel taps
- Diet: ad libitum
- Water: supplied via a polythene bottle and sipper tube
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21±2
- Humidity (%): 55 ±15 %
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light):12

Route of administration:

inhalation: vapour

Vehicle:

no vehicle used

Details on exposure:

TYPE OF INHALATION EXPOSURE: snout only

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
-Animals were exposed to the test material by snout-only inhalation. Prior to exposure of animals, the test material atmospheres were generated for each exposure chamber and samples analysed. Each mouse was placed in an individual polymethyl methacrylate restraining tube so that only the snout protruded. Each restraining tube was marked with the animal and group numbers. The restraining tubes were attached to the appropriate chamber so that the snout of each mouse projected into the lumen of the chamber. When the pre-exposure observations were complete, the syringe pump was switched on and the exposure timed for six hours following a 4.5 minute equilibration period, the theoretical time required for the concentration of vapour to reach 90% of its final value under the conditions of exposure employed (Silver and Arsenal, 1946). After six hours, the test atmosphere
supply was switched off and the mice removed from the restraining tubes for examination.

Duration of treatment / exposure:

6 h

Frequency of treatment:

once

Remarks:

Doses / Concentrations:
0, 467, 1558, 4675 mg/m3 (150, 500, 1500 ppm)
Basis:
nominal conc.

No. of animals per sex per dose:

10 (5 for positive control)

Control animals:

yes

Positive control(s):

chlorambucil
- Route of administration: oral
- Doses / concentrations: 30 mg/kg

Tissues and cell types examined:

bone marrow erythrocytes

Details of tissue and slide preparation:

CRITERIA FOR DOSE SELECTION: based on the preliminary toxicity testing

TREATMENT AND SAMPLING TIMES ( in addition to information in specific fields): samples were taken 24 and 48 h after treatment

DETAILS OF SLIDE PREPARATION: Animals were killed by cervical dislocation following carbon dioxide inhalation. Femurs from each animal were rapidly dissected out and cleaned of adherent tissue. The epiphyses were cut off to obtain access to the marrow canal. Marrow cells were flushed out with 2.5 ml foetal calf serum using a syringe and needle. The recovered cells were centrifuged at 1000 rpm for five minutes. The bulk of the supernatant fluid was discarded and the cell pellet resuspended in the remaining fluid. Single drops of the cell suspension were transferred to clean, dry slides, two or three smears (for the preliminary toxicity test or main micronucleus test respectively) prepared, and the slides left to air-dry. Following fixation in methanol for ten minutes, they were stained manually in 5% Giemsa stain (in Sorensen's buffer: pH 6.8), washed in buffer, air-dried, cleared for five minutes in xylene and made permanent using DPX mountant.


METHOD OF ANALYSIS: The slides were examined under the light microscope. At high magnification (x 1000, oil immersion) a total of at least 2000 erythrocytes per animal were examined. Each erythrocyte scored was classed as polychromatic or mature. Each erythrocyte scored was also examined for the presence or absence of micronuclei. Thereafter, the frequencies of micronucleated cells per 1000 erythrocytes were calculated. The ratio of polychromatic to mature cells was also determined (indicating the rythm of cell division). The frequency of micronuclei in polychromatic cells provides an index of induced genetic damage.

Evaluation criteria:

Positive for clastogenicity was a statistically and biologically significant increase in micronucleated polychromatic cells, compared to vehicle control, in at least one treatment group; particularly if supported by evidence of a dose-related response.

Statistics:

Mann-Whitney U procedure (Mann and Whitney, 1942), two-tailed test, one-tailed test.

Sex:

male/female

Genotoxicity:

negative

Toxicity:

no effects

Vehicle controls validity:

not examined

Negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

RESULTS OF RANGE-FINDING STUDY
- Dose range: 45, 150, 450, 1500, 2000 ppm
- Clinical signs of toxicity in test animals: unconscious and death at 2000 ppm, unconscious, slow and laboured respiration, all extremities red coloured. No adverse reactions to treatment were observed in animals exposed to 450, 150, 45 ppm test substance.
- Evidence of cytotoxicity in tissue analyzed: no bone marrow toxicity observed
- Harvest times: 48 hours

RESULTS OF DEFINITIVE STUDY
- Induction of micronuclei (for Micronucleus assay): see table
- Ratio of PCE/NCE (for Micronucleus assay): see table

The micronucleus test - group means and standard deviations (sd) by sex

test group	dose (ppm)	sampling time (h)	Sex	total polychromatic cells scored	total micronucleated polychromatic cells	mean micronucleated polychromatic cells per 1000 and sd	total mature cells scored	total micronucleated mature cells per 1000 and sd	polychromatic cells/mature cells
Air	0	24	M	5183	7	1.3±0.9	5652	4	0.7±0.4
			F	5709	3	0.5±0.5	5607	3	0.6±0.9
Carbon disulphide	150		M	5208	2	0.4±0.5	5871	4	0.6±0.9
			F	6030	6	1.0±0.7	5469	5	0.9±0.8
	500		M	6194	14	2.0±1.6	5505	2	0.4±0.5
			F	5788	10	1.6±1.1	5148	3	0.6±0.5
	1500		M	6713	8	1.0±1.2	5089	2	0.4±0.5
			F	7640	9	1.2±0.9	5129	2	0.4±0.5
Chlorambucil	30 mg/kg		M	5473	322	59.0±27.6	5176	3	0.6±0.9
			F	5807	403	69.3±27.5	5201	7	1.3±0.8
Air	0	48	M	5090	4	0.8±0.8	6101	7	1.1±0.8
			F	5588	4	0.7±0.8	4561	1	0.2±0.4
Carbon disulphide	150		M	5353	2	0.4±0.5	5699	4	0.7±0.6
			F	5976	9	1.5±1.1	5079	0	0.0±0.0
	500		M	6153	7	1.1±1.2	5300	3	0.6±0.9
			F	6518	6	0.9±0.6	5105	2	0.4±0.5
	1500		M	7324	8	1.0±0.9	5072	0	0.0±0.0
			F	6558	15	2.1±1.4	5022	0	0.0±0.0

 

Conclusions:

Interpretation of results: negative
No evidence of induced chromosomal or other damage leading to the formation of micronuclei in erythrocytes of the bone marrow was detected after exposure of the animals to CS2 via inhalation.
Carbon disulphide is both a reagent in the manufacture, as well as a decomposition product of xanthates. SIBX readily decomposes to carbon disulphide, especially in the presence of moisture/water. Therefore, the health effects of carbon disulphide (CS2) need to be considered in the assessment of SIBX.
In addition, xanthates decompose on aging to form a number of byproducts, depending on the pH, temperature, etc. Risks associated with xanthate are, therefore, a function of the breakdown of the product or un-reacted raw materials remaining in the product.

Executive summary:

The effect of carbon disulphide on chromosome structure in the bone marrow erythrocytes of mice was examined. The animals (males and females) were exposed via inhalation snout-only, for 6 h to the following concentrations: 0, 467, 1558, 4675 mg/m3 (0, 150, 500, 1500 ppm). The exposure concentrations were based on a preliminary toxicity test. Chlorambucil (30 mg/kg bw) was used as a positive control, adminstered via the oral route. Animals were sacrifised and examined 24 and 48 h after exposure. No evidence of induced chromosomal or other damage leading to the formation of micronuclei in erythrocytes of the bone marrow was detected, uder the present test condition, after exposure of the animals to CS2 via inhalation. Mice exposed at 1500 ppm, however, showed a small increase in the ratio of polychromatic/mature cells, which may indicate disturbance of erythropoiesis. Carbon disulphide was tested for induction of micronuclei in the bone marrow ertythrocytes of mice according to the OECD Guidelines 474 (1983).

Reference 6

Endpoint:

genetic toxicity in vivo, other

Remarks:

Type of genotoxicity: other: review paper covering many studies

Type of information:

other: published data

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for type of information:

Carbon disulphide is both a reagent in the manufacture, as well as a decomposition product of xanthates. SIBX readily decomposes to carbon disulphide, especially in the presence of moisture/water. Therefore, the health effects of carbon disulphide (CS2) need to be considered in the assessment of SIBX. In addition, xanthates decompose on aging to form a number of byproducts, depending on the pH, temperature, etc. Risks associated with xanthate are, therefore, a function of the breakdown of the product or un-reacted raw materials remaining in the product.

Qualifier:

no guideline available

Principles of method if other than guideline:

Review of a large series of publications on studies in which a wide array of methods was applied.

GLP compliance:

not specified

Type of assay:

other: review paper covering many studies

Species:

other: A series of studies with various animal species was reviewed.

Strain:

other: A series of studies with various animal species was reviewed.

Sex:

male/female

Details on test animals or test system and environmental conditions:

Not applicable: review paper.

Route of administration:

other: Invasive (injection) and non-invasive (inhalation, oral, dermal) routes were employed in the different studies reviewed.

Vehicle:

Not applicable: review paper.

Details on exposure:

Not applicable: review paper.

Duration of treatment / exposure:

Not applicable: review paper.

Frequency of treatment:

Not applicable: review paper.

Conclusions:

Interpretation of results: negative
In the majority of the in vivo tests assessing CS2 mutagenic potential, a negative result was obtained, except for one case. The validity of the studies is uncertain due to technical issues (e.g. invalid controls).
Carbon disulphide is both a reagent in the manufacture, as well as a decomposition product of xanthates. SIBX readily decomposes to carbon disulphide, especially in the presence of moisture/water. Therefore, the health effects of carbon disulphide (CS2) need to be considered in the assessment of SIBX.
In addition, xanthates decompose on aging to form a number of byproducts, depending on the pH, temperature, etc. Risks associated with xanthate are, therefore, a function of the breakdown of the product or un-reacted raw materials remaining in the product.

Executive summary:

In male and female rats inhaling 63 or 125 mg carbon disulfide/m3, 7 hours per day for 1 or 5 days, there was no significant increase in the frequency of chromosomal aberrations in bone marrow cells (Belisles et al., 1980). In another study (Vasil’eva, 1982), oral exposure to carbon disulfide gave a mutagenic response, manifested as chromosomal aberrations and polyploid cells in the bone marrow of female rats and in rat embryos exposed on days 10–13 of gestation. According to the reviewer,'it is difficult to assess the validity of these findings, as the reporting was brief e.g., the statistical significance was often not indicated and the effective dose was not reported, except to indicate that it was one-tenth of the LD50 '. In the investigation of Belisles et al. (1980), male rats were exposed to 63–125 mg/m3 of CS2, 7 h/d for 5 d; no significant increase in dominant lethal mutations was observed, nor was there a dose related increase in sperm abnormalities in rats or mice exposed according to the same protocol. However, lack of an effect on sperm abnormalities in positive control rats suggests that there was a problem with the test methods in this study.

Additional information

Additional information from genetic toxicity in vitro:

No mutagenic activity of CS2 detected in the reliable study of Akzo Chemicals International BV 1992.Carbon disulphide was examined for its mutagenic activity in four histidine-dependent auxotrophs of Salmonella typhimurium, strains TA98, TA100, TA1535, TA1537.Carbon disulphide is both a reagent in the manufacture, as well as a decomposition product of xanthates. SIBX readily decomposes to carbon disulphide, especially in the presence of moisture/water. Therefore, the health effects of carbon disulphide (CS2) need to be considered in the assessment of SIBX.

No mutagenic activity of Isobutyl Alcohol detected in the reliable study of Kreja L, Seidel H-J 2002.. Isobutyl Alcohol was examined for its mutagenic activity inChinese hamster lung fibroblasts (V79) cell line.

2-methylpropan-1-ol /Isobutyl alcohol/ is both reagents used in the manufacture of sodium O-isobutyl dithiocarbonate . Therefore, 2-methylpropan-1-ol /Isobutyl alcohol/ need to be considered in the assessment of sodium O-isobutyl dithiocarbonate

No mutagenic activity of Isobutyl Alcohol detectedin the reliable study ofShimizu H, et al.1985. Isobutyl Alcohol was examined for its mutagenic activity in Salmonella typhimurium, strains TA98, TA100, TA1535, TA1537, and TA1538 and E. coli WP2 uvr A.

 

2-methylpropan-1-ol /Isobutyl alcohol/ is both reagents used in the manufacture of sodium O-isobutyl dithiocarbonate . Therefore, 2-methylpropan-1-ol /Isobutyl alcohol/ need to be considered in the assessment of sodium O-isobutyl dithiocarbonate

 

In the reliable study of Engelhardt, D. et al.2000, oral gavage dose of 500, 1,000 or 2,000 mg/kg of isobutanol in mouse did not have any chromosome-damaging (clastogenic) effect, and there were noindications of any impairment of chromosome distribution in the course of mitosis.

2-methylpropan-1-ol /Isobutyl alcohol/ is both reagents used in the manufacture of sodium O-isobutyl dithiocarbonate . Therefore, 2-methylpropan-1-ol /Isobutyl alcohol/ need to be considered in the assessment of sodium O-isobutyl dithiocarbonate

No evidence of induced chromosomal or other damage leading to the formation of micronuclei in erythrocytes of the bone marrow was detected after exposure of the mouse to CS2 via inhalationin the reliable study of Akzo Chemicals International BV 1992..

Carbon disulphide is both a reagent in the manufacture, as well as a decomposition product of xanthates. SIBX readily decomposes to carbon disulphide, especially in the presence of moisture/water. Therefore, the health effects of carbon disulphide (CS2) need to be considered in the assessment of SIBX.

Justification for selection of genetic toxicity endpoint
Negative in all test conducted.

Justification for classification or non-classification

Based on the hazard assessment of SIBX in section 2.1 and 2.2. in IUCLID 6 available data for the substance and following the “Guidance on Information Requirement and Chemical Safety Assessment R.8. Characterisation of dose [concentration]- response for human health” andaccording to the criteria described in Directive 67/548 and in the CLP Regulation:

 

Directive 67/548	Mutagenicity-Genetic Toxicity Muta. Cat. 1; R46 May cause heritable genetic damage. Muta. Cat. 2; R46 May cause heritable genetic damage. Muta. Cat. 3; R68 Possible risk of irreversible effects.
CLP	Germ cell mutagenicity Muta. 1A Muta. 1B Muta. 2 H340: May cause genetic defects <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>. H341: Suspected of causing genetic defects <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>.

 

 

It is concluded that the substance SIBX does not meet the criteria to be classified for human health hazards for Mutagenicity-Genetic Toxicity