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EC number: 911-254-5 | CAS number: -
- 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
Endpoint summary
Administrative data
Key value for chemical safety assessment
Genetic toxicity in vitro
Description of key information
Gene mutation in bacteria: Key study: Read-across from experimental results on the substance 6-tert-Butyl-2,4-xylenol. Test equivalent to OECD guideline 471. GLP study.
The substance is not mutagenic in Salmonella typhimurium TA100, TA98, TA1535, TA1537 and Escherichia coli WP2 uvrA, with and without metabolic activation.
Chromosomal aberrations in mammalian cells: Key study: Read-across from experimental results on the substance 6-tert-Butyl-2,4-xylenol. Test equivalent to OECD guideline 473. GLP study.
The substance did not produce chromosomal aberrations.
Gene mutation in mammalian cells: Key study: Experimental results. Test according to OECD guideline 476. GLP study.
The test substance is considered to be non-mutagenic in this HPRT assay.
Link to relevant study records
- Endpoint:
- in vitro gene mutation study in bacteria
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Reliability:
- 1 (reliable without restriction)
- Rationale for reliability incl. deficiencies:
- comparable to guideline study
- Remarks:
- Meets the requirements of GLP. There are no deviations from the recommended guideline.
- Qualifier:
- according to guideline
- Guideline:
- JAPAN: Guidelines for Screening Mutagenicity Testing Of Chemicals
- Deviations:
- no
- Qualifier:
- equivalent or similar to guideline
- Guideline:
- OECD Guideline 471 (Bacterial Reverse Mutation Assay)
- Deviations:
- no
- GLP compliance:
- yes
- Type of assay:
- bacterial reverse mutation assay
- Species / strain / cell type:
- S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
- Species / strain / cell type:
- E. coli WP2 uvr A
- Metabolic activation:
- with and without
- Metabolic activation system:
- S9 mix
- Test concentrations with justification for top dose:
- 0, 6.25, 12.5, 25, 50, 100 and 200 μg/plate (-S9 mix)
0, 6.25, 12.5, 25, 50, 100, 200 and 400 μg/plate (+S9 mix)
0, 6.25, 12.5, 25, 50, 100 and 200 μg/plate (TA1537) (+S9 mix) - Vehicle / solvent:
- - Vehicle(s)/solvent(s) used: DMSO
- Untreated negative controls:
- yes
- Negative solvent / vehicle controls:
- not specified
- True negative controls:
- no
- Positive controls:
- yes
- Remarks:
- without metabolic activation
- Positive control substance:
- sodium azide
- Remarks:
- TA 1535: 0.5 µg/plate
- Untreated negative controls:
- yes
- Negative solvent / vehicle controls:
- not specified
- True negative controls:
- no
- Positive controls:
- yes
- Remarks:
- without metabolic activation
- Positive control substance:
- other: AF2 (2-(2-Furyl)-3-(5-nitro-2-furyl) acrylamide
- Remarks:
- TA 100, WP2: 0.01 µg/plate and TA 98: 0.1 µg/plate
- Untreated negative controls:
- yes
- Negative solvent / vehicle controls:
- not specified
- True negative controls:
- no
- Positive controls:
- yes
- Remarks:
- without metabolic activation
- Positive control substance:
- 9-aminoacridine
- Remarks:
- TA 1537: 80 µg/plate
- Untreated negative controls:
- yes
- Negative solvent / vehicle controls:
- not specified
- True negative controls:
- no
- Positive controls:
- yes
- Remarks:
- with metabolic activation
- Positive control substance:
- other: 2-aminoanthracene
- Remarks:
- TA 100: 1 µg/plate; TA 1535: 2 µg/plate; WP 2: 10 µg/plate; TA 98: 0.5 µg/plate; TA 1537: 2 µg/plate
- Details on test system and experimental conditions:
- METHOD OF APPLICATION: plate incorporation method
NUMBER OF REPLICATIONS: 2
OTHER:
Number of plates/test: 3 - Key result
- 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
- Vehicle controls validity:
- not specified
- Untreated negative controls validity:
- valid
- Positive controls validity:
- valid
- Key result
- 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 specified
- Untreated negative controls validity:
- valid
- Positive controls validity:
- valid
- Conclusions:
- Not mutagenic in Salmonella typhimurium TA100, TA98, TA1535, TA1537 and Escherichia coli WP2 uvrA, with and without metabolic activation.
