RD 14153

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

The substance was considered to be non-mutagenic under the conditions of an Ames test and in an in vitro mouse lymphoma assay.

The substance was considered to be non-clastogenic to human lymphocytes in an in vitro chromosome aberration test.

Link to relevant study records

Reference

Reference 1

Endpoint:

in vitro cytogenicity / chromosome aberration study in mammalian cells

Type of information:

experimental study

Adequacy of study:

key study

Study period:

The study was oconducted between 31 March 2016 and 01 June 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 473 (In Vitro Mammalian Chromosome Aberration Test)

Version / remarks:

26 September 2014

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of assay:

in vitro mammalian cell transformation assay

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Sponsor Lot/Batch number 5399661C10
- Expiration date of the lot/batch: 12 January 2020
- Purity test date:

RADIOLABELLING INFORMATION (if applicable)
- Radiochemical purity:
- Specific activity:
- Locations of the label:
- Expiration date of radiochemical substance:

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Room temperature in the dark
- Stability under test conditions:
- Solubility and stability of the test substance in the solvent/vehicle:
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium:

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing:
- Preliminary purification step (if any):
- Final dilution of a dissolved solid, stock liquid or gel:
- Final preparation of a solid:

FORM AS APPLIED IN THE TEST (if different from that of starting material)

OTHER SPECIFICS:

Species / strain / cell type:

lymphocytes:

Details on mammalian cell type (if applicable):

CELLS USED
- Source of cells: non-smoking human volunteers
- Suitability of cells:
- Cell cycle length, doubling time or proliferation index: ~ 16h
- Sex, age and number of blood donors if applicable: Male, 27-28, 2
- Whether whole blood or separated lymphocytes were used if applicable: separated whole blood

- Methods for maintenance in cell culture if applicable: Cells (whole blood cultures) were grown in Eagle's minimal essential medium with HEPES buffer (MEM), supplemented “in-house” with L-glutamine, penicillin/streptomycin, amphotericin B and 10 % foetal bovine serum (FBS), at approximately 37 ºC with 5 % CO2 in humidified air

MEDIA USED
- Type and identity of media including CO2 concentration if applicable: 9.05 mL MEM, 10% (FBS)
- Properly maintained: yes

Additional strain / cell type characteristics:

not specified

Metabolic activation:

with and without

Metabolic activation system:

S9 Mix

Test concentrations with justification for top dose:

The test item was considered to be a UVCB* mixture and therefore the maximum recommended dose was initially set at 5000 μg/mL. The purity of the test item
was 100% and was not accounted for in the test item formulations.
The test item was insoluble in culture media at 50mg/mL and DMSO at 500, 250 and 125 mg/ml but was suspendable in Acetone at 125 mg/mL in solubility checks performed in-house.
Due to the sensitivity of human lymphocytes to acetone, the formulations were prepared at twice the concentration required in culture and dosed in 50 μl aliquots. Consequently, the maximum practical concentration was 625 μg/mL.

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: acetone
- Justification for choice of solvent/vehicle: The test item was considered to be a UVCB* mixture and therefore the maximum recommended dose was initially set at 5000 μg/mL.
The purity of the test item was 100% and was not accounted for in the test item formulations.
The test item was insoluble in culture media at 50mg/mL and DMSO at 500, 250 and 125 mg/ml but was suspendable in Acetone at 125 mg/mL in solubility checks performed in-house.
Due to the sensitivity of human lymphocytes to acetone, the formulations were prepared at
twice the concentration required in culture and dosed in 50 μl aliquots. Consequently, the
maximum practical concentration was 625 μg/mL.

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

Remarks:

Acetone

Positive controls:

yes

Positive control substance:

mitomycin C

Details on test system and experimental conditions:

METHOD OF APPLICATION: in medium; in agar (plate incorporation); preincubation; in suspension; as impregnation on paper disk
- Cell density at seeding (if applicable):

DURATION
- Preincubation period: 4 hr
- Exposure duration: 4 hr and 24 hr
- Expression time (cells in growth medium):


DETERMINATION OF CYTOTOXICITY
- Method: mitotic index;

OTHER EXAMINATIONS:
- Determination of polyploidy:
- Determination of endoreplication:
- Methods, such as kinetochore antibody binding, to characterize whether micronuclei contain whole or fragmented chromosomes (if applicable):

- OTHER:

Evaluation criteria:

The following criteria were used to determine a valid assay:
 The frequency of cells with structural chromosome aberrations (excluding gaps) in the vehicle control cultures was within the laboratory historical control data range. The level of spontaneous background aberrations was slightly elevated above the normal range and the experiment still considered valid.
 All the positive control chemicals induced a positive response (p≤0.01) and demonstrated the validity of the experiment and the integrity of the S9-mix.
 The study was performed using all three exposure conditions using a top concentration which meets the requirements of the current testing guideline.
 The required number of cells and concentrations were analyzed.

