Cyclopentanone

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

Several genotoxicin vitro tests are available on Cyclopentanone. Two have been selected as key study. A complete Ames test performed in 2015 (reliability 1) and chromosome aberration test conducted in 2007 (reliability 1). The other tests available on cyclopentanone have been selected as supporting studies. A mutation test on mammalian cells is missing on cyclopentanone. This gap has been fulfilled by a read-across with cyclohexanone.

Link to relevant study records

Reference

Reference 1

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:

from 2014-11-28 to 2015-04-03

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: OECD 471 guideline study in compliance with the GLP. No deviation from the protocol of the study.

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to other 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)

Deviations:

no

Principles of method if other than guideline:

Not applicable.

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Target gene:

- Histidine: TA 1535, TA 100, TA 1537 and TA 98
-Tryptophan: Escherichia coli WP2 uvr A

Species / strain / cell type:

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

Details on mammalian cell type (if applicable):

Not applicable

Additional strain / cell type characteristics:

other: see Table 7.6.1/1

Species / strain / cell type:

E. coli WP2 uvr A

Details on mammalian cell type (if applicable):

Not applicable

Additional strain / cell type characteristics:

other: see Table 7.6.1/1

Metabolic activation:

with and without

Metabolic activation system:

S9 from induced phenobarbital/Beta-naphthoflavone rat liver.

Test concentrations with justification for top dose:

- Range finding test: 10; 100; 500; 1000; 2500 and 5000 µg/plate
- First experiment (Direct plate incorporation method, with and without metabolic activation): 312.5, 625, 1250, 2500 and 5000 µg/plate
- Second experiment (Direct plate incorporation method, without metabolic activation) (Pre-incubation method, with metabolic activation): 312.5, 625, 1250, 2500 and 5000 µg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: water for injections, batch No. 4F1081 (CDM Lavoisier)
- Justification for choice of solvent/vehicle: the substance was soluble in water (solubility: 301 g/l at 20°C)

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

Remarks:

water

True negative controls:

no

Positive controls:

yes

Positive control substance:

9-aminoacridine

2-nitrofluorene

sodium azide

benzo(a)pyrene

methylmethanesulfonate

other: 4-nitroquinoline 1-oxide (4NQO); 2-anthramine (2AM)

Remarks:

see Table 7.6.1/2

Details on test system and experimental conditions:

METHOD OF APPLICATION:
The preliminary test, both experiments without S9 mix and the first experiment with S9 mix were performed according to the direct plate
incorporation method in agar. The second experiment with S9 mix was performed according to the pre-incubation method.

DURATION
- Incubation period: at 37°C for 48 to 72 hours.
- Preincubation period: 60 min at 37ºC.

NUMBER OF REPLICATIONS: 3 plates/dose/strain. Two independent experiments were performed.

DETERMINATION OF CYTOTOXICITY
- Method: The evaluation of the toxicity was performed on the basis of the observation of the decrease in the number of revertant colonies and/or a
thinning of the bacterial lawn.

OTHER: SCORING METHOD: the number of revertants per plate was scored for each strain and for each experimental point using an automatic counter (Sorcerer Automatic Colony Counter for the scoring of colonies and Ames Study Manager for the data management, Perceptive Instruments Ltd, Bury St Edmunds IP33 3TA, UK).

Evaluation criteria:

Acceptance criteria :
Each main experiment was considered valid if the following criteria are fully met:
- the mean number of revertants in the vehicle controls is consistent with our historical data, in each strain and test condition (Appendix 2),
- at least five analyzable dose-levels (i.e. including at least three non-cytotoxic dose-levels) are obtained for each strain and test condition,
- the mean number of revertants in the positive controls is higher than that of the vehicle controls (at least 2-fold increase (for the TA 98, TA 100 and WP2 uvrA strains) or at least 3-fold increase (for the TA 1535 and TA 1537 strains)).

When these criteria were not met for one strain or test condition, the corresponding results were invalidated and the experiment was repeated.

Evaluation criteria :
In all cases, biological relevance (such as reproducibility and reference to historical data) was taken into consideration when evaluating the results.

The test item is considered to have shown mutagenic activity in this study if:
- a reproducible 2-fold increase (for the TA 98, TA 100 and WP2 uvrA strains) or 3-fold increase (for the TA 1535 and TA 1537 strains) in the mean number of revertants compared with the vehicle controls is observed, in any strain, at any dose-level,
- and/or a reproducible dose-response relationship is evidenced.

