Dibutyl phthalate

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:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: comparable to guideline study with acceptable restrictions

Data source

Reference

Reference 1

Reference Type:

publication

Title:

Chromosome aberration and sister chromoatid exchange tests in Chinese hamster ovary cells in vitro III: Results with 27 chemicals

Author:

Gulati DK, Witt K, Anderson B

Year:

1989

Bibliographic source:

Environ. Mol. Mutagen. 13, 133-193

Reference 2

Reference Type:

publication

Title:

Tests for the induction of chromosomal aberrations and sister chromatid exchanges in cultured Chinese hamster ovary (CHO) cells.

Author:

Gulati DK, Sabharwal PS, Shelby MD

Year:

1985

Bibliographic source:

Progr. Mutat. Res. 5, 413-427

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 473 (In Vitro Mammalian Chromosome Aberration Test)

Deviations:

no

GLP compliance:

not specified

Type of assay:

in vitro mammalian chromosome aberration test

Test material

Test material information

Constituent 1

Reference substance name:

Bis(2-ethylhexyl) phthalate

EC Number:

204-211-0

EC Name:

Bis(2-ethylhexyl) phthalate

Cas Number:

117-81-7

IUPAC Name:

bis(2-ethylhexyl) phthalate

Details on test material:

- Name of test material (as cited in study report): Di-(2-ethylhexyl)phthalate DEHP
- Source : Fluka
- Purity : >99%

Batch 1 Lancaster Synthesis. Ltd. - DMSO (Ppt at >500 µg/ml)
Batch 2 Matheson Coleman & Bell 96% DMSO (Ppt at >500 µg/ml)
Batch 3 W. R. Grace & Co. 99.6% DMSO (Ppt at >500 µg/ml)

Method

Target gene:

Chromosomal aberrations

Species / strain

Species / strain / cell type:

Chinese hamster Ovary (CHO)

Details on mammalian cell type (if applicable):

- Type and identity of media: McCoy's 5A medium (modified) supplemented with L-glutamine (2 mM), antibiotics, and 10% fetal bovine serum (FBS)
- Properly maintained: yes
- Periodically checked for Mycoplasma contamination: yes
- Periodically checked for karyotype stability: no
- Periodically "cleansed" against high spontaneous background: no

Metabolic activation:

with and without

Metabolic activation system:

liver fraction (S9) prepared from Aroclor 1254-induced male Sprague Dawley rats (Microbiological Associates, Bethesda, MD)

Test concentrations with justification for top dose:

0, 5, 16, 50, 600, 1600, 2000, 3000, 4000, 5000 µg/ml

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO

Controls

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: mitomycin C (-S9) and cyclophosphamide (+S9)

Details on test system and experimental conditions:

METHOD OF APPLICATION: in medium;

DURATION
- Preincubation period: 24h
- Exposure duration: 10-11h
- Harvest time: 12-13.5 h
For chemicals that caused cell cycle delay, harvest times were extended, generally in 5 h increments, with colcemid present for the last 2 h. For chromosomal aberrations tests, harvest times were similarly extended based on the observation of cell cycle delay in the sister chromatic exchange trials.

SPINDLE INHIBITOR (cytogenetic assays): Colcemid (2-3h prior harvest)
STAIN (for cytogenetic assays): Giemsa 6%

NUMBER OF CELLS EVALUATED: 100 cells were scored for each dose in early studies and 200 cells per dose in later studies

DETERMINATION OF CYTOTOXICITY
- Method: mitotic index;

OTHER EXAMINATIONS:
- Determination of polyploidy: yes
- Determination of endoreplication: yes

Statistics:

The percentage of cells with aberrations was analyzed. Both the dose-response curve and individual dose points were statistically analyzed. A statistically significant (P < 0.003) trend test or a significantly elevated dose point (P < 0.05) was sufficient to indicate a chemical effect.