Statistics:

The frequency of cells with aberrations excluding gaps and the frequency of polyploid cells was compared, where necessary, with the concurrent vehicle
control value using Fisher's Exact test.
A toxicologically significant response is recorded when the p value calculated from the statistical analysis of the frequency of cells with aberrations excluding
gaps is less than 0.05 when compared to its concurrent control and there is a dose-related increase in the frequency of cells with aberrations which is reproducible. Incidences where marked statistically significant increases are observed only with gap-type aberrations will be assessed on a case by case basis.

Species / strain:

lymphocytes: Human

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity, but tested up to precipitating concentrations

Vehicle controls validity:

valid

Positive controls validity:

valid

Conclusions:

RD 14153 did not induce a statistically significant increase in the frequency of cells with chromosome aberrations, in either the absence or presence of a liver enzyme metabolizing system. The test item was, therefore, considered to be non-clastogenic to human lymphocytes in vitro.

Executive summary:

Duplicate cultures of human lymphocytes, treated with the test item, were evaluated for chromosome aberrations at four dose levels, together with vehicle and positive controls. In this study, three exposure conditions were investigated; 4 hours exposure in the presence of an induced rat liver homogenate metabolizing system (S9), at a 2% final concentration with cell harvest after a 20-hour expression period, 4 hours exposure in the absence of metabolic activation (S9) with a 20-hour expression period and a 24-hour exposure in the absence of metabolic activation. The dose levels used in the Main Experiment were selected using data from the preliminary toxicity test where the results indicated that the maximum concentration should be limited on precipitate.

All vehicle (Acetone) controls had frequencies of cells with aberrations within the range expected for normal human lymphocytes. All the positive control items induced statistically significant increases in the frequency of cells with aberrations. Thus, the sensitivity of the assay and the efficacy of the S9-mix were validated. The test item did not induce any statistically significant increases in the frequency of cells with aberrations, using a dose range that included a dose level that was the lowest precipitating dose level.

Conclusion

The test item, RD 14153 was considered to be non-clastogenic to human lymphocytes in vitro.

Reference 2

Endpoint:

in vitro gene mutation study in mammalian cells

Type of information:

experimental study

Adequacy of study:

key study

Study period:

The study was conducted between 24 March 2016 and 04 May 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 490 (In Vitro Mammalian Cell Gene Mutation Tests Using the Thymidine Kinase Gene)

Version / remarks:

28 July 2015

Deviations:

not specified

Qualifier:

according to guideline

Guideline:

EU Method B.17 (Mutagenicity - In Vitro Mammalian Cell Gene Mutation Test)

Version / remarks:

30 May 2008

Deviations:

not specified

Qualifier:

equivalent or similar to guideline

Guideline:

EPA OPPTS 870.5300 - In vitro Mammalian Cell Gene Mutation Test

GLP compliance:

yes (incl. QA statement)

Type of assay:

in vitro mammalian cell transformation assay

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Sponsor Lot/Batch Number 5399661C10
- Expiration date of the lot/batch:24 FDebruary 2020
- Purity test date:

RADIOLABELLING INFORMATION (if applicable)
- Radiochemical purity:
- Specific activity:
- Locations of the label:
- Expiration date of radiochemical substance:

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Room temperature in the dark
- Stability under test conditions:
- Solubility and stability of the test substance in the solvent/vehicle:
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium:

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing:
- Preliminary purification step (if any):
- Final dilution of a dissolved solid, stock liquid or gel:
- Final preparation of a solid:

FORM AS APPLIED IN THE TEST (if different from that of starting material)

OTHER SPECIFICS:

Species / strain / cell type:

mouse lymphoma L5178Y cells

Details on mammalian cell type (if applicable):