The test item is considered to have shown no mutagenic activity in this study if:
- neither an increase in the mean number of revertants, reaching 2-fold (for the TA 98, TA 100 and WP2 uvrA strains) or 3-fold (for the TA 1535 and TA 1537 strains) the vehicle controls value, is observed at any of the tested dose-levels,
- nor any evidence of a dose-response relationship is noted.

Statistics:

No data

Species / strain:

S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- Precipitation: no

RANGE-FINDING/SCREENING STUDIES:
To assess the toxicity of the test item to the bacteria, six dose-levels (one plate/dose-level) were tested in the TA 98, TA 100 and WP2 uvrA strains, both with and without S9 mix.
Using a test item concentration at 50 mg/mL in the vehicle and a treatment volume of 100 µL/plate, the highest recommended dose-level of 5000 µg/plate was achievable. Thus, the dose-levels selected for the preliminary test were 10, 100, 500, 1000, 2500 and 5000 µg/plate. The evaluation of the
toxicity was performed on the basis of the observation of the decrease in the number of revertant colonies and/or a thinning of the bacterial lawn.
No precipitate was observed in the Petri plates when scoring the revertants at any of the tested dose levels. No noteworthy toxicity was noted towards the three strains used, either with or without S9 mix.


COMPARISON WITH HISTORICAL CONTROL DATA: The control data reported in these report are in the range of the historical control data observed in the laboratory. The study was therefore considered valid.

ADDITIONAL INFORMATION ON CYTOTOXICITY: No toxicity was noted towards all the strains used.

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

 See attached document    

 

Conclusions:

Interpretation of results (migrated information):
negative (with and without metabolic activation)

Under the experimental conditions of this study, the test item Cyclopentanone did not show any mutagenic activity in the bacterial reverse mutation test with Salmonella typhimurium and Escherichia coli strains, either in the presence or in the absence of a rat liver metabolizing system.

Executive summary:

This study was performed to investigate the potential of the test item, Cyclopentanone, to induce reverse mutations in Salmonella typhimurium and Escherichia coli. The study was performed according to OECD guideline no. 471 and EC guideline n° B13/14 and in compliance with the Principles of Good Laboratory Practice. 

 

A preliminary toxicity test was performed to define the dose-levels of Cyclopentanone to be used for the mutagenicity study. The test item was then tested in two independent experiments, both with and without a metabolic activation system, the S9 mix, prepared from a liver post‑mitochondrial fraction (S9 fraction) of rats induced with Aroclor 1254.

Both experiments were performed according to the direct plate incorporation method except for the second test with S9 mix, which was performed according to the pre-incubation method (60 minutes, 37°C).

Four strains of bacteria Salmonella typhimurium (TA 1535, TA 1537, TA 98, TA 100) and one strain of Escherichia coli (WP2 uvrA) were used. Each strain was exposed to five dose-levels of the test item (three plates/dose‑level). After 48 to 72 hours of incubation at 37°C, the revertant colonies were scored.

The evaluation of the toxicity was performed on the basis of the observation of the decrease in the number of revertant colonies and/or a thinning of the bacterial lawn.

The test item was dissolved in water for injections.

 

The test item was freely soluble in the vehicle at 50 mg/mL. Consequently, with a maximum dose-volume of 100 µL/plate, the dose-levels for the preliminary toxicity test were 10, 100, 500, 1000, 2500 and 5000 µg/plate.

No precipitate was observed in the Petri plates when scoring the revertants at any of the tested dose‑levels, and no noteworthy toxicity was noted towards the three strains used, either with or without S9 mix.

Since the test item was freely soluble and non-toxic in the preliminary test, the highest dose-level selected for the main experiments was 5000 µg/plate, according to the criteria specified in the international guidelines.

The number of revertants for the vehicle and positive controls was as specified in the acceptance criteria. The study was therefore considered valid.

The selected treatment-levels were 312.5, 625, 1250, 2500 and 5000 µg/plate, for both mutagenicity experiments with and without S9 mix.

No precipitate was observed in the Petri plates when scoring the revertants at any of the tested dose‑levels, and no toxicity was noted towards all the strains used.

The test item did not induce any noteworthy increase in the number of revertants, in any of the five tested strains, either with or without S9 mix. These results met thus the criteria of a negative response.

Under the experimental conditions of this study, the test item Cyclopentanone did not show any mutagenic activity in the bacterial reverse mutation test with Salmonella typhimurium and Escherichia coli strains, either in the presence or in the absence of a rat liver metabolizing system.