- Executive summary:
Genotoxicity of 6-tert-butyl-2,4-xylenol was studied by the reverse mutation assay in bacteria, according to the JAPAN Guidelines for Screening Mutagenicity Testing Of Chemicals (equivalent to OECD Guideline 471). 6 -tert-Butyl-2,4-xylenol was found to be not mutagenic in Salmonella typhimurium TA100, TA98, TA1535, TA1537 and Escherichia coli WP2 uvrA, with and without metabolic activation.
- Endpoint:
- in vitro gene mutation study in bacteria
- Type of information:
- read-across from supporting substance (structural analogue or surrogate)
- Adequacy of study:
- key study
- Justification for type of information:
- REPORTING FORMAT FOR THE ANALOGUE APPROACH
The substance CAS No. 1879-09-0 is one of the main components of the reaction mass of 2-tertbutyl-4,6-dimethylphenol and 4-tert-butyl-2,5-dimethylphenol and it is present in a concentration of more than 70%. Therefore, the results obtained with the substance CAS No. 1879-09-0 can be used for the read-across approach.
See attached the reporting format. - Reason / purpose for cross-reference:
- read-across source
- Key result
- 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
- Vehicle controls validity:
- not specified
- Untreated negative controls validity:
- valid
- Positive controls validity:
- valid
- Key result
- 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 specified
- Untreated negative controls validity:
- valid
- Positive controls validity:
- valid
- Remarks on result:
- other: read-across from an analogue determined to be not mutagenic in the bacteria
- Conclusions:
- Based on read-across approach from experimental data on analogue substance 6-tert-butyl-2,4-xylenol (CAS 1879-09-0), the reaction mass of 2-tert-butyl-4,6-dimethylphenol and 4-tert-butyl-2,5-dimethylphenol is considered not mutagenic in Salmonella typhimurium TA100, TA98, TA1535, TA1537 and Escherichia coli WP2 uvrA, with and without metabolic activation.
- Executive summary:
Genotoxicity of 6-tert-butyl-2,4-xylenol was studied by the reverse mutation assay in bacteria, according to the JAPAN Guidelines for Screening Mutagenicity Testing Of Chemicals (equivalent to OECD Guideline 471). 6 -tert-Butyl-2,4-xylenol was found to be not mutagenic in Salmonella typhimurium TA100, TA98, TA1535, TA1537 and Escherichia coli WP2 uvrA, with and without metabolic activation. Based on these results, the read-across approach was applied and the reaction mass of 2-tert-butyl-4,6-dimethylphenol and 4-tert-butyl-2,5-dimethylphenol is considered not mutagenic in Salmonella typhimurium TA100, TA98, TA1535, TA1537 and Escherichia coli WP2 uvrA, with and without metabolic activation.
- Endpoint:
- in vitro cytogenicity / chromosome aberration study in mammalian cells
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Reliability:
- 1 (reliable without restriction)
- Rationale for reliability incl. deficiencies:
- comparable to guideline study
- Remarks:
- Meets the requirements of GLP. There are no deviations from the recommended guideline.