Results and discussion

Test results

Species / strain:

Chinese hamster Ovary (CHO)

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 examined

Positive controls validity:

valid

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

Downloaded from the NTP site:

http://ntp-apps.niehs.nih.gov/ntp_tox/index.cfm?fuseaction=invitroca.cadata&study_no=923560&cas_no=117%2D81%2D7&endpointlist=CAB

If this is the first time you are viewing this file, please choose 'Save As' from the 'File' menu
and resave this file as an Excel file type. This will greatly speed up future viewings of this file.
In Vitro Cytogenetics - Chromosome Aberrations
Info (Collapse/expand this info box)
Current Search Criteria
Chemical Name:	Di(2-ethylhexyl) phthalate
CAS Number:	117-81-7
Study Type:	Chromosome Aberrations
Study ID:	923560
Table Instructions and Notes:
Below is a summary of Chromosome Aberrations for the selected Study ID. Solvent control marked in white.
Study Result: Negative
Activation	Trial	Trial Call
No Activation	1	Negative
No Activation	2	Negative
Induced Rat Liver S9	3	Negative
Induced Rat Liver S9	4	Negative
Trial #:1   Activation: No Activation   Date: 12/10/1982   Harvest Time: 13.5 hrs   Trial Call: Negative
		Dose	Total Cells Examined	Total Aberrations			Complex Aberrations			Simple Aberrations			Other Abs.
		µg/mL		No. of	Abs	% Cells	No. of	Abs	% Cells	No. of	Abs	% Cells	No. of	Abs	% Cells
				Abs.	Per	With	Abs.	Per	With	Abs.	Per	With	Abs.	Per	With
					Cell	Abs.		Cell	Abs.		Cell	Abs.		Cell	Abs.
Abs: Aberrations
Vehicle Control:	Negative	0	100	0	0.000	0.000	0	0.000	0.000	0	0.000	0.000	0	0.000	0.000
Vehicle Control:	Dimethylsulfoxide	0	100	0	0.000	0.000	0	0.000	0.000	0	0.000	0.000	0	0.000	0.000
Positive Control:	Mitomycin C	0.5	100	99	0.990	63.000	26	0.260	25.000	43	0.430	32.000	30	0.300	28.000
Test Chemical:	Di(2-ethylhexyl)phthalate (DEHP)	50	100	0	0.000	0.000	0	0.000	0.000	0	0.000	0.000	0	0.000	0.000
		160	100	0	0.000	0.000	0	0.000	0.000	0	0.000	0.000	0	0.000	0.000
		500	100	0	0.000	0.000	0	0.000	0.000	0	0.000	0.000	0	0.000	0.000
		1600	100	0	0.000	0.000	0	0.000	0.000	0	0.000	0.000	0	0.000	0.000
		5000	100	0	0.000	0.000	0	0.000	0.000	0	0.000	0.000	0	0.000	0.000
	Trend:			0.000			0.000			0.000
	Probability:			0.000			0.000			0.000
Trial #:2   Activation: No Activation   Date: 12/21/1982   Harvest Time: 12.0 hrs   Trial Call: Negative
		Dose	Total Cells Examined	Total Aberrations			Complex Aberrations			Simple Aberrations			Other Abs.
		µg/mL		No. of	Abs	% Cells	No. of	Abs	% Cells	No. of	Abs	% Cells	No. of	Abs	% Cells
				Abs.	Per	With	Abs.	Per	With	Abs.	Per	With	Abs.	Per	With
					Cell	Abs.		Cell	Abs.		Cell	Abs.		Cell	Abs.
Abs: Aberrations
Vehicle Control:	Negative	0	100	2	0.020	2.000	1	0.010	1.000	1	0.010	1.000	0	0.000	0.000
Vehicle Control:	Dimethylsulfoxide	0	100	2	0.020	2.000	2	0.020	2.000	0	0.000	0.000	0	0.000	0.000
Positive Control:	Mitomycin C	0.5	100	76	0.760	48.000	25	0.250	21.000	34	0.340	24.000	17	0.170	13.000
Test Chemical:	Di(2-ethylhexyl)phthalate (DEHP)	2000	100	3	0.030	3.000	1	0.010	1.000	2	0.020	2.000	0	0.000	0.000
		3000	100	1	0.010	1.000	0	0.000	0.000	1	0.010	1.000	0	0.000	0.000
		4000	100	1	0.010	1.000	0	0.000	0.000	1	0.010	1.000	0	0.000	0.000
		5000	100	1	0.010	1.000	0	0.000	0.000	1	0.010	1.000	0	0.000	0.000
	Trend:			-1.064			-2.126			0.308
	Probability:			0.856			0.983			0.379
Trial #:3   Activation: Induced Rat Liver S9   Date: 12/10/1982   Harvest Time: 12.0 hrs   Trial Call: Negative
		Dose	Total Cells Examined	Total Aberrations			Complex Aberrations			Simple Aberrations			Other Abs.
		µg/mL		No. of	Abs	% Cells	No. of	Abs	% Cells	No. of	Abs	% Cells	No. of	Abs	% Cells
				Abs.	Per	With	Abs.	Per	With	Abs.	Per	With	Abs.	Per	With
					Cell	Abs.		Cell	Abs.		Cell	Abs.		Cell	Abs.
Abs: Aberrations
Vehicle Control:	Negative	0	100	0	0.000	0.000	0	0.000	0.000	0	0.000	0.000	0	0.000	0.000
Positive Control:	Cyclophosphamide	50	100	74	0.740	51.000	16	0.160	15.000	40	0.400	32.000	18	0.180	17.000
Vehicle Control:	Dimethylsulfoxide	0	100	0	0.000	0.000	0	0.000	0.000	0	0.000	0.000	0	0.000	0.000
Test Chemical:	Di(2-ethylhexyl)phthalate (DEHP)	50	100	0	0.000	0.000	0	0.000	0.000	0	0.000	0.000	0	0.000	0.000
		160	100	0	0.000	0.000	0	0.000	0.000	0	0.000	0.000	0	0.000	0.000
		500	100	0	0.000	0.000	0	0.000	0.000	0	0.000	0.000	0	0.000	0.000
		1600	100	0	0.000	0.000	0	0.000	0.000	0	0.000	0.000	0	0.000	0.000
		5000	100	0	0.000	0.000	0	0.000	0.000	0	0.000	0.000	0	0.000	0.000
	Trend:			0.000			0.000			0.000
	Probability:			0.000			0.000			0.000
Trial #:4   Activation: Induced Rat Liver S9   Date: 12/21/1982   Harvest Time: 12.0 hrs   Trial Call: Negative
		Dose	Total Cells Examined	Total Aberrations			Complex Aberrations			Simple Aberrations			Other Abs.
		µg/mL		No. of	Abs	% Cells	No. of	Abs	% Cells	No. of	Abs	% Cells	No. of	Abs	% Cells
				Abs.	Per	With	Abs.	Per	With	Abs.	Per	With	Abs.	Per	With
					Cell	Abs.		Cell	Abs.		Cell	Abs.		Cell	Abs.
Abs: Aberrations
Vehicle Control:	Negative	0	100	1	0.010	1.000	1	0.010	1.000	0	0.000	0.000	0	0.000	0.000
Positive Control:	Cyclophosphamide	50	100	74	0.740	52.000	16	0.160	14.000	27	0.270	24.000	31	0.310	21.000
Vehicle Control:	Dimethylsulfoxide	0	100	3	0.030	3.000	2	0.020	2.000	1	0.010	1.000	0	0.000	0.000
Test Chemical:	Di(2-ethylhexyl)phthalate (DEHP)	1000	100	4	0.040	4.000	4	0.040	4.000	0	0.000	0.000	0	0.000	0.000
		2000	100	4	0.040	3.000	3	0.030	2.000	1	0.010	1.000	0	0.000	0.000
		3000	100	2	0.020	2.000	1	0.010	1.000	1	0.010	1.000	0	0.000	0.000
		4000	100	2	0.020	2.000	0	0.000	0.000	2	0.020	2.000	0	0.000	0.000
	Trend:			-0.768			-1.634			0.909
	Probability:			0.779			0.949			0.182

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative

DEHP did not induce any noteworthy increase in the number of cells with structural chromosome aberration, both with and without S9 mix, in either experiment or at either harvest time. 

Executive summary:

The potential of DEHP to induce structural chromosome aberrations in Chinese hamster ovary cells was evaluated with and without a metabolic activation system according a protocol similar to the OECD 473.

Cells were treated for about 10-11 h and colcemid was added 2-3 hr prior to tell harvest by mitotic shake-off.

The chromosome number was recorded for each cell and chromosome or chromatid type aberrations were classified into three categories: simple (breaks, fragments, double minutes), complex (interchanges, rearrangements), and other (pulverized, more than ten aberrations/cell).

Under these experimental conditions, DEHP did not induce any noteworthy increase in the number of cells with structural chromosome aberration, both with and without S9 mix, in either experiment or at either harvest time.