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EC number: 246-896-9 | CAS number: 25360-10-5
- Life Cycle description
- Uses advised against
- Endpoint summary
- Appearance / physical state / colour
- Melting point / freezing point
- Boiling point
- Density
- Particle size distribution (Granulometry)
- Vapour pressure
- Partition coefficient
- Water solubility
- Solubility in organic solvents / fat solubility
- Surface tension
- Flash point
- Auto flammability
- Flammability
- Explosiveness
- Oxidising properties
- Oxidation reduction potential
- Stability in organic solvents and identity of relevant degradation products
- Storage stability and reactivity towards container material
- Stability: thermal, sunlight, metals
- pH
- Dissociation constant
- Viscosity
- Additional physico-chemical information
- Additional physico-chemical properties of nanomaterials
- Nanomaterial agglomeration / aggregation
- Nanomaterial crystalline phase
- Nanomaterial crystallite and grain size
- Nanomaterial aspect ratio / shape
- Nanomaterial specific surface area
- Nanomaterial Zeta potential
- Nanomaterial surface chemistry
- Nanomaterial dustiness
- Nanomaterial porosity
- Nanomaterial pour density
- Nanomaterial photocatalytic activity
- Nanomaterial radical formation potential
- Nanomaterial catalytic activity
- Endpoint summary
- Stability
- Biodegradation
- Bioaccumulation
- Transport and distribution
- Environmental data
- Additional information on environmental fate and behaviour
- Ecotoxicological Summary
- Aquatic toxicity
- Endpoint summary
- Short-term toxicity to fish
- Long-term toxicity to fish
- Short-term toxicity to aquatic invertebrates
- Long-term toxicity to aquatic invertebrates
- Toxicity to aquatic algae and cyanobacteria
- Toxicity to aquatic plants other than algae
- Toxicity to microorganisms
- Endocrine disrupter testing in aquatic vertebrates – in vivo
- Toxicity to other aquatic organisms
- Sediment toxicity
- Terrestrial toxicity
- Biological effects monitoring
- Biotransformation and kinetics
- Additional ecotoxological information
- Toxicological Summary
- Toxicokinetics, metabolism and distribution
- Acute Toxicity
- Irritation / corrosion
- Sensitisation
- Repeated dose toxicity
- Genetic toxicity
- Carcinogenicity
- Toxicity to reproduction
- Specific investigations
- Exposure related observations in humans
- Toxic effects on livestock and pets
- Additional toxicological data
Genetic toxicity: in vitro
Administrative data
- Endpoint:
- in vitro cytogenicity / chromosome aberration study in mammalian cells
- Remarks:
- Type of genotoxicity: chromosome aberration
- Type of information:
- migrated information: read-across from supporting substance (structural analogue or surrogate)
- Adequacy of study:
- key study
- Reliability:
- 1 (reliable without restriction)
- Rationale for reliability incl. deficiencies:
- other: GLP Guideline study
Data source
Reference
- Reference Type:
- study report
- Title:
- Unnamed
- Year:
- 1 997
- Report date:
- 1997
Materials and methods
Test guideline
- Qualifier:
- according to guideline
- Guideline:
- OECD Guideline 473 (In Vitro Mammalian Chromosome Aberration Test)
- Deviations:
- no
- GLP compliance:
- yes
- Type of assay:
- in vitro mammalian chromosome aberration test
Test material
- Reference substance name:
- Tert-Dodecanethiol (CAS # 25103-58-6)
- IUPAC Name:
- Tert-Dodecanethiol (CAS # 25103-58-6)
- Details on test material:
- - Supplier: Elf Aquitaine Production
- Name of test material (as cited in study report): t-dodecyl mercaptan
- Physical state: liquid
- Analytical purity: 98.58%
- Purity test date: April 1996
- Lot/batch No.: 42414
- Expiration date of the lot/batch: December 1997
