Bisdecanoyl peroxide

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro cytogenicity / chromosome aberration study in mammalian cells

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 2002-02-25 to 2002-08-5

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2002

Report date:

2002

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 473 (In Vitro Mammalian Chromosome Aberration Test)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.10 (Mutagenicity - 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:

Bisdecanoyl peroxide

EC Number:

212-092-1

EC Name:

Bisdecanoyl peroxide

Cas Number:

762-12-9

Molecular formula:

C20H38O4

IUPAC Name:

decanoyl decaneperoxoate

Test material form:

solid: compact

Method

Species / strain

Species / strain / cell type:

primary culture, other: human lymphocytes

Details on mammalian cell type (if applicable):

- they have stable karyotype with 46 chromosomes
- they have an average cell cycles time of 12-14 hours

Metabolic activation:

with and without

Metabolic activation system:

The S9 mix consists of induced enzymatic systems contained in rat liver post-mitochondrial fraction and the cofactors necessary for their function. S9 fraction was obtained from the liver of rats treated with Aroclor 1254 (500 mg/kg,intraperitoneal route)

Test concentrations with justification for top dose:

With and without S9:
- 3-hour treatment, 20-hour harvest: 0, 1.07; 2.13; 4.26; 8.52; 17.05; 34.09; 68.18; 136.36 µg/ml
- 20-hour treatment, 20-hour harvest and 44-hour treatment, 44-hour harvest: 0, 4.26; 8.52; 17.05; 34.09; 68.18; 136.36 µg/ml

Vehicle / solvent:

- Ethanol
- The substance was not soluble in water and in dimethylsulfoxide

Controls

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: without S9: mitomycine C, with S9: Cyclophosphamide

Details on test system and experimental conditions:

METHOD OF APPLICATION: in medium
DURATION
- Exposure duration: 3 hours
- Cells were harvested 20 hours after beginning of treating, corresponding approximately 1.5 normal cell cycles, or for one test 44 hours after the beginning of the treatment.

NUMBER OF CELLS EVALUATED: 200

DETERMINATION OF CYTOTOXICITY
- Method: mitotic index;

OTHER EXAMINATIONS:
- Determination of polyploidy: microscopic evaluation
- Determination of endoreplication: microscopic evaluation

Evaluation criteria:

A reproductible and statistically significant increase in the frequency of cells with structural chromosome aberrations for at least one of the dose-levels and one of the two harvest times was considered as a positive result. Reference to historical data or other considerations of biological relevance, was also taken into account in the evaluation of the findings.

Statistics:

If necessary, the comparison was performed with chi deux test, in which p = 0.05 was used at the lowest level of significance.

Results and discussion

Test results

Species / strain:

primary culture, other: human lymphocytes

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Additional information on results:

- At 136.36 µg/ml Ph and osmolality values were equivalent to those of the vehicule control culture
- Water solubility: no
- Precipitation: a slight precipitation was observed at the end of the treatment, at dose-levels >=68.18µg/ml
- Cytotoxicity: both with and without S9 mix, except for some slight decreases in the mitotic index noted mainly at dose-levels = 68.18 µg/mL, no noteworthy toxicity was induced.
- All the experiment were performed in duplicate

Applicant's summary and conclusion

Conclusions:

DIDECANOYL PEROXIDE did not induce chromosome aberrations in cultutred human lymphocytes.

Executive summary:

DIDECANOYL PEROXIDE was tested in an in vitro cytogenetics assay using duplicate human lymphocyte cultures prepared from the pooled blood of three female donors in two independent experiments both in the absence and presence of metabolic activation (S9 mix), according to the OECD n° 473 Guideline and EC 92/69/EEC B.10 guidelines in compliance with the Principles of Good Laboratory Practice.

This substance was tested in two independent experiments, both with and without a metabolic activation system.

In the first experiment, lymphocyte cultures were exposed to the test or control items, with or without S9 mix, for 3 hours then rinsed. Cells were harvested 20 hours after the beginning of treatment, corresponding to approximately 1.5 normal cell cycles.

As this first experiment was negative, a second experiment was performed as follows:

. without S9 mix, cells were exposed continuously until harvest to the test or control items.

. with S9 mix, cells were exposed to the test or control items for 3 hours and then rinsed.

Cells were harvested 20 hours and 44 hours after the beginning of treatment, corresponding to approximately 1.5 normal cell cycles and 24 hours later, respectively.

Mitomycine C and cyclophosphamide were employed as positive control chemicals in the absence and presence of liver S-9 respectively. Cells receiving these were sampled in each experiment, 20 hours after the start of treatment; both compounds induced statistically significant increases in the proportion of cells with structural aberrations.

Cultures treated with DIDECANOYL PEROXYDE in the absence and presence of S-9 (Experiment 1 and 2) resulted in frequencies of cells with structural aberrations, which were similar to those seen in concurrent negative controls. All cultures receiving the test article had numbers of cells with structural aberrations (excluding gaps) that were within historical negative (normal) control ranges.

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

In conclusion, DIDECANOYL PEROXYDE did not induce chromosome aberrations in cultured human peripheral blood lymphocytes when tested in the absence and presence of S-9mix.