- Qualifier:
- according to guideline
- Guideline:
- JAPAN: Guidelines for Screening Mutagenicity Testing Of Chemicals
- Deviations:
- no
- Qualifier:
- equivalent or similar 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
- Species / strain / cell type:
- other: Chinese hamster lung (CHL/IU) cells
- Metabolic activation:
- with and without
- Metabolic activation system:
- S-9: Rat liver, induced with phenobarbital and 5,6-benzoflavone
- Test concentrations with justification for top dose:
- -S9 (continuous treatment): 0, 0.008, 0.017, 0.033 mg/ml
-S9 (short-term treatment): 0, 0.008, 0.017, 0.033 mg/ml
+S9 (short-term treatment): 0, 0.014, 0.028, 0.056 mg/ml - Vehicle / solvent:
- - Vehicle(s)/solvent(s) used: Dimethyl sulfoxide (DMSO)
- Untreated negative controls:
- yes
- Negative solvent / vehicle controls:
- yes
- Positive controls:
- yes
- Positive control substance:
- mitomycin C
- Remarks:
- 0.00005 mg/ml, without metabolic activation
- Untreated negative controls:
- yes
- Negative solvent / vehicle controls:
- yes
- Positive controls:
- yes
- Positive control substance:
- cyclophosphamide
- Remarks:
- 0.005 mg/ml, with and without metabolic activation
- Details on test system and experimental conditions:
- DURATION
- Exposure duration: 24 and 48 h (without S9 mix) and 6 h (with and without S9 mix)
NUMBER OF CELLS EVALUATED: 200 (24 and 48 h) and 1, 10 and 200 (6 h)
DETERMINATION OF CYTOTOXICITY
- Method: mitotic index; cloning efficiency; relative total growth; other: growth inhibition
OTHER EXAMINATIONS:
- Determination of polyploidy: yes
- Other: structural aberrations, nº of cells with aberrations
OTHER:
Number of plates/test : 2 - Key result
- Species / strain:
- other: Chinese hamster lung (CHL/IU) cells
- Metabolic activation:
- with and without
- Genotoxicity:
- negative
- Remarks:
- clastogenicity and polyploidy
- Cytotoxicity / choice of top concentrations:
- cytotoxicity
- Vehicle controls validity:
- valid
- Positive controls validity:
- valid
- Additional information on results:
- Cytogenetic effects were not seen under the conditions of this experiment.
- Conclusions:
- The test item 6-tert-Butyl-2,4-xylenol did not induce chromosomal aberrations.
- Executive summary:
6-tert-Butyl-2,4-xylenol was studied in a chromosomal aberration test in cultured Chinese hamster lung (CHL/IU) cells, according to the JAPAN Guidelines for Screening Mutagenicity Testing Of Chemicals (equivalent to OECD Guideline 473). Neither structural chromosomal aberrations nor polyploidy were induced in CHL/IU cells up to the concentration giving 50% cell growth inhibition, in the absence or presence of an exogenous metabolic activation system.
- Endpoint:
- in vitro cytogenicity / chromosome aberration study in mammalian cells
- Type of information:
- read-across from supporting substance (structural analogue or surrogate)
- Adequacy of study:
- key study
- Justification for type of information:
- REPORTING FORMAT FOR THE ANALOGUE APPROACH
The substance CAS No. 1879-09-0 is one of the main components of the reaction mass of 2-tertbutyl-4,6-dimethylphenol and 4-tert-butyl-2,5-dimethylphenol and it is present in a concentration of more than 70%. Therefore, the results obtained with the substance CAS No. 1879-09-0 can be used for the read-across approach.
See attached the reporting format. - Reason / purpose for cross-reference:
- read-across source
- Key result
- Species / strain:
- other: Chinese hamster lung (CHL/IU) cells
- Metabolic activation:
- with and without
- Genotoxicity:
- negative
- Remarks:
- clastogenicity and polyploidy
- Cytotoxicity / choice of top concentrations:
- cytotoxicity
- Vehicle controls validity:
- valid
- Positive controls validity:
- valid
- Remarks on result:
- other: read-across from an analogue determined to not induce chromosomal aberrations in a chromosomal aberration test in cultured Chinese hamster lung (CHL/IU) cells.
- Conclusions:
- Based on read-across approach from experimental data on analogue substance 6-tert-butyl-2,4-xylenol (CAS 1879-09-0), the reaction mass of 2-tert-butyl-4,6-dimethylphenol and 4-tert-butyl-2,5-dimethylphenol is considered to not produce chromosomal aberrations.
- Executive summary:
6-tert-Butyl-2,4-xylenol was studied in a chromosomal aberration test in cultured Chinese hamster lung (CHL/IU) cells, according to the JAPAN Guidelines for Screening Mutagenicity Testing Of Chemicals (equivalent to OECD Guideline 473). Neither structural chromosomal aberrations nor polyploidy were induced in CHL/IU cells up to the concentration giving 50% cell growth inhibition, in the absence or presence of an exogenous metabolic activation system. Based on these results, the read-across approach was applied and the reaction mass of 2-tert-butyl-4,6-dimethylphenol and 4-tert-butyl-2,5-dimethylphenol is considered not mutagenic in a chromosomal aberration test, with and without metabolic activation.
- Endpoint:
- in vitro gene mutation study in mammalian cells
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Study period:
- March 16th to June 18th, 2010
- Reliability:
- 1 (reliable without restriction)
- Rationale for reliability incl. deficiencies:
- guideline study
- Remarks:
- Meets the requirements of GLP. There are no deviations from the recommended guideline.
- Qualifier:
- according to guideline
- Guideline:
- OECD Guideline 476 (In Vitro Mammalian Cell Gene Mutation Test)
- Deviations:
- no
- Qualifier:
- according to guideline
- Guideline:
- EU Method B.17 (Mutagenicity - In Vitro Mammalian Cell Gene Mutation Test)
- Deviations:
- no
- GLP compliance:
- yes (incl. QA statement)
- Type of assay:
- in vitro mammalian cell gene mutation test using the Hprt and xprt genes
- Target gene:
- HPRT locus in V79 cells of the Chinese hamster
- Species / strain / cell type:
- Chinese hamster lung fibroblasts (V79)
- Details on mammalian cell type (if applicable):
- - Type and identity of media: the V79 cell line are stored in liquid nitrogen in the cell bank of Harlan CCR
- Properly maintained: yes
- Periodically checked for Mycoplasma contamination: yes
- Periodically checked for karyotype stability: yes
- Periodically "cleansed" against high spontaneous background: yes - Metabolic activation:
- with and without
- Metabolic activation system:
- S9 mix
- Test concentrations with justification for top dose:
- Experiment I:
without S9 mix: 0.6, 1.3, 2.5, 5.0, 10.0, 20.0 and 30.0 µg/mL
with S9 mix: 3.8, 7.5, 15.0, 30.0, 40.0, 50.0 and 60.0 µg/mL
Experiment II:
without S9 mix: 2.5, 5.0, 10.0, 20.0, 40.0, 50.0 and 60.0 µg/mL
with S9 mix: 2.5, 5.0, 10.0, 20.0, 40.0, 50.0 and 60.0 µg/mL - Vehicle / solvent:
- - Vehicle(s)/solvent(s) used: DMSO
- Justification for choice of solvent/vehicle: according to its solubility properties and its relative non-toxicity to the cells. - Negative solvent / vehicle controls:
- yes
- Remarks:
- DMSO
- True negative controls:
- no
- Positive controls:
- yes
- Positive control substance:
- ethylmethanesulphonate
- Remarks:
- without metabolic activation
- Negative solvent / vehicle controls:
- yes
- Remarks:
- DMSO
- True negative controls:
- no
- Positive controls:
- yes
- Positive control substance:
- 7,12-dimethylbenzanthracene
- Remarks:
- with metabolic activation
- Details on test system and experimental conditions:
- METHOD OF APPLICATION: in medium MEM (minimal essential medium)
DURATION
- Preincubation period: first experiment: 2 days; second experiment: 3 days
- Exposure duration: first experiment: 4 h and second experiment: 4 h and 24 h
- Expression time (cells in growth medium): 7 days
SELECTION AGENT (mutation assays): for the selection of mutant cells the medium is supplemented with 11 µg/mL 6-thioguanine
STAIN (for cytogenetic assays): 10 % methylene blue in 0.01 % KOH solution
NUMBER OF REPLICATIONS: 2
NUMBER OF CELLS EVALUATED: Approximately 1500000 (single culture) and 500 cells (in duplicate) were seeded in MEM with 10 % FBS (complete medium) for the determination of mutation rate and toxicity, respectively.
DETERMINATION OF CYTOTOXICITY
- Method: cloning efficiency - Evaluation criteria:
- A test item is classified as positive if it induces either a concentration-related increase of the mutant frequency or a reproducible and positive response at one of the test points.
A test item producing neither a concentration-related increase of the mutant frequency nor a reproducible positive response at any of the test points is considered non-mutagenic in this system.
A positive response is described as follows:
A test item is classified as mutagenic if it reproducibly induces a mutation frequency that is three times above the spontaneous mutation frequency at least at one of the concentrations in the experiment.
