Registration Dossier
Registration Dossier
Data platform availability banner - registered substances factsheets
Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.
The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.
Diss Factsheets
Use of this information is subject to copyright laws and may require the permission of the owner of the information, as described in the ECHA Legal Notice.
EC number: 208-706-2 | CAS number: 538-93-2
- 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 gene mutation study in bacteria
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Study period:
- 19 Sep - 28 Sep 2017
- Reliability:
- 1 (reliable without restriction)
- Rationale for reliability incl. deficiencies:
- guideline study
Data source
Reference
- Reference Type:
- study report
- Title:
- Unnamed
- Year:
- 2 017
- Report date:
- 2017
Materials and methods
Test guideline
- Qualifier:
- according to guideline
- Guideline:
- OECD Guideline 471 (Bacterial Reverse Mutation Assay)
- Version / remarks:
- 1997
- Deviations:
- no
- GLP compliance:
- yes (incl. QA statement)
- Remarks:
- Certificate produced by "Landesamt für Umwelt, Wasserwirtschaft und Gewerbeaufsicht Rheinland Pfalz"
- Type of assay:
- bacterial reverse mutation assay
Test material
- Reference substance name:
- Isobutylbenzene
- EC Number:
- 208-706-2
- EC Name:
- Isobutylbenzene
- Cas Number:
- 538-93-2
- Molecular formula:
- C10H14
- IUPAC Name:
- (2-methylpropyl)benzene
- Test material form:
- liquid
- Details on test material:
- - batch no.: EXP-18/11/346
- State of aggregation: liquid
- Log KOW: 3.94 (calculated); 4.8 at 23°C and pH 6.0 (measured)
- Molecular weight: 134.22 g/mol
Constituent 1
- Specific details on test material used for the study:
- SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material:BASF SE; batch no. EXP-18/11/346
- Purity: 99.9 area-%
- Physical state: liquid
- Homogeneity: The homogeneity of the test substance was ensured by mixing before preparation of the test substance solutions.
STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: room temperature
- Stability under test conditions: The stability of the test substance under storage conditions was guaranteed until Oct 2020
- Stability of the test substance in the solvent/vehicle: The stability of the test substance in the vehicle DMSO was not determined analytically, because the test substance was administered immediately after preparation and is usually stable.
TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: The test substance was weighed and topped up with the chosen vehicle to achieve the required concentration of the stock solution. The test substance was dissolved in dimethyl sulfoxide (DMSO). To achieve a clear solution of the test substance in the vehicle, the test substance preparation was shaken thoroughly. The further concentrations were diluted according to the planned doses. All test substance formulations were prepared immediately before administration.
FORM AS APPLIED IN THE TEST (if different from that of starting material): dissolved in dimethyl sulfoxide (DMSO)
Method
- Target gene:
- his, trp
Species / strain
- Species / strain / cell type:
- S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2
- Metabolic activation:
- with and without
- Metabolic activation system:
- S9 mix (supplemented with cofactors) derived from phenobarbital (i.p.) and β-naphthoflavone (orally) induced rat liver
- Test concentrations with justification for top dose:
- In agreement with the recommendations of current guidelines 5 mg/plate were selected as maximum test dose.
Doses in the 1st Experiment (Standard plate test with and without S9 mix): 0; 33; 100; 333; 1000; 2500 and 5000 μg/plate
Doses in the 2nd Experiment (Preincubation test with and without S9 mix): 0; 33; 100; 333; 1000; 2500 and 5000 μg/plate (TA 1535, TA 100, TA 98 and E. coli);
0; 3.3; 10; 33; 100; 333 and 1000 μg/plate (TA 1537); No mutagenicity was observed in the standard plate test. Due to toxicity, the doses were adjusted in the preincubation test - Vehicle / solvent:
- - Vehicle(s)/solvent(s) used: DMSO
- Justification for choice of solvent/vehicle: Due to the insolubility of the test substance in water, DMSO was used as vehicle, which had been demonstrated to be suitable in bacterial reverse mutation tests and for which historical control data are available
Controls
- Untreated negative controls:
- yes
- Remarks:
- sterility controls (plates were treated with soft agar, S9 mix, buffer, vehicle and the test substance but without the addition of tester strains)
- Negative solvent / vehicle controls:
- yes
- True negative controls:
- no
- Positive controls:
- yes
- Positive control substance:
- 4-nitroquinoline-N-oxide
- 9-aminoacridine
- other: 2-aminoanthracene
- Remarks:
- additional positive controls: N-methyl-N'-nitro-N-nitrosoguanidine (5 μg/plate; dissolved in DMSO; strains: TA 1535, TA 100; without S9 mix)
- Details on test system and experimental conditions:
- METHOD OF APPLICATION: in agar (plate incorporation); preincubation
- Cell density at seeding (if applicable): approx. 10^8 cells/ml
CELLS USED
- Source of cells: Moltox Molecular Toxicology, Inc., Boone, NC 28607; USA
- Suitability of cells: The Salmonella strains were checked for the following characteristics at regular intervals: deep rough character (rfa); UV sensitivity (Δ uvrB); ampicillin resistance (R factor plasmid). E. coli WP2 uvrA was checked for UV sensitivity. Histidine and tryptophan auxotrophy was checked in each experiment via the spontaneous
rate.