Reference 2

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

Study period:

from 18 jan 2007 TO 24 MAY 2007

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP study according to guideline with pure test substance.

Qualifier:

according to guideline

Guideline:

OECD Guideline 473 (In Vitro Mammalian Chromosome Aberration Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of assay:

in vitro mammalian chromosome aberration test

Species / strain / cell type:

lymphocytes: Human

Details on mammalian cell type (if applicable):

- Type and identity of media:
Blood samples were obtained from healthy donors not receiving medication. For this study, blood was collected from a female donor
(26 year-old) for Experiment I, and from a 44 year old male donor for Experiment II.
Blood samples were drawn by venous puncture and collected in heparinized tubes by Dr. V. Theodor (64380 Rossdorf, Germany).
The tubes were sent to RCC-CCR to initiate cell cultures within 24 hrs after blood collection. If necessary, the blood was stored before use at 4° C.

Metabolic activation:

with and without

Metabolic activation system:

Phenobarbital/beta-naphthoflavone induced rat liver S9 (from 8 - 12 weeks old male Wistar HanIbm rats, weight approx. 220 - 320 g) for details see "details on test system & conditions"

Test concentrations with justification for top dose:

Doses levels were:
0; 277.6; 485.7 and 850 µg/mL with or without S9 mix

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: deionised water
- Justification for choice of solvent/vehicle: The solvent was chosen to its solubility properties and its relative nontoxicity to the cell cultures.
- volume of vehicle/solvent in the medium: 10%

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: for details see "details on test system & conditions"

Details on test system and experimental conditions:

METABOLIC ACTIVATION SYSTEM: (details)
Phenobarbital/beta-naphthoflavone induced rat liver S9 (from 8 - 12 weeks old male Wistar HanIbm rats, weight approx. 220 - 320 g induced
by applications of 80 mg/kg b.w. phenobarbital i.p. (Desitin; 22335 Hamburg, Germany) and beta-naphthoflavone p.o. (Aldrich, 89555 Steinheim,
Germany) each, on three consecutive days. The livers were prepared 24 hours after the last treatment. The S9 fractions were produced by dilution
of the liver homogenate with a KCl solution (1+3) followed by centrifugation at 9000 g. Aliquots of the supernatant were frozen and stored in
ampoules at -80° C. Small numbers of the ampoules can be kept at -20°C for up to one week.
The protein concentration of the S9 preparation was 25.3 mg/mL (Lot no. 061006) in both experiments.)

POSITIVE CONTROL(S) SUBSTANCE
> without S9 mix:
ethylmethanesulphonate
770.0 µg/mL (6.21 mM) (22 hrs preparation interval)
660.0 µg/mL (5.32 mM) (22 hrs preparation interval)
495.0 µg/mL (3.98 mM) (46 hrs preparation interval)
Remark: Solutions were prepared on the day of experiment. The stability of the positive control substance in solution was proven by the mutagenic
response in the expected range.

> with S9 mix:
cyclophosphamide
30.0 µg/mL (0.106 mM)
Remark: The dilutions of the stock solutions were prepared on the day of experiment. The stability of CPA in solution at room temperature is good.
At 25° C only 3.5 % of its potency is lost after 24 hours

DETAILS ON TEST SYSTEM AND CONDITIONS
> PRELIMINARY TEST:
- METHOD OF APPLICATION: in medium
- DURATION:
- Exposure duration: 4h-22h-46h

> EXPERIMENT I & II
- METHOD OF APPLICATION: in medium
- DURATION:
exposure period duraition
Without S9 mix With S9 mix
Exp. I Exp. II Exp. I Exp. II
Exposure period 4 hrs-22 hrs 46 hrs 4 hrs 4 hrs
Recovery 18 hrs 18 hrs 42 hrs
Preparation interval 22 hrs-22 hrs 46 hrs 22 hrs 46 hrs

Selection time
-spindle inhibition: colcemid
- stain : Giemsa
- number of replication: 22h # 1,5 fold of the normal cell time
NUMBER OF CELLS EVALUATED :
In each experimental group two parallel cultures were analysed. 100 metaphase plates per culture were scored for structural chromosomal
aberrations. 1000 cells were counted per culture for determination of mitotic index.

DETERMINATION OF CYTOTOXICITY
- Method: mitotic index

OTHER EXAMINATIONS:
- Determination of polyploidy: the number of polyploid cells in 250 metaphase cells (% polyploid metaphases) was scored

OTHER: SCORING METHOD:
The slides were evaluated (according to standard protocol of the "Arbeitsgruppe der Industrie, Cytogenetik" ) using NIKON microscopes
with 100 x oil immersion objectives. Breaks, fragments, deletions, exchanges and chromosomal disintegrations were recorded as structural
chromosome aberrations. Gaps were recorded as well, but they were not included in the calculation of the aberration rates . 100 well spread
metaphase plates per culture were scored for cytogenetic damage on coded slides. Only metaphases with 46+/-1 centromer regions were
included in the analysis.

Evaluation criteria:

- A test item is classified as non-mutagenic if:
* the number of induced structural chromosome aberrations in all evaluated dose groups is in the range of our historical control data
(0.0 - 4.0 % aberrant cells, excluding gaps).
* no significant increase of the number of structural chromosome aberrations is observed.
- A test item is classified as mutagenic if:
* the number of induced structural chromosome aberrations is not in the range of our historical control data
(0.0 -4.0 % aberrant cells, excluding gaps).
and
* either a concentration-related or a significant increase of the number of structural chromosome aberrations is observed.

Although the inclusion of the structural chromosome aberrations is the purpose of this study, it is important to include the polyploids and
endoreduplications. The following criteria is valid:
A test item can be classified as aneugenic if:
- the number of induced numerical aberrations is not in the range of our historical control data (0.0 - 1.5 % % polyploid cells).

Statistics:

Statistical significance was confirmed by means of the Fisher´s exact test (p < 0.05). However, both biological and statistical significance should
be considered together. If the above mentioned criteria for the test item are not clearly met, the classification with regard to the historical data and
the biological relevance is discussed and/or a confirmatory experiment is performed.

Species / strain:

lymphocytes: Human

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity nor precipitates, but tested up to recommended limit concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Additional information on results:

no (no visible precipitation no increase in osmolality or pH value)

COMPARISON WITH HISTORICAL CONTROL DATA: yes

ADDITIONAL INFORMATION ON CYTOTOXICITY: no

Remarks on result:

other: other: Human lymphocytes

Remarks:

Migrated from field 'Test system'.

Table 1: Summary of results of the chromosomal aberration study with Cyclopentanone distilled

Exp.	Preparation	Test item	Polyploid	Mitotic indices	Aberrant cells
	interval	concentration	cells	in %	in %
		in µg/mL	in %	of control	incl. gaps*	excl. gaps*	with exchanges
Exposure period 4 hrs without S9 mix
I	22 hrs	Solvent control^1	0.0	100.0	1.0	1.0	0.0
		Positive control^2	0.0	105.6	9.0	8.0^S	2.0
		277.6	0.0	114.0	0.0	0.0	0.0
		485.7	0.0	121.0	0.0	0.0	0.0
		850.0	0.0	123.8	1.0	1.0	0.0
Exposure period 22 hrs without S9 mix
I	22 hrs	Solvent control^1	0.0	100.0	0.5	0.0	0.0
		Positive control^3	0.0	35.8	12.0	11.0^S	2.5
		277.6	0.2	88.6	1.0	1.0	0.0
		485.7	0.0	81.0	1.5	1.5	0.0
		850.0	0.0	82.9	1.0	1.0	0.0
Exposure period 46 hrs without S9 mix
II	46 hrs	Solvent control^1	0.0	100.0	1.5	1.5	0.0
		Positive control^4	0.0	81.5	10.5	10.0^S	4.5
		277.6	0.0	77.2	1.5	1.5	0.0
		485.7	0.0	65.6	1.0	1.0	0.0
		850.0	0.0	69.5	2.0	1.5	0.0

*  Including cells carrying exchanges                         

S    Aberration frequency statistically significant higher than corresponding control values                                  

1    Deionised water 10.0 % (v/v)                                

2    EMS          770.0 µg/mL                

3    EMS          660.0 µg/mL                

4    EMS 495.0 µg/mL  

Summary of results of the chromosomal aberration study with Cyclopentanone distilled

Exp.	Preparation interval	Test item concentration in µg/ml	Polyploid cells in %	Mitotic indices in % of control	Aberrant cells in %
					incl. gaps*	excl. gaps*	with exchanges
Exposure period 4 hrs with S9 mix
I	22 hrs	Solvent control^1	0.0	100.0	2.0	1.5	0.0
		Positive control^2	0.0	48.5	16.5	15.5^S	0.5
		277.6	0.0	93.0	1.0	1.0	0.0
		485.7	0.0	102.0	0.5	0.5	0.0
		850.0	0.0	106.0	2.0	1.0	0.0
II	46 hrs	Solvent control^1	0.0	100.0	2.0	1.5	0.0
		Positive control^2	0.0	26.0	7.5	7.5^S	3.0
		277.6	0.2	87.7	2.5	2.0	0.0
		485.7	0.0	116.7	1.5	1.0	0.0
		850.0	0.2	87.4	1.5	1.5	0.0

*     Including cells carrying exchanges        

S     Aberration frequency statistically significant higher than corresponding control values          

1      Deionised water 10.0 % (v/v)   

2      CPA   30.0 µg/mL

ACCEPTABILITY OF THE ASSAY
The chromosomal aberration assay is considered acceptable if it meets the following criteria:
a) The number of aberrations found in the solvent controls falls within the range of historical laboratory control data range: 0.0 - 4.0 % aberrant cells, excluding gaps.
b) The positive control substances should produce significant increases in the number of cells with structural chromosome aberrations, which are within the range

of the laboratory's historical control data:

Test group Final concentration	Aberrant cells in % (excl. gaps) Range	Test group Final concentration	Aberrant cells in % (excl. gaps) Range
Without S9 mix		With S9 mix
EMS 330 - 770 µg/ml	7.5 - 47.0 %	CPA 15.0 - 37.5 µg/mL	7.5 - 41.0

Conclusions:

Interpretation of results (migrated information):
negative with metabolic activation
negative without metabolic activation

Negative with and without metabolic activation

Executive summary:

The test item Cyclopentanone distilled (99.9%), dissolved in deionised water, was assessed for its potential to induce structural chromosome aberrations in human lymphocytes in vitro in two independent experiments.

The following study design was performed:

	Without S9 mix		With S9 mix
	Exp. I	Exp. II	Exp. I	Exp. II
Exposure period	4 hrs-22 hrs	46 hrs	4 hrs	4 hrs
Recovery	18 hrs		18 hrs	42 hrs
Preparation interval	22 hrs-22 hrs	46 hrs	22 hrs	46 hrs

In each experimental group two parallel cultures were set up. Per culture 100 metaphase plates were scored for structural chromosome aberrations.

The highest applied concentration in this study (850.0 µg/mL, 10 mM) was chosen with respect to the current OECD Guideline 473.

In both independent experiments, neither a statistically significant nor a biologically relevant increase in the number of cells carrying structural chromosomal aberrations was observed after treatment with the test item.

No relevant increase in the frequencies of polyploid metaphases was found after treatment with the test item as compared to the frequencies of the controls.

Appropriate mutagens were used as positive controls. They induced statistically significant increases (p 0.05) in cells with structural chromosome aberrations.

In conclusion, it can be stated that under the experimental conditions reported, the test item did not induce structural chromosome aberrations as determined by the chromosome aberration test in human lymphocytes in vitro.

Therefore, Cyclopentanone distilled is considered to be non-clastogenic in this chromosome aberration test in the absence and presence of metabolic activation.

Reference 3

Endpoint:

in vitro gene mutation study in mammalian cells

Remarks:

Type of genotoxicity: gene mutation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The purity of the substance was unknown. The protocol and the criteria of evaluation were well described.

Qualifier:

equivalent or similar to guideline

Guideline:

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

Deviations:

not specified

Principles of method if other than guideline:

In vitro mammalian cell gene mutation tests

GLP compliance:

not specified

Type of assay:

mammalian cell gene mutation assay

Species / strain / cell type:

mouse lymphoma L5178Y cells

Details on mammalian cell type (if applicable):

- Type and identity of media: Fischer medium supplemented with 2 mM L-glutamine, sodium pyruvate, 110 µg/mL, 0.05% pluronic F68, antibiotics, and 10% heat-inactivated donor horse serum
- Periodically checked for Mycoplasma contamination: yes
- Periodically "cleansed" against high spontaneous background: yes

Metabolic activation:

with and without

Metabolic activation system:

S9 mix was prepared from rat liver induced with Aroclor 1254

Test concentrations with justification for top dose:

0, 312.5, 625, 1750, 2500, 5000 µg/mL

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: distilled water or DMSO
No more data

Untreated negative controls:

not specified

Negative solvent / vehicle controls:

yes

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

other: 3-Methylcholanthrene (3-MC, concentration unknown); Ethyl methanesulphonate (EMS, concentration unknown

Details on test system and experimental conditions:

- Method of application: in medium
- Duration:
* Exposure duration: 4 hours
* Expression time: 48 hours
* Selection time: 11-14 days
- Selection agent: trifluorothymidine (3 µg/mL)
- Number of replicates: 3

DETERMINATION OF CYTOTOXICITY:
- Method: relative total growth (RTG)

OTHER: colonies were counted using an Artek 880 Automated Colony Counter, with the colony size discriminator control in the "off" position.

Evaluation criteria:

* Positive (+): a test was considered as positive when, out of 3 trials, a positive trial was reproducible.
* Negative (-): a test was considered as negative, when, out of 3 trials, a positive response or a positive dose was not reproducible
* Questionable (?): a test was considered as questionable when, out of 3 trials, neither a positive nor a negative response was reproduced

Statistics:

The statistical analysis was based upon the mathematical model proposed fort his system and consisted of a dose-trend test and a variance analysis of pair-wise comparisons of each dose against the vehicle control.

Species / strain:

mouse lymphoma L5178Y cells

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity nor precipitates, but tested up to recommended limit concentrations

Remarks:

> 5000 µg/mL

Vehicle controls validity:

valid

Untreated negative controls validity:

not specified

Positive controls validity:

valid

Additional information on results:

Tables in the publication are not exploitable (illegible)

Remarks on result:

other: all strains/cell types tested

Remarks:

Remarks: L5178Y tk+/tk- Mouse Lymphoma cell forward mutation assay.

Conclusions:

Interpretation of results (migrated information):
negative

Negative with and without metabolic activation.

Executive summary:

In a mammalian cell gene mutation assay in L5178Y mouse lymphoma cells (McGregor DB, 1988), cells cultured in vitro were exposed to cyclohexanone (purity unknown) at concentrations of 0, 312.5, 625, 1750, 2500, 5000 µg/mL in the presence and absence of mammalian metabolic activation (S9-mix from rat liver induced with Aroclor 1254). No significant reduction in survival or increase in mutant fraction occurred in either the presence or absence of S9 mix at cyclohexanone concentrations up to 5000 µg/mL.

Reference 4

Endpoint:

in vitro gene mutation 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:

See below attached read-across justification.

Species / strain:

mouse lymphoma L5178Y cells

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not specified

Positive controls validity:

valid

Remarks on result:

other:

Remarks:

data on a analogue (cyclohexanone)

Executive summary:

Read accross with Cyclohexanone was used for mutations in mammalian cells:

Summary of the study in mammalin cells for cyclohexanone:

In a mammalian cell gene mutation assay in L5178Y mouse lymphoma cells (McGregor DB, 1988), cells cultured in vitro were exposed to cyclohexanone (purity unknown) at concentrations of 0, 312.5, 625, 1750, 2500, 5000 µg/mL in the presence and absence of mammalian metabolic activation (S9-mix from rat liver induced with Aroclor 1254). No significant reduction in survival or increase in mutant fraction occurred in either the presence or absence of S9 mix at cyclohexanone concentrations up to 5000 µg/mL. Cyclohexanone does not induce mutation in mammalian cells. Threfore, by analogy, cyclopentanone is expected to not induce mutation in mammalian cells.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Genetic toxicity in vivo

Description of key information

No in vivo tests are available. Conclusion can be drawn only based on the in vitro studies.

Additional information

Two studies with reliability 1 according to Klimisch rating were available and were selected as key study. Results were negative in complete Ames test with and without metabolic activation (Rhodia report, Citox Lab. 2015), and negative in chromosomal aberration in human lymphocytes, with and without metabolic activation (Rhodia report, RCC 2007). Two other studies on Cyclopentanone were available and were selected as supporting studies. Results were negative in simplified Ames test with and without metabolic activation (RTC, 1999), negative in a complete Ames test (Florin, 1980).

Three other studies on Cyclohexanone were available with reliability 2 according to Klimisch rating. Results for these studies were negative in a Ames test with and without metabolic activation, negative in a chromosomal aberration test in human lymphocytes with or without metabolic activation and negative in a mammalian cell gene mutation assay in L5178Y mouse lymphoma cells. Only the last study (mutation in mammalian cell test) has been reported in the IUCLID since the other tests are available on cyclopentanone. A read-across with cyclohexanone was done only for mutation in mammalian cells (see justification of the read-acroos) in order to fulfil the gap.

Justification for classification or non-classification

Based on negative cyclopentanone and cyclohexanone in vitro data, no genotoxic classification is required for cyclopentanone.