Diundecyl phthalate

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Data source

Reference

Reference Type:

publication

Title:

Mutagenicity Testing of Di(2-ethylhexy1)phthalate and Related Chemicals in Salmonella

Author:

Zeiger E

Year:

1985

Bibliographic source:

Environmental Mutagenesis 7:213-232 (1985)

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

not specified

GLP compliance:

not specified

Remarks:

This information was not provided

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Diundecyl phthalate

EC Number:

222-884-9

EC Name:

Diundecyl phthalate

Cas Number:

3648-20-2

Molecular formula:

C30H50O4

IUPAC Name:

1,2-diundecyl benzene-1,2-dicarboxylate

Method

Target gene:

Histidine-requiring gene in Salmonella typhimurium

Species / strain

Species / strain / cell type:

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

Metabolic activation:

with and without

Metabolic activation system:

S9 fraction from Aroclor 1254-induced male Sprague-Dawley rats (RLI) or male Syrian hamsters (HLI).

Test concentrations with justification for top dose:

Main test (2 experiments): 0 (solvent control), 10, 33, 100, 333, 1000, 3333 and 10000 μg/plate with S9 mix, and 0 (solvent control), 10, 33, 100, 333 and 1000 μg/plate without S9 mix.
The final dose level selection was based on the results of a preliminary range-finding study conducted with TA100 in the presence and absence of S9.

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: Dimethylsulfoxide (DMSO)
- Justification for choice of solvent/vehicle: insoluble in water

Controls

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

Remarks:

(DMSO)

True negative controls:

no

Positive controls:

yes

Positive control substance:

9-aminoacridine

sodium azide

other: 4-nitro-o-phenylenediamin: -S9: TA98 (5.0 μg/plate); 2-aminoanthracene: +S9: TA100 (1.0 μg/plate), TA1535 (2.5 μg/plate), TA1537 (2.5 μg/plate), and TA98 (1 μg/plate)

Details on test system and experimental conditions:

METHOD OF APPLICATION: in medium; Preincubation

DURATION
- Preincubation period: 20 min at 37ºC
- Exposure duration: 48 hours at 37ºC

SELECTION AGENT (mutation assays): the lack of amino-acid (Histidine) in the medium. Only the mutants can grow due to their capability to synthesize the essential amino acid.

NUMBER OF REPLICATIONS: 2 independent tests with 3 plates/dose/strain.

DETERMINATION OF CYTOTOXICITY
- Method: Not reported but usually by reduced number of spontaneous revertants, microcolony formation, thinning of background lawn.

Evaluation criteria:

A mutagenic response was defined as a reproducible, dose-related increase in the number of histidine-independent colonies over the spontaneous incidence; there was no requirement for a specific magnitude of increase.

Statistics:

No statistical methods were used.

Results and discussion

Test results

Test results 1

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:

not applicable

Positive controls validity:

valid

Test results 2

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:

not applicable

Positive controls validity:

valid

Test results 3

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:

not applicable

Positive controls validity:

valid

Test results 4

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:

not applicable

Positive controls validity:

valid

Test results 5

Species / strain:

E. coli WP2

Genotoxicity:

other: not tested

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- Precipitation: precipitates were observed at a dose of 10000 μg/plate with metabolic activation.

RANGE-FINDING/SCREENING STUDIES:
A preliminary range-finding study was conducted with TA100 in the presence and absence of S9.

Remarks on result:

other: E. coli WP2 not tested

Any other information on results incl. tables

First and second (repeat) experiments yielded similar results, the results presented in the table below are from the second experiment.

Table 1. Results with diundecyl phthalate (lab: SRI; solvent: DMSO)

Dose	TA100						TA1535						TA1537						TA98
	NA		10% HLI		10% RLI		NA		10% HLI		10% RLI		NA		10% HLI		10% RLI		NA		10% HLI		10% RLI
(µg/plate)	mean	SEM	mean	SEM	mean	SEM	mean	SEM	mean	SEM	mean	SEM	mean	SEM	mean	SEM	mean	SEM	mean	SEM	mean	SEM	mean	SEM
0.000	116	7.8	135	6.9	114	6.9	35	4.6	16	1.5	9	2.3	5	1.5	5	0.7	7	2.1	20	3.5	28	2.3	28	0.9
10.000	121	21.2					29	1.8					6	1.5					14	0.3
33.000	96	5.9					31	0.9					7	2.1					17	0.0
100.000	103	6.1	108	12.5	140	9.3	31	2.9	12	2.3	8	0.9	3	0.3	5	1.5	7	0.3	17	2.2	21	4.0	29	2.0
333.000	90	6.7	121	7.2	133	4.8	28	4.8	8	1.2	7	0.7	5	1.5	7	1.7	6	1.5	13	0.7	22	4.7	29	2.6
1000.000	89	13.2	109	2.2	127	12.3	23	4.3	7	0.9	11	2.1	4	1.5	5	0.9	4	1.5	13	0.6	26	3.5	24	3.2
3333.000			99	4.8	114	13.5			9	1.7	6	0.0			5	1.9	6	2.1			26	1.2	23	3.2
10000.000			89 P	9.0	114 P	3.3			12 P	1.7	10 P	1.3			8 P	1.5	6 P	0.6			20 P	3.7	26 P	0.6
POSITIVE	361	3.2	1316	178.5	1046	72.0	449	32.9	564	13.0	209	9.0	181	11.0	357	66.4	210	1.8	876	40.4	1543	78.5	919	31.5

Lab SRI, SRI International

Solvent: DMSO, dimethyl sulfoxide

NA, not activated; 10% HLI, Aroclor 1254-induced Syrian hamster liver S-9; 10% RLI, Aroclor 1254-induced rat liver S-9

p: precipitate present on plates

Applicant's summary and conclusion

Conclusions:

Diundecyl phthalate was not mutagenic with Salmonella typhimurium strains TA100, TA98, TA1535 and TA1537 with and without metabolic activation.

Executive summary:

In a bacterial reverse mutation assay following a method similar to OECD guideline 471, the test item diundecyl phthalate diluted in Dimethylsulfoxide (DMSO) was tested with Salmonella typhimurium strains TA100, TA98, TA1535 and TA1537 with and without metabolic activation (S9) using the preincubation method. Based on results of a preliminary assay, for the main test two independent experiments and 3 replicates of each were conducted with doses of 0 (solvent control), 10, 33, 100, 333, 1000, 3333 and 10000 μg/plate with S9 mix, and 0 (solvent control), 10, 33, 100, 333 and 1000 μg/plate without S9 mix. Concurrent solvent and positive controls were included in every experiment and their responses were considered valid. Precipitates were observed at a dose of 10000 μg/plate with metabolic activation. The test item did not show mutagenic activity in any of the bacterial strains tested.