- Methods for maintenance in cell culture: deep-frozen (-70°C to -80°C) bacterial cultures were thawed at room temperature, and 0.1 mL of this bacterial suspension was inoculated in nutrient broth solution (8 g/L Difco nutrient broth + 5 g/L NaCl) and incubated in the shaking water bath at 37°C for about 12 - 16 hours (overnight). The optical density of the fresh bacteria cultures was determined. Fresh cultures of bacteria were grown up to late exponential or early stationary phase of growth (approximately 10^9 cells per mL).
DURATION
- Preincubation period: about 20 minutes
- Exposure duration: 48 - 72 h
DETERMINATION OF CYTOTOXICITY
- Method: decrease in the number of revertants (factor ≤ 0.6) and clearing or diminution of the background lawn (= reduced his- or trp- background growth) - Evaluation criteria:
- The test substance was considered positive in this assay if the following criteria were met:
• A dose-related and reproducible increase in the number of revertant colonies, i.e. at least
doubling (bacteria strains with high spontaneous mutation rate, like TA 98, TA 100 and E.coli
WP2 uvrA) or tripling (bacteria strains with low spontaneous mutation rate, like TA 1535 and
TA 1537) of the spontaneous mutation rate in at least one tester strain either without S9 mix
or after adding a metabolizing system.
A test substance was generally considered non-mutagenic in this test if:
• The number of revertants for all tester strains were within the range of the historical negative
control data under all experimental conditions in at least two experiments carried out
independently of each other.
Results and discussion
Test resultsopen allclose all
- Key result
- Species / strain:
- S. typhimurium TA 1535
- Metabolic activation:
- with and without
- Genotoxicity:
- negative
- Cytotoxicity / choice of top concentrations:
- cytotoxicity
- Vehicle controls validity:
- valid
- Untreated negative controls validity:
- not applicable
- Positive controls validity:
- valid
- Key result
- Species / strain:
- S. typhimurium TA 100
- Metabolic activation:
- with and without
- Genotoxicity:
- negative
- Cytotoxicity / choice of top concentrations:
- cytotoxicity
- Vehicle controls validity:
- valid
- Untreated negative controls validity:
- not applicable
- Positive controls validity:
- valid
- Key result
- Species / strain:
- S. typhimurium TA 1537
- Metabolic activation:
- with and without
- Genotoxicity:
- negative
- Cytotoxicity / choice of top concentrations:
- cytotoxicity
- Vehicle controls validity:
- valid
- Untreated negative controls validity:
- not applicable
- Positive controls validity:
- valid
- Key result
- Species / strain:
- S. typhimurium TA 98
- Metabolic activation:
- with and without
- Genotoxicity:
- negative
- Cytotoxicity / choice of top concentrations:
- cytotoxicity
- Vehicle controls validity:
- valid
- Untreated negative controls validity:
- not applicable
- 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:
- cytotoxicity
- Vehicle controls validity:
- valid
- Untreated negative controls validity:
- not applicable
- Positive controls validity:
- valid
- Additional information on results:
- TEST-SPECIFIC CONFOUNDING FACTORS
- Precipitation: In the standard plate test, precipitation of the test substance was found from about 333 μg/plate onward with and without S9 mix.
