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Toxicological information

Genetic toxicity: in vitro

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Administrative data

Endpoint:
in vitro cytogenicity / chromosome aberration study in mammalian cells
Remarks:
Type of genotoxicity: chromosome aberration
Type of information:
migrated information: read-across based on grouping of substances (category approach)
Adequacy of study:
key study
Study period:
09 Apr - 10 May 2010
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
GLP guideline study, tested with the source substance CAS 26399-02-0. According to the ECHA guidance document “Practical guide 6: How to report read-across and categories (March 2010)”, the reliability was changed from RL1 to RL2 to reflect the fact that this study was conducted on a read-across substance.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2010
Report Date:
2010

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 473 (In Vitro Mammalian Chromosome Aberration Test)
Deviations:
no
GLP compliance:
yes
Type of assay:
in vitro mammalian chromosome aberration test

Test material

Reference
Name:
Unnamed
Type:
Constituent

Method

Target gene:
Not applicable
Species / strain
Species / strain / cell type:
lymphocytes: cultured peripheral human lymphocytes
Metabolic activation:
with and without
Metabolic activation system:
rat liver S9-mix
Test concentrations with justification for top dose:
3, 10 and 33 µg/mL

Vehicle / solvent:
- Vehicle(s)/solvent(s) used: Ethanol
Controlsopen allclose all
Untreated negative controls:
not specified
Negative solvent / vehicle controls:
yes
Remarks:
Ethanol
True negative controls:
no
Positive controls:
yes
Positive control substance:
cyclophosphamide
Remarks:
with rat liver S9-mix

Migrated to IUCLID6: 10 µg/mL
Untreated negative controls:
not specified
Negative solvent / vehicle controls:
yes
Remarks:
Ethanol
True negative controls:
no
Positive controls:
yes
Positive control substance:
mitomycin C
Remarks:
without rat liver S9-mix

Migrated to IUCLID6: 0.5 µg/mL for a 3 h exposure period, 0.2 µg/mL for a 24 h exposure period and 0.1 µg/mL for a 48 h exposure period
Details on test system and experimental conditions:
METHOD OF APPLICATION: in medium

DURATION
- Exposure duration: 3, 24 and 48h
- Fixation time (start of exposure up to fixation or harvest of cells): 3h treatment: 24 and 48h; 24h treatment: 24h; 48h treatment: 48h

SPINDLE INHIBITOR (cytogenetic assays): colchicine 0.5 µL/mL medium
STAIN (for cytogenetic assays): Giemsa 5% (v/v) in tap water

NUMBER OF REPLICATIONS: 2 (duplicates at the 3h-exposure time)

NUMBER OF CELLS EVALUATED: 100 per culture

DETERMINATION OF CYTOTOXICITY
- Method: mitotic index of 1000 cells

OTHER EXAMINATIONS:
- Determination of polyploidy: yes
Evaluation criteria:
A test substance was considered positive (clastogenic) in the chromosome aberration test if: a) It induced a dose-related statistically significant (Chi-square test, one-sided, p < 0.05) increase in the number of cells with chromosome aberrations. b) A statistically significant and biologically relevant increase in the frequencies of the number of cells with chromosome aberrations was observed in the absence of a clear dose-response relationship.
A test substance was considered negative (not clastogenic) in the chromosome aberration test if none of the tested concentrations induced a statistically significant (Chi-square test, one-sided, p < 0.05) increase in the number of cells with chromosome aberrations. The preceding criteria are not absolute and other modifying factors might enter into the final evaluation decision.
Statistics:
Chi-square test, one-sided, p < 0.05

Results and discussion

Test results
Species / strain:
lymphocytes: cultured human peripheral lymphocytes
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
Additional information on results:
TEST-SPECIFIC CONFOUNDING FACTORS
- Precipitation: At a concentration of 33 µg/mL 2-ethylhexyl oleate precipitated in the culture medium
- Other confounding effects: 2-ethylhexyl oleate showed no significant effects on the number of polyploid cells

RANGE-FINDING/SCREENING STUDIES: The highest concentration analysed was selected based on the solubility of the test substance in the culture medium (3 h and 24 h continuous exposure) or on toxicity, inhibition of the mitotic index of about 50% or greater (48 h continuous exposure).

ADDITIONAL INFORMATION ON CYTOTOXICITY:
No cytotoxicity was observed in the duplicate cultures of the 3h exposure time.

Remarks on result:
other: strain/cell type: cultured human peripheral lymphocytes
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

 Table 1: Cytotoxic and Genotoxic observations

Test item

Concentration

Mitotic Index

Aberrant cells in %

 

in µg/mL

in %

with gaps

without gaps

Exposure period 3 h, fixation time 24 h, without S9 mix

Ethanol

1.0% (v/v)

100

2

2

MMC

0.5

67

31

30

Test substance

3

99

1

1

10

98

2

2

33

92

1

1

Exposure period 3 h, fixation time 24 h, with S9 mix

Ethanol

1.0% (v/v)

100

1

1

CP

0.5

51

38

38

Test substance

3

101

1

1

10

108

0

0

33

103

3

3

Exposure period 24 h, fixation time 24 h, without S9 mix

Ethanol

1.0% (v/v)

100

1

1

MMC

0.2

54

34

33

Test substance

3

99

1

1

10

103

3

3

33

70

4

3

Exposure period 48 h, fixation time 48 h, without S9 mix

Ethanol

1.0% (v/v)

100

2

0

MMC

0.1

120

51

49

Test substance

3

108

1

0

10

100

0

0

33

99

2

2

Exposure period 3 h, fixation time 48 h, with S9 mix

Ethanol

1.0% (v/v)

100

0

0

CP

10.0

--

44

44

Test substance

3

100

2

2

10

94

2

2

33

97

1

0

                    MMC: Mitomycin           CP: Cyclophosphamide

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative