Branched hexatriacontane

Genetic toxicity: in vitro

Administrative data

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:

1995-01-12 to 1995-04-24

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: This study is classified reliable without restriction. The study adhered to OECD Guideline 473 and followed GLP recommendations

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1995

Report date:

1995

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 473 (In Vitro Mammalian Chromosome Aberration Test)

GLP compliance:

yes (incl. QA statement)

Type of assay:

in vitro mammalian chromosome aberration test

Test material

Test material information

Constituent 1

Reference substance name:

1-dodecene dimer, hydrogenated

IUPAC Name:

1-dodecene dimer, hydrogenated

Details on test material:

- Substance type: 1-dodecene dimer, hydrogenated
- Physical state: Liquid, clear colourless
- Lot/batch No.: C1527
- Storage condition of test material: Room temperature

Method

Species / strain

Species / strain / cell type:

lymphocytes: Human

Additional strain / cell type characteristics:

not applicable

Metabolic activation:

with and without

Metabolic activation system:

Aroclor 1254 induced rate liver S9

Test concentrations with justification for top dose:

Experiment 1 and 2: 39, 78.1, 156.25, 312.5, 625, 1250, 2500 and 5000 µg/plate (±S9)

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: acetone
- Justification for choice of solvent/vehicle: The emulsion most stable in appearance was that formed with acetone, therefore this was selected as the vehicle.

Controls

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

Remarks:

Acetone

True negative controls:

no

Positive controls:

yes

Positive control substance:

cyclophosphamide

Remarks:

and ethyl methanesulphonate

Details on test system and experimental conditions:

METHOD OF APPLICATION: in medium

DURATION
- Exposure duration: 48 hours
- Expression time (cells in growth medium): Cells grown in Eagle's minimal essential medium at 37˚C in CO2
- Selection time (if incubation with a selection agent): Mitosis was arrested by addition of demecolcine (Colcemid 0.1 µg/mL) two hours before the required harvest time
- Fixation time (start of exposure up to fixation or harvest of cells): 4 hours
SPINDLE INHIBITOR (cytogenetic assays): demecolcine
STAIN (for cytogenetic assays): 5% Gurrs Giemsa R66

NUMBER OF REPLICATIONS: Duplicate

NUMBER OF CELLS EVALUATED: 2000

DETERMINATION OF CYTOTOXICITY
- Method: mitotic index

Evaluation criteria:

A total of 2000 lymphocyte cell nuclei were counted and the number of cells in metaphase recorded and expressed as the mitotic index and as a
percentage of the vehicle control value.

Statistics:

The frequency of cells with aberrations (both including and excluding gaps) and the frequency of polyploid cells was compared with the concurrent
vehicle control value using Fisher's Exact test or Chi-squared test.

Results and discussion

Test results

Species / strain:

lymphocytes: Human

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

Remarks on result:

other: all strains/cell types tested

Any other information on results incl. tables

RESULTS OF CHROMOSOME ABERRATION TEST - EXPERIMENT 1

 

HARVEST TIME: 20 HOURS                METABOLIC ACTIVATION: NO

 

Treatment Group	Replicate Identification	Number of Cells Scored	Total Gaps	Chromatid		Chromosome		Others	Total Aberrations		Aberrant Cells
				Breaks	Exchanges	Breaks	Exchange		(+GAPS)	(-GAPS)	(+GAPS)	(-GAPS)
Vehicle Control	A	100	0	1	0	1	0	0	2	2	1	1
	B	100	0	1	0	1	0	0	1	1	1	1
	Total	200	0	2 (1.0)	0	1 (0.5)	0	0	3 (1.5)	3 (1.5)	2 (1.0)	2 (1.0)
1250µg/mL	A	100	0	0	0	0	0	0	0	0	0	0
	B	100	0	0	0	0	0	0	0	0	0	0
	Total	200	0	0	0	0	0	0	0	0	0	0
2500µg/mL	A	100	0	0	0	0	0	0	0	0	0	0
	B	100	0	0	0	0	0	0	0	0	0	0
	Total	200	0	0	0	0	0	0	0	0	0	0
5000µg/mL	A	100	0	0	0	0	0	0	0	0	0	0
	B	100	1	0	0	0	1	0	2	1	2	1
	Total	200	1 (0.5)	0	0	0	1 (0.5)	0	2 (1.0)	1 (0.5)	2 (1.0)	1 (0.5)
Positive Control	A	50	8	14	2	3	0	0	27	19	25	17
	B	50	16	12	9	3	0	0	40	24	24	19
	Total	100	24(24.0)	26 (26.0)	11        (11.0)	6    (6.0)	0	0	67   (67.0)	43  (43.0)	49*** (49.0)	36*** (36.0)

X - > 10 aberrations per cell (not included in total aberrations)      Figures in brackets - aberrations per 100 cells            *** represents p ≤0.001

HARVEST TIME: 20 HOURS                METABOLIC ACTIVATION: YES

 

Treatment Group	Replicate Identification	Number of Cells Scored	Total Gaps	Chromatid		Chromosome		Others	Total Aberrations		Aberrant Cells
				Breaks	Exchanges	Breaks	Exchange		(+GAPS)	(-GAPS)	(+GAPS)	(-GAPS)
Vehicle Control	A	100	1	0	0	0	0	0	1	0	1	0
	B	100	0	0	0	0	0	0	0	0	0	0
	Total	200	1 (0.5)	0	0	0	0	0	1 (0.5	0	1 (0.5)	0
1250	A	100	0	1	0	0	0	0	1	1	1	1
	B	100	0	0	0	0	0	0	0	0	0	0
	Total	200	0	1 (0.5)	0	0	0	0	1 (0.5)	1 (0.5)	1 (0.5)	1 (0.5)
2500	A	100	0	0	0	0	0	0	0	0	0	0
	B	100	1	0	0	0	0	0	1	0	1	0
	Total	200	1 (0.5)	0	0	0	0	0	1 (0.5)	0	1 (0.5)	0
5000	A	100	1	2	0	0	0	0	3	2	3	2
	B	100	2	0	0	0	0	0	2	0	2	0
	Total	200	3 (1.5)	2 (1.0)	0	0	0	0	5 (2.5)	2 (1.0)	5 (2.5)	2 (1.0)
Positive Control	A	50	7	7	2	5	0	0	21	14	15	10
	B	50	10	7	3	4	1	0	25	15	19	13
	Total	100	17 (8.5)	14 (7.0)	5          (2.5)	9     (4.5)	1       (0.5)	0	46  (23.0)	29   (14.5)	34***  (17.0)	23*** (11.5)

X - > 10 aberrations per cell (not included in total aberrations)      Figures in brackets - aberrations per 100 cells            *** represents p ≤0.001

Applicant's summary and conclusion

Conclusions:

Interpretation of results:
negative

The test material did not induce a statistically significant increase in the frequency of cells with chromosome aberrations or polyploid cells in either the presence or absence of a liver enzyme metabolising system. 1-dodecene dimer, hydrogenated is therefore considered to be non-clastogenic to human lymphocytes in vitro.

Executive summary:

In a chromosome aberration test (Wright, N.P., 1995; Klimisch score = 1), Human lymphocytes, treated with 1-dodecene dimer, hydrogenated were evaluated for chromosome aberrations at three dose levels, in duplicate, together with vehicle and positive controls. Four treatment conditions were used, i.e. 4 hours exposure with the addition of an induced rat liver homogenate metabolising system at 10% in standard co-factors with cell harvest after 16 and 40-hour expression periods and 20 and 44-hour continuous exposures in the absence of activation. In Experiment 1 the dose range for evaluation was selected from a series of 8 dose levels on the basis of toxicity.

 

All vehicle (solvent) controls gave frequencies of cells with aberrations within the range expected for normal human lymphocytes. All the positive control treatments gave significant increases in the frequency of cells with aberrations indicating the satisfactory performance of the test and of the activity of the metabolising system. The test material induced no statistically significant increases in the frequency of cells with aberrations or polyploid cells.

The test material 1-dodecene dimer, hydrogenated was shown to be non-clastogenic to human lymphocytes in vitro under the conditions of this test.