Constituent 1
Method
Species / strain
- Species / strain / cell type:
- other: Human lymphocytes
- Metabolic activation:
- with and without
- Metabolic activation system:
- rat liver post-mitochondrial fraction (S-9) from Aroclor 1254 induced animals
- Test concentrations with justification for top dose:
- 16.89, 22.53, 30.03 µg/ml (20-h treatment, -S9)
53.39, 71.19, 94.92 µg/ml (3-h treatment, -S9)
16.89, 22.53, 30.03 (44-h treatment, -S9)
94.92 µg/ml (3-h treatment, +S9)
Controls
- Untreated negative controls:
- yes
- Negative solvent / vehicle controls:
- yes
- True negative controls:
- no
- Positive controls:
- yes
- Positive control substance:
- other: 4-Nitroquinoline 1-oxide (-S9) and cyclophosphamide (+S9)
- Details on test system and experimental conditions:
- t-Dodecyl mercaptan was tested in an in vitro cytogenetics assay using duplicate human lymphocyte cultures from a male human donor. Treatments covering a broad range of doses, separated by narrow intervals, were performed both in the absence and presence of metabolic activation by a rat liver post-mitochondrial fraction (S-9) from Aroclor 1254 induced animals. The highest dose level used, 300 µg/mL was just in excess of the limit of solubility in culture medium.
Treatment in the absence of S-9 was continuous for 20 or 44 hours (20+0, 44+0). Treatment in the presence of S-9 was for 3 hours only followed by a 17 or 41 hour recovery period (3+17, 3+41). The test article dose levels for chromosome analysis were selected by evaluating the effect of t-dodecyl mercaptan on mitotic index. Following 20+0 hour treatments, -S-9 and 3+17 hour treatments, +S-9, chromosome aberrations were analysed at three consecutive dose levels. The highest concentrations chosen for analysis, 30.03 µg/mL and 94.92 µg/mL, induced approximately 48% and 70% mitotic inhibition (reduction in mitotic index) in the absence and presence of S-9 respectively.
The effects of these single concentrations only, (30.03 µg/mL, without and 94.92 µg/mL with S-9) were initially investigated at the delayed (44+0, 3+41) sampling time. Slides from cultures treated with 16.89 and 22.53 µg/mL in the absence of S-9 were subsequently examined to further investigate chromosome damage induced under these conditions.
Appropriate negative (solvent) control cultures and untreated cultures were included in the test system under each treatment condition.
SPINDLE INHIBITOR (cytogenetic assays): colchicine
STAIN (for cytogenetic assays): Giemsa
NUMBER OF REPLICATIONS: 2
NUMBER OF CELLS EVALUATED: Where possible, 100 metaphases from each code were analysed for chromosome aberrations.
DETERMINATION OF CYTOTOXICITY
Slides were examined, uncoded, for mitotic index (MI) or percentage of cells in mitosis. Slides from enough dose levels from each treatment regime were scored to determine if chemically induced mitotic inhibition had occurred. This is defined as a clear decrease in mitotic index compared with negative controls (based on at least 1000 cells counted), preferably dose-related.
OTHER EXAMINATIONS:
- Determination of polyploidy/ endoreplication: Only cells with 44-46 chromosomes were considered acceptable for analysis of structural aberrations. Any cell with more than 46 chromosomes, that is polyploid, endoreduplicated and hyperdiploid cells, observed during this search was noted and recorded separately. - Evaluation criteria:
- The test article was to be considered as positive in this assay if:
1) a statistically significant increase in the proportion of cells with structural aberrations (excluding gaps) occurred at one or more concentrations, and
2) the proportion of cells with structural aberrations at such doses exceeded the normal range.
A positive result only at the delayed harvest was to be taken as evidence of clastogenicity provided criteria 1 and 2 were met. Increases in numbers of cells with gaps or increases in the proportions of cells with structural aberrations, not exceeding the normal range or occurring only at very high or very toxic concentrations, were likely to be concluded as "equivocal". Full assessment of the biological importance of such increases is likely only to be possible with reference to data from other test systems. Cells with exchange aberrations or cells with greater than one structural aberration were to be considered of particular biological significance. - Statistics:
- Fisher's exact test. Probability values of p <0.05 were accepted as significant
Results and discussion
Test results
- Species / strain:
- lymphocytes: human
- Metabolic activation:
- with and without
- Genotoxicity:
- ambiguous
- Cytotoxicity / choice of top concentrations:
- cytotoxicity
- Remarks:
- 30.03 µg/mL and 94.92 µg/mL, induced approximately 48% and 70% mitotic inhibition (reduction in mitotic index) in the absence and presence of S-9 respectively
- Vehicle controls validity:
- valid
- Untreated negative controls validity:
- valid
- Positive controls validity:
- valid
- Additional information on results:
- Treatment of cultures with t-dodecyl mercaptan in the absence and presence of S-9 resulted, at the 20 hour sampling time, in frequencies of cells with aberrations which were similar to those seen in concurrent negative controls. Frequencies of cells with aberrations (excluding gaps) fell just outside historical negative control ranges in one culture at the highest dose level analysed after treatment both with and without S-9, but insofar as the effect was small and not seen in both replicates it was considered unlikely to be biologically significant. Treatment of cultures with t-dodecyl mercaptan for 44 hours in the absence of S-9 resulted in numbers of cells with aberrations which were significantly higher than in concurrent negative controls at all dose levels analysed. The numbers of cells with aberrations (excluding gaps) observed exceeded the historical negative control range, but this effect was only seen in both replicates at the highest concentration tested (30.03 µg/mL) at which severe mitotic inhibition was apparent. At both 16.89 and 22.53 µg/mL numbers of aberrant cells exceeded the normal range in only one of the two replicate cultures analysed. No increase in aberrant cells was seen at the delayed sampling time after treatment in the presence of S-9.
- Remarks on result:
- other: all strains/cell types tested
- Remarks:
- Migrated from field 'Test system'. Remarks: Human lymphocytes
Any other information on results incl. tables
t-Dodecyl Mercaptan: cells with structural aberrations
TABLE 1
20 hour treatment -S-9, 0 hour recovery (20+0) Donor sex: male
Treatment |
Replicate |
Cells |
Cells with |
Cells with Significance |
Mitotic |
(µg/mL) |
scored |
aberrations including gaps |
aberrations § encluding gaps |
index (mean) |
|
Solvent |
A |
100 |
4 |
2 |
4.7 |
B |
100 |
4 |
4 |
4.1 |
|
Totals |
200 |
8 |
6 |
(4.4) |
|
16.89 |
A |
100 |
6 |
3 |
3.9 |
B |
100 |
7 |
3 |
4.3 |
|
Totals |
200 |
13 |
6 NS |
(4.1) |
|
22.53 |
A |
100 |
7 |
3 |
3.4 |
B |
100 |
6 |
3 |
4.3 |
|
Totals |
200 |
13 |
6 NS |
(3.9) |
|
30.03 |
A |