HISTORICAL CONTROL DATA (with ranges, means and standard deviation)
- Positive historical control data: see table 2
- Negative (solvent/vehicle) historical control data: see table 1
ADDITIONAL INFORMATION ON CYTOTOXICITY:
- A bacteriotoxic effect was observed depending on the strain and test conditions from about 3.3 μg/plate onward (for details see table 3)
Any other information on results incl. tables
Tab. 1: Historical Negative Controls
Strain S9 Mix |
Positive |
No. of |
No. of |
Min |
Max |
Mean |
SD |
|
|
|
control |
Plates |
Values |
|
|
|
|
TA 1535Without |
(All) |
414 |
152 |
7 |
16 |
10 |
2.0 |
With |
(All) |
414 |
152 |
6 |
18 |
10 |
2.0 |
|
|
|
|
|
|
|
|
TA 100Without |
(All) |
426 |
152 |
71 |
132 |
100 |
11.4 |
With |
(All) |
417 |
153 |
70 |
147 |
107 |
13.7 |
|
|
|
|
|
|
|
|
TA 1537Without |
(All) |
411 |
152 |
5 |
13 |
8 |
1.7 |
With |
(All) |
411 |
152 |
5 |
16 |
9 |
2.1 |
|
|
|
|
|
|
|
|
TA 98Without |
(All) |
420 |
152 |
14 |
34 |
21 |
3.3 |
With |
(All) |
413 |
152 |
12 |
38 |
28 |
4.5 |
|
|
|
|
|
|
|
|
E. coliWithout |
(All) |
396 |
152 |
15 |
34 |
24 |
3.9 |
With |
(All) |
399 |
152 |
17 |
36 |
25 |
4.4 |
Tab. 2: Historical Positive Controls
Strain S9 Mix |
Positive |
No. of |
No. of |
Min |
Max |
Mean |
SD |
|
|
|
control |
Plates |
Values |
|
|
|
|
TA 1535Without |
MNNG |
312 |
110 |
1541 |
6171 |
3967 |
1253.9 |
With |
2-AA |
312 |
110 |
105 |
520 |
197 |
56.3 |
|
|
|
|
|
|
|
|
TA 100Without |
MNNG |
315 |
110 |
1126 |
5557 |
3298 |
1109.6 |
With |
2-AA |
309 |
111 |
272 |
3021 |
1748 |
587.2 |
|
|
|
|
|
|
|
|
TA 1537Without |
AAC |
309 |
110 |
253 |
2190 |
1044 |
404.3 |
With |
2-AA |
312 |
110 |
50 |
399 |
141 |
50.3 |
|
|
|
|
|
|
|
|
TA 98Without |
NOPD |
309 |
110 |
324 |
1746 |
863 |
206.8 |
With |
2-AA |
315 |
110 |
493 |
3096 |
1524 |
529.1 |
|
|
|
|
|
|
|
|
E. coliWithout |
4-NQO |
306 |
110 |
164 |
1721 |
860 |
431.9 |
With |
2-AA |
306 |
110 |
61 |
537 |
133 |
61.8 |
Tab. 3: Observed bacteriotoxicity
Decreased revertant numbers were observed at following concentrations (μg/plate):
Experiment |
S9 |
TA 1535 |
TA 100 |
TA 1537 |
TA 98 |
E.coli |
1st-SPT |
Without |
- |
- |
333 – 5000 |
1000 – 5000 |
- |
With |
- |
- |
100 – 5000 |
5000 |
- |
|
2nd-PIT |
Without |
333 – 5000 |
333 – 5000 |
3.3 – 10, 100 - 1000 |
100 – 5000 |
- |
With |
2500 – 5000 |
1000 – 5000 |
1000 |
1000 – 5000 |
- |
- = no adverse effect observed
Reduced background growth was observed at following concentrations (μg/plate):
Experiment |
S9 |
TA 1535 |
TA 100 |
TA 1537 |
TA 98 |
E.coli |
1st-SPT |
Without |
2500 – 5000 |
2500 – 5000 |
1000 – 5000 |
2500 – 5000 |
- |
With |
2500 – 5000 |
2500 – 5000 |
1000 – 5000 |
2500 – 5000 |
- |
|
2nd-PIT |
Without |
333 – 5000 |
333 – 5000 |
333 – 1000 |
333 – 5000 |
333 – 5000 |
With |
333 – 5000 |
333 – 5000 |
333 – 1000 |
333 – 5000 |
333 – 5000 |
- = no adverse effect observed
Applicant's summary and conclusion
- Conclusions:
- Under the experimental conditions of this study, the test substance is not mutagenic in the Salmonella typhimurium/Escherichia coli reverse mutation assay in the absence and the presence of metabolic activation.
- Executive summary:
The test substance was tested for its mutagenic potential based on the ability to induce point mutations in selected loci of several bacterial strains, i.e. Salmonella typhimurium and Escherichia coli, in a reverse mutation assay.
STRAINS: TA 1535, TA 100, TA 1537, TA 98 and E. coli WP2 uvrA
DOSE RANGE: 33 μg - 5000 μg/plate (SPT)
3.3 μg - 5000 μg/plate (PIT)
TEST CONDITIONS: Standard plate test (SPT) and preincubation test (PIT) both with and without metabolic activation (liver S9 mix from induced rats).
SOLUBILITY: In the standard plate test, precipitation of the test substance was found from about 333 μg/plate onward with and without S9 mix.
TOXICITY: A bacteriotoxic effect was observed depending on the strain and test conditions from about 3.3 μg/plate onward.
MUTAGENICITY:
A relevant increase in the number of his+ or trp+ revertants (factor ≥ 2: TA 100, TA 98 and E.coli WP2 uvrA or factor ≥ 3: TA 1535 and TA 1537) was not observed in the standard plate test or in the preincubation test without S9 mix or after the addition of a metabolizing system.
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.
Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.