The test item is classified as mutagenic if there is a reproducible concentration-related increase of the mutation frequency. Such evaluation may be considered also in the case that a threefold increase of the mutant frequency is not observed.
However, in a case by case evaluation this decision depends on the level of the corresponding solvent control data. If there is by chance a low spontaneous mutation rate within the laboratory´s historical control data range, a concentration-related increase of the mutations within this range has to be discussed. The variability of the mutation rates of solvent controls within all experiments of this study was also taken into consideration. - Statistics:
- A linear regression (least squares) was performed to assess a possible dose dependent increase of mutant frequencies using SYSTAT®11 (SYSTAT Software, Inc., 501, Canal Boulevard, Suite C, Richmond, CA 94804, USA) statistics software. The number of mutant colonies obtained for the groups treated with the test item were compared to the solvent control groups. A trend is judged as significant whenever the p-value (probability value) is below 0.05. However, both, biological and statistical significance were considered together.
- Key result
- Species / strain:
- Chinese hamster lung fibroblasts (V79)
- Metabolic activation:
- with and without
- Genotoxicity:
- negative
- Cytotoxicity / choice of top concentrations:
- cytotoxicity
- Vehicle controls validity:
- valid
- Positive controls validity:
- valid
- Additional information on results:
- TEST-SPECIFIC CONFOUNDING FACTORS
- Precipitation: no precipitation of the test item was observed up to the maximum concentration in all experiments.
RANGE-FINDING/SCREENING STUDIES: In the range finding pre-experiment test item concentrations between 13.9 and 1783.0 µg/mL (≈10 mM) were used to evaluate toxicity in the presence (4 h treatment) and absence (4 h and 24 h treatment) of metabolic activation.
Relevant toxic effects were observed at 13.9 µg/mL and above in the absence of metabolic activation and at 55.7 µg/mL and above with metabolic activation (4 h treatment). Following continuous treatment (24 hours) strong toxic effects occurred at 55.7 µg/mL and above.
COMPARISON WITH HISTORICAL CONTROL DATA: the numbers of mutant colonies per 1000000 cells found in the solvent controls fall within the laboratory historical control data range
ADDITIONAL INFORMATION ON CYTOTOXICITY: In the experimental part without S9 mix the relative cloning efficiency I was approximately 90.0 % in cultures I and II (10 μg/mL). In the presence of S9 mix the relative cloning efficiency I was reduced to 58.0 % in culture I (40.0 μg/mL) and 31.0 % in culture II (50.0 μg/mL). However, due to strong test item induced cytotoxicity higher test item concentrations than the evaluated were not evaluable for mutagenicity. In the main experiment II the cytotoxicity criteria, given as relative cloning efficiency I reduced to 10 – 20 %, were fulfilled in both experimental parts. Following 24 hours treatment in the absence of S9 mix the relative cloning efficiency I was reduced to 6.6 % in culture I and to 11.6 % in culture II after treatment with a test item concentration of 40.0 μg/mL. After 4 hours treatment with 50.0 μg/mL in the presence of S9 mix the relative cloning efficiency I was reduced to 6.9 % and 12.1 % (cultures I and II). - Conclusions:
- In conclusion, it can be stated that under the experimental conditions reported the test item did not induce gene mutations at the HPRT locus in V79 cells. The test substance is considered to be non-mutagenic in this HPRT assay.
- Executive summary:
The study was performed to investigate the potential of the test substance to induce gene mutations at the HPRT locus in V79 cells of the Chinese hamster. The assay was performed in two independent experiments, using two parallel cultures each. The first main experiment was performed with and without liver microsomal activation and a treatment period of 4 hours. The second experiment was performed with a treatment time of 4 hours with and 24 hours without metabolic activation. The highest concentration in the pre-experiment (1783.0 µg/mL) was equal to a molar concentration of about10 mM. The dose range of the main experiments was limited by toxicity of the test item.No substantial and reproducible dose dependent increase of the mutation frequency was observed in both main experiments.Appropriate reference mutagens, used as positive controls, induced a distinct increase in mutant colonies and thus, showed the sensitivity of the test item and the activity of the metabolic activation system. In conclusion, it can be stated that under the experimental conditions reported the test item did not induce gene mutations at the HPRT locus in V79 cells.