CELLS USED
- Source of cells: MRC Cell Mutation Unit, University of Sussex, Brighton, UK
- Suitability of cells:
- Cell cycle length, doubling time or proliferation index:12 h
- Sex, age and number of blood donors if applicable:
- Whether whole blood or separated lymphocytes were used if applicable:
- Number of passages if applicable:
- Methods for maintenance in cell culture if applicable:
- Modal number of chromosomes:
- Normal (negative control) cell cycle time:

MEDIA USED
- Type and identity of media including CO2 concentration if applicable:
- Properly maintained: [yes/no]
- Periodically checked for Mycoplasma contamination: [yes/no]
- Periodically checked for karyotype stability: [yes/no)
- Periodically 'cleansed' against high spontaneous background: [yes/no]

Additional strain / cell type characteristics:

not applicable

Metabolic activation:

with and without

Metabolic activation system:

S9

Test concentrations with justification for top dose:

Following solubility checks performed in-house, the test item was accurately weighed and formulated in acetone prior to serial dilutions being prepared. The test item was considered to be a complex mixture (UVCB) therefore the maximum proposed dose level in the solubility test was set at 5000 μg/mL (500 mg/mL), the maximum recommended dose level, and no correction for the purity of the test item was applied. However, the test item was not suitable for dosing at 500 mg/mL due to the low solubility of the test item, therefore, the concentration was reduced to 125 mg/mL. Acetone is toxic to L5178Y cells at dose volumes greater than 0.5% of the total culture volume. Therefore, the test item was formulated at 125 mg/mL and dosed at 0.5% to give a maximum achievable dose level of 625 μg/mL.
There was no marked change in pH when the test item was dosed into media in the solubility test and the osmolality did not increase by more than 50 mOsm (Scott et al. 1991).

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: acetone
- Justification for choice of solvent/vehicle: low solubility of test item

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

Positive controls:

yes

Positive control substance:

ethylmethanesulphonate

Details on test system and experimental conditions:

METHOD OF APPLICATION: in medium
- Cell density at seeding (if applicable): 1.5 x 100000 cells /mL

DURATION
- Preincubation period:
- Exposure duration: 24h
- Expression time (cells in growth medium):
- Selection time (if incubation with a selection agent):
- Fixation time (start of exposure up to fixation or harvest of cells):

SELECTION AGENT (mutation assays):

SPINDLE INHIBITOR (cytogenetic assays):

STAIN (for cytogenetic assays):

NUMBER OF REPLICATIONS:

METHODS OF SLIDE PREPARATION AND STAINING TECHNIQUE USED:

NUMBER OF CELLS EVALUATED:

NUMBER OF METAPHASE SPREADS ANALYSED PER DOSE (if in vitro cytogenicity study in mammalian cells):

CRITERIA FOR MICRONUCLEUS IDENTIFICATION:

DETERMINATION OF CYTOTOXICITY
- Method: mitotic index; cloning efficiency; relative total growth; other:
- Any supplementary information relevant to cytotoxicity:

OTHER EXAMINATIONS:
- Determination of polyploidy:
- Determination of endoreplication:
- Methods, such as kinetochore antibody binding, to characterize whether micronuclei contain whole or fragmented chromosomes (if applicable):

- OTHER:METHOD OF APPLICATION: in medium
- Cell density at seeding (if applicable):0.3 x 10,000,000 cells/mL

DURATION
- Exposure duration: 4 and 24h
- Expression time (cells in growth medium): 2 days

Evaluation criteria:

Dose selection for the mutagenicity experiments was made using data from the preliminary toxicity test in an attempt to obtain the desired levels of toxicity. This optimum toxicity is approximately 20% survival (80% toxicity), but no less than 10% survival (90% toxicity). Relative Total Growth (RTG) values are the primary factor used to designate the level of toxicity achieved by the test item for any individual dose level. However, under certain circumstances, %RSG values may also be taken into account when designating the level of toxicity achieved. Dose levels that have RTG survival values less than 10% are excluded from
the mutagenicity data analysis, as any response they give would be considered to have no biological or toxicological relevance.
An approach for defining positive and negative responses is recommended to assure that the increased MF is biologically relevant. In place of statistical analysis generally used for other tests, it relies on the use of a predefined induced mutant frequency (i.e. increase in MF above the concurrent control), designated the Global Evaluation Factor (GEF) of 126 x 10-6, which is based on the analysis of the distribution of the vehicle control MF data from participating
laboratories.
Providing that all acceptability criteria are fulfilled, a test chemical is considered to be clearly positive if, in any of the experimental conditions examined, the increase in MF above the concurrent background exceeds the GEF and the increase is concentration related (e.g., using a trend test). The test chemical is then considered able to induce mutation in this test system.
Providing that all acceptability criteria are fulfilled, a test chemical is considered to be clearly negative if, in all experimental conditions examined there is no concentration related response or, if there is an increase in MF, it does not exceed the GEF. The test chemical is then considered unable to induce mutations in this test system.

Key result

Species / strain:

mouse lymphoma L5178Y cells

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity, but tested up to precipitating concentrations

Vehicle controls validity:

valid

Positive controls validity:

valid

Additional information on results:

The test item did not induce any increases in the mutant frequency at the TK +/- locus in L5178Y cells that exceeded the GEF, consequently it is considered to be non-mutagenic in this assay.

Conclusions:

The test item did not induce any increases in the mutant frequency at the TK +/- locus in L5178Y cells that exceeded the GEF, consequently it is considered to be non-mutagenic in this assay.

Executive summary:

One main Mutagenicity Test was performed. In this main test, L5178Y TK +/- 3.7.2c mouse lymphoma cells (heterozygous at the thymidine kinase locus) were treated with the test item at eight dose levels in duplicate, together with vehicle (acetone), and positive controls using 4 hour exposure groups both in the absence and presence of metabolic activation (2% S9), and a 24 hour exposure group in the absence of metabolic activation The dose range of test item used in the main test was selected following the results of a preliminary toxicity test.

The maximum dose level used in the Mutagenicity Test was limited by the presence of test item precipitate. Precipitate of the test item was observed at 2.5 and 5 μg/mL in the Mutagenicity Test. The vehicle control cultures had mutant frequency values that were acceptable for the L5178Y cell line at the TK +/- locus. The positive control substances induced marked increases in the mutant frequency, sufficient to indicate the satisfactory performance of the test and of the activity of the metabolizing system. The test item did not induce any toxicologically significant increases in the mutant frequency at any of the dose levels in the main test, in any of the three exposure groups.

The test item did not induce any increases in the mutant frequency at the TK +/- locus in L5178Y cells that exceeded the GEF, consequently it is considered to be non-mutagenic in this assay.

Reference 3

Endpoint:

in vitro gene mutation study in bacteria

Remarks:

Type of genotoxicity: gene mutation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

The study was conducted between 23 March 2016 and 11 April 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)

Version / remarks:

30 May 2008

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.5100 - Bacterial Reverse Mutation Test (August 1998)

Deviations:

no

Qualifier:

according to guideline

Guideline:

JAPAN: Guidelines for Screening Mutagenicity Testing Of Chemicals

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Sponsor Lot/Batch number 5399661C10
- Expiration date of the lot/batch: 12 January 2020
- Purity test date:

RADIOLABELLING INFORMATION (if applicable)
- Radiochemical purity:
- Specific activity:
- Locations of the label:
- Expiration date of radiochemical substance:

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Room temperature in the dark
- Stability under test conditions:
- Solubility and stability of the test substance in the solvent/vehicle:
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium:

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing:
- Preliminary purification step (if any):
- Final dilution of a dissolved solid, stock liquid or gel:
- Final preparation of a solid:

FORM AS APPLIED IN THE TEST (if different from that of starting material)

OTHER SPECIFICS:

Species / strain / cell type:

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

Additional strain / cell type characteristics:

not applicable

Species / strain / cell type:

E. coli WP2 uvr A

Additional strain / cell type characteristics:

not applicable

Metabolic activation:

with and without

Metabolic activation system:

S9 Mix

Test concentrations with justification for top dose:

Preliminary test (Plate incorporation method): 0 (Solvent control) 1.5, 5, 15, 50, 150, 500, 1500 and 5000 μg/plate
Main test (Pre-incubation method): 0 (solvent control): 15, 50, 150, 500, 1500 and 5000 μg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: dimethyl formamide
- Justification for choice of solvent/vehicle: The test item was insoluble in sterile distilled water, dimethyl sulphoxide, dimethyl formamide and acetonitrile at 50 mg/mL, acetone at 100 mg/mL and tetrahydrofuran at 200 mg/mL in solubility checks performed in–house. The test item formed the best doseable suspension in dimethyl formamide, therefore, this solvent was selected as the vehicle

Untreated negative controls:

yes

Remarks:

untreated

Negative solvent / vehicle controls:

yes

Remarks:

dimethyl formamide

Positive controls:

yes

Positive control substance:

N-ethyl-N-nitro-N-nitrosoguanidine

Remarks:

Used as positive control for TA100, TA1535 and WP2uvrA in the absence of S9Mix

Positive controls:

yes

Positive control substance:

9-aminoacridine

Remarks:

Used as positive control for TA1537 in the absence of S9 Mix

Positive controls:

yes

Positive control substance:

4-nitroquinoline-N-oxide

Remarks:

Used as positive control for TA98 in the absence of S9 mix

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Positive controls:

yes

Positive control substance:

other: 2-aminoanthracene (2AA)

Remarks:

Positive control for TA100, TA1535, TA1537 and WP2uvrA in the presence of S9 Mix

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Positive controls:

yes

Positive control substance:

benzo(a)pyrene

Remarks:

Positive control for TA98 in the presence of S9 Mix

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation);

DURATION
- Pre-incubation period: 20 min
- Exposure duration: 48 hr

DETERMINATION OF CYTOTOXICITY
- Method: relative total growth:

Evaluation criteria:

There are several criteria for determining a positive result. Any one, or all of the following can be used to determine the overall result of the study:
1. A dose-related increase in mutant frequency over the dose range tested (De Serres and Shelby, 1979).
2. A reproducible increase at one or more concentrations.
3. Biological relevance against in-house historical control ranges.
4. Statistical analysis of data as determined by UKEMS (Mahon et al., 1989).
5. Fold increase greater than two times the concurrent solvent control for any tester strain (especially if accompanied by an out-of-historical range response (Cariello and Piegorsch, 1996)).
A test item will be considered non-mutagenic (negative) in the test system if the above criteria are not met.

Statistics:

Statistical significance was confirmed by using Dunnetts Regression Analysis (* = p < 0.05) for those values that indicate statistically significant increases in the frequency of revertant colonies compared to the concurrent solvent control.

Key result

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

Key result

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

Key result

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

Key result

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

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:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other:

Remarks:

no significant increases in the frequency of revertant colonies were recorded

Conclusions:

No significant increases in the frequency of revertant colonies were recorded for any of the bacterial strains, with any dose of the test item, either with or without metabolic activation (S9-mix) in either Experiment 1 (plate incubaiton method) or Experiment 2 (pre-incubation method).

RD 14153 was considered to be non-mutagenic under the conditions of this test.

Executive summary:

Salmonella typhimurium strains TA1535, TA1537, TA98 and TA100 and Escherichia coli strain WP2uvrA were treated with suspensions of the test item using both the Ames plate incorporation and pre-incubation methods at up to eight dose levels, in triplicate, both with and without the addition of a rat liver homogenate metabolizing system (10% liver S9 in standard co-factors). The dose range for Experiment 1 was predetermined and was 1.5 to 5000 μg/plate. The experiment was repeated on a separate day (pre-incubation method) using fresh cultures of the bacterial strains and fresh test item formulations. The dose range was amended following the results of Experiment 1 and was 15 to 5000 μg/plate. Six test item concentrations were selected in Experiment 2 in order to achieve both four non-toxic dose levels and the potential toxic limit of the test item following the change in test methodology.

No significant increases in the frequency of revertant colonies were recorded for any of the bacterial strains, with any dose of the test item, either with or without metabolic activation (S9-mix) in either Experiment 1 (plate incubaiton method) or Experiment 2 (pre-incubation method). RD 14153 was considered to be non-mutagenic under the conditions of this test.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Genetic toxicity in vivo

Description of key information

Testing is unnecessary because a negative result, with and without metabolic activation, was obtained in in vitro tests for gene mutation and chromosomal aberrations.

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

In an Ames test no significant increases in the frequency of revertant colonies were recorded for any of the bacterial strains, with any dose of the test item, either with or without metabolic activation (S9-mix) in either Experiment 1 (plate incubaiton method) or Experiment 2 (pre-incubation method).

During testing in a mouse lymphoma assay the test item did not induce any increases in the mutant frequency at the TK +/- locus in L5178Y cells that exceeded the GEF.

In a chronosome aberration test, the substance did not induce a statistically significant increase in the frequency of cells with chromosome aberrations, in either the absence or presence of a liver enzyme metabolizing system.

Justification for classification or non-classification

The substance produced a negative result, with and without metabolic activation, in three in vitro tests for gene mutagenicty or chromosomal aberration.