100 |
3 |
1 |
2.1 |
B |
100 |
10 |
6 |
2.5 |
|
Totals |
200 |
13 |
7 NS |
(2.3) |
|
NQO, 2.5 |
A |
25 |
S |
S |
|
B |
25 |
$ |
$ |
||
Totals |
50 |
16 |
16 p 0.001 |
TABLE 2
3 hour treatment +S-9, 17 hour recovery (3+17) Donor sex: male
Treatment |
Replicate |
Cells |
Cells with |
Cells with Significance |
Mitotic |
(µg/mL) |
scored |
aberrations including gaps |
aberrations § excluding gaps |
index (mean) |
|
Solvent |
A |
100 |
1 |
1 |
5.5 |
B |
100 |
2 |
1 |
5.0 |
|
Totals |
200 |
3 |
2 |
(5.3) |
|
53.39 |
A |
100 |
5 |
3 |
3.2 |
B |
100 |
3 |
0 |
5.2 |
|
Totals |
200 |
8 |
3 NS |
(4.2) |
|
71.19 |
A |
100 |
$ |
4 |
4.3 |
B |
100 |
3 |
2 |
2.9 |
|
Totals |
200 |
11 |
6 NS |
(3.6) |
|
94.92 |
A |
100 |
0 |
0.7 |
|
B |
100 |
6 |
4 |
2.5 |
|
Totals |
200 |
16 |
11 p <0.01 |
(1.6) |
|
CPA, 12.5 |
A |
25 |
19 |
i |
|
B |
25 |
13 |
|||
_ |
Totals |
50 |
32 |
25 p <0.001 |
TABLE 3
44 hour treatment -S-9, 0 hour recovery (44+0) Donor sex: male
Treatment |
Replicate |
Cells |
Cells with |
Cells with Significance |
Mitotic |
(µg/mL) |
scored |
aberrations including gaps |
aberrations § encluding gaps |
index (mean) |
|
Solvent |
A |
100 |
1 |
0 |
2.8 |
B |
100 |
3 |
2 |
4.3 |
|
Totals |
200 |
4 |
2 |
(3.6) |
|
16.89 |
A |
100 |
9 |
2 |
3.3 |
B |
100 |
11 |
3.2 |
||
Totals |
200 |
20 |
8 p <0.05 |
(3.3) |
|
22.53 |
A |
100 |
5 |
3 |
2.8 |
B |
100 |
9 |
7 |
2.8 |
|
Totals |
200 |
14 |
10 p < 0.05 |
(2.8) |
|
30.03 |
A |
56 |
9 |
7 |
0.6 |
B |
100 |
24 |
14 |
0.7 |
|
_ |
Totals |
156 _ |
33 |
21 p <0.001 |
(0.7) |
TABLE 4
3 hour treatment +S-9, 41 hour recovery (3+41) Donor sex: male
Treatment |
Replicate |
Cells |
Cells with |
Cells with Significance |
Mitotic |
(µg/mL) |
scored |
aberrations including gaps |
aberrations § excluding gaps |
index (mean) |
|
Solvent |
A |
100 |
2 |
1 |
4.3 |
B |
100 |
2 |
2 |
3.6 |
|
Totals |
200 |
4 |
3 |
(4.0) |
|
94.92 |
A |
100 |
5 |
4 |
3.3 |
B |
100 |
4 |
2 |
1.8 |
|
Totals |
200 |
9 |
6 NS |
(2.6) |
Applicant's summary and conclusion
- Conclusions:
- Interpretation of results (migrated information):
ambiguous without metabolic activation at cytotoxic concentrations
negative with metabolic activation
It is concluded that tert-dodecanethiol induced chromosome aberrations in cultured human peripheral blood lymphocytes. The effect, however, was restricted to prolonged, cytotoxic treatment in the absence of S-9. - Executive summary:
In a chromosomal aberration assay performed according to OECD guideline #473, human lymphocytes were exposed to tert-dodecanethiol concentrations up to 94 µg/ml, with and without metabolic activation. No effects were observed at the 20-hour sampling time. At 44 hours in the absence of S9, the number of cells with aberrations was significantly higher than in concurrent negative controls at all dose levels analyzed. The numbers of cells with aberrations observed exceeded the historical control range, but this effect was only seen in both replicates at the highest concentration tested (30.03 µg/mL) at which severe mitotic inhibition was apparent. It was concluded that tert-dodecanethiol induced chromosomal aberrations in cultured human peripheral blood lymphocytes; however, this effect was restricted to prolonged, cytotoxic treatment in the absence of S9, and is therefore, considered to be ambiguous.
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