Referenceopen allclose all
Toxicity (inhibition growth) was observed at concentrations of 200 µg/plate (100 µg/plate for TA100 and TA1537) (-)S9 Mix and 400 µg/plate (200 µg/plate for TA100 and TA1537) (+) S9 Mix.
No relevant and reproducible increase in mutant colony numbers/106cells was observed in the main experiments up to the maximum concentration. Nearly all mutant frequencies remained well within the historical range of solvent controls. The two values of mutant colony numbers/106cells (34.7 and 35.9) slightly exceeded the historical range of solvent controls of (3.0 – 33.2 mutant colony numbers/106 cells). This effect however was judged to be not biologically relevant for the outcome of the study. The induction factor did not exceed the threshold of three times the corresponding solvent control in any test item dose group in any culture. No significant dose dependent trend of the mutation frequency indicated by a probability value of <0.05 was determined in any of the experimental groups.
Endpoint conclusion
- Endpoint conclusion:
- no adverse effect observed (negative)
Genetic toxicity in vivo
Endpoint conclusion
- Endpoint conclusion:
- no study available
Additional information
Gene mutation in bacteria: Key study: Genotoxicity of 6-tert-butyl-2,4-xylenol was studied by the reverse mutation assay in bacteria, according to the JAPAN Guidelines for Screening Mutagenicity Testing Of Chemicals (equivalent to OECD Guideline 471). 6 -tert-Butyl-2,4-xylenol was found to be not mutagenic in Salmonella typhimurium TA100, TA98, TA1535, TA1537 and Escherichia coli WP2 uvrA, with and without metabolic activation.Based on these results, the read-across approach was applied and the reaction mass of 2-tert-butyl-4,6-dimethylphenol and 4-tert-butyl-2,5-dimethylphenol is considered not mutagenic in Salmonella typhimurium TA100, TA98, TA1535, TA1537 and Escherichia coli WP2 uvrA, with and without metabolic activation.
Chromosomal aberrations in mammalian cells: Key study: 6-tert-Butyl-2,4-xylenol was studied in a chromosomal aberration test in cultured Chinese hamster lung (CHL/IU) cells, according to the JAPAN Guidelines for Screening Mutagenicity Testing Of Chemicals (equivalent to OECD Guideline 473). Neither structural chromosomal aberrations nor polyploidy were induced in CHL/IU cells up to the concentration giving 50% cell growth inhibition, in the absence or presence of an exogenous metabolic activation system. Based on these results, the read-across approach was applied and the reaction mass of 2-tert-butyl-4,6-dimethylphenol and 4-tert-butyl-2,5-dimethylphenol is considered not mutagenic inachromosomal aberration test, with and without metabolic activation.
Gene mutation in mammalian cells: Key study: The study was performed to investigate the potential of the test substance to induce gene mutations at the HPRT locus in V79 cells of the Chinese hamster. The assay was performed in two independent experiments, using two parallel cultures each. The first main experiment was performed with and without liver microsomal activation and a treatment period of 4 hours. The second experiment was performed with a treatment time of 4 hours with and 24 hours without metabolic activation. The highest concentration in the pre-experiment (1783.0 µg/mL) was equal to a molar concentration of about10 mM. The dose range of the main experiments was limited by toxicity of the test item.No substantial and reproducible dose dependent increase of the mutation frequency was observed in both main experiments. Appropriate reference mutagens, used as positive controls, induced a distinct increase in mutant colonies and thus, showed the sensitivity of the test item and the activity of the metabolic activation system. In conclusion, it can be stated that under the experimental conditions reported the test item did not induce gene mutations at the HPRT locus in V79 cells.
Justification for selection of genetic toxicity endpoint
No study was selected, since the results obtained in the in vitro studies (Ames test, Chromosome aberrations test and Mammalian cell gene mutation assay) were negative.
Justification for classification or non-classification
Based on the results obtained in the in vitro genetic toxicity studies, the substance is considered as negative in all of them. Therefore, the substance is not classified